A study of the temperature dependence of bienzyme systems and enzymatic chains

It is known that most enzyme-facilitated reactions are highly temperature dependent processes. In general, the temperature coefficient, Q10, of a simple reaction reaches 2.0-3.0. Nevertheless, some enzyme-controlled processes have much lower Q10 (about 1.0), which implies that the process is almost temperature independent, even if individual reactions involved in the process are themselves highly temperature dependent. In this work, we investigate a possible mechanism for this apparent temperature compensation: simple mathematical models are used to study how varying types of enzyme reactions are affected by temperature. We show that some bienzyme-controlled processes may be almost temperature independent if the modules involved in the reaction have similar temperature dependencies, even if individually, these modules are strongly temperature dependent. Further, we show that in non-reversible enzyme chains the stationary concentrations of metabolites are dependent only on the relationship between the temperature dependencies of the first and last modules, whilst in reversible reactions, there is a dependence on every module. Our findings suggest a mechanism by which the metabolic processes taking place within living organisms may be regulated, despite strong variation in temperature

Motor activity of paramecium | Dvigatel'naia aktivnost' parametsii.

A systemic study of the mechanisms of motor activity of paramecium was carried out. The movements of paramecium responding to various influences were photographed. The analysis of the data revealed the time dependences of the rate of movement, rate of rotation, and the radius and the pitch of the helix trajectory. Mathematical models of the membrane and a unit that transforms the calcium signal to programs of regulating the effectors were constructed. A system of equations for constructing the trajectory of movement was proposed. It is concluded that the biomolecular system that involves calmodulin, calmodulin-dependent ionic channels, adenylate cyclase, guanylate cyclase, phosphodiesterases, Ca(2+)-calmodulin, cAMP, cGMP-dependent protein kinases, and phosphoprotein phosphatases is capable of regulating motor reactions necessary for complex maneuvering of paramecium under various conditions

Motor activity of paramecium

A systemic study of the mechanisms of motor activity of paramecium was carried out. The movements of paramecium responding to various influences were photographed. The analysis of the data revealed the time dependences of the rate of movement, rate of rotation, and the radius and the pitch of the helix trajectory. Mathematical models of the membrane and a unit that transforms the calcium signal to programs of regulating the effectors were constructed. A system of equations for constructing the trajectory of movement was proposed. It is concluded that the biomolecular system that involves calmodulin, calmodulin-dependent ionic channels, adenylate cyclase, guanylate cyclase, phosphodiesterases, Ca2+-calmodulin, cAMP, cGMP-dependent protein kinases, and phosphoprotein phosphatases is capable of regulating motor reactions necessary for complex maneuvering of paramecium under various conditions

A study of the temperature dependence of bienzyme systems and enzymatic chains

It is known that most enzyme-facilitated reactions are highly temperature dependent processes. In general, the temperature coefficient, Q10, of a simple reaction reaches 2.0-3.0. Nevertheless, some enzyme-controlled processes have much lower Q10 (about 1.0), which implies that the process is almost temperature independent, even if individual reactions involved in the process are themselves highly temperature dependent. In this work, we investigate a possible mechanism for this apparent temperature compensation: simple mathematical models are used to study how varying types of enzyme reactions are affected by temperature. We show that some bienzyme-controlled processes may be almost temperature independent if the modules involved in the reaction have similar temperature dependencies, even if individually, these modules are strongly temperature dependent. Further, we show that in non-reversible enzyme chains the stationary concentrations of metabolites are dependent only on the relationship between the temperature dependencies of the first and last modules, whilst in reversible reactions, there is a dependence on every module. Our findings suggest a mechanism by which the metabolic processes taking place within living organisms may be regulated, despite strong variation in temperature

A study of the temperature dependence of bienzyme systems and enzymatic chains

It is known that most enzyme-facilitated reactions are highly temperature dependent processes. In general, the temperature coefficient, Q 10 , of a simple reaction reaches 2.0 -3.0. Nevertheless, some enzyme-controlled processes have much lower Q 10 (about 1.0), which implies that the process is almost temperature independent, even if individual reactions involved in the process are themselves highly temperature dependent. In this work, we investigate a possible mechanism for this apparent temperature compensation: simple mathematical models are used to study how varying types of enzyme reactions are affected by temperature. We show that some bienzyme-controlled processes may be almost temperature independent if the modules involved in the reaction have similar temperature dependencies, even if individually, these modules are strongly temperature dependent. Further, we show that in non-reversible enzyme chains the stationary concentrations of metabolites are dependent only on the relationship between the temperature dependencies of the first and last modules, whilst in reversible reactions, there is a dependence on every module. Our findings suggest a mechanism by which the metabolic processes taking place within living organisms may be regulated, despite strong variation in temperature

Численное моделирование современного состояния вод и морского льда Северного Ледовитого океана

The paper presents results of numerical simulation of variability of the sea ice area and water circulation in the Arctic Ocean performed with use of the atmosphere reanalysis data for the period from middle of the last century to the present time. The model results reflect the ocean responses to changes of the atmosphere circulation regimes that manifests in changes of trajectories of waters coming into the Arctic Ocean from the Pacific and Atlantic oceans. The model results show influence of the Pacific and Atlantic waters on distribution and thickness of the Arctic ice. В работе представлены результаты численного моделирования изменчивости площади морского льда и циркуляции вод Северного Ледовитого океана с использованием данных реанализа атмосферы. Результаты моделирования отражают реакцию океана на смену режимов циркуляции атмосферы, что проявляется в изменении траектории движения вод, поступающих в Арктический бассейн из Тихого и Атлантического океанов. Показано влияние тихоокеанских и атлантических вод на распределение и толщину арктического льда.

Tensile Deformation and Fracture Behavior of API-5L X70 Line Pipe Steel

Thermo-mechanical controlled processing (TMCP) is employed to obtain the required level of mechanical properties of contemporary HSLA steel plates utilized for gas and oil pipeline production. The strength and crack resistance of pipeline steels are mainly determined by its microstructure and crystallographic texture. In this study, the influence of the structural and textural states of industrially produced API-5L X70-X80 pipeline steels on tensile mechanical properties was analyzed. TMCP routes with different hot rolling temperatures and cooling rates were employed. The texture of steel was assessed using the Taylor factor, which was calculated based on electron backscatter diffraction (EBSD). The decrease in rolling temperature resulted in the sharper texture characterized by {001} planes banding (cleavage planes in the bcc lattice) parallel to rolling direction. The tensile deformation behavior at the stage of necking was determined by the crystallographic and morphological texture of the material and demonstrated significant anisotropy. Rupture of all investigated samples was accompanied by the development of splitting on the fracture surface. The splitting was localized in the rolling plane similar to the splitting in standard Charpy tests of pipeline steels. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.Funding: This research was funded by Russian Science Foundation, grant number 22-29-00411

STUDY OF THE STRUCTURE AND MECHANICAL CHARACTERISTICS OF THE 1550 ALUMINUM ALLOY DOPED WITH ERBIUM

Presents the results of studying the structure and mechanical properties of the alloy 1550 doped with Er. A decrease in porosity and refinement of the average grain size during ultra-sonic treatment were revealed. An increase in the mechanical characteristics of the alloy 1550 with erbium is noted.Исследование выполнено за счет гранта Российского научного фонда (проект № 20-79-00060)

Гигиеническая оценка источников питьевого водоснабжения населения западного региона Украины

Актуальність роботи обумовлена суттєвими еколого-гігієнічними проблемами водопостачання населення Західного регіону України. Методи досліджень – бібліометричні, компелятивні, аналітичні. Результати досліджень та їх обговорення. Представлено характеристику водопостачання мешканців великих міст Західного регіону України, який включає Львівську, Івано–Франківську, Тернопільську, Волинську, Рівненську, Хмельницьку, Чернівецьку та Закарпатську області. Встановлено, що основними водогосподарськими проблемами цих міст є надмірне водоспоживання, значні втрати води у розподільних мережах, низька якість та ненадійне функціонування систем водопостачання, незадовільні екологічні характеристики систем водозабезпечення і каналізації тощо. Обгрунтовано необхідність термінового вирішення проблеми якості питної води у містах регіону шляхом впровадження колективних систем доочищення води із залученням бюджетних, позабюджетних коштів та іноземних інвестицій.The relevance of the work is due to the significant environmental and hygienic problems of water supply the population of the Western region of Ukraine faces to. The objective of the work: to made a hygienic assessment of the drinking water supply sources for the population of the western region of Ukraine. Research methods – bibliometric, compiled, analytical. Results and discussion. The characteristic of water supply of residents of large cities of the Western region of Ukraine, including those of Lviv, Ivano-Frankivsk, Ternopil, Volyn, Rivne, Khmelnytsky, Chernivtsi and Transcarpathian regions is presented. It has been established that the main water management problems of the cities under survey are excessive water consumption, significant water losses in distribution networks, poor quality and unreliable functioning of water supply and sewage systems, and the poor environmental performance of the latter. The necessity of an urgent solution to the drinking water quality problem in the cities under investigation through the introduction of collective systems of water purification with the involvement of budgetary, extra-budgetary funds and foreign investment has been substantiated.Актуальность работы обусловлена существенными эколого-гигиеническими проблемами водоснабжения населения Западного региона Украины. Методы исследований – библиометрические, компелятивные, аналитические. Результаты исследований и их обсуждение. Представлена характеристика водоснабжения жителей больших городов Западного региона Украины, который включает Львовскую, Ивано–Франковскую, Тернопольскую, Волынскую, Ровенскую, Хмельницкую, Черновицкую и Закарпатскую области. Установлено, что основными водохозяйственными проблемами этих городов является чрезмерное водопотребление, значительные потери воды в распределительных сетях, низкое качество и ненадежное функционирование систем водоснабжения и канализации, неудовлетворительные экологические характеристики систем водообеспечення и канализации и т.п. Обоснована необходимость срочного решения проблемы качества питьевой воды в городах региона путем внедрения коллективных систем доочистки воды с привлечением бюджетных, внебюджетных средств и иностранных инвестиций

Thermal effect of bainitic transformation in tube steels during accelerated cooling

An original laboratory bench, which allows for modeling technological rates of cooling of hot-rolled sheets in the process of controlled thermomechanical processing (TMCP) has been designed. Samples cut from an industrial sheet of 06G2MB type pipe steel used in production of large diameter pipes with strength grade X80 have been used. Time dependencies of the actual temperature at initial cooling rates of 100 – 500 K / s have been obtained. All processing modes resulted in almost identical structures mainly formed due to the bainitic transformation. The dispersion of structures decreased with the increase of the cooling rate. Thermotechnical calculations were carried out assuming that the temperature equalization over the sample thickness was instant. The times of transformation amounted to 1 – 9 s. Most of the transformation at all cooling modes occurred in conditions close to the isothermal one. The athermal nature of the bainitic transformation in TMCP was recorded. Within the observed interval of cooling rates, the temperature at the starting point of the bainitic transformation was 660 – 730°C. The heat effect approximately was equal to 120 kJ / kg, which is twice larger than the thermal effect of the martensite transformation for low-carbon steels. This fact suggests that the kinetics of the bainitic transformation is largely determined by the energy of the slowest process, namely, the re-arrangement of carbon atoms in the austenite occurring parallelly to the shear transformation of FCC lattice into BCC one. It is assumed that energy contribution of the redistribution process of carbon atoms (if their amount is small) to the thermal effect of the bainitic transformation is comparable, at least, to the energy effect of the shear lattice rearrangement. © 2018, Institute for Metals Superplasticity Problems of Russian Academy of Sciences. All rights reserved.Благодарности/Acknowledgements. Работа выпол-нена на  оборудовании ОАО «Аусферр». Работа выпол-нена в  рамках государственного задания ФАНО России, тема «Структура» (”Structure“), номер госрегистрации 0120146333. Авторы выражают признательность за со-действие программе поддержки ведущих университетов РФ в целях повышения их конкурентоспособности № 211 Правительства РФ №02.А03.21.0006./The study was performed on the equipment from OAO “Ausferr”. The study was performed within the framework of the state assignment from the Federal Agency for Scientific Organizations of Russian Federation, theme “Structure”, registration number 0120146333. The authors express their gratitud