Nanoscale investigation of polymer cement concretes by small angle neutron scattering

An analysis of dense cements, such as polymer cement concrete, is made to produce original innovative components for different types of constructing materials. These materials present good functional properties (ageing resistance, crack formation resistance, hardness, and stability of mechanical modules) and can be used for various applications. In this paper, experimental tests on Portland cement with added γ-Al 2 O 3 and redispersible dry polymer performed using small angle neutron scattering are reported. The objective of the investigation was to assess the key parameters of the material (e.g., porosity, fractal dimensions, and size distribution) at the nanoscale level as well as to obtain useful structural information for expanding the possibility of applications. The results obtained can contribute to the optimisation of the consistency of the material, the design of operating conditions of elements of structures and facilities, and the design of the procedures that support ecological criteria and enhance quality and safety levels. © 2017 Walter de Gruyter GmbH, Berlin/Boston

TTX-sensitive Na+ and nifedipine-sensitive Ca2+ channels in rat vas deferens smooth muscle cells

The inward currents in single smooth muscle cells (SMC) isolated from epididymal part of rat vas deferens have been studied using whole-cell patch-clamp method. Depolarising steps from holding potential -90 mV evoked inward current with fast and slow components. the component with slow activation possessed voltage-dependent and pharmacological properties characteristic for Ca2+ current carried through L-type calcium channels (I-Ca). the fast component of inward current was activated at around -40 mV, reached its peak at 0 mV, and disappeared upon removal of Na ions from bath solution. This current was blocked in dose-dependent manner by tetrodotoxin (TTX) with an apparent dissociation constant of 6.7 nM. On the basis of voltage-dependent characteristics, TTX sensitivity of fast component of inward current and its disappearance in Na-free solution it is suggested that this current is TTX-sensitive depolarisation activated sodium current (I-Na) Cell dialysis with a pipette solution containing no macroergic compounds resulted in significant inhibition of I-Ca (depression of peak I-Ca by about 81% was observed by 13 min of dialysis), while I-Na remained unaffected during 50 min of dialysis. These data draw first evidence for the existence of TTX-sensitive Na+ current in single SMC isolated from rat vas deferens. These Na+ channels do not appear to be regulated by a phosphorylation process under resting conditions. (C) 1999 Elsevier Science B.V. All rights reserved.Natl Acad Sci Ukraine, Bogomoletz Inst Physiol, Nerve Muscle Physiol Dept, UA-24 Kiev, UkraineUniversidade Federal de São Paulo, Escola Paulista Med, Dept Pharmacol, São Paulo, BrazilUniversidade Federal de São Paulo, Escola Paulista Med, Dept Pharmacol, São Paulo, BrazilWeb of Scienc

Capturing the Fire: Flame Energetics and Neutronizaton for Type Ia Supernova Simulations

We develop and calibrate a realistic model flame for hydrodynamical simulations of deflagrations in white dwarf (Type Ia) supernovae. Our flame model builds on the advection-diffusion-reaction model of Khokhlov and includes electron screening and Coulomb corrections to the equation of state in a self-consistent way. We calibrate this model flame--its energetics and timescales for energy release and neutronization--with self-heating reaction network calculations that include both these Coulomb effects and up-to-date weak interactions. The burned material evolves post-flame due to both weak interactions and hydrodynamic changes in density and temperature. We develop a scheme to follow the evolution, including neutronization, of the NSE state subsequent to the passage of the flame front. As a result, our model flame is suitable for deflagration simulations over a wide range of initial central densities and can track the temperature and electron fraction of the burned material through the explosion and into the expansion of the ejecta.Comment: 21 pages, 24 figures, to appear in Ap

Особенности диагностики и лечения спонтанных внеорганных гематом мягких тканей шеи и груди

The possibilities of computed tomography in the diagnosis of spontaneous hematomas (sh) of the soft tissues of the neck and chest and the features of their treatment are shown. Computed tomography with intravenous bolus contrast enhancement is the main method for diagnosing sh, which allows you to specify its exact localization, distribution, determine the structure and volume of the hematoma, the contrast agent exiting the contours of the vessel, and, taking into account the data obtained and the clinic, determines the tactics of treatment.Stable sh does not require surgical treatment. In the case of a large volume of chest hematoma, compression syndrome, hemothorax, drainage is indicated. Unstable sh dictate the need for angiography and, if necessary, endovascular embolization.Показаны возможности компьютерной томографии в диагностике спонтанных гематом (СГ) мягких тканей шеи и груди и особенности их лечения. Компьютерная томография с внутривенным болюсным контрастным усилением является основным методом диагностики СГ, позволяющим указать точную ее локализацию, распространение, определить структуру и объем гематомы, выход контрастного препарата за контуры сосуда и с учетом полученных данных и клиники определяет тактику лечения.Стабильные СГ не требуют хирургического лечения. В случае наличия большого объема гематомы груди, компрессионного синдрома, гемоторакса - показано дренирование. Нестабильные СГ, диктуют необходимость выполнения ангиографии и при необходимости эндоваскулярной эмболизации

Методический подход к оценке уровня адаптивности организационных структур управления компаниями

Purpose: to present and justify a methodical approach to assessing the level of adaptability of organizational management structures to the conditions of a dynamically changing external environment.Methods: a wide range of general scientific methods is used – system analysis, synthesis, graphical interpretation of data. During the study, the method of expert assessments was used to assess the level of adaptability. In order to classify the types of management structures depending on their adaptability, a cluster analysis was carried out.Results: the article presents an approach to the definition of the concepts of "adaptation" and "adaptability" in relation to management structures. In order to develop a methodical approach to assessing the level of adaptability of organizational structures, the types of their adaptation were systematized, the main characteristics of the structures were identified and the scale was developed to assess the level of their adaptability. The use of the expert method made it possible to assess the level of adaptability of the main types of organizational structures to the conditions of a changing business space and rank them depending on this level. As a result of the cluster analysis, all the studied types of management structures were classified depending on their adaptability.Conclusions and Relevance: the developed methodical approach to assessing the level of adaptability of management structures made it possible to determine the adaptive properties of both hierarchical and organic management structures, assess their level of adaptability and identify the most adaptive among them. It has been established that the basis for the successful development of companies in the conditions of turbulent business space is the use of organic structures or changing individual parameters of hierarchical structures in order to increase their adaptability. Adaptation can be carried out using any structure, both traditional hierarchical and organic, by forming new management structures or increasing the adaptability of existing ones. Further research in this area should be devoted to the development of an effective mechanism for adapting management structures to the conditions of a changing business space.Цель статьи – представить и обосновать методический подход по оценке уровня адаптивности организационных структур управления компаниями к условиям динамично меняющейся внешней среды.Методы. Использован широкий спектр общенаучных методов – системного анализа, синтеза, графической интерпретации данных. При проведении исследования для оценки уровня адаптивности использовался метод экспертных оценок. С целью классификации видов структур управления в зависимости от их адаптируемости был проведен кластерный анализ.Результаты работы. В статье представлен подход к определению понятий «адаптация» и «адаптивность» применительно к структурам управления. С целью разработки методического подхода к оценке уровня адаптивности организационных структур проведена систематизация видов их адаптации, выявлены основные характеристики структур и разработана шкала оценки уровня их адаптивности. Использование экспертного метода позволило оценить уровень адаптивности основных видов организационных структур к условиям изменяющегося бизнес-пространства, и проранжировать их в зависимости от этого уровня. В результате проведения кластерного анализа все исследуемые виды структур управления были классифицированы в зависимости от их адаптируемости.Выводы. Разработанный методический подход к оценке уровня адаптивности структур управления позволил определить адаптивные свойства как иерархических, так и органических структур управления, оценить уровень их адаптивности и выявить среди них самые адаптивные. Установлено, что основой успешного развития компаний в условиях турбулентности бизнес-пространства является использование органических структур или изменение отдельных параметров иерархических структур с целью повышения их адаптивности. Адаптация может осуществляться при использовании любой структуры, как традиционной иерархической, так и органической, путем формирования новых структур управления или повышения адаптивности уже существующих. Дальнейшие исследования в этой сфере должны быть посвящены разработке действенного механизма адаптации структур управления к условиям изменяющегося бизнес-пространства

Spin Texture in a Cold Exciton Gas

We report on the observation of a spin texture in a cold exciton gas in a GaAs/AlGaAs coupled quantum well structure. The spin texture is observed around the exciton rings. The observed phenomena include: a ring of linear polarization, a vortex of linear polarization with polarization perpendicular to the radial direction, an anisotropy in the exciton flux, a skew of the exciton fluxes in orthogonal circular polarizations and a corresponding four-leaf pattern of circular polarization, a periodic spin texture, and extended exciton coherence in the region of the polarization vortex. The data indicate a transport regime where the spin polarization is locked to the direction of particle propagation and scattering is suppressed.Comment: version 2 contains updated supplementary materia

The history of ethical regulation of biomedical research in the CIS member states

The history of development the ethical and legislative tools for regulation the biomedical research in the states-members of Commonwealth of Independent States (CIS) in the frame of the close collaboration the Forum for Ethics Committees in the Commonwealth of Independent States (FECCIS) and Inter-Parliamentary Assembly CIS (IPA CIS) is demonstrated in this article. The collaboration between FECCIS and IPA CIS stands on the unique experience of IPA CIS in the building of the new, humanistic legislation in the field of health care and on the initiatives of FECCIS to create a single legal space inside and outside of the CIS region. The necessity to promote the dignity, rights, and well-being of human participants in health research was the real reason for creation the Model Law «On the Protection of Human Rights and Dignity in Biomedical Research in the CIS». The process of the law creation, its direction, structure, compliance with international ethical standards and implementation in the local legislation of CIS states are analysed by the main authors of Model Law «On the Protection of Human Rights and Dignity in Biomedical Research in the CIS» and presented in this review

Solution combustion synthesis of α-Al2O3 using urea

The processes involved in the solution combustion synthesis of α-Al2O3 using urea as an organic fuel were investigated. The data describing the influence of the relative urea content on the characteristic features of the combustion process, the crystalline structure and the morphology of the aluminium oxide are presented herein. Our data demonstrate that the combustion of stable aluminium nitrate and urea complexes leads to the formation of α-alumina at temperatures of approximately 600-800 °C. Our results, obtained using differential thermal analysis and IR spectroscopy methods, reveal that the low-temperature formation of α-alumina is associated with the thermal decomposition of an α-AlO(OH) intermediate, which was crystallised in the crystal structure of the diaspore. © 2012 Elsevier Ltd and Techna Group S.r.l

Orbital dynamics of "smart dust" devices with solar radiation pressure and drag

This paper investigates how perturbations due to asymmetric solar radiation pressure, in the presence of Earth shadow, and atmospheric drag can be balanced to obtain long-lived Earth centred orbits for swarms of micro-scale 'smart dust' devices, without the use of active control. The secular variation of Keplerian elements is expressed analytically through an averaging technique. Families of solutions are then identified where Sun-synchronous apse-line precession is achieved passively to maintain asymmetric solar radiation pressure. The long-term orbit evolution is characterized by librational motion, progressively decaying due to the non-conservative effect of atmospheric drag. Long-lived orbits can then be designed through the interaction of energy gain from asymmetric solar radiation pressure and energy dissipation due to drag. In this way, the usual short drag lifetime of such high area-to-mass spacecraft can be greatly extended (and indeed selected). In addition, the effect of atmospheric drag can be exploited to ensure the rapid end-of-life decay of such devices, thus preventing long-lived orbit debris

Влияние ранней диагностики травматических повреждений на развитие легочных осложнений у пострадавших с сочетанной травмой

Despite the existing progress in providing care to patients with severe multisystem chest injury using advanced diagnostic methods, a high mortality rate still reaches 20–30%.Aim of study. To assess the impact of early diagnosis and correction of chest injuries on the development of complications in patients with multisystem trauma.Material and methods. The results of diagnosis and treatment of 89 patients with severe multisystem closed chest injury were studied. According to the time of admission to the Institute, the patients were divided into two groups: Group I, who were admitted to the Institute within the first hours after the injury (51 patients), and Group II, who were transferred from other medical institutions on the 3rd–7th day (38). CT was performed as a standard method of diagnosis and monitoring the dynamics of the process. With the development of purulent-inflammatory pulmonary complications, the bacteriological test of bronchoalveolar lavage was performed. Treatment included complex intensive therapy, drainage of the pleural cavity and emergency surgical interventions, if necessary.Results. In Group I, lung contusion occurred in 43 (84%) patients, and after 7-10 days, the contusion foci partially regressed in 20 (46.5%) patients. In 8 (16%) patients with lung rupture, infiltrative changes in the lung were resolved on the 18th-30th day, while 4 (50%) of them had pneumonia outside the contusion zones. In Group II, patients were put on a ventilator and inflammatory changes in the lungs were revealed in 30 patients (79%). Lung rupture associated with the contusion was revealed in 2 (5.2%). When comparing the groups by the composition of the isolated microflora, it was found that in patients of group II, Acinetobacter spp was more often found (46.7% vs. 17.1% in group I patients, p=0.021) and Enterococcus spp. (30.0% and 8.6%, respectively, p=0.058), as well as Klebsiella pneumoniae (46.7% and 37.1%, p=0.6). At the same time, Staphylococcus aureus was not found in these patients, while it was detected in 14.3% of patients from Group I (p=0.09). Medical care in Group I was carried out according to the principles of the “golden hour”: within the first hour from the moment of admission to the patients with the presence of pneumothorax and hemothorax, the pleural cavity was drained. In Group II, this procedure was performed in other medical institutions and in 5 additional patients at the Institute.Conclusions. Early computed tomography diagnosis of multisystem trauma makes it possible to assess the severity of injuries to the chest organs and other areas of the body and determine the treatment tactics. A comprehensive approach to the management of patients, including early diagnosis of trauma, drainage of the pleural cavity, determination of management tactics, bacterial test of the lower respiratory tract discharge, helps reduce infectious complications by an average of 45.46%. Актуальность. Несмотря на имеющийся прогресс в оказании помощи пострадавшим с тяжелой сочетанной травмой с использованием передовых методов диагностики, сохраняется высокий уровень летальности, достигающий 20–30%.Цель исследования. Оценить влияние ранней диагностики и коррекции повреждений груди на развитие осложнений у пострадавших с сочетанной травмой.Материал и методы. Изучены результаты диагностики и лечения 89 пострадавших с тяжелой сочетанной травмой. В соответствии со временем поступления в институт пациенты разделены на две группы: I группа — поступили в институт в первые 3 часа после травмы (51 больной), II — переведены из других лечебных учреждений на 3-и–7-е сутки (38). Компьютерную томографию выполняли как стандартный метод диагностики и контроля за динамикой процесса. При развитии гнойно-воспалительных легочных осложнений проводили бактериологическое исследование бронхоальвеолярного лаважа. Лечебные мероприятия включали в себя комплексную интенсивную терапию, дренирование плевральной полости и при необходимости проведение неотложных хирургических вмешательств.Результаты. В I группе ушиб легких был у 43 пациентов (84%), через 7–10 дней очаги ушиба частично регрессировали у 20 пострадавших (46,5%). При разрыве легкого у 8 (16%) инфильтративные изменения легкого разрешались на 18–30-е сутки, при этом у 4 (50%) из них было присоединение пневмонии вне зон контузии. Во II группе пострадавшие поступали на искусственной вентиляции легких, и воспалительные изменения в легких были у 30 больных (79%). Разрыв легкого на фоне ушиба был у 2 (5,2%). При сравнении групп по составу выделенной микрофлоры обнаружено, что у пациентов II группы чаще выделяли Acinetobacter spp. (46,7% против 17,1% у пациентов I группы, p=0,021) и Enterococcus spp. (30,0% и 8,6% соответственно, p=0,058), а также Klebsiella pneumoniae (46,7% и 37,1%, p=0,6). При этом Staphylococcus aureus у данных пациентов не встречался, тогда как его обнаруживали у 14,3% больных из I группы (p=0,09). Медицинскую помощь в I группе осуществляли по принципам «золотого часа»: в течение первого часа от момента поступления пострадавшим с наличием пневмо- и гемоторакса выполняли дренирование плевральной полости. Во II группе этот прием проводили в других лечебных учреждениях и у 5 пострадавших дополнительно в институте.Выводы. Ранняя компьютерно-томографическая диагностика сочетанной травмы дает возможность оценить тяжесть повреждений органов груди, других областей тела и определить тактику лечения. Комплексный подход к ведению пострадавших, включающий раннюю диагностику травмы, дренирование плевральной полости, определение тактики ведения, бактериальную оценку отделяемого нижних дыхательных путей, способствует снижению инфекционных осложнений в среднем на 45,46%.