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20426 Uppsatser om Stora tekniska system - Sida 60 av 1362
Analys av fördelningssystem för bostadshus
The purpose of this project is to analyze earthing systems for houses. By practical measurements and theoretical analyzes consequences of possible faults, that can occur within the facility and in the low-voltage distribution network, is illustrated. The reason for this project is that nowadays one has to arrange with a main equipotential bonding system for buildings. Apart from that, if necessary, bathrooms must be provided with a supplementary equipotential bonding system.The practical measurements verify that potential differences in facilities may be due to voltage drops in the PEN conductor between the origin of the electrical installation and the power transformer.Based on the theoretical analyzes of possible faults, it is considered that the requirement for supplementary equipotential bonding systems for bathrooms in most cases can be questioned, when basic insulation, fault protection, residual current devise and main equipotential bonding system already provides an adequate level of protection.A PEN conductor loss may result in a situation where metallic parts attached to the equipotential bonding system starts working as earth electrodes. Equipotential bonding system may also increase the incidence of stray currents. If TN-C-S systems is provided with a local connection to earth a redundant system against PEN conductor loss is obtained.
Appar eller ej inom Fleet Management-området : Organisatoriska och tekniska utmaningar vid apputveckling
En trend i den teknologiska utvecklingen på senare tid har varit att skapa en ökad rörlighet hos användaren. En bidragande faktor till detta är den snabba förbättringstakten hos de smartphones som i större utsträckning har funktionalitet som tidigare endast datorer hade. Detta har i sin tur förändrat de förväntningar slutanvändarna har på tjänsters tillgänglighet, vilket har lett till att produktiva mobila applikationer, appar, har funnit sin plats i vardagen.Denna studie är genomförd på Scanias Fleet Management-avdelning som erbjuder en webbaserad tjänst där åkerier kan administrera, övervaka och följa upp sina fordonsflottor. Syftet med studien var att undersöka om en förlängning av Scanias existerande webbtjänst till den mobila sfären är rätt steg att ta och vilka organisatoriska och tekniska utmaningar en ingång inom apputveckling ger upphov till. För att bemöta denna problematik har en omfattande kvalitativ undersökning genomförts där tre huvudgrupper av respondenter har intervjuats: jämförbara företag som har ställts inför liknande utmaningar, apputvecklingsföretag som har förståelse för appområdet samt Fleet Management-tjänstens existerande användare.
Stubbtransporter och bränslekvalitet hos stubbved :
Stump wood is a hot alternative when the heating plants demands more and more forest fuel. The aim with the study has bean to calculate the costs in four different systems for transportations of stump wood, examine if there are any differences in fuel quality for the stump wood in the different systems, analyse if the fuel quality in stump wood is affected with the time it lays by the road side and how much space the stump wood demands on the road side. To calculate the costs for the different systems a system analysis was carried out, where some of the costs were collected through field studies on Holmen Skog stump experiment and other costs were collected from literature and contacts. Data for the fuel quality study was collected from Eons heat plant in Norrköping. Data for the study of how much space stump wood takes along a roadside was collected from field studies.
Betesdrift vid automatisk mjölkning i ekologisk produktion :
An automatic milking (AM) system should be combined with some form of controlled cow traffic to minimize the time spend on fetching cows to milking and to increase the milking frequency. By restricting the hours spent on pasture per day you optimise the AM system use during pasture period. A reason for this is becuase cows do not return to the stable for milking during night which cause that the milking unit stands empty those hours. In organic production it is required that the cows should be able to graze a certain amount of daily dry matter (DM) intake on the pasture. In the county of Dalarna where the farm is located the yield of the pasture is about 3000 kg DM per grazing season and hectar.This means that the pasture area should be 14,25 hectare to 57 milking cows.
Barn och trygghet i förskolan : En studie om förskollärares uppfattningar om trygghet hos små barn i stora förskolegrupper.
Barn och trygghet i förskolan ? en studie om förskollärares uppfattningar om trygghet hos små barn i stora förskolegrupper.Syftet med undersökningen är att beskriva och synliggöra hur förskollärare resonerar kring små barn och trygghet i stora barngrupper i förskolan. Det har skett kvalitativa intervjuer med fyra förskollärare på tre olika förskolor som alla har haft grupper som överstigit tjugo barn och i åldrarna ett till fem år. Resultatet visar att barngruppens storlek har betydelse för de små barnens känsla av trygghet i förskolan och samarbetet med föräldrarna är betydelsefullt när det gäller barnens trygghet i förskolan.Antal sidor: 28Children and their secureness at preschool ? a study of preschool teachers? opinions about small children?s sense of security in large preschool groups..
Mätsystem för effektförluster i en högfrekvenstransformator
To measure losses in a transformer with today?s methods is either slow or insecure. There s a new method developed by Alstom that hasn't been actualize in to a test-system and that has been the assignment in this project. The idea is built on a switched system and a CLR- circuit in the resonant frequency. The test-system has a calculated power-loss that make the efficiency to be as high as 99,8% and in reality over 95%.
TOMO Hugglink
Tomo Hugglink (TOMO Skog) is an innovation for harvest and transport of biofuels. The system consists of a truck, a chipping unit and crane mounted on a link and a wood chip trailer. The system works in such a way that the chipping unit is disconnected and placed on the site and wood chips are loaded directly into the wood chip trailer.The aim of this study was:- To examine the performance of the TOMO Hugglink system under different conditions such as the size, placement and quality of the pile.- To calculate the cost per raw ton for two vehicle combinations at different transport distances and to examine the effect of a reduction in set-up time and an increase in load weight.- To identify possible improvements with the TOMO Hugglink system.A time study was conducted within the thesis work to make it possible to determine production and time consumption. In the subsequent economic analysis the cost per tone at different transport distances was calculated for two different lorry concepts. Furthermore the effect of a reduction in set-up time and an increase in load weight was calculated.Under current conditions the utilization of the chipper is low and only 29 % of the total system time is occupied by chipping.
Utgödsling på vatten spegel för mjölkkor - lantbrukarnas erfarenheter och effekter på stalluftens kvalitet.
Investeringar i mekaniserade utgödslingsanordningar började göras av svenska lantbrukare i mitten på 1900- talet. Med en hög mekaniseringsgrad följer också fler driftstörningar, avbrott och reparationer. Idag hålls över hälften av Sveriges mjölkkor i lösdriftssystem där två typer av golv kan användas ? hela och dränerande golv (s.k. spaltgolv).
Elhybridteknik i bandvagnssystemet : Den militära nyttan i logistikfunktionen
Fossila bränslen är ändliga resurser och FMV menar i sin Tekniska Prognos 2013 att Försvarsmakten redan nu bör planera för en omställning till alternativa tekniker till dagens förbränningsmotor. Den teknik som verkar mest lämplig som interimslösning mellan framtidens vision om ren eldrift och förbränningsmotorn är elhybridteknik. Uppsatsen undersöker hur Försvarsmaktens logistikfunktion påverkas om bandvagnssystemet skulle övergå till seriehybridteknik. Uppsatsens ansats är kvalitativ med en kombination av textstudier, intervjuer samt ett frågeformulär som besvaras av totalt tre personer fördelat på Amf1, FMTS och I19 där samtliga innehar mångårig erfarenhet av bandvagnssystemet. Formulären kompletteras med intervjuer med dessa personer samt personer på BAE Systems som bidrar med teknisk expertis.
Interacting with EDIT. A Qualitative Study on, and a Re-design of, an Educational Technology System
This thesis aimed to study the interaction between an educational technology system and its users and give suggestions for design improvements. The technology system is called EDIT (Educational Development through Information Technology) and has been developed and applied at Linköping University?s Faculty of Health Science. EDIT supports Problem Based Learning and enables scenarios to be presented through the World Wide Web. The study was divided into two parts.
En förstudie till kvalitetsutveckling på GD-tryck
The print- and mailroom at Gefle Dagblad (GD-tyck) is handling an increasing amount of commercial jobsalong with the newspaper production. Investments have above all been done in the mailroom to be able tooffer commercial costumers a higher degree of finishing and there are plans to expand further in the commercialmarket. GD-tryck is of the opinion that they need to secure the quality of their production to be ableto do such expansion, which is the reason why a quality system of some kind may be appropriate. Howeverthere are no plans to certify such a quality system according to ISO 9001:2000.In this exam report the present methods of working have been analysed from a quality perspective.Suggestions on how GD-tryck should be working with quality development is presented in the fields whereshortage of quality has been discovered. The suggestions taken together do not form a quality system butcan be looked at as ideas of approach to quality fields that have to be developed if a working quality systemshall be accomplished.Many of the quality fields that have been discussed do not have anything to do with technical qualitydirectly but are in some degree requirements for a working quality system.
Anarkistisk klassifikation: förhållandet mellan epistemologi och bibliografisk klassifikation analyserat utifrån Paul Feyerabends anarkistiska teori
The aim of this master?s thesis is to investigate how Paul Feyerabend?s anarchistic theory of knowledge can help our understanding of bibliographical classification and to analyse how epistemological assumptions are manifested in bibliographic classification. Paul Feyerabend?s anarchistic theory of knowledge and science is the theoretical approach of this thesis. The first part of the thesis consists of an introduction to bibliographical classification and epistemology.
Effektivisering av energianvändningen i en förskola
This rapport contains an examination of the energy consumption of a kindergarten, which areas that have the largest impact on the energy consumption and what can be done to reduce those areas in ways that are relatively easy and profitable. It is also analyzed if it is possible to reduce the energy consumption from today?s consumption to a consumption that fulfils the demands placed on low energy houses by FEBY.The focus has been on reducing the energy consumption of the areas ventilation, heating system and hot water system, since those seemed to be the easiest ones to affect and since the building is quite recently built.There are different kinds of ventilation systems, at the moment the building have a CAV-system, which means that the ventilation is too high during large parts of the day. There are different ways to manage the ventilation system, for example presence detection, humidity sensors, CO2 sensors, temperature sensors and season adjustment. Many of those are in the end dependent on CO2 sensors to guarantee a good indoor climate, therefore the focus have been placed on this system.
Klassificering av processutrustning - en grund för riskbaserat underhåll
In this report a systematic working procedure for risk classification of processing equipment from a maintenance point of view is described. How this system has been worked out is also an important part of the report. The classification system is adapted for use in complex processing plants. Preemraff Göteborg has been subject for the underlying study and application of the system.The system aims to give a good overview of the maintenance related risks at the plant. Furthermore, the analysis result is a good motivation for the suggested maintenance activities and as motivation for extended or decreased maintenance resources in total.
Musikjournalisternas nya roll : i den svenska dagspressen
Denna uppsats undersöker hur svenska musikjournalisters roll gentemot sina läsare påverkats av internets utbredning och den ökande fildelningen i samband med den digitala och tekniska utvecklingen. Genom fem kvalitativa intervjuer med musikjournalister från de fyra största tidningarna i Sverige: Dagens nyheter, Svenska dagbladet, Aftonbladet och Expressen, under-söks hur musikjournalisterna själva uppfattar denna utveckling. Med utgångspunkt i teorin om agenda-setting har resultatet sedan analyserats och diskuterats. Slutsatsen är att musikjourna-listernas makt gentemot sina läsare har minskat det senaste decenniet. Läsarna ser inte längre musiksidorna i dagspressen som lika viktiga för deras musikkonsumtion.