• Journal of the Korean Society of Tobacco Science
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• v.8 no.1
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• pp.33-39
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• 1986

조연제종류 및 함량 변화가 궐련지의 연소성과 회색상에 미치는 영향을 연구한 결까 flax와 kenaf의 연소속도 띤 회고결성이 NBKP보다 양호하였으며 탄산칼숨 함량이 증가함에 따라 각 펄프 공히 연소속도는 빨라지나 회고결성은 저하되었다. 구연산·초산·주석산나트륨은 첨가량이 3%까지 증가되어도 연소속도에는 큰차가 없으나 4호이상부터 빨라지는경향이었다. 인산나트륨은 함량이 증가하면서 연소속봉는 늦어진 반면 회고결성은 양호해졌다. 구연산나트룸에 요소·푸말산나트륨·인산암모늄·인산·말레인산나트륨 및 guanyl urea phosphate를 첨가시 인산암모늄의 회죈변동율이 170%로 회고결성이 가장 양호하였으나 연소속도는 대체로 늦어지는 경향이다. 조연제의 함량이 증가함에 따라 회의 백색도는 55전후에서 30으로 감소하는 경향이다.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.405-405
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• 2016

CIGS 박막 태양전지에서 완충층으로 사용되는 ZnS는 단파장 영역에서 높은 투과도와 CIGS 계면과의 좋은 접착을 가지고 친환경적이며 3.74eV의 에너지 밴드갭을 가지고 있기 때문에 CdS를 사용했을 때 보다 더 넓은 에너지 영역의 광자를 p-n 접합 경계 영역으로 통과 시킬 수 있고 Cd-free 물질이라는 점에서 기존의 CdS 완충층의 대체 물질로 각광 받고 있다. 본 연구에서는 CIGS 박막에 화학습식공정 방법을 이용하여 최적화된 ZnS 박막의 증착 조건을 찾기 위해 실험 변수인 시약의 농도, 실험온도, 열처리 조건 등의 다양한 변화를 통해 실험을 진행하였고, 박막의 갈라짐과 pin-hole 현상을 개선하고 균일한 막을 제조하기 위해 구연산 나트륨 농도에 따른 ZnS 박막의 특성을 연구하였다. 본 실험 결과로서 실험변수인 황산아연의 농도 0.15M, 암모니아는 0.3M, 티오요소 1M, 공정 온도 $80^{\circ}C$의 최적화 된 조건에서 가장 좋은 품질의 ZnS 박막을 제조하였지만, ZnS 박막의 열처리 후 산소의 양이 줄어감에 따라 박막의 표면이 갈라지고 pin-hole 현상이 발생하는 것을 확인할 수 있었다. 박막의 품질을 개선하기 위해 구연산 나트륨을 첨가하여 실험한 결과 구연산 나트륨의 0.05M의 농도에서는 박막 표면에 90nm의 갈라짐의 크기와 pin-hole 현상이 남아있는 것을 확인하였고, 농도가 높아질수록 점차 크기가 줄어들면서 0.4M에서는 갈라짐이 거의 없는 표면과 pin-hole 현상도 없어지는 것을 확인하였고, 약 144nm의 박막 두께와 3.8eV의 에너지 밴드갭을 가지고, 약 81%의 높은 광투과율을 갖는 고품질의 ZnS 박막을 제작할 수 있었다.

• Microbiology and Biotechnology Letters
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• v.42 no.4
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• pp.413-416
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• 2014

The antibacterial activity of chitosan against Escherichia coli and Staphylococcus aureus was investigated in the presence of NaCl, acetic acid, lactic acid, and citric acid to assess its potential use as a food preservative. The inhibitory activity of chitosan decreased slightly upon adding NaCl to culture broth containing 100 ppm of chitosan (MW 3,000), while adding acetic acid, lactic acid, or citric acid enhanced the inhibitory activity of chitosan on growing cells. Our results indicate that food components, such as NaCl, acetic acid, lactic acid, and citric acid, can significantly affect the bactericidal activity of chitosan.

• Korean Chemical Engineering Research
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• v.56 no.5
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• pp.679-686
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• 2018

Reverse osmosis (RO) concentration of sodium chloride, sodium acetate, and sodium citrate solutions has been performed by polyamide RO membrane. Concentration polarization phenomena was also studied by changing pressure, solute kinds, and initial solution concentration. Pressure effect on permeation flux was that the increase of flux was accompanied by the increase of pressure. Flux increase was observed by the decrease of initial solution concentration. Surface concentration on the RO membrane increases and so flux declines due to the concentration polarization. In the later phase of concentration, concentration polarization effect was decreased by the back diffusion of solute from the polariztion layer. In case of sodium citrate, its large ion size and charge density resulted in the discrepancy between theory and experimental data of concentration polarization. It may be due to electric repulsion on the membrane surface.

• Proceedings of the Korean Society for Food Science of Animal Resources Conference
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• 1999.06a
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• pp.211-211
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• 1999

• Korean Journal of Food Science and Technology
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• v.54 no.1
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• pp.75-79
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• 2022

Fresh, washed ginseng can be contaminated with microorganism loads as high as 6.5 log CFU/g for total bacteria and 4.3 log CFU/g for mold. The goal of this study was to test eight antibacterial agents on ginseng. Immersing fresh ginseng washed in 1% (w/w) sodium citrate, sodium diacetate, sodium acetate, citric acid, and sodium lactate solution for 1 h resulted in a bactericidal effect of 31.0-97.5% for total bacteria. Among the organic acids, sodium citrate had the best antibacterial effect, with total bacteria reduced from 6.5 log to 4.9 log CFU/g. A 1% (w/w) vitamin B₁ lauryl sulfate solution with surfactant function by hydrophilic and hydrophobic sites can reduce 2.7 log CFU/g (99.8% inactivation) on total bacteria. In the 1% (w/w) calcium oxide solution, total bacteria were reduced by 3 log, showing an excellent inactivation effect of 99.9%. Calcium oxide is a highly useful material for inactivation of microorganisms in fresh ginseng.

• Proceedings of the Korean Vacuum Society Conference
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• 2004.08a
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• pp.196-196
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• 2004

• Journal of Oral Medicine and Pain
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• v.32 no.4
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• pp.383-396
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• 2007

The aim of this study was to measure the suprathreshold taste intensity for NaCl, sucrose, citric acid, and quinine HCl in elderly Korean women using a whole-mouth, sip-and-spit procedure, employing the method of magnitude matching. The results were analysed in terms of aging, menopause, and salivary flow rate. 31 elderly women (mean age; $50.8{\pm}5.1$ years) and 30 young women (mean age; $25.1{\pm}1.71$ years) were included for the study. Subjects were instructed to give nonmodulus magnitude estimates to the intensities of five concentrations each of sucrose, NaCl, citric acid, and quinine HCl; distilled water; 6 loudness level of a 1,000-Hz tone, using the same 9-point intensity scale. Each of the 21 taste stimuli and 6 auditory stimuli are presented in random order twice. The auditory function is used to assess the absolute intensity function of the subject's taste system. The results were as follows; 1. Comparing to young women, elderly women showed decreased taste intensities for lower concentration solutions of NaCl and sucrose. However, other solutions didn't show any difference in taste intensities between young and elderly women. 2. There were not significant difference in perceived taste intensities for NaCl, sucrose, citric acid, and quinine HCl between menopause and pre-menopause women in elderly women group. 3. There were not significant difference in perceived taste intensities for NaCl, sucrose, and quinine HCl between low salivation women and high salivation women in elderly women group. 4. The low salivation women in elderly group showed higher taste intensity for low concentration citric acid than high salivation women.

• Food Science of Animal Resources
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• v.22 no.1
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• pp.44-49
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• 2002

The effect of citric acid and sodium chlorite(NaClO$_2$) mixtures at 100, 200 and 500 ppd(w/v) on the growth of microorganisms from broiler thigh surface was investigated. Absorbance and aerobic plate counts(APC) of inoculated nutrient broth refrigerated storage at 4∼5$^{\circ}C$ were measured after each additive was added. APC on thigh surface after immersion in each selected solution was enumerated during storage at 4∼5$^{\circ}C$ Absorbance of all citric acid and sodium chlorite mixture(0:100, 25:75, 50:50, 75:25 and 100:0, w/w) except 200 and 500 ppm of 100:0 at Day 0 were lower than the control during storage (p<0.05). And higher concentration of mixture tended to have lower absorbance. APC on thigh surface treated with 500 ppm citric acid and sodium chlorite mixture at 50 : 50 and 75 : 25 ratio were lower than others (p<0.05). Similar antimicrobial activity of additives was found in nutrient broth and on broiler thigh surface.

• Korean Journal of Plant Resources
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• v.8 no.3
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• pp.259-264
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• 1995

To elucidate the effect on the quality of products, various components of ume fruit(Prunus mume)flesh of six species during development and maturation. The weigh and the rate of flesh of ume fruit was increased until maturation, except of small ume. The relative hardness of ume fruit flesh was 2.5~3.9 Kg and decreased at full ripe. The major organic acids of ume fruit flesh was citric acid and malic acid. Citric acid became increased, but malic acid was decreased during maturation and total content of that was increased during maturation Free sugars determined from the ume fruit flesh were fructose, glucose, sucrose. Ascorbic acid content was $0.6\sim2mg%$ in the ume fruit flesh. The contents of K and Ca were abundant minerals in ume fruit flesh.