Engineering Commons^™

Design And Development Of Deep Eutectic Solvent Assisted Pressurized Liquid Extraction Of Nutraceuticals, Harish Babu B

Theses and Dissertations

Over recent decades, the usage of nutraceuticals has been exponentially increasing as alternates to pharmaceutical drugs. However, extraction of these therapeutically significant compounds from their corresponding sources requires the use of volatile organic solvents like hexane, ethanol and chloroform which increases the global warming potential. This problem has been overcome in recent decades by the use of supercritical carbon dioxide (SCO2) as the extraction solvent. Since SCO2 is non-polar in nature, the extraction of polar compounds with better efficiency is questionable.

On the other hand, modernization in solvent engineering has created generations of green solvents like ionic liquids (ILs), deep …

Hybrid Hydrolysis And Fermentation Of Prosopis Juliflora Pods For Biohydrogen Production By Dark Fermentation, Gayathri G

Theses and Dissertations

The rapid consumption of fossil fuels has resulted in the energy crisis and many environmental issues, including air pollution and the greenhouse effect. Hydrogen is the independent source of the highest energy content, with 122 KJ g-1. Biohydrogen produced from lignocellulosic biomass (LCB) is an excellent alternative fuel for its cleanability, renewability and sustainability. Biohydrogen production from dark fermentation using lignocellulosic biomass provides low cost and a sustainable pathway to utilize a vast amount of waste.

Dark fermentation has considerable potential for hydrogen production because it does not require sunlight, allowing for full-time operation and minimizing bioreactor complexity. The major …

Energy System For Evaluation Of Modification Methods On Energy Transfer Efficiency And Optimization Ofmembranes, Tian Li, Hong Zhou, Wei Ding, Jinjun Wang, Tiancheng Zhang

Department of Civil and Environmental Engineering: Faculty Publications

Saving energy is crucial for utilizing membrane technology, but there is no energy parameter for understanding the relationships among membrane performance and energy. Here, φ is defined as the energy transfer efficiency of the membrane, and its numerical expression of membrane performance is poor (e.g., in the range of 10⁻²³). The method of modifying membranes is a crucial determinant for developing membrane science, but researchers using current parameters to evaluate modification methods might lead to erroneous conclusions. Hence, the newly established system θ is used to analyze the influence of different modification methods on energy consumption, which not …

Are Vehicle Tires Major Contributors To Microplastic Emissions Into The China Seas? A Simple Model Perspective., Shuolin Xiao, Yuran Liang, Xiaowei Zhu, Simone Q. Kyes, Xiaofeng Cai

Mechanical and Materials Engineering Faculty Publications and Presentations

Microplastics pose a substantial threat to our environment. Given China's large population and rapid economic growth, it is urgent to estimate the annual emissions of microplastics into its marine environment. The microplastics show a significant variation in their source emissions as well as in their physical and chemical properties, leading to differences in their transport and fate in aquatic environments. To account for these variations, we developed a process-oriented model that considers microplastics from different sources and the inter-provincial variation in their retention rate to assess annual microplastic emissions into the China seas. On a national scale, of the microplastics …

Development Of An Empirical Ground-Motion Model For Post-Mining Induced Seismicity Near Gardanne, France, Pierre Gehl, Pascal Dominique, Hideo Aochi, Mickael Delatre, Jannes Kinscher, Isabelle Contrucci

Journal of Sustainable Mining

Since the closure of mining activities in 2003, the coal basin of Gardanne in South-East France has experienced thousands of small-magnitude earthquake events, mostly triggered by the flooding of mine workings. Some of these events have been powerful enough to be strongly felt by the population, generating nuisance and concern about potential damage to buildings. The aim of this study is to improve the characterisation of the level of ground motion at the surface, by developing a ground-motion model for post-mining induced seismicity, based on several years of recorded data. A Bayesian-based method is applied to the data in order …

A Systematic Survey On 5g And 6g Security Considerations, Challenges, Trends, And Research Areas, Paul Scalise, Matthew Boeding, Hamid Sharif, Joseph Delloiacovo, John Reed

Department of Electrical and Computer Engineering: Faculty Publications

With the rapid rollout and growing adoption of 3GPP 5thGeneration (5G) cellular services, including in critical infrastructure sectors, it is important to review security mechanisms, risks, and potential vulnerabilities within this vital technology. Numerous security capabilities need to work together to ensure and maintain a sufficiently secure 5G environment that places user privacy and security at the forefront. Confidentiality, integrity, and availability are all pillars of a privacy and security framework that define major aspects of 5G operations. They are incorporated and considered in the design of the 5G standard by the 3rd Generation Partnership Project (3GPP) with the goal …

Wireless Power Transfer Using Electronic Textiles: A Comparative Review, Showrov Rahman, Marjan Al Haque, Mohammad Solaiman, Rashed Hasan Ratul, Istiak Ahmed, Shawana Tabassum, Izabela Ciesielska-Wrobel

Electrical Engineering Faculty Publications and Presentations

Wireless power transfer (WPT) has already been established as a popular technology in multiple areas such as electric vehicle charging, smartphone charging, or powering bio-medical implants. In recent years, wireless power transfer in electronic textiles (e-textiles) or smart textiles has seen rapid growth with the advancement of textile materials and flexible electronic components. Although many reviews and surveys on WPT can be found in the literature for other popular fields, this is not the case for the application of WPT in e-textiles. To address this issue, a comparative review of previous literature on WPT in e-textiles is presented in this …

A Review Of Proton Exchange Membrane Degradation Pathways, Mechanisms, And Mitigation Strategies In A Fuel Cell, Dharmjeet Madhav, Junru Wang, Rajesh Keloth, Jorben Mus, Frank Buysschaert, Veerle Vandeginste

Department of Chemical and Biomolecular Engineering: Faculty Publications

Proton exchange membrane fuel cells (PEMFCs) have the potential to tackle major challenges associated with fossil fuel-sourced energy consumption. Nafion, a perfluorosulfonic acid (PFSA) membrane that has high proton conductivity and good chemical stability, is a standard proton exchange membrane (PEM) used in PEMFCs. However, PEM degradation is one of the significant issues in the long-term operation of PEMFCs. Membrane degradation can lead to a decrease in the performance and the lifespan of PEMFCs. The membrane can degrade through chemical, mechanical, and thermal pathways. This paper reviews the different causes of all three routes of PFSA degradation, underlying mechanisms, their …

Hydraulic Borehole Mining (Hbm) Technology Employed In Lignite Mining – Technical, Economic And Market Aspects, Bartłomiej Jura, Piotr Krawczyk, Jacek Skiba, Natalia Howaniec

Journal of Sustainable Mining

The results of a cost-effectiveness and economic efficiency assessment of the Hydraulic Borehole Mining (HBM) technology applied to lignite mining are presented. The Dynamic Generation Cost, the Net Present Value, and the Internal Rate of Return were calculated for the extraction of lignite at a rate of about 3.44 million Mg/year from a mining parcel of 1 2.5 km, taking into account CAPEX and OPEX. The cost of mining 1 Mg of lignite using the HBM technology was reported to be lower than its market prices before the energy crisis in Europe caused by the war in Ukraine. The values …

Predicting Open-Pit Mine Production Using Machine Learning Techniques, Faustin Nartey Kumah, Alex Kwasi Saim, Millicent Nkrumah Oppong, Clement Kweku Arthur

Journal of Sustainable Mining

In mining, where production is affected by several factors, including equipment availability, it is necessary to develop reliable models to accurately predict mine production to improve operational efficiency. Hence, in this study, four (4) machine learning algorithms – namely: artificial neural network (ANN), random forest (RF), gradient boosting regression (GBR) and decision tree (DT)) – were implemented to predict mine production. Multiple Linear Regression (MLR) analysis was used as a baseline study for comparison purposes. In that regard, one hundred and twenty-six (126) datasets from an open-pit gold mine were used. The developed models were evaluated and compared using the …

The Santa Clara, 2024-02-16, Santa Clara University

The Santa Clara

No abstract provided.

Evolution Of Sbs-Modified Asphalt Performance Under Aging And Rejuvenation Cycle Conditions, Ke Shi, Feng Ma, Jenny Liu, Zhen Fu, Ruimeng Song, Dongdong Yuan, Aboudou Wassiou Ogbon

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Improving the poor long-term service performance of rejuvenated SBS-modified asphalt (REF-LT) is highly challenging. In this study, a blend of aged and virgin binders was used to rejuvenate REF-LT and the evolution of the asphalt performance was observed during regeneration and reaging processes. An SBS-modified asphalt (SBM) and base asphalt (BA) were mixed with REF-LT in specified ratios to prepare SBM- and BA-rejuvenated asphalts. The rejuvenated asphalts were subjected to short- and long-term aging. The high/low-temperature rheological properties, fatigue resistance, rejuvenation mechanism, and changes in the functional groups of the rejuvenated and reaged asphalts were characterized using a dynamic shear …

Characterization Of Alkali-Silica Reaction (Asr) Products And C-S-H Using Swir Spectroscopy For Nondestructive Detection Of Asr, Pengfei Ma, Wenyu Liao, Ying Zhuo, Hongyan Ma, Yanping Zhu, Genda Chen

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This study explores the feasibility of characterizing alkali-silica reaction (ASR) products and calcium silicate hydrates (C-S-H) from short-wave infrared (SWIR) spectroscopy. ASR products and C-S-H samples with different Ca/Si ratios were synthesized and analyzed through XRD, 29Si nuclei magnetic resonance (NMR) and SWIR spectroscopy. Fourier-transform infrared spectroscopy (FTIR) was collected to help interpret the results from the SWIR spectroscopy. The obtained spectroscopic features were applied to quantify the ASR product abundance denoted by the length expansion of mortar bars after an accelerated ASR test. The results show that the SWIR spectra of the synthetic ASR gels are similar regardless of …

Copper−Cystine Biohybrid-Embedded Nanofiber Aerogels Show Antibacterial And Angiogenic Properties, Anik Karan, Navatha S. Polavaram, Margarita Darder, Yajuan Su, Syed Muntazir Andrabi, S M Shatil Shahriar, Johnson V. John, Zeyu Luo, Mark A. Decoster, Yu Shrike Zhang, Jingwei Xie

Department of Mechanical and Materials Engineering: Faculty Publications

Copper−cystine-based high aspect ratio structures (CuHARS) possess exceptional physical and chemical properties and exhibit remarkable biodegradability in human physiological conditions. Extensive testing has confirmed the biocompatibility and biodegradability of CuHARS under diverse biological conditions, making them a viable source of essential Cu²⁺. These ions are vital for catalyzing the production of nitric oxide (NO) from the decomposition of Snitrosothiols (RSNOs) found in human blood. The ability of CuHARS to act as a Cu²⁺ donor under specific concentrations has been demonstrated in this study, resulting in the generation of elevated levels of NO. Consequently, this dual function makes …

Power Allocation For Next Generation Iot Systems Using Cnoma, Srikamu C

Theses and Dissertations

The global Pandemic/COVID-19 keeps people connected through wireless commu- nication. The tremendous growth of mobile data traffic and an increase in massive IoT connectivity among different devices leads to a scarcity of wireless resources. One of the advancing technologies for the 5G Beyond communication network, Non-Orthogonal Multiple Access (NOMA), is used for M2M, V2V, and connecting low-power IoT devices. NOMA outperforms OMA schemes such as FDMA, TDMA, CDMA, and OFDMA of 1G, 2G, 3G, and 4G in terms of data rate, latency, and spectral efficiency. NOMA exploits the multiplexing of signals in the power domain with the same frequency/time, and …

Fly Ash Coated With Alumina Sol For Improving Strength And Thermal Insulation Of Mullite Porous Ceramics, Minghui Li, Peilin Li, Qingqing Gao, Saisai Li, Ruoyu Chen, Haiming Wen, Canhua Li

Materials Science and Engineering Faculty Research & Creative Works

The manufacturing of mullite porous ceramics with high strength and low thermal conductivity was achieved through foam gel-casting processes using fly ash coated with alumina sol layers. This research aimed to investigate the effect of alumina sol concentration on foaming slurry rheology, as well as the influence of alumina sol coating layers on the microstructure, phase compositions and properties of the resulting mullite porous ceramics. Increasing the alumina sol concentration from 5 to 20 wt% improved both the viscosity and thixotropy of the foaming slurries while enhanced the shear thinning behavior. Porous ceramics prepared with fly ash coated with alumina …

Numerical And Experimental Investigation Of Negative Stiffness Beams And Honeycomb Structures, Yasser Darwish, Mohamed A. Elgawady

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Metamaterial structures that exhibit negative stiffness (MSNS) behavior have shown the potential to be used as energy dissipation systems in different applications. Negative stiffness honeycomb structures consist of multiple pre-buckled beams that snapping through from one pre-buckled mode to another buckled mode, when subjected to transverse loads, displaying negative stiffness, and dissipating a significant portion of the input energy. This paper presents finite element models (FEMs) developed to investigate the performance of negative stiffness pre-buckled beams and honeycombs. The FEMs were validated using experimental results of single pre-buckled beams and honeycomb structures. The experimental testing of the pre-buckled beams was …

Development Of Inorganically Cross-Linked Sulfonated Polyacrylamide Preformed Particle Gels For Conformance Control: Impact Of Anionic Groups, Reem Elaf, Ahmed Hamza, Hassan Nimir, Mohammed Saad, Ibnelwaleed A. Hussein, Baojun Bai

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Modern oil and gas extraction faces challenges, notably from the surplus of produced water, hampering hydrocarbon recovery and raising environmental and economic concerns. A promising solution is the injection of preformed particle gels (PPGs) into the reservoir's fractures and high permeability zones, facilitating production processes. This study introduces a novel class of inorganically cross-linked PPGs with exceptionally high swelling capacities, comprising sulfonated polyacrylamide cross-linked with aluminum attached to acetate, nitrate, sulfate, and lactate anions individually. These PPGs function as superabsorbents, capable of absorbing water at a ratio of 100-700 times their dry weight while maintaining adequate gel strength up to …

Permeability Enhancement And Coal Fines Removal Through Oxidation Treatment In Coalbed Methane Reservoirs, Yu Lu, Yili Kang, Chengzhong Bu, Ying Li, Chong Lin, Zhenjiang You

Research outputs 2022 to 2026

This study utilized anthracite coal samples from Zhijin Block and applied NaClO as the oxidant to investigate the effects of oxidation treatment on permeability enhancement and coal fines migration. Subsequent to oxidation treatment, the coal samples demonstrated an average increase of 42.17% in the equivalent hydraulic aperture (EHA). This treatment also resulted in the expansion of fluid flow channels, contributing to an average permeability enhancement of 108.85% in the coal samples. Resulting from the non-uniform dissolution of the oxidant on the fracture surface of coal, self-propping fractures were formed, effectively maintaining the conductivity of fractures. The oxidation treatment converted the …

An Innovative Fracture Plugging Evaluation Method For Drill-In Fluid Loss Control And Formation Damage Prevention In Deep Fractured Tight Reservoirs, Chengyuan Xu, Lei Liu, Yang Yang, Yili Kang, Zhenjiang You

Research outputs 2022 to 2026

Lost circulation, resulting from the undesired loss of drilling fluid into formation fractures, stands as a significant technical obstacle in the exploration and production of oil, gas, and geothermal reservoirs. Effective mitigation of this challenge requires the development and application of robust experimental evaluation methods to assess the effectiveness of fracture plugging. The traditional approach to fracture plugging evaluation relies on a uniform evaluation index and experimental parameters for various lost circulation types. Unfortunately, this practice frequently results in inconsistent performance of loss control formulas during laboratory experiments and field tests. To address this issue, this paper introduces an innovative …

Numerical Investigation Of The Thermo-Hydraulic Performance Of A Shark Denticle-Inspired Plate Fin Heat Exchanger, Aakash S. Hurry, Ana Vafadar, Kevin Hayward, Ferdinando Guzzomi, Kanishk Rauthan

Research outputs 2022 to 2026

Growing demand for increased power dissipation is fuelling the need for the design of more efficient heat exchangers. Modifying fin geometry is an effective way of improving heat transfer efficiency and of reducing flow resistance for plate fin heat exchangers. To date, fin designs have mostly revolved around classical shapes such as pins, ellipses, and rectangles, due to limitations of conventional manufacturing technologies. However, with recent advancements in metal additive manufacturing, there is an opportunity of redesigning approaches and ways of thinking to create novel fin geometries. In this study, biomimicry was used as a tool to reverse engineer a …

Efficiency Optimization Method For Data Sampling In Power Grid Topology Scheduling Simulation, Yingying Zhao, Pusen Dong, Tianchen Zhu, Fan Li, Yun Su, Zhenying Tai, Qingyun Sun, Hang Fan

Journal of System Simulation

Abstract: To address the large simulation computational workload and low simulation speed caused by the scale and complexity of the new power system, a simulation acceleration method for topology scheduling based on the distributed and quantization mechanisms is proposed. The parallelization of topology scheduling models is used to increase the scale of data simulation sampling in unit time. The introduced quantization operators accelerate the computation speed of the topology scheduling model operators, reduces the time cost of the every single simulation. Case studies confirm the effectiveness of the topology simulation acceleration, in which the available transfer capacity of the simulated …

Runoff Intelligent Prediction Method Based On Broad-Deep Fusion Time-Frequency Analysis, Ying Han, Lehao Wang, Shumei Wang, Xiang Zhang, Xingxing Luo

Journal of System Simulation

Abstract: Broad learning system(BLS) is introduced to tackle the existed disadvantage that LSTM-based runoff prediction model is easy to fall into local optimization. To reduce the influence of noise on the prediction results, the variational mode decomposition (VMD) is adopted to transform the onedimensional time-domain runoff signal to the two-dimensional time-frequency plane. The runoff prediction model based on VMD-LSTM-BLS is proposed. The simulation results demonstrate that the prediction accuracy of the new model is more significantly improved compared with the baseline model and the existing LSTM-based runoff prediction model.

Simulation Platform Of Agv System Scheduling Algorithms In Uncertain Environment, Zhihao Shi, Haihui Shen

Journal of System Simulation

Abstract: As a complete automated guided vehicle(AGV) system scheduling algorithm, it must include conflict-handling strategy, together with common dispatching strategy and routing algorithm. However, due to the uncertainty, characteristics of such scheduling algorithm are difficult to be analyzed theoretically, and the relevant study is lacking. An AGV system simulation platform based on the discreteevent simulation technique is designed and developed, which can flexibly set the scheduling problem, choose the dispatching strategy, routing algorithm, and conflict-handling strategy for the scheduling algorithm, to run the simulation. The platform has a visual interface, from which the running status of AGVs and the performance …

Research On Motion Planning Of Hexapod Robot Based On Drl And Free Gait, Xinpeng Wang, Huiqiao Fu, Guizhou Deng, Kaiqiang Tang, Chunlin Chen, Canghao Liu

Journal of System Simulation

Abstract: To improve the passability and the motion performance of the hexapod robot in the unstructured environment, a multi-contact motion planning algorithm based on DRL and free gait planner is proposed. Firstly, the free gait planner obtains the reachable footholds under the target state and outputs the optimal gait sequence. The center of mass motion policy of the hexapod robot in the randomly generated plum blossom pile environment is obtained by using deep reinforcement learning training. To ensure the reachability between adjacent states of the robot in motion, the state transition feasibility model is used to judge the state transition …

Robust Predictive Control Of Nonplanar Fully-Actuated Uavs, Yun Ma, Yuan Wang, Meng Li, Peng Wang, Yanling Tang

Journal of System Simulation

Abstract: Targeting the problem that nonplanar fully-actuated unmanned aerial vehicles (UAVs) are susceptible to external winds and unmodeled dynamics, the predictive control system with good robustness is designed. A nonlinear motion model with six degrees of freedom is established through the Newton-Euler approach. A linear extended state observer is designed to estimate the state variables by transforming the system affected by matched and unmatched disturbances into an equivalent system only affected by the matched disturbances. A predictive controller is designed for the equivalent system to reduce the output oscillation and input surging and a disturbance compensator is also designed to …

Reconnaissance Mission Planning Method For Air-Ground Heterogeneous Unmanned Systems, Guohui Zhang, Ya'nan Zhang, Ang Gao, Aoyu Xu

Journal of System Simulation

Abstract: Compared with the air-based homogeneous unmanned system, the motion capabilities, resource payloads, and combat scenes in the air-ground heterogeneous unmanned system increase the number of constraint conditions and significantly increase the computational complexity of the solution model. The modeling of collaborative combat missions and the efficient solution of large-scale problems are the key issues. With the time, path cost, and reconnaissance benefit as the objective functions, considering the constraints such as the endurance of unmanned platforms, a multi-objective programming model for the reconnaissance missions of an air-ground heterogeneous unmanned system is constructed. Aiming at the urban combat environments with …

Blood Lead, Cadmium And Hair Mercury Concentrations And Association With Soil, Dust And Occupational Factors In E-Waste Recycling Workers In Bangladesh, Sarker Masud Parvez, Farjana Jahan, Jaynal Abedin, Mahbubur Rahman, Shaikh Sharif Hasan, Nafisa Islam, Nirupam Aich, Mohammad Moniruzzaman, Zahir Islam, Masatake Fujimura, Rubhana Raqib, Luke D. Knibbs, Peter D. Sly

Department of Civil and Environmental Engineering: Faculty Publications

Background: Electronic waste (e-waste) recycling activities release toxic metals, which pose substantial hazard to the environment and human health. We evaluated metal concentrations in biological and environmental samples, and examined the associations between biological lead (Pb), cadmium (Cd), and mercury (Hg) with soil and dust metals, and other possible determinants, among populations exposed and non-exposed to e-waste in Bangladesh.

Methods: A total of 199 e-waste workers and 104 non-exposed individuals were recruited. We measured blood Pb (BPb) and Cd (BCd) concentrations and total Hg (THg) from hair samples. Data were collected on occupational, and behavioral factors. We fitted …

A Simplification Method Of Large-Scale Unit Commitment Model Based On Boundary Method, Yanping Xu, Mingxin Zhao, Xiaohui Qin, Keyou He, Xiaohan Wu, Pei Zhang

Journal of System Simulation

Abstract: As the scale of power grid expands, in the market environment, the variables and constraints in the security-constrained unit commitment (SCUC) model considering power grid security constraints increase significantly and the solvability of the model reduces. When the model scale is too large, even the existing commercial solvers cannot solve it. Aiming at the model rapid solving, from the perspective of reducing the number of model constraints, a linear constraint simplification method based on the boundary method is proposed. The proposed method can effectively reduce the model's size by eliminating the redundant linear constraints. The IEEE-39, WECC 179 and …

Optimal Scheduling Strategy Of Virtual Power Plant With Carbon Emission And Carbon Penalty Considering Uncertainty Of Wind Power And Photovoltaic Power, Jijun Shui, Daogang Peng, Yankan Song, Qiang Zhou

Journal of System Simulation

Abstract: To better meet the development needs of China's new power system, an optimal scheduling strategy of virtual power plant(VPP) with carbon emission and carbon penalty considering the uncertainty of wind power and photovoltaic power is proposed. The mathematical description of photovoltaic(PV), wind turbine(WT), combined heat and power(CHP) unit and energy storage system (ESS) is carried out, and a wind-solar output model considering the uncertainty is established. The scenario generation and reduction method is used to generate the typical scenario. To maximize the overall operation benefit of VPP, considering carbon emission cost and carbon penalty, an optimal scheduling model of …