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The relevance of the research.One of the leaders in production of aluminum powders in Russia OOO «SUAL-PM» has passed from production of coarse powders to production of micron powders with higher reactivity. Aluminiummicropowders are used in many branches of industry: powder metallurgy, self-propagating high-temperature synthesis of new materials, hydrogen energy, pyrotechnics and rocket fuels. Increase of aluminium powders reactivity in various processes leads to reduction in energy consumption and resource saving. The main aim of the researchwas to obtain and explain experimental data on changes in activity parameters of aluminiummicropowders after radiation exposure, depending on the γ-radiation dose. Objects: micron-scaled aluminium powdersASD-6,ASD-6М. Methods: differential thermal analysis, X-raydiffractionanalysis, method of aluminiummicropowdersexposurewithγ-radiation, method of calculation ofthe activity parameters of aluminium powders. Results. Quantitative indicators of the reactivity of aluminiummicropowders ASD-6 and ASD-6M before and after exposure with γ-radiation were obtained. The radiation source was the Co60 isotope with the energy of 1,17 and 1,33 MeV, i.e. the energy substantially below the threshold of photonuclear reactions. The doses to the powder samples exposure were 1, 2, 4, 8, and 10 Mrad. After γ-radiation exposure the micropowders oxidation start temperature has maximally decreased on 90 and 85 °C; maximal oxidation rate increased by 83 and 36 %; the degree of oxidation (at heating up to 1250 °C) increased by 5,1 %, and minimally decreased by 1,3 % for the ASD-6 and the ASD-6M micropowders, accordingly. The specific thermal effect of oxidation after γ-radiation exposure with all doses was greater than for non-exposed powders; the maximum values of the specific thermal effect was on 199,5 kJ/mol for ASD-6, and 134,8 kJ/mol for ASD-6M higher than thermal effects for non-exposed powders, which significantly exceeds the standard heat of aluminium melting (10,8 kJ/mol). Consequently, such a state of the «aluminium – aluminium oxide» system is characterized by the stored energy, 9 times higher than the standard heat of aluminium melting, which is impossible according to thermodynamics. At the same time, it is known that energy is stored in nanopowders due to the formation of a double electric layer in aluminium particles.

The relevance. Aluminum micropowders are the precursors in many industries, such as powder metallurgy, self-propagating high-temperature synthesis of new materials, hydrogen energy, pyrotechnics and rocket fuels. Improvement of characteristics of aluminum powders contributes to their quality. The known methods of aluminum powders activation by addition of rare-earth elements, vanadium compounds, silicon, boron and other elements into the aluminum mixtures composition lead to contamination of aluminum with impurities. β-radiation exposure of micropowders with the energy less than 8 MeV does not lead to induced radioactivity and activates aluminum micropowders at the same time. The main aim of the paper was reception and explanation of experimental results on the activity parameters of aluminum micro-powders after exposure, depending on the β-radiation dose. Objects: micron-scaled aluminium powders ASD-6, ASD-6М, ASD-8, ASD-10 obtained by aluminium fusion sputtering. Methods: differential thermal analysis, X-ray diffraction analysis, the method of aluminum micropowders exposure with β-radiation, the method of calculation of the activity parameters of aluminum powders. Results. The quantitative indicators of the ASD-6, ASD-6М, ASD-8, ASD-10 aluminum micro-powders reactivity before and after exposure in the ELU-4 accelerator by 4-MeV β-radiation (i. e. the energy is significantly lower than the threshold of photonuclear reactions) were obtained in the work. The doses of powder samples exposure were 1, 2, 4 Mrad. After β-radiation exposure the oxidation start temperature decreased maximally to 205 °C; maximum oxidation rate increased by 0,19 mg/min (106 m%); the oxidation degree of the ASD-6M micropowder increased by 18,9 %, and of the ASD-10 minimally decreased by 12,3 %; the specific thermal effect of oxidation after all doses of β-radiation increased maximally for ASD-10 by 188,6 kJ/mol. Energy storage by micropowders after β-radiation is caused by the formation of a double electric layer in aluminum particles.

A considerable concern in exploring clean, efficient, and renewable energy resources to effectively replace fossil fuels and to combat the environmental problems and energy scarcities for a sustainable future has been observed. In this context, hydrogen is a clean, renewable, energetically efficient fuel with infinite potential for the future, which can generate a large amount of energy through the electrocatalytic splitting of earth‐abundant water resources. Noble metals, owing to their extraordinary efficiency and stability, are state‐of‐the‐art catalysts for the oxygen evolution reaction (OER) process. However, their scarcity and high cost hamper their commercialization. To replace these expensive noble‐metal‐based materials, researchers are extensively working on the development of cost effective, stable, conductive, and efficient non‐noble metal based materials such as transition metal oxides, borides, nitrides, sulfides, phosphides, selenides, perovskites oxides, and layered double hydroxides, where the incorporation of heteroatoms improves the electrocatalytic activity by modifying the electronic structure and enhances the conductivity and stability. In the case of transition‐metal based metal organic frameworks (MOFs) and MOF‐derived materials, the unique structure of MOFs with a high surface area and porosity, as well as rich redox chemistry of transition metals, leads to excellent response towards the OER process. Moreover, direct utilization of carbonaceous materials or making their composites with transition metals not only enhances the conductivity due to their conductive nature but also promotes stability by strongly binding with the electrocatalyst. Owing to the presence of functional groups on the surface or through different interactions, they provide multiple paths for facile electron and ion transport due to the sheet/network like structure, which help in the fine dispersion of electrocatalyst due to high surface area, prevent agglomeration, and in turn results in improved electrocatalytic activity. Besides these advances, a) there is still a need for a thorough understanding of reaction mechanism via in situ spectroscopic techniques to further optimize the composition and design of electrocatalyst to get desired results, b) the stability of the materials should be further enhanced to practically utilize synthesized material under harsh conditions without degradation, and c) the utilization of these optimized OER catalysts in a solar cell to consume solar energy (renewable energy source), remains a key requirement of the modern era. [ABSTRACT FROM AUTHOR]

The effect of histamine on background spontaneous electrical activity of the interrelated bladder and urethra was studied in rats. The basic characteristics of pacemaker activity (action potential amplitude, average peak rise rate, peak rise time, peak half-width, rhythmogenicity frequency) were analyzed both in normal conditions and upon exposure to histamine (10-4 mol/L). A comparison of the action potential parameters in the above organs demonstrated far lower values of the amplitude (by 34.19%; p ≤ 0.001), peak rise rate (by 30.39%; p ≤ 0.01) and peak rise time (by 18%; p ≤ 0.01) at a reduced rhythmogenicity frequency. Histamine evoked a considerable increase in the amplitude and its rise rate in the bladder (by 50.59 and 56.36%, respectively; p ≤ 0.001) and rhythmogenicity frequency (by 18%; p ≤ 0.01) at a constancy of the remaining two parameters. In the urethra, no obvious changes were detected in the action potential parameters. Morphohistochemical analysis also supported the involvement of histamine in the activation of rhythmogenicity only in the bladder. Thus, histamine is not implicated in the genesis of tonic contractions in the urethra, in contrast to its activating effect on the bladder. [ABSTRACT FROM AUTHOR]

This work aims to fill a lacunae in the project-oriented production systems literature providing a formal analytic description of the rework effects formulae and the determination of the extended design time due to a certain degree of overlapping in a pair of activities. It is made through the utilization of concepts of workflow construction with hidden (semi) Markov models theory and establishing a way to disaggregate activities into sub-activities, in order to determine the activity parameters used by the project scheduling techniques. With the aim to make a correlation between the entropy of the state transitions and the probability of changes, the information theory is also used, and the concept of impact caused by the probability of changes is provided. Numerical examples are shown for the purpose to demonstrate the applicability of the concepts developed, and one example of overlapping of two activities is shown. The original contributions of this work are shown on the last section. [ABSTRACT FROM PUBLISHER]

Abstract: To assess and compare different model Leu-Lys-containing cationic α-helical peptides, their antimicrobial activities were tested against Escherichia coli as target organism over a broad peptide concentration range. The natural cationic α-helical peptides magainin 2 and PGLa and the cyclic cationic peptide gramicidin S were also tested between comparison. The dose–response curves differed widely for these peptides, making it difficult to rank them into an activity order over the whole concentration range. We therefore compared five different inhibition parameters from dose–response curves: ICmin (lowest concentration leading to growth inhibition), IC50 (concentration that gives 50% growth inhibition), ICmax (related to minimum inhibition concentration and minimum bactericidal concentration), inhibition concentration factor (ICF; describing the increase in concentration of the peptide between minimum and maximum inhibition), and activity slope (A S; related to the Hill coefficient). We found that these parameters were covariant: two of them sufficed to characterize the dose dependence and hence the activity of the peptides. This was corroborated by showing that the dose dependences followed the Hill equation, with a small, constant aberration. We propose that the activity of antimicrobial peptides can readily be characterized by both IC50 and ICF (or A S) rather than by a single parameter and discuss how this may relate to investigations into their mechanisms of action. [Copyright &y& Elsevier]

This short-term longitudinal study examined (1) the test-retest reliability of seven parameters of activity engagement (frequency, importance, difficulty, ability, future, change, number of activities), (2) the correlations among these parameters, and (3) the role of demographic, health and personality traits as predictors of activity parameters. A total of 107 retired seniors completed questionnaires on three different occasions over a one-year period. Participants showed good consistency in activity dimension ratings across time. Results also showed that activity parameters were significantly inter-correlated. Finally, predictors varied according to activity parameters, but variables of education, extraversion, openness and, to a lesser extent, health, predicted several activity parameters. [ABSTRACT FROM AUTHOR]

Cover Feature: Recent Advances in Electrocatalysis of Oxygen Evolution Reaction using Noble-Metal, Transition-Metal, and Carbon-Based Materials (ChemElectroChem 3/2021) Keywords: Electrocatalysts; Hydrogen production; Oxygen Evolution Reaction (OER); Activity parameters; Metal Organic Frameworks (MOFs) EN Electrocatalysts Hydrogen production Oxygen Evolution Reaction (OER) Activity parameters Metal Organic Frameworks (MOFs) 427 427 1 02/13/21 20210201 NES 210201 B The Cover Feature b illustrates noble-metal, transition-metal, and carbon-based compounds effectively utilized for oxygen evolution reaction electrocatalysis. Electrocatalysts, Hydrogen production, Oxygen Evolution Reaction (OER), Activity parameters, Metal Organic Frameworks (MOFs). [Extracted from the article]