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Full-Text Articles in Engineering

In Vitro Blood Clot Formation And Dissolution For Testing New Stroke-Treatment Devices, Kayla Wood, Sam E. Stephens, Feng Xu, Alshaimaa Hazaa, James C. Meek, Hanna K. Jensen, Morten O. Jensen, S. Ranil Wickramasinghe Aug 2022

In Vitro Blood Clot Formation And Dissolution For Testing New Stroke-Treatment Devices, Kayla Wood, Sam E. Stephens, Feng Xu, Alshaimaa Hazaa, James C. Meek, Hanna K. Jensen, Morten O. Jensen, S. Ranil Wickramasinghe

Biomedical Engineering Faculty Publications and Presentations

Strokes are among the leading causes of death worldwide. Ischemic stroke, due to plaque or other buildup blocking blood flow to the brain, is the most common type. Although ischemic stroke is treatable, current methods have severe shortcomings with high mortality rates. Clot retrieval devices, for example, can result in physically damaged vessels and death. This study aims to create blood clots that are representative of those found in vivo and demonstrate a new method of removing them. Static blood clots were formed using a 9:1 ratio of whole sheep blood and 2.45% calcium chloride solution. This mixture was heated …


Comparative Study And Design Optimization Of A Dual-Mechanical-Port Electric Machine For Hybrid Electric Vehicle Applications, Hao Chen, Ayman M. El-Refaie, Yuefei Zuo, Shun Cai, Libing Cao, Christopher H. T. Lee Aug 2022

Comparative Study And Design Optimization Of A Dual-Mechanical-Port Electric Machine For Hybrid Electric Vehicle Applications, Hao Chen, Ayman M. El-Refaie, Yuefei Zuo, Shun Cai, Libing Cao, Christopher H. T. Lee

Electrical and Computer Engineering Faculty Research and Publications

A new dual-mechanical-port (DMP) electric machine for hybrid electric vehicle applications, particularly in the power-split continuously variable transmission systems, is proposed in this paper. In order to comprehensively and quantitatively evaluate the pros and cons of the proposed machine, a comparative study of four DMP electric machines with different topologies is conducted. These four investigated DMP electric machines include a conventional DMP machine, a DMP machine with spoke-type permanent magnets, a DMP machine with reluctance rotor, and a DMP machine with open slots which is the proposed machine in this paper. Even though these four machines have similar topologies, they …


Optimization Of Solar-Coal Hybridization For Low Solar Augmentation, Aaron T. Bame, Joseph Furner, Ian Hoag, Kasra Mohammadi, Kody Powell, Brian D. Iverson Aug 2022

Optimization Of Solar-Coal Hybridization For Low Solar Augmentation, Aaron T. Bame, Joseph Furner, Ian Hoag, Kasra Mohammadi, Kody Powell, Brian D. Iverson

Faculty Publications

This work presents a process to determine the preliminary optimal configuration of a concentrating solar power-coal hybrid power plant with low solar augmentation, and is demonstrated on a regenerative steam Rankine cycle coal power plant in Castle Dale, UT, USA (average DNI of 542 W m−2). A representative plant model is developed and validated against published data for a coal power plant. The simplifications that lead to the representative model from a coal power plant model include combining multiple feedwater heaters, combining turbines, and using a mass-average calculation for extraction steam properties. Comparing net power generation and boiler …


Application Of Deep Learning For Medical Sciences And Epidemiology Data Analysis And Diagnostic Modeling, Somenath Chakraborty Jul 2022

Application Of Deep Learning For Medical Sciences And Epidemiology Data Analysis And Diagnostic Modeling, Somenath Chakraborty

Dissertations

Machine Learning and Artificial Intelligence have made significant progress concurrent with new advancements in hardware and software technologies. Deep learning methods heavily utilize parallel computing and Graphical Processing Units(GPU). It is already used in many applications ranging from image classification, object detection, segmentation, cyber security problems and others. Deep Learning is emerging as a viable choice in dealing with today’s real-time medical problems. We need new methods and technologies in the field of Medical Science and Epidemiology for detecting and diagnosing emerging threats from new viruses such as COVID-19. The use of Artificial Intelligence in these domains is becoming more …


Analytical Investigation Of Sound Radiation From Functionally Graded Thin Plates Based On Elemental Radiator Approach And Physical Neutral Surface, B. N. Singh, R. N. Hota, S. Dwivedi, Ratneshwar Jha, V. Ranjan, K. Řehák Jul 2022

Analytical Investigation Of Sound Radiation From Functionally Graded Thin Plates Based On Elemental Radiator Approach And Physical Neutral Surface, B. N. Singh, R. N. Hota, S. Dwivedi, Ratneshwar Jha, V. Ranjan, K. Řehák

Henry M. Rowan College of Engineering Departmental Research

This paper analyzes the sound radiation behavior of a clamped thin, functionally graded material plate using the classical plate theory and Rayleigh Integral with the elemental radiator approach. The material properties of the plate are assumed to vary according to the power-law distribution of the constituent materials in the transverse direction. The functionally graded material is modeled using a physical neutral surface instead of a geometric middle surface. The effects of the power-law index, elastic modulus ratio, different constituent materials, and damping loss factor on the sound radiation of functionally graded plate are analyzed. It was found that, for the …


Control Mechanisms For Adaptive Nanoscale Devices, David Arredondo Jul 2022

Control Mechanisms For Adaptive Nanoscale Devices, David Arredondo

Nanoscience and Microsystems ETDs

Nanotechnology promises to revolutionize many areas of applied science including materials, synthetic biology, and medicine. Devices may consist of solution-phase information processing systems or molecular robots. Of particular interest are DNA-based systems due to their composability and relatively simple interactions that are suited to bottom-up design. This work introduces high-level designs of robust control mechanisms for nanoscale devices with immediate applications in molecular computing, synthetic biology, and DNA robotics.

Nanoscale systems are dominated by probabilistic chemical behavior, so engineers must take careful consideration to produce predictable systems. Probabilistic behavior in chemical reaction networks (CRNs) yields deterministic evolution of species concentrations …


The Migrant Crisis At The U.S. Southern Border, Matthew Ingber, Conner Muth, Nathanael Hall Jul 2022

The Migrant Crisis At The U.S. Southern Border, Matthew Ingber, Conner Muth, Nathanael Hall

Immigration Scholarship: History, Trends and Development in Global Immigration

The immigration policy of The United States of America is a divisive topic within American society. There is no doubt that this policy needs reform. This paper will investigate the ways in which The U.S. immigration policy at the Southern border negatively impacts those seeking asylum and will conclude with suggested policy changes that would potentially have the greatest positive impact on these individuals. Ever since 2016 media outlets have declared war on people crossing the southern border illegally. Media giants such as Fox News have repeatedly grouped those individuals within the same constructs as rapists, gang members, drug smugglers, …


Hydrochemistry Of High-Mountain Pamir Rivers: Formation, Changes And Influence On The Chemical Composition Of Irrigation Water, Parviz Inomovich Normatov, Inom Normatov, Akobir Karimzoda, Rano Eshankulova, Ayubdzon Normatov, Nurmakhmad Shermatov Jul 2022

Hydrochemistry Of High-Mountain Pamir Rivers: Formation, Changes And Influence On The Chemical Composition Of Irrigation Water, Parviz Inomovich Normatov, Inom Normatov, Akobir Karimzoda, Rano Eshankulova, Ayubdzon Normatov, Nurmakhmad Shermatov

Journal of Environmental Science and Sustainable Development

The purpose of the research is to analyze the prospects for the agriculture development in the Central Asian region and Tajikistan in particular, in terms of identifying the main favorable and constraining factors for the further agriculture development. The Pyanj river is one of the main tributaries of the Transboundary Amu Darya River in the Central Asian region, whose waters are a source of drinking water supply for the population and 80% used for irrigation of agricultural land. The trend of deteriorating water quality of Central Asian River systems recently has been increasing, and monitoring water quality from the formation …


Isogeometric Reconstruction And Crash Analysis Of A 1996 Body-In-White Dodge Neon, Kendrick M. Shepherd Jul 2022

Isogeometric Reconstruction And Crash Analysis Of A 1996 Body-In-White Dodge Neon, Kendrick M. Shepherd

Faculty Publications

Isogeometric analysis (IGA) has attracted attention from academia and industry because of its high-fidelity results, ability to represent geometry exactly, and potential to streamline the engineering design-through-analysis process. However, one of the greatest challenges limiting the scope of IGA is the ability to rapidly convert CAD geometry into a set of splines suitable for engineering analysis¾particularly for a wide set of shapes of industrial relevance. In this presentation, we describe a new, mathematically rigorous, potentially automatable framework using Ricci flow and subsequent metric optimization through which surface geometries can be rebuilt as sets of watertight, analysis-suitable, boundary-conforming semistructured NURBS patches. …


Optimized Three Deep Learning Models Based-Pso Hyperparameters For Beijing Pm2.5 Prediction, Andri Pranolo, Yingchi Mao, Aji Prasetya Wibawa, Agung Bella Putra Utama, Felix Andika Dwiyanto Jul 2022

Optimized Three Deep Learning Models Based-Pso Hyperparameters For Beijing Pm2.5 Prediction, Andri Pranolo, Yingchi Mao, Aji Prasetya Wibawa, Agung Bella Putra Utama, Felix Andika Dwiyanto

Knowledge Engineering and Data Science

Deep learning is a machine learning approach that produces excellent performance in various applications, including natural language processing, image identification, and forecasting. Deep learning network performance depends on the hyperparameter settings. This research attempts to optimize the deep learning architecture of Long short term memory (LSTM), Convolutional neural network (CNN), and Multilayer perceptron (MLP) for forecasting tasks using Particle swarm optimization (PSO), a swarm intelligence-based metaheuristic optimization methodology: Proposed M-1 (PSO-LSTM), M-2 (PSO-CNN), and M-3 (PSO-MLP). Beijing PM2.5 datasets was analyzed to measure the performance of the proposed models. PM2.5 as a target variable was affected by dew point, pressure, …


Passive Prosthetic Ankle Design Based On Indonesian Anthropometry, Wahyu Dwi Lestari Jul 2022

Passive Prosthetic Ankle Design Based On Indonesian Anthropometry, Wahyu Dwi Lestari

Journal of Mechanical Engineering Science and Technology (JMEST)

Foot prosthesis is a replacement for the foot to overcome activity limitations due to disease, birth defects, accidents, or amputations. Many foot prosthetics have been developed in recent years to treat patients. However, prostheses on the market today have drawbacks, including their high price, lack of comfort, stiff ankles, and low durability. The main objective of this study is to develop an existing ankle-foot prosthesis design that approximates the resemblance of a human foot according to the anthropometry of Asians, especially Indonesians. This study contains the design of a prosthetic foot with a skin design model and a support core. …


Surface Quality Of Fe, Ni And Cr Added Hyper-Eutectic Al-Si Automotive Alloys Under Up-Milling And Down-Milling Operation, Akib Abdullah Khan, Mashiur Rahman Shoummo, Mohammad Salim Kaiser Jul 2022

Surface Quality Of Fe, Ni And Cr Added Hyper-Eutectic Al-Si Automotive Alloys Under Up-Milling And Down-Milling Operation, Akib Abdullah Khan, Mashiur Rahman Shoummo, Mohammad Salim Kaiser

Journal of Mechanical Engineering Science and Technology (JMEST)

Effect of the elements Fe, Ni, and Cr on the surface quality under machining of hyper-eutectic aluminiumbased Al-Si automotive alloys has been carried out as the elements improve the properties of this alloy. Machining is done on a horizontal type milling machine using a high-speed steel slab milling cutter in dry condition. Only the cutting speed varies throughout the experiment, while the machining feed and depth of cut remain fixed. The experimental results show that the addition of these alloying elements increases the roughness and hardness specially due to formation of Fe-rich intermetallic ��-����5��������. However, the needle-like ��-����5�������� has been …


Effect Of Variation Of Sic Mass Fraction On Mechanical Properties Of Al-Sic Composite Using Stir Casting Method, Sumarji Sumarji, Naufal Fardio Albajili, Mahros Darsin, Rahma Rei Sakura, Andi Sanata Jul 2022

Effect Of Variation Of Sic Mass Fraction On Mechanical Properties Of Al-Sic Composite Using Stir Casting Method, Sumarji Sumarji, Naufal Fardio Albajili, Mahros Darsin, Rahma Rei Sakura, Andi Sanata

Journal of Mechanical Engineering Science and Technology (JMEST)

Al-SiC is a composite composed of AA6061 as a matrix and SiC as a reinforcement particle. The variation of mass added will affect the mechanical properties of the composite because Al-SiC is hardenable, which means that its mechanical properties can be improved by adding the reinforcement component. However, an excessive portion of SiC leads to a decrease in mechanical properties. The purpose of this study was to find the optimal composition of the addition of SiC into the aluminium matrix to gain maximum tensile strength and hardness. The mass fraction variation that would be used in this composite was the …


Effect Of Homogenization Pressure On Bacterial Cellulose Membrane Characteristic Made From Pineapple Peel Waste, Muhamad Muhajir, Heru Suryanto, Yanuar Rohmat Aji Pradana, Uun Yanuhar Jul 2022

Effect Of Homogenization Pressure On Bacterial Cellulose Membrane Characteristic Made From Pineapple Peel Waste, Muhamad Muhajir, Heru Suryanto, Yanuar Rohmat Aji Pradana, Uun Yanuhar

Journal of Mechanical Engineering Science and Technology (JMEST)

Many studies were conducted to maintain the environment by reducing the waste, especially pineapple peel waste. This study aims to explore the effect of various pressure of the homogenization process on bacterial cellulose membrane surface morphology and structure produced using extract of pineapple peel waste. The methods include the preparation of pellicle samples from the product of the fermentation process of Acetobacter xylinum using a medium from the extract of pineapple peel waste. Bacterial cellulose pellicles were crushed using a blender. Mashed bacterial cellulose pellicle was homogenized in High-Pressure Homogenizer with pressure variation of 150 bar, 300 bar, 450 bar, …


Machine Vision For The Various Road Surface Type Classification Based On Texture Feature, Susi Marianingsih, Widodo Widodo, Marla Sheilamita S. Pieter, Evanita Veronica Manullang, Hendry Y. Nanlohy Jul 2022

Machine Vision For The Various Road Surface Type Classification Based On Texture Feature, Susi Marianingsih, Widodo Widodo, Marla Sheilamita S. Pieter, Evanita Veronica Manullang, Hendry Y. Nanlohy

Journal of Mechanical Engineering Science and Technology (JMEST)

The mechanized ability to specify the way surface type is a piece of key enlightenment for autonomous transportation machine navigation like wheelchairs and smart cars. In the present work, the extracted features from the object are getting based on structure and surface evidence using Gray Level Co-occurrence Matrix (GLCM). Furthermore, K-Nearest Neighbor (K-NN) Classifier was built to classify the road surface image into three classes, asphalt, gravel, and pavement. A comparison of KNN and Naïve Bayes (NB) was used in present study. We have constructed a road image dataset of 450 samples from real-world road images in the asphalt, gravel, …


Gasohol Engine Performance With Various Ignition Timing, Hendry Y. Nanlohy, Suyatno Suyatno, Helen Riupassa, Marthina Mini, Trismawati Trismawati, Mebin Panithasan Jul 2022

Gasohol Engine Performance With Various Ignition Timing, Hendry Y. Nanlohy, Suyatno Suyatno, Helen Riupassa, Marthina Mini, Trismawati Trismawati, Mebin Panithasan

Journal of Mechanical Engineering Science and Technology (JMEST)

Experimental research has been conducted on the effect of ignition timings on the characteristics and performance of gasohol engines such as power, torque, specific fuel consumption, and thermal efficiency. The fuel used in this research is pure gasoline and a mixture of 50% bioethanol (BE50). The results show that the ignition timing that gives the maximum effect occurs at the top and bottom dead points of 9 degrees for gasoline and 12 degrees for BE50 fuel. Furthermore, the maximum power is obtained at 6,500 rpm, and at an ignition time of 12 degrees BTDC the maximum power generated is 4.63 …


Accessdesign: An Inclusive Co-Design Toolkit For The Creation Of Accessible Digital Tools., Claudia Fernandez-Rivera, Sarah Boland, Eamon Aswad, John Gilligan, Dympna O'Sullivan, Emma Murphy Jul 2022

Accessdesign: An Inclusive Co-Design Toolkit For The Creation Of Accessible Digital Tools., Claudia Fernandez-Rivera, Sarah Boland, Eamon Aswad, John Gilligan, Dympna O'Sullivan, Emma Murphy

Articles

Existing toolkits and resources to support co-design are not always accessible to designers and co-designers with disabilities. In this paper we present a study based on an innovative co-design programme, in collaboration with St John of God Community Services, where 3rd year computer science students work with service users with intellectual disabilities to create digital applications together. We conducted a series of co-design focus group sessions involving the service users who were previously involved in the co-design collaboration with SJOG Services and TU Dublin. The data collected during these design sessions has been integrated to form an accessible design toolkit …


Evaluation Of The Chloride Ions Penetration Into Concrete Structure With The Surface Penetrants Served In Cold Marine Environment For 20 Years, Yanhua Kuang, Yuki Sakoi Associate Professor, Naoto Takashima Postgraduate, Minoru Aba Professor, Yoichi Tsukinaga Professor, Jul 2022

Evaluation Of The Chloride Ions Penetration Into Concrete Structure With The Surface Penetrants Served In Cold Marine Environment For 20 Years, Yanhua Kuang, Yuki Sakoi Associate Professor, Naoto Takashima Postgraduate, Minoru Aba Professor, Yoichi Tsukinaga Professor,

International Conference on Durability of Concrete Structures

The intrusion of chloride ions in concrete served in the marine environment is the leading cause of corrosion of steel bars. This paper examined the result of a long-term survey on the actual structure (the Tomakomai breakwater) treated with a set of penetrants partly. The survey was conducted twice, in the 12th and 20th years after construction.

The results showed that the penetrants could effectively reduce the penetration of chloride ions into concrete. After using the penetrants, the calculated surface chloride ion concentration was decreased by 5.04%/72.18% (the 12th year/the 20th year). As the service years increase, surface chloride ion …


Comparison Of Machine Learning Techniques For Activities Of Daily Living Classification With Electromyographic Data, Sergio A. Salinas, Mohamed Elgalhud, Luke Tambakis, Sanket Salunke, Kshitija Patel, Kenneth Mcisaac, Katarina Grolinger, Ana Luisa Trejos, Abdelkader Ouda, Hamada Ghenniwa Jul 2022

Comparison Of Machine Learning Techniques For Activities Of Daily Living Classification With Electromyographic Data, Sergio A. Salinas, Mohamed Elgalhud, Luke Tambakis, Sanket Salunke, Kshitija Patel, Kenneth Mcisaac, Katarina Grolinger, Ana Luisa Trejos, Abdelkader Ouda, Hamada Ghenniwa

Electrical and Computer Engineering Publications

Advances in data science and wearable robotic devices present an opportunity to improve rehabilitation outcomes. Some of these devices incorporate electromyography (EMG) electrodes that sense physiological patient activity, making it possible to develop rehabilitation systems able to assess the patient’s progress when performing activities of daily living (ADLs). However, additional research is needed to improve the ability to interpret EMG signals. To address this issue, an off-line classification approach for the 26 upper-limb ADLs included in the KIN-MUS UJI dataset is presented in this paper. The ADLs were performed by 22 subjects, while seven EMG signals were recorded from their …


61st Annual Rocky Mountain Conference On Magnetic Resonance Jul 2022

61st Annual Rocky Mountain Conference On Magnetic Resonance

Rocky Mountain Conference on Magnetic Resonance

Final program, abstracts, and information about the 61st annual meeting of the Rocky Mountain Conference on Magnetic Resonance, co-endorsed by the Colorado Section of the American Chemical Society and the Society for Applied Spectroscopy. Held in Copper Mountain, Colorado, July 25-29, 2022.


Flow In Additively Manufactured Super-Rough Channels, Samuel Altland, Xiaowei Zhu, Stephen Mcclain, Robert Kunz, Xiang Yang Jul 2022

Flow In Additively Manufactured Super-Rough Channels, Samuel Altland, Xiaowei Zhu, Stephen Mcclain, Robert Kunz, Xiang Yang

Mechanical and Materials Engineering Faculty Publications and Presentations

Metal additive manufacturing has enabled geometrically complex internal cooling channels for turbine and heat exchanger applications, but the process gives rise to large-scale roughness whose size is comparable to the channel height (which is 500 μm). These super-rough channels pose previously unseen challenges for experimental measurements, data interpretation and roughness modelling. First, it is not clear if measurements at a particular streamwise and spanwise location still provide accurate representation of the mean (time- and plane-averaged) flow. Second, we do not know if the logarithmic layer survives. Third, it is unknown how well previously developed rough-wall models work for these large-scale …


Run-To-Run Control Via Constrained Optimization Of A Mechanical Serial-Sectioning System, Damian L. Gallegos-Patterson Jul 2022

Run-To-Run Control Via Constrained Optimization Of A Mechanical Serial-Sectioning System, Damian L. Gallegos-Patterson

Mechanical Engineering ETDs

This thesis develops a methodology for run-to-run (R2R) control of a mechanical serial sectioning (mss) system for microstructural investigations. mss is a destructive material characterization process which repeatedly removes a thin layer of material and images the exposed surface. The images are then used to gain insight into the internal structure and arrangement of a material and are often used to generate a 3-dimensional (3D) reconstruction of the sample. Currently, an experienced human operator selects the parameters for mss to achieve the desired per slice removal rate. The proposed R2R control methodology automates this process while improving the precision and …


Studies On Air Injection In A Wastewater-Fed Subsurface Drip Irrigation System, Henry A. Gonzalez Hernandez Jul 2022

Studies On Air Injection In A Wastewater-Fed Subsurface Drip Irrigation System, Henry A. Gonzalez Hernandez

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

In 2020, the Ogallala High Plains Aquifer supplied irrigation water for approximately 3.6 million hectares in Nebraska, making it the most irrigated state in the United States. Although Nebraska is highly dependent in groundwater, locations included in the Gering-Fort Laramie Irrigation District (border of Nebraska and Wyoming) rely on surface water resources. In addition to these conventional water sources, using non-conventional alternatives for crop production can be just as important during water shortage times such as the one that e occurred in 2019 with the collapse of the Goshen/Gering-Fort Laramie Canal. Feedlot runoff presents a great opportunity in Nebraska, but …


Development Of A Decellularized Hydrogel Composite And Its Application In A Novel Model Of Disc-Associated Low Back Pain In Female Sprague Dawley Rats, David Lillyman Jul 2022

Development Of A Decellularized Hydrogel Composite And Its Application In A Novel Model Of Disc-Associated Low Back Pain In Female Sprague Dawley Rats, David Lillyman

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

Chronic low back pain is a global socioeconomic crisis compounded by an absence of reliable, curative treatments. The predominant pathology associated with chronic low back pain is degeneration of intervertebral discs in the lumbar spine. During degeneration, nerves can sprout into the intervertebral disc tissue and be chronically subjected to inflammatory and mechanical stimuli, resulting in pain. Pain arising from the intervertebral disc, or disc-associated pain, is a complex, multi-faceted disorder which necessitates valid animal models to screen therapeutics and study pathomechanisms of pain.

While many research teams have created animal models of disc degeneration, the translation of these platforms …


Efficiency Of Bank Filtration In The Removal Of Cyanotoxins Under Different Levels Of Nutrients, Luke Walkenhorst Jul 2022

Efficiency Of Bank Filtration In The Removal Of Cyanotoxins Under Different Levels Of Nutrients, Luke Walkenhorst

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

Harmful Algal Blooms (HABs) are an increasing concern not only in Nebraska, but across the world. Increasing global temperatures in conjunction with overuse of synthetic fertilizers are leading causes to the increasing frequency and concern of HABs. In the present work, the effectiveness of simulated bank filtration (BF), as an economical water treatment option, to remove cyanotoxins under different levels of nutrients (nitrates and phosphates) was investigated. Vertical flow-through columns pre-acclimated with two levels of nutrients (e.g., nitrate and phosphate—10 vs. 50 mg/L) were exposed to two different levels of cyanotoxins (10 vs. 75 μg/L). Results from the study confirmed …


Probabilistic Risk Assessment For Life Extension Of Turbine Engine Rotors, Jace A. Carter, Tarun Goswami Jul 2022

Probabilistic Risk Assessment For Life Extension Of Turbine Engine Rotors, Jace A. Carter, Tarun Goswami

Biomedical, Industrial & Human Factors Engineering Faculty Publications

Maintaining the component service life beyond its historical limits requires the ability to accurately quantify component reliability and address the uncertainties in material responses. A probabilistic method for predicting the total fatigue life was developed and applied to determine the probability of failure of a Ti-6Al-4V turbine disk component. The total fatigue life incorporates a dual mechanism approach including the crack initiation life and propagation life while simultaneously determining the associated initial flaw sizes. A microstructure-based model was employed to address the uncertainties in material response and relate the crack initiation life with crack size. The propagation life was characterized …


Electrodeposition Mechanism And Process Of A Novel Cyanide-Free Gold Sulfite Bath, Jia-Qiang Yang, Lei Jin, Wei-Qing Li, Zhao-Yun Wang, Fang-Zu Yang, Dong-Ping Zhan, Zhong-Qun Tian Jul 2022

Electrodeposition Mechanism And Process Of A Novel Cyanide-Free Gold Sulfite Bath, Jia-Qiang Yang, Lei Jin, Wei-Qing Li, Zhao-Yun Wang, Fang-Zu Yang, Dong-Ping Zhan, Zhong-Qun Tian

Journal of Electrochemistry

A novel cyanide-free gold sulfite process is introduced in this paper. In the bath, chloauric acid was directly employed as the main salt, and hydroxyethylidene diphosphonic acid (HEDP) was used as the stabilizer and coating grain refiner. The bath stability, the gold coating morphology and the mechanism of gold electrodeposition were studied in detail. The results showed that HEDP could significantly improve the bath stability. Moreover, the grains of the gold coating obtained from the gold sulfite bath without HEDP was rod-like, which grew gradually with the increasing of the deposition time, resulting in that the appearance of the coating …


Electrochemical Deposition Of Copper Pillar Bumps With High Uniformity, Bai-Zhao Tan, Jian-Lun Liang, Zi-Liang Lai, Ji-Ye Luo Jul 2022

Electrochemical Deposition Of Copper Pillar Bumps With High Uniformity, Bai-Zhao Tan, Jian-Lun Liang, Zi-Liang Lai, Ji-Ye Luo

Journal of Electrochemistry

Electrochemical deposition of copper pillar bumps (CPBs) is one of the key technologies for the advanced packaging. In this study, the effects of the additive concentration, the electrolyte convection, the current density, and the electroplating system on the uniformity of the CPBs have been systematically investigated. The results showed that the profiles of the CPBs were mainly determined by the additive concentration, the bath convection and the current density, while the heights of the CPBs were mainly affected by the electroplating system. For the CPBs profiles, it was found that the low leveler concentration and high current density would generally …


Investigation Of Through-Hole Copper Electroplating With Methyl Orange As A Special Leveler, Jia-Ying Xu, Shou-Xu Wang, Yuan-Zhang Su, Yong-Jie Du, Guo-Dong Qi, Wei He, Guo-Yun Zhou, Wei-Hua Zhang, Yao Tang, Yu-Yao Luo, Yuan-Ming Chen Jul 2022

Investigation Of Through-Hole Copper Electroplating With Methyl Orange As A Special Leveler, Jia-Ying Xu, Shou-Xu Wang, Yuan-Zhang Su, Yong-Jie Du, Guo-Dong Qi, Wei He, Guo-Yun Zhou, Wei-Hua Zhang, Yao Tang, Yu-Yao Luo, Yuan-Ming Chen

Journal of Electrochemistry

Methyl Orange (MO) with two kinds of functional groups can act as both an accelerator and an inhibitor, which has been used as a special leveler to simplify the electroplating additive system in the through-hole (TH) copper electroplating experiments. In this work, the role of MO in TH electroplating is characterized by molecular dynamics simulations and quantum chemical calculations. It is suggested that MO can spontaneously flatten the copper surface and be well adsorbed on the cathode surface, which inhibit the copper electrodeposition on the cathode. Electrochemical behavior of MO was evaluated by galvanostatic measurements (GM) and cyclic voltammetry (CV) …


Research Progress Of Copper Electrodeposition Filling Mechanism In Silicon Vias, Yun-Na Sun, Yong-Jin Wu, Dong-Dong Xie, Han Cai, Yan Wang, Gui-Fu Ding Jul 2022

Research Progress Of Copper Electrodeposition Filling Mechanism In Silicon Vias, Yun-Na Sun, Yong-Jin Wu, Dong-Dong Xie, Han Cai, Yan Wang, Gui-Fu Ding

Journal of Electrochemistry

Aiming at the electroplating filling problem of deep via TSV (through silicon via) interconnection, the multi-compatible integrated manufacturing technology team at the Shanghai Jiao Tong University has completed the numerical solution of the equations and realized the numerical simulation of TSV filling mode by applying the finite element method with arbitrary Lagrange Euler algorithm. The filling mechanisms of blind vias, the butterfly filling form for the through vias and the simultaneous filling mode of vias with different aspect ratios are analyzed by simulation, contributing to the parameter optimization and sample manufacturing. The effects of electroplating current density and heat treatment …