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Enhanced photocatalytic degradation of lindane using metal–semiconductor Zn@ZnO and ZnO/Ag nanostructures

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Journal of Environmental Sciences 2018年第12期30卷 107-115页

作者： Hyeon Jin jung Ravindranadh Koutavarapu Seulki Lee Ju hyun Kim hyun chul Choi Myong Yong Choi Department of Chemistry (BK21+) and Research Institute of Natural Science Gyeongsang National University Department of Chemistry Chonnam National University

To achieve enhanced photocatalytic activity for the degradation of lindane, we prepared metal–semiconductor composite nanoparticles（NPs）. Zn@ZnO core–shell（CS） nanocomposites, calcined ZnO, and Ag-doped ZnO（ZnO/Ag） nanostructures were prepared using pulsed laser ablation in liquid, calcination, and photodeposition methods, respectively, without using surfactants or catalysts. The as-prepared catalysts were characterized by using X-ray diffraction（XRD）, field-emission scanning electron microscopy, high-resolution transmission electron microscopy, ultraviolet–visible（UV–vis） spectroscopy, and photoluminescence spectroscopy. In addition, elemental analysis was performed by energy dispersive X-ray spectroscopy. The obtained XRD and morphology results indicated good dispersion of Zn and Ag NPs on the surface of the ZnO nanostructures. Investigation of the photocatalytic degradation of lindane under UV–vis irradiation showed that Zn@ZnO CS nanocomposites exhibit higher photocatalytic activity than the other prepared samples. The maximum degradation rate of lindane was 99.5% in 40 min using Zn@ZnO CS nanocomposites. The radical trapping experiments verified that the hydroxyl radical（·OH） was the main reactive species for the degradation of lindane.

关键词： Zn@ZnO ZnO/Ag Lindane Pulsed laser ablation in liquid Photocatalysis

Pancreatic metastasis of leiomyosarcoma in the right thigh:A case report

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World Journal of Gastroenterology 2007年第7期13卷 1135-1137页

作者： Yang Seok Koh jung chul Chol Kyoon Cho hyun Jong Kim Division of Hepatobiliary & Pantreatic Surgery Department of Surgery Chonnam National University Medical School Gwangju 501757 Korea

Pancreatic tumors are primary in most of the cases. Pancreatic metastases associated with other primary malignancies, especially pancreatic metastasis of leiomyosarcoma, are uncommon. A 66-year-old woman underwent surgical resection of malignant mesenchymoma （70% osteosarcoma and 30% leiomyosarcoma） in the right thigh. In the postoperative period, a pancreatic mass was identified radiologically by abdominal computed tomography. Pylorus-preserving pancreaticoduodenectomy was performed. The surgical specimen revealed leiomyosarcoma metastasized to the pancreas. A metastatic nodule on the remnant pancreatic tail was discovered 9 mo after the first pancreatic resection, and distal pancreatectomy was performed. Cases of pancreatic metastasis from leiomyosarcoma are extremely rare, especially when the tumor was resectable. We report here a unique case of pancreatic metastasis from a leiomyosarcoma in the dght thigh that had been treated surgically.

关键词： Pancreatic tumor Leiomyosarcoma Metastasis

Enrichment by air classification of indium components from In-containing scrap powders scraped by sand-blasting chamber shields of sputter coaters

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Rare Metals 2010年第1期29卷 1-8页

作者： Sungkyu Lee Soo-Bok Jeong Hang-chul jung hyun Seon Hong Yongseung Yun Sang Mo Woo Plant Engineering Center Institute for Advanced Engineering633-2 Goan-ri Baegam-myeon Cheoin-gu Yongin-si Gyeonggi-do 449-863 Korea Division of Chemical and Materials Engineering Ajou University 5 Wonchon Youngtong Suwon Gyeonggi-do 443-749 Korea Minerals and Materials Processing Division Korea Institute of Geo-science and Mineral Resources (KIGAM) 30 Gajeong-dong Yuseong-gu Daejeon 305-350 Korea Plant Engineering Center Institute for Advanced Engineering633-2 Goan-ri Baegam-myeon Cheoin-gu Yongin-siGyeonggi-do 449-863 Korea 9 Digit Co. Ltd. 20BL-10L Namdong Industrial Complex428-9 Nonhyeon-dong Namdong-gu Incheon 405-848 Korea

Raw scrap powders containing 10 wt.% In were recovered by sand-blasting chamber shields of sputter coaters and used as a sole source of indium components for both sieving and air-classification. Sieving was performed first as a feasibility test, and enrichment of indium component was possible up to 19 wt.% with a mesh size of 635. With this experimental basis, the raw scrap powders were air-classified into 12 lots according to the revolution per minute （r/min） of a single horizontally arranged classifying wheel： 4000, 6000, 8000, 10000, 12000, and 14000 r/rain. The particle cut size varied from 56 to 5 μm with turbo wheel speeds corresponding to 4000 to 14000 r/min, respectively, and enrichment of indium component was possible in fine overflow fractions at all turbo wheel speeds while the indium components were not concentrated in all of the coarse underflow fractions. The grade of the indium components became higher with decreasing particle size of the air-classified scrap powders, with the highest grade obtained in the fine overflow fraction with a turbo wheel speed of 14000 r/min. The amount of indium in the fine overflow fractions varied between 15.9 wt.% and 31.5 wt.%. All in all, the grade or purity of the indium component improved rather significantly from 15.9 wt.% to 31.5 wt.% by air-classification, but this also resulted in overall decrease in recovery rate from 99.33% to 49.64%. Therefore, enrichment and separation of indium should be optimized for maximum recovery and grade of the indium components, which can be used as raw materials in the subsequent electro-refining processes.

关键词： indium air-classification recycling indium tin oxide gas-cyclone dry dispersion

Formation Mechanism of Chunky Graphite and Its Preventive Measures

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Journal of Materials Science & Technology 2008年第3期24卷 289-295页

作者： Hideo Nakae Sanghoon jung Ho-chul Shin Department of Materials Science and Engineering Waseda University National Institute of AIST Corporate Res.and Dev.Div. Hyundai.Kia Motors

The formation mechanism of chunky graphite has been reviewed and studied. The study consisted of a unidirectional solidification method, a small droplet method and a furnace cooling method. Four kinds of iron samples were prepared, namely, the pure Fe-C, Fe-C-S, Fe-C-Ce and Fe-C-Si-Ce alloys, and three kinds of nickel samples, namely the Ni-C, Ni-C-S and Ni-C-Mg alloys. The results of the unidirectional solidification of the Ni-C alloys showed that spheroidal graphite is not observed in the continuous solidified region, in which only flake-like graphite is observed, while spheroidal graphite is usually observed in the quenched liquid region. The existence of spheroidal graphite in the solidified phase is recognized only in the discontinuous growth mode of the Ni-C-Mg alloy solidified at 150 mm/h. This means that the spheroidal graphite is directly crystallized from the melt and entrapped by the flake-like chunky graphite that is formed by the continuous growth mode. In the small droplet method, a small piece of the Fe-C or Fe-C-Ce sample was melted on a pure graphite plate then cooled at a different cooling rate in a He-3%H2 atmosphere. The graphite in the Fe-C-Ce alloy is usually spherical. Nevertheless, the graphite morphology of the final solidified area changed from spherical to chunky and chunky to ledeburite with an increase in the cooling rate. This means that the chunky graphite is formed in the residual liquid region by the solidification into Fe-graphite system. The sample was cooled in a furnace, and the graphite morphology changes from spherical to chunky and chunky to ledeburite with the decrease in the Si content. These phenomena can be confirmed by the cooling curves of these samples.

关键词： Chunky graphite Spheroidal graphite Solidification Cooling curve

Antiphospholipid syndrome with renal and splenic infarction after blunt trauma:A case report

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World Journal of Clinical Cases 2022年第26期10卷 9404-9410页

作者： Na-A Lee Eui-Sung Jeong hyun-Seok Jang Yun-chul Park Ji-Hyoun Kang jung-chul Kim Young-Goun Jo Division of Trauma Department of SurgeryChonnam National University Medical School and HospitalGwangju 61469South Korea Division of Rheumatology Department of Internal MedicineChonnam National University Medical School and HospitalGwangju 61469South Korea

BACKGROUND In trauma patients,bleeding is an immediate major *** the same time,there are few cases of acute vascular occlusion after blunt trauma,and it is unclear what assessment and diagnosis should be considered for these ***,we describe a patient diagnosed with antiphospholipid syndrome after a hypercoagulable workup for acute renal and splenic vascular occlusion due to blunt *** SUMMARY A 20-year-old man was admitted to the emergency department with abdominal pain after hitting a tree while riding a sled 10 h *** had no medical *** investigations revealed occlusion of the left renal artery with global infarction of the left kidney and occlusion of branches of the splenic artery with infarction of the central portion of the *** revascularization of the left renal artery occlusion through percutaneous transluminal angioplasty failed due to difficulty in passing the wire through the total *** the presence of acute multivascular occlusions in a young man with low cardiovascular risk,additional laboratory tests were performed to evaluate *** results suggested a high possibility of antiphospholipid *** with a subcutaneous injection of enoxaparin was started and changed to oral warfarin after two *** diagnosis was confirmed,and he continued to visit the rheumatology outpatient clinic while taking *** A hypercoagulable workup can be considered in trauma patients with acute multivascular occlusion,especially in young patients with low cardiovascular risk.

关键词： Wounds and injuries Wounds Nonpenetrating Antiphospholipid syndrome Renal artery obstruction Splenic infarction Case reports

Yolk-shell-structured （***.s）9S8 solid-solution powders：Synthesis and application as anode materials for Na-ionbatteries

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Nano Research 2017年第9期10卷 3178-3188页

作者： jung hyun Kim Yun Chan Kang Department of Materials Science and Engineering Korea University Anam-Dong Seongbuk-Gu Seou1136-713 Republic of Korea

Multicomponent metal sulfide materials with a yolk–shell structure and a single phase were studied for the first time as anode materials for sodium-ion batteries. Yolk–shell-structured Fe–Ni–O powders with a molar ratio of iron and nickel components of 1/1 were prepared via one-pot spray pyrolysis. The prepared Fe–Ni–O powders were transformed into yolk–shell-structured (Fe0.5Ni0.5)9S8 solid-solution powders via a sulfidation process. The initial discharge and charge capacities of the (Fe0.5Ni0.5)9S8 powders at a current density of 1 A·g−1 were 601 and 504 mA·h·g−1, respectively. The discharge capacities of the (Fe0.5Ni0.5)9S8 powders for the 2nd and 100th cycle were 530 and 527 mA·h·g−1, respectively, and their corresponding capacity retention measured from the 2nd cycle was 99%. The (Fe0.5Ni0.5)9S8 powders had high initial discharge and charge capacities at a low current density of 0.1 A·g−1, and the reversible discharge capacity decreased slightly from 568 to 465 mA·h·g−1 as the current density increased from 0.1 to 5.0 A·g−1. The synergetic effect of the novel yolk–shell structure and the multicomponent sulfide composition of the (Fe0.5Ni0.5)9S8 powders resulted in excellent sodium-ion storage performance.

关键词： metal sulfide multicomponent sulfide yolk–shell sodium-ion batteries spray pyrolysis

Oxygen vacancy engineering for tuning the catalytic activity of LaCoO_(3) perovskite

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Journal of Rare Earths 2024年第3期42卷 506-514,I0003页

作者： Jeong hyun Cho Minjae Kim Inchan Yang Kyung Tae Park Chang Houn Rhee Hai Woong Park Ji chul jung Department of Chemical Engineering Myongji UniversityYongin 17058Republic of Korea Institute of Advanced Composite Materials Korea Institute of Science and TechnologyWanju-gunJeollabuk-do 55324Republic of Korea Iron&Steel Process Engineering Research Group POSCOPohang 37859Republic of Korea Hydrogen Research Center Research Institute of Industrial Science&Technology(RIST)Pohang 37673Republic of Korea

Herein, we attempted to engineer oxygen vacancies on the surface of LaCoO_(3) perovskite through simple post-treatments(acid or reductive thermal treatments). Acid treatment induces oxygen vacancies through the selective etching of the La cations, whereas thermal treatment in a reducing atmosphere generates oxygen vacancies by directly removing lattice oxygen. The characterization results confirm that the number of surface oxygen vacancies, which are crucial in various catalytic oxidation reactions,considerably increases in the LaCoO_(3) catalysts treated with acid or reducing gas. Acid treatment enriches the oxygen vacancies while maintaining the structure of the LaCoO_(3) catalysts, which can not be achieved through reductive thermal treatment. Therefore, the acid treatment is considered a promising technique for oxygen vacancy engineering of perovskite catalysts for tuning their catalytic activities. Furthermore,the catalytic activities of the posttreated LaCoO_(3) catalysts for CO oxidation were evaluated and are noted to be considerably better than those of the pristine LaCoO_(3) catalyst due to their abundant oxygen vacancies. Consequently, we conclude that the oxygen vacancies of perovskite catalysts can be effectively engineered via two simple methods and play a significant role in CO oxidation.

关键词： LaCoO_(3)perovskite Acid treatment Reductive thermal treatment Oxygen vacancy CO oxidation Rare earths

Effects of Polymeric Stabilizers on the Synthesis of Gold Nanoparticles

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Journal of Materials Science & Technology 2014年第2期30卷 107-111页

作者： Eun jung Kim Jeong hyun Yeum Jin hyun Choi Department of Advanced Organic Materials Science and Engineering Kyungpook National University Department of Bio-fibers and materials Science Kyungpook National University

Gold nanoparticles （AuNPs） stabilized with sodium alginate （SA）, glycol chitosan （GC）, polyvinyl alcohol （PVA）, and polyethyleneimine （PEI） were synthesized in aqueous solutions at room temperature. Different sizes and size distributions of AuNPs were obtained according to the polymeric stabilizers. The mean particle diameters of AuNPs synthesized with GC and PVA as stabilizers were about 5.1 and 5.3 nm, respectively, while those of AuNPs stabilized with SA and PEI were 8.4 and 10.8 nm, respectively. When SA was used, relatively large particles aggregated to form large clusters. In the case of GC, a number of small particles built up large clusters. When PVA was used, the size and the number of nanoperticles were estimated small with a low weight content of Au. For this reason, the PVA-stabilized AuNPs formed clusters with a small hydrodynamic size. The AuNPs synthesized in the aqueous solution of PEI without a reducing agent, sodium borohydride, were uniform in size and formed the smallest nanoclusters （67.4 nm）. In this case, the highest Au content was obtained. Sufficiently grown nanoparticles with a high Au content and a limited hydrodynamic size are considered to be suitable for a variety of applications.

关键词： Gold nanoparticles Sodium alginate Glycol chitosan Polyvinyl alcohol Polyethyleneimine

Anti-obesity Effects of Ginsenosides in High-Fat Diet-Fed Rats

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Chinese Journal of Integrative Medicine 2019年第12期25卷 895-901页

作者： hyun-jung Park Ji hyun Kim Insop Shim Department of Physiology College of MedicineKyung Hee UniversitySeoul(130-701)Republic of Korea Department of Food Science&Biotechnology College of Science and EngineeringSuwon-si(16227)Republic of Korea

Objective: To examine the anti-obesity effects of ginsenosides in Korea Red Ginseng(KRG, Panax ginseng) in rats fed with a high-fat diet(HFD). Methods: Twenty-five 4-week-old obesity rats after receiving an HFD for 5 weeks;subsequently, they were additionally treated with ginsenosides Rb1, Rd, Rg1, or Re(10 mg/kg, intraperitoneal injection) for a further 3 weeks(n=5 in each group). The control rats were fed a normal diet. The food consumption, body weight, locomotor activity, serum lipids, adipose tissues, nitric oxide(NO) expression, leptin, neuropeptide Y(NPY), cholecystokinin(CCK) in the brains were measured. Results: In the HFD-fed rats, body weight, body fat mass, serum levels of leptin and NO were significantly higher than in the control rats(P<0.05 or P<0.01). However, the treatment of Rd, Re, and Rb1 markedly decreased body fat mass and body weight(P<0.05). The serum level of leptin and NO in ginsenoside-treated rats were markedly lower than the control group(P<0.01). The expression of NPY and CCK in the hypothalamic nuclei showed insignificant difference among groups. However, the expression of NPY immunoreactive neurons in the hypothalamus was significantly reduced in the Rb1-treated group(P<0.05). Conclusion: PD-type ginsenoside Rb1 from the crude saponins of KRG may be a useful compound for the treatment of obesity and related disorders through the modulation of peripheral and central appetite-regulating signals.

关键词： Panax ginseng ginsenosides hypothalamus obesity