Sökresultat:
355 Uppsatser om Discharge limits - Sida 3 av 24
Alternativ till fortsatt elektrisk generering i Olidan
In this thesis a possible cost effective runner change of some of the units in the hydroelectric power station Olidan is investigated. The possibility to drive a unit at the same efficiency point through a change of the turbine shaft speed and the rate of discharge is tested. Furthermore the theories behind model testing, determination of efficiency increase from model to prototype and efficiency measurements shall be discussed and analyzed with Olidan as a starting point.A predicted curve has been built on information from model tests and field measurements on the existing runners and runner data from the test of the new model. The predicted curve shows the difference in efficiency between an existing runner and a modern one. It is the difference in efficiency that is used in the calculations that are to show whether changing to a pair of new runners will be cost effective or not.
Strategi för utvecklande av reglerbudata
This Master Thesis discusses the development of bids for regulation power with consideration of change of discharge. The study was initiated by Vattenfall PD and is a limited part of a substantial development project at the same division. The background of the project is the new demands from SvK, which among other things includes more detailed regulation bids. As from the 1st of November 2008, the regulation bids are supposed to be calculated regarding each specific regulation object, something that is defined by SvK. These new demands changes Vattenfall?s conditions and will increase the need for detailed knowledge about available regulation power and costs for regulation.In this study a strategy for regulation bids was developed.
Elementkoncentrationer i gran utmed en markfuktighetsgradient :
One key factor in silviculture today is sustainability. In order to achieve sustainability it may be important to restore lost nutrients to the forest after clearcutting. In order to calculate the removal, you need to know how much of different elements you will find in different tree compartments. The aim of this study was to investigate if the concentration of elements in different tree compartments of spruce (Picea abies (L.) Karst) were related to the moisture conditions of the site. Five plots at Risfallet (60º 21´ N, 16º 13´ E), was placed along a moisture gradient in a 40- year spruce stand.
HAVS ombord - en studie av hand- och armvibrationssyndrom och dess förebyggande åtgärder
On board ships different type of maintenance activities take place. Some of those require working with vibrating handheld tools. Traditionally there is a high awareness of the risks with different type of duties such as protecting the skin from oil or other chemicals, the eyes from splashes and hearing from high noise levels. The experience we have from our time as on-board cadets are that there is less information about vibration hazards available compared to the information concerning other hazards on board.There are threshold values that workers, by law, are not allowed to exceed when working with handheld vibrating tools. The purpose of this study is to investigate how common the use of this type of equipment that can cause damage by vibrations, to the hands and arm amongst the deck crew, and if the crew informed about the risks involved.
Geografiska informationssystem för studier av polyaromatiska kolväten (PAH) : undersökning av djupvariation i BO01-området, Västra hamnen, Malmö, samt utveckling av en matematisk formel för beräkning av PAH-koncentrationer från ett kontinuerligt utsläpp
At the end of August 1999, the local government council of Malmö city decided thatthe area known as Kvarteret Bilen would be made available for the European HousingExhibition 2001 (Bo01-mässan). Kvarteret Bilen extends over approximately 80hectars and includes the western parts of the Western Harbour area (Västra hamnen)of Malmö.Kvarteret Bilen as a whole, but especially the western sections of this area, the socalledBo01 section, has been the subject of heated discussions. This is mainly due tothe fact that the ground in question has proven to be contaminated to a certain extentby different chemical compounds. Investigations undertaken during 1998 showed sporadically high concentrations forespecially one chemical group: polycyclic aromatic hydrocarbons (PAH).The first part of the paper describes the use of a mathematical equation (Fetter 1994)to calculate the concentration of PAH from a continuous discharge at a given time byemploying Geographical Information System (GIS). Even the constraints of theequation are discussed, as well as the consequences that follow as a result of usingGIS.The second part of the paper focuses on the connections between the content ofcarcinogenic PAH in Kvarteret Bilen and the ground water level and type of fillingmaterial.
Följdeffekter av olika användningssätt för vedråvara : en ekonomisk studie
Since the turn of the millennium a sharp increase in the interest for bio energy has been observed. Important reasons for this growing interest can be due to the fact that fossil fuels are a finite resource. A net discharge of greenhouse gases occur when fossil fuels are burned. The discharge of greenhouse gases are considered to be the main reason to the greenhouse effect. Means of control to increase the use of bio energy has been introduced and, as intended, the use of bio energy has increased.
As a result of the legal provisions the ability to pay for bio energy has increased, which the forest industry view as a problem.
I domen rekonstrueras verkligheten : en dokumentanalys om hur genus reproduceras och upprätthålls i LVU-mål
Title: "In the verdict, reality is reconstructed" - a documentary study of how sex is reproduced in verdicts of LVU-cases.The aim in our study is to see how existing circumstances revolving power between the gender, are contained in court, through language and differences in the sentences and expressions that are used in the verdicts. In this study we have reviewed verdicts about young people who are taken in to custody care by Lag (1990:52) med särskilda bestämmelser om vård av unga.We have reviewed verdicts from the county administrative court in Kalmar, from January in 2007 to October in 2008. Through the analysis we have taken into considerations and worked with earlier research and litterateur containing different theoretical approaches to feminism.The result of the study shows, that despite of a neutral law, girls and boys, women and men are judged and treated different, because of their sex. Depending on your sex, you are expected to behave according to norms and values. These norms and values are not the same for girls and boys.
Dagvattnets föroreningar som potentiellt hot för en god ekologisk och kemisk status i ytvattnet : En kartläggning av Vallentuna tätorts dagvattenhantering utifrån dess tillsynsbehov
The EU's Water Framework Directive aims to a long-term and sustainable use of our water resources and wants to ensure good water quality in Europe's water bodies. Discharge of polluted stormwater into receiving waters can be a threat to their ecological and chemical status. Municipalities are responsible for supervision of the environmental quality standards (EQS) and therefore need to gain knowledge of current stormwater management, the expected level of pollution emissions and possible appropriate purification steps to ensure that the goal of good water quality is achieved.This master thesis aims to provide this knowledge in the example case of Vallentunas urban area and wants to prepare future oversight so that it can be assessed how much the discharge of polluted stormwater into the local receiving water is a threat to its status. With the help of maps, aerial photographs, site observations and individual discussions those areas are mapped where appearance of moderate to highly polluted stormwater could be suspected. The degree of pollution at the discharge points is determined based on land use upstream and uses standard values according to the administrators assistance "Tillsyn av dagvatten" (MSL 2014).The study identifies 100 areas in need of supervision regarding their stormwater management.
Optimering av ett småskaligtvattenkraftsystem
This master thesis covers the seasonal planning of a small scale hydropower system. The system in this study is owned and operated by Mälarenergi Vattenkraft AB. The total system consists of 4 different main rivers with 24 hydropower stations and several dams. The total installed power in the system is 43.75 MW. Most of the hydropower stations are regarded as small scale hydropower stations and thus entitled to green certificates.In this report the issue of planning is formulated as an optimization problem.
Mikrosimulering för analys av Mästergatans förlängning i Enköping
Two of the main approach roads into the city of Enköping are Salavägen and Stockholmsvägen. They are connected to each other through the street Bangårdsgatan in the roundabout Salatullen and crossing Fannakorset, respectively. These crossings are from time to time heavily loaded, which is why the municipality plan for a new street in parallel to Bangårdsgatan. The traffic will then be spread out and is thereby reducing the density. The new street is actually an extension of the existing Mästergatan, a side street to Salavägen, to the east and connecting it to Stockholmsvägen or a street nearby.The purpose of this Master thesis is to show how the new street can be drawn in order to discharge the traffic in the area between the roundabout Salatullen and the crossing Fannakorset.
Vibrationsdämpning av värmepump
Thermia Värme AB is one of the market leading manufactures of heat pumps. In order tomaintain this position, the company wants to improve the vibration characteristics of theirproducts. The aim of this thesis is to develop product design changes that lead to a reductionof vibrations in the heat pump Thermia Diplomat 8.The main cause for vibrations in the system is flow pulsation and mechanical forces inducedby the scroll compressor. Vibration is transmitted through the compressor piping and receivedby the heat exchangers, from where it is further transmitted to the connection points for theradiator and heat source circuits.A number of design changes in order to improve the vibration characteristics have beenevaluated through calculations and practical experiments. The changes have included thecompressor and heat exchanger mountings, the compressor suction and discharge line pipingand also pulsation dampening.The results of the experiments show that the vibration levels in the connections for the heatingand brine circuits can be decreased strikingly through changes in suction and discharge linepiping.
Association between animal-based measures and register-based welfare indicators in dairy cows : a study of the advisory service "Ask the Cow" and the web report "Animal Welfare Signals"
Animal welfare can be measured in several different ways; for example by using animal-based measurements. It has been shown that register data from the Swedish Official Milk Recording Scheme can be helpful when identifying herds at risk of having poor animal welfare, which led to a development of the advisory service of ?Ask the Cow? and the web report ?Animal Welfare Signals?. The aim of this project was to find out if register data from ?Animal Welfare Signals? can be used as a screening tool for detecting herds at risk of having poor animal welfare and in need of an ?Ask the Cow?.
Dämplindningens inverkan på spänningens kurvform i en vattenkraftsgenerator
Harmonics are a well-known problem that has to be dealt with in the design of thegenerator. Internationally accepted standards limits the amount of harmonics allowedin the no-load voltage. These limits can be difficult to fulfill with integral slot winding,where the number of slots per pole and phase is an integer. The presence of thedamper winding often makes the problem with harmonics even worse and harmonicswith frequencies of order 6q±1 arise with significant amplitude. How the damperwinding is designed affect the content of harmonics in the no-load voltage and the aimwith these ? has been to investigate in which extent design of the damper windingaffects the contents of harmonics.Simulations with the 2-D finite element method have showed that if the damper barsis centered in the pole shoe, the amplitude of the harmonics of order 6q±1dependsboth on the ratio between the stator slot pitch and damper bars slot pitch and if thedamper bars are connected between the poles or not.If the damper bars is displaced with ¼ stator slot pitch alternately, the amplitude ofthe harmonics of order 6q±1 is reduced and the influence of the ratio between thestator slot pitch and the damper bars slot pitch will vanish.
Upplevelser av stroke. En litteraturstudie om patienters och anhörigas upplevelser av följder, rehabilitering och hemgång.
Stroke is one of the most common disabiliting diseases. A greater knowledge of the personal experiences after a stroke could improve the rehabilitation and the relations during the rehabilitation. The purpose with this literature review was to describe how strokepatients and their relatives experienced the consequences, rehabilitation and discharge after a stroke. This study is based on nine scientific articles and the results points out that patients and their relatives experiences can be positively influenced by participation and information..
Sensory nerve conduction studies in young adults for the expansion of a reference material
Neurography is the most objective and reliable measure of the peripheral nerve function, and it is used to diagnose both local and generalized neuropathies. Neurography can measure both motor and sensory nerve functions. The principle for sensory neurgraphy is to stimulate over the nerve and record proximal or distal from the stimulated electrode.At the Department of Clinical Neurophysiology, University Hospital Uppsala, a problem has been identified, in that young adult patients tend to show unexpected abnormal neurography values in relation to the expected, indicated by the reference limits, without clinical correlates. This concerns foremost the sensory amplitudes in median and ulnar nerves. The hypothesis is that the requirement of young adults? amplitudes is too high.