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Self-Limiting Growth of ZnO Thin Films and Substrate-Temperature Effects on Film Properties (자기제한적 표면반응에 의한 ZnO 박막성장 및 기판온도에 따른 박막특성)

  • Lee, D.H.;Kwon, S.R.;Lee, S.K.;Noh, S.J.
    • Journal of the Korean Vacuum Society
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    • v.18 no.4
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    • pp.296-301
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    • 2009
  • An inductively coupled plasma assisted atomic layer deposition(ICP-ALD) system has been constructed for the deposition of ZnO thin films, and various experiments of ZnO thin films on p-type Si(100) substrates have been carried out to find the self-limiting reaction conditions for the ICP-ALD system under non-plasma circumstances. Diethyl zinc[$Zn(C_2H_5)_2$, DEZn] was used as the zinc precursor, $H_2O$ as the oxidant, and Ar as the carrier and purge gas. At the substrate temperature of $150^{\circ}C$, atomic layer deposition conditions based on self-limiting surface reaction were successfully obtained by series of experiments through the variation of exposure times for DEZn, $H_2O$, and Ar. ZnO deposition was repeated at different substrate temperatures of $90{\sim}210^{\circ}C$. As a result, the thermal process window(ALD window) for ZnO thin films was observed to be $110{\sim}190^{\circ}C$ and the average growth rate was measured to be constant of 0.29 nm/cycle. Properties of the film's microstructure and composition(Zn, O, etc.) were also studied. As the substrate temperature increases, the crystallinity was improved and ZnO(002) peak became dominant. The films deposited at all temperatures were high purity, and the films deposited at high temperatures had the composition ratio between Zn and O closer to one of a stable hexagonal wurtzite structure.

Antagonistic Mode of Action of Fenoxaprop-P-ethyl Phytotoxicity with Bentazon (Fenoxaprop-P-ethyl의 제초활성에 대한 Bentazon의 길항작용기구)

  • Ma, S.Y.;Kim, S.W.;Chun, J.C.
    • Korean Journal of Weed Science
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    • v.18 no.2
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    • pp.161-170
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    • 1998
  • Antagonistic mode of action of fenoxaprop-P-ethyl [ethyl(R)2-4-{(6-chloro-2-benzoxazolyloxy) phenoxy}propionate] with bentazon was investigated with respect to absorption, translocation, metabolism, and change in target site response of fenoxaprop-P-ethyl using four-leaf stage of rice(Oryza sativa L.) and barnyardgrass [Echinochloa eras-galli (L.) P. Beauv.]. Shoots of rice and barnyardgrass was more sensitive to fenoxaprop-P-ethyl than the roots. More than 90% of fenoxaprop-P-ethyl was absorbed within 6 hours after treatment and 30% of the absorbed was acropetally and basipetally translocated at 24 hours after treatment. Fenoxaprop-P-ethyl was rapidly transformed to its acid form, fenoxaprop(2-[4-(6-chloro-2-benzoxazolyloxy)phenoxy]propionic acid), which was subsequently metabolized to polar conjugates. However, changes in absorption, translocation, and metabolism of fenoxaprop-P-ethyl by bentazon treatment were not found in both species. Background activity of acetyl-CoA carboxylase(ACCase) in rice and barnyardgrass was 26.5 and 23.2nmol/min/mg, respectively. Concentration required to inhibit fifty percent enzyme activity$(I_{50})$ in vitro was 6.5~7.4${\mu}M$ of fenoxaprop-P-ethyl and more than 500${\mu}M$ of bentazon. There were no significant differences in $I_{50}$ value between two treatments of fenoxaprop-P-ethyl alone and its bentazon mixture. However, bentazon reduced ACCase activity in vivo and inhibited electron transport in chloroplast thylakoid. Based on the results obtained, it is concluded that the antagonistic effect of bentazon occurs due not to direct effect on target site of fenoxaprop-P-ethyl, but to indirect involvement in reducing herbicidal activity of fenoxaprop-P-ethyl through physiological disturbances caused by bentazone at whole chloroplast level.

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Weed Occurrence Accompanied by Sowing Time and Control System in Dry-seeded Rice Fields (벼 건답직파(乾畓直播) 재배시기별(栽培時期別) 잡초발아양상(雜草發芽樣相) 및 방제체계(防除體系))

  • Choi, C.D.;Choi, J.S.;Kim, C.R.;Choi, B.S.;Yeo, S.K.
    • Korean Journal of Weed Science
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    • v.18 no.2
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    • pp.116-121
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    • 1998
  • Field experiment were carried out to elucidate the changes of weed occurrence according to the sowing time and to establish the efficient weed control system in dry seeded rice cultivation. E crus-galli and D. sanguinalis are tow major weeds at the earlier sowings, but C. difformis was dominating at the later sowing. In the case of E. crus-galli, there was a tendency of gaining its dominance values as the rice growth stage advances. The later the sowing time was, the more weeds occurred at the early rice growth stages: However, when measured at heading, total dry weight was greater at the earlier sowings. Yield loss due to weeds were also greater at the earlier sowings. Community diversity of weeds was greater at the later sowings, while specific weed was gradually dominating as rice growth stage advances, regardless of sowing time. When herbicides were applied before 15 DAS, weeds were effectively controlled only upto 35 DAS. So systemic herbicide application, one on 0 to 10 DAS and the other on just after flooding, appeared to be recommendable in direct seeded rice cultivation.

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Study on brewing of sweet potato starch (고구마 전분질원료를 이용한 주류제조에 관한 연구)

  • 정기택;유대식
    • Korean Journal of Microbiology
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    • v.9 no.3
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    • pp.103-120
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    • 1971
  • We have been studied on brewing sweet starch. We obtained the results as follows ; 1) 5 strains, T-T-2, T-T-4, T-K-2, T-T-18, T-T-1, were the most available in view of fermentative power by capacity of $CO_2$. 2) 5 strains, T-T-4, T-T-2, T-T-1, T-T-3, T-K-2, produced capacity of alcohol more than 5.78%. 3) 6 strains, T-T-2, T-K-2, T-T-4, T-S-2, T-I-3, T-I-1, are available not only taste and flavour, but productive power of alcohol in sweet potato starch. 4) The form of 6 strains are long oval and round and most of them are similar to the other yeast in size. 5) In giant colony the color was cream color and cream buff, and T-K-2 was formed by $15{\times}12mm$ on diameter and by 3.5mm on high. 6) Optimum temperature of most of all strains is 25~ $300^{\circ}C$but T-K-4 is 28-30.deg.C. 7) Optimum pH is 3.4-4.6. 8) T-S-2 was died off at 65.deg.C, the other strains died $60^{\circ}C$. 9( Making Bun-kok with non-heated wheat bran .alpha.-amylase was more increased by 4.5-13.5 mg of glucose in reaction solution and .betha.-amylase more 1.6-3.4ml of N/10-$KMnO_4$ Solution than Bun-kok with heated wheat bran. 10) It seems that mycellium grows better than original in substance containing 0.4 ~ 1.2% of HCl. 11) Making Bun-kok to add 0.8% HCl, .alpha.-amylase was increased 9.93-20.7mg of glucose and .betha.-amylase ws increased 2.6~4.3ml of N/10-$KMnO_4$ solution to reaction solution. 12) 1.2%-HCl, or higher concentration, acts as inhibitor, in the meanwhile the concentration between 0.4~0.8% of HCl acts as activator. 13) We must make Bun-kok for 42 hours, at 28~$30^{\circ}C$) After we made Bun-kok using S-O-II and R-J-I one by one, Bun-kok which mix each other in equal quantity is increased more than original on enzyme acrivity. 15) Oxidation is the best way of refining sweet potato starch in N/10-phosphate buffer solution (pH 7.5). 16) When we prepared sweet potato starch, first pH was 3.0.

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Regional Citrate Anticoagulatinln for Continuous Renal Replacement Therapy in Children (소아의 지속적 신대체요법에서 Citrate 항응고요법의 경험)

  • Hahn Hye-Won;Park Young-Seo
    • Childhood Kidney Diseases
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    • v.9 no.1
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    • pp.76-82
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    • 2005
  • Purpose : Regional anticoagulation with trisodium citrate for continuous renal replacement therapy(CRRT) is an effective and safe method, with lower bleeding risk. However it is not widely used because of complex current protocols used to prevent anticipated metabolic derangements. We evaluated simplified regional anticoagulation protocols with ACD-A(R) solution and commercially available calcium-containing dialysis solution. Methods : The medical records of twenty-eight patients who underwent CRRT were reviewed. Hemofilter life span according to the anticoagulation method used was compared, and laboratory findings at Pre- and 48 hours post-CRRT initiation were compared in the citrate-based CRRT group. Results : Of the twenty-eight Patients, five patients underwent citrate-based CRRT Hemofilter life span was 1.60 $\pm$ 0.72 days, showing no significant differences with the hemofilter life span in the heparin based and LMWH based CRRT group. No patients experienced hemorrhagic complications. PT, aPTT, sodium, t$CO_{2}$, iCa levels showed no difference in pre- and post-CRRT. Total calcium levels were increased. At the recommended postfilter iCa level, j.e., 0.25-0.39 mmol/L, all five patients needed increased amount of citrate infusion, and Ca infusion requirement was decreased. Conclusion : Simplified regional citrate anticoagulation with calcium-containing dialysate is an effective and safe method, and is not associated with increased hemofilter clotting. However, increased postfilter iCa level is recommended.

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Removal of Heavy Metals from Wastewater Using Steelmaking Slag and Sludge (제강 슬래그 및 분진에 의한 폐수 중 중금속 제거)

  • Hyun, Jae-Hyuk;Kim, Min-Gil;Nam, In-Young;Baek, Jung-Sun
    • Resources Recycling
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    • v.8 no.1
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    • pp.11-17
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    • 1999
  • This study was carried out to investigate the efficiency of stcclmaldng slag and sludge in removing metals existing in wastewater or leachate. Laboratory experiments were performed as a function of initial concentration of metals. pH a and temperature of the background solution and the presence of che1ating agent, EDTA. The test conditions were temperatures r ranging from $25^{\circ}C$ to $50^{\circ}C$; initial concentrations varying from 5mg/L to 50 mg/L; pH between 3 and 11; and Cu. Cd‘ and Pb a as adsorbates. The results of tests showed that overall rates of metals removal were 20~30% at pH 3 and greater than 90% at p pH 7 and 11. Metals were removed from the solution predominantly via adsorption in acidic conditions, and the combined e effects of adsorption and precipitation in neutral and alkaline conditions. In view of the test results and other engineering c characteristics of steelmaking slag and sludg$\xi$, these industrial by-products from steel industry have a high potential to be used l in wastewater treatment and are particularly beneficial when used as landfill liner additives due to thelJ ability to remove heavy m metals from leachate.

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Foucault et la sexualité biologique (푸코와 생물학적 성 담론)

  • Hong, Eun-Young
    • Journal of Korean Philosophical Society
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    • v.105
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    • pp.423-460
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    • 2008
  • Les positions qu'essait d'expliquer les $probl{\grave{e}}mes$ divers ${\grave{a}}$ propos de la $sexualit{\acute{e}}$, faisaient ressortir les points biologiques des actions $d^{\prime}{\hat{e}}tre$ humain par ${\acute{e}}volutionnisme$ plutot qu'explique les $probl{\grave{e}}mes$ de la nature humaine, $d{\acute{e}}sirs$ sexuelles, par les $sci{\acute{e}}t{\grave{e}}s$, les cultures et les'institutions. En face des questions des $possibilit{\acute{e}}s$ d'explications biologiques sur toutes les actions sexuelles, ils sont $plac{\acute{e}}s$ en crise. Le fait que $l^{\prime}{\hat{e}}tre$ humain est un'etre historique, n'implique pas ce qu'il est evolutionnaire. Pour cette raison, c'est difficile qu'on accepte le determisme biologique, $l^{\prime}{\acute{e}}volutionnisme$, sans conditions. En opposition avec cettes $id{\acute{e}}es$, Michel Foucault voudrait insister sur le fait de penser au sexe comme les $r{\acute{e}}sultats$ des productions sociologiques, politiques. Selon Foucault, la $sexualit{\acute{e}}$ n'est pas $donn{\acute{e}}$ de la nature que le pouvoir essaierait de mater, ou un domaine obscure que le savoir tendrait de $d{\acute{e}}voiler$, mais une sorte de dispositif historique. Donc, dans cet article, j'essaie d'examiner les processus, les differences, et les $probl{\grave{e}}mes$ entre les deux positions, puis je considere les limites philosophiques, des deux argumentations, et ses implications philosophique. Cela permet d'approcher ${\grave{a}}$ l'horizon divers du discours sexuelles de la $compr{\acute{e}}hension$.

Natural Rubber-Clay Nanocomposites by Latex Method : Morphology and Mechanical Properties (라텍스법에 의한 천연고무-클레이 나노 복합재료: 모폴로지와 기계적 물성)

  • Kim, W.H.;Kang, J.H.;Kang, B.S.;Cho, U.R.
    • Elastomers and Composites
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    • v.41 no.1
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    • pp.27-39
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    • 2006
  • In this study, modified DA-MMT filled NR/DA-MMT nanocomposites were manufactured by a latex method and a compounding method. Cure characteristics and mechanical properties of the Cloisite 15A, carbon black, Na-MMT filled NR compounds and the DA-MMT filled NR compound by a latex method were also evaluated. The filler content of all compounds was 10phr except the carbon black filled compound. Degree of intercalation and dispersion was characterized by X-ray diffraction (XRD) and transmission electron microscope (TEM). According to the XRD diffraction pattern and TEM analysis, extensive intercalation and homogeneous dispersion of the clay were obtained after the two-roll milling. Although the layer distance was increased, some parts of DA-MMT showed the layer distance of Na-MMT after vulcanization. DA-MMT filled NR compounds showed the highest ODR torques, tensile strength, modulus, and tear energy. The NR/DA-MMT nanocomposite (by a latex method) compared with a NR/DA-MMT nanocomposite (by a compounding method) was found that the improvement of the mechanical properties was mainly due to the degree of dispersion of the clay.

Characteristics of the Angular-dependent Exchange Coupling Bias in Multilayer [Pt/Co]N-IrMn with Toward-in Plane Applied Fields (박막수직방향에서 면방향으로 회전하는 인가자기장에 대한 다층박막 [Pt/Co]N-IrMn의 교환바이어스의 각도의존특성)

  • Kim, S.S.;Yim, H.I.;Rhee, J.R.;Lee, S.S.;Hwang, D.G.
    • Journal of the Korean Magnetics Society
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    • v.18 no.4
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    • pp.142-146
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    • 2008
  • The angular dependence of the exchange bias($H_{ex}$) and coercivity($H_c$) in multilayer $[Pt/Co]_N-IrMn$ with applied measuring field rotated toward in-plane at angle $\theta$ from perpendicular-to-plane, has been measured. Multilayer films consisting of $Si/SiO_2/Ta(50)/Pt(4)/[Pt(15)/Co(t_{Co})]_N/IrMn(50)/Ta(50)(in\;{\AA})$ were prepared by magnetron sputtering under typical base pressure below $2{\times}10^{-8}$ Torr at room temperature. Magnetization measurements were performed on a vibrating sample magnetometer and extraordinary Hall voltage measurement systems after cooling from 550 K under a field of 2 kOe applied along the perpendicular to film direction. The hysteresis loop shifts from the origin not only along the field axis but also along the magnetization axis. $H_{ex}$ and $H_c$ show a $1/cos{\theta}$ and $1/|cos{\theta}|$ dependence on the angle($\theta$) between the applied measuring field and the perpendicular-film direction, respectively. This $1/cos{\theta}$ dependence can be accounted for by considering the angular dependence of strong out-of-plane magnetic anisotropy introduced during the field cooling.

Biomonitoring of Toxic Effects of Pesticides in Occupationally Exposed Individuals

  • Arshad, Muhammad;Siddiqa, Maryam;Rashid, Saddaf;Hashmi, Imran;Awan, Muhammad Ali;Ali, Muhammad Arif
    • Safety and Health at Work
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    • v.7 no.2
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    • pp.156-160
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    • 2016
  • Background: Workers in pesticide manufacturing industries are constantly exposed to pesticides. Genetic biomonitoring provides an early identification of potential cancer and genetic diseases in exposed populations. The objectives of this biomonitoring study were to assess DNA damage through comet assay in blood samples collected from industry workers and compare these results with those of classical analytical techniques used for complete blood count analysis. Methods: Samples from controls (n = 20) and exposed workers (n = 38) from an industrial area in Multan, Pakistan, were subjected to various tests. Malathion residues in blood samples were measured by gas chromatography. Results: The exposed workers who were employed in the pesticide manufacturing industry for a longer period (i.e., 13-25 years) had significantly higher DNA tail length ($7.04{\mu}m$) than the controls ($0.94{\mu}m$). Workers in the exposed group also had higher white blood cell and red blood cell counts, and lower levels of mean corpuscular hemoglobin (MCH), MCH concentration, and mean corpuscular volume in comparison with normal levels for these parameters. Malathion was not detected in the control group. However, in the exposed group, 72% of whole blood samples had malathion with a mean value of 0.14 mg/L (range 0.01-0.31 mg/L). Conclusion: We found a strong correlation ($R^2=0.91$) between DNA damage in terms of tail length and malathion concentration in blood. Intensive efforts and trainings are thus required to build awareness about safety practices and to change industrial workers' attitude to prevent harmful environmental and anthropogenic effects.