Dimension on Discrete Spaces

In this paper we develop some combinatorial models for continuous spaces. In this spirit we study the approximations of continuous spaces by graphs, molecular spaces and coordinate matrices. We define the dimension on a discrete space by means of axioms, and the axioms are based on an obvious geometrical background. This work presents some discrete models of n-dimensional Euclidean spaces, n-dimensional spheres, a torus and a projective plane. It explains how to construct new discrete spaces and describes in this connection several three-dimensional closed surfaces with some topological singularities It also analyzes the topology of (3+1)-spacetime. We are also discussing the question by R. Sorkin [19] about how to derive the system of simplicial complexes from a system of open covering of a topological space S.Comment: 16 pages, 8 figures, Latex. Figures are not included, available from the author upon request. Preprint SU-GP-93/1-1. To appear in "International Journal of Theoretical Physics

Phase transformation B1 to B2 in TiC, TiN, ZrC and ZrN under pressure

Phase stability of various phases of MX (M = Ti, Zr; X = C, N) at equilibrium and under pressure is examined based on first-principles calculations of the electronic and phonon structures. The results reveal that all B1 (NaCl-type) MX structures undergo a phase transition to the B2-structures under high pressure in agreement with the previous total-energy calculations. The B1-MX structures are dynamically stable under very high pressure (210-570 GPa). The pressure-induced B2 (CsCl-type) MC phases are dynamically unstable even at high pressures, and TiN and ZrN are found to crystallize with the B2-structure only at pressures above 55 GPa. The first-order B1-to-B2 phase transition in these nitrides is not related to the softening of phonon modes, and the dynamical instability of B2-MX is associated with a high density of states at the Fermi level.Comment: 9 pages, 4 figure

Comparative first-principles molecular dynamics study of TiN(001)/SiN/TiN(001) and TiN(001)/SiC/TiN(001) interfaces in superhard nanocomposites

Heterostructures TiN(001)/SiN/TiN(001) and TiN(001)/SiC/TiN(001), with one monolayer (ML) of interfacial SiN and SiC, respectively, inserted between five monolayer thick B1-TiN, were investigated using first-principles quantum molecular dynamics (QMD) calculations. The temperature dependent QMD simulations at 300 K in combination with subsequent variable-cell structural relaxation revealed that the TiN(001)/SiN/TiN(001) interface exists as pseudomorphic B1-SiN layer only at 0 K, and as a superposition of distorted octahedral SiN6 and tetrahedral SiN4 units aligned along the (110) direction at a finite temperature. Thus, at 300 K, the interfacial layer is not epitaxial. Instead it consists of aggregates of the B1-SiN-like and Si3N4-like distorted clusters. However, in the the TiN(001)/SiC/TiN(001) heterostructures, the interfacial layer remains epitaxial B1-SiC at 0 K as well as at 300 K, with only a small shift of nitrogen atoms on both sides of the interface towards the silicon atoms. A comparison with the results obtained by earlier "static" ab initio DFT calculations at 0 K shows the great advantage of the QMD calculations that allow us to reveal structural reconstructions caused by thermal activation. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/2054

Estimation of Reserves for Improving the Results of Patients with Multipresistant Pulmonary Tuberculosis in the Application of Surgical Methods Based on Analysis of the Efficiency of Conservative Treatment of a Specified Cohort

In order to improve the results of treatment of patients with multi-resistant pulmonary tuberculosis with the use of surgical methods, the effectiveness estimation of conservative treatment of 176 patients with this form of tuberculosis according to cohort analysis data in two districts of Kyiv were done.In the list were included following parameters: type of the tuberculosis, its clinical-radiological form and the prevalence of the process, the results of conservative treatment in patients who completely finished the course of anti-TB chemotherapy and the results of conservative treatment of 81 patients who had indications for surgical treatment but had not been operated. Processing of the materials of the study was carried out with the use of licensed software products included in the Microsoft Office Professional 2007 package. The predicted results of treatment were calculated on the condition of surgical intervention.Out of the total sample of patients, 31.3 % of the patients completed treatment. Mortality was 16.5 %, transferred to palliative care 11.9 %. More than one in three patients (35.2 %) stopped treatment at different times from the start.According to the clinic of thoracic surgery SU "National Institute of Phthisiology and Pulmonology named after F.G. Yanovsky NAMS of Ukraine ", the overall effectiveness of treatment for patients with limited multidrug-resistant tuberculosis with the use of surgical intervention is about 95 % in the absence of mortality. We have modelled the potential results of treatment of the selected cohort in case of the surgical stage is fully and timely applied in a complex of therapeutic treatment. If all 81 patients with indications for surgical treatment used that way, then, with the above efficiency, a complete cure could be predicted in 77 patients (44.5 % of the total number of observations), which in turn would allow predicting the achievement completion of treatment at 64.2 % with complete cure for 60.6 % of patients.Thus, it is established that the positive result of surgical treatment in the general complex of treatment measures in patients with multidrug-resistant pulmonary tuberculosis is able to improve the results of treatment of this contingent more than twice, reduce the mortality almost by three times, reduce the need for repeated courses of treatment from 7.4 % to 1.7 %, as well as to reduce the epidemiological reservoir of infection due to a significant decrease in the number of patients with failure to treat tuberculosis, interrupted and palliative treatment

Soviet Illegal Whaling: The Devil and the Details

In 1948, the U.S.S.R. began a global campaign of illegal whaling that lasted for three decades and, together with the poorly managed “legal” whaling of other nations, seriously depleted whale populations. Although the general story of this whaling has been told and the catch record largely corrected for the Southern Hemisphere, major gaps remain in the North Pacific. Furthermore, little attention has been paid to the details of this system or its economic context. Using interviews with former Soviet whalers and biologists as well as previously unavailable reports and other material in Russian, our objective is to describe how the Soviet whaling industry was structured and how it worked, from the largest scale of state industrial planning down to the daily details of the ways in which whales were caught and processed, and how data sent to the Bureau of International Whaling Statistics were falsified. Soviet whaling began with the factory ship Aleut in 1933, but by 1963 the industry had a truly global reach, with seven factory fleets (some very large). Catches were driven by a state planning system that set annual production targets. The system gave bonuses and honors only when these were met or exceeded, and it frequently increased the following year’s targets to match the previous year’s production; scientific estimates of the sustainability of the resource were largely ignored. Inevitably, this system led to whale populations being rapidly reduced. Furthermore, productivity was measured in gross output (weights of whales caught), regardless of whether carcasses were sound or rotten, or whether much of the animal was unutilized. Whaling fleets employed numerous people, including women (in one case as the captain of a catcher boat). Because of relatively high salaries and the potential for bonuses, positions in the whaling industry were much sought-after. Catching and processing of whales was highly mechanized and became increasingly efficient as the industry gained more experience. In a single day, the largest factory ships could process up to 200 small sperm whales, Physeter macrocephalus; 100 humpback whales, Megaptera novaeangliae; or 30–35 pygmy blue whales, Balaenoptera musculus brevicauda. However, processing of many animals involved nothing more than stripping the carcass of blubber and then discarding the rest. Until 1952, the main product was whale oil; only later was baleen whale meat regularly utilized. Falsified data on catches were routinely submitted to the Bureau of International Whaling Statistics, but the true catch and biological data were preserved for research and administrative purposes. National inspectors were present at most times, but, with occasional exceptions, they worked primarily to assist fulfillment of plan targets and routinely ignored the illegal nature of many catches. In all, during 40 years of whaling in the Antarctic, the U.S.S.R. reported 185,778 whales taken but at least 338,336 were actually killed. Data for the North Pacific are currently incomplete, but from provisional data we estimate that at least 30,000 whales were killed illegally in this ocean. Overall, we judge that, worldwide, the U.S.S.R. killed approximately 180,000 whales illegally and caused a number of population crashes. Finally, we note that Soviet illegal catches continued after 1972 despite the presence of international observers on factory fleets

Mechanism of Photoluminescence in Erbium-Doped Chalcogenide

The monograph describes the technique of the synthesis of glasses and the method of the growth of erbium-doped single crystals. The photoluminescence spectra of Ag0.05Ga0.05Ge0.95S2-Er2S3 glasses and glasses from the Ga2S3-La2S3-Er2S3 system have been investigated in the visible and near-infrared ranges. According to the energy transitions in the erbium ions, a radiation mechanism for conversion and up-conversion luminescence has been established. The role of structural ordering and the influence of defects on the radiation efficiency of Er3+ ions have been investigated. The spectra of photoluminescence of (Ga54.59In44.66Er0.75)2S300 and (Ga69.75La29.75Er0.5)2S300 single crystals have been studied. The efficiency of the radiation of the amorphous and crystalline materials has been compared. Also, the temperature dependence of the integral intensity of the radiation of glasses and single crystals has been studied. It is established that in a limited temperature range, these materials can be used for the manufacture of non-contact optical thermosensors

Статеві особливості рухової підготовленості дітей 6—10 років

The objective is to determine the gender-specific peculiarities of motor preparedness of children aged 6-10. Materials and methods: the participants in the study were girls aged 6 (n = 36), aged 7 (n = 48), aged 8 (n = 57), aged 9 (n = 38), aged 10 (n = 46); boys aged 6 (n = 48), aged 7 (n = 45), aged 8 (n = 60), aged 9 (n = 47), aged 10 (n = 40). To achieve the tasks set, the study relied on the following research methods: analysis of scientific literature, pedagogical testing and methods of mathematical statistics of research data reduction. The study used discriminant analysis as the modeling method.Results: the classification results of motor preparedness of girls and boys aged 6-10 indicate that the study has correctly classified 81.9-100% of the initial observations. The graphic material demonstrates the density of objects within each class and a clear distinction between the classes. This allows to maintain that there is a significant difference between girls and boys aged 6-10 in their motor preparedness.Conclusions. The girls aged 6-10 show the best results in movement coordination related to combinations of movements of arms and legs, as well as flexibility. The girls aged 10 show the best results in test No. 10 “300-m Race”. The boys aged 6-10, unlike the girls, show the best results in the development of general coordination of movements, strength, speed strength, strength and general endurance. It is possible to argue with a high level of reliability that by their classification characteristics girls and boys belong to different classes, and significantly differ in motor preparedness.Цель: определить гендерные особенности двигательной подготовленности детей 6–10 лет.Материалы и методы: в исследовании приняли участие девочки 6 лет (n = 36), 7 лет (n = 48), 8 лет (n = 57), 9 лет (n = 38), 10 лет (n = 46); мальчики 6 лет (n = 48), 7 лет (n = 45), 8 лет (n = 60), 9 лет (n = 47), 10 лет (n = 40). Для решения поставленных задач были применены следующие методы исследования: анализ научной литературы, педагогическое тестирование и методы математической статистики обработки результатов исследования. Как метод моделирования использован дискриминантный анализ.Результаты: результаты классификации двигательной подготовленности девочек и мальчиков 6-10 лет указывают, что 81,9–100% исходных наблюдений классифицированы верно. Графический материал свидетельствует о плотности объектов в каждом классе и о выразительной черте между классами. Это дает возможность утверждать, что между девочками и мальчиками 6–10 лет существует существенная разница в двигательной подготовленности.Выводы. Девочки 6–10 лет показывают лучшие результаты в координации движений, связанных с сочетанием движений рук и ног и гибкости. В 10 лет девочки показывают лучшие результаты в тесте № 10 «Бег 300 м». Мальчики 6–10 лет отличаются от девочек лучшим развитием общей координации движений, силы, скоростной силы, силовой и общей выносливости. По классификационным характеристикам с высокой степенью достоверности девочки и мальчики относятся к разным классам и существенно отличаются по уровню двигательной подготовленности. Мета: визначити статеві особливості рухової підготовленості дітей 6—10 років. Матеріали і методи: у дослідженні прийняли участь дівчатка 6 років (n=36), 7 років (n=48), 8 років (n=57), 9 років (n=38), 10 років (n=46); хлопчики 6 років (n=48), 7 років (n=45), 8 років (n=60), 9 років (n= 47), 10 років (n=40). Для вирішення поставлених завдань були застосовані такі методи дослідження: аналіз наукової літератури, педагогічне тестування та методи математичної статистики обробки результатів дослідження. Як метод моделювання використаний дискримінантний аналіз.Результати: результати класифікації рухової підготовленості дівчаток і хлопчиків 6—10 років вказують, що 81,9—100 % вихідних спостережень класифіковані вірно. Графічний матеріал свідчить про щільність об’єктів у кожному класі та про виразну межу між класами. Це дає можливість стверджувати, що між дівчатками та хлопчиками 6—10 років існує суттєва різниця у руховій підготовленості.Висновки. Дівчатка 6—10 років показують кращі результати у координації рухів, пов’язаних з поєднанням рухів рук і ніг та гнучкості. У 10 років дівчатка показують кращі результати у тесті № 10 «Біг 300 м». Хлопчики 6—10 років відрізняються від дівчаток кращим розвитком загальної координації рухів, сили, швидкісної сили, силової і загальної витривалості. За класифікаційними характеристиками з високою ступінню достовірності дівчатка і хлопчики відностяться до різних класів і суттєво відрізняються за руховою підготовленістю