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Articles 4711 - 4740 of 14165

Full-Text Articles in Engineering

Analyzing Evolution Of Rare Events Through Social Media Data, Xiaoyu Lu Aug 2019

Analyzing Evolution Of Rare Events Through Social Media Data, Xiaoyu Lu

Dissertations

Recently, some researchers have attempted to find a relationship between the evolution of rare events and temporal-spatial patterns of social media activities. Their studies verify that the relationship exists in both time and spatial domains. However, few of those studies can accurately deduce a time point when social media activities are most highly affected by a rare event because producing an accurate temporal pattern of social media during the evolution of a rare event is very difficult. This work expands the current studies along three directions. Firstly, we focus on the intensity of information volume and propose an innovative clustering …

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Roles Of Surfactant And Binary Polymers On Dissolution Enhancement Of Bcs Ii Drugs From Nanocomposites And Amorphous Solid Dispersions, Md Mahbubur Rahman Aug 2019

Roles Of Surfactant And Binary Polymers On Dissolution Enhancement Of Bcs Ii Drugs From Nanocomposites And Amorphous Solid Dispersions, Md Mahbubur Rahman

Dissertations

Drug nanocomposites and amorphous solid dispersions (ASDs) are two major formulation platforms used for the bioavailability enhancement of BCS Class II drugs. The major drawback of nanocomposites is their inability to attain high drug supersaturation during in vitro (<50% relative supersaturation) and in vivo dissolution. On the other hand, formulating an amorphous solid dispersion (ASD) with high drug loading (>20%) that releases drug rapidly, while generating and maintaining high supersaturation over at least three hours is challenging. The goal of this thesis is to develop a fundamental understanding of the impact of anionic surfactants–polymers on in vitro drug release from nanocomposites and ASDs, while addressing the above challenges. To achieve this goal, the following objectives are set: (1) compare griseofulvin …

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Enzymatic Biofuel Cells In A Sandwich Geometry With Compressed Carbon Nanotubes/Enzyme Electrodes & Hybrid Patch Applications, Biao Leng Aug 2019

Enzymatic Biofuel Cells In A Sandwich Geometry With Compressed Carbon Nanotubes/Enzyme Electrodes & Hybrid Patch Applications, Biao Leng

Dissertations

Enzymatic biofuel cells (EBFCs) convert the chemical energy of biofuels, such as glucose and methanol, into electrical energy by employing enzymes as catalysts. In contrast to conventional fuel cells, EBFCs have a simple membrane-free fuel cell design due to the high catalytic specificity of the enzymes, but the power densities obtained are lower. Although the primary goal of research on EBFCs has been to develop a sustainable power source that can be directly implanted in the human body to power bio-devices, other applications such as the use of a flexible film or fuel cell patch as a wearable power source …

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Regulation Of Copper Surface Via Redox Reactions For Enhancing Carbon Dioxide Electroreduction, Bao-Hua Hang, Jin-Tao Zhang Aug 2019

Regulation Of Copper Surface Via Redox Reactions For Enhancing Carbon Dioxide Electroreduction, Bao-Hua Hang, Jin-Tao Zhang

Journal of Electrochemistry

A large-scale application of fossil fuels has led to excessive emission of carbon dioxide (CO2), resulting in serious environmental issues. A promising path to reducing CO2 emissions is recycling CO2 into valuable chemicals and fuels through an electrochemical process. Herein, the redox reactions between copper (Cu) and ferric chloride (FeCl3) have been utilized to regulate the Cu surface composition and structure, aimed to improve the electrocatalytic activity toward CO2 reduction. Typically, a series of samples (named Cu-1h, Cu-2h, Cu-3h and Cu-4h) were prepared via the redox reactions for various time from 1 to …

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Single-Layer Oxygen Deficiency Δ-Mno2 For Electrochemical Co2 Reduction, Yue-Feng Zhang, Jian-Jun Liu, Zeng-Xi Wei, Xin-Xin Tian, Jian-Min Ma Aug 2019

Single-Layer Oxygen Deficiency Δ-Mno2 For Electrochemical Co2 Reduction, Yue-Feng Zhang, Jian-Jun Liu, Zeng-Xi Wei, Xin-Xin Tian, Jian-Min Ma

Journal of Electrochemistry

Manganese dioxide (MnO2) has been widely used in catalysis. In addition, since the defect engineering can change the electronic properties of the catalyst, here we have systematically studied electrocatalytic carbon dioxide reduction reaction (CO2RR) on δ-MnO2 with and without oxygen deficiency, denoted as Ov-MnO2 and MnO2, respectively. We calculate the electronic properties and the intermediate of free energy for MnO2 and Ov-MnO2 with the help of spin-polarized density functional theory. By analyzing this result, we can find that the introduction of defects change the δ-MnO2 from semiconducting properties to …

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Statuses, Challenges And Strategies In The Development Of Low-Temperature Carbon Dioxide Electroreduction Technology, Xu-Rui Zhang, Xiao-Lin Shao, Jin Yi, Yu-Yu Liu, Jiu-Jun Zhang Aug 2019

Statuses, Challenges And Strategies In The Development Of Low-Temperature Carbon Dioxide Electroreduction Technology, Xu-Rui Zhang, Xiao-Lin Shao, Jin Yi, Yu-Yu Liu, Jiu-Jun Zhang

Journal of Electrochemistry

Low-temperature carbon dioxide (CO2) electrochemical reduction technology is a hotspot for research and development in recent years as a way to reduce the negative impact of CO2 on the environment and to generate energy storage through converting electricity to low-carbon fuels. Although basic research on catalyst activity, product selectivity, and reaction mechanism has been widely reported, the design and practicality of catalytic stability and corresponding electrochemical reactor systems have not been given sufficient attention and systematic development.  In this paper, two important factors affecting the development of CO2 electrochemical reduction technology in low temperature aqueous solution …

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Recent Advances In Bismuth-Based Co2 Reduction Electrocatalysts, Rui Zhou, Na Han, Yan-Guang Li Aug 2019

Recent Advances In Bismuth-Based Co2 Reduction Electrocatalysts, Rui Zhou, Na Han, Yan-Guang Li

Journal of Electrochemistry

Carbon dioxide (CO2) is an economical, secure and sustainable carbon resource around us. Its effective capture and recycling have been the focus of our entire society. Using the electrochemical method, CO2 can be reduced to different value-added chemicals or fuels. This approach not only would mitigate CO2 accumulation in the atmosphere, but also would help alleviate our dependence on fossil fuel. In this article, the basic principle and process of electrochemical CO2 reduction are first introduced. The recent development in bismuth-based catalysts for electrocatalytic CO2 reduction is reviewed with an emphasis on their preparation, …

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Electrocatalytic Reduction Of Carbon Dioxide To Carbon Monoxide Using Cobalt Nitride, Chen Ma, Peng-Fei Hou, Peng Kang Aug 2019

Electrocatalytic Reduction Of Carbon Dioxide To Carbon Monoxide Using Cobalt Nitride, Chen Ma, Peng-Fei Hou, Peng Kang

Journal of Electrochemistry

Electrocatalytic reduction of carbon dioxide (CO2) is a promising method to alleviate global warming issues, although it still faces many challenges. Herein, we report cobalt nitride for electrocatalytic reduction of CO2 to carbon monoxide (CO) in an aqueous electrolyte. A comparison of catalysts with different preparation temperatures and atmospheres suggests that nitrogen doping is critical to improve catalytic activity. For the most active catalyst of 700-Co5.47N/C, the CO current density reached 9.78 mA·cm-2 at potential of -0.7 V vs. RHE. In addition, the CO/H2 ratio could be adjusted from 1:3 to 3:2 by …

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Effect Of Morphology Of Fe-N Codoped Carbon Nanomaterial On Electrochemical Reduction Reactions, Er-Ling Li, Fa Yang, Ming-Bo Ruan, Ping Song, Wei-Lin Xu Aug 2019

Effect Of Morphology Of Fe-N Codoped Carbon Nanomaterial On Electrochemical Reduction Reactions, Er-Ling Li, Fa Yang, Ming-Bo Ruan, Ping Song, Wei-Lin Xu

Journal of Electrochemistry

Graphene nanosheets (GS) and carbon nanotubes have been considered as good catalysts candidates for applications in energy conversion and storage. However, hybrids of GS and carbon nanotubes are always formed in transition metal-based nitrogen-doped system, making the system quite complex for exploring the structure-activity relationship. To prepare the catalysts with desired species controllably, we try to adjust the outcomes with the effect of nitrogen on the growth of carbon nanotubes. In this work, a series of Fe-N co-doped carbon hybrid catalysts containing N-doped GS or hybrids of GS/bamboo carbon nanotubes (BCNTs) or BCNTs were obtained with one-step pyrolyzed method. To …

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Preparations And Electrocatalytic Properties Of Cu-Bipy-Btc-Derived Carbon-Based Catalyst For Oxygen Reduction Reaction, Li-Hua Zhang, Jun-Feng Chen, Wan-Tang Huang, Yong-You Hu, Jian-Hua Cheng, Yuan-Cai Chen Aug 2019

Preparations And Electrocatalytic Properties Of Cu-Bipy-Btc-Derived Carbon-Based Catalyst For Oxygen Reduction Reaction, Li-Hua Zhang, Jun-Feng Chen, Wan-Tang Huang, Yong-You Hu, Jian-Hua Cheng, Yuan-Cai Chen

Journal of Electrochemistry

Efficient and low-cost oxygen reduction reaction (ORR) electrocatalyst plays a key role for fuel cells. In this paper, ORR active metal organic framework (MOF: Cu-bipy-BTC, bipy = 2,2?-bipyridine, BTC = 1,3,5-tricarboxylate) was prepared using hydrothermal method, and then carbon-based material MOF-800 was obtained from pyrolyzing Cu-bipy-BTC at 800 °C. Scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), nitrogen sorption isotherm and X-ray photolectron spectroscopy (XPS) were used to characterize the morphologies and structures of the catalysts. Linear sweep voltammetry (LSV) and current-time curve (i-t) were adopted to evaluate the electrocatalytic properties of the catalysts. The results …

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Preface To Special Issue Of Electrochemical Reduction Of Carbon Dioxide, Qing Li, Min Liu Aug 2019

Preface To Special Issue Of Electrochemical Reduction Of Carbon Dioxide, Qing Li, Min Liu

Journal of Electrochemistry

No abstract provided.

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Copper-Based Compounds For Electrochemical Reduction Of Carbon Dioxide, Fan Yang, Pei-Lin Deng, You-Jia Han, Pan Jing, Bao-Yu Xia Aug 2019

Copper-Based Compounds For Electrochemical Reduction Of Carbon Dioxide, Fan Yang, Pei-Lin Deng, You-Jia Han, Pan Jing, Bao-Yu Xia

Journal of Electrochemistry

The electrochemical reduction of carbon dioxide (CO2) to useful chemicals and fuels has attracted enormous interest since the deteriorating global warming and energy shortage problems resulted from ever-increasing CO2 emission. Designing efficient catalysts is of capital significance to realize the efficient and selective conversion of CO2. Among various catalysts explored, copper-based compounds have promising potentials with acceptable efficiency for hydrocarbon production. Herein, recent advances on copper-based materials are summarized for electrochemical CO2 conversion. We intend to include the dimensional structure, different forms (alloy, oxide) and molecular catalysts in copper-based catalysts. Moreover, the reaction mechanisms …

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Recent Progress In Copper-Based Catalysts For Electrochemical Co2 Reduction, Wen Lei, Wei-Ping Xiao, De-Li Wang Aug 2019

Recent Progress In Copper-Based Catalysts For Electrochemical Co2 Reduction, Wen Lei, Wei-Ping Xiao, De-Li Wang

Journal of Electrochemistry

As the situation of energy crisis and environmental pollution become more and more serious, the electrochemical reduction of carbon dioxide (CO2) has attracted lots of attention because of its multiple meanings such as environment, resources and economic benefits. In this paper, the state of the art electrochemical reduction of CO2 in aqueous solution is reviewed, and the latest research progress in Cu-based catalysts with different structures and morphologies is summarized. In the end, the application prospects, opportunities and challenges of Cu-based materials are briefly presented to provide an outlook for future research directions.

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Reduction Of A Detailed Soot Model For Simulations Of Pyrolysing Solid Fuels, Alexander J. Josephson, Emily M. Hopkins, David O. Lignell, Rod R. Linn Aug 2019

Reduction Of A Detailed Soot Model For Simulations Of Pyrolysing Solid Fuels, Alexander J. Josephson, Emily M. Hopkins, David O. Lignell, Rod R. Linn

Faculty Publications

This work presents a computationally inexpensive soot formation model for use in simulating large solid-complex fuel systems. The proposed model evaluates three variables: number density of tars, bulk mass density of soot particles, and particle number density. Each of these variables are influenced by soot formation phenomena, and this model evaluates the most common of these phenomena: soot nucleation, surface reactions, and coagulation. Two separate simulations were carried out using this model and results were compared against simulations using a more detailed and computationally expensive model. Results are promising and show a meaningful reduction in model complexity and computational cost …

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Methods For Estimating Supersaturation In Antisolvent Crystallization Systems, Jennifer M. Schall, Gerard Capellades, Allan S. Myerson Aug 2019

Methods For Estimating Supersaturation In Antisolvent Crystallization Systems, Jennifer M. Schall, Gerard Capellades, Allan S. Myerson

Henry M. Rowan College of Engineering Departmental Research

The mole fraction and activity coefficient-dependent (MFAD) supersaturation expression is the least-assumptive, practical choice for calculating supersaturation in solvent mixtures. This paper reviews the basic thermodynamic derivation of the supersaturation expression, revisits common simplifying assumptions, and discusses the shortcomings of those assumptions for the design of industrial crystallization processes. A step-by-step methodology for estimating the activity-dependent supersaturation is provided with focus on ternary systems. This method requires only solubility data and thermal property data from a single differential scanning calorimetry (DSC) experiment. Two case studies are presented, where common simplifications to the MFAD supersaturation expression are evaluated: (1) for various …

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Lactonic Sophorolipid Increases Surface Wettability Of Poly- L -Lactic Acid Electrospun Fibers, Alexis M. Ziemba, Keith P. Lane, Bailey Balouch, Anthony R. D'Amato, Filbert Totsingan, Richard A. Gross, Ryan J. Gilbert Aug 2019

Lactonic Sophorolipid Increases Surface Wettability Of Poly- L -Lactic Acid Electrospun Fibers, Alexis M. Ziemba, Keith P. Lane, Bailey Balouch, Anthony R. D'Amato, Filbert Totsingan, Richard A. Gross, Ryan J. Gilbert

Chemical and Biochemical Engineering Faculty Research & Creative Works

The hydrophobicity of electro spun poly-l-lactic acid (PLLA) fibers hinders their integration with surrounding tissue for a variety of applications. In this study, we increased PLLA fiber hydrophilicity by incorporating the natural surfactant, lactonic sophorolipid (LSL). PLLA+LSL fibers had similar fiber morphology but significantly greater surface wettability, which suggested LSL accumulation on the fiber surface. Differential scanning calorimetry results also suggested that LSL was phase separated from PLLA. Despite the altered surface wettability of these fibers, there was no change in fibroblast adhesion. Future studies may explore the use of this natural surfactant to deliver bioactive factors to enhance fibroblast …

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Incorporating Solvent-Dependent Kinetics To Design A Multistage, Continuous, Combined Cooling/Antisolvent Crystallization Process, Jennifer M. Schall, Gerard Capellades, Jasdeep S. Mandur, Richard D. Braatz, Allan S. Myerson Aug 2019

Incorporating Solvent-Dependent Kinetics To Design A Multistage, Continuous, Combined Cooling/Antisolvent Crystallization Process, Jennifer M. Schall, Gerard Capellades, Jasdeep S. Mandur, Richard D. Braatz, Allan S. Myerson

Henry M. Rowan College of Engineering Departmental Research

Combined cooling and antisolvent crystallization enables crystallization of many pharmaceutical products, but its process design typically neglects solvent composition influences on crystallization kinetics. This paper evaluates the influence of solvent-dependent nucleation and growth kinetics on the design of optimal, multistage mixed-suspension, mixed-product removal (MSMPR) crystallization cascades. The ability to independently select temperature and solvent compositions in each stage of the cascade serves to greatly expand the attainable region for a two-stage cascade, with diminishing returns for additional stages. Failure to include solvent-dependent kinetics can result in simulating incorrect attainable regions, active pharmaceutical ingredient (API) yields, and crystal size distributions. This …

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Phase Rule Classification Of Physical And Chemical Critical Effects In Liquid Mixtures, James K. Baird, Xingjian Wang, Joshua R. Lang, Pauline Norris Aug 2019

Phase Rule Classification Of Physical And Chemical Critical Effects In Liquid Mixtures, James K. Baird, Xingjian Wang, Joshua R. Lang, Pauline Norris

PRC-Affiliated Research

The isobaric heat capacity and the coefficient of thermal expansion of a binary liquid mixture with a critical point of solution diverge as functions of temperature in the critical region. When the same liquids are used as solvents for chemical reactions, the van't Hoff plot of the extent of reaction diverges in the critical region. According to the phase rule, the physical and chemical properties are isomorphic in the sense that in each case the critical behavior is determined by three fixed thermodynamic intensive variables.

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Phase Rule Classification Of Physical And Chemical Critical Effects In Liquid Mixtures, James K. Baird, Xingjian Wang, Joshua R. Lang, Pauline Norris Aug 2019

Phase Rule Classification Of Physical And Chemical Critical Effects In Liquid Mixtures, James K. Baird, Xingjian Wang, Joshua R. Lang, Pauline Norris

PRC-Affiliated Research

The isobaric heat capacity and the coefficient of thermal expansion of a binary liquid mixture with a critical point of solution diverge as functions of temperature in the critical region. When the same liquids are used as solvents for chemical reactions, the van't Hoff plot of the extent of reaction diverges in the critical region. According to the phase rule, the physical and chemical properties are isomorphic in the sense that in each case the critical behavior is determined by three fixed thermodynamic intensive variables.

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Phase Rule Classification Of Physical And Chemical Critical Effects In Liquid Mixtures, James K. Baird, Xingjian Wang, Joshua R. Lang, Pauline Norris Aug 2019

Phase Rule Classification Of Physical And Chemical Critical Effects In Liquid Mixtures, James K. Baird, Xingjian Wang, Joshua R. Lang, Pauline Norris

PRC-Affiliated Research

The isobaric heat capacity and the coefficient of thermal expansion of a binary liquid mixture with a critical point of solution diverge as functions of temperature in the critical region. When the same liquids are used as solvents for chemical reactions, the van't Hoff plot of the extent of reaction diverges in the critical region. According to the phase rule, the physical and chemical properties are isomorphic in the sense that in each case the critical behavior is determined by three fixed thermodynamic intensive variables.

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Computational And Experimental Approach To Understanding The Structural Interplay Of Self-Assembled End-Terminated Alkanethiolates On Gold Surfaces, Juganta K. Roy, Erick S. Vasquez, Henry P. Pinto, Swati Kumari, Keisha B. Walters, Jerzy Leszcynski Aug 2019

Computational And Experimental Approach To Understanding The Structural Interplay Of Self-Assembled End-Terminated Alkanethiolates On Gold Surfaces, Juganta K. Roy, Erick S. Vasquez, Henry P. Pinto, Swati Kumari, Keisha B. Walters, Jerzy Leszcynski

Chemical and Materials Engineering Faculty Publications

Applications of self-assembled monolayers (SAMs) on surfaces are prevalent in modern technologies and drives the need for a better understanding of the surface domain architecture of SAMs. To explore structural interaction at the interface between gold surfaces and a hydroxyl-terminated alkanethiol, 11-hydroxy-1-undecanethiol, (C11TH) we have employed a combined computational and experimental approach. Density functional theory (DFT) calculations were carried out on the thiol–gold interface using both the Perdew–Burke–Ernzerhof (PBE) and van der Waals (optB86b) density functionals. Our ab initio molecular dynamics (AIMD) simulations revealed that the interface consists of four different distinguished phases, each with different C11TH orientations. Experiments involved …

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Multiphase Cfd Modeling In Particle-Laden Flows, Zhizhong Ding Aug 2019

Multiphase Cfd Modeling In Particle-Laden Flows, Zhizhong Ding

LSU Doctoral Dissertations

Multiphase modeling is prevalent and useful in solving problems involving multiphase interactions such as fluid and solid. Applications conclude but not limited to fluidized bed, hydraulic conveying, and many others. Modeling techniques with multiple scales can provide various states of details with diverse computational resources used. In this dissertation, two CFD multiphase models are used to disclose interaction details in the particulate system. Two-Fluid Model is used to solve pulsed fluidized bed problem and immersed boundary method based direct numerical method is used to solve particle’s behavior in shear flow. Getting a better understanding of these problems to help to …

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Catalyst-Assisted Transformation Of Shale Gas To Transportation Fuels: Performance Of A Single-Site Cobalt Catalyst In Dehydrogenation And Oligomerization Processes, Ethan Edwards Aug 2019

Catalyst-Assisted Transformation Of Shale Gas To Transportation Fuels: Performance Of A Single-Site Cobalt Catalyst In Dehydrogenation And Oligomerization Processes, Ethan Edwards

The Journal of Purdue Undergraduate Research

No abstract provided.

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Role Of Submicrometer Particles In Advanced Technologies Of Carbon Capture, Zhichao Li Aug 2019

Role Of Submicrometer Particles In Advanced Technologies Of Carbon Capture, Zhichao Li

McKelvey School of Engineering Graduate Student Theses & Dissertations

Oxy-combustion and post-combustion carbon capture technologies are two of the most promising strategies for carbon capture and storage (CCS), which is a commonly accepted approach to address the challenge of climate change. Pressurized oxy-combustion has been actively studied due to its great potential to enhance the power plant energy efficiency by recovering latent heat from water vapor condensation without incurring additional gas compression cost. On the other hand, amine-based CO2 scrubbers have been demonstrated to have high removal efficiency of CO2 with the possibility to recycle amine solutions, which makes the technology a promising candidate for post-combustion carbon capture. Nonetheless, …

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Role Of Submicrometer Particles In Advanced Technologies Of Carbon Capture, Zhichao Li Aug 2019

Role Of Submicrometer Particles In Advanced Technologies Of Carbon Capture, Zhichao Li

McKelvey School of Engineering Graduate Student Theses & Dissertations

Oxy-combustion and post-combustion carbon capture technologies are two of the most promising strategies for carbon capture and storage (CCS), which is a commonly accepted approach to address the challenge of climate change. Pressurized oxy-combustion has been actively studied due to its great potential to enhance the power plant energy efficiency by recovering latent heat from water vapor condensation without incurring additional gas compression cost. On the other hand, amine-based CO2 scrubbers have been demonstrated to have high removal efficiency of CO2 with the possibility to recycle amine solutions, which makes the technology a promising candidate for post-combustion carbon capture. Nonetheless, …

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Evaluation Of Biodegradability Characteristics Of Cellulose-Based Film As Per Is/Iso 14855-1, Narayan C. Saha Dr, Gaurav Madhu Dr, Diksha B. Kadu Ms Aug 2019

Evaluation Of Biodegradability Characteristics Of Cellulose-Based Film As Per Is/Iso 14855-1, Narayan C. Saha Dr, Gaurav Madhu Dr, Diksha B. Kadu Ms

Journal of Applied Packaging Research

Biodegradable polymers (especially those derived from plant sources) begin their lifecycle as renewable resources, usually in the form of starch or cellulose. In this paper, the evaluation of biodegradability of cellulose-based polymer film under controlled composting conditions as per the guidelines of IS/ISO 14855 (Part-1) standard has been described. Microcrystalline cellulose (MCC) powder was taken as positive-control polymer. The apparatus used to analyse the degree and rate of biodegradation was developed indigenously. The validation of the biodegradability testing apparatus was also performed as per the prescribed test method given in IS/ISO 14855-1.

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Synthesis, Characterization And Selected Application Of Chitosan-Coated Magnetic Iron Oxide Nanoparticles, Hany A. Elazab Dr Aug 2019

Synthesis, Characterization And Selected Application Of Chitosan-Coated Magnetic Iron Oxide Nanoparticles, Hany A. Elazab Dr

Chemical Engineering

In this research, we report an efficient method to prepare highly active chitosan-coated magnetic iron oxide nanoparticles by implementing co-precipitation technique which is used for waste water treatment applications. Chitosan-coated magnetic iron oxide nanoparticles were synthesized and characterized using TEM, XRD, and XPS. A comparative study has been made between chitosan powder and chitosan coated with magnetic nanoparticles with respect to the rate of adsorption of copper from aqueous solution. It was also experimentally verified that chitosancoated magnetic iron oxide nanoparticles are much more effective in adsorption of heavy metals than chitosan powder and it takes just few minutes instead …

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Synthesis And Characterization Of Dinitro Pentamethylene Tetramine (Dpt), M. M. Seleet, S. A. Hassanien, M. A. Radwan, M. A. Sadek Aug 2019

Synthesis And Characterization Of Dinitro Pentamethylene Tetramine (Dpt), M. M. Seleet, S. A. Hassanien, M. A. Radwan, M. A. Sadek

Chemical Engineering

Preparation of dinitro pentamethylene tetramine (DPT) through the action of nitrating mixture formed of ammonium nitrate and fuming nitric acid on hexamine in presence of acetic acid, acetic anhydride and p-formaldehyde has been carried out. DPT was also prepared from hexamine dinitrate which is an important intermediate appears through preparation of DPT from hexamine directly. Prepared DPT was purified and then characterized through the determination of melting point, element test, FTIR spectrometry, UV spectrometry, and high performance liquid chromatography "HPLC". The obtained results were reliable and consistent with the literature.

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Investigation Of The Electrode Polarization Effect For Biosensor Applications, Anil Koklu Aug 2019

Investigation Of The Electrode Polarization Effect For Biosensor Applications, Anil Koklu

Mechanical Engineering Research Theses and Dissertations

My research focuses on electrokinetic transport. Particularly, in this dissertation, we focus on fabrication and testing of micro electrodes with nanostructured surfaces to minimize the electrode polarization (EP) effects for biosensor applications. In the first study, electrochemical deposition of gold nanoparticles on to planar gold electrodes was used to generate rough surfaces. Dendritic nanostructures that reduced EP up to two orders of magnitude was obtained by optimizing the deposition conditions. These structures also enhanced dielectrophoresis (DEP) response of our bio-chips, making them usable in physiological buffers. In further studies we discovered a universal scaling of EP in the frequency domain, …

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A Study Of The Electron Regeneration Efficiency Of Solar Cells Fabricated Using Cmc/Pva-, Alginate-, And Xanthan-Based Electrolytes, Nur Farha Shaafi, Saifful Kamaluddin Muzakir, Bouchta Sahraoui Aug 2019

A Study Of The Electron Regeneration Efficiency Of Solar Cells Fabricated Using Cmc/Pva-, Alginate-, And Xanthan-Based Electrolytes, Nur Farha Shaafi, Saifful Kamaluddin Muzakir, Bouchta Sahraoui

Makara Journal of Technology

A photovoltaic (PV) mechanism consists of three important steps, i.e., (i) electron excitation upon absorption of photon with energy higher than the bandgap of fluorophore, (ii) excited-state electron injection from the fluorophore to the pho-toelectrode, and (iii) electron regeneration from the electrolyte to the fluorophore. An efficient electron regeneration could be achieved upon fulfillment of the requirements of energy alignment, i.e., lowest unoccupied molecular orbital of fluorophore (LUMOfluorophore) > redox potential of electrolyte > highest occupied molecular orbital of fluorophore (HOMOfluorophore). This study investigated the electron regeneration efficiency of excitonic solar cells fabricated using three polymer-based electrolytes, i.e., (i) 60% carboxymethyl cellulose …

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