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623 Uppsatser om Fuel cell - Sida 3 av 42

Utvärdering av ett Bränslecellsdrivet Flygplan.

 With the increases in fuel costs due to the depletion of the world oil reserves and the increase of greenhouse gasses as a consequence to using oil as a fuel many companies are looking to new and innovative ways to power their aircraft. One of these new ways to power an aircraft is using Fuel cells powered using hydrogen and oxygen, thus producing nothing but water vapour and small amounts of nitrogen dioxide as well as trace amounts of other emissions. Both Boeing (1) and Politecnico di Torino (2) have shown that it is possible to build an all-electric aircraft powered by Fuel cells. Both flights used small, two-seater aircraft and a constant between them was the loss of the co-pilot seat due to weight and lack of space. As this paper will deal with a commercial aircraft a primary concern is the cargo and passenger capacity and whatever impact switching propulsion system has on these.

Visualisering av basalcellscancer med Tissue Viability Imaging - ett icke-invasivt diagnostiskt alternativ

Basal cell carcinoma (BCC) is the most common non-melanoma skin cancer. It can be divided in different subtypes. The most common type is superficial and is most frequently occurring on the trunk and on the face. In severe cases it can be difficult to differentiate basal cell carcinoma from other skin tumors, therefore a skin biopsy is conclusive diagnostic method. In terms of treatment, curettage is a common non-surgical treatment of basal cell carcinoma.

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.

Uppvämningssystem med biobränsle : en fallstudie på Malmviks gård

The use of bio fuel is increasing every year. Nowadays you will find different alternatives to oil and electricity heating system. In this essay I have examined what the economic conditions are to invest in a bio fuel furnace. I have chosen to assume from a specific farm and do a case study on this farm. Malmvik farm is located just outside of Stockholm.

4-1BB is up-regulated in human mast cells, when exposed to tumor conditioned medium

Mast cells have for a long time been known to accumulate around tumors (Maltby et al., 2009). Studies show that they may be important and sometimes essential in tumor angiogenesis, tumor growth and metastasis of tumors (Soucek, et al., 2007; Xiang et al., 2010). In an expression array study (Wensman et al, submitted manuscript) performed on mouse mast cells exposed to tumor conditioned medium, the gene 4-1BB was among the most up-regulated genes compared to control medium. 4-1BB codes for a membrane receptor protein of the tumor necrosis factor superfamily and has been shown to be important in T cell regulation in tumor diseases. This study was performed to investigate if human mast cells up-regulate 4-1BB when they get exposed to tumor conditioned medium.

Fordonsgas från deponier : en potentialstudie i Biogas Öst-regionen

The demand for biogas as vehicle fuel has risen sharply and there is a great need for increased production. A possible addition of vehicle gas can be produced by upgrading landfill gas which is formed by degradation of organic waste. This thesis investigates the potential of producing vehicle fuel from landfill gas in the region of Biogas Öst.In 2008, an amount of 32 million Nm3 landfill gas was extracted in the region. This level can be maintained for another ten years if the efficiency of gas extraction is improved. The annual production will decrease with time since landfills aren?t allowed to receive more organic waste.

The change of haemoglobin during blood donation, and an assessment of a photometrical method for non-invasive haemoglobin analysis

In Sweden, lowest acceptable haemoglobin levels in blood donators are 125g/L for women and 135g/L for men for a test sample taken in the beginning of the blood donation. Levels, which are 10g/L lower, are accepted if the sample is taken after the blood donation. Earlier studies show that the haemoglobin level decreases for a person that is lying down.The two aims of this study were to examine how much the haemoglobin levels change during blood donation and to examine if the photometrical instrument Pronto-7TM shows equivalent results to that of the established method Cell-Dyn Sapphire.In the study, 120 blood donors participated. Blood samples were taken in the beginning and in the end of the donation. Analyses by Pronto-7TM were done before and after the donation.The haemoglobin level decreased significantly during the blood donation.

Utveckling av tjänster för ett mobilt medium

The mobile revolution is here to stay, and today most people have (at least) one cell phone at home. Some even a PDA (Personal Digital Assistant)as a complement for the simpler tasks at the office, e.g sending e-mail, word processing, browsing the Internet etc. Many business have also given the employees the opportunity to do some of the business tasks inbetweeen customer visits with the help from a cell phone or PDA.Despite all this, the so called Internet connected mobile revolution is often mentioned as a big failure. Maybe because the people in general tended not to use the new technology as much as the companies predicted. This could be because they still haven't learned how it works, or just don't seem to have the need for services provided.After a couple of failures in the development process, almost every cell phone has support for mobile Internet today.

Produktivitet i robotcell

The report describes the process of identifying the interference that exists in a newly installed automated robotic cell and suggest improvements to increase productivity. The cell is used for lifting up extruded aluminum sections onto a conveyor which deliver the material to a anodising line at a company that manufactures aluminum extrusions.To find the areas with the best possibility for improvements in the cell we used a variety of job measurements e.g. measure of standard times for each operation in the cell. The core of the report is a study of the robots.One reason for this study is that the robots do not reach the productivity they were purchased to. The main cause not reaching the productivity is the visionsystem.

Facebook, E-post, SMS & Mobiltelefoni : en explorativ studie om hur unga vuxna upplever den ständiga tillgängligheten

Purpose/Aim: In the information and communication technology society (ICT) we live in today it is easy to feel that we are constantly expected to be available. The daily contact with the Internet and the use of cell phones has changed our way to communicate. With this in mind in combination with the increased stress among young adults my aim is to investigate how young adults, aged 23-26 years, experience to be constantly connected and available through the Internet and the cell phone. What are their opinions, attitudes and feelings about what this entails in their lives?Material/Method: The essay is based on four focus group interviews with sixteen students from Uppsala University aged 23-26, two groups consisting of women and two groups consisting of men.

Jämförelse av metoder för peroxidbestämningar i bränslen : A comparison of methods for determination of peroxide content in fuel

New energy resources that can replace petroleum diesel are needed and biodiesel may be an excellent substitute. During storage and use, biodiesel can oxidize and form peroxides, leading to degradation of the fuel. It is therefore important to determine the peroxide content of the fuel. In this thesis the triphenylphosphine method, which involves GC-MS analysis has been compared to the standard iodometric method which involves titration with sodium thiosulfate. Working standards were made to see how well the iodometric method worked and also in order to make a calibration curve in GC-MS.

Skogsbränslets fraktionsfördelning

This study has analyzed particel size distribution and needle content in chipped logging residuals (branches and tops) delivered to the district heating plant Ryaverket in city of Borås, Sweden. Two fuel assortments has been analyzed: Chipped logging residuals from pure softwood and from mixed fuel (connifers and broadleaves). The samples has been sieved at Linneaus University laboratory.The study of particle sizes indicates that only 53,2 % of delivered fuel is within the fuels specification (7? 45 mm). The needle content is in this study 12,4 % (dry mass) which is higher than expected..

Modellering av ett bränslesystem i Modelica : tillämpat på ett obemannat flygplan

Mathematical models possible to simulate are of great importance in order to make successful projects in the aircraft manufacturing industry. An aircraft fuel system is very complex, containing pipes, tanks, orifices, valves and pumps. The principal of this thesis is using the tool Easy5, which no longer is considered reliable enough in terms of development and support. This thesis tries to evaluate the Modelica language as a possible alternative to Easy5. To make this evaluation, the components concerned in the fuel library in Easy5 are implemented to the Modelica language.

Energisäkerheten för fjärrvärmeanläggningars bränsletillförsel i Mälardalsområdet

There are several energy systems in the Swedish society and to ensure the comfort and health of the citizens it is of importance that the different energy systems are functioning properly. District heating is one of these energy systems and many household depend only on district heating to warm up their homes. District heating is dependent on several processes where every step needs to function in order to deliver the produced heat to the end consumer. Previous studies have investigated the distribution of district heating and how to make customers choose district heating as their heating method. The supply of fuel to the district heating plant has not been studied as much, even though it is an important part of the whole system. This thesis is a part of the project NORD-STAR (Nordic Strategic Adaption Research), which has focused on climate adaption in the Nordic countries.

Rörsvetsning i konceptet Factory-in-a-Box

This Master of Science thesis was a part of Pharmadule Emtungas project to construct a mobile automated cell for welding of carbon steel pipe (Heating, Ventilation and Sanitation). Pharmadule Emtunga is using a modular building concept for building pharmaceutical factories. The modules contain these pipes. The goal of the thesis was to present concepts for technical solutions regarding welding methods and fixtures for the cell. Conceptual models for the cell were made with aid of CAD software.

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