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1021 Uppsatser om Zero flow - Sida 39 av 69

Lagring av kyla med horisontella markvärmeväxlare för kylning av koncepthus i Mellanöstern

Norconsult AB has developed a solarhousing concept, a house designed for the warm climate in the Middle East andwith large quantities of solar panels installed. The cooling system for the house was designed in an earlier report, the purpose of this thesis is to investigate the possibility of short and long term storage of thermal energy via an underground energy storage volume.Two different designs of the storage and three different filling materials have been integrated into a model to simulate different cases. The first design consisted of pipes installed in the ground, without insulation. The second design consisted of an insulated concrete box installed to prevent thermal energy from the surrounding soil to flow towards the lower temperature regions within the storage. The three different filling materials were dry saudi sand, water saturated saudi sand and the filling material used by the client for energy storage in Sweden.The results from the simulations show that neither of the designs, regardless of the filling material, managed to extract enough thermal energy from the house to the ground to uphold the demands of indoor climate.

Förhållandet mellan hudblodflöde och fysisk aktivitet.

SAMMAMFATTNINGBakgrund: Reaktiv hyperemi definieras som ett övergående ökat blodflöde över det normala efter en tids ischemi. Det kan registreras med laserdopplerteknik. Att registrera reaktiv hyperemi är ett sätt att värdera mikrocirkulationen. Det finns många flödesvariabler att studera varav tid till maxflöde efter ocklusion är en. Det har gjorts studier som undersöker om det finns ett samband mellan reaktiv hyperemi och fysisk aktivitet/syreupptagningsförmåga.

Energi- och exergiflöden i stålframställningsprocesser vid
SSAB Tunnplåt AB i Luleå

Energy costs are high nowadays and that is the reason why the energy consumption needs to become as small as possible in most of the companies. To accomplish the small energy usage one needs to map the energy flows, study them and monitor them. One method that can be used for this is energy balance calculation. The method gives an opportunity to separate different energy flows and see where each flow is heading. There is also another method which is more advanced than energy balance calculation.

Skapandet av ett integrerat ledningssystem

To be able to compete on the market environmental Management System has become an important part of operations work. However, many companies still haven?t implemented an environmental management systems due to lack of time and the high costs. One of the companies with this problem is Falu Bildemontering. Their goal is to accredited according to the ISO 14 001 certificate.

Optimering av driftläggningar i Fortums nät

Future emission legislation puts great emphasis on increasing the efficiency of the engine, thereby reducing fuel consumption. The tribological contact between cylinder liner and piston ring is where an great amount of energy is lost due to friction, and by reducing these losses an reduction in fuel consumption can be achieved.The aim of this thesis was to evaluate the tested piston ring coatings against a plasma sprayed cylinder liner and rank these combinations of materials for friction and wear resistance. The coatings that were tested was Cr + Al2O3, (Al,Cr)N, two types of CrN and WC / C.The experimental tests were performed with a so-called pin-plate, where used oil with addition of an acidic mixture of sulfuric and nitric acid to mimic the acidic condensate formed when exhausts recirculate, were added with a continuous flow. The results were then analyzed by weighing, studies by optical microscopy and scanning electron microscopy (SEM) and profile measurements.The results from each material combination were that the plasma coated cylinder liner wears too aggressively in order to yield a ranking of the piston ring coatings based on the parameters of friction and wear resistance. It is therefore proposed that an alternative coating on the cylinder liner should be developed, lacking the large abrasive wear on piston rings and that can withstand the corrosive environment resulting in engines equipped with EGR.

Makten över kommunikationen : en kvalitativ studie av kommunikatörens yrkesroll

The communicator has a professional role which is relatively unspecified and hard to define. To work with communication can mean several different tasks, who also might vary between different types of organizations. The purpose with our study is to clarify the professional title communicator and its meaning. By applying a power perspective on the communicators experienced professional role in meaning to find out who has the power over the communication.     Our study is made of qualitative interviews with four professional communicators working in private organizations. We have used semi structured interviews in our study which means that we before we went through with the interviews defined themes which the interviews were built upon.

Bättre åtkomst till avverkningstrakter med anpassat marktryck från avverkningsmaskinerna

The global climate-change means increasing mean-temperature and higher precipitation in Sweden, which leads to shorter periods of frozen ground in the forest. At the same time the harvesting machines are getting bigger and more powerful. The forest industry aim at an even wood flow, and the ground damage has to be as low as possible. The two biggest causes for ground-damage is the bearing capacity of the forest ground and the ground-pressure of the harvesting machines. The aim of this study was to find out some rules for the machine choice considering ground pressure, when harvesting on ground with low bearing capacity.A field study, using a Valmet 890.3 forwarder, was carried out where different ground pressures and their effect on the ground were tested on two different types of ground.Additionally, an inventory of damaged harvesting grounds was made.

Varför är Bivarödsånsvatten så brunt?

The river Bivaröd is one of the river Helgeån tributaries which has the highest and the fastest increase in water colour. The reason behind this increase is unclear but several factors have been suggested to affect this pattern. In this work, I studied the role of land use, iron and precipitation for water colour increase in river Bivaröd for the period 1976 -2011. Data from a field study along with data from SRK for river Helgeån were used for the analyses. The results showed that both water colour and iron concentration increase and that there is a strong correlation between these two variables.

Kapitalreglering - Finansmarknadernas räddning, eller bara ett spel för galleriet?

Background: The regulation of banks is increasing in order to stabilize the financial market. Despite this increase in regulation, financial crises still continue to occur. The Basel Committee on Banking Supervision is gradually increasing the capital requirements for banks, yet the increase in capital requirements doesn?t seem to solve the problem. This raises the question: how does capital regulation affect banks? Purpose: The purpose of this study is, primarily to illustrate the effects that capital regulation has on risk and efficiency on banks within the European Union, but secondary also study the relationship between risk, efficiency and capital regulation.Method: To achieve the purpose of this study, a deductive approach has been used, where the problem is assumed to be due to an agency problem.

Tillägnande av ordförråd hos sent anlända elever i nationella gymnasiekurser

AbstractIt is unclear how L2 students acquire vocabulary ? how is it taught ? or wheather it can even be taught. In an SSL (Swedish as second language) program for young adults the ambition has been to integrate the L2 students? into the national high school (gymnasium) courses as quickly as possible, in order to meet the students? demands for subject education and to challenge them on an appropriate knowledge level. Teachers noticed quite early that the course ? integrated L2 students seemed to have a deeper understanding of words and an easier flow in their speech.

Gestaltningsförslag till ny förskola på Zakrisdal

Due to increasing regulations regarding new diesel vehicles particulate matteremissions the new Scania truck, Scania Euro 6, has been equipped with a particulatefilter. This component effectively stores the particles in the exhaust gas but must becleaned in order to prevent itself from clogging. The filter is cleaned through aprocess named regeneration which is a thermodynamic process in which thetemperature of the filter is raised through fuel supplied to the exhaust gas.The purpose of this thesis is to contribute to the development of improved controlstrategies of the temperature during the regeneration process through thedevelopment of model-based controllers. These controllers are designed in order tohave good performance in stationary as well as automatic regeneration.In order to develop these model-based controllers a model of the system isconstructed. The model is described as a linear thermodynamic grey-box model withflow varying parameters, showing good results in validation.The model provides a simulation environment during the controller design, which isfocused around the development of linear regulators with the exhaust gas mass flowas a scheduling variable whose size determines controllers? mode of operation.

Jämförande simulering och modellering av framtida järnvägars elenergiförsörjning

In this thesis, the Train Power System Simulator (TPSS) has been compared and verified with the commercial simulator TracFeed® Simulation (TracFeed). The basis for the comparison was a given part of the Swedish railway system, with steel transportation trains. Primarily, emphasis was placed on running time and energy consumption in simulation results. Two transformer systems were analyzed, booster and auto transformers. The high voltage transmission line, parallel to the railroad track, was disconnected in some simulations.

FPGA för displayhantering och grafikgenerering i fordonsmiljö

This report is part of the major thesis carried out at Stoneridge Electronics in Bromma,Stockholm during autumn and winter 2005-2006. The background to the thesis is the trendwithin the automotive industry where color displays have become more common for presentationof information to the driver, a trend that has come to the commercial vehicle market. Thepurpose of the thesis has been to evaluate whether programmable logic, with respect to FPGAtechnology, could be suitable for display control and graphics generation of these more complexcolor displays in automotive environment.Within the scope of the thesis the FPGA technology has been investigated, i.e. whatopportunities and threats there are with aspect to environmental and security requirements. Inaddition, the market of FPGAs and pre-built IP-cores has been investigated.

Effekterna av praktisk ocklusionsträning periodiserat med ett traditionellt styrketräningsprogram på anaerob prestation

Background: Practical blood flow restriction (pBFR) combined with resistance training has been proven to facilitate muscle strength despite training at low intensity. However, research investigating the effects of long-term pBFR-training and its periodization with strength training (ST) at a higher intensity is lacking, as well as the effects of occlusion training on blood lactate levels (BLL) over time.Purpose: To compare the effects of 2 weeks of pBFR training followed by 2 weeks of ST (BFR-ST) with 2 weeks of ST followed by 2 weeks of pBFR training (ST-BFR) on anaerobic performace and BLL.Method: 5 adults (age 23 ± 2 years) with a minimum of 1 year of ST experience were recruited and randomized into BFR-ST (n=2) or ST-BFR (n=3). Anaerobic performance was measured using a 30-s Wingate-test and BLL samples were collected <1 and 5 minutes post-Wingate. Data and samples were collected before the intervention and after the 2 protocols.Results: No differences were seen between groups in anaerobic output or BLL after 4 weeks of training (p>0,1 for all values). A decrease in time to peak power (tPP) were seen in both groups with an advantage for BFR-ST (-37 ± 8 %) over ST-BFR (-27 ± 22 %).

Utveckling av produktionslina

The company is currently in a stage of improvement and has therefore taken the help of students at School of Engineering, Jonkoping University. The current production is batch, production layout is fixed. A bottleneck is created after the first station which leads to large efficiency loss.  The meaning of this report was to provide a layout suggestion with balanced workstations to a new production line. The conditions were that the production line would be one-way, driven by customers order and meet a demand of 40 products per week.

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