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676 Uppsatser om Wind load - Sida 29 av 46
Punktlasttestning av olika bergartstyper i Kiirunavaaras liggvägg
Examensarbetet ingår i den slutliga delen av kandidatutbildningen i naturresursteknik och utgör 15 högskolepoäng. Utbildningen är inriktad mot geologi och det avslutande arbetet ska ha anknytning till ämnet. Under våren 2012 presenterade representanter för LKAB förslaget att basera examensarbetet på att dokumentera hållfastheten hos bergarter från Kiirunavaaras liggvägg med hjälp av punktlasttestning. Tidigare undersökningar av hållfastheten hos bergarterna i Kiirunavaara har främst gjorts genom enaxiella tryckhållfasthetsmätningar. Det finns ett behov av att undersöka hållfastheten hos bergarterna i Kiirunavaara då gruvbrytningen sker djupare ned i jordskorpan och kraven på säkerheten ständigt ökar.
Motiverad för riskmedvetenhet? En studie om stadsarkitekterna i Dalarnas läns medvetenhet om, motivation för och arbete med risker vid fysisk planering.
The purpose of this study is to examine how risk is perceived by the urban architect's in the region Dalarna, as well as how this is reflected in their everyday work with risk and decision- making according to urban planning. The ambition is also to show how their risk awareness could be improved. The study is written in cooperation with Länsstyrelsen Dalarna as a part of their regional long-term goal to improve the region's proactive risk' and crisis management. The study is based upon 12 semi-structured interviews with local urban architects conducted during the summer and autumn 2007. The result shows that some architects are motivated for working with risk and think that risk awareness should be integrated in their everyday work, while others are not motivated and think that risk is more of a passing trend.
Växter vid havet :
Detta examensarbete behandlar växter som trivs vid havet. Arbetet baseras på frågan vilka växter som tål ett vindpinat och utsatt läge?
Arbetet beskriver vad man skall tänka på när man börjar planera en trädgård vid havet. I arbetet har jag tagit upp vilka träd och perenner som man kan använda sig av när man skall skapa en trädgård vid havet.
Syftet med arbetet är att man skall kunna använda sig av mitt arbete när man åker till plantskolan för att inhandla växter.
Diagnostiksystem i gaffeltruckar
This is a final thesis done at BT, considering one of their forklift truck models called Reflex. The first part of this report is about a preliminary investigation investigating what kind of diagnostic systems BTwants to use, and also which demands there are to meet all expectations on such system. Secondly a diagnostic system, which will show if the drive wheel is worn out, will be presented. In the preliminary investigation, two kinds of diagnostic systems were mentioned. These were Model based diagnosis and Predictive analysis.
Acceptansgränsen för solceller i lågspänningsnät : Kan den ökas?
Microproduction, also called distributed generation, is something that has become more and more popular in the electric grid. Microproduction can however lead to unacceptable performance if several units are installed in the same low voltage network. It is therefore good to know a limit where the performance of the low voltage network becomes unacceptable based on given parameters. This limit is usually called hosting capacity.In this report the hosting capacity with respect to voltage and current have been studied in three low voltage networks which are located in Falu Elnäts concession area. This has been done by simulations in a GIS-program where critical times of the grid have been simulated.
Investigation of yeast Grown in SSF Dring Biothanol Production from Lignocellusosic Material
Ethanol produced from lignocellulosic biomass has the potential to become a promisingalternative to gasoline. In this work the simultaneous saccharification and fermentation (SSF)technology was applied for ethanol production from hardwood with focus on cell growth,ethanol production and contamination.The SSF was performed at PH 5.5 and 35°C for different suspended solid concentrations(8%, 10% and 12%) of pretreated birch slurry which contained 16 % total suspended solids.Two different hexose fermenting yeast strain (Ethanol Red) and pentose fermenting yeaststrain were used.Quantifying the concentration of chemical components and metabolites in the fermentationmedium demonstrated that glucose and xylose are the major fermentable sugars in the slurry.The higher load of slurry (12%) represents a higher content of carbohydrates and potentiallyhigher end concentration of ethanol. Moreover, more lactic acid is produced with the lowerload of slurry (8 % or 10 %), presumably due to a result of a less inhibitory environment forbacterial growth. In this context, acetic acid sticks out as the most important inhibitor withconcentrations of 15.2 and 12.5 and 9.7 g/l respectively in the 12 %, 10 % and 8 % (ofsuspended solids) trials. Using pentose fermenting yeast may lead to higher ethanolproduction, lower xylose uptake and lower lactic acid formation.
Mjölkureahalten som mått på vom-mikrobernas kväveförsörjning och kons miljöbelastning
The aim of this literature study was to analyze how milk urea concentration is working as a measure of the nitrogen supply to rumen microbes and indicator of the environmental load. Questions included in this literature study were how to improve the dairy cattle nitrogen efficiency and what correlations there are between milk urea, nitrogen efficiency and crude protein content in the feed. Effects on the reproduction from high ration protein content are also addressed. Dairy cattle are today fed with large proportions of protein which could lead to high expenditure of feed and environmental pollutions. The nitrogen can be lost to the environment by different pathways; leaching, denitrification or by emission to the air.
Mjölkureahalten som mått på vommikrobernas kväveförsörjning och kons miljöbelastning
The aim of this literature study was to analyze how milk urea concentration is working as a measure of the nitrogen supply to rumen microbes and indicator of the environmental load. Questions included in this literature study were how to improve the dairy cattle nitrogen efficiency and what correlations there are between milk urea, nitrogen efficiency and crude protein content in the feed. Effects on the reproduction from high ration protein content are also addressed. Dairy cattle are today fed with large proportions of protein which could lead to high expenditure of feed and environmental pollutions. The nitrogen can be lost to the environment by different pathways; leaching, denitrification or by emission to the air.
Rum och rörelse - analys av alléns betydelse för människa och landskap
Within literature, politics and science, there is a claim that ?tree avenues are important?. But the question and the goal for this essay are to explore the pretext to how and why. Planting tree avenues is a 4000 year old tradition and they are a common element in the Swedish and Scanian landscape since the 18th century. They were first mainly planted by aristocratic land-owners or on their initiative, but since the 19th century also by farmers.
Samband mellan luftföroreningar och klimatfaktorer - en statistisk unersökning
That air pollutants of different kind has impact on our climate can hardly haveavoided anyone during the past years environment explosion in the media. But howis it actually with the reverse, i. e. the climate's impact on air pollutants? The aimwith our degree thesis is to try to find out if different weather factors, statisticallyseen, promotes atmospheric pollutants and particles in the air and vice versa.We got access to data on air pollutants and weather factors that was registeredduring year 2007 at Femmanhusets air pollutant and weather station in Gothenburg.In order to do a statistical investigation of these data, and to be able to analyze if itoccurs relations of various kind, we used the statistics program SPSS.
Lähäckar för minskad vinderosion och andra ekosystemtjänster
Människans näringar och kulturer har orsakat landskapsförändringar som på många håll i världen lett till flera ekologiska konsekvenser som erosion liksom övergödning av vattendrag och hav. Skogsbruk såväl som jordbruk har därutöver resulterat i stora utarmningar av den
biologiska mångfalden på jorden. Sedan en tid har jordbrukets negativa konsekvenser fått alltmer uppmärksamhet inom bland annat politik, forskning och näringsliv, varav somliga människor aktivt försökt stoppa det negativa händelseförloppet som manifesterat många av
världens odlingslandskap. Diskussioner som innefattar ekosystemet och dess så kallade tjänster för människans såväl som andra organismers överlevnad och välbefinnande erhåller därutöver mer och mer fokus i strävan mot miljövänligare alternativ för storskalig odling. I
sökandet efter mer ekologiskt sunda odlingssystem har intresset igen väckts för agroforestrysystem, som kombinerar vedartade växter med vanligt förekommande grödor.
Etableringen av lähäckar på respektive intill odlingarealer i Skåne kan bidra med flertalet ekosysystemtjänster vilka bevisats stoppa ex.
Tågtrafikledare i praktiken : Informationshantering och systemanvändning vid Gävle driftledningscentral
In Sweden whenever trains or maintenance workers want access to the railway system, their requests of usage and movements are being supervised, granted and handled by train dispatchers. The profession holds a key role in making the complex railway system work in terms of efficiency, safety and delivering on-time arrivals. This master thesis, delegated by the Swedish Transport Administration, has been carried out at the Division of Human Computer Interaction at Uppsala University and at the train traffic control center in Gävle. The aim has been to map what information the train dispatchers use in order to make safety-related decisions concerning their working goals. And further to describe and analyze how the train dispatchers, visavi their tools and systems in the work domain, gather necessary information.The result indicates a complex, diverse and spread out setting of different programs, procedures and tools that make satisfactory fulfilment of efficiency, safety and punctuality in relation to the time table hard.
Utvärdering av utrustning för skörd av äpplen avsedda för färskkonsumtion
During the autumn 2009, a 15 hp degree project was accomplished. The objective of the study was to describe different equipment alternatives, suitable for fresh market apple harvest. A field study was conducted during the harvest period to evaluate the efficiency (kg / person/ hour), using the different equipment. Four different systems are described in the study; Pick-ing-bag, Picking-train, Pluk-O-Trak and the Conveyor Harvester. The information about the systems is based on interviews with growers together with previous studies.
Våtmarker för näringsretention i Lillån : var bör de ligga och vilken effekt kan vi förvänta
Construction of wetlands in the agricultural landscape may reduce nitrogen and phosphorus
transfer to streams, thereby reducing the eutrophication of lakes and seas. The agriculturalstream Lillån, a tributary to stream Sagån, ends up in Lake Mälaren and is transporting large amounts of these plant nutrients. The aim of this study was to estimate how hypothetical wetlands of different size and location may reduce nitrogen and phosphorus load from stream Lillån. Estimated nutrient retention in several small wetlands was compared to retention in a single large wetland based on existing data from the agricultural stream and from a nearby smaller stream. Retention in the stream was suggested to decrease along with the nutrient concentration in the water.
Implementering av höghastighetsgränssnitt i 0,15 µm halvledarprocess
This study investigated the possibility of implementing three standards, Transistion Minimized Differential Signaling (TMDS) and two versions of Stub Series Terminated Logic (SSTL), for inter-chip communication in a specific manufacturing process. The two SSTL standards were implemented in one transceiver system while TMDS was implemented in a separate system. The evaluation was done with Spice simulations on schematic level with some parasitic capacitance and resistance. The idea was to investigate the possibility of implementing these standards and get an idea of eventual shortcomings. In order to create models as a basis for evaluation, simulation environments with models for circuit board and packages were created and transmitters and receivers were designed.