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Study On Dye-Sensitized Solar Cells Based On Tio2 Composite Nanomaterials, Cuiping Kang, Muhammad Aqeel Ashraf, Yung-Tse Hung Dec 2019

Study On Dye-Sensitized Solar Cells Based On Tio2 Composite Nanomaterials, Cuiping Kang, Muhammad Aqeel Ashraf, Yung-Tse Hung

Civil and Environmental Engineering Faculty Publications

With the continuous development of nanomaterials, how to improve the conversion efficiency of DSSCs has been the focus of scholars. Nano-TiO2 material is a wide bandgap semiconductor with a bandgap of 3.2eV. It exhibits good performance in dye adsorption, charge separation, electron transport, etc., and has good chemical stability and strong acid and alkali resistance. Therefore, it was always the material of choice for the preparation of photoanodes. In this paper, different thicknesses of TiO2 NRs barrier layers were prepared on FTO substrates by solvothermal method and two-step spin coating method, and their electrochemical and photoelectric properties were tested by …


An Application Of Bayesian Multilevel Model To Evaluate Variations In Stochastic And Dynamic Transition Of Traffic Conditions, Emmanuel Kidando, Ren Moses, Thobias Sando, Eren Erman Ozguven Dec 2019

An Application Of Bayesian Multilevel Model To Evaluate Variations In Stochastic And Dynamic Transition Of Traffic Conditions, Emmanuel Kidando, Ren Moses, Thobias Sando, Eren Erman Ozguven

Civil and Environmental Engineering Faculty Publications

© 2019, The Author(s). This study seeks to investigate the variations associated with lane lateral locations and days of the week in the stochastic and dynamic transition of traffic regimes (DTTR). In the proposed analysis, hierarchical regression models fitted using Bayesian frameworks were used to calibrate the transition probabilities that describe the DTTR. Datasets of two sites on a freeway facility located in Jacksonville, Florida, were selected for the analysis. The traffic speed thresholds to define traffic regimes were estimated using the Gaussian mixture model (GMM). The GMM revealed that two and three regimes were adequate mixture components for estimating …


Spark Plasma Sintering Of Low Modulus Titanium-Niobium-Tantalum-Zirconium (Tntz) Alloy For Biomedical Applications, Nicholas Mavros, Taban Larimian, Javier Esqivel, Rajeev Kumar Gupta, Rodrigo Contieri, Tushar Borkar Dec 2019

Spark Plasma Sintering Of Low Modulus Titanium-Niobium-Tantalum-Zirconium (Tntz) Alloy For Biomedical Applications, Nicholas Mavros, Taban Larimian, Javier Esqivel, Rajeev Kumar Gupta, Rodrigo Contieri, Tushar Borkar

Mechanical Engineering Faculty Publications

In metallurgy, titanium has been a staple for biomedical purposes. Its slow toxicity and alloying versatility make it an attractive choice for medical applications. However, studies have shown the difference in elastic modulus between titanium alloys (116 GPa) and human bone (10–40 GPa), which contributes to long term issues with loose hardware fixation. Additionally, long term studies have shown elements such as vanadium and aluminum, which are commonly used in Ti-6Al-4V biomedical alloys, have been linked to neurodegenerative diseases like Alzheimer and Parkinson. Alternative metals known to be less toxic are being explored as replacements for alloying elements in titanium …


Advances In Remote Sensing To Understand Extreme Hydrological Events, Dongkyun Kim, Minha Choi, Jongho Kim, Ungtae Kim Nov 2019

Advances In Remote Sensing To Understand Extreme Hydrological Events, Dongkyun Kim, Minha Choi, Jongho Kim, Ungtae Kim

Civil and Environmental Engineering Faculty Publications

No abstract provided.


Periodic Operation Of A Dynamic Dna Origami Structure Utilizing The Hydrophilic–Hydrophobic Phase‐Transition Of Stimulus‐Sensitive Polypeptides, Marisa A. Goetzfried, Kilian Vogele, Andrea Mückl, Marcus Kaiser, Nolan B. Holland, Friedrich C. Simmel, Tobias Pirzer Nov 2019

Periodic Operation Of A Dynamic Dna Origami Structure Utilizing The Hydrophilic–Hydrophobic Phase‐Transition Of Stimulus‐Sensitive Polypeptides, Marisa A. Goetzfried, Kilian Vogele, Andrea Mückl, Marcus Kaiser, Nolan B. Holland, Friedrich C. Simmel, Tobias Pirzer

Chemical & Biomedical Engineering Faculty Publications

Dynamic DNA nanodevices are designed to perform structure‐encoded motion actuated by a variety of different physicochemical stimuli. In this context, hybrid devices utilizing other components than DNA have the potential to considerably expand the library of functionalities. Here, the reversible reconfiguration of a DNA origami structure using the stimulus sensitivity of elastin‐like polypeptides is reported. To this end, a rectangular sheet made using the DNA origami technique is functionalized with these peptides and by applying changes in salt concentration the hydrophilic–hydrophobic phase transition of these peptides actuate the folding of the structure. The on‐demand and reversible switching of the rectangle …


Alterations In Phenotype And Gene Expression Of Adult Human Aneurysmal Smooth Muscle Cells By Exogenous Nitric Oxide, Kurt Farrell, Phillip Simmers, Gautam Mahajana, Ludovic Boytard, Andrew Camardo, Jyotsna Joshi, Anand Ramamurthi, Florence Pine, Chandrasekhar R. Kothapalli Nov 2019

Alterations In Phenotype And Gene Expression Of Adult Human Aneurysmal Smooth Muscle Cells By Exogenous Nitric Oxide, Kurt Farrell, Phillip Simmers, Gautam Mahajana, Ludovic Boytard, Andrew Camardo, Jyotsna Joshi, Anand Ramamurthi, Florence Pine, Chandrasekhar R. Kothapalli

Chemical & Biomedical Engineering Faculty Publications

Abdominal aortic aneurysms (AAA) are characterized by matrix remodeling, elastin degradation, absence of nitric oxide (NO) signaling, and inflammation, influencing smooth muscle cell (SMC) phenotype and gene expression. Little is known about the biomolecular release and intrinsic biomechanics of human AAA-SMCs. NO delivery could be an attractive therapeutic strategy to restore lost functionality of AAA-SMCs by inhibiting inflammation and cell stiffening. We aim to establish the differences in phenotype and gene expression of adult human AAA-SMCs from healthy SMCs. Based on our previous study which showed benefits of optimal NO dosage delivered via S-Nitrosoglutathione (GSNO) to healthy aortic SMCs, we …


Biophysical And Biomechanical Properties Of Neural Progenitor Cells As Indicators Of Developmental Neurotoxicity, Gautam Mahajan, Moo-Yeal Lee, Chandrasekhar R. Kothapalli Oct 2019

Biophysical And Biomechanical Properties Of Neural Progenitor Cells As Indicators Of Developmental Neurotoxicity, Gautam Mahajan, Moo-Yeal Lee, Chandrasekhar R. Kothapalli

Chemical & Biomedical Engineering Faculty Publications

Conventional in vitro toxicity studies have focused on identifying IC50 and the underlying mechanisms, but how toxicants influence biophysical and biomechanical changes in human cells, especially during developmental stages, remain understudied. Here, using an atomic force microscope, we characterized changes in biophysical (cell area, actin organization) and biomechanical (Young's modulus, force of adhesion, tether force, membrane tension, tether radius) aspects of human fetal brain-derived neural progenitor cells (NPCs) induced by four classes of widely used toxic compounds, including rotenone, digoxin, N-arachidonoylethanolamide (AEA), and chlorpyrifos, under exposure up to 36 h. The sub-cellular mechanisms (apoptosis, mitochondria membrane potential, DNA damage, glutathione …


Agricultural Drought Assessment Based On Multiple Soil Moisture Products, Jongjin Baik, Muhammad Zohaib, Ungtae Kim, Muhammad Aadil, Minha Choi Aug 2019

Agricultural Drought Assessment Based On Multiple Soil Moisture Products, Jongjin Baik, Muhammad Zohaib, Ungtae Kim, Muhammad Aadil, Minha Choi

Civil and Environmental Engineering Faculty Publications

In this study, we evaluated three soil moisture (SM) products (Advanced Microwave Scanning Radiometer-2 [AMSR2], Advanced SCATterometer [ASCAT], and European Reanalysis Interim [ERA-interim]) across Australia in four climate zones by comparing against the Australian Water Resources Assessment-Landscape (AWRA-L) SM products from July 2012 to June 2017. The ASCAT SM indicated better performance than other SM products over Australia. To evaluate the applicability and reliability for monitoring agricultural drought, an agricultural drought index, the Soil Water Deficit Index, was estimated from three SM products and compared with three commonly-used drought indices (atmospheric water deficit [AWD], Evaporative Stress Index, and Reconnaissance …


Co-Optimization Approach To Post-Storm Recovery For Interdependent Power And Transportation Systems, Yinyin Ge, Lili Du, Hongzing Ye Jul 2019

Co-Optimization Approach To Post-Storm Recovery For Interdependent Power And Transportation Systems, Yinyin Ge, Lili Du, Hongzing Ye

Electrical and Computer Engineering Faculty Publications

The power and transportation systems are urban interdependent critical infrastructures (CIs). During the post-disaster restoration process, transportation mobility and power restoration process are interdependent, and their functionalities significantly affect other well-beings of other urban CIs. Therefore, to enhance the resilience of urban CIs, successful recovery strategies should promote CI function cooperatively and synergistically to distribute goods and services efficiently. This paper develops an integrative framework that addresses the challenges of enhancing the recovery efficiency of urban power and transportation systems in short-term recovery period. Specifically, the post-storm recovery process is considered as a scheduling problem under the constraints representing crew …


Design And Analysis Of Novel Actuation Mechanism With Controllable Stiffness, Erivelton Gualter Dos Santos, Hanz Richter Feb 2019

Design And Analysis Of Novel Actuation Mechanism With Controllable Stiffness, Erivelton Gualter Dos Santos, Hanz Richter

Mechanical Engineering Faculty Publications

Actuators intended for human–machine interaction systems are usually designed to be mechanically compliant. Conventional actuators are not suitable for this purpose due to typically high stiffness. Advanced powered prosthetic and orthotic devices can vary their stiffness during a motion cycle and are power-efficient. This paper proposes a novel actuator design that modulates stiffness by means of a flexible beam. A motorized drive system varies the active length of the cantilever beam, thus achieving stiffness modulation. New large deflection formulation for cantilever beams with rolling contact constraints is used to determine the moment produced by the actuator. To validate the proposed …


Primary Dendrite Trunk Diameter In Al-7wt% Si Alloy Directionally Solidified Aboard The International Space Station, S. R. Upadhyay, Surendra N. Tewari, M. Ghodes, R. N. Grugel, D. R. Poirier, M. Lauer Jan 2019

Primary Dendrite Trunk Diameter In Al-7wt% Si Alloy Directionally Solidified Aboard The International Space Station, S. R. Upadhyay, Surendra N. Tewari, M. Ghodes, R. N. Grugel, D. R. Poirier, M. Lauer

Chemical & Biomedical Engineering Faculty Publications

Under a NASA (National Aeronautics and Space Agency)-ESA (European Space Agency) collaborative research project, MICAST (Microstructure formation in casting of technical alloys under a diffusive and magnetically controlled convection conditions), three Al-7wt% Si samples (MICAST-6, MICAST-7 and MICAST2-12) were directionally solidified at growth speeds varying from 10 to 50 µm s-1 aboard the International Space Station to determine the effect of mitigating convection on the primary dendrite array. The observed primary dendrite trunk diameters during steady-state growth of MICAST samples show a good agreement with predictions from a coarsening based model developed by the authors. The trunk diameters in …


Water Pollution In Old Towns Affecting The Environment And Ecological Restoration, Zou Hang, Muhammad Aqeel Ashraf, Yung Tse Hung Jan 2019

Water Pollution In Old Towns Affecting The Environment And Ecological Restoration, Zou Hang, Muhammad Aqeel Ashraf, Yung Tse Hung

Civil and Environmental Engineering Faculty Publications

© 2019 Technoscience Publications. All rights reserved. In order to solve the problem that the traditional activated sludge method is not effective in recovering the ecological process of water pollution in urban areas, the membrane bioreactor-based sewage treatment process was studied experimentally. Two flat-plate ultrafiltration membranes were used to form the ultrafilter tank in the experimental device sampled, and the processes of nitrate cycle and sludge cycle were adopted. Ozonation and granular activated carbon filtration were adopted to treat the micropollutants. After repeated experiments in 17 experimental cycles, the obtained experimental data were analysed, and it was found that under …


Impact Of Sea Surface Temperature And Surface Air Temperature On Maximizing Typhoon Rainfall: Focusing On Typhoon Maemi In Korea, Jeonghyeon Choi, Jeonghoon Lee, Sangdan Kim Jan 2019

Impact Of Sea Surface Temperature And Surface Air Temperature On Maximizing Typhoon Rainfall: Focusing On Typhoon Maemi In Korea, Jeonghyeon Choi, Jeonghoon Lee, Sangdan Kim

Civil and Environmental Engineering Faculty Publications

In this study, the effects of surface air temperature (SAT) and sea surface temperature (SST) changes on typhoon rainfall maximization are analysed. Based on the numerically reproduced Typhoon Maemi, this study tried to maximize the typhoon-induced rainfall by increasing the amount of saturated water vapour in the atmosphere and the amount of water vapour entering the typhoon. Using the Weather Research and Forecasting (WRF) model, which is one of the regional climate models (RCMs), the rainfall simulated by WRF while increasing the SAT and SST to various sizes at initial conditions and boundary conditions of the model was analysed. As …


State Estimation For An Agonistic‐Antagonistic Muscle System, Thang Tien Nguyen, Holly Warner, Hung La, Hanieh Mohammadi, Daniel J. Simon, Hanz Richter Jan 2019

State Estimation For An Agonistic‐Antagonistic Muscle System, Thang Tien Nguyen, Holly Warner, Hung La, Hanieh Mohammadi, Daniel J. Simon, Hanz Richter

Electrical and Computer Engineering Faculty Publications

Research on assistive technology, rehabilitation, and prosthetics requires the understanding of human machine interaction, in which human muscular properties play a pivotal role. This paper studies a nonlinear agonistic‐antagonistic muscle system based on the Hill muscle model. To investigate the characteristics of the muscle model, the problem of estimating the state variables and activation signals of the dual muscle system is considered. In this work, parameter uncertainty and unknown inputs are taken into account for the estimation problem. Three observers are presented: a high gain observer, a sliding mode observer, and an adaptive sliding mode observer. Theoretical analysis shows the …


Application Of Rb/Sr Ratio In Paleo-Climate Inversion, Shupei Ouyang, Muhammad Aqeel Ashraf, Yung-Tse Hung Jan 2019

Application Of Rb/Sr Ratio In Paleo-Climate Inversion, Shupei Ouyang, Muhammad Aqeel Ashraf, Yung-Tse Hung

Civil and Environmental Engineering Faculty Publications

In order to study the intensity of chemical weathering during the formation of sedimentary strata in the site profile, the evolution of climatic environment in the region where the site profile is located was revealed. The rubidium (Rb) and strontium (Sr) values in the rubidium (Rb) and strontium (Sr) were tested and analysed. The Rb/Sr ratio has become an ideal alternative indicator in the study of regional environmental evolution. The Rb value in the strata section of Zhongba site is low, and the average value (calculated based on 202 sample values) is only 80 g/g. The Sr value was higher, …


High Order Volumetric Directional Pattern For Video-Based Face Recognition, Almabrok Essa, Vijayan Asari Jan 2019

High Order Volumetric Directional Pattern For Video-Based Face Recognition, Almabrok Essa, Vijayan Asari

Electrical and Computer Engineering Faculty Publications

Describing the dynamic textures has attracted growing attention in the field of computer vision and pattern recognition. In this paper, a novel approach for recognizing dynamic textures, namely, high order volumetric directional pattern (HOVDP), is proposed. It is an extension of the volumetric directional pattern (VDP) which extracts and fuses the temporal information (dynamic features) from three consecutive frames. HOVDP combines the movement and appearance features together considering the nth order volumetric directional variation patterns of all neighboring pixels from three consecutive frames. In experiments with two challenging video face databases, YouTube Celebrities and Honda/UCSD, HOVDP clearly outperformed a set …


Metabolic Cost Calculations Of Gait Using Musculoskeletal Energy Models, A Comparison Study, Anne D. Koelewijn, Dieter Heinrich, Antonie J. Van Den Bogert Jan 2019

Metabolic Cost Calculations Of Gait Using Musculoskeletal Energy Models, A Comparison Study, Anne D. Koelewijn, Dieter Heinrich, Antonie J. Van Den Bogert

Mechanical Engineering Faculty Publications

This paper compares predictions of metabolic energy expenditure in gait using seven metabolic energy expenditure models to assess their correlation with experimental data. Ground reaction forces, marker data, and pulmonary gas exchange data were recorded for six walking trials at combinations of two speeds, 0.8 m/s and 1.3 m/s, and three inclines, -8% (downhill), level, and 8% (uphill). The metabolic cost, calculated with the metabolic energy models was compared to the metabolic cost from the pulmonary gas exchange rates. A repeated measures correlation showed that all models correlated well with experimental data, with correlations of at least 0.9. The model …


Charged Nanoparticles Quench The Propulsion Of Active Janus Colloids, Marola W. Issa, Nicky R. Baumgartner, Mohammed A. Kalil, Shawn D. Ryan, Christopher L. Wirth Jan 2019

Charged Nanoparticles Quench The Propulsion Of Active Janus Colloids, Marola W. Issa, Nicky R. Baumgartner, Mohammed A. Kalil, Shawn D. Ryan, Christopher L. Wirth

Mathematics and Statistics Faculty Publications

Active colloidal particles regularly interact with surfaces in applications ranging from microfluidics to sensing. Recent work has revealed the complex nature of these surface interactions for active particles. Herein, we summarize experiments and simulations that show the impact of charged nanoparticles on the propulsion of an active colloid near a boundary. Adding charged nanoparticles not only decreased the average separation distance of a passive colloid because of depletion attraction as expected but also decreased the apparent propulsion of a Janus colloid to near zero. Complementary agentbased simulations considering the impact of hydrodynamics for active Janus colloids were conducted in the …