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Articles 2041 - 2070 of 5711

Full-Text Articles in Engineering

Hybrid Non-Destructive Assessment For Flow Induced Vibration Piping Systems Using Coupled Fluid-Structure Interaction, Keen Kuan Kong Apr 2020

Hybrid Non-Destructive Assessment For Flow Induced Vibration Piping Systems Using Coupled Fluid-Structure Interaction, Keen Kuan Kong

Student Works (2020-2029)

Pipelines and piping systems are of great importance in many industries such as water supply, petroleum and petrochemicals and nuclear power generation. They provide transport for high-velocity pressurized fluids operating under time-varying conditions. They are required to operate non-stop for a schedule of 24 hours a day, 7 days a week. Piping vibration failures have been one of the major causes of downtime, fires and explosions in industrial plant over the past 30 years. Failure of piping systems can have disastrous effects, leading to injuries and fatalities as well as to substantial cost to industry and the environment. Flow-induced vibration …


Modeling Nonlinear Heat Transfer For A Pin-On-Disc Sliding System, Brian A. Boardman Mar 2020

Modeling Nonlinear Heat Transfer For A Pin-On-Disc Sliding System, Brian A. Boardman

Theses and Dissertations

The objective of this research is to develop a numerical method to characterize heat transfer and wear rates for samples of Vascomax® 300, or Maraging 300, steel. A pin-on-disc experiment was conducted in which samples were exposed to a high-pressure, high-speed, sliding contact environment. This sliding contact generates frictional heating that influences the temperature distribution and wear characteristics of the test samples. A two-dimensional nonlinear heat transfer equation is discretized and solved via a second-order explicit finite difference scheme to predict the transient temperature distribution of the pin. This schematic is used to predict the removal of material from the …


Focused Beam System Biaxial Material Characterization, Nicholas A. O'Gorman Mar 2020

Focused Beam System Biaxial Material Characterization, Nicholas A. O'Gorman

Theses and Dissertations

Electromagnetic material characterization is the process of determining the constitutive parameters (complex permittivity and permeability) of given a sample. Due to the large number of unknowns involved, multiple unique measurements are required for material property extraction. Many measurement methods, such as waveguides and striplines, possess a rigid internal structure that the sample being measured must adhere to. This rigidity limits these methods to samples that fit within the device and inhibits oblique sample orientations, limiting the number of independent measurements that can be obtained. A focus beam system, due to being an open system with greater freedom in sample size …


A Wirelessly Controlled Smart Bandage With 3d-Printed Miniaturized Needle Arrays, Hossein Derakhshandeh, Fariba Aghabaglou, Alec Mccarthy, Azadeh Mostafavi, Chris Wiseman, Zack Bonick, Ian Ghanavati, Seth Harris, Craig Kreikemeier-Bower, Seyed Masoud Moosavi Basri, Jordan Rosenbohm, Ruiguo Yang, Pooria Mostafalu, Dennis Orgill, Ali Tamayol Mar 2020

A Wirelessly Controlled Smart Bandage With 3d-Printed Miniaturized Needle Arrays, Hossein Derakhshandeh, Fariba Aghabaglou, Alec Mccarthy, Azadeh Mostafavi, Chris Wiseman, Zack Bonick, Ian Ghanavati, Seth Harris, Craig Kreikemeier-Bower, Seyed Masoud Moosavi Basri, Jordan Rosenbohm, Ruiguo Yang, Pooria Mostafalu, Dennis Orgill, Ali Tamayol

Department of Mechanical and Materials Engineering: Faculty Publications

PUBLIC ACCESS


Results Of Improvement Of The Technological Process Of Sorting Of Draged Seeds, R.K. Djamolov, E.T. Maksudov, K. Djamolov Mar 2020

Results Of Improvement Of The Technological Process Of Sorting Of Draged Seeds, R.K. Djamolov, E.T. Maksudov, K. Djamolov

Irrigation and Melioration

The article presents the results of experiments conducted to justify the parameters of the seed selection unit to improve the process of sorting seeds. The experiments were carried out by changing the angle of inclination of the seed tray to the horizontal plane from α = 390 to α = 540 and the radius of the lower part of the tray in the aisle R = 140-180 mm. The experimental results show that the bottom of the tray, made in the form of a semicircle, allows the seeds to move up the pipe when the seeds fall from the tray …


A Novel Self-Healing System: Towards A Sustainable Porous Asphalt, Shi Xu, Xueyan Liu, Amir Tabakovic, Erik Schlangen Mar 2020

A Novel Self-Healing System: Towards A Sustainable Porous Asphalt, Shi Xu, Xueyan Liu, Amir Tabakovic, Erik Schlangen

Articles

Self-healing asphalt, aimed to produce a sustainable asphalt pavement using green technology, has been studied in the past two decades. Technologies including encapsulated rejuvenator and induction heating have been proposed, demonstrated in the laboratory, and gradually evaluated in field application. This paper looks into the synergy effect of the above two technologies, where induction heating serves as the asphalt damage repair mechanism, requiring just 2 min heating time and encapsulated rejuvenator will replenish (rejuvenate) aged asphalt binder and reinstate bitumen’s healing ability. Moreover, the increased temperature from induction heating could in turn accelerate the diffusion process of rejuvenator into aged …


Energy Saving Issues In Pumping Units, A.I. Anarbaev, D.B. Kodirov, R.A. Zakhidov, B. Usmanov Mar 2020

Energy Saving Issues In Pumping Units, A.I. Anarbaev, D.B. Kodirov, R.A. Zakhidov, B. Usmanov

Irrigation and Melioration

The article presents the issues of energy saving, which are becoming increasingly relevant due to the constant increase in tariffs and the introduction of the demands on energy efficiency and energy conversation. To save energy at pumping units, the characteristics of controlling the electric drive of pumping stations with frequency-controlled control are considered. For adequate adjustment by the technological process of water movement and power supply, corresponding analytical dependencies are obtained. An analysis of the physical expressions of water pumping processes allowed us to determine energy-saving modes of operation and technologies for improving the efficiency of equipment.


Importance Of Creating A System Of Land And Cadastral Data For Subjects Of Agriculture, К. Rakhmonov, M.O. Abdurakhimova Mar 2020

Importance Of Creating A System Of Land And Cadastral Data For Subjects Of Agriculture, К. Rakhmonov, M.O. Abdurakhimova

Irrigation and Melioration

A separate model and model were developed for compiling cadastral maps used by the authors for agricultural organizations. The model is intended for enterprises operating in the Tashkent region. The article is based on the scientific and methodological order and the system of destruction of irrigated lands. Based on the experience of leading foreign countries in this area, the possibilities of introducing modern electronic computers in Uzbekistan are presented. The procedure for converting data into a specific algorithm is recommended for the formation of a system of land cadastral data in agricultural entities. It is necessary to create an information …


Apple Orchard Drip Irrigation Conditions Of The Tashkent Region Of Uzbekistan, Sardor Gulyamov, Bakir Serikbaev, Anvar Sherov Mar 2020

Apple Orchard Drip Irrigation Conditions Of The Tashkent Region Of Uzbekistan, Sardor Gulyamov, Bakir Serikbaev, Anvar Sherov

Irrigation and Melioration

The article presents the results of many years of theoretical experimental field research on drip irrigation of the apple orchard of the Golden variety in the conditions of the Tashkent region. Based on the analysis of climatic, soil, hydrogeological, geological, hydrological and economic conditions of the experimental plot, as well as biological features of the garden, the values of total water consumption, water consumption deficit, irrigation, irrigation rate and the number of irrigation by the bioclimatic method are determined.


Calculation Of The Placement Of Vertical Drainage Wells Near An Open Water Source In The Conditions Of Waterlogging Of Built-Up Areas, B.K. Saliev Mar 2020

Calculation Of The Placement Of Vertical Drainage Wells Near An Open Water Source In The Conditions Of Waterlogging Of Built-Up Areas, B.K. Saliev

Irrigation and Melioration

The article discusses the methodology for calculating the intercepting drainage well that reveals the upper layer of the multilayer horizon, and presents analytical dependencies based on the hydrodynamic theory and formulas for approximate calculation of the location of the axial line of the blocking drainage between the source of flooding and the protected built-up area from flooding. In particular, mathematical methods have been improved to solve the forecast problems of flooding in conditions of different pressure, based on the relationship between the depressions and the incoming flow of pressure water into the drainage well. The presence of underground pressure water …


Multisector Water Consumption Database: Surkhandarya Region Of The Republic Of Uzbekistan, М. Ikramova, С. Batishev, О. Ikramov, H. Kabilov, D. Nazaraliev, А. Khodjiev, I. Akhmedkhodjaeva Mar 2020

Multisector Water Consumption Database: Surkhandarya Region Of The Republic Of Uzbekistan, М. Ikramova, С. Batishev, О. Ikramov, H. Kabilov, D. Nazaraliev, А. Khodjiev, I. Akhmedkhodjaeva

Irrigation and Melioration

The available water resources in the country are used by the different sectors of economy as industry, agriculture, energy, communal service and etc. In this case the water distribution within the river basin requires perfect information service and data exchange facilities. In the paper the developed unified multi-sector on-line database is presented aimed to monitor the water distribution among sectors of economy, database structure, and data exchange tools. The software works at operative mood, allows evaluating the combined water use efficiency by water users.


Field Research Methods And Some Results For Distribution Of Suspended Sediment In Flow Constrained By Transverse Dams, M.R. Bakiev, K.T. Yakubov, O.M. Matkarimov, Z.B. Dovlatov Mar 2020

Field Research Methods And Some Results For Distribution Of Suspended Sediment In Flow Constrained By Transverse Dams, M.R. Bakiev, K.T. Yakubov, O.M. Matkarimov, Z.B. Dovlatov

Irrigation and Melioration

The article presents methods for determining the main parameters of flow of medium hydraulic size sediment, turbidity, sampling methods in field and the instruments used for sampling, methods of processing the samples in laboratory. Methods for setting sections and gage points and conducting field and laboratory research have been developed for flow deformed by blank and through flow transverse dams, water surface longitudinal and transverse slope takes place in the flow constrained by transverse dams, changes in suspended sediment distribution occur inversely. Location of sections for sampling is determined in the article: in the headrace –beyond dam influence zone, maximal …


Hydromechanical Parameters Of River Sediment, A.M. Arifjanov, D.Sh. Allayorov Mar 2020

Hydromechanical Parameters Of River Sediment, A.M. Arifjanov, D.Sh. Allayorov

Irrigation and Melioration

The main problem today in irrigation canals is the danger of siltation, in this process it is important to correctly assess the factors affecting the throughput (hydromechanical parameters of sediment) and using their justification of the hydraulic elements of the flow. The article presents the results of theoretical studies of the main hydromechanical parameters (hydraulic fineness) of river sediments, in hydraulic structures, in particular in irrigation canals, which currently increasingly affect adversely moving water. It has been established that the hydraulic size entering the right bank irrigation sump of the Kokand hydropower complex varies in the range of 189-429 mm/s, …


Minimizing Control Circuits Using Logic Elements, R.T. Gaziyeva, A.M. Nigmatov, E.O. Ozodov Mar 2020

Minimizing Control Circuits Using Logic Elements, R.T. Gaziyeva, A.M. Nigmatov, E.O. Ozodov

Irrigation and Melioration

In this article considered information about contact and non-contact automation. In most cases, contact automation is used in many pumping stations. These phenomena are a power surge or voltage drop. And also the use of contact automation occupies a large place and inconvenience in operation. Non- contactless automation solves these problems. Pumping stations are usually designed with the calculation of their operation without permanent duty personnel. At large stations, a small staff is provided, which primarily carries out control functions. Set the automatic operation of pumping units. Often, automatic selection of switched-on units is carried out, reserve is withdrawn, station …


Importance Of Creating A System Of Land And Cadastral Data For Subjects Of Agriculture, К. Rakhmonov Mar 2020

Importance Of Creating A System Of Land And Cadastral Data For Subjects Of Agriculture, К. Rakhmonov

Irrigation and Melioration

The generation of electronic data using the land plot scheme while maintaining the land cadastre provides significant convenience for users. Based on this concept, the author explains the conditions, factors and elements of the formation of the contours of land within the land, which plays an important role in the land cadastral work. In particular, the elements of the contour of the earth, that is, the conditions and composition of the border, the area and the order of formation of numbers, are reflected in a separate figure. It is known that the composition of agricultural land plays an important role …


Method Of Determining The Parameters Of The Working Bodies Of The Centrifugal Fan Installed To The Sprayer, D. Dzhuraev, M.S. Halilov, I.Zh. Toirov, A.E. Urishev Mar 2020

Method Of Determining The Parameters Of The Working Bodies Of The Centrifugal Fan Installed To The Sprayer, D. Dzhuraev, M.S. Halilov, I.Zh. Toirov, A.E. Urishev

Irrigation and Melioration

The article presents the data of scientists who conducted theoretical and experimental research on centrifugal fans, they refined the calculations, improved technical characteristics and aerodynamic designs of centrifugal fans. Aerodynamic and technological schemes of centrifugal fans installed to the sprayer have been developed. The theoretical and experimental studies conducted by scientists are described: Nevelson MI, Cherkassky VM, Kalinushkin MP, Ivanov O. P., Turbin B. G., on the basis of which the authors developed a method for calculating the main parameters of the working bodies centrifugal fan. Based on the developed calculation methodology, the main parameters of the working bodies of …


Experience Of Creation The Combined Power Complexes On The Basis Of Renewable Energy Sources, R.A. Zakhidov, A.I. Anarbaev, D.B. Kodirov, F.H. Mukhtarov Mar 2020

Experience Of Creation The Combined Power Complexes On The Basis Of Renewable Energy Sources, R.A. Zakhidov, A.I. Anarbaev, D.B. Kodirov, F.H. Mukhtarov

Irrigation and Melioration

At the article the combined energy complexes based on renewable energy sources implemented in various countries is analyzed. The regime issues of the most efficient use of maximum generation of electrical energy from solar, wind, biogas sources at reserved diesel station are given. Designs of generator modules based on a kinetic energy buffer storage device for preserving the quality of electricity from renewable energy sources with frequent changes in electrical loads of consumers are considered.


Analysis Of Results Of Researches Of Electrotechnological Treatment Of The Cotton Trouble Up To The First Crop Collection, A. Muhammadiev, A.I. Pardaev Mar 2020

Analysis Of Results Of Researches Of Electrotechnological Treatment Of The Cotton Trouble Up To The First Crop Collection, A. Muhammadiev, A.I. Pardaev

Irrigation and Melioration

This article discusses the electrophysical characteristics of plants, more precisely the disclosure of the mechanism of electrical action on the plant through the study of the specific electrical resistance, as well as the task of developing the technological parameters of the electro-technological processing of crops. Knowledge of current value is given, passing through the minted and the rest of the cotton, determination of the negative impact of electrotechnological stamping of cotton on growth and development, yield, by electrotechnological method, including studies of the minted part of cotton, the death of the leaves, the seeds of the pests, the absence of …


Importance Of Creating A System Of Land And Cadastral Data For Subjects Of Agriculture, К. Rakhmonov Mar 2020

Importance Of Creating A System Of Land And Cadastral Data For Subjects Of Agriculture, К. Rakhmonov

Irrigation and Melioration

The generation of electronic data using the land plot scheme while maintaining the land cadastre provides significant convenience for users. Based on this concept, the author explains the conditions, factors and elements of the formation of the contours of land within the land, which plays an important role in the land cadastral work. In particular, the elements of the contour of the earth, that is, the conditions and composition of the border, the area and the order of formation of numbers, are reflected in a separate figure. It is known that the composition of agricultural land plays an important role …


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

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

Department of Mechanical and Aerospace Engineering eNewsBrief

No abstract provided.


Fatigue Behavior Of An Advanced Melt-Infiltrated Sic/Sic Composite With Environmental Barrier Coating At 1200°C In Air And In Steam, Thaddeus M. Williams Mar 2020

Fatigue Behavior Of An Advanced Melt-Infiltrated Sic/Sic Composite With Environmental Barrier Coating At 1200°C In Air And In Steam, Thaddeus M. Williams

Theses and Dissertations

Advanced aerospace applications such as aircraft turbine engine components, hypersonic flight vehicles, and spacecraft reentry thermal protection systems require structural materials that have superior long-term mechanical properties under high temperature, high pressure, and varying environmental factors, such as moisture. Because of their low density, high strength and fracture toughness at high temperatures SiC fiber-reinforced SiC matrix composites are being evaluated for aircraft engine hot-section components. In these applications the composites will be subjected to various types of mechanical loadings at elevated temperatures in oxidizing environments. Because their constituents are intrinsically oxidation-prone, the most significant problem hindering SiC/SiC composites is oxidation …


Structural Dynamic And Inherent Damping Characterization Of Additively Manufactured Airfoil Components, Andrew W. Goldin Mar 2020

Structural Dynamic And Inherent Damping Characterization Of Additively Manufactured Airfoil Components, Andrew W. Goldin

Theses and Dissertations

The push for low cost and higher performance/efficient turbine engines have introduced a new demand for novel technologies to improve robustness to vibrations resulting in High Cycle Fatigue (HCF). There have been many proposed solutions to this, some passive and some active. With the advent of Additive Manufacturing (AM), new damping techniques can now be incorporated directly into the design and manufacture process to suppress the vibrations that create HCF. In this study, this novel unfused pocket damping technology is applied to a blade structure and the resulting damping effectiveness is quantified. The application of this technology to complex geometries …


Structures And Electrochemical Properties Of Sn-Cl Co-Doped Li2Mno3 As Positive Materials For Lithium Ion Batteries, Fei Wang, Huan-Huan Zhai, Du-Dan Wang, Yu-Peng Li, Kang-Hua Chen Feb 2020

Structures And Electrochemical Properties Of Sn-Cl Co-Doped Li2Mno3 As Positive Materials For Lithium Ion Batteries, Fei Wang, Huan-Huan Zhai, Du-Dan Wang, Yu-Peng Li, Kang-Hua Chen

Journal of Electrochemistry

Positive material Li2MnO3 shows the highest ratio of lithium to manganese among lithium-rich materials and exhibites the theoretical capacity up to 458 mAh·g-1, making it one of the most promising cathode materials. However, this material has the intrinsic low electrical conductivity and poor cycle stability. In this paper, Li2MnO3, the lithium-rich positive material, was prepared by sol-gel method using acetate as raw material and citric acid as a complexing agent. By using SnC2O4 as a tin source, Sn4+ instead of Mn4+ was introduced to obtain the …


Electrochemical Preparations And Applications Of Nano-Catalysts With High-Index Facets, Chi Xiao, Na Tian, Zhi-You Zhou, Shi-Gang Sun Feb 2020

Electrochemical Preparations And Applications Of Nano-Catalysts With High-Index Facets, Chi Xiao, Na Tian, Zhi-You Zhou, Shi-Gang Sun

Journal of Electrochemistry

The performance of catalysts highly depends on their surface structure and composition. Nanocrystals bounded by high-index facets usually exhibit high catalytic activity due to their high-density low-coordinated step atoms with high reactivity. In this paper, we have reviewed the preparations of noble metals (e.g., Pt, Pd and Rh) nanocatalysts with high-index facets by electrochemical square-wave potential method developed in our group. The square-wave potential method includes a nucleation procedure to generate nuclei, followed by a square-wave potential procedure for a certain period of time for the growth of nuclei into nanocrystals. The formation mechanism of high-index facets is also discussed. …


Recent Progress In The Mechanistic Understanding Of Co2 Reduction On Copper, Matthew M Sartin, Wei Chen, Fan He, Yan-Xia Chen Feb 2020

Recent Progress In The Mechanistic Understanding Of Co2 Reduction On Copper, Matthew M Sartin, Wei Chen, Fan He, Yan-Xia Chen

Journal of Electrochemistry

In this review, we present the major developments in the understanding of the mechanisms of the electrochemical reduction of CO2 from a historical perspective. Most of the work discussed in this review was carried out at copper electrodes, as this is the only material at which hydrocarbons are produced in reasonable quantities. The emphasis focuses on the differentiation of mechanisms for the generation of C1 and C2 products as well as factors and methods for controlling the product selectivity of CO2 reduction. We have highlighted ambiguities, assumptions, and important methodologies, such as differential electrochemical mass spectrometry and electrochemical …


Effect Of Nitrogen Content In Catalyst Precursor On Activity Of Fen/C Catalyst For Oxygen Reduction Reaction, Zhi Yang, Ya-Yun Shen, E Zhou, Cheng-Ling Wei, Hao-Li Qin, Juan Tian Feb 2020

Effect Of Nitrogen Content In Catalyst Precursor On Activity Of Fen/C Catalyst For Oxygen Reduction Reaction, Zhi Yang, Ya-Yun Shen, E Zhou, Cheng-Ling Wei, Hao-Li Qin, Juan Tian

Journal of Electrochemistry

Non-noble metal catalysts with high activity and low cost have attracted increasing interest as potential catalysts for oxygen reduction reaction (ORR) to replace Pt-based catalysts. In this paper, the effect of nitrogen content in catalyst precursor on ORR activity of FeN/C catalyst was investigated by X-ray diffraction (XRD), Brunauer-Emmet-Teller (BET) surface area and pore size distribution measurements, transmission electron microscope (TEM), thermogravimetric analysis (TGA), and rotating disk electrode (RDE) techniques. The results show that the most active catalyst was obtained by pyrolysis in argon at 1050 °C with a catalyst precursor containing 20wt% 1,10-phenanthroline, 1wt% Fe and Black Pearl 2000. …


Lithium Storage Performance Of High Capacity Material Si@CPzs In Lithium Ion Batteries, Qing-Nuan Zhang, Fang-Fang Zhang, Hong-Xia Li, Bing-Jun Yang, Xiao-Cheng Li, Juan Yang Feb 2020

Lithium Storage Performance Of High Capacity Material Si@CPzs In Lithium Ion Batteries, Qing-Nuan Zhang, Fang-Fang Zhang, Hong-Xia Li, Bing-Jun Yang, Xiao-Cheng Li, Juan Yang

Journal of Electrochemistry

Carbon layers with different thicknesses were introduced into the surfaces of silicon (Si) nanoparticles by sol-gel method using poly (cyclotriphosphazene-co-4, 4'-sulfonyldiphenol) as the carbon source. Technologies of X-ray diffraction, thermo-gravimetric analysis, Brunauer-Emmett-Teller and transmission electron microscopy were employed to analyze the structures and components of the as-prepared Si@CPZS composites. Electrochemical performance of Si@CPZS with different carbon thicknesses was studied. The results showed that Si@CPZS with carbon thickness of 10 nm possessed the best performance. Its capacity remained 940 mAh·g-1 after 290 cycles under 500 mA·g-1. As the addictive, the graphite-based anode contained 30% of …


Research Progresses In Ni-Co-Mn/Al Ternary Concentration Gradient Cathode Materials For Li-Ion Batteries, Chun-Fang Zhang, Wen-Gao Zhao, Shi-Yao Zheng, Yi-Xiao Li, Zheng-Liang Gong, Zhong-Ru Zhang, Yong Yang Feb 2020

Research Progresses In Ni-Co-Mn/Al Ternary Concentration Gradient Cathode Materials For Li-Ion Batteries, Chun-Fang Zhang, Wen-Gao Zhao, Shi-Yao Zheng, Yi-Xiao Li, Zheng-Liang Gong, Zhong-Ru Zhang, Yong Yang

Journal of Electrochemistry

Nickel-rich ternary materials with large reversible capacity as well as high operating voltage are considered as the most promising candidate for next generation lithium-ion batteries (LIBs). However, the inferior cycle stability and thermal stability have limited their widely commercial applications. Concentration gradient design of Ni-Co-Mn/Al ternary concentration gradient materials have been extensively studied in the past decade, which can ensure high cycle capacity while maintaining excellent cycle stability. In this paper, the latest research progresses in Ni-Co-Mn/Al ternary concentration gradient materials for LIBs are reviewed. Firstly, we summarize the different synthesis methods of ternary concentration-gradient materials, especially focusing on the …


Challenges In The Activity And Stability Of Pt-Based Catalysts Toward Orr, Tuo Zhao, Er-Gui Luo, Xian Wang, Jun-Jie Ge, Chang-Peng Liu, Wei Xing Feb 2020

Challenges In The Activity And Stability Of Pt-Based Catalysts Toward Orr, Tuo Zhao, Er-Gui Luo, Xian Wang, Jun-Jie Ge, Chang-Peng Liu, Wei Xing

Journal of Electrochemistry

The development of highly efficient oxygen reduction reaction (ORR) catalysts is the key to the commercialization of fuel cells, where the sluggish ORR reaction rate needs to be overcome by adjusting the intermediates adsorption energies on the catalytic surfaces. To-date, platinum (Pt)-based materials are the-state-of-the-art catalysts in terms of both activity and stability in ORR, making them the preferred choice for commercial applications. However, the high cost of Pt-based catalysts limits their widespread use, leading to massive effects paid in reducing Pt loading, improving catalyst activity and stability. This article illustrates the challenges in the ORR reaction and introduces the …


Research Progresses In Polymeric Proton Exchange Membranes For Fuel Cells, Xu-Po Liu, Yun-Feng Zhang, Shao-Feng Deng, De-Li Wang, Han-Song Cheng Feb 2020

Research Progresses In Polymeric Proton Exchange Membranes For Fuel Cells, Xu-Po Liu, Yun-Feng Zhang, Shao-Feng Deng, De-Li Wang, Han-Song Cheng

Journal of Electrochemistry

Proton exchange membrane (PEM) is one of the key components in PEM fuel cells, which possesses the function of separating the cathode and anode, affording proton transport channels and preventing fuel permeability. The property of PEM significantly influences the performance and service life of fuel cells. Nowadays, the commercially used Nafion membranes have the shortcomings of serious fuel permeability, low proton conductivity at elevated temperature and high price, which limits the rapid development of PEM fuel cells. Therefore, it seems to be urgent to develop novel PEMs with low cost and good comprehensive properties. Polymeric proton exchange membrane is an …