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3796 Uppsatser om Nyckelord: Mixing-layer - Sida 2 av 254

Energianvändning i serverhallar: energiflöden och kylning

This thesis examines different methods for the cooling of data centers. Several means of cooling with the refrigeration cycle have been studied, as well as the feasibility of using free cooling in different parts of Sweden. In addition, the possibilities of transferring excess heat to a nearby district heating system were investigated. It was found that in all investigated cases except two, the data center could be cooled solely with free cooling for at least 300 days a year when only the outside air temperature was considered as a constraining factor. The limit was then set to 20 °C.The vast majority of all district heating systems in Sweden get little to none of their heat from other excess heat sources.

Teknik för egen foderberedning :

There is an uncertainty in the market for grain forcing the meat/milk producers to review alternative feeds to a larger extent, in order to get control over the feed costs. This has led to that the meat/milk producers need to have a good knowledge regarding how the different feeds influences the animals and which technical equipment to use for handling. For those that produce their own feedmix, there is a need to put interest in new crops and their characteristics to be able to get the knowledge of what is required for their own production. It is beneficial to keep an open dialogue with advisors to be updated in new crops and new technology for feeding. When mixing feed at farm level, the legislation is not very clear since it the target group is large scale mixing plants. We have brought up the most important rules and regulations from the EU parliament Council as well as the ones from the Swedish Board of Agriculture (SJV), regarding feed mixing on farm and factory level. We have studied beans and pea at two different moisture levels, in order to evaluate how the moisture level affects the distribution of particles when milling with a plaitmill and a hammermill.

Biogasproduktion genom tvåstegsrötning av drankvatten

During the 19-century a global warming has been observed, which includes increases in global air and ocean temperatures, widespread melting of ice and snow, and rising global sea level. There is a clear connection between emissions of greenhouse gases caused by the human and the increase in temperature. Climatic changes caused by global warming can be stopped trough decreased emission of fossil fuels, for example by an increased use of biogas. Biogas is a renewable energy source which is produced through anaerobic (oxygen free) digestion of organic material. The gas is a mixture of methane (CH4) and carbon dioxide (CO2) and can be among others used as fuel in vehicles.

Gaspotentialen i en deponi, idag och i en framtid :

Deposited waste material degrades within a short period in anaerobic environments. The methane gas that is formed provides a harmful contribute to the greenhouse effect, 23 times larger impact than carbon dioxide. It is therefore desirable to minimize the emissions of methane gas from landfills. This may be achieved by drain the landfill of gas. In this thesis the amount of produced methane gas at the landfill at Örebro has been calculated. Estimations have also been made of the amount of methane gas that might be produced in the landfill in the future.

Biodiversitet av evertebrater på vegetativa tak

In a city sometimes conflicts arise between either to save the species-rich vacant lots where many species thrive, or to build new buildings. Green roofs can then serve as a refuge for plants and animals that have had their natural habitat destroyed or diminished. Today we know too little about green roofs contribution to the biodiversity in the cities. We also know very little about how various types of vegetation on roof can increase biodiversity and its ability to attract different species.The aim with this study was to examine how different types of vegetation on the roofs affect the biodiversity of the invertebrate and how species-composition and number of individuals differ between the roof- and groundlevel.This study has been carried out on Augustenborg Botanical Roof Gardens in Malmo, and in an area about 1.5 kilometers away from Augustenborg. Three different types of vegetation on the roof and ground floor were selected: sedum- ruderal and grass.

Bok- och grankonkurrens i Sydsverige - markegenskaper och naturlig föryngring :

In southern Sweden, beech (Fagus silvatica) and spruce (Picea abies) are two species with similar demands on soil properties. With increased global warming and high acid deposition the future may bring larger areas were the two species are overlapping, competing for the same soil. The aim of this study was to compare spruce and beech concerning distribution, cultivation and soil properties. From available data comparisons were made between spruce and beech forests in Sweden. Soil analyses were made on samples from beech forest in southern Sweden, with and without natural regeneration of spruce.

Introduktion av buskskikt i ungskogar

Young stands in urban forests often lack a shrub layer, though shrubs play an important structural and biological role in forests. All layers interact with one another to form a multilayered stand, in which shrubs have a vital role.In this diploma thesis, theoretical models for forest dynamics are compared with four reference stands to detect factors, and principals for introduction of shrubs in young stands. In these stands four different ways of introduction were found. In one trees and shrubs were planted together at the same time. Shrubs spontaneous spread under a canopy of mature forest, in another.

Teknik för en flerskiktadwebbapplikation

The report analyses if some common problems can be avoided by using modern technology. As a reference system ?Fartygsrapporteringssystemet? is used. It is an n-tier web application built with modern technology at time, 2003-2004. The aim is to examine whether ASP.Net MVC, Windows Communication Foundation, Workflow Foundation and SQL Server 2005 Service Broker can be used to create an n-tier web application which also communicate with other systems and facilitate automated testing.

Materialhantering till och från robot

Material handling is a term that includes all kinds of handling of material from a raw product to a finished one. ABB is active in the following segments; foundry, packaging and palletizing, metal industry and plastics industry.The demands for efficiency and reliability have been set very high in the industrial sector. Optimizing of the material handling will give the company higher cost-effectiveness. Around the robot there are different kinds of material flows, to optimize the cycle time, consisting of carriages combined in different ways.Motion Control is a complex system with main functions such as; positioning, synchronizing, indexing and more. The products in the system need to cooperate to make these functions possible therefore integration of motor- and servo products are important.

LAN-refresh och WAN-migrering

This work has been carried out at a company in the region which has about 30000 employeeswith about 400 sites all over the world. The company outsources their network including theLAN refresh and the WAN migration. They needed help with an upgrade of their LAN at theirScandinavian headquarters and to find a new solution for their WAN. The reason why the upgradeof the LAN was needed was that the equipment was too old and did not pass the securityrequirements. They also required a solution to segment their LAN, which consisted of a singlelarge VLAN with 1,300 employees.

Minimera färgbortfall vid vattentvätt inom textilkonservering Med användning av cyklododekan, tvålagersmetoden eller ultrarent vatten

Uppsats för avläggande av filosofie kandidatexamen iKulturvård, Konservatorprogrammet15 hpInstitutionen för kulturvårdGöteborgs universitet2014:26.

Hur ser lavars fördelning ut runt stammen på ek, och påverkas den av trädets storlek och dess närmiljö?

The aim of this study was to describe preferences of geographic direction of ten, oak-living epiphytic lichen species and how they responded to sun exposure, nearby bushes and trees, bark fissure depth and circumference. The frequency of every species was recorded in arcs of ten degrees around the tree at a height of 130 to 180 cm above the ground. An estimation of the amount of every species in every arc was also recorded. To analyse how the distribution of the lichen species responded to the different factors their concentration for every tree was plotted against the four factors. The distribution of Cliostomum corrugatum had a positive response to high sun exposure and a negative response to a thick layer of bushes and trees.

Skiktning och strukturell utveckling i unga naturlika skogsplanteringar: :

Multilayered woodland types are an important part of the urban forest. The knowledge how to establish and maintain such plantations are not as deep as other knowledge fields concerning forestry. Therefore this study has looked upon how to achieve multilayered structures in young nature-like woodland plantations. As a theoretical base for the study three different major knowledge culture have been studied that concerns the subject, ecology, forestry and landscape management/design. This three theoretical framework concludes that many natural processes strive in the opposite direction of multilayered structures in their youth.

Design comparison between HiperLAN/2 and IEEE802.11a services

This paper is a study and comparison between the two Wireless LAN (WLAN) standards HiperLAN/2 and IEEE 802.11a. WLANs are used instead or together with ordinary LANs to increase mobility in for example an office. HiperLAN/2 is an European standard developed by ETSI and the IEEEs standard is American. A WLAN-card consists roughly of a Medium Access Control (MAC), Physichal layer (PHY) and an antenna. The antenna is the same for the different standards.

Hårdgörning av Asp

Hårdgörning av trä syftar till att göra materialet hårdare. Detta går att åstadkomma genom komprimering, det komprimerade materialet tenderar dock att återgå mot sin ursprungsform då materialet utsätts för fukt om ingen låsning sker. Låsningen kan ske mekaniskt i en treskiktskonstruktion som motverkar träets fuktrörelser. Dessa skivor har dock visat sig vara instabila och tidigare försök har uppvisat deformationer i form av kupning. Denna undersökning syftar till att utreda förutsättningarna för att använda komprimerad asp samt att ta fram underlag för framtagning av en kommersiell produkt.Praktiska tester har genomförts för att studera hårdhet, återfjädring och densitet hos det komprimerade virket.

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