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884 Uppsatser om Hydraulic engineering - Sida 1 av 59

Energivinst vid hybridisering av hydrauliskt system

Today's high oil prices and more stringent environmental requirements have led to that manufacturers of mobile construction equipment try to make their products more energy efficient. With this in mind a project about hybridization of hydraulic systems has been formed. The purpose of this project was to analyze the savings that can be achieved by hybridization of hydraulic systems. A reach stacker truck (Kalmar DRD450-80S4XS) were simulated in some load cases with conventional hydraulic systems and with three types of hybridized hydraulic systems. Different parts of the hydraulic systems were also analyzed separately.

Styrtransmission för bandfordon

The purpose of this master thesis is to construct a steering transmission, for a trackedvehicle, containing two hydraulic circuits which are connected. The steeringtransmission should be mechanical to avoid steer-by-wire.BAE Systems Hägglunds has in an earlier study examined a system with two hydraulicpumps and one hydraulic motor, but the safety of the system wasn?t sufficient.To achieve sufficient redundancy there must be two hydraulic motors, which arecontrolled separately. When the two systems are connected in one point, this point is acritical part of the system because it directly affects both circuits. If one of the hydrauliccircuits fails the other should be able to operate independently as a steeringtransmission.

Sensor för hydraulolja

This is the final documentation of the basis that can be the foundation of how to solve theproblem with leaking hydraulic oil in a shoe press at the company Albany InternationalAB in Halmstad, Sweden.The project has been performed at Halmstad University as a degree project commissionedby Albany International AB. The purpose of the degree project was to find a way ofdetecting the hydraulic leak of a shoe press. The reason is that the shoe press runsunattended during nights and weekends, this can cause an extensive decontaminationwork and production stop if leak. The hydraulic oil could be leaking in large amounts orslowly as a fine mist. The development of a working system that can detect a hydraulicoil leak and stop the machine before a large amount of hydraulic oil leaks out wouldconsiderably reduce the cost of the decontamination work.

Provning av parallellkopplade hydraulpumpar i hjullastare

Volvo Construction Equipment is a world leading company in construction machinery. Tomaintain the best products, development is prioritized. The master thesis regards sound reductionof the hydraulic system on a wheel loader. The background to the master thesis is asimulation made on the hydraulic system, performed autumn 2005. The result of the simulationshows that the energy of the pressure ripple is reduced when the paralleled hydraulicpumps are phase shifted and reduces each others pump pulsations.

Social Engineering : En studie om medvetenhet och förebyggande åtgärder mot Social Engineering på svenska organisationer 

Abstrakt Social Engineering är konsten att manipulera människor, för att på så sätt vinna deras förtroende. Med hjälp av detta förtroende kan attackeraren sedan kringgå säkerhetssystem och få tillgång till organisationers information. Vi har i denna uppsats genomfört elva intervjuer på tre stora organisationer med både IT-chefer och övrig personal. Med dessa intervjuer har vi sedan försökt få en bild av hur medvetenheten ser ut samt vilka åtgärder organisationerna tar för att förhindra Social Engineering. Med denna uppsats vill vi belysa den ovisshet som råder kring Social Engineering, men även farorna och hur effektiv en attack av denna typ kan vara.

En analys av steg och konsekvenser vid införande av MVC

Abstract The purpose of this essay is to find difficulties and risks in the re-engineering process when restructuring to Model-View-Controller (MVC). A thoroughly theory study has been conducted to be able to understand the important steps in the re-engineering process. The methods and concepts of this essay are re-engineering, UML, system development life cycle, design patterns and MVC. The science approach used is design science where the artifact being developed are a set of models.In the analysis phase of the process the system is analyzed. The result of the analysis is notes of difficulties found and models showing the structure of the system.

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.

Grundvattenmodellering i Badelundaåsen

Over an extended period of time there have been plans to establish a shared facility in Lennheden to extract groundwater from the Badelunda esker to provide drinking water for the cities of Borlänge and Falun. The city of Falun is dissatisfied with the quality of its drinking water and the city of Borlänge is concerned about the risk of contamination of its existing groundwater supply at its current location. To provide a basis for a decision on this issue, the company Midvatten AB has been commissioned to perform hydrogeological investigations in the area of Lennheden.The purpose of this thesis is to design a functional groundwater model of the area between Lennheden, place of planned extraction, and Övre Tjärna, place of existing extraction, to get a better understanding of the groundwater situation in the area. A groundwater model enables simulations of different scenarios in risk assessment and contaminant transport. The aim of the thesis is that the model can be used as an aid in Midvatten?s investigations in Lennheden and that it also can be used in future projects in the area.The model has been made in Processing Modflow 5.3 and encompasses an area of 19,5 × 11 km along the Badelunda esker and the river Dalälven between Djurmo and Frostbrunnsdalen.

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.

Reverse engineering : En processkartläggning på reverse engineering

Alstom Power Sweden AB in Norrköping isexpanding their business in the presentsituation and has implemented aprocedure for reverse engineering as apart of this work. Reverse engineeringat Alstom is an extensive procedurethat is calculated to be performedunder very time demanding conditions.This thesis is a continued exertion ofthe implementation process in order toidentify and describe the mostimportant process steps in purpose to beable to manage and improve theprocess.This thesis was written with twoprimary objectives. The first was todescribe and map out the procedure torecreate technical data of a turbineblade, based on a validation of thereverse engineering process that hasbeen performed at Alstom in Norrköping.The second purpose was to describe thekey factors to achieve successful usageof reverse engineering that have beennoticed in the literature study.The work is based on a literature studyon the subject reverse engineeringwhich produced the theoreticalknowledge of the method to reproducetechnical data to a product. Theliterature study has also led to adescription of reverse engineering froma legal perspective to clarify how farit is allowed to apply the methodaccording to the patent laws. With theliterature study as support and furtherhelp and guidance from individualswithin the reverse engineering unit atAlstom, a complete picture andunderstanding of the process has beenproduced and documented..

Social-engineering ett hot mot informationssäkerheten?

Den här rapporten tar upp ett annorlunda hot mot informationssäkerheten, som inte hårdvaraeller mjukvara kan stoppa. Detta hot kallas för social-engineering, och det som gör detta hotfarligt är att de anställda och chefer i en organisation, kan hjälpa utövaren av socialengineeringutan att de själva vet om det.Det går inte att förhindra att dessa attacker sker, men man kan förhindra de negativakonsekvenserna av en sådan attack. Denna rapport tar upp hur man ska göra för att enorganisation ska kunna fortsätta med sin verksamhet, efter en attack av social-engineering. Ivärsta fall kan en attack av social-engineering innebära att ett företag aldrig återhämtar sig.Detta kan bero på att organisationen har förlorat alla sina kunder, förlorat marknads andelar,eller för att de ansvariga och viktiga personerna i organisationen har blivit dömda föroaktsamhet och sitter i fängelse.Denna rapport ska informera och få er att vara uppmärksamma och medvetna om dessahot, som ni kanske inte vet finns. Ni ska få kunskap och lära er känna igen de olikaförklädnaderna en utövare av social-engineering antar..

Social Engineering : En fallstudie i informationssäkerhet och säkerhetsmedvetande i en stor offentlig organisation

Social engineering handlar om metoder för att infiltrera organisationers datorsystemgenom att manipulera eller utnyttja användarna för att komma över information. Det är idag ett betydande säkerhetsproblem eftersom få organisationer utbildar sin personal i att hantera den här typen av angrepp. Med den här uppsatsen vill vi undersöka fenomenet. Intervjuer har utförts inom en stor organisation för att få inblick i hur stor medvetenheten om fenomenet är och vad som görs för att skydda sig emot det. Det finns tydliga tecken på att social engineering fortfarande är ett relativt okänt område som inte har spenderats tillräckligt med resurser på.

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.

Trådlösa nätverk i hemmet : Säkerhetsmedvetenhet och utbildningsbehov

Abstrakt Social Engineering är konsten att manipulera människor, för att på så sätt vinna deras förtroende. Med hjälp av detta förtroende kan attackeraren sedan kringgå säkerhetssystem och få tillgång till organisationers information. Vi har i denna uppsats genomfört elva intervjuer på tre stora organisationer med både IT-chefer och övrig personal. Med dessa intervjuer har vi sedan försökt få en bild av hur medvetenheten ser ut samt vilka åtgärder organisationerna tar för att förhindra Social Engineering. Med denna uppsats vill vi belysa den ovisshet som råder kring Social Engineering, men även farorna och hur effektiv en attack av denna typ kan vara.

Transporttidsmodellering vid provpumpning i heterogen jord : spårämnesförsök i en isälvsavlagring

When protection zones for wells are delineated, it is important to acquire good knowledge about possible travel time from different points in the catchment area to the well. Often, simple analytical methods are used for estimating travel times and the assumption is made that the hydraulic conductivity is relatively homogenous within the aquifer. Nevertheless, many aquifers are strongly heterogeneous which may lead to differences between estimates and actual travel times. As a part of the process to develop improved methods for delineating protection zones for groundwater supply wells, a tracer experiment was performed in a glaciofluvial esker formation in Järlåsa. On the basis of the experiment, a numerical flow model was created for the test site.The purpose of this master?s thesis was to apply the flow model to an aquifer where the hydraulic conductivity shows great variability and should be described by a stochastic distribution.

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