513 research outputs found
Los tres mosqueteros novela escrita en frances
No full text7 t. en 2 v.Contiene: t.I -- t.II -- t.III, encuadernados juntos en un primer volumen. -- t. IV-- t.V -- t. VI -- t.VII, encuadernados juntos en un segundo volumen.Donación de J. L. Estrada (Biblioteca General)Digitalizada en formato pd
Afstandbestuurde elektronische programma schakelaar voor kabel-T.V. systemen
No full textBij een kabelnet volgens het sterprincipe kan men kies-T.V. toepassen. De abonnee bedient thuis een in de centrale aanwezige schakelaar; deze schakelaar moet aan hoge overspraakeisen voldoen. De mogelijkheden van een ’space’-schakelaar worden hier onderzocht: op alle ingangen komt een programma terwijl 1 ingang met de uitgang wordt doorverbonden. Aangetoond zal worden dat een dergelijke schakelaar voor 10 programma’s thans op eenvoudige wijze te realiseren is, tegen redelijke kosten, terwijl het aantal programma’s desgewenst uit te breiden is.Electrical Engineering, Mathematics and Computer ScienceTransmissie van Informati
T.V. Bulpin, Storm over the Transvaal
No full textThomas Victor ("T.V.") Bulpin (1918-1999), the well-known and prolific South African author, wrote nearly thirty books and more than two thousand articles and other publications, mostly on South African hunting, travel and history. Among his well-known “classics” are books, such as Lost Trails on the Lowveld (first published in 1950); The Ivory Trail (1954); Islands in a Forgotten Sea (1959); The Hunter is Death (1962); Natal and the Zulu Country (1966); The Great Trek (1968); Illustrated Guide to Southern Africa (1980) and Tavern of the Seas: The Story of Cape Town, Robben Island and the Cape Peninsula (published posthumously, 2003). Since 2010, several of Bulpin’s well-known books have been republished by Protea Book House in Pretoria – the latest being Storm over the Transvaal (which was first published in 1955 by Howard Timmins in Cape Town)
Flow patterns around longitudinal training dams
No full textWith the intention to reduce the negative effects of ongoing bed erosion, as well as to improve several other river functions such as protection against floods, provision of safe and efficient navigation and ecology, a ‘pilot project longitudinal training dams’ was initiated. The training dams have recently been implemented in the Waal between Tiel and Sind Andries. In this project, river groynes have been completely removed and replaced by dams that lie parallel to the river bank. With help of the longitudinal training dams, a two-channel river system is created in which the river is divided into a main and side channel. The dams are placed in a continuous manner with openings in between that are relatively small compared to the dam length. At the beginning and end of the dam an inlet and outlet region is situated, as shown in Fig. 1. The combination of inlet and openings allows for water and sediment to be divided between the main and the side channel. Both inlet and openings are constructed with the help of a porous rock-layer. The crest heights can be altered by adding or removing stones. This is expected to influence the amount of water and sediment entering the side channel and can therefore be used as a regulation tool. A.J.F. Hoitink, T.V. de Ruijsscher, T.J. Geertsema, B. Makaske, J. Wallinga, J.H.J. Candel, J. Poelman (Eds.) NCR days 2017, Febr. 1-3, 2017. Book of abstracts, NCR publication 41-2017.Rivers, Ports, Waterways and Dredging EngineeringHydraulic Structures and Flood RiskEnvironmental Fluid Mechanic
A methodology for the selection of a routine purity test for insoluble beta(1?3)glucan
No full textBeta(1?3)glucan isolated from the cell wall of Saccharomyces cerevisiae is a biological response modifier (BRM) stimulating resistance against bacterial, viral, fungal and protozoal diseases. This polysaccharide has a high molecular weight, which makes it very difficult to achieve a purity test. A comparative study of different analytical procedures for beta(1?3)glucan from S. cerevisiae was conducted in order to establish a reliable routine analytical methodology for quality control of this active ingredient in pharmaceutical products. With this aim, different combinations of the analytical procedure steps were tested, including three alternatives for the acid hydrolysis step, three for neutralization, two for gas-liquid chromatographic derivatization and two internal standards. The glucose yield, precision, time consumption and reagent cost per sample were determined for 10 sample replicates. All gas chromatographic determinations were conducted using packed GLC columns and an FID detector. The selected analytical method showed 83.61 � 3.48% glucose yield, the shortest relative time consumption (54.2%) and the lowest cost of reagents (7.4%) and consisted of a combination of 72% sulfuric acid hydrolysis, 25% ammonium hydroxide neutralization and alditol acetate derivatization using xylose as internal standard. Copyright � 2009 Prous Science, S.A.U. or its licensors. All rights reserved
Flow past a square prism: A numerical study
No full textThe ERCOFTAC test case for flow past a square-prism at a Reynolds number of 21,400 was studied numerically using the flow solver ReFRESCO. The main objectives were to evaluate the performance of a Reynolds Averaged Navier-Stokes (RANS) based turbulence models in Unsteady RANS (URANS) simulations, identify sensitivities to numerical parameters and find out if Detached-Eddy Simulation (DES) based turbulence models provide lower modelling errors than in URANS simulations for this practical test-case. In this respect, the effect of the iterative error and the discretization error using k-omega SST-2003 model [15] was studied and turbulence models such as the SST-DDES turbulence model [19] and the TNT-XLES turbulence model [20] were also applied. The results using the URANS results have highlighted the importance of small temporal and spatial resolution in the calculation domain in order to reduce the effect of the discretization errors. Moreover, large time-integration periods (larger than 60 shedding cycles) should be required to ensure that the statistical noise does not affect the solution Verification procedure which would otherwise hamper the estimated numerical uncertainties. As expected from the studies of Pereira et al. [7], the results with the DES based turbulence models have shown that numerical settings for URANS are insufficient for DES and large comparison errors have been found for many quantities such as the time-averaged pressure distribution at the surface and the integral quantities. The numerical studies with the k-omega SST model [15] have shown that if the numerical uncertainties identified in the study are controlled, Verification & Validation studies using this model could provide low modelling errors for this test-case for the investigated mean flow quantities. For the DES results, since the poor comparisons with experimental results with respect to URANS results using the k-omega SST (2003) turbulence model are caused by poor numerical settings, studies using finer grids, smaller time-steps and lower iterative criteria than the ones used in the present work are recommended.Mechanical, Maritime and Materials EngineeringMaritime Technolog
Criteria of Grain Refinement Induced by Ultrasonic Melt Treatment of Aluminum Alloys Containing Zr and Ti
No full textIt is well known that ultrasonic melt treatment (UST) promotes grain refinement in aluminum alloys. Cavitation-aided grain refinement has been studied for many years; however, it is still not being applied commercially. The current article summarizes the results of experimental work performed on various alloying systems at different stages of solidification. The influence of UST parameters and solidification conditions on the final grain structure is analyzed. It was found that small additions of zirconium and titanium can significantly increase the efficiency of UST, under the stipulation that grain refinement is performed in the temperature range of primary solidification of Al3Zr. The possible mechanisms for this effect are discussed.Materials Science and EngineeringMechanical, Maritime and Materials Engineerin
FireFly Dating: Bachelor End Project
No full textThe FireFly company was created on the idea of blind dating. Most dating apps need the user to have an extensive conversation through a chat box before settling for a date. The product of FireFly tries to remedy that by having the first conversation be face to face. Over ten weeks, we have built the FireFly Dating application. We started researching other dating applications and matching algorithms to decide the requirements for FireFly Dating. After this, we implemented these requirements from scratch. In the final product, users can register an account, like or dislike other users profiles to indicate preferences for the matching algorithm, enroll for a blind date, and get matched. The application also includes an automated emailing system and a full reporting and feedback system. Furthermore, the system allows for an Administrator to get an overview of the application’s data. The Administrator can insert, edit or archive Dating Establishments and Time Slots. As well as view user reports and ban users if necessary. The final application is a product that portrays the Product Owner’s vision in that dating should be easily accessible and offline. At the end of the project, together with the Product Owner, it can be concluded that the FireFly Dating application was successful
Unequal networks: Spatial segregation, relationships and inequality in the city
No full textDoes the neighbourhood in which people live matter for the resourcefulness of their personal network and thus for their opportunities in life? Do residents of a multi-ethnic ‘problem’ area maintain fewer relationships with fellow-residents compared to residents of a homogeneous problem-free neighbourhood? And do ‘diversity-seekers’ who choose to live in a mixed neighbourhood translate their liking for diversity into more mixed networks and more bridging ties? This book brings together key insights from urban studies and network studies in order to understand whether and how spatial segregation matters for personal networks and inequality. By approaching these questions through different urban sociological perspectives, the book engages with current debates on poverty concentration as well as ethnic diversity, gentrification and social capital. The study is based on detailed quantitative and qualitative data on the personal networks of people living in three differently composed neighbourhoods in Rotterdam, the second largest city in the Netherlands.Urban Renewal and HousingOTB Research Institut
Providing cable TV service in large metropolitan areas: a study of consumer demand, 1990
No full textCable television was introduced in America in 1948. Since its beginning, the cable industry has reaped substantial gains in sales and revenue. Its expected to grow even more in the future, due to the technological breakthrough in video two-way communication. Although the future of cable T.V. seems bright, the implementation of cable systems in large urban areas has been lagging. The reason given is that providing cable service in such areas will not be cost effective. The intent of this study is to facilitate cable operators and others in evaluating future potential markets for cable T.V., and to provide a foundation in which subsequent studies can be conducted. The approach in this study is to develop a consumer demand model to investigate the relationships between demand for cable T.V. and those factors which influence consumer demand, for the purpose of predicting demand for cable T.V. in large urban areas. The results of this study provide sufficient evidence that consumer demand for cable T.V. does exist in large urban centers, and contracts the notion that operating a cable T.V. system in these areas would not be cost effective. This thesis was originally written in 1982, and was successfully defended. However, due to unfavorable circumstances it was retyped, revised and resubmitted in the spring of 1990
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