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2022 ◽  
Vol 1049 ◽  
pp. 204-208
Author(s):  
Zhamal A. Kochkarov ◽  
A.A. Baysangurova ◽  
Radima A. Bisergaeva ◽  
M.M. Isaev ◽  
A.I. Khasanov

Interest in a comprehensive study of lead tungstate single crystals is due to its scintillation properties [1-5]. It was found that lead tungstate occupies an exceptional position in the family of tungstates with a scheelite structure. Lead tungstate single crystal is a scintillation material [1] used in the LHC electromagnetic calorimeter and photon detector in the ALICE experiment at CERN [1, 2]. Now it can be said unequivocally that lead tungstate is the most promising scintillation material in the next decade.


2021 ◽  
Vol 5 (4) ◽  
pp. 229-235
Author(s):  
T. M. Inerbaev ◽  
A. U. Abuova ◽  
A. K. Dauletbekova ◽  
F. U. Abuova ◽  
G. A. Kaptagay ◽  
...  

The magnetic anisotropy energy and the stability of crystal modifications of D03 and L21 of Fe3Ga compounds are studied with the density functional theory methods. The magnetic anisotropy energy of the D03 structure is more than twice the same value for the L21 structure. The features in the electronic structure lead to the difference in the magnitude of spin-orbit interaction, explaining the found effect. The L21 structure is more thermodynamically stable in the entire range of the considered pressures. Under pressure, the considered crystal modifications of Fe3Ga lose their stability due to the appearance of imaginary frequencies in their phonon spectra.


2021 ◽  
Author(s):  
A. V. Krysko ◽  
J. Awrejcewicz ◽  
K. S. Bodyagina ◽  
V. A. Krysko

AbstractMathematical models of planar physically nonlinear inhomogeneous plates with rectangular cuts are constructed based on the three-dimensional (3D) theory of elasticity, the Mises plasticity criterion, and Birger’s method of variable parameters. The theory is developed for arbitrary deformation diagrams, boundary conditions, transverse loads, and material inhomogeneities. Additionally, inhomogeneities in the form of holes of any size and shape are considered. The finite element method is employed to solve the problem, and the convergence of this method is examined. Finally, based on numerical experiments, the influence of various inhomogeneities in the plates on their stress–strain states under the action of static mechanical loads is presented and discussed. Results show that these imbalances existing with the plate’s structure lead to increased plastic deformation.


2021 ◽  
Author(s):  
Laura Marr ◽  
Dipsikha Biswas ◽  
Leonard A Daly ◽  
Christopher Browning ◽  
John Pollard ◽  
...  

The macromolecule glycogen is the major glucose reserve in eukaryotes and defects of glycogen metabolism and structure lead to glycogen storage diseases and neurodegeneration. Glycogenesis begins with self-glucosylation of glycogenin (GN), which recruits glycogen synthase (GS). GS is activated by glucose-6-phosphate (G6P) and inactivated by phosphorylation, but how these opposing processes are coupled is unclear. We provide the first structure of phosphorylated human GS-GN complex revealing an autoinhibited GS tetramer flanked by two GN dimers. Phosphorylated N- and C-terminal tails from two GS protomers converge to form dynamic "spike" regions, which are buttressed against GS regulatory helices. This keeps GS in a constrained "tense" conformation that is inactive and more resistant to G6P activation. Mutagenesis that weaken the interaction between the regulatory helix and phosphorylated tails leads to a moderate increase in basal/unstimulated GS activity, supporting the idea that phosphorylation contributes to GS inactivation by constraining GS inter-subunit movement. We propose that multivalent phosphorylation supports GS autoinhibition through interactions from a dynamic "spike" region, thus allowing a "tuneable rheostat" for regulating GS activity. Our structures of human GS-GN provide new insights into the regulation of glycogen synthesis, facilitating future studies of glycogen storage diseases.


Author(s):  
Diego Arcis ◽  
Sebastián Márquez

We endow the space of rooted planar trees with the structure of a Hopf algebra. We prove that variations of such a structure lead to Hopf algebras on the spaces of labeled trees, [Formula: see text]-trees, increasing planar trees and sorted trees. These structures are used to construct Hopf algebras on different types of permutations. In particular, we obtain new characterizations of the Hopf algebras of Malvenuto–Reutenauer and Loday–Ronco via planar rooted trees.


2021 ◽  
pp. 8-11
Author(s):  
L. M. Simkalova ◽  
E. A. Bokova ◽  
G. E. Ivanov ◽  
A. A. Gavrilin

Healthy nutrition is the most important component of the quality of life of the population. Disorders of the nutritional structure lead to the development of alimentary-dependent diseases, including cardiovascular, oncological, diabetes mellitus, obesity, osteoporosis, etc., that are the main causes of premature mortality of the population of economically developed countries, including Russia. This is due, among other things, to the low level of knowledge of the population about the principles of healthy nutrition. In order to eliminate the existing gap in the competence of the population on healthy nutrition, the Centre for Hygienic education of the population of the Russian Federal Service for Supervision of Consumer Rights Protection and Human Welfare, Moscow, as a part of the implementation of the federal project ‘Formation of a system of motivation of citizens to a healthy lifestyle, including healthy nutrition and rejection of bad habits' (‘Strengthening the Public Health'), which is a part of the national project ‘Demography', conducts systematic activities aimed at creating and maintaining an information and educational environment.


Minerals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 702
Author(s):  
Yuliya Zvir ◽  
Carlos Pimentel ◽  
Carlos M. Pina

The determination of the degree of Mg-Ca order in the dolomite structure is crucial to better understand the process or processes leading to the formation of this mineral in nature. I01.5/I11.0 intensity ratios in the X-ray powder diffractograms are frequently measured to quantify dolomite cation order in dolomites. However, the intensity of diffraction peaks can be affected by factors other than the Mg-Ca distribution in the dolomite structure. The most relevant among these factors are (i) deviations from the ideal dolomite stoichiometry, and (ii) the partial substitution of Mg and Ca atoms by Fe, Mn, and Zn impurities. Using the VESTA software, we have constructed crystal structures and calculated I01.5/I11.0 ratios for dolomites with Mg:Ca ratios ranging from 0.5 to 1.5, and with Fe, Mn, and Zn contents up to 30%. Our results show that both deviations from dolomite ideal stoichiometry and the presence of impurities in its structure lead to a significant decrease in I01.5/I11.0 intensity ratios, an effect which must be considered when cation orders of natural dolomites from different origins are compared.


2021 ◽  
pp. 403-420
Author(s):  
Alejandro Villamor Iglesias

Invertebrate animals are usually seen as a kind of “aliens” which do not deserve any moral consideration. However, there is a growing amount of evidence indicating that many of them do have the capacity to experience pain. The same criteria that are usually applied in order to infer that vertebrates are sentient beings (behavioral response, learning capacity, memory, a certain specific neurophysiological structure…) lead to the idea that many invertebrates are sentient as well. Therefore, under the skeptical premise that we have no direct evidence of the experience of pain in vertebrates, we are forced to hold that it exists in both vertebrates and invertebrates.


2021 ◽  
Author(s):  
Travis Holt ◽  
Tina M. Loraas

This study examines the effects of information structure on auditor judgment and decision-making. Based on cognitive load theory, we predict that the variety of evidence inspired by big data such as visualizations or emails likely lead to increased perceptions of ambiguity which in turn impacts audit-related decisions. Additionally, we examine whether those effects are moderated by time budget pressure. We conduct an experiment with 120 auditors and find that auditors presented with varied data, such as emails or visualizations, provide more conservative risk assessments and write down recommendations in an inventory obsolescence setting than auditors presented with a less ambiguous, more traditional memo format. Our findings also indicate that time budget pressure moderates the effects of information structure resulting in the most conservative obsolescence risk and inventory write-down assessments when presented with varied data in a high time budget pressure environment. We believe our study has important implications that should be considered before the implementation of technology-enabled tools to analyze big data on financial statement audits.


Author(s):  
Виктор Михайлович Юров ◽  
Канат Мэтович Маханов ◽  
Василий Сергеевич Портнов

В представленной работе рассмотрен поверхностный слой угольного вещества, структура и характеристики которого отличны от структуры объема. Этот слой имеет два уровня: d(I) равный 151,5 нм и d(II)≈10 ⋅ d равный 1515 нм для антрацита. Для чистых металлов d(I) равно 1 - 6 нм, что на 2 порядка меньше поверхностного слоя угольного вещества. Толщина этого слоя имеет порядок толщин высших фуллеренов С, равного 135 нм. Все эти особенности угольного вещества, имеющего углеродную основу и представляющего собой полимер с надмолекулярной структурой, приводят к тому, что именно поверхностный слой определяет физические процессы в нем, связанные с протеканием газов и жидкости, а также с явлениями взрывоопасности. In the present work, the surface layer of a coal substance is considered, the structure and characteristics of which are different from the bulk structure. This layer has two levels: d (I) equal to 151,5 nm and d(II) ≈ 10 ⋅ d equal to 1515 nm for anthracite. For pure metals d(I) is equal 1 - 6 nm, that is 2 orders of magnitude lesser than the surface layer of the coal substance. The thickness of this layer is of the order of 135 nm for the higher C fullerenes. All these features of a coal substance, which has a carbon base and is a polymer with a supramolecular structure, lead to the fact that it is the surface layer that determines the physical processes in it associated with the flow of gases and liquids, as well as with the phenomena of the explosion hazard.


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