http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Yang, Won-Young,Lee, Sang-Hee,Lee, Eun-Ok,Chung, Guk-Hoon,Lee, Youn-Sik Korean Chemical Society 2002 Bulletin of the Korean Chemical Society Vol.23 No.1
Poly(ethylene glycol)-phosphatidylethanolamine conjugate (PEG-PE) has been used in preparing longcirculating liposomes. As a substitute for PEG-PE which can also be used in the long-circulating liposome formualtions, but can be prepared more readily with a lower cost, PEG-Phe-Chol was synthesized from PEG, phenylalanine, and cholesterol. The addition of the PEG derivative to distearoylphosphatidylcholine (DSPC) led to the formation of mixed micelles as well as liposomes when the derivative content was 10 mol% or greater. On the other hand, the addition of just 5 mol% PEG-Phe-Chol to dioleoylphosphatidylethanolamine (DOPE) generated mixed micelles as well as liposomes, but the formation of mixed micelles was completely inhibited by the addition of cholesterol. The leakage of entrapped calcein out of DOPE/cholesterol (7/3) liposomes containing 5 mol% PEG-Phe-Chol was about 45% during the incubation time for 24 h in 50% rabbit plasma, which was similar to that of the same liposomes containing 5 mol% PEG-dipalmitoylphosphatidylethanolamine (DPPE) under the identical conditions.
Yang, Yi,Ok, Yong Sik,Kim, Ki-Hyun,Kwon, Eilhann E.,Tsang, Yiu Fai Elsevier 2017 Science of the Total Environment Vol. No.
<P><B>Abstract</B></P> <P>In recent years, many of micropollutants have been widely detected because of continuous input of pharmaceuticals and personal care products (PPCPs) into the environment and newly developed state-of-the-art analytical methods. PPCP residues are frequently detected in drinking water sources, sewage treatment plants (STPs), and water treatment plants (WTPs) due to their universal consumption, low human metabolic capability, and improper disposal. When partially metabolized PPCPs are transferred into STPs, they elicit negative effects on biological treatment processes; therefore, conventional STPs are insufficient when it comes to PPCP removal. Furthermore, the excreted metabolites may become secondary pollutants and can be further modified in receiving water bodies. Several advanced treatment systems, including membrane filtration, granular activated carbon, and advanced oxidation processes, have been used for the effective removal of individual PPCPs. This review covers the occurrence patterns of PPCPs in water environments and the techniques adopted for their treatment in STP/WTP unit processes operating in various countries. The aim of this review is to provide a comprehensive summary of the removal and fate of PPCPs in different treatment facilities as well as the optimum methods for their elimination in STP and WTP systems.</P> <P><B>Highlights</B></P> <P> <UL> <LI> There is a large variation in PPCP removal in STPs and WTPs (−157–100%). </LI> <LI> PPCP removal is dependent on compound characteristics and process-specific factors. </LI> <LI> Advanced treatment technologies are effective for PPCP removal. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>
Fabrication of spherical biochar by a two-step thermal process from waste potato peel
Yang, Xiao,Kwon, Eilhann E.,Dou, Xiaomin,Zhang, Ming,Kim, Ki-Hyun,Tsang, Daniel C.W.,Ok, Yong Sik Elsevier 2018 Science of the Total Environment Vol.626 No.-
<P><B>Abstract</B></P> <P>The aim of this study was to develop a new approach for the preparation of spherical biochar (SBC) by employing a two-step thermal technology to potato peel waste (PPW). Potato starch (PS), as a carbon-rich material with microscale spherical shape, was separated from PPW as a precursor to synthesizing SBC. The synthesis process comprised (1) pre-oxidization (preheating under air) of PS at 220 °C and (2) subsequent pyrolysis of the pretreated sample at 700 °C. Results showed that the produced SBC successfully retained the original PS morphology and that pre-oxidization was the key for its shape maintenance, as it reduced surface tension and enhanced structural stability. The SBC possessed excellent chemical inertness (high aromaticity) and uniform particle size (10–30 μm). Zero-cost waste material with a facile and easy-to-control process allows the method to be readily scalable for industrialization, while offering a new perspective on the full use of PPW.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Potato starch (PS) derived from potato peel waste (PPW) has highly regular spherical shape. </LI> <LI> PS morphology was retained with pre-oxidation process after pyrolysis. </LI> <LI> PS's spherical shape affords great homogeneity to the produced biochar. </LI> <LI> Mechanism of shape maintenance was studied via various spectral characterizations. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>
Yang, Wen,Ok, Yong Sik,Dou, Xiaomin,Zhang, Yu,Yang, Min,Wei, Dongbin,Xu, Peng Elsevier 2019 Environmental research Vol.175 No.-
<P><B>Abstract</B></P> <P>Breaking down the structural bonds and eliminating the functional groups are more efficient than destroying the whole molecule in antibiotic production wastewater (APW) pretreatment before further biotreatment. Two sulfated titania (TiO<SUB>2</SUB>/SO<SUB>4</SUB>) solid superacids, SSA1 and SSA2 were synthesized, characterized and used for hydrolytic pretreatment of spiramycin in APW. Spiramycin removal followed an order of SSA2>SSA1>TiO<SUB>2</SUB>≈pH = 3>control. The hydrolytic efficiencies increased at elevated temperature from 25 °C to 65 °C. The hydrolytic kinetics followed a first-order model and SSA2 performed the fastest. The performances were positively correlated with both the total acidity determined by <I>n</I>-butylamine titration and the strength of acid sites measured by NH<SUB>3</SUB>-temperature-programmed desorption (TPD). The residual solution for SSA2 presented the least antibacterial potency and anaerobic inhibition among all treatments. The hydrolyzed product was identified as the <I>m/z</I> 699.4321 fragment using UPLC-Q/TOF-MS, which was formed after losing a functional mycarose moiety from the parent molecular. The solid superacids were effective in selectively eliminating 433 mg/L of spiramycin and the antibacterial potencies of the spiramycin production wastewater, which contained very high concentrations of COD (33,000 mg/L). This hydrolytic method avoids using and handling hazardous and corrosive mineral acids on site. It is attractive as a selective catalytic pretreatment method to cleave antibiotics’ functional groups and to reduce its inhibitory effects before sequential biotreatments.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Solid superacids were made by calcining the reaction products of H<SUB>2</SUB>SO<SUB>4</SUB> and titania. </LI> <LI> Functional group breakage was catalyzed by the acid sites of solid superacids. </LI> <LI> The Lewis and Brønsted acidic sites all contributed to the hydrolytic reaction. </LI> <LI> The antibacterial potency and the anaerobic inhibition were effectively decreased. </LI> <LI> Superacids performed well in hydrolytic pretreatment of the production wastewater. </LI> </UL> </P>
Yang, Jae E.,Ok, Yong Sik Informa UK (TaylorFrancis) 2017 Archiv für Acker- und Pflanzenbau und Bodenku Vol.63 No.1
<P>This study was conducted to investigate the kinetics of Hg adsorption by noncrystalline Al hydroxide as influenced by various pH conditions and cysteine (cys), glycine (gly), and citric acid (cit), which have different structures and functionalities, as low-molecular-weight organic ligands using the GEOCHEM-PC software. The influence of these organic ligands on the kinetics of Hg adsorption varied according to their concentration, structure, and functionality and pH. The adsorption of Hg followed multiple first order kinetics with initial rapid adsorption, followed by slow adsorption. Cysteine suppressed or enhanced Hg adsorption, depending on pH and its concentration. Glycine and citric acid exerted suppressing and enhancing effects, respectively, with the exception of at pH 4.5 and at lower concentrations, at which no influence was observed as compared to the control. Two mechanisms were thought to mediate the adsorption of Hg(II); specific surface complexation in the control, cysteine and glycine systems, and ligand exchange in the citric acid system. The Hg adsorption at all levels of organic ligands decreased with increasing pH, with the exception of at the higher concentration of cysteine, at which the reverse trend was observed. The influence of organic ligands on the dynamics of Hg in the freshwater environment merits further study.</P>