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10700 Uppsatser om Laboratory work - Sida 4 av 714
Optimering av glödgningsparametrar för kromstål
At Sandvik Materials Technology, Argon gas is used as furnace atmosphere when heattreating hot rolled wire. Upon heating chromium steel wire, a rich oxidelayer forms on the wire surface. The abstract of this masters thesis is to enhance the understanding of the constitution of the oxidelayers and the influence of the furnace atmosphere. This will be achieved by performing a number of annealing experiments on laboratory level. Also, the aim is to understand the chemical reactions and physical mecanisms controlling the pickling process.
Laboratory tests for sperm quality and fertility in stallions
Syftet med denna litteraturgenomgång var att presentera några av de vanligast förekommandelaboratorietesterna som används idag vid utvärdering av spermakvalité hos hingstar. Engranskning har också gjorts för att försöka utröna om det går att förutse hingstars fertilitetutifrån resultaten av dessa tester. De metoder som presenteras analyserar motilitet, morfologioch funktion hos spermierna i ett ejakulat. För att kunna fullfölja en befruktning krävs det attspermien uppfyller vissa kriterier. Detta för att kunna ta sig fram till äggcellen och smältasamman med denna och bilda ett embryo.
Optimering av den kemiska reningen vid Fläskebo deponi
Landfill leachate contains a variety of contaminants and is created when rainwater percolates the landfill. For landfill management the leachate is the main issue that can cause problems to the environment. At the landfill of Fläskebo, Renova AB treats the leachate in a local treatment plant. The treatment consists of a chemical treatment step with chemical precipitation, flocculation, sedimentation and filtration, and a final step with a carbon and peat filter. Renova has to ensure that the condition of the leachate reaches the regulation set for the landfill before it is released to the recipient.
Oljetemperaturens inverkan på motoroljans degradering i lastbil
The market for heavy duty engines is constantly requiring engines that should be more andmore powerful, while still maintaining low fuel consumption. As a result of increasing enginepower, the engine and coolant temperature increases as well due to insufficient coolingperformance (because of design issues, cost etc.).Also, emission legislations, both current and future, require more and more measures to betaken by engine manufacturers. One way of meeting the legislations is the use of cooled EGR(Exhaust Gas Recirculation), which also lead to increased coolant temperatures.Both these factors also naturally lead to increased engine oil temperatures, the consequencesof which are not thoroughly investigated.This thesis project aims to investigate effects of high temperatures on engine oil degradation,with focus on the greatest degradation process: oxidation. To do this several engine runs havebeen performed on a 310 hp engine with EGR to see what happens to the engine oil in a realengine when exposed to high temperatures. During the tests oil samples have been taken andanalysed for important parameters.As a complement to these engine tests some laboratory oxidation testing have also beenperformed, to be able to compare engine test data with laboratory tests.One goal of the project was to try to formulate an empirical oxidation model, which would beable to predict oil oxidation levels in an engine, given any running parameters.
Industriforskning och informationssökning: en användarstudie av en grupp forskare vid ABB Corporate Research
The thesis aims at, from a user perspective, examining how a group of industrial researchers understand the information seeking in their every day work. A qualitative method is employed. The empirical material consists of open-ended interviews with in all ten researchers. All of them work at the Swiss-Swedish Technology Company ABB's research laboratory in Västerås. The thesis is based on the opinion that the scientific knowledge production has become commercialised and that the scientific communication is going through certain changes.
Avbördningskapacitet för Traryd kraftverk: en modellstudie vid dimensionerande flöde
Sydkraft Vattenkraft AB owns and operates the Traryd hydropower plant, located in the river Lagan in the southern part of Sweden. The gravity dam is classed according to RIDAS guidelines (Hydropower Industry Dam Safety Guidelines) as a class 1B dam. This means that the dam must discharge a class 1-flow which has a return period of 10 000 years. The inflow into the dam has been calculated in an earlier report to 495 m3/s, with a waterline at an elevation of 126, 3 meters above sea level. The gravity dam has a discharge system with two rectangular weirs, which results in a smaller discharge than the necessary 495 m3/s.
Lusten till matematik : En studie om hur elever kan utveckla lusten och motivationen till matematik genom olika arbetsätt
The purpose of this study is to compare different ways to teach mathematics in the school's lower age groups, and to examine whether certain practices increase students' desire and motivation to learn the subject. The questions used to determine the purpose is the following: What vision has the students in the class at maths? How does the teaching of mathematics in the class look like?What vision has the students in the class at working with different approaches in education?Does the traditional approach and the options that I am examining meet the steering documents requirements? The essay is organized as a qualitative study. The study was conducted in an elementary school in Sweden, third grade. The methods used included interviews with students and observations in the classroom.
Texturbestämning genom fält-, pipett- och hydrometermetoder :
Texture is an important soil property and accurate particle size analysis of soil texture is therefore crucial. There are a number of well-established and newly developed methods available for determining soil texture. In order to compare the results of these methods, the differences between them must be determined.
The difficulties, problems and differences regarding texture class determination were examined through a study performed on forest soil samples. The study compared different methods (pipette, hydrometer and field methods) and two types of dispersing agents (sodium pyrophosphate and sodium hexametaphosphate (calgon)) commonly used for particle size analysis.
Digitalisera loggboken : En analys av utmaningarna med att utveckla IT-stöd för kunskapsintensiva verksamheter
Failed system development projects are a common sight within the IT-industry. During the last ten years we have seen several more or less disastrous high profile projects being reported in the news. One aspect that might hold some of the responsibility for these failures is the fact that more organisations are knowledge intensive which makes their work processes difficult to capture in computer systems. How requirements engineering is handled becomes even more important in these cases, where processes are unpredictable and rely on individual judgement and knowledge. In this study we have examined the challenges of developing systems for knowledge intensive businesses through a method of qualitative case study of a university laboratory.
Oosporbildning av Phythophthora infestans i potatis och bägarnattskatta
Potato late blight is one of the most important potato diseases worldwide. The disease is caused by an oomycete called Phytophthora infestans. The host range of P. infestans includes potato (Solanum tuberosum) and hairy nightshade (Solanum physalifolium). Hairy nightshade has recently established itself as an important weed in the southernmost part of Sweden.
Validering av metoder för analys av Cu, Fe och Na i processvatten med AAS-grafitugn
Södra Cell Mörrum is one of the five paper pulp plants that are included in Södra Cell, and the paper pulp that is produced here is not only sold to Swedish paper mills. Most of the paper pulp is exported to different countries in Europe. In the manufacturing process the plant needs different kind of process water and there are guideline values for how much copper, iron and sodium this water is allowed to contain. Analyzes of this water is in the current situation done with an atomic absorption spectrometric instrument (AAS-instrument) with a flame. Measurements done with flame-AAS of samples that have concentrations near the guideline values for copper, iron and sodium, are not reliable. The reason for not being reliable is that the quantitation limits of these metals are higher than the limit values.
Gymnasieelever och bråkräkning
For many years, I have tried to understand why students end up in difficulties in mathematics. As a future teacher, it is extremely important to have knowledge of the various factors that leads to difficulties in mathematics. As a teacher it is obvious to meet the students who find mathematics a difficult subject, and, therefore it is necessary to have a broader knowledge of how to respond and support these students. According to Ahlberg, number of students with mathematics difficulties is increasing every year, therefore, it is important to help students and organize a supporting school environment that promotes and encourages learning (Ahlberg 2001, p. 104-105).
Enstudie om lågtempererat värmesystem i vägg : -Fokus på inomhusklimatet och energianvändning
Today the human being see energy as a matter of course but the resources that is used for extract energy is today not enough for the world demand. Of all the energy that is used in Sweden today approximately 40 % goes to the building stock. This number will most likely increase if not necessary actions will be made on the already existing building stock since new houses constantly are built which will be added up on the already existing energy supply. This takes cause of action on the already existing building stocks, to fulfill the demands of the future use of energy that has been set by the authority. At the same time the thermal conditions cannot be influenced by the necessary changes that must be made.
Matematik+andraspråkselever = matematiksvårigheter? : Varför och vad kan lärarna göra?
The purpose of my examination work was to show the need for support for students with another mother-tongue than Swedish, so that these students would be able to get through mathematics tuition better. To achieve this purpose, I chose to start from the perspective that presented itself at interviews with two class teachers and two mother-tongue supervisors. I also chose to use the qualitative research interview as study method, as I tried to understand those informing me in a thorough and in-depth way. In my study I have had a sociocultural perspective as starting point where the conceptions teaching, language and communication, support and individualizing are central for the development of knowledge. The questions for my study during this process were as follows: What difficulties, according to the teachers interviewed can occur for second language students in mathematics? What ways and methods of working do the teachers chosen give priority to, so that the second language students` results in mathematics will improve? The results from my interviews show that the difficulties with mathematics for second anguage students can be perceived as being dependent on a combination of reasons, where amongst other things language plays a central part.
Design av styrsystem till rotationsstol och utveckling av numerisk modell av otolitmembran
This master thesis is made of two parts. The first part concerns the method and results ofdesigning a motion control system for a piece of research-equipment called BIRGIT. Theequipment is made to be used for research on eyemovements. In the second part, a computermodel of a part of the balance organ in the inner-ear is developed. The work has been done atthe Bernadotte laboratory at S:t Erik Eye Hospital.The equipment the control system is made for is a so-called rotationchair.