The most precise determination of the neutron lifetime using the beam method was completed in 2005 and reported a result of τ(n)=(886.3±1.2stat±3.2syst) s. The dominant uncertainties were attributed ...to the absolute determination of the fluence of the neutron beam (2.7 s). The fluence was measured with a neutron monitor that counted the neutron-induced charged particles from absorption in a thin, well-characterized 6Li deposit. The detection efficiency of the monitor was calculated from the areal density of the deposit, the detector solid angle, and the evaluated nuclear data file, ENDF/B-VI 6Li(n,t)4He thermal neutron cross section. In the current work, we measure the detection efficiency of the same monitor used in the neutron lifetime measurement with a second, totally absorbing neutron detector. This direct approach does not rely on the 6Li(n,t)4He cross section or any other nuclear data. The detection efficiency is consistent with the value used in 2005 but is measured with a precision of 0.057%, which represents a fivefold improvement in the uncertainty. We verify the temporal stability of the neutron monitor through ancillary measurements, allowing us to apply the measured neutron monitor efficiency to the lifetime result from the 2005 experiment. The updated lifetime is τ(n)=(887.7±1.2stat±1.9syst) s.
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CMK, CTK, FMFMET, IJS, NUK, PNG, UM
The article provides an overview of modern ideas about biodegradation and biodeterioration and of polymer materials. The mechanisms of bacteria sedimentation and attachment and the formation of ...biofilms are described. Schemes of influencing abiotic and biological environmental factors are considered: the impact of polysaccharides and proteins contained in biofilms on a polymer material, implementation of enzymatic biodegradation reactions, as well as the influence of the material composition and its nature on the tendency to biodegradation.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Abstract
The article considers the possibility of using magnetohydrodynamic water treatment together with high-molecular polycarboxylates. The principle of calculating MHDT devices for increasing the ...efficiency of a polycarboxylate-based reagent is proposed. It is shown that the method of increasing the efficiency of a polycarboxylate-based salt deposition inhibitor in cooling water systems simultaneously with the use of magnetohydrodynamic treatment of circulating water allows reducing the reagent consumption, avoiding the use of nitrates and phosphates, and reducing technological costs. The effectiveness of the combined use of a polycarboxylate-based salt deposition inhibitor with the MHDT device has been confirmed by tests on the cooling water system equipment of an industrial enterprise. When testing the reduction of salt deposits with a polycarboxylate-based salt deposition inhibitor and MHDT, the inhibitor dosage was reduced from 5 to 1 ppm. Monitoring the efficiency of the heat exchanger (by temperature difference) showed that there were no deposits on the plates for three months. The number of heat exchanger repairs has been reduced by more than three times.
Цель. Оценка величины послеоперационного свода - расстояния от задней поверхности факичной интраокулярной линзы (ФИОЛ) до передней поверхности хрусталика, его зависимость отданных предоперационного ...исследования и выбора размера ФИОЛ. Материал и методы. Проведен ретроспективный анализ 1 28 глаз (64 пациентов) за период с февраля 2019 г. по май 2021 г. Возраст пациентов варьировал от 21,0 до 42,0 года (в среднем 29,5±5,5 года). Всем пациентам были имплантированы ФИОЛ Staar EVO Visian ICL (V4C). Срок наблюдения составил от 3 до 24 месяцев. Корреляционный анализ по методу Пирсона (г) и метод множественной пошаговой линейной регрессии позволил определить фактическую степень взаимоотношений между послеоперационным сводом и рядом изучаемых признаков (возраст, передне-задняя ось глаза (ПЗО), сфероэквивалент рефракции (СЭ), white-to-white (от белого до белого, WTW), глубина передней камеры (ПК), размер интраокулярной линзы (ИОЛ)). Принятый уровень достоверности р<0,05. Результаты. При измерении на 1-е сутки после операции послеоперационный свод варьировал от 142 до 1340 мкм (в среднем 576.56±245.77 мкм). При проведении статистического анализа выявлено, что послеоперационный свод имел умеренную взаимосвязь с WTW, размером ФИОЛ и глубиной ПК. Корреляции не отмечалось с возрастом, сфероэквивалентом, ПЗО. Выявлена высокая взаимосвязь размера ИОЛ с WTW и заметная взаимосвязь с глубиной ПК. По результатам пошаговой регрессии R2 равен 0,359. Таким образом, 35,9% вариации зависимой переменной (свод на 1 -е сутки) объясняется вариацией независимых переменных (размер мер ФИОЛ, глубина ПК, WTW). Заключение. Проведенная оценка величины послеоперационного свода и его зависимости отданных предоперационного исследования показала, что наибольшее влияние на формирование послеоперационного свода оказывали размер ФИОЛ и глубина ПК. В 86% случаев был достигнут оптимальный послеоперационный свод. Существующая на сегодняшний день методика выбора размера ФИОЛ при помощи калькулятора производителя не всегда позволяет получить ожидаемую высоту послеоперационного свода. В ряде случаев необходимо выбирать меньший размер ФИОЛ для получения оптимального свода.
Greenhouse gas emissions are the primary cause of global warming. Under the Paris Agreement, all countries have developed programs to reduce anthropogenic Impact on the environment. In the ...petrochemical Industry, for example, Isoprene, Is a major contributor to the production of carbon dioxide, generating large amounts of acidic and hydrocarbon gases that are burned and released Into the atmosphere. This study aimed to investigate the absorption of greenhouse gases from isoprene production by the marine microalgae Isochrysis galbana and Tetraselmis suecica, as well as the freshwater microalgae Chlorella vulgaris. Microalgae cells were cultured In a bioreactor. The grown microalgae strains and mineralized water were fed to the bioreactor. Gases discharged from isoprene production were passed through the bioreactor. Inlet and outlet gas compositions were monitored by chromatography. Absorption of gases discharged from isoprene production by microalgae was studied for the first time. Chlorella vulgaris microalgae reduced methane and carbon dioxide contents by an average of 20 times. A mixture of microalgae Tetraselmis suecica and Isochrysis galbana reduced methane and carbon dioxide contents by a factor of 10 but completely absorbed hydrocarbon gases from methane to pentane. The results Indicate that microalgae cultivation can be used as a reliable and stable technology for the biofixation of the gases discharged In Isoprene production. This technology can eliminate the combustion stage of hydrocarbon gases in isoprene production and significantly reduce carbon dioxide emissions into the atmosphere.
Abstract
Based on the analysis of the literature, the number of corrosive particles entering the aircraft engine with air has been determined. It is shown that the atmosphere of the continents has ...the smallest number of chlorides, their maximum content on the seashore, the troposphere above 10 km has a stable amount of aerosol particles. A method for estimating the chloride content has been developed to predict the rate of sulfide-oxide corrosion of parts of the hot TRD tract.
Aspects of the long-term strength and thermal fatigue of refractory metal-powder alloy KhN56KVMTYuB for gas turbine engine (GTE) disks operating in contact with corrosive environments are considered. ...The alloy is tested for long-term strength at 700, 750 and 800°C in air and in a salt medium by two methods differing in the manner of introduction of the corrosive medium and in the states of its aggregation (a solution or a melt). Samples subjected to preliminary high-temperature corrosion in salt solutions or melts are tested for the resistance to thermal fatigue in vacuum. The structure of the corroded samples is studied after testing by static and thermocycling loading.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
This article investigates the change in the structure of heat-resistant nickel alloys doped with cobalt, chromium, molybdenum, aluminum, niobium, tungsten, and titanium and aluminum, cobalt, rhenium, ...tantalum, ruthenium, molybdenum, tungsten, and chromium under the influence of a solution of 75%Na
2
SO
4
+ 25%NaCl in temperature range 600–750°C. As the results of the study show, a corrosive film of a layer structure based on oxides of chromium, aluminum, nickel and nickel sulfides is formed on the metal surface. It has been established that the nature of corrosion destruction of metal depends on the composition and content of alloying elements in it.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
—
The work was aimed at detection of potential degraders of polyethylene terephthalate (PET), polystyrene (PS), and steel 20 based on comparison of the taxonomic composition of the biofilm ...communities formed on these materials immersed in aqueous environments of diverse origin (marine, natural freshwater, and industrial) in different climatic regions. The libraries obtained by high-throughput sequencing of the 16S rRNA gene V3–V4 region were mainly grouped according to the media types. The composition and relative abundance of the taxa (both at the phylum/class and the genus levels) differed significantly between the groups of libraries; within the groups, these parameters varied depending mainly on the incubation time and on antimicrobial treatment (for industrial samples), while the material of the samples had less effect. Our results indicated that industrial recirculated water was more aggressive against polymer materials, with potential degraders of the polymers (PET and PS) belonging to the genera
Pseudomonas, Acidovorax
, and
Arenimonas.
Iron- and sulfur-oxidizing bacteria of the genera
Sulfurimonas
and
Mariprofundus
are probably involved in steel biocorrosion in seawater
.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
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