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Synthesis and Fluxionality of a Tungsten-Triosmium Cluster Compound $CpWOs_3(CO)_{11}({\mu}_3-CTol)$

  • Park, Joon T.;Shapley, John R.
    • Bulletin of the Korean Chemical Society
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    • v.11 no.6
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    • pp.531-534
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    • 1990
  • The reaction of $Os_3(CO)_{10}(NCMe)_2$ with a tungsten alkylidyne $Cp(CO)_2W{\equiv}CTol(Cp={\eta}^5-C_5H_5,\;Tol=p-C_6H_4Me)$ produces the compound, $CpWOs_3(CO)_{11}({\mu}_3-CTol)$(1). The structure of compound 1 can be viewed as one in which the metalla-alkyne, $Cp(CO)_2W{\equiv}CTol$, is ${\mu}_3-{\eta}^2-{\bot}$ (perpendicular) bound to an $Os_3(CO)_9$ fragment. Variable-temperature $^{13}C$ NMR spectra of 1 show no evidence for the analogous rotation of the metalla-alkyne molecule as shown alkyne rotation in $Os_3(CO)_9(C_2Tol_2)$ compound. This lack of the metalla-alkyne fluxionality supports the apparent saturated nature of compound 1.

Study on characteristic of mycelial culture in ear mushroom (목이의 균사생육 특성에 관한 연구)

  • Yu, Young-Jin;Choi, Kyu-Hwan;Jeong, Jong-Seong;Lee, Gi-Kwon;Choi, So-Ra
    • Journal of Mushroom
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    • v.11 no.1
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    • pp.15-20
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    • 2013
  • This study was performed to obtain the scientific data an artificial culture of ear mushroom(Auricularia auricula). Liquid cultural of Auricularia auricula. mycelium was characterized with respect to temperature, pH, compositions of inorganic, carbon and nitrogen. The its optimum temperature and media pH were at $25^{\circ}C$ and pH 5.0~6.0 on the mycelial growth, respectively. The optimum inorganic compositions and concentration for mycelial growth were $MgSO_4$ 0.05%(w/v) and $KH_2PO_4$ 0.1%(w/v), respectively. The optimum carbon sources and nitrogen sources were black-sugar 2%(w/v) and soybean powder at 0.3~0.5%(w/v) with7 days optimum culture time.

Influence of pH, Emulsifier Concentration, and Homogenization Condition on the Production of Stable Oil-in-Water Emulsion Droplets Coated with Fish Gelatin

  • Surh, Jeong-Hee
    • Food Science and Biotechnology
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    • v.16 no.6
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    • pp.999-1005
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    • 2007
  • An oil-in-water (O/W) emulsion [20 wt% com oil, 0.5-6.0 wt% fish gelatin (FG), pH 3.0] was produced by high pressure homogenization, and the influence of pH, protein concentration, and homogenization condition on the formation of FG-stabilized emulsions was assessed by measuring particle size distribution, electrical charge, creaming stability, microstructure, and free FG concentration in the emulsions. Optical microscopy indicated that there were some large droplets ($d>10\;{\mu}m$) in all FG-emulsions, nevertheless, the amount of large droplets tended to decrease with increasing FG concentration. More than 90% of FG was present free in the continuous phase of the emulsions. To facilitate droplet disruption and prevent droplet coalescence within the homogenizer, homogenization time was adjusted in O/W emulsions stabilized by 2.0 or 4.0 wt% FG. However, the increase in the number of pass rather promoted droplet coalescence. This study has shown that the FG may have some limited use as a protein emulsifier in O/W emulsions.

A Study on Hg Analysis in Urine by Using Cold Vapor Generator (Cold Vapor Generator를 이용한 뇨중 수은 분석에 관한 연구)

  • 김석원;김덕묵
    • Journal of environmental and Sanitary engineering
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    • v.6 no.2
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    • pp.109-121
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    • 1991
  • For the analysis of mercury in blood and urine, many literatures have been reffered and many kinds of reducing agents for mercury reduction and many acids for pretreatmr are known to be varied. $So HNO_{3}$ and $H_{2}SO_{4}$ among acids and $SnCl_{2}$ and $NaBH_{4}$ as a reducing agent being chosen for the establishment of more efficient and less erroneous analysis, and comparing the absorbance by using vapor generator, the results are followings. 1. The difference of absorbance from concentration of $HNO_{3}$ and $H_{2} SO_{4}$ was not nearly found when mercury reduced by $NaBH_{4}$ after pretreatment. But for more precise analysis, conc acid treatment need to be used. 2. Higher absorbance was shown by using conto acid treatment (P<0.005) when mercury reduced by $NaBH_{4}$ after treating acid primer. And sample which has 99.5% reliability in T-test, treated by conc $H_{2}SO_{4}$(P<0.005) was shown higher absorbance than treat by CORC $HNO_{3}$. 3. The difference of absorbance was not in the slightest in higher 0.1 w/v% $NaBH_{4}$ proved by uruskal-wallis H-Test 4. Some difference of absorbance in $SnCl_{2}$(P<0.005) having 99.5% reliability was found but there was no difference in these 20 w/v% , 25 w/v% and 30 w/v% SnCl$_{2}$ by the experiment of T-test. 5. According to these test results, organic materials were much affect the absorballce when reducing mercury by using $SnCl_{2}$ rather than by $NaBH_{4}$. For bio sample which is contained various organic substances, reduclng agent $NaBH_{4}$ is a lot more efficient to reduce the error then $SnCl_{2}$. 6. analytic method for this study is as following. 7. As the recovery test was done by this, the rate of recovery was shown form 94% to 100.7% .

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Sono-electrochemical Determination of Uric Acid (요산의 초음파 전기화학적 정량)

  • Cho Hyung-hwa;Bae Zun-ung
    • Journal of the Korean Electrochemical Society
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    • v.3 no.4
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    • pp.232-234
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    • 2000
  • Determination of uric acid by electrochemical method using ultrasonic stimulation has been investigated. Effects of sonication power, sonication time, pH of the solution and temperature were studied to obtain the optimal analytical conditions. The stability of the electrode was also examined. The optimal conditions for the sonovoltammetric determination of uric acid were as follows: temperature, $25.0^{\circ}C$ pH 7.0; sonication power, $20W/cm^2$. The calibration curve for the determination of uric acid by sono-LSV was linear over the range of$8.0{\times}10^{-6}\~5.0\times10^{-4}M$ and the limit of detection was $6.5\times10^{-6}M$.

Preparation of Liquid Crystal Emulsion for Transdermal Delivery of Glycyrrhizic Acid and Physical Characteristics and In Vitro Skin Permeation Studies (글리시리직애씨드의 경피 전달을 위한 액정 에멀젼의 제조와 물리적 특성 및 In Vitro 피부투과 연구)

  • Jung, Jin Woo;Yoo, Cha Young;Park, Soo Nam
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.41 no.4
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    • pp.315-324
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    • 2015
  • In this study, we prepared liquid crystal emulsion composed of amphiphilic substance $C_{14-22}$ alcohol, $C_{12-20}$ alkyl glucoside, behenyl alcohol and studied liquid crystal emulsion of properties and in vitro skin permeation. The results of formulation experiments, the clear liquid crystalline structure was observed in the ratio of $C_{14-22}$ alcohol 0.8%, $C_{12-20}$ alkyl glucoside 3.2%, behenyl alcohol 4% in the formulation. The results of physical property measurements, the viscosity of liquid crystal emulsion and O/W emulsion applied as a control group was respectively $1871.26{\sim}1.15Pa{\cdot}s$, $1768.69{\sim}1.14Pa{\cdot}s$ and the shear stress of O/W emulsion was 178.68 ~ 909.18 Pa, that of liquid crystal emulsion was 190.45 ~ 919.38 Pa. The storage modulus of O/W emulsion was 3428.53 ~ 9157.45 Pa, that of liquid crystal emulsion was 4487.82 ~ 8195.59 Pa. The tan (delta) value of O/W emulsion which means a ratio of viscosity to elasticity was 0.43 ~ 0.19, and that of liquid crystal emulsion was 0.23 ~ 0.25. The water content value on the skin for liquid crystal emulsion was significantly higher from 1 h to 6 h compared with that of O/W emulsion and the transepidermal water loss on the skin was significantly superior in skin moisture loss suppression from 30 min to 4 h compared with that of O/W emulsion. The results of skin permeation using glycyrrhizic acid, the result of skin permeation amount of liquid crystal emulsion for 24 h was $64.58{\mu}g/cm^2$, that of O/W emulsion was $37.07{\mu}g/cm^2$, that of butylene glycol solution was $41.05{\mu}g/cm^2$. Hourly permeability results, it is showed that skin penetration effect of the liquid crystal emulsion increases after 8 h. These results suggest that liquid crystal emulsions are effective for skin moisturizing effect and function as potential efficacy ingredient delivery system for the transdermal delivery.

Properties of Bac W42, a Bacteriocin Produced by Bacillus subtilis W42 Isolated from Cheonggukjang

  • Kindoli, Salum;Lee, Hwang A;Kim, Jeong Hwan
    • Journal of Microbiology and Biotechnology
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    • v.22 no.8
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    • pp.1092-1100
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    • 2012
  • Ten Bacillus strains with antimicrobial activities were isolated from Cheonggukjang produced at different parts in Korea. They all inhibited Listeria monocytogenes ATCC 19111 and nine inhibited Bacillus cereus ATCC 14579. Four isolates (W42, H27, SKE 12, and K21) showing strong inhibiting activities were identified as B. subtilis. B. subtilis W42 was the most inhibiting strain. The antimicrobial activity of culture supernatant from B. subtilis W42 was destroyed completely by proteinase K treatment, indicating that a bacteriocin was the responsible agent. The bacteriocin, Bac W42, was most stable at pH 7 and stable between pH 3-6 and 8-9. Bac W42 was stable up to $80^{\circ}C$. BHI (brain heart infusion) and TSB (tryptic soy broth) were the best media for the activity (320 AU/ml) followed by LB (160 AU/ml). Bac W42 was partially purified by column chromatographies. The specific activity was increased from 1,151.2 AU/ml to 9,043.5 AU/ml and the final yield was 26.3%. Bac W42 was 5.4 kDa in size as determined by SDS-PAGE. Bac W42 showed bactericidal activity against L. monocytogenes ATCC 19111.

A Serial Multiplier for Type k Gaussian Normal Basis (타입 k 가우시안 정규기저를 갖는 유한체의 직렬곱셈 연산기)

  • Kim, Chang-Han;Chang, Nam-Su
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.43 no.2 s.344
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    • pp.84-95
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    • 2006
  • In H/W implementation for the finite field the use of normal basis has several advantages, especially, the optimal normal basis is the most efficient to H/W implementation in $GF(2^m)$. In this paper, we propose a new, simpler, parallel multiplier over $GF(2^m)$ having a Gaussian normal basis of type k, which performs multiplication over $GF(2^m)$ in the extension field $GF(2^{mk})$ containing a type-I optimal normal basis. For k=2,4,6 the time and area complexity of the proposed multiplier is the same as tha of the best known Reyhani-Masoleh and Hasan multiplier.

Effects of Distribution of Axle Load and Inflation Pressure of Tires on Fuel Efficiency of Tractor Operations (차축의 중량 분포와 타이어의 공기압이 트랙터 작업의 연료 효율에 미치는 영향)

  • Lee, Jin-Woong;Kim, Kyeong-Uk;Gim, Dong-Hyeon;Choi, Kyu-Jeong
    • Journal of Biosystems Engineering
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    • v.36 no.5
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    • pp.303-313
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    • 2011
  • This study was conducted to investigate the effects of axle weight distribution and inflation pressure of tire on the fuel economy of tractors as well as operational range of tractor engine in terms of engine speed and power when a 4WD tractor of 38.2 kW rated power at 2500 rpm is used for plowing and flooded-field rotavating in paddy fields. (1) Plowing operation required an average engine power of 9.6~13.5 kW which equals 25~35% of rated PTO power. Engine speed ranged from 1,320.4 to 1,737.4 rpm, work velocity from 3.4 to 4.8 km/h, and fuel consumption from 3.2 to 4.2 L/h, respectively. (2) Flooded-field rotavating required an average engine power of 11.5~18.5 kW which equals 30~48.4% of rated PTO power. Out of this 6.2~12.2 kW was used for PTO power. Engine speed ranged from 1,557 to 2,067 rpm, work velocity from 2.5~5.4 km/h and fuel consumption from 3.2~5.5 L/h, respectively. (3) Axle weight distribution, inflation pressure of tire and moisture content of soil did not affect significantly the specific volumetric fuel consumption but affected significantly the fuel consumption per unit area of operation. Fuel savings amounted to 65% in plowing operation and 20% in flooded-field rotavating when the axle weight distribution and inflation pressure of tire were optimally adjusted. (4) Optimal adjustment of axle weight distribution and inflation pressure of tire are expected to save fuel consumption by 10~65% per unit area of operation in plowing and 10~20% in flooded-field rotavating.

A Multiplier for Type k Gaussian Normal Basis (타입 k 가우시안 정규기저를 갖는 유한체의 병렬곱셈 연산기)

  • Kim, Chang-Han;Kim, Sosun;Chang, Nam-Su
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.43 no.1 s.343
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    • pp.45-58
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    • 2006
  • In H/W implementation for the finite field, the use of normal basis has several advantages, especially, the optimal normal basis is the most efficient to H/W implementation in $GF(2^m)$. In this paper, we propose a new, simpler, parallel multiplier over $GF(2^m)$ having a Gaussian normal basis of type k, which performs multiplication over $GF(2^m)$ in the extension field $GF(2^{mk})$ containing a type-I optimal normal basis. For k=2,4,6 the time and area complexity of the proposed multiplier is the same as tha of the best known Reyhani-Masoleh and Hasan multiplier