Engineering Commons^™

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 …

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 …

Electrodeposition Of Functional Epitaxial Films For Electronics, Kui Huang, Rong-Jiao Huang, Su-Qin Liu, Zhen He

Journal of Electrochemistry

Electrodeposition is a solution-based synthesis technique that can be used to fabricate various functional materials on conductive or semiconductive substrates under ambient conditions. Electrodeposition is usually triggered by an artificial electric stimulation (i.e., applied potential/current) to the substrate to oxidize or reduce ions, molecules, or complexes in the deposition solution layer near the substrate surface, which drives this solution layer to depart from its thermodynamic equilibrium and consequently causes the assembly of targeted deposits on the substrate. During electrodeposition, many experimental parameters could affect the properties of the deposits in different ways. To date, many elements (both metals and nonmetals), …

Simulating Sub-Threshold Communication Channels Through Neurons, Richard Maina

School of Computing: Dissertations, Theses, and Student Research

Molecular Communication is an emerging paradigm with the potential to revolutionize the technology behind wearable and implantable devices and the broad range of functions they support, from tracking physical activity to medical diagnostics. This can be achieved through intra-body communication networks that take advantage of natural biological processes as a means of transmitting, propagating and receiving information. In this thesis we focus particularly on using the neuron as a means to facilitate information transfer for interconnected wearable or implantable devices through a technique known as sub-threshold electrical stimulation. We develop upon a prior work by introducing a linear model of …

Understanding The Role Of Antioxidant Nanoparticles In Improving The Outcome Of Secondary Injury In Traumatic Brain Injury, Aria W. Tarudji

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

Following traumatic brain injury (TBI), excess reactive oxygen species (ROS) and other free radicals are released, inducing the cascade of secondary injury that exacerbate the outcomes of TBI. Antioxidant nanoparticles (ANPs) have shown promising outcomes in reducing the progression of TBI, which may be due to the higher accumulation and retention of ANPs in the injured brain. However, there is limited knowledge of: 1) antioxidant activities needed in TBI treatment, 2) correlation between longer retention, bioavailability, and target engagement with antioxidant treatments, and 3) sexual dimorphism to ANP treatments.

This dissertation assesses multiple ANPs with various scavenging activities and durations …

Flood Hazard Index Application In Arid Catchments: Case Of The Taguenit Wadi Watershed, Lakhssas, Morocco, Mustapha Ikirri, Farid Faik, Fatima Zahra Echogdali, Isabel Margarida Horta Ribeiro Antunes, Mohamed Abioui, Kamal Abdelrahman, Mohammed S. Fnais, Abderrahmane Wanaim, Mouna Id-Belqas, Said Boutaleb, Kochappi Sathyan Sajinkumar, Adolfo Quesada-Román

Michigan Tech Publications, Part 1

During the last decade, climate change has generated extreme rainfall events triggering flash floods in short periods worldwide. The delimitation of flood zones by detailed mapping generally makes it possible to avoid human and economic losses, especially in regions at high risk of flooding. The Taguenit basin, located in southern Morocco, is a particular case. The mapping of the flood zones of this basin by the method of the Flood Hazard Index (FHI) in a GIS geographic information systems environment was based on the multi-criteria analysis, taking into consideration the seven parameters influencing these extreme phenomena, namely rainfall, slope, flow …

Mechanism And Application Of Nickel Nano-Cone By Electrodeposition On A Flexible Substrate, Xiu-Ren Ni, Ya-Ting Zhang, Chong Wang, Yan Hong, Yuan-Ming Chen, Yuan-Zhang Su, Wei He, Xian-Ming Chen, Ben-Xia Huang, Zhen-Lin Xu, Yi-Feng Li, Neng-Bin Li, Yong-Jie Du

Journal of Electrochemistry

Nano-array structure possesses promising prospect in power supply, optical device and electronic manufacturing. In this paper, a black nickel nano-cone array was prepared on a flexible substrate by galvanostatic deposition and the corresponding factors involved in the fabrication of nickel nano-cone array was explored. Experimental results showed that a large current density and low main salt concentration were not favored to the formation of cone nickel structure. It was also found that ammonium chloride, as the crystal modifier, was crucial to deposit the uniform nano-cone array. In addition, the growth mechanism of nickel nano-cone was further studied by molecular dynamics …

Effect Of Corrosion Inhibitors On Copper Etching To Form Thick Copper Line Of Pcb In Acidic Etching Solution, Xiao-Li Wang, Wei He, Xian-Ming Chen, Hong Zeng, Yuan-Zhang Su, Chong Wang, Gao-Sheng Li, Ben-Xia Huang, Lei Feng, Gao Huang, Yuan-Ming Chen

Journal of Electrochemistry

The chemical compounds of 2-mercaptobenzothiazole (2-MBT), benzotriazole (BTA) and phenoxyethanol (MSDS) as corrosion inhibitors were used to inhibit the copper etching to form the thick copper line of PCB in the acidic etching solution. The inhibition status was characterized with contact angle measurement, electrochemical test and etch factor calculation, while the corrosion morphology of copper surface was studied by scanning electron microscope. The adsorption mechanism of corrosion inhibitors on copper surface is analyzed by molecular dynamics and quantum chemistry calculations. The results indicated that the synergistic function of the two inhibitors could effectively promote their adsorption on the copper surface …

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

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

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) …

An Algorithm For Task Allocation And Planning For A Heterogeneous Multi-Robot System To Minimize The Last Task Completion Time, Abhishek Patil, Jungyun Bae, Myoungkuk Park

Michigan Tech Publications, Part 1

This paper proposes an algorithm that provides operational strategies for multiple heterogeneous mobile robot systems utilized in many real-world applications, such as deliveries, surveillance, search and rescue, monitoring, and transportation. Specifically, the authors focus on developing an algorithm that solves a min-max multiple depot heterogeneous asymmetric traveling salesperson problem (MDHATSP). The algorithm is designed based on a primal-dual technique to operate given multiple heterogeneous robots located at distinctive depots by finding a tour for each robot such that all the given targets are visited by at least one robot while minimizing the last task completion time. Building on existing work, …

Stratospheric Effects On Uv, Speed Of Sound, Pressure, And Temperature, Joshua V. Chis, Joana Diaz, Brianna E. Ortiz, Imani G. Robertson, Jelani A. Shadd

DePaul Discoveries

The atmosphere is composed of several layers, each with its own distinct environment varying in temperature, pressure, and levels of UV radiation. Quantifying these varying parameters proves to be useful in understanding atmospheric composition in greater detail. Variance in the composition of the atmosphere allows for the study of the evolution of physical phenomena at different altitudes. Our group quantified this variance using a high-altitude weather balloon and designed an experimental method to observe the nature of sound propagation through varying altitudes. The goal was to develop an altitude-dependent model of the speed of sound by using an open-air, microcontroller-based …

Propuestas Y Resultados De Investigación Transmoderna, Translocal Y Digital Desde Jóvenes Semilleristas, Xiomara Gonzalez Gaitan

Institucional

En el presente libro se recopilan las propuestas, avances y resultados de los proyectos en curso de los Semilleros de Investigación de la Universidad de Cundinamarca (Colombia), que se presentaron en el «II Encuentro de Semilleros de Investigación: ciencia, tecnología e innovación en la era digital» en su versión de 2020. Publicamos estos proyectos con la intención de difundir el conocimiento y como muestra del esfuerzo y del alcance de la labor investigadora de los semilleristas de la Universidad de Cundinamarca. Esperamos que los lectores encuentren en estas propuestas caminos para resolver problemas o inspiración para construir nuevas propuestas de …

High-Performance Catalytic Four-Channel Hollow Fibers With Highly Dispersed Nickel Nanoparticles Prepared By Atomic Layer Deposition For Dry Reforming Of Methane, Baitang Jin, Shiguang Li, Xinhua Liang

Chemical and Biochemical Engineering Faculty Research & Creative Works

Highly dispersed nickel (Ni) nanoparticles (NPs) with an average particle size of 4.3 nm were uniformly deposited on the outer surface, the inner channel surface, and inside the pores of 20 cm long four-channel α-Al₂O₃hollow fibers (HFs) by atomic layer deposition (ALD) for dry reforming of methane (DRM). Cerium oxide (CeO₂) was added to promote the catalytic performance of Ni/Al₂O₃-HF catalysts. Rationally designed filling methods, by tuning the reactor size and inert fillings, can reduce the catalyst bed voidage in a fixed bed reactor for better reactant gas distribution, effectively …

Ground Station Eat, Utah State University Space Dynamics Laboratory

Space Dynamics Laboratory Publications

Ground Components

Two primary subsystems

•Ground Station(s)

•  May be your own or commercial
• Includes radio(s), antenna(s), rotor, etc.
• Heavily intertwined with satellite communications system
• Influences link budget

•Ground data system

• Your command, control, and telemetry interface
• Operator facing tools
• Front end processor
• Includes computer(s), networking equipment, displays, software tools, etc.
• Directly links to your ground station via network

•Additional ground subsystems could include:

• Payload ground (i.e. optical ground terminal)
• Space comm networks (i.e. Iridium)

Game On

DePaul Magazine

Video game industry icon Eugene Jarvis and DePaul alumna and Trustee Sasha Gerritson take the College of Computing and Digital Media to the next level with a landmark gift. The gift renames the college in honor of Jarvis and launches the Jarvis Student Center for Innovation and Collaboration, a multidisciplinary, student-focused space.

Designing Harvesting And Hauling Cost Models For Energy Cane Production For Biorefineries, Prabodh Illukpitiya, Firuz Yuldashev, Kabirat Nasiru

Agricultural and Environmental Sciences Faculty Research

The harvesting and hauling operations of bioenergy feedstock is an important area in biofuel production. Production costs can be minimized by maintaining optimal machinery units for these operations. The objective of this study is to design an optimal harvesting unit for bioenergy refinery and estimate harvesting and hauling costs of energy cane. A biorefinery with the annual capacity of processing twenty-five million imp. gallons of ethanol were considered. Given the efficiency of harvesting, a two-row soldier system was considered. Considering the year-round supply of energy cane to the refinery, the optimal machinery unit was designed, and the combined operation costs …

Computational Models To Detect Radiation In Urban Environments: An Application Of Signal Processing Techniques And Neural Networks To Radiation Data Analysis, Jose Nicolas Gachancipa

Beyond: Undergraduate Research Journal

Radioactive sources, such as uranium-235, are nuclides that emit ionizing radiation, and which can be used to build nuclear weapons. In public areas, the presence of a radioactive nuclide can present a risk to the population, and therefore, it is imperative that threats are identified by radiological search and response teams in a timely and effective manner. In urban environments, such as densely populated cities, radioactive sources may be more difficult to detect, since background radiation produced by surrounding objects and structures (e.g., buildings, cars) can hinder the effective detection of unnatural radioactive material. This article presents a computational model …

Water Control Principle Of Lateral Water Cutoff Curtain And Numerical Analysis Of Its Water Interception Effect In Yuanbaoshan Open-Pit Coal Mine——Taking Yuanbaoshan Open-Pit Coal Mine As An Example, Zhao Chunhu, Wang Mingxing, Cao Haidong, Qu Guowen, Wang Yong, Guo Yingjie

Coal Geology & Exploration

In the process of open-pit coal mining, drainage is an important aspect causing the loss of groundwater resources. Taking Yuanbaoshan open-pit coal mine in Chifeng City, Inner Mongolia as the research object, this paper analyzes the control principle of the curtain wall construction driven by open-pit mining on the groundwater system according to the hydrogeology of the study area and the characteristics of open-pit coal mine development. It comes to the conclusion that the weaker the permeability of the curtain wall, the greater the thickness, and shortening the distance from the recharge water body is the basic idea of reducing …

Research On Three-Component Responses Characteristics Of Axial Anisotropy Tunnel-Hole Transient Electromagnetic, Guo Jianlei, Gao Xiaowei, Hou Yanwei

Coal Geology & Exploration

Large interpretation errors may exist in exploration areas with obvious conductivity anisotropy when applying tunnel-hole transient electromagnetic method. In this paper, the control equation is built by introducing the conductivity anisotropy tensor, which allows the current density of the rectangular loop source to be added into the Maxwell equation Ampere loop theorem based on the finite difference time domain (FDTD) algorithm in order to realize the loading of any current source. The control equation is discretized by the difference instead of the differential to realize the forward calculation of the tunnel-hole transient electromagnetic 3D model. Forward modeling is carried out …

Imaging Method Of Borehole Transient Electromagnetic Anomaly Response Boundary In Coal Mines Based On Clustering, Fan Tao, Li Ping, Zhang Youzhen, Zhao Rui, Fang Zhe, Fan Yilin, Liu Lei, Wang Cheng, Li Yuteng

Coal Geology & Exploration

In order to improve the ability to recognize and interpret the abnormal response boundary in the transient electromagnetic inversion imaging results of boreholes in coal mines, and to complete geophysical interpretation such as an accurate description of hidden water disasters in front of the heading face and a fine analysis of hidden disaster-causing factors, this paper proposes the application of apply clustering method of unsupervised machine learning to analyze the borehole transient electromagnetic processing results. According to the numerical distribution characteristics of resistivity and the characteristics of the two clustering methods, the K-Means clustering algorithm is selected to aggregate and …

Application Of Surface And Borehole Tem Joint Exploration In 2 000 M Deep Mineral Exploration, Wu Junjie, Liu Bin, Zhi Qingquan, Deng Xiaohong, Wang Xingchun, Yang Yi, Liu Dongming, Qiu Jinzhu

Coal Geology & Exploration

Deep mineral exploration is a challenge. The borehole Transient Electromagnetic Method (TEM) goes deep underground through the sensor along the borehole, and gets closer to the deep target, so as to improve the ore discovery rate and prospecting effect. TEM is widely used in deep prospecting and exploration in foreign countries, and has achieved many important results. However, in China, due to the slow development of instruments, theoretical research and interpretation technology, it is less used in practical deep prospecting. This paper introduces a typical case about the 2 000 m deep prospecting in Baiyun Gold Deposit in Qingchengzi, Liaoning …

Application Of Borehole Transient Electromagnetic Method In Detection Of Floor Failure Depth In Fully Mechanized Top Coal Caving Face, Wang Cheng, An Youxin, Zhu Hongjun, Guo Jianlei

Coal Geology & Exploration

The carboniferous-Permian No. 6 coal seam in the eastern Jungar Coalfield of Ordos Basin is an extra-thick coal seam, and the coal floor is particularly threatened by the Ordovician limestone aquifer. The mining effect will lead to the formation of the bottom mining damage zone, and new water-conducting channels may be formed, which in turn will cause sudden water disasters. Aiming at the testing problem of floor mining failure zone, the method of transient electromagnetic method in hole with moving source and receiving is proposed to obtain resistivity characteristic data of strata from floor drilling before and after mining. Firstly, …

Present Study Situation Review Of Borehole Transient Electromagnetic Method, Sun Huaifeng, Zhang Yingying, Zhao Youchao, Liu Yuchao, Zhao Hualiang

Coal Geology & Exploration

In the borehole transient electromagnetic method (TEM), the receiving probe is placed in the borehole, which is different from either aerial or ground TEM. In such methods, as the probe will be closer to the detection target and far away from surface, not only stronger response signals can be observed, but also the interference of various electromagnetic signals outside the borehole can be attenuated effectively. It can meet the demand of meticulous detection with large burial, especially the detection demand of deep blind ore and water hazard. The present situation of using various methods in the study in forward modeling, …

Mechanical Properties And Impact Energy Index Of Coal Affected By Gas Pressure And Evolutionary Mechanism, Ding Xin, Xiao Xiaochun, Pan Yishan

Coal Geology & Exploration

The frequent occurrence of gas emission and outburst accidents caused by rock bursts in deep coal seams poses a great threat to safe underground production. Therefore, clarifying the evolution law of the mechanical properties and burst potential of gas on coal and rock is the basis for establishing effective prevention and control measures. Using the self-developed visual coal fluid-solid coupling test system, we carried out the physical experiment to study the gas adsorption, mechanical properties and fragment distribution of coal affected by gas pressure, and analyzed the evolution characteristics and mechanism of the bursting energy index. The results show that …

Construction And Application Of Feasibility Evaluation Model For Gas Extraction In Goafs Of Abandoned Coal Mines, Yang Ming, Zhu Lin, Quan Xingyuan, Xu Jing, Liu Maomao, Zhang Tao

Coal Geology & Exploration

Against the background of carbon neutrality and carbon peaking policy, the development of gas resources in abandoned coal mines can generate high resource, economic and environmental benefits. The evaluation index system is established through field research and literature review from technical feasibility and economic rationality aspects. The game theory-fuzzy comprehensive evaluation model is established by combining the weighting method of game theory with the fuzzy comprehensive evaluation method. The abandoned Gushuyuan Mine is used as an example to verify the rationality of the evaluation model. The weights of gas resource conditions and gas preservation conditions in the first-level indicators are …

Distribution Characteristics And Formation Mechanism Of High Salinity Groundwater In Northeast Ningdong Coalfield, Jin Dewu, Wang Tiantian, Zhao Baofeng, Li Debin, Zhou Zhenfang, Shang Hongbo

Coal Geology & Exploration

High salinity groundwater is widely and unevenly distributed in northeast Ningdong Coalfield of Ningxia Hui Autonomous Region, and it varies greatly throughout the coalfield. This paper studies the distribution characteristics and formation mechanism of high salinity groundwater. Firstly, spatial distribution characteristics of high salinity groundwater was researched, and then, Piper trilinear graph, Gibbs graph and ion proportionality coefficient were used to investigate the formation mechanism of high salinity groundwater. The results show that groundwater salinity value varies from 0.30 g/L to 23.56 g/L, and the average value is 5.84 g/L. The proportions of fresh water, brackish water, salt water and …

Landscape Planning Model Design And Layout Of Loess Hills In Coal Mining Area Of Northern Shaanxi：A Study Of The Subsidence Area Of Ningtiaota Coal Mine, Shang Jianxuan, Gao Yakun, Yang Fan, Bi Yinli, Quan Wenzhi, Ma Shaopeng, Zhang Yanxu

Coal Geology & Exploration

The coal mining area of northern Shaanxi is an important coal base of China, and the large amount of coal mining will cause surface subsidence and landscape disturbance. Taking the subsidence area of Ningtiaota Mine in northern Shaanxi as an example, this paper comprehensively analyzes the landscape problems in loess hilly landform through the combination of indoor statistical analysis, field investigation, qualitative-quantitative methods. The landscape pattern planning, design and layout are carried out, which provides reference for the landscape planning of underground mine area in this landform types. It is found that there are four problems in the above ground …

Influence Of Coal Mining On Shallow Groundwater Environment Response To Coal Mining And Mine Water Ecological Utilization Analysis, Chai Jianlu

Coal Geology & Exploration

The contradiction between coal and water is prominent in the upper and middle reaches of the Yellow River Basin, and coal mining activities has caused certain damage to groundwater environment in those areas. So the quantity and quality characteristics of mine water for the Yushenfu mining area in Yulin City of northern Shaanxi Province were analyzed to reveal the influence of coal mining on the groundwater environment, and the ecological utilization study of mine water was also carried out based on field investigation, data analysis and laboratory tests. The results show that the mine water content coefficient in the study …