One of Many Sources of Defect Generation in SiC

2000 ◽  
Vol 640 ◽  
Author(s):  
Igor I. Khlebnikov ◽  
Tangali S. Sudarshan ◽  
Yuri I. Khlebnikov ◽  
Colin Wood
Keyword(s):  
Silicon Carbide ◽  
Grown Crystal ◽  
Stable Phase ◽  
Planar Defects ◽  
Defect Generation ◽  
Unique Material ◽  
Polytype Transformation ◽  
Many Sources ◽  
The Given ◽  
First Time

ABSTRACTSilicon carbide is a unique material for the study of process of defect generation and crystallization. In this paper, for the first time, we report the observation of the entrapment of whiskers and dendrites (tree-like defects) within the volume of the growing monocrystalline SiC. The encapsulation of the tree-like defects in the volume of the grown crystal leads to solid state polytype transformation. According to Oswald rule, the most probable transformation sequence is as follows: 2H→3C→xR→4H, 6H until a stable phase is established for the given conditions of crystal growth. We observe that the entrapments of tree-like defects are the source of SiC defects such as micropipes and planar defects. It is very likely that the above process is also the source of dislocations. Practically, every branch of the tree-like structure generates the above mentioned defects (micropipes, planar defects, etc.). Our investigation (by EDAX) shows that the chemical composition of the tree-like defect is the same as that of bulk SiC. In this paper, we will present the mechanism of the entrapment of the tree-like defects in the bulk crystal.

Root with Alternation of -ravn-/-rovn- (From Materials of the Academic Description of Russian Spelling)

2020 ◽  
Vol 81 (6) ◽  
pp. 90-96
Author(s):  
E. V. Arutiunova ◽  
E. V. Beshenkova ◽  
O. E. Ivanova
Keyword(s):  
Russian Language ◽  
Study Guides ◽  
Russian Academy Of Sciences ◽  
Academy Of Sciences ◽  
The Given ◽  
First Time ◽  
The Russian Language

The study investigates the rule of spelling the root -ravn-/-rovn- and is considered to be a fragment of the academic description of Russian spelling, which is currently being under investigation at the Russian Language Institute of the Russian Academy of Sciences. The authors clarify the meanings that determine the spelling of the unstressed root, supplement the lists of exceptions, denote words with meanings not corresponding to the given values-criteria, and, for the first time in linguistics, investigate the words that can be correlated with different values-criteria, that is, they have double motivation. The rule codifies the spelling of words that have double motivation and fluctuate in usus, dictionaries, study guides and reference books. Spelling recommendations for these words correspond to the current linguistic norm and were approved by the Spelling Commission of the Russian Academy of Sciences in 2019. The linguistic commentary to the rule contains the most significant etymological facts concerning the root -ravn-/-rovn- and summarises the scientific and methodological attempts to figure out the distribution of vocabulary with root -ravn-/-rovn- based on the meanings selected in the spelling rules. In the paper it is shown that the instability in spelling of various verbs with the root -ravn-/-rovn- in modern writing and dictionaries is determined by the double motivation of words, as well as contradictory recommendations and gaps in the rules.

LUMINESCENCE OF THE BLACK SEA MICROSCOPIC FUNGI CULTURES

2017 ◽  
Author(s):  
Olga Mashukova ◽  
Olga Mashukova ◽  
Yuriy Tokarev ◽  
Yuriy Tokarev ◽  
Nadejda Kopytina ◽  
...  
Keyword(s):  
Fresh Water ◽  
Black Sea ◽  
Ethyl Alcohol ◽  
Light Emission ◽  
Sea Water ◽  
Control Culture ◽  
Chemical Stimulation ◽  
The Black Sea ◽  
The Given ◽  
First Time

We studied for the first time luminescence characteristics of the some micromycetes, isolated from the bottom sediments of the Black sea from the 27 m depth. Luminescence parameters were registered at laboratory complex “Svet” using mechanical and chemical stimulations. Fungi cultures of genera Acremonium, Aspergillus, Penicillium were isolated on ChDA medium which served as control. Culture of Penicillium commune gave no light emission with any kind of stimulation. Culture of Acremonium sp. has shown luminescence in the blue – green field of spectrum. Using chemical stimulation by fresh water we registered signals with luminescence energy (to 3.24 ± 0.11)•108 quantum•cm2 and duration up to 4.42 s, which 3 times exceeded analogous magnitudes in a group, stimulated by sea water (p < 0.05). Under chemical stimulation by ethyl alcohol fungi culture luminescence was not observed. Culture of Aspergillus fumigatus possessed the most expressed properties of luminescence. Stimulation by fresh water culture emission with energy of (3.35 ± 0.11)•108 quantum•cm2 and duration up to 4.96 s. Action of ethyl alcohol to culture also stimulated signals, but intensity of light emission was 3–4 times lower than under mechanical stimulation. For sure the given studies will permit not only to evaluate contribution of marine fungi into general bioluminescence of the sea, but as well to determine places of accumulation of opportunistic species in the sea.

scholarly journals On the formation and stability of fermionic dark matter halos in a cosmological framework

2020 ◽  
Author(s):  
Carlos R Argüelles ◽  
Manuel I Díaz ◽  
Andreas Krut ◽  
Rafael Yunis
Keyword(s):  
Black Hole ◽  
Dark Matter ◽  
Space Distribution ◽  
Coarse Grained ◽  
Dark Matter Halos ◽  
The Core ◽  
The Galaxy ◽  
Gravitating Systems ◽  
The Given ◽  
First Time

Abstract The formation and stability of collisionless self-gravitating systems is a long standing problem, which dates back to the work of D. Lynden-Bell on violent relaxation, and extends to the issue of virialization of dark matter (DM) halos. An important prediction of such a relaxation process is that spherical equilibrium states can be described by a Fermi-Dirac phase-space distribution, when the extremization of a coarse-grained entropy is reached. In the case of DM fermions, the most general solution develops a degenerate compact core surrounded by a diluted halo. As shown recently, the latter is able to explain the galaxy rotation curves while the DM core can mimic the central black hole. A yet open problem is whether this kind of astrophysical core-halo configurations can form at all, and if they remain stable within cosmological timescales. We assess these issues by performing a thermodynamic stability analysis in the microcanonical ensemble for solutions with given particle number at halo virialization in a cosmological framework. For the first time we demonstrate that the above core-halo DM profiles are stable (i.e. maxima of entropy) and extremely long lived. We find the existence of a critical point at the onset of instability of the core-halo solutions, where the fermion-core collapses towards a supermassive black hole. For particle masses in the keV range, the core-collapse can only occur for Mvir ≳ E9M⊙ starting at zvir ≈ 10 in the given cosmological framework. Our results prove that DM halos with a core-halo morphology are a very plausible outcome within nonlinear stages of structure formation.

Defect Generation and Annihilation in 3C-SiC-(001) Homoepitaxial Growth by Sublimation

2013 ◽  
Vol 740-742 ◽  
pp. 283-286
Author(s):  
Philip Hens ◽  
Julian Müller ◽  
Günter Wagner ◽  
Rickard Liljedahl ◽  
Erdmann Spiecker ◽  
...  
Keyword(s):  
Chemical Vapor ◽  
Structural Defects ◽  
Silicon Substrates ◽  
Growth Step ◽  
Planar Defects ◽  
Defect Generation ◽  
Defect Clusters ◽  
Homoepitaxial Growth ◽  
Cubic Silicon Carbide ◽  
Thick Layers

In this paper we present a concept on the defect generation and annihilation during the homoepitaxial growth step of cubic silicon carbide by sublimation epitaxy on templates grown by chemical vapor deposition on silicon substrates. Several structural defects like stacking faults, twins and star defects show opposite evolution from the template layer into the sublimation grown material. While single planar defects tend to annihilate with increasing layer thickness, the defect clusters assigned to the star defects are enlarging. These issues contribute to a balance of how to achieve the best possible quality on thick layers.

How Crystals Form from a Cloud of Atoms

2011 ◽  
Vol 675-677 ◽  
pp. 3-7
Author(s):  
Peter Häussler ◽  
Martin Stiehler
Keyword(s):  
Structure Formation ◽  
Fundamental Equation ◽  
Structural Features ◽  
Local Order ◽  
Total System ◽  
Angular Momenta ◽  
General Dynamics ◽  
Bloch’S Theorem ◽  
The Given ◽  
First Time

Structure formation, the condensation of a cloud of atoms to a crystal is still not well understood. Disordered sytems (amorphous/liquid) should be in the center of this research, they are the precursors of any crystal. We consider elementary systems, as well as binary, or ternary amorphous alloys, irrespective whether they are metallically, covalently or ionically bonded and describe the process of structure formation in the formal language of thermodynamics but, as far as we know for the first time, by an extended version (general dynamics), based on the complete Gibbs fundamental equation, applied to internal subsystems. Major structural features evolve from global resonances between formerly independent internal subsystems by exchanging momenta and angular momenta, both accompanied by energy. By this they adjust mutually their internal features and create spherical-periodic structural order at medium-range distances. Under the given external constraints the resonances get optimized by selforganization. Global resonances of the type considered have clearly to be distinguished from local resonances between individual ions (described by quantum chemistry) forming local order. The global resonances cause anti-bonding (non-equilibrium) as well as bonding (equilibrium) states of the coupled total system, occupying the latter to form new structurally extended order. The transition to equilibrium creates entropy which itself leaves the system together with energy. At resonance the energetical splitting between the bonding and anti-bonding state is largest, the creation of entropy and the decrease of the total energy therefore, too. The crystal, finally, evolves by additionally optimizing a resonance based on angular momentum, and the additional adjustments of the local resonances to the global ones, theoretically done by applying Bloch’s theorem.

scholarly journals How Important is Gambling in National GDP: Case Study from Austria, Croatia, Italy and Slovenia

ECONOMICS ◽  
2019 ◽  
Vol 7 (1) ◽  
pp. 31-49
Author(s):  
Andrej Raspor ◽  
Iva Bulatović ◽  
Ana Stranjančević ◽  
Darko Lacmanović
Keyword(s):  
Research Question ◽  
The State ◽  
State Budget ◽  
Significant Information ◽  
Main Research ◽  
Benchmark Analysis ◽  
The World ◽  
State Budgets ◽  
The Given ◽  
First Time

Abstract Purpose – The situation in the field of gambling is changing due to the rise of Internet and Mobile gambling. In general gambling consumption is increasing every year, but the distribution of consumption has radically changed from Land Based gambling to Remote gambling. The purpose of this article is to present an overview of the world gambling industry and a specific overview in Austria, Croatia, Italy and Slovenia in order to find some main similarities and differences in observed period. Design/Methodology/Approach – The main research question is How important is gambling for the involved countries and what proportion of the national GDP does the gambling revenue account for? This paper presents the analysis of five statistical databases for the last sixteen years in order to find out some patterns, cyclical or seasonal features or other significant information that allows us to do forecasting of the future revenue with a certain degree of accuracy. We have systematically searched and collected data from the World Bank and the National Statistical Offices websites of the given countries. Statistical methods were used for benchmark analysis, while Box and Jenkins approach and ARIMA modelling were used for forecasting. Findings – The smallest increase was recorded in Slovenia and the largest in Italy. The same effects were also observed in the GDP of these countries. Thus, the state budgets of Croatia and Italy are increasingly dependent on gambling taxes. It also has negative wages. The gambling addictions among the locals have become more frequent as well. Originality of the research – The article shows the forecasts of the gambling revenue and its share in the GDP by 2027. We want to alert decision makers to adopt appropriate policies. States need to rethink their views on gambling and the excessive dependence of the state budget on gambling taxes. This is the first time a single comparative analysis of these countries and the above mentioned forecast has been conducted.

scholarly journals Formations of Silicon Carbide and Epoxy Matrix Radiator: An Experimental Design, Dimension and Formulations

2019 ◽  
Vol 9 (1) ◽  
pp. 1793-1796
Keyword(s):  
Heat Transfer ◽  
Silicon Carbide ◽  
Experimental Design ◽  
Epoxy Resin ◽  
Epoxy Matrix ◽  
Research Work ◽  
Heat Transfer Analysis ◽  
The Given ◽  
Design Dimension

The greatest dealon the article have to approach the experimental design, dimensions and formulations in Silicon Carbide and Epoxy Matrix Radiator. The experiment prepared as per the fabrication chart behind that known about the characterization of material and proposal layout of fabrication work. Among the research work, concentrated the formation of silicon carbide epoxy matrix radiator in the given configuration and composition prepared as a high thermal conductive Epoxy resin is mixed at the ratio of 20wt% of epoxy resin 80% of Silicon Carbide. As silicon carbide has higher thermal conductivity and lowerthermal expansion than Aluminium and then the experimented result determined by the rate of heat transfer analysis such as the mode of heat transfer like Conduction, Convection and Radiation of the materials (Aluminium 6061 and Sic + Epoxy Resin). The following heat transfer characteristics formulated and calculated as per the given design, dimension and configuration of the materials.

scholarly journals BLOCK CIPHERS ON THE BASIS OF REVERSIBLE CELLULAR AUTOMATA

2020 ◽  
Vol 10 (1) ◽  
pp. 8-11
Author(s):  
Yuliya Tanasyuk ◽  
Petro Burdeinyi
Keyword(s):  
Cellular Automata ◽  
Block Cipher ◽  
Key Generation ◽  
One Dimensional ◽  
C Programming Language ◽  
C Programming ◽  
Shared Secret ◽  
Reversible Cellular Automata ◽  
The Given ◽  
First Time

The given paper is devoted to the software development of block cipher based on reversible one-dimensional cellular automata and the study of its statistical properties. The software implementation of the proposed encryption algorithm is performed in C# programming language in Visual Studio 2017. The paper presents specially designed approach for key generation. To ensure desired cryptographic stability, the shared secret parameters can be adjusted to contain information needed for creating substitution tables, defining reversible rules, and hiding final data. For the first time, it is suggested to create substitution tables based on iterations of a cellular automaton that is initialized by the key data.

scholarly journals MULTIPARAMETRIC OPTIMIZATION OF THE SHAPE AND THICKNESS OF INSULATED ENERGY EFFICIENT CONSTRUCTED BUILDING WITH A SPECIFIC NUMBER OF FACES

2021 ◽  
pp. 196-204
Author(s):  
Viacheslav Martynov
Keyword(s):  
Energy Efficiency ◽  
Energy Efficient ◽  
Heat Losses ◽  
Geometrical Parameters ◽  
Energy Efficient Buildings ◽  
Multiparametric Optimization ◽  
Heat Influx ◽  
Number Of Faces ◽  
The Given ◽  
First Time

To calculate the optimal parameters of outbuildings, a mathematical model and method for optimizing the shape and resistance of heat transfer for opaque and transparent structures with a certain constant number of faces, building volume and amount of insulation to minimize the thermal balance of enclosing structures with the environment during the heating period In the course of calculations the geometrical parameters of translucent, opaque structures in the heat-insulating shell of buildings are determined taking into account heat losses, heat influx from solar radiation by the criterion of ensuring minimum heat losses through enclosing structures, rational parameters (buildings) The given technique and mathematical models should be used in the future in the design of energy efficient buildings in the reconstruction and thermal modernization of buildings. This will increase their energy efficiency and, accordingly, the energy efficiency class of buildings. For the research faceted attached building in the form of a triangular pyramid, the reduction in heat loss was 14.82 percent only due to the optimization of the shape and redistribution of the insulation. Similar results were obtained for other initial forms. For the first time, a computerized method was proposed, an algorithm and application package Optimparam for multiparameter shape optimization and insulation of translucent and opaque structures for outbuildings with a given number of arbitrarily arranged faces were developed.

scholarly journals IDENTITY IMPLICATIONS: «FROM THE COUNTRY OF RICE AND OPIUM» BY SOFIIA YABLONSKA

2018 ◽  
Vol 31 ◽  
pp. 251-266
Author(s):  
Tymofii HAVRYLIV
Keyword(s):  
Travel Literature ◽  
Spatial Dimension ◽  
Interdisciplinary Studies ◽  
Complex Nature ◽  
Time Space ◽  
The World ◽  
Self Knowledge ◽  
The Given ◽  
First Time ◽  
Ukrainian Society

This article is one of the first scholarly attempts to analyze the creative work of Ukrainian filmmaker and traveler Sofiia Yablonska-Uden. For the first time in the Ukrainian and the world literary studies, identical implications are analyzed in the «From the Country of Rice and Opium» by S. Yablonska. The purpose of the article is to highlight the complex nature of identity issues in travel literature. In terms of identity, the journey performs two fundamental, closely interconnected tasks: knowledge of the other and self-knowledge. Hermeneutic approaches are used in the article. The main results can be summarized as follows: 1) the journey has its own time-spatial dimension, consisting of two disproportionate moments: preparation for travel and travel itself, and begins literally and symbolically with the overcoming, or the crossing of the border; 2) the intention of the trip contains an identity challenge that affects the preparation, organization, realization of the travel, the way and the content of documenting impressions; 3) such parameters of travel as an accident, an adventure, a game which formed the world of traveler's impressions, are subordinated to the identity problem in the given work; 4) the essay character of the book makes it possible to talk about implications as a response to an identity challenge. The book of travel essays «From the Country of Rice and Opium» of S. Yablonska-Uden is a sample of a successful combination of the business and private aspects of travel, intentions of knowledge and self-knowledge, poetry and faculty; learning about another people and countries, the writer learns a lot of things about himself. Travel literature is an important study object of Ukrainian writing, which opens the prospects for further interdisciplinary studies. The study of travel literature, an identity issue, is extremely relevant both for the development of Ukrainian society and for the formation of optimal responses to the challenges of our time. Keywords travel, travel literature, identity, identical implications, time-space disposition.

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