Sök:

Sökresultat:

758 Uppsatser om Penetration calculations - Sida 12 av 51

Konstruktion av säkerhetslagerför svänghjul

This thesis is the result of the investigation and solution of a mechanicalproblem regarding flywheel malfunctions. A flywheel is, in short, a devicethat relies on a rotating object?s moment of inertia to store energy overshort time spans. This project is part of the development of a fourthflywheel prototype at the division for electricity at Uppsala university,which uses magnetic levitation to keep a hollow cylinder rotating at veryhigh speeds inside a vacuum chamber. Should the magnets fail however, orsome other error occur that leads to an uncontrolled state of rotation, thecylinder needs to be stabilized mechanically by a device usually referredto as ?back-up bearing?.

Abdominellt ultraljud av vuxna nötkreatur : en praktisk guide

Ultrasound is a diagnostic aid often overlooked by the veterinary practicioner who works with farm-animals. However, it?s use increases, particulary for breeders where ultrasound has long been used to evaluate ovaries and to diagnose pregnancy or disturbances in reproduction. There is much knowledge in how to examine ovaries and uterus by transrectal ultrasound, but when it comes to doing ultrasound of other organs in the abdomen the knowledge is more limited. Cows are very large animals, so it is not possible to examine everything inside the abdomen with ultrasound, simply because the ultrasound beam has a limited penetration. There is also lots of gas inside the gastro-intestinal tract of a cow, mainly in the large intestine and the rumen, and that makes it impossible to examine the organs behind the gas since the ultrasound waves are reflected when reaching the soft tissue-gas interface.

Förändring av radiocesiumtillståndet i jordbruksgrödor i Gävleborgs, Västmanlands och Uppsala län efter Tjernobylolyckan samt en fallstudie med stallbalansberäkningar på en mjölkgård :

Several radioactive nuclides were deposited in Sweden after the Chernobyl accident in 1986. The greatest attention was given to 137Cs because of its relative long physical half life of about 30 years. 137Cs will be present in nature for more than 100 years before it has vanished completely. When radiocaesium decays to a stable end product ionizing radiation is emitted, which can cause cancer in humans that has been exposed to a high radiation dose. Radiocaesium behaves like potassium and is easily taken up into biological systems.

PARS PRO TOTO? Tillgång till Internet som en del av tillgängligheten på sex folkbibliotek

Internet access has been a part of the range in public libraries for approximately a decade. The Swedish municipals, in charge of the public libraries, and the libraries themselves, have a great deal of saying in how they should be run, what to offer the public, how many hours they have to stay open etcetera. The Library law is very vague on many things, including public Internet access. Even though Sweden is ranked as first runner up worldwide when it comes to Internet penetration among the population (Internet World Stats 2007), approximately twenty percent in the 16-74 age group does not have Internet access at home, at work or at school (SCB 2006a). In this master thesis we try to determine, through personal interviews, how six of those in charge feel about Internet at their libraries, all located in medium-sized municipals (20 000 ? 40 000 inhabitants), why they have chosen the rules and regulations they have and their thoughts about what they consider to be the most important assignment of public libraries.

Effektivisering av en administrativ process

For a long time Lean has been a well-known concept among manufacturers. Theinterest of understanding Lean and the ability to implement it is common amongcompanies. The concept of Lean, used in the right way, can help companies to reducetheir lead times, their complexity and increase the efficiency of the working processes(Hyer och Wemmerlöv, 2002). Unfortunately the work towards increased efficiencyhas primarily been focused on manufacturing and plant work, resulting in that Leanhas been adjusted to these areas. The conclusion of this is that companies don´tprioritize to improve processes such as administrative ones.

Vindkraftsetablering i skog

This thesis assignment at C-level is focused on calculation models and prediction methodswhish can be used in the stage we call ?prospecting? of possible windmill locations. Thelocation is southeast of Halmstad at the Farm ?Stjernarpsgods?. The rapport has two mainareas directed towards this task.

Näringsbelastning på en anlagd våtmark från åker, skog och enskilda avlopp :

This work is a part of the project ?Våtmarker i odlingslandskapet ? uppföljning av miljömålen? (Wetlands in arable land ? following-up of the environmental goals). The main objective with this project is to study nitrogen and phosphorus retention in a constructed wetland by using mass balance calculations. Continuous measurements of nutrients and water flow through the inlet and the outlet of the wetland are made. However, substantial amounts of nitrogen and phosphorus were assumed to reach the wetland with a drain-pipe transporting wastewater from nearby houses (10 persons).

Inventering och klassificering av kvarlämnad virkesvolym vid slutavverkning :

This final thesis is performed on commission of Hargs Bruk Ltd. Hargs Bruk manages one of Sweden?s largest privately owned forests. A main part of the managed forest is situated in Roslagen in eastern Uppland. Since 1934 felling calculations have been performed within the estate every tenth year.

Elstart Motorsåg

As requested by the company Husqvarna AB, we have developed a prototype of an electrical start device to a chainsaw. This was done through the development of new details in Catia, which has been integrated with existing details. Electrical components have been purchased by HAB electronics. In parallel with the modeling calculations was done, which was the basis for determine dimensions and the choice of an electric motor and gears. Prototype 1 improved gradually and led to prototype number 2, which became the final result.

Solenergi : en lönsam investering för ett lantbruk?

A possible way to reduce pollution and slow down the process of global warming is to increase the usage of renewable energy sources. One of these renewable energy sources is solar power. With the aid of solar panels and solar cells the energy from the sun can be transformed into both heating and electricity. The requirement to use the sun in this fashion is a suitable surface, for example a big roof, an angle between 40-60 degrees and that the surface should be exposed to the south. Almost every farm meets these requirements.

LIP : en effektivitetsstudie

Lokala investeringsprogram was a subsidy program which supported environmental reforms during the years 1998 to 2002. The subsidies were given to Swedish municipalities. Most of the evaluations of the subsidised projects have now been completed and included in a database. The purpose with this thesis is to analyse whether the instrument has been effective with respect to carbon dioxide reductions and costs. These calculations have focused on subsidy and cost efficiency. The analysis has been compared with a previous report called "LIP ur ett samhällsekonomiskt perspektiv". The result shows that the reduction cost for one kg CO2 has been almost one SEK, which is twice as high as the cost reported in a previous report, half a SEK.

Beräkning av värmeenergiförluster i flerbostadshus genom analys av den totala fjärrvärmeenergianvändningen :

This thesis has been carried out on behalf of IV Produkt AB and intends to set an average ratio of thermal energy losses in apartment buildings that were built during the 1960-1990. This shall be derived by analyzing the total district energy consumption that has been divided into three parts: heat energy losses (the actual heating requirements), the heating of domestic hot water and heating energy consumption for the controlled ventilation.Three different residential areas that were built during the years 1962-1966 and one that was built in 1993 has been analyzed. All residential areas are located in Växjö urban and contains between four and six apartment buildings.The analyzed objects have a mechanical exhaust ventilation systems and district heating as the heating method. No own laboratory work or experiments have been done in this thesis, the calculations have been done on the basis of parameters from VEAB, interviews with property managers, and literature studies. By calculations, we have got a result that is reported in Chapter 6.

Produktivitetsanalys ur ett LEAN-perspektiv : En studie hos OPPC, AstraZeneca

The objective of this thesis is to map the resources and methods used at the department OPPC, at AstraZeneca, and derived from that give suggestions on possible solutions that will increase their productivity.Mapping of the product flow, as well as gathering of process data, has mainly been done using observations, but consultation with the process technicians has also played a great role. Further have theoretical methods been used, based on literature studies, within the areas of Lean production and statistics.The work has incrementally gone forward since the steps taken has been restricted by the irregularity of production which led to the need of creating a fictive production flow. This has affected the lead-time calculations in the way that they are meant to give an indication, rather than an absolute truth, on how different methods described shall be used.The current state analysis showed multiple areas of improvement when defining capacity as value adding time in relation to total throughput time. Using the "standard scenario" as a basis showed that the actual production flow only constituted 50% of the total project time. Further it showed that the workflow contained more non-value adding activities than value adding activities, which is a result of how the work is distributed within the department as well as in the different projects.

Tillförlitlighet i Stockholms elnät : En analys med hjälp av Tekla NIS

Outages in the electric grid can be costly for society. Because of this, reliability is one of the parameters used to regulate network companies. Reliability in electrical grids can be measured with SAIDI, system average interruption duration index, which for Fortum Distribution has increased in Stockholm?s distribution network (11 kV) in the early 2000?s.By using outage data for Stockholm from 2011-2013, sets of parameters to be used for reliability calculations in the network information program Tekla NIS were derived. Two different options for investment were then analysed: changing old cables with high fault frequencies, and installing automatic switching in distribution substations.

Inverkan av försvagningar på bärförmåga för stålbalkar med långa spännvidder : En jämförelse mellan Eurokod och BKR

The purpose of this thesis is to investigate the degree of influence of holes in the web of steel beams with long spanson weakening of their bearing capacity. Making holes in the web of the beam generally reduces the bearing capacity of the beam. However, it might be necessary seen from both an architectural perspective as well as from a building services perspective by creating an opportunity for building installations.The objective of this thesis is to examine how much an I-beam can be weakened without sacrificing safety and functionality. The investigation has been done by using Finite Element Method through commercial software.The regulation for structural design of building structures in Sweden used to be specified in the document known as BKR. But this was replaced by the European norm Eurocode back in May 2011.

<- Föregående sida 12 Nästa sida ->