• 미생물학회지
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• 제9권4호
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• pp.175-178
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• 1971

Because of the cases of Japanese Encephalitis(J.E.) were reported every year in Korea. We, Dong-A Pharmaceutical Co., Ltd., produced J.E. virus vaccine, with lower price, since 1970 in order to prevent ourselves from being infected by the disease. And inoculated the J.E. virus vaccine for the children with a great success. We are going to report several questions which brought about in producing the J.E. virus vaccine by alcohol precipitation, protamine sulfate treatment method. The results obtained were as folows ; 1) In process treated with 40% alcohol, we used to ethanol made in Germany, but it was too expensive to use it. As the result which we had studied about it, we were satisfied with J.E. virus vaccine which produced with alcohol made in Korea, and then, we treated with accurate specific gravity of 40% ethanol for the precipitation of the virus. And also, we knew that it was the best method to be treated it for 3hrs, $13^{\circ}C$. 2) When we treated with protamine sulfate (0.025mg/ml), we acquired the highest potent titer, and suited into purpose for the nitrogen concentration. 3) The filtration of the purified J.E. virus vaccine, in case of millipore filter paper of large pore size was not suitable for the sterility. Therefore the pore size less than 0.8.$\mu$ (AA filter paper) in millipore filter paper was very suitable. But it seemed to be important subhects that the smaller was the pore size, the lower was the potent titer.

• 한국지반신소재학회논문집
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• 제6권1호
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• pp.33-38
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• 2007

연직배수재는 필터와 코어로 형성되며, 필터의 주요기능으로 첫째, 흙 입자의 유실을 방지할 수 있는 흙 보유성과 둘째, Clogging 또는 Blinding현상 발생 없이 간극수를 원활히 배출시키는 투수성을 갖추어야 한다. 상대적으로 투수성이 낮은 지반에서 미세입자로 인하여 필터의 투수성을 저하시키는 필터폐색(Clogging) 현상이 발생하는데 필터의 폐색현상(Clogging)이 점진적으로 증가하면, 간극수의 흐름을 저하시켜 결국 압밀지연을 초래한다. 지반-필터의 거동에 따른 설계(시방)기준은 토목섬유 필터의 간극크기와 흙의 입도의 상관관계에 의해 결정되어야 하나, 국내에서는 필터폐색(Clogging)현상과 지반-필터의 거동 분석 없이 필터재의 유효입경(AOS, Apparent Opening Size)만을 고려하여 필터의 설계(시방)기준을 일률적으로 적용하고 있다. 따라서, 본 연구에서는 3가지 종류의 연직배수재 필터를 대상으로 필터의 거동 및 필터폐색(Clogging)현상을 평가하고자 실내시험을 수행하였고, 이를 토대로 ${\bigcirc}{\bigcirc}$지역에서 연직배수재 필터의 설계(시방)기준을 선정하여 적용하였다.

• KSBB Journal
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• 제6권2호
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• pp.135-141
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• 1991

This study thus looks into two treatment processess : i) Anaerobic digester coupled with hollow fibre membrane unit. Treatment of starch waste with anaerobic digester-membrane system was studied. $0.17\m^2$ area of hollow fibre membrane unit of known pore size was immersed into laboratory-scale anaerobic digestion system. The pore size of membrane was varied from 0.03 to $\0.15mu$m. The hydraulic retention time of anaerobic digester was varied from 1.5 to 10 days. The effect of hydraulic retention time on treatment efficiency was significant while effect of membrane size was not significant. The gas production was about 0.74㎥/kg COD treated. The COD removal efficient was about 80-95% depending on the hydraulic retention time. ii ) Crossflow ultrafiltration as post treatment to anaerobic filter. The effluent from anaerobic filter, which had a total COD in the range of 4,500-5,200 mg/L was treated by crossflow ultrafiltration units. The study conducted with different membrane pore size indicated that membrace with 1,000,000 molecular weight cut-off size gave a higher COD removal efficiency in the range of 83-87% while giving a study flux of $120-130 L/\m^2$.h. A study was conducted to see the long term clogging effect of membrane also.

• 한국세라믹학회지
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• 제46권5호
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• pp.534-539
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• 2009

Reaction Bonded Silicon Carbide(RBSC) has been used for engineering ceramics due to low-temperature fabrication and near-net shape products with excellent structural properties such as thermal shock resistance, corrosion resistance and mechanical strength. Recently, attempts have been made to develop hot gas filter with gradient pore structure by RBSC to overcome weakness of commercial clay-bonded SiC filter such as low fracture toughness and low reliability. In this study a fabrication process of porous RBSC with multi-layer pore structure with gradient pore size was developed. The support layer of the RBSC with multi-layer pore structure was fabricated by conventional Si infiltration process. The intermediate and filter layers consisted of phenolic resin and fine SiC powder were prepared by dip-coating of the support RBSC in slurry of SiC and phenol resin. The temperature of $1550^{\circ}C$ to make Si left in RBSC support layer infiltrate into dip-coated layer to produce SiC by reacting with pyro-carbon from phenol resin.

• 한국분말재료학회지
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• 제22권2호
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• pp.100-104
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• 2015

The porous metals are known as relatively excellent characteristic such as large surface area, light, lower heat capacity, high toughness and permeability. The Fe-Cr-Al alloys have high corrosion resistance, heat resistance and chemical stability for high temperature applications. And then many researches are developed the Fe-Cr-Al porous metals for exhaust gas filter, hydrogen reformer catalyst support and chemical filter. In this study, the Fe-Cr-Al porous metals are developed with Fe-22Cr-6Al(wt) powder using powder compaction method. The mean size of Fe-22Cr-6Al(wt) powders is about $42.69{\mu}m$. In order to control pore size and porosity, Fe-Cr-Al powders are sintered at $1200{\sim}1450^{\circ}C$ and different sintering maintenance as 1~4 hours. The powders are pressed on disk shapes of 3 mm thickness using uniaxial press machine and sintered in high vacuum condition. The pore properties are evaluated using capillary flow porometer. As sintering temperature increased, relative density is increased from 73% to 96% and porosity, pore size are decreased from 27 to 3.3%, from 3.1 to $1.8{\mu}m$ respectively. When the sintering time is increased, the relative density is also increased from 76.5% to 84.7% and porosity, pore size are decreased from 23.5% to 15.3%, from 2.7 to $2.08{\mu}m$ respectively.

• 한국지하수토양환경학회지:지하수토양환경
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• 제20권4호
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• pp.31-40
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• 2015

Various types of inorganic and organic colloids are present in natural water including groundwater. Previous studies showed that Fe, Mn and Al are colloid-forming elements and dissolved concentrations can be erroneous for these elements if water samples are not properly filtered. Dissolved concentrations of elements including Ca, Na, Mg, K, Fe, Mn, Si and Al in groundwater from alluvial and bedrock aquifers, and surface water near Nakdong River were determined to evaluate effects of colloids on dissolved concentrations in natural water samples using various pore sizes of filters. Groundwater is mostly anoxic and have elevated concentrations of Fe and Mn, which provides a unique opportunity to observe the effects of colloids on dissolved concentrations of colloid-forming elements. Membrane filters with four kinds of pore sizes of 1000 nm, 450 nm, 100 nm, and 15 nm were used for filtration of water samples. Concentrations of dissolved concentrations in each filtrate did not show significant differences from 1000 nm to 100 nm. However, concentrations of all elements considered were decreased in the filtrates obtained using 15 nm pore size filters by 10 to 15% compared to those using 450 nm except for bedrock groundwater. Al in surface water showed a distinct linear decrease with the decrease of filter pore sizes. These results showed that 100 nm pore size had little effect to remove colloidal particles in alluvial groundwater and surface water in our study. In contrast, significant concentration decreases in 15 nm pore size filtrates indicate that the presence of 15 to 100 nm colloidal particles may affect determination of dissolved concentrations of elements in natural water.

• 한국세라믹학회지
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• 제32권9호
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• pp.989-994
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• 1995

Rigid porous carbon fiber composites with the uniform pore size distribution were prepared by vacuum forming from water slurries containing carbonized PAN fibers, a phenolic resin and ceramic binders. The composites were designed to use for highly efficient carbon fiber filters for particulate filtration and gas adsorption. As the as-received carbon fibers of 1mm in length were milled to an approximate average length of 300${\mu}{\textrm}{m}$, modulus of rupture (MOR) of the composite filter was increased from 1MPa to the value larger than 5 MPa. Modulus of rupture (MOR) for the composite filter fabricated using the milled carbon fiber was increased from 5 MPa to 10 MPa as the carbonization temperature of the PAN fiber was raised from 90$0^{\circ}C$ to 140$0^{\circ}C$. The air permeability and an average pore size of the composite filter were increased from 40 to 270cc/min.$\textrm{cm}^2$ and from 35 to 80${\mu}{\textrm}{m}$, respectively, as the apparent porosity increased from 80 to 95%. It was shown that the MOR of the carbon fiber composite filter was dependent primarily on the average length of carbon fiber, carbonization temperature and the type of bonding materials.

• 한국분말재료학회지
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• 제11권4호
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• pp.288-293
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• 2004

The application concept of using a fail safety filter on the filtering system is to prevent the particle leakage when the main filter element is broken at high temperature. In this study, the metal filters were fabricated by pressureless sintering method. The mixture of stainless steel powders and filler metal binder solved in the water solutions of 5% PVA was compacted to form the cylindrical filter without pressure. The compacted filter were sintered in the vacuum sintering furnace at 120$0^{\circ}C$ for 1 hour. The metal filter(produced with powder of 640-840 ${\mu}m$ size) having more than above 50% porosity, 500${\mu}m$ pore size, and permeability of 7.3${\times}$10$^{-11}$m$^{2}$ plugged within 2.5 minute to prevent the leakage of maximum slip particle size of less than 3${\mu}m$.

• 한국환경보건학회지
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• 제30권5호
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• pp.402-409
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• 2004

I performed the research about the drinking water treatment by precoat filtration and activated carbon adsorption process in the D water treatment plant at Gwangju. D water treatment plant inlet water is supplied from Juam lake in Jeollanamdo. The results are as follows; 1. Element disk used in this experiment are R(pore size $10{\mu}m$), B(pore size $20{\mu}m$). And diatomaceous earth are A(cake pore size $3.5{\mu}m$), B(cake pore size $7{\mu}m$) and C(cake pore size $17{\mu}m$) 2. Filtrate of precoat filter during 30 min are B-C 10.2 > BB 5.7 > R-A 5.4 ($m^3/m^2$). 3. The water quality through B-C+AC and R-A+AC are DOC 1.76 mg/1, 1.288 m/l respectively. 4. total THMs produced by chlorination are $84.2{\mu}g/l$(B-C+AC), $66.11{\mu}g/l$ (R-A+AC), $97{\mu}g/l$ (rapid sand filtration water) respectively. 5. The R-A+AC and B-C+AC process can be substitute of CWTS.

• 생명과학회지
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• 제22권6호
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• pp.723-729
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• 2012

난배양성 미생물의 배양과 보다 다양한 미생물의 분리를 위하여 Filter plate microbial trap (FPMT)을 개발하였고, 이 장치를 사용하여 Greenland의 토양에서 세균을 분리하였다. FPMT는 배지와 하단부의 membrane filter(0.45 ${\mu}m$ pore size)로 구성되어 있다. 시료에 포함된 세균과 화학물질이 FPMT 내로 이동하고, 세균이 증식하는 원리이다. 그 결과, FPMT를 이용한 새로운 in situ 배양방법을 통해 통상적인 Petri dish 배양방법보다 더 많은 종과 기존의 방법으로는 배양할 수 없는 세균을 분리하였다. 이 장치는 앞으로 다양한 환경에서 난배양성 미생물을 분리하는데 유용함을 확인하였다.