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1685 Uppsatser om Frequency distribution - Sida 26 av 113

Genus och vetenskaplig kommunikation: en bibliometrisk studie av amerikansk biblioteksforskning

The purpose of this paper is to examine how the relationship between the socially constructed genders is manifested in American library science. To visualize gender, bibliometric analyses of peer reviewed articles published in three core journals of library science between 1980 and 2000 inclusive, are performed. The three journals are: College and Research Libraries, Journal of Academic Librarianship and Library Quarterly. Questions: 1. Does gender affect the publishing process regarding the distribution of female and male authors? 2.

Kartläggning av spånprodukter vid Sävar såg

A change towards using more biofuels than fossil fuels is taking place in Sweden, and in many other parts of the world. This makes the use of fuel pellets increasingly popular, causing a greater demand for sawmill sawdust products. There is a trend towards the use of multiple types of shredders, instead of a single type in each sawmill. The purpose of the study was to characterize the different flows of saw particles that can be found at Sävar såg when cutting thick or thin wood with different cutting techniques. The saw particles size, shape, moisture content and heat value were analysed by the cutting stations: first cutting fast and slow, second cutting fast and slow, grading fast and slow and planning.

Statistisk kartläggning av dimma längs E4:an mellan Helsingborg och Jönköping

Fog is a small-scale weather phenomenon that are fascinating to people. However, the presence of fog in road traffic reduces the visibility and increases the risk of road accidents. By the Swedish Road Weather Information System (VViS), the safety on roads could ameliorate and road accidents caused by fog and other weather hazards could be prevented. Fog is however a complex and usually local phenomenon, why fog formation generally is not easy to predict. For that reason, a statistical mapping of fog, especially along a motorway with high traffic volumes, could be useful in planning to prevent road accidents.

Mikroproducenternas påverkan på Elinorr

The Swedish energy system will be influenced by many future changes, such as energy and climate policy objectives. The installation of more renewable electricity could increase by using solar energy. Over the recent years, grid-connected photovoltaic (PV) systems have increased dramatically in Sweden, partly due to various support systems and compensation models. These support systems have been designed to make it easy for individuals and businesses to invest in self-generated electricity and thus contribute to the transformation of the energy system.The introduction of a higher proportion of solar energy may in turn affect the Swedish electricity system. This could mean that the electricity companies will be facing a number of changes in the near future.

Naturlig nedbrytning av klorerade lösningsmedel i grundvatten

Chlorinated solvents are common contaminants in soil and water. Under anaerobic conditions microbes are capable of transforming chlorinated solvents into ethylene which would result in a remediation of the contaminated area. In order to use natural attenuation as a remediation method evidence of continuous degradation is required. Furthermore, the degradation must occur at a sufficient rate and continuous monitoring of the site is needed until the demanded levels are achieved. A field study was performed on the basis of data from a dry-cleaning facility contaminated mainly by perchloroethylene.

Risken för översvämningar vid de svenska kärnkraftverken : en statistisk och historisk extremvärdesanalys

This thesis investigates the overall risks of flooding over the Design Basis Flooding Level (DBFL) at the Swedish nuclear power plants (Oskarshamn, Ringhals and Forsmark), using statistical data and methods, but also considers historical events which might affect the overall risk of flooding at the specified sites.Considering the nuclear accident which happened in Fukushima in conjuction with the earthquake and tsunami which struck eastern Japan on 11 March 2011, operators and licensors of nuclear power plants all over the world conducted reviews and investigations on the overall risks posed to the plants from external events. One important such event is extreme water level.One part of the thesis includes an extreme value analysis (using Generalized Extreme Value distribution and Generalized Pareto distribution) of water level data from SMHI (Sweden's Meteorological and Hydrological Institute) measured at stations close to the Swedish nuclear power plants. The results of the statistical studies indicate that considering the return period used in the thesis (100 000 years), the water levels at the Swedish nuclear power plants are not expected to exceed DBFL.The other part of the thesis consists of a historical study of extreme weather-related events. The results of this study indicate that no historical events seem to have occured which would indicate a higher risk of flooding than the one suggested by the statistical study. .

Kraftig anemi hos tax :

The Clinical Pathology Laboratory at SLU in Uppsala has analysed several blood samples from Dachshunds with severe anemia. As there are no previous studies on this topic, a study was performed to evaluate if Dachshunds are more prone to severe anemia compared with other breeds. In addition, a retrospective case study on Dachshunds with severe anemia was done to search for common risk factors or diseases. Hemoglobin values in samples from 1272 Dachshunds and 2269 German Shepherds analyzed from September 1994 to October 2007 were used to compare the frequency of severe anemia in Dachshund and German shepherd. The samples were identified by laboratory information system.

?Jag är en av de få som blir lycklig...? - bibliotekariers attityder och förhållningssätt på fem folkbibliotek till statens distributionsstödda titlar.

The purpose of this master?s thesis is to study attitudes and standpoints among a few librarians towards literature with state supported distribution provided by the Swedish Arts Council. By qualitative interviews with librarians at five different public libraries, the thesis examines which attitudes that flourish concerning the titles, how the circular of books is treated, where the titles belong on the literature map and if the system is producing a standardisation of this literature and if the conception of quality is relevant. We also study how the librarians relate to intentions of the Swedish Art Council with the distributed titles and how they regard their availability. Our theoretical framework is based on Hans Hertel?s model of five literary circulations and Theodor W.

Det gör ont när stockar spricker!

The aim of this study was to provide SCA Forest Norrbotten District with material to assist in their work towards decreasing the frequency of bucking splits in their saw timber logs. SCA Forest supplies the Munksund sawmill with pine timber. Periodically the sawmill experiences problems related to bucking splits in their logs. The purpose of this study was to find an available method to measure the occurrence of splits directly on incoming timber. The ambition was also to gain some knowledge about possible variations between different logging crews in terms of split frequency. If possible, this information could be used to investigate if certain crews produced more splits than others, and thereby making it possible to provide feedback to the logging machine operators. The study consisted of two major parts, a literature review, and a practical sawmill study.

Mätningar av statiska och dynamiska egenskaper för bakaxel.

To design new and high tech products the engineers rely more and more on computer based simulations to investigate the properties and behavior for a component or system.To verify these computer based simulations the dynamic properties for the components of the drivetrain needs to be verified. Therefore measurements of the stiffness and vibrations for the rear axle has been performed. This report show how the measurements has been implemented and evaluated, along with some interesting results for the rear axles properties.The static stiffness for the drive shaft along with the axle-gear has been determined. It is found that the stiffness for the whole rear axle is near the stiffness for the drive shaft, which means that the drive shaft becomes the dominant component of the system and affects the rear axle stiffness the most. The measured stiffness of the driveshaft is close to its theoretical stiffness.The stiffness for solely the hypoid-gear have been calculated using the stiffness for the rear axle and driveshaft, and thus has a range for the stiffness of the hypoid gear been determined.The backlash for the whole rear axle and for some individual components has been determined, where the backlash between pinion and crown-wheel has negligible impact on the total backlash.Measurements of the crown-wheel and pinion movements have been conducted, where the direction of movement is consistent with the theoretical direction of the forces.The vibration measurements show that the vibrations are more severe at certain rotational speeds.

Anslutning av vindkraftpark till befintligt nät

Detta examensarbete är utfört på Fortum Service AB samt Fortum Distribution AB iKungsbacka. När en förfrågan om anslutning av en produktionsanläggning kommer tillelnätsägaren är det elnätsägarens skyldighet att göra beräkningar om huruvida nätetbehöver förstärkas eller inte. Uppgiften för examensarbetet var att se på vilket sätt enplanerad vindkraftanslutning kan påverka elkvaliteten samt att se på kabelsträckningar.Även alternativa anslutningar och grov kostnadskalkyl skulle presenteras.För elkvalitetsberäkningarna användes AMP och ASP som är riktlinjer för anslutning avproduktionsanläggningar till elnätet. Data om kraftverken följde meduppdragsbeskrivningen.Det presenteras olika kabelsträckningsalternativ i rapporten. För de olika sträckningarnagörs även en jämförelse mellan konstruktionsspänningsalternativen 12 och 24 kV.

Sveriges potential för elproduktion från takmonterade solceller : Teoretisk, teknisk och ekonomisk analys

The Swedish potential of electricity production from roof mounted solar panels has been determined in three steps: accessing the existing roof top areas, simulating the amount of electricity solar panels can produce on these areas and finally analyzing how large the necessary economical change is to make the solar cells profitable.The total existing amount of roof top areas are 319 square kilometers and the area distribution follows the distribution of people. This leads to an installed power of 47,9 GW which are expected to produce 49,0 TWh electricity per year. If the quality of the electricity is prioritized the highest the power is reduced to 3,7 GW, generating 3,8 TWh yearly, but if the hosting capacity is calculated from Sweden?s total electricity need, the capacity is 42 TWh per year.Today, solar panels are not profitable in Sweden for houses, even though there is a subsidy of 35 % of the investment costs, discounted in 25 years. The profitability is calculated with a cost of capital of 5 %, a price on electricity of 1 SEK/kWh and an investment cost of 20 SEK/Wp.

Magnetfält alstrade kring nätstationer i samband med lokaldistribution av elkraft : Magnetic fields generated by electrical substations during distribution of electric power

Abstract: This report covers primarily the work of documenting electromagnetic fields generated by one of the later parts in the electrical power distribution chain: The electrical substation, wherein 10 kV is transformed to 400 V for use by private consumers. Thus it is one of the most widespread and frequently occurring parts in the Swedish power grid and of particular interest, as electrical substations are found everywhere in populated areas, often in close vicinity to people and animals.The report deals with a number of formulated questions and/or hypothesis? stated at the onset of the work undertaken, theory that is relevant for the topics the report covers, the details of the field work undertaken and the following analysis of the readings, which in term provide answers for the questions stated in the beginning. It also covers what is the currently known short term and long term risks associated with electromagnetic fields in the power frequent spectrum and of varying intensity in the vicinity of humans.The analysis also provides recommendations and identifies several points to carefully consider when planning for new installations or replacements of some parts of existing installations.For enhanced reading comprehension there is, aside from sections with pictures and attached explanatory texts and templates, several graphs, one-line diagram and maps of the power grid among the appendixes to the rapport..

Utvärdering av en Magnetic Harmonic Traction Drive

In this report a new gear concept is evaluated using the magnetic finite element method (FEM)software MagNet and Ansys as well as the mechanical FEM software Abaqus. The gear conceptis evaluated in terms of maximum torque capability, torsional stiffness, gear ratio and efficiency.ABB Corporate Research has proposed a new gear concept which should be less expensive thangearboxes used today. The new concept is called aMagnetic Harmonic Traction Drive and usesthe principles of a harmonic drive gear to achieve a high reduction ratio. The gear conceptreplaces the wave generator used in traditional harmonic drives with magnets and uses tractioninstead of gear teeth to transfer the torque. The main components in the gearbox are the magnets,the flexspline, the magnetic portion and the circular spline.

Vem har bäst betyg? : en kvantitativ studie om betygsfördelning

Aim: The study aims to investigate the distribution of grades between students in a practical subject and in a theoretical subject.The problem:What is the grade distribution in physical education and mathematics, with respect to gender, socioeconomic background, parental education, ethnicity, and physical activity?Method:To answer the aim of the study a quantitative method was chosen. As the collection method used was questionnaires to 620 students in the 9th grade in Stockholm. Of the 620 questionnaires, 597 questionnaires were used for the static analysis. The method of analysis used cross tables and logistic regression analysis.

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