• Safety and Health at Work
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• v.15 no.2
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• pp.123-128
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• 2024

Background: Coal miners are highly prone to occupational health risks, such as black lung disease. This study aims to assess the prevalence of black lung disease and the factors associated with black lung disease among coal miners in Asia. Method: This systematic review, conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines, searched through the scientific literature of the following databases: EBSCO, ScienceDirect, PubMed, and Scopus. We selected articles that studied black lung disease among coal miners from 48 countries in Asia and were published between 2014 and 2023. Article quality was evaluated using the Critical Appraisal Skills Program. Result: The seven articles that we review studied a total of 653,635 coal miners from various types of coal mines from three countries in Asia. Of these miners, 59,998 experienced black lung disease. Black lung disease is prevalent among 9.18% of coal miners in Asia, which is approximately four times higher than the worldwide prevalence. Common factors that influence black lung disease in Asia include age, years of dust exposure, smoking, drinking, working types, and sizes of mines, type of mines, respiratory functions, spirometry parameters, tenure, lack of attention to occupational health, inefficient surveillance, and weak occupational health service. Conclusion: Although the prevalence of black lung disease among coal miners in Asia is considerably high, it can be addressed through effective prevention measures, monitoring, control, and case reporting.

• Korean Journal of Agricultural Science
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• v.45 no.4
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• pp.799-809
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• 2018

This study was performed to compare the physicochemical characteristics between imported dry-cured Hams from black and white pigs available in the domestic market. The black dry-cured hams contain higher moisture and ash contents than that of white hams, whereas the black dry-cured hams had lower fat contents than that of the black ones (p < 0.05). The hams from black ones had lower lightness ($L^*$) and yellowness ($b^*$) values than those from the white ones (p < 0.05). Moreover, the pH values and salt contents of the hams from the black ones were higher than those from the white ones (p < 0.05). Moreover, the black ones had a higher water holding capacity (WHC) than that of the white ones (p < 0.05). The thiobarbituric acid reactive substances (TBARS) values of the black ones were lower than those of the white ham samples (p < 0.05). For texture profile analysis, hardness, gumminess, chewiness, cohesiveness and shear force values were significantly lower in the black ones than in the white samples (p < 0.05). Saturated fatty acids in the white ones were higher than in the black ones, whereas unsaturated fatty acids in the black ones were higher (p < 0.05). Free amino acids such as aspartic acid and glutamic acid in the black ones were higher than in the white ones (p < 0.05). The shrinkage of muscle fiber was stronger in the white ones. Considering the meat quality parameters of ham, the black ones showed a superior meat quality. In general, this research can be used as fundamental information for the mass production of dry-cured hams in Korea.

• Journal of The Korean Astronomical Society
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• v.28 no.1
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• pp.71-75
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• 1995

In the previous work we made a long term evolution code for the central black hole in an active galactic nucleus under the assumption that the Blandford-Znajek process is the source of the emission. Using our code we get the evolution of the angular velocity of the precession for a supermassive black hole. We consider a hole at the center of an axisymmetric, ellipsoidal galactic nucleus. Our numerical results show that, only for the cases such that the stellar density or the mass of the black hole is large enough, the precession of the black hole - presumably the precession of the galactic jet - is interestingly large.

• Publications of The Korean Astronomical Society
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• v.18 no.1
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• pp.11-14
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• 2003

In the earlier papers we analyzed the axisymmetric, nonstationary electrodynamics of the central black hole and a surrounding thin accretion disk in an active galactic nucleus. Based on those papers we analyze the axisymmetric, nonstationary force-free black hole magnetosphere and the motion of the plasma. We concentrate on deriving the totally new equations for the entropy incrrease and the angular momentum, energy extraction of the black hole.

• Proceedings of the Korea Information Processing Society Conference
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• 2000.10a
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• pp.441-444
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• 2000

BPA(Black Printer Algorithm)은 잉크젯 프린터에서 사용되는 C(사이안), M(마젠타), Y(옐로우) 잉크에 대한 검정(Black) 잉크의 양을 결정하는 알고리즘이다. CMY 잉크로 인쇄한 이미지의 칼라 품질은 모니터가 재생할 수는 있는 칼라 영역보다 적다. 또한 CMY 잉크를 각각 100% 씩 섞었을 때 이론적으로는 검정 색이 나와야 하나 실제는 검정 색을 정확하게 재현하지 못한다. 그래서 대부분의 프린터는 검정(K) 잉크를 기본으로 제공하며 CMY 잉크로 표현될 회색 영역의 부분을 검정 잉크로 대신 표현해 주기 때문에 프린터의 재현 영역을 확장시킬 수 있다. 또한 검정 잉크의 사용으로 인쇄품질의 색조 대비(contrast)를 증가시킬 수 있고 CMY 잉크를 검정 잉크로 대신 인쇄하기 때문에 CMY 잉크를 절약하는 효과를 얻을 수 있다. 본 논문에서는 본 잉크젯 프린터의 K(black) 잉크와 CMY(cyan, magenta, yellow) 잉크와의 관계를 살펴보았고 이 특성을 이용해 검정 잉크를 조절하는 방법 중에 하나인 3차 다항식의 BPA(Black Printer Algorithm)를 구현하였다. 결과에서는 성능 테스트에 대한 내용과 성능 향상을 위한 방법에 대해 논의하였다.

• Journal of the Korean Ceramic Society
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• v.43 no.5 s.288
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• pp.315-319
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• 2006

There have been some studies on the use of coal waste as a raw material for clay bricks due to the lack of naturally producing minerals. It can help resolving the problems of pollution, forest conservation and flood control by utilizing coal waste. However, high content of carbon materials usually leads to the black core in clay bricks after firing process, and diminishes the mechanical and aesthetical properties of clay brick. In this study, the effect of firing process is investigated for the removal of black core in clay bricks with carbon content. The removal kinetics of black core are also compared and investigated with the firing schedule and black core removal.

• Plant Resources
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• v.7 no.3
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• pp.195-199
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• 2004

It has been believed that supplementation of human diets with soybean products markedly reduces human cancer mortality rates. Specifically the black colored soybean has been considered as having a medicinal effect since ancient times in Korea. Six genotypes of black colored soybean and a normal variety were investigated for their biological effect. While the isoflavone content of black colored soybean was higher than the normal soybean, saponin content of the seeds was not different among varieties. In the case of antioxidant activity, black colored soybean showed over 3 times increase in the active effect than the control variety. When feeding soybean extract, a general change of alcohol resolving effect, such as alcohol dehydrogenase activity, was observed in the blood and liver of rats.

• Journal of Information Display
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• v.12 no.2
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• pp.97-99
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• 2011

We report flexible, bistable cholesteric displays utilizing polyester (PET) substrates with printed internal black electrodes. The black electrodes consist of carbon ink dispersed in butyl carbitol using a patented roll-to-roll gravure-offset printing. A transparent conducting polymer printed on PET serves as the counter electrode. The electro-optic material is a chiral nematic mixture dispersed in a low-concentration polymer binder. The device can be switched between scattering (black) and reflective (vibrant green) states upon application of an electric pulse. The internal black electrode enhances the contrast of the display and simplifies the roll-to-roll manufacture of flexible displays.

• Preventive Nutrition and Food Science
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• v.14 no.2
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• pp.134-141
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• 2009

The changes in components and biological activities of doenjang samples prepared with black soybeans and fermented with Bacillus subtilis SCB were investigated. The amino nitrogen (A-N) contents of samples increased with increasing black soybean content. A doenjang product made using a 1:1 ratio of soybeans-black soybeans showed a maximum level of genistein and daidzein isoflavones ($1111.6{\mu}g/g$) at 110 days of fermentation, along with decreasing contents of genistin and daidzin due to the conversion to aglycones. The black soybean-only doenjang sample showed higher protease activity, including caseinolytic and fibrinolytic enzyme activities, than the other samples, and had relatively higher polyphenol content and DPPH radical scavenging activity. Therefore, doenjang made with additions of black soybeans and fermented by B. subtilis SCB may have improved physiological properties, suggesting this to be a valuable method of preparation.

• Carbon letters
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• v.2 no.3_4
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• pp.165-169
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• 2001

Modification of C/C composite bipolar plate for improving electrical conductivity was carried out by addition of electroconductive carbon black (EC-CB). Carbon black was carefully mixed to methanol-containing phenolic resin, impregnated into 2D-carbon fabrics, hot pressed and then carbonized to obtain composite plate. Inclusion of electro-conductive carbon black enhanced the electrical conductivity of the C/C composites by increasing the conduction path. Addition of 10 vol% carbon black increased the electrical conductivity from 5.5/${\Omega}cm$ to 32/${\Omega}cm$ and reduced the crack formation by filling effect, resulting in the increase of flexural properties of composite plate. However, at carbon black content over 10 vol%, flexural properties decreased by delaminating role of excess carbon black at the interface in C/C composites.