338 research outputs found
Influence of neutral currents on electron and gamma polarizations in the process e+N→e′+N+γ
No full textThe differential cross section of electron inelastic scattering by nuclei followed by γ radiation is calculated using the multipole decomposition of the hadronic currents and by taking into account the longitudinal polarization of the initial electron and the circular polarization of the γ radiation. We performed the analysis of the angular and energy dependence of the degree of electron and photon polarization which can yield information on values of weak neutral currents parameters. © 2014 N. V. Samsonenko et al
Influence of neutral currents on electron and gamma polarizations in the process e + N - e + N +y
No full textThe differential cross section of electron inelastic scattering by nuclei followed by γ radiation is calculated using the multipole decomposition of the hadronic currents and by taking into account the longitudinal polarization of the initial electron and the circular polarization of the γ radiation. We performed the analysis of the angular and energy dependence of the degree of electron and photon polarization which can yield information on values of weak neutral currents parameters. © 2014 N. V. Samsonenko et al
Patterning of Surfaces for Subsequent Roll Bonding in a Low-Oxygen Environment Using Deformable Mesh Inlays
No full textY. Frolov: ORCID 0000-0001-6910-6223; O. Bobukh: ORCID 0000-0001-7254-3854; A. Samsonenko: ORCID 0000-0001-6992-2327ENG: Efficient roll bonding for the manufacturing of clad strips not only requires surface activation but also is improved by a surface patterning to reduce the initial contact area. This increases contact stresses and facilitates a joining without an increasing rolling force. Experiments to pattern surfaces with deformable inlays during cold rolling for a subsequent bonding in low-oxygen atmosphere were carried out using two types of rolling mills, two types of inlays and two types of assemblies. Digital twins of selected experiments were created by means of the FE simulation software QForm UK 10.2.4. The main set of rolling parameters, which play a significant role during formation of the pattern shape considering deformation of the patterning tool, were investigated. The pilot roll bonding of patterned components under vacuum conditions, provided using vacuum sealer bags, allowed for an experimental realization of this approach. The concept technological chain of roll bonding in a low-oxygen or oxygen-free environment comprises the following stages: roll patterning; surface activation and sealing of the strips in a vacuum bag; subsequent roll bonding of the prepared strips inside the protective bag. The difference between the shape of the pattern created and the initial shape of the mesh insert can be quantitatively described by the change of its angle. This difference reaches maximum values when smaller rolls are used with increased rolling reductions. This maximum value is limited by the springback of the deformed insert; the limit is reached more easily if the inlay is not positioned on the rolling plane.Institut für Werkstoffkunde (Materials Science), Leibniz Universität Hannover, Hannover, German
Determination of the deformation parameters of the steel reinforcing phase inside the aluminum matrix during hot rolling
No full textM. Nosko: ORCID 0000-0002-8792-4016; D. Konovodov: ORCID 0000-0001-8282-4991; A. Samsonenko: ORCID 0000-0001-6992-2327; O. Bobukh: ORCID 0000-0001-7254-3854ENG: Purpose. Comparison of deformation parameters during rolling of reinforced composites based on aluminum alloy using braided and expanded steel meshes as a reinforcing phase. Methodology. An experimental study on the effect of pressure on the deformation of the reinforcing phase during rolling of aluminum composites is carried out. A wire mesh and expanded mesh made of stainless steel was used as a reinforcing phase. The effect of deformation on the change in the lattice angle of the reinforcing phase is investigated. Findings. In this work, experimental data on the parameters of deformation of the wire mesh and expanded mesh are obtained. A comparison is made of the shape change in such grids under hot rolling conditions between two aluminum plates, which play the role of a matrix. It is found that the elongation coefficients of the lattice for the experiment with a wire mesh μc is equal to 1.68–2.3, which is greater than the coefficient of elongation of the lattice in the expanded mesh of 1.55–2.2. Therefore, expanded sheets make the best reinforcing layer for aluminumbased composites produced by the rollbonding process. Expanded mesh also reduces the risk of rupture at the intersection of wires. Originality. In the work, for the first time, a comparison of the deformation parameters during roll bonding of composites based on an aluminum alloy, reinforced with a braided and expanded steel mesh, has been given. Obtaining composite materials by means of hot roll bonding requires an understanding of the flow of composite components during deformation and their influence on each other. These peculiarities have not been studied sufficiently. Currently, there is no reliable method for predicting the behavior of the material of a solid reinforcing phase of various shapes inside a composite. Practical value. Advantages of using an expanded steel mesh for reinforcing aluminumbased composites have been confirmed. Scientific results can be used to refine calculating methods for metal flow at high hydrostatic pressure with variable components of the stress tensor and the major stresses.UKR: Мета. Порівняння параметрів деформації при прокатці армованих композитів на основі алюмінієвого сплаву з використанням в якості армуючої фази плетеної та просічновитяжної сталевої сітки. Методика. Виконано експериментальне дослідження впливу обтиснення на деформацію армуючої фази при прокатці алюмінієвих композитів. В якості армуючої фази використана плетена та просічновитяжна сітка з нержавіючої сталі. Досліджено вплив деформації на зміну кута гратки армуючої фази. Результати. У роботі отримані експериментальні дані стосовно параметрів деформації плетеної та просічновитяжної сітки. Проведене порівняння формозміни та ких сіток в умовах гарячої прокатки між двох алюмінієвих пластин, що відіграють роль матриці. Встановлено, що коефіцієнти видовження ґратки для експерименту із плетеною сіткою μc дорівнював 1,68–2,3 що більше, ніж коефіцієнт видовження ґратки із просічновитяжної сітки – 1,55–2,20. Тому, просічновитяжна сітка є кращою в якості армуючого шару для композитів на основі алюмінію, отриманих процесом прокатки–з’єднання. Також просічновитяжна сітка дозволяє зменшити ризик розриву в місцях перехрещення дротів. Наукова новизна. У роботі вперше наведене порівняння параметрів деформації під час прокатки–з’єднання композитів на основі алюмінієвого сплаву, армованих плетеною та просічновитяжною сіткою. Технологія виготовлення композиційних матеріалів із різними видами армуючого елемента за допомогою гарячого з›єднання прокаткою вимагає розуміння властивостей кожного елементу композиту в зоні деформації та їх впливу один на одного. Такі особливості ще не були достатньо досліджені. Тому, наразі, не існує надійного методу прогнозу вання поведінки жорсткої армуючої фази всередині м’якої алюмінієвої матриці. Практична значимість. Підтверджені переваги використання просічновитяжної сітки для армування композитів на основі алюмінію. Результати роботи можуть бути використані для уточнення методів розрахунку течії металу в умовах високого гідростатичного тиску зі змінними компонентами тензора напружень і головними напруженнями
Arene-ruthenium(II) complexes with tetracyclic oxime derivatives: synthesis, structure and antiproliferative activity against human breast cancer cells
No full textSix new arene-ruthenium(II) complexes containing two different η6-arene ligands – benzene and hexame- thylbenzene, with indenoquinoxalinone oxime analogues (11H-indeno[1,2-b]quinoxalin-11-one oxime, 6H- indeno[1,2-b]pyrido[3,2-e]pyrazin-6-one oxime and 6–(hydroxyimino)indolo[2,1-b]quinazolin-12(6H)-one oxime (tryptanthrin-6-oxime)) as N,N’- chelating ligands are reported. The complexes were characterized by elemental analysis, IR, UV–VIS, 1H and 13C NMR spectroscopy and by single-crystal X-ray structure analysis. Complexes adopt a half-sandwich «piano-stool» geometry with oxime ligands in anionic form, the ruthenium(II) center coordinates one arene, one N,N-bidentate oximate and one chloride ligand. The computational analysis of non-covalent intermolecular interactions revealed weak attraction between the oxime oxygen atoms and the nearest hydrogen atoms of the oxime and the arene ligands. The cytotoxic activity of the complexes was eval- uated against human breast cancer cell line MCF-7 and cisplatin-resistant human breast cancer cell line MCF-7CR as well as non-cancerous human breast epithelial cell line MCF10A. The cytotoxicity tests show micromolar IC50 values and tryptanthrin-6-oxime hexamethylbenzene-ruthenium(II) complex was found to exhibit the best antiproliferative activity among the studied compounds against the MCF-7 and MCF-7CR cell lines (IC50 9.0 ± 4.4 and 8.9 ± 1.5 μM, respectively)
Business Participation in the Development of Technoparks in the Electronic Industry of Russia
No full textThe article analyzes peculiarities of technoparks development in Russia and offers recommendations for strengthening the role of small and medium-sized businesses in the expansion of these innovative associations in the electronic industry, highlights the features and problems of the development of Russian technology parks. The key conclusion is that, despite a fairly large number of technoparks in Russia, the state still does not have a unified methodology for assessing their performance, the goals and key principles of their existence have not been defined, and the role of small and medium-sized businesses in technology parks has not been determined. The participation of small and medium-sized businesses in the development of Russian technology parks is fraught with a number of difficulties, including: lack of start-up capital and further financial support for companies; lagging small and medium-sized companies behind the pace of a rapidly changing technology and innovation environment. Despite the difficulties in the development of the electronic industry in Russia, technoparks have sufficient prospects and act as a tool for improving the situation in the field of Russian electronics. Among the author’s recommendations for strengthening the position of small and medium-sized businesses in the functioning of technoparks, including in the electronic industry, the following were proposed: improving the legislative framework in the field of technoparks functioning; expansion of both state support and non-state forms of support in technology parks; strengthening financing of small and medium-sized businesses in the system of relationships with large businesses; expansion of the cooperative model of functioning of technoparks in the electronic industry. The special need for close cooperation within the technology parks of small and medium-sized businesses and large companies was emphasized. General scientific methods of system analysis and synthesis, groupings, statistical methods, graphic methods and others were used as research methods in the work. © 2022, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd
Scattering of electrons by a Coulomb center
No full textNew results are obtained from which it follows that systematic use of the one-to-one correspondence between a physical quantity and an operator, which permits the existence of a non-negative quantum distribution function, leads to an "effective" smearing of the potential and to the appearance of a form factor, i.e., to the existence of structure in the scattering center. © 1980 Plenum Publishing Corporation
Cause of acute kidney injury and unilateral kidney enlargement in a child with acute lymphoblastic leukemia: a case report
No full textWe want tо present a rare clinical case challenging in diagnosing the cause of acute kidney injury in a child with acute lymphoblastic leukemia (ALL)
Enhancement of CO2 Uptake and Selectivity in a Metal-Organic Framework by the Incorporation of Thiophene Functionality
No full textThe complex [Zn2(tdc)2dabco] (H2tdc = thiophene-2,5-dicarboxylic acid; dabco = 1,4-diazabicyclooctane) shows a remarkable increase in carbon dioxide (CO2) uptake and CO2/dinitrogen (N2) selectivity compared to the nonthiophene analogue [Zn2(bdc)2dabco] (H2bdc = benzene-1,4-dicarboxylic acid; terephthalic acid). CO2 adsorption at 1 bar for [Zn2(tdc)2dabco] is 67.4 cm3·g–1 (13.2 wt %) at 298 K and 153 cm3·g–1 (30.0 wt %) at 273 K. For [Zn2(bdc)2dabco], the equivalent values are 46 cm3·g–1 (9.0 wt %) and 122 cm3·g–1 (23.9 wt %), respectively. The isosteric heat of adsorption for CO2 in [Zn2(tdc)2dabco] at zero coverage is low (23.65 kJ·mol–1), ensuring facile regeneration of the porous material. Enhancement by the thiophene group on the separation of CO2/N2 gas mixtures has been confirmed by both ideal adsorbate solution theory calculations and dynamic breakthrough experiments. The preferred binding sites of adsorbed CO2 in [Zn2(tdc)2dabco] have been unambiguously determined by in situ single-crystal diffrac..
Scattering of electrons by a Coulomb center
No full textNew results are obtained from which it follows that systematic use of the one-to-one correspondence between a physical quantity and an operator, which permits the existence of a non-negative quantum distribution function, leads to an "effective" smearing of the potential and to the appearance of a form factor, i.e., to the existence of structure in the scattering center. © 1980 Plenum Publishing Corporation
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