200 research outputs found

    New Airbus A350 XBW and Boeing 787 Dreamliner

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    This article focuses on two planes: «Airbus A350 XWB» and «Boeing 787 Dreamliner». In this article reviewed the competition of «Airbus» and «Boeing», reviewed the market promotion of «Boeing 787 Dreamliner» and «Airbus A350 XWB», identified and justified the introduction of these aircrafts to airlines and passengers.Данная статья посвящена двум самолетам: самолет «Airbus A350 XWB» и самолет «Boeing 787 Dreamliner». В данной статье рассмотрена конкуренция «Аэробуса» и «Боинга», рассмотрено рыночное продвижение самолетов «Boeing 787 Dreamliner» и «Airbus A350 XWB», выявлено и обосновано привнесение данных самолетов авиакомпаниям и пассажирам

    Simultaneous observation of the forward and backward scattered radio reflections from ionized meteor trails

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    © 2017 IEEE. The authors consider a possibility of observation of meteor trails providing simultaneous scattering of a probing signal both in forward and backward directions. Such trails might present some valuable data on physics of meteor phenomena useful both for improving of theoretical models and for development of advanced technologies for meteor burst communications. By computer simulation, we identified principal distinctive properties of the 2-way scattering meteor trails and assessed their percentage at different geographical locations of a meteor radio link

    Analysis and Simulation of Channel Nonreciprocity in Meteor-Burst Communications

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    © 1963-2012 IEEE.This paper addresses the problem of nonreciprocity of propagation conditions in meteor-burst communication systems (MBCSs). In prior publications, this problem has not gained appropriate attention. The channel nonreciprocity may have a significant impact on such advanced communication systems as meteor synchronization systems with nanosecond precision and meteor key distribution systems intended to securely create two identical copies of a shared secret key at both channel sides. These systems are based on the processing of phase characteristics of meteor radio reflections that need to be accurately modeled. We propose a new MBCS simulation model that is based on a rigorous solution to the problem of oblique diffraction of radio waves on ionized meteor trails. Our diffraction approach allows more accurate simulation of the amplitude and phase characteristics of oppositely propagating signals that makes possible detailed investigation of the channel nonreciprocity effects. Using this approach, we present some preliminary simulation results on the channel nonreciprocity at meteor-burst propagation that prove satisfactory immunity of MBCS to ionospheric disturbances even while operating in severe conditions of polar regions

    PLASMON SOLITONS, KINKS AND FARADAY WAVES IN TWO-DIMENSIONAL LATTICE OF METAL NANOPARTICLES

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    We consider nonlinear discrete modes in a two-dimensional lattice of metallic nanoparticles driven by optical radiation at a frequency close to the frequency of the surface plasmon resonance of an individual nanoparticle. We suppose that the particles are small enough and the interparticle distance is large enough to treat nanoparticle within point-dipole approximation. We also assume that nanoparticles are made of silver and possess an intrinsic nonlinear Kerr-type response. Since each particle acts as a resonantly excited oscillator with slow (in comparison with the light period) inertial response, we employ a slowly varying amplitude approach to describe dynamical behavior of particle polarizations. Following a standard linear stability analysis, we obtain areas of bistability and modulation instability for the homogeneous stationary solution of the corresponding dynamical system in the plane ‘intensity-frequency’. Based on these data, we present and analyze examples of generation of plasmonic Faraday waves, stable two-dimensional solitons, oscillons, and kinks (switching waves), which separate two different homogeneous states of particle polarizations. We also discuss realistic duration of the laser pulse which should be large enough to cause the formation of the considered nonlinear modes and small enough to prevent particle ablation

    Wernicke encephalopathy after sleeve gastrectomy

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    The article describes the case of a patient with Wernicke encephalopathy, which developed 3 months after the sleeve gastrectomy. An MRI of the brain was performed to verify the diagnosis, which revealed a symmetrical non-uniform increase in the MR signal on T2-WI and Tirm from the medial part of the thalamus, mastoid bodies and gray matter around the aqueduct of Sylvius. Thiamine infusion was promptly initiated as therapy. During treatment, acute neurological symptoms almost regressed, the patient was discharged in a satisfactory condition with preservation of vertical nystagmus under the supervision of specialists at the place of residence. Wernicke–Korsakoff syndrome more often occurs as a complication of alcoholism and arising from thiamine deficiency. However, the fact that this condition also occurs under the influence of other etiopathogenetic factors is often ignored by clinicians. In the management of patients after bariatric interventions, this condition is much more common in malabsorptive operations. However, a combination of certain factors can be described in patients after restrictive types of bariatric surgeries

    Mathematical model of the competition life cycle under limited resources conditions: Problem statement for business community

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    Present study is devoted to the development of competition life cycle mathematical model in the closed business community with limited resources. Growth of each agent is determined by the balance of input and output resource flows: input (cash) flow W is covering the variable V and constant C costs and growth dA/dt of the agent's assets A. Value of V is proportional to assets A that allows us to write down a first order non-stationary differential equation of the agent growth. Model includes the number of such equations due to the number of agents. The amount of resources that is available for agents vary in time. The balances of their input and output flows are changing correspondingly to the different stages of the competition life cycle. According to the theory of systems, the most complete description of any object or process is the model of its life cycle. Such a model describes all stages of its development: from the appearance ("birth") through development ("growth") to extinction ("death"). The model of the evolution of an individual firm, not contradicting the economic meaning of events actually observed in the market, is the desired result from modern AVMs for applied use. With a correct description of the market, rules for participants' actions, restrictions, forecasts can be obtained, which modern mathematics and the economy can not give. © 2017 Author(s).15-06-04863Present study was carried out under financial support of the Russian Fund of Fundamental Research grant № 15-06-04863 "Mathematical models of local payment system lifecycles"

    Certain features of using modified collagen-containing raw materials with prolonged shelf life in food technology

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    In the current circumstances, trends in nutrition of a person striving to lead a healthy life-style require intake of meat products with the reduced energy value, minimal amounts of fat, increased protein mass fraction, presence of substances improving homeostasis of the body. The synergism of the modern nutrition science and meat industry enables creating food products that satisfy consumers’ demand. Today, in the Russian Federation, a theoretical and practical base of the technology development has been collected to the full extent in the field of rational processing of secondary raw materials in the food industry, optimal use of animal secondary raw materials, study of the protein ingredients of animal and plant origin and their deep scientifically substantiated processing, improvement of technological processes and equipment, and correspondently, product range extension. The paper broadens the information about the modified collagen-containing raw materials (cattle rumen), examines physico-chemical characteristics of the collagen-containing raw material and its changes in the process of freeze-drying with a special attention paid to the study of changes in the histological structure. The presence of the relatively uniform fibrillar structure was determined, which facilitated discovering the functional potential of proteinoids that form the fibrillar matrix in the composition of products from different groups. Analysis of IR-spectra revealed several significant absorption bands linked with the state of peptide bonds. The character of bands is linked with the complex of valence and deformation vibrations of the N- and С- types. It is believed that IR-spectra reflect conformations in the protein secondary structure, which suggests preserving properties of the tropocollagen particle or collagen molecule. Freeze-dried modified collagen-containing cattle rumen was tested by the example of jellies. The obtained databank broadens information about physico-chemical properties of modified collagen-containing raw materials (cattle rumen).In the current circumstances, trends in nutrition of a person striving to lead a healthy life-style require intake of meat products with the reduced energy value, minimal amounts of fat, increased protein mass fraction, presence of substances improving homeostasis of the body. The synergism of the modern nutrition science and meat industry enables creating food products that satisfy consumers’ demand. Today, in the Russian Federation, a theoretical and practical base of the technology development has been collected to the full extent in the field of rational processing of secondary raw materials in the food industry, optimal use of animal secondary raw materials, study of the protein ingredients of animal and plant origin and their deep scientifically substantiated processing, improvement of technological processes and equipment, and correspondently, product range extension. The paper broadens the information about the modified collagen-containing raw materials (cattle rumen), examines physico-chemical characteristics of the collagen-containing raw material and its changes in the process of freeze-drying with a special attention paid to the study of changes in the histological structure. The presence of the relatively uniform fibrillar structure was determined, which facilitated discovering the functional potential of proteinoids that form the fibrillar matrix in the composition of products from different groups. Analysis of IR-spectra revealed several significant absorption bands linked with the state of peptide bonds. The character of bands is linked with the complex of valence and deformation vibrations of the N- and С- types. It is believed that IR-spectra reflect conformations in the protein secondary structure, which suggests preserving properties of the tropocollagen particle or collagen molecule. Freeze-dried modified collagen-containing cattle rumen was tested by the example of jellies. The obtained databank broadens information about physico-chemical properties of modified collagen-containing raw materials (cattle rumen)

    Forecasting the development of mechanical engineering using the system dynamics method

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    At modern conditions of world economy tendencies, the connections between subjects of economy are becoming more difficult and closer. In particular, if in the past were spread hard forms of private ownership of enterprises at present-day world is going conversion to more flexible and mobile composition of subjects' activities. Computer simulation modeling is giving the best results at the areas were the participants of social and economic activities are spending significant efforts and sufficiently much time for visuality playing and analysis of possible variants of the development of the events. The more difficult is the situation the more objects, factors, and possible variants of events' progress is necessary to play in different combinations between together and bigger effect possible to expect from application of simulation model for analyzing of the situation and for searching and making optimized decisions. The application of system dynamics method allows executing forecasting of economic agents including the sectors of economy. © 2020 American Institute of Physics Inc.. All rights reserved

    Comparative Analysis of Clinical, Hormonal and Morphological Studies in Patients with Neuroendocrine ACTH-Producing Tumours

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    This paper highlights the problem of neuroendocrine tumours (NETs) with clinical symptoms of hypercorticism caused by hypersecretion of adrenocorticotropic hormone (ACTH) by tumour cells. In most cases (85%), the tumours were localized in the pituitary gland (Cushing's disease); 15% of the patients had an extrapituitary tumour that manifest as an ectopic ACTH secretion (EAS). Comparative analysis of clinical, hormonal, histological, and immunohistochemical characteristics of pituitary and extrapituitary ACTH-secreting NET was performed. It included 46 patients with CD and 38 ones exhibiting ectopic ACTH secretion (EAS). Results of the study suggest differences between CD and EAS in terms of the severity of clinical manifestations and duration of the disease. Hormonal studies showed that EAS unlike CD was associated with high plasma ACTH and cortisol levels, late-evening salivary cortisol and daily urinary free cortisol, the absence of a 60% or greater reduction of cortisol in the HDDST test, and the presence of a low (less than 2) ACTH gradient in response to desmopressin administration with catheterization of cavernous sinuses. The study of morphofunctional characteristics of the removed NET demonstrated the ability of both pituitary and extrapituitary NETs to express ACTH as well as GH, PRL, LH, and FSH. The angiogenic markers (CD31 and VEGF) were detected with equal frequency regardless of the NET localization. The histological structure of all corticotropinomas suggested their benign origin, but extrapituitary NETs were represented by different morphological types with varying malignancy, invasiveness, and metastatic properties. A higher cell proliferation potential (Ki-67) was documented for NET in patients presenting with an ectopic ACTH secretion compared to those having corticotropinomas
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