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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

An Analysis of Lithic Production at the Late Nuragic Site of Sa Conca Sa Cresia,Sardinia, Italy

Kraus, Michael A.C., Jr. 29 September 2017 (has links)
No description available.
2

Modifikace letounu EV-55 v kategorii CS/FAR 23, Commuter / Modification of EV-55 aircraft in the category CS/FAR 23 Commuter

Gabrlík, Jan January 2011 (has links)
This thesis deal with extended EV-55 version concept according to CS/FAR- 23 Commuter category specifications. Thesis objectives are design weights determination, mass analysis, calculation of aeroplane performances and comparison of aeroplane performances with current aeroplane.
3

Návrh příďového podvozku pro letouny řady Zlín 40 / Design of the nose landing gear for Zlin 40 aircraft

Bednář, Peter January 2021 (has links)
This master’ thesis deals with the design of the front landing gear for Zlín 40 aircrafts. The main emphasis in the research part of the work is placed on the selection of a new nose landing gear and the subsequent design of the structure. For the structural design was prepared a new mass analysis and load cases. The load-bearing capacity of the structure is verified using analytical and numerical methods of FEM. An important step of the work is the design concept of structure. The aim of the work is to point out the new possibilities of the nose landing gear structure and verify its feasibility for the case of future implementation.
4

An explicit finite difference method for analyzing hazardous rock mass

Basson, Gysbert 12 1900 (has links)
Thesis (MSc)--Stellenbosch University, 2011. / ENGLISH ABSTRACT: FLAC3D is a three-dimensional explicit nite difference program for solving a variety of solid mechanics problems, both linear and non-linear. The development of the algorithm and its initial implementation were performed by Itasca Consulting Group Inc. The main idea of the algorithm is to discritise the domain of interest into a Lagrangian grid where each cell represents an element of the material. Each cell can then deform according to a prescribed stress/strain law together with the equations of motion. An in-depth study of the algorithm was performed and implemented in Java. During the implementation, it was observed that the type of boundary conditions typically used has a major in uence on the accuracy of the results, especially when boundaries are close to regions with large stress variations, such as in mining excavations. To improve the accuracy of the algorithm, a new type of boundary condition was developed where the FLAC3D domain is embedded in a linear elastic material, named the Boundary Node Shell (BNS). Using the BNS shows a signi cant improvement in results close to excavations. The FLAC algorithm is also quite amendable to paralellization and a multi-threaded version that makes use of multiple Central Processing Unit (CPU) cores was developed to optimize the speed of the algorithm. The nal outcome is new non-commercial Java source code (JFLAC) which includes the Boundary Node Shell (BNS) and shared memory parallelism over and above the basic FLAC3D algorithm. / AFRIKAANSE OPSOMMING: FLAC3D is 'n eksplisiete eindige verskil program wat 'n verskeidenheid liniêre en nieliniêre soliede meganika probleme kan oplos. Die oorspronklike algoritme en die implimentasies daarvan was deur Itasca Consulting Group Inc. toegepas. Die hoo dee van die algoritme is om 'n gebied te diskritiseer deur gebruik te maak van 'n Lagrangese rooster, waar elke sel van die rooster 'n element van die rooster materiaal beskryf. Elke sel kan dan vervorm volgens 'n sekere spannings/vervormings wet. 'n Indiepte ondersoek van die algoritme was uitgevoer en in Java geïmplimenteer. Tydens die implementering was dit waargeneem dat die grense van die rooster 'n groot invloed het op die akkuraatheid van die resultate. Dit het veral voorgekom in areas waar stress konsentrasies hoog is, gewoonlik naby areas waar myn uitgrawings gemaak is. Dit het die ontwikkelling van 'n nuwe tipe rand kondisie tot gevolg gehad, sodat die akkuraatheid van die resultate kon verbeter. Die nuwe rand kondisie, genaamd die Grens Node Omhulsel (GNO), aanvaar dat die gebied omring is deur 'n elastiese materiaal, wat veroorsaak dat die grense van die gebied 'n elastiese reaksie het op die stress binne die gebied. Die GNO het 'n aansienlike verbetering in die resultate getoon, veral in areas naby myn uitgrawings. Daar was ook waargeneem dat die FLAC algoritme parralleliseerbaar is en het gelei tot die implentering van 'n multi-SVE weergawe van die sagteware om die spoed van die algoritme te optimeer. Die nale uitkomste is 'n nuwe nie-kommersiële Java weergawe van die algoritme (JFLAC), wat die implimentering van die nuwe GNO randwaardekondisie insluit, asook toelaat vir die gebruik van multi- Sentrale Verwerkings Eenheid (SVE) as 'n verbetering op die basiese FLAC3D algoritme.
5

Modifikace letounu EV-55 v kategorii CS/FAR 23 Commuter / Modification of EV-55 aircraft in the category CS/FAR 23 Commuter

Gabrlík, Jan January 2013 (has links)
This thesis deal with extended EV-55 version concept according to CS/FAR- 23 Commuter category specifications. Thesis objectives are design weights determination, mass analysis, calculation of aeroplane performances and comparison of aeroplane performances with current aeroplane.
6

Increased leaching of metals as a result of foundation work / Ökad urlakning av metaller till följd av grundläggningsarbete

Mattisson, Emmy January 2018 (has links)
Heavy metal contamination in the environment is a global issue that is likely to increase in the future. This report investigates a construction area in which increased concentrations of the heavy metals cadmium, cobalt, copper, nickel and zinc and a decreased pH-value has been observed in the surface water recipient. The focus is on assessing contamination characteristics and identifying suitable remediation methods to avoid a river protected by environmental quality standards further downstream from getting contaminated. The bedrock in the area is sulphide containing and releases acidic leachate when oxidising, which is assumed to have occurred due to plane blasting and filling of residual rock. The contamination characteristics were assessed with the statistical methods modified double mass analysis and principal components analysis. A water balance was established to obtain the flowrates, discharge volumes and to determine the masses of the released metals in the surface water. Identification of suitable remediation methods was performed through a literature study of available remediation methods and using the findings of the assessments as basis. The results showed that there was a significant increase in metal concentrations and decrease in pH-value roughly around the same time as blasting and filling of residual rocks in the area was begun and that there were elevated levels of sulphide and sulphur, but they could not be specifically linked to any media. The yearly masses of metals released from the area into the surface water were between 77-98 % higher than allowed by the established guidelines. By separating the water assumed to carry the majority of the contaminants from the remaining natural water in the watershed, the volume that needs to be treated can be halved. As the contamination is so extensive, a mixture of remediation methods was proposed, including installing green roofs to decrease the runoff from the area, confining the crushed rock with bentonite and installing a filter for fast, efficient reduction. For long-term remediation, it is suggested to optimise the existing sedimentation basins and wetlands. The conclusions were that it will be very expensive to remediate the contamination, due to the extent and magnitude, and that handling sulphide containing bedrock for construction purposes should be legally regulated in order to avoid negative environmental and economic impacts. / Förorening av tungmetaller i naturen är ett globalt problem som troligtvis kommer öka i framtiden. Den här rapporten undersöker en byggarbetsplats där ökade koncentrationer av metallerna kadmium, kobolt, koppar, nickel och zink samt ett minskat pH-värde har observerats i ytvattenrecipienten. Fokus ligger på att analysera föroreningskaraktärer och identifiera lämpliga åtgärdsmetoder för att undvika att en å nedströms som är skyddad av miljökvalitetsnormer ska förorenas. Berggrunden i området är sulfidförande och släpper ut surt lakvatten när den oxiderar, vilket är antaget har hänt till följd av plansprängning och utfyllnad av överblivet bergmaterial. Föroreningskaraktärerna analyserades med de statistiska metoderna modified double mass analysis och principalkomponentsanalys. En vattenbalans etablerades för att ta fram flöden, volymer och för att bestämma massorna av de frigjorda metallerna i ytvattnet. Identifiering av lämpliga åtgärdsmetoder gjordes med en litteraturstudie av tillgängliga metoder som grund. Resultaten visade att det är en signifikant ökning av metallkoncentrationer och minskning i pH-värde runt samma tid som sprängning och utfyllning av bergmaterial påbörjades samt att det är förhöjda halter av sulfid och svavel, men de kunde inte bli associerade med ett specifikt media. De årliga massorna av frigjorda metaller som släpps ut från området i ytvattnet är mellan 77-98 % högre än tillåtet av de etablerade riktlinjerna. Genom att separera vattnet som kan antas innehålla majoriteten av föroreningarna från det naturliga vattenflödet i avrinningsområdet kan volymen som behöver renas halveras. Eftersom föroreningen är så omfattande föreslås en kombination av åtgärdsmetoder; installation av gröna tak för att minska avrinningen från området, inneslutning av utfyllnadsmaterialet med bentonit och installation av ett filter för snabb, effektiv reduktion. För mer långsiktig rening föreslås det att optimera de existerande sedimentationsdammarna och våtmarken. Slutsatsen är att det kommer bli väldigt dyrt att åtgärda föroreningen på grund av dess omfattning, och hantering av sulfidförande berg för exploateringssyfte borde vara lagstadgat för att undvika miljömässiga och ekonomiska kostnader.
7

Jednomotorový víceúčelový dopravní letoun v kategorii CS/FAR 23 / Single-engined multipurpose transport aeroplane by the CS/FAR 23 category

Fiala, Luboš January 2013 (has links)
Thesis deals with design of a single-engine aircraft. The purpose of this aircraft design is to carry up nine passengers. The work outlines technical solution of several structural elements. The design starts with aerodynamic calculations, mass analysis and concludes with calculation of flight performance and development cost estimation.
8

Aerodynamický návrh transsonického bezpilotního kluzáku / Aerodynamic design of transonic UAV glider

Kóňa, Marián January 2015 (has links)
This master thesis is focused on aerodynamic design of transonic glider, which is assigned for following an airliner at cruising regime of flight. Main goal of the thesis is to determine basic geometrical design of airplane with respect to Whitcomb aera rule, mass analysis and drag polar. Weight analysis includes determining center of gravity according to longitudinal static stability margin. The drag polar of the airplane is determine for cruising regime of flight, that means the regime of following an airliner.
9

MULTI-DIMENSIONAL MASS SPECTROMETRY, MICROBES, AND THE DEMONS AMONGST THEM: RAPID UNTARGETED PROFILING OF MICROORGANISMS

L. Edwin Gonzalez (7289045) 30 November 2023 (has links)
<p dir="ltr">Mass spectrometry has been at the forefront of complex mixture analysis and, as a result, has greatly advanced the understanding of biological systems with its application in the biological sciences. One area in which mass spectrometry has succeeded is the area of microbiology and the identification of pathogens and has gained much attention from the biothreat detection community. Although this technology has matured in the past decade, very few systems have been developed for point-of-need analysis in cases such as the detection of biothreats. Current MS systems for the analysis of microbes utilizing MALDI-TOF-MS require large instruments to accommodate a drift tube long enough for high resolution mass analysis and high vacuum which is not amenable to the miniaturization requirements of point-of-need analysis. The previously mentioned methods also require extensive manipulation of the sample which takes time and can pose a risk to instrument operators in the biothreat detection space. Additionally, most mass spectrochemical instruments provide only one-dimension of data which can limits classification accuracy when using classification algorithms to provide an identity on a microbiological sample which could consist of any of the numerous common bacterial pathogens or biothreats.</p><p dir="ltr">A possible solution to this problem is the implementation of two-dimensional tandem mass spectrometry (2D MS/MS) which allows the analysis of the product ions of all precursor ions representing the result in the 2D MS/MS data domain. This methodology is possible with a linear quadrupolar ion trap mass analyzer and can be applied to miniature ion trap technology for portability. In this dissertation, a progression of mass spectrochemical analysis of biological systems from conventional methods to the implementation of 2D MS/MS is demonstrated: by (i) the development of a rapid biomolecule extraction method to analyze bacterial spores, using a (ii) modified linear quadrupolar ion trap mass spectrometer, (iii) then a miniature ion trap mass spectrometer, and (iv) finally adding numerical methods to discriminate between biological systems using data acquired on each 2D MS/MS instrument. This work is then taken a step further by developing a high throughput experimentation method in which DESI is coupled to 2D MS/MS to analyze a moderate number of samples rapidly, automatically, and with high reproducibility.</p>

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