• 제목/요약/키워드: $MgB_{2}$ powder

검색결과 266건 처리시간 0.025초

국내 알루미늄 노출실태 및 노출기준 개정 제안 (Proposals for Revising the Occupational Exposure Limits for Aluminum in Korea)

  • 김승원;피영규;백용준;정태진;이혜실
    • 한국산업보건학회지
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    • 제34권1호
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    • pp.85-97
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    • 2024
  • Objectives: This study was intended to investigate the revision status of the occupational exposure standards for aluminum at home and abroad; to investigate worker exposure at domestic aluminum manufacturing and handling workplaces; to conduct social and economic evaluation for the revision of domestic aluminum exposure limits. Methods: We investigated the current status of occupational exposure limits for aluminum at home and abroad, and analyzed supporting data. An exposure survey was conducted targeting domestic aluminum manufacturing and handling workplaces. Based on these, revised aluminum occupational exposure limits were proposed. Results: The major aluminum exposure limits at home and abroad show a notable difference. The toxicity of aluminum, which was revealed through animal experiments and epidemiological investigations. The average concentration of aluminum in the air at 12 workplaces was 0.016 mg/m3, and the maximum was 0.0776 mg/m3. When total dust and respiratory dust were measured side by side and simultaneously for the same process, 12.1% of the total mass concentration of aluminum dust was respiratory dust. As a result of measuring and comparing the size distribution of dust with an optical particle counter in real time, 48.1% of the total dust in the form of welding fume and pyro-powder was respiratory dust. Based on the literature review and workplace survey, three proposals for changing the aluminum exposure limit were proposed. Proposal (1): For all types, 10 mg/m3 is unified as the exposure limit except for soluble salts and alkyls. Proposal (2): 1(R) mg/m3 as the exposure limit for all forms except soluble salts and alkyl. Proposal (3): 1(R) mg/m3 for pyro-powder and welding fume, and 10 mg/m3 for metal dust, aluminum oxide, and insoluble compounds as exposure standards. A pyro-powder was defined as dry aluminum powder of 200 mesh size (74 ㎛) or smaller (larger size classified as metal dust). Reason for setting: In the workplace survey, the ratio of respiratory dust to total dust was analyzed to be about 1:10, so it was judged that the domestic standard and the ACGIH standard were compatible. Conclusions: In all scenarios according to the revision of the exposure standard, the B/C ratio was greater than 1 or only benefits existed, so it was evaluated as sufficiently reasonable as a result of the socio-economic evaluation.

동결건조 양파분말을 첨가한 두부의 품질특성 (Quality Characteristics of Soybean Curd Mixed with Freeze Dried Onion Powder)

  • 강난숙;김준환;김종국
    • 한국식품저장유통학회지
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    • 제14권1호
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    • pp.47-53
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    • 2007
  • 동결건조 양파분말을 첨가하여 기능성 두부를 제조하고 품질특성 변화를 조사하였다. 두부의 수분함량은 양파건조 분말의 첨가량이 증가할수록 그 값이 다소 증가하는 현상을 나타내었다. 색도 변화에 있어 백색도(L값)는 양파건조분말 0.1%를 첨가했을 때 83.06으로 가장 높게 나타났다. 적색도(a값)는 대조구나 양파건조분말 첨가구에서 $-1.03{\sim}1.54$로 거의 변화가 없었다. 황색도(b값)의 경우 양파건조분말 첨가구는 $13.00{\sim}13.93$으로 비슷하게 나타났다. Sucrose함량은 0.2% 첨가구가 $303.50\;{\mu}g/100g$로 가장 높았고, fructose, glucose 및 maltose함량은 0.2% 첨가구에서 각각 $67.48{\mu}g/100g,\;44.60{\mu}g/100g$$43.37{\mu}g/100g$으로 높게 나타났다. 주된 유기산은 tartaric acid로 대조구가 $282.62{\mu}g/100g$으로 가장 많았으며, citric과 oxalic acid함량 또한 대조구가 $94.83{\mu}g/100g$$11.53{\mug/100g$으로 가장 많았다. 주요 유리 아미노산은 L-glutamic acid, L-arginine, L-valine, L-serine, L-tyrosine 및 L-threonine 등 이였고, 0.2% 첨가구에서는 L-glutamic acid, L-arginine 및 L-valine가 $114.17{\mu}g/100g,\;141.40{\mu}g/100g$$124.30{\mu}g/100g$으로 많은 함량을 나타내었다. 페놀성분으로는 quercitrin, protocatechuic acid, cafferic acid 등이 주요 페놀성분으로 확인되었다. 무기질로는 P, Ca, Mg의 경우는 0.2% 첨가구가 206.46 mg%, 170.88 mg% 및 70.49 mg%로 많은 함량을 나타내었다. 조직감 특성 중견고성의 경우는 대조구,0.1% 첨가 및 0.2% 첨가는 서로 비슷하게 나타났으며 첨가량이 증가할수록 견고성이 낮았다. 관능적 품질특성은 색, 냄새, 맛, 조직감, 전체적인 기호도는 양파분말을 첨가함에 따라 낮아지는 경향을 보였다. 따라서 위의 결과를 종합해 볼 때 두부제조시 동결건조 양파분말의 첨가량은 0.2% 정도가 가장 바람직할 것으로 판단된다.

$FeS_{2}$의 압축성 연구 (Compressibility of $FeS_{2}$)

  • 김영호;황길찬;조현구
    • 한국광물학회지
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    • 제19권3호
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    • pp.189-195
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    • 2006
  • 황철석에 대한 압축성 연구를 다이아몬드 앤빌 기기 및 방사광을 이용하고 에너지분산 X-선회절법을 적용하여 상온에서 시행하였다. 황철석의 체적탄성률은 실험조건과 실험기기에 따라 매우 큰 변이를 보이고 있는데 이는 압력전달매체의 특성에 따른 것으로 알려져 있다. $FeS_{2}#1$(황철석+NaCl)과 $FeS_{2}#2$(황철석+MgO)에 대해 압력전달 매체로 각각 NaCl과 유체를 이용하여 체적탄성률 138.9 GPa와 198.2 GPa를 각각 얻었다. 이러한 값은 시료방의 압력상태에 따른 예측 결과치에 대치되는 것으로 그 원인은 압력전달액체의 상변이에 따른 것으로 추정되며 이외에 고상검출기의 차이, E*d값의 차이 등도 영향을 미친 것으로 판단된다. 모든 실험은 포항가속기연구소 1B2 빔라인에서 시행되었다.

감태 첨가 크래커의 항산화 활성 및 품질 특성 (Antioxidant Activities and Quality Characteristics of Cracker Added with Ecklonia cava)

  • 유민영;한영실
    • 한국식품영양학회지
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    • 제31권6호
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    • pp.821-827
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    • 2018
  • Ecklonia cava which is a kind of phaeophyta and belongs to Laminariales Alariaceae is a perennial seaweed distributed over Jeju and Dokdo islands. The purpose of this study evaluate antioxidant activities of Ecklonia cava crackers. Crackers were prepared with different measurements (0, 2, 4, 6, 8 g) of Ecklonia cava; indicated as S1, S2, S3, S4 and S5, and are used to examine and compare antioxidant activities, and quality characteristics. Ecklonia cava powder was used, after being extracted with 70% ethanol in hot water and done in freeze dehydration. To examine antioxidant activities of Ecklonia cava and cracker, DPPH radical scavenging activity, total phenolic and reducing power were tested. Total phenolic content was 36.86 mg GAE/g. DPPH radical scavenging activity and reducing power showed good vitality as amounts of Ecklonia cava powder increased (p<0.001). pH level decreased as amounts of power increased. L (lightness) values and b (yellowness) values decreased with an increased concentration of Ecklonia cava powder (p<0.001), whereas (redness) values didn't show tendency. S5 indicated the lowest spreadness. According to sensory evaluation, S4 (6 g) was preferred the most in terms of color, flavor, taste, appearance, texture, and overall palatability. Results suggest that Ecklonia cava powder has antioxidant effect and is useful as a functional food resource.

액상 및 반고체배지 발효에 의한 Bacillus thuringiensis 살충제의 제조 (Formulations of Bacillus thuringiensis Insecticides by Liquid and Semi-Solid Fermentations.)

  • 이형환
    • 한국미생물·생명공학회지
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    • 제26권4호
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    • pp.369-372
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    • 1998
  • Microbial insecticide formulations were prepared by liquid and semi-solid fermentations using Bacillus thuringiensis subsp. kurstaki, HL-106 (BTK-HL106), B. thuringiensis subsp. israelensis HL-63 (BTI-HL63) and B. sphaericus 1593 (BS-1593) strains. The liquid fermentation medium contained molasses 2%, dextrose 1.5%, peptone 2%, D-xylose 0.025%, CaCl$_2$ 0.1%, K$_2$HPO$_4$ 0.1%, KH$_2$PO$_4$ 0.1%, MgSO$_4$$.$7H$_2$O 0.03%, FeSO$_4$$.$7H$_2$O 0.002%, ZnSO$_4$$.$7H$_2$O 0.02%. The composition of the semi-solid fermentation medium was rice bran 45.2%, zeolite 31%, yeast powder 0.02%, corn powder 5%, dextrose 3%, lime 0.3%, NaCl 0.06%, CaCl$_2$ 0.02%, and H$_2$O 15.42%. Insecticide formulations produced in the liquid fermentation named BTK-HL106, BTI-HL63 and BS-1593 pesticides and those in the semi-solid fermentation were designated as BTK-HL106-1, BTI-HL63-1 and BS-1593-1 pesticides, respectively. The number of spore (endotoxin crystals) was 2.65${\times}$10$\^$9/ spores per $m\ell$ in the BTK-HL106 and 3.5${\times}$10$\^$10/ in the BTK-HL106-1 3.8${\times}$10$\^$9/ spores in the BTI-HL63 and 7.0${\times}$10$\^$10/ in the BTI-HL63-1, and 7.5${\times}$10$\^$9/ in the BS-1593 and 1.4${\times}$10$\^$10/ in the BS-1593-1. The spores in the BS-1593 formulation was produced two times more than the other formulations. The spores in the BTI-HL63-1 were contained twice than those in the BTK-HL106-1, and five times than those in the BS-1593-1. The results indicated that spore (endotoxin crystals) productions in the semi-solid fermentation increased about ten times than those in the liquid fermentations. $LC_{50}$s of the BTI-HL63 and BS-1593 were 4.5 $\mu\textrm{g}$, and those of the BTI-HL63-1 and BS-1593-1 were 1.5 $\mu\textrm{g}$. $LC_{50}$ of the BTK-HL106 was 1.5 mg and that of the BTK-HL106-1 was 0.9 mg. The $LC_{50}$s of the formulations in the semi-solid fermentations showed about two to three times higher than those in the liquid fermentations.

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Isolation of New Strain of Cordyceps militaris HB8 and Optimal Condition for Production of Adenosine and Cordycepin in Fruit Body

  • Li, Jin Feng;Hoang, Van An;Ahn, Jong Chan;Yang, Dong Uk;Lee, Dong Wook;Yang, Deok Chun
    • 한국자원식물학회지
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    • 제33권6호
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    • pp.696-706
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    • 2020
  • Cordyceps has been used in traditional Chinese medicine more than 2000 year ago. In this study, the new Cordyceps militaris was founded and isolated from O-dae mountain in Korea, and was identified its genetic characteristics. The newly isolation strain HB8 was most closet to Cordyceps militaris W141449 (99.82%), Cordyceps militaris JLCY-LI819 (99.82%) and Cordyceps militaris 4642 (99.81%), respectively. the genotypic result was show that train HB8 was belonging to the Cordyceps militaris genus, therefore, Cordycep militaris HB8 proposed with accession number MT835161. This study we find the optimal condition for production of cordycepin from Cordyceps militaris HB8 was 8 mg/g (200 g of pupa, 1 g of KH2PO4, 0.5 g of K2HPO4, 20 g of glucose, 1 g of MgSO4, 0.05 g of vitamin B1, and 1 mg of NAA per liter; light condition 300-700 Lux and day/night was 14 h/10 h) and the optimum condition for the production of adenosine was 2.6 mg/g (15 g of skim milk powder, 1 g of KH2PO4, 0.5 g of K2HPO4, 20 g of glucose, 1 g of MgSO4, 0.05 g of vitamin B1, and 1 mg of NAA per liter; light condition 300-700 Lux and day/night was 14 h/10 h).

버찌 분말을 첨가하여 제조한 국수의 품질특성 (Quality Characteristics of Noodles Containing Various Levels of Flowering Cherry(Prunus serrulata L. var. spontanea Max. wils.) Fruit Powder)

  • 김성희;정복미
    • 한국식품조리과학회지
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    • 제29권1호
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    • pp.19-28
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    • 2013
  • This study was carried out to investigate the quality characteristics and storage of noodle with added flowering cherry fruit powder. Wet noodles were prepared at concentration of 1, 2, and 3% (w/w) of the fruit based on flour weight. Moisture content of the noodles with or without flowering cherry fruit powder was 33.09~33.50%. Ca, K and Mg contents of flowering cherry fruit noodle were increasing at increasing concentrations of flowering cherry fruit powder. Cooked weight, volume, and water absorption decreased with increased fruit powder, whereas turbidity increased. For Hunter's color values of noodles, L (lightness) and b (yellowness) values decreased with increasing concentration of flowering cherry fruit powder, whereas a (redness) value increased. For mechanical characteristics of the noodles, adhesiveness of cooked noodle with flowering cherry fruit powder were higher than those of control. The pH of flowering cherry fruit noodle was lower than that of control during storage. Bacterial counts of wet noodle with flowering cherry fruit powders were lower than those of the control on the 10th day of storage at $5^{\circ}C$. From the sensory evaluation of 20's, texture, taste, and overall preference were not significantly different between the control and the fruit groups, but the color scores of 2% and 3% flowering cherry fruit noodle were significantly higher than that of 1% fruit noodle (p<0.05). In 40's sensory evaluation, color and overall preference scores of flowering cherry fruit noodle were significantly higher than those of control. In conclusion, the results of this study were suggested that the addition of flowering cherry fruit powder in combination with flour was tended to improve antimicrobial effects during storage when compared to control.

유색보리 분말을 첨가한 식빵의 품질특성 (Quality Characteristics of Pan Bread Added with Color Barley Powder)

  • 정현철;유승석
    • 한국조리학회지
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    • 제20권4호
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    • pp.127-143
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    • 2014
  • 본 연구에서는 기능성 물질이 함유된 유색보리와 유색보리 분말을 첨가한 식빵 반죽 및 식빵을 제조하여 이화학적, 관능적 특성을 첨가량을 달리하여 측정하였다. 유색보리 분말의 수분함량은 9.35%, 조단백은 9.37%, 조지방은 1.64%, 조회분은 2.96%로 나타났다. 수용성 식이섬유 함량은 3.21 g/100 g, 불용성 식이섬유 함량은 4.91 g/100 g, 총 식이섬유 함량은 8.12 g/100 g으로 나타났고, ${\beta}$-glucan 함량은 49.31 mg/g으로 나타났다. DPPH radical 소거능은 56.76%로 나타났고, 총 페놀 함량은 234.34 mg/100g으로 나타났다. 유색보리 분말을 첨가한 식빵 반죽의 farinograph 측정 결과 consistency, water absorption, development time, time breakdown은 첨가량이 증가할수록 감소하였고, tolerance index는 첨가량이 증가할수록 증가하였다. Alveogram 측정 결과 overpressure P값, extensibility L값, swelling index G값, deformation energy W값은 첨가량이 증가할수록 감소하였다. Amylograph 측정 결과 pasting temp. T값은 첨가량이 증가할수록 증가하였고, peak viscosity P값, hot past viscosity H값, breakdown P-H값은 첨가량이 증가할수록 감소하였다. 유색보리 분말을 첨가한 식빵의 굽기 손실률, 비용적은 첨가량이 증가할수록 감소하였다. 색도 L값, b값은 첨가량이 증가할수록 감소하였고, a값은 첨가량이 증가할수록 증가하였다. 유색보리 분말 첨가한 식빵의 texture 경도, 점착성은 첨가량이 증가할수록 증가하였고, 응집성, 탄력성, 씹힘성은 첨가량이 증가할수록 감소하였다. 기호도는 맛, 부드러움, 씹힘성은 10% 첨가군이 높게 나타났고, 전반적인 기호도도 10% 첨가군이 5.04로 가장 높게 나타났다.

뇌조직의 리포푸신, 아세틸콜린 및 그 관련효소 활성에 미치는 누에분말의 영향 (Effects of Silkworm(Bombyx mori L..) Powder on Lipofuscin, Acetylcholine and Its Related Enzyme Activities in Brain of Rats)

  • 최진호;김대익;박수현;김정민;조원기;이희삼;류강선
    • 생명과학회지
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    • 제10권6호
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    • pp.564-569
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    • 2000
  • This study was designed to investigate the effect of silkworm (Bombyx mori L.) powder on lipofuscin, acetylcholine (ACh) and its related enzyme activities in brain of rats. Sprague-Dawley (SD) male rats ($160{\pm}10g$) were fed basic diet (control group), and experimental diets (SWP-200 and SWP-400 groups) added 200 and 400 mg/kg BW/day for 6 weeks. In case of liver membranes, lipofuscin (LF) levels resulted in a slight decreases (4.6% and 11.5%, respectively) in SWP-200 and SWP-400 groups compared with control group. But in case of barin as the most sensitive organ, LF levels were remarkably inhibited about 16.7% and 20.0% in SWP-200 and SWP-400 groups compared with control group. There were no significant differences in acetylcholine (ACh) syntheses as a very important neurotransmitter, and choline acetyltransferase (ChAT) activities as a synthesis enzyme of ACh, and acetylcholinesterase (AChE) activities as a hydrolysis enzyme, which were concerned in transmission of neuron through synapses in brain of SWP-200 and SWP-400 groups compared with control group. Monoamine oxidase-B (MAO-B) activities were significantly inhibited (about 10.2%) in brain of SWP-400 groups compared with control group. These results suggest that inhibiting effects of LF accumulation and MAO-B activity of silkworm powder (SWP) may play a pivotal role in attenuating a various age-related changes for improvement of brain function.

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Lactobacillus plantarum 첨가 고추장의 C57BL/6 마우스에서 대장염 예방 증진효과 (Improvement of colitis preventive effects of Gochujang by addition of Lactobacillus plantarum on C57BL/6 mice)

  • 박의성;허주희;임양이;주재현;박건영
    • 한국식품저장유통학회지
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    • 제24권8호
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    • pp.1188-1194
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    • 2017
  • DSS로 대장염을 유도한 C57BL/6 마우스에게 잡곡(보리, 수수, 기장)과 죽염, 종균(AB, ABL)을 접종한 메주로 만든 고추장을 섭취시켰다. MG-AB와 MG-ABL을 섭취한 마우스는 control에 비교해 대장의 길이를 증가시키고, 무게/길이비율은 감소시켜 대장염의 염증반응을 억제시켰다. MG-ABL은 혈청에서 IL-6의 발현을 control과 MG-AB군에 비해 유의적으로 감소시켰고, apoptosis 관련 인자인 Bax와 Bcl-2의 발현을 조절하여 apoptosis를 유도하였다. 따라서 MG-ABL은 발효 시 첨가된 Lab. plantarum로 인해 대장조직의 손상을 억제하고 전염증성 사이토카인과 apoptosis 관련 인자를 조절하여 대장염을 억제하는 것으로 나타났다.