How Crystals Form from a Cloud of Atoms

2011 ◽  
Vol 675-677 ◽  
pp. 3-7
Author(s):  
Peter Häussler ◽  
Martin Stiehler

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.

2020 ◽  
Vol 81 (6) ◽  
pp. 90-96
Author(s):  
E. V. Arutiunova ◽  
E. V. Beshenkova ◽  
O. E. Ivanova

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.


Author(s):  
Olga Mashukova ◽  
Olga Mashukova ◽  
Yuriy Tokarev ◽  
Yuriy Tokarev ◽  
Nadejda Kopytina ◽  
...  

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.


Author(s):  
Carlos R Argüelles ◽  
Manuel I Díaz ◽  
Andreas Krut ◽  
Rafael Yunis

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.


2020 ◽  
Author(s):  
Adrián López Martín ◽  
Mohamed Mounir ◽  
Irmtraud M Meyer

Abstract RNA structure formation in vivo happens co-transcriptionally while the transcript is being made. The corresponding co-transcriptional folding pathway typically involves transient RNA structure features that are not part of the final, functional RNA structure. These transient features can play important functional roles of their own and also influence the formation of the final RNA structure in vivo. We here present CoBold, a computational method for identifying different functional classes of transient RNA structure features that can either aid or hinder the formation of a known reference RNA structure. Our method takes as input either a single RNA or a corresponding multiple-sequence alignment as well as a known reference RNA secondary structure and identifies different classes of transient RNA structure features that could aid or prevent the formation of the given RNA structure. We make CoBold available via a web-server which includes dedicated data visualisation.


ECONOMICS ◽  
2019 ◽  
Vol 7 (1) ◽  
pp. 31-49
Author(s):  
Andrej Raspor ◽  
Iva Bulatović ◽  
Ana Stranjančević ◽  
Darko Lacmanović

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.


2020 ◽  
Author(s):  
Velio Coviello ◽  
Lucia Capra ◽  
Gianluca Norini ◽  
Norma Dávila ◽  
Dolores Ferrés ◽  
...  

Abstract. The M7.1 Puebla-Morelos earthquake that occurred on 19 September 2017, with epicenter located ∼ 70 km SW from Popocatépetl volcano, severely hit central Mexico. Seismic shaking of the volcanic edifice induced by the earthquake triggered hundreds of shallow landslides on the volcanic flanks, remobilizing loose pyroclastic deposits and saturated soils. The largest landslides occurred on the slopes of aligned ENE-WSW-trending ravines on opposite sides of the volcanic cone, roughly parallel to the regional maximum horizontal stress and local volcanotectonic structural features. This configuration may suggest transient reactivation of local faults and extensional fractures as one of the mechanisms that has weakened the volcanic edifice and promoted the largest slope failures. The seismic records from a broadband station located at few kilometers from the main landslides are used to infer the intensity of ground shaking that triggered the slope failures. The material involved in the larger landslides, mainly ash and pumice fall deposits from late Holocene eruptions with a total volume of about 106 cubic meters, transformed into two large debris flows on the western slope of the volcano and one on its eastern side. The debris flows were highly viscous and contained abundant large woods (about 105 cubic meter). Their peculiar rheology is reconstructed by field evidences and analyzing the grain size distribution of samples from both landslide scars and deposits. This is the first time that such flows were observed at this volcano. Our work provides new insights to constrain a multi-hazard risk assessment for Popocatépetl and other continental active volcanoes.


2020 ◽  
pp. 67-73
Author(s):  
P.I. Tkachenko ◽  
I.I. Starchenko ◽  
S.O. Bilokon ◽  
N.V. Lokhmatova ◽  
N.P. Bilokon ◽  
...  

The great diversity of the jaw cysts makes the issues of their diagnosis, differential diagnosis, and treatment quite important, always requiring an individual approach, given the features of each clinical case. Although the jaw cysts were first mentioned by Scultetus in 1654, the researchers still have different views on the semiotics and classifying individual nosological forms and, consequently, on choosing treatment methods, preventing possible complications and recurrences, and making prognosis. Asymptomatic clinical course and absence of characteristic clear clinical manifestations of the jaw cysts and similarity of their signs at separate developmental stages regardless of the nosological form and origin site make this pathology relevant in the practice of maxillofacial surgery. Traumatic and aneurysmal pseudocysts are common in the nomenclature of tumor-like formations of the jaws. The paper is concerned with the etiology and pathogenesis, clinical morphological features, and modes of treatment of traumatic and aneurysmal jaw cysts, based on the generalization of the findings of the scientific researches, to emphasize the above nosological forms to the medical community. The study encompasses a thorough analysis of the fundamental scientific works and publications in periodicals on the above issues. The clinical part of the study concerned a comprehensive examination of 46 children with traumatic and aneurysmal jaw cysts who received treatment at the surgical unit of the Poltava Municipal Children’s Clinical Hospital during the period of 5 years. In addition, 8 adult patients with traumatic cysts were examined and received outpatient treatment at the Department’s clinic. Common clinical and additional examination methods, diagnostic puncture, EOD, radiography, CT, and MRI were used to make the clinical diagnosis in serious cases. The microscopic structure of the specimens made from the postoperative material using conventional techniques was studied. During 2014-2019, 46 children with non-odontogenic jaw cysts (NJC) were treated at the Department of Children’s Oral Surgery, including 24 patients (52.2%) with traumatic cysts (TC) and 15 patients (32.6%) with aneurysmal cysts (AC). That is, TC and AC accounted for 39 cases (84.8%) of NJC. At the same time, while the general age of patients with NJC ranged from 5 to 15 years, TC and AC were most common in children aged 10-15 years, which is consistent with other researchers’ data, who observed the highest incidence in puberty. 25 (64,1%) boys and 14 girls (35.9%) have been involved in the study. Generalized statistical analysis revealed that traumatic cysts accounted for 52.2% of children, 32.6% for aneurysmal and 15.2% for other types of non-odontogenic jaw cysts. The patients were predominantly males, and even trauma in the past medical history did not always correspond to and confirm the type of cystic formation. The presented material suggests a rather unclear diagnostic “boundary” between traumatic and aneurysmal cysts, when, in fact, the main differential diagnostic criterion is a carefully gathered anamnesis, even at the prehospital stage. The given material can be the basis for further in-depth scientific and practical studies on immunohistochemical structural features of traumatic and aneurysmal jaw cysts.


Author(s):  
Yuliya Tanasyuk ◽  
Petro Burdeinyi

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.


Author(s):  
Viacheslav Martynov

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.


Author(s):  
Tymofii HAVRYLIV

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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