Sökresultat:
1451 Uppsatser om Ratio of peak hour to average day - Sida 1 av 97
Dimensionerande vattenförbrukning och dess variationer
I Sverige användes det år 2010 ca 907 miljoner kubikmeter dricksvatten från kommunala uttag. Allt detta vatten måste kunna transporteras, vilket görs genom vattenledningar. För att dimensionera dessa krävs att man vet hur mycket vatten som skall distribueras och hur det varierar bl.a. beroende på när under dygnet, veckan och året som uttag sker.Vid dagens tillvägagångssätt för dimensionering av vattenledningar till nya områden använder man bland annat typexempel på förbrukningsvariationer under dygnet för ett liknande område. Dessutom används erfarenhetsbaserade värden på maxtim- och maxdygnsfaktorer.Dagens dimensioneringsätt har ej kunnat säkerställas på grund av otillräcklig och bristfälligt detaljerad data över förbrukningsmängd.
Skogsbränsledrivare i klen förstagallring med contorta
The aim for the study was to examine a harwarder´s (combined harvester-forwarder) productivity when harvesting forest fuel in first thinning stands that contains Lodgepole pine and calculate the economy of the harvesting work and estimate the quality of the thinning . The field study area where located near Arvån, about 15 kilometres south ?east from the city of Lycksele. The field studies were taken place in three different stands. All tree stands had the same tree age, but the tree species combination and the density varied.
Effekten av höghöjdsvistelse på anaerob arbetsförmåga
Syftet med denna studie var att undersöka om vistelse på hög höjd påverkar den anaeroba arbetsförmågan. Sex aktiva universitetsstudenter, fyra män och två kvinnor, deltog frivilligt i studien. Expeditionen till Nepal varade i 40 dagar och under den perioden sov och vandrade försökspersonerna mellan 1400 och 5100 meter över havet. Före och efter expeditionen genomförde försökspersonerna ett anaerobt wingatetest där peak power, average power, minimum power and power drop uppmättes. Resultatet visade en signifikant sänkning av average power efter den genomförda expeditionen på hög höjd, med ett medelvärde på 8.44 ± 0,84 w/kg före expeditionen och 7.81 ± 0,87 w/kg efter expeditionen.
Produktivitet och lönsamhet vid skogsbränsleuttag i klena gallringar : en tidsstudie av Vimek 608 BioCombi i contortabestånd
The annual demands for forest fuels increases in Sweden. At present, large unutilized biomass resources is found in young, dense forests from which about five million oven-dry tonnes (ODt) (23 TWh) could annually be extracted as forest fuel. But harvesting small trees give high logging costs and new cost-efficient harvesting techniques are therefore required. The aim was to study the productivity of Vimek 608 BioCombi in forest fuel thinning of Lodgepole pine and to calculate the economy of the harvesting and estimate the thinning quality. The time study was performed in Åmarken in the county of Västerbotten.
Productivity of integrated harvesting of pulpwood and energy wood in first commercial thinnings
The aim of this study was to quantify the productivity and the costs of different harvesting systems (teams), containing harvesters equipped with accumulating harvester heads and forwarders, in first commercial thinnings were an integrated harvest of pulpwood and energy wood were performed. In the beginning the plan was to study and measure 20 sites before and after harvest. Due to storms during the summer of 2010, complete data could only be obtained from 8 of these 20 sites. Seven of these sites were privately owned and one was owned by UPM, all of the sites had been pre-commercially thinned. The mean stem density before harvest was 2578 stems per ha and the mean stem volume was 0.074 m3solid over bark.On average 1518 stems/ha was harvested.
Magnesiumstatus hos mjölkkor : en fältstudie
Magnesium is an essential mineral that is important for several physiologic and biochemical processes in the body. Deficiency of magnesium is mainly associated with grass tetany, but can also appear in cows during the indoor period. Since long it is known that potassium has a negative effect on the absorption of magnesium. Due to the fact that potassium fertilisation leads to a higher potassium content in forage, it is of interest to study interactions of potassium on the magnesium balance in dairy cows. There are few studies about magnesium feeding to dairy cows in Sweden and the purpose of this study was to investigate how much magnesium and from which feed-sources dairy cows in Sweden get their magnesium.
Data was collected from seven farms in the northern part of Uppland and from seven farms in Skaraborg in Sweden.
Quantification of sleep in dairy cows in three different stages of lactation
The aim of this project was to quantify the total sleep time in modern dairy cows during24-hour periods and to investigate whether the total amount of sleep as well as timespent in different sleep stages varies between the dry period, early- and peak lactation.The distribution of sleep time between night and day was also examined. Furthermore,correlations between sleep and lying time, fluctuations in body temperature and heartbeat were included in the aim. Eight dairy cows of the Swedish Red breed were used inthis study, which was carried out between June and September 2010. In order toquantify sleep non-invasive electrophysiological recordings were performed.Simultaneously with collecting sleep data, body position and body temperature werealso recorded. No heart rate data was obtained due to difficulties of maintainingelectrodes for heart beat measurements attached to the skin.
Tidsupplösning vid miljövärdering av fjärrvärme : Kontorsbyggnad med solvärmeproduktion - en fallstudie
The demand for environmental assessments on buildings and energy consumption is increasing as well as the energy performance requirements for buildings. At the same time it is increasingly common with self-producers of heat and electricity generation.The main purpose with this master thesis is to investigate how time resolution affects the environmental assessment of energy consumption in office buildings connected to district heating (DH). Environmental assessments were done with both attributional LCA and consequential LCA with system expansion.Fortum´s DH system in Stockholm was analyzed and district heating production was simulated in a Matlab-model. Greenhouse gas (GHG) emissions for the production were calculated. The heat demand of the office Gångaren 16 in Stockholm was simulated in IDA ICE.
Referenser i informationsåtervinning: utvärdering av en sökstrategi för citationsindex
In this essay, a search strategy for citation index is studied. The strategy, which is essentially a citation cycle, starts with documents retrieved by a subject search, wherefrom new documents are identified following the network of citations backwards and forwards in time. Based on the theory of polyrepresentation, the strategy exploits overlaps between cognitively different interpretations of the same documents in order to automatically select references seed documents used as a starting point for the forward chaining. The purpose of the investigation is to evaluate the retrieval effectiveness of the search strategy and to find out whether the strategy can be used to expand a subject search with the help of the network of references in order to retrieve new relevant documents. Two questions are formulated: 1a.
Trefaktorsmodellen : Undersökning på svenska börsnoterade aktiebolag
Previous work by researchers as Eugene F. Fama and Kenneth R. French, show that average return on stocks are related to a firms characteristics like size and book-to-market ratio. These kinds of patterns in average return is not explained by The Capital Asset Pricing Model (CAPM), and are therefore seen as anomalies. Fama and French have proposed a three-factor model, which captures patterns observed in U.S average returns associated with size and value.
Bolånetakets påverkan på efterfrågan av hyresrättslägenheter
This Degree project is a study about the Mortgage Cap, introduced in October of 2010, and its impact on the demand for rented apartments. The mortgage cap was introduced to decrease the households? loan-to-value ratio and thereby increase their economical resistance during times of financial instability.The past ten years Swedish households have continuously increased their average loan-to-value ratio. In an attempt prevent this negative development Finansinspektionen introduced a mortgage cap stating that banks should no longer grant mortgages corresponding to more than 85 percent of the property?s market value.In order to answer the main question two methods were used both a survey and two interviews.
Effektutveckling i den koncentriska fasen i bänkpress och knäböj
Aim: The aim of the study was to investigate 1RM and what power could be generated in bench-press and half squat concentric at certain percentages of 1RM. Special interest was put to evaluate men (M) and women (K), strength trained (ST) verses non strength trained (EST) in generating absolute power as well as power relative to 1RM.Method: In total 59 subjects mean (± SD) age 24.9 ± 4.1 years divided into four test groups: 20 male non strength trained GIH-students (EST M), 20 female non strength trained GIH-students (EST K), 10 male strength trained - sprinters on national/regional level (ST M), 10 female strength trained - sprinters (ST K) on national/regional level. They did two tests on 1RM and power in events of concentric bench-press and half squat in a Smith machine. In the first test session 3 ? 5 lifts were made to measure 1RM in each event.
Konceptstudie av drivmodul till bandskotare med hybriddrift
BAE Systems Hägglunds has a long history of producing high performance terrain tracked vehicles (mostly for military applications), and they are now aiming at developing a tracked forwarder with similar techniques.The forwarder will be of series hybrid type where a diesel engine via a generator will power the motors (one for each drive wheel). Thanks to individually controlled motors and the gentle rubber tracks, this forwarder is calculated to have a considerably higher average speed in the terrain and to be more gentle to the soil. The forwarder with a weight of 11 metric tons and a load capacity of 15 metric tons is specified to have an average working speed of 7-10 km/h, a top speed in terrain of 15 km/h and a top speed on roads of 40 km/h.This master?s thesis aims at developing a conceptual design of the forwarder?s drive module which includes electric motor, gear unit, brake and drive wheel.To investigate if the requirements can be fulfilled a study of the dimensioning loading scenarios has been carried out. The resulting needs regarding the torque has been considered in order to determine the required gear ratios for different motor options.
De svenska börsbolagens prioriteringar mellan investeringspolitik och utdelningspolitik : En studie av sambandet mellan investeringspolitik och utdelningspolitik i förhållande till börsvärde
The relationship between dividend policy and investment is a controversial area and the relationship between these two may differ depending on the company's priorities. The study examines this more closely by studying dividend policy's impact on investment and how it differs depending on the company?s market capitalization. The study is based on companies listed on the OMX Stockholm within the segments Large Cap and Small Cap, during the period between 2003-2012. Secondary data was obtained from each company's annual reports where relevant data was used to operationalized into measurable variables.
Buntning av grot med lastbilsmonterad utrustning :
During the transportation of logging residues (LR) the material´s low density is a problem that results in low use of pay-load capacity. Comminution or compression of LR are possible methods to increase pay-loads. In the present thesis studied a bundling machine which was mounted on a truck chassis, and the subsequent transport and crushing. The truck bundler created bundles that were larger and longer than other bundling equipment on the market. The objectives were to determine the total time consumption and its allocation over work element and machinery, to measure dry matter (DM) content of green and brown LR-bundles.