• Title/Summary/Keyword: S/H

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SUMMATION FORMULAS DERIVED FROM THE SRIVASTAVA'S TRIPLE HYPERGEOMETRIC SERIES HC

  • Kim, Yong-Sup;Rathie, Arjun Kumar;Choi, June-Sang
    • Communications of the Korean Mathematical Society
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    • v.25 no.2
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    • pp.185-191
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    • 2010
  • Srivastava noticed the existence of three additional complete triple hypergeometric functions $H_A$, $H_B$ and $H_C$ of the second order in the course of an extensive investigation of Lauricella's fourteen hypergeometric functions of three variables. In 2004, Rathie and Kim obtained four summation formulas containing a large number of very interesting reducible cases of Srivastava's triple hypergeometric series $H_A$ and $H_C$. Here we are also aiming at presenting two unified summation formulas (actually, including 62 ones) for some reducible cases of Srivastava's $H_C$ with the help of generalized Dixon's theorem and generalized Whipple's theorem on the sum of a $_3F_2$ obtained earlier by Lavoie et al.. Some special cases of our results are also considered.

A Study of Health and Safety Management Practices of Contractors in Southern Vietnam

  • Phung, Van Manh;Manu, Patrick;Mahamadu, Abdul Majeed
    • International conference on construction engineering and project management
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    • 2015.10a
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    • pp.127-131
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    • 2015
  • In spite of the socio-economic benefits of the construction industry, it accounts for many deaths, injuries and illnesses in many countries. In developing countries like Vietnam, the situation is even worse. Health and safety (H&S) management plays a crucial role in the efforts to improve H&S performance as it contributes to mitigating the risks of occupational injuries and illnesses. However, within the wider H&S literature in Vietnam, there is no insight into the current state of affairs of H&S management, particularly in terms of the management practices that need attention in order to improve H&S management across the construction sector. This study therefore presents the findings of an inquiry into the H&S management practices of contractors in Vietnam. The study employed a questionnaire survey which yielded 58 responses from contractors, particularly those operating in Southern Vietnam. Some commonly implemented H&S management practices by the contractors are: provision of personal protective equipment (94%), allocation of H&S supervisor on site (90%), and displaying of company H&S policy on construction sites, company website, and head/branch offices (86%). Some of the less implemented practices are: networking/engaging with other companies/institutions (e.g. government offices) about H&S issues (39%), rewarding workers for safe work behaviour (39%), reviewing and updating H&S plans (48%), and displaying regulatory H&S posters on site (45%). The findings have provided some insight into the current state of affairs of the H&S management practices of contractors in Southern Vietnam and could thus inform efforts by industry stakeholders to improve the aspects of H&S management that are lagging.

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The Rate of Superoxide Radical (${O_2}^-$.) Production in Normal Fenton's Reagent at Different pHs (펜톤반응에서 pH의 변화에 따른 superoxide radical (${O_2}^-$.)의 생성)

  • 김용수;공성호;김재호
    • Journal of Soil and Groundwater Environment
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    • v.7 no.2
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    • pp.73-81
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    • 2002
  • In normal Fenton's reagent, the reductive mechanism of carbon tetrachloride (CT) with superoxide radical (${O_2}^-$.) was observed and the rate of ${O_2}^-$. production was investigated as a function of $H_2O$$_2$ concentration and pH. As pH was increased, the rate of 1-hexanol degradation was rapidly decreased from 90% (at pH 3) to 5% (at pH 11). On the other hand, more degradation of carbon tetrachloride was observed at higher pH regimes indicating Fenton's reaction is an oxidant-reductant co-existing system at neutral pHs. The rate of $O_2^{-}$ . production was observed at different $H_2$$O_2$ concentrations and at different pHs. The rate increased from (45.3$\pm$7.8) x $10^{-6}$ M/s to (151.0$\pm$26.2) x $10^{-6}$ M/s ($294mM H_2$$O_2$) at pH 11: the rate 3150 increased from (22.1$\pm$3.8) x $10^{-6}$ M/s at pH 7 to (151.0$\pm$26.2) x $^10{-6}$ M/s at pH 11 with 294mM $H_2$$O_2$, These results showed that Fenton's reagent could be applied at wide pH regimes. Especially, carbon tetrachloride, which can not be easily adsorbed to soils and then can be dissolved into groundwater causing a cancer, could be efficiently treated by Fenton's reagent.reagent.

Corrosion of Fe-2%Mn-0.5%Si Steels at 600-800℃ in N2/H2O/H2S Atmospheres

  • Kim, Min-Jung;Park, Sang-Hwan;Lee, Dong-Bok
    • Journal of the Korean institute of surface engineering
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    • v.44 no.5
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    • pp.201-206
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    • 2011
  • Fe-2%Mn-0.5%Si alloys were corroded at 600, 700 and $800^{\circ}C$ for up to 70 h in 1 atm of $N_2$ gas, or 1 atm of $N_2/H_2O$-mixed gases, or 1 atm of $N_2/H_2O/H_2S$-mixed gases. Oxidation prevailed in $N_2$ and $N_2/H_2O$ gases, whereas sulfidation dominated in $N_2/H_2O/H_2S$ gases. The oxidation/sulfidation rates increased in the order of $N_2$ gas, $N_2/H_2O$ gases, and, much more seriously, $N_2/H_2O/H_2S$ gases. The base element of Fe oxidized to $Fe_2O_3$ and $Fe_3O_4$ in $N_2$ and $N_2/H_2O$ gases, whereas it sulfidized to FeS in $N_2/H_2O/H_2S$ gases. The oxides or sulfides of Mn or Si were not detected from the XRD analyses, owing to their small amount or dissolution in FeS. Since FeS was present throughout the whole scale, the alloys were nonprotective in $N_2/H_2O/H_2S$ gases.

Effect of aerobic exercise on peroxisome proliferator-activated receptor α anti-inflammatory in white adipose tissue (백색지방조직에서 peroxisome proliferator-activated receptor α 항염증에 대한 유산소 운동의 영향)

  • Sun-Hyo Jeong
    • Journal of the Korean Applied Science and Technology
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    • v.40 no.1
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    • pp.1-12
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    • 2023
  • It was investigated whether a combination of PPARα activator fenofibrate and swimming exercise (H/F/S) would have a beneficial synergistic effect on improving inflammation of white adipose tissue compared to the single prescription of fenofibrate (H/F) and swimming exercise (H/S) in male mice that fed high fat diet. The body weight, weight of white adipose tissue and total cholesterol levels in the serum increased in mice-fed high fat diets (H) compared to mice-fed low fat diets (L). Compared to H, both H/F and H/S decreased these. These levels reduced by fenofibrate were more effectively reduced by the combination of fenofibrate and swimming exercise (H/F/S). As a result of examining the expression of inflammatory cytokines genes and fatty acid oxidation genes in white adipose tissue, H increased compared to L, both H/F and H/S decreased compared to H, and H/F/S decreased further compared to H/F. Thus, this study revealed that the combination of fenofibrate and swimming exercise in male mice fed high-fat diet suppresses inflammation of white adipose tissue caused by obesity through promoted fatty acid oxidation more effectively than the fenofibrate alone, and suggested a practical way to improve inflammation of adipose tissue caused by obesity.

A Study on the comparison on Adsorption characteristics of Zeolite and DETOX for the removal of H2S (H2S 제거를 위한 Zeolite와 DETOX의 흡착 특성 비교 연구)

  • Park, Dae-Seok;Lim, Ji-Young;Cho, Young-Gun;Song, Seung-Jun;Kim, Jin-Han
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.15 no.7
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    • pp.4675-4681
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    • 2014
  • This study examined the $H_2S$ removal characteristics, such as breakthrough time, adsorption capacity, and adsorption rate of adsorbents between Zeolite 3A and DETOX in terms of the $H_2S$ inflow concentration and adsorption temperature. The adsorption capacity of Zeolite 3A increased with increasing mass flow rate of hydrogen sulfide($H_2S$) inflow, but the breakthrough time decreased. On the other hand, both the adsorption capacity and breakthrough time of DETOX decreased with increasing mass flow rate of $H_2S$ inflow. The adsorption capacity and breakthrough time of Zeolite 3A decreased with increasing adsorption temperature but those of DETOX increased. The adsorption capacity of DETOX was higher than that of Zeolite 3A by a factor of 2.5 - 16.4 because the collision frequency that overcomes the activation energy barrier increased with increasing adsorption temperature. For Zeolite 3A and DETOX, the adsorption rate of $H_2S$ increased with increasing mass flow rate of $H_2S$ inflow and adsorption temperature. The adsorption rate of $H_2S$ for Zeolite 3A was 4 times as much as that for DETOX. For the removal of $H_2S$ in biogas, DETOX had an advantage over Zeolite 3A because DETOX had a much longer breakthrough time and greater adsorption capacity in the temperature range of 308~318K than Zeolite 3A.

Preponderant Occurrence of sl natural methane hydrates: Spectroscopic analysis of crystalline structure transition (sI 천연 메탄하이드레이드의 존재 : 결정구조 변화의 분광학적 분석)

  • Yeon, Sun-Hwa;Seol, Ji-Woong;Lee, Huen
    • 한국신재생에너지학회:학술대회논문집
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    • 2006.06a
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    • pp.387-390
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    • 2006
  • We report here that under strong attacksof external $CH_4$ guest molecules the sII and sH methane hydrates are structurally transformed to the crystalline me framework of sI, leading to favorable change of the lattice dimension of the host-guest networks. The High Power Decoupling $^{13}C$ NMR and Raman spectroscopies were used to identify structure transitions of the mixed $CH_4+C_2H_6$ hydrates (sIIl) and hydrocarbons (methylcyclohexane, isopentane) + $CH_4$ hydrates (sH). The resulting spectra indicate that most of the synthesized sII and sH hydrates were transformed to methane hydrate of sl under 110 bar and particularly the coexistence of sl with sII or sH appear according to the surrounding methane-rich gas conditions. The present findings might be expected to Provide rational evidences regarding the preponderant occurrence of naturally-occurring sI methane hydrates in marine sediments.

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The Effect of addition of kinds of sugar and drying method on Quality and Storage Characteristics of Beef jerky (첨가당과 건조방법이 육포의 품질과 저장성에 미치는 영향)

  • 조은자;이정은
    • Korean journal of food and cookery science
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    • v.16 no.6
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    • pp.511-520
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    • 2000
  • To investigate the effect of sugar and drying method on quality and storage characteristics of beef jerky, storage, textural and sensory characteristics were examined. Water activity was decreased as storage time was prolonged and the honey and rice syrup-added natural dried samples(N-H, N-R) were recorded the lowest value, 0.71 at five weeks of storage. During the storage period, pH values of all the samples were decreased and honey-added and heated air dried beef jerky(H-H) had the lowest pH value, 5.22. L, a, b values had a tendency to decrease, during the storage period. During the storage period, TBA values of all samples showed increasing tendency. Sugarsyrup-added samples(N-S, H-S, S-S$\^$*/) had the lowest TBA value, and those of honey-added samples(N-H, H-H, S-H$\^$**/) were highest, regardless of drying method. Total plate counts of bacteria and the number of lactic acid bacteria were increased as storage time was prolonged. Sugar syrup-added and heated air dried beef jerky(H-S) had the lowest in total plate counts of bacteria and the number of lactic acid bacteria, at five weeks of storage. Textural properties value of all samples were increased as storage time was longer. Honey-added samples showed the higest springness and cohesiveness value and sugarsyrup-added and natural dried sample showed the highest value in chewiness, gummness and hardness. In the almost sensory score of natural dried beef jerky was decreased asstorage time was prolonged, regardless of packaging method. The sensory score of heated air dried samples were higher than those of natural dried samples, regardless of packaging method. $\^$*/S-S sucrose syrup added smoking dried sample, $\^$**/S-H honey added smoking dried sample

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Roles of Mitogen-Activated Protein Kinases (MAPKinases) in H-ras-induced Invasiveness and Motility of MCF10A Cells

  • Lee, Eun-Jung;Kim, Mi-Sung;Aree Moon
    • Proceedings of the Korean Society of Applied Pharmacology
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    • 2001.11a
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    • pp.104-104
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    • 2001
  • Ras는 세포의 성장과 분화 등 여러 필수적인 세포기능에 없어서는 안될 중요한 역할을 담당하며 Ras가 mutation되면 암 등의 치명적인 결과를 초래한다. Ras 발현은 유방암에서 tumor aggressiveness의 지표로 간주되고 있으며 유방세포의 침습성과 연관이 있다고 알려져 있으므로 ras가 전이과정에 미치는 영향에 관한 연구는 중요한 의미를 갖는다. 본 연구의 선행연구결과, H-ras와 N-ras 모두 transformed phenotype을 나타내지만 H-ras 만이 암전이에 있어서 중요한 침윤성을 유도하는 것을 밝혔다. 이 결과는 MCF10A 세포에서 H-ras와 N-ras에 의한 신호전달경로가 각각 다른 생물학적 전이활성을 나타냄을 시사한다. 세포의 이동성은 침습성에 있어서 결정적인 역할을 하므로, 본 연구에서 H-ras와 N-ras로 형질전환된 MCF10A세포에서 이동성을 시험한 결과, 세포의 이동성이 N-ras가 아닌 H-ras MCF10A 세포에서만 크게 증가된다는 것을 보았다. 이는 침습성을 나타내는 H-ras가 세포의 이동성을 증가시키는데 작용한다는 것을 말한다. H-ras에 의해 유도된 침습성과 이동성에 대한 분자적 기전에 관하여 연구하기 위하여 H-ras MCF10A와 N-ras MCF10A 세포에서 Ras의 downstream effector들, 특히 mitogen-activated protein kinases(MAPKinases)들인 JNK1, ERK, p38의 활성화를 살펴본 결과 p38 MAPKinase가 H-ras MCF10A 세포에서 현저하게 활성화됨을 보았다. p38 MAPKinase 저해제인 SB203580를 처리하던지 dominant negative p38 (DN p38) transfectant로 p38을 불활성화시켰을 때 세포침습성 및 이동성이 저해되는 결과를 얻었다. SB203580 처리한 H-ras MCF10A 세포에서 전이에 관여하는 효소인 MMP-2 분비가 감소되었다. H-ras에 의해 유도된 침습성과 이동성은 DN JNK1 transfectant에서는 변화가 없었으나 DN MEK transfectants에서는 유의성있게 감소되었다. 이상의 결과를 종합하면, MCF10A 세포의 침윤성과 이동성에는 p38 MAPKinase 활성이 중심적인 역할을 하며, JNK 활성은 영향을 미치지 않고, ERK-1/2 활성은 충분하지는 않으나 필요하다는 것을 알 수 있었다.

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Efficient Synthesis of hypho-2,5-$S_2B_7H_{11}$ and Preparation of New nido-, arachno-, and hypho-Metalladithiaborane Clusters Derived from Its Anion hypho-$S_2B_7H_{10}{^-}$

  • 강창환;김성준;고재정;강상욱
    • Bulletin of the Korean Chemical Society
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    • v.16 no.11
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    • pp.1067-1074
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    • 1995
  • Reaction of arachno-S2B7H8- with either THF or 1,2-dimethoxyethane upon refluxing condition results in the formation of the previously known compound hypho-S2B7H10-. Protonation of hypho-S2B7H10- with HCl/Et2O generates hypho-2,5-S2B7H11 in good yield. This hypho-S2B7H10- anion has been employed to generate a series of new nido-, arachno-, and hypho-metalladithiaborane clusters. Reaction of the anion with Cp(CO)2FeCl results in direct metal insertion and the formation of a complex containing the general formula (η5-C5H5)FeS2B7H8. Spectroscopic studies of nido-6-CpFe-7,9-S2B7H8 Ⅰ demonstrated that compound Ⅰ was shown to have an nido-type cage geometry derived from an octadecahedron missing one vertex, with the iron atom occupying the three-coordinate 6-position in the cage and the two sulfurs occupying positions on the open face of the cage. Reaction of hypho-S2B7H10- with CoCl2/Li+[C5H5]- gave the previously known complex arachno-7-CpCo-6,8-S2B6H8 Ⅱ. Also, the reaction of the anion with [Cp*RhCl2]2 gave the complex arachno-7-Cp*Rh-6,8-S2B6H8 Ⅲ, the structure of which was shown to be that of complex Ⅱ. The similarity of the NMR spectra of Ⅱ and Ⅲ suggest that Ⅲ adopts cage structure similar to that previously confirmed for Ⅱ. A series of 9-vertex hypho clusters in which the sulfur atoms are bridged by different species isoelectronic with a BH3 unit, such as HMn(CO)4 or SiR2 have been prepared. Compounds Ⅳ,Ⅴ and Ⅵ are each 2n+4 skeletal electron systems and would be expected according to skeletal electron counting theory to adopt hypho-type polyhedral structures derived from an icosahedron missing three vertices. The complex hypho-1-(CO)4Mn-2,5-S2B6H9 Ⅳ was obtained by the reaction of the anion with (CO)5MnBr and has been shown from spectroscopic data to consist of a (CO)4Mn fragment bound to the two sulfur atoms S2 and S5 of hypho-S2B7H10-. Also, similar hypho-type complexes hypho-1-R2Si-2,5-S2B6H8 (R=CH3 Ⅴ, R=C6H5 Ⅵ) have been prepared from the reaction of hypho-S2B7H10- with R2SiHCl.