Engineering Commons^™

Formation And Morphological Evolution Of Nanoporous Anodized Iron Oxide Films, Jin-Wei Cao, Nan Gao, Zhao-Qing Gao, Chen Wang, Sheng-Yan Shang, Yun-Peng Wang, Hai-Tao Ma

Journal of Electrochemistry

The preparation of iron oxide films with nanoporous structure by anodization has attracted much attention for its potential applications. However, the formation mechanism of porous structure during anodization is still unclear. In this paper, the composition of anodic current during the formation of nanoporous anodized iron oxide film was analyzed in combination with the current density-potential response (I-V curve) and the derivation of Faraday’s law. The results showed that the anodic current consisted of an ionic current (leading to the migration of ions to form oxide) and an electronic current (leading to the oxygen evolution), and the …

Photoelectrochemical Sensing Based On Zr-Mofs For Homocysteine Detection, Wen-Xia Dong, Guang-Ming Wen, Bin Liu, Zhong-Ping Li

Journal of Electrochemistry

Due to the independent form of the light source and detection system, photoelectrochemical (PEC) sensor has the advantages of low background, high sensitivity and simple operation. So far, PEC systems have been widely used in the fields including the actual detection of metal ions, biological antibodies or antigens in environmental pollutants. When the photosensitive material is irradiated by a light source with an energy being equal to or greater than its band gap, electrons (e^-) transition occurs from the valence band to the conduction band, leaving a hole (h⁺), at the same time, the generated electron-hole …

Functional Sulfate Electrolytes Enable The Enhanced Cycling Stability Of Nati2(Po4)3/C Anode Material For Aqueous Sodium-Ion Batteries, Shu-Jin Li, Zhi-Kang Cao, Wen-Kai Wang, Xiao-Han Zhang, Xing-De Xiang

Journal of Electrochemistry

Aqueous sodium-ion batteries show promising application in fields of large-scale storage of intermittent renewable energies owing to the earth-abundant sodium resources and incombustible aqueous electrolytes. Primary factors determining whether they can be commercially utilized are low cost and long lifetime. Among current electrode materials, NASICON-type NaTi₂(PO₄)₃ arouses wide interests as an anode material for aqueous sodium-ion batteries as it offers a high specific capacity, fast Na-transport ability and reasonable working potential, however, suffering from insufficient cycling performance caused by severe dissolution of active materials in traditional aqueous electrolytes. In this work, a functional sulfate electrolyte …

Effect Of Glycol Based Coolant Pollution On Pem Fuel Cells Stack And Recovery Measures, Cong-Yi Zhu, Xiao-Hui Li, Quan-Quan Gan

Journal of Electrochemistry

As the heat conduction medium of fuel cell cooling system, coolant is very important for the thermal management of fuel cell stack. In practical application, coolant leakage into the stack often occurs. Due to the randomness of fault location of components, the location of coolant leakage is uncertain, which may occur on the cathode side or anode side of some or all single cells. The main effects of coolant pollution on fuel cell stack are as follows: the output of open circuit voltage decreases sharply, the consistency of single cells voltage decreases and so on, which seriously affects the normal …

Structure Analysis Of Pemfc Cathode Catalyst Layer, Rui-Qing Wang, Sheng Sui

Journal of Electrochemistry

The sluggish oxygen reduction reaction (ORR) on the cathode of the proton exchange membrane fuel cell (PEMFC) has always been one of the key factors limiting its commercialization. The optimization of the cathode catalytic layer structure plays an important role in improving fuel cell performance and reducing production costs. In this paper, two different catalysts (platinum nanoparticles (Pt-NPs) and platinum nanowires (Pt-NWs)) were prepared by using catalyst coated substrate (CCS) method. By constructing a double-layer catalytic layer structure, we analyzed the effect of different catalytic layer structures by performing a single cell test. The results showed that the dense platinum …

Copper Nanoparticles In-Situ Anchored On Nitrogen-Doped Carbon For High-Efficiency Oxygen Reduction Reaction Electrocatalyst, Hui-Fang Yuan, Yue Zhang, Xing-Wu Zhai, Li-Bing Hu, Gui-Xian Ge, Gang Wang, Feng Yu, Bin Dai

Journal of Electrochemistry

Compared with noble metal platinum (Pt)-based catalysts, inexpensive non-noble metal electrocatalysts have attracted extensive attention for oxygen reduction reaction (ORR). Herein, chitosan as a kind of biomass resource rich in nitrogen and carbon was used to prepare nitrogen-doped carbon (N-C) and N-C in-situ anchored by copper nanoparticles (Cu/N-C). The as-obtained N-C and Cu/N-C nanoparticles were successfully used as non-noble eletrocatalysts tested for ORR. Compared with the N-C, the Cu/N-C showed the high surface area of 607.3 m ²·g^-1 with the mean pore size of 2.5 nm and the pore volume of 0.40 cm³·g^{-1 …}

Cyclic Voltammetric Simulations On Batteries With Porous Electrodes, Xue-Fan Cai, Sheng Sun

Journal of Electrochemistry

Lithium-ion batteries (LIBs) are among the most widely used energy storage devices. Whole-cell modeling and simulations of LIBs can optimize the design of batteries with lower costs and higher speeds. The Pseudo-Two-Dimensional (P2D) electrochemical model is among the most famous whole-cell models and widely applied in LIB simulations. P2D model consists of a series of kinetic equations to model Li⁺/Li diffusion in working/counter electrodes and electrolytes, which are filled in the porous electrodes and separator, and reactions at the interface of electrolyte and active particles. The traditional applications of P2D model, however, are limited to the cases where …

Effect Of Aluminum Alloy Surface Modification On Adhesion Of The Modified Polyurethane Coating And Its Corrosion Protective Performance, Xian-Yin Kuang, Shao-Qiang Jin, Yan-Hui Cao, Yan-Mei Zhang, Shi-Gang Dong, Long-Hui Zhu, Li-Wen Lin, Chang-Jian Lin

Journal of Electrochemistry

The ordinary organic coatings on aluminum alloy usually encounter a problem of low adhesion to the substrate, which results in destruction and failure of the long-term protective performance of the anticorrosion systems. The surface modification of aluminum alloy is able to enhance the adhesion of organic coating on aluminum alloys, and to improve their protective performance. In this work, a combined surface modification of anodic oxidation and mussel adhesion protein/CeO₂/3-aminopropyltriethoxysilane composite film (MCA) was developed on the aluminum alloy. The adhesion of modified polyurethane coated on the treated aluminum alloy and its corrosion protective performance were evaluated comprehensively …

Solution-Processed Flexible Broadband Zno Photodetector Modified By Ag Nanoparticles, N. P. Klochko, K. S. Klepikova, I. V. Khrypunova, V. R. Kopach, I. I. Tyukhov, S. I. Petrushenko, S. V. Dukarov, V. M. Sukhov, M. V. Kirichenko, A. L. Khrypunova

Faculty Research, Scholarly, and Creative Activity

In this work, we present flexible broadband photodetectors (PDs) fabricated by a deposition of nanostructured zinc oxide (ZnO) films on polyimide (PI) substrates by using cheap and scalable aqueous method Successive Ionic Layer Adsorption and Reaction (SILAR). In order to increase the long-wavelength absorption of the nanostructured ZnO layer, we created its intrinsic defects, including oxygen vacancies by post-treatment at 300 °C in vacuum and thus the light-sensitive material ZnO/PI was obtained. Then we applied silver nanoparticles (Ag NPs) from a silver sol onto a nanostructured ZnO film, which were visualized using SEM in the form of spheres up to …

Mathematical Model Of The Efficiency Of Investments Aimed In The Implementation Of Water-Saving Technologies

Irrigation and Melioration

In Uzbekistan, research work is being carried out aimed at improving the economic mechanisms for the introduction of water-saving technologies for irrigating agricultural crops. At the same time, the issues related to the analysis of the effectiveness of the use of water-saving technologies when irrigating cotton, the development of mathematical methods for assessing the effectiveness of investments, as well as their introduction into practice have not been sufficiently studied. This article provides a mathematical model of the efficiency of investments aimed at introducing water-saving technologies. The results of a numerical experiment of a mathematical model show that the introduction of …

Efficient Use Of Water Resources In The Basins Of Small Rivers, F. Gapparov, M.F. Gafforova

Irrigation and Melioration

The article provides a recommendation for the efficient use of water resources in the basins of small foothill rivers. The research was carried out on the example of the Govasay river basin located in the northern part of the Fergana Valley. The efficiency factor of the canal has been determined and a technical assessment has been given for the management of water resources in the river basin; the efficiency of the canal is 65-75%. A program for the operational management of water resources in The Govasay river basin and a GIS map of water consumers in the Govasay river basin …

Model Of Groundwater Level Control Using Horizontal Drainage, A. Arifjanov, M. Otaxonov, Z. Abdulkhaev

Irrigation and Melioration

The article describes the main factors affecting the rise in the level of groundwater in the city of Fergana and ways to eliminate them. Currently, in order to reduce the negative impact of rising groundwater levels on the environment, crops, buildings and structures, as well as underground utilities, it is proposed to design horizontal drainage in urban areas and a mathematical model has been developed for changing the groundwater level. For this, long-term data from observation wells were analyzed and the hydraulic parameters of horizontal drainage were selected taking into account the hydrogeology of the area. Taking into account the …

Results Of Proximate Analysis Of Energy Use Of Municipal Solid Waste, N.N. Abduganiev

Irrigation and Melioration

In the modern industrialized world, various raw materials are processed and used for human consumption. While some of the raw materials are converted into the desired product, the rest is thrown into the environment as waste. It is known that solid waste is a type of biomass that is formed in the course of human life. The article presents the results of a preliminary analysis of studies on the use of solid waste energy in the Urta-Chirchik district of the Tashkent region. Sorting results showed that the total volume of municipal solid waste in the district consists mainly of wood …

Shredding Of Cotton Stalks Under The Action Of Toothpicks In A Combined Unit, B. Khudayarov, U. Kuziev, B. Sarimsakov, М. Kholbutaev

Irrigation and Melioration

The article presents materials devoted to the justification of the parameters of the crown-wheel of the combined aggreagate. The technological process of work and the design of the working part, which is crushed by crushing cotton stalks, without breaking them, laying them on the movement of the unit, has been substantiated and developed. The optimal parameters of the crown-wheel and the tooth are determined by solving the regression equations that determine the optimal values of the vertical load on the teeth and its working quality. The results of theoretical and experimental research show that the amount of crushing of cotton …

Influence Of Electrophysical Methods On The Processes Of Root Formation Of Grapes, N.M. Markayev

Irrigation and Melioration

The article describes the possibilities of electrophysical processing before planting cuttings during vegetative cultivation of grape seedlings. The processes of root formation in cuttings using the electrophysical method in the article Acceleration of the process of root formation in cuttings of black raisins, treated at 71 V/m and an electric field strength of 15 hours, and an increase in the viability, quality, growth and survival of rooted seedlings up to 16.67-34% Presented the results of experiments on the increase and methods of electrotechnological processing of grape cuttings. The result of the study is the analysis and results of the processes …

Conditions, Criteria And Principles For Creating An Agri-Cultural Land Market In Uzbekistan, A.R. Nurnazarov

Irrigation and Melioration

The article analyzes the prerequisites for creating a market for agricultural land in the Republic of Uzbekistan, special attention is paid to land reform, land degradation (reduction of the bonitet score from 60 in 1991 to 50 or more at present, pasture degradation by 20-30%) and increase in economic from their use, the role of land rent in payments for land. 6 basic principles for creating a land market have been established and systematized, the relationship between X-rays and water in the irrigated farming zone, the role of the market in increasing the efficiency and effectiveness of the use of …

Economic Assessment Of The Effect Of Family Income On Students' Disciplines, Sh.A. Muratov

Irrigation and Melioration

The importance of higher education in scientific research, its role in poverty reduction and population growth has been studied theoretically. Also, when using the data of social surveys conducted by 538 respondents (students) studying in higher education institutions, they were awarded the Order of the logistics regulator in the economic assessment of the factors influencing the rate of mastery of disciplines. Factors influencing the acquisition of subjects by students: the main income of the family comes from non-farm (69,9 %), sex (52,2 %), studying at a higher education institution on a state grant (108,8 %), the student's course of study …

Innovative Rotor Casing And Leveling Apron For Combined Tillage Machine, A.A. Akhmetov, L.B. Muratov

Irrigation and Melioration

Investigations of the design of a combined machine equipped with an innovative casing and a leveler apron are presented, and the parameters of the leveler apron are substantiated. It was experimentally established that when the height of the drawing prism is exceeded by more than 200 mm, due to the falling of the crumbling part of the soil onto the rotor, the soil is thrown forward in the direction of the machine. Therefore, to eliminate soil waste, it is necessary either to reduce the height of the drag prism, or to increase the distance between the rotor and the leveling …

Ensuring The Uniformity Of Movement Of The Working Bodies Of The Machine For Processing Ridges In The Depth Of Travel, А. Tukhtakuziev, K.G. Abdulkhaev

Irrigation and Melioration

The article theoretically investigates the issue of identifying ways to ensure the deepening of the working bodies of the machine for processing ridges to a given processing depth and its required uniformity of stroke. The research results show that the deepening of the working bodies of the ridges processing machine to a given processing depth and its required uniformity is provided mainly due to the correct choice of the vertical distance from its reference plane to the lower connection points. The novelty of the conducted research lies in the fact that an analytical dependence has been obtained that allows us …

Develepment Of Land Market In Eastern European Countries And Experience For Uzbekistan, A.R. Nurnazarov

Irrigation and Melioration

The article examines the experience of the formation of the agricultural land market in Eastern European countries since the 90 s of the twentieth century, the problems and features of its devel-opment, the impact of the land market on the economies of countries. Particular attention is paid to the transformation of land ownership, methods of land privatization, land pricing, restrictions on land purchase, regulation of land relations in market conditions, issues of granting the right to pur-chase land to foreign individuals and legal entities, requirements for land owners for the presence of a special agricultural education or 3-5 years of …

The Developmet Of Competences Via Techniques For Enhancing Esp (English For Specific Purposes) Vocabulary Of Learners, G. Eshchanova

Irrigation and Melioration

In the article a recent trend in higher education is ESP (English for Specific Purposes) courses is discussed. These courses are designed around students’ needs based on their field of study. The goal is to strengthen students’ proficiency and help them to get ready to cope with everyday situations and deal with professionals in many fields such as: engineering, medicine, education and IT. There are many training sessions organized by international experts whose goal is to train local teachers to teach these courses successfully. In order to develop an ability to learn new vocabulary, for both general English and technical …

Development Of Girls’ Sports, A.R. Khodjanov, V.V. Mahmudov

Irrigation and Melioration

The article addresses current issues of higher education, taking into account its specifics. She has been providing appropriate advice on improving girls' physical well-being. The use of opportunities and qualities has an impact on the creation of comfortable conditions for female athletes. For girls involved in sports, the creation of impressive quality and possible conditions is considered. As a result, the girls-athletes of our institute took 2-3 places in the district and city qualifying rounds of chess, table tennis and won a ticket to the republican stage. At the republican stage, 2 female students of our team took 4th place …

The Imrovement Of Esp Teaching Via Methodical Provision At Technical Institution: Specializm-Oriented English Via Agriculture, G. Eshchanova, U. Nullaev

Irrigation and Melioration

In the given article the ways that ESP combines subject matter and English language teaching is discussed. This approach can be highly motivating for students because students are able to apply what they learn in their English classes to their main field of study, whether it be law, computing, business, tourism, etc. Being able to use the vocabulary and structures that they learn in a meaningful context reinforces what is taught and increases their motivation. Nevertheless, ESP concentrates more on language in context than on teaching grammar and language structures. Additionally, the ways of teaching English in ESL classes and …

Study Of The Thermodynamic Properties Absorbation Sulfur Storage Gas Of Zinc And Copper Industry, Berdiyarov Tilovkabulovich Berdiyarov Dr., Sh. T. Khojiev, S. T. Matkarimov, Sh. Munosibov

Technical science and innovation

The article considers the problems of utilization of industrial gases formed in the production of copper and ore containing sulfur anhydrides. Currently, the composition of process gases entering the gas purification department is approximately 6-7% SO₂, 0.2-0.3% SO₃ and other gases, until sulfuric acid is obtained from these gases, the sulfate is treated in a counter-scheme with 8% sulfate acid. The aim is to first reduce the temperature of the exhaust gases and second to avoid flying components such as as As, F, Se. As a result of the studies, the amount of SO₂ in the …

Rapid Ac Electrokinetic Micromixer With Electrically Conductive Sidewalls, Fang Yang, Wei Zhao, Cuifang Kuang, Guiren Wang

Faculty Publications

We report a quasi T-channel electrokinetics-based micromixer with electrically conductive sidewalls, where the electric field is in the transverse direction of the flow and parallel to the conductivity gradient at the interface between two fluids to be mixed. Mixing results are first compared with another widely studied micromixer configuration, where electrodes are located at the inlet and outlet of the channel with electric field parallel to bulk flow direction but orthogonal to the conductivity gradient at the interface between the two fluids to be mixed. Faster mixing is achieved in the micromixer with conductive sidewalls. Effects of Re numbers, applied …

The History Of The Tectonic Development Of The South-Eastern Part Of The Turan Plate And The Beshkent-Kashkadarya Foothill Depression Of The Modern Tien Shan, Azamjon Zakirov, Ravshan Zakirov, Irmuxamat Khalismatov, Zakirova Feruzaxon, Borshov Victor

Technical science and innovation

The article examines the history of the tectonic development of the southeastern part of the Turan Plate and the Beshkent-Kashkadarya foothill depression, which have been studied and discussed by many researchers. The history of the tectonic development of the research area is relatively complete since the Pre-Jurassic deposits. The pre-Jurassic deposits on the territory of the Amu Darya syneclise are confined mainly to the Khiva and Zaunguz grabens, delimited by the Central Amu Darya ridge.

At the end of the Oligocene, tectonic activity increased sharply within the Turanian Plate, which included the research area. It flowed more intensively both from …

Imitation Models Of The Railway Organization For Railway Transport Flows, J Usmonov, T Djuraev

Technical science and innovation

Considered the questions of solving the problem of optimization of cargo traffic management in the railway transport throughout the logistics chain, organizing the formation and implementation of cargo loading plans that do not allow exceeding the maximum and reduce the minimum levels of availability of a particular cargo on the destination road. And also the article justifies the solution of the problem of finding the maximum flow in the railway network, it is noted that in any transport network the maximum flow is equal to the minimum capacity. If the flow is maximal, then there is a section whose transmission …

Evaluation Of The Thickness Of Vacuum Metal And Semiconductor Coatings Using Computer Programs, Bahrom Igamov, Ilkhom Bekpulatov, Aleksey Kamardin, Tulkun Kamilov, Ilhom Turapov, D Igamova

Technical science and innovation

Comparative studies of the thickness of coatings of such metals as Cu, Ag, Cr, Co, and also Mn4 Si7 on polished substrates made of Si, Si O2 / Si structure, ST - 50 glass ceramic, mica were carried out. The coatings were deposited in vacuum using thermal evaporation and magnetron sputtering. The thickness and uniformity of deposited coatings on rotating substrates are estimated by optical measurements and computer simulation. Mathematical models for the formation of coatings on flat substrates have been developed. The possibility of the optimal position of the substrate for the formation of functional coatings uniform in thickness …

Development Of Asphalt-Resin-Paraffin Deposits Solvent, Gulmira Todjiyeva, F Badriddinova, M Tursunov, H Kadirov, E Cherkasova

Technical science and innovation

A solvent which is a mixture of aromatic hydrocarbons of the C₉ fraction and aliphatic alcohols in a 1:1 ratio, a nonionic surfactant in an amount of 1 - 3% by weight has been developed. It leads to an increase in the dissolving and washing capabilities of the solvent for more than 2 times in relation to paraffin-type AS. The ability of the chemical composition, which is a solvent composition, to have a depressant-dispersing effect in relation to paraffin-type AS has been determined.

Despite a large number of studies devoted to the development of technologies for the removal of …

Research Of New Fireproof Supplied Polymer Composites Based On Epoxy Resin For Metal Structures, Kuvondiq Murtazaev, F.N. Nurkulov, D.N. Mukhiddinov, M.T. Аbdirova

Technical science and innovation

In the article proposes new compositions based on fire retardant expanded polymer composites of epoxy resin ED-20 and phosphorus-containing oligomers, catalysts, aluminum hydroxide and nitrogen-containing compounds.

The obtained sample of fire retardant expanded polymer composites based on epoxy resin, as well as the initial substances, were investigated by IR spectroscopy (Nicolet 5700), thermogravimetric analysis (TG) (SDT Q600) of physical and chemical properties and determination of fire retardant efficiency according to GOST R 53295-2009.

Infrared spectroscopy has been used to determine the bends and epoxy groups that characterize composites, as well as to determine the frequencies of phosphorus, nitrogen, and metal-containing …