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957 Uppsatser om Thermal heat losses - Sida 32 av 64
Integrering av kommunikation i ingenjörsutbildningar : Ett underlag för kompetensutveckling för universitetslärare vid KTH
The sun is an endless energy source and the heat it produces can be used to heatup our homes. This technology is relatively old and was introduced in the late70-s. There are two kinds of solar collectors that are most frequently used todayand these are plain solar collectors and vacuum solar collectors. The plain solarcollectors are the once that are used the most but the vacuum solar collectorshave increased more as a percentage the last couple of years.The biggest question asked regarding an investment in solar heating is if theplant is economically profitable. This question has no direct answer because itis dependent on a couple of prerequisites.
Strötorvsanvändning i djurstallar : en litteraturgenomgång
Peat litter has been used in animal houses for a long time. Because of its good ability to absorb liquid and nutrients from the manure it can create a dry surface for animals and a valuable manure product. Through changes in agricultural practises the use of peat litter has diminished and is to a great extent replaced by straw, sawdust and cutter shavings although Sweden is rich in peat-findings.
The aim of this work was to summarize the presented knowledge about the used of peat
litter, techniques, advantages and disadvantages and to compare with other commonly
used litter materials. Articles on peat litter have been searched for in magazines, databases and books at SLU library. Visits to peat industries, interviews with peat producers and with peat researchers contributed to the material.
Peat is not a uniformly material.
Kalvhyddans utformning : påverkan på kalvens hälsa och komfort
This paper aims to, through a literature review, examine how to best design and adapt calf huts to meet the calf's physiological requirements and reduce the infection pressure for enteric and respiratory diseases. It illuminates how the calf relates to different temperatures and climate, which temperature control mechanisms it uses and its ability to perform these regulations, as well as providing a summary of the past decades´ research on the calf huts housing system. These two theory chapters, along with a concluding discussion, provide a better understanding of how to, especially in temperate climates, design the most suitable calf hut, which cater to the calf's both thermal comfort and physical health. The literature suggests that the calf's own temperature control works well to counteract the temperature outside the desired range, and that one of the most important factors rather is ventilation of a calf hut, which reduces moisture and pathogens. The conclusion of this paper is mainly that there is not an obvious way to place and construct a calf hutch and that most design principles contribute to both positive and negative effects simultaneously.
Optimering av glidlager och utveckling av dess konstruktion
I detta projekt har vi fördjupat oss i en glidlagerkonstruktion som befinner sig i en skruvpress. Skruvpressen kompakterar en okänd massa som är sekretessbelagd. Robustus har ett förslag på överdimensionering av det nuvarande glidlagret. Målet med projektet var att analysera och optimera några glidlager i förhållande till det befintliga glidlagret samt att ta hänsyn till materialval och den miljö som lagret kommer att befinner sig i. Det som analyserna och optimeringen visade var att det befintliga glidlagret hade den bästa geometrin bland alla lösningar men inte det optimala materialet.
Vidareutveckling av skrotfallsprognos : på Sapa Heat Transfer AB
Sapa Heat Transfer AB (SHT AB) är en av tre delar inom koncernen Sapa Group, som ägs av det norska företaget Orkla ASA. SHT AB har produktion både i Sverige (Finspång) och i Kina (Shanghai). Företaget är en världsledande leverantör och utvecklare av aluminiumband som används i olika typer av värmeväxlare, främst inom bilindustrin.I flera steg av produktionen, som innefattar omsmältning, varm- och kallvalsning samt skärning, uppkommer ett skrotfall av aluminium. Detta skrot tas omhand och återanvänds som råvara i företagets omsmältverk. SHT AB har idag inget automatiserat IT-stöd för att prognostisera skrotavfallet, dessa beräkningar görs istället med hjälp av Excel.
En r?rspis: och hur den ?r uppbyggd
This thesis researches the construction of the Swedish masonry heater called r?rspis.
A r?rspis has an inner smoke channel system that stores heat and it was developed in the
early 19th century alongside the Swedish kakelugn (tiled stove). Unlike the tiled stove,
the R?rspis was commonly found in simpler environments and is part of the cultural her itage of the rural population.
Mätsystem för effektförluster i en högfrekvenstransformator
To measure losses in a transformer with today?s methods is either slow or insecure. There s a new method developed by Alstom that hasn't been actualize in to a test-system and that has been the assignment in this project. The idea is built on a switched system and a CLR- circuit in the resonant frequency. The test-system has a calculated power-loss that make the efficiency to be as high as 99,8% and in reality over 95%.
Effekter av tidiga reflektioner vid musikreproduktion
In this project the focus has been on the system for recombination at Oskarshamn 2. The recombining systems have on several occasions switched paths due to low pressure before the last ejector that?s feeding the recombiner. Of the mentioned reason, events and several measuring points have been analyzed in this report since the installation of the recombining systems.In order to prove theories and demonstrate what may be the cause of this problem, we used heat balance calculations by the program Probera. Using the program, we can demonstrate that the catalytic process does not reach the desired temperature with the amount of combustible substance.
Molecular testing of raspberry plants infected with tomato black ring virus
Nematode-transmitted plant viruses (such as nepoviruses) cause great economically losses in commercially important plants such as tomatoes, grapevines and raspberries all over the world. To avoid spread of the viruses the interest in mapping the viruses has increased. One of the important nepoviruses infecting European red raspberries (Rubus idaeus) is Tomato black ring virus (TBRV). TBRV has earlier been confirmed in raspberry samples from Belarus by ELISA and the aim of this bachelor degree project was to confirm these results by amplifying, cloning and sequencing the coat protein (CP) gene of the virus. In total eight viral cDNA samples, from two different raspberry samples, were amplified and sequenced.
Träbroar för järnvägstrafik
This report is a study in voltagelevel in connection with regeneration of brake energy from the tramtype M31 in Gothenburg.In the act of braking, the tram M31 uses electrical braking where the electrical motors generates energy and if possible send it back to the overheadline, where other trams in the nearby can use this regenerated energy for its own driving force. In cases where no other energyconsumers are located in the same section, there is a resistance witch task is to convert this energy into heat. The regulation of this resistance appears to cause an increase in the voltagelevel into far too high levels.Investigations of the trams regulationequipment and its construction have been done. Further have measurements on the overheadline been performed in order to map the voltagevariations during a longer period of time.The result have been showing that the voltagelevel during regeneration often is as high as 880V-920V, more extreme values have not been observed in a large scale. The values are especially high compared to the nominal voltagelevel.
Lactobacillus reuteri som probiotisk terapi mot bakteriell vaginit hos avelsråttor :
Lactobacillus reuteri has been used as probiotics in piglet and chicken feedings as
well as in different diary products for humans. In this EEF-work I have shown that
L. reuteri can be an alternative for treatment of vaginitis in laboratory rats used for
breeding. In a breeding stock with 3000 animals some animals had a vaginal
infection with ??haemolytic streptococci group G.
Rennäringens kulturella värden : en studie om svenskars preferenser
The Swedish reindeer husbandry has had economic difficulties for some years. Due to this, and the fact that the reindeer husbandry plays an important role in Sámi culture, the Swedish state has chosen to support the industry. If these grants where to be withdrawn, the reindeer husbandry as well as the Sámi culture would decrease, which would cause welfare losses for the people living in Sweden. The aim of this study was to elicit what the Swedes are willing to pay to maintain the amount of reindeer husbandry and Sámi culture. By using Contingent Valuation and a survey the willingness to pay was estimated.
DATORSTÖD FÖR ARBETE : KONSEKVENSER FÖR VAL AV AFFÄRSSYSTEM En studie av en service- och supportavdelning
This report is focusing on problems with introducing standard enterprise resource planning systems (ERP) in businesses. A study has been carried out on a service and support department at a Swedish heat metering company, SVM North Node. The study aims to help the company become a better customer in choice and customization of a new ERP system. We make a description of the department studied and the work carried out there, on the basis of learning, knowledge and cooperation. As a final point we present some ideas on how computer systems could support their work, hoping that this will result in them making adequate demands on a new ERP system..
Den ekonomiska lönsamheten för solvärme i Sverige
The sun is an endless energy source and the heat it produces can be used to heatup our homes. This technology is relatively old and was introduced in the late70-s. There are two kinds of solar collectors that are most frequently used todayand these are plain solar collectors and vacuum solar collectors. The plain solarcollectors are the once that are used the most but the vacuum solar collectorshave increased more as a percentage the last couple of years.The biggest question asked regarding an investment in solar heating is if theplant is economically profitable. This question has no direct answer because itis dependent on a couple of prerequisites.
Energioptimering av Hemsö fästning med förslag på energieffektivare systemlösningar
The report is a master thesis about energy efficient measures for an underground facility Hemsö fortress.Several proposals are evaluated economically.Statistics of the electricity used and measurements of several heat pumps are analyzed to find energysavings potentials.The results indicate that several units of a dehumidification system are responsible for over 70 % of theyearly electricity cost. The air that is being dehumidified by these units can otherwise cause damage ofculturally important interior designs.The proposal with highest profit suggests an alternative method for dehumidification. The cooler in theair handling units in Hemsö fortress have capacity to dehumidify the air. However complementary fansneed to be installed to circulate humid air towards the air handling units. The solution can be implementedin three different locations within the facility.