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An integrated approach to the design of moonpools for subsea operationsDay, A. H. January 1987 (has links)
The use of moonpools for the launch and retrieval of diving bells and remotely operated vehicles from a mother ship is well established, and the advantages of the moonpool approach are well known. The use of moonpools in Floating Production Systems is also becoming more common, as a means of allowing the marine riser to enter the vessel. The moonpool offers protection from wind and current forces and reduces the effects of angular motions of the vessel. The only problem with the moonpool concept is that the water column inside a badly designed moonpool may suffer from large and apparently unpredictable vertical surges, making operations through the moonpool hazardous, and in extreme cases threatening the seaworthiness of the vessel. The work described here shows how a moonpool design may be optimised for a particular vessel in order that such problems may be avoided. The dynamics of the problem are established, such that the water column oscillation and the forces on a subsea unit in the moonpool may be predicted. The effects of a variety of geometrical configurations are then studied, both mathematically and experimentally, in order to select configurations which allow large modifications of the moonpool response. A quantitative measure of moonpool performance is proposed, allowing individual designs to be ranked in terms of the long term expected downtime due to the moonpool. Finally, the understanding and results thus gained are integrated in order to produce a practical design procedure for a moonpool of any size, in any vessel, and in any operational area. A worked example based on a real design problem is presented in order to illustrate the practical application of the method.
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Theoretical analysis of the dispersion of unguided finned rockets caused by elastic motion of the launcher during firingParker, Nicholson, 1921- January 1961 (has links)
No description available.
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Axially accelerated saboted rods subjected to lateral forces.Rabern, Donald Allen. January 1988 (has links)
The methodology and analysis used to characterize the performance of a sabot/rod as it is subjected to lateral and axial loading during launch is presented. The methodology described incorporates the experimental and numerical portions of the evaluation. Three separate sabot/rod designs are evaluated for their performance in the launch tube and are compared with one another. The experimental portion of the research involved full-scale testing of two separate sabot/rod designs in a 120-mm launch tube that was slightly bent. When launched through the bent tube, the sabot/rod system was forced to negotiate lateral displacements at axial velocities of approximately 5400 fps. This combination of axial velocity and lateral displacement produced significant lateral loading on the sabot/rod system. A 2.3-MeV x-ray unit was used to determine the lateral displacement that occurred as the sabot/rod was forced through the bent tube. After the sabot/rod exited the launch tube, the sabot separation and rod straightness were recorded by four 150-keV x-ray units. The in-bore radiography experiments used x-ray shielding techniques to reduce x-ray scatter, and layered indexed film and intensifier screens to record the sabot/rod image. The processed film was computer scanned with a microdensitometer and was remapped on the computer to enhance the x-ray image. Results indicated rod lateral displacement accuracy to 0.007 in. Test results were used to benchmark the numerical analyses used to characterize the in-bore performance of each sabot/rod system studied. The numerical portion of the research involved three-dimensional modeling of the sabot/rod systems in three launch-tube environments: a perfectly straight launch tube, an existing accuracy tube, and the slightly bent tube used in the experimental program. Because of the good agreement between the experimental and numerical models, stress, strain, and displacement time histories were obtained from the numerical work and used to evaluate each of the three sabot/rod systems in three launch environments. A dynamic analysis was performed for each of nine separate models. Sliding surfaces, nonlinear constitutive relations, and multiple materials were used for each analysis. Results from both the experimental and numerical analyses are presented.
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High pressure LOx/H₂ rocket engine combustion.Smith, Joshua J. January 2007 (has links)
Title page, abstract and table of contents only. The complete thesis in print form is available from the University of Adelaide Library. / This thesis describes a study based on propellant injection conditions which was performed with a single shear coaxially injected liquid rocket engine combuster. Steady state operation was closely examined with the thrust chamber operating at sub critical, near critical and supercritical pressure levels with respect to the thermodynamic critical pressure of oxygen. It was found that unstable combustion could not be triggered whatsoever with LOx/H₂ propellants at near or supercritical pressure, irrespective of operating conditions. Such findings illustrate that operating near or above the critical pressure of propellants (oxygen) results in inherently stable combustion process over a broad range of operating conditions. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1283711 / Thesis (Ph.D.) -- University of Adelaide, School of Mechanical Engineering, 2007
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High pressure LOx/H₂ rocket engine combustion.Smith, Joshua J. January 2007 (has links)
Title page, abstract and table of contents only. The complete thesis in print form is available from the University of Adelaide Library. / This thesis describes a study based on propellant injection conditions which was performed with a single shear coaxially injected liquid rocket engine combuster. Steady state operation was closely examined with the thrust chamber operating at sub critical, near critical and supercritical pressure levels with respect to the thermodynamic critical pressure of oxygen. It was found that unstable combustion could not be triggered whatsoever with LOx/H₂ propellants at near or supercritical pressure, irrespective of operating conditions. Such findings illustrate that operating near or above the critical pressure of propellants (oxygen) results in inherently stable combustion process over a broad range of operating conditions. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1283711 / Thesis (Ph.D.) -- University of Adelaide, School of Mechanical Engineering, 2007
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Success factors for launching a new product for micro enterprisesStrandberg, Mikael, Abdiu, Daniel, Stridsberg, Martin January 2006 (has links)
Dagens marknadssituation är uppbyggd av hård konkurrens och snabba förändringar. Nya tekniken påverkar hur ett företag kan bedriva sin affärsverksamhet och ger upphov till nya marknadsmöjligheter. Dessa faktorer gör att dagens företag snabbt måste kunna ändra och anpassa sig till nya situationer inom korta produktlivscykler. Nya föränderliga teknologier och nya marknadssituationer har tvingat företag att vara mer innovativa och bedriva en affärsstrategi där förändring och produktutveckling är i fokus. För att kunna lyckas nå ut med nya produkter på marknaden är det viktigt att ha en marknadslanseringsstrategi och veta de kritiska framgångsfaktorerna. En förståelse över de kritiska framgångsfaktorerna kan utgöra en grund för hur en produktlansering skall se ut och verkställas. Syftet med uppsatsen är att från ett marknadsföringsperspektiv identifiera och analysera kritiska framgångsfaktorer när en ny produkt skall lanseras för mikroföretag. Uppsatsarbetet har genomförts genom en litteraturstudie där teori om marknadsföring och marknadslanseringsteori har behandlats. Vidare har tre interjuver gjorts med företagen Din Scooter HB, Luda Elektronik HB och SafeTool AB. Alla tre är mikroföretag som ligger inom gruppen små och medelstora företag. Analysen av litteraturstudien och den empiriska undersökningen har bidragit till en identifiering av kritiska framgångsfaktorer vid produktlansering. Några av de kritiska framgångsfaktorerna som har blivit identifierade är; pris, tid, kundmedvetenhet och vara marknadsinriktad. Vidare har en modell tagits fram för att visualisera de kritiska framgångsfaktorerna och hur de korrelerar med varandra där en beskrivning utav själva modellen finns och varför det här är så viktigt just för mikroföretag. En förståelse över dessa framgångsfaktorer kan effektivisera och förbättra marknadslanseringen. Resultatet av detta kan stärka företagets position på marknaden och ge möjlighet till mer kundfokuserade produkter och bättre lönsamhet. / Today’s marketplace is characterized by strong competition, speed and change. New technologies affect the way of doing business and rise new market possibilities. These factors force today’s companies to quickly respond to new changes and demand situations within short product life cycles. Fast changing technology and new market situations have forced businesses to be more innovative and apply strategy of change with continuous innovations of their products. To be able to reach out with new products on the market successfully it is of great importance to have a product launch strategy and know the critical success factors of a product launch. An understanding of the critical success factors can work as a guideline for new product launches and how to manage them. The purpose with the thesis is to identify and analyze critical success factors for launching a new product for micro enterprises using a marketing perspective. The thesis has been conducted by studying theory regarding marketing and product launch theory. Further, interviews has been conducted with; DinScooter HB, Luda Elektronik HB and SafeTool AB. All of these three companies are micro enterprises within the definition of SME’s. The analysis of the theoretical framework and the empirical research has resulted in an identification of critical success factors for a product launch. Some of the critical success factors that have been found are; pricing, timing, awareness of the customer and being market driven. Further, a model that visualizes the different factors and their correlation is presented where an explanation of the model is given and why this is of importance for micro enterprises. An understanding of these factors can improve the product launch and make it more effective and efficient. The result of that can be stronger position on the market, more customer focused products and higher profits.
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Success factors for launching a new product for micro enterprisesStrandberg, Mikael, Abdiu, Daniel, Stridsberg, Martin January 2006 (has links)
<p>Dagens marknadssituation är uppbyggd av hård konkurrens och snabba förändringar. Nya tekniken påverkar hur ett företag kan bedriva sin affärsverksamhet och ger upphov till nya marknadsmöjligheter. Dessa faktorer gör att dagens företag snabbt måste kunna ändra och anpassa sig till nya situationer inom korta produktlivscykler. Nya föränderliga teknologier och nya marknadssituationer har tvingat företag att vara mer innovativa och bedriva en affärsstrategi där förändring och produktutveckling är i fokus. För att kunna lyckas nå ut med nya produkter på marknaden är det viktigt att ha en marknadslanseringsstrategi och veta de kritiska framgångsfaktorerna. En förståelse över de kritiska framgångsfaktorerna kan utgöra en grund för hur en produktlansering skall se ut och verkställas. Syftet med uppsatsen är att från ett marknadsföringsperspektiv identifiera och analysera kritiska framgångsfaktorer när en ny produkt skall lanseras för mikroföretag. Uppsatsarbetet har genomförts genom en litteraturstudie där teori om marknadsföring och marknadslanseringsteori har behandlats. Vidare har tre interjuver gjorts med företagen Din Scooter HB, Luda Elektronik HB och SafeTool AB. Alla tre är mikroföretag som ligger inom gruppen små och medelstora företag. Analysen av litteraturstudien och den empiriska undersökningen har bidragit till en identifiering av kritiska framgångsfaktorer vid produktlansering. Några av de kritiska framgångsfaktorerna som har blivit identifierade är; pris, tid, kundmedvetenhet och vara marknadsinriktad. Vidare har en modell tagits fram för att visualisera de kritiska framgångsfaktorerna och hur de korrelerar med varandra där en beskrivning utav själva modellen finns och varför det här är så viktigt just för mikroföretag. En förståelse över dessa framgångsfaktorer kan effektivisera och förbättra marknadslanseringen. Resultatet av detta kan stärka företagets position på marknaden och ge möjlighet till mer kundfokuserade produkter och bättre lönsamhet.</p> / <p>Today’s marketplace is characterized by strong competition, speed and change. New technologies affect the way of doing business and rise new market possibilities. These factors force today’s companies to quickly respond to new changes and demand situations within short product life cycles. Fast changing technology and new market situations have forced businesses to be more innovative and apply strategy of change with continuous innovations of their products. To be able to reach out with new products on the market successfully it is of great importance to have a product launch strategy and know the critical success factors of a product launch. An understanding of the critical success factors can work as a guideline for new product launches and how to manage them. The purpose with the thesis is to identify and analyze critical success factors for launching a new product for micro enterprises using a marketing perspective. The thesis has been conducted by studying theory regarding marketing and product launch theory. Further, interviews has been conducted with; DinScooter HB, Luda Elektronik HB and SafeTool AB. All of these three companies are micro enterprises within the definition of SME’s. The analysis of the theoretical framework and the empirical research has resulted in an identification of critical success factors for a product launch. Some of the critical success factors that have been found are; pricing, timing, awareness of the customer and being market driven. Further, a model that visualizes the different factors and their correlation is presented where an explanation of the model is given and why this is of importance for micro enterprises. An understanding of these factors can improve the product launch and make it more effective and efficient. The result of that can be stronger position on the market, more customer focused products and higher profits.</p>
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A collaborative optimization approach to improve the design and deployment of satellite constellationsBudianto, Irene Arianti 12 1900 (has links)
No description available.
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Reusable launchersBerry, W. January 1993 (has links)
This research on Reusable Launchers was motivated by the need to reduce substantially the cost of space transportation. The specific objective was to explore the perception that launcher reusability is the key to achieving these major cost reductions. The exploration was achieved by undertaking a comparative system study on potentially feasible reusable launcher concepts, using a consistent set of design tools, a standard analysis methodology and a standard reference mission. To set the background for the research, the results of an extensive literature review are presented on the vehicle studies and technology developments that are engaged across the world on reusable launchers. Comprehensive vehicle studies appear to be engaged without justification for the choice of selected concepts in the absence of results from comparative system studies of reusable launchers. Technology developments also appear to be engaged without clear links to needs derived from vehicle system studies. The challenge of reusability is then addressed. Firstly, to set the performance and cost targets of reusable launchers, the capabilities of current expendable launchers are derived. Secondly, to establish the operational requirements for reusable launchers, the probable space transportation needs for the early 21st century are derived. Thirdly, the concepts and characteristics of reusable launchers are derived, allowing the selection, on a rationale basis, of a short-list of 13 potentially feasible reusable launcher concepts for analysis in the research. The performance equations of reusable launchers are then derived, leading to the preparation of the comparative analysis tools. The major work of the research, which comprises the performance analysis, technical feasibility assessment and cost analysis of each candidate vehicle, are then presented and compared. A set of acceptance requirements for performance, technical feasibility and operational costs of reusable launchers is then derived. The results of the comparative analysis for each candidate launcher are then measured against these requirements. The results of the comparative analysis show that only 2 of the 13 candidate reusable launcher concepts are able to meet all the acceptance requirements. These two acceptable vehicles are both rocket-propelled. They are, in order of preference: a single-stage-to-orbit, rocket-propelled, vertical launch and vertical landing vehicle; a two-stage-to-orbit, rocket-propelled, vertical launch and horizontal landing vehicle. The operational costs per launch for these two vehicles, based on a utilisation plan of 3 vehicles operating for 20 years at a launch rate of 12 launches per year, was calculated to be about 20% of the current costs of the European Ariane 44L expendable launcher. This warrants their further evaluation in a thorough feasibility study. The more complex, air-breathing propelled, horizontal launch and landing vehicles were found to be unable to meet the performance, technical feasibility and cost requirements; Several vehicles were found to be unable to deliver a positive payload mass to orbit; Several vehicles were found to have technology requirements that were deemed to be infeasible to achieve; Several vehicles were found to have operational costs ranging from equal to double that of the European Ariane 44L expendable launcher, which was adopted as a comparative reference vehicle. The contributions of this research to the advancement of knowledge on reusable launchers are: a clear identification of the performance capability limits of 13 plausible reusable launcher concepts; an analysis methodology for determining the performance capability limits for any reusable launcher concept; a clear identification of the reasons for the poor practical performance of air-breathing propulsion systems for Earth-to-orbit launchers, which results from their installed operational characteristics.
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Cross-culture study of the use of social media in Sweden and ChinaFeng, Kaiqi, He, Qiuhang, Li, Ang January 2015 (has links)
No description available.
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