Thermodynamic and geomechanical processes research in the development of gas hydrate deposits in the conditions of the Black Sea

Purpose. Research of thermodynamic and geomechanical processes occurring in a gas hydrate body under the influence of an activating agent (sea water from surface layers) in the conditions of the Black Sea by mathematical modeling using finite element method. Methods. The modeling of thermodynamic and geomechanical processes is performed with the use of ANSYS v17.0 software and in accordance with the climatic, hydrogeological and physic-mechanical properties of the numerical model elements in the Black Sea gas hydrate deposit under consideration, which are similar to natural ones. The thermodynamic processes were studied in the section “Steady-State Thermal”, and the geomechanical (stress-strain state) in “Static Structural”. Findings. The spatial model is developed, which allows to simulate thermodynamic and geomechanical processes in a gas hydrate body under the influence of a thermal agent. As a result of modeling, it was determined that under these conditions the temperature in the gas hydrate body varies with the distance from the production well similarly in both directions according to the polynomial dependence. What is more, at a distance from the well of 18.7 m the temperature is stable and equals +22°С, and in the range of 18.7 – 24.9 m – decreases by 3.1 times and reaches a value of +7°С. It was found out that deformations in a gas hydrate body under the influence of an activating agent, which is fed under pressure above the initial, are directed from the lateral boundaries to the center of the gas hydrate body in the direction of productive dissociation zones. This, in its turn, results in the displacement of the gas hydrate volume to the reaction proceeding center, improving the quality of the decomposition process and allows mining of 87 – 91% gas hydrate volume, which is presented in the model. Originality. For the first time, for the conditions of the Black Sea gas hydrate deposits, an analytical assessment of the dissociation zone distribution from the production well under the influence of the thermal agent and the changes of the stress-strain state of the gas hydrated body during its decomposition, has been carried out. This allows to improve the technology of the gas hydrate deposits development in the conditions under consideration. Practical implications. The technological scheme for the development of a gas hydrate body based on the combined approach to the effects of activators (temperature and pressure) is proposed, which eliminates the need to warm the boundary sections of the deposit and increases the amount of the supplied activating agent and its temperatures, which in its turn leads to a decrease in the resource and energy consumption.Мета. Дослідження термодинамічних і геомеханічних процесів, що протікають у газогідратному тілі при впливі активуючого агента (морської води з поверхневих шарів) в умовах Чорного моря шляхом математичного моделювання методом кінцевих елементів. Методика. Моделювання термодинамічних і геомеханічних процесів виконано за допомогою програмного забезпечення ANSYS v17.0 з відповідністю кліматичних, гідрогеологічних та фізико-механічних властивостей елементів чисельної моделі у розглянутому газогідратному родовищі Чорного моря, які є аналогічними натурним. Термодинамічні процеси досліджувалися у розділі програми “Steady-State Thermal”, а геомеханічні (напружено-деформований стан) – в “Static Structural”. Результати. Розроблена просторова модель, що дозволяє моделювати термодинамічні та геомеханічні процеси у газогідратному тілі при впливі теплового агента. В результаті моделювання встановлено, що у розглянутих умовах температура в газогідратному тілі змінюється з відстанню від видобувної свердловини аналогічно в обидві сторони за поліноміальною залежністю, причому на відстані від свердловини 18.7 м температура стабільна і становить +22°С, а в інтервалі 18.7 – 24.9 м – знижується у 3.1 рази і досягає значення +7°С. Виявлено, що деформації у газогідратному тілі при впливі активуючого агента, який подається під тиском, що перевищує початковий, спрямовані від бокових меж у центр газогідратного тіла у напрямі продуктивних зон дисоціації, що, в свою чергу, призводить до зміщення об’єму газогідрату в центр протікання реакції, покращуючи якість процесу розкладання і дозволяючи відпрацювати 87 – 91% об’єму газогідрата, представленого в моделі. Наукова новизна. Вперше для умов газогідратних родовищ Чорного моря проведена аналітична оцінка характеру поширення зони дисоціації від видобувної свердловини при впливі теплового агента та змін напружено-деформованого стану газогідратного тіла при його розкладанні, що дозволяє удосконалити технологію розробки газогідратних покладів у розглянутих умовах. Практична значимість. Запропоновано технологічну схему розробки газогідратного тіла на основі комбінованого підходу до впливу активаторами (температурою та тиском), що усуває необхідність прогріву граничних ділянок покладу і збільшення кількості активуючого агента, що подається, та його температури, що, в свою чергу, веде до зниження ресурсо- й енерговитрат.Цель. Исследование термодинамических и геомеханических процессов, протекающих в газогидратном теле при воздействии активирующего агента (морской воды с поверхностных слоев) в условиях Черного моря посредством математического моделирования методом конечных элементов. Методика. Моделирование термодинамических и геомеханических процессов выполнено при помощи программного обеспечения ANSYS v17.0 с соответствием климатических, гидрогеологических и физико-механических свойств элементов численной модели в рассматриваемом газогидратном месторождении Черного моря, которые являются аналогичными натурным. Термодинамические процессы исследовались в разделе программы “Steady-State Thermal”, а геомеханические (напряженно-деформированное состояние) – в “Static Structural”. Результаты. Разработана пространственная модель, позволяющая моделировать термодинамические и геомеханические процессы в газогидратном теле при воздействии теплового агента. В результате моделирования установлено, что в рассматриваемых условиях температура в газогидратном теле изменяется с расстоянием от добывающей скважины аналогично в обе стороны по полиномиальной зависимости, причем на расстоянии от скважины 18.7 м температура стабильна и составляет +22°С, а в интервале 18.7 – 24.9 м – снижается в 3.1 раза и достигает значения +7°С. Выявлено, что деформации в газогидратном теле при воздействии активирующего агента, подаваемого под давлением, превышающее начальное, направлены от боковых границ в центр газогидратного тела в направлении продуктивных зон диссоциации, что, в свою очередь, приводит к смещению объема газогидрата в центр протекания реакции, улучшая качество процесса разложения и позволяя отработать 87 – 91% объема газогидрата, представленного в модели. Научная новизна. Впервые для условий газогидратных месторождений Черного моря проведена аналитическая оценка характера распространения зоны диссоциации от добывающей скважины при воздействии теплового агента и изменений напряженно-деформированного состояния газогидратного тела при его разложении, что позволяет усовершенствовать технологию разработки газогидратных залежей в рассматриваемых условиях. Практическая значимость. Предложена технологическая схема разработки газогидратного тела на основании комбинированного подхода к воздействию активаторами (температурой и давлением), устраняющая необходимость прогрева граничных участков залежи и увеличения подаваемого количества активирующего агента и его температуры, что, в свою очередь, ведет к снижению ресурсо- и энергозатрат.The results of the current researches were obtained within the framework of the research works of GP-473 Development of scientific principles of phase transformations of technogenic and natural gas hydrates and creation of the newest technologies of their extraction” (State Registration No.0115U002294) and GP-487 “Scientific substantiation and development of energy saving and low waste technologies of hydrocarbon and mineral raw materials extraction” (State Registration No.0116U008041)

Spectral signatures of thermal spin disorder and excess Mn in half-metallic NiMnSb

Effects of thermal spin disorder and excess Mn on the electronic spectrum of half-metallic NiMnSb are studied using first-principles calculations. Temperature-dependent spin disorder, introduced within the vector disordered local moment model, causes the valence band at the $\Gamma$ point to broaden and shift upwards, crossing the Fermi level and thereby closing the half-metallic gap above room temperature. The spectroscopic signatures of excess Mn on the Ni, Sb, and empty sites (Mn$_\mathrm{Ni}$, Mn$_\mathrm{Sb}$, and Mn$_\mathrm{E}$) are analyzed. Mn$_\mathrm{Ni}$ is spectroscopically invisible. The relatively weak coupling of Mn$_\mathrm{Sb}$ and Mn$_\mathrm{E}$ spins to the host strongly deviates from the Heisenberg model, and the spin of Mn$_\mathrm{E}$ is canted in the ground state. While the half-metallic gap is preserved in the collinear ground state of Mn$_\mathrm{Sb}$, thermal spin disorder of the weakly coupled Mn$_\mathrm{Sb}$ spins destroys it at low temperatures. This property of Mn$_\mathrm{Sb}$ may be the source of the observed low-temperature transport anomalies.Comment: 5 pages, 7 figures, updated version with minor revisions and an additional figure, accepted in Phys. Rev. B (Rapid Communication

Advances in Instrumentation and Monitoring in Geotechnical Engineering

[Extract] Geotechnical instrumentation to monitor the performances of earth and earth-supported structures is increasingly becoming popular. Verification of long-term performances, validation of new theories, construction control, warning against any impending failures, quality assurance, and legal protection are some of the many reasons for geotechnical instrumentation. They are not only used in field situations, but in laboratories too. With the recent advances in materials and technology, and the need for more stringent performance control, there had been significant developments in the recent past in instrumentation and monitoring techniques

Synthesis, characterization and evaluation of new thiazole derivatives as anthelmintic agents

616-623A series of 2-amino substituted 4-phenyl thiazole derivatives has been synthesized by the conventional method. The thiazole derivatives have been synthesized by three steps. The obtained five derivatives have been purified by recrystallization process by using methanol as solvent and column chromatography [IVd Compound] and have been characterized by melting point, TLC, FTIR, 1H NMR and mass spectral data. All the five derivatives have been evaluated using in silico studies by using different softwares (Lipinski’s Rule of 5, OSIRIS molecular property explorer, Molsoft molecular property explorer, PASS and docking studies). These compounds have then been evaluated for anthelmintic activity against Indian adult earth worms (Pheretima postuma). All the compounds show significant anthelmintic activity. The compound IVc and IVe are shown to be potent compounds when compared with the standard drug (Mebendazole). Molecular docking studies have guided and prove the biological activity of the sythesised compounds against beta tubulin protein (1OJ0)

Synthesis, characterization and evaluation of new thiazole derivatives as anthelmintic agents

A series of 2-amino substituted 4-phenyl thiazole derivatives has been synthesized by the conventional method. The thiazole derivatives have been synthesized by three steps. The obtained five derivatives have been purified by recrystallization process by using methanol as solvent and column chromatography [IVd Compound] and have been characterized by melting point, TLC, FTIR, 1H NMR and mass spectral data. All the five derivatives have been evaluated using in silico studies by using different softwares (Lipinski’s Rule of 5, OSIRIS molecular property explorer, Molsoft molecular property explorer, PASS and docking studies). These compounds have then been evaluated for anthelmintic activity against Indian adult earth worms (Pheretima postuma). All the compounds show significant anthelmintic activity. The compound IVc and IVe are shown to be potent compounds when compared with the standard drug (Mebendazole). Molecular docking studies have guided and prove the biological activity of the sythesised compounds against beta tubulin protein (1OJ0).

A Study of Within-Host Dynamics of Dengue Infection incorporating both Humoral and Cellular Response with a Time Delay for Production of Antibodies

Abstract a. Background: Dengue is an acute illness caused by a virus. The complex behaviour of the virus in human body can be captured using mathematical models. These models helps us to enhance our understanding on the dynamics of the virus. b. Objectives: We propose to study the dynamics of within-host epidemic model of dengue infection which incorporates both innate immune response and adaptive immune response (Cellular and Humoral). The proposed model also incorporates the time delay for production of antibodies from B cells. We propose to understand the dynamics of the this model using the dynamical systems approach by performing the stability and sensitivity analysis. c. Methods used: The basic reproduction number (R0) has been computed using the next generation matrix method. The standard stability analysis and sensitivity analysis were performed on the proposed model. d. Results: The critical level of the antibody recruitment rate(q) was found to be responsible for the existence and stability of various steady states. The stability of endemic state was found to be dependent on time delay(τ). The sensitivity analysis identified the production rate of antibodies (q) to be highly sensitive parameter. e. Conclusions: The existence and stability conditions for the equilibrium points have been obtained. The threshold value of time delay (τ0) has been computed which is critical for change in stability of the endemic state. Sensitivity analysis was performed to identify the crucial and sensitive parameters of the model

Asynchronous Execution Platform for Edge Node Devices

A Asynchronous distributed execution platform which enables efficient and seamless task submissions on a remote node from a cluster of edge node devices using a reactive framework and provide real-time metrics of execution persisted on elastic database. Queues are used for job submission along with different compute units delivering the infrastructure for execution of submitted jobs. The proposed system is a generic framework that can be used in any enterprise web application where execution on a remote node is required. Through this we aim to provide an enterprise grade solution for task submission and management on a remote machine, using new, efficient technologies like SpringBoot and RabbitMQ. There is a demand in remote computing and huge workloads that cannot be executed on small local machines, our system can be used directly or indirectly by incorporated in other solutions

Computational Relativistic Astrophysics With Adaptive Mesh Refinement: Testbeds

We have carried out numerical simulations of strongly gravitating systems based on the Einstein equations coupled to the relativistic hydrodynamic equations using adaptive mesh refinement (AMR) techniques. We show AMR simulations of NS binary inspiral and coalescence carried out on a workstation having an accuracy equivalent to that of a $1025^3$ regular unigrid simulation, which is, to the best of our knowledge, larger than all previous simulations of similar NS systems on supercomputers. We believe the capability opens new possibilities in general relativistic simulations.Comment: 7 pages, 16 figure