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44 results on '"Wong, Jonathan Woon Chung"'

19. Impact of different processing techniques on reduction in oil content in deep-fried donuts when using kombucha cellulose hydrolysates

Author

He, Shan, primary, Zhang, Yang, additional, Gu, Caiqing, additional, Wu, Yixiao, additional, Farooq, Muhammad Adil, additional, Young, David James, additional, Wong, Jonathan Woon Chung, additional, Chang, Kun, additional, Tian, Bin, additional, Kumari, Ankita, additional, Rahaman, Abdul, additional, and Gao, Jingrong, additional

Published
2022
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28. Upsized Vortex Fluidic Device Enhancement of Mechanical Properties and the Microstructure of Biomass-Based Biodegradable Films

Author

He, Shan, primary, Vimalanathan, Kasturi, additional, Su, Peng, additional, Jellicoe, Matt, additional, Luo, Xuan, additional, Xing, Wenjin, additional, Cai, Wanling, additional, Gibson, Christopher T., additional, Chen, Yaonan, additional, Wong, Jonathan Woon Chung, additional, Zhang, Wei, additional, Tang, Youhong, additional, and Raston, Colin L., additional

Published
2021
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35. Quantum effect and Mo–N surface bonding states of α-MoC1−xmodified carbon nitride for boosting photocatalytic performanceElectronic supplementary information (ESI) available: Details of photocatalyst synthesis, degradation experiment, calculation method. FTIR, Raman, EDX, total density of states. See DOI: https://doi.org/10.1039/d2cy01157c

Author

Zhu, Zhi, Kumar, Reeti, Luo, Liwen, Varjani, Sunita, Huo, Pengwei, Wong, Jonathan Woon-Chung, and Zhao, Jun

Abstract

Photocatalytic degradation of pharmaceuticals in the aquatic environment is considered a promising strategy to address water pollution. In this study, a novel photocatalyst was constructed by decorating g-C3N4(CN) with α-MoC1−xquantum dots (α-MoC1−x-QDs) through a facile calcination method. The catalyst showed enhanced tetracycline (TC) degradation performance under visible light. The unique Mo–N surface bonding states and quantum effect leading to superior TC degradation activity (89.1%) compared to pure CN (21.8%) were reported and revealed. More importantly, the mechanism for the significant enhancement of photocatalytic activity of the catalyst was investigated by DFT (density functional theory) calculations and photo-electrochemistry measurements. The results confirmed that the effect of α-MoC1−x-QDs on CN improved the light absorption capacity obviously, and the Mo–N surface bonding states accelerated the charge migration from CN to α-MoC1−x-QDs. Moreover, the TC degradation pathway, intermediates and photogenerated carrier transfer behaviors were also discussed in depth. This research provides a new strategy for the construction of noble-metal-free co-catalyst/semiconductor composite materials in the photocatalytic degradation of antibiotics.

Published
2022
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37. Isolation and characterization endophytic bacteria from hyperaccumulator Sedum alfredii Hance and their potential to promote phytoextraction of zinc polluted soil

Author

Wu QiTang, Long Xinxian, Chen Yagang, Chen Xue-mei, Wong Jonathan Woon-Chung, and Wei ZeBin

Subjects
Siderophore, biology, Physiology, General Medicine, biology.organism_classification, Applied Microbiology and Biotechnology, Endophyte, Sedum alfredii, Botany, Hyperaccumulator, Stenotrophomonas, Axenic, Microbial inoculant, Bacteria, Biotechnology
Abstract

The aim of this study was to isolate and characterize endophytic bacteria from roots, stems and leaves of Zn/Cd hyperaccumulator Sedum alfredii. Endophytic bacteria were observed in roots, stems and leave of S. alfredii, with a significantly higher density in roots, followed by leave and stems. A total of fourteen bacterial endophytes were isolated and are closely related phylogenetically to Pseudomonas, Bacillus, Stenotrophomonas, Acinetobacte by 16S rRNA sequence analysis. Most of the endophytic bacteria were found to exhibit high Zn and Cd resistance characteristics, but difference existed among this isolates. The fourteen endophytic bacteria all had the capacity to produce IAA. Moreover, strains VI8L1, VI8L2, VI8L4, VI8R2, VI8R3 and II2R3 could solubilize Ca3(PO4)2, strains VI8L2, II8L4 and VI8R2 could produce siderophore, and strains VI8L2 and VI8R3 had the capacity of nitrogen fixation. Both plate and broth assay proved that strain VI8L1, VI8L2, II8L4 and VI8R2 were able to effectively solubilize ZnCO3 and Zn3(PO4)2. The filtrate liquid media after growth of strains VI8L1, VI8L2, II8L4 and VI8R2 extracted much higher Zn from artificially ZnCO3 and Zn3(PO4)2 contaminated soils than those extracted by axenic SMS broth, and the filtrates of the culture media supporting growth of strains VI8L2, II8L4 and VI8R2 also extracted significantly greater quantities of Zn from the Dabaoshan contaminated soils. This Zn mobilizing, plant growth promoting and metal resistant endophytic bacteria may offer promise as inoculants to increase soil Zn bioavailability and improve growth and Zn accumulation by S. alfredii.

Published
2010
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38. Sulfur-doped g-C3N4for efficient photocatalytic CO2reduction: insights by experiment and first-principles calculationsElectronic supplementary information (ESI) available. See DOI: 10.1039/d0cy02382e

Author

Zhu, Zhi, Liu, Zhixiang, Tang, Xu, Reeti, Kumar, Huo, Pengwei, Wong, Jonathan Woon-Chung, and Zhao, Jun

Abstract

The development of doped g-C3N4photocatalyst has demonstrated potential advantages for the artificial photosynthesis of hydrocarbon fuels by utilizing solar energy and CO2. Herein, a new two-dimensional S-doped g-C3N4(S-CN) was designed and synthesized. S-CN displayed a high CO evolution rate of 16.02 μmol g−1in water (10 times more than bulk g-C3N4) at a molar ratio of thiourea to DCNA of 0.4. Also, S-CN could maintain its activity for up to 15 h during the stability test. S–C bond formation was revealed for the first time by combining material characterization and density functional theory (DFT) calculations. The S 3p state made an excellent contribution to moving up the conduction band position and altering the S-CN band gap. The doped S atoms caused charge rearrangement and significantly enhanced the electron–hole separation, enhancing the CO2reduction activity compared to bulk-CN. The present work provides a broadening window for the development of non-metal-doped g-C3N4with outstanding CO2photoreduction performance.

Published
2021
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39. The role of oxidative stress in the growth of the indoor mold Cladosporium cladosporioides under water dynamics.

Author

Wu, Haoxiang and Wong, Jonathan Woon Chung

Subjects
*OXIDATIVE stress, *CLADOSPORIUM, *PEARSON correlation (Statistics), *SUSTAINABLE development, *WATER supply
Abstract

Moisture is one of the critical abiotic factors that can affect mold growth. Indoor humidity is typically fluctuating, which renders a transient water supply for mold growth. Understanding mold growth under water dynamics and its underlying mechanisms can help in the development of novel and sustainable mold prevention strategies. In this study, pre‐germination and germinated spores of Cladosporium cladosporioides were exposed to daily wet‐dry cycles with different combinations of wetting and drying duration. Afterward, growth delay, cellular H2O2 concentration, and catalase (CAT) activity were measured and compared. We found that under daily wet‐dry cycles, the longer the growth delay was observed, the higher the cellular H2O2 concentration was detected, with the 12‐12 wet‐dry cycle (12‐hour wet and 12‐hour dry) showing the longest growth delay and highest cellular H2O2 production. A positive correlation between cellular H2O2 concentration and growth delay was suggested by Pearson correlation coefficient and linear regression analysis (P <.0001, R2 = 0.85). Furthermore, under daily wet‐dry cycles, molds derived from pre‐germination spores generally exhibited shorter growth delay, lower cellular H2O2 concentration, and higher CAT activity than molds developed from germinated spores. These results together suggest that the growth delay of C. cladosporioides under water dynamics is associated with oxidative stress. [ABSTRACT FROM AUTHOR]

Published
2020
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42. Sodium release characteristics and revegetation of fine bauxite refining residue (red mud)

Author

Ho, Goen, Wong, Jonathan Woon-Chung, Ho, Goen, and Wong, Jonathan Woon-Chung

Abstract

The revegetation of bauxite refining residue, red mud, produced from alumina refining is extremely difficult because of the high amount of Na in the residue especially in the desilication product (DSP). The high Na content imparts to red mud highly saline and sodic characteristics. The present study was to develop means to revegetate red mud through the control of Na release and the utilization of acidic and organic ameliorants together with tolerant plant species. Neutralization of red mud with HCl showed that the DSP, which was found to be a zeolite mineral akin to nosean, decomposed at pH between 5.4 and 7.0 and with a maximum Na release of 98.6 meq/100 g occurring at pH 5.4. At pH >7, the release of Na was due to the cation exchange between Na+ in red mud with H+ , and Ca2+ from dissolution of calcite. At pH between 5.4 to 7.0, Na release from the DSP was due to acid hydrolysis. The cation exchange capacity (CEC) obtained with monovalent cations was higher than with divalent cations. About 83 meq Na /100 g red mud could be displaced by K+ with repeated washings. Divalent cations could only displace about one third of the Na. The external CEC of red mud was estimated to be 15.4 meq/100 g while the internal CEC of red mud was 49.6 meq/100 g. A selectivity sequence for red mud was established: K > Li > NH4 > Ba ≥ Ca> Mg at a cation fraction on red mud ≥ 0.2. Four first-order reactions could be used to describe the release of Na from Na-K and Na-Ca exchanges in red mud with a total release of 61 and 31 meq/100 g red mud respectively. Sodium located in the external sites was released in about 6 h and 3 days for K and Ca exchange respectively. The final rates of Na desorption from the DSP were low for both exchanges. This indicates that the sodicity of red mud may increase with time. A glasshouse pot trial was used to investigate the effectiveness of copperas (FeSO4) and gypsum (CaSO4) for red mud reclamation. Copperas was effective in reducing the EC and Na content o

Published
1990

43. Rapid Biodegradation of Benzo[a]pyrene by Bacillus subtilis BUM Under Thermophilic Condition.

Author

Zhao, Zhenyong and Wong, Jonathan Woon-Chung

Subjects
*POLYCYCLIC aromatic hydrocarbons & the environment, *BIODEGRADATION of hydrocarbons, *BACILLUS subtilis, *MYCOBACTERIUM, *COMPOSTING, *THERMOPHILIC microorganisms, *PHENANTHRENE, *THERMOPHILIC bacteria
Abstract

Two thermophilic bacterial strains, Bacillus subtilis BUM (BUM) and Mycobacterium vanbaalenii BU42 (BU42), were tested for their potential in biodegradation of benzo[a]pyrene. Neither BUM nor BU42 utilized benzo[a]pyrene as the sole substrate under thermophilic condition. In the presence of 50, 250, and 500 mg L−1 phenanthrene, the biodegradation of benzo[a]pyrene by BUM occurred and removals in 30 days were 14.8%, 38.8%, and 63.6%, respectively. This is the first report on the biodegradation of benzo[a]pyrene by isolated thermophilic microorganism. The BUM strain was further tested for its ability in a soil composting system. Within a composting period of 42 days, removal of benzo[a]pyrene in the absence of BUM was 30.3%. Treatment with the inoculation of BUM significantly increased the removal of benzo[a]pyrene to 52.2%. Maximum zero-order degradation rates of benzo[a]pyrene by BUM in aqueous biodegradation experiment and soil composting system were 12.3 mg L−1 day−1 and 9.7 mg kg−1 day−1, respectively, which were significantly greater than most of the reported degradation rates by mesophiles. Experimental results affirmed that the strain BUM can effectively degrade benzo[a]pyrene under thermophilic condition. [ABSTRACT FROM AUTHOR]

Published
2010
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44. Pulverized coal fly ash : its trace element contents and its application in agriculture.

Author

Wong, Jonathan Woon-chung., Chinese University of Hong Kong Graduate School. Division of Biology., Wong, Jonathan Woon-chung., and Chinese University of Hong Kong Graduate School. Division of Biology.

Abstract

by Wong Woon-chung Jonathan., Bibliography: leaves 232-260, Thesis (M.Ph.)--Chinese University of Hong Kong, 1984, http://library.cuhk.edu.hk/record=b5885475, Use of this resource is governed by the terms and conditions of the Creative Commons “Attribution-NonCommercial-NoDerivatives 4.0 International” License (http://creativecommons.org/licenses/by-nc-nd/4.0/)

Published
1984

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