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1825 Uppsatser om Hydraulic transport capacity - Sida 2 av 122
Hydraulisk och termisk grundvattenmodellering av ett geoenergilager i Stockholmsåsen
Geothermal energy can be extracted from an aquifer, where the groundwater is used as heatexchange medium while heat and cold are stored in the surrounding material in the aquiferand to some extent in the groundwater. Application of aquifer storage for the use ofgeothermal energy is mainly used in large scale facilities and is limited to sites with suitableaquifers in the form of ridges, sandstone and limestone aquifers.Löwenströmska hospital in the municipality of Upplands Väsby, north of Stockholm, islocated nearby the northern part of the Stockholm esker. This means that it can be profitableand environmentally beneficial for the hospital to examine the possibilities of aquifer storagein the esker material next to its property.The purpose of this master thesis has been to investigate if geothermal energy storage with aseasonal storage of heat and cold can be applied within Löwenströmska hospital?s propertyarea using groundwater modeling. A hydraulic groundwater model was constructed inMODFLOW based on a simplified conceptual model of the groundwater system.
Biochar as soil amendment in flow-through planters - for increased treatment of zinc roof runoff
In times of increased flooding, enhanced by climate change, polluted stormwater poses an increased threat to the environment through contaminated water entering waterways. Bioretention utilizes natural processes in soil and vegetation to treat pollutants and combat this threat. Biochar produced through pyrolysis, has a high cation exchange capacity (CEC) and could therefore increase treatment in bioretention systems. This research applies a literature review, interview, and a model to explore the benefits and disadvantages of biochar in order to specify a soil-mix through an understanding of the production process and preferred application rate. High purification through CEC, increased water holding capacity, and carbon sequestration being the benefits discussed.
Förstudie till våtmark i Rimbo : Design för optimal hydrologi och kväverening
The euthropthication of the Baltic Sea is a threat that is beginning to be taken seriously by the governments concerned. In Sweden, regulations concerning the allowed nitrogen (N) concentration in the effluent water from wastewater treatment plants are being tightened up. The Rimbo wastewater treatment plant has been imposed to reduce the annual mean concentration of total N in the effluent water to levels below 15 mg l-1. A more and more common way to reduce the nitrogen level in wastewater is to let the water pass through a wetland. This study investigates the possibility to build this kind of wetland at the outlet of the Rimbo wastewater treatment plant.A prestudy of the topography, soil characteristics and groundwater flow indicates that the land area in question is well suited for the construction of a wetland.
Oljefilmens tjocklek mellan kolvring och cylinderlopp
Hägglunds Drives in Mellansel, Sweden, manufacture radial piston hydraulic motors foremostwithin applications in the industry. These motors have several sliding contacts, one of these, isthe contact between piston ring and cylinder bore. The radial piston hydraulic motors advantageis to produce high torque in very low rotation velocity, this result in that the maximum slidingvelocity between piston ring and cylinder bore, during the whole stroke, is very low. Theconsequence of this low sliding velocity is that the contact between piston ring and cylinderbore, during the whole stroke, is bound to the boundary lubrication regime. This result in, thatthe piston ring is exposed to wear, thus affect the service life of the complete hydraulic motor.To minimize wear of piston ring, it is essential to determine the oil film thickness between thepiston ring and cylinder bore.
Spridning av bekämpningsmedel i banvall : Modellutveckling och känslighetsanalys
The stability of railway embankment is essential for safe transport. In order to ensure safe transport, water should be allowed to freely drain. Furthermore, as the engine driver has to be able to see signs, and people working on the embankment are supposed to easily see flaws on the rails to ensure safety for the passing trains, plants should not be allowed to grow on the embankment. In Sweden there are 12 000 kilometers of railway tracks and 25?30 % of them are treated for weed control every year.
TCP/IP i taktiska ad hoc-nät
TCP (Transmission Control Protocol) is a transport protocol designed for the wired Internet. In wireless networks packet losses occur more frequently due to the unreliability of the physical link. The main problem is that TCP treats all losses as congestion, which leads to a lower throughput. Ad hoc networks are multihop wireless networks of mobile nodes, where each node can allow other packets to pass through it. Topology changes often occur and may lead to packet losses and delays, which TCP misinterprets as congestion.
Kartläggning av ruttplaneringsprocesser för rundvirkestransportörer
Transportation represents 10-15 % of wood supply costs. It is therefore important to improve efficiency in the transport system to decrease these costs. The aim of this study is to map the timber vehicle routing processes used by a sample of timber hauling contractors and to identify possible links between the vehicle routing process and service and economic variables. The study was carried out at Södra Skog in autumn 2008. 15 timber hauling contractors were sampled and interviewed about their work with timber transports.
Berättelse och mekaniker i konflikt : Ludonarrativ dissonans effekt på narrativ transport
För att kunna skapa intressanta och engagerande berättelser i spel behövs förståelse för hur spels unika egenskaper påverkar berättande. Ett spelnarrativa kan delas upp i det inbäddade narrativet, som består av till exempel texter och dialog, samt det emergenta narrativet, som uppstår ur spelets gameplay. När dessa två delar inte stämmer överens uppstår ludonarrativ dissonans. I detta arbete undersöks hur ludonarrativ dissonans påverkar narrativ transport, det vill säga inlevelse i en berättelse. Två versioner av ett berättelsedrivet spel skapades med olika mekanikerna för att uppnå låg respektive hög ludonarrativ dissonans.
Gemensamberedningen av EU:s Maritima Grönbok ur ett Resiliensperspektiv : En studie om den adaptiva kapaciteten i Regeringskansliets inre processer
The study aims to give a description of the conditions in which matters is prepared withinSwedish Government`s offices, to describe the adaptive capacity in the agency`s internalprocesses by investigating the experiences of some civil servants restricted to the Ministry ofEnterprise and the Ministry of Environment in their work with the EU Maritime Policy GreenPaper. The results have been analyzed against the basis of eight identified criteria of buildingadaptive capacity in socially dominated systems. The criteria are comprised of both individualand organizational abilities. Only two of them were fully met; the criteria about diversity inexperiences and knowledge and the criteria about information and how the information hasbeen applied. However, the process has traces of all the identified criteria.
Impact of EU-regulation on pigs? welfare during transport
Each year 225 million pigs are transported within the European Union (EU) for slaughter, fattening and breeding. This results in poor animal welfare due to the fact that animals are exposed to several numbers of stress factors in the vehicle during loading, transit and unloading. Animal welfare can be defined as how well the animal attempts to cope with its environment and during transport there is often severe difficulty for the pigs to cope properly. There is a growing societal concern for animal welfare. This resulted in that the European Union enacted a law called the EU-regulation with certain directives of how to improve the welfare of the animals during transport.
Effekten av uteblivna miljöersättningar för anläggning av våtmarker
Environmental subsidies are used as incitements to farmers for development of sustainable land use. In 2014, applications for funding constructed wetlands were not available. This paper examines the environmental consequences of this lack of funding in one intensively cultivated region Skåne län, southern Sweden.A review of wetland applications between year 2007-2013 show that the average rate of applications has been 31 projects per year with a wetland size of 4,48 ± 1,61ha per project (mean±95% CI). Based on interviews, the result suggests that the lack of funding in one year leads to between 102 and 140 ha of constructed wetlands that is not built. This correspond to a total loss of increased nitrogen retention capacity between 6,0 and 91,7 tons/year and a loss of increased phosphorus retention capacity between 0,17and 2,1 tons/year in the drainage basins of Skåne.Further the interviews show that continuity of environmental regulations and funding is important for the farmers? interest in environmental measures.It is concluded that the total loss of increased retention capacity is small compared to the annual transport of nitrogen and phosphorus in the drainage basins.
Fiberföstärkning av Limträbalkar
Glulam is a product that was engineered to make use of timber in a more efficient way. Bychoosing timber of similar quality and discarding natural defects during production, thedevelopment of a stronger cross-section is achieved.Carbon fiber is a relatively new material with a high tension capacity. This feature is used toexamine how the bending capacity of the beams improve by adhering carbon fiber laminateson the lower edge of the beamsThe strength of the material is tested with three experiments: carbon fiber on the bottom of thebeam (a), carbon fiber attached to the lower sides of the beam (b) and carbon fiber in thebeam, covered with a layer of wood (c)The results show that the first case, where the carbon fiber is attached to the bottom of thebeam, gave the best result with an increase in capacity of 59 % compared to the nonreinforcedcontrol. The other two cases also show an improvement in capacity, beam-type 3had a capacity increase of 47% and beam-type 4 increased with 25 %Tests were also made with glulam beams reinforced with fiberglass, but these tests were notanalyzed in depth because the purpose was to compare the capacity to carbon fiber. Thisbeam improved its capacity by 40.3%.The tests show that carbon fiber as a reinforcement material for glulam is a good choice whenthere is a requirement for stronger cross-sections in both new production and renovation ofold buildings.
H?LLBARA INTERMODALA TRANSPORTER I EU En studie om EU:s transportpolitiks inflytande p? samverkan mellan transportslag f?r h?llbar mobilitet
The transport sector is one of the biggest pollutants in the European Union. In relation to
transport policies and environmental policies, intermodal transportation solutions are of high
relevance to establish a sustainable transport sector for the future. Intermodality which is
defined as smooth transition between transport modes is a key figure for how modal shares
are divided between the modes of transportation. The aim of this bachelor?s thesis is to
examine the research gap whether policies intended for a specific transport mode affects each
other in relation to EU policies intended for intermodality.
Samspelseffekter vid kapacitetsförbättringar. : Exempel från Dalabanan.
The trend in the transport sector is moving towards eco-friendly, fast and convenient transportation,this results in higher demands on railway transports. To meet the demand and quality requirements,the Swedish railway network will have to expand. The cheapest way is to expand little by little butwhat impact do these small steps actually have on the capacity?This thesis examines the interactions of different improvement for the capacity on a single-trackrailway. Through simulations in the software tool RailSys this report studies what effect block signals,extra meeting stations and rebuilding existing two track passing loops to three track loops have onthe capacity.
Spatial TDMA in Ad Hoc Networks with Antenna Arrays
In modern military operations the requirements of transmitting large amounts of information have increased substantially during the last decade. This increases the demand for high-capacity radio networks. It is also very important that military decisions are made on recent and correct information and this implies that low and known delays are required. The existing military radio ommunications, within the Swedish army, do not meet the requirements for capacity and delay. We have investigated how the capacity and average delay can be improved in an Ad Hoc network with STDMA by using antenna arrays.