Engineering Science and Materials Commons^™

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.

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 …

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 …

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.

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, …

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 …

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 …

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 …

Increasing The Efficiency Of Water Distribution Management When Operating Pumping Stations Of The Irrigation System, O.Y. Glovatsky, R.R. Ergashev, B. Hamdamov, N.M. Ismailov, B.T. Kholbutaev

Irrigation and Melioration

The article is to control the parameters of the unsteady movement of water in the canals and the pumping station, which ensure the maintenance of the specified operating modes of the pumping stations under non-stationary conditions. To achieve this goal, it is necessary to solve the problems of coordinating the operating modes of the units of the head pumping station (PS) with the operating modes of the partitioning structures in the conditions of emptying and filling the ponds of the main canal with water. The article discusses the implementation of the method of water distribution control on the mathematical model …

Analysis Of Theoretical And Natural Field Studies Of Reservoir Silling, A.M. Arifjanov, F. Gapparov, T.U. Apakhujayeva, S.N. Xoshimov

Irrigation and Melioration

The article developed a mathematical model of the processes of siltation of reservoirs, taking into account the energy state of the flow, and proposed a calculation method. In the process of siltation of the reservoir, the dependence of the volume on the change in the water level in the reservoir was estimated. On the basis of studies carried out in full-scale field conditions, the recommended calculation method is comparatively evaluated and analyzed. Field studies were carried out in the Chimkurgan, Tashkent and Yuzhno-Surkhan reservoirs. A relationship is obtained that expresses the dependence of the relative volume of siltation of the …

Planed Dimension Of Flow Deformed By A Single Dam That Is Impermeable To Water From The Body, M.R. Bakiev, K.T. Yakubov, I.J. Asamatdinov

Irrigation and Melioration

Coastal erosion is a type of water erosion that causes significant damage to the national economy each year: leaching of overland coastal crops, failure of protective dams, destruction of irrigation canals, dilapidated buildings and structures, among others. To combat leaching, cross-dams are used which are waterproof and water-permeable. The aim of this work was to develop a method for calculating the planned dimension of compressed flow with a transverse dam, which included comparing the lengths of the upper and lower tilt zones, the boundaries of individual zones and the results of research in the laboratory and in nature. According to …

Research Of Energy Indicators Of Electric Drives With Frequency Converters (Frequency Converters) On The Operating Equipment Of Cotton Cleaning Plants, A.J. Isakov, B.K. Tukhtamishev, J.N. Tolipov

Irrigation and Melioration

The article deals with the theoretical and practical substantiation of the replacement of an unregulated electric drive of the main technological equipment of cotton refineries with a frequency-controlled electric drive. The influence of a change in the load on the motor shaft on the main parameters of the steady state is considered. In an asynchronous motor, with an increase in the load, slip increases to such a value at which the torque of the motor balances the increased moment of resistance. Considering that when the stator slip resistance is less than the critical one is a small fraction of the …

Stabilization Of Discharge Processes Involved In Electrical Fields Of Electrostatic Precipitators, Sh.M. Muzafarov, B.N. Erkinov, A.I. Pardaev, V.E. Baliskiy, B.К. Tаgaev

Irrigation and Melioration

The article provides information on achievements in the field of electrical gas cleaning. A critical analysis of the principle of operation of the electrostatic precipitators developed and currently in operation is carried out. The possibility of increasing the efficiency of electrical gas cleaning using unipolar voltage pulses is analyzed. A theoretical analysis of the processes in the discharge gap was carried out using the existing theory of electric discharges in gases. Based on the analysis of the data, the discharge mechanism is established in a sharply inhomogeneous electric field at a pulsed voltage. It is established that when using voltage …

Determination Of The Rational Values Of The Parameters Of The Disc Rollers Of The Combined Unit, A.K. Igamberdiev, D.K. Muqimova

Irrigation and Melioration

In our country, repeated crops are sown in newly plowed lands. In such conditions, the use of combined units that perform several technological operations simultaneously in one pass is considered effective. However, due to the inadequacy and validity of the parameters of the working bodies for the quality of pre-sowing tillage in newly plowed lands, there is an increase in the number of passes, fuel consumption, loss of soil moisture and other costs and, as a result, the possibility of timely sowing and friendly germination of repeated crops is reduced . The rational parameters of the new design of disk …

Autonomous Photovoltaic System For Year-Round Guarantee Supply Of Electricity To Rural Facilities, M.N. Tursunov, Х. Sabirov, U.R. Kholov, Т.Z. Аkhtamov

Irrigation and Melioration

The article discusses the physical and technical features of the experimental results of studying the parameters of an autonomous photovoltaic station (AFES) with a power of 2600 W designed and manufactured on the basis of 16 photovoltaic batteries made of polycrystalline silicon with an efficiency of 15.6 %. It is shown that an autonomous photovoltaic efficiently and reliably provides electric energy a lighting system for car parking in the winter season (January and February) and it is planned to lift water from a well with a depth of 70-80 m for irrigation and maintenance of the Heliopoligon from April 2020. …

Resource-Saving Technologies For The Production Of Elastic Leather Materials: Collective Monograph, Olena Korotych, Anatolii Danylkovych, Serhii Bilinskyi, Serhii Bondarenko, Slava Branovitska, Vasyl Chervinskyi, Nataliia Khliebnikova, Alona Kudzieva, Viktor Lishchuk, Nataliia Lysenko, Olena Mokrousova, Nataliia Omelchenko, Vera Palamar, Yuliia Potakh, Oksana Romanyuk, Olga Sanginova, Oleksandr Zhyhotsky

Chemistry Publications and Other Works

This monograph contains a collection of recent research papers focusing on advancing existing technologies and developing new technologies to improve the environmentally friendliness and save resources during the production of elastic leather materials. The papers are organized based on the type of technological process used to preserve raw hides. A lot of attention is devoted to mathematical planning, simulations, and multicriteria optimization of the technological processes using newly developed chemical reagents. The monograph contains a complex study of physicochemical properties and characteristics of the resulting leather materials. The developed technologies were tested by the private joint-stock company Chinbar (Kyiv, Ukraine) …

The Concept Of The Mathematical Description Of The Multi-Coordinate Mechatronic Module Of The Robot, Temurbek Omonboyevich Rakhimov

Acta of Turin Polytechnic University in Tashkent

The article deals with the concept of mathematical de- scription of multi-coordinate mahatronic modules of robots. The main results of the work are a generalized structure of a multi- coordinate mechatronic module of motion, a kinematic diagram of an electromagnetic multi-coordinate mechatronic module with three independent coordinate linear and angular movements is proposed, consisting of four electromagnets, controlled couplings designed to transmit the reciprocating motion of the moving parts of electro- magnets to the output rods and a cable, which are associated with the links of work and bringing them into linear and angular mo- tion. A simulation model of …

Measurement And Modeling Of Micro Residual Stresses In Pure Zirconium And Zr-2.5nb Polycrystals, Abdulla Alawadi

Electronic Thesis and Dissertation Repository

In CANada Deterium Uranium (CANDU) nuclear reactors, Zr-2.5Nb alloy pressure tubes separate the hot water and cold moderator. Pressure tubes are susceptible to the diffusion of hydrogen from water and formation of a brittle phase called zirconium hydrides. The diffusion and formation of hydrides are affected by the state of stresses within the tubes. As such, it is of great significance to understand the source of the stresses that develop within the tubes. This thesis focuses on the characterization of the micro and nano scale residual stresses that develop in pure zirconium and Zr-2.5Nb polycrystals. With using three-dimensional synchrotron X-ray …

An Affordable And Portable Palpable System For Sensing Breast Tissue Abnormalities, Cody J. Clarke

Montview Journal of Research & Scholarship

Due to the high cost of equipment and lack of trained personnel, manual palpation is a preferred alternative breast examination technique over mammography. The process involves a thorough search pattern using trained fingers and applying adequate pressure, with the objective of identifying solid masses from the surrounding breast tissue. However, palpation requires skills that must be obtained through adequate training in order to ensure proper diagnosis. Consequently, palpation performance and reporting techniques have been inconsistent. Automating the palpation technique would optimize the performance of self-breast examination, optimize clinical breast examinations (CBE), and enable the visualization of breast abnormalities as well …

Me-Em 2019-20 Annual Report, Department Of Mechanical Engineering-Engineering Mechanics, Michigan Technological University

Department of Mechanical Engineering-Engineering Mechanics Annual Reports

Table of Contents

• Element 1
• Element 2
• Element 3
• Element 4
• Enrollment & Degrees
• Graduates
• Department
• Alumni
• Donors

Effect Of Motor-Assisted Elliptical Training Speed And Body Weight Support On Center Of Pressure Movement Variability, Farahnaz Fallahtafti, Chase M. Pfeifer, Thad W. Buster, Judith M. Burnfield

Department of Mechanical and Materials Engineering: Faculty Publications

Background: A motor-assisted elliptical trainer is being used clinically to help individuals with physical disabilities regain and/or retain walking ability and cardiorespiratory fitness. Unknown is how the device’s training parameters can be used to optimize movement variability and regularity. This study examined the effect of motor-assisted elliptical training speed as well as body weight support (BWS) on center of pressure (CoP) movement variability and regularity during training. Methods: CoP was recorded using in-shoe pressure insoles as participants motor-assisted elliptical trained at three speeds (20, 40, and 60 cycles per minute) each performed at four BWS levels (0%, 20%, 40%, and …

Me-Em Enewsbrief, September 2020, Department Of Mechanical Engineering-Engineering Mechanics, Michigan Technological University

Department of Mechanical Engineering-Engineering Mechanics eNewsBrief

No abstract provided.

Electrochemical Carbon Dioxide Reduction In Flow Cells, Jia Fan, Na Han, Yan-Guang Li

Journal of Electrochemistry

Electrochemical carbon dioxide reduction (CO₂RR) is an appealing approach to convert atmospheric CO₂ to value-added fuels and industrial chemicals, and may play an important role during the transition to a carbon-neutral economy. In order to make this technology commercially viable, it is essential to pursue CO₂RR in flow reactors instead of conventional H-type reactors, and to combine electrocatalyst development with system engineering. In this review, we overview the cell configurations and performance advantages of the two types of flow reactors, analyze their shortcomings, and discuss the effects of their different components including gas diffusion electrode …

Recent Progress On Enhancing Effect Of Nanosized Metals For Electrochemical Co2 Reduction, Yu-Ning Zhang, Dong-Fang Niu, Shuo-Zhen Hu, Xin-Sheng Zhang

Journal of Electrochemistry

The electrochemical conversion of CO₂ to chemical raw material for further utilization shows promising future to alleviate global warming and realize carbon cycle in nature, which is of great significance to the green chemistry and sustainable development. This review briefly introduces the advantages of CO₂ electrochemical reduction (CO₂ER) and its basic reaction principles, and summarizes the recent progress in a series of activity enhancement strategies based on nanosized metal catalysts. The influences of alloy effect, interface engineering, synergistic effect, surface defect engineering and support effect on the catalytic performance of nanosized metals for CO₂ER …

Recent Progress In Bifunctional Catalysts For Zinc-Air Batteries, Neng-Neng Xu, Jin-Li Qiao

Journal of Electrochemistry

Zinc-air battery has attracted great attention from researchers due to its high energy density and power density, which is expected to be widely used in energy conversion and storage. Air electrode as the core area of oxygen catalytic reaction is the focus of the entire zinc-air battery research. Recently, many research achievements have been made in non-noble metal bifunctional catalysts/electrodes with high activity, low cost and abundant species. In this review, we mainly focus on the reaction mechanism and the recent progress in non-noble metal oxide catalyst, carbon-based catalyst, and carbon-based transition metal compound composite and self-supporting electrode. In addition, …

Electrochemical Energy Storage And Conversion Based On Organic Electrodes, Jian-Hang Huang, Xiao-Li Dong, Zhao-Wei Guo, Yuan-Yuan Ma, Yan-Rong Wang, Yong-Gang Wang

Journal of Electrochemistry

Aqueous batteries have been considered to be a competitive candidate for large-scale energy storage. However, most of aqueous batteries adopt inorganic electrode materials with metallic elements, which are based on the reversible insertion of metal ions, making their application being highly hindered by limited cycle life, environmental issue, high cost and low reserves. On the other hand, organic electrode materials offer the advantages of abundant reserves, tunable structures, renewability and environmental benignity. Furthermore, the wide internal space enables these organics to flexibly store various charge carriers. Organics have been investigated as the alternative to inorganic electrode materials. Herein, we review …

Research Progress Of Metal-Nitrogen-Carbon Catalysts Toward Oxygen Reduction Reaction Inm Changchun Institute Of Applied Chemistry, Ming-Jun Xu, Jie Liu, Jun-Jie Ge, Chang-Peng Liu, Wei Xing

Journal of Electrochemistry

The development of highly active and stable catalysts toward oxygen reduction reaction (ORR) has been facing severe challenges. In recent years, pyrolytic M-N-C catalysts and metal-organic framework derived materials made the performance of non-noble metal catalysts greatly improved, however, the molecular and atomic level understanding in the reaction active sites and the mechanism are still lacking. Here, we summarize the recent research progress made in the Changchun Institute of Applied Chemistry. We present a microporous metal-organic-framework confined strategy toward the preferable formation of ORR catalysts. Firstly, we studied the active site and proposed a new active site structure for the …

Electrolyte Tailoring For Electrocatalytic Reduction Of Stable Molecules, Jin-Han Li, Fang-Yi Cheng

Journal of Electrochemistry

Reduction of stable molecules such as CO₂ and N₂ is important process in electrochemical energy conversion and storage technologies for electrofuels production. However, for the inert nature of CO₂/N₂ molecule and competitive proton reduction in conventional aqueous electrolytes, selective electrochemical carbon/nitrogen fixation suffers from high overpotential, low reaction rate and low selectivity. While addressing these issues has witnessed substantial advances in electrocatalysts, much less attention has been placed on the electrolytes, which play an important role in regulating the local environment and thus the performance of catalysts under operating conditions. Rational design of electrolytes has …

Fuel Cell Performance Of Non-Precious Metal Based Electrocatalysts, Yan-Feng Zhang, Fei Xiao, Guang-Yu Chen, Min-Hua Shao

Journal of Electrochemistry

The commercialization of proton exchange membrane fuel cells (PEMFCs) is hindered by high cost and low durability of Pt based electrocatalysts. Developing efficient and durable non-precious metal catalysts is a promising approach to addressing these conundrums. Among them, transition metals dispersed in a nitrogen (N)-doped carbon support (M-N-C) show good oxygen reduction reaction activity. This article reviews recent progress in M-N-C catalysts development, focusing on the catalysts design, membrane electrode assembly fabrication, fuel cell performance, and durability testing. Template-assisted approach is an efficient way to synthesize M-N-C materials with homogeneously dispersed single atom active site and reduced metal particles, carbides …

Design And Development Of Strong And Ductile Single Bcc Refractory High-Entropy Alloys For High-Temperature Applications, Chanho Lee

Doctoral Dissertations

The objectives of this proposed study are to (1) design and develop single BCC phase refractory high-entropy alloys (HEAs) for the high-temperature applications, (2) investigate the deformation mechanisms of refractory HEAs, (3) improve an integrated approach, coupling focused experiments and theoretical modeling, to design, discover, and develop HEAs, and (4) understand the alloy design-microstructure-property-performance links underlying the mechanical behavior of refractory HEA systems for gas-turbine applications

A traditional alloy system generally includes one or two principal elements that form the matrix with other additional elements, e.g., iron or aluminum alloys, to strengthen some specific properties, such as strength and corrosion …