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1524 Uppsatser om Sub surface flow wetlands - Sida 10 av 102

Mätning av abrasivflöde för vattenskärningsmaskiner

The content of the following report is the summarized result of three students thesis at Blekinge Institute of Technology in co-operation with Water Jet Sweden AB. This report will give the reader a description of principles how to measure the abrasive mass flow in a waterjet cutting system. The work began with a visit to Water Jet Sweden AB to get a closer look at the problem. When the analysis of the problem was done the criteria were defined in the form of demands and desires. The main task of the criteria was to guide the search for the solution.

Höghastighetståg - Är det framtiden?

AbstractConsider a ?uid being heated from below. The heating leads to an upward convectiveforce that is counteracted by the viscous forces of the ?uid. If the convectiveforce is large enough in comparison to the viscous forces the ?uid will be put in anunstable state.

Undersökning av bindningsmekanismer vid pressning av metallaminat : Investigation of bondning mechanisms at the pressing of metal laminates

Increased understanding of the mechanisms that operate in conjunction with the welding of metal surfaces may help to improve existing manufacturing processes, and to enable new products and combinations of materials. The purpose of the project has therefore been to acquire a deeper understanding of what is happening in the bond for steel and for the factors that form the basis for a bond to develop between metals in the production of laminates by pressing. The merge has been done by pressing and the surfaces after the experiments have been studied in detail in the scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDX) and with interferenceprofilometry in Wyko, to provide a greater understanding of the mechanisms that influence the bonding in the interface between metals. The project was limited to contain the materials Docol 1000, HyTens 1200, Aluminum AA3003 and a commercial steel. The parameters varied in the experiments to study their influence closer are temperature, pressure, heat treatment and pretreatment. This has been implemented by pressing with varying temperature and pressure.

Rayleigh-Bénard konvektion.

AbstractConsider a ?uid being heated from below. The heating leads to an upward convectiveforce that is counteracted by the viscous forces of the ?uid. If the convectiveforce is large enough in comparison to the viscous forces the ?uid will be put in anunstable state.

CFD simulering av kallras : Undersökning av temperatur- och luftbeteende intill höga glasfasader och i vistelsezon med golvvärme som en värmekälla

Glass has sophisticated front properties and are used as facades in high buildings. During cold periods, these glass facades could cause thermal discomfort, due to cold downdraught. Cold downdraught can be countered by placing heaters under glass surfaces. Nowadays technology offers highly insulating windows, which is why there is an interest to investigate the indoor climate with only underfloor heating. The research in this area is limited, and few empirical methods are available.

Brunnsviken : Utvärdering av åtgärder för förbättrad vattenkvalitet

Periods of hypoxia are a recurring issue in Brunnsviken. Main factors that trigger hypoxia in Brunnsviken are eutrophication  due to anthropogenic emission of nutrients, stratification in the water column due to salinity and temperature differences  that prevents mixing and a sill inlet that prevents water exchange. As an attempt to improve the oxygen levels, bottom water is pumped from Brunnsviken causing aerated surface water to flow back into the basin.  The objective of this Master?s thesis was to study the change in dissolved oxygen levels due to pumping.

Elevers förståelse av fotosyntesen och dess koppling till andra organismer

The effects of the deregulation of the electricity market 1996 in Sweden on short-term hydropower regulation are unknown. This report investigates patterns in subdaily regulation in the Ångerman River Basin during the period 1993-2011. Differences in subdaily flows and zero flow events between the periods 1993-1995 and 1996-2011 were studied by analyzing hourly data from 8 regulated and 8 unregulated locations with four subdaily flow variation indices. No correlations between the market deregulation and the regulation intensity in the Ångerman River basin were detected. The number of days natural ranges of variability were exceeded and the magnitude of subdaily variation were significantly higher at regulated locations.

Modellering av ett bränslesystem i Modelica : tillämpat på ett obemannat flygplan

Mathematical models possible to simulate are of great importance in order to make successful projects in the aircraft manufacturing industry. An aircraft fuel system is very complex, containing pipes, tanks, orifices, valves and pumps. The principal of this thesis is using the tool Easy5, which no longer is considered reliable enough in terms of development and support. This thesis tries to evaluate the Modelica language as a possible alternative to Easy5. To make this evaluation, the components concerned in the fuel library in Easy5 are implemented to the Modelica language.

Kvantifiering av föroreningstillskott från dagvatten inom skyddsområdet för Göta Älv : en simuleringsstudie med modellen SEWSYS

The river Göta Älv reaches between Vänern and Gothenburg and is the main raw water source for Gothenburg that supplies about 700 000 people with water. To protect and maintain a high water quality, continuously samples and water analyses are made throughout the river. In 1998 a protection area was founded between surte and Lärjeholm where the raw water intake is. This was made to increase the awareness of the importance to protect the water. However, there is a lot of contribution of untreated stormwater to Göta Älv within the protection area.Göteborg Water and Sewage Works commissioned this thesis where two areas, Tagene industrial area and Kärra residential area, with untreated stormwater outlets within the protection area are studied.

Opera i Stockholm : Stadsgårdskajen

The report is about efficiency of a current production group where there is no clear production flow and there are some buffers between the operations. The efficiency is done with the help of a tool that is calledWork process of flow production which is used by Atlas Copco CTO. The most obviously results are that the lead time drops from 25 hours to 425 minutes and that the balancing loss decreases from 85 % to 8 %. The report focus on decreasing transports, decreasing buffers, more reliability in lead time and quality. And a more stimulating labour content for the workers is another result..

Mätning av abrasivflöde för vattenskärningsmaskiner

The content of the following report is the summarized result of three students thesis at Blekinge Institute of Technology in co-operation with Water Jet Sweden AB. This report will give the reader a description of principles how to measure the abrasive mass flow in a waterjet cutting system. The work began with a visit to Water Jet Sweden AB to get a closer look at the problem. When the analysis of the problem was done the criteria were defined in the form of demands and desires. The main task of the criteria was to guide the search for the solution. The work proceeded with an extensive search for abrasive flow meters along with obtaining information about flow measurement in general. When the search for abrasive flow meters resulted in nothing all the efforts were concentrated on finding a principle of measurement that could cope with the criteria.

Information ochmaterialflödesförbättrings analys

This examination work is performed at the institution of industrial economy and production at Jonkoping technical university, for JELD-WEN Door Solutions plant in Forserum.Today the focus in the company is on to reduce their inventories binding of capitals as well as inventory of products and that includes to get a good control of the supply and handling of material which is of great importance.JELD-WEN Door Solutions is one of the worlds leading producers of windows and doors and the head-office is located in Oregon, USA.A great number of wooden doors are manufactured by the company in varying of constructions, classifications and performance.The production of the plant in Forserum has a project- and customer focus manufacturing where only internal doors are produced. The overall market they are concentrated on is to different institution such as schools, hospitals etc.The purpose of this work is to investigate possibilities to improvement of material- and production control at JELD-WEN. The report will handle the master production schedule to and from the production divisions within manufacturing industry. Focus will be on the way for information- and material flows from arrival, transport within the company and further on to customers.Further a map of the flow was performed which gave a clearer picture of the connection between the flow of information- and material for the manufacturing process. On the basis of the mapping of the flow, the group discovered that the flow of material had some improvement potential.

Översvämningsrisker längs Funboån

Flooding events are no longer rare, floods occur all over the world. Accordingly, it is vital for the society and different authorities to work with flood mapping. To meet the goal of Uppsala kommun to map the risks of floods in Uppsala län, a map of the different areas around Funboån which are inside the area of risk for flooding have been developed.In the work, cross sections and the water flow have been measured. Moreover, an echo-sounding have been carried out in Funboån to map the bottom topography. From the bottom map and laser scanned data covering the study area, a terrain model was created.

Beräkning av massbalanser för metaller i vatten samt miljöriskbedömning av Nerån vid Österbyverken i Östhammars kommun

Österbyverken is an industrial estate in Östhammars municipality in Uppland, Sweden. Many different activities have taken place on the estate the last 600 years. During the last 15 years both health and environmental studies have been made by different companies. At the most recent study a great increase of metals in Nerån, a river that runs partly through and partly next to the estate, was identified with mass balances. The purpose of this thesis is to accomplish a deepened study about the reasons for the increase of metals in Nerån.

Avgränsning av tillrinningsområden till grundvattenmagasin : vilken information ger berggrundens överyta?

Delineation of recharge areas for aquifers is performed in the groundwater mapping process at the Swedish geological survey, SGU. This work is time consuming and performed manually. It is therefore desirable to develop a more general and repeatable method for defining recharge areas for aquifers.The purpose of this study was to investigate two other possible methods to delineate recharge areas for aquifers. The first method was to examine the possibility of using the topography of the bedrock to define the recharge areas for aquifers. To enable this, a method for generating the topography of the bedrock was developed.

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