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729 Uppsatser om Erosion of rock mass - Sida 7 av 49
Inventering av värmelager för kraftvärmesystem
When a combined heat and power plant produces heat and power it often faces a deficit of heat load during the summer or other periods of time. This heat is often unnecessarily cooled away or the power production has to be reduced or shut off. If it is possible to store heat from periods with low heat demand to periods with high heat demand one can get many benefits. Among these benefits are: increased power production, decreased operation with partial load, uniformly distributed load.To be able to store heat in situations like this long-term thermal heat storages are needed. In this thesis five different types of stores are presented: rock cavern storage, tank storage, pit water storage, borehole storage and aquifer storage.
Nötning: analys och materialval i kvarn för malning av råmjöl
Kalksten och råmjöl sliter kraftigt på allt det kommer i kontakt med. Råmjölet blästrar och kalkstenen gnider sig in i och slår mot materialet i råkvarnskrets 8 vid Cementa AB:s anläggning i Slite. Underhållskostnaderna är stora för råkvarnskrets 8 och i denna rapport utreds möjligheterna att göra besparingar genom ett nytt materialval. Vid valet av material tas hänsyn till nötningsbeständighet, pris och livslängd hos både material och maskin. Nötningsbeständigheten beror av duktilitet, hårdhet, dämpningsförmåga, med mera.
Skatteverkets massmediala kommunikation av inkomstdeklaration nummer 1
The purpose of this study is to study the Swedish Tax information campaigns in 2010-2012. Questions about what worked better than others, and what impact this has had has been set up. The study shows that work has essentially divorced by 2011,worked with a significant amount of local material. This work had an impact on mass media published locally in newspapers. This work fits well with research in the area showing that messages should be tailored to the target audience and capture the target group's interest.
Revisionsbranschens relation till massmedia - En studie om hur revisionsbranschen påverkas av massmedias rapportering
Background: Media has for a long time been reporting about the audit industry, often focusing on so-called auditing scandals. Economic journalism has grown stronger, the corporations are given more and more power in society and the public interest is increasing. We intend to examine how mass media affects the expectations gap and how the auditing firms operate strengthening the society?s confidence in the industry after mass medial exploitation. We also want to investigate whether the relatively new phenomenon social media is affecting the auditing firms and industry?s external communication, as well as what consequences negative publicity may have for the individual auditor.Aim: The aim of the study is to create an understanding of the audit industry?s relation to the media as well as to describe and analyze how mass media?s coverage is affecting the audit industry, auditing firms as well as the individual auditor.
Val av teknik för hastighetsmätning i kallvalsverk
An often encountered problem when implementing a mass flow regulator in a rolling mill is the one with measurement of speed. The most widely used solution is to fit a pulse counter to a wheel that is in contact with the strip. Common problems with this design are for instance scratch marks on the strip and problems with the flatness measuring system. One way of circumventing the aforementioned problems would be a non-contact measuring system. The market of today only offers systems based on the Doppler principle.This report evaluates three different systems for non-contact speed measurement. Important areas in the evaluation have been the ability to operate under normal rolling conditions, integration in existing control system and how well the sensor can be fitted to the rolling mill.
Konsekvenser av ny teknik på en sjukhusmottagning
An often encountered problem when implementing a mass flow regulator in a rolling mill is the one with measurement of speed. The most widely used solution is to fit a pulse counter to a wheel that is in contact with the strip. Common problems with this design are for instance scratch marks on the strip and problems with the flatness measuring system. One way of circumventing the aforementioned problems would be a non-contact measuring system. The market of today only offers systems based on the Doppler principle.This report evaluates three different systems for non-contact speed measurement. Important areas in the evaluation have been the ability to operate under normal rolling conditions, integration in existing control system and how well the sensor can be fitted to the rolling mill.
Mätning av partikelmassa i avgaser från en dieselmotor
This master thesis was a continuation of a previous study in the diesel exhaust characterization, which is part of the academical work embedded in the EMIR-1 project. The main objective of this thesis work was to finish the installation and make the proper modifications of the particulate mass measuring system located in one of the engine test cells at KTH, in order to be able to measure the mass of the particles from the exhaust of diesel engines.This experiment requires a diluted flow sample from the exhaust that should be sent to the device that makes possible the measurement of particle mass, called TEOM. In the first stage of this project, the objective was to study and make the proper modifications in the existing KTH diluter because there were several problems to obtain a constant dilution ratio from it during tests.This modifications were made and it resulted in a great improvement in the maximum inlet and outlet flow that this diluter can handle. Therefore another modification is proposed for controlling the inlet exhaust flow so it will be possible to regulate the dilution ratio and make it constant along a wide range of engine loads and speeds.The second and most important stage was to make particulate mass measurements possible by analyzing the frequency signal from the TEOM device. The idea was to obtain the frequency of oscillation from the tapered element in the TEOM, and therefore with the proper correlations, be able to predict the particulate mass concentration in the exhaust flow from the engine.An electrical problem in the TEOM circuit was detected and corrected, so the signal that carries the frequency from the TEOM can be analyzed properly.
Är det möjligt att bedöma olika typer av tandslitage på kliniska bilder?
Sammanfattning
Tandslitage är ett vanligt förekommande problem. Det finns olika typer av tandslitage såsom attrition(fysiologisk), erosion(kemisk) och abrasion(mekanisk). De bakomliggande orsaksfaktorerna skiljer sig åt för de olika typerna av tandslitage. Attritioner delas upp i normalt och patologiskt. Normalt tandslitage beror på ålder och kost, medan patologiskt tandslitage som även kallas bruxism, kan orsakas av stress och oro.
Masskattning av tunga fordon i realtid genom systemidentifiering
As trucks are getting more and more advanced, information about their weight has become a key factor for controlling them in a more fuel efficient and safe manner. Knowing the mass of a heavy duty vehicle in real time has been a difficult challenge for the truck manufacturers. With the processing power for electronic control units in trucks steadily increasing, more advanced algorithms for calculating the mass has been developed, but at the moment there still is a wish for better performance.Since there is a lack of good information regarding the external forces acting on the vehicle, forces that depends on the slope of the road, foundation of the road and the wind, the methods have to be able to disregard these. Such an approach, based on an indirect least square solution, has been evaluated in this thesis. The results have been promising and based on these a recommendation about further evaluation has been made..
Grazemore DSS för att prediktera beteskvalitet för mjölkkor :
The aim of this study was to examine if the predictions of the herbage quality in the software Grazemore Decision Support System (DSS) gives a reliable ground for milk production in the north of Scandinavia.
Pasture samples from one research farm (Umeå) and one organic farm (Nordingrå) was analysed on crude protein and organic matter digestibility. The results were statistically compared to the predicted values. Measured and predicted herbage mass was compared and a control if the predictions of milk production improved if the predicted input were replaced by the values from the analysis, was made.
The concentration of crude protein was underestimated by the model on both farms and the relationship between actual and predicted values was poor. Mean Prediction Error (MPE) was 24% and 31% respectively.
Krafter på rörsystem vid transient flöde : En jämförelse mellan RELAP5 och Fluent
At Forsmarks Kraftgrupp AB (FKA) forces on pipe systems due to transient flow are frequently calculated as a step to verify their structural integrity. In nuclear industries these forces are often calculated with a one dimensional thermal-hydraulic analysis-code called RELAP5. When calculations regarding more complex geometries are needed, the three dimensional code Fluent is often used. This code is highly time consuming and requires large computational power.This projects aim is to compare calculations of pressure, flow and forces carried out by RELAP5 and Fluent for an arbitrary pipe section during transient flow conditions. This has been accomplished by constructing a simple geometry for which a transient flow is simulated in both programs.
Svensk massmedias EU-gestaltning Analys av Dagens Nyheters och Expressens EU-artiklar utifrån ett inrikes- och utrikespolitiskt perspektiv
During the time of membership in The European Union Swedish domestic policy has gone through many changes. A lot more political areas are being influenced by the EU policy. Today every ministry has got some sort of EU office. Swedish politicians are functioning on two arenas, domestic and European. At the same time Swedish membership has gone from being highly discussed to being a state of normality.
Ensemble som gruppsituation
Syftet med detta examensarbete a?r att underso?ka och fa? en djupare fo?rsta?else fo?r de olika grupprocesser, roller och den kommunikation som uppsta?r i en rock- och popensemblesituation och hur verksamma la?rare tar detta i beaktning i sin undervisning. Fo?r att ta oss na?rmare syftet utfo?rde vi intervjuer med fyra verksamma ensemblela?rare pa? estetiska programmet pa? gymnasiet. Vi hade a?ven fo?r avsikt att observera en grupp elever vid tre olika lektionstillfa?llen fo?r att koppla samman la?rarnas tankar och a?sikter med vad som ha?nder i praktiken.
Erosion vid dagvattendammar : litteraturstudie med inventering av 13 dagvattendammar
Vatten har alltid haft en stark dragningskraft på människan. De flesta uppfattar vatten som avkopplande och rogivande. I alla tider har dammar, fontäner och vattendrag utgjort en väsentlig del av landskapsarkitekturen. I våra dagar utgör dagvattendammarna ett tillskott i vår miljö, där syftet i första hand är att fördröja dagvatten. Denna funktion kombineras i många fall av önskan om att skapa rekreativa våtmarksområden som kan utgöra ett positivt inslag, särskilt i urban eller halvurban miljö, där tillgången till naturen saknas.
Dental erosion : kolsyrade vattens erosiva potential
Syftet med studien var att undersöka den erosiva potentialen av vanligt förekommande kolsyrade vatten med eller utan smaksättning. Studien genomfördes som en laboratoriestudie vid Institutionen för Odontologi vid Göteborgs universitet. Totalt omfattades studien av 34 buteljerade kolsyrade vatten med eller utan smak, tre kolsyrade vatten producerade i kolsyreapparat samt sex referensdrycker. Samtliga produkter testades genom registrering av initialt pH med pH-elektrod och buffring med 0,1 M NaOH till det värde då pH neutraliserats. Dryckens surhetsgrad beräknades därefter vilket anses som ett mått på dess erosiva potential.