Use of accelerated helium-3 ions for determining oxygen and carbon impurities in some pure materials

Methods are developed for the determination of O impurity in Be and Si carbide and concurrent determination of C and O impurities in Si and W by irradiation with accelerated He-3 ions and subsequent activity measurements of C-11 and F-18 formed from C and O with the aid of a gamma-gamma coincidence spectrometer. Techniques for determining O in Ge and Ga arsenide with radiochemical separation of F-18 are also described

Оценка аспектов устойчивого развития в деятельности транспортных компаний

Managing a company's sustainable development has an impact not only on internal processes, but also on interaction with suppliers and improvement of the system of responsible supply chain management. In this regard, it becomes necessary for transport companies as providers of logistics services to pay attention to compliance with sustainability criteria so that cooperation with them has a positive effect on the reputation and positions in customer sustainability rankings. This paper examines the criteria for evaluating the maturity of practices implemented by a logistics service provider for large manufacturing companies in relation to their environmental and social impact. The relevance of the work lies in the need to create tools for assessing the level of sustainable development of companies in the transport industry and develop recommendations for industry-wide standards.The results of the study might be of interest to managers and specialists of logistics companies and employees of transport universities in view of special importance of high-quality education for achieving sustainable development goals. Управление устойчивым развитием компании оказывает влияние не только на внутренние процессы, но и на взаимо­действие с поставщиками и совершенствование системы ответственного управления цепочкой поставок. В этой связи перед транспортными компаниями как поставщиками логистических услуг возникает необходимость уделять внимание соответствию критериям устойчивого развития, чтобы сотрудничество с ними положительно влияло на репутацию и позиции в рейтингах устойчивого развития клиентов. В данной работе рассмотрены критерии оценки зрелости практик, внедряемых поставщиком логистических услуг для крупных производственных компаний в отношении их экологического и социального воздействия. Актуальность работы заключается в необходимости сформировать ин­струменты для оценки уровня устойчивого развития компа­ний транспортной отрасли и выработки рекомендаций для общеотраслевых стандартов.Результаты исследования представляют интерес для руководителей и специалистов логистических компаний и для работников транспортных вузов в виду особой значи­мости качественного образования Для достижения целей устойчивого развития.

Optomechanical manipulation with hyperbolic metasurfaces

Auxiliary nanostructures introduce additional flexibility into optomechanical manipulation schemes. Metamaterials and metasurfaces capable to control electromagnetic interactions at the near-field regions are especially beneficial for achieving improved spatial localization of particles, reducing laser powers required for trapping, and for tailoring directivity of optical forces. Here, optical forces acting on small particles situated next to anisotropic substrates, are investigated. A special class of hyperbolic metasurfaces is considered in details and is shown to be beneficial for achieving strong optical pulling forces in a broad spectral range. Spectral decomposition of the Green functions enables identifying contributions of different interaction channels and underlines the importance of the hyperbolic dispersion regime, which plays the key role in optomechanical interactions. Homogenised model of the hyperbolic metasurface is compared to its metal-dielectric multilayer realizations and is shown to predict the optomechanical behaviour under certain conditions related to composition of the top layer of the structure and its periodicity. Optomechanical metasurfaces open a venue for future fundamental investigations and a range of practical applications, where accurate control over mechanical motion of small objects is required

Russian retail ESG transformations development

The article analyse the formation of the sustainable development paradigm and the ESG agenda in Russia. The activities of the largest Russian retailers: leaders in sustainable development and companies with a weaker position in this area is revealed. The relationship between the form of the company and its position in the ESG ratings has been noted. Thus, companies that are required to provide information publicly are higher in level than non-public ones. A characteristic feature of passing the ESG rating assessment is getting high scores in terms of the G-aspect and the E-aspect associated with the demands of the modern market. The authors recommended deepening activities in the field of sustainable development in terms of training employees in digital and environmental competencies, and to strengthen communication strategies regarding the ESG agenda of the largest retailers

Solution-processed flexible broadband ZnO photodetector modified by Ag nanoparticles

In this work, we present flexible broadband photodetectors (PDs) fabricated by a deposition of nanostructured zinc oxide (ZnO) films on polyimide (PI) substrates by using cheap and scalable aqueous method Successive Ionic Layer Adsorption and Reaction (SILAR). In order to increase the long-wavelength absorption of the nanostructured ZnO layer, we created its intrinsic defects, including oxygen vacancies by post-treatment at 300 °C in vacuum and thus the light-sensitive material ZnO/PI was obtained. Then we applied silver nanoparticles (Ag NPs) from a silver sol onto a nanostructured ZnO film, which were visualized using SEM in the form of spheres up to 100 nm in size that increased the photocurrent and figures of merit of thus obtained light-sensitive material ZnO_Ag/PI due to localized surface plasmon resonance and double Schottky barriers at the Ag-ZnO interface. To fabricate photodetectors based on a photoconductive effect, these ZnO/PI and ZnO_Ag/PI materials were equipped with ohmic aluminum contacts. The spectral responsivity (Rλ up to 275 A/W to UV light) of solution-processed flexible broadband photodetector based on ZnO_Ag/PI material at different wavelengths of light and light power densities is better than Rλ of the ZnO/PI photodetector, and at least an order of magnitude higher than Rλ of photodetectors based on nanostructured zinc oxide described in recent articles. The external quantum efficiency (EQE) of both PDs in this study in UV–Vis-NIR spectra is very high in the range from 1∙102 to 9∙104 % and is better or of the same order of magnitude as the EQE data of modern flexible broadband high-sensitivity PDs based on nanostructured heterostructures containing ZnO. The specific detectivity in UV–Vis-NIR spectra is large for ZnO/PI (from 3.5∙1010 to 1∙1012 Jones) and especially for ZnO_Ag/PI (from 1.6∙1011 to 8.6∙1013 Jones), which indicates the ability of the PDs based on light-sensitive materials ZnO/PI and ZnO_Ag/PI to recognize a very weak light signal

Development of a universal kit for rapid detection of aggressive chemicals, rocket fuel components and uranium components and uranium compounds in various environments

The materials of the article are devoted to the issues of ecology and safety at enterprises and railway transport. The urgency of developing a universal kit for rapid detection of aggressive chemicals, rocket fuel components and uranium compounds in various environments is due to the fact that the presence on the surface and in water can lead to poisoning and chemical burns of working personnel and the public. It is also caused by the need to make managerial decisions when eliminating the consequences of accidents at food and related industries. The article discusses the methods of rapid detection of aggressive chemicals and suggests scientific, methodological and technological approaches to the development of a universal set of tools for group rapid detection of aggressive chemicals and uranium compounds in water and on the surfaces of objects using aerosol devices with original indicator formulations. The place of research is Moscow and the Moscow regio

ВЫБОР ЭКСТРАКТИВНЫХ АГЕНТОВ ДЛЯ РАЗДЕЛЕНИЯ СМЕСИ ХЛОРОФОРМ - МЕТАНОЛ -ТЕТРАГИДРОФУРАН

Variants of the extractive distillation of chloroform - methanol - tetrahydrofuran equimolar mixture with industrial separating agents are considered. The basic system shows opposite deviations from the ideal behavior, because it contains binary azeotropes with minimum and maximum boiling points (3.3.1-4 system according to Serafimov’s classification). The choice of selective substances for extractive distillation was carried out taking into account the concentration dependences of the excess molar Gibbs energy of the binary constituents of the derivative system “chloroform - methanol - tetrahydrofuran - industrial test agent (ethylene glycol (EG), dimethyl sulfoxide (DMSO), N-methylpyrrolidone (N-MP))” at 101.32 kPa. Based on the results of the evaluation of the thermodynamic criterion, DMSO and N-MP are recommended. Both agents show selective effect when separating two binary constituents. EG is selective only with respect to chloroform-tetrahydrofuran mixture. Since the tested agents show different selective effects, the final agent choice determines the qualitative composition of the product flows in the column for the extractive distillation of the three-component mixture (the first column of the flowsheet) and, accordingly, the structure of the total flowsheet. The schemes consist of two two-column complexes for extractive distillation (for the basic three-component mixture and for the binary mixture). The maximum contribution to the total reboiler energy consumption of the distillation columns is made by the first extractive distillation column: 65% (EG), 53% (N-MP) and 24% (DMSO). The use of the most selective agent reduces the energy consumption of this column: the reboiler load is maximal in the case of EG, in comparison with which the load is 47% lower in the case of N-MP and 76% lower in the case of DMSO.Рассмотрены варианты экстрактивной ректификации эквимолярной смеси хлороформ - метанол - тетрагидрофуран с промышленными разделяющими агентами. Базовая система проявляет разноименные отклонения от идеального поведения, так как содержит бинарные азеотропы с минимальной и максимальной температурой кипения (система 3.3.1-4 по классификации Л.А. Серафимова). Выбор селективных веществ для экстрактивной ректификации трехкомпонентной смеси проведен с учетом концентрационных зависимостей избыточной молярной энергии Гиббса бинарных составляющих производной системы хлороформ - метанол - тетрагидрофуран - тестируемый промышленный агент: этиленгликоль (ЭГ), диметилсульфоксид (ДМСО), N-метилпирролидон (N-МП) при 101.32 кПа. По результатам оценки термодинамического критерия рекомендованы ДМСО и N-МП, которые проявляют селективное действие при разделении двух бинарных составляющих. ЭГ селективен только в отношении смеси хлороформ - тетрагидрофуран. Поскольку тестируемые агенты проявляют различное селективное действие, выбор агента определяет качественный состав продуктовых потоков колонны экстрактивной ректификации трехкомпонентной смеси (первая колонна схем разделения) и, соответственно, структуру схем в целом. Схемы состоят их двухколонных комплексов экстрактивной ректификации: базовой трехкомпонентной смеси и бинарной азеотропной смеси. Максимальный вклад в суммарные энергозатраты на разделение (нагрузка кипятильника ректификационной колонны) во всех вариантах вносит колонна экстрактивной ректификации трехкомпонентной смеси, который составляет: 65 % (ЭГ), 53 % (N-МП) и 24 % (ДМСО). Применение наиболее селективного агента обеспечивает снижение энергозатрат этой колонны: нагрузка на кипятильник максимальна в случае ЭГ, в сравнении с которым при использовании N-МП нагрузка ниже на 47 % , для ДМСО - на 76 %