Sökresultat:
307 Uppsatser om Nuclear magnetic resonance - Sida 10 av 21
Val av överlastskydd för elektriska ventilmanöverdon på kärnkraftverket i Forsmark
At nuclear power plants, electrical valve actuators are important for ensuring that the reactor core is water covered and the pressure in the reactor tank and containment is limited. The electrical actuators are provided with overload protection in case of drawing higher current then the motors are rated for. When safety manoeuvres are needed, the overload protection must not trig and cause the valve to stop before completing the manoeuvre. Analyses have showed that the current settings of the overload protection may cause an illegitimate trig at the worst theoretically possible accident. A new method has been developed with conservative assumptions and applies overload protections for all electrical valve actuators at the three reactors in Forsmark..
Hur påverkar byggnadsmaterial av stål en induktiv hörslingas fältstyrka samt frekvensgång?
This research analyzed differences in measurements of magnetic field strength and frequency response in five audio induction loops installed in rooms of wooden construction materials and five audio inductive loops installed in rooms of steel reinforced concrete constructions. The inductive loops were installed at floor level and the measurements were made at the listening height of 1.2m. Measurements of background noise, field strength and frequency response were made at fifteen different measurement points across the room. The research measurements showed that there are differences in field strength and frequency response between these two conditions, whether the audio induction loop is installed in a wooden construction or the audio induction loop is installed in a reinforced concrete construction. The results had a significance level of p=0,05..
Spelarens påverkan på spelet : En studie i upplevd Agency inom dataspel
Detta arbete har som syfte att studera upplevd Agency. I bakgrunden för arbetet presenteras tidigare studier kring Agency och val i spel. Dessa används sedan för att ta fram tre designprinciper: Tydlighet, motivation och variation. Arbetets frågeställning gick ut på att se om dessa principer i praktiken ökade Agency och vilken princip som var effektivast.För att besvara frågeställningen till arbetet skapades sex stycken banor till spelet Magnetic. Tre följde de ovan nämnda designprinciperna och tre bröt emot dessa.
AUTOMATISK PAN/TILT-KONTROLLER FÖR ANTENNINRIKTNING
This report describes the design and construction of a prototype that automatically aims a microwave link towards a target. The link, that is located on a mobile aerial mast, is used by Saab Training Systems as a part of an infrastructure network. The report also discusses the development of a GUI that communicates with the control unit by Bluetooth.The control unit, called Pan/Tilt-controller, controls the position of the link by stepping motors. One motor controls the azimuth angle and the other one controls the elevation angle.By a GUI the operator enters the coordinates on its own position and the targets position. Hereafter a bearing is calculated and it will be sent up to the control unit.The control unit will sense its own direction by a magnetic sensor that works as an electronic compass.
Effekten av ett probiotikum i en besättning med hög incidens spädgrisdiarré
Magnetic resonance imaging (MRI) has the potential to be used for the diagnosis and study of osteoarthrosis in the equine tarsal region. In the development of new diagnostic MRI techniques cadaver specimens are often used. To allow the use of cadaver legs for these types of studies it is important to know the effect of time after death on the MRI image. Since the relaxation times are temperature dependent, it is interesting to examine whether the time after death and the temperature of the cadaver may play a role in the image appearance and quality. The radio pulse sequences that show the different types of tissues are also important to know when pathological evaluation with MRI is used.
En jämförelse av stickprovsmetoder vid mätning av radioaktivetet på en yta
This study compares the sample variance of the mean in a simple random sample (SRS) and a systematic sample from a surface. The study also compares the prediction error variance in a SRS and systematic sample from a random field. Recommendations are presented on which method to use in the clearance and exemption process in the nuclear industry. The results indicate that quadratic systematic sampling outperformed SRS in most instances and proved to be especially efficient in the presence of a long-ranged covariance function and high sampling intensity (i.e. short distances between observations).
?Förhoppningsvis är man två? : En studie över hur 18-åringar i en mindre stad i Sverige resonerar kring kön, kropp och sexualitet
The essay is about how teenagers around 18 years of age in a small town in Sweden talk about gender, body and sexuality. The study is based on two focus group interviews with five boys and four girls. We have then thematized and analyzed the material with queer theory.The results show how young people see heterosexuality as something 'natural' and gender as biologically determined. The teenagers are critical towards anything that deviates from the traditional nuclear family consisting of mother, father and children. Norms are created in their speech as some of them acts as so called "border guards" for these norms.
En simuleringsmiljö för distribuerad navigering
This master thesis studies distributed navigation which isa function implemented in a future network based combat information system to improve the accuracy in navigation for combat vehicles in a mechanized battalion, above all in the event of loss of GPS. In the event of loss of the GPS the vehicles obtain dead reckoning performance through the backup system that consists of an odometer and a magnetic compass. Dead reckoning means a drift in the position that makes the accuracy in the navigation worse. The distributed navigation function uses position and navigation data with measurements between the vehicles to estimate the errors and uncertainties in positions, which are used to improve the accuracy in position for the vehicles. To investigate and demonstrate distributed navigation, a simulation environment has been produced in Matlab.
Rolf Edberg : En studie av ett miljöfilosofiskt författarskap
In this essay I have tried to present the ideas and thoughts of the Swedish author Rolf Edberg (1912-1997), journalist, ambassador and county governor. By many regarded as an environment philosopher and the introducer of deep ecology into Sweden. The essay emphasizes Edberg as a modern renaissance man of important knowledge with a rhetorical force to present and generalize the problems the planet Earth is meeting. The paper compares him with Henry Thoreau but also finds a close but perhaps unintended relationship with the German philosopher Ernst Haeckel although Edberg himself claimed to be a Darwinist at heart.The essay stresses on four characteristic features in his authorship namely 1) a holistic view of nature and man, rejecting dualism for monism; 2) a cosmic relationship within the whole universe and also between organic and inorganic matter; 3) the planet Earth is in a crisis due to an uneven and unjust distribution of the resources of the Earth, the nuclear weapon threat and the overpopulation; 4) the evolution and not the religion has the answer to our existential questions..
EAS-tagg med fuktsensor : Design och utvärdering av EAS-alarmteknologi för fuktdetektering
Electronic article surveillance (EAS) is widely used in shops and libraries together with an RF-tag attached to the goods or books in order to prevent shoplifting. By implementing the addition of a moisture sensor to the RF-tag, other functions become possible, including the ability to use as an alarm with regards to frozen goods, which have been shipped but which have melted and have, subsequently, refrozen. In- relation to care for the elderly, one time-consuming step involves checking whether there is the necessity for a change of diaper and this can, instead, be based on an RF-tag with an EAS-system alarm. A preliminary investigation was made using the moisture sensors, which involved how the resistance changes when liquid and/or heat is applied. A simulation of the LCCR circuit (RF-tag with the sensor) was conducted in order to determine how the resonance frequency changes for different resistances levels.
Livet efter sfi : Vilka tankar har några sfi-elever om sin delaktighet i det nya landet och hur har de lyckats med att förverkliga uppsatta mål?
Boplatsvallar, often translated as semi-subterranean settlements, is an ancient monument with a diffuse definition. Defined as ?embankments that partially or completely surround a often lowered/dug down surface- this category of ancient monuments is also made up of a former category which traditionally was interpreted as winter settlements from the late Stone age in Sweden. This view of the ancient monuments carried over, to a certain extent, to this new definition. Should this be the case, that this category of ancient monuments are remains of winter settlements, used recurringly over an extended period of time, then they should exhibit similar signals in regards to the distribution of the anthropogenically altered soil chemical and soil physical properties at the sites.The area around Lillsjön, Anundsjö parish in Ångermanland, have four boplatsvallar located separately in the regional area.
Visualiseringsverktyg för Sykedjor
This thesis has been done in order to ease the process of drawing schematics ofelectrical wiring. The need arose after demand from the government due to a seriesof incidents that took place during the revision of the nuclear power plant in year2009.The task of the project has been to create a computer program that can generate agraphical representation of the electrical components relations. The basis for theprogram has been an example of how the client wants the graphical representation tolook. During the course of the project weekly meetings have occured in which theclient has reviewed the work.The result of the project is a program written in Visual Basic Applications that can berun in Microsoft Excel. The program is capable of generating graphics for a majority ofthe cases.
FRAM i främmande farvatten : En funktionell resonans analys på högfartsnavigering i maritim miljö
This is a study that was conducted during a three day exercise of the Swedish Armed Forces called ?Amfibieförbandet?, which is shortened as AMF, in Gothenburg. During the exercise three scientists followed the crew on the boats and this is one of the studies that became the result of the observation made during the exercise. The boats that was used during the three days were the boat called ?Stridsbåt 90H? by the Swedish armed forces.
Att arbeta med ständig osäkerhet : En studie av High Reliability Organization
There are certain organizations that manage to handle risk in such a successful way that they almost stay error-free, in spite of the fact that they daily face the risks of accidents. These organizations are usually given the name High Reliability Organizations (HRO). While the most common example is that of a nuclear plant the variety of what organizations can fit into the category is extensive.The purpose of this study is to describe safety culture and theories about HRO and how these can be found in practise within an organization.This qualitative research uses influences of ethnography in its method. The ethnographical approach was picked due to the field of the study and the cultural context in which it is set.The results of the study identify a number of elements sorted into four themes. These themes are deemed compatible or non-compatible with relevant existing theories.
OCT (Optical Coherense Tomography): Teknik och tillämpning
Före år 1895 kunde läkarna endast ställa en sannolik diagnos utifrån vad patienten kunde berätta och om det syntes någon förändring på utsidan av kroppen. Med röntgen blev det möjligt att se insidan av patienten utan att först skära upp densamma, man kan säga att säga att röntgen blev startskottet för diagnostisk avbildning.Vidareutvecklingen av röntgen gav CT (Computed Tomography) där röntgenrör och detektorer roterar runt patienten samtidigt som patientbordet förflyttas. Förutom CT utvecklades även MRI (Magnetic Resonance Imaging), PET (Positron Emission Tomography) och Ultraljud. Gemensamt för alla dessa olika metoder är att det produceras 3D-bilder.1990 kom en helt ny metod för diagnostisk avbildning, OCT (Optical Coherence Tomography), genom att mäta fasförskjutningen och intensitet av reflekterande ljus, ger det i realtid och oförstörande mätning (in vivo) en upplösning på 1 till 15 µm, mycket högre än alla andra vanliga bildåtergivningstekniker. OCT-maskinen kan jämföras med ultraljud, som använder reflektion av ljudvågor för tolkning [1].De första OCT-maskinerna var av typ TD (Time Domain), dessa hade låg upplösning och låg skanningshastighet.