Sökresultat:
667 Uppsatser om Temperature dependence - Sida 29 av 45
Experimentell konstruktion av pickupsystem anpassat för trummor med hjälp av MATLAB
For several years Uppsala University together with several companies has been involved in a WISENET project aimed at improving railway transport security. By placing a sensor system near the wheels of each wagon, the temperature of the bearings can be measured and transmitted to a collector placed centrally on the wagon. This in turn transmits the collected data to RFID receivers placed intermittently along the railway.As the signals are transmitted wirelessly, problems may occur as the antennas get dirty or coated with ice and snow. To determine the effects of these coatings, several tests were performed examining the reflection coefficient S11, the impedance Z11 and the efficiency eta of an antenna, and how they varied when various coatings were placed over the antenna. Examined coatings were ice, snow and water to determine the effects of weather, and various metal-based coatings: powdered iron both pure and partially oxidized, and iron ore granules.
Utveckling av HPLC-metoder för kvantifiering av nyckelkomponenter i en villkorad emulsion
Traditionally, rolling mills use emulsions based on a mixture of oil and water for lubrication. Since two years ago SAPA has been using (instead of oil) a synthetic lubricant so called conditional emulsion for hot-rolling of aluminum. This lubricant is water based and homogenous at ambient temperature, but switches to a two-phase system at heating above the cloud point.This project aims to validate and if necessary modify an existing HPLC method for quantifying two out of three key components (A, B and C) in the conditional emulsion. Attempts to develop a method to quantify the pH adjusting components, X and Y were also made. These two methods are required to optimize the lubricant.Due to the complexity of the components, it has been difficult to present a method for quantification, and HPLC with ELS detection was chosen after a long series of trials.
Alpin permafrost i Kebnekaisefjällen : Modellering med logistisk regression och BTS-data
Denna studie är ett försök att modellera den alpina permafrostens utbredning inom Kebnekaisemassivet i norra Lappland. En karta som visar sannolikheten för permafrostens utbredning har skapats med hjälp av data från Bottom Temperature of Snow cover (BTS) - mätningar samt statistisk modellering genom logistisk regression.Fältstudien genomfördes under mars till april 2011 med totalt 56 BTS-punkter från 1073 till 1805 m.ö.h. Permafrostförekomsten bestämdes vara en funktion av höjden. För att utreda detta användes stepwise selection som är en metod för att identifiera statistiskt signifikanta variabler gentemot en beroende variabel. De andra parametrarna som testades var topografins sluttningsgradient, riktningen av den maximala lutningen och den potentiella solinstrålningen.
Energibalansberäkning
Abstrakt - As energy prices rise, energy-saving in buildings is becoming increasingly important. By applying different construction and installation technologies, to new buildings the energy consumption can be reduced effectively, compared to similar existing buildings. These technical measures are often an investment in the long term and will reduce energy costs significantly. The purpose of this report is to show how to reduce energy consumption in a small house. It is presented in this report that both building's technical saving arrangements (the sealing of a building) and an installation technical arrangement (changing from the F-system to the FTX-system) would reduce energy consumption in newly built detached houses, if compared with a similar existing house but without these technical measures. The report presents also detailed calculations showing how much energy an existing 2-storey house, built in the year 2007 in Eskilstuna, consumes and how much energy would be saved if these corrective measures were applied to a new building. It is also reported how much money would be saved each year over a 10 year period if the measures were applied. The results show that both solutions are a good investment in the reduction of energy consumption and hence the cost involved. Keywords: energy, heat energy, infiltration, FTX-system, free temperature effectively. .
Klimatkabinett : Komponenter och konstruktion
This report describes the construction of a climate-cabinet for testing of HV-cards (High Voltage) produced at VG Scienta. The main part of the report describes all the different components of the cabinet. The most important parts are a PID regulator from Eurotherm model 2408, a solid state contactor (SSC), a thermocouple, a finned resistor from DBK and different fans. The report even includes the connection between components by cable wiring, isolation, grounding, fuses and shaping of metal goods.As the cabinet also communicates with a computer, the report includes the solution of the data communication using the software iTools from Eurotherm. The communication part includes information about a converter that converts EIA422 to USB.The cabinet was produced at a company, called VG Scienta, in Uppsala during the spring 2010.
Konstruktion av formkropp pa JAS 39 E/F Gripen
The aim of this work is to develop new conceptual designs for the fairings that are situated between the fin and the rear fuselage on the new version of the JAS 39 Gripen aircraft, called the Gripen E/F. The designs presented should show a profit in the form of lower weight. To achieve weight loss, the possibilities of using other construction materials other than those which are available at Saab today were studied. Therefore, a material survey was carried out in which the market for modern construction materials was studied to get an idea of today?s level of technology.
Brandskydd av stålkonstruktioner : Lathund för brandskyddsdimensionering av stålprofiler
This bachelor thesis covers fire protection methods of structural steel and the aim is to develop an information tool designed for inexperienced structural engineers. The information tool covers basic fire protection methods and the general way to produce a fire resistance for structural steel. The layout of this information tool is a simple folder that contains information about the most important steps when producing fire protection for a steel structure.The thesis starts with a general overview of the fire protection needed in buildings to fulfill national legislative and regulatory requirements. To get an understanding of how steel components behave during the influence of fire, a brief overview is presented of the material properties of steel. This chapter also contains a review of previous research in the area.
Status och hotbild för den oceaniska laven broktagel Bryoria bicolor i sydvästsverige :
Horse-hair lichen Bryoria bicolor is a red-listed lichen species in the category Vulnerable. It is an oceanic lichen and it is often found on boulders and cliffs in a semi-open environment with a high humidity in the agricultural landscape. The species can also be found as an epiphyte on trees, mostly in boreal forests in the provinces of Dalarna, Härjedalen and Jämtland. In the agricultural landscape, there has been indications on that B. bicolor show a decline, and this studie aimed at examining the extent and causes of this decline.
Jämförelse av solhybrider
Research in solar energy is taking big steps in both solar heating and solar electricity. It´s not only the technologies alone, but also the combination of both solar electricity and solar heating which is what is called a solar hybrid. The idea of a solar hybrid is that a solar cells efficiency decrease with increased temperature and can with help from a solar collector be cooled and the heat can be utilized. This thesis report compares heat production and electricity production with respect of, in first hand, a solar hybrids geometry in the cooler. The theory chapter describes solar heating and how different solar cell technologies work and their environmental impact at the production and how compatible these technologies are for the solar hybrid.
Accelererat åldrande av produkter Apelsinjuice och hallondryck
Brämhults Juice AB is one of Sweden?s leading producers of fresh fruit juices and drinks. The fruit drinks last 3 days once opened and when stored in a refrigerator kept at 7°C. Since factors that shorten the drinks? best before date are usually not noticed until the entire batch has expired, it would be advantageous to find a way to accelerate the drinks? natural deterioration, so that an unusal short best before date is noticed before more products are shipped off to the stores.
Medicinen är kryckan, inte lösningen: personals upplevelser av de psykosociala inslagen i läkemedelsassisterad underhållsbehandling
The meaning of the concept of psychosocial treatment is ambiguous. The purpose of this study was to examine how professionals within some care institutions, which provide methadone, buprenorphine or naloxone treatment, regard and carry out the psychosocial features of such treatment. Central issues discussed were; how personnel approach the psychosocial features of the treatment, what personnel regard as a focus in the psychosocial treatment, what conditions personnel consider affect treatment positively in order for it to be successful and how personnel see the relation between the medical and psychosocial features of the treatment. The method used was interviews with nine professionals in six qualitative interviews. The theoretical perspectives and concepts used in our analysis were; the theory of biological dependence, an organizational perspective, Prochaska and DiClemente's Stages of Change Model, the concept of individual reality and the concept of marginal conflict.Results show that the conditions most important for successful treatment are; that the patient has a place to live, an occupation, motivation, that the patient take responsibility for his/hers progress and have realistic expectations about the effects of the medicine.
y måste bero av x ? gymnasieelevers förståelse av det matematiska begreppet funktion
Objective: The aim of the study is to describe pupils' understanding of the mathematical concept of function. How do pupils define the concept of function? What images of the concept of function evoke when they solve tasks, which involve identifying and constructing functions?Theory: A student's thinking about a mathematical concept depends on more than just the formal definition of the concept; therefore Tall and Vinner introduce the term concept image to describe the role cognitive structures play when students learn about concepts. The cognitive structure includes all mental images, associated properties and processes that an individual associates with a given concept. According to Sfard, an individual's understanding of mathematical concepts may have different character: an operational conception, where a concept is conceived as a process and a structural conception, where the given concept is conceived as an object, that is, as a whole.Method: 16 pupils at the Science Program at two different upper secondary schools inSweden answered a questionnaire on the mathematical concept of function.
Att vara partner eller kontrollant. En studie av Sidas uppföljningskrav
External forces have significant impact on organisations. This study analyzes the implications of one type of external forces in aid-focused NGOs through two qualitative case studies where it is investigated if Sida?s reporting requirements have the intended effects: learning and control using a theoretical framework where it is recognised that the requirements may also result in dysfunctional behaviour: decoupling and colonisation. The study shows that when the demands are the result of institutional pressure rather than an ambition to generate learning and control, the demands tend to be unrealistic and the NGOs therefore decouple the formal fulfilment of the demands from the actual activities. It is argued that a partnership, which incorporates trust and dialogue, is a prerequisite, not only for learning, but also control.
Att vara partner eller kontrollant. En studie av Sidas uppföljningskrav:
External forces have significant impact on organisations. This study analyzes the implications of one type of external forces in aid-focused NGOs through two qualitative case studies where it is investigated if Sida?s reporting requirements have the intended effects: learning and control using a theoretical framework where it is recognised that the requirements may also result in dysfunctional behaviour: decoupling and colonisation. The study shows that when the demands are the result of institutional pressure rather than an ambition to generate learning and control, the demands tend to be unrealistic and the NGOs therefore decouple the formal fulfilment of the demands from the actual activities. It is argued that a partnership, which incorporates trust and dialogue, is a prerequisite, not only for learning, but also control.
Hur kan blöt vetedrank lagras, hanteras och utfodras till mjölkkor? :
Distillers? grain is a by-product of ethanol production. Corn, wheat and barley are the grains
that are generally used in the distillery process. Distillers? grain is rich in protein and
phosphorus.