• KSBB Journal
• /
• v.18 no.3
• /
• pp.211-216
• /
• 2003

The removal yield of dissolved organic matter in drinking water by biological activated carbon (BAC) process was investigated. The tested processes wer raw water-AC process (BAC1), raw water-ozonation-BAC process (BAC2), and raw water-ozonation-coagulation/sedimentation-BAC process (BAC3). The amounts of organic matter was measured as dissolved organic carbon (DOC), ulta-violet radiation at 254 nm wavelength ($UV_{254}$), total nitrogen (T-N), ammonia nitrogen (NH_3$-N), and total phosphate (T-P). As a results, 30.7% DOC was removed by BAC2 process, which showed higher removal efficiency than BAC1 or BAC3 processes. The removal yield of $UV_{254}$ in BAC1, BAC2, and BAC3 processes were observed as 45.3%, 44.6%, 58.4%, respectively. And the removal yield of ammonia nitrogen were 66%, 81%, 29% in each BAC processes. The optimal empty bed contact time (EBCT) of BAC processes was estimated as 10 minute. This study has shown that BAC process combined with ozone treatment was efficient for removing dissolved organic matter in water.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.14 no.3
• /
• pp.127-133
• /
• 2009

In order to determine organic carbon oxidation by manganese and iron oxides, six core sediments were obtained in slope and basin sediments of Ulleung Basin in East Sea. The basin sediments show high organic carbon contents (>2%) at the water depths deeper than 2,000 m; this is rare for deep-sea sediments, except for those of the Black Sea and Chilean upwelling regions. In the Ullleung Basin, the surface sediments were extremely enriched by Manganese oxides with more than 2%. Maximum contents of Fe oxides were found at the depth of $1{\sim}4cm$ in basin sediments. However, the high level of Mn and Fe oxides was not observed in slope sediment. Surface manganese enrichments (>2%) in Ulleung Basin may be explained by two possible mechanisms: high organic carbon contents and optimum sedimentation rates and sufficient supply of dissolved Manganese from slope to the deep basin. Reduction rates of iron and manganese oxides ranged from 0.10 to $0.24\;mmol\;m^{-2}day^{-1}$ and from 0.30 to $0.57\;mmol\;m^{-2}day^{-1}$, respectively. In Ulleung Basin sediments, $13{\sim}26%$ of organic carbon oxidation may be linked to the reduction of iron and manganese oxides. Reduction rates of metal oxides were comparable to those of Chilean upwelling regions, and lower than those of Danish coastal sediments.

• The Korean Journal of Food And Nutrition
• /
• v.15 no.2
• /
• pp.137-143
• /
• 2002

Lyophilizate of immatured wax gourd extract was 3.1 %, matured wax gourd extract was 1.0%, and its main ingredient was sugar, which accounts for 89.7% in total residue. In matured wax gourd, pectin contents was 4.11 mg/ml, and in immatured wax gourd 4.43 mg/m1. In matured wax gourd sarcocarp, sugar contents was 0.1% of sucrose, 0.32% of glucose, 0.35% of fructose, the first unidentified sugar was 0.06% and the second was 0.04%, and all total 0.87%. In sarcocarp of immatured wax gourd, sucrose was 0.33%, glucose was 1.04%, frutcose was 1.12%, and the first unidentified sugar 0.18%, and the second was 0.l2, which total 2.79%. In matured wax gourd core, pH was 4.64, sarcocarp 4.94, immatured wax gourd core 4,96, sarcocarp 5.40. According to the organic acid analysis, in sarcocarp of matured wax gourd, citric acid of 0.409 was contained, magic acid 0.084, succnic acid 0.048%, in matured wax gourd core, citric acid was 0.648, magic acid 0.127, succinc acid 0.058%, in immatured wax gourd, citric acid 0.023, magic acid 0.219, succinic acid 0.298%, in immutured wax gourd, citric acid was 0.039, malic acid 0.350, succinic 0.224%. Fumaric acid was trace in all cases. Total organic acid in matured wax gourd core was 0.833, immatured wax gourd core was 0.624 and immatured wax gourd sarcocarp was 0.546, matured wax gourd sarcocarp was 0,541%. In inhibition rate to propionibacterium acnes, control was 0(ø, cm), wax gourd that was not heated was 2.6, and wax gourd which was heated was 2.5, concentrated by 1/5 was 1.9, wax gourd by 1/10 was 2.5, freezing dry was 2.3. Wax gourd which not heated on producing melanin in B-16 melanoma cell, the melanins forming unit was 15$\mu$1/m1 in addition of 0.01%, while that as a control was 29$\mu$1/m1.

• 한국석유지질학회:학술대회논문집
• /
• autumn
• /
• pp.56-62
• /
• 2001

울릉분지 남서부 해역에서 채취한 두 개의 피스톤 코어 (piston core) 시료를 이용하여 퇴적학 및 지화학적 특성을 연구하였다. 코어는 제4기말의 이질 퇴적물로 대부분 구성되어 있고, 테프라 (tephra layer)와 사질 퇴적물이 일부 협재되어 나타난다. 기존 확인된 울릉분지의 테프라를 이용하여 층서 대비를 한 결과, 두 코어는 대양보다는 높은 퇴적률 (10-12cm/kyr)을 갖는다. 이는 코어가 약 4만 4천년 전의 기록부터 시작하고 있음을 의미한다. 동위원소 층서 2 (마지막 빙기) 중에 형성된 구간에서는 저탁류의 영향을 많이 받은 여러 종류의 퇴적상들이 교호하여 나타난다. 코어의 하부 구간에서는 가스의 방출에 의하여 형성된 것으로 사료되는 수평균열이 다수 관찰된다. 두 코어에서 측정된 유기탄소 (organic carbon) 함량은 평균 $1.8\% $(0.1-4.5\%)$으로 열린 바다 (open sea) 퇴적물의 유기탄소 함량보다 높다. 이는 Termination I 시기 때 해수면 상승으로 인해 산소가 다소 결핍된 환경으로 전이되면서 유기탄소의 양이 증가하였음을 보여주는 것으로 해석된다.

• The Transactions of the Korean Institute of Electrical Engineers B
• /
• v.53 no.5
• /
• pp.338-343
• /
• 2004

In general, the insulation and protective sheaths on electrical conductors are made of combustible substances like PVC, natural or synthetic rubbers, and other organic or synthetic materials. When an electrical fire starts due to overheating of conductors/joints or sparking/arcing, the first thing to ignite is usually the insulation on the cables. When the insulation bums, the produced fumes are very toxic. To solve the problem, we have surely need the fire resistance cable that doesn't bum in a high temperature and emit toxic fume for operating a disaster prevention installation. In this paper, we have simulated the thermal analysis for the fire resistance cable according to the values of current in a overload and a short, and the values of outside flame with the fire resistance cable of the L's company product(600 V, FR-8 : Four Core) using the finite element method(Flux2D).

• Journal of agricultural medicine and community health
• /
• v.35 no.1
• /
• pp.21-35
• /
• 2010

There are many work-related injuries and diseases of fisheries in Korea. Fishermen have exposed to harmful environment, such as natural disasters, ultraviolet, noise, vibration, organic solvents, ergonomic risk factors, loss of fresh water and food, and psychologic stress. They have suffered from numerous work-related health problems, including musculoskeletal disorders, cardiovascular diseases, infectious diseases, pyschological diseases, decompression sickness, and so on. Sea accidents can cause deaths of fishermen and if sea pollution is occurred, fishermen have a great economic damage. However, the concern of these injuries and diseases has been little because they are small in number and have decreased. Fisheries are important core industries, so the problems of fisheries have to be solved by a government. But work-related injuries and diseases are not investigated properly and accurate diagnoses are not made due to loss of concern. We hope that this article will be a cornerstone to solving the work-related problems of fisheries.

• Proceedings of the Polymer Society of Korea Conference
• /
• 2006.10a
• /
• pp.174-174
• /
• 2006

By condensing two different functional monomers, highly fluorescent aromatic polymers were prepared to produce a conjugated- conjugated spacer-type copolymer or conjugated-non-conjugated spacer-type copolymer. As synthesized polymers were soluble in an organic solvent and showed significantly enhanced optical properties compared to its monomer. Variation in the monomer composition afforded polymers having multifunctionaility such as photochromic-fluorescent polymers. Transparent thin films of the polymer as a solid medium were prepared using spin coating method and fabricated as a photoswitch, which showed photo-induced conductivity switching properties depending on the core monomeric unit in the polymers.

• Nuclear Engineering and Technology
• /
• v.44 no.8
• /
• pp.971-976
• /
• 2012

Silica-coated Au with Ag, Co, Cu, and Ir bimetallic radioisotope nanoparticles were synthesized by neutron irradiation, after coating $SiO_2$ onto the bimetallic particles by the sol-gel St$\ddot{o}$ber process. Bimetallic nanoparticles were synthesized by irradiating aqueous bimetallic ions at room temperature. Their shell and core diameters were recorded by TEM to be 100 - 112 nm and 20 - 50 nm, respectively. The bimetallic radioisotope nanoparticles' gamma spectra showed that they each contained two gamma-emitting nuclides. The nanoparticles could be used as radiotracers in petrochemical and refinery processes that involve temperatures that would decompose conventional organic radioactive labels.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2017.05a
• /
• pp.28-29
• /
• 2017

Recently, the tendency of the insulation of buildings to be important is making the buildings airtight. However, in order to get closer to the technology, it is necessary to improve the performance of walls and panels of buildings, but it is a problem due to the increase of the unit price. We will review the basic data on the density and table flow characteristics of high thermal insulation materials.

• Korean Journal of Medicinal Crop Science
• /
• v.13 no.2
• /
• pp.110-114
• /
• 2005

Extracts from sawdust of Pinus densiflora were showed antifungal activity against Lentinula edodes. It was extracted by hot water and then successively extracted by n-hexane, ethyl acetate, and methanol. The yields of the n-hexane-soluble, ethyl acetatesoluble, methanol-soluble and methanol-insoluble fractions of water extracts were 8.2%, 10.6%, 32.0%, and 49.2%, respectively. The ethyl acetate-soluble fraction showed the greatest antifungal activity against L. edodes: 41.5% inhibition at 1,000 ppm. However, there were not significant differences of antifungal activities between n-hexane-soluble fraction and methanol-soluble fraction at a concentration of 1,000 ppm. The hot water extracts showed 23.5% of antifungal activity against L. edodes at a concentration of 1000 ppm. The four antifungal compounds were separated from ethyl acetate fraction by thin layer chromatography.