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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Construction technique and strength of connected regolith bag structures

Singh, Mandeep, January 2007 (has links) (PDF)
Thesis (M.S.)--Auburn University, 2007. / Abstract. Vita. Includes bibliographic references (ℓ. 101-103)
2

Evaluation of large sand-filled geotextile containers as a temporary flood protection product

Harms, Steven 13 January 2015 (has links)
The effectiveness of temporary flood protection is highly variable depending on the location, application, and the nature of flood events. This thesis evaluates sand-filled geotextile containers used as flood protection products within a framework of standardized tests. Specifically, Syn-Tex Wave Breakers and Super Sandbags are tested in both laboratory and field settings to quantify seepage rates, stability and durability. This allows informed decisions to be made regarding appropriate applications for each temporary flood protection product, and identifies areas for product improvement and development. The products tested performed well over the range of loading conditions applied. Large sand-filled geotextiles would be well-suited for situations where stakeholders have a low tolerance for risk, and there is adequate site access for the construction equipment required for installation. An ideal installation would be a long, relatively straight stretch where vertical product/wall and product/product interfaces can be minimized.
3

Experimentellt vidareutvecklad modell för dimensionering av skadebegränsandeåtgärder mot RSV-penetration vid ammunitionsröjning / Experimentally developed model for the design of protective measures againstshaped charge jet penetration during EOD operations

Johnsson, Fredrik January 2014 (has links)
Vid röjning av RSV-ammunition saknas idag adekvat beslutstöd för att dimensionera skadebegränsande åtgärder mot jetstrålens verkan. I uppsatsen vidareutvecklas en beräkningsmodell som författaren tidigare föreslagit. Syftet är att skapa ett verktyg som kan införas i ammunitionsröjningsverksamheten. Fullskaliga skjutförsök har genomförts för att klarlägga inverkan av förhållanden som är typiska vid ammunitionsröjning; en skyddskonstruktion byggd av sandsäckar och med ett långt detonationsavstånd till röjningsobjektet. Försöksresultatet visar att den grundläggande hydrodynamiska penetrationsteorin inte är användbar för dessa förhållanden. Vidare ger sandsäckskonstruktionen signifikant bättre skydd mot jetstrålen än en homogen grusbädd. Genom störningsanalys har känsligheten hos de enskilda parametrarna i beräkningsmodellen för verksamhetstypiska fel utretts. Härefter har Monte Carlo-simulering använts för att analysera den sammanlagda inverkan som dessa fel kan ge. Resultatet har legat till grund för att bestämma modellens säkerhetsmarginal. Militär nytta innebär att modellen skall kunna tillämpas fältmässigt, med korta tidsförhållanden och utan tillgång till avancerade beräkningshjälpmedel. Detta har lett fram till att ett enkelt diagram inkluderats i det kompletta dimensioneringsverktyget. Verktyget föreslås införas i regelverk och utbildningssystem för att avhjälpa den brist som råder idag. / During the clearance of shaped charge ammunition, explosive ordnance disposal (EOD) personnel lack adequate means for the design of protective measures against the jet. In this thesis a calculation model, previously suggested by the author, is developed further. The aim is to create a tool that can be applied to EOD operations. Full-scale experiments have been conducted to clarify the effects of conditions that are typical for EOD operations: protective measures built from sandbags with a long standoff distance to the ordnance. The results indicate that the hydrodynamic penetration theory is not suitable for these conditions. Furthermore, a sandbag construction provides significantly better protection against the jet than a homogeneous gravel construction. By disturbance analysis, the sensitivity of the individual parameters in the model is studied for typical errors. Subsequently, Monte Carlo simulation has been used to analyse the effect these errors can cause. The simulation results have then been the used to determine the model´s margin of safety. Military utility implies that it should be possible to use the model under field conditions, with limited time frames and without access to advanced calculating means. This has resulted in a simple diagram included in the comprehensive design tool. It is proposed that the tool is implemented in regulations and curricula in order to remedy today’s lack of decision support.

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