Diatoms are single-celled algaes that make photonic-crystal-like silica shells or frustules with ... more Diatoms are single-celled algaes that make photonic-crystal-like silica shells or frustules with hierarchical micro- & nano-scale features consisting of two-dimensional periodic pores. This article reports the use of diatom frustules as an integration platform to enhance localized surface plasmon resonances of self-assembled silver nanoparticles (NPs) on the surface of diatom frustules. Theoretical and experimental results show enhanced localized surface plasmons due to the coupling with the guided-mode resonances of the frustules. We observed 2 × stronger optical extinction and over 4 × higher sensitivity of surface-enhanced Raman scattering of Rhodmine 6G from the NPs-on-diatom than the NPs-on-glass structure.
We experimentally demonstrate an ultra-sensitive immunoassay biosensor using diatom biosilica wit... more We experimentally demonstrate an ultra-sensitive immunoassay biosensor using diatom biosilica with self-assembled plasmonic nanoparticles. As the nature-created photonic crystal structures, diatoms have been adopted to enhance surface plasmon resonances of metal nanoparticles on the surfaces of diatom frustules and to increase the sensitivity of surface-enhanced Raman scattering (SERS). In this study, a sandwich SERS immunoassay is developed based on the hybrid plasmonic-biosilica nanostructured materials that are functionalized with goat anti-mouse IgG. Our experimental results show that diatom frustules improve the detection limit of mouse IgG to 10 pg/mL, which is ˜100× better than conventional colloidal SERS sensors on flat glass. Ultra-sensitive immunoassay biosensor using diatom biosilica with self-assembled plasmonic nanoparticles.
ABSTRACT We present theoretical design and experimental demonstration of surface-normal modulatio... more ABSTRACT We present theoretical design and experimental demonstration of surface-normal modulation on a gold metallic photonic crystal slab. It requires a moderate index modulation of 0.0043 that is induced by thermal-optical effects of the glass substrate.
Industrial & Engineering Chemistry Research, 2012
The calcium looping process (CLP), which is being developed at The Ohio State University (OSU), i... more The calcium looping process (CLP), which is being developed at The Ohio State University (OSU), is a clean coal technology for the production of hydrogen (H 2) and electricity from coal-derived syngas. It integrates the water−gas shift (WGS) reaction with in situ removal of carbon dioxide (CO 2) and other contaminants like sulfides and halides, thus resulting in the production of high-purity H 2. The in situ removal of CO 2 drives the equilibrium-limited WGS reaction forward. The CLP has the potential to reduce the overall footprint of a coal-to-H 2 process because of the integration of several unit operations in a single-stage reactor. The high-temperature operation and the different exothermic reactions involved provide various sources of heat, which, when integrated appropriately, result in a process with low energy penalty. Prior work conducted in a fixed-bed reactor has shown that high carbon monoxide (CO) conversions and high H 2 purities can be obtained, depending on the operating pressures. On the basis of the encouraging results obtained from the fixed-bed reactor, a subpilot-scale fluidized-bed reactor (carbonator) has been designed and constructed at OSU. In this work, the design of this reactor has been detailed and some operational results have been provided.
Industrial & Engineering Chemistry Research, 2013
ABSTRACT The decreasing CO2 capture capacity of calcium sorbents over multiple reaction cycles po... more ABSTRACT The decreasing CO2 capture capacity of calcium sorbents over multiple reaction cycles poses a significant challenge to the large-scale cyclic carbonation-calcination process. Several approaches, including intermediate hydration, have been suggested to overcome this limitation. Until this study, most hydration studies have been performed at laboratory-scale using thermogravimetric techniques at conditions that may not be feasible for process scale-up. Moreover, data on the design of a steam hydrator suitable for the calcium looping process is not available. For the first time, this study reports the design of a bench-scale high-temperature steam hydrator for calcium sorbent reactivation. The hydrator, consisting of a fluidized-bed reactor with additional internals, was evaluated using cold-flow tests following which several reaction parameters were investigated in the hot unit. The results obtained from these high-temperature steam hydration tests (300–500 °C) are discussed here. Specifically, at an average temperature of 473 °C and PH2O = 1 atm, the 30 min hydration conversion exceeded 70%. In addition, the sorbent reactivity toward CO2 was appreciably recovered proportional to the extent of hydration. Lastly, the potential to extract the heat of reaction (>450 °C) for process heat integration further expands the marketability of this high-temperature steam hydrator as a viable option for a wide range of applications ranging from CO2 capture to chemical heat pump systems.
Journal of Clinical Neuroscience - J CLIN NEUROSCI, 1995
This paper presents a vialidation of a real-timie digital simulator (FLTDS) of frequency dependen... more This paper presents a vialidation of a real-timie digital simulator (FLTDS) of frequency dependent transmission liine mod- el with a published field test. The real-time transmission line mod- el is based on iMarti's time domain formulation which is adopted in the EMTlP and EMTDC programs. Improvements to speed up the calculation are made in order to realize electromagnetic tran- sient simulation in real-time by parallel processing using two digi- tal signal processors (DSP's) for eaicb line. The Field test is repro- duced by R'TDS and the simulation results are compared with the published field test results to show a good agreement between the two sets. Details of the system data for the field test are also given in this paper. I. INTRODUCTION The Real-Time Digital Simulator (RTDS) or digital TNA is the first completely digital real time ,electromagnetic transients ac and dc simulator and relay tester ever developed based on Digital Signal Processors (DSP's) in a...
Diatoms are single-celled algaes that make photonic-crystal-like silica shells or frustules with ... more Diatoms are single-celled algaes that make photonic-crystal-like silica shells or frustules with hierarchical micro- & nano-scale features consisting of two-dimensional periodic pores. This article reports the use of diatom frustules as an integration platform to enhance localized surface plasmon resonances of self-assembled silver nanoparticles (NPs) on the surface of diatom frustules. Theoretical and experimental results show enhanced localized surface plasmons due to the coupling with the guided-mode resonances of the frustules. We observed 2 × stronger optical extinction and over 4 × higher sensitivity of surface-enhanced Raman scattering of Rhodmine 6G from the NPs-on-diatom than the NPs-on-glass structure.
We experimentally demonstrate an ultra-sensitive immunoassay biosensor using diatom biosilica wit... more We experimentally demonstrate an ultra-sensitive immunoassay biosensor using diatom biosilica with self-assembled plasmonic nanoparticles. As the nature-created photonic crystal structures, diatoms have been adopted to enhance surface plasmon resonances of metal nanoparticles on the surfaces of diatom frustules and to increase the sensitivity of surface-enhanced Raman scattering (SERS). In this study, a sandwich SERS immunoassay is developed based on the hybrid plasmonic-biosilica nanostructured materials that are functionalized with goat anti-mouse IgG. Our experimental results show that diatom frustules improve the detection limit of mouse IgG to 10 pg/mL, which is ˜100× better than conventional colloidal SERS sensors on flat glass. Ultra-sensitive immunoassay biosensor using diatom biosilica with self-assembled plasmonic nanoparticles.
ABSTRACT We present theoretical design and experimental demonstration of surface-normal modulatio... more ABSTRACT We present theoretical design and experimental demonstration of surface-normal modulation on a gold metallic photonic crystal slab. It requires a moderate index modulation of 0.0043 that is induced by thermal-optical effects of the glass substrate.
Industrial & Engineering Chemistry Research, 2012
The calcium looping process (CLP), which is being developed at The Ohio State University (OSU), i... more The calcium looping process (CLP), which is being developed at The Ohio State University (OSU), is a clean coal technology for the production of hydrogen (H 2) and electricity from coal-derived syngas. It integrates the water−gas shift (WGS) reaction with in situ removal of carbon dioxide (CO 2) and other contaminants like sulfides and halides, thus resulting in the production of high-purity H 2. The in situ removal of CO 2 drives the equilibrium-limited WGS reaction forward. The CLP has the potential to reduce the overall footprint of a coal-to-H 2 process because of the integration of several unit operations in a single-stage reactor. The high-temperature operation and the different exothermic reactions involved provide various sources of heat, which, when integrated appropriately, result in a process with low energy penalty. Prior work conducted in a fixed-bed reactor has shown that high carbon monoxide (CO) conversions and high H 2 purities can be obtained, depending on the operating pressures. On the basis of the encouraging results obtained from the fixed-bed reactor, a subpilot-scale fluidized-bed reactor (carbonator) has been designed and constructed at OSU. In this work, the design of this reactor has been detailed and some operational results have been provided.
Industrial & Engineering Chemistry Research, 2013
ABSTRACT The decreasing CO2 capture capacity of calcium sorbents over multiple reaction cycles po... more ABSTRACT The decreasing CO2 capture capacity of calcium sorbents over multiple reaction cycles poses a significant challenge to the large-scale cyclic carbonation-calcination process. Several approaches, including intermediate hydration, have been suggested to overcome this limitation. Until this study, most hydration studies have been performed at laboratory-scale using thermogravimetric techniques at conditions that may not be feasible for process scale-up. Moreover, data on the design of a steam hydrator suitable for the calcium looping process is not available. For the first time, this study reports the design of a bench-scale high-temperature steam hydrator for calcium sorbent reactivation. The hydrator, consisting of a fluidized-bed reactor with additional internals, was evaluated using cold-flow tests following which several reaction parameters were investigated in the hot unit. The results obtained from these high-temperature steam hydration tests (300–500 °C) are discussed here. Specifically, at an average temperature of 473 °C and PH2O = 1 atm, the 30 min hydration conversion exceeded 70%. In addition, the sorbent reactivity toward CO2 was appreciably recovered proportional to the extent of hydration. Lastly, the potential to extract the heat of reaction (>450 °C) for process heat integration further expands the marketability of this high-temperature steam hydrator as a viable option for a wide range of applications ranging from CO2 capture to chemical heat pump systems.
Journal of Clinical Neuroscience - J CLIN NEUROSCI, 1995
This paper presents a vialidation of a real-timie digital simulator (FLTDS) of frequency dependen... more This paper presents a vialidation of a real-timie digital simulator (FLTDS) of frequency dependent transmission liine mod- el with a published field test. The real-time transmission line mod- el is based on iMarti's time domain formulation which is adopted in the EMTlP and EMTDC programs. Improvements to speed up the calculation are made in order to realize electromagnetic tran- sient simulation in real-time by parallel processing using two digi- tal signal processors (DSP's) for eaicb line. The Field test is repro- duced by R'TDS and the simulation results are compared with the published field test results to show a good agreement between the two sets. Details of the system data for the field test are also given in this paper. I. INTRODUCTION The Real-Time Digital Simulator (RTDS) or digital TNA is the first completely digital real time ,electromagnetic transients ac and dc simulator and relay tester ever developed based on Digital Signal Processors (DSP's) in a...
Uploads
Papers by alan wang