Renewable energy sources are becoming more attractive due to the impending climate changes. The market for wood pellet is growing and is already used in households, heating plant and industries. To enhance the properties and refine the raw material a lot of the moisture need to be dried out before is can be processed into wood pellets. The demand for wood pellets has been growing in Sweden and the rest of Europe in recent years. To meet the demand more pellets needs to be produced. SCA BioNorr produces approximately 175 ktons of wood pellets annually but have permission to increase production to 240 ktons. BioNorrs bio-pellet plant has limitations which obstructs the increase of production, the largest one is related to the drying capacity. Another limitation regards the pellet press in the plant. The purpose of the project is to determine if a pre-dying technology called mechanical dewatering will allow increased production and decrease the energy demand for the complete drying process. Mechanical dewatering presses the raw material to extract water hence decreasing the moisture content of the raw material which feeds into the pellet plant. The chosen technology is called Saalasti Press 1803(SP1803) from the company Saalasti Oy. A model with a simplified representation of the pellet plant was made in Excel together with a representation of the SP1803. The model was designed towards the maximal flue gas flow in the pellet plant, and the raw material flow into the SP1803 unit matched their maximal capacity. That means that a proportion of the raw material will be processed by the SP1803 units and a proportion will bypass them. These different material flows are mixed before feeding into the pellet plant. The economical results was based on the cost of investment and costs and income from the increased production. Profitability was calculated by the pay back time and the proceeds during the economical lifespan. A sensitivity analysis was made on some parameters to distinguish how these affected profitability. Calculations was based on operating data from 2017 to 2019.  The results shows a considerable increase in production, 27 ktons for one SP1803 unit to 67 ktons for three SP1803 units. The annual production increased to 203 ktons for one SP1803 to 235 ktons for three SP1803 units. The specific energy demand in relation to pellet amount dropped from 0.81 [MWh/ton pellet] to 0.71 for one SP1803 and 0.63 for three units which is a decrease of between 14 to 29 %. The profitability on an investment of up to three SP1803 units was good, with the best one being an investment of one SP1803 unit. The pay back time for one SP1803 unit was 1.7 years and 2.4 for three units. The proceeds for one SP1803 unit was 59 Mkr and 70 Mkr for three units. The sensitivity analysis showed that the price of raw material and the product price affected the profitability most. All cases of the sensitivty analysis was profitable.  For continued evaluation an analysis of the pellet plant with an implemented SP1803 unit to find an optimal operating mode which allows increased production with low energy demand is recommended. This would require a more detailed representation of the pellet plant which takes altering operating parameters into account due to risk of over-drying and risk of fires in the plant. / Med det rådande klimathotet blir hållbara energikällor alltmer attraktiva. Biopellets är en växande bränslekälla i en marknad som redan är etablerad och används inom hushållsbruk, värmeverk och industri. För att pellets ska ha bra energiegenskaper så behöver råvaran förädlas, där en stor del av fukten i råvaran torkas ut innan det pressas till pellets. Efterfrågan på biopellets har ökat de senaste åren i Sverige och restan av Europa. För att möta efterfrågan behöver produktionen av pellets öka. SCA BioNorr i Härnösand producerar idag årligen ca 175 kton pellets men har tillstånd att producera 240 kton. I BioNorrs process finns det begränsningar som hindrar produktionsökningen. Den största begränsande faktorn är pelletsbrukets torkkapacitet. En annan begränsning är produktionskapaciteten på pelletmaskinerna i bruket.  Projektets mål är att bestämma om förtorkningstekniken mekanisk avvattning kan tillåta ökad produktion och sänka energibehovet för hela processen samt utvärdera lönsamhet på en investering på upp till 3 st enheter. Mekanisk avvattning som förtork går ut på att pressa ut en mängd vatten ur råvaran, och därav sänka fukhalten på råvaran innan det matas in till bruket. Den valda tekniken var Saalasti Press 1803(SP1803) från företaget Saalasti Oy.  I Excel modellerades mass och energibalans för en förenklad representation av BioNorrs pelletsbruk, samt en representation av SP1803. Modellen styrdes mot maximala rökgasflödet i bruket för att tillåta maximal produktion av pellets, samt att råvaruflödet in till SP1803-enheterna motsvarar dess maximala processkapacitet. Det innebär att en andel av totala råvaruflödet går genom SP1803 och en andel passerar. Dessa flöden blandas innan de matas in till pelletsbruket. De ekonomiska resultaten beräknades på investeringskostnader samt kostnader och intäkter gentemot produktionsökningen. Lönsamheten bestämdes genom återbetalningstid och avkastning vid 5 % kalkylränta över den ekonomiska livslängden, vilket valdes till 5 år. En känslighetsanalys utfördes på några utvalda parametrar för att urskilja hur de priserna påverkade lönsamheten. För beräkningarna användes driftdata från 2017 till 2019.  Resultaten visade en betydlig ökning i produktion, från 27 kton för 1 st SP1803 upp till 67000 ton pellets för 3 st SP1803-enheter. Årsproduktionen visade en tydlig ökning, från 203 kton för 1 st SP1803 upp till 235 kton för 3 st SP1803. Det specifika energibehovet relaterat till mängd pellets minskade från 0.81 [MWh/ton pellets] till 0.71 för 1 st SP1803 och ner till 0.63 för 3 st SP1803 vilket är en effektivisering på mellan 14 till 29 %. Lönsamheten på en investering på upp till 3 st SP1803 var god, mest lönsam var investeringen för 1 st SP1803. Återbetalningstiden varierade mellan 1.7 år för 1 st SP1803 till 2.4 för 3 st. Avkastningen över den ekonomiska livslängden beräknades till 59 Mkr för 1 st SP1803 till 70 Mkr för 3 st. Känslighetsanalysen visade att råvarupriset och produktpriset hade störst påverkan på lönsamheten. Samtliga fall i känslighetsanalysen var lönsamma.

The automotive industry is constantly being challenged by customers and authorities to enhance the efficiency of the internal combustion engine (ICE) in order to achieve improved fuel consumption and reduced emissions. There are several interfaces within the design of an ICE that causes frictional losses, one of them is the valvetrain. An approach to reducing the friction in the valvetrain of modern engines is to implement cam-follower rollers, resulting in a rolling rather than sliding contact when interacting with the camshaft. The prominent type of wear in rolling contacts is surface fatigue, and specifically a phenomenon called micropitting. The company in collaboration with this project is Applied Nano Surfaces Sweden AB (ANS), located in Uppsala, Sweden. The company have specialized in surface treatment methods of mechanical components. ANS has developed a mechano-chemical treatment method called ANS Triboconditioning, which have shown beneficial friction and wear reducing properties when applied to metal surfaces. This thesis was conducted to investigate how the ANS Triboconditioning would affect the frictional behaviour compared to established surface treatment methods and the occurrence of micropitting in rolling contact configurations. Two types of test programs was implemented into a Wazau UTM 2000 Twin-Disc Tribometer. No clear trend could be established from the micropitting tests and therefore no conclusion regarding if ANS Triboconditioning affects the occurrence of micropitting damage in a positive or negative manner could be stated. The results from the friction test indicated an overall reduction in friction for the test specimens that had been treated with ANS Triboconditioning when compared to specimens that only had been treated with already established surface treatment methods. Summarized, additional tests and analyses are necessary in order to statistically confirm the observed results and determine their respective trends.

No description available.

Volvo Trucks is the second-largest heavy-duty truck provider in the world. As of now they are working towards fossil free transport solutions. This comes with a fast development pace and an increasing need of being able to verify new and complex assembly processes to ensure an integration of the production of new truck models together with the current vehicles that are being produced.  This project is a master thesis that focuses on improving the quality and verification capabilities of the Pilot Plant at the Volvo Tuve site. The goal of the project is to design and develop a modular transport solution that can be used to move truck chassis at a predefined speed to be able to simulate and perform assembly tasks with the same parameters in the test environment as in the factory process along the driven line. The design was developed using the product development process described by Ulrich et al., 2020, with slight modification. The resulting design is able to move the truck chassis at the requested predefined speeds that are possible on the driven line in the factory. This solution gives Volvo the ability to perform simulations of specific and critical assembly steps, potentially resulting in fewer failures during production ramp-up of their new truck models.  Calculations were made to in order to verify the strength and functionality of the design.

In this master thesis project carried out on Scania’s interaction design department in Södertälje an evaluation of the technology gaze interaction has been done. The aim was to see if the technology was suitable for implementation in a truck environment and what potential it had. The work started by doing a context analysis to get a deeper knowledge of the research done on within the area related to the subject. Following the context analysis a comprehensive need finding process was done. In this process, data from interviews, observations, ride along with truck drivers, benchmarking and more was analysed. The analysis of this was used to identify the user needs. Based on the user needs the concept development phase was conducted. The whole development phase was done in different stages and started off by an idea generation process. The work flow was made in small iterations with the idea to continuously improve the concepts. All concepts were evaluated in a concept scoring chart to see which of the concepts that best fulfilled the concept specifications. The concepts that best could highlight the techniques strengths and weaknesses were chosen and these are Head Up Display Interaction and Gaze Support System.. These concepts focused on the interaction part of the technique rather than a specific function. Test of the two concepts were conducted in a simulator to get data and see how they performed compared to today´s Scania trucks. The result overall was good and the test subjects were impressed with the systems. However there was no significance in most of the cases of driving except for some conditions where the concepts prove to be better than the systems used today. Gaze interaction is a technology that is suitable for a truck driving environment given that a few slight improvements are made. Implementation of the concepts have a good potential of reducing road accidents caused by human errors.

The subject of this thesis covers the process of online parameter estimation of agile satellites. Accurate knowledge of parameters such as moment of inertia and centre of mass play a crucial role in satellite attitude control and pointing performance. Typically, identification of parameters such as these is performed on-ground using post-processing algorithms. This thesis investigates the potential of performing the identification procedures in real-time on-board operating satellites, using only measurements available from typical satellite attitude sensors.    The thesis covers the areas of system identification and modelling of spacecraft attitude dynamics. An algorithm based on the Unscented Kalman Filter is developed for online parameter estimation of spacecraft moment of inertia parameters. The proposed method is successfully validated, both through simulation environments, and in practice using Airbus’ satellite hardware demonstrator INTREPID, a three-axis air-bearing table equipped with CMG actuators and typical attitude sensors.

The study has consisted of creating a place for snow storage with a connecting storm water facility. This is based on findings regarding concentrations of pollutants in Luleå's snow storages in combination with Luleå's standards for design of these storages. For Luleå Municipality, the stormwater issue is relevant as the number of floods will increase as Luleå expands. This results in a greater ratio of hard-made surfaces with increased surface runoff that create risks of flooding and property damage, something that will intensify even further with climate change. Besides this, the runoff concentration of pollutants that are transported out into recipients also increases. The study has been carried out in Luleå, via Luleå Municipality and LTU. The purpose of the study was to answer the following questions:"What concentrations of pollutants are found in Luleå's meltwater?", "What does Luleå' smanagement of snow storage look like, and why?", "Where can a snow storage be placed in Luleå to enable year-round recreation?” and "Which stormwater solution should be chosen to filter pollutants from this snow deposit?". This was answered via seven different means of gathering data: literature studies, field studies/observations, meetings/interviews & E-mail exchanges, selection of a stormwater facility, calculations, simulations, and conceptual design. Through these means, the study concluded that the concentrations of pollutants in meltwater are generally greater than in stormwater, that there are recommendations regarding the size, location and safety of Luleås snow storages, that any snow storage should preferably be located where motor traffic is not present and that its space should be usable year round with regard to recreation, and that a wetland is the most suitable facility for filtering the pollutants in the meltwater from this deposit. Overall, the results conveys that the spaces set aside for snow and meltwater treatment should enable year-round recreation, in addition to their technical functions. However, does the results show nothing in terms of management of extreme cases of rainfall nor any types flooding preventions relating to stormwater management. This paper does not provide any suggestions for a snow storage site nor a stormwater treatment facility for cities with a similar or different climate. The reason that onlyr ecreation and pollution treatment were considered is because these are the most relevant in this context, firstly since toxins are more prevalent in meltwater than in stormwater, and because recreation associated with snow is a given aspect of usage. Thus were a suitable frame of question and suitable means used to generate reasonable and acceptable results.

The Swedish Defence Materiel Administration, FMV’s, test site in Vidsel, Norrbotten, has access to the largest area for testing and evaluating military aircraft, missiles and unmanned vehicles over land in Europe. The facility has the capacity to create many different types of test enviroments, which are continously developed to meet the customers growing requirements where the main focus is using different types of aerial targets. This project is a thesis for a Master in Mechanical Engineering and Machine Design. The purpose of the project was to develop a new brake system for the aerial tow target, SM3C. The goal of the project was to come up with a concept with enough support to say what, why and how the new concept meets the desired requirements. With a structured and iterative product development process, based on Ulrich & Eppingers theories, the identified needs of the new brake system and data from the existing product resulted in a product specification with quantifiable metrics. From the development process and product specification, the project resulted in a detailed and designed concept that was more standardized, modular and less complex than the existing product with support from theoretical analysis, experiments and simulations of the brake system. / Försvarets Materialverk, FMVs, provplats i Vidsel, Norrbotten, har tillgång till Europas största provområde för test och evaluering av stridsflygplan, robotar och obemannade farkoster över land. Provplatsen kan presentera en mängd olika testmiljöer som kontinuerligt utvecklas för att möta kundernas växande krav där fokus ligger på olika typer av luftmål. Projektet innefattar ett examensarbete för en civilingenjörsutbildning i maskinteknik med syfte att utveckla ett nytt bromssystem till det luftburna släpmålet, SM3C. Målet med projektet var att tillsammans med en funktionsanalys av det befintliga bromsystemet komma fram till ett koncept med tillräckligt underlag som kunde påvisa vad, varför och hur konceptet uppfyller de önskade kraven. Med en strukturerad och iterativ produktutvecklingsprocess, baserad på Ulrich & Eppingers teorier, bearbetades behoven av ett nytt bromssystem tillsammans med analysen av den befintliga produkten vilket gav en kravspecifikation med kvantifierbar data. Utifrån kravspecifikationen och utvecklingsprocessen, resulterade projektet i ett detaljkonstruerat koncept som var mer standardiserat, modulärt och mindre komplext än befintligt system med stöd från utförda analyser, experiment och simuleringar.

Background Nuclear reactors utilizing molten fuels rather than solid fuels show a massive advantage in energy yield, waste handling and safety features. The only successful reactor utilizing a molten fuel was called the ‘Molten Salt Reactor Experiment’ (MSRE), built and operated in the Oak Ridge national laboratory (ORNL) in Tennessee, U.S.A. during the 1960s. The molten salts in question are fluoride compounds under the name of “FLiBe”. In this thesis, the heat exchangers of the MSRE are modelled and simulated, with the aim to test whether current computational fluid dynamics (CFD) software and mathematical models can accurately predict molten salt heat transfer behaviour.  Methods All programs used are open-source and/or free-access to facilitate open collaboration between researchers in this growing field. All models and findings produced in this thesis are free to use for future research. The program Onshape was used to draw CAD-models based on hand-drawn technical documents released by ORNL. Several programs, e.g., Simscale and Salome, were used to create high detailed meshes of the heat exchangers. The CFD software Simscale and OpenFOAM have been used to simulate the heat exchangers, using the 𝑘 − 𝜔 𝑆𝑆𝑇 Reynolds averaged Navier-Stokes (RANS) turbulence model to perform a multiregion conjugate heat transfer (CHT) analysis. The program Paraview has been used for all post-processing on the large datasets.  Results A working toolchain with open-source programs for CFD has been identified. Highly detailed, full-scale and accurate CAD-drawings of the two heat exchangers have been produced. Models have been finely meshed, containing tens of millions of cells, with good quality measures. The simulations produced physically sound and valuable data: Great heat transfer predictive capability with high accuracy to the data presented by ORNL. Pressure data showed a consistent over-prediction with a factor of ~2. Possibility of error within the MSRE measurement.  Conclusions CHT using modern turbulence methods work well for the intended purpose and can be used by industry to simulate molten salt heat transfer. Open-source programs perform well and can be used by researchers to share ideas and progress. Doubts around certain measurements from the MSRE, showing large uncertainties. Future projects have been outlined to continue the work performed in this thesis. Molten salt reactors show fantastic promise as an energy generation method and should be seriously considered for the future of clean, reliable energy.

Magistro darbo objektas – Lietuvos universitetų leidyklų veikla. Darbo tikslas – atsižvelgiant į Lietuvoje po 1990 m. įvykusius pokyčius ekonomikoje bei švietimo sistemoje, išanalizuoti Lietuvos universitetų leidybinės veiklos evoliuciją, įvertinant kiekvienos aukštosios mokyklos leidyklos veiklą ir leidybinį repertuarą. Leidyklų veikla tiriama 1991-2003 m. laikotarpiu, nes 1990 m. žymių pokyčių universitetų leidyboje neįvyksta bei nėra statistinių duomenų. Pagrindiniai darbo uždaviniai: aptarti universitetinės leidybos raidą pasaulyje ir pagrindinius jos veiklos principus; išanalizuoti Lietuvos universitetų leidyklų statistinius duomenis, nustatyti lyderius ir jų veiklos specifiką; išanalizuoti universitetų leidinius, jų repertuarą. Prieita prie išvados, kad steigiant universitetus, taip pat buvo kuriami leidybos skyriai, kurių pagrindinė paskirtis – leisti bei platinti mokslo ir mokomąja literatūrą akademinei bendruomenei. Leidyklos yra nepelno siekiančios organizacijos, gaunančios finansavimą iš įvairių Respublikos ministerijų, komisijų ir kitų rėmėjų bei universitetų biudžetų, kuriems yra pavaldžios. Kiekviena universiteto leidykla savo leidybinėje veikloje orientuojasi į aukštojoje mokykloje dėstomų studijų programų aprūpinimo literatūra bei akademinės bendruomenės informavimo ir jos narių darbų publikavimo poreikius. Dauguma universitetų leidyklų įsteigė mažas spaustuves ir įsigijo įrangą, kuri paspartino ir atpigino knygų leidybą, tačiau dalį spaudos darbų užsako... [toliau žr. visą tekstą] / The subject of work – activities of the publishing offices of Lithuania – The main purpose – to examine Lithuanian publishing offices evolution evaluating each high schools practice and publications repertoire considering the changes appeared in economy and educating system in Lithuania after 1990. Publishing offices activities are studied during period of 1991 – 2003, because there wasn’t any essential shift in university publishing and there is no statistical information presented about 1990. The main purpose shall be obtained by accomplishing these tasks: to dispute about university’s publishing processes and the main principles of it’s activities in the world; to analyze statistical information of publishing offices of the Lithuanian universities, to estimate leaders and the main principles of their activities; to analyze the publications and repertoire of universities. To conclude, every established university had it’s own publishing department, which was to publish and distribute scientific and educational literature to academic society. Publishing offices are non-profit organizations, which are financed by various Republic ministries, committees and other supporters also university budgets to which they are subordinated. Most of universities publishing houses established small printing houses and obtained equipment, which made printing quicker and cheaper. All Lithuanian universities concern about distribution, but this sphere is too complicated to many of them. The... [to full text]