Sök:

Sökresultat:

2488 Uppsatser om Free surface flow - Sida 13 av 166

En flödesutjämnande driftstrategi för Uppsalas fjärrvärmesystem : En ändrad styrning av framtemperaturen

This thesis examines a possible control strategy to minimize flow fluctuations in Uppsala?s district heating system. High variations in flow rate may lead to complications caused by hydraulic constraints in the district heating system. These complications, such as inadequate pressure and temperature levels, increase the risk of heat delivery failures. It is therefore important to avoid such situations both for the producer and for the customers.Typically, the forward temperature is controlled by using a rough correlation with respect to the outdoor temperature.

Utvärdering av den biologiska reningen av processavloppsvattnet vid GE Healthcare i Uppsala

GE Healthcare operates in Uppsala (Sweden) and develops systems, equipments and medium to purify medical substances. Discussions with the local authority concerning planed far-reaching changes and upgrades of the biological process techniques for sewage management, aroused the question about revising the terms of permit for the activity. Therefore it seemed necessary to evaluate a newly installed biological process technique, which is the background of this thesis. The evaluated biological treatment process was built in 2003 and consists of a biological reactor filled with moving bed carriers with a high surface area for biological growth. At the time of the project the biological wastewater treatment plant consisted of a flow equalization facility and two following parallel biological processes; a biological reactor with moving bed carriers and a tower trickling filter.The aim of this thesis was to survey the function of the biological reactor with respect to the reduction of organic matter.

Yngre barns möte med matematik

Purpose: The purpose of the study is to find out what mathematical content primary school children encounter in their free options at school.Through observation, the study defines mathematical areas that primary school students encounter in their free options at school. We want the study to show the reader the mathematics that students continuously meet without associating it with regular mathematics as taught in school.A number of mathematical areas have been defined in the analysis of the observations. These areas have subsequently been discussed more thoroughly. Finally, the areas have been arranged in a grid system to clarify the results.In our study, we have discovered that mathematics exists in all the observed situations the students participated in.We believe that observation as a method can give teachers a tool for helping students associate practical actions during their free options with the more theoretical aspects of formal teaching of mathematics. We discuss this further in the study..

Effektivisering av produktionsgrupp : Improving the efficiency of a production group

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..

Pilot study: influence of the Samoan dog population on visitors

A range of public health and animal welfare problems has been shown to be associated with free-roaming dogs. With a high density of free-roaming dogs and with a major tourism industry, Samoan tourists are likely to be influenced by the presence of the dogs. The tourists are mainly from the Oceanic region; with New Zealand and Australia as the biggest contributors. The aim of this study was to examine the potential impacts of dogs on visitors to Samoa. A questionnaire was handed out to 281 visitors all over Samoa, collecting opinions and information on visitors? experiences and behaviour regarding the Samoan dogs.

Prefabricerade stödmurar i betong :

This is a booklet with information and inspiration about precast retaining walls. The three chapters contain information about concrete as a material, how the surface of the wall can be altered, and a chapter with ideas for a new precast wall. I have obtained information through books, interviews, lectures and fairs. The retaining walls on the market do not correspond to the requirements of the Landscape Architects I have interviewed. I have therefore considered their opinions in the chapter containing my new ideas for new retaining walls.

Simulering av översvämningar i Nedre Dalälven

Mosquitoes are found in extremely large numbers in the lower parts of the River Dalälven. In the year 2000 the mosquito nuisance was especially high, resulting in foundation of the Biological mosquito control project. Since 2001 mosquito larvae are controlled by using a biological pesticide BTI (Bacillus thuringiensis ssp israelensis). The mosquito fauna in the area is dominated by flood water mosquitoes, a group of mosquitoes that are very aggressive and form new generations of mosquitoes during every single flooding event during the summer. To be able to efficiently control the mosquitoes it is essential to know the extension and locality of the flooding.

Vårdpersonalens kunskaper om munvård och deras inställning till tandvårdens uppsökande verksamhet samt personalens uppfattning om hur den fungerar - en enkätstudie

The aim of this study was to examine nursing personnel?s knowledge about oral health care and attitudes towards the free assessment of the oral status done by the dental service for elderly and handicapped persons in a municipality in the south part of Skåne, and also how personnel experience the free assessment of the oral status done by the dental service and how it functioned at the facilities. The study was carried out by sending out 150 questionnaires to nursing personnel at six special housing facilities. 73% (110 personnel?s) answered the questionnaires.

Syntes och egenskapskarakterisering av volframoxid framställd med magnetronsputtring

The system tungsten-oxygen has potential of being suitable for decorative coatings since ceramic coatings are often hard and wear resistant, and since modulations in oxygen content or incorporation of small ions could give bright colours. The aim of this report was to investigate the relationship between process parameters and  the properties of the films, with the wear resistance being of special interest.Samples with tungsten to oxygen ratios in the range of 100:0 to 25:75 at% were made using reactive sputter deposition, either with constant gas flow, or gas flow controlled by optical emission of the plasma. The hysteresis of the system, which means that a certain gas flow will cause different pressure and/or target voltage depending on in what way the flow is reached, makes it interesting to control the process where the system makes the steep change from metallic tungsten to ceramic tungsten oxide. This is difficult and thus requires precise control equipment.The samples were analysed using X-ray diffraction, X-ray photoelectron spectroscopy and an empirical wear test suitable for small components like cell phone cover for example, in order to characterize the structure, composition and wear resistance of the coatings. The results could be divided into three groups: (I) tungsten-like, with very low oxygen content; (II) mixed phase and (III) tungsten oxide like, with oxygen content close to 75 at%.

Sammanvägda avrinningskoefficienter i rationella metoden : en jämförelse mellan idag och 1970-talet

Storm water is rain and melted snow that runs off, primarily from impervious surfaces.Future storm water management is facing the challenges of increased precipitation, asclimate changes, and increased areas of impervious surfaces due to the expansion anddensification of the cities. Impervious surfaces reduce the potential for water to infiltratein the ground leading to increased surface runoff and higher peak discharge.The runoff coefficient is closely related to the percentage of impervious surfaces andrepresents the maximum percentage of a catchment that can contribute to runoff. In thisstudy, the objective was to evaluate the weighted runoff coefficient for three differenturban types; apartment buildings, townhouses and residential areas and a comparisonbetween today and the 1970`s was made.The runoff coefficient was determined by manual mapping of the different surface typesin each area based on data in the form of orthophotos and aerial photographs. The surfacetypes that were mapped were asphalt, permeable areas, tiles, sand/gravel and roof.Tiles and sand/gravel were the most difficult surface types to map. In order to see towhat extent these categories influenced the weighted runoff coefficient a sensitivityanalysis was carried out and the runoff coefficient based on surface type was changed indifferent scenarios.The results of the sensitivity analysis showed that the surface types tiles and sand/gravelhad little impact on the weighted runoff coefficient which in mainly due to the fact thatthe percentage of these surfaces types of the total area is small.The result of the study showed that the largest change in the runoff coefficient occurredin residential areas where the increase in the percentage of impervious surfaces causedby new roofs in the form of porches and garages and from paved or tiled driveways.

I välgörande syfte : En explorativ studie av välgörenhetsorganisationers marknadsföringsstrategier i relation till donatorernas engagemang

According to Swedish tax legislation, investment funds are taxed differently depending on if the are Swedish or foreign. The difference between the investment funds lies within the taxation of received dividends and the opportunity to shift the liability of tax of received dividends on to the funds shareholders. This measure is only available to Swedish funds. The question in this thesis is whether this difference is discriminatory against foreign investors and therefore constitutes a forbidden restriction against the free movement of capital stated in article 63 EUF Treaty.The European Court of Justice (ECJ) has given several preliminary rulings on this type of legislation and its compatibility with the principle of free movement of capital. It is not compatible with the free movement according to the court.

Beteende hos lekvandrande lax i Klarälven ? utvärdering av en fiskfälla

During the migration season in 2013 a study on spawning migrating salmon and the effect of water flow on the behavior was conducted of the salmon at the Forshaga hydropower station in the River Klarälven. The River Klarälven with its nine hydropower plants on the Swedish side, constituting migration obstacles for the migrating salmon. Fortum Generation AB has together with the County Administrative Board restored a salmon trap at the lowermost hydropower station in Forshaga, aiming at making it possible for the salmon to swim into the trap, and thereafter be transported by truck past the power plants and then continue their journey to the spawning grounds on their own. Unfortunately, it is believed that the trap does not work as well as it should. In this study, I focused on salmon position in relation to water flow and if the number of salmon that swam into the fish trap differed between salmon with previous experience of the trap (experienced) and salmon without experience (unexperienced).

Modellerade och uppmätta kväveflöden i energiskog som bevattnas med avloppsvatten

The aim of this essay was to study the nitrogen flow in two willowplantations, at different locations in the south of Sweden, that wereirrigated with sewage. The study was also performed to compare thedifferences in nitrogen flows between two years, 1998 and 1999. The studywas made in three parts. First, the denitrification activity was measuredusing the acetylen inhibition method. Second the nitrogen flow, as well asthe water- and heat flows, were modeled through the SOIL-SOILN-modelThird; the nitrogen flow was calculated to compare with the results fromthe model.The results from the measurements were then compared with the resultsfrom the SOILN-simulations to detect differences in the denitrificationrate.

Analys av kundorderuppfyllelseprocessen på Pallco AB

This thesis has been performed as a part of the Bachelor degree in Industrial Engineering and Management at the School of Engineering in Jönköping. The thesis is written on behalf of Pallco AB, which is an engineering company that performs subcontracting, surface treatment, and assembly of components, mainly in steel and aluminium. The thesis focuses on identifying and analyzing the customer order fulfillment process of three customers at Pallco AB.The main objective of the thesis is to distinguish time differences in the company?s administrative work for each of the three customers. Furthermore, Lean thinking is following as a thread through the whole thesis.

Just In Time : Effektivisering av materialflöden med hjälp av principer från Inventory Management och Production Management

AbstractManagement is a field that started getting attention in the beginning of the 20th century by Frederick Taylor. His publication is called the Principles of Scientific Management and is based on the principles of using scientific methods to find the best way of conducting each operation within a production facility. Many of Taylor?s principles may appear obsolete today but the matter of an effective material flow is still highly current. Efficiency is the relationship between the input into an operation and its result.

<- Föregående sida 13 Nästa sida ->