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231 Uppsatser om U-värde transmission - Sida 4 av 16

VÀxthusvÀvens fukttransmission ? Hur struktur och materialval pÄverkar vÀxthusvÀvens fuktgenomslÀpplighet

VÀxthus anvÀnds för att ge ett bÀttre odlingsklimat Ät grödor och vÀxter. För ytterligare förbÀttring av förhÄllandena anvÀnds vÀxthusvÀvar som exempelvis kan reglera temperatur, fuktighet och ljustillförsel. VÀven som behandlas i denna rapport Àr en sÄ kallad energivÀv som frÀmst har till uppgift att minska energiÄtgÄngen vid uppvÀrmning.NÀr vÀven Àr fördragen nattetid, ökar luftfuktigheten dÄ grödorna avger fukt dygnet runt. Fukten kan kondenseras mot energivÀven, vilket gör att det bildas droppar pÄ vÀven som kan falla ned pÄ vÀxtligheten. Den höga luftfuktigheten kan medföra svampsjukdomar och i övrigt ocksÄ bidra till att tillvÀxten avstannar.

Emerging zoonotic viruses : what characterizes them and what are the risk factors for their emergence?

Emerging infectious diseases poses a great future threat, not only to humans but also to domestic animals and wildlife. Even though the majority of these infections only cause minor health problems, the relatively recent emergence of HIV clearly illustrates that the next major human pandemic may surface at any time. Regardless of what the name indicates, most emerging human pathogens are not believed to be recently evolved, but to have existed previously in the natural environment. Most emerging pathogens are zoonotic, i.e. able to infect animals besides humans.

Optimering av sintrade kugghjul

Powder Metal (PM) gears are machine element components which operate under the same principle as conventional gears, but, due to their intrinsic material characteristic need to be designed slightly different, and its manufacturing process offers advantages previously unobtainable by conventional steel gear manufacturing methods. The use of PM in similar applications, such as synchronous hubs, makes them a suitable candidate for production in such material. The current master thesis work focuses on gear design using PM by utilizing finite element method (FEM) to reduce weight and inertia taking into account root bending strength and tooth deflection.First a topological optimization is used to determine feasible candidates for different web designs which have as objective to reduce volume, similar topologies were shown during different loading conditions; and hence, this topology was chosen as a suitable candidate. A shape optimization of the topological candidate was performed having as state variables root bending strength, independent for compressive and tensile side of the tooth loading; and tooth deflection, which in concept can be correlated to static transmission error (TE).Another aspect in this thesis analysed is the possibility to incorporate non-trochoid root geometry, a trochoid root is always present when machining with a hob, into the gear root and hence reduce the stress concentration here. Due to the use of PM, a non-symmetric optimized root can be achieved and hence be optimizing compression and tension.Results showed significantly lower inertia, for example certain results showed 40% reduced when compared to solid gear, with adverse effects as increase in tooth deformation and increase in maximum principal stress.

Enegiutredning Hotell Princess

This report will show the energy usage of Hotel Princess in Sandviken, Sweden. When the hotel changed owner an examination of the hotels heating, ventilation and sanitary systems were done. The report showed flaws in the ventilation system, and is why the new owner wanted a closer look at the energy use of the hotel. The original building was built in the 1930s and two major extensions have been built, one in the 1950s and the most recent in the 1980s. An assumption made is that the building parts were built to the restrictions during the time. Activities on the hotel include sleep over, conference, night club, massage and swimming in the hotels pool section.

Optimerad styrning av kondensatorbatterier - Ny möjlighet att minska förluster med elektronisk brytteknik

Transmission of reactive power is well known to cause active power losses. Thus, newcomponents who can help minimizing these expensive reactive power flows are ofgreat interest to the power distribution companies. ABB Corporate Research hasdeveloped the first electronic power breaker. One possible application for thisbreaker is transient-free switching of capacitor banks. This could prove a usefuldistribution voltage complement to the switch-sync technique, mainly applied to transmissionvoltage level.

LimtrÀstomme till hallbyggnader : Utformning och dimensionering av momentstyva ramhörn och 3D-modell framtagning

Industrial buildings are increasing all over Sweden. Farmers are building new modern facilities and the government chooses to build new halls to invest i youth sports. Glulam is the most common framework but there are limitations because of the transport. Therefore, there is a need to develop new solutions to increase the use of glulam.The maximum torque in the eaves was found in the frame with a roof pitch of 18 degrees and a wingspan of 25 meters. Using hand calculations according to Eurocode and comparison with the computer software StatCon, the maximum torque, shear force and utilization rate is calculated.

Axle Link - en kortslutningsskyddad sÀker DC-överföring

Denna examensrapport redogör för hur man kan fÄ en kortslutningsskyddadoch sÀker inkoppling av en DC-lÀnk mellan tvÄ skiljda elektriska system.Rapporten bygger pÄ hur en lastbil ska kunna fÄ en större sÀkerhet för attbibehÄlla sina elektriska bromsar om tex ett av bromssystemen tappar sinordinarie matning.Lastbilens bromssystem bestÄr idag av tvÄ skiljda elektriska system med ett 24volts strömförsörjande batteri vardera. Det ingÄr tvÄ stycken elektriskabromsar i varje system. Om det tex blir fel pÄ en av bromsarna och dennapÄverkar ett av systemen vill man kunna koppla bort denna enskilda bromsmed sitt system. Man vill Àven kunna försörja den fungerande bromsen somsitter i samma system via en sÄ kallad Axle Link. Denna strömmatningslÀnksitter mellan tvÄ hjulpar pÄ samma axel.I denna studie undersöktes möjligheten att realisera en kortslutningsskyddadoch sÀker DC-överföring via en Axle Link, i första hand med diskretakomponenter.

Implementation av fÀltbuss ASIC i FPGA

HMS Industrial Networks AB is in need of changing a communications solution that iscurrently based on an ASIC. This will be achieved by moving the communications solution toa FPGA with the help of the programming language VHDL. By doing this, it is possible toreduce the need for specific circuits, get a more flexible platform and thus get a cheapersolution.This report describes a solution for how to move a network protocol from an ASIC to anFPGA. The report shows that the network slave device is working under the guidelines forthis project. This means that it is quite realistic to implement a fieldbus protocol on an FPGA,using VHDL and to maintain the same functionality as the earlier communications solution..

Rabies, dogs and education : A cross-sectional study on the knowledge, attitude and practice in school children in Tamil Nadu

Although known and feared for thousands of years, rabies remains a real and present threat to thousands of people, especially in low- and middle income countries. In India, rabies is an endemic disease, causing human deaths every year. The primary mode of transmission is through the bite of an infected dog. Fighting the disease in the dog population through vaccinations remains the most efficient way to eradicate the disease. The knowledge of rabies in India is unsatisfactory, as a lot of people lack awareness about the severity of the disease and the importance of washing the bitten area and seeking medical attention for post exposure prophylaxis when bitten by a dog.

Kommunicera, informera och modellera : Kommunikationsprocessen inom Clas Ohlson

Kommunikation har stor pa?verkan pa? hur en organisation fungerar och hur va?l den arbetar enhetligt mot sina uppsatta ma?l. Kommunikation a?r ett komplext a?mne som kan vara sva?rt att fo?rsta? och beskriva. O?vergripande finns tva? skolor vars synsa?tt a?mnar angripa fo?rklarandet av kommunikation.

Emerging infectious diseases : using PCV2 as a model of disease transmission dynamics at the livestock-wildlife interface in Uganda

Uganda anses vara ett högriskland för utveckling av nya plötsligt uppdykande sjukdomar (emerging infectious diseases, EID). Grisproduktionen i Uganda har ökat drastiskt de senaste Ären och en stor del av Ugandas grisar Àr frigÄende. De kan dÀrför lÀtt komma i kontakt med vilda djur i deras nÀromrÄde. Porcint circovirus 2 (PCV2) Àr ett ubikvitÀrt virus och etiologiskt agens för bland annat porcine multisystemic wasting syndrome (PMWS). Förutom att infektera tamgrisar över hela vÀrlden sÄ har PCV2 ocksÄ visats kunna infektera vildsvin.

Verktyg för vÀrdering av miljöpÄverkan vid investeringar i det svenska elstamnÀtet

During the period 2009-2013, investments in the Swedish national grid increase by a factor of ten compared to previous years. In order to fulfil their mission to manage the national grid in a safe, efficient and environmentally sound way, Svenska KraftnÀt (Swedish National Grid) needs to take all these perspectives into account while planning new investments. To compare and relate perspectives of technology, economy and environment the same yard stick must be used. That yard stick is commonly money. A problem arises however as environmental issues are difficult to price.The purpose of this master?s degree project was to develop a tool for evaluation of environmental impact related to investments in the Swedish national grid.

"Man kan inte vara ledare om man inte har nÄgra följare" : En kvalitativ studie om hur chefer upplever sin position

According to science internal communication is a complicated, yet very important, issue of organizations today. An organization with a successful internal communication shows better results both economically and in terms of coworker satisfaction. The two main theories on communication are sensemaking and transmission. After a century with a transmissionary point of view, researchers stress the importance of sensemaking internal communication.Main question of this thesis is ?Which of the two main theories is the most useful when anchoring important messages in large organizations??According to the results of this study, conducted by interviews, neither one is more useful than the other.

IT-relaterade problem pÄ arbetsplatser : En studie om Àldre arbetstagares krav, kontroll och sociala stöd i IT-relaterade arbetsuppgifter

According to science internal communication is a complicated, yet very important, issue of organizations today. An organization with a successful internal communication shows better results both economically and in terms of coworker satisfaction. The two main theories on communication are sensemaking and transmission. After a century with a transmissionary point of view, researchers stress the importance of sensemaking internal communication.Main question of this thesis is ?Which of the two main theories is the most useful when anchoring important messages in large organizations??According to the results of this study, conducted by interviews, neither one is more useful than the other.

TrÄdlös energiöverföring via elektromagnetisk induktion

This paper describes a method for wireless energy transfer via near-field electromagnetic inductionthat is inexpensive, simple and can be applied to almost any type of system, regardless of size andenergy demands.The method uses a primary unit consisting of an oscillator, amplifier and inductive coil thattransfers energy to a secondary unit consisting of a coil, rectifier and voltage regulator. Two typesof oscillators and several amplifier designs were realized and evaluated together with a multitudeof flat coils of both monofilar and bifilar type.The results show that it is important to use an oscillator whose frequency is dependent on theinductance of the connected transmission coil, such as the Colpitts oscillator. This is preferable toan oscillator with a preset frequency, such as a Schmitt-trigger oscillator..

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