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Plastic anisotropy calculation of severely-deformed Al-Mg-Si alloy considering texture changes in electron backscatter diffraction

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Journal of Materials Science & Technology 2019年第7期35卷 1439-1443页

作者： I Putu Widiantara hae Woong Yang Min Jun kim Young Gun Ko Plasticity Control & Mechanical Modeling Lab. School of Materials Science & Engineering Yeungnam University

The investigation studied the plastic anisotropy of the severely-deformed Al-Mg-Si alloy by considering texture *** sample deformed via asymmetrical rolling under cross-shear condition was annealed at 598 K where recrystallization was in *** is found upon annealing that the intensity of Cube({001})was comparable to those of plane-strain components while the intensities of shear components remained constant despite their instabilities in the recrystallization *** annealing,the average Lankford value(r)of the present sample was close to a unity whereas the in-plane anisotropy(△r)decreased,resulting in nearly isotropic characteristics of Al-Mg-Si alloy.

关键词： Al-Mg-Si alloy Anisotropy Recrystallization Microstructures

Soleus arthrogenic muscle inhibition following acute lateral ankle sprain correlates with symptoms and ankle disability but not with postural control

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Journal of Sport and Health Science 2024年第4期13卷 559-568,F0003页

作者： Kyung-Min kim Joo-sung kim Alan R.Needle Department of Sport Science Sungkyunkwan UniversitySuwon-si 16419Republic of Korea Department of Health and Human Performance Texas State UniversitySan MarcosTX 78666USA Department of Public Health&Exercise Science Appalachian State UniversityBooneNC 28608USA Department of Rehabilitation Science Appalachian State UniversityBooneNC 28608USA

Background:Acute lateral ankle sprains(ALAS)are associated with long-term impairments and instability tied to altered neural *** muscle inhibition(AMI)has been observed in this population;however,relationships with injury-related impairments are unclear,potentially due to the resting,prone position in which AMI is typically *** AMI during bipedal stance may provide a better understanding of this ***:AMI was assessed in 38 young adults(19 ALAS within 72 h of injury:10 males,21.4±2.7 years;19 healthy controls:10 males,21.9±2.2 years;mean±SD)using the Hoffmann reflex(H-reflex)during bipedal *** stimulation was administered to identify the _(max)imal H-reflex(H_(max))and _(max)imal motor response(M_(max))from the soleus,fibularis longus,and tibialis anterior *** primary outcome measure was the H_(max)/M_(max) *** outcomes included acute symptoms(pain and swelling),postural control during bipedal stance,and self-reported ***:No significant group-by-limb interactions were observed for any ***,a significant group main effect was observed in the soleus muscle(F(1,35)=6.82,p=0.013),indicating significantly lower H_(max)/M_(max) ratios following ALAS(0.38±0.20)compared to healthy controls(0.53±0.16).Furthermore,lower H_(max)/M_(max) ratios in the soleus significantly correlated with acute symptoms and self-reported function but not with postural ***:This study supports previous evidence of AMI in patients with ALAS,providing insight into neurophysiologic impacts of musculoskeletal *** results suggest that assessing AMI in a standing position following acute injury may provide valuable insight into how AMI develops and guide potential therapeutic options to curb and offset the formation of joint instability.

关键词： Acute injuries Balance Hoffmann reflex Neural excitability Patient-reported outcomes

Intestinal challenge with enterotoxigenic Escherichia coli in pigs,and nutritional intervention to prevent postweaning diarrhea

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Animal Nutrition 2017年第4期3卷 322-330页

作者： Yawang Sun sung Woo kim Department of Animal Science North Carolina State University College of Animal Science and Technology Southwest University

Gut health of nursery pigs immediately after weaning is tightly associated with their growth performance and economic values. Postweaning diarrhea(PWD) is one of the major concerns related to gut health of nursery pigs which often is caused by infections of enterotoxigenic Escherichia coli(ETEC),mainly including F4(K88)^+ and F18^+ E. coli. The main virulence factors of ETEC are adhesins(fimbriae or pili) and enterotoxins. The common types of fimbriae on ETEC from PWD pigs are F18^+ and F4^+. Typically, PWD in pigs is associated with both F18^+ and F4^+ ETEC infections whereas pre-weaning diarrhea in pigs is associated with F4+ ETEC infection. Enterotoxins including heat-labile enterotoxins(LT) and heatstable peptide toxins(ST) are associated with causing diarrhea in pigs. At least 109 to 1010 ETEC are required to induce diarrhea in nursery pigs typically lasting 1 to 5 days after ETEC infection. Antibiotics used to be the most effective way to prevent PWD, however, with the increased bacterial resistance to antibiotics, alternatives to the use of antibiotics are urgently needed to prevent PWD. Immunopropylaxis and nutritional intervention of antimicrobial minerals(such as zinc oxide and copper sulfate), organic acids, functional feedstuffs(such as blood plasma and egg yolk antibodies), direct fed microbials, phytobiotics, and bacteriophage can potentially prevent PWD associated with ETEC. Some other feed additives such as nucleotides, feed enzymes, prebiotic oligosaccharides, and clay minerals can enhance intestinal health and thus indirectly help with preventing PWD. Numerous papers show that nutritional intervention using selected feed additives can effectively prevent PWD.

关键词： Enterotoxigenic Escherichia coli Feed additives Immunopropylaxis Nutritional intervention Pigs Postweaning diarrhea

Innovative strategies toward challenges in PV-powered electrochemical CO_(2)reduction

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Journal of Energy Chemistry 2021年第9期30卷 410-416页

作者： Siraj Sultan Jin Hyun kim Seung Hyeon kim Youngkook Kwon Jae sung Lee Department of Energy Engineering School of Energy and Chemical EngineeringUlsan National Institute of Science and Technology(UNIST)Ulsan 44919South Korea

The solar energy-driven electrochemical CO_(2)reduction to value-added fuels or chemicals is considered as an attractive path to store renewable energy in the form of chemical energy to close the carbon ***,CO_(2)reduction suffers from a number of challenges including slow reaction rates,low selectivity,and low energy conversion ***,innovative strategies have been developed to mitigate this *** the development of flow cell reactors with a gas diffusion electrode,ionic liquid electrolytes,and new electrocatalysts have dramatically improved the reaction rates and selectivity to desired *** this perspective,we highlight the key recent developments and challenges in PVpowered electrochemical CO_(2)reduction and propose effective strategies to improve the reaction kinetics,to minimize the electrical energy losses,and to tune the selectivity of the catalysts for desired products,and then suggest future direction of research and development.

关键词： Electrochemical CO_(2)reduction Photovoltaic cell Ionic liquid electrolytes Flow cell electrolyzers Gas diffusion electrode

Corrosion and optimum corrosion protection potential of friction stir welded 5083-O Al alloy for leisure ship

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中国有色金属学会会刊：英文版 2009年第4期19卷 898-903页

作者： sung-Hyeon PARK Jong-Shin kim Min-Su HAN Seong-Jong kim Division of Maritime Transportation System Mokpo Maritime University Korea Register of Shipping Division of Marine Engineering Mokpo Maritime University

Electrochemical tests were undertaken to determine the optimum conditions in seawater for corrosion protection of friction stir-welded 5083-O Al *** trend observations show that the limiting potential that avoids the effects of hydrogen embrittlement is -1.6 V,corresponding to the crossover point between concentration polarization and activation ***,the optimum protection potential is between -1.5 and -0.7 V since the current density at these values is low in the potentiostatic *** a galvanic cell is formed in the seawater,the welds exhibit electrochemically stable *** parts in galvanic tests with various area ratios are stable and have excellent anticorrosion characteristics.

关键词：搅拌摩擦焊接保护电位海水腐蚀铝合金氧铝船舶休闲防腐

Changes in endoscopic patterns before and during COVID-19 outbreak:Experience at a single tertiary center in Korean

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World Journal of Clinical Cases 2021年第15期9卷 3576-3585页

作者： Kook Hyun kim sung Bum kim Tae Nyeun kim Division of Gastroenterology and Hepatology Department of Internal MedicineYeungnam University College of MedicineDaegu 42415South Korea

BACKGROUND The surge of coronavirus disease 2019(COVID-19)patients has markedly influenced the treatment policies of tertiary hospitals because of the need to protect medical staff and contain viral transmission,but the impact COVID-19 had on emergency gastrointestinal endoscopies has not been *** To compare endoscopic activities and analyze the clinical outcomes of emergency endoscopies performed before and during the COVID-19 outbreak in Daegu,the worst-hit region in South *** This retrospective cohort study was conducted on patients aged≥18 years that underwent endoscopy from February 18 to March 28,2020,at a tertiary hospital in ***,laboratory findings,types and causes of emergency endoscopies,and endoscopic reports were reviewed and compared with those obtained for the same period in 2018 and *** From February 18 to March 28,a total of 366 emergent endoscopic procedures were performed:Upper endoscopy(170,50.6%),endoscopic retrograde cholangiopancreatography(113,33.6%),and colonoscopy with sigmoidoscopy(53,15.8%).The numbers of procedures performed in 2018 and 2019 dropped by 48.8%and 54.8%,respectively,compared with those in *** the COVID-19 outbreak,the main indications for endoscopy were melena(36.7%),hematemesis(30.6%),and hematochezia(10.2%).Of the endoscopic abnormalities detected,gastrointestinal bleeding was the most common:39 cases in 2018,51 in 2019,and 35 in *** The impact of COVID-19 is substantial and caused dramatic reductions in endoscopic procedures and changes in patient ***-term follow-up studies are required to determine the effects of COVID-19 induced changes in the endoscopy field.

关键词： COVID-19 Coronavirus Endoscopy Emergency endoscopy

Preparation and Characterization of Porous PVdF-HFP/clay Nanocomposite Membranes

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Journal of Materials Science & Technology 2010年第7期26卷 633-638页

作者： Mi Jin Koh hae Young Hwang Deuk Ju kim Hyeng Jun kim Young Taik Hong Sang Yong Nam School of Materials Science and Engineering Engineering Research Institutei-Cube CenterGyeongsang National UniversityJinjuKorea Fuel Cell Research Center Korea Institute of Science and TechnologySeoul 136-791Korea Energy Material Research Center Korea Research Institute of Chemical TechnologyDaejeon 305-600Korea

Polyvinylidene fluoride-hexafluoropropylene （PVdF-HFP） / clay nanocomposite membranes were prepared by phase inversion method through controlling retention time to apply for a lithium ion secondary batteries. Increased membrane porosity with macrovoids was observed at increasing retention time. Partially intercalated structures of PVdF-HFP/clay nanocomposite membranes were confirmed by X-ray diffraction （XRD） analysis. PVdF-HFP membranes containing various kind of clay showed the increase of membrane modulus compared to the pristine PVdF-HFP membrane.

关键词： PVdF-HFP Porosity Mechanical properties Clay Separator

Effects of humic acid on phytodegradation of petroleum hydrocarbons in soil simultaneously contaminated with heavy metals

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Journal of Environmental Sciences 2011年第12期23卷 2034-2041页

作者： Soyoung Park Ki Seob kim Jeong-Tae kim Daeseok Kang Kijune sung Department of Ocean Engineering Pukyong National University Busan 608-737 Korea Department of Ecological Engineering Pukyong National University Busan 608-737 Korea

The use of humic acid （HA） to enhance the efficiency of phytodegradation of petroleum hydrocarbons in soil contaminated with diesel fuel was evaluated in this study. A sample of soil was artificially contaminated with commercially available diesel fuel to an initial total petroleum hydrocarbons （TPH） concentration of 2300 mg/kg and four heavy metals with concentrations of 400 mg/kg for Pb, 200 mg/kg for Cu, 12 mg/kg for Cd, and 160 mg/kg for Ni. Three plant species, Brassica campestris, Festuca arundinacea, and Helianthus annuus, were selected for the phytodegradation experiment. Percentage degradation of TPH in the soil in a control pot supplemented with HA increased to 45% from 30% without HA. The addition of HA resulted in an increases in the removal of TPH from the soil in pots planted with B. campestris, F. arundinacea, and H. annuus, enhancing percentage degradation to 86%, 64%, and 85% from 45%, 54%, and 66%, respectively. The effect of HA was also observed in the degradation of n-alkanes within 30 days. The rates of removal of n-alkanes in soil planted with B. campestris and H. annuus were high for n-alkanes in the range of C11–C28. A dynamic increase in dehydrogenase activity was observed during the last 15 days of a 30-day experimental period in all the pots amended with HA. The enhanced biodegradation performance for TPHs observed might be due to an increase in microbial activities and bioavailable TPH in soils caused by combined effects of plants and HA. The results suggested that HA could act as an enhancing agent for phytodegradation of petroleum hydrocarbons in soil contaminated with diesel fuel and heavy metals.

关键词： phytodegradation TPHs humic acid n-alkanes DHA combined effects

Electrocrystallization of Monodisperse Nanocrystal Copper on Highly Oriented Pyrolytic Graphite Electrode

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Chinese Journal of Chemistry 2005年第2期23卷 121-126页

作者：黄令 LEE,Eun-sung kim,Kwang-Bum DepartmentofChemistry XiamenUniversityXiamenFujian361005China DepartmentofMetaUurgicalEngineering YonseiUniversitySeoul120-749SouthKorea

Mechanism of copper electrocrystallization on highly oriented pyrolytic graphite electrode from a solution of 1 mmol/L CuSO 4 and 1.0 mol/L H 2 SO 4 has been studied using cyclic voltammogram and chronoamperometry. The results show that in copper electrodeposition the charge‐transfer step is fast and the rate of growth is controlled by the rate of mass transfer of copper ions to the growing centers. Reduction of Cu(II) ions did not undergo underpotential deposition. The initial deposition kinetics of Cu electrocrystallization corresponds to a model including progressive nucleation and diffusion controlled growth. Copper nanocrystals with size of 75.6 nm and relative standard deviation of 9% can be obtained by modulation potential electrodeposition.

关键词： electrocrystallization electrodeposition nucleation and growth nanocrystal copper