• 한국약용작물학회지
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• 제11권4호
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• pp.316-320
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• 2003

A protocol is described for rapid multiplication of Zanthoxylum piperitum DC. (Rutaceae), an important aromatic and medicinal plant, through shoot-tip explant cultures. Murashige and Skoog (MS) medium supplemented with various concentrations of N-6-benzyladenine (BA), N-6-benzylaminopurine (BAP) and thidiazuron (TDZ), in single or in combination with ${\alpha}-naphthaleneacetic$ acid (NAA), was used to determine the rate of shoot proliferation. N-6-benzyladenine (BA) used at 0.5mg/l, was the most effective in initiating multiple shoot proliferation at the rate of 23 microshoots per shoot-tip explants after 40 days of culture. Shoot multiplication increased 1.2-fold in each successive subculture. Induction of rooting (98%) was achieved by transferring the shoots to the same basal medium containing 2 mg/l indole-3-butyric acid (IBA). Plantlets went through a hardening phase in a controlled growth chamber, prior to in vivo transfer. These results represented that possible application for the mass production of plantlets through in vitro culture system of Zanthoxylum piperitum DC.

• Food Science and Biotechnology
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• 제18권1호
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• pp.150-156
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• 2009

In this study, Staphylococcus carnosus isolated from traditional sucuk (Turkish dry-fermented sausage) was used in combination with Lactobacillus plantarum as a lactic culture in sucuk production. Sucuk produced with only L. plantarum was evaluated as a control group. Microbiological, physicochemical, and volatile profile characteristics of sucuk samples were investigated during ripening. In both sausages with S. carnosus and control group, pH value decreased to below 5.0 at the $3^{rd}$ day. In all samples, Aw value decreased as the ripening time progressed. Sausages with S. carnosus showed the higher nonprotein nitrogen (NPN) value than control group. However, the highest mean value for thiobarbituric acid reactive substances (TBARS) was observed in control group. Enterobacteriaceae dropped to undetectable levels at the $3^{rd}$ day in both groups. S. carnosus increased approximately 1 log unit within the first 3 days of the fermentation. In the presence of S. carnosus, significant changes were observed in only a few volatile compounds.

• Food Science and Biotechnology
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• 제18권6호
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• pp.1495-1499
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• 2009

The volatiles formed from the reactions of L-ascorbic acid with L-alanine at 5 different pH (5, 6, 7, 8, or 9) and $140{\pm}2^{\circ}C$ for 2 hr was performed using solid-phase microextraction-gas chromatography-mass spectrometry (SPME-GC-MS) analysis were identified to be 25 different kinds. The reaction between L-ascorbic acid and L-alanine led mainly to the formation of pyrazines. Many of these were alkylpyrazines, such as 3-ethyl-2,5-dimethylpyrazine, 2,5-dimethylpyrazine, 2-ethyl-5-methylpyrazine, 3,5-diethyl-2-methylpyrazine, methylpyrazine, 2-ethyl-6-methylpyrazine, and 2,3-diethyl-5-methylpyrazine, other compounds identified were furans, phenols, benzoquinones, 2,4,6-trimethylpyridine, and 2-methylbenzoxazole. The studies showed that furans, such as furfural and benzofuran were formed mainly at acidic pH. In contrast, higher pH values could promote the production of pyrazines.

• Journal of Electrical Engineering and Technology
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• 제8권4호
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• pp.911-919
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• 2013

This paper reports the development of test bed with the energy recovering technique using two-step boost converter. The device is utilized for LDC aging test of Hyundai Motor's LPI AVANTE HEV in mass production. The developed power recycle type test bed is designed as 1.5 kW class to test up to the maximum load power of LDC and is also designed to supply scant power supply up to 500 W after power recycle. The theoretical design analysis and operational characteristics analysis results of test bed are reported, and its practicality and reliability are verified through the test result. Also, the finally developed test bed confirms approximately 79~85 % energy saving effect compared to the usual traditional aging test system.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 추계학술대회 논문집 Vol.21
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• pp.442-442
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• 2008

Hydrogen was produced by water plasma excited in very high frequency inductively coupled tube reactor. Mass spectrometry was used to monitor gas phase species at various process conditions. Water dissociation rate depend on the process parameters such as ICP power, flow-rate and pressure. Water dissociation percent in ICP reactor decrease with increase of chamber pressure and $H_2O$ flow rate, while increase with increase of ICP power. In our experimental range, maximum water dissociation rate was 65.5% at the process conditions of 265 mTorr, 68 sccm, and 400 Watt. The effect of $CH_4$ addition to a water plasma on the hydrogen production has been studied in a VHF ICP reactor. With the addition of $CH_4$ gas, $H_2$ production increases to 12% until the $CH_4$ flow rate increases up to 15 sccm. But, with the flow rate of $CH_4$ more than 20 sccm, chamber wall was deposited with carbon film because of deficiency of oxygen in gas phase, hydrogen production rate decreased. The main roles of $CH_4$ gas are to reacts with O forming CO, CHO and $CO_2$ and releasing additional $H_2$ and furthermore to prevent reverse reaction for forming $H_2O$ from $H_2$ and $O_2$. But, $CH_4$ addition has negative effects such as cost increase and $CO_x$ emission, therefore process optimization is required.

• Asian-Australasian Journal of Animal Sciences
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• 제33권2호
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• pp.277-285
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• 2020

Objective: This study was performed to investigate the effects of supplementing sesame seed meal (SSM) with phytase and lysine on performance, egg quality, blood biochemical and antioxidant status of laying hens. Methods: A total of 960, 56-wk-old laying hens were divided into 12 dietary groups with eight replicates per group (10 birds per replicate). A completely randomized design with factorial arrangement 2×3×2 consisted of two levels of lysine supplement (0% and 10% over requirement), three SSM levels (0%, 10%, and 20%) with or without phytase (0 and 300 g/ton). The feeding trial lasted 10 weeks. Results: Birds fed diets with 10% SSM had higher feed intake than groups fed 0% and 20% SSM. The addition of phytase to experimental feeds, improved feed conversion ratio, increased egg weight and mass (p<0.01). Egg quality criteria was not affected by supplementing phytase; however, supplementing 300 g/ton phytase to hens diet, led to a significant (p<0.05) increase in egg shell strength. Egg yolk cholesterol and serum low-density lipoprotein cholesterol, atherogenic index and total cholesterol were decreased (p<0.01) by diet containing 20% SSM. The high-density lipoprotein cholesterol was increased (p<0.05) in serum of hens fed 20% SSM than the other groups. It was also observed that total antioxidant capacity and total superoxide dismutase content of hens fed 20% SSM was significantly higher than control group (p<0.05). Conclusion: As from results, dietary supplementation of SSM and phytase had no negative effects on laying hens performance or egg quality while improving the egg oxidative stability.

• Journal of Microbiology and Biotechnology
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• 제25권3호
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• pp.358-365
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• 2015

ε-Poly-L-lysine (ε-PL) is a homopolymer of L-lysine molecules connected between the epsilon amino and alpha carboxyl groups. This polymer is currently used as a natural preservative in food. Insufficient biomass is a major problem in ε-PL fermentation. Here, to improve cell growth and ε-PL productivity, various nitrogen-rich nutrients were supplemented into flask cultures after 16 h cultivation, marking the onset of ε-PL biosynthesis. Yeast extract, soybean powder, corn powder, and beef extract significantly improved cell growth. In terms of ε-PL productivity, yeast extract at 0.5% (w/v) gave the maximum yield (2.24 g/l), 115.4% higher than the control (1.04 g/l), followed by soybean powder (1.86 g/l) at 1% (w/v) and corn powder (1.72 g/l) at 1% (w/v). However, supplementation with beef extract inhibited ε-PL production. The optimal time for supplementation for all nutrients examined was at 16 h cultivation. The kinetics of yeast-extract-supplemented cultures showed enhanced cell growth and production duration. Thus, the most commonly used two-stage pH control fed-batch fermentation method was modified by omitting the pH 5.0-controlled period, and coupling the procedure with nutrient feeding in the pH 3.9-controlled phase. Using this process, by continuously feeding 0.5 g/h of yeast extract, soybean powder, or corn powder into cultures in a 30 L fermenter, the final ε-PL titer reached 28.2 g/l, 23.7 g/l, and 21.4 g/l, respectively, 91.8%, 61.2%, and 45.6% higher than that of the control (14.7 g/l). This describes a promising option for the mass production of ε-PL.

• KSBB Journal
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• 제10권2호
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• pp.196-203
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• 1995

국내에서 선멸된 Streptomyces sp. 809-11 균주의 항생물질 polyoxins의 생합성 능력을 향상시키기 위하여 주요 영양원에 따른 균체의 중식 및 polyoxins 의 생합성에 미치는 영향을 조사하였다. 본 실험결 과 가용성 전분만을 사용한 배지에서는 초기 대수척 성장기의 균체량은 증가하였으나 polyoxins의 생합 성량은 적게 나타났으며, 포도당만을 이용한 경우는 사상균사체의 형성을 증가시켜 polyoxins의 생합성 량을 증가시켰으나 초기 균체의 성장률은 매우 저조 하였다. 따라서 균체의 성장과 polyoxins의 생합성 향상 두 가지 측면을 모두 고려하여 볼 때 탄소원 으로 가용성 전분과 포도탕을 혼용하여 사용하는 것이 바람직한 것으로 나타났다. 질소원으로 사용한 $(NH_2)_4S0_4$는 비교적 고놓도인 151.4mM에서 최대 항생제 생합성량을 보여주었으며, 인산염으로 사용된 $K_2HPO_4$는 0.5mM 정도에서 최적의 poly oxms 생합성을 보여 주였다. 유가식배양을 도입하 여 초기에는 균체 성장을 위하여 전분과 포도탕이 함유된 배지에서 배양하였고, 탄소원의 고갈시점에 는 사상 균사체의 분화 촉진을 위하여 포도당을 공 급한 결과 polyoxins의 생합성량을 회분식 배양에 비하여 두 배 이상으로 증가시켰다.

• 한국지반공학회논문집
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• 제30권9호
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• pp.67-75
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• 2014

방대한 저장량으로 차세대 에너지원으로 평가받는 메탄가스 하이드레이트는 생산과정에서 유발될 수 있는 문제를 최소화하고 최적의 생산조건을 선정하기 위한 하이드레이트 포함한 다공질 재료의 THM 현상에 대한 프로그램의 개발이 절실하다. 기존의 해석 프로그램들은 국제공동연구를 통하여 프로그램들간의 상호 비교검증을 진행하고 있으나, 예측값의 불일치와 수렴성에 문제가 있는 것으로 나타났다. 본 논문에서는 다공질 재료내 메탄 하이드레이트의 해리 현상을 해석할 수 있는 fully coupled THM 유한요소 프로그램을 개발하였다. Methane hydrate, soil, water, 및 methane gas의 질량보존의 법칙, 에너지 보존의 법칙, 그리고 힘평형 방정식으로부터 지배방정식을 유도하였다. 다양한 주변수들의 조합을 통하여 주변수를 변위, 가스 포화도, 유체압, 온도, 하이드레이트 포화도로 선택하였으며, 상변화 전영역에서 해석이 가능하도록 하였다. 하이드레이트의 해리를 예측하는 모델은 kinetic model을 이용하였다. 개발된 THM 유한요소 프로그램을 이용하여 메탄가스 생산에 관한 Masuda의 실내 모형실험 결과와 비교적 분석을 수행하였으며, 해의 수렴성과 안정성을 확인할 수 있었다.

• 한국전기전자재료학회논문지
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• 제22권5호
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• pp.448-454
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• 2009

Hydrogen was produced from water plasma excited in high frequency (HF) inductively coupled tubular reactor. Mass spectrometry was used to monitor gas phase species at various process conditions, Water dissociation rate depend on the process parameters such as ICP power, $H_{2}O$ flow-rate and process pressure, Water dissociation percent in ICP reactor decrease with increase of chamber pressure, while increase with increase of ICP power and $H_{2}O$ flow rate. The effect of $CH_4$ gas addition to a water plasma on the hydrogen production has been studied in a HF ICP tubular reactor. The main roles of $CH_4$ additive gas in $H_{2}O$ plasma are to react with 0 radical for forming $CO_x$ and CHO and resulting additional $H_2$ production. Furthermore, $CH_4$ additives in $H_{2}O$ plasma is to suppress reverse-reaction by scavenging 0 radical. But, process optimization is needed because $CH_4$ addition has some negative effects such as cost increase and $CO_x$ emission.