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2018

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Articles 31 - 60 of 9951

Full-Text Articles in Engineering

Numerical Modeling Of Graphene Nano-Ribbon By Dgtd Taking Into Account The Spatial Dispersion Effects, Ping Li, L. (Lijun) J. Jiang, H. Baǧci Dec 2018

Numerical Modeling Of Graphene Nano-Ribbon By Dgtd Taking Into Account The Spatial Dispersion Effects, Ping Li, L. (Lijun) J. Jiang, H. Baǧci

Electrical and Computer Engineering Faculty Research & Creative Works

It is well known that graphene demonstrates spatial dispersion properties [1]-[3], i.e., its conductivity is nonlocal and a function of spectral wave number (momentum operator) q. In this work, to fully account for effects of spatial dispersion on transmission of high-speed signals along graphene nanoribbon (GNR) interconnects, a discontinuous Galerkin time-domain (DGTD) algorithm is proposed. The atomically thick GNR is modeled using a nonlocal transparent surface impedance boundary condition (SIBC) [4] incorporated into the DGTD scheme. Since the conductivity is a complicated function of q (and one cannot find an analytical Fourier transform pair between q and spatial differential operators), …

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Pengatur Suhu Dan Kelembaban Kumbung Jamur Otomatis, Aji Nugroho Dec 2018

Pengatur Suhu Dan Kelembaban Kumbung Jamur Otomatis, Aji Nugroho

Elinvo (Electronics, Informatics, and Vocational Education)

Temperature and humidity have an important role in the cultivation of oyster mushrooms to obtain optimal growth of oyster mushrooms. The optimum temperature required ranges from 24 ° C - 27 ° C and 80% - 90% humidity. The watering of mushroom kumbung should be done regularly, in order to maintain the temperature and humidity of the surrounding air, then conducted research that aims to create a tool that can regulate the temperature and humidity kumbung mushrooms automatically to facilitate farmers keep the temperature and humidity stability continuously. This automatic adjustment system uses DHT-11 sensors as air and humidity and …

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Aplikasi Alat Ukur Debu Berbasis Sms Dan Analisis Model Dispersi Gauss, S. Syahrorini, A. Ahfas Dec 2018

Aplikasi Alat Ukur Debu Berbasis Sms Dan Analisis Model Dispersi Gauss, S. Syahrorini, A. Ahfas

Elinvo (Electronics, Informatics, and Vocational Education)

Udara merupakan komponen penting dalam kehidupan ini, untuk itu perlu dijaga kualitas udara dari polusi udara. Penurunan kualitas udara akibat polusi debu bisa menyebabkan penyakit saluran pernafasan. Untuk mempermudah penyampaian hasil pengukuran debu udara ambien sesuai perkembangan teknologi bisa menggunakan sms. Perancangan alat ukur debu berbasis sms menggunakan sensor debu gp2y1010au0f mendeteksi konsentrasi debu, rangkaian amplifier, mikrokontroler Arduino Uno, modul SMS Gateway sim 900 dan LCD (Liquid Crystal Display). Aplikasi pengukuran di PG. Krembung Sidoarjo Jatim pada Desa Lemujut berjarak 1800 m dan desa Mojoruntut berjarak 1500 m. Hasil pengukuran menunjukkan konsentrasi dibawa baku mutu udara ambien, jadi …

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Pengembangan Media Pembelajaran Kendali Fuzzy Logic Berbasis Arduino Nano Pada Mata Kuliah Praktik Sistem Kendali Cerdas, Hernawan Prabowo, Fatchul Arifin Dec 2018

Pengembangan Media Pembelajaran Kendali Fuzzy Logic Berbasis Arduino Nano Pada Mata Kuliah Praktik Sistem Kendali Cerdas, Hernawan Prabowo, Fatchul Arifin

Elinvo (Electronics, Informatics, and Vocational Education)

Dewasa ini berbagai aplikasi dalam bidang industri yang canggih banyak menggunakan kecerdasan buatan. Mata kuliah praktik Sistem Kendali Cerdas di Jurusan Pendidikan Teknik Elektronika & Informatika FT UNY memerlukan sebuah media pembelajaran yang terintegrasi antara hardware dan software agar kualitas pembelajaran sesuai dengan tuntutan dunia Industri. Hasil penelitian ini untuk menghasilkan media pembelajaran kendali fuzzy logic yang teruji kinerja dan kelayakannya pada mata kuliah praktik Sistem Kendali Cerdas. Pendekatan penelitian menggunakan Research and Development dengan 9 tahapan prosedur pengembangan meliputi: (1) potensi dan masalah, (2) pengumpulan data, (3) desain produk, (4) validasi desain, (5) revisi desain, (6) ujicoba produk, (7) …

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Implementation Of Scalar Control Method For 3 Phase Induction Motor Speed Control, Abdul Muis Prasetia, Hadi Santoso Dec 2018

Implementation Of Scalar Control Method For 3 Phase Induction Motor Speed Control, Abdul Muis Prasetia, Hadi Santoso

Elinvo (Electronics, Informatics, and Vocational Education)

This paper presents design and implementation of scalar control for 3 phase induction motor. This method leads to be able to adjust the speed of the motor by control the frequency and amplitude of the stator voltage of 3 phase induction motor, the ratio of stator voltage to frequency should be kept constant, which is called as V/F or scalar control of 3 phase induction motor drive. The proposed control system is used to generate control signals to overcome the nonlinear dynamics of 3 phase induction motor. Simulation results show that the 3 phase induction motor is able to track …

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Analisis Forensik Digital Pada Frozen Solid State Drive Dengan Metode National Institute Of Justice (Nij), Imam Riadi, Rusydi Umar, Imam Mahfudl Nasrulloh Dec 2018

Analisis Forensik Digital Pada Frozen Solid State Drive Dengan Metode National Institute Of Justice (Nij), Imam Riadi, Rusydi Umar, Imam Mahfudl Nasrulloh

Elinvo (Electronics, Informatics, and Vocational Education)

Kejahatan komputer memiliki bukti digital dari tindak kejahatan dan perlu dilakukan analisa. Perkembangan teknologi komputer yang demikian pesat telah membawa perubahan pada bidang perangkat keras. Pada perangkat keras saat ini terdapat Solid State Drive (SSD) sebagai media penyimpanan utama komputer, karena teknologi SSD memiliki kecepatan akses data yang cepat. Penggunaan software pembeku drive pada komputer sering dilakukan oleh teknisi komputer, karena dapat menghemat biaya perawatan. Software tersebut digunakan untuk melindungi komputer dari perubahan yang tidak dikehendaki, sistem komputer yang tanam software tersebut menjadikan perubahan yang terjadi pada sistem komputer tidak disimpan pada media penyimpanan setelah komputer dimatikan. …

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Sistem Buka Tutup Pintu Otomatis Berbasis Suara, Sinta Ariyanti, Slamet Seno Adi, Sugeng Purbawanto Dec 2018

Sistem Buka Tutup Pintu Otomatis Berbasis Suara, Sinta Ariyanti, Slamet Seno Adi, Sugeng Purbawanto

Elinvo (Electronics, Informatics, and Vocational Education)

Biometric identification is one of the media on the operation of the system of home automation are much sought after.This is because conventional identification such as the use of your PIN, password, and a key card is already not enough reliable, in terms of security and how to operate.Biometrics is essentially an introduction to someone based on the unique personality of each person owned such as facial recognition, fingerprints, voice recognition, the introduction of the retina, and signature.Voice recognition is a process to identify a person by recognizing speech from that person.The purpose of this research is to know the …

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Modifikasi Alat Medis Stetoskop Untuk Monitoring Suara Jantung Menggunakan Tampilan Gui Matlab, Dessy Irmawati, Ridho Prasakti Dec 2018

Modifikasi Alat Medis Stetoskop Untuk Monitoring Suara Jantung Menggunakan Tampilan Gui Matlab, Dessy Irmawati, Ridho Prasakti

Elinvo (Electronics, Informatics, and Vocational Education)

Heart sounds are very important for the initial diagnosis of a disease. This article aims to modify the stethoscope's medical device by adding a Low Pass Filter (LPF) and a condenser sensor so that data can be recorded in a digital device. The stages of tool development begin with analysis, design, development and testing. At the analysis stage, it was stated that a conventional medical stethoscope can only be done by a medical expert directly, where data cannot be stored for detailed analysis purposes, the device is not equipped with LPF which can limit the frequency in a certain range, …

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Reosquido Desalinasi Metode Evaporasi Dengan Ultraviolet Berbasis Mikrokontroller, Muhammad Abdul Azis, Nuryake Fajaryati Dec 2018

Reosquido Desalinasi Metode Evaporasi Dengan Ultraviolet Berbasis Mikrokontroller, Muhammad Abdul Azis, Nuryake Fajaryati

Elinvo (Electronics, Informatics, and Vocational Education)

This research aims to create a Reosquido desalination tool for evaporation methods using a microcontroller. This tool can control the temperature to speed up the evaporation process in producing fresh water. The method applied to Reosquido desalination uses Evaporation. The first process before evaporation is the detection of temperature in sea water that will be heated using an element heater. The second process of temperature measurement is to turn off and turn on the Arduino Uno controlled heater, when the temperature is less than 80 ° then the heater is on. The third process is evaporation during temperatures between 80 …

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Sistem Pendeteksi Dini Kebakaran Gedung Berbasis Zigbee Mesh Network, Ponco Wali Pranoto, Rovadita Anggorowati Dec 2018

Sistem Pendeteksi Dini Kebakaran Gedung Berbasis Zigbee Mesh Network, Ponco Wali Pranoto, Rovadita Anggorowati

Elinvo (Electronics, Informatics, and Vocational Education)

Perkembangan teknologi khususnya dalam hal informasi dan komunikasi menjadi peran penting dalam dunia masa kini, sebagai contoh penerapan teknologi informasi dan komunikasi telah merambah dalam segala aspek kehidupan diantaranya ialah rumah tangga, otomotif, militer, kesehatan, industri, hingga lingkungan. Salah satu contoh perkembangan teknologi informasi dan komunikasi saat ini ialah wireless sensor network (WSN) yang mana pengembangan dan penelitiannya masih sangat terbuka lebar. Pada penelitian ini peneliti membangun sebuah sistem deteksi bahaya kebakaran dengan mengimplementasikan Zigbee Mesh Network berbasis wireless sensor network (WSN). Untuk sensor pendeteksi bahaya kebakaran yang digunakan adalah LM35, dan MQ-2 selain itu untuk komunikasi wireless nya menggunakan …

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"Whole-Brained" Engineering Education In Undergraduate Studies At The University Of Dayton, Kylie Moellering Dec 2018

"Whole-Brained" Engineering Education In Undergraduate Studies At The University Of Dayton, Kylie Moellering

Undergraduate Voices

This inquiry is a case study which explores, explicates, and summarizes the recent shift to “whole-brained” engineering education for undergraduate-level students at the University of Dayton. This case study is primarily structured around the experiences and insights of an interviewee, Dr. Ken Bloemer, who is the Director of the Visioneering Center at the University of Dayton. The Visioneering Center is principally focused on promoting the progress of engineering education at the university. Voices from scholarly literature pertaining to this vision and other undergraduate engineering curricula are then used to reinforce the interviewee’s views and give deeper insight into the various …

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Undergraduate Voices, Volume 1 (2018): Addendum, Amir Kalan Dec 2018

Undergraduate Voices, Volume 1 (2018): Addendum, Amir Kalan

Undergraduate Voices

Additional articles approved for publication in December 2018 in Volume 1.

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Desain Dan Implementasi Real-Time Visible Light Communication System Berbasis Bpsk, Trio Adiono, Syifaul Fuada Dec 2018

Desain Dan Implementasi Real-Time Visible Light Communication System Berbasis Bpsk, Trio Adiono, Syifaul Fuada

Elinvo (Electronics, Informatics, and Vocational Education)

Salah satu teknik multiplexing yang saat ini populer digunakan untuk aplikasi akses komunikasi cepat berbasis cahaya tampak adalah Orthogonal Frequency Division Multiplexing (OFDM). Meskipun lebih kompleks dibandingkan modulasi berbasis Pulse Time Modulation (PTM), teknik OFDM disinyalir dapat lebih menghemat bandwidth komunikasi karena membagi bandwidth lebar menjadi spektrum yang sempit (sub-carrier) dan saling overlap. Sebagai akibat, transfer data akan lebih cepat dibandingkan PTM. Pada penelitian sebelumnya, penulis telah berhasil mendesain sistem low-cost VLC dengan modulasi digital 1-PWM (3,3 kbps) dan 2-PWM (6,2 kbps). Motivasi dari penelitian ini adalah menigkatkan laju data dengan menggunakan OFDM. Modulasi binary shift-keying modulation …

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Amorphous Metal Oxide Semiconductor Thin Film Transistors For Printed Electronics, Mustafa Mohammad Yousef Dec 2018

Amorphous Metal Oxide Semiconductor Thin Film Transistors For Printed Electronics, Mustafa Mohammad Yousef

Theses

There is an acute market need for solution-processable semiconductor inks that can form the essential components of the printed analog and digital circuits. Currently, the industry is migrating beyond simply printing conductive metals for interconnects and embracing higher integration by printing transistors directly on the same substrate. This thesis focuses on investigating solution-processed amorphous indium gallium zinc oxide (IGZO) as a semiconducting channel layer of a field-effect transistor to enable low-cost, large-area printed electronics that are physically flexible and optically transparent. Specifically, we aim to achieve field-effect mobility exceeding 1 cm2/Vs, to overcome the limits faced in existing …

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Performance Of C2H4 Reductant In Activated-Carbon-Supported Mnox-Based Scr Catalyst At Low Temperatures, Guangli Liu, Dongtai Han, Jie Cheng, Yongshi Feng, Wenbin Quan, Li Yang, Kozo Saito Dec 2018

Performance Of C2H4 Reductant In Activated-Carbon-Supported Mnox-Based Scr Catalyst At Low Temperatures, Guangli Liu, Dongtai Han, Jie Cheng, Yongshi Feng, Wenbin Quan, Li Yang, Kozo Saito

Mechanical Engineering Faculty Publications

Hydrocarbons as reductants show promising results for replacing NH3 in SCR technology. Therefore, considerable interest exists for developing low-temperature (< 200 °C) and environmentally friendly HC-SCR catalysts. Hence, C2H4 was examined as a reductant using activated-carbon-supported MnOx-based catalyst in low-temperature SCR operation. Its sensitivity to Mn concentration and operating temperature was parametrically studied, the results of which showed that the catalyst activity followed the order of 130 °C > 150 °C > 180 °C with an optimized Mn concentration near 3.0 wt.%. However, rapid deactivation of catalytic activity also occurred when using C2H4 as the reductant. The mechanism of deactivation was explored and is …

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Costs And Benefits Of Flood Mitigation In Louisiana, Arash Taghi Nezhad Bilandi Dec 2018

Costs And Benefits Of Flood Mitigation In Louisiana, Arash Taghi Nezhad Bilandi

LSU Doctoral Dissertations

Assessing the costs and benefits of hazard mitigation efforts is an essential component of disaster management, planning, and resilience assessment. These calculations are particularly important in locations vulnerable to multiple hazards with high frequencies, such as coastal Louisiana. This study aims to provide an improved understanding of the costs and benefits of flood mitigation efforts in Louisiana funded by federal government grants between 2005 and 2015. Project data provided by the Governor’s Office of Homeland Security and Emergency Preparedness (GOHSEP) were summarized and missing values were imputed using robust statistical approaches. Elevation project cost was investigated for prediction by statistical …

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Constructions Of Noble Metal Nanocrystals With Specific Crystal Facets And High Surface Area, Qiao-Li Chen, Hui-Qi Li, Ya-Qi Jiang, Zhao-Xiong Xie Dec 2018

Constructions Of Noble Metal Nanocrystals With Specific Crystal Facets And High Surface Area, Qiao-Li Chen, Hui-Qi Li, Ya-Qi Jiang, Zhao-Xiong Xie

Journal of Electrochemistry

Noble metal nanocrystals (NCs) have widespread applications in catalysis. Their catalytic performances are strongly related to the surface structures while the atomic utilization efficiency of noble metal is considerably correlated with the surface area. Thus, advantages of both specific surface structure and large surface area are highly required to show off simultaneously so as to optimize the catalytic performance and decrease the usage of noble metal. However, it seems that the two advantages are incompatible with each other in one NC since it is difficult for small NCs to keep their specific facets, while NCs with specific surface structure usually …

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Voltage Distribution Of Self-Humidifying Air-Cooled Pemfc, Kai-Feng Tan, Wei-Rong Chen, Ming Han, Xue-Xia Zhang Dec 2018

Voltage Distribution Of Self-Humidifying Air-Cooled Pemfc, Kai-Feng Tan, Wei-Rong Chen, Ming Han, Xue-Xia Zhang

Journal of Electrochemistry

In this work, the self-adaptive characteristics of self-humidifying air-cooled PEMFC stack was investigated. The performance and the unit-cell voltage distribution of the stack were measured and analyzed through the unit-cell I-V curve fitting. The operating conditions for this experimental study were set as follows: hydrogen pressure at the anode was 2 bar, the fan power used for the reactant oxygen feed and stack cooling was at 0.3 W, and the duration and time gap of water purged from hydrogen chamber were 1 s and 10 s, respectively. The experimental results showed that the self-humidifying air-cooled PEMFC stack used for this …

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Progress Of Self-Humidifying Membrane Electrode Assembly For Low Temperature Proton Exchange Membrane Fuel Cell, Bin Chi, Yue-Kun Ye, Shi-Jie Jiang, Shi-Jun Liao Dec 2018

Progress Of Self-Humidifying Membrane Electrode Assembly For Low Temperature Proton Exchange Membrane Fuel Cell, Bin Chi, Yue-Kun Ye, Shi-Jie Jiang, Shi-Jun Liao

Journal of Electrochemistry

The self/non-humidification membrane electrode assembly（SH-MEA）is an important pathway towards the self- humidification fuel cell and plays a crucial role for the large scale commercialization of low temperature proton exchange membrane fuel cell (LT-PEMFC), because it not only can reduce the volume and complexity of fuel cell system, resulting in the decrease of the cost, but also can improve the output power density of the fuel cell system. Currently, the researches on the self-humidifying MEA of LT-PEMFC mainly focus on three aspects: the preparation of self-humidification proton exchange membrane, the construction of self-humidification catalyst layer, and the construction of composite self-humidifying …

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A Review Of Proton Exchange Membrane Fuel Cell Catalyst Layer By Electrospinning, Yong Liu, Han Ding, De-Chun Si, Jie Peng, Jian-Bo Zhang Dec 2018

A Review Of Proton Exchange Membrane Fuel Cell Catalyst Layer By Electrospinning, Yong Liu, Han Ding, De-Chun Si, Jie Peng, Jian-Bo Zhang

Journal of Electrochemistry

The limitation of catalyst layer for proton exchange membrane fuel cell (PEMFC) in cost, durability and performance constitutes the bottleneck for the commercialization of fuel cell vehicles. Electrospun catalyst layer, with high catalyst utilization, increased triple phase boundary (TPB) and triple phase channel (TPC), has been developed by many researchers. This paper reviews the research progress in the electrospun catalyst layer for PEMFC, combined with the author’s work. Firstly, the development progress of catalyst layer is summarized, and the catalyst layer is classified and analyzed based on its fabrication method and structure character. Next, the fabrication process, physical property characterization, …

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Effects Of So2 In Air On Performance Of Direct Methanol Fuel Cell, Bin Qin, Fen-Ning Jing, Xue-Jing Sun, Gong-Quan Sun, Hai Sun Dec 2018

Effects Of So2 In Air On Performance Of Direct Methanol Fuel Cell, Bin Qin, Fen-Ning Jing, Xue-Jing Sun, Gong-Quan Sun, Hai Sun

Journal of Electrochemistry

Direct methanol fuel cells (DMFC) generally use oxygen as an oxidant. Contaminants such as sulfides and nitrides in the air can affect the performance of the DMFC. In this work, the effects of SO2 on the performance of DMFC were investigated and the mechanism of poisoning was analyzed, by means of constant current discharge curve, polarization performance curve, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). In the CV scan, the permeated methanol was oxidized at a low potential to eliminate its effect on the SO2 poisoning behavior test. The results showed that the SO2 poisoning resulted …

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Fe-N Doped Hollow Carbon Nanospheres Linked By Carbon Nanotubes For Oxygen Reduction Reaction, Ya-Lin Zhang, Chi Chen, Liang-Liang Zou, Zhi-Qing Zou, Hui Yang Dec 2018

Fe-N Doped Hollow Carbon Nanospheres Linked By Carbon Nanotubes For Oxygen Reduction Reaction, Ya-Lin Zhang, Chi Chen, Liang-Liang Zou, Zhi-Qing Zou, Hui Yang

Journal of Electrochemistry

The development of non-precious metal catalysts for oxygen reduction reaction (ORR) is essential for large-scale application of proton exchange membrane fuel cells. Herein, we present the in situ formed Fe-N doped hollow carbon nanospheres linked by carbon nanotubes composite, synthesized by using ZIF-8 as sacrificed template to form polydopamine (PDA) hollow nanospheres, followed by complexing with FeCl3, high temperature heat-treatment and NH3-etching. ZIF-8 was gradually decomposed simultaneously with PDA coating due to the loss of Zn2+ grabbed by PDA. NH3 etching resulted in the improved surface area, while the reducibility of NH3 resulted in …

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Acid Treated Carbon As Anodic Electrocatalysts Toward Direct Ascorbic Acid Alkaline Membrane Fuel Cells, He-Mu Chen, Chen-Xi Qiu, Yuan-Yuan Cong, Hui-Yuan Liu, Zi-Hui Zhai, Yu-Jiang Song Dec 2018

Acid Treated Carbon As Anodic Electrocatalysts Toward Direct Ascorbic Acid Alkaline Membrane Fuel Cells, He-Mu Chen, Chen-Xi Qiu, Yuan-Yuan Cong, Hui-Yuan Liu, Zi-Hui Zhai, Yu-Jiang Song

Journal of Electrochemistry

In order to improve the hydrophilicity and electrocatalytic activity, commercial carbon black (BP 2000) was subjected to acid treatment to obtain acid-treated carbon (ATC). The generation of rich oxygen-containing groups on the surface of the ATC was proved by X-ray photoelectron spectra (XPS), Fourier transform-infra red spectra (FTIR), thermogravimetric analysis (TG) and contact angle measurement. UV-vis spectra were firstly recorded to calculate activation energy (Ea) of ascorbic acid (AA) chemical oxidation in alkaline conditions by oxygen in air and the Ea value was determined to be 37.1 kJ·mol-1. Additionally, electrochemical impedance spectra (EIS) were used to evaluate unprecedented …

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Durability Performance Of The High-Power Fuel Cell System, Ke-Yong Wang, Wei-Yu Shi, Ren-Fang Wang, Jia Liu, Zhong-Jun Hou Dec 2018

Durability Performance Of The High-Power Fuel Cell System, Ke-Yong Wang, Wei-Yu Shi, Ren-Fang Wang, Jia Liu, Zhong-Jun Hou

Journal of Electrochemistry

Fuel cell durability is the crucial challenge in fuel cell vehicle, and the lifetime of more than 5000 hours is believed to be necessary for vehicle application. Few works on durability test of the full fuel cell system have been reported. In this work, the long lifetime HySYS-30 fuel cell system was developed in Sunrise Power based on the improved MEA durability and system control strategy. The durability performance of the system was investigated under vehicle duty cycle for more than 6000 hours, and only 8.1% performance loss was observed, implying that the durability of HySYS-30 fuel cell system could …

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Fuel Cell Performance Curve After Mea Optimization Structural Optimization Of Low Pt Membrane Electrode Assembly, Yan Rao, Shang Li, Fen Zhou, Tian Tian, Qing Zhong, Zhao-Hui Wan, Jin-Ting Tan, Mu Pan Dec 2018

Fuel Cell Performance Curve After Mea Optimization Structural Optimization Of Low Pt Membrane Electrode Assembly, Yan Rao, Shang Li, Fen Zhou, Tian Tian, Qing Zhong, Zhao-Hui Wan, Jin-Ting Tan, Mu Pan

Journal of Electrochemistry

Membrane electrode assemblies (MEAs) are the key component of proton exchange membrane fuel cell. For a long time, much attention has been paid to develop MEA technology. At present, the research, development and industrialization of fuel cell has entered a new era. More strict requirements for MEA, especially for the reduction of Pt loading with a challenging target of 0.125 mg·W-1 have to be met. In this paper, the performance losses under low Pt loading are analyzed in terms of activation polarization, ohm polarization and mass-transfer polarization. It is proposed that research should be focused on the activity of …

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Recent Progress In Pt-Based Catalysts For Oxygen Reduction Reaction, Jing Li, Xin Feng, Zi-Dong Wei Dec 2018

Recent Progress In Pt-Based Catalysts For Oxygen Reduction Reaction, Jing Li, Xin Feng, Zi-Dong Wei

Journal of Electrochemistry

One major challenge for a large-scale commercialization of the proton-exchange membrane fuel cells (PEMFCs) technologies that enable a shift to ‘zero-emission’ personal transportation, is the expensive and unstable Pt catalysts, which are mainly used to catalyze the sluggish kinetics of the oxygen reduction reaction (ORR) occurred on the air electrode of PEMFCs. Many research works have targets to improve the stability of Pt-based catalysts and to construct Pt/transitional metal alloys with low Pt loading amount. Herein, we provide a minireview for the Pt-based ORR catalysts based on our recent work, which covers a brief background introduction, the stability improvement of …

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Caging Porous Co-N-C Nanocomposites In 3d Graphene As Active And Aggregation-Resistant Electrocatalyst For Oxygen Reduction Reaction, Lu-Yang Xiu, Meng-Zhou Yu, Peng-Ju Yang, Zhi-Yu Wang, Jie-Shan Qiu Dec 2018

Caging Porous Co-N-C Nanocomposites In 3d Graphene As Active And Aggregation-Resistant Electrocatalyst For Oxygen Reduction Reaction, Lu-Yang Xiu, Meng-Zhou Yu, Peng-Ju Yang, Zhi-Yu Wang, Jie-Shan Qiu

Journal of Electrochemistry

Oxygen reduction reaction (ORR) is the cornerstone reaction of many renewable energy technologies such as fuel cells and rechargeable metal-air batteries. The Pt-based electrocatalysts exhibit the highest activity toward ORR, but their large implementation is greatly prohibiting by unaffordable cost and inferior durability. During electrode manufacturing and electrochemical reaction, severe aggregation of catalyst nanoparticles induced by size effect further limits the operational performance of electrocatalysts. We report a new strategy for fabrication of active and aggregation-resistant ORR electrocatalyst by caging metal-organic frameworks derived Co-N-C nanocomposites in permeable and porous 3D graphene cages via sprayed drying the mixed colloids of ZIF-67 …

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Palladium Adatoms On Gold Nanoparticles As Electrocatalysts For Ethanol Electro-Oxidation In Alkaline Solutions, Hui-Mei Chen, Shang-Qian Zhu, Jia-Le Huang, Min-Hua Shao Dec 2018

Palladium Adatoms On Gold Nanoparticles As Electrocatalysts For Ethanol Electro-Oxidation In Alkaline Solutions, Hui-Mei Chen, Shang-Qian Zhu, Jia-Le Huang, Min-Hua Shao

Journal of Electrochemistry

Palladium (Pd) is a good catalyst for ethanol electro-oxidation in alkaline solutions. The activity of Pd is further improved in this study by modifying the gold (Au) nanoparticles with Pd adatoms using a simple spontaneous deposition process. The Pd overlayer on the Au core (Au@Pd) is un-uniform with some Au atoms exposed to the electrolyte. The activity of Au@Pd/C toward ethanol oxidation reaction (EOR) is much higher than that of Pd/C in an alkaline solution. The peak current density of Au@Pd/C is 4.6 times higher than that of Pd/C with a 100 mV lower onset potential. The enhanced activity may …

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Transient Transmission Oscillations In Doped And Undoped Lithium Niobate Induced By Near-Infrared Femtosecond Pulses, Bryan J. Crossman, Gregory J. Taft Dec 2018

Transient Transmission Oscillations In Doped And Undoped Lithium Niobate Induced By Near-Infrared Femtosecond Pulses, Bryan J. Crossman, Gregory J. Taft

Physics Faculty Publications

Transient transmission oscillations in X-cut and Z-cut congruent, iron-doped, and magnesium-doped lithium niobate samples were measured using 50 fs, 800 nm, 0.5 nJ pulses from a self-mode-locked Ti:sapphire laser in an optical pump–probe system. Several Raman-active oscillation modes excited by these pulses were observed as changes in the transmitted probe intensity versus time delay between the pump and probe pulses. The samples were rotated to determine how the incident polarization of the pump pulses affects the mode excitations. The observed Raman-active oscillations correspond to previously reported symmetry modes measured with traditional, continuous-wave, Raman spectroscopy using the same scattering …

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Morphological Control Of Ptcu2 Octahedron And Oxygen Reduction Electrocatalytic Performance Of Ptcu For Fuel Cell, Long-Sheng Cao, Lei Wan, Zhi-Gang Shao, Hong-Mei Yu, Ming Hou, Bao-Lian Yi Dec 2018

Morphological Control Of Ptcu2 Octahedron And Oxygen Reduction Electrocatalytic Performance Of Ptcu For Fuel Cell, Long-Sheng Cao, Lei Wan, Zhi-Gang Shao, Hong-Mei Yu, Ming Hou, Bao-Lian Yi

Journal of Electrochemistry

Platinum acetylacetonate (Pt(acac)2) and copper acetylacetonate (Cu(acac)2) were co-reduced to prepare PtCu2 octahedron alloy catalyst in N,N-dimethylformamiade by solvothermal method. The PtCu2 showed lattice compression, and high ratio of non-oxidized Pt with high electronic binding energy. All those structural features contributed to weak adsorption strength of oxygen species on Pt and lower d-band centre position. The influence of structure-directing agent on morphology of PtCu alloy was systematically studied. In the half cell test, as a result of the uniform morphology and regular octahedron of PtCu2 formed, the mass activity and area specific activity …

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