545 research outputs found
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)
PRACTICE OF VACCINATION AGAINST PNEUMOCOCCAL INFECTION IN YOUNG CHILDREN AT THE VACCINE PREVENTION CENTRE IN LIPETSK
No full textFlow 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
Change of phenotypic properties of escape mutants and readaptants of influenza virus a (H1N1) pdm09 under the influence of selected mutations in the molecule of hemagglutinin [ИЗМЕНЕНИЕ ФЕНОТИПИЧЕСкИХ СВОЙСТВ ЭСкЕЙП-МУТаНТОВ И РЕаДаПТаНТОВ ВИРУСа ГРИППа а(H1n1)pdm09 ПОД ВОЗДЕЙСТВИЕМ СЕЛЕкЦИОНИРОВаННЫХ МУТаЦИЙ В МОЛЕкУЛЕ ГЕМаГГЛЮТИНИНа]
No full textIntroduction. After the emergence and spread of pandemic H1N1 viruses in 2009, antigenic epitopes recognized by neutralizing antibodies against the hemagglutinin of influenza A/Moscow/01/09(H1N1)pdm09 viruses were studied. Targets and goals. The purpose of the study was to obtain readapted variants of the virus from a low-virulent escape-mutant that has an increased affinity of the avian and the human types cellular receptors compared to the wild type and the comparative study of their antigenic and receptor specificity. Material and methods. Viruses were accumulated in 10-day-old chicken embryos. The MAB panel against HA of influenza virus strain A/IIV-Moscow/01/09(H1N1)sw1 was used in the form of ascites fluids from mice. Immunization of mice, HI testing, elution of viruses from chicken erythrocytes, PCR and sequencing of readapted variants were performed by standard methods. Results. The amino acid substitution A198E acquired in the process of readaptation leads to changes in the antigenic specificity. A correlation was found between a decrease in virulence of a low-virulent escape mutant associated with the substitution D190N in the hemagglutinin molecule and an increase in the hemagglutinating titer to inhibitors in normal mouse serum. Viruses with low affinity of cellular receptor analogs and carrying amino acid substitutions have an increased ability to elute from chicken erythrocytes. Discussion. The results discuss the effect of mutations in the HA molecule of the influenza A(H1N1) pdm09 virus to the change in antigen specificity; virulence for mice, adsorption-elution at cellular receptors. Conclusion. A comparative study of the antigenic specificity and receptor-binding activity of the escape mutants was conducted for the hemagglutinin of the influenza virus A/Moscow/01/2009 (H1N1)swl, and the readapted variants obtained for one of the escape mutants with reduced virulence for mouse. Monitoring the pleiotropic effect of mutations in the hemagglutinin H1 molecule is necessary to predict variants of the virus with pandemic potential. © 2019 Izdatel'stvo Meditsina. All rights reserved
Параметризация кривых в AutoCAD на примере овалов Кассини
No full textA new approach to the integrated study of descriptive geometry and computer graphics in a higher educational institution on the basis of in-depth study of some topics is proposed. The technique is demonstrated in a practical example devoted to the consideration of the possibility of quick creation and investigation of the properties of Cassini ovals on the basis of creating a parametric block using the analytical formula in the system of automated design AutoCAD Autodesk. In the process of investigation, the features of fourth-order curves are analyzed as a result of the intersection of the torus by planes parallel to the axis of rotation of the torus, the dependence of the shape of the curves on the ratio of the parameters. 3D-models of torus surfaces and their sections corresponding to the conditions for constructing curves are constructed. The method of reconstructing the metric of tori along the contours of the obtained sections in the form of Cassini ovals is considered.Предложен новый подход к интегрированному изучению курсов начертательной геометрии и компьютерной графики для инженерных направлений подготовки в учебных заведениях высшего профессионального образования на основе углубленного изучения отдельных тем. Методика продемонстрирована на практическом примере, в котором рассмотрены возможности создания и исследования свойств овалов Кассини на базе создания параметрического блока по аналитической формуле в AutoCAD. В процессе исследования проанализированы особенности кривых четвертого порядка как результата пересечения тора плоскостями, параллельными оси вращения тора, зависимость формы кривых от соотношения параметров. В работе рассматривается задача воссоздания метрики торов по контурам полученных сечений методами начертательной геометрии и с помощью SD-моделирования. На основе полученных кривых построены поверхности с образующими или направляющими, являющимися овалами Кассини
Using Parametric Blocks for Construction of Flat Algebraic Curves in AutoCAD by the Example of Cassini Ovals
No full textDesigning surfaces of complex shape is in demand in various industries. Forms of such surfaces are flat curves. However, the variety of these curves remains unclaimed by constructors, architects, designers due to the lack of tools for the rapid construction of these curves in modern graphical systems AutoCAD, Inventor, Revit, KOMPAS, etc. The article suggests a convenient and generally available method for constructing any curves defined by mathematical methods in AutoCAD by creating parametric blocks. For example, the lines obtained by the section of the torus by a plane parallel to the axis are chosen (curves of the fourth order are Cassini's ovals). In the process of investigation, the features of fourth-order curves are analyzed as a result of the intersection of the torus by planes parallel to the rotation axis of the torus, the shape dependence of the shape of the curves on the ratio of the parameters. We consider the problem of reconstructing the tonic metric and forming a model of a spatial object along the contours of the obtained sections by the methods of descriptive geometry and using 3-d modeling. On the basis of the obtained curves, surfaces with generators or guides, which are Cassini ovals, are constructed
Параметризация кривых в AutoCAD на примере овалов Кассини
No full textA new approach to the integrated study of descriptive geometry and computer graphics in a higher educational institution on the basis of in-depth study of some topics is proposed. The technique is demonstrated in a practical example devoted to the consideration of the possibility of quick creation and investigation of the properties of Cassini ovals on the basis of creating a parametric block using the analytical formula in the system of automated design AutoCAD Autodesk. In the process of investigation, the features of fourth-order curves are analyzed as a result of the intersection of the torus by planes parallel to the axis of rotation of the torus, the dependence of the shape of the curves on the ratio of the parameters. 3D-models of torus surfaces and their sections corresponding to the conditions for constructing curves are constructed. The method of reconstructing the metric of tori along the contours of the obtained sections in the form of Cassini ovals is considered.Предложен новый подход к интегрированному изучению курсов начертательной геометрии и компьютерной графики для инженерных направлений подготовки в учебных заведениях высшего профессионального образования на основе углубленного изучения отдельных тем. Методика продемонстрирована на практическом примере, в котором рассмотрены возможности создания и исследования свойств овалов Кассини на базе создания параметрического блока по аналитической формуле в AutoCAD. В процессе исследования проанализированы особенности кривых четвертого порядка как результата пересечения тора плоскостями, параллельными оси вращения тора, зависимость формы кривых от соотношения параметров. В работе рассматривается задача воссоздания метрики торов по контурам полученных сечений методами начертательной геометрии и с помощью SD-моделирования. На основе полученных кривых построены поверхности с образующими или направляющими, являющимися овалами Кассини
ОПЫТ ВАКЦИНАЦИИ ПРОТИВ ПНЕВМОКОККОВОЙ ИНФЕКЦИИ ДЕТЕЙ РАННЕГО ВОЗРАСТА В ЦЕНТРЕ ВАКЦИНОПРОФИЛАКТИКИ Г. ЛИПЕЦКА
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Об интеграции курсов компьютерной и инженерной графики для инженерных специальностей
No full textThe review of teaching properties of computer and engineering graphics courses and the possibilities of it’s merging. The analysis of conditions of studying quality and student interest in study process increase.Рассмотрены вопросы преподавания курсов компьютерной и инженерной графики и возможностях их слияния. Проанализированы предпосылки повышения качества обучения и заинтересованности студентов в учебном процессе
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