Materials Science and Engineering Commons^™

Development Of Ex-Situ Accelerated Chemical Stress Test Protocol For Common Anionic Exchange Membrane Chemistries, Michael D. Friend, Michael D. Friend

Master's Theses

The development of sustainably produced hydrogen fuel (“green hydrogen”) is key for the transition to clean energy sources. Green hydrogen is produced via water electrolysis. As with many clean energy sources, one of the major barriers for scaling water electrolysis is cost. A newer category of water electrolysis is Anionic Exchange Membrane (AEM) water electrolysis. AEM electrolysis systems have the potential to cost less as they do not require the expensive precious metal catalysts the current high preforming Proton Exchange Membrane water electrolysis technologies do. However, AEM lifetimes must be long enough to be cost competitive and AEM chemical durability …

Material Classification With Spectropolarimetric Lidar, Alexander J. Watson

Theses and Dissertations

A method for characterizing unknown targets using a hyperspectral polarimetric light detection and ranging (LiDAR) system is presented. Light reflected from manmade objects tends to be more polarized than light reflected from objects in the natural world. As such, polarization measurements can be used in remote sensing applications to differentiate artificial and natural objects. Previous works have attempted to characterize objects through passive polarimetric imagery. Methods developed by Cain and Lemaster and Cunningham facilitate reconstruction of the Stokes Vector from returning light. Martin used multispectral polarimetry to classify targets when the angle of incidence (AOI) is close to 0º. Here, …

Structure-Property Relations Of Binary Ferrite Melts, C. J. Benmore, C. Shi, O. L.G. Alderman, J. P. Harvey, D. Lipke, J. K.R. Weber

Materials Science and Engineering Faculty Research & Creative Works

Molten ferrite systems are used in the smelting and refining processes in steelmaking, to reduce the loss of metals in slags and to accelerate reaction rates. Here, high-energy x-ray diffraction experiments have been performed on aerodynamically levitated molten spheres of 43BaO-57FeOX and 43SrO-57FeOX at 1873 K using laser beam heating. The composition was varied within the range of x = 1-1.5 by changing the oxygen partial pressure of the levitation gas. The corresponding x-ray pair distribution functions have been interpreted using empirical potential structure refinement (EPSR) modeling. In oxygen-rich melts (x = 1.5), our EPSR models indicate very similar structures …

Enhancing Cycle Life Of Graphite ‖ Lifepo4 Batteries Via Copper Substituted Li2Ni1-XCuXO2 Cathode Prelithiation Additive, Jian-Ming Zheng, Jing-Wen Zhang, Tian-Peng Jiao

Journal of Electrochemistry

Lithium nickel oxide (Li₂NiO₂), as a sacrificial cathode prelithiation additive, has been used to compensate for the lithium loss for improving the lifespan of lithium-ion batteries (LIBs). However, high-cost Li₂NiO₂ suffers from inferior delithiation kinetics during the first cycle. Herein, we investigate the effects of the cost-effective Cu substitution of Li₂Ni_1-xCu_xO₂ (x = 0, 0.2, 0.3, 0.5, 0.7) synthesized by high-temperature solid-phase method on the structure, morphology, electrochemical performance of graphite‖LiFePO₄ battery. The X-ray Diffraction (XRD) refinement result demonstrates that Cu substitution strategy is favorable …

Metal Nitrides As Cathode Hosts For Lithium-Sulfur Batteries, Hai-Ji Xiong, Cheng-Wei Zhu, Ding-Rong Deng, Qi-Hui Wu

Journal of Electrochemistry

Lithium-sulfur batteries are considered as one of the potential solutions as integrating renewable energy systems for large-scale energy storage because of their high theoretical energy density (2600 Wh·kg^–1) and specific capacity (1675 mAh·g^–1). Currently, various strategies have been proposed to overcome the technical barriers, e.g., “shuttle effect”, capacity decay and volumetric change, which impede the successful commercialization of lithium-sulfur batteries. This paper reviews the applications of metal nitrides as the cathode hosts for high-performance lithium-sulfur batteries, summarizes the design strategies of different host materials, and discusses the relationship between the properties of metal nitrides and their …

Sno2 Particles Embedded Into Carbon Coated Mesoporous SioX Rod As High Volumetric Capacity Anode For Lithium-Ion Batteries, Jia-Lin Guo, Ni-Ni Li, Peng Zheng

Journal of Electrochemistry

Due to the high capacity and moderate volume expansion of silicon protoxide SiO_x (160%) compared with that of Si (300%), reducing silicon dioxide SiO₂ into SiO_x while maintaining its special nano-morphology makes it attractive as an anode of Li-ion batteries. Herein, through a one-pot facile high-temperature annealing route, using SBA15 as the silicon source, and embedding tin dioxide SnO₂ particles into carbon coated SiO_x, the mesoporous SiO_x-SnO₂@C rod composite was prepared and tested as the anode material. The results revealed that the SnO₂ particles were distributed uniformly in the …

Fatigue Behaviour Of Al 6063 Alloy In Heat Treated, Deep Cryogenic Treated And Equal Channel Angular Pressing (Ecap) Processed Conditions, Sreearravind M

Theses and Dissertations

This research focuses on improving the Low Cycle Fatigue (LCF) life of Al6063 using three different processing techniques – Heat Treatment (HT), Deep Cryogenic Treatment (DCT), and Equal Channel Angular Pressing (ECAP). Al 6063, widely used in structural applications, has limited fatigue performance, necessitating the exploration of advanced processing techniques to enhance its LCF life.

In HT phase, Al 6063 T5 samples were subjected to solid solution HT followed by air and water quenching. The air-quenched (T6A) and water-quenched (T6W) samples were subjected to precipitation hardening. The Ultimate Tensile Strength (UTS) of the T6A sample increased to 188 MPa from …

In-Situ Thermal Measurement Of Polymers, Carson Powers, Jungkyu Park, Dal Hyung Kim, Fahim Dorsey, Peter Bearden

Symposium of Student Scholars

In this research, we conducted a detailed experimental

investigation into how strain affects the thermal conductivity of

Ecoflex elastomer, utilizing a newly developed method for

measuring thermal conductivity under mechanical strain for the

first time. In situ thermal conductivity measurement apparatus

was developed by combining the KLA T150 nanoscale tensile tester

and a custom-fabricated thermal measurement sensor. The

development of an experimental method for measuring the thermal

conductivity of nanomaterials under mechanical testing

simultaneously will contribute to the development of novel

materials for flexible electronics by helping us to better

understand the strain effect on their thermal performance.

Interestingly, the …

A Comparative Mathematical Analysis Of Ice Modulation Measurement Techniques: Unifying Thermal Hysteresis, Freezing Point Depression, And Colligative Effects, Hayden Calvert Barry

Engineering Undergraduate Senior Theses

Thermal hysteresis (TH) measurement techniques for ice binding proteins (IBPs) have historically lacked standardization, making cross-study comparisons challenging and potentially impeding development of these materials for practical applications. This study provides a comprehensive comparison of three measurement techniques: differential scanning calorimetry (DSC), microlitre osmometry, and cryostage microscopy. Through systematic experimentation with Wild Type III Antifreeze Protein (AFP) at varying concentrations (10μM, 100μM, 1mM), along with cell lysate AFP and Pseudomonas syringe ice nucleating protein (INP), mathematical relationships were established between measurement techniques, and cryostage microscopy was identified as the most reproducible and reliable method. Regression analysis revealed strong relationships between …

Static Performance And Stability Of A Multi-Span Hybrid Continuous Rigid Frame Bridge With High Piers, Huang Yu, Liu Guanyu, Yi Jianbo, Xing Xuan, Su Miao, Peng Hui

Journal of China & Foreign Highway

In order to study the static performance and stability of a steel-concrete composite continuous rigid frame bridge in Suichang,Zhejiang Province,a single girder and girder lattice finite element model for the whole bridge was established by using Midas Civil,and a local solid finite element model was established by using Ansys.A detailed analysis of the structural displacement and stress state of the bridge in use and the local stress in the solid section of the pier and girder under different loads was carried out.The influence of the pile-bottom restraint stiffness and pier-girder connection form on the overall stability of the bridge was …

Influence Of Train Speed On Thermal Insulation And Anti-Thawing Length For Tunnel In Cold Region, Huang Huanan, Chen Yong, Wang Yibo, Wu Yaping

Journal of China & Foreign Highway

To study the influence of train speed on thermal insulation and anti-thawing measures for surrounding rock of tunnels in cold regions,it is necessary to analyze the temperature field.By using the Kunlun Mountain Tunnel Project in cold regions as a case study,the effects of external atmospheric temperature,piston wind effects caused by varying train speeds,and the driving resistance on the distribution of the tunnel ’s internal temperature field were considered.A three-dimensional numerical calculation model including the surrounding rock,concrete lining,and tunnel air was established by utilizing the thermo-fluid-structure interaction (TFSI ) technique.The thermal environment variations caused by trains at different speeds were predicted.The …

Parametric Analysis Of Composite Slab With Steel Bar Trusses At Construction Stages, Zhang Junhao, He Jun, Tan Chao, Feng Sidong, Wang Zitong

Journal of China & Foreign Highway

To clarify the structural behavior of composite slab with steel bar trusses at key construction stages including hoisting and concrete post-pouring,a composite beam bridge with a main span of 60 m in Georgia ’s E60 Highway was investigated.A finite element model was developed by using ABAQUS to simulate the construction process and analyze the influence of parameters such as prefabricated bottom slab material,number of hoisting points,slab thickness,and number of steel bar trusses on the principal stress of concrete and mid-span deflection.The results indicate that ultra-high-performance concrete (UHPC ) prefabricated bottom slabs prevent plastic damage and enhance slab stiffness.Normal concrete (NC) …

Cracking Characteristics Of Cement-Stabilized Macadam With Early Strength Agent Under Variable Temperature And Humidity Curing Conditions, Ge Dongdong, Liu Dingyuan, Lyu Songtao, Jiang Xiangyang, Xue Yanhua, Yu Yang

Journal of China & Foreign Highway

In environments with large temperature variations and low humidity,the curing conditions of cement-stabilized macadam fail to meet the specifications,leading to slow early strength development and increased susceptibility to cracking.This study aimed to investigate the effects of actual environmental temperature,humidity,curing age,and addition of early strength agents on the cracking characteristics of cement-stabilized macadam.Variable temperature conditions were determined based on actual environmental temperature data.Four curing conditions were set by combining temperatures (variable temperature and standard temperature ) with relative humidity of 95%,80%,and 65%,respectively.Three types of specimens were prepared with 0%,10%,and 15% early strength agent contents and cured for 14 and 28 days,respectively.The …

Identification And Prediction Model For Traffic Blockage State Of Highways To Xizang, Wu Ling, Liu Jianbei, Zhang Zhiwei, Shan Donghui, Chi Gandu

Journal of China & Foreign Highway

To identify the traffic blockage state on highways to Xizang in extreme environments,comprehensive evaluation indicators for traffic blockage state based on the entropy-weighted TOPSIS method were proposed by using the traffic blockage event parameters observed on four major highways to Xizang:Sichuan ‒ Xizang Highway,Yunnan ‒ Xizang Highway,Qinghai ‒ Xizang Highway,and Xinjiang ‒ Xizang Highway.The K-Medoids clustering algorithm was used to categorize the traffic blockage state into different levels.By considering factors such as hazard types,road types,traffic volume,and vehicle type ratios,a classification model for the traffic blockage state on highways to Xizang was constructed based on machine learning algorithms.The results show that …

Seismic Performance Of Bridge Pile Foundation Considering Effects Of Material Freeze-Thaw Deterioration And Permafrost Degradation, Zhang Xiyin, Yu Shengsheng, Wang Wanping, Wen Hairong

Journal of China & Foreign Highway

In cold and high-seismic regions,such as the Qinghai‒Xizang Plateau in China,the deterioration of material properties caused by freeze-thaw cycles and permafrost degradation due to climate change have become increasingly severe,posing significant challenges for the seismic performance assessment of bridge pile foundations.To systematically investigate the impact of permafrost degradation and material freeze-thaw deterioration on the seismic performance of bridge pile foundations and ensure proper seismic design,a finite element model was established,considering the dual effects of permafrost degradation and material freeze-thaw deterioration.A comparative analysis was conducted to evaluate the influence mechanisms of various factors on the seismic performance of bridge pile foundations …

Design And Simulation Evaluation Of Converged Toll Collection Schemes For Senegalese Highways, Lai Zengcheng, Zhang Ning, Yang Shichun, Ding Xueqi, Ji Yanjie

Journal of China & Foreign Highway

The Senegalese highway toll collection system is inefficient,and significant congestion and delays frequently occur at toll stations in the face of sudden traffic surges during holidays.This paper examined the limitations of the existing toll collection methods on Senegalese highways and combined the image detection algorithm and electronic license plate recognition technology with the existing MTC and ETC toll collection methods to construct a converged toll collection method based on vehicle information recognition.The paper aimed to optimize the Senegalese highway toll collection system,reduce its cost of use,and improve the efficiency of toll collection.The BPV Thiès toll station in Senegal was selected …

Model Test On Bearing Capacity Of Gravity Anchor Foundation Considering Rock Socketed Effect, Yin Jingze, Guo Chao, Zhang Xinmin, Li Wei, Shi Haiyang, Fu Baiyong

Journal of China & Foreign Highway

The calculation of the bearing capacity of traditional gravity anchor foundation instructed by Code for Design of Ground Base and Foundation of Highway Bridges and Culverts (JTG D 63—2007 ) only considers the friction effects of the basement and neglects the rock socketed effect of bottom plate,which is simply regarded as a safety margin,on the improvement of bearing capacity.To study the influence of rock socketed effect on the bearing capacity of gravity anchor,this paper designed two groups of indoor scale model tests on non-rock-socketed and rock-socketed gravity anchors with a scale of 1∶50 to discuss the bearing capacity and load …

Theoretical And Experimental Studies On Adaptive Spatial Rotating Main Cable Saddle, Chen Yuanlin, Huang Anming, Chen Long, Xie Jun

Journal of China & Foreign Highway

To ensure the accuracy of the main cable alignment during adaptive rotation,an adaptive spatial rotating main cable saddle suitable for spatial suspension bridges was designed.The main cable saddle had two adaptive rotating pair mechanisms with axes passing through the IP point.By using a specific suspension bridge as a case study,the design was validated through a combination of finite element analysis and model testing to assess the reliability and structural safety of the adaptive rotation mechanism.The results show that the adaptive spatial rotating main cable saddle can automatically adjust its orientation based on variations in the main cable load during construction,with …

Section Form Of Open-Cut Tunnel By Ultra-Large-Diameter Shield Empty-Push Technology, Sun Chao, Zhang Guangwei

Journal of China & Foreign Highway

Based on the engineering background of the open-cut section by the shield machine with overall movement in the rapid transformation project of Wanghai Road,Shenzhen City,the structural stress and economy of three types of section forms under construction and operation conditions were analyzed to determine the optimal section design.The load-structure model was used to analyze the parameters affecting the internal force of the optimal section.The research results show that the top and bottom plates and side walls in the scheme with ribs set at the corner (scheme 3) have uniform force,and force during the construction period is close to that during …

Application Of Superelevation Detection Technology In Ship Collision Prevention System Of Cross-Sea Bridges, Song Xiaodong, Duan Min, Ren Quanli, Hu Jianan, Yang Naiheng, Chen Jingwen, Tong Jianrong

Journal of China & Foreign Highway

Cross-sea bridges are an important component of national infrastructure and an important regional transportation hub,which have a significant impact on economic development,regional integration,and cultural exchange.Ship superelevation is an important factor that threatens the safety of bridges.Therefore,superelevation detection is an important means to improve the service level of channel navigation,standardize the navigation order of ships in the water area near the bridge,and enhance the ship collision prevention ability of bridges.This paper conducted theoretical analysis and engineering feasibility research on superelevation detection by using laser alignment,laser ranging,optoelectronic detection,LiDAR detection,and machine vision.According to the superelevation detection requirements of the Hong Kong-Zhuhai-Macao Bridge,two technical …