• Bulletin of the Korean Chemical Society
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• 제15권9호
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• pp.786-791
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• 1994

A simple and rapid sample pretreatment process necessary for determination of metal oxides in water was proposed. Samples were injected into the continuous-flow tube installed inside the microwave oven and the treated samples were cooled before entered to the Ion Chromatography (IC) or Inductively Coupled Plasma (ICP). By coupling this microwave digestion system with IC or ICP, a fully automatic analytical procedures may be easily established. In this study, two different types of digestion methods were considered; the open tubing method (OTM) and the restraint tubing method (RTM). The RTM was proved to be 3 times faster in digestion period and 10 times higher in detection range than the OTM. Validation of proposed sample digestion system was carried out by using an ICP. The results showed that both of continuous-flow methods, the OTM and the RTM were comparable in accuracies with the conventional batch-type vessel digestion method.

• International Journal of Advanced Culture Technology
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• 제9권1호
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• pp.1-6
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• 2021

This study aims to test the relationship between the change in population size and population composition and crime changes. The analytical model includes variables representing changes in population size and population composition, three dependent variables for crime changes, and three control variables. Changes in popuvpdllation size and population composition are measured by indicators such as population size, gender, age groups, and immigrants and foreign workers, and crime changes by felonious, burglary, and violent crime volumes. The sample includes 154 cities and counties in South Korea, and the sample period is from 2010 to 2017. As a result of the analysis, I examine that the decrease in the number of young and men are likely to lead to a decline in felonious and violent crimes, but a high rate of the elderly and the increasing racial heterogeneity are likely to accelerate the fear and worries about crimes.

• 한국식품과학회지
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• 제21권2호
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• pp.203-211
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• 1989

근채류를 열풍건조할 경우 수축변형 및 표면 경화현상을 일으켜 품질변화를 수반하게 되므로 본 연구에서는 온도, 상대습도 및 풍속을 조절할 수 있고 건조중의 시료크기 변화를 측정할 수 있는 실험실 규모의 건조장치를 제작하여 무우 및 고구마의 건조특성과 수축특성에 영향을 미치는 외부 요인들에 대해 조사하였다. 건조속도는 무우 및 고구마 모두 항률건조기, 감률건조기, 감률건조 2단계 a 및 b의 4단계로 구분되어 나타났다. 수축속도 곡선은 각각 건조속도에 대응하여 기울기가 다른 4단계로 나타났으며 항률건조 기간에서는 수축속도가 서서히 증가하다가 감률건조 1단계에서 급격히 증가하였고 감률건조 2단계의 초기에 상당하는 점에서 최대에 달하였다. 또한 시료의 두께. 상대습도 및 초기 함수율 등은 표면적 수축에 큰 영향을 미쳤고 시료의 두께가 얇을수록, 그리고 상대습도 및 초기 함수율이 높을수록 평형 상태에서의 수축율은 증가하였다.

• 한국지진공학회논문집
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• 제15권1호
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• pp.29-38
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• 2011

이 연구에서는 평면, 입면 및 구조적 특성이 다양한 철근 콘크리트 고층 아파트 건물의 고유주기를 예측할 수 있는 새로운 식을 제안하였다. 제안식은 벽체의 진동이론과 지진시 계측된 건물들의 고유주기로부터 개발 되었으며, 평면에서 다양한 방향으로 설계된 전단벽의 구조적 특성을 적절히 반영할 수 있다. 제안식의 검증을 위해 신축 중인 국내 아파트 건물 10개동의 고유주기를 측정하였으며, 측정된 고유주기는 제안식 및 KBC 2009, ASCE 7-10과 같은 기준식들과 비교 하였다. 비교 결과, 제안식은 기준식에 비해 최근의 철근콘크리트 전단벽 건물 특성을 합리적으로 반영함으로써 고유주기를 보다 정확하게 예측하는 것으로 나타났다.

• 한국식품영양학회지
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• 제34권1호
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• pp.58-68
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• 2021

This study investigated the microbial community and quality characteristics of traditional soybean pastes (doenjang) based on the aging period in Gyeongnam province. The samples were collected from seven regions in Gyeongnam Province (Goseong, Hadong, Haman, Hamyang, Sacheon, Sancheong and Uiryeong). Contents of moisture, salinity, pH, and acidity of doenjang after 210 days aging were 56.40~65.21%, 9.05~16.08%, 4.88~6.86 and 0.64~2.14%, respectively. Lightness significantly decreased over the aging period, while the redness tended to increase over the aging period. Yellowness was from 21.39~26.81 to 21.10~28.36. Reducing sugar content was from 0.31~1.45% to 0.11~3.13%. The amino-type content increased from 141.87~495.13 mg/100 g to 328.53~823.67 mg/100 g. In contrast, the ammonia-type content declined from 136.74~364.70 mg/ 100 g to 128.62~331.00 mg/100 g. The overall total microbial count did not significantly differ, but it tended to decrease in sample GD4. Fungus declined overall or was not detected. Coliform groups were not detected in all samples. Lactobacillus and Bacillus cereus tended to decrease over the aging period. The common fungus and bacterium were Aspergillus oryzae and Tetragenococcus halophilus, respectively. After the aging period, the predominant fungi were Candida versatilis, Candida apicola, and Debaryomyces hansenii. The predominant bacteria were Tetragenococcus halophilus and Cronobacter sakazakii.

• 동의생리병리학회지
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• 제18권2호
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• pp.419-426
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• 2004

This experimental study was designed to investigate the effects of Yukgunja-tang(YGJT) on the inhibition of cerebral ischemia in rats. And We measured regional cerebral blood f1ow(rCBF) and pial arterial diameter(PAD) in cerebral ischemic rats, and cytokines production in serum Of cerebral ischemic rats. The results were as follows; Both rCBF and PAD were significantly and stably increased by YGJT(10 mg/kg, i.p.) during the period of cerebral reperfusion, which contrasted with the findings of rapid and marked increase in control group. In cytokine production of serum by drawing from femoral arterial blood after middle cerebral arterial occlusion(MCAO) 1 hr, IL-1β and TGF-β production of sample group were similar to that of control group, but sample group was decreased TNF-α production compared with control group, and was significantly increased IL-10 production in compared with control group. In cytokine production of serum by drawing from femoral arterial blood after reperfusion 1 hr, sample group was significantly decreased IL-1β and TNF-α production compared with control group, but TGF-β production of sample group was similar to that of control group, and sample group was significantly increased IL-10 production compared with control group. In cytokine production of serum by drawing from femoral arterial blood after reperfusion 4 hrs, sample group was significantly decreased IL-1β production compared with control group, and sample group was decreased TNF-α production in compared with control group, but TGF-β production of sample group was similar to that of control group, and sample group was increased IL-10 production compared with control group. This results were suggested that YGJT has inhibitive effect on the brain damage by inhibited IL-1β production and TNF-α production, but accelerated IL-10 production. We thought that YGJT should have an anti-ischemic effect through the improvement of cerebral hemodynamics and inhibitive effect on the brain damage.

• 한국식품영양과학회지
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• 제35권8호
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• pp.1031-1037
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• 2006

감마선 조사된 시판 인스턴트 분말수프의 가속 저장($60^{\circ}C$, 4주) 중 이화학적 품질특성을 평가하였다. 감마선 조사 직후 지방산패도는 조사선량이 증가함에 따라 증가하였으나 조사구 및 비조사구 모두 저장기간이 늘어남에 따른 변화는 없었다. 시료의 pH 변화는 비조사구에 비해 조사구에서 낮아지는 경향을 보였으며 저장기간이 길어질수록 pH값이 유의적으로 감소하였다(p<0.05). 감마선 조사된 수프의 점도는 비조사구에 비해 조사구에서 조사선량이 증가함에 따라 유의적으로 감소하는 경향을 보였으며(p<0.05) 저장기간에 따른 차이는 미미하였다. 감마선 조사된 수프의 색도는 저장기간이 늘어남에 따라, 그리고 조사선량이 증가함에 따라 명도가 감소하는 경향을 나타내었다. 이상의 결과에서 감마선 조사는 수프의 지질산화를 증가시키고 점도감소가 초래되어 이를 방지하기 위한 추가연구가 요구된다.

• Animal Bioscience
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• 제36권10호
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• pp.1536-1545
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• 2023

Objective: The objective was to evaluate the effects of UV-B irradiated vitamin D-enriched yeast supplementation on milk yield, milk composition, vitamin D in milk, milk fatty acids, blood chemistry, and 25(OH)D status in dairy cows. Methods: Six Thai Friesian cows (milk production, 11.2±2.0 kg/d; body weight, 415.0±20.0 kg; and days in milk, 90.0±6.0) were allocated to each treatment in a 3×3 Latin square design, with three treatments and three periods. Each period of the Latin square lasted 49 days consisting of 14 days for diet adaptation and 35 days for sample collection. Dairy cows were randomly assigned to one of three treatments: i) feeding a basal diet without yeast (CON); ii) basal diet + 5 g of live yeast (75 IU/head/d of vitamin D₂; LY); and iii) basal diet + 5 g of UV-B irradiated vitamin D enriched yeast (150,000 IU/head/d of vitamin D₂; VDY). Feed intake and milk production were recorded daily, milk sample collection occurred on days 14 and 35 of each collection period, and blood plasma was collected on days 0, 7, 14, 21, 28, and 35 of each collection period. Results: The results show that after a trial period of 14 and 35 days, the VDY group had significantly higher vitamin D content in milk than the LY and CON groups (376.41 vs 305.15, 302.14 ng/L and 413.46 vs 306.76, 301.12 ng/L, respectively). At days 7, 14, 21, 28, and 35 of the experiment, cows fed the VDY group had significantly higher 25(OH)D₂ status in blood than the CON and LY groups (51.07 vs 47.16, 48.05 ng/mL; 54.96 vs 45.43, 46.91 ng/mL; 56.16 vs 46.87, 47.16 ng/mL; 60.67 vs 44.39, 46.17 ng/mL and 63.91 vs 45.88, 46.88 ng/mL), respectively. Conclusion: In conclusion, UV-B irradiated vitamin D-enriched yeast supplementation could improve vitamin D content in the milk and 25(OH)D status in dairy cows during the lactation period.

• Restorative Dentistry and Endodontics
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• 제24권1호
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• pp.147-155
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• 1999

The purpose of this study was to investigate the effect of phosphoric acid concentration on the movement of 2-hydroxyethylmethacrylate(HEMA) from bonding resin - resin composite combination through dentin in vitro. Freshly extracted human third molar teeth were divided into four groups each of 10 teeth. A closed chamber with 1 ml distilled water was attached to the CEJ of each tooth. An occlusal cavity of 4mm diameter & remaining dentin thickness of 1.0-1.5mm was prepared in each tooth. Dentin was treated with 10% phosphoric acid gel for 15 seconds. 32% phosphoric acid gel for 15 seconds, or with 35% phosphoric acid gel for 15 seconds. A control group not treated with acid gel was also prepared. The cavities were rinsed, dried and then treated with the HEMA-containing All-Bond 2 primer & bonding resin which was light-cured for 10 seconds. The cavities were then restored with Z100 composite resin(shade:A3.5:3M Dent. Prod. USA) & light cured for 30 seconds. Water samples were retrieved from the chambers over a time course (4.32, 14.4, 43.2, 144 & 432 minutes ; 1, 3 & 10 days) and analyzed by high performance liquid chromatography. The results were as follows. 1. HEMA was detected in the pulp chambers of all teeth from 4.32 minutes after resin placement The highest rate of release was in the first sample period (0-4.32 min) & rate of release declined exponentially thereafter. 2. No significant differences were found for mean release rate for HEMA over a time course among the four groups (p>0.05). 3. The diffusion rate was significantly (p<0.05) less for 10% phosphoric acid gel than 32% phosphoric acid gel at the second sample period(4.32-14.4 min). 4. No significant differences were found for cumulative HEMA diffusion among the four groups at 10 days(p>0.05) and mean total(cumulative) release at 10 days for all groups was in the 9 - 16 nmol range. 5. The cumulative release was significantly (p<0.05) less for 10% phosphoric acid gel than 32% phophoric acid gel at the third(14.4-43.2 min) & fourth(43.2-144 min) sample period.

• 한국식품조리과학회지
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• 제16권6호
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• pp.511-520
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• 2000

약포의 첨가당과 건조방법이 육포의 품질과 저장성에 미치는 영향을 알아보기 위하여 저장상, 기계적 특성과 관능검사를 실시하였다 육포의 저장 기간 중에 수분활성 도는 경시적으로 감소경향을 나타내었고 저장 5주에는 꿀과 조청을 첨가한 천연건조시료(N-H, N-R)가 모두 0.71로 가장 낮은 값을 보였다. 모든 시료의 pH는 저장에 따라 감소하였으며 꿀을 첨가하여 열풍 건조한 육포(H-H)가 5.22로 가장 낮았다. 색도의 L, a, b값은 저장기간 중에 모두 감소 경향을 보였다. 저장기간 중 모든 시료에 있어서 TBA값이 증가하는 것으로 나타났고, 설탕시립첨가육포(N-S, H-S, S-S)는 건조방법과 관계없이 가장 낮은 값을 보였으며 꿀첨가육포(N-H, H-H, S-H)가 가장 높았다. 모든 시료의 총미생물수와 젖산균수는 저장 기간이 경과함에 따라 증가하였으며, 저장 5주시 설탕시럽첨가 열풍건조한 육포(H-S)가 가장 낮았다. 모든 시료의 기계적 조직특성은 저장기간이 경과함에 따라 증가하였다. 탄력성과 응집성은 대체로 꿀첨가시료가 가장 높았고 씹힘성과 점착성·견고성은 설탕시럽첨가 천연건조 시료가 가장 높게 나타났다. 천연건조시료는 포장방법에 관계없이 거의 모든 항목에 걸쳐 저장기간이 경과함에 따라 관능점수가 감소하였고, 열풍건조시료들의 관능점수는 포장방법에 관계없이 천연건조시료들에 비해 현저히 높은 점수를 나타내었다.