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574 Uppsatser om Load-bearing brick vault - Sida 31 av 39

Människan som resurs

In the recent years auditing scandals all around the world, deficient internal control has attracted a lot of attention. This has contributed to further requirements on insight and internal control. Those scandals have seriously damaged the auditor?s profession and contributed to a reduced trust among the public. Therefore an extensive work to recover and stringed the trust was started all around the world.

Ekonomi vid uttag av långa toppar som skogsbränsle i slutavverkning :

The market for biofuels from the forests have had a positive development and the job initiators for this master´s thesis wanted to examine the profitability of a method for harvesting forest fuel, which was unfamiliar to them. The method was the ?long tree tops-method?, here called the LT-method. The LT-method is characterised by the fact that timber is harvested as the only roundwood assortment while the rest of the stem, which in other cases would become pulpwood, is harvested as forest fuel together with the logging residues. The method is based on the assumption that advantages in handling of the forest fuel assortment such as increased load weights for forest hauling and truck transportation, should compensate for the lower price for pulpwood when sold as forest fuel. The aim of the study was to compare the profitability of the LT-method with the GROT-method (harvest of timber, pulpwood and logging residues) and conventional logging without any harvest of forest fuel, and aslo to try to identify factors affecting the profitability of the different methods.

Konstruktion av serviceutrustning till tunnelborrningsmaskin

The Master Thesis work this report is based upon has been conducted in cooperation with Svea Teknik AB. Svea Teknik is a consultant firm which is developing parts of a tunnel boring machine on behalf of Atlas Copco. The machine is being developed to mechanically excavate hard rock by fixating itself in the tunnel and then press a large rotating cutter-wheel equipped with disc-cutters against the tunnel wall. The disc-cutters are the tools that are in direct contact with the hard rock and are therefore exposed to extensive wear and needs to be replaced on a regular basis.The purpose of this Master Thesis has been to develop a service equipment that will enable time effective and safe changes of disc-cutters. The disc-cutters have a diameter of 17 inches and weigh about 130 kg.

Hackelselängdens betydelse för tuggtid och foderkonsumtion hos mjölkkor :

Today, our cows experience a harder pressure to achieve higher milk yield. To manage this challenge the animal needs first class feeding and treatment. An important aspect of the feeding is to fulfil the need from the cows of especially fiber; and fiber with a sufficient proportion of long particles. Both too much and too little fiber is bad for the wellbeing of the cow, and she might get diseases like acidosis. Many models for feed management have been developed to secure that the animal gets enough of e.g. fiber with a sufficient proportion of long particles.

MOLNU : Att utveckla ett gemensamt gränssnitt

Climate and environmental issues is now high on the agenda. We live in a generation that must try to solve some major environmental problems. Buildings and habitations account for approximately 40 % of Sweden's total energy today. To reduce this figure, as needed, more research in the field of energy efficiency is required.This thesis concerns the heating of buildings. The load on district heating is heavy during certain times of the day.

Reaktionskrafter i dragarmarna på en traktors trepunktslyft : Teori och praktik

Tractors of today come equipped with a CAN-system. A CAN-system sends information from sensors to electronic control units who process the signals. The sensors measure several interesting parameters such as force, pressure and speed for various components of the tractor. This thesis discuss a force sensor which is placed in the pivot of the tractors three point linkage, the sensor measure the horizontal reaction force from the load that the tractor is exposed to. Signals from this sensor can be used to measure the force from any implement that the tractor is exposed to during an operation.

Sustainable phosphorus management of horse paddocks at Julmyra

Horse keeping is gaining an increasing interest in Sweden. During 2004 to 2010 the number of horses increased with 10 - 20 %, and was estimated to be 362 700 in 2010. Julmyra Horse Center (JHC), situated in Heby municipality, is a gated community for people sharing a large interest for horses and a vision of a sustainable horse management has been formulated. This study evaluates how the horse keeping of today at JHC, and how an expansion of the horse keeping may affect the risk of enhanced phosphorus load to the nearby lake system Vansjön ? Nordsjön.

Hundar kring benen. En analys av belastning och storleksvariation hos hundarna i det mesolitiska Skåne

This paper deals with variations in the osteological material of dog (Canis familiaris L.) from the Mesolithic Scania, southern Sweden. The general aim is to discuss the use and specialisation of dog during the period, and differences or relations between cultures and traditions within the Mesolithic period. The study is based on a analysis of the bone material from the sites; Ageröd I:A-D, Ageröd I:H-C, Bredasten, Bökeberg III, Hög, Löddesborg, Ringsjöholm, Segebro, Sjöholmen, Skateholm I-II and Tågerup, phase 1-3, with datings from Late Maglemose Culture to Early Ertebølle Culture. The seminar paper also includes descriptive statistics of the osteometrical data of Denmark, from several studies of Degerbøhl (1927) and Noe-Nygaard (1995, 2003). The study is focused on the relation between size, robusticity, muscle grooves and ligaments of mandibula, tibia, radius, humerus, femur and metacarpalia/metatarsalia.

Skillnaden i muskelaktivitet vid jämförelse av olika vadskydd

SammanfattningSyftet med studien var att undersöka om det fanns någon skillnad i muskelaktivitet ivadmuskulaturen när olika eller inget vadskydd användes vid vadpress. Jämförelsegjordes mellan vadskydd (A), stickat av ett modifierat polyolefingarn och ett tillstickningen identiskt och utseende näst intill identiskt vadskydd (B) av polyamid,samt utan vadskydd.Testgruppen bestod av 13 män från militärhögskolan i Halmstad. Testpersonernagenomförde vadpress i smithmaskin* på en belastning av 50% av 1RM*.Muskelaktiviteten mättes med hjälp av sEMG* och tre mätningar per persongenomfördes. Det första utan vadskydd, andra med vadskydd A och det tredje medvadskydd B. Resultaten visade ingen signifikant skillnad i muskelaktivitet mellan användandet avvadskydd A och vadskydd B eller mellan vadskydd A och utan vadskydd.Mätmetoden sEMG är känslig och kan ha gett missvisande resultat. Fler studierbehöver göras dels angående skillnad i muskelaktivitet och dels för att testavadskyddens eventuella andra egenskaper, positiva eller negativa.

Hjulskotarens tekniska utveckling

Den första serietillverkade hjulskotaren i Sverige presenterades 1962. Skotaren blev revolutionerande för mekaniseringen av terrängtransporterna. Hästarna ersattes och var i början av 1970-talet nästan borta från skogsbruket. Mekaniseringen innebar stor produktivitetsökning med ökade avverkningsvolymer. Hjulburna skotare har sedan introduktionen tills idag varit dominerande i det svenska skogsbruket. Under 2012 fanns ett fjortontal tillverkare av hjulskotare, vilka succesivt fått bredare hjul, mer avancerade motorer och transmissioner. Syftet med denna studie var att sammanställa tekniska data och försäljningssiffror i Sverige för hjulskotare tillverkade i de Nordiska länderna från deras introduktion 1962 fram till och med 2012 samt att besvara den frågeställning som ställts upp i studien genom att statistiskt styrka trender genom att testa hypoteserna H0: ?1 = 0 och H1: ?1 ? 0. Litteraturstudien har utförts med datainsamling av tekniska specifikationer samt årtal då serietillverkning av skotarna påbörjats.

Konceptstudie av drivmodul till bandskotare med hybriddrift

BAE Systems Hägglunds has a long history of producing high performance terrain tracked vehicles (mostly for military applications), and they are now aiming at developing a tracked forwarder with similar techniques.The forwarder will be of series hybrid type where a diesel engine via a generator will power the motors (one for each drive wheel). Thanks to individually controlled motors and the gentle rubber tracks, this forwarder is calculated to have a considerably higher average speed in the terrain and to be more gentle to the soil. The forwarder with a weight of 11 metric tons and a load capacity of 15 metric tons is specified to have an average working speed of 7-10 km/h, a top speed in terrain of 15 km/h and a top speed on roads of 40 km/h.This master?s thesis aims at developing a conceptual design of the forwarder?s drive module which includes electric motor, gear unit, brake and drive wheel.To investigate if the requirements can be fulfilled a study of the dimensioning loading scenarios has been carried out. The resulting needs regarding the torque has been considered in order to determine the required gear ratios for different motor options.

Specificering av produktionstransformatorer : Rekommenderade avsteg från IEC 60076 för att vid upphandling beskriva en robust enhet

As break downs of production transformers are costly and often result in long outages it is essential for reliability of operation that the transformers are manufactured to be robust. The aim of this M.Sc. thesis is to investigate if deviations should be made from the standard IEC 60076 ? Power Transformers in order to describe a robust large power transformer for procurement.The investigation has been conducted in three stages. In the first stage a definition of the term robust was developed in consultation with the client Vattenfall Vattenkraft.

Komfortsanalys med hänsyn till vibrationer orsakade av människoaktiviteter. : Ett modernt dimensioneringsproblem för huskonstruktörer

Comfort analyses regarding human induced vibrationsIt is not too common among civil engineers in Sweden to perform comfort analyses considering the vibrations caused by human activities. In addition, the Swedish standards lack requirements to be used for comfort analyses in design of floor-systems. The demand for large spans in combination with slender slabs, is today a reason to investigate the floor-system constructions, in order to prevent disturbing vibrations and oscillations.The purpose of this thesis is to create a guide for how a comfort analysis, considering vibrations, should be implemented. Göran Svedenbjörk who is an expert in structural dynamics has been interviewed where he presents his latest project Värtaterminalen and answers some questions about vibrations due to human activities.Floor-systems, consisting of concrete slabs supported by steel or concrete beams, have been investigated with simulations in the finite element program Abaqus. In the simulations, the influence of various factors on the natural frequency of floor-systems and the acceleration level caused by dynamic loads, is studied.

Stenmaterial vid asfalttillverkning

Denna rapport beskriver arbetet med utvecklingen av en ny modell för kaplanturbiner. Utvecklingen bygger på två kopplade differentialekvationer som under arbetets gång anpassats och implementerats i turbinmodellen.Modellen beskriver hur vattenflöde och turbinmoment påverkas av avvikelsen från den optimala kombineringskurvan för vinklarna på turbinens ledskena och löphjul, och är anpassad för ett referensaggregat med tillgängliga provdata. Även övriga enheter i vattenkraftaggregatet modelleras och sätts samman med frekvensregulator och elnät för att simulera aggregatets reglerstabilitet i önätsdrift.Verifieringen av turbinmodellen sker genom försök att återskapa de befintliga verkningsgradskurvorna med hjälp av modellen. Resultatet visar en god följning av de verkliga kurvformerna, dock med något lägre maximal verkningsgrad.Verifieringen av önätmodellen sker genom att prova stabiliteten i nätfrekvens och turbineffekt vid stegpålastningar. Resultatet ger en stabilare reglerstabilitet än i verkligheten, men uppfyller ändå förväntningarna på en fungerande modell.This report describes the development of a new kaplan turbine model.

Lättridningens påverkan på hästens rörelsemönster i trav :

The interest in horses and equestrian sport is constantly increasing, and so is the will in both riders and trainers to learn more about the effect the rider and its equipment have on the horse. The last twenty years, more and more studies have been performed were the horse and its kinematics have been in focus. The access to more advanced technology has made it possible to study areas, which earlier have been hard to reach. The knowledge about kinematics in the horse, and how riders and their equipment interact with the horse?s movement, is also of great interest to veterinarians in equine practice.

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