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  • 1.
    Aarenstrup, Filip
    University West, Department of Engineering Science, Division of Mechanical Engineering and Natural Sciences.
    Effektivisering av informationsflödet mellan säljkontoren i orderprocessen inom Höganäs AB2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Höganäs AB is one of Sweden’s oldest companies established in 1797, the company have 1900 employees today and is one of the leading producers of metal powder in the world. From the subsidiary Höganäs Sweden AB 300,000 tonnes of metal powder was dispatched 2015. The material was sent to Höganäs customers that mainly consist of component manufacturers in the automotive, wood and other manufacturing industry.

    The purpose of this thesis is to suggest a new operational working process that will increase the efficiency of the order handling process. Throughout the investigation the present state of the process has been outlined and identified at Höganäs Sweden AB.

    Höganäs AB’s order handling process consists of many operations and interfaces that are involved to secure high delivery performance to the customers. The complexity of the process increases due to this and demands an effective communication between involved interfaces. The order handling process may vary depending on factors such as delivery terms, payment terms, transport, product, country, customs clearance and quantity. The variation of these factors makes it difficult to implement a standardized approach.

    It is valuable to Höganäs AB to streamline the process. The data recorded in the business system from the customer order is an important basis for production-, dispatch- and planning departments. The recorded data can be obtained earlier if high quality conditions are created that can increase the delivery performance and affect customer relationships positively.

    With support from the collected theory and the study that contains qualitative and quantitative primary data from Höganäs Sweden AB a new working process have been formed that excels the efficiency in the process. The new approach streamlines the overall process time by 40 percent and the overall lead time with 32 percent. In addition to the increased efficiency the number of information exchanges in the process was reduced significantly.

  • 2.
    Abbas, Ahmad
    et al.
    University West, Department of Engineering Science.
    Ali, Mouhamad Riyadh
    University West, Department of Engineering Science.
    Kollimationsfel hos avvägare, estimeringsmetoder och osäkerhetsanalys2022Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Leveling is a traditional method used for height measuring between two or more points. When leveling with leveling instruments, various errors can occur that affect the height measurements, for example accidental and random errors that are human sources of error. Another type of error that affects the height measurements is systematic errors, these errors already exist in the instrument itself such as collimation error. Collimation error means that the line of sight on the leveling instrument is not horizontal, this means that the leveling instrument does not show the true value of the measurements.

    To check whether there is a collimation error in the instruments, a collimation check has been performed. There are two traditional methods used to perform collimation control, Two peg test and Alternative two peg test. The purpose of this study is to check and recommend which of the two methods provides the most accuracy and is the most practical to use. This is done by a comparison between the two methods that have been performed with leveling instruments that have been checked for collimation with the two methods.

    The collimation checks were performed on the University West campus with four different leveling instruments. The first checks were performed to obtain the size of the collimation error on the leveling instruments and to compare the size of the collimation error between the two methods, two peg test and alternative two peg test. The instruments were then corrected by leveling the line of sight and then performing additional collimation checks to compare the collimation errors after the correction. For the two peg test method, a total distance of 40 meters is used and for the alternative two peg test, a total distance of 30 meters is used.

    The results of the collimation checks showed that all the leveling instruments had collimation errors. After adjustment and further collimation control with the two methods, it turned out that the alternative two peg test is the method that is most practical and provides the best accuracy.

  • 3.
    Abbas, Mohamed
    University West, Department of Engineering Science, Division of Industrial Engineering and Management, Electrical- and Mechanical Engineering.
    Småskaliga elproduktionskällor som bygger på förnyelsebar energi lämpliga för installation i städer eller tätorter2021Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This study maps several different small-scale and renewable electricity generation plants that are suitable for installation in the urban environment such as solar panels, wind turbines and water reactors. The thesis is studying the conditions and potential for these power sources to be installed and operated in residential areas.

    The premise covers how these facilities work, the factors affecting different facilities and the number of uses in the urban environment. The premise also includes a couple of investment cost analyzes for solar and wind power. The profitability analysis contains an economic comparison between wind or solar power and ordinary electricity from electricity companies.

    The thesis shows how profitable it is for a medium-sized house with an annual consumption of about 16,000 kWh to install solar cells or a small wind turbine, where all revenues such as state aids and surplus sales are counted towards payments such as investment costs.

    The result from the profitability analysis indicates that it is more profitable to invest in renewable production plants than to buy ordinary electricity from electricity companies. Profitability is beneficial for private individuals and society.

  • 4.
    Abbas, Tabassom
    et al.
    University West, Department of Engineering Science, Division of Industrial Engineering and Management, Electrical- and Mechanical Engineering.
    Sandblom, Sofia
    University West, Department of Engineering Science, Division of Industrial Engineering and Management, Electrical- and Mechanical Engineering.
    Digitalisering av arbetsflöde för avvikelsehantering på inköpt material: En fallstudie utförd på Nolato Cerbo AB i Trollhättan2020Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    A case study was performed at Nolato Cerbo AB in Trollhättan, with the objective to design a suggestion of a digital workflow for deviation handlingfor purchased material. The following questions were issued to fulfil the objective of the case study:

    • Is a workflow for deviation handling for purchased material possible to digitalize in order to facilitate documentation, traceability and information handling?

    • How should the workflow be designed in order to reach the involved personnel's requirements and needs?

    • Which advantages and disadvantages could emerge from the implementation of a digital workflow? To be able to map the current workflow and its issues, interviews with the involved departments were conducted. The interviews also brought up the employees' opinions of a digital workflow. A flowchart was created and waste in the workflow was identified. A benchmarking was performed at Varner Retail Logistics AB, to get an insight of how another company uses a digital workflow for deviation handling. A new flowchart for deviation handling for purchased material was created, where the manual parts of the flow were digitalized. After a test had been performed with concerned employees, it could be stated that the digital workflow will facilitate documentation, traceability and information handling. The requirements and needs for the involved personnel were also fulfilled. Advantages that the respondents consider can be achieved with the digital workflow was time save, no manual handling of paper, a faster distribution of information and that the correct information will be filled in from the beginning. Disadvantages that the respondents consider can emerge is that it will take some time for the employees to learn and adapt to the new way of working and the limitations of the mobileapplication. The conclusions that were drawn was that the digital workflow will be able to be used if it's designed according to the suggestion, although changes to the workflow might be performed in the future. There might also be employees at Nolato CerboAB which afraid of digitalization and changes. For the implementation to be successful, an education and information about the possibilities that digitalization brings will be required.

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  • 5.
    Abdallah, Ali
    et al.
    University West, Department of Engineering Science, Division of Industrial Engineering and Management, Electrical- and Mechanical Engineering.
    Yosef, Janan
    University West, Department of Engineering Science, Division of Industrial Engineering and Management, Electrical- and Mechanical Engineering.
    Elbilsladdning längs E62021Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In Sweden, there are about 220,000 electric cars and the goal is to have 2.5 million electric cars by 2030. To achieve the goal, the charging infrastructure in Sweden needs to increase, especially along the motorways. The task is to investigate the possibility of expanding the charging infrastructure on the E6 between Gothenburg and Malmö. The chosen location for installation of a charging station along the E6 between Gothenburg and Malmö is at Heberg outside Falkenberg. This locationis suitable since it has a large parking lot and a restaurant where potential customers can rest and eat food while their electric car is being charged. There are different types of electric cars, plug-in hybrids and pure electric cars. 71% of all electric vehicles are plug-in hybrids while 29% are pure electric cars. Plug-in hybrids have an electric motor and a fuel engine while pure electric cars only have an electric motor. About 25.000 cars travel on the E6 at Heberg daily and about 4% of these are electric cars, and therefore it is estimated that about 50 electric cars per day will be charged at the selected location. The installation consists of 6 charging stations at Laxbutiken in Heberg, two fast chargers and four semi-fast chargers. The fast chargers are Terra 184 CC with an output of 180 kW and can charge up to three cars simultaneously. The semi-fast chargers are Chargestorm Connected 2 with two charging points for each pole and a power of 22 kW. Fast chargers can charge a car in 20-30 minutes, while with a semi-fast charger it takes 1-2 hours. The charging time depends on the size of the battery and the power. The total power required for the charging posts is 448 kW. A substation will be installed with an 800 kVA transformer to ensure that expansion is possible in the future without replacing the transformer. The cables are also dimensioned so they can also handle a future power increase. The cost of the project will be approximately SEK 1.856.000 including materials, cables and charging stations. The expected income is approximately SEK 894.000 in the first year. Payment terminals will be rented and installed at each charging station at a cost of SEK 85.740 including rent and transaction fees. With 50 % financial support from klimatklivet, the investment will be paid back within 1.1 years.

  • 6.
    Abdallah, Houda
    et al.
    University West, Department of Engineering Science.
    Saleh, Najat
    University West, Department of Engineering Science.
    Cyberattacks through Stegomalware2022Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Stegomalware is a type of malware that utilizes steganography to evade detection. It hides amalicious code inside an innocuous cover medium. The cover medium could be of any type: image, audio, video or even network protocols. Stegomalware has also shown to be a highly effective method to bypass detection. This has led it to increase in popularity among cybercriminals. In this thesis, the aim is to shed light on these cyberattack techniques and show the potential harm that could impact organizations, people, and transmitted data over the network. This is done by exploring the following: state of the art, the use of malware steganography in cyberattacks, most used techniques, and how to defend against them. The prevalent tools used by cybercriminals along with various existing stegomalware prevention and detection techniques have been surveyed and studied. A practical implementation was done with the purpose of observing the technical process that takes place at the point of data hiding. In total two tests were done, with both using the Least Significant Bit (LSB) algorithmto achieve the desired results. 

  • 7.
    Abdallah, Hussein
    et al.
    University West, Department of Engineering Science, Division of Industrial Engineering and Management, Electrical- and Mechanical Engineering.
    Gustafsson, Robin
    University West, Department of Engineering Science, Division of Industrial Engineering and Management, Electrical- and Mechanical Engineering.
    Elbilsladdning längs vägen Trollhättan-Sälen2021Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The number of electric cars has increased drastically in recent years and interest in renewable energy is growing. In addition, the need for good charging infrastructure on the roads, which is sufficient for all new electric cars, is also increasing. This thesis is about placing charging infrastructure along the road Trollhättan-Sälen. 

    The report contains information about the different types of electric cars that currently exist with different safety levels and contact types. Different methods are used to calculate the range of electric cars. The report also contains information about the rules and laws that apply when installing charging stations.

    To find out where new charging infrastructure is needed on the route, a study is made of how many electric cars that travel on the specific roads each day. This is done to produce an estimate of the need for charging stations. However, it is difficult to know how long the cars need to be charged as there are large differences in the capacity of electric cars depending on which model it is. Also, not everyone stays the same time or charges until the battery is full. 

    Other studies were also carried out before the work began to get a better understanding of the conditions that exist on the section Trollhättan to Sälen. It is important to place the charging stations where new charging infrastructure is actually needed. Åmål, Sunne and Limedforsen were chosen based on the investigation done before placement. 

    Several companies were contacted during the project, although it was only one company that could state the prices of the products. Therefore, ABB was chosen as the supplier and prices for charging stations come from ABB. EBRE's cost calculation is used to obtain the prices for the substation, transformer, shaft and cable, etc. 

  • 8.
    Abdallah, Karl
    et al.
    University West, Department of Engineering Science, Division of Mechanical Engineering and Natural Sciences.
    Sisodia, Raoul
    University West, Department of Engineering Science, Division of Mechanical Engineering and Natural Sciences.
    Kvalitetsproblem med inre dörrpanel2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This thesis work has been conducted at International Automotive Components Group in Torslanda, Sweden. The company produces door panels, instrument panels, consoles and cockpits for the automotive industry.

    During the production of door panels, defects such as pressure marks and scratches emerge which results in scrap and rework. The objective of the thesis work was to identify the causes of pressure marks and scratches and also to suggest measures to reduce the amount of scrap and rework on door panels.

    Through observations, interviews and experiments, several causes leading to pressure marks and scratches on door panels were identified. Small pieces of plastics on fixtures, the operator's rough handling and specific process steps are the main causes that result in pressure marks and scratches.

    Pressure marks and scratches emerge at several places on the door panels during the production. To reduce the amount of pressure marks and scratches both short-term and long-term measures were suggested. Some of the measures are:

    •  Use vacuum cleaners at some stations
    •  Add padding on unpadded areas and edges
    •  Make new instructions that emphasize to keep production stations clean and to avoid rough handling
    •  Introduce workshops to engage operators
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  • 9.
    Abdallah, Kristian
    University West, Department of Engineering Science, Division of Mechanical Engineering and Natural Sciences.
    Pedestrian Protection System: Hood lift study2015Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Every year approximately 400 000 pedestrians are killed worldwide in road related injuries where children and elderly are the most exposed age groups. The design of the front-end of a vehicle and the structural stiffness have a significant influence on the kinematics and injury risks of the pedestrian body. To create a clearance between the rigid hood structure and the hood, the hood is lifted. A lifted hood does however not provide protection over the cowl, windscreen and A-pillar areas.

    This study is performed at Autoliv Sverige AB and the purpose is to examine how fast the hood can be lifted 100 mm using a pedestrian protection airbag. The airbag give an extended protection while covering the cowl, windscreen and A-pillar areas.

    A concept generation session was performed where modifications of the current pedestrian protection airbag, for a faster hood lift, were proposed. The generated concepts proceeded to a concept screening session where the Autoliv evaluation matrix was used.

    The selected concepts went further to static testing where the performance of each concept was tested. The performance include the lift time of 100 mm for the most rearward section of the hood, positioning of the cushion and pressure distribution. The tests were carried out in a room temperature environment.

    To conclude the thesis work, one winning concept could not be obtained. Two concepts excelled themselves from all the concepts and a difference in the performances between these two concepts could not be found.

    In this thesis no calculations on costs such as material costs and manufacturing costs has been made. This can be the major aspect on choosing one winning concept but due to the fact that there is no time for a cost analysis in this thesis, the PPA development team will take over.

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  • 10.
    Abdalrhman, Slah Aldeen
    University West, Department of Engineering Science, Division of Production Systems.
    Virtual model of a production process: Seam sealing line at Scania2019Independent thesis Advanced level (degree of Master (One Year)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The concept of digital factories is becoming more popular among the manufactures due to its contributions in simplifying the work of plant engineers and reducing time to market of the products [1]. The main aim of this thesis was to investigate the possible applications of a digital copy of production processes by creating a virtual model of a seam sealing line in the paint department at Scania in Oskarshamn. The main usage of the virtual model was to perform offline programming of the robots. The benefits of offline programming were investigated and compared to online programming. Some comparisons between offline and online programming were made when it comes to the time needed for programming, the accuracy of generated robot paths, the workflow of both approaches and the required knowledge to turn from online programming to offline programming.

    The result of the conducted experiment showed that the time of robot programming can be reduced, and the accuracy of robot paths increases by implementing an offline programming tool. The other application of virtual which was investigated in this thesis was virtual commissioning. Virtual commissioning is a method used to test and validate robot and control (PLC) programs in a virtual environment before implementing in the real plant. The software in the loop was selected as an approach for building the virtual commissioning model after presenting the different existed approaches. The result of the model showed great benefits of virtual commissioning not just in reducing the time of traditional of the new built line but even when replacing parts in an already existing manufacturing. Virtual commissioning is still new in the manufacturing, therefore, there are many issues which should be solved to get an optimal model that imitates perfectly the real plant.

  • 11.
    Abdi, Abdurazak
    et al.
    University West, Department of Engineering Science.
    Omar, Hassan
    University West, Department of Engineering Science.
    Undersökning av två faktorer autentiseringsmöjligheter för inloggning till Linux-server samt Microsoft-Azure MFA2023Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Två-faktorautentisering är en tvåstegsverifieringsprocess som syftar till att ge ytterligare säkerhetsnivå genom att kräva att användaren verifierar sig med hjälp av en sekundär metod,för att säkerställa att personer som försöker få tillgång till ett online-konto är rätt person och utan 2fa kan hackare få tillgång till känslig information eller konto enbart genom att känna till offrets lösenord.I denna studie kommer mest använt 3 olika alternativa två faktor autentiseringsmöjligheter för inloggning till Linux servrar undersökas för att se vilken 2fa som är både användarvänlig och säker att använda. Faktorer som kommer att undersökas är kostnad, plattformskompatibilitet, tillförlitlighet, säkerhetsmässigt och tid samt backupalternativ.undersökningen kommer vara baserat på intervjuer om Högskolan Västs IT avdelnings nya två faktor autentiseringssystem för anställda. Det kommer ställas frågor till systemspecialist som har tagit fram två faktorer autentiseringslösningen och Högskolans anställda som kommer använda azure mfa lösningen. Frågorna kommer vara baserad anställdas behov av två faktor autentiseringssystem och hur de anställda upplever den nya två faktor autentiseringslösningen.Resultaten från de praktiska testerna påvisar att Yubikey var den mest säkra autentiseringsmetoden och duo var den mest användarvänliga metoden. Resultaten som samlats från intervjuerna visade att anledningen till att Högskolan Västs IT-avdelning vill implementera två faktorer autentiseringen var att skydda mot Phishing attacker som kan vara svåra att upptäcka

  • 12.
    Abdo, Adel
    et al.
    University West, Department of Engineering Science, Division of Industrial Engineering and Management, Electrical- and Mechanical Engineering.
    Tesfai, Henon
    University West, Department of Engineering Science, Division of Industrial Engineering and Management, Electrical- and Mechanical Engineering.
    Öka energieffektiviteten genom Industri 4.02021Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This bachelor’s thesis has been carried out in consultation with PTC in Trollhättan, Sweden. The report consists of a comprehensive literature study on the various aspects involved, Reduce electricity waste by Industry 4.0. The various aspects concerning “Reduce electricity waste by Industry 4.0” have been investigated and a decision was made by the authors that by understanding the various aspects within the relevant subject, a deeper understanding will exist when the result is demonstrated. The various aspects are basic information about Industry 4.0, preventive maintenance, general knowledge about ventilation, minimizing the temperature increase and reducing energy consumption in an industrial premises with the help of ventilation and an information section about the lithium ion battery. 

    Finally, a result has been produced for crushing and the separation room to reduce the energy consumption in the room. The result consists of two parts in the same solution. The two steps are by reusing the air in the room as much as they can reduce the energy consumption in having to heat or cool the new external air. The second step is that with the help of AI and Big data technology, the computer system that controls the ventilation system will learn and recognize patterns of the weather and temperature in the external environment outside the industrial premises. Once the computer system has learned this, it can implement the lesson of when it is time for new external air to replace the existing air in the room and when it is time to try to reuse the air in the room to reduce energy consumption in heating and cooling the air. 

    Through personal communication with the supervisor Johan Dahlström a result has been produced by the authors. Results are considered to achieve the goal of reducing energy consumption with the help of Industry 4.0.

  • 13. Abdul Rashid, S. H.
    et al.
    Eriksson, Kristina M.
    University West, Department of Engineering Science, Division of Production Systems.
    Human Values: Increasing importance in the automotive production systems2001Conference paper (Refereed)
  • 14.
    Abdulhasan, Zaid
    et al.
    University West, Department of Engineering Science, Division of Mathematics, Computer and Surveying Engineering.
    Al-Zurbatee, Hawraa
    University West, Department of Engineering Science, Division of Mathematics, Computer and Surveying Engineering.
    Drönarens utvecklingsmöjligheter tillkostnadseffektiv kartframställning2020Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Unmanned Aerial System (UAS) or drone as it is called in modern day language, is an unmanned aircraft. The first time it has been used was in the military. During the past years, the use of UAS has been more common. It is because of this engineering that the collection of data is possible. The drones themselves are equipped with cameras. The collection of data happens when the cameras take pictures on top of the ground level during the flight.The aim of this study is to find pros and cons about UAS photography during map making and tofind out if this engineering could replace or complement the traditional way of map making. The RMS value (also known as Root Mean Square value) varies between different screening and that could be due to different factors. Some of the factors could be what type of ground it is, asphalt and gravel, flight height, or one could investigate which type and size of support dots that has been used, the weather and so on. The two last examples could affect the precision of the measurements. The result of this study is that UAS-photography could replace or complement the traditional mapmaking methods. This study has through different scientific articles and earlier studies with the help of UAS photography been able to make map making more effective. The total time for these measurements were very short compared to the traditional measurements. This could bring a faster map making via UAS-photography. The precision in the experiment has been approved by the HMK-recommendations that are 5 centimeters

  • 15.
    Abdulkareem, Haji  
    et al.
    University West, Department of Engineering Science, Division of Industrial Engineering and Management, Electrical- and Mechanical Engineering.
    Javidan, Mustafa
    University West, Department of Engineering Science, Division of Industrial Engineering and Management, Electrical- and Mechanical Engineering.
    Nätutvecklingsplan för området Hälltorp i Trollhättan2019Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    After many long power failure occurrences on the overhead line that feeds the receiving substation Torsred, and because of the household expansion in nearby area, Trollhättan Energi Elnät AB has decided that a new receiving substation that replaces the existing one should be built at a new location. This thesis includes investigation and calculation of a new electricity network and suggestions on how the new electricity network can integrate with the existing one. Also, a new selective coordination plan and new backup power alternatives are investigated.

    The existing receiving substation Torsred is fed by Vattenfall Eldistribution AB:s 130/10 kV transformer OT00 by an 1 km long overhead line. The neutral point in Torsred is connected to the high voltage bar and consists of neutral grounding resistor and neutral point reactor. The total load current in Torsred is 925 A and during short-circuit in the busbar 154 MVA short-circuit power emerges. The substation Ängen with a short-circuit power 138 MVA is an underlying substation to Torsred that feeds the areas Öresjö, Edsäter and Hjärtum. All the outgoing electric lines in Torsred and Ängen are protected with relay protection and with different time- and current setting on these relays is selectivity installed for the underlying electrical network.

    The new receiving substation is planned to be built near the feeding point OT00. According to calculations the short-circuit power in the new receiving substations will be 227 MVA and in Ängen 200 MVA. The capacitive current increases because the over 1 km overhead line is demolished, and additional 7,5 km underground cable is added on in the new electrical network. A neutral point reactor needs to be upgraded to a 20 A bigger than the existing one because of the increasing capacitive generation in the electrical network. The price to build the receiving substation will be about 9 Mkr. The existing receiving substation Torsred will be demolished and replaced with a new 800 kVA network substation which will be used to feed a couple of the low voltage network in the area Strömslund. The distribution substation Ängen will be modernized. The total price for the whole project is calculated to 11,4 Mkr.

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  • 16.
    Abdulla, Zine
    University West, Department of Engineering Science, Division of Mathematics, Computer and Surveying Engineering.
    Varför blir inte detaljplanelagd mark för bostadsändamål bebyggd?2018Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    According to Boverket's housing market survey 2018, which is a result of a national survey of the housing market in Sweden, there is a deficit in housing in 243 of Sweden's 290 municipalities. In order to meet increased demand for housing, increased housing construction is needed. Detailed development plans govern the rights, construction rights, which indicate what and to what extent property owners can build land. Detailed development plans are the legally binding documents that are established and adopted by municipalities in order to determine, among others, the use of land and water areas. There are several reasons for housing shortage and one is that Sweden's population continues to increase, both due to natural population growth and because of immigration. A growing population entails, for instance, an increase in housing demand, which in turn places demands on the housing market. The demand and supply of housing need to match each other. Another reason is that today it is the private sector that accounts for the majority of housing supply. The private sector does not have the responsibility that municipalities have in terms of meeting the residents' housing needs. The private actors intend to make a profit. Consequently, privately owned construction and housing companies build when it is economically beneficial and not just because there is a housing requirement. Due to the fact that there are still housing shortages in most municipalities, which is problematic, it is interesting to investigate which factors are important for housing construction.

    Current detailed development plans for housing purposes were studied. The detailed development plans that had not been implemented were used as starting material during interviews with relevant actors.

    The purpose of the study was to try to find out what factors affect the fact that detailed development plan land for housing purposes is not built.

    The study's results show that among the factors it is primarily the market situation, high business activity and recession, which affect whether housing construction is going to start or not. There are also factors such as construction law handling times that affect how soon a residential building can get started.

    The conclusion of the study was, among other things, that the market situation seems to be the most influential factor and because the market is governed by profit-dependent players, supply and demand will not always meet. Other conclusions that were drawn were that what is being built is not what is requested and that the building permits take longer than is required by plan- och bygglagen.

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  • 17.
    Abdullah, Loai
    et al.
    University West, Department of Engineering Science, Divison of Natural Sciences, Surveying and Mechanical Engineering.
    Hansson, Robert
    University West, Department of Engineering Science, Divison of Natural Sciences, Surveying and Mechanical Engineering.
    Dimensionering av skruvförband i spannmålselevator2013Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
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  • 18.
    Abdulmohsin, Haider
    University West, Department of Engineering Science, Division of Mechanical Engineering and Natural Sciences.
    Prediction of cutting forces for second layer removal in metal cutting process2016Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Machining processes studies and theories can be referred back to the beginnings of machine age, but recent developments in information technologies (Computers, processors, etc.) make it easier for the researchers to predict material behaviour during different machining processes.

    Machining is not a simple process to analyse due to the amount of variables affecting on it, in this study the author is trying to analyse and explain the forces acting on a AISI 1045 workpiece during the removal of material’s second layer using FEM, one of the challenging problems was to re implement the forces resulted from the first layer removal in the new cutting process to give the study more reliable output to compare with the actual results obtained previously the procedure used to reach this is explained in chapter 3, there are many software used to define FEM analysis each has its benefits and limitations, LS-DYNA which is used in this study is one of those software "it is capable of simulating nonlinear problems involving large deformations, sophisticated material models and complex contact conditions".

    As well as LS-DYNA, HyperMesh and Ls-prepost are used in this study to mesh the tools and workpiece, and pre-set the material parameters respectively.

  • 19.
    Abebe Mengistu, Bemnet
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing.
    Internal sensor measurement to reduce the need of coordinate measuring machines2017Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This thesis presents the approach of determining the machining  errors on a five axis CNC machine using sensors already fitted in the machine to extract valuable data up on process called CITE(CNC Integrity Tracing Equipment) system and measuring the machined workpiece geometry using CMM(Coordinate measurement machine). CITE measurement system is the data acquisition hardware and software system developed by University West for collecting position information from encoders of a machine tool. The collected information could then be used to assess the quality and adjustment of a machine tool, CNC programs and the CNC control parameters. The aim of this study is to examine the roundness and concentricity detection capacity of the CITE system by conducting different milling methods and a turning process. In an example cutting of a workpiece, the CITE measurement system was used for recording the machining process. After that, radial error, centre point deviation and circle roundness errors, analysed using MATLAB based on collected CNC tool movement data. CMM measurement used to verify the results obtained from the CITE measurement system. The investigation conducted on the small circles shows that the CITE measurement system have capability of identifying radial errors in different method of millings (slot, up and down). Centre point deviation and roundness errors measured by the CITE system doesn`t show significant differences between milling methods as seen on CMM measurement.

  • 20.
    Abelsson, Ove
    et al.
    University West, Department of Engineering Science.
    Bogdanovic, Dragan
    University West, Department of Engineering Science.
    Reservdelshantering för maskinunderhåll2011Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Underhållsavdelningen på Volvo Aero ansvarar för reservdelshanteringen vid köp av nya utrustningar. För att minska tiden för produktionsstopp måste reservdelar finnas tillgängliga på lager när ett behov uppstår. Vid inköpsstadiet erhålls en rekommenderad reservdelslista från maskinleverantören. Erhållen reservdelslista används främst när maskindelar går sönder, för att se vilka möjliga leverantörer som finns. Något arbete med vilka reservdelar som bör finnas tillgängliga utförs inte. Den strategi som används idag är att reservdelar beställs hem efter den erfarenhet som erhålls under maskinens drift.

    Ett arbetssätt har tagits fram för att hantera den rekommenderade reservdelslistan och därmed öka tillgängligheten i utrustningen och få en bättre ekonomi. Arbetssättet består av fyra steg. Första steget är att se över vilka av de rekommenderade reservdelarna som finns på Volvo Aeros egna förråd. Steg två är att ta fram en ny beställningspunkt för de reservdelar som redan finns på lager förutsatt att förbrukningen kommer att öka. Steg tre är att val om lagerläggning räknas ut matematiskt då livslängden för reservdelen är känd. Steg fyra innebär att feleffektsanalys skall göras för beslut om lagerläggning för reservdelar med icke känd livslängd. I den rekommenderade reservdelslistan ska information som till exempel artikelbenämning, fabrikat, typbeteckning dessutom erhållas om respektive reservdel. Arbetssättet ska tillsammans med informationen från reservdelslistan avgöra om vilka reservdelar som ska lagerläggas.

    Ett verktyg har också tagits fram för att förenkla arbetssteg ett till fyra. För att verktyget ska kunna användas fullt ut måste maskinleverantören följa Volvo Aeros tekniska specifikation, där det står beskrivet att rekommenderade reservdelar skall anges med en viss data. Data som artikelbenämning, fabrikat och typbeteckning måste finnas i Volvo Aeros system på alla reservdelar som lagrats för att steg ett ska kunna utföras. Den nuvarande tekniska specifikationen bör dessutom kompletteras med uppgifterna om felfrekvens, hur många av reservdelen som finns i maskin och om reservdelen är reparerbar. Dessa uppgifter är en hjälp för att lättare avgöra om reservdelarna skall lagerläggas alternativt köpas vid behov. Arbetssättet och tilläggen i den tekniska specifikationen ska förhoppningsvis leda till ett mer strukturerat arbetssätt och en mer ekonomisk reservdelshantering.

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  • 21.
    Abolhanna, Hussein
    University West, Department of Engineering Science.
    Jämförelse av toppeffekten mellan nätstationsmätare och Velanders formel2023Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Elnätet dimensioneras för att klara årets största effekttoppar. Det är viktigt att överväga sammanlagringen mellan flera kunder, eftersom individuella kunders effekttoppar skulle ge felaktiga uppskattningar av nätstationens högsta förbrukning. Idag finns det timinformation om varje nätstations förbrukning, vilket inte fanns tidigare. Tidigare uppskattades storleken på effekttoppar i nätstationen från den årliga förbrukningen för uppkopplade kunder enligt den så kallade Velanders formel. För att utvärdera denna uppskattning av toppeffekten jämfördes nätstationens och underliggande kunders timförbrukning med de effekter som beräknats med denna formel. Resultatet av jämförelsen visade att formeln i vissa stationer överskattade eller underkastade storleken på den förväntade toppeffekten. Det förändrade energi-till-effektförhållandet på grund av laddning av en elbil gör att nya Velanderkonstanter behöver tas fram för hushåll med elbilsladdare. För att kunna göra dettaär det även viktigt att elnätsföretagen får information om montering av laddboxar och dess maximala laddeffekt. Historisk har elnätet ofta överdimensionerats, till stor del på grund av osäkerheten om förväntad förbrukningen och den ofta relativt låga kostnadsökningen medatt välja en grövre kabel i samband med utbyggnad av elnätet. Med elektrifieringen av fordonsflottan och produktionen av el med solceller hos konsumenter ökar belastningen på lågspänningsnäten och inmatning kan förekomma till nätstationer. Genom förbättrad mätning i nätstationer kan skillnaden mellan verkliga toppeffekten och dimensionerad maximal effekt minskas. Detta i sin tur kan minska behovet av nyinvestering i nätet för att klara energiomställningen. 

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  • 22.
    Abou Nada, Fahed
    et al.
    Lund University, Department of Physics, Division of Combustion Physics, Box 118, Lund, Swede.
    Lantz, Andreas
    Siemens Industrial Turbomachinery AB, Finspång, Sweden.
    Larfeldt, Jenny
    Siemens Industrial Turbomachinery AB, Finspång, Sweden.
    Markocsan, Nicolaie
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing.
    Alden, Marcus
    Lund University, Department of Physics, Division of Combustion Physics, Box 118, Lund, Swede.
    Richter, Mattias
    Lund University, Department of Physics, Division of Combustion Physics, Box 118, Lund, Swede.
    Remote temperature sensing on and beneath atmospheric plasma sprayed thermal barrier coatings using thermographic phosphors2016In: Surface & Coatings Technology, ISSN 0257-8972, E-ISSN 1879-3347, Vol. 302, p. 359-367Article in journal (Refereed)
    Abstract [en]

    Investigations on remote temperature sensing of yttria stabilized zirconia (YSZ) thermal barrier coatings (TBCs) at the surface and at the bond-coat/top-coat interface were carried out. Using Y2O3:Eu thermographic phosphor as an embedded temperature sensing layer, sub-surface temperature probing through 300 mu m of atmospheric plasma sprayed YSZ is demonstrated. The Y2O3:Eu thermographic phosphor displays a temperature sensitivity ranging between 400 degrees C up to a maximum of 900 degrees C when utilizing the luminescence originating from the 611 nm emission band. Dysprosium stabilized zirconia (10 wt.% DySZ), a TBC material, is also investigated and established as a temperature sensor from 400 degrees C up to a temperature of 1000 degrees C using both the intensity decay time and emission intensity ratio methods. In addition, the luminescence of presumed optically inactive YSZ materials was spectroscopically investigated in terms of optical interferences caused by impurities. A validation temperature probing measurement through 300 mu m of YSZ top-coat was successfully performed in a SGT-800 Siemens burner running at six different operating conditions in an atmospheric combustion rig. (C) 2016 Elsevier B.V. All rights reserved.

  • 23.
    Abrahamsen, Alexandra
    University West, Department of Engineering Science.
    Data Science for In-process Chatter Classification2022Independent thesis Advanced level (degree of Master (One Year)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Milling is one of the most crucial processes in machining. Every industry demands a stable milling process for a smoother finish and material cost reduction. Chatter is a vibrating phenomenon which affects the workpiece's quality, its dimensional accuracy, and tool life. It is required to classify the chatter phenomenon to devise an effective chatter prevention strategy.

    Several classification strategies are being used, including frequency and time-related strategies. Since the chattering phenomenon is a frequency-based phenomenon so a frequency-based feature set can be of vital importance. However, frequency-based strategies have a problem of noise. The noise problem can be addressed by combining frequency and time-domain methods.

    Thus, a hybrid approach based on the frequency and time-based feature set is developed and used in conjunction with k-means-based unsupervised learning to come up with a practical but reliable classifier. The proposed classifier algorithm offers good performance, clearly distinguishing between chatter and stable conditions.

    Based on the chatter classification in this work, it is possible to identify thresholds for chattering detection. It is essential to mention that the thresholds obtained from this work will only be useful for the machine and tool used in the experiments and will not be of use for other machines and need more investigation. 

  • 24.
    Abrahamsen, Alexandra
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing.
    Life cycle assessment of grit blasting and femtosecond laser patterning: a comparison of surface preparation techniques2020Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The purpose of the study is to assess the life cycle impacts of conventional grit-blasting and FSL patterning as an alternative surface preparation. FSL has notable advantages in that it does not leave any contaminationon surface, whereas grit blasting does. By employment of Life Cycle Analysis (LCA) method, a powerful methodology for evaluating the environmental impacts of the process used in the production of a product could be utilised. The LCA methodology largely relies on data about inputs, outputs and environmental impacts of a process. It has four iterative phases, namely clear definition of goal and scope, inventory analysis, impact assessment and interpretation. The goal was set as the evaluation of the environmental impact between conventional grit-blasting and femtosecond laser patterning. The scope restricted the system boundary to 'cradle to gate' without the consideration of machinery. Data was gathered from multiple sources under limitations imposed by COVID-19 and other factors. The impact assessment employed the LCA Impact 2002+ Endpoint methodology to process data inputs to determine the comparative impacts of both systems on climate change, ecosystem quality, resources, and human health. The interpretation of the LCA Impact 2002+ method applied to a Canadian scenario showed that the femtosecond laser was significantly less damaging on all metrics except for human health. Human health was disadvantaged for the femtosecond laser solely because of ionising radiation, which could potentially be mitigated through radiation safety protocols. A sensitivity analysis using the Impact 2002+ model was run for India. The results were very different and showed less damage to all four categories for grit blasting. This is driven by the higher electricity consumption (57 times more) of the femtosecond laser process combined with the difference in the source of power generation in India, where the generation of electricity causes more damage due to its greater reliance on non-renewable fossil fuels. Further exploration can be done to enhance the data inputs into this model as per the limitations and assumptions already stated.

  • 25.
    Abrahamsson, Amanda
    et al.
    University West, Department of Engineering Science, Division of Industrial Engineering and Management, Electrical- and Mechanical Engineering.
    Wilsson, Camilla
    University West, Department of Engineering Science, Division of Industrial Engineering and Management, Electrical- and Mechanical Engineering.
    Framtagning av koncept för en ergonomisk materialhantering i en tillverkningsgrupp2022Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This bachelor´s thesis has been carried out at Parker Hannifin Manufacturing Sweden AB in Trollhattan. The thesis presents concept development for a workspace in a manufacturing group that processes details with a maximum weight of 13 kg. The details are moved between trolleys and the milling machine center Heckert 4, all work is performed on a height-adjustable floor to give the operator the right conditions for working with the machine. The affected workspace is currently not ergonomically adapted for the operators when ergonomic risks in the form of manual lifting, rotations and bent working positions occur in the daily work. The purpose of this thesis is therefore to improve the workspace of the milling machine center Heckert 4 in such a way that it becomes more ergonomic and risk-free for the operators. The goal of this thesis was to generate a concept for a more ergonomic workspace and to prevent the risk of injuries forthe operators.

    The work began with information being collected in the form of observations and interviews. Through this, a description of the current situation could be established, and a list of needs and requirements was put together. A risk analysis was carried out on the current situation and contributed to additional requirements in the list. Subsequently, ideas were generated for solutions to the problems that were highlighted in the current situation description. These were then combined into concepts that contained solutions for the ergonomic risks that were earlier identified. With a concept screening matrix, the concepts were screened down and assessed against the current situation. The highest ranked concepts were further evaluated in a concept scoring matrix that ultimately resulted in a winning concept. The winning concept was further modeled and improved.

    The resulting concept that is presented to Parker for continued work is concept I+. Concept I+ consists of two movable surfaces located on the height-adjustable floor at each side of Heckert 4. Two counters are located on either side of the floor to ease the work for the operators. One counter is equipped with a tool stand with space for the tool kittingtrays to be used to kit the necessary tools.

    The concept I+ reduces ergonomic risks by allowing the parts to be pushed instead of manual lifting in combination with turning of the torso. As the details can be placed on the benches when the floor is raised, the bending act that the operators previously performed is eliminated. If Parker decides to continue developing this concept, they will have a more risk-free workspace with improved ergonomics and reduced risk of injuries.

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  • 26.
    Abrahamsson, Sten
    et al.
    Gotland University.
    Tosteby, Jonas
    University West, Department of Engineering Science, Division of Process and Product Development.
    Isaksson, Raine
    Gotland University.
    Integrated Management Systems: testing a model for integration2011In: 14th Toulon-Verona Conference: Organizational Excellence in Service. Conference Proceedings / [ed] Jacques Martin & Claudio Baccarani., Alicante: University of Alicante , 2011, p. 22-35Conference paper (Refereed)
    Abstract [en]

    Management systems are widely used for creating order, minimising risks and for assuring performance. Management systems are in many occasions integrated since this has been found to be beneficial. In this paper a model for a fully integrated management system (IMS) based on the three axes of level, extent and scope of integration is tested for relevance. The studied system permits the integration of all relevant process dimensions. The research is only in a pilot stage, but the initial results are promising and indicate that there are advantages in using the process view as a base for identifying critical aspects to be managed. A review of the current situation for system integration is studied and the model is subjected to some tests using Sweden as a case. The background study shows that system integration still is limited, especially when comparing with a fully integrated IMS. The feedback from the organisations interviewed is positive and supports continued work with development of the model.

  • 27.
    Abrehdary, Majid
    et al.
    University West, Department of Engineering Science, Division of Mathematics, Computer and Surveying Engineering.
    Sjöberg, Lars
    University West, Department of Engineering Science, Division of Mathematics, Computer and Surveying Engineering. Royal Institute of Technology, Stockholm (SWE).
    A New Moho Depth Model for Fennoscandia with Special Correction for the Glacial Isostatic Effect2021In: Pure and Applied Geophysics, ISSN 0033-4553, E-ISSN 1420-9136, Vol. 178, no 3, p. 877-888Article in journal (Refereed)
    Abstract [en]

    In this study, we present a new Moho depth model in Fennoscandia and its surroundings. The model is tailored from data sets of XGM2019e gravitationl field, Earth2014 topography and seismic crustal model CRUST1.0 using the Vening Meinesz-Moritz model based on isostatic theory to a resolution of 1° × 1°. To that end, the refined Bouguer gravity disturbance is determined by reducing the observed field for gravity effect of topography, density heterogeneities related to bathymetry, ice, sediments, and other crustal components. Moreover, stripping of non-isostatic effects of gravity signals from mass anomalies below the crust due to crustal thickening/thinning, thermal expansion of the mantle, Delayed Glacial Isostatic Adjustment (DGIA), i.e., the effect of future GIA, and plate flexure has also been performed. As Fennoscandia is a key area for GIA research, we particularly investigate the DGIA effect on the gravity disturbance and gravimetric Moho depth determination in this area. One may ask whether the DGIA effect is sufficiently well removed in the application of the general non-isostatic effects in such an area, and to answer this question, the Moho depth is determined both with and without specific removal of the DGIA effect prior to non-isostatic effect and Moho depth determinations. The numerical results yield that the RMS difference of the Moho depth from our model HVMD19 vs. the seismic CRUST19 and GRAD09 models are 3.8/4.2 km and 3.7/4.0 km when the above strategy for removing the DGIA effect is/is not applied, respectively, and the mean value differences are 1.2/1.4 km and 0.98/1.4 km, respectively. Hence, our study shows that the specific correction for the DGIA effect on gravity disturbance is slightly significant, resulting in individual changes in the gravimetric Moho depth up to − 1.3 km towards the seismic results. On the other hand, our study shows large discrepancies between gravimetric and seismic Moho models along the Norwegian coastline, which might be due to uncompensated non-isostatic effects caused by tectonic motions.

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  • 28.
    Abrehdary, Majid
    et al.
    University West, Department of Engineering Science, Division of Mathematics, Computer and Surveying Engineering.
    Sjöberg, Lars
    University West, Department of Engineering Science, Division of Mathematics, Computer and Surveying Engineering. Division of Geodesy and Satellite Positioning, Royal Institute of Technology (KTH), SE-10044 Stockholm, (SWE).
    Moho density contrast in Antarctica determined by satellite gravity and seismic models2021In: Geophysical Journal International, ISSN 0956-540X, E-ISSN 1365-246X, Vol. 225, no 3, p. 1952-1962Article in journal (Refereed)
    Abstract [en]

    As recovering the crust-mantle/Moho density contrast (MDC) significantly depends on the properties of the Earth’s crust and upper mantle, varying from place to place, it is an oversimplification to define a constant standard value for it. It is especially challenging in Antarctica, where almost all the bedrock is covered with a thick layer of ice, and seismic data cannot provide a sufficient spatial resolution for geological and geophysical applications. As an alternative, we determine the MDC in Antarctica and its surrounding seas with a resolution of 1°x 1° by the Vening Meinesz-Moritz gravimetric-isostatic technique using the XGM2019e Earth Gravitational Model and Earth2014 topographic/bathymetric information along with CRUST1.0 and CRUST19 seismic crustal models. The numerical results show that our model, named HVMDC20, varies from 81 kg m-3 in the Pacific Antarctic mid-oceanic ridge to 579 kg m-3 in the Gamburtsev Mountain Range in the central continent with a general average of 403 kg m-3. To assess our computations, we compare our estimates with those of some other gravimetric as well as seismic models (KTH11, GEMMA12C, KTH15C and CRUST1.0), illustrating that our estimates agree fairly well with KTH15C and CRUST1.0 but rather poor with the other models. In addition, we compare the geological signatures with HVMDC20, showing how the main geological structures contribute to the MDC. Finally, we study the remaining glacial isostatic adjustment effect on gravity to figure out how much it affects the MDC recovery, yielding a correlation of the optimum spectral window (7< n <12) between XGM2019e and W12a GIA models of the order of ~0.6 contributing within a negligible \pm 14 kg m-3 to the MDC. 

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  • 29.
    Abrehdary, Majid
    et al.
    University West, Department of Engineering Science, Division of Mathematics, Computer and Surveying Engineering.
    Sjöberg, Lars
    University West, Department of Engineering Science, Division of Mathematics, Computer and Surveying Engineering. Royal Institute of Technology (KTH), Division of Geodesy and Satellite Positioning, Stockholm, SE-10044, Sweden.
    Recovering Moho constituents from satellite altimetry and gravimetric data for Europe and surroundings2019In: Journal of Applied Geodesy, ISSN 1862-9016, E-ISSN 1862-9024, Vol. 13, no 4, p. 291-303Article in journal (Refereed)
    Abstract [en]

    In this research, we present a local Moho model, named MOHV19, including Moho depth and Moho density contrast (or shortly Moho constituents) with corresponding uncertainties, which are mapped from altimetric and gravimetric data (DSNSC08) in addition to seismic tomographic (CRUST1.0) and Earth topographic data (Earth2014) to a resolution of 1° × 1° based on a solution of Vening Meinesz-Moritz' theory of isostasy. The MOHV19 model covers the area of entire European plate along with the surrounding oceans, bounded by latitudes (30 °N–82 °N) and longitudes (40 °W–70 °E). The article aims to interpret the Moho model resulted via altimetric and gravimetric information from the geological and geophysical perspectives along with investigating the relation between the Moho depth and Moho density contrast. Our numerical results show that estimated Moho depths range from 7.5 to 57.9 km with continental and oceanic averages of 41.3 ± 4.9 km and 21.6 ± 9.2 km, respectively, and an overall average of 30.9 ± 12.3 km. The estimated Moho density contrast ranges from 60.2 to 565.8 kg/m3, with averages of 421.8 ± 57.9 and 284.4 ± 62.9 kg/m3 for continental and oceanic regions, respectively, with a total average of 350.3 ± 91.5 kg/m3. In most areas, estimated uncertainties in the Moho constituents are less than 3 km and 40 kg/m3, respectively, but they reach to much more significant values under Iceland, parts of Gulf of Bothnia and along the Kvitoya Island. Comparing the Moho depths estimated by MOHV19 and those derived by CRUST1.0, MDN07, GRAD09 and MD19 models shows that MOHV19 agree fairly well with CRUST1.0 but rather poor with other models. The RMS difference between the Moho density contrasts estimated by MOHV19 and CRUST1.0 models is 49.45 kg/m3.

  • 30.
    Abrehdary, Majid
    et al.
    University West, Department of Engineering Science, Division of Mathematics, Computer and Surveying Engineering.
    Sjöberg, Lars E.
    University West, Department of Engineering Science, Division of Mathematics, Computer and Surveying Engineering. Royal Institute of Technology (KTH), Division of Geodesy and Satellite Positioning, Stockholm, SE-100 44, Sweden.
    Sampietro, Daniele
    GReD S.r.l., Via Cavour 2, Lomazzo (CO), 22074, Italy.
    Contribution of satellite altimetry in modelling Moho density contrast in oceanic areas2019In: Journal of Applied Geodesy, ISSN 1862-9016, E-ISSN 1862-9024, Vol. 3, no 1, p. 33-40Article in journal (Refereed)
    Abstract [en]

    The determination of the oceanic Moho (or crust-mantle) density contrast derived from seismic acquisitions suffers from severe lack of data in large parts of the oceans, where have not yet been sufficiently covered by such data. In order to overcome this limitation, gravitational field models obtained by means of satellite altimetry missions can be proficiently exploited, as they provide global uniform information with a sufficient accuracy and resolution for such a task. In this article, we estimate a new Moho density contrast model named MDC2018, using the marine gravity field from satellite altimetry in combination with a seismic-based crustal model and Earth's topographic/bathymetric data. The solution is based on the theory leading to Vening Meinesz-Moritz's isostatic model. The study results in a high-accuracy Moho density contrast model with a resolution of 1° × 1° in oceanic areas. The numerical investigations show that the estimated density contrast ranges from 14.2 to 599.7 kg/m3 with a global average of 293 kg/m3. In order to evaluate the accuracy of the MDC2018 model, the result was compared with some published global models, revealing that our altimetric model is able to image rather reliable information in most of the oceanic areas. However, the differences between this model and the published results are most notable along the coastal and polar zones, which are most likely due to that the quality and coverage of the satellite altimetry data are worsened in these regions.

  • 31.
    Abrehdary, Majid
    et al.
    University West, Department of Engineering Science, Division of Mathematics, Computer and Surveying Engineering.
    Sjöberg, Lars Erik
    Hogskolan i Gavle, Gavle, Sweden .
    Estimating a combined Moho model for marine areas via satellite altimetric: gravity and seismic crustal models2020In: Studia Geophysica et Geodaetica, ISSN 0039-3169, E-ISSN 1573-1626, Vol. 64, p. 1-25Article in journal (Refereed)
    Abstract [en]

    Isostasy is a key concept in geoscience in interpreting the state of mass balance between the Earth's lithosphere and viscous asthenosphere. A more satisfactory test of isostasy is to determine the depth to and density contrast between crust and mantle at the Moho discontinuity (Moho). Generally, the Moho can be mapped by seismic information, but the limited coverage of such data over large portions of the world (in particular at seas) and economic considerations make a combined gravimetric-seismic method a more realistic approach. The determination of a high-resolution of the Moho constituents for marine areas requires the combination of gravimetric and seismic data to diminish substantially the seismic data gaps. In this study, we estimate the Moho constituents globally for ocean regions to a resolution of 1° × 1° by applying the Vening Meinesz-Moritz method from gravimetric data and combine it with estimates derived from seismic data in a new model named COMHV19. The data files of GMG14 satellite altimetry-derived marine gravity field, the Earth2014 Earth topographic/bathymetric model, CRUST1.0 and CRUST19 crustal seismic models are used in a least-squares procedure. The numerical computations show that the Moho depths range from 7.3 km (in Kolbeinsey Ridge) to 52.6 km (in the Gulf of Bothnia) with a global average of 16.4 km and standard deviation of the order of 7.5 km. Estimated Moho density contrasts vary between 20 kg m-3 (north of Iceland) to 570 kg m-3 (in Baltic Sea), with a global average of 313.7 kg m-3 and standard deviation of the order of 77.4 kg m-3. When comparing the computed Moho depths with current knowledge of crustal structure, they are generally found to be in good agreement with other crustal models. However, in certain regions, such as oceanic spreading ridges and hot spots, we generally obtain thinner crust than proposed by other models, which is likely the result of improvements in the new model. We also see evidence for thickening of oceanic crust with increasing age. Hence, the new combined Moho model is able to image rather reliable information in most of the oceanic areas, in particular in ocean ridges, which are important features in ocean basins.

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  • 32.
    Abu Ghanem, Anas
    University West, Department of Engineering Science, Division of Mathematics, Computer and Surveying Engineering.
    IPv4 mot IPv6 IPsec tunnel2020Independent thesis Basic level (university diploma), 5 credits / 7,5 HE creditsStudent thesis
    Abstract [en]

    The exam report studies the difference in how data traffic is affected between IPsec VPN tunnels over IPv4 versus IPv6. The data traffic that is sent over the tunnels is UDP and TCP packets where the speed of data is measured.

    From the produced result values, it can be concluded that IPsec VPN tunnel over IPv4 is better compared to IPv6 as the bandwidth is faster, but the difference is so small that the effect is insignificant.

  • 33.
    Abu Ghanem, Anas
    et al.
    University West, Department of Engineering Science, Division of Mathematics, Computer and Surveying Engineering.
    Eftekhari, Sina
    University West, Department of Engineering Science, Division of Mathematics, Computer and Surveying Engineering.
    A study of the network traffic between Bitcoin nodes2021Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Bitcoin is a digital cash money system that is decentralized and not controlled by a central authority. It functions as a cryptocurrency across a peer-to-peer network and all nodes in the network have a public registry of who owns what and who transact what. Transactions are secured through cryptography and with time gets locked in blocks of data and added to the blockchain. All transactions and new blocks are sent using TCP protocol to transport these packets to other nodes in the network.

    Bitcoin protocol uses different message types in the communications between the nodes in the network. This work has examined all the message types that are used in the Bitcoin network during two different stages: Downloading of the blockchain to a Bitcoin node versusrunning the node after the blockchain has been downloaded.

    From the produced results, it can be concluded that the network traffic between Bitcoin nodes varies depending on what messages are required to be sent and which phase the node is in.

  • 34.
    Abudaher, Mohammed
    et al.
    University West, Department of Engineering Science, Division of Computer and Electrical Engineering.
    Alomari, Kamal
    University West, Department of Engineering Science, Division of Computer and Electrical Engineering.
    Energieffektivisering i köpcentret Sisjö Entré i Göteborg2014Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Energy efficiency means that energy is used in an efficient way that impacts positively on the environment and society.

    Sisjö Entré is a shopping center which has an annual energy consumption of 1 865 270 kWh, and according to Energy Authority, the recommended value is 1 530 000 kWh per year. That means that energy consumption at the center should reduce by approximately 18 % to comply with the recommended value. The mall consists of 17 stores and the thesis examines five stores which are Toys Я Us, Rusta, Burger King, Babyproffsen and Webhallen. Measurements are taken on ventilation and lighting installations with the aim of studying the loads in the stores that consume the most energy. The goal is to come up with suggestions of actions to reduce energy consumption and costs.

    We concluded that lighting consumes the most energy in the warehouses; Toys Я Us, Rusta, Babyproffsen and Webhallen, while the largest load in the restaurants (Burger King) is the kitchen, which accounts for 75 % of the restaurants total consumption.

    In Rusta, we discovered that the electricity meter showed a lower value than the true consumption. After investigation, we concluded that the fault could be either in the electricity meter or in its current transformer and must be addressed.

    We have given a proposal to replace parts of the existing lighting installations, and given suggestion for sectioning certain parts in some stores. Further, we have given suggestions for reducing operating times on the ventilation units.

    Based on the above proposals and energy calculations, we concluded that these five stores has the potential to reduce the annual energy consumption from 1 865 270 kWh to 1 576 670 kWh, leading to a reduction by 15.5 %. This reduces costs by about 228 000 SEK per year

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  • 35.
    Abuibaid, Abdallah
    University West, Department of Engineering Science.
    Enhancement of an assembly linethrough robotization of the manual station2023Independent thesis Advanced level (degree of Master (One Year)), 20 HE creditsStudent thesis
    Abstract [en]

    This work is being carried out in collaboration with the TYRI Light industry to improve their existing assembly line, which currently has 8 stations. Out of these, three stations are operated by humans, and the rest are automated. The main focus of this project is on the first station, which is currently operated manually. While another master’s student from University West focuses on improving an automated second station and enhancing the fourth station, which is operated by a human worker. The seventh station, which operated manually, requires a human worker because of its complexity and flexibility of human.At this first station, there are two tasks involved. The first task is picking up components and placing them on an empty fixture, while the second task is picking up the finished product from the fixture and placing it on the palletizing process. Currently, it takes 19 seconds for a human worker to complete these tasks before sending the fixture to the next station.The goal of this project is to investigate whether this first station can be improved by using a robot instead. If a robot can perform these two tasks faster than 19 seconds, enhance workplace safety, and handle both tasks effectively without a need for more robots or external assistants. To achieve this, a discussion was made with the TYRI supervisor to select a collaborative robot for this task. To validate the work, ABB RobotStudio simulation software is used. The collaborative robot should be equipped with a specially designed gripper, which is suitable for the collaborative mode. Furthermore, in order to make the gripper suitable for TYRI’s components measurements, it was customized by a mechanism feature, which RobotStudio has.With the help of literature studies and various methods, the successful implementation of the robot was achieved. The robot was integrated outside the assembly line and was able to handle both tasks at the first station. Which indeed improved workplace safety. However, the robot took a total of 30.8 seconds to complete the tasks, which is longer than the 19 seconds goal was aimed for. As a result, the robot didn’t meet the desired cycle time required in this case

  • 36.
    Abusultan, Mukhlis
    University West, Department of Engineering Science.
    Robotize pizza making – Robizza: A conceptual model design and analysis for automating pizzerias2022Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Food Industry Automation is one of the sectors that took an advantage of industry fourth revolution, where food industry robots start to play a significant role in planting, transporting, processing, and even preparing various dishes. Pizza making is one of the food sectors that is entirely done by food experts and pizza chefs in small and medium business pizzerias, and even though pizza factories have mass production of pizza, they still don’t produce the required freshness and good taste pizza like the one you find it in pizza restaurants. The project studies food industry automation and then designs a conceptual model for robotizing pizza making process, providing a fully automated solution for medium and small pizza-making bakeries. Demonstrating what technologies are required to implement the idea and how to overcome challenges such as quality assurance and preserving hygiene standards adds to that, showing technical limitations and opportunities. The project study is based on theoretical and experimental aspects using an application development kit, Arduino IDE, and simulating the whole process with ABB robot studio simulation. 

  • 37.
    Adamsson, Kristoffer
    University West, Department of Engineering Science, Division of Industrial Engineering and Management, Electrical- and Mechanical Engineering.
    Analys och optimering av verktygsförslitning vid skärande bearbetning i superlegering2018Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In the aerospace industry today, super alloys are used in components for jet engines. To increase the efficiency of these engines, through higher combustion temperatures, new materials are developed which maintain their strength at elevated temperatures. The increase in strength as well as the ability to maintain the strength at elevated temperatures, makes them more difficult to manufacture with metal cutting technology.

    The Sector Workshop at GKN Aerospace Sweden in Trollhättan produces a large number of products with a variety of cutting tools. Some of these tools, for a certain product, have been investigated in this work. The products are manufactured from a hard-wearing superalloy which results in extremely high tool wear and high tooling costs.

    To enable improvements in the metal cutting process, a literature study was first conducted. The study focus was to identify information about the various tool wears that occur in metal cutting process of super alloys. Thereafter, specifically selected tools were analyzed. The analysis consisted primarily of a classification of the different tool wear types. In parallel with the tools being classified, measurements were made of the size of wears using a digital microscope.

    The collected data was later used for a statistical analysis, which identified the tool wear type that was the most common. The analysis showed that most of the tools had chipping. Then, to identify where in the machining process the chipping occurred further analyzes were made where the tool wear curves for two cutting tools were plotted. During this analysis to produce the tool wear curves, it was found that the chipping appeared when the tools engaged the workpiece.

    In the later parts of the work, a list of proposal was generated about how the metal cutting process could change to reduce the identified tool wears. One suggestion was to optimize the tool engagement of the workpiece. Also, an optimization of cutting data and especially the spindle speed were also recommended to reduce chipping. This due to some of the chipping could be caused by chatter vibration. For the ceramic tools an increased cutting speed was recommended because machining today was carried out at a much lower cutting speed than research results indicate is necessary for ceramic cutting tools in super alloys. Finally, a checklist for manufacturing personnel was formulated, which could be used to optimize tool wear at GKN Aerospace Sweden.

  • 38.
    Adegoke, Olutayo
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing.
    Processability of Laser Powder Bed Fusion of Alloy 247LC: Influence of process parameters on microstructure and defects2020Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    This thesis is about laser powder bed fusion (L-PBF) of the nickel-based superalloy: Alloy 247LC. Alloy 247LC is used mainly in gas turbine blades and processing the blades with L-PBF confers performance advantage over the blades manufactured with conventional methods. This is mainly because L-PBF is more suitable, than conventional methods, for manufacturing the complex cooling holes in the blades. The research was motivated by the need for academia and industry to gain knowledge about the processability of the alloy using L-PBF. The knowledge is essential in order to eventually solve the problem of cracking which is a major problem when manufacturing the alloy. In addition, dense parts with low void content should be manufactured and the parts should meet the required performance. Thus, the thesis answered some of the important questions related to process parameter-microstructure-defect relationships.

    The thesis presented an introduction in chapter 1. A literature review was made in chapter 2 to 4. In chapter 2, the topic of additive manufacturing was introduced followed by an overview of laser powder bed fusion. Chapter 3 focused on superalloys. Here, a review was made from the broader perspective of superalloys but was eventually narrowed down to the characteristics of nickelbased superalloys and finally Alloy 247LC. Chapter 4 reviewed the main research on L-PBF of Alloy 247LC. The methodology applied in the thesis was discussed in chapter 5. The thesis applied statistical design of experiments to show the influence of process parameters on the defects and microstructure, so a detail description of the method was warranted. This was given at the beginning of chapter 5 and followed by the description of the L-PBF manufacturing and the characterization methods. The main results and discussions, in chapter 6, included a preliminary investigation on how the process parameters influenced the amount of discontinuity in single track samples. This was followed by the results and discussions on the investigation of voids, cracks and microhardness in cube samples (detail presentation was given in the attached paper B). Finally, the thesis presented results of the microstructure obtainable in L-PBF manufactured Alloy 247LC. The initial results of the microstructure investigation were presented in paper A.

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  • 39.
    Adegoke, Olutayo
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing.
    Processability of Laser Powder Bed Fusion of Alloy 247LC-Influence of process parameters on microstructure and defects2021Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This thesis is about laser powder bed fusion (L-PBF) of the nickel-basedsuperalloy Alloy 247LC. Alloy 247LC is mainly used in gas turbine blades and processing the blades with L-PBF may confer performance advantage over the blades manufactured with conventional methods. This is mainly because L-PBFis more suitable, than conventional methods, for manufacturing the complex cooling holes in the blades. The research was motivated by the need for academia and industry to gain knowledge about the processability of the alloy using L-PBF. The knowledge is essential to eventually solve the problem of cracking encountered when processing the alloy. In addition, dense parts with low void content should be processed and the microstructure and properties should meett he required performance. Heat-treatment is usually performed to acquire final properties, so it is also of interest to study this aspect. Thus, the thesis answered some of the important questions related to process parameter-microstructure- property relationships.

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  • 40.
    Adegoke, Olutayo
    et al.
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing.
    Andersson, Joel
    University West, Department of Engineering Science, Division of Welding Technology.
    Brodin, Håkan
    Materials Technology Additive Manufacturing Product Development-Industrial Gas Turbines, Siemens Industrial Turbomachinery, Finspång, SE-612 83, Sweden.
    Pederson, Robert
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing.
    Influence of laser powder bed fusion process parameters on voids, cracks, and microhardness of nickel-based superalloy alloy 247LC2020In: Materials, ISSN 1996-1944, E-ISSN 1996-1944, Vol. 13, no 17, article id 3770Article in journal (Refereed)
    Abstract [en]

    The manufacturing of parts from nickel-based superalloy Alloy 247LC by laser powder bed fusion (L-PBF) is challenging, primarily owing to the alloy’s susceptibility to cracks. Apart from the cracks, voids created during the L-PBF process should also be minimized to produce dense parts. In this study, samples of Alloy 247LC were manufactured by L-PBF, several of which could be produced with voids and crack density close to zero. A statistical design of experiments was used to evaluate the influence of the process parameters, namely laser power, scanning speed, and hatch distance (inherent to the volumetric energy density) on void formation, crack density, and microhardness of the samples. The window of process parameters, in which minimum voids and/or cracks were present, was predicted. It was shown that the void content increased steeply at a volumetric energy density threshold below 81 J/mm3. The crack density, on the other hand, increased steeply at a volumetric energy density threshold above 163 J/mm3. The microhardness displayed a relatively low value in three samples which displayed the lowest volumetric energy density and highest void content. It was also observed that two samples, which displayed the highest volumetric energy density and crack density, demonstrated a relatively high microhardness; which could be a vital evidence in future investigations to determine the fundamental mechanism of cracking. The laser power was concluded to be the strongest and statistically most significant process parameter that influenced void formation and microhardness. The interaction of laser power and hatch distance was the strongest and most significant factor that influenced the crack density. © 2020 by the authors.

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  • 41.
    Adegoke, Olutayo
    et al.
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing.
    Andersson, Joel
    University West, Department of Engineering Science, Division of Welding Technology.
    Brodin, Håkan
    Siemens Industrial Turbomachinery, Finspång, 612 83, Sweden.
    Pederson, Robert
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing.
    Review of laser powder bed fusion of gamma-prime-strengthened nickel-based superalloys2020In: Metals, ISSN 2075-4701, Vol. 10, no 8, article id 996Article in journal (Refereed)
    Abstract [en]

    This paper reviews state of the art laser powder bed fusion (L-PBF) manufacturing of γ′ nickel-based superalloys. L-PBF resembles welding; therefore, weld-cracking mechanisms, such as solidification, liquation, strain age, and ductility-dip cracking, may occur during L-PBF manufacturing. Spherical pores and lack-of-fusion voids are other defects that may occur in γ′-strengthened nickel-based superalloys manufactured with L-PBF. There is a correlation between defect formation and the process parameters used in the L-PBF process. Prerequisites for solidification cracking include nonequilibrium solidification due to segregating elements, the presence of liquid film between cells, a wide critical temperature range, and the presence of thermal or residual stress. These prerequisites are present in L-PBF processes. The phases found in L-PBF-manufactured γ′-strengthened superalloys closely resemble those of the equivalent cast materials, where γ, γ′, and γ/γ′ eutectic and carbides are typically present in the microstructure. Additionally, the sizes of the γ′ particles are small in as-built L-PBF materials because of the high cooling rate. Furthermore, the creep performance of L-PBF-manufactured materials is inferior to that of cast material because of the presence of defects and the small grain size in the L-PBF materials; however, some vertically built L-PBF materials have demonstrated creep properties that are close to those of cast materials.© 2020 by the authors. Licensee MDPI, Basel, Switzerland.

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  • 42.
    Adegoke, Olutayo
    et al.
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing.
    Andersson, Joel
    University West, Department of Engineering Science, Division of Welding Technology.
    Brodin, Håkan
    Siemens Industrial Turbomachinery, 612 83, Finspång (SWE).
    Pederson, Robert
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing.
    Harlin, Peter
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing. Sandvik Additive Manufacturing, Sandviken (SWE).
    Influence of laser powder bed fusion process parameters on the microstructure and cracking susceptibility of nickel-based superalloy Alloy 247LC2022In: Results in Materials, ISSN 2590-048X, Vol. 13, article id 100256Article in journal (Refereed)
    Abstract [en]

    Microstructures of material conditions of nickel-based superalloy Alloy 247LC fabricated using laser powder bed fusion (L-PBF) were investigated. Experiments designed in a prior study revealed the L-PBF process parameters for which the material conditions displayed a reduced susceptibility to cracking. Certain process parameters produced material conditions with an increased susceptibility to cracking. In this study, the material conditions were investigated in detail to reveal their microstructure and to determine the cause of cracking. The reason for the transition between a reduced to an increased susceptibility to cracking was examined. The results revealed solidification cracking occurred at high-angle grain boundaries. Solidification cracking may have been promoted at high-angle grain boundaries because of the undercooling contribution of the grain boundary energy. Furthermore, Si segregation was observed in the cracks. Thus, the presence of Si most likely promoted solidification cracking. It was observed that a high crack density, which occurred in the high energy density material condition, was associated with a large average grain size. The fact that certain combination of process parameters produced microstructures with a low susceptibility to cracking, indicates that reliable Alloy 247LC material may be printed using L-PBF by employing improved process parameters. © 2022

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  • 43.
    Adegoke, Olutayo
    et al.
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing.
    Andersson, Joel
    University West, Department of Engineering Science, Division of Welding Technology.
    Ojo, Olanrewaju A.
    University of Manitoba, Winnipeg, Canada.
    Brodin, Håkan
    Siemens Industrial Turbomachinery AB, Finspang, Sweden .
    Pederson, Robert
    GKN Aerospace, Redditch, United Kingdom.
    Laser beam powder bed fusion and post processing of alloy 247LC2019In: MS and T 2019 - Materials Science and Technology, Materials Science and Technology , 2019, p. 27-34Conference paper (Refereed)
    Abstract [en]

    Alloy 247LC is sensitive to cracking during laser beam powder bed fusion (PBF-LB) manufacturing. Post processing is thus required to close cracks and achieve desired properties. In this study, samples of Alloy 247LC were manufactured by PBF-LB and subsequently post processed by hot isostatic pressing (HIP), HIP + solution and ageing heat treatments. The microstructure was characterized. Results showed cracks in the as-built condition. Cracks were not detected after HIP. Bright microconstituents were observed in the region between the cells, mainly, because of the partitioning of Hf and Ta into the intercellular region, where they presumably form carbides. What is assumed to be oxides were prominent in the microstructure. Thermodynamic calculations showed rapid formation of ?’ precipitates in the alloy, due to the high total concentration of Al and Ta and this was linked to the high hardness values in the as-built condition. © 2019 MS&T19®

  • 44.
    Adegoke, Olutayo
    et al.
    Siemens Energy, Finspång (SWE).
    Kumara, Chamara
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing. FEV Sverige AB, Trollhättan (SWE).
    Thuvander, Matttias
    Department of Physics, Chalmers University of Technology, Gothenburg (SWE).
    Deirmina, Faraz
    Siemens Energy, Finspång (SWE).
    Andersson, Joel
    University West, Department of Engineering Science, Division of Welding Technology.
    Brodin, Håkan
    Siemens Energy, Finspång (SWE).
    Harlin, Peter
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing. Sandvik Additive Manufacturing, Sandviken (SWE).
    Pederson, Robert
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing.
    Scanning electron microscopy and atom probe tomography characterization of laser powder bed fusion precipitation strengthening nickel-based superalloy2023In: Micron, ISSN 0968-4328, E-ISSN 1878-4291, Vol. 171, article id 103472Article in journal (Refereed)
    Abstract [en]

    Atom probe tomography (APT) was utilized to supplement scanning electron microscopy (SEM) characterizationof a precipitation strengthening nickel-based superalloy, Alloy 247LC, processed by laser powder bed fusion (LPBF). It was observed that the material in the as-built condition had a relatively high strength. Using both SEMand APT, it was concluded that the high strength was not attributed to the typical precipitation strengtheningeffect of γ’. In the absence of γ’ it could be reasonably inferred that the numerous black dots observed in thecells/grains with SEM were dislocations and as such should be contributing significantly to the strengthening.Thus, the current investigation demonstrated that relatively high strengthening can be attained in L-PBF even inthe absence of precipitated γ’. Even though γ’ was not precipitated, the APT analysis displayed a nanometer scalepartitioning of Cr that could be contributing to the strengthening. After heat-treatment, γ’ was precipitated and itdemonstrated the expected high strengthening behavior. Al, Ta and Ti partitioned to γ’. The strong partitioningof Ta in γ’ is indicative that the element, together with Al and Ti, was contributing to the strain-age crackingoccurring during heat-treatment. Cr, Mo and Co partitioned to the matrix γ phase. Hf, Ta, Ti and W were found inthe carbides corroborating previous reports that they are MC. 

  • 45.
    Adegoke, Olutayo
    et al.
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing.
    Polisetti, Satyanarayana Rao
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing.
    Xu, Jinghao
    Linköpings universitet, Linköping.
    Andersson, Joel
    University West, Department of Engineering Science, Division of Welding Technology.
    Brodin, Håkan
    Siemens Industrial Turbomachinery, Finspång.
    Pederson, Robert
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing.
    Harlin, Peter
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing. Sandvik Additive Manufacturing, Sandviken.
    Influence of laser powder bed fusion process parameters on the microstructure of solution heat-treated nickel-based superalloy Alloy 247LC2022In: Materials Characterization, ISSN 1044-5803, E-ISSN 1873-4189, Vol. 183, article id 111612Article in journal (Refereed)
    Abstract [en]

    In this study, Alloy 247LC samples were built with different laser powder bed fusion (L-PBF) process parameters. The samples were then subjected to solution heat treatment at 1260 °C for 2 h. The grain size of all the samples increased significantly after the heat treatment. The relationship between the process parameters and grain size of the samples was investigated by performing a design of experiment analysis. The results indicated that the laser power was the most significant process parameter that influenced the grain height and aspect ratio. The laser power also significantly influenced the grain width. The as-built and as-built + heat-treated samples with high, medium, and low energy densities were characterized using a field emission gun scanning electron microscope equipped with an electron backscatter diffraction detector. The micrographs revealed that the cells present in the as-built samples disappeared after the heat treatment. Isolated cases of twinning were observed in the grains of the as-built + heat-treated samples. The disappearance of cells, increase in the grain size, and appearance of twins suggested that recrystallization occurred in the alloy after the heat treatment. The occurrence of recrystallization was confirmed by analyzing the grain orientation spread of the alloy, which was lower and more predominantly <1° in the as-built + heat-treated conditions than in the as-built conditions. The microhardness of the as-built + heat-treated samples were high which was plausible because γ’ precipitates were observed in the samples. However, the L-PBF process parameters had a very low correlation with the microhardness of the as-built + heat-treated samples.

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  • 46.
    Aden, Mohamud Abdullahi
    et al.
    University West, Department of Engineering Science.
    Araya, Abel Russom
    University West, Department of Engineering Science.
    Hotet Ransomware mot företag, myndigheter och kommuner2022Independent thesis Basic level (university diploma), 5 credits / 7,5 HE creditsStudent thesis
    Abstract [en]

    Ransomware has increased in recent years, which has caused many companies devastating consequences. Incidents with ransomware can seriously affect business processes and leave companies without the data needed to run and deliver mission-critical services.

    This thesis is based on how to prioritize the threat of Ransomware in companies, authorities and municipalities. After years in the media about Ransomware attacks that have taken place against Swedish companies and authorities, this essay examines how well prepared and aware companies and authorities are about Ransomware attacks, everything from whether an attack has taken place, how they experience it and what solutions they have used to solve it.

    Based on the literature study and investigation we have conducted about Ransomware attacks and in combination with the interview study, conclusions can be drawn that with various organizations in both the private and the public sector, there are different views and experiences about an increased threat. But both the public and private sectors have plans, routines and strategies against Ransomware-attacks.

  • 47.
    Adli, E.
    et al.
    University of Oslo, Oslo, Norway.
    Gjersdal, H.
    University of Oslo, Oslo, Norway.
    Røhne, O.M.
    University of Oslo, Oslo, Norway.
    Dorholt, O.
    University of Oslo, Oslo, Norway.
    Bang, D.M.
    University of Oslo, Oslo, Norway.
    Thomas, D,
    ESS ERIC, Lund, Sweden.
    Shea, T.
    ESS ERIC, Lund, Sweden.
    Andersson, R.
    ESS ERIC, Lund, Sweden.
    Ibison, M.G.
    University of Liverpool and Cockcroft Institute, Daresbury, UK.
    Welsch, C.P
    University of Liverpool and Cockcroft Institute, Daresbury, UK.
    Joshi, Shrikant V.
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing. University West, Department of Engineering Science, Research Enviroment Production Technology West.
    The Ess Target Proton Beam Imaging Systemas In-Kind Contribution2017In: Proceedings of IPAC2017, Copenhagen, Denmark, 2017, p. 3422-3425Conference paper (Refereed)
  • 48.
    Adli, Erik
    et al.
    University of Oslo, Oslo (NOR).
    Gjersdal, Håvard
    University of Oslo, Oslo (NOR).
    Sjøbæk, Kyrre N.
    University of Oslo, Oslo (NOR).
    Christoforo, Grey
    University of Oslo, Oslo (NOR).
    Fackelman, Eric D.
    University of Oslo, Oslo (NOR).
    Røhne, Ole M.
    University of Oslo, Oslo (NOR).
    Ringnes, Jonas S.
    University of Oslo, Oslo (NOR).
    Solbak, Simen R.
    University of Oslo, Oslo (NOR).
    Lithun, Maren C.
    University of Oslo, Oslo (NOR).
    Thomas, Cyrille
    ESS ERIC, Lund (SWE).
    Levinsen, Yngve
    ESS ERIC, Lund (SWE).
    Rosengren, Kaj
    ESS ERIC, Lund (SWE).
    Shea, Thomas
    ESS ERIC, Lund (SWE).
    Bell, Gerard
    STFC (GBR).
    Ibison, Mark
    University of Liverpool and Cockcroft Institute, Daresbury (GBR).
    Joshi, Shrikant V.
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing.
    Björklund, Stefan
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing.
    Progress Of The Ess Proton Beam Imaging Systems2022In: LINAC2022, ACoW Publishing , 2022, p. 395-398Conference paper (Refereed)
    Abstract [en]

    The ESS Target Proton Beam Imaging Systems has the objective to image the 5 MW ESS proton beam as it entersthe spallation target. The imaging systems has to operate in a harsh radiation environment, leading to a number of challenges : development of radiation hard photon sources, long and aperture-restricted optical paths and fast electronics required to provide rapid information in case of beam anomalies. This paper outlines how main challenges of the imaging systems have been addressed, and the status of deployment as ESS gets closer to beam.

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  • 49.
    Adolfsson, Sebastian
    University West, Department of Engineering Science, Division of Production System.
    RatSLAM with Viso2: Implementation of alternative monocular odometer2017Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In this work, a ROS (Robot Operating System) version of Open RatSLAM, [1] [2], was tested with Viso2 [3] as an alternative monocular odometer. A land based rover [4] was used to perform data acquisition and a remote control tool was developed to facilitate this procedure, implemented as ROS nodes on both Ubuntu 16.04 and on Android 7.0.An additional requirement that comes from using Viso2 is the need for camera information together with the image stream, which might require camera calibration. A ROS node to manually add this camera information was made as well as a node to change the generated odometry message from Viso2 to a form that RatSLAM uses. The implemented odometer uses feature tracking to estimate motion, which is fundamentally different to matching intensity profiles which the original method does and can hence be used when different properties of the visual odometry function is desired. From experiments, it was seen that the feature tracking method from Viso2 generated amore robust motion estimate in terms of real world scale and it was also able to better handle environments of varying illumination or that contains large continuous surfaces of the same colour. However, the feature tracking may give slight variations in the generated data upon successive runs due to the random selection of features to track. Since the structure of RatSLAM gives the system ability to make loop closures even with large differences in position, an alternative odometry does not necessarily give a significant improvement in performance of the system in environments that the original system operates well in. Even though both algorithms show difficulty with estimating fast rotations, especially when the camera view contains areas with few features, the performance improvement in Viso2 together with its ability to better maintain the real-world scale motivates its usefulness. The source code, as well as instructions for installation and usage is public

  • 50.
    Adolfsson, Sebastian
    University West, Department of Engineering Science, Division of Production System.
    RatSLAM with Viso2: Implementation of alternative monocular odometer2017Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In this work, a ROS (Robot Operating System) version of OpenRatSLAM, [1] [2], was tested with Viso2 [3] as an alternative monocular odometer. A land based rover [4] was used to perform data acquisition and a remote control tool was developed to facilitate this procedure, implemented as ROS nodes on both Ubuntu 16.04 and on Android 7.0.  An additional requirement that comes from using Viso2 is the need for camera information together with the image stream, which might require camera calibration. A ROS node to manually add this camera information was made as well as a node to change the generated odometry message from Viso2 to a form that RatSLAM uses. The implemented odometer uses feature tracking to estimate motion, which is fundamentally different to matching intensity profiles which the original method does and can hence be used when different properties of the visual odometry function is desired. From experiments, it was seen that the feature tracking method from Viso2 generated a more robust motion estimate in terms of real world scale and it was also able to better handle environments of varying illumination or that contains large continuous surfaces of the same colour. However, the feature tracking may give slight variations in the generated data upon successive runs due to the random selection of features to track. Since the structure of RatSLAM gives the system ability to make loop closures even with large differences in position, an alternative odometry does not necessarily give a significant improvement in performance of the system in environments that the original system operates well in. Even though both algorithms show difficulty with estimating fast rotations, especially when the camera view contains areas with few features, the performance improvement in Viso2 together with its ability to better maintain the real-world scale motivates its usefulness.  The source code, as well as instructions for installation and usage is public.

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