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945 Uppsatser om Stability calculations - Sida 49 av 63
Projektering av småhus med solvärme som huvudkälla
In this report a study has been done regarding different heating systems on which are the mostcomprehensive with solar heating systems. The report has also been focusing if solar power can beused as a primary heating source for supplying more than 50 % of the buildings total heatingproduction. The University of Dalarna constructed a demo-house for this purpose and according tocalculations the total solar usage is more than 50 %. This house has been made for referenceregarding the design of the heating system of property 5:37.Further studies have been made to compare different heating systems that are compatible with asolar system, where the compared systems purpose is to be independent of direct using electricity. Asystem of this design is regarded as sustainable according to environmental as economic issues.
Utvärdering av ett system för Rapid Control Prototyping inom området robotstyrning
In this report a system for Rapid Control Prototyping, RCP, is evaluated through animplementation of the motor control methods Field Oriented Control, FOC, and Space VectorPulse Width Modulation, SVPWM. The evaluation emphasizes on time-consumption andresource utilization on the used hardware and on usability for of software.A new mechatronic laboratory is under development at ABB Corporate Research in Västerås. Itwill be used for both mechanical and motion control design using existing and new hardware.The control structure in a traditional robot system will be interfaced to a rapid prototypingsystem which should allow easy changes to algorithms at different levels in the system.The system designated for this project comes from National Instruments and constitutesLabVIEW Real-time and FPGA module as the software tools. The hardware is a NI Single-Board RIO (Reconfigurable Input Output), sbRIO, development board including a Field-Programmable Gate Array, FPGA, from Xilinx and a microprocessor from FreescaleSemiconductor. Graphical programming is performed in the LabVIEW environment, andthrough Xilinx tools the LabVIEW FPGA code is compiled to VHDL code.A pre-study was carried out to clarify the concept of RCP and investigate different systems forRCP and their traits.
Detektor på skördare för utsortering av träd med metallskrot
Fortifikationsverket which is the landlord for the Swedish national defence has a great problem in their forestry due to the relatively large amount of metal objects in their timber. These metal objects cause different types of economical losses in the timber refinement chain. To enable out sorting of logs containing metal objects already in the harvesting phase, Fortifikationsverket is interested of the possibility to utilize some type of metal detector in a harvesting head for that purpose.The goal of this study was to, with help of a case study, enlighten the problem that metal objects in timber cause for Fortifikationsverket and their customers of timber and to investigate conditions of to mount and utilize some kind of metal detector in a harvesting head at present.The saw timber deliveries by Fortifikationsverket during the time period 2003-2005 was used as a reference volume for calculations of economical losses. In this case study was included two sawmills where timber from Fortifikationsverket were delivered to for further refinement. Factors investigated were the type of damage metal objects caused in these two sawmills and the economical signification of these damages.
Dimensionering av Traverskranbana
Kranlaster som verkar på kranbanor varierar med tiden och kan inte behandlas som statiska laster, detta gör att en statisk beräkning inte är tillräckligt säker, därför bör kranbalkar utformas på så sett att den klarar av statiska såväl som dynamiska kranlaster.Arbetet valdes efter förstudier som gjordes på internet för att få grundläggande kunskap om ämnet. Informationen söktes på svenska, engelska och tyska för att kunna hitta relevanta och pålitliga källor som behandlar traverskranbanor enligt eurokod. Tack vare råd från Björn Åsted från Stålbyggnadsinstitutet (SBI), kunde en bok på tyska hittas. För att kunna jämföra resultaten används ett svenskt program CraneGirder EC3 under arbetet.Rapporten innehåller en beräkningsmodell för en valsad profil balk, beräkningar baserades på eurokod ekvationer och föreskrifter vilket var som dimensionerings underlag för arbetet. I denna rapport hänvisas hur en kranbana skall dimensioneras med hög utnyttjandegrad, ett antal kontroller gjordes för att säkerställa att balken och dess detaljer, såsom räl och svets är säkert utformade mot utmattning och deformation.
Korrelation mellan hållfasthet i kalkcementpelare och oförstärkt lera : En studie av sonderingar utförda på projekt BanaVäg i Väst
A today common soil reinforcement method is the installation of lime-cement columns. Lime-cement columns have been used since the 1970?s and have been a useful method for stabilizing soil at great depths. It is mostly used for stabilizing road and railway embankments because the method is economically viable and the columns are easy to install. The total costs for the installation of the lime-cement columns is dependent on the numbers of installed columns, what percentage of lime and cement that has been used and the pattern in which the columns has been installed.
Buskröjning längs skogsbilvägar : en produktivitetsstudie av två kättingslagor
To regularly remove woody vegetation along the roadside of forest roads is an important part of the road maintenance, since the vegetation binds moisture in the road side and, thus, the removal makes the road drying faster with results in improved bearing capacity. Vegetation removal also makes it easier to upgrade the road by material recycling from the ditch and, moreover, the visibility along the road is maintained.The aim of the study was to evaluate what type of chain flail is the best and most cost-effective for removal of different kind of woody vegetation along forest roadsides.Time studies were made on two chain flails when removing woody vegetation in three different classes; easy-, middle- and heavy shrub removal. The studied flails were one light and rather simple flail named Optimal M160 and a heavier and more advanced flail named Slagkraft H210. The removal was made according to Holmen Skogs? specification and the quality of the cleaning was measured by objective belt inventory.The productivity was higher with the heavy flail within all cleaning classes.
Samordnad varudistribution : Jämförelse mellan två logistikmodeller med nuläget i Sundsvalls Stenstad
As the cities are becoming more crowded, the urban distribution has become a major logistical challenge. Some commonproblems in the inner cities arelimited accessibility and idling. Many of Sweden's municipalities are above the limit values for PM10limit set by the EU.Sundsvall is one of these municipalities and has the vision to create a sustainable city and region. Sundsvall LogistikparkAB is part of an EU project, SMARTSET, which is collaborationbetween several cities in Europe. SMARTSETSundsvall is about to develop a market-based sustainable model for city logistics.
Energieffektivisering genom förvärmning av flis till kokare med sekundärvärme
The Swedish pulp and paper industry meets higher demand for energy efficiencyi mprovements with increasing energy prices and changes in the Swedish renewable energy certificate system. One action of energy efficiency improvement is by using secondary heat, that otherwise would have been treated as waste heat, for use in a system with lower temperature demands. The aim of this Master´s thesis is to identify possible secondary heat sources in a typical Swedish pulp and paper mill and to investigate what economic benefits the secondary heat will provide when being used for pre heating of wood chips to a kraft digester.The Master´s thesis focuses on three secondary heat sources; dry warm air, warm water and moisture saturated warm air located inside the pulp or paper mill. Two types of kraft digesters are simulated within this study, a typical Scandinavian digester and a modern twin vessel steam phase digester.Due to quality aspects and low temperature level drying is the drying technology with dry warm air rejected. Using warm water in direct contact with wood chips increases the quantity of water to the evaporation plant and thus reduced pulp or paper production and is therefore also rejected.
"Fettskatten" - ett sätt att banta de samhällsekonomiska kostnaderna till följd av övervikt?
The rise in prevalence and severity of obesity and related diseases imposes increasing costs on society. The objective of this thesis is to discuss and estimate the possible effects of a so-called fat tax as a tool for minimizing these costs. Two alternatives for differentiation of the value-added tax (VAT) on food are compared. The first alternative is an increase of the VAT levied on food containing saturated fatty acids. The second alternative is a subsidy on fruit and vegetables in the form of a VAT at zero percent, instead of today?s twelve percent.
Analys av energianvändningen i kvarteren Carolina och Jenny : en fallstudie
An energy study has been performed on two blocks in an area called Gävle Strand. The buildings are owned by a tenant-owner?s association called brf Carolina and were built by the company Skanska 2008. The builder as well as brf Carolina are pussled by the fact that electricity use is higher than expected while heating is less. Skanska is also very interested in finding out how much heat recovery from stale exhaust air through a geo-thermal heat pump is contributing to the general heating requirement and energy balance in four out of the ten buildings located on the properties.To find possible answers to the higher electricity use a literature survey on user behaviour was conducted.
Robotfotboll
SUMMARYInventory of raw materials holds an important role in companies within the manufacturingsector. The inventory works as a buffer that secure the supply of materials to the productionunit. The aim of the inventory is to ensure that the company is able to meet the customers?demands despite fluctuations and variations in the material flow. The size of the warehouseand the layout are physical limitations for the quantity of articles that can be stored.
Dimensionering av grundläggning med hjälp av Eurokod
AbstractWork to develop the Eurocodes started in 1975 by the European Commission adopted a program to eliminate trade barriers within the construction area. The goal was to create common European design standards that would replace the member countries' own rules. Eurocodes will replace The National Board of Housing Building and Planning, National Rail, The National Road Administration and other agencies' calculation rules for the buildings structures. The transition to the use of Eurocodes looks like this:Eurocodes set to Swedish standards between 2002 ? 2007They can be used parallel with national standards 2006 - 2009 The total transition is at the end of 2010/2011.Right now is going on a lot of work for replacement of the existing standards to Eurocodes. The transition to the new calculations` standards, many construction companies and consulting firms facing a big changes and competitions.
Studie av energianvändningen på Spira förskola: En jämförande studie av faktiskt och simulerad energianvändning samt en parameterstudie av ingående data vid simuleringar av energianvändning
I detta arbete har den faktiska och simulerade energianvändningen på Spira förskola i Luleå undersökts. Den faktiska specifika normalårskorrigerade energianvändningen fastställdes till 121,4 kWh/kvm år. Vid projektering av förskolan uppskattades den specifika energianvändningen med hjälp av simuleringsprogrammet VIP-Energy till 78,5 kWh/m2 år. Därmed översteg den verkliga användningen den simulerade med 54,6 %.En parameterstudie av indata till simuleringsprogramet har också genomförts med avsikt att fastställa den totala förändringen i energianvändning då indata ändras. Följande parametrar har studerats;?Drifttid hos ventilationssystemet?Horisontvinkel?Inomhustemperatur?Klimatzonen?Kvot mellan till- och frånluft?Luftomsättning för ventilationssystemet?Solreflektion från omgivande mark?Temperaturverkningsgrad?Vindhastighet?Vridning av byggnadenNyckeltal som kan användas för att snabbt uppskatta påverkan på den totala energianvändningen har också sammanställts för majoriteten av de studerade parametrarna.
Kvarteret Kajutan - Från lågenergi till plusenergi
Energy and environmental demands regarding buildings have become an increasinglydiscussed topic, both in Sweden and in Europe as a whole. The general trend indicatesthat greater efforts are being put into the energy efficiency of the built environment.There are already numerous examples of houses with a low energy demand, and thenumber of low energy buildings is constantly growing.At the time being, the maximum level for energy demands for housing in Stockholm is110 kWh/m2year, but as soon as next year the limit will be changed to 90. The Swedishagency Energimyndigheten is currently conducting a project to interpret the EU Directiveon the so-called Nearly zero energy buildings, and the preliminary results indicate thatthe level of requirements for purchased energy will end up with about 55 kWh / m2year,which is in line withtoday?s recommendationsfound in FEBY's Kravspecifikation förPassivhus.Starting with a low-energy house in Henriksdalshamnen in Stockholm, we have analyzedvarious energy-efficiency measures and their influence on power and energy needs. Thefinancial aspects associated with the measures have been studied using a model of lifecycle costs.The measures were initially studied individually to give an idea of how much impact theyeach had.
Livscykelanalys för koldioxidutsläpp från flerbostadshus
Today, about 15 to 20 percent of Sweden?s total emission of carbon dioxide can be traced to the household sector. By examining apartment blocks in a life cycle perspective, the origin of the carbon dioxide emission has been charted and analyzed. This information has been used to create a computational model that calculates the total emission of carbon dioxide from a specific apartment block. The results from the analyzed apartment blocks indicate that both the use of energy and the emission of carbon dioxide have been reduced since the 1960s. Through the examination of building materials, it is possible to lower the emission of carbon dioxide that origins from the construction phase of an apartment block.