• 한국식품조리과학회지
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• 제31권2호
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• pp.118-127
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• 2015

본 연구는 당뇨병의 예방과 관리를 위한 청국장의 가치를 평가하고자 대두, 약콩, 및 흑미, 흑임자, 다시마와 같은 블랙푸드를 첨가한 약콩청국장 분말의 섭취가 STZ 유도 당뇨 쥐의 혈당 및 염증 관련 인자에 미치는 영향을 분석하였다. 그 결과 당뇨로 증가된 혈당은 약콩청국장 분말 45.5% 및 블랙푸드를 첨가하여 만든 약콩청국장 분말 50.0%을 섭취시킨 DY와 DYB군에서 저하되는 것으로 나타났다. 또한 정상군에 비해서 당뇨군에서 인슐린 농도와 분비능은 낮은 반면에, 인슐린 저항성은 높았다. 그러나 약콩청국장 분말 45.5%과 블랙푸드를 첨가한 약콩청국장 분말 50.0%의 공급으로 인슐린 농도와 분비능을 다소 개선시킬 수 있는 것으로 나타났다. 또한 유리지방산 농도는 C군에 비해서 DC군에서 높았으며, 당뇨 유도로 높아진 유리지방산은 대두청국장 분말 55.0%의 공급으로 조절되는 것으로 나타났다. 염증 지표로 leptin의 농도는 C군에 비해서 인슐린 분비량이 낮은 당뇨를 유도한 모든 군에서 leptin의 농도가 낮았으며 청국장 분말의 공급 유무나 형태가 당뇨 유도군의 leptin 분비에는 아무런 영향을 미치지 못하였다. 또 다른 지표로 adiponectin의 농도는 C군에 비해 당뇨 유도군들에서 낮았으며, 청국장 분말의 공급 유무 및 형태에 따른 효과는 없는 것으로 나타났다. 그리고 혈당 농도와 관련된 인자와의 상관관계를 분석한 결과 HOME-IR과 adiponectin 농도와는 양의 상관관계를, 그리고 인슐린 농도는 HOME-${\beta}$ 및 leptin 농도와 음의 상관관계를 보였다. 또한 인슐린 농도는 leptin 농도와 양의 상관관계를, 그리고 adiponectin 농도와는 음의 상관관계인 것으로 나타났으며 leptin과 adiponectin 농도는 음의 상관관계를 보였다. 이상의 결과에서 당뇨 유도로 혈당과 인슐린 저항성은 높고 인슐린 분비능, leptin 및 adiponectin 농도는 낮았다, 그러나 혈당과 인슐린저항성 및 분비능은 44.5%의 약콩이나 50.0%의 블랙푸드를 첨가한 약콩청국장 분말 식이의 공급으로 다소 조절되는 것으로 나타났다. 따라서 약콩 및 블랙푸드를 첨가한 약콩청국장이 향후 당뇨 환자의 관리와 합병증 예방을 위한 건강 기능성 식품으로서 가치가 있을 것으로 사료된다.

• Journal of the Korean Wood Science and Technology
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• 제28권3호
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• pp.52-61
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• 2000

아까시나무와 현사시나무를 채취, 건조하고 아세톤-물의 혼합용액으로 추출한 후 hexane, chloroform, ethylacetate 및 물 분획으로 분류하고 동결건조하여 갈색 분말로 조제하였다. 각각의 분획은 메탄올-물 및 에탄올-헥산의 혼합용액으로 Sephadex LH-20 칼럼상에서 크로마토그래피를 수행하였다. 아까시나무의 목질부 추출성분은 (+)-leucorobinetinidin과 같은 flavan 화합물과 robtin, dihydrorobinetin 및 robinetin 등의 flavanonol 화합물을 포함하며 현사시나무의 수피 추출성분은 (+)-catechin과 naringenin, eriodictyol, sakuranetin, aromadendrin 및 taxifolin 등의 후라보노이드 화합물, 그리고 살리신 유도체인 salireposide 및 소량의 aesculin과 쿠마린산 등 다양한 종류의 페놀성 화합물로 구성되어 있었으며 aesculin은 현사시나무의 수피 조성분에서는 아직 우리 나라에서 보고되지 않았다. 단리된 페놀성 성분의 구조 분석을 위하여 NMR 및 FAB-MS 분석을 수행하였다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.1322-1325
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• 2005

The main objectives of this research work are to develop conductive glass fiber woven roving and carbon fiber unidirectional fabric composite materials and to determine their electromagnetic shielding effectiveness(EMSE). Epoxy is the matrix phase and glass, carbon fiber are the reinforcement phase of the composite material. Carbon black are incorporated as conductive fillers to provide the electromagnetic shielding properties of the composite material. The amount of carbon black in the composite material is varied by changing the carbon black composition, woven roving and unidirectional (fabric) structure. The EMSE of various fabric composites is measured in the frequency range from 300MHz to 800MHz. The variations of EMSE of woven roving and unidirectional composites with fabric structure, metal powder composite are described. Suitability of conductive fabric composites for electromagnetic shielding applications is also discussed.

• 한국가구학회지
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• 제22권1호
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• pp.13-17
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• 2011

Recently, interest in indoor air quality is increasing. Especially, radon radioactivity among the indoor air is a well-known risk factor for lung cancer because of ionizing radiation in the form of ${\alpha}$-particles. This study was carried out to investigate effect of black charcoal and activated carbon for reduction of radon radiation that emitted from building materials. Black charcoal and activated carbon were used as a barrier which was against the infiltration of radon. The source of radon was gypsum board. Two types of charcoal barrier were powder- and board-type with 5 mm, 10 mm thickness respectively. The method for this determination is evaluated radon concentration in chamber. The measurements were performed with radon detector, SARAD3120. Results of this study are as following: Black charcoal and activated carbon confirmed the highly efficient barrier. Radon concentration was reduced from 72% to 85% as compared the control chamber. Radon reduction capability, however, was no difference as barrier's types. Results obtained in ventilation condition, radon concentration shows 5.93 pCi/L on average in the closed condition and shows 2.69 pCi/L in the opened condition.

• 한국재료학회지
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• 제21권4호
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• pp.196-201
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• 2011

It is known that the relative dielectric constant of insulating polyethylene matrix composites with conducting materials (such as carbon black and metal powder) increases as the conducting material content increases below the percolation threshold. Below the percolation threshold, dielectric properties show an ohmic behavior and their value is almost the same as that of the matrix. The change is very small, but its origin is not clear. In this paper, the dielectric properties of carbon black-filled polyethylene matrix composites are studied based on the effect medium approximation theory. Although there is a significant amount of literature on the calculation based on the theory of changing the parameters, an overall discussion taking into account the theory is required in order to explain the dielectric properties of the composites. Changes of dielectric properties and the temperature dependence of dielectric properties of the composites made of carbon particle and polyethylene below the percolation threshold for the volume fraction of carbon black have been discussed based on the theory. Above the percolation threshold, the composites are satisfied with the universal law of conductivity, whereas below the percolation threshold, they give the critical exponent of s = 1 for dielectric constant. The rate at which the percentages of both the dielectric constant and the dielectric loss factor for temperature increases with more volume fraction below the percolation threshold.

• Composites Research
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• 제17권5호
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• pp.68-77
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• 2004

레이더 혹은 전자-통신장비에서 방출되는 전자파의 흡수/차폐는 군사적인 목적뿐만 아니라 상업적 목적으로도 매우 중요하다. 효과적인 전자기파 흡수체를 설계하기 위해서는 흡수체에 사용되는 재료의 대상 주파수 대역에서의 전자기적 성질을 정확히 알아야 하며, 손실재의 함량에 따른 정확한 전자기물성 예측이 가능해야 한다 본 연구에서는 전도성 카본 블랙 나노 입자를 함유하는 폴리에스터 복합재료의 유전성질을 자유공간 기법을 이용하여 X-Band 주파수 대역에 걸쳐 측정하고 카본 블랙의 함량에 따라 정량적으로 분석하였으며, 임의의 카본 블랙 함량을 갖는 고분자 수지의 유전 물성을 주파수에 따라 예측할 수 있는 방법을 제시하고 검증하였다.

• 대한안전경영과학회지
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• 제25권4호
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• pp.153-161
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• 2023

Carbon black is a material in the form of fine black powder obtained by incomplete combustion or pyrolysis of hydrocarbons, and is composed of 90-99% carbon, and the rest is composed of hydrogen and oxygen. In the event of an emergency during the manufacture of carbon black, the generated tail gas should be safely discharged through an emergency line to prevent fire, explosion, and environmental pollution accidents caused by the tail gas. If the pressure continues to rise, the pressure control valve shall operate and the rupture plate shall be ruptured sequentially and the tail gas shall be discharged to the vent stack through the emergency line. As an emergency emission system, even if some untreated substances in the tail gas are released into the atmosphere, they are lighter than air, so it is safe to discharge them to a safe place through the Vent Stack. If the gas pressure is rising or worse, it is discharged from the Vent Stackine, and discharging fuel.

• 한국세라믹학회지
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• 제45권4호
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• pp.214-219
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• 2008

The zirconia ceramics are widely used because of their excellent mechanical properties. Recently, many researches to make a colored zirconia was achieved to satisfy the individual aesthetic requirements. In this study, the synthesis of black-color spinel-based inorganic pigments which are stable above $1400^{\circ}C$ and the fabrication of black-colored zirconia using the synthesized pigments are investigated. Inorganic pigments which have spinel structure and near black color were synthesized by a solid state reaction method using a $Fe_2O_3,\;Cr_2O_3$, CoO and NiO powder as a starting materials at $1600^{\circ}C$. Most of synthesized pigments were black colored spinel phases and single spinel phase was successfully synthesized at the composition range of $Cr_2O_3:25{\sim}35%,\;Fe_2O_3:45{\sim}55%$, CoO:20% and NiO:$6{\sim}10%$. The black-colored zirconia was fabricated at $1410^{\circ}C$ with the 5 wt% synthesized pigments and their properties were evaluated. The results showed that the strength value was more than 848 MPa, absorption rate was 0.1%, the brightness of color was $L^*:40{\sim}42$, the tone of color is $a^*:0.2{\sim}0.8$ and $b^*:-1.1{\sim}2.4$. As a result, the black-colored zirconia was suitable for a artificial jewelry or decoration zirconia goods.

• 한국세라믹학회지
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• 제27권2호
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• pp.265-273
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• 1990

Fine Si-Al-OH-C coprecipitate powders were prepared from Si(OC2H5)4, Al(i-OC3H7)3, and carbon black by a hydrolysis method before fabrication of Sialon-SiC composite powder by carbothermal reduction at 1350$^{\circ}C$ for 10h under N2/H2 mixed atmosphere. The characterization of the synthesized Sialon-SiC composite powders was performed using XRD, BET, SEM, TEM and particle size analysis methods. The average particle size and specific surface area of the synthesized Sialon-SiC composite powder were 0.13$\mu\textrm{m}$ and 20.1㎡/g, respectively when Z=1 and N2 : H2=50 : 50.

• 한국분말재료학회지
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• 제28권4호
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• pp.342-351
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• 2021

Because of its unique properties, tungsten is a strategic and rare metal used in various industrial applications. However, the world's annual production of tungsten is only 84000 t. Ammonium paratungstate (APT), which is used as the main intermediate in industrial tungsten production, is usually obtained from tungsten concentrates of wolframite and scheelite by hydrometallurgical treatment. Intermediates such as tungsten trioxide, tungsten blue oxide, tungstic acid, and ammonium metatungstate can be derived from APT by thermal decomposition or chemical attack. Tungsten metal powder is produced through the hydrogen reduction of high-purity tungsten oxides, and tungsten carbide powder is produced by the reaction of tungsten powder and carbon black powder at 1300-1700℃ in a hydrogen atmosphere. Tungsten scrap can be divided into hard and soft scrap based on shape (bulk or powder). It can also be divided into new scrap generated during the production of tungsten-bearing goods and old scrap collected at the end of life. Recycling technologies for tungsten can be divided into four main groups: direct, chemical, and semi-direct recycling, and melting metallurgy. In this review, the current status of tungsten smelting and recycling technologies is discussed.