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Biochemical and Biomolecular Engineering Commons™

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Electrical and Computer Engineering Faculty Research & Creative Works

Articles 1 - 11 of 11

Full-Text Articles in Biochemical and Biomolecular Engineering

Graphene Oxide–Driven In Situ Bismuth Reduction Enables Highly Efficient Electroreduction Of Co2 To Formic Acid, Hao Feng, Bohong Zhang, Jie Huang, Xinhua Liang Oct 2026

Graphene Oxide–Driven In Situ Bismuth Reduction Enables Highly Efficient Electroreduction Of Co2 To Formic Acid, Hao Feng, Bohong Zhang, Jie Huang, Xinhua Liang

Electrical and Computer Engineering Faculty Research & Creative Works

To enable large scale efficient electrochemical CO2 reduction reaction (CO2RR) to formic acid (HCOOH), it is important to develop catalysts that can be operated in a wide potential window with good stability. Herein, we successfully synthesized Bi2O3 catalyst supported on graphene oxide (GO) and graphene (G) and found that Bi2O3/GO catalyst had a better overall performance than Bi2O3/G. The Bi2O3/GO catalyst demonstrated an outstanding CO2RR performance with a greater than 90% faradaic efficiency (FE) across a wide applied potential window …

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Converting Co2 Into Carbon Nanotubes Via Sequential Co2 Methanation And Methane Pyrolysis, Kaiying Wang, Hao Feng, Ahmad Helaley, Xiaoqing He, Bohong Zhang, Jie Huang, Xinhua Liang Jun 2026

Converting Co2 Into Carbon Nanotubes Via Sequential Co2 Methanation And Methane Pyrolysis, Kaiying Wang, Hao Feng, Ahmad Helaley, Xiaoqing He, Bohong Zhang, Jie Huang, Xinhua Liang

Electrical and Computer Engineering Faculty Research & Creative Works

This study presents a sequential thermochemical catalytic process for converting CO2 into carbon nanotubes (CNTs), achieving nearly 99% overall CO2 conversion and solid carbon yields of up to 49% in a single pass. The overall transformation is divided into two thermodynamically favorable steps: (1) low-temperature CO2 methanation to CH4 over a sol-gel-prepared Ni87Ce6.5Zr6.5-SG catalyst, which achieved >95% CO2 conversion at 250 °C in a single pass, and (2) subsequent methane pyrolysis to CNTs and H2 over a Ni@Al2O3-IE core-shell catalyst, which showed improved stability and carbon …

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Open-Ended Hollow Coaxial Cable Resonator Sensor, Jie Huang, Chen Zhu, Rex E. Gerald Ii Oct 2021

Open-Ended Hollow Coaxial Cable Resonator Sensor, Jie Huang, Chen Zhu, Rex E. Gerald Ii

Electrical and Computer Engineering Faculty Research & Creative Works

An open-ended hollow coaxial cable resonator probe configured to receive an aerosol sample for analysis. A metal post shorts the resonator's inner and outer conductors. A metal plate is spaced apart from an open end of the resonator by a dielectric layer that contains the received aerosol sample. Interrogator circuitry coupled to the resonator transmits an electromagnetic wave within the resonator and generates an electric field at the open end of the resonator. The interrogator circuitry is responsive to the generated electric field for determining a resonance frequency and an impedance of the resonator when the aerosol sample is present …

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Sensor Application Of Poly (Ethylene Glycol) Diacrylate Hydrogels Chemically-Anchored On Polymer Surface, Zhan Gao, Chang-Soo Kim, David B. Henthorn Apr 2013

Sensor Application Of Poly (Ethylene Glycol) Diacrylate Hydrogels Chemically-Anchored On Polymer Surface, Zhan Gao, Chang-Soo Kim, David B. Henthorn

Electrical and Computer Engineering Faculty Research & Creative Works

We demonstrate a device process combining two photo patternable polymers, poly (ethylene glycol) (PEG)-diacrylate-based-hydrogel and epoxy-based photoresist SU-8, to implement an optofluidic bioanalytical platform through a surface anchoring technique. As an exemplary sensor application, optical dissolved oxygen sensors are fabricated and their performance characterized. The PEG-rich hydrogel is used as a matrix material for the immobilization of oxygen-responsive fluorophore, dichlorotris (1, 10-phenanthroline) ruthenium (II) hydrate. This hydrogel is chemically anchored on the surface of negative-tone photoresist, SU-8, through a free radical reaction in which 1-hydroxycyclohexyl phenyl ketone served as the surface bound photo initiator. The sensor exhibits a reversible Stern-Volmer …

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Colorimetric Oxygen Imaging And Quantification With Easily Accessible Optical Devices, Satya Achanta, Sanghan Park, Chang-Soo Kim Dec 2012

Colorimetric Oxygen Imaging And Quantification With Easily Accessible Optical Devices, Satya Achanta, Sanghan Park, Chang-Soo Kim

Electrical and Computer Engineering Faculty Research & Creative Works

Optical oxygen imaging is essential in monitoring two-dimensional analysis of oxygen distribution. Two easily accessible optical devices were used for oxygen analysis to demonstrate the feasibility of an innovatively simple method. a light panel screen with light-emitting diode (LED) backlight was used as a light source to excite a luminophore film responsive to oxygen. Meso-scale fluidic sensor platform was prepared using porphyrin complex (PtOEP) as the luminophore embedded within ethyl cellulose (EC) polymer matrix. Green LED light uniformly displayed from the light panel excited the luminophore film to exhibit two-dimensional luminescence distribution corresponding to wet gaseous oxygen. a color camera …

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An Oxidase-Based Electrochemical Fluidic Sensor With High-Sensitivity And Low-Interference By On-Chip Oxygen Manipulation, Nitin Radhakrishnan, Jongwon Park, Chang Soo Kim Jul 2012

An Oxidase-Based Electrochemical Fluidic Sensor With High-Sensitivity And Low-Interference By On-Chip Oxygen Manipulation, Nitin Radhakrishnan, Jongwon Park, Chang Soo Kim

Electrical and Computer Engineering Faculty Research & Creative Works

Utilizing a simple fluidic structure, we demonstrate the improved performance of oxidase-Based enzymatic biosensors. Electrolysis of water is utilized to generate bubbles to manipulate the oxygen microenvironment close to the biosensor in a fluidic channel. for the proper enzyme reactions to occur, a simple mechanical procedure of manipulating bubbles was developed to maximize the oxygen level while minimizing the pH change after electrolysis. the sensors show improved sensitivities based on the oxygen dependency of enzyme reaction. in addition, this oxygen-rich operation minimizes the ratio of electrochemical interference signal by ascorbic acid during sensor operation (i.e., amperometric detection of hydrogen peroxide). …

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Optofluidic Glucose Sensor Utilizing An Epoxy-Based, Transparent Dry Film Resist, Zhan Gao, Sijia Gong, Chang Soo Kim, David B. Henthorn Dec 2011

Optofluidic Glucose Sensor Utilizing An Epoxy-Based, Transparent Dry Film Resist, Zhan Gao, Sijia Gong, Chang Soo Kim, David B. Henthorn

Electrical and Computer Engineering Faculty Research & Creative Works

An enzymatic, fluorescent glucose sensor was constructed with a novel epoxy-Based, optically transparent dry film resist (PerMX 3000 series, DuPont). This material was utilized as the main active material for fluidic structure and optical interrogation. This sensor was based on the enzymatic reaction of glucose oxidase (GOD) and utilized a ruthenium complex fluorophore as the reporting agent. Both the oxygen-sensitive ruthenium complex and GOD were incorporated into poly (ethylene glycol) (PEG)-Based hydrogel materials, which were lithographically patterned and embedded inside the PerMX fluidic channel after wafer-bonding process. the optofluidic sensing platform with this embedded sensing elements exhibited a wide dynamic …

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Optofluidic Biosensors Based On Color Imaging, Jongwon Park, Chang-Soo Kim Oct 2010

Optofluidic Biosensors Based On Color Imaging, Jongwon Park, Chang-Soo Kim

Electrical and Computer Engineering Faculty Research & Creative Works

A color CCD (charge-coupled device) camera is used as a chemical detector to quantify fluorescence emission intensities from two kinds of optofluidic device platforms. the fluorophores responsive to oxygen are immobilized in photo-patternable hydrogel matrices. the first device is a hydrogel sensor array formed within a commercial silicone elastomer imaging chamber. the second one involves a double-chamber fluidic device composed of a permeable membrane layer and dry film photoresist layers. the results suggest that digital color imagers, in combination with a simple color separation method, can serve as the high-quality chemical detectors for fluidic biosensors and biological culture platforms. © …

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Color Intensity Method For Hydrogel Oxygen Sensor Array, Jongwon Park, Wonhak Hong, Chang-Soo Kim Oct 2010

Color Intensity Method For Hydrogel Oxygen Sensor Array, Jongwon Park, Wonhak Hong, Chang-Soo Kim

Electrical and Computer Engineering Faculty Research & Creative Works

The oxygen imaging technique to obtain a 2-D distribution is a convenient method because it does not require individual addressing of each sensing element in a sensor array. Until recently, color charge coupled devices (CCDs) have rarely been used for oxygen imaging in spite of usefulness for analyzing the spectral content of images. in this work, a color CCD camera was used for luminescence intensity imaging. Two methods of color intensity analysis are investigated and compared. the first method is to analyze the total Red-Green-Blue (RGB) color intensity of the original color image. the second method involves extracting the red …

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Incorporation Of Cerium And Neodymium In A Uranyl Hydroxide Solid, Chang-Soo Kim, David J. Wronkiewicz, R. J. Finch, E. C. Buck Jan 2002

Incorporation Of Cerium And Neodymium In A Uranyl Hydroxide Solid, Chang-Soo Kim, David J. Wronkiewicz, R. J. Finch, E. C. Buck

Electrical and Computer Engineering Faculty Research & Creative Works

The migration behavior of radionuclides in a nuclear-waste repository will be influenced, in part, by their equilibrium solubilities in the presence of radionuclide-bearing solids and/or adsorption affinities as trace components onto the surfaces of solid host phases. Uranium phases that precipitate on the surface of altered spent nuclear fuel may thus influence the mobility of radionuclides released in the near-field environment, since by proximity, these will be the first phases that the radionuclides encounter following their release from the spent fuel matrix. We have evaluated the potential for incorporating radionuclides into crystalline compounds by precipitating uranyl phases from aqueous solutions …

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Growth Of Ultrafine Particles By Brownian Coagulation, S. H. Suck Salk, R. E. Thurman, Chang-Soo Kim Jan 1986

Growth Of Ultrafine Particles By Brownian Coagulation, S. H. Suck Salk, R. E. Thurman, Chang-Soo Kim

Electrical and Computer Engineering Faculty Research & Creative Works

Current atmospheric observations tend to support the view that continental tropospheric aerosols (particularly urban aerosols) show multimodal mass distributions in the size range of 0.01-100 μm. The origin of these aerosols is both natural and anthropogenic. Recently, trimodal sub-μm size distributions from combustion measurements at 0.008, 0.035 and 0.15 μm were also observed. Our interest in the present study is the secondary process of growth of sub-μm size aerosols by the coagulation process alone. Using the 'J-space' (integer-space) distribution method of Salk (Suck) and Brock (1979, J. Aerosol Sci. 10, 58-590), we report an accurate numerical simulation study of the …

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