• Journal of the korean veterinary medical association
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• v.32 no.4
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• pp.206-219
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• 1996

동물의 전염성 해면형 뇌증에는 양과 염소의 스크래피, 사슴과 엘크의 만성소모형, 밍크의 전염성 밍크 뇌증, 소 및 소과 야생동물의 소 해면형 뇌증 그리고 고양이의 고양이 해면형 뇌증등이 알려져 있다. 전염성 해면형 뇌증의 원인은 알려져 있지 않으며, 스트레인간의 차이는 숙주의 프리온 유전자에 있어서의 대립유전자의 차이에 의존되는 것으로 추정되고 있다. 이러한 동물의 전염성 해면형 뇌증들은 우리나라에서의 발생보고가 없는 해외 가축전염병이며 현재 영국에서 문제되고 있는 소 해면형 뇌증 즉 일명 광우병은 영국에서 1986년 최초로 확인된 새로운 가축전염병으로서 사람의 크로이츠휄트-야콥병과의 어떤 연관 가능성 때문에 수의학계의 관심의 대상이 되고 있는 질병이다. 영국정부 보건장관 스티픈 도렐은 최근(1996년 3월 20일)에 과거 10년 동안 영국의 소에 감염되어 온 소 해면형 뇌증이 사람의 희귀한 뇌 질환인 크로이츠휄트-야콥병의 새로운 스트레인과 관련성이 있는 증거가 있을 수 있는 것으로 과학자문위원회가 믿고 있다고, 영국하원에서 보고한 바 있다. 한편, 영국의 농업장관 더글러스 호그는 영국에서 30개월 이상된 소를 도살할 때에는 모든 뼈를 제거하여야 하며, 모든 포유동물의 조직은 농업용 사료로 사용해서는 아니된다는 새로운 규정을 공표하였다. 그러나 영국의 쇠고기는 안심하고 먹을 수 있다고 발표하면서 만일 문제가 된다면, 영국에서 사육하는 1천 1백만 마리의 소를 전부 도살할 용의가 있다고 하였다. 이러한 영국정부 견해는 다음 날 CNN News 등 세계 각 매스컴을 통하여 보도되었으며, 아직까지 과학적인 증거가 확립된 바는 없지만, 수의학이나 의학적인 사실 확인의 여부를 떠나, 사회 경제적인 문제로 큰 놀라움과 많은 의문사항을 남겨둔 채, 영국산 소와 쇠고기의 수입금지 조치 등 국제적인 문제로 확대되었다. 본편에서는 동물의 전염성 해면형 뇌증에 대하여 종합적으로 고찰해 보고자 한다.

• Magazine of the Korea Concrete Institute
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• v.11 no.2
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• pp.221-230
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• 1999

Corrosion of rebars can occur if there are cracks, moisture and availability of oxygen or carbonation proceeds, chloride penetrates and diffuses in concrete. Once rebars in concrete corrodes, subsequently accompanied with scaling, spalling in concrete cover. As a result of them, the RC structure is seriously deteriorated. In this study, theoretical review and experiments for cathodic protection(CP) have been performed to control corrosion of rebars in concrete contained chlorides and pre-crack. For CP the impressed current system was applied, the protection effect was investigated when rebars was directly contacted with salt water due to crack and open to much chlorides in concrete. In order to investigate the effect of protection, when CP was energized for 1 year, half-cell potential, potential-decay with current density, corrosion ratio, etc. were measured. With the cathodic protection by impressed current system, the depolarized values of all specimen were met NACE Standard, the effect of 34~84% of the ratio of corrosion area and 84~86% of cross-section reduction were calculated.

• Journal of the Korea Institute of Building Construction
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• v.19 no.6
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• pp.511-520
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• 2019

The critical chloride content of rebar embedded in concrete was experimentally evaluated according to the admixture replacement ratio and admixture type. Four types of reinforced concrete were mixed OPC 100%, OPC 70% + GGBFS 30%, OPC 40% + GGBFS 60%, and OPC 40% + GGBFS 40% + FA 20%. NaCl solution was supplied to the specimens, and the open circuit potential of the embedded rebar was monitored. The specimens determined to initiate corrosion were cut at intervals of 5mm from the NaCl solution supply surface and conducted to chlorine ion profile. Corrosion initiation time of rebar embedded in concrete was delayed as the admixture replacement ratio increased. Looking at the critical chloride content of the types of reinforced concrete, it was highest in OPC 1.46kg/㎥, followed in order by S30 0.98kg/㎥, TBC 0.74kg/㎥, and S60 0.71kg/㎥.

• Resources Recycling
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• v.20 no.1
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• pp.3-13
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• 2011

Taiwan's annual steel production reached 21.29 million tons. EAF accounted for about half of this total, or 11.2 million tons in 2008. The other 10.09 million tons came from blast furnace and converter process methods. The annual EAF carbon steel production is about 9.76 million tons, and the quantity of dust generated from the EAF process is 160 thousand tons, or about 16kg of dust per ton of steel was produced. In 2009, there is Walez process for carbon steel EAF dust recycling, and the capacity is about 70,000 tons per year; and there is RHF/SAF process for stainless steel EAF dust, the capacity is 60,000 tons per year which is enough to treat stainless steel EAF dust in Taiwan. There are many new treatment facilities processes will be that introduced to recycle the EAF dust in the near future, these processes will perform smoothly and successfully in Taiwan. The estimation of recycled crude ZnO is about 90,000 tons each year. The recycling and upgrading crude zinc oxide will be the next important issue in Taiwn zinc and steel industry.

• Journal of the Korea Organic Resources Recycling Association
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• v.15 no.2
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• pp.109-117
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• 2007

In order to investigate the quantitative and qualitative properties of leachate with different composition of MSW in solid waste landfill, three lysimeters filled with bottom ash only (Lysimeter A), bottom ash 70%+municipal solid waste 30% (Lysimeter B), and municipal solid waste only (Lysimeter C) respectively were operated under actual meteorological conditions. From the results, Lysimeter A and Lysimeter B were much higher than Lysimeter C in terms of cumulative generation rates of leachate. The pH in leachate from Lysimeter A are in the range of pH 9 to 11, however, the pH of the leachate was gradually changed to the neutral with time. In the case of $Cl^-$, leachates from Lysimeter A and B with bottom ash have high $Cl^-$ concentration whereas leachate produced from Lysimeter C has low $Cl^-$ concentration. In the Lysimeter C with municipal solid waste only, concentration of organic materials in the leachate was much higher than that of leachate produced from the other Lysimeters.

• Journal of Advanced Marine Engineering and Technology
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• v.38 no.7
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• pp.883-889
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• 2014

It is generated for cavitation erosion due to the local static boiling by pressure differentials in high speed rotating fluid environment. The cavitation is influenced by various elements such as pressure, velocity, temperature, pH of fluid and medium. In particular, the damage of material is accelerated due to the electrochemical corrosion by $C1^-$ and cavitation erosion due to cavities in seawater. In this paper, hence, it investigated for martensite stainless steel the damage behavior with applied current density and cavitation time in natural seawater solution. Less damage depth at the cavitation condition was observed than static condition as a result of galvanostatic experiment. Furthermore, it was shown that dramatic increase of weightloss, damage rate and damage depth after 3 hour of cavitation test.

• Journal of Korean Society of Environmental Engineers
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• v.29 no.2
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• pp.192-196
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• 2007

In this study, a formation of N-nitrosodimethylamine(NDMA), a disinfection by-product, was investigated as a result of monochloramine addition in water. The NDMA formation was studied in terms of pH, dimethylamine(DMA), monochloramine concentration, and nitrogen composition in monochloramine. At a fixed DMA concentration of 0.01 mM or 0.05 mM, the NDMA formed concentration was quite different when the monochloramine to DMA ratio is less or greater than 1. The NDMA formation increased with increasing pH and a ratio of nitrogen composition in monochloramine to total nitrogen composition. At pH 7 and 8, more than five times higher NDMA formation was produced as a result of five times increase in DMA concentration. It was likely that monochloramine could be related to stimulate NDMA formation, if monochloramine may be produced with chlorine disinfection, in water treatment systems.

• Membrane Journal
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• v.11 no.2
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• pp.74-82
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• 2001

By using a phenomenological approach, model equations incorporating the resistance-in¬series concept were established to evaluate quantitatively concentration polarization in the boundary layer in feed adjacent to the membrane surface in the vapor permeation and separation of volatile organic compounds (VOCS)/$N_2$ mixture through po]y(dimethylsiloxane) (PDMS) membrane. The vapor permeations of various VOCS/$N_2$ mixtures through PDMS membrane were carried out at various feed flow rates. Chlorinated hydrocarbons, such as, methylene chloride, chlorofonn, 1,2-clichloroethane and 1,1,2-trichloroethane were used as organic vapor. By fitting the model equations to the experimental penneation data. the model parameters were detennined. respectively. Both the mass transfer coefficient of VOC across tbe boundary layer and concentration polarization modulus as a measure of the extent of concentration polarization were eitimated Quantitatively by the mooe1 equations with the determined model parameters. From the analysis on the detennined model parameters, the boundary layer resistance due to the concentration polarization of VOCs component was found to be more significant when the condensability of voe was greater. This study seeks to emphasize the importance of the boundary resistance on the vapor penneation of the vapor/gas mixtures with high permeability and high selectivity towards the minor component VOC.

• Korean Chemical Engineering Research
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• v.52 no.3
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• pp.360-365
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• 2014

Vapor-phase hydrogen peroxide(VPHP) has been used as a sterilant in the field of medical and pharmaceutical application due to low corrosive than chlorine contained sterilant. In addition, it is well known that VPHP is effective for decontamination of chemical warfare agents by adding ammonia gas. In this study, the decontamination efficiency was confirmed about CEPS, DFP and dimethoate as simulants of HD, GD and VX using VPHP respectively. For this purpose, VPHP generated from self configured device was injected into decontamination chamber and maintained for reaction time. After the decontamination, the residues are analyzed by GC/MS and decontamination efficiency was calculated. Through by-product for each simulants, the similarities in reaction mechanism of chemical warfare agents were confirmed. CEPS was completely decontaminated at 30% relative humidity within 60 min. By adding ammonia gas, DFP and dimethoate were completely decontaminated within 30 and 150 min respectively.

• Journal of the Korea Institute of Building Construction
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• v.16 no.6
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• pp.479-485
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• 2016

This paper presents an experimental study conducted to investigate the effect of recycled fine aggregate (RFA) on the mechanical properties and chloride diffusion behavior of mortar. The test results revealed that the addition of RFA plays an important role in the mechanical properties and pore structures of the investigated mortar specimens as well as chloride diffusion behavior. The mechanical properties such as compressive strength and flexural strength of recycled fine aggregate mortar (RFAM) were gradually decreased as RFA replacement ratio increase. The pore structure of RFAM was examined by permeability tests. The RFAM showed a increment in the permeability according to replacement ratio increase of RFA. But the chloride diffusion coefficient of RFAM was almost same up to 50% replacement ratio of RFA due to a chloride binding phenomenon of RFAM which may compensate the higher permeability of RFAM.