2,899 research outputs found
Immune-based therapy using gamma interferon ingaron in the treatment of HIV/AIDS patients with active pulmonary tuberculosis (PTB) not previously highly active antiretroviral therapy (HAART)
CADASTRAL ASSESSMENT OF CRIMEAN BEACHES AS AN INSTRUMENT FOR SUSTAINABLE COASTAL DEVELOPMENT
One of the important steps towards sustainable development of territories is the assessment of the reserves and rate of consumption of natural resources. Such assessments are also supported at the international level. The recreational resources represent the most important type of natural resources for the coastal zone of Crimea. They are the basis for recreational tourism and, therefore, determine the economic status of the peninsula as a whole. Currently, however, the coastal zone of Crimea is being developed quite chaotically. The need for a specialized information system capable of timely reflecting natural and manmade changes in the coastal zones is widely recognized. The paper presents a system that was developed using ESRI ArcGIS formats capable of not only capturing changes occurring in the environment, but to also identifying options for a more efficient use of the recreational resources of the peninsula. The approach and unique algorithms developed by the authors of this paper were applied to four Crimean beaches
Perspective Non-Fluorinated and Partially Fluorinated Polymers for Low-Temperature PEM FC
The main requirement to the materials used to make membranes polymer electrolyte membrane fuel cells (PEM FC) is the combination of high proton conductivity and resistance to the FC operation conditions. Thus, the search for inexpensive and high-performance non-fluorinated or partially fluorinated materials for use as FC membranes is an actual task today, since the use of membranes based on perfluorosulfonate acid has a number of disadvantages limiting their application. The aim of this study is the investigation of sulfonated polyimide (SPI) and materials for use as FC membranes. The relevance of research stems from the fact that the use of the SPI will allow to increase the resistance of the membrane to the constantly changing environment in which PEM operates. The objects of research are sulfonated polyimides. SPIs, especially aromatic SPIs, are attractive to researchers, because of the possibility of obtaining a wide variety of chemical structures and also due to their excellent thermal, mechanical properties and high resistance to aggressive media. The results of this study will be methods of obtaining and evaluating the advantages and disadvantages of SPI-based materials. For the first time, special attention will be paid to advanced development based on SPI with the addition of crown-ether fragments
Some aspects of biogeography with reference to zoning of the Far- Eastern Seas of Russia and adjacent waters of the Pacific Ocean
Formation of biogeography, its methodological features, and its status as interdisciplinary science combining biological and geographical aspects are discussed. There is noted that the descriptive period of biogeography has passed, and now any «manifestation of life on the globe» requires its explanation. These explanations are reduced to three non-adversarial restrictions: environmental (ecology), temporal (history of origin, evolution), and spatial (geography). General regularities of life distribution over the Earth surface are analyzed, in particular the features of pelagic organisms habitat, and the concept of «dynamic biogeography» is discussed. Latitudinal zoning of epi- and mesopelagic layers in the Far-Eastern Seas of Russia and adjacent Pacific waters is proposed on the basis of data about areas and distribution of 493 species of nekton (fishes and squids) for the 30-year period (1980-2009) obtained from 27 thousand trawl samples caught in 272 expeditions. This zoning uses a new approach related to the chorological direction in marine biogeography realized with the index of latitudinal zoning (ILZ). For this index calculation, all types of species areas (formerly expressed in verbal forms) were identified with numerical codes, which were averaged for all species in each sample, then the regions with certain ILZ values and borders between them were determined on the maps of ILZ distribution, and latitudinal zones and subzones were defined. There is found that the epipelagic layer of the Okhotsk and Bering Seas corresponds to the high-boreal latitudinal subzone and the epipelagic layer of the northwestern Japan Sea and the major part of Russian EEZ in the Pacific corresponds to the low-boreal latitudinal subzone. Fauna of nekton in the mesopelagic layer of all studied regions corresponds by its chorological structure to the low-boreal latitudinal subzone. So, zoning of epipelagic and mezopelagic layers is significantly different, with the fragmentation reducing with depth, possibly due to weakening of climatic factors influence. The biogeographical zoning is not literally zonal but corresponds to structure of the environments (water masses, fronts, currents, gyres, eddies, etc.)
Mathematical Modeling Vibration Protection System for the Motor of the Boat
Abstract The nonlinear mathematical model of the system to mount the motor in a niche of the outboard motor boat, which protects against external influences by means nonlinear shock absorbers and dampers, has been developed. The mathematical model of the system is represented by three nonlinear differential equations of second order. The nonlinear shock absorbers and dampers, as a function of the generalized coordinates are represented by polynomials up to the fifth degree inclusive. For approximate analytical solution of the nonlinear mathematical model is applied the modified method of polynomial transformations and the numerical method of Runge-Kutta
Multilevel modelling of mechanical properties of textile composites: ITOOL Project
The paper presents an overview of the multi-level modelling of textile composites in the ITOOL project, focusing on the models of textile reinforcements, which serve as a basis for micromechanical models of textile composites on the unit cell level. The modelling is performed using finite element analysis (FEA) or approximate methods (method of inclusions), which provide local stiffness and damage information to FEA of composite part on the macro-level
Nanocomposite Polyimide Materials
The transition to nanosized fillers allows to significantly improve the characteristics of composites while reducing their degree of filling, and in some cases to achieve new properties unattainable with the use of traditional fillers and modifiers. Polymeric nanocomposites have unique barrier properties, electrical conductivity, thermal conductivity, increased strength, heat resistance, and thermal stability, as well as reduced flammability. It is known that the addition of nanodispersed layered silicates and various forms of carbon nanofillers to polymeric matrices can significantly affect the mechanisms of thermal and thermooxidative destruction and burning of nanocomposites. In this chapter, we compare the properties of composite materials based on nanostructured silicon carbide and carbon nanotubes with modified and unmodified surfaces obtained on three types of polyimide matrices (matrix No. 1 based on pyromellitic dianhydride and 4,4′-oxydianiline, matrix No. 2 based on 3,3‘,4,4’-benzophenone tetracarboxylic acid dianhydride and p-phenylenediamine, and matrix No. 3 based on pyromellitic dianhydride and 4-[4-(4-aminophenoxy) phenoxy] phenylamine). The dynamic viscosity of polyamide acid, the physicomechanical characteristics of film polymer composite materials, the determination of thermal stability, and thermooxidative destruction mechanism of composites were determined
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