• 한국토양비료학회지
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• 제5권1호
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• pp.1-8
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• 1972

수도재배(水稻栽倍)에 있어서 용성인비중(熔成燐肥中)에 함유(含有)된 규산(珪酸)의 효과를 기대(期待)하기 위하여서는 현행(現行) 용성인비(熔成燐肥)는 인산(燐酸)의 함량(含量)이 높으므로 다량시비(多量施肥)를 할경우 인산(燐酸)의 과용(過用)이 문제(問題)시되므로 인산함량(燐酸含量)이 낮고 규산함량(珪酸含量)이 많은 인산저농도(燐酸低濃度) 용성인비(熔成燐肥)를 제조(製造)하여 규산(珪酸) 및 인산(燐酸)의 효과를 기대(期待)코저 시험(試驗)하여 다음의 결과(結果)를 얻었다. 1. 고온로(高溫爐)에서 인광석(燐鑛石)을 주원료(主原料)로 하여 용융(熔融)한 결과(結果) 인산함량(燐酸含量)이 9.9%(구용율(枸溶率) 97%)이며 가용성(可溶性) 규산함량(珪酸含量)이 33%인 인산저농도(燐酸低濃度)의 용성인비(熔成燐肥)를 제조(製造)했다. 2. 정조중(精租重)은 시비수준(詩肥水準)에 따라 고도(高度)의 유의성(有意性)이 있었으며 300kg/10a구(區)에서 수량(收量)이 가장 높았다. 3. 인산저농도(燐酸低濃度)의 용성인비(熔成燐肥)를 이용(施用)하므로서 수도(水稻)의 수량구성요인(收量構成要因)중 수당입수(穗當粒數), 임실율(稔實率) 및 천입량(千粒量)이 증가(增加)되었다. 4. 생육기간중(生育期間中) 인산(燐酸)의 흡수량(吸收量)은 초기(初期)에서는 대조구(對照區)와 소량시비구(少量施肥區)가 많았으나 수확기(收穫期)에는 300kg/10a구(區)가 흡수량(吸收量)이 가장 컸고 500kg/10a 구(區)에는 억제(抑制)되는 경향(傾向)이었다. 규산(珪酸)의 흡수량(吸收量)은 인산(燐酸)과 같이 생육기간(生育初期)에는 소량시비구(少量施肥區) 흡수량(吸收量)이 높았으나 유수형성이후(幼穗形成以後) 수확기(收穫期)동안은 300kg/10a 구(區)까지 흡수량(吸收量)이 급격(急激)히 증가(增加)되었고 50kg/10a구(區)는 300/10a 구(區)와 비슷하였다. 5. 시험후(試驗後) 토양(土壤)중의 가용성배합량(可溶性酸含量)은 시비수준(施肥水準)에 따라 증가(增加)하였으며 기타 양(陽)이온도 같은 경향이었으나 인산(燐酸)은 100kg/10a 구(區)가 약간 낮았고 다른 구(區)는 대조구(對照區)와 비슷하였다. 6. 인산저농도(燐酸低濃度) 용성인비(熔成燐肥)의 이용(施用)으로 규산(珪酸)과 인산(燐酸)의 효과를 공(共)히 기대(期待)할 수 있으나 시험후토양(試驗後土壤)의 인산함량(燐酸含量)이 많이 잔류(殘有)되어 있으므로 인산농도(燐酸濃度)를 더 낮추어야할 필요성(必要性)이 있다.

• 한국미생물·생명공학회지
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• 제17권4호
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• pp.358-364
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• 1989

토양으로부터 분리한 Streptomyces sp. YSA-130으로부터 활성이 좋은 결정화된 alkaline protease를 분리하였다. Alkaline protease 생산의 최적 배양조건은 2.0% soluble starch, 1.0% soytone, 0.3% $K_2$HPO$_4$, 0.02% MgSO$_4$.7$H_2O$, 0.8% $Na_2$CO$_3$ 3$0^{\circ}C$, pH 10.5에서 72 시간 배양하였을 때 였다. Alkaline protease이 정제는 (NH$_4$)$_2$SO$_4$. 분별침전, 투석, DEAE cellulose column chromatography, Sephadex G-75 gel filtration, crystallization으로 하였으며, 그 결과 비활성도 14,290unit/mg, 정제도 23.8 배였고, 수율은 20.0% 이었다. Alkaline protease의 반응 최적온도와 pH는 6$0^{\circ}C$ 와 11.5이었으며, 효소의 pH 안정성은 5.5-12.0에서 안정하였고, 온도 안정성은 5$0^{\circ}C$까지 안정하였으며, $Ca^{++}$ ion 첨가시 6$0^{\circ}C$까지 안정성이 증가하였다. Alkaline protease의 분자량은 30,000이었으며 금속이온, EDTA, 환원제는 활성에 영향이 없었고 DFP에 의해 저해되었다. 계면활성제에 저항성이 크고 $H_2O$$_2$에 대한 잔존활성은 60% 을 유지하였다.

• 한국양식학회지
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• 제15권1호
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• pp.49-60
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• 2002

Research on practices for improving water quality in channel catfish Ictalurus punctatus ponds was conducted at the Auburn University Fisheries Research Station, Auburn, Alabama, in 1998 and 1999. The objective of this two-year study was to determine better management practices to enhance water quality and improve production efficiency. In the first year, oxidation of bottom soil by drying, tilling, and applying sodium nitrate was performed (dry-till and dry-till with sodium nitrate treatments). The second year, based on the results obtained during the first year, precipitation of phosphorus (P) from water by applying gypsum was compared to the dry-till treatment (dry-till and dry-till with gypsum treatments). Control ponds were not subjected to bottom drying, tilling, sodium nitrate, or gypsum treatment. Channel catfish fingerings were stocked at 15,000/ha. In the first year, water in ponds from dry-till and dry-till with sodium nitrate treatments had lower concentrations (P < 0.01) of soluble reactive P, nitrate ($NO_{3} ^{-}) and nitrite ($NO_{2} ^{-}) nitrogen (N), total ammonia ($NH_3$) nitrogen, total suspended solids and turbidity, and higher values of pH, Secchi disk visibility, total alkalinity, total hardness, and calcium ($Ca^{2+}) hardness than water in control ponds. Ponds of the dry-till treatment also had lower concentrations (P < 0.01) of total P and total N than control ponds. Total fish production and survival rate did not differ among the treatments (P > 0.05). The findings suggested that drying and tiling pond bosoms between crops could achieve water quality improvement. Applying sodium nitrate to dry, tilled pond bosoms did not provide water quality improvement. In the second year, the treatment with the best results from the first year, dry-till, was compared with a dry-till with gypsum treatment. Enough gypsum was applied to give a total hardness of about 200 mg/L, and gypsum was reapplied as needed to maintain the hardness. Compared to the control, dry-till and dry-till with gypsum treatments had lower concentrations (P < 0.01) of total and soluble reactive P, total N, and total $NH_3$-N, and higher concentrations (P < 0.01) of dissolved oxygen. Ponds of the duty-till with gypsum treatment also had lower concentrations (P < 0.01) of chlorophyll $\alpha$, chemical oxygen demand, and total alkalinity than the control. Total fish production and survival rate did not differ (P > 0.05) among the treatments. These findings suggest that drying and tilling pond bosoms between crops and treating low hardness waters with gypsum could achieve water Quality improvement.

• 보존과학회지
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• 제17권
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• pp.73-82
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• 2005

분황사석탑은 가장 오래된 신라시대의 모전석탑이다. 탑신부는 벽돌처럼 제작된 검은 안산암으로 이루어져 있으며, 화강암으로 조성된 감실이 1층탑신석에 있다. 1915년 대대적인 수리가 행해졌으나, 현재 석탑의 구성암석에서는 여러 손상의 형태들이 나타나고 있다. 특히 구성화강암 표면에서는 박리 사질상입자분해 등이 심하게 나타나고 있다. 본 연구에서는 다양한 분석을 통하여 구성화강암의 정확한 훼손현황을 살펴보았고, 탑신부에 나타나고 있는 백화현상과의 관계를 통해 그 손상원인을 찾아보았다. 연구결과, 구성 화강암은 석탑 표면에 발생된 백화현상의 원인 물질로 인해 훼손이 가중되고 있는 것으로 알려졌다. 백화현상의 원인 물질은 질산나트륨. 황산칼슘, 황산나트륨 등의 수용성 염류로, 백색 줄눈몰타르에서 기인한 것이다. 석탑의 외부는 이러한 백색 줄눈몰타르가 수분과 반응하여 재결정화되고 있지만, 많은 부분이 빗물에 의해 씻겨 내려가다가 밖으로 배수되는 것으로 생각된다. 이 과정에서 빗물에 용해된 염성분들이 감실을 구성하고 있는 화강암을 거쳐가게 되고, 다공성의 화강암은 모세관현상에 의해 이 염들을 수분과 함께 암석의 내부로 흡수한다. 그러므로 구성화강암이 갖고 있는 염문제를 줄일 수 있는 방법은 백색 줄눈몰타르를 용해성이 적은 다른 물질로 대체하는 것이다. 또한 석탑내부로 흘러들어온 수분이 백색 줄눈몰타르를 용해시킬 수 있기 때문에, 상부에서 석탑내부로 수분이 흘러내리지 않도록 조치를 취하는 것이 필요하다.

• 한국수산과학회지
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• 제43권1호
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• pp.18-24
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• 2010

The biochemical composition of wild and cultured yellow croaker, Larimichthys polyactis, was analyzed in this study. The moisture contents in wild and cultured yellow croaker was high: $75.2{\pm}1.60%$ and $79.5{\pm}1.95%$, respectively. The crude lipid contents of wild and cultured yellow croaker were low; moreover, the crude protein and ash contents did nol differ significantly (P>0.05). The total amino acid content of wild and cultured yellow croaker did not differ significantly; however, the cystine content of wild yellow croaker was higher than than of cultured yellow croaker. The essential /nonessential amino acid (E/NE) ratio in wild and cultured yellow croaker was $0.76{\pm}0.01$ and $0.77{\pm}0.02$, respectively. The free amino acid and extractive nitrogen contents of cultured yellow croaker were high and differed significantly. The water soluble vitamin ($B_1$, $B_2$, $B_6$, $B_{12}$, C and folate) and fat-soluble vitamin (A and E) contents did not differ significantly. expect for niacin. The niacin content of cultured yellow croaker was higher than that of wild yellow croaker. The fatty acid composition of wild and cultured yellow croaker did not differ significantly The sodium, magnesium, and copper contents in wild yellow croaker were relatively low. In comparison, the calcium, phosphorus and iron contents in cultured yellow croaker were relatively high. Overall, the biochemical composition of wild and cultured yellow croaker did not differ significantly.

• 한국미생물·생명공학회지
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• 제34권4호
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• pp.323-328
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• 2006

식충식물에서 채취된 시료로부터 protease치 생산균으로 분리된 SH-8은 그람 양성간균으로 16S rRNA외 부분 염기서열에 근거하여 Bacillus속 균주로 확인되었다. Protease 생산을 위한 배지를 제조하기 위해 질소원, 탄소원, 인, 금속이온의 성분을 변화시키면서 균의 성장과 효소 생산성을 비교하였다. 포도당을 탄소원으로 사용하였을 때는 균의 성장은 정상적으로 일어나지만, pretense생산이 완전히 억제되는 것으로 나타났으며, 가용성 전분을 탄소원으로 사용하였을 때 효소 생산성이 가장 높았다. 질소원으로는 yeast extact가 효소 생산에 가장 적합하였으며, 농도가 높으면 효소 생산성이 저하되었다. 한편 2가 금속이온중 $Zn^{2+}$, $Cu^{2+}$, $Co^{2+}$, $Mn^{2+}$을 배지에 첨가하였을 때는 균의 성장이 심하게 저해되었으며, 효소 생산도 되지 않았다. $CaCl_2$를 첨가한 배지에서는 효소 생산성이 증가되었으며, 효소 반응에 $CaCl_2$를 첨가하였을 때도 효소 활성이 증가하였다. 이로보아 $CaCl_2$는 Bacillus sp. SH-8의 protease 생산성과 활성을 모두 증가시키는 것으로 판단된다. 가용성 전분(2%), yeast extract(0.3%), $CaCl_2$(0.3%), $CaCl_2$(0.01%)와 $KH_2PO_4$(0.01%)를 포함하는 것으로 구성된 최적화 배지에서 최대효소 생산성은 435 U/ml로 나타났으며 26시간이 되었을 때 배양액 내 효소활성은 급격히 감소하였다.

• Journal of Pharmaceutical Investigation
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• 제36권4호
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• pp.271-276
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• 2006

Felodipine, a calcium-antagonist of dihydropyridine type, is a poorly water soluble drug and has very low bioavailability. As preceding studies, use of solid dispersion systems and surfactants(solubilizers) has been suggested to increase dissolution and to improve bioavailability of felodipine. But in case of solid dispersion systems, large amount of toxic organic solvents should be used and manufacturing process time become longer than conventional process. In case of using surfactants, as time elapsed, decreasing of dissolution rate of felodipine due to crystallization has been reported. In this study, Copovidon as a hydrophilic polymer and $Transcutol^{\circledR}$ as a surfactant were combined to formulations if order to increase dissolution of felodipine and conventional wet granulation process were applied to manufacturing of formulations. The effect of Copovidon and $Transcutol^{\circledR}$ on the dissolution oi felodipine was investigated in-vitro. When Copovidon and $Transcutol^{\circledR}$ used simultaneously, the dissolution rate of felodipine was prominently increased compared with when used separately and the maximum increase in the dissolution of felodipine was 5.8 fold compared to control. This is most probably due to synergy effect by combination of Copovidon and $Transcutol^{\circledR}$. Felodipine sustained release tablets were successfully formulated using several grades of HPMC as a release retarding agent. The stability of felodipine sustained release tablet was evaluated after storage at accelerated condition($40^{\circ}C/75%\;RH$) for 6months in HDPE(High density polyethylene) bottle. Neither significant degradation nor change of dissolution rate for felodipine was observed after 6months. In conclusion, felodipine sustained release tablet was successfully formulated and dissolution of felodipine, poorly water soluble drug, was prominently increased and also stability was guaranteed by using combination system of hydrophilic polymer and surfactant.

• 한국산업보건학회지
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• 제34권2호
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• pp.166-178
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• 2024

Objectives: The 12 occupational exposure limits(OELs) for chromium and its compounds in Korea were set by applying the American Conference of Governmental Industrial Hygienists (ACGIH) Threshold Limit Values (TLVs). However, this is significantly different from the TLVs after the existing TLVs were integrated and withdrawn in 2018, so it is necessary to review the revision. Methods: Various documents related to chromium OELs were reviewed, including the ACGIH TLV Documentations for chromium and its compounds. A field survey was conducted targeting workplaces handling chromium and its compounds. Based on this, a revised OELs were proposed and a socio-economic evaluation was conducted. Results: The OELs for chromium compounds in Korea was first enacted in 2002, and in 2007, the OELs for chromium (hexavalent) compounds (insoluble) was lowered from 0.05 mg/m³ to 0.01 mg/m³. In 2008, the OELs for strontium chromate was newly established as 0.0005 mg/m³, and in 2018, the OELs for calcium chromate was newly established as 0.001 mg/m³. Total chromium and hexavalent chromium were measured for each of 6 samples at 2 welding sites, 4 plating sites, and 2 spray coating sites. When omparing the average of the results measured by ICP, a total chromium analysis method, and the analysis results by IC, a hexavalent chromium analysis method, only workplace 4 was the same, and total chromium was evaluated more, and total chromium was evaluated at 0.0004 to 0.0027 mg/m³. And hexavalent chromium was evaluated as non-detection ~ 0.0014 mg/m³. Amendment ①: The exposure standard for hexavalent chromium is not divided into water soluble, insoluble, chromium ore processing, and other hexavalent chromium compounds, and is integrated into 0.01 mg/m³, which is the level of chromium (hexavalent) compound (insoluble)., OELs for chromium (metal) and chromium (trivalent) compounds are integrated into chromium (trivalent) compounds, and the exposure level is maintained. Amendment ②: As in the amendment ①, the OELs are integrated, but the level is lowered to 0.005 mg/m³, which is the OELs of OSHA, and there is a grace period of 4 years. Amendment ③: As in the amendment ①, the OELs are integrated, but the level is lowered to 0.0002 mg/m³, which is the exposure standard of ACGIH, and there is a grace period of 5 years. Conclusions: Amendment ①: The change in the OELs is insignificant, so the cost required is small, and the benefit/cost ratio is greater than 1, so there is no problem in applying the amendment. Amendment ②: In all scenarios except chromium 6(insoluble), the benefit/cost ratio is greater than 1, so it is thought that there will be no major problem in applying the amendment. Amendment ③: Since the benefit/cost ratio is less than 1 in all scenarios, it is thought that the total social benefit that can be obtained when applying the amendment is not large.

• 대한지역사회영양학회지
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• 제7권5호
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• pp.639-653
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• 2002

The purpose of this study was to investigate the regional 야fferences in dietary supplement use and related factors among college students participating in nutritional education programs via the internet. The subjects in this study were 797 college students (male: 518, female: 279). A cross-sectional survey was conducted using a self-administered questionnaire about dietary supplement use, demographic characteristics, health-related lifestyles, nutrient intake, and data were collected via the internet and by mail. Dietary supplements were taken by 82.2% of subjects (males: 76.3%, females: 85.3%). There was a significant regional difference in supplement use (p<0.01). The supplements, used most frequent by male students in the Seoul and Incheon areas were lactic acid beverages and gagogi, in that order. Male students in the Kyunggi area used gagogi and lactic acid beverages in that order. Lactic acid beverages and Chinese medicine were used most frequently by male students in the Chungcheong area. Male students in the Kyungsang area used lactic acid beverages and water-soluble vitamins, in that order. Male students in Seoul and Kyungsang areas showed significantly higher percentage of keep on taking supplements compared to other areas (p<0.05). Both male and female students in the Seoul area had more frequent medical examinations, in comparison to students in other areas (p<0.05). Male students in the Kyungsang and Seoul areas took significantly more calcium (p<0.05) and iron (p<0.05), in comparison to students in other areas. Female students id the Kyunsang area took significantly more Vitamin A, phosphorous and iron (p<0.05), while those in the Seoul area took significantly more Vitamin C (p <0.01) and calcium (p<0.05) . Male students in the Chungcheong area took significantly less seaweed, in comparison to students in other areas (p<0.05) . Male students in the Seoul area had the highest amount of animal fat and oil, while those in the Incheon area ate the lowest amount of animal oil and fat (p<0.05). Female students in the Kyunggi area ate the highest amount of fruit, while those in the Incheon area ate the lowest amount of fruit (p< 0.05) , Female students in the Incheon area ate the highest amount of seaweed, while those in the Kyunggi area ate the lowest amount of seaweed (p<0.01). Therefore, it can be concluded that it is necessary to develop dietary supplements to optimize the nutritional status of college students in different areas of Korea.

• 원예과학기술지
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• 제17권1호
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• pp.11-14
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• 1999

참다래 및 야생다래에서 수액 채취시기에 따른 수액특성, 수액내 유리당, 무기물 및 아미노산함량 변화를 조사하였다. 참다래 및 야생다래에서 수액 채취시기에 따른 수액량은 채취 시기가 늦을수록 심하게 감소하는 경향을 보였다. 수액내 수분함량, 당도, 점도 및 pH는 두 종간 차이가 없었으나 산함량 및 탁도는 야생다래보다는 참다래에서 다소 높은 경향을 보였다. 당은 참다래에서 fructose, glucose, sucrose, galactose, manitol이 함유되어 있었고 야생다래에서는 fructose, glucose가 함유되어 있었는데 당의 대부분은 fructose였다. 수액내 주요 무기물은 칼슘, 카리 및 마그네슘으로 칼슘함량이 상대적으로 가장 높았다. 두 종에서 각각 17종의 아미노산이 함유되어 있었는데 이들중 주요 아미노산은 glutamic acid, lysine 및 isoleucine이었는데 이중 glutamic acid함량이 가장 높았다. 참다래에서 histidine, methionine과 tylosine을 제외한 나머지 성분은 야생다래에 비해 높았다. 무기물 및 아미노산함량은 수액 채취시기가 늦을수록 증가하는 반면 유리당함량은 감소하는 경향을 보였다. 수액의 품질은 채취시기가 늦을수록 향상되는 것으로 나타났으나 수액채취량은 현저히 감소하는 경향을 보였다.