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1233 Uppsatser om Load-carrying capacity - Sida 15 av 83
Frekvensreglering i det nordiska kraftsystemet
Svenska Kraftnät is (together with the other transmission system operators of the Nordic power system) responsible for keeping balance between the generated and demanded power in the Nordic power system. Spontaneous load variations and system disturbances, however, lead to power imbalance followed by frequency variations. The frequency deviations can be limited to an acceptable level by the spinning reserve, mainly by hydro power control. But there are also other system properties which have a great influence on the frequency and system stability. The frequency and voltage dependence of the loads have a direct influence on the power balance.
Skotares bränsleförbrukning :
In published studies it is found that the fuel consumption on a forwarder is relatively constant, on time basis. A certain variation between different sizes of forwarders occurs as well as between different working elements.
The aim of the study was to establish a forwarders comparatively fuel consumption when driving on road and in the terrain, loaded and unloaded, with high and low gear and with high and low speed as well as with hydrostatic and hydrodynamic transmission. A hypothesis was that low rpm gives lower fuel consumption on distance basic, at all trials.
The test driving was made with a Hemek 750 which is a three geared hydrostatic machine and with a Hemek 700 which is a hydrodynamic machine with six gears.
Varierande Vägar till Frihet - Hur staten och civilsamhället interagerar för demokrati i Vitryssland, Moldavien och Ukraina
The three post-communist states - Belarus, Moldova, and Ukraine ? have gone different ways in terms of freedom and democracy since the breakdown of the Soviet Union 1991. During these years, the state and the civil society have been fundamental actors in the struggle against, and even for, authoritarianism.A strong state with great capacity in Belarus has undermined the chances for the civil society to fulfil its task as a watchdog of the state and link between the citizens and the government.Failed authoritarianism in Moldova has led to a situation where both the state and the civil society are weak. The major problem is lack of organization and cohesion; both the state and the civil society have often been divided by ethnical differences and are therefore not strong enough to promote democracy.In Ukraine, the dominance of a strong state ended in 2004 when the Orange Revolution took place, sometimes called a ?peak of democracy? where popular mobilization and protests succeeded in it's opposition against the state.
Analys av off-design prestanda för ett absorptionskylsystem
This master thesis project at KTH is performed in the Mechanical and Aerospace Engineeringdepartment at University of Florida (UF). The thesis is a small part of a gas turbine researchproject where a vapour absorption refrigeration system (VARS) and a high pressure regenerativeturbine engine (HPRTE) are integrated together. The main objective is to build a computermodel of the VARS. The computer model is supposed to be used to analyse the off-designperformance of the VARS and should also be easy to integrate as a subroutine in a more complexsystem model. To model the VARS some knowledge of the absorbent/refrigerant mixture had tobe well known, in this case a mixture of ammonia and water.
Spårbilsstation i Upplands Väsby kommun
Upplands Väsby municipality has a vision that podcars in the future will become an effective alternative in public transport, with reduced car-dependency as a result. The system would also attract new inhabitants and businesses to the municipality.This report deals with various issues that podcar stations may face. Also, suggestions for possible track laying at the stations and station design are presented. Two areas are investigated. Eds allé which is a neighborhood that is planned for housing and where the station may be planned into the cityscape from the start.
Byggnadens andra skepnad : En anpassning för att möta samhällets behov och krav
Population growth leads to an increased need for new buildings, both residential and commercial. The regulations of structural design also changes with time. From a sustainable community perspective it may be profitable if existing buildings, that no longer performs their original function, are reconditioned. Knowledge and understanding of the surroundings of the residence must be available. Regulations regarding accessibility to all has increased.
? Ibland ka?nner jag mig o?vergiven da?rfo?r att personalen har sa? mycket andra ma?nniskor att ta hand om?. : - En kvalitativ intervjustudie som presenterar na?gra a?ldres a?sikter om hur relationen till va?rdare kan pa?verka a?ldre i deras var
The purpose of this thesis is to examine the relationship between the elderly at a retirement home and their professional caretakers with focus on the perspective of the elderly. Chosen method, a qualitative interview analysis has been conducted to describe how the relationship affects the elderly in their everyday lives. The total amount of interviews were four. The relationship between the elderly and their professional caretakers has rarely been examined in previous research from an elder?s perspective.The results indicate that the elderly often are satisfied with the way the professional caretakers treat them.
Ersättningsmodeller för ballasttransporter : vid anläggning och underhåll av skogsbilvägar
Construction and maintenance of forest truck roads are a necessary element of industrial forestry. Payment for contracting services in this context can be done according to a number of payment models. This study will focus on the methods and consequences associated with a change of Holmen Skog?s payment model from per hour to per metric ton for ballast hauling.
The aim of this study is to improve the economic efficiency of Holmen Skog?s ballast hauling in construction and maintenance of forest truck roads. This is done by formulating and evaluating a proposal for a payment model based on crowns per ton.
Metod för användning av Geografiska Informations System vid långsiktig vägplanering : en studie genomförd på Sveaskogs marker i Norrbotten
The forest industry is one of the most important industry branches in Sweden. Since the demand of high precision wood deliveries has increased, the demand on a well constructed forest road net also has increased. A good road net gives the wood-supplier competition advantages and also increases its service level towards its customers, lumber-mills and pulp-mills. In some parts of Norrbotten, the road net is still insufficient and not yet built out enough, and that is why it is important to know how to act and where to improve the road net in these areas.
The purpose of this thesis was to create a work-model for long term road planning in areas with no road net or a not yet complete road net. The model has been created in an ArcGis environment, where a long chain of tools has been tied together with the program ?Model builder?.
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.
Identifiering och reducering av köer i samband med återbesök
Purpose ? The purpose of this thesis is to develop a total cost model for container transports and create a tool that calculates a suitable transport quantity from an economic view, which fulfills the demands on delivery service. To achieve this purpose the following questions will be answered:Which costs are affected by the decision between the two transport alternatives LCL and FCL? How does the decision of sending product LCL or FCL influence the delivery service? How can a tool be constructed to simplify the decision-making process regarding the choice of sending products LCL or FCL? Method ? A total cost model was developed. This model is supported from existing literature.
Effect of cow traffic system on cow performance and AMS capacity
Robotic milking in Automatic Milking systems (AMS) is proposed to reduce manual labour and at the same time increase milk yield by increasing milking frequency. In order to increase milking frequency, it is essential to have well-functioning cow traffic. Investing in an AMS is a great capital investment for the farmer, thus it is of major importance to ensure maximal AMS capacity. This study investigated the effect of the traffic systems Feed First? and Free cow traffic with and without waiting area (WA) on cow performance and AMS capacity.
Undersökning av elkvalitet i distributionsnät med omfattande vindkraftselproduktion
The goal for this master thesis project has been to investigate the power quality in adistribution grid, which has a high fraction of dispersed power production due towindmills. The study has been done on a grid in Laholm South of Halmstad, whereapproximately 45 windmills are connected to the distribution grid owned by SHKEnergi. The investigation has been focused on to two radialy fed 20 kV lines, wheretwelve windmills are connected.Voltage variations have been studied by creating a model of the grid in the simulationprogram SIMPOW. The largest deviation that has been found in any point of the gridis ±1.9 % of the nominal voltage. This deviation is a result of varying powergeneration from the windmills and the voltage regulation at the connection point ofthe line.
Kinematisk och dynamisk modellering av den haptiska enheten TAU i sex frihetsgrader
The thesis presents an optimally designed kinematic structure for a new 6-DOF haptic devicebased on TAU configuration. The configuration of the TAU-2 proposed by Suleman Khan andKjell Andersson [1] was modified and its mobility was verified by using Grübler criterion tohave a 6 DOF. Analytical kinematic models for the inverse and forward kinematics weredeveloped for the haptic TAU configuration to determine a set of optimal design parameters.Kinematic performance indices such as volume of the workspace, kinematic isotropy and payload index, were defined based on the singular values of the Jacobian matrix. The Jacobianmatrix was scaled to homogenize the physical units. The Jacobian matrix dependent on theposition and orientation of the end-effector gives local isotropy and pay load index, so globaldesign indices were defined, which represent the performance of the mechanism in the wholeworkspace.
End of line test : En studie av företaget Emotrons linjetestning i produktionen
Emotron is a company specialised in developing, producing and marketing equipment to con-trol, monitor and protect processes and machinery driven by electric motors, with an applica-tion focus. Examples of uses for their products are fans, pumps, lifts and cranes.The project is to look at Emotrons end of line test. The company has seen that at the final test-ing there is a bottleneck that restricts the outflow and prevents an increase in the number of tested products.The purpose of this project is to review how Emotrons end-of-line test works today and if there is a possibility to make the test more efficient in such a way that the quality is not at risk, while increasing the outflow of tested products.The projects first step is to look at and analyse what is causing the bottleneck at the end-of-line. When the analysis is complete, the next step is to review whether there is a possibility to solve the bottleneck and if so in what way can this be done. Emotrons most overall objective of the project is to increase the outflow of the number of tested products without jeopardizing the quality.An analysis has been made on frequency inverters, soft starters and shaft power monitors.