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574 Uppsatser om Temperature gradient - Sida 4 av 39

Hygienisering av torkat bioavfall

The main project Dry preservation of food waste from households includes a new technique concerning drying and storage of dried biowaste as well as a study of the sorting of household waste and further usage of the dried biowaste. A question asked in the project is, can the dried biowaste be used as a soil amendment? If organic waste is used as a soil amendment, precaution concerning hygienic safety risks has to be accounted for. The objective of this M. Sc.

Kylkedjan för snittblommor - en kartläggning av distributionen

Title:Chillchain for cut flowers ? how the distribution works.Author:Anna-Maja Svarén, student at Lund Institute of Technology, mechanical engineering.Supervisors:Annika Olsson, Department of Design Sciences.Bengt Sahlberg, Bioett AB.Problem:How does the distribution of cut flower works regarding temperature, losses, responsibility, complaints, packaging and weak points?Purpose:The purpose is to map the distribution of cut flowers, with focus on losses in the temperature, from farm to store. The goal is to identify weak points in the chillchain and to se how wrong temperatures affect the flowers. The results can be a help to secure the chillchain.Method:The work started with a problem; map the distribution of cut flowers with focus on temperature losses. Data was collected on the basis of this problem, then analysed, and finally conclusions were drawn.Conclusions:The affect handling and distribution has on a cut flower is very complex.

TILLFÄLLIGA EFFEKTTOPPAR I FJÄRRVÄRMEN : Kan man med hjälp av lagrad värme undvika att de uppstår i betonghus?

Climate and environmental issues is now high on the agenda. We live in a generation that must try to solve some major environmental problems. Buildings and habitations account for approximately 40 % of Sweden's total energy today. To reduce this figure, as needed, more research in the field of energy efficiency is required.This thesis concerns the heating of buildings. The load on district heating is heavy during certain times of the day.

Axial- och gradientkrympning hos golv på mark enligt Eurokod 2 : Sprickbredders beroende av betongkvalité, tvångseffekter och armeringshalt

AbstractConcrete foundation slabs are usually exposed to unilateral drying during the curing process. The unilateral drying causes an axial shrinkage and a concave curvature of the construction. The curvature results from the fact that the upper part of the slab is drying and shrinking faster than the lower part. This is called gradient shrinkage.A problem occurs when the slab is considered fully restrained by adjoining structural parts. The deformations caused by axial contraction due to the constant part of the shrinkage and the curvature caused by gradient shrinkage of the slab are then prevented by the fact that the slab is fully restrained.

Geotermi i Ungern : Undersökning av Ungerns energisituation inriktat på geotermi samt kapacitetsfaktorn för det största geotermiska värmeverket i Mellaneuropa.

Hungary?s share of renewable energy in 2010 was 7.9 %, and their renewable energy goal for 2020 is 14.65 %. Geothermal energy is one option that could help to achieve the goal, since Hungary has favorable bedrock, the Temperature gradient is above average and thepermeability is high. Today Hungary is importing just over half of its primary energy supply. Because of political conflicts between nations Hungary wants to expand its own production of energy.

MOLNU : Att utveckla ett gemensamt gränssnitt

Climate and environmental issues is now high on the agenda. We live in a generation that must try to solve some major environmental problems. Buildings and habitations account for approximately 40 % of Sweden's total energy today. To reduce this figure, as needed, more research in the field of energy efficiency is required.This thesis concerns the heating of buildings. The load on district heating is heavy during certain times of the day.

Utvärdering av laddningskoncept för lastbilsbatterier

When drivers overnight in the truck lots of electric energy is consumed by heaters, fans, lights and other extra equipment. If the engine is not running, this energy is taken from the lead/acid batteries of the truck which then needs to be recharged during operating hours. The fact that the charge acceptance of the lead/acid batteries is dependent on the temperature makes it hard to fully recharge the batteries at lower temperatures. A negative charge balance can lead to starting problems within a few days use in cold climate.In this thesis work, the effects of different battery charging concept are evaluated on the most common Scania battery (175Ah). A battery model is implemented in Matlab and some simulations of charging are made.

CFD simulering av kallras : Undersökning av temperatur- och luftbeteende intill höga glasfasader och i vistelsezon med golvvärme som en värmekälla

Glass has sophisticated front properties and are used as facades in high buildings. During cold periods, these glass facades could cause thermal discomfort, due to cold downdraught. Cold downdraught can be countered by placing heaters under glass surfaces. Nowadays technology offers highly insulating windows, which is why there is an interest to investigate the indoor climate with only underfloor heating. The research in this area is limited, and few empirical methods are available.

Utveckling av en ytmonterad fördelningsmätare som underlag för individuell debitering av vattenförbrukning i fastigheter

The master thesis, conducted at Metrima AB, concerns the development of a non-intrusivedistribution meter as a basis for individual tap water billing in apartments.The project is conducted in response to the market interest in individual tap water billing inapartments as an answer to environmental concerns regarding water consumption. Due to thehigh installation cost of traditional water meters, a new method of determining waterconsumption, without having to cut water pipes, is proposed.The proposed method distributes the total water consumption for an apartment complex toindividual apartments according to distribution meters, measuring water run-time, in eachapartment. The water run-time is estimated by measuring the water pipe?s outward vibrationsand temperature changes.A test environment was established and a prototype built, using a tilt- and vibration sensor forvibration sensing and a precision temperature sensor to measure temperature changes. As bothsensors work well in the test environment, further testing was done in 3 apartments for aduration of 5 days.

Sekundärnät för lågtempererad fjärrvärme

Lower energy use in buildings is a result of increasingly stringent energy requirements across Europe. When conventional district heating technology is used in areas with low energy consumption heatlosses do not fall even though the amount of energy delivered is reduced. This reduces income for thedistrict heating company. To maintain their economic viability the district heating companies? majorchallenge is to implement new solutions that minimize heat loss.

Klimatet på tre platser i Sverige 2071-2100 i jämförelse med Europas klimat 1961-1990 med fokus på temperatur, nederbörd och avdunstning : En analytisk studie från en simulering av Rossby Centres regionala klimatmodell, rca3.

Due to human influences on the climate an increase in Earth's mean temperature is today an accepted conception. With a rising temperature discussions have started how the climate in an area will change in the future. Equally interesting and important is it also to study the precipitation in an area. Precipitation is the factor, next to temperature, that affects most how a climate in an area looks like and feels. Since precipitation is connected to evaporation the latter parameter is also of interest to study.

Undersökning av bindningsmekanismer vid pressning av metallaminat : Investigation of bondning mechanisms at the pressing of metal laminates

Increased understanding of the mechanisms that operate in conjunction with the welding of metal surfaces may help to improve existing manufacturing processes, and to enable new products and combinations of materials. The purpose of the project has therefore been to acquire a deeper understanding of what is happening in the bond for steel and for the factors that form the basis for a bond to develop between metals in the production of laminates by pressing. The merge has been done by pressing and the surfaces after the experiments have been studied in detail in the scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDX) and with interferenceprofilometry in Wyko, to provide a greater understanding of the mechanisms that influence the bonding in the interface between metals. The project was limited to contain the materials Docol 1000, HyTens 1200, Aluminum AA3003 and a commercial steel. The parameters varied in the experiments to study their influence closer are temperature, pressure, heat treatment and pretreatment. This has been implemented by pressing with varying temperature and pressure.

Modellering och reglering av ureainsprutning på kraftvärmeverket FTG

The aim of this thesis is to improve the control of urea injection at the combined power and heating plant Framtidens Gärstad (FTG). Tekniska Verken i Linköping AB is the owner of the plant.The FTG plant consists of a boiler where garbage combustion is done. From the combustion nitrogen oxides are emitted. These nitrogen oxides are hazardous to the environment. To reduce the nitrogen oxides, injection of urea into the boiler is used.

Kromatinstabilitet som grund för kvalitetsbedömning av hingstsperma :

This study is part of a project to evaluate and develop metods to control the semen quality in stallions. The study was carried out in cooperation between SLU and Flyinge AB. The objective of the study was to analyse -if there are individual differences in sperm chromatin integrety between different stallions -if there is a correlation between subjectively evaluated sperm motility and sperm chromatin integrity -if sperm chromatin integrity is changed after selection of the semen with a centrifugation method through the silica-spheres, gradient or a single-layer, i.e to use the chromatin integrity analysis as a method to evaluate the selection method. The use of chilled transported semen has increased a lot during the last 10 years, especially among the Swedish warmblood breed. Because the foaling percentage has decreased with the increased use of chilled transported semen, there is a need to develop methods to control the sperm quality. Evaluation of the chromatin integrity could be one way to evaluate the quality of the semen. Chromatin is the DNA in the nucleus of the sperm.

Sjöars känslighet för klimatförändringar ? vilka faktorer påverkar?

The Earths climate is changing at a higher rate, i.e between 1861 and 1994 the annual mean temperature in Scandinavia increased with 0,68º C and according to recent climate models the annual mean temperature is likely to rise with another 3º C during this century.A warmer climate in many ways is associated with changing conditions for lake ecosystems. An expected higher water temperature and a stronger summer stratification of the water column increases the risk of anoxic conditions at the lake bottom. Thus anoxic conditions are likely to cause a phosphate leakage from the sediment, i.e. a higher internal loading of phosphate.In this project, the extremely warm summer of 2002 has been used as an example for a possible scenario for a future climate. By comparing levels of phosphorus in the summer of 2002 with a ten-year median value, a phosphorus related sensitivity to climate change has been analyzed for 55 Swedish lakes.

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