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2020

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Articles 61 - 90 of 312

Full-Text Articles in Engineering Science and Materials

Licoo2 As Sulfur Host To Enhance Cathode Volumetric Capacity For Lithium-Sulfur Battery, Lu Wang, Xue-Ping Gao Oct 2020

Licoo2 As Sulfur Host To Enhance Cathode Volumetric Capacity For Lithium-Sulfur Battery, Lu Wang, Xue-Ping Gao

Journal of Electrochemistry

Lithium-sulfur battery is one of the most promising secondary battery systems due to its super high theoretical gravimetric and volumetric energy densities (2600 Wh·kg-1 and 2800 Wh·L-1, respectively). However, the practical volumetric capacity of sulfur cathode is still unsatisfied due to the overuse of low-density host materials, such as carbon nanomaterials. Herein, commercial LiCoO2 with the high tap density of 2.94 g·cm-3 was used as the host material to build high density sulfur-based composite and compact electrode for increasing the volumetric capacity. Obviously, the tap density of the as-prepared S/LiCoO2 composite was 1.90 g·cm …

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Research Progress Of Key Components In Lithium-Sulfur Batteries, Jia-Jia Chen, Quan-Feng Dong Oct 2020

Research Progress Of Key Components In Lithium-Sulfur Batteries, Jia-Jia Chen, Quan-Feng Dong

Journal of Electrochemistry

Due to the much higher theoretical specific capacity and energy density than the ones of traditional lithium ion battery, Li-S batteries have long been at the pinnacle in the realms of high-energy Li-metal batteries. However, the complicated electrochemical reactions on the sulfur cathode and Li anode, induced by the thermodynamic and kinetic behaviors of lithium polysulfides, are the intrinsic bottleneck to realize the full potential of Li-S batteries for practical application. In this review, we firstly discuss the roles, and thermodynamic and kinetic behaviors of polysulfides in the charging and discharging processes of Li-S batteries. Then, the functional design and …

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A Model For The Anodic Carbonization Of Alkaline Polymer Electrolyte Fuel Cells, Qi-Hao Li, Ying-Ming Wang, Hua-Long Ma, Li Xiao, Gong-Wei Wang, Jun-Tao Lu, Lin Zhuang Oct 2020

A Model For The Anodic Carbonization Of Alkaline Polymer Electrolyte Fuel Cells, Qi-Hao Li, Ying-Ming Wang, Hua-Long Ma, Li Xiao, Gong-Wei Wang, Jun-Tao Lu, Lin Zhuang

Journal of Electrochemistry

The alkaline polymer electrolyte fuel cell (APEFC) has made appreciable progress in recent years but is still suffering performance loss during discharge with air as the oxidant. Several theories have been suggested to interpret the loss. However, efforts are still needed to reach a clear quantitative understanding. Based on the major experimental findings in combination with thermodynamics and kinetics of the reactions involved in the anode, this paper presents a model featuring layered carbonization in the anode and relevant grouped equations. The simulation results generated from the latter are compared with experiments, and possible principles to suppress the performance loss …

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Research Progress Of Sulfur Cathode Catalytic Conversions For Lithium-Sulfur Batteries, Qin-Jun Shao, Jian Chen Oct 2020

Research Progress Of Sulfur Cathode Catalytic Conversions For Lithium-Sulfur Batteries, Qin-Jun Shao, Jian Chen

Journal of Electrochemistry

The electrochemical reduction of sulfur (S) takes place through multistep reactions when S is used as a cathode material. The complete discharge of S to form final product lithium sulfide (Li2S) is a two-electron reaction. The formation of low-order lithium polysulfides (LiPS) needs to overcome certain energy barriers. And the reduction of Li2S2 to Li2S is the rate-limited step. The reaction kinetic of sulfur cathode is the critical key to determine the electrochemical performance of Li-S batteries, such as specific energy, specific power and low temperature performance, etc. Accelerating the rate-limited step kinetics …

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Liquid Metal Electrodes For Electrochemical Energy Storage Technologies, Hao-Miao Li, Hao Zhou, Kang-Li Wang, Kai Jiang Oct 2020

Liquid Metal Electrodes For Electrochemical Energy Storage Technologies, Hao-Miao Li, Hao Zhou, Kang-Li Wang, Kai Jiang

Journal of Electrochemistry

Electrochemical energy storage technologies (ESTs) with low cost, long lifespan and high safety are of great importance for efficient integration of renewable energy into the grid. Liquid metal electrodes (LMEs) possessing the merits of high electronic conductivity, easy manufacture and amorphous structure is of great application value in the field of energy storage batteries. During charge-discharge processing, the LMEs could avoid the issues of structural deformation and dendrite growth in solid metal electrodes, which could effectively extend the cycle life of the LME based batteries. Moreover, LME based batteries are easy to be scaled up and less expensive, which are …

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Porous Electrodes In Electrochemical Energy Storage Systems, Wei-Xiao Ji, Gong-Wei Wang, Qiang Wang, Li-Jun Bai, De-Yang Qu Oct 2020

Porous Electrodes In Electrochemical Energy Storage Systems, Wei-Xiao Ji, Gong-Wei Wang, Qiang Wang, Li-Jun Bai, De-Yang Qu

Journal of Electrochemistry

Professor C.S. Cha was among the pioneers who have introduced modern electrochemistry to China. Under his leadership, the electrochemical research group in Wuhan University became one of the global powerhouses in fundamental and applied electrochemical researches. During the past many decades, Professor Cha and his colleagues in the university have educated and trained many students who have become part of the backbone of electrochemistry worldwide. In this review, we demonstrate the solid foundation laid by Professor Cha and his colleagues in Wuhan University, and the advancements made in the area of porous electrodes by the authors. All the authors in …

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Highly Efficient Co2 Utilization Via Molten Salt Co2 Capture And Electrochemical Transformation Technology, Bo-Wen Deng, Hua-Yi Yin, Di-Hua Wang Oct 2020

Highly Efficient Co2 Utilization Via Molten Salt Co2 Capture And Electrochemical Transformation Technology, Bo-Wen Deng, Hua-Yi Yin, Di-Hua Wang

Journal of Electrochemistry

The molten electrolytes exhibit high CO2 absorption capacities, wide electrochemical windows and excellent reaction kinetics, which are promising electrolyte candidates for efficient capture and electrochemical conversion of high-flux CO2 driven by renewable and clean electricity sources. This short review introduces the recent advancements of CO2 electroreduction achieved by the authors using molten salt CO2 capture and electrochemical transformation (MSCC-ET) technology, involving CO2 absorption kinetics, cathodic kinetics, controllable synthesis of carbon products with unique nanostructures, development of inert oxygen evolution anodes and CO2 conversion efficiency as well as energy efficiency. The challenges and prospects are …

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Advances In The Application Of Biomimetic Surface Engineering In The Oil And Gas Industry, Yanbao Guo, Zheng Zhang, Siwei Zhang Oct 2020

Advances In The Application Of Biomimetic Surface Engineering In The Oil And Gas Industry, Yanbao Guo, Zheng Zhang, Siwei Zhang

Friction

Friction is widespread in almost every field in the oil and gas industry, and it is accompanied by huge energy losses and potential safety hazards. To deal with a series of questions in this regard, biomimetic surfaces have been developed over the past decades to significantly reduce economic losses. Presently, biomimetic surface engineering on different scales has been successfully introduced into related fields of the oil and gas industry, such as drill bits and the inner surfaces of pipes. In this review, we focused on the most recent and promising efforts reported toward the application of a biomimetic surface in …

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Rubber Plunger Surface Texturing For Friction Reduction In Medical Syringes, Haytam Kasem, Harel Shriki, Lihi Ganon, Michael Mizrahi, Kareem Abd-Rbo, Abraham J. Domb Oct 2020

Rubber Plunger Surface Texturing For Friction Reduction In Medical Syringes, Haytam Kasem, Harel Shriki, Lihi Ganon, Michael Mizrahi, Kareem Abd-Rbo, Abraham J. Domb

Friction

Friction is a genuine issue in the use of many medical devices involving rubbery materials such as plungers in medical syringes. This paper presents a new direction for the reduction of friction in medical syringes based on surface texturing of the rubber plunger. The specimens were prepared by casting poly(vinylsiloxane) (PVS) rubber into a pre-fabricated negative template obtained by 3D printing. Friction tests were performed on a home-made test-rig. It was clearly shown that friction resistance can be considerably manipulated when using textured plungers.

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Erosive Wear Properties Of Za-27 Alloy-Based Nanocomposites: Influence Of Type, Amount, And Size Of Nanoparticle Reinforcements, Aleksandar Vencl, Ilija Bobić, Biljana Bobić, Kristina Jakimovska, Petr Svoboda, Mara Kandeva Oct 2020

Erosive Wear Properties Of Za-27 Alloy-Based Nanocomposites: Influence Of Type, Amount, And Size Of Nanoparticle Reinforcements, Aleksandar Vencl, Ilija Bobić, Biljana Bobić, Kristina Jakimovska, Petr Svoboda, Mara Kandeva

Friction

Metal matrix nanocomposites (MMnCs) comprise a metal matrix filled with nanosized reinforcements with physical and mechanical properties that are very different from those of the matrix. In ZA-27 alloy-based nanocomposites, the metal matrix provides ductility and toughness, while usually used ceramic reinforcements give high strength and hardness. Tested ZA-27 alloy-based nanocomposites, reinforced with different types (SiC and Al2O3), amounts (0.2 wt.%, 0.3 wt.%, and 0.5 wt.%) and sizes (25 nm, 50 nm, and 100 nm) of nanoparticles were produced through the compocasting process with mechanical alloying pre-processing (ball milling). It was previously shown that the presence of nanoparticles in ZA-27 …

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Friction And Wear Behaviors Of Mos2-Multi-Walled-Carbon-Nanotube Hybrid Reinforced Polyurethane Composite Coating, Zhaozhu Zhang, Mingming Yang, Junya Yuan, Fang Guo, Xuehu Men Oct 2020

Friction And Wear Behaviors Of Mos2-Multi-Walled-Carbon-Nanotube Hybrid Reinforced Polyurethane Composite Coating, Zhaozhu Zhang, Mingming Yang, Junya Yuan, Fang Guo, Xuehu Men

Friction

MoS2-multi-walled-carbon-nanotube (MWCNT) hybrids containing two-dimensional MoS2 and one-dimensional MWCNTs were synthesized through a one-step hydrothermal reaction. X-ray-diffraction and transmission-electron-microscopy results demonstrated that MoS2 nanosheets were successfully synthesized, and uniformly anchored on the MWCNTs' surfaces. Furthermore, the effects of the MoS2-MWCNT hybrids on the tribological performances of polyurethane composite coatings were investigated using a UMT-2MT tribo-tester. Friction and wear test results revealed that the friction coefficient and wear rate of a 3 wt% MoS2-MWCNT-1 filled polyurethane composite coating were reduced by 25.6% and 65.5%, respectively. The outstanding tribological performance of the MoS2-MWCNT-1 reinforced polyurethane composite coating was attributed to the excellent …

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Sliding Friction Of Shale Rock On Dry Quartz Sand Particles, Huijie Zhang, Shuhai Liu, Huaping Xiao Oct 2020

Sliding Friction Of Shale Rock On Dry Quartz Sand Particles, Huijie Zhang, Shuhai Liu, Huaping Xiao

Friction

The sliding friction of rock, involving all kinds of particles at the contact surface, is relevant to many problems, ranging from those in artificial engineering to earthquake dynamics. In this work, the frictional performance of the shale rock-dry quartz sand contact was investigated using a self-developed testing device. The study showed that the coefficient of friction of the contact increases with nominal stress and that the corresponding friction force increases approximately linearly with nominal stress, which is directly related to the contact stress between each single sand particle and rock shale. An overall dynamic coefficient, γ, reflecting the response of …

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Friction Predication On Pin-To-Plate Interface Of Ptfe Material And Steel, Zhuming Bi, Donald W. Mueller Oct 2020

Friction Predication On Pin-To-Plate Interface Of Ptfe Material And Steel, Zhuming Bi, Donald W. Mueller

Friction

In this paper, the friction behavior at a pin-to-plate interface is investigated. The pin and plate are made of Polytetrafluoroethylene (PTFE) and steel, respectively, and there is a reciprocating motion at the interface. Governing mathematical models for the relations of design variables and frictions are investigated, and a general procedure is proposed to solve the developed models and predict the friction forces at the interface subjected to given test conditions. Novel models have been developed to represent intrigued friction behaviors affected by various factors such as pin geometrics and finishes, lubrication conditions, and reciprocating speed. The test data from experiments …

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Significant Friction Reduction Of High-Intensity Pulsed Ion Beam Irradiated Wc-Ni Against Graphite Under Water Lubrication, Gaolong Zhang, Yuechang Wang, Ying Liu, Xiangfeng Liu, Yuming Wang Oct 2020

Significant Friction Reduction Of High-Intensity Pulsed Ion Beam Irradiated Wc-Ni Against Graphite Under Water Lubrication, Gaolong Zhang, Yuechang Wang, Ying Liu, Xiangfeng Liu, Yuming Wang

Friction

Two types of commercial WC-Ni samples were irradiated with the High-intensity pulsed ion beam (HIPIB). Both the surface characteristics and tribo-characteristics of the non-irradiated and irradiated WC-Ni samples, sliding against graphite under water lubrication, were compared. Quite low steady friction coefficients (approximately of 0.02) of the irradiated WC-Ni were observed. The surface topographies and components were investigated. The quite low friction of the irradiated WC-Ni samples was ascribed to the higher fluid retention capability of the latter and the tribofilm formed during sliding.

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Metal-Containing Nanomaterials As Lubricant Additives: State-Of-The-Art And Future Development, Igor E. Uflyand, Vladimir A. Zhinzhilo, Victoria E. Burlakova Oct 2020

Metal-Containing Nanomaterials As Lubricant Additives: State-Of-The-Art And Future Development, Igor E. Uflyand, Vladimir A. Zhinzhilo, Victoria E. Burlakova

Friction

This review focuses on the effect of metal-containing nanomaterials on tribological performance in oil lubrication. The basic data on nanolubricants based on nanoparticles of metals, metal oxides, metal sulfides, nanocomposities, and rare-earth compounds are generalized. The influence of nanoparticle size, morphology, surface functionalization, and concentration on friction and wear is analyzed. The lubrication mechanisms of nanolubricants are discussed. The problems and prospects for the development of metal-containing nanomaterials as lubricant additives are considered. The bibliography includes articles published during the last five years.

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Experimental Study On The Tribo-Chemical Smoothening Process Between Self-Mated Silicon Carbide In A Water-Lubricated Surface-Contact Reciprocating Test, Le Jin, Herbert Scheerer, Georg Andersohn, Matthias Oechsner, Dieter Hellmann Oct 2020

Experimental Study On The Tribo-Chemical Smoothening Process Between Self-Mated Silicon Carbide In A Water-Lubricated Surface-Contact Reciprocating Test, Le Jin, Herbert Scheerer, Georg Andersohn, Matthias Oechsner, Dieter Hellmann

Friction

Silicon carbide (SiC) can be tribo-chemically smoothened during a self-mated sliding procedure in the aqueous environment. As well reported in the point-contact tests, this smoothening process works well due to the abundant water as oxidant. After this smoothening process, the tribo-surface is well polished, a closely mated tribo-gap naturally forms, and an ultra-low friction state is built. However, water in the tribo-gap could be insufficient in industrial applications, e.g., the seal gap in mechanical seals. In this study, the tribo-chemical smoothening behavior in such environment was researched. A surface-contact reciprocating test was used to simulate the aqueous environment where water …

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Water-Based Superlubricity In Vacuum, Chen Xiao, Jinjin Li, Lei Chen, Chenhui Zhang, Ningning Zhou, Tao Qing, Linmao Qian, Jiyang Zhang, Jianbin Luo Oct 2020

Water-Based Superlubricity In Vacuum, Chen Xiao, Jinjin Li, Lei Chen, Chenhui Zhang, Ningning Zhou, Tao Qing, Linmao Qian, Jiyang Zhang, Jianbin Luo

Friction

This study achieved water-based superlubricity with the lubrication of H3PO4 solution in vacuum (highest vacuum degree <10-4 torr) for the first time by performing a pre-running process in air before running in vacuum. The stable water-based superlubricity was sustainable in vacuum (0.02 torr) for 14 h until the test was stopped by the user for non-experimental factor. A further analysis suggested that the superlubricity may be attributed to the phosphoric acid-water network formed in air, which can efficiently lock water molecules in the liquid lubricating film even in vacuum owing to the strong hydrogen bond interaction. Such capability to lock water is strongly affected by the strength of hydrogen bond and environmental conditions. The realization of water-based superlubricity with H3PO4 solution in vacuum can lead to its application in space environment.

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Tribological Performance Of Novel Nickel-Based Composite Coatings With Lubricant Particles, Ignacio Tudela, Andrew J. Cobley, Yi Zhang Oct 2020

Tribological Performance Of Novel Nickel-Based Composite Coatings With Lubricant Particles, Ignacio Tudela, Andrew J. Cobley, Yi Zhang

Friction

The present study is focused on the evaluation of the tribological performance of novel Ni/hBN and Ni/WS2 composite coatings electrodeposited from an additive-free Watts bath with the assistance of ultrasound. Lubricated and non-lubricated scratch tests were performed on both novel composite coatings and on standard Ni deposits used as a benchmark coating to have an initial idea of the effect of the presence of particles within the Ni matrix. Under lubricated conditions, the performance of the Ni/hBN composite coating was very similar to the benchmark Ni coating, whereas the Ni/WS2 behaved quite differently, as the latter did not only show …

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Numerical Analysis Of Time-Varying Wear With Elastic Deformation In Line Contact, Wanglong Zhan, Ping Huang Oct 2020

Numerical Analysis Of Time-Varying Wear With Elastic Deformation In Line Contact, Wanglong Zhan, Ping Huang

Friction

Wear is an important factor for failures of mechanical components. Current research on wear is mainly focused on experiments while the numerical simulation of wear is hardly used owing to the complexities of the wear process. Explaining the effect of friction on the wear process is important, as it will lead to a deeper understanding of the evolution of wear. This study proposed a numerical method to expound the wear process in the contact between an elastic cylinder and a half-space simulating the ring-block tester. There are two difficulties during the calculation; one is that the contact shapes vary with …

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Optimal Control Of Active Nematics, Michael M. Norton, Piyush Grover, Michael F. Hagan, Seth Fraden Oct 2020

Optimal Control Of Active Nematics, Michael M. Norton, Piyush Grover, Michael F. Hagan, Seth Fraden

Department of Mechanical and Materials Engineering: Faculty Publications

In this work we present the first systematic framework to sculpt active nematic systems, using optimal control theory and a hydrodynamic model of active nematics. We demonstrate the use of two different control fields, (i) applied vorticity and (ii) activity strength, to shape the dynamics of an extensile active nematic that is confined to a disk. In the absence of control inputs, the system exhibits two attractors, clockwise and counterclockwise circulating states characterized by two co-rotating topological þ1 2 defects. We specifically seek spatiotemporal inputs that switch the system from one attractor to the other; we also examine phase-shifting perturbations. …

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Microfluidic Systems With Embedded Cell Culture Chambers For High Throughput Biological Assays, Arian Jaberi, Amir Monemian Esfahani, Fariba Aghabaglou, Jae Sung Park, Sidy Ndao, Ali Tamayol, Ruiguo Yang Oct 2020

Microfluidic Systems With Embedded Cell Culture Chambers For High Throughput Biological Assays, Arian Jaberi, Amir Monemian Esfahani, Fariba Aghabaglou, Jae Sung Park, Sidy Ndao, Ali Tamayol, Ruiguo Yang

Department of Mechanical and Materials Engineering: Faculty Publications

The ability to generate chemical and mechanical gradients on chips is important both for creating biomimetic designs or enabling high-throughput assays. However, there is still a significant knowledge gap in the generation of mechanical and chemical gradients in a single device. In this study, we developed gradient-generating microfluidic circuits with integrated microchambers to allow cell culture and to introduce chemical and mechanical gradients to cultured cells. A chemical gradient is generated across the microchambers, exposing cells to a uniform concentration of drugs. The embedded microchamber also produces a mechanical gradient in the form of varied shear stresses induced upon cells …

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Study Of Dynamics Of The Twisting Process In Pneumomechanical Spinning In The Presence Of Double False Spinning, Mirzohid Sayidmurodov Oct 2020

Study Of Dynamics Of The Twisting Process In Pneumomechanical Spinning In The Presence Of Double False Spinning, Mirzohid Sayidmurodov

Acta of Turin Polytechnic University in Tashkent

В данной работе представлены результаты исследования динамики процесса кручения пряжи пневмомеханического прядения (пневмомеханического прядения) при наличии двойного ложного кручения, построены динамические математические модели процесса кручения пряжи пневмомеханического прядения. при наличии двойного ложного скручивания в режимах неустановившегося пуска и остановке формовочно-скручивающего устройства.

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Theoretical Studies Of Spinning Line Parameters Of Ring Spinning Machines, Nurilla Dadaxanov Oct 2020

Theoretical Studies Of Spinning Line Parameters Of Ring Spinning Machines, Nurilla Dadaxanov

Acta of Turin Polytechnic University in Tashkent

The article studies the angle of discharge of exhaust devices and obtaining of analytical dependencies for calculating the angle of flow around the sliver of the exhaust cylinder on the spinning line of ring spinning machines.

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A New Technical Solution For Cleaning The Water Intake Structure Of Pumping Stations From Siltation And Its Experimental Research, M.M. Mukhammadiev, S.R. Juraev Oct 2020

A New Technical Solution For Cleaning The Water Intake Structure Of Pumping Stations From Siltation And Its Experimental Research, M.M. Mukhammadiev, S.R. Juraev

Irrigation and Melioration

The article considers one of the most pressing problems of pumping stations in the irrigation system today, their blurring of the bottom of the water intake (avancamera and water intake chambers), analyzes the existing proposals, designs and technical solutions and their advantages and disadvantages. Given the above advantages and disadvantages, a new design has been proposed for the treatment of water intake structures from turbid sediments with minimal energy and capital expenditures, very cheap and simple to operate and reliable. The design includes a turbid suction pump and a turbid pump, as well as a pulp pipeline. The pressurized water …

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Assessing Surface Water Features Using Landsat-8 Oli And Sentinel-1 Satellite Images Case Study Sirdaryo Region, S.M. Muratov, Kh.A. Abdivaitov, Sh.F. Rahmatillayev Oct 2020

Assessing Surface Water Features Using Landsat-8 Oli And Sentinel-1 Satellite Images Case Study Sirdaryo Region, S.M. Muratov, Kh.A. Abdivaitov, Sh.F. Rahmatillayev

Irrigation and Melioration

Water resources have become a very big problem in every part of Uzbekistan for several decades. Water is used not only exclusively for agricultural development, but also for many other purposes, such as industrial and chemical activities. Therefore, it is important to study the properties of surface water objects using optical and microwave satellite images. The Syrdarya region was selected for research. Because in the past, there have been no studies of water bodies using satellite images. The article presents the results of studies on the assessment of water properties from optical and microwave satellite images. In research for optical …

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Distribution Of Pressure And Specific Energy In The Twirled Stream For Confusor, A.A. Yangiev, D.S. Adjimuratov Oct 2020

Distribution Of Pressure And Specific Energy In The Twirled Stream For Confusor, A.A. Yangiev, D.S. Adjimuratov

Irrigation and Melioration

Article brings up the advantage of confusor part application in outflow part of vortex spillway, which may be more rational from the point of view of providing non-cavitation operation of flow swirler. Analytical design method and program developed is given of pressure and specific energy for aerated part of swirled flow in vortex spillway confusor part, which match with experimental results, it allows for fast and quite accurate realization of distribution analysis for pressure and specific energy in swirled flow along the length of the confusor for various rates of taper.

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Economic Assesment Of The Impact Of Climate Factors On Wheat Yield In Samarkand Region, Sh.B. Babakholov Oct 2020

Economic Assesment Of The Impact Of Climate Factors On Wheat Yield In Samarkand Region, Sh.B. Babakholov

Irrigation and Melioration

Agricultural production is highly vulnerable to climate shocks and predicted climate consequences may pose severe challenges to the resilience of Uzbek agricultural system, especially in terms of food security and income stability of rural producers. In this context, present study proposed to assess the impact of climate factors, such particular changes in mean temperature and rainfalls on total output of wheat-cultivating farmers in Samarkand region. By considering irrigation source and heterogeneous geography of the region, farmers engaged in wheat production were analyzed in two: upstream and downstream zones using Fixed effect panel approach. The empirical findings of study revealed that, …

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Change In Level Water In Pumping-Plant Intake, R.R. Ergashev, B.T. Xolbutayev Oct 2020

Change In Level Water In Pumping-Plant Intake, R.R. Ergashev, B.T. Xolbutayev

Irrigation and Melioration

A decrease in the water level in the pump chamber of the pumping stations leads to the formation of whirlpools in front of the suction pipes. As a result of air intake, the pump unit operates in cavitation mode and their intensive wear occurs. As the data obtained from the Karshi machine channel show, mainly a decrease in design water levels in the downstream waters is observed at the first pumping station. Depending on the number of simultaneously operating pumping units, the minimum water level in the head pumping station should be from 4.5 m to 5.7 m. The received …

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Modeling The Impact Of Changes In The Ground Water Level On The Stability Of Agricultural Landscapes Using Gis, A.M. Arifjanov, L.N. Samiev, F.K. Babajanov, G.M. Xamdamova, Sh.N. Yusupov Oct 2020

Modeling The Impact Of Changes In The Ground Water Level On The Stability Of Agricultural Landscapes Using Gis, A.M. Arifjanov, L.N. Samiev, F.K. Babajanov, G.M. Xamdamova, Sh.N. Yusupov

Irrigation and Melioration

The article presents modern GIS methods for determining the stability of changes in irrigated areas and the depth of the ground water level.the most correct solutions are given in modeling this process. To distinguish agricultural landscapes, the classification of agricultural acreage in the lower part of the Amu Darya river region was made using 16-day periodic rasters 2017 of 2018 and the NDIS MOD13Q1 sensor of agricultural acreage, type NDVI. The annual change in the level of underground water in relation to the state of rivers and channels is analyzed. A steady change in agricultural acreage on the right Bank …

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Determination And Assessment Of The Spatio-Temporal Changing Dynamics In The Groundwater Level And Mineralization In Irrigated Areas Under Climate Change (As An Example Of Syrdarya Province), S. Khasanov, S. Adilov, R. Kulmatov Oct 2020

Determination And Assessment Of The Spatio-Temporal Changing Dynamics In The Groundwater Level And Mineralization In Irrigated Areas Under Climate Change (As An Example Of Syrdarya Province), S. Khasanov, S. Adilov, R. Kulmatov

Irrigation and Melioration

In the irrigated lands of the Aral Sea Basin, salinization processes are taking place as a result of rising groundwater levels and increasing its mineralization due to the unsustainable use of water and land resources. This, in turn, leads to the withdrawing of arable land and a decrease in crop yields. This is especially the case in the irrigated areas of the lower reaches of the Amudarya and Syrdarya rivers, located in Uzbekistan, southern Kazakhstan, and Turkmenistan. This research was aimed to learn and evaluate the long-term changing behavior of groundwater level and mineralization in the irrigated areas of the …

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