Materials Science and Engineering Commons^™

Ohmic Contacts For Fabrication Of Sic Cmos Devices, Anthony Di Mauro

Graduate Theses and Dissertations

Today’s world of electronics is dominated by semiconductor devices which utilize silicon as their substrate material. Though, silicon is not ideal for semiconductor devices in high-voltage or high-temperature applications. Additionally, the efficiency of silicon devices becomes drastically reduced in nonideal operating conditions. Therefore, finding alternatives to silicon?based devices has been a topic for decades now. A few great candidates to replace silicon devices for said applications include Silicon Carbide (SiC), Gallium Nitride (GaN), and Aluminum Arsenide (AlAs). SiC has grown its reputation as the best candidate, when compared to other potential alternatives, due to its wide bandgap, high operating frequency, …

Aqueous Supercapacitors With Wide Operative Voltage Window And Long Cycling Life Enabled By Electrolyte Hybridization Effect, Shi-Hua Ma, Qi Yin, Jin-Ping Zhao

Journal of Electrochemistry

Developing supercapacitors (SCs) with long cycling life and wide operative voltage window is a significant topic in the field of aqueous electrolytes. Although the design of water in salt (WIS) electrolytes has pushed the development of aqueous electrolytes to a new height, the WIS electrolytes with an operative voltage window of up to 2.5 V is still very scarce. Herein, in order to enrich the type of aqueous electrolyte with high operative voltage, tetramethylammonium trifluoromethanesulfonate (TMAOTf) based WIS electrolyte was used as a model to construct WIS based hybrid electrolyte with acetonitrile (ACN) co-solvent and LiTFSI co-solute. In view of …

The 9th National Conference Of Solid State Battery Successfully Held In Xiamen, Fujian, Zheng-Liang Gong

Journal of Electrochemistry

No abstract provided.

Journal Of Electrochemistry, The Flagship Journal Of Chinese Chemical Society Electrochemical Committee, Made A Public Appearance At The 22nd National Electrochemical Congress, Editorial Office Of J.Electrochem.

Journal of Electrochemistry

No abstract provided.

The Award Ceremony Of The 2nd Xiamen University Short Video Abstract Contest For Science And Technology Journal Papers Came To A Successful Conclusion, Editorial Office Of J.Electrochem.

Journal of Electrochemistry

No abstract provided.

Understanding The Plastic Issue (Poster Presentation), Regan Bossie, Peter Nguyen, John Mcswiggin, Adam Meadows

Sustainability Conference

The Plastic-Free Campus Initiative is an Embry-Riddle initiative advocating for the reduction and elimination of single-use plastics on the Daytona Beach campus.

Our poster presentation aims to highlight current issues and concerns by presenting plastic production trends, quantifying how plastic pollution has affected global ecosystems, and discussing the material characteristics of plastics and their consequences. The poster will provide an overview of the current state of global recycling and will outline key concerns that microplastics, and plastics in general, pose to public health. By presenting the current facts and concerns related to plastic and recycling, we hope to encourage individuals …

Computational Design Of Complex Concentrated Alloys, Hamid Sharifi

Doctoral Dissertations

A high-throughput parameterization of modified embedded atom model (MEAM) interatomic potentials for combinations of Cu, Ti, Ni, Cr, Co, Al, Fe, and Mn was carried out using a genetic algorithm. Unary systems were parameterized based on DFT calculations and experimental results. MEAM potentials for 28 binary and 56 ternary combinations of the elements were parameterized to DFT results that were carried out with semi-automated frameworks. Specific attention was made to reproduce properties that impact compositional segregation, material strength, and mechanics. Utilizing the MEAM interatomic potentials and a Monte Carlo scheme, phase segregation in the CrNiCo, CuNiCr and CuNiCo fcc alloys …

Machine Learning-Driven Process Analysis And Optimization In Solid-State Welding And Fusion-Based Additive Manufacturing, Radif Uddin Ahmed

Master's Theses

In the modern era of advanced manufacturing, optimizing process parameters is pivotal in ensuring the quality and reliability of sophisticated component fabrication. This study presents a novel, data-driven approach to parameter optimization in two cutting-edge manufacturing techniques: Friction Stir Welding (FSW) and Laser Powder Bed Fusion (LPBF). By leveraging machine learning methodologies, this research addresses the critical challenge of efficiently determining optimal process parameters, a task traditionally relying on time-consuming and resource-intensive trial-and-error methods. This study will lead to a robust data-driven framework for process analysis of more advanced manufacturing techniques like the Additive Friction Stir Deposition (AFSD) process. Friction …

Quantifying Chemomechanical Weakening In Muscovite Mica With A Simple Micromechanical Model, Jordan J. Sickle, William M. Mook, Frank W. Delrio, Anastasia G. Ilgen, Wendelin Wright, Karin A. Dahmen

Faculty Journal Articles

In response to gradual nanoindentation, the surface of muscovite mica deforms by sudden stochastic nanometer-scale displacement bursts. Here, the statistics of these displacement events are interpreted using a statistical model previously used to model earthquakes to understand how chemically reactive environments alter the surface properties of this material. We show that the statistics of nanoindentation displacement bursts in muscovite mica are tuned by chemomechanical weakening in a manner similar to how the statistics of model events are tuned by a mechanical weakening parameter that describes how easily system-spanning cracks can be nucleated. Because the predictions of this model are independent …

Refining Chlorosulfonation Methods For The Synthesis Of A Perfluoroalkyl Arylsulfonimide (Pfsi) Monomer, Ainsley P. Foster, Benjamin Varney, Hua Mei

Science University Research Symposium (SURS)

Proton-exchange membrane (PEM) fuel cells are sources of energy that are clean, quiet, and highly responsive to changes in power needs, making them promising for use in automobiles and other portable power devices. The electrolyte of a PEM cell–the layer responsible for conductivity–is a polymer membrane, commonly consisting of perfluoroalkyl sulfonic acid (PFSA) polymers. Perfluoroalkyl arylsulfonimide (PFSI) polymers are expected to improve the efficiency of PEM fuel cells through optimal stability and proton conductivity. The trifluovinylether (TFVE) aryl perfluorosulfonamide monomer is a new PFSI monomer proposed to fulfill these benefits once polymerized. A six-step synthesis route was initially designed to …

Liquid Crystalline Collagen Assemblies As Substrates For Directed Alignment Of Human Schwann Cells, Homa Ghaiedi, Luis Carlos Pinzon-Herrera, Saja Alshafeay, Leonard Harris, Jorge Almodovar, Karthik Nayani

Chemical Engineering Faculty Publications and Presentations

Collagen is a key component of the extracellular matrix (ECM) and well-oriented domains of collagen are important for mimicking the local cell environment in vitro. While there has been significant attention directed towards the alignment of collagen, formation of large-scale oriented domains remains a key challenge. Type I collagen self-assembles to form liquid crystalline (LC) mesophases in acidic conditions at concentrations above 100 mg mL−1. The LC mesophase provides an efficient platform for large-scale alignment and patterning of collagen coated substrates. However, there still exist challenges related to solubilizing and processing of collagen at such high concentrations in order …

Size And Shape Dependence Of Hydrogen-Induced Phase Transformation And Sorption Hysteresis In Palladium Nanoparticles, Xingsheng Sun, Rong Jin

Chemical and Materials Engineering Faculty Publications

Phase transitions of metals in hydrogen (H) environments are critically import- ant for applications in energy storage, catalysis, and sensing. Nanostructured metallic particles can lead to faster charging and discharging kinetics, increased lifespan, and enhanced catalytic activities. However, establishing a direct causal link between nanoparticle structure and function remains challenging. In this work, we establish a computational framework to explore the atomic config- uration of a metal-hydrogen system when in equilibrium with a H environ- ment. This approach combines Diffusive Molecular Dynamics with an itera- tion strategy, aiming to minimize the system’s free energy and ensure uniform chemical potential across …

Insulator-To-Metal Transition And Isotropic Gigantic Magnetoresistance In Layered Magnetic Semiconductors, Gokul Acharya, Bimal Neupane, Chia-Hsiu Hsu, Xian P. Yang, David Graf, Eun Sang Choi, Krishna Pandey, Md Rafique Un Nabi, Santosh Karki Chhetri, Rabindra Basnet, Sumaya Rahman, Jian Wang, Zhengxin Hu, Bo Da, Hugh O.H. Churchill, Guoqing Chang, M. Zahid Hasan, Yuanxi Wang, Jin Hu

Physics Faculty Publications and Presentations

Magnetotransport, the response of electrical conduction to external magnetic field, acts as an important tool to reveal fundamental concepts behind exotic phenomena and plays a key role in enabling spintronic applications. Magnetotransport is generally sensitive to magnetic field orientations. In contrast, efficient and isotropic modulation of electronic transport, which is useful in technology applications such as omnidirectional sensing, is rarely seen, especially for pristine crystals. Here a strategy is proposed to realize extremely strong modulation of electron conduction by magnetic field which is independent of field direction. GdPS, a layered antiferromagnetic semiconductor with resistivity anisotropies, supports a field-driven insulator-to-metal transition …

Lithicone-Protected Lithium Metal Anodes For Lithium Metal Batteries With Nickel-Rich Cathode Materials, Ridwan A. Ahmed, Kevin V. Carballo, Krishna P. Koirala, Qian Zhao, Peiyuan Gao, Ju-Myung Kim, Cassidy S. Anderson, Xiangbo Meng, Chongmin Wang, Ji-Guang Zhang, Wu Xu

Mechanical Engineering Faculty Publications and Presentations

The high energy density advantage of lithium (Li) metal batteries (LMBs) makes them increasingly desirable; however, problems such as strong reactivity and dendrite growth of Li metal anode limit their practical uses. In this work, a novel Li-containing glycerol (LiGL) or lithicone protection layer on a 50 μm thick Li metal anode is employed for improving the performance of LMBs. This LiGL layer was accurately deposited via a molecular layer deposition (MLD) process at 150°C, using lithium tert-butoxide and glycerol as precursors. The as-formed LiGL coating layer is highly tunable in its thickness by simply adjusting MLD cycles and shows …

Progress And Prospects Of Road Engineering Disease Treatment Technology In Permafrost Regions, Gao Feng, Zeng Xianzhang, Zhong Wenhua, Huang Shengyong, Zhang Junhui

Journal of China & Foreign Highway

Freeze-thaw disasters are key issues affecting the service performance and operational safety of road projects in permafrost regions.Under the combined influence of warming and humidification of the permafrost environment and engineering thermal effects，the degradation of permafrost is accelerating，exacerbating the risk of road freeze-thaw diseases.Roads in these regions are more frequently maintained and repaired to ensure service performance，with a service life lower than designed.Therefore，deepening the understanding of the disaster mechanism of road geotechnical structures and strengthening the study on engineering disease treatment technology are of great significance in promoting the construction and maintenance of high-quality and high-grade highways in frozen regions.This …

Treatment Methods Of Unstable Expansive Soil Slope Excavation In Overlying Rock Layer In Alpine Region, Shi Xiaobo, Cui Guangyan, Mou Chao, Wen Ye, Xie Feng, Fu Xiaoyang

Journal of China & Foreign Highway

To deeply study the treatment method for instability of highway cutting slope under the condition of expansive soil overlying rock layer in an alpine region，the comprehensive treatment method of unstable slope under this bad geology was put forward based on the unstable slope project of Zhangbei‒Shangyi Expressway.The governance protection structure consisted of a rigid protection system，drainage system，thermal insulation system，flexible protection system，and waterproof system.The rigid protection system was an anti-slide pile setting at the height of 1/3 of the first grade slope，of which parameters were calculated by cutting the slope of the rock layer in the unstable area to reduce the …

Review Of Snow And Ice Melting Techniques For Road And Bridge In Cold Regions, Tang Liyun, Shao Haitao, Tang Huaming, Qiu Peiyong, Du Xiaoqi, Zhang Lei, Peng Hui

Journal of China & Foreign Highway

Snow and ice melting of road and bridge surfaces is crucial for traffic safety，but current research on snow and ice melting techniques mainly focuses on engineering effects and technical evaluation，without the analysis and elaboration from the perspective of their mechanisms.To this end，based on the different mechanisms，this study divided snow and ice melting techniques into three types and summarized them：passive deicing，active deicing，and energy utilization deicing.This study systematically evaluated the advantages and disadvantages of traditional deicing methods such as deicing agents and mechanical deicing，analyzed two active deicing techniques，namely inhibitive freezing pavement and phase change material pavement，discussed the environmental-friendly method for road deicing …

Properties And Application Of Cement Improved Loess Under Low Temperature Environment In Cold Region, Li Xiangyang

Journal of China & Foreign Highway

According to the cold climate and low annual average temperature in cold regions of China，the field curing conditions of cement improvement of collapsibility loess under low temperature，room temperature，and medium temperature were simulated at 5 ℃，10 ℃，20 ℃，and 30 ℃，respectively.Based on laboratory experiments，this study analyzed the effects of curing temperature，cement content，and curing age on RCBR，unconfined compressive strength，and dynamic resilience modulus of cement improved loess.The effects of cement content and curing temperature on freeze-thaw durability and erosion resistance of cement improved loess were studied by the freeze-thaw cycle test and dynamic water erosion test.Combined with the laboratory results，the 4% and 5% cement …

Effect Of Chloride Ions On Salt Expansion Of Salinized Subgrade Fill Soil In Cold Regions, Hu Wenzhu, Wang Zhaowei, Cao Yong, Zhang Jing, Bai Ruiqiang

Journal of China & Foreign Highway

Salinized subgrade fill soil in cold regions typically comprises composite saline soil rich in sodium chloride and sodium sulfate.This study aimed to explore the mechanism of the effect of chloride ion content on salt expansion of the salinized subgrade in cold regions.Based on the calculation theory of the sodium chloride-sodium sulfate-water ternary system solution in the Pitzer ion model and combined with the FREZCHEM model，the study quantitatively analyzed the intrinsic connection between water activity，freezing factor，and supersaturation ratio with temperature and concentration ratio （η=mCl-/mSO2-4）.It investigated the variation patterns of the freezing temperature and crystallization supersaturation ratio of composite saline soil with …

Model Test On Soil Deformation Mechanism And Damage Mode Caused By Mud Leakage From Drilled Piles In Karst Area, Jiang Mingying, Chen E ’Mei, Liu Yongcheng, Zhu Yadong, Jiang Wenkui, Xie Ruiting

Journal of China & Foreign Highway

Pile holes are often drilled through cavities in karst areas，which induces mud leakage and causes hole wall instability，ground collapse，or equipment trapping and hinders smooth construction.It is important to know the collapse mechanism of boreholes due to mud leakage，so as to optimize and determine the construction process of pile holes.In this paper，indoor model tests were used to study the deformation mechanism and damage mode of soil caused by drilling through cavities and mud leakage in pile holes under the conditions of upper clay and lower sandy soil in the karst area，so as to provide an experimental basis for the decision of …

Back‑Calculation Of Subgrade Modulus Based On Genetic Algorithm And Viscoelasticity Theory, Dai Fugui, Wang Xihui, Wu Yaguang, Li Hai

Journal of China & Foreign Highway

To improve the applicability of the PFWD detection method for the back-calculation of subgrade modulus，taking the subgrade splicing project of the west loop line in Nairobi as an example，this paper adopted 3D Kelvin viscoelasticity model and quasi-static response analysis to deduce the displacement function of viscoelastic subgrade under long-term fixed loads，and combined the principle of liner superposition of viscoelasticity with genetic algorithm to propose a new method based on multi-population genetic algorithm for the modulus back-calculation of viscoelastic subgrade.Among them，the corresponding program for back-calculation was written by Matlab.The comparison between theoretical derivation and field tests shows that the peak value …

Correlation Between Pavement Distress And Structural Hidden Distress, Liu Xianming, Xia Han, Hu Dongping, Yan Chen, Yang Rui, Zhong Xinran

Journal of China & Foreign Highway

The hidden distress in the pavement structure does great harm to the performance and service life of the road.In this work，based on the statistical idea of pavement distress rate in the Highway Performance Assessment Standards （JTG 5210—2018），an index of characterizing hidden distress in the pavement structure，namely pavement structure distress rate，was proposed.Based on the actual highway inspection project，the pavement distress and the hidden distress in the depth of 1 m below the pavement of a two-way four-lane highway with a length of 38 km were studied.The overall situation of pavement distress and hidden distress and their spatial distribution were analyzed statistically …

Review Of Evaluation Methods For Mixing Workability Of Asphalt Mixture, Dong Fuqiang, Zu Yuanzhe, Yu Xin, Chen Bei, Liu Lin

Journal of China & Foreign Highway

To clarify the evaluation methods an d research status of mixing workability of asphalt mixture， by consulting relevant research literature in China and abroad and analyzing different evaluation methods，indexes，and research findings of the workability of asphalt mixture，the applicability and evaluation effects of different workability evaluation methods were systematically summarized，and the comparative analysis and comprehensive review were made on the main influencing factors of the mixing workability.The results show that in most evaluation methods for the mixing workability of asphalt mixture，corresponding indexes are constructed to quantitatively evaluate the workability by quantifying the resistance or energy consumption in the mixing process.Besides，in some …

Research Review Of Biomass Ash As Concrete Admixture, Ma Bicong, Liang Jian, Weng Yiling

Journal of China & Foreign Highway

In order to provide a comprehensive overview of research progress in the use of biomass ash as concrete admixture，the physical and chemical properties，mechanism of action，factors affecting the production process of biomass ash，and the effects of biomass ash incorporation on the working properties，mechanical properties，and durability of concrete were studied.The results show that biomass ash has a smaller density and a larger specific surface area than traditional mineral admixture，and the total amount of active components，namely SiO2 + Al2O3 + Fe2O3 （SAF） in most biomass ashes exceeds the requirements of class F volcanic ash （≥70%）.Incorporating biomass ash can effectively improve the mechanical properties …

Structural Repair And Performance Evaluation Of Aged Sbs Modified Asphalt, Xu Guang, Li Qishi, Kuang Huaping, Zhang Henglong, Zhou Ruibo, Chen Yanmei

Journal of China & Foreign Highway

To rejuvenate the excellent performance of aged styrene-butadiene-styrene （SBS） modified asphalt，colza oil bio-asphalt （COA） and polymethylene polyphenyl isocyanate （PAPI） were used in this study for adjusting the asphalt components and repairing SBS molecular structure，respectively.The above-mentioned dual regeneration mechanism was verified by comparing the effects of different rejuvenation components on the physical and rheological properties，as well as the molecular weight distribution of short-term aged SBS modified asphalt.Moreover，according to the change law of rheological properties of unaged base asphalt and SBS modified asphalt under the effect of dual regeneration agent，the influence of the regeneration agent on the phase angle platform area was …

Compaction Characteristics Of Granular Material And Its Structural Mechanical Behavior Considering Orthotropy, Huang You, Zhang Yunbao, Liu Zhaohui, Pan Yu, Liu Zebin, Fang Ronghai

Journal of China & Foreign Highway

The orthotropy of granular materials is closely related to the compaction process and has a significant impact on the mechanical behavior of pavement structures.In this study，in order to study the effect of the compaction process on the orthotropy of granular materials，different compaction methods and compaction energies were employed to compact granular materials for pavement into specimens，and improved dynamic resilient mechanical tests were conducted.Orthotropic coefficients （α2） of typical granular materials were obtained，and the finite element method was used to conduct mechanical analysis of asphalt pavement structures considering the orthotropy of granular materials.The results show that the dry density of specimens by …

Effect Of Basalt Fiber On Strength Of Cement‑Stabilized Macadam Base, Shu Hongbo, Tang Zhengguang, Zhang Yanhong, Bu Xilian, Liang Dong

Journal of China & Foreign Highway

To study the performance of basalt fiber in improving the poor angularity of the crushed cobble base，based on the orthogonal test，this paper determined that the optimal dosage of basalt fiber in the cement-stabilized crushed cobble was 1 kg/m3 （15 mm） + 2 kg/m3 （25 mm）.Besides，unconfined compressive strength and splitting strength tests were carried out on mixtures under three working conditions including the cement-stabilized crushed cobble，cement-stabilized crushed cobble with the optimal dosage of basalt fiber，and cement-stabilized macadam （limestone machine-crushed stone ）.The results show that influenced by the aggregate angularity，the strength of the cement-stabilized macadam （limestone machine-crushed stone ） mixture is better …

Vessel Collision Force And Anti‑Collision Performance Of Long‑Span Beam‑Arch Composite Rigid Frame Bridge, Zhang Wenming, Wang Zhiwei, Lai Yaping

Journal of China & Foreign Highway

Beam-arch composite rigid frame bridge is a new bridge type，and it has few vessel collision studies.By taking the Lijia Jialing River Bridge as the engineering background，the standard value of vessel collision force and anti-collision performance of the long-span beam-arch composite rigid frame bridge were studied.After determining the representative vessel type and vessel collision calculation conditions，the vessel-bridge collision processes of the single-pier models under various calculation scenarios were simulated by using ANSYS/LS-DYNA nonlinear finite element transient dynamic software.The simulation results of collision forces were compared with the results of several empirical formulas.Finally，the full bridge model and the ultimate bearing capacity of …

Installation And Connection Mode Of Stiffening Beam Segment Of Steel Truss Suspension Bridge, Chen Changsong, Wu Junjie

Journal of China & Foreign Highway

During the construction of long-span steel truss suspension bridges，the main girder can be connected in segment-by-segment articulated connection method and rigid-articulated connection combination method.Taking a Yangtze River Highway Bridge in Hubei Province as an example，this paper established the plane calculation model of the full bridge using the Bridge Design and Construction Monitoring System BDCMS to simulate the above two connection methods of the main girder in construction.From the comprehensive analysis of chord member internal forces and line shape of the stiffening beam，this paper finds that the rigid-articulated connection combination method is more appropriate in the construction.In addition，this paper researched the …

Seismic Responses Of Cable‑Sta Yed Bridge Considering Ponding Effect Under Near‑Fa Ult Ground Motions, Lyu Long, Yu Deen, Yuan Yuhang, Yang Huaiyu

Journal of China & Foreign Highway

To study the influence of the pon ding e ffect on seismic responses of the cable-stayed bridge under near-fault ground motions，taking a double-tower cable-stayed bridge as the engineering background，this paper analyzed the ponding response of the main bridge and the main beam of the approach bridge of the cable-stayed bridge under near-fault ground motions and the influence of the ponding response on the structural seismic response.Besides，the influence of viscous dampers and elastic cables on the ponding effect of the cable-stayed bridge under near-fault ground motions was studied，which was compared with the seismic response of the cable-stayed bridge under far-fault ground …