Browsing by Author "Huang, Cheng-Yu"

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Biomass and lipid production of a novel microalga, Chlorellaceae sp P5, through heterotrophic and swine wastewater cultivation
(2018-05-01)
Chiang, Yin-Ling
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Chen, Yu-Pei
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Yu, Ming-Chen
;
Hsieh, Sung-Yuan
;
Hwang, Ing-Er
A potential novel genus of microalgae was isolated from swine wastewater. According to a phylogenetic analysis of 18S rRNA and internal transcribed spacer (ITS) sequences, as well as the ITS2 secondary structure, this strain was designated as Chlorellaceae sp. P5. Acclimatization to various temperatures, pH conditions, and salinities demonstrated that this strain can grow at temperatures of 20 degrees C-40 degrees C, in an acidity range of pH 4-7, and with salinity as high as 3% NaCl. To optimize biomass production, response surface methodology was used which included variables associated with carbon and nitrogen sources. In this study, flask cultivation yielded 1.66 g l(-1) d(-1) of biomass under 15.19 g l(-1) glucose and 8.26 mM ammonium bicarbonate. The fatty acid composition suggested that the lipid from Chlorellaceae sp. P5 can be typically used for biodiesel production, with a low degree of unsaturated fatty acids. Moreover, a high content of the first-limiting amino acid (lysine) and 9,12-Octadecadienoic acid (linoleic acid, C18:2) for nutritional supplements was also observed. With respect to swine wastewater treatment, the isolated strain showed an excellent removal rate of ammonia and phosphate over 97.3 mg l(-1) of NH3-N and 20.3 mg of l(-1) PO43- in the sterilized and none-sterilized wastewater. The biomass and lipid derived from Chlorellaceae sp. P5 can be attained at 0.49 g l(-1) d(-1) and 0.13 g l(-1) d(-1) by swine wastewater cultivation with 5% CO2 supply, respectively. According to the various characteristic analyses, Chlorellaceae sp. P5 has great potential for different industrial developments such as biodiesel and wastewater treatment. Published by AIP Publishing.
Characterization of sub-THz photonic-transmitters based on CaAs-AlGaAs uni-traveling-carrier photodiodes and substrate-removed broadband antennas for impulse-radio communication
(2008-07-01)
Li, Yu-Tai
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Shi, J. -W.
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Huang, Cheng-Yu
;
Chen, Nan-Wei
;
Chen, Shu-Han
A novel photonic transmitter for wireless terahertz (THz) impulse-radio (IR) communication is realized by monolithic integration of a GaAs-AlGaAs-based uni-traveling-carrier (UTC) photodiode with a substrate-removed broadband antenna. The device can radiate strong sub-THz pulses (20-mW peak-power) with a narrow pulsewidth (< 2 ps) and wide bandwidth (100 similar to 250 GHz). The maximum average power emitted by our device, under the same THz time-domain spectroscopic setup, is around ten times higher than that of the low-temperature-grown GaAs-based photoconductive antenna, while with a much lower dc bias (9 versus 35 V). The bias-dependent peak output powers of our devices suggest their suitability for application as a data modulator/emitter for photonic THz IR communication.
Chemical Mass Closure and Chemical Characteristics of Ambient Ultrafine Particles and other PM Fractions
(2010)
Chen, Sheng-Chieh
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Tsai, Chuen-Jinn
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Huang, Cheng-Yu
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Chen, Hong-Dar
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Chen, Shui-Jen
Ambient ultrafine particles (UPs or PM(0.1)), PM(2.5) and PM(10) were investigated at the roadside of Syuefu road in Hsinchu city and in the Syueshan highway tunnel in Taipei, Taiwan. A SMPS (TSI Model 3936), three Dichotomous samplers (Andersen Model SA-241), and three MOUDIs (MSP Model 110) were collocated to determine the PM number and mass concentrations simultaneously. The filter samples were further analyzed for organic carbon (OC), element carbon (EC), water-soluble ions, and trace elements. The OC artifact was studied and quantified using the quartz behind quartz (QBQ) method for all PM fractions. Taking into account the OC artifact, chemical mass closure (ratio of the reconstructed chemical mass to the gravimetrical mass) of PM(0.1), PM(2.5), and PM(10) was then calculated and found to be good. The chemical analysis results of UPs at both sites showed that UPs in the present tunnel was mostly contributed from the vehicle emissions while UPs at the roadside was mainly influenced by urban sources.
Dustiness test of nanopowders using a standard rotating drum with a modified sampling train
(2009-01-01)
Tsai, Chuen-Jinn
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Wu, Chien-Hsien
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Leu, Ming-Long
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Chen, Sheng-Chieh
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Huang, Cheng-Yu
The standard rotating drum tester was used to determine the dustiness of two nanopowders, nano-TiO(2) and fine ZnO, in standard 1-min tests. Then, the sampling train was modified to determine the number and mass distributions of the generated particles in the respirable size range using a Scanning Mobility Particle Sizer (SMPS), an Aerodynamic Particle Sizer (APS) and a Multi-orifice Uniform Deposit Impactor (MOUDI) in the 30-min tests. It was found that very few particles below 100 nm were generated and the released rate of particles decreased with increasing rotation time for both nanopowders in the 30-min tests. Due to the fluffy structure of the released TiO(2) agglomerated particles, the mass distributions measured by the MOUDI showed large differences with those determined by the APS assuming the apparent bulk densities of the powders. The differences were small for the ZnO agglomerates, which were more compact than the TiO(2) agglomerates.
Exposure assessment and engineering control strategies for airborne nanoparticles: an application to emissions from nanocomposite compounding processes
(2012-07-01)
Tsai, Candace S. -J.
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White, David
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Rodriguez, Henoc
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Munoz, Christian E.
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Huang, Cheng-Yu
"In this study, nanoalumina and nanoclay particles were compounded separately with ethylene vinyl acetate (EVA) polymer to produce nanocomposites using a twin-screw extruder to investigate exposure and effective controls. Nanoparticle exposures from compounding processes were elevated under some circumstances and were affected by many factors including inadequate ventilation, surrounding air flow, feeder type, feeding method, and nanoparticle type. Engineering controls such as improved ventilation and enclosure of releasing sources were applied to the process equipment to evaluate the effectiveness of control. The nanoparticle loading device was modified by installing a ventilated enclosure surrounding the loading chamber. Exposures were studied using designed controls for comparison which include three scenarios: (1) no isolation; (2) enclosed sources; and (3) enclosed sources and improved ventilation. Particle number concentrations for diameters from 5 to 20,000 nm measured by the Fast Mobility Particle Sizer and aerodynamic particle sizer were studied. Aerosol particles were sampled on transmission electron microscope grids to characterize particle composition and morphology. Measurements and samples were taken at the near-and far-field areas relative to releasing sources. Airborne particle concentrations were reduced significantly when using the feeder enclosure, and the concentrations were below the baseline when two sources were enclosed, and the ventilation was improved when using either nanoalumina or nanoclay as fillers."
Exposure assessment of nano-sized and respirable particles at different workplaces
(2011-09-01)
Tsai, Chuen-Jinn
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Huang, Cheng-Yu
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Chen, Sheng-Chieh
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Ho, Chi-En
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Huang, Cheng-Hsiung
In this study, nanoparticle (NP, diameter < 100 nm) and respirable particles measurements were conducted at three different nanopowder workplaces, including the mixing area of a nano-SiO(2)-epoxy molding compound plant (primary diameter: 15 nm), bagging areas of a nano-carbon black (nano-CB) (primary diameter: 32 nm) and a nano-CaCO(3) (primary diameter: 94 nm) manufacturing plant. Chemical analysis of respirable particle mass (RPM) and NPs was performed to quantify the content of manufactured nanoparticles in the collected samples. Nanopowder products obtained from the plants were used in the laboratory dustiness testing using a rotating drum tester to obtain particle mass and number distributions. The obtained laboratory data were then used to elucidate the field data. Both field and laboratory data showed that NP number and mass concentrations of manufactured materials were close to the background level. Number concentration was elevated only for particles with the electrical mobility diameter > 100 nm during bagging or feeding processes, unless there were combustion-related incidental sources existed. Large fraction of nanomaterials was found in the RPM due to agglomeration of nanomaterials or attachment of nanomaterials to the larger particles. From this study, it is concluded that RPM concentration measurements are necessary for the exposure assessment of nanoparticles in workplaces.
Measurements of respirable dust and nanoparticle concentrations in a titanium dioxide pigment production factory
(2010)
Huang, Cheng-Hsiung
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Tai, Chih-Yuan
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Huang, Cheng-Yu
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Tsai, Chuen-Jinn
;
Chen, Chun-Wan
This study compared respirable dust and nanoparticle concentrations measured by different sampling devices at a titanium dioxide pigment factory. Respirable particle mass concentrations, nanoparticle concentrations, particle size distribution and particle metallic content were measured at different sampling locations. The sampling results of the Multi-orifice Uniform Deposit Impactor (MOUDI) showed that the particle size distribution at this titanium dioxide production factory fell in the range of 1-10 mu m. Generally, the higher levels of the respirable particle mass concentrations and nanoparticle number concentrations were near the packing site of the pigment titanium dioxide production factory. Metal analysis results revealed that the titanium dioxide concentrations in respirable dust and nanoparticles were within the limits specified by National Institute for Occupational Safety and Health (NIOSH). During sampling, particle metallic content analysis is essential for identifying the source of particles and for measuring respirable dust and nanoparticle concentrations.
Sparse Volterra Nonlinear Equalizer by Employing Pruning Algorithm for High-Speed PAM-4 850-nm VCSEL Optical Interconnect
(2019-01-01)
Chuang, Chun-Yen
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Chang, Wei-Fan
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Wei, Chia-Chien
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Ho, Ching-Ju
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Huang, Cheng-Yu
A pruned Volterra equalizer that reduces computational complexity by up to 85.2% in 112-Gbps PAM-4 optical interconnects is proposed. The BER performance is competitive with LASSO-based Volterra equalizers, and training time is twice as fast.
Sub-THz Photonic-Transmitters Based on GaAs/AlGaAs Uni-Traveling Carrier Photodiode and Micromachined Circular Disk Monopole Antenna for Ultra-wideband Communication
(2008)
Li, Yu-Tai
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Pan, Ci-Ling
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Shi, J. -W.
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Huang, Cheng-Yu
;
Chen, Nan-Wei
By incorporating GaAs/AlGaAs based uni-traveling-carrier photodiodes with broadband micromachined monopole antennas, the demonstrated photonic-transmitter can radiate strong sub-THz pulses (20mW peak-power) with a wide bandwidth (100 similar to 250GHz), which was measured by another photonic-receiver for ultra-wideband communication. (c) 2008 Optical Society of America
The Influence of Relative Humidity on Nanoparticle Concentration and Particle Mass Distribution Measurements by the MOUDI
(2011)
Chen, Sheng-Chieh
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Tsai, Chuen-Jinn
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Chen, Hong-Dar
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Huang, Cheng-Yu
;
Roam, Gwo-Dong
A humidity control system was operated upstream of two collocated-MOUDIs (micro-orifice uniform deposit impactors) for sampling ambient aerosol particles. One MOUDI used silicone-grease-coated aluminum foils (ALs) as the impaction substrates and was considered as the reference impactor, while the other used uncoated ALs or uncoated Teflon filters (TFs) as the impaction substrates for quantifying the effect of different relative humidities (RHs) and impaction substrates on the PM(0.1) concentrations and mass distributions of ambient PMs. Test results showed that decreasing RH in general increased particle bounce from uncoated substrates with the bounce from uncoated ALs being more severe than that from uncoated TFs. Particle bounce did not influence the overall mass distribution of ambient fine particles when RH ranged between 40% and 80%, whereas it led to undersampling of particles greater than 2.5 mu m in aerodynamic diameter severely. Oversampling of PM(0.1) occurred by as much as 95%-180% or 25%-55% when the MOUDI used uncoated ALs or TFs, respectively, as RH was reduced from 50% to 25%. Particle bounce was found to be negligible, and PM(0.1) and PM(2.5) could be sampled accurately with less than 5% error at the RH of 75%-80% or 65%-80% when uncoated ALs or TFs were used, respectively.