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894 Uppsatser om Mechanical properties - Sida 39 av 60
Beräkning av värmeenergiförluster i flerbostadshus genom analys av den totala fjärrvärmeenergianvändningen :
This thesis has been carried out on behalf of IV Produkt AB and intends to set an average ratio of thermal energy losses in apartment buildings that were built during the 1960-1990. This shall be derived by analyzing the total district energy consumption that has been divided into three parts: heat energy losses (the actual heating requirements), the heating of domestic hot water and heating energy consumption for the controlled ventilation.Three different residential areas that were built during the years 1962-1966 and one that was built in 1993 has been analyzed. All residential areas are located in Växjö urban and contains between four and six apartment buildings.The analyzed objects have a mechanical exhaust ventilation systems and district heating as the heating method. No own laboratory work or experiments have been done in this thesis, the calculations have been done on the basis of parameters from VEAB, interviews with property managers, and literature studies. By calculations, we have got a result that is reported in Chapter 6.
Generationsskiften inom skogsbruk och deras konsekvenser för naturvården
The attitudes towards nature conservation in forestry are based on the individual forest owner. The theme of the interviews is the opinion on nature conservation in forestry. The purpose of this study is to identify if there is any difference in attitude to nature conservation in forestry according to the age of the forest owner. The study discusses different factors that affect the private forest owners consideration of nature conservation and give an insight in different generations attitude to nature conservation. Other topics that are discussed is if future change of generation will change the consideration of nature conservation in Swedish forestry and what is needed to enhance the interest in nature conservation among forest owners.This study is the result of interviews with a number of forest owners in the county of Uppsala, Sweden.
FÖRBÄTTRAD MONTERING OCH DESIGNAV BAGAGELUCKA
This thesis includes a mechanical engineering design work performed incollaboration between ÅF and Halmstad University. The work is done by FredyOlsson?s methods of Principle- and Primary Construction and David Ullman?stheories of Design for Assembly.The group was commissioned by ÅF to produce a concept to narrow down theassembly time of today?s luggage doors by reducing the numbers of adjustmentoptions. They also wanted it to be easier to mount the assembly by making itpossible to adjust the door in a closed position. Today luggage door takes, with its10 adjustment possibilities, around 4 hours each to assemble and ÅF wanted anassembly time around 10 minutes per door.Initially a preliminary study was made where the group began reviewing today'sconstruction and mounting of rails and doors on buses.
Frekvensreglering i det nordiska kraftsystemet
Svenska Kraftnät is (together with the other transmission system operators of the Nordic power system) responsible for keeping balance between the generated and demanded power in the Nordic power system. Spontaneous load variations and system disturbances, however, lead to power imbalance followed by frequency variations. The frequency deviations can be limited to an acceptable level by the spinning reserve, mainly by hydro power control. But there are also other system properties which have a great influence on the frequency and system stability. The frequency and voltage dependence of the loads have a direct influence on the power balance.
Kommunikativ interaktion i den synkrona elektroniska referenstjänsten : Den interpersonella kommunikationen mellan användare och bibliotekarie
The aim of this master thesis is to gain greater knowledge of interpersonal communication. This study explores on one hand how interpersonal communication can be used as an important part of reference work in a Swedish electronic synchronous reference service, and on the other how interpersonal communication affects the relationship between user and librarian. By using communication theory and establishing a positive relational contact with the user in the electronic environment, the outcome of the reference encounter can be successful for both the librarian and the user. Furthermore, the importance of recognising relational barriers is of great relevance to the relational contact. The scope of this master thesis is to find what relational factors are used and can be used in the interaction between user and librarian.
Genernas påverkan på köttkvaliteten
Multiple factors are involved in control of beef sensory quality so great variation can be induced. The perception of meat quality can be affected anywhere in the product chain. Both the environment and the set of genes of the animals have an effect on the final output. A problem facing the beef industry today is the significant variations in meat quality between individual animals, which is reflected in the uneven quality of the meat that reaches the consumer. If the quality of meat in stores varies significantly over time, the consumers? trust may decrease.
Pelletering av tallspån : grundläggande studier
Wood pellets are an upgraded product of residuals from several wood processing industries, for example saw mills and pulp industries. The pellets are produced by pressing the milled and dried sawdust to cylindrical units with a higher density than the initial raw material. Pellets have great benefits compared to the raw material: high energy per volume, good transport and storage properties and homogeneity.
Several parameters collaborate in the whole process, which makes it complex. Wood is a heterogeneous material, chemically and structurally dependent on wood parts, habitat and storage procedures.
Utvärdering av befintliga passivhus : En byggnadsfysikalisk bedömning och mätningar om temperatur, och fukt analys på ytterväggarna
Energy price are on the way up to a high level that will not diminish in the future make us to focus more on the sustainable development for a better solution of residential houses. Passive house or low energy housing are one of the solution to make residential more environment friendly, in same time it´s a financial security using less energy, and saving money. The last 10 years in Germany and all around Europe the concept of passive house been developed, and people aim to know more about these concept that leading the market more attractive for passive houses. A passive house is a well designed building highly insulated and air tight with mechanical ventilated system for the whole building envelope that minimizes the use of energy for heating [1].The housing company Mimer has chosen to invest in low energy consumption in every new housing project. These future plan projects are decided to use less than 75 kwh per square meter annually in purchased energy [2].This thesis is about new constructed passive houses, and focuses on the evaluations of the temperature, and moisture condition for attic, external walls and joist.
Patotyptest av potatiscystnematoden :
There are two species of potato cyst nematode (PCN), the yellow, Globodera rostochiensis, and the white, Globodera pallida. Each of them can appear in different pathotypes. These are separated by testing the nematode ability to multiply on a number of potato cultivars with different resistance properties. The aim of this project was to examine the virulence of Swedish and foreign PCN populations and to compare two test methods. Biotests are today the only available tests used to study virulence.
Möjlig kvittblivning och eftermarknad av ridbaneunderlag - topplager
The aim of this study is to find information about what to do when riding arena footings are worn-out. Especially, the surface layer of riding arena footings is very interesting because of its importance of giving grip in every step for the horse, as well as shock ab-sorption. Generally, surface layers are containing several different parts in order to achieve desirable properties. These different parts can consist of organic material or in-organic material (mostly gravel). Gravel and many other materials in the top-layer are environmental friendly, and therefore, easy to get rid of.
Cisterciensklostrens odlingar i Sverige under medeltiden
The aim of this paperisto find out which plants the Cistercian monks might have cultivated in Sweden during the Middle Ages and which types of plants it would have been practical to grow inside or outside of the Cistercian monastery precinct. Archaeologicaland archaeobotanical studies have been consulted to find out which plants were available in Sweden during the Middle Ages. Examples, mainly from Scandinavia, but also from the continent, are used to show that the monasteries were large institutionsthat had to feed a large number of people and that there would not have been enough space to cultivate everything needed within the monastery precinct.Secondary sources have in the main been used to gather this information, except in the case of the Swedish monastery of Nydala where F-Topo, a database developed by the County Museum of Jönköping,has been used to analyse the amount of land and the types of properties owned by the monastery.The conclusion is that for practical reasons the monks would have cultivated plants that needed to be close at hand, that were rare or delicate, that could not be stored for long periods and that were used in small quantities within the monastery precinct. This would include medicinal plants, herbs for cooking and some vegetables like lettuce, spinach,and similar,that do not keep well. Most other items, grains, cabbages, root vegetables, peas and beans could equally well be cultivated outside the walls.
Konstruktion av testrigg för moderna ångexpandrar
This report summarize what have been done during the Master of Science Thesis that Klas Schjelderup has written for the company RANOTOR Utvecklings AB. The company is developing modern steam engines and this work should develop a machine to perform tests on a new type of piston seal that hopefully could be used in the future. The steam engines will be both volumetric and energy compact, around 1600hp/literof cylinder volume, and it will have a lot of practical applications.The new type of piston seal is hydrostatic lubricated which means that a fluid is separating two faces that normally is in contact. In this case pressurized water is used to separate the piston seal from the cylinder wall. RANOTOR have earlier formulated that at least the expander in the modern steam engine have to be oil-free, due to other components functionality in the closed water system.
Klimat i djurtransportbil med slaktgrisar sommartid : jämförelse mellan naturlig och mekanisk ventilation
SAMMANFATTNING
Uppskattningsvis transporteras 171 miljoner grisar inom EU varje år, varav ca 3,5
miljoner i Sverige. Grisarna kommer, under hela förloppet från förflyttningen från box i
stallet till bedövningen i slakteriet, att utsättas för stressande moment. Orsakerna är
bland annat omgrupperingar, nya miljöer, vibrationer i bilen samt, speciellt under
sommaren, värmestress.
Temperaturen i djurtransportbilen är en nyckelfaktor som dessutom kan förstärka
effekten av andra stressorer. Lastning i höga temperaturer ökar risken för värmestress.
Värmestress innebär att djuren får allt svårare att avge sin värme. Även den relativa
luftfuktigheten har betydelse, framförallt vid temperaturer över 30°C.
Det är ventilationen i transportbilen som ska transportera bort värme och fukt från
bilen.
Processchemaläggare för mångkärniga processorer ? Fördelning av minnesbelastning i NUMA-system
For systems with multicore processors contention for shared resources is a problem that occurs when several memory-intensive processes are executed in parallel within the same memory domain. This contention has a direct influence on the performance of the system and is a complex problem that has been recognized for a long time. An attractive and actively studied way to minimize this problem is by using a process scheduler adapted to allocate processor cores in a way such that contention for shared resources is minimized.With the introduction of multicore NUMA-systems (Non-Uniform Memory Access) the situation has become even more complex. In these systems the access time for processor cores to different memory domains vary depending on factors such as distance and load. Thus, the process scheduler also has to consider where the memory of each process is placed to minimize the distance and balance the load on each memory domain.This report presents a user-level process scheduler for a NUMA-system based on the multicore processor Tilera TILEPro64.
Utvärdering av dimensionell stabilitet i PWR-patroner i Ringhals
Dimensional stability is an important aspect of fuel mechanical design and licensing of new fuel designs for nuclear power plants. Dimensional changes within the reactor can affect the safety margins against overheating of the cladding and the pellets, therefore it is crucial that the dimensional changes are kept to a minimum.The profits per produced kiloWatt hour continue to decrease for the Swedish nuclear power plants. Some reactors are even operated with a calculated loss. To reduce fuel costs and thereby improve the profit some reactors are operated with higher uranium enrichment, so that the assemblies can reach a higher average burnup. This increases the neutron fluence to the pellets, cladding an spacers.