
Sökresultat:
97 Uppsatser om Disturbances - Sida 3 av 7
En vindkraftparks inverkan på Gävle Energis elnät
The effects from a planned wind farm on the grid utility Gävle Energis electrical grid have been studied. The wind farm is planned to be built in the forest 15 km north of Gävle and will have 23 turbines with rated power from 2 to 2.5 MW, resulting in a total installed power between 46 MW and 57.5 MW. The grid connection will be made at 70 kV. The aim of the analysis was to determine what effects the wind farm would have on the power grid in the form of electrical Disturbances (flicker etc.), need for new investment and raised operational cost. To allow the connection of the wind farm technical solutions (new lines, power stations and grid reinforcements) have been constructed.
Kärnkraft : Ett arbete för drifttekniker?
The gas turbines in the Swedish secondary reserve are reaching the end of their technical lifetime, hence alternative solutions need to be considered. One of the solutions thought to have the greatest potential is the use of so called consumptionreduction. By entering contracts with large consumers, agreements are made to reduce consumption in the event of major Disturbances in the power system and thus being used as a secondary reserve. This thesis investigates the feasibility of consumption reduction as part of the secondary reserve. This has been achieved by developing a requirement specification for the disturbance reserve and by studying the technical and economic potential for consumption reduction among a range of consumers.The technical potential for consumption reduction that fulfils the requirements for participating in the secondary reserve are on average 750 MW in SE 3 and 98 MW in SE 4.
Utveckling av metod för utvärdering av synnervens funktion hos häst :
VEP, visual evoked potential is an electrophysiologic test that can be used for evaluating the higher visual pathways. The aim of this study was to investigate if it is possible to adapt this method to horses. This method could have a clinical use in addition to the existing diagnostic methods that are available to evaluate vision in horses.
Firstly, this study contains a summary of relevant studies done on animals and, secondly, an experimental part where the possibility of recording VEP in nonsedated and sedated horses is investigated and where to position the recording electrode to obtain the best results.
Our results show that it is possible to record VEP in horses in a clinical setting. VEP was best recorded in the sedated horse to avoid movement artifacts and other Disturbances.
Framtagning av förbättringsförslag för SNCR-system
The gas turbines in the Swedish secondary reserve are reaching the end of their technical lifetime, hence alternative solutions need to be considered. One of the solutions thought to have the greatest potential is the use of so called consumptionreduction. By entering contracts with large consumers, agreements are made to reduce consumption in the event of major Disturbances in the power system and thus being used as a secondary reserve. This thesis investigates the feasibility of consumption reduction as part of the secondary reserve. This has been achieved by developing a requirement specification for the disturbance reserve and by studying the technical and economic potential for consumption reduction among a range of consumers.The technical potential for consumption reduction that fulfils the requirements for participating in the secondary reserve are on average 750 MW in SE 3 and 98 MW in SE 4.
Öppen dagvattenhantering i urbana miljöer :
Storm water causes a number of problems in our country, particularly in city environment with its surfaces of non-absorbing ground materials. At heavy rain falls there are floods due to lack of capacity in the drain system when meeting heavy water masses over a short time. When the drain system is overloaded huge water masses reach the recipient untreated and there causing Disturbances in the aquatic ecosystem. Due to emissions from mainly traffic, industries and other human activities the storm water is polluted. Earlier the problem used to be solved technically, by increasing the capacity of the tubes and by construction of reservoirs to delay the floods peaks.
PSQS ? Power Supply Quality Simulator
Kitron had wishes to be able to test and measure how disturbance affects their vehicle electronic units before they have been verified by SP Technical Research Institute of Sweden in Borås. This work started with the writing of a demand specification together with Kitron for a product PSQS, Power Supply Quality Simulator, which can generate some test pulses according to a standard for electronic units to Volvos vehicles. A design proposal was developed with the help the demand specification and was verified with the help of simulations. All electric schematics was designed with the guide of the design proposal. The pulses realized in the works of this thesis are those which Kitron experienced that they have a need to test in their own premises and which are possible to generate with the means available.
Immunohistochemical study of hemoglobin-related proteins in endometrium from fertile and infertile women
In couples diagnosed with unexplained infertility, the woman has normal ovulatory cycles and no organic pathology, and the man has normal semen. The period during which the implantation of an embryo can occur is defined as the window of implantation (WOI). For infertile women, Disturbances in the endometrium maturation are hypothesized to impair the uterine receptivity for embryo implantaition. However, there are still no methods found to predict endometrial receptivity.Hemoglobin related-proteins hypothesized to be involved in embryo implantation have been found in the endometrium in both fertile and infertile women. The aim of this study was to determine whether there were differences in the expression of hemoglobin-related proteins, hemoglobin-?, cytoglobin, fetal hemoglobin and haptoglobin in the endometrium of fertile and infertile women.
Hur inverkar olika andel vallfoder i utfodringen på produktion, hälsa och beteende hos mjölkkor? :
Cows are ruminants and they need fibers in their feed and sufficient eating time to function psychologically and physiologically. Many of our cows don?t get enough forage and too much concentrates, which given in the wrong way may cause health and behavior problems. Too much concentrates at once makes the pH in the rumen sink and this may cause decreased fiber utilization since the microbes in the rumen are negatively affected by this. The cow may also get serious problems such as laminitis and abomasal dislocation.
Social media & marknadsföring
The gas turbines in the Swedish secondary reserve are reaching the end of their technical lifetime, hence alternative solutions need to be considered. One of the solutions thought to have the greatest potential is the use of so called consumptionreduction. By entering contracts with large consumers, agreements are made to reduce consumption in the event of major Disturbances in the power system and thus being used as a secondary reserve. This thesis investigates the feasibility of consumption reduction as part of the secondary reserve. This has been achieved by developing a requirement specification for the disturbance reserve and by studying the technical and economic potential for consumption reduction among a range of consumers.The technical potential for consumption reduction that fulfils the requirements for participating in the secondary reserve are on average 750 MW in SE 3 and 98 MW in SE 4.
Diagnos av stiktion i reglerventiler för prediktivt underhåll
This master thesis reviews advances in detection and diagnosis of static friction (stiction) in control valves. Control valves suffering from stiction results in oscillating control loops which in turn decreases both the process stability and reliability. Perstorp AB sees a necessity to automatically detect stiction in valves before the effects of the malfunctioning valves have become too severe. This thesis presents an introduction to maintenance, control loops and how stiction in valves can affect performance of control loops.A selection of methods presented in the literature are introduced and examined using normal operating data from the site in Perstorp. Common for all selected methods is their intuitive ideas and that they are based on normal operating data and minimum amount of process knowledge.
RCC-Jordfelsskydd, mätmodul för övertonsanalys
The majority of all power cuts that affects individuals and communities are caused by earth faults on the power transmission lines at 10kV and 20kV level [1]. If these power cuts could be eliminated, less Disturbances and interrupts would lead to large amounts of money savings.Swedish Neutral has developed such a protection system. When an earth fault occurs power is injected into the neutral point of the transformer. The RCC (Residual Current Compensation) protection calculates a compensation current exactly 180 degrees out of phase to the fault current. Doing this, the voltage at the fault location becomes very close to zero, without affecting the power transmission.The protection system can only compensate automatically for the fundamental frequency (50Hz), and manually for the 3rd, 5th, 7th and 9th harmonics.
Elevers inställning till matematik : - en jämförande studie av elevers uppfattning av matematikämnet och matematikundervisningen
Based on earlier experiences of mathematics and mathematical learning, both as a student and as a teacher, I became more and more interested in how well the publicly accepted opinions about mathematics as an uninteresting, difficult and ?geeky? subject corresponded to reality. What do Swedish pupils really think about mathematics and is it possible to identify any differences in their attitudes based on the pupils? age?From this point of view the following questions were formulated:·What are pupils? attitudes towards mathematics in grades 3, 6 and 9 and how do they conceive their learning conditions?·Is it possible to detect any differences in the attitudes and preferences depending on the pupils? age?The result of this study compares well with previous studies done in this and overlapping fields and indicates that:·Younger pupils tend to have a better liking of mathematics but with increasing age that interest fades out.·Most pupils, without regard to age, consider mathematics to be one of the most important subjects, despite the fact that many pupils also find mathematics difficult and boring.·For pupils of all ages, the teacher is the most important factor in the learning process. Older students have more specific demands on the teacher for knowledge and pedagogical skills.·A high noise level, talking and Disturbances in the classroom are the most bothering elements when it comes to learning mathematics.
Planeringsverktyg för ABB Capacitors : Planering av körsekvens
ABB Capacitors is looking to introduce LEAN within their organization. The purpose of this research is to suggest ways to improve the production planning in order to facilitate the company?s production processes. This should be done in accordance with the LEAN concept.Today, ABB will produce two of the customers? orders at the same time.
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.
Faktorer som stör patientens sömn under sjukhusvistelsen samt sjuksköterskans omvårdnadsåtgärder för att främja sömnen : En litteraturstudie
Background: Sleeping is a condition that is necessary for all people because the body isgiven time to recover. Studies have shown that patients found it difficult to sleep during thehospital stay and it turned out to be several factors that disturbed the sleep during the night.The nurse should note the patient?s need for sleep and take into account environmental andother sleep Disturbances to be able to implement nursing interventions. Purpose: The purposeof this study was to elucidate the factors that interfere with patient?s sleep duringhospitalization and nursing care to promote the patient?s ability to sleep.