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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.
281

An integral-representation approach for time-dependent viscous flows

Rizk, Yehia Mohamedattia 05 1900 (has links)
No description available.
282

Separate numerical treatment of attached and detached flow regions in general viscous flows

Gulcat, Ulgen 05 1900 (has links)
No description available.
283

Optimized Schwarz methods for the advection-diffusion equation and for problems with discontinuous coefficients

Dubois, Olivier, 1980- January 2007 (has links)
Optimized Schwarz methods are iterative domain decomposition procedures with greatly improved convergence properties, for solving second order elliptic boundary value problems. The enhanced convergence is obtained by replacing the Dirichlet transmission conditions in the classical Schwarz iteration with more general conditions that are optimized for performance. The convergence is optimized through the solution of a min-max problem. The theoretical study of the min-max problems gives explicit formulas or characterizations for the optimized transmission conditions for practical use, and it permits the analysis of the asymptotic behavior of the convergence. / In the first part of this work, we continue the study of optimized transmission conditions for advection-diffusion problems with smooth coefficients. We derive asymptotic formulas for the optimized parameters for small mesh sizes, in the overlapping and non-overlapping cases, and show that these formulas are accurate when the component of the advection tangential to the interface is not too large. / In a second part, we consider a diffusion problem with a discontinuous coefficient and non-overlapping domain decompositions. We derive several choices of optimized transmission conditions by thoroughly solving the associated min-max problems. We show in particular that the convergence of optimized Schwarz methods improves as the jump in the coefficient increases, if an appropriate scaling of the transmission conditions is used. Moreover, we prove that optimized two-sided Robin conditions lead to mesh-independent convergence. Numerical experiments with two subdomains are presented to verify the analysis. We also report the results of experiments using the decomposition of a rectangle into many vertical strips; some additional analysis is carried out to improve the optimized transmission conditions in that case. / On a third topic, we experiment with different coarse space corrections for the Schwarz method in a simple one-dimensional setting, for both overlapping and non-overlapping subdomains. The goal is to obtain a convergence that does not deteriorate as we increase the number of subdomains. We design a coarse space correction for the Schwarz method with Robin transmission conditions by considering an augmented linear system, which avoids merging the local approximations in overlapping regions. With numerical experiments, we demonstrate that the best Robin conditions are very different for the Schwarz iteration with, and without coarse correction.
284

A cross-sectional study on sustainable solutions for commercial property in the City of Johannesburg for 2012

Crous, Jaco 12 1900 (has links)
ENGLISH ABSTRACT: This study determined the status, in 2012, of the implementation of Sustainable solutions (SS) to commercial buildings in the City of Johannesburg. The term “going green” was seen as an alternative approach to business, but demonstrated necessity in the property industry. As greenhouse gas emissions drive the rising average global temperature at an alarming rate, the business environment cannot only be aware of the impact that business industries have on the livelihood of the growing population, but need to act promptly to ensure sustainability. Environmental sustainability is an important topic in decision making for businesses in South Africa and this study grouped renewable energy (RE) and energy efficiency (EE) to create sustainable solutions as the main concept of environmental sustainability. Renewable energy refers to finding an energy source like the sun or wind, but the main focus is on the purpose of sustainability of the energy resource and the supply. Eskom obtains 97% of their electricity for South Africa from coal power plants, but the reality is that coal is a limited resource that will not be available indefinitely unlike renewable energy. Energy efficiency on the other hand focuses on reducing the energy requirements of commercial buildings. As this concept received sufficient attention in South Africa, the present study was conducted to obtain further information to drive energy efficient practices. With energy efficiency, making basic adjustments in the design of new buildings to use less electricity can greatly contribute to their longevity and reduce the overall running costs that in turn enhance the sustainability for organisations that own or manage properties. By gathering the principals for renewable energy from natural resources and implementing energy efficient practices, the concept of sustainable solutions was conceived. The implementation of sustainable solutions also increases the value of properties, fosters economic enhancement, fosters socioeconomic improvement and most importantly improves the environment by reducing carbon emissions.
285

SupaMoto - ett innovativt sätt för Base of the Pyramid att spisa hälsosamt : En fallstudie på Emerging Cooking Solutions i Zambia

Boman, Hanna, Johnsson, Matilda January 2014 (has links)
”Base of the Pyramid” (BOP) beskriver de fyra miljarder människor som lever i extrem fattigdom. Även om de är fattiga har de tillsammans stark konsumentkraft, vilket gör BOP till en marknad som inte ska förbises. Företaget Emerging Cooking Solutions (ECS) tillverkar pellets av överbliven biomassa i Zambia som kan användas som bränsle i matlagningsspisar de säljer. Fallstudien på ECS avser att undersöka hur ett innovationsnätverk har möjlighet att påverka etablering av en innovation, i detta fall pellets, på en BOP-marknad. Från befintlig forskning kring BOP, innovationsprinciper samt de 4 A:na identifierades de fyra kategorierna: funktion, kostnad, distribution samt miljö som ett företag bör arbeta utifrån när de utvecklar och etablerar en produkt. Därefter analyseras kategorierna efter innovationsnätverkets nivåer. Studien visar att ifall en innovation är anpassad efter BOP-marknadens krav, samtidigt som den har tydligt koncept, är företaget mer benäget att attraherar rätt aktörer som kan påverka deras etablering. Ifall konceptet har andra värdefulla påföljder, såsom positiv miljöpåverkan, istället för bara ekonomiska kan företaget gynnas ytterligare av nätverket.
286

Solution of unbounded field problems by boundary relaxation.

Cermak, Ivan Anthony. January 1969 (has links)
No description available.
287

Projective solution of antenna structures assembled from arbitrarily located straight wires.

Chan, Kwok Kee. January 1973 (has links)
No description available.
288

The adsorption characteristics of polymeric depressants at the talc-water interface /

Morris, Gayle E. Unknown Date (has links)
Thesis (PhD)--University of South Australia, 1996
289

A dynamic light scattering investigation into the dynamics of non ideal ternary polymer solutions : a thesis presented in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Physics at Massey University

Nash, William January 2004 (has links)
Content removed due to copyright restriction: Nash, W., Pinder, D.N., Hemar, Y., Singh, H. Dynamic light scattering investigation of sodium caseinate and xanthan mixtures (2002) International Journal of Biological Macromolecules, 30 (5), pp. 269-271. Pinder, D.N., Nash, W., Hemar, Y., Singh, H. Dynamic light scattering investigation of guar/dextran mixtures in aqueous solutions (2003) Food Hydrocolloids, 17 (4), pp. 463-468. / Dynamic light scattering has been used to investigate three different non ideal ternary polymer systems. The three systems investigated were sodium caseinate and xanthan aqueous solutions, guar and dextran aqueous solutions and dextran and pullulan aqueous solutions. All solutions have been investigated at a temperature of 25°C. Sodium caseinate and xanthan aqueous solutions with total polymer concentrations ranging from 0.01% w/w to 0.15% w/w and ratios of sodium caseinate of x = 1:3, 1:2, 2:1, and 3:l have been investigated. Guar and dextran aqueous solutions with total polymer concentrations ranging from 0.01% w/w to 0.06% w/w at a ratio of guar to dextran of 1:6 have been investigated. Dextran and pullulan aqueous solutions with total polymer concentrations ranging from 1% w/w to 10% w/w with ratios of dextran to pullulan of 1:3, 1:1, and 3:l have been investigated. The solution concentrations have been chosen to fall in the semi-dilute range, while still being miscible. Three different methods of analysis have been applied to resolve the field autocorrelations function into a sum of decaying exponentials; CONTIN, CONTIN multiq, and a Kohlrausch-Williams-Watts fit. These resulting decay rates have been interpreted using the theoretical method outlined by Sun and Wang. The CONTIN multiq method provided the best overall fit to the data. The Sun and Wang method has not provided results which are consistent with those reported elsewhere in the literature. Additional theoretical effort must be applied to interpret the results from dynamic light scattering on these novel non-ideal systems.
290

Measurement and modelling of long chain branching in chain growth polymerization /

Thomas, Sydney. January 1998 (has links)
Thesis (Ph.D.) -- McMaster University, 1998. / Includes bibliographical references (leaves 139-148). Also available via World Wide Web.

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