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233 Uppsatser om Photovoltaic cells - Sida 15 av 16

Utvärdering av en ny selektionsmetod för hingstsperma : med avseende på membranintegriteten och membranstabiliteten

Today, equine breeding is based on performance and conformation, resulting in a vast variation in fertility among different horses, with noticeable economic losses as a consequence. The horse breeding industry is therefore in need of methods that diagnose the spermatozoa concerning their quality and provide the best sperm for AI. The commonly used selection methods for sperm today are: centrifugation, where extender is added, the sample is centrifuged and then resuspended; swim-up self-migration; adherence separation; and density gradient centrifugation. However, none of these methods are in used routinely in practice before inseminating mares with fresh or cooled semen. The aim of this study was to evaluate a new selection method, Single Layer Centrifugation (SLC), and its effect on sperm viability. The viability was analyzed with regard to membrane integrity and membrane stability of ejaculated spermatozoa.

Djuromvårdnad vid fång

Laminitis is a common but devastating condition, and affected horses are often euthanized or influenced a very long time. Many horses never return to their original capacity. Laminitis is often associated with severe pain and a long time of convalescence. Symthoms includes lameness, hoof hyperthermia, strenghthened digital pulse and pain. The horse often tries to move the body weight away from the forelegs which are often more severly affected than the hindlimbs.

Det onkolytiska parvoviruset H-1PV : tumörsupprimerande mekanismer

H-1 parvovirus (H-1PV) är ett autonomt onkolytiskt parvovirus. Dess naturliga värddjur är råtta, men det kan även infektera andra vertebrater. H-1PV kan tas upp av alla celler men är endast skadligt för prolifererande celler i neonatala djur och tumöromvandlade celler. Vid infektion av tumörceller kan tumörsupprimerande mekanismer genereras. Dessa kan vara direkt cytotoxiska och celldödande, eller indirekta genom att aktivera viralt eller tumörspecifikt immunsvar.

Mineralämnen i fullfoder : studier på 20 mjölkkogårdar i Halland

In 2003 the recommended phosphorus allowance for dairy cows in Sweden was lowered approximately 10 %. For a cow at a production level of 35 kg ECM it decreased from 0,40 to 0,36 % of dry matter. To investigate if the decrease has been implemented at farm level, analysis of following minerals; P, Ca, Mg, K, Na, S, Se, Cu, Mn and Zn was performed on the TMR at 20 farms in Sweden in the summer of 2004. The purpose was to describe the actual allowance of different minerals as compared to the new recommendations. One hypothesis was that the decrease in recommended allowance of phosphorus would lead to the need of new mineral feeds on the market.

Aktiv lastbilsstol för bättre förarergonomi och hälsa

The project concerns a predevelopment work for Scania AB, a leading manufacturer of heavytrucks, and was performed as a master thesis work for the program Design and ProductDevelopment at KTH. The purpose of this work was to examine how the work situation of truckdrivers, especially long-haulage drivers, can be improved with respect to prolonged sedentaryoccupation. Mental fatigue and under-stimulation due to low cognitive load during long drivescan be major risk factors for traffic accidents. Physical strain injuries to both the skeleton andmuscles are common for this working group and minimal opportunity for daily exercise alsoincreases the risk of developing blood clots in the legs, which can have serious consequences forthe driver's health.An extensive background study, both theoretical and exploratory, was performed to identify thedrivers' concerns and comfort needs. Various treatments such as massage and active sitting wereinvestigated and existing products within the area studied.

Mätning av partikelmassa i avgaser från en dieselmotor

This master thesis was a continuation of a previous study in the diesel exhaust characterization, which is part of the academical work embedded in the EMIR-1 project. The main objective of this thesis work was to finish the installation and make the proper modifications of the particulate mass measuring system located in one of the engine test cells at KTH, in order to be able to measure the mass of the particles from the exhaust of diesel engines.This experiment requires a diluted flow sample from the exhaust that should be sent to the device that makes possible the measurement of particle mass, called TEOM. In the first stage of this project, the objective was to study and make the proper modifications in the existing KTH diluter because there were several problems to obtain a constant dilution ratio from it during tests.This modifications were made and it resulted in a great improvement in the maximum inlet and outlet flow that this diluter can handle. Therefore another modification is proposed for controlling the inlet exhaust flow so it will be possible to regulate the dilution ratio and make it constant along a wide range of engine loads and speeds.The second and most important stage was to make particulate mass measurements possible by analyzing the frequency signal from the TEOM device. The idea was to obtain the frequency of oscillation from the tapered element in the TEOM, and therefore with the proper correlations, be able to predict the particulate mass concentration in the exhaust flow from the engine.An electrical problem in the TEOM circuit was detected and corrected, so the signal that carries the frequency from the TEOM can be analyzed properly.

Canine S- and M/L- cone electroretinograms

Full-field flash electroretinography is an electrodiagnostic method used to examine the function of retinal cells. Light stimulation of the eye elicits electrical potentials in the retina. By aid of a corneal electrode and a reference electrode close to the back of the eye, the electrical potentials can be recorded and presented as an electroretinogram (ERG). ERGs driven by mainly one type of cones can be used to examine the function of a single cone class. In human beings, studies have shown the cone class sensitive to light of short wavelengths, the S-cones, to be more vulnerable to acquired damage than the other cone classes (Daley et al., 1987; Gouras et al., 1993; Greenstein et al., 1989). Dogs have two cone classes, S-cones, and M/L-cones (most sensitive to medium to long wavelengths).

Faktorer som påverkar magnesiumabsorptionen i våmmen hos kor

In metabolism Mg plays an important role because it affects many cellular enzymes in the body. The energy metabolism and protein synthesis are dependent on Mg as an enzyme activator, Mg is also involved in the synthesis of RNA and DNA. Absorption of Mg primarily takes place over the ruminal epithelium in ruminants. The main storage of Mg is in the bones but that can only be reached if the cow is in great need of calcium or phosphorus, it's a hormonal regulated process that induces catabolism of bones. Free and available sources of Mg are found in soft tissues and in the extra cellular fluids that includes cerebrospinal fluids and blood.

Optimerade material för optiska komponenter i koncentrerande solfångare

The energy consumption continues to increase as the use of electronics and energy consuming equipment increases. The use of fossil fuels has to be phased out for this to be sustainable in the long run while the use of renewable energy continues to increase. A renewable energy source is solar energy but the production of heat and electricity are today very expensive compared to other energy sources and an important task for the solar energy market to grow is therefore to minimize the production cost of the solar collectors while increasing its efficiency to produce heat and/or electricity. One way to convert solar energy into heat is by using solar collectors and electricity can be produced by utilizing the produced heat, or by applying solar cells.This thesis aims to recommend a reflective material for the next generation solar collectors from Absolicon and to recommend a commercially available coating for the receiver tube of the solar collector. A market study has been carried out to investigate the cost-related aspects along with the optical and durable aspects for the optical material of the solar collector.

Mastcellens roll vid atopisk dermatit hos hund

SAMMANFATTNINGDenna litteraturstudie har gjorts med syfte att utöka kunskapen om atopisk dermatit hos hund med fokus på mastcellens roll i immunopatogenesen. Atopisk dermatit är en relativt vanlig sjukdom som kan drabba alla hundar oavsett ras; den är oftast livslång och kräver visst arbete för att diagnosticera och behandla med gott resultat. Förutom att det är ett problem hos hundar, finns även ett nära samband med atopiska sjukdomar hos människa, och hundar fungerar som en bra modell för forskning på humansidan.Trots omfattande forskning, vet man fortfarande inte varför sjukdomen uppkommer. Många teorier finns kring den immunologiska bakgrunden, men stora delar är fortfarande okända. Att mastcellen spelar en nyckelroll är dock allmänt vedertaget.

Utvärtes behandling av sarkoider på häst med Aldara eller Xxterra : en jämförande pilotstudie

Sarcoid is the most common tumor in horses all over the world. The sarcoid is a benign, locally invasive, usually fibroblastic proliferative skin neoplasm. Even if the etiology is not completley verified, the epidemiology and clinical behavior suggest a infectious intervention, probably BPV type 1 or type 2. However, it is known that the cause is multifactorial. A genetic prepdispositon has been identified associated to genes within the Major Histocompatibility Complex (MHC), but also to breed, age and perhaps gender.

Utvärtes behandling av sarkoider på häst med Aldara TM eller Xxterra TM : en jämförande pilotstudie

Sarcoid is the most common tumor in horses all over the world. The sarcoid is a benign, locally invasive, usually fibroblastic proliferative skin neoplasm. Even if the etiology is not completley verified, the epidemiology and clinical behavior suggest a infectious intervention, probably BPV type 1 or type 2. However, it is known that the cause is multifactorial. A genetic prepdispositon has been identified associated to genes within the Major Histocompatibility Complex (MHC), but also to breed, age and perhaps gender.

Genetisk och immunologisk bakgrund till atopisk dermatit hos hund

Atopisk dermatit är en sjukdom som drabbar ungefär en tiondel av världens hundar. Sjukdomen ger som följd av allergenexponering symptom såsom klåda, hudlesioner och otitis externa. Patogenesen för atopisk dermatit är komplex och multifaktoriell. Målet med denna litteraturstudie var att undersöka hur genetiska och immunologiska faktorer bidrar till sjukdomens patogenes. En obalans i T-hjälpar-(Th)-svaret vid atopisk dermatit är allmänt accepterad.

Systemlösningar för plus- eller passivhus : En studie med syftet att lösa energibehovet för ett specifikt hus.

The purpose of the house which is the basis of this report is to be able present itself on the market as a relatively cheap and at the same time a climate friendly choice. The house is supposed to be able to be built anywhere in Sweden and the rest of Scandinavia in a short period of time. This puts demand on what kind of heating system the house can have, since not all places have the geographic advantage of being able to use geothermal or district heating. Therefore the heating system choices will only include those that are not limited by their geographic location. The house will be built in modules which only require the groundwork to be done before the house can be erected. In this report "System solutions for plus or passive-housing" a comprehensive literature search has been conducted as well as a number of calculations.

Framtidens energieffektiva flerbostadshus

The housing sector of today represents for almost 40% of the energy consumption, an energy consumption of which the major part consists of non-renewable energy sources. This is not sustainable and utilization of new energy-efficient technologies in buildings can be a step in the right direction, towards a sustainable energy society.This report has been made on behalf of and in cooperation with Älvstranden Utveckling AB in Gothenburg to examine how future energy-efficient technologies can affect the energy demand in energy-efficient multi-dwelling buildings.The report is based on Älvstrandens passive house, Hamnhuset, a house whose energy consumption is far below the BBR's requirements. The report looks at the opportunities for improvement within windows, insulation, solar energy technologies, as well as white goods. Computer simulations are then made to apply the selected technologies into a reference building. Technologies are selected from an energy efficient perspective and no account has been taken of other aspects such as the economy.

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