• 대한화학회지
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• 제14권2호
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• pp.161-168
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• 1970

In order to obtain the more effective evidence, supporting the hypothesis which have been previously described by former report that pepsin (EC 3.4. 4.1) forms a hydrophobic bond with the nonpolar side chain of its substrate, the inhibitory effect of carboxylic acids(from formic acid to iso-butyric acid) on the activity of pepsin to the synthetic dipeptide, N-Carbobenzoxy-L-glutamyl-L-tyrosine, was discussed. The kinetic study showed that the inhibition by carboxylic acids was competitive. The Kidecreased with increasing size of the inhibitor molecule. The $-{\Delta}F^{\circ}$increased linearly with increasing number of carbon atoms in the hydrocarbon chain of the inhibitor. It was confirmed that the hydrophobic bond between more than one side chain of amino acid residues(phenylalanine) in the binding region of the active center of pepsin and the side chain of amino acid residues in the substrate was formed as the first step of its enzymic mechanism. The inhibitory effect of carboxylic acids was due to the competition of the hydrocarbon group of the carboxylic acids with the side chain of the substrate for the hydrophobic binding site(the side chain of phenylalanine) of the pepsin.

• Asian-Australasian Journal of Animal Sciences
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• 제3권3호
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• pp.183-186
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• 1990

Monensin administered as a slow release capsule to Droughtmaster steers grazing mixed pastures containing Stylosanthes hamata or grass pastures fertilized with N, had no effect on growth rate over 111 day period. Monensin significantly increased the level of propionic acid (p<0.001) and decreased the level of butyric acid (p<0.01) in the rumen. The lack of response to monesin was partly attributed to the poor pasture conditions and growth rate of the steers during part of the experimental period. An implant of oestradiol improved growth rates during the period of poor forage quality and in the subsequent 56 days when pastures were of high quality following rain. Mean growth rates over the entire 157 days for control, monensin and monensin/oestradiol treatments were 0.37, 0.37 and 0.50 kg/d respectively. It was concluded that when pasture conditions are sufficient only for the maintenance of liveweight, production can be improved by an oestradiol implant but not by feeding an ionophore such as monensin.

• 한국가금학회지
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• 제30권4호
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• pp.275-280
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• 2003

본 연구의 목적은 단백질 수준이 산란계 사료내 게르마늄 흑운모의 첨가가 생산성, 난각특성 및 분내 악취성분 함량에 미치는 영향을 조사하기 위하여 실시하였다. 사양시험은 51주령 ISA Brown 갈색계 144수를 공시하였으며, 처리구는 옥수수-대두박 위주의 저단백질 사료 (LPD), 고단백질 사료 (HPD), LPD 사료에 게르마늄흑운모를 1.0 첨가한 처리구와 (LPDGB; LPD+1.0% germanium biotite, (주)서봉바이오베스텍), HPD사료에 게르마늄흑운모를 1.0%(HPD-GB; HPD+1.0% germanium biotite)로 4개 처리를 하여 처리당 3반복, 반복당 12마리씩 완전 임의배치하였다. 총 56일간의 사양시험기간 동안, 산란율에서는 HPD 처리구가 유의적으로 증가하는 경향을 보였다(P<0.01). 난중은 게르마늄흑운모의 첨가함에 따라 유의적으로 감소하는 경향을 나타내었으며(P<0.01), 난각강도에서는 처리구간 유의적인 차이는 나타나지 않았다 (P>0.05). 둔단부 두께를 측정한 결과 게르마늄흑운모 첨가에 따라 유의적으로 감소하는 경향을 나타내었다. (P<0.02) 예단부, 중앙부의 난각두께를 측정한 결과 처리구간 유의적 차이는 보이지 않았다. 난황계수에서는 HPD사료를 급여한 처리구가 LPD 사료를 급여한 처리구보다 낮았다(P<0.01). 분중 Propionic acid(P<0.01)와 butyric acid (P<0.03)에서는 게르마늄흥운모를 첨가함에 따라 유의적으로 감소하는 경향을 나타내었다. Butyric acid에서는 HPD 처리구가 유의적으로 증가하는 경향을 보였다.(P<0.02). Acetic aicd에서도 게르마늄흑운모 첨가 처리구가 무첨가 처리구보다 유의적으로 감소하는 경향을 보였다.(P<0.01). $NH_3$-N에서는 LPD 사료의 경우보다 HPD 사료에서 게르마늄흑운모 첨가 효과가 나타난 것으로 보인다(P<0.05). 결과적으로 산란계 사료내 게르마늄흑운모의 첨가는 분내 휘발성 지방산 발생을 감소시켜 축사환경의 개선효과가 있을 것으로 사료된다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.144.1-144.1
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• 2016

We fabricate organic single crystal nanowire heterojunction p-n diode poly(3-hexylthiophene)(P3HT) and from Phenyl-C61-butyric acid methyl ester(PCBM) using by liquid-bridge mediated nanotransfer molding(LB-nTM) method. LB-nTM has been reported an one step direct printing method for making well-aligned nanowire arrays. Moreover, multi-patterning nanostructures can be fabricated with the consecutive printing process. As a result, it is possible to make simple and basic concept of heterojunction devices such as lateral organic p-n nanojunction diode. P3HT/PCBM nanowires heterojunction diode has rectifying behavior with on/off ratios of ~20.

• 한국초지조사료학회지
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• 제11권1호
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• pp.53-59
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• 1991

This experiment was conducted to investigate the effects of propionic acid and wilting on fermentation quality of Italian ryegrass silage. Grass material was wilted for a day before ensiling and propionic acid(0. 0, 0. 2. 0. 5 and 0.8 7~ of fresh matter) was applicated at ensiling time. Chemical composition, fermentation acids, pH, microbial population and distribution of the nitrogen contents were evaluated. The results obtained are summarized as follows: 1. The contents of dry matter and water soluble carbohydrate in the silage were increased by wilting, and crude fibre, NDF and ADF were decreased with increasing propionic acid levels. 2. The pH values of the silage increased by increasing DM content, but decreased with increasing propionic acid levels. Lactic acid content lowed in wilted silage, and acetic acid and butyric acid formation were decreased with increasing propionic acid levels. 3. Total nitrogen content in the silage was i n ~ r e a s e d ( ~ < . 05) by addition of propionic acid and wilting, and was the highest in the prewilting-0.8 Q propionic acid applicated silage. The production of NHBN was decreased with propionic acid and was the lowest in the 0.8 % treated silage. 4. The number of total bacteria and yeasts were estimated $10^6~10^7$, $10^2~10^3$ respectively. Moulds number were decreased with increasing propionic acid levels.

• 한국식품저장유통학회지
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• 제19권4호
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• pp.594-603
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• 2012

과잉으로 생산되는 복분자의 소비 촉진과 신수요 창출을 위해 복분자 식초를 제조한 후 이화학적 성분분석 및 항산화 효과를 조사하였다. 알코올 발효의 최적 조건은 당도 15 $^{\circ}Brix$, 온도 $30^{\circ}C$, 발효기간 4일이었으며, 초산 발효의 최적 조건은 초기 알코올 함량 6%, 초기 산도 2%, 온도 $30^{\circ}C$, 발효기간은 9일이었다. 최적 조건으로 발효된 복분자 식초의 유리당은 surcose, fructose 및 glucose로 확인되었으며, 주요 유기산은 acetic acid, malic acid, succinic acid 및 malonic acid로 나타났다. 또한 유리아미노산 총 함량은 108.03 ${\mu}g/mL$로 alanine, glutamic acid, ${\gamma}$-amino-N-butyric acid 및 o-phosphoethanolamine가 주된 성분으로 나타났으며, 무기성분은 K, Na, Mg, Ca과 같은 알칼리성 원소를 다량 함유한 것으로 나타났다. 복분자 식초의 총 폴리페놀 및 안토시아닌의 함량은 각각 25.19, 80.71 mg/100 mL이었으며, DPPH, $ABTS^{{\cdot}+}$ 라디칼 소거 활성, 환원력, ${\beta}$-carotene bleaching의 실험에서 복분자 식초는 양성 대조군과 유사한 높은 항산화 활성을 가지는 것으로 나타났다.

• Asian-Australasian Journal of Animal Sciences
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• 제15권11호
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• pp.1606-1610
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• 2002

The dynamics of fermentation were studied with Italian ryegrass ensiled in the laboratory silos. The silos were kept in the room set at 25$^{\circ}C$, and then were opened on 0.5, 1, 2, 3, 5, 7 and 14 days after ensiling, respectively. The samples were taken from three silos at each sampling time for chemical analyses. Mono-and disaccharides composition was determined for glucose, fructose and sucrose by high performance liquid chromatography. The Italian ryegrass silage succeeded to achieve lactate type fermentation; high values of lactic acid (85.83 g/kg) and lactic acid/acetic acid at the end of ensiling (14 day), low values of pH (3.74), acetic acid (5.38 g/kg), ethanol (19.20 g/kg) and $NH_3-N/Total\;N$ (75.84 g/kg), no or only small amounts of butyric acid, valeric acid and propionic acid. The fermentation dynamics showed a fast and large pH decrease caused by a fast and large production of lactic acid during the first 5 days. Mono-and disaccharides composition largely decreased within initial 0.5 day (12 h) of ensiling. Sucrose disappeared rapidly within initial 0.5 day of ensiling, and fructose and glucose contents showed an initial rise during ensiling, and then decreased gradually. These indicated that the enzymes of plant tissue were active within 2 days of ensiling, which caused the initial rise in fructose and glucose from the hydrolysis of sucrose and fructans. After 5 days of ensilage, glucose was consumed completely, suggesting that glucose was the first fermentation substrate. After 2 days of ensiling, sum amounts of lactic acid and remaining mono-and disaccharides proved to be larger than the quantity of mono-and disaccharides in the initial grass. From the facts mentioned above, it was suggested that considerable amounts of lactic acid were produced from some other substrate such as fructans than initial mono-and disaccharides.

• 한국환경과학회지
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• 제23권10호
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• pp.1693-1701
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• 2014

A rapid and simple method for the quantitative determination of volatile fatty acids (VFAs; propionic acid, n-butyric acid, i-valeric acid and n-valeric acid) and indoles (phenol, p-cresol, 4-ethyl phenol, indole and skatole) in pig slurry and dog excrement using solid-phase micro-extraction (SPME) coupled to gas chromatography was evaluated. $50/30{\mu}m$ DVB/CAR/PDMS (Divinylbenzene/Carboxen/Polydimethylsiloxane) fiber was used to extract the target compounds in aqueous media. Sample amount and adsorption time was standardized for the routine analysis. Detection limits were from 0.11 to $0.15{\mu}gL$ for VFAs and from 0.12 to $0.28{\mu}gL$ for indoles and the correlations observed ($R^2$) were 0.975~1.000. This method was applied to the pig slurry, fertilizer, compost and dog excrement. In nearly all cases, the indoles were detected in concentrations of higher than their limits of detection (DOLs). But the VFAs in swine manure were below their DOLs.

• 한국안전학회지
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• 제23권5호
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• pp.67-72
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• 2008

The lower flash points for the flammable binary systems, 2-propanol+formic acid and 2-propanol+n-butyric acid, were measured by Cleveland open cup tester. The optimization method using van Laar equation and the Raoult's law were used to estimate the lower flash points and were compared with experimentally-derived data. The calculated values based on the optimization method were found to be better than those based on the Raoult's law.

• Bulletin of the Korean Chemical Society
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• 제33권9호
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• pp.2897-2902
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• 2012

New photovoltaic donor materials, 4,4'-(2,2'-bithiazole-5,5'-diyl)bis(N,N-diphenylbenzenamine) (BDT) and 4-(2,2'-bithiazol-5-yl)-N,N-diphenylbenzenamine (BT), were synthesized. A solution processable triphenylamine-containing bithiazole (BDT and BT) was blended with a [6,6]-phenyl $C_{61}$ butyric acid methyl ester (PCBM) acceptor to study the performance of small-molecule-based bulk heterojunction (BHJ) photovoltaic devices. Optimum device performance was achieved after annealing, for device with a BDT/PCBM ratio of 1:4. The open-circuit voltage, short-circuit current, and power conversion efficiency of the device with the aforementioned BDT/PCBM ratio were 0.51 V, 4.10 $mA\;cm^{-2}$, and 0.68%, respectively, under simulated AM 1.5 solar irradiation (100 $mW\;cm^{-2}$).