• 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.

• 대한수학회보
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• 제34권2호
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• pp.185-191
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• 1997

The notions of implicative semigroup and ordered filter were introduced by M. W. Chan and K. pp. Shum [3]. The first is a generalization of implicative semilattice (see W. C. Nemitz [6] and T. S. Blyth [2]) and has a close relation with the implication in mathematical logic and set theoretic difference (see G. Birkhoff [1] and H. B. Curry [4]). For the general development of implicative semilattice theory the ordered filters play an important role, which is shown by W. C. Nemitz [6].

• 한국양식학회지
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• 제10권3호
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• pp.261-271
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• 1997

해수 순환여과식 양식 시스템의 여과 재료별 암모니아 제거 능력을 정량적으로 평가하기 위하여 5종류의 침지식 여과 재료인 모래(직경 2-3 mm), 산호사 (직경 30-50 mm), 자갈 (직경 20-40 mm), 폴리에틸렌 망 (네트론) 및 플라스틱 파판(스카이라이트)의 암모니아 제거량과 산소 소비량을 측정하고 그리고 회전원판식 여과 재료의 암모니아 제거량을 측정하여 비교하였다. 실험 기간중 사육조의 암모니아 농도는 0.052-0.904(평균 0.338$\pm$0.219) mg/l였고, 수온은 19.2-21.4 (평균 20.2$\pm0.58) ^{\circ}C$의 범위였으며 사육수의 암모니아 농도 (x : mg/l)에 대한 여과 재료별 단위 용적당 일간 암모니아 제거량 (y : g/m supper(3)/day)의 1/2-order kinetic 식과 1일 평균 암모니아 제거량(g/m supper(3)/day)은 다음과 같다. 모래 : Y=135.5X 상(0.5)-25.1 (r 상(2)=0.8110), 45.1 자갈 Y=43.7X 상(0.5)-5.5 (r 상(2)=0.2596), 17.1 산호사 : Y=125.1X 상(0.5)-33.0 (r 상(2)=0.7307), 31.8 폴리에틸렌 망 : Y=87.4X 상(0.5)-20.1 (r 상(2)=0.6780), 25.2 플라스틱 파판 : Y=71.1X 상(0.5)-17.6 (r 상(2)=0.5206), 19.2 회전원판 : Y=127.6X 상(0.5)-33.4 (r 상(2)=0.7146), 32.8 사육조의 용존산소 농도 범위 3.8-7.5 (평균 5.7$\pm0.98)\;mg/\ell$ 에서의 여과 재료 단위 용적($m^3$/day))당 1일 산소 소비량은 모래, 산호사, 폴리에틸렌망을 이용한 여과조에서 각각 442.1, 291.1, 및 236.9 g/$m^3$/day 로 모래 여과조의 산소 소비량이 가장 많았으며, 자갈과 플라스틱 파판은 각각 135.6 및 134.2 g/$m^3$/day로 가장 적었다. 한편 회전원판 여과조는 물에 노출되는 구조적 특성 때문에 산소 소비량 측정은 불가능하였다.

• 한국환경과학회지
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• 제13권9호
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• pp.799-806
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• 2004

The filtration tests were made in cell with a low concentrated suspension. The suspension with a concentration of $C_{M}$=1.14～2.67$\cdot$$10^{-3}$ g/g consists of paper paint and water. The particles in the suspension have a particle size x<1${\mu}m$. The used depth filters consists of glass fibres, which are coated by polymer. The filtration in depth filters accorded in different mechanism, which were explained by physical models. The model which would be allows to make a promise of the filtration reaction. This filter media allows to get a high filtration time and a good separation rate. The Particle distribution is measured by a photon correlation spectroscopy(PCS). PCS measures particle sizes 0.03 ${\mu}m$${\mu}m$ in the suspension. The filtered suspension has a very low concentration Co{\le}5{\times}10_{-4}$ g/g of solid in sample. The PCS also informs us about the number of the particles in the suspension. The makes it possible to calculate the concentration of the in sample.

• 한국통신학회논문지
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• 제33권3C호
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• pp.271-280
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• 2008

M채널 NPR(Near-Perfect Reconstruction) pseudo-QMF(Quadrature Mirror Filter) 뱅크의 설계는 일반적으로 SF(Spectral Factorization) 접근 방식을 혼합하여 많이 사용하며, 분리와 합성 필터들은 프로토타입 저역통과 필터(prototype lowpass filter : p-LPF)를 코사인 변조하여 사용한다. 그러나 이 방식은 $2M^{-th}$ 대역 필터 $G(z)=z^{-(N-1)}H(z^{-1})H(z)$의 SF 방식에 의해 p-LPF H(z)을 설계하기 때문에 p-LPF가 선형위상을 갖지 못할 뿐만 아니라 진폭왜곡이 최적화되지도 않았다. 따라서 대부분의 방법들이 재생 진폭왜곡 보다는 중첩상쇄왜곡을 줄이기 위한 p-LPF 설계를 제안하였다. 본 논문에서는 NPR pseudo-QMF 뱅크 구현에 필요한 p-LPF 설계를 위해 폐쇄형전달함수를 갖는 선형위상의 Maxflat(maximally flat) FIR 필터를 이용하는 새로운 방식을 제안하였다. 또한 폐쇄형주파수함수를 이용하여 $2M^{-th}$ 대역 필터 $G(z)=H^2(z)$로 표현되는 2M개 채널들의 전체진폭응답이 단일응답을 갖도록 p-LPF H(z)을 최적화하는 방법이 제안되었다. 실험 결과 시스템 최대진폭 왜곡이 $3.5{\times}10^{-4}\;({\simeq}-70dB)$보다 적고 각 분리 및 합성 필터들의 저지대역 감쇠가 -100dB 이상의 매우 뛰어난 NPR pseudo-QMF 뱅크 설계가 가능함이 증명되었다.

• Fisheries and Aquatic Sciences
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• 제1권2호
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• pp.242-249
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• 1998

The engineering aspect of water treatment processes in the recirculating aquaculture system was studied. To recycle the water in the aquaculture system, a wastewater treatment process was required to maintain high water quality for the growth and health of the cultured fish. In this study, three different biofilm processes were used to reduce the concentration of organic matters and ammonia from the recirculating water - two phase fluidized bed, three phase fluidized bed, and trickling filter. The objectives of this research were to evaluate the optimum treatment conditions of the biofilm processes for the recirculating aquaculture system, and thereby reduce the volume of biofilm processes, which are commonly used for the recycle water treatment processes for aquaculture. The result of this study showed that the removal efficiency of organic matters by trickling filter was found to be lower than that of the fluidized bed. In the trickling filter system, anthracite showed better organic removal efficiency than crushed stone as a media. In the two phase fluidized bed, the maximum removal efficiency of either organics or ammonia was obtained when both the packing rate of media was maintained to $40\%$ of total reactor depth excepting sediment zone and the bed expansion rate was maintained to $100\%$. When 100 tilapia (Oreochromis niloticus) of each average 200g was reared, the pollutant production rate was 0.07g $NH_4\;^+-N/kg$ fish/day and 0.06g P04-3-P/kg fish/day, and sludge production rate was 0.39 g SS/kg fish/day. In the two phase and three phase fluidized bed, the volume of water treatment tank could be calculated from an empirical equation by using the relationship between the influent COD to $NH_4\;^+-N$ ratio (C/N, -), media concentration (Cm, g/L), influent ammonia nitrogen concentration (Ni, mg/L), effluent ammonia nitrogen concentration (Ne, mg/L), bed expansion rate $(E,\;\%)$, and influent flowrate $(Q,\;m^3/hr)$. The empirical equation from this study is $$V_2\;=\;10^{3.1279}\;C/N^{3.5461}\;C_m\;^{-3.7473}\;N_i\;^{4.6477}\;E^{0.0326}\;N_e\;^{-0..8849}\;Q\;(Two\;Phase\;FB) V_3\;=\;10^{11.7507}\;C/N^{-1.2330}\;C_m\;^{-6.5715}\;N_i\;^{1.5091}\;N_e\;^{-1.8489}\;Q (Three\;Phase\;FB)$$

• 분석과학
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• 제23권1호
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• pp.54-59
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• 2010

액체크로마토그래피/질량분석법(LC/MS)을 이용하여 화장품에 들어있는 파라벤류등을 동시 분석하였다. 화장품 시료를 메탄올에 직접 용해시키고 $0.45\;{\mu}m$ 필터로 여과하여 메탄올/물을 이동상으로 하여 Extend $C_{18}$의 비극성 컬럼을 사용하여 기울기 용리 조건에서 12분 안에 분리하여 SIM(selected ion monitoring)방법으로 정량하였다. LC/MS 분석결과 검량선은 $0.05-10\;{\mu}g$/mL 농도범위에서 $r^2$=0.9993의 상관계수를 갖는 좋은 직선성을 나타내었으며, 검출한계는 $0.01\;{\mu}g$/mL 이었다.

• 한국응용과학기술학회지
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• 제29권4호
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• pp.577-584
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• 2012

액체크로마토그래피법(HPLC)을 이용하여 화장품에 들어있는 자외선차단제류 등을 동시 분석하였다. 화장품 시료를 Tetrahydrofurane(THF)에 직접 용해시키고 $0.45{\mu}m$ 필터로 여과하여 물/메탄올/THF를 이동상으로 하여 Extend C18의 비극성 컬럼을 사용하여 기울기용리조건에서 20분 안에 분리하여 UV/Vis detector방법으로 정량하였다. HPLC분석결과 검량선은 $50{\sim}800{\mu}g/mL$ 농도범위에서 상관계수가 $r^2$=0.9992 이상의 좋은 직선성을 나타내었으며 검출한계는 $0.01{\mu}g/mL$였다.

• 한국대기환경학회지
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• 제23권3호
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• pp.277-285
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• 2007

Porous cordierite beads, of which the average pore size was $130{\mu}m$ and porosity was about 80%, were prepared by the foaming method and then their application as support of the $Pt/{\gamma}-alumina$ catalyst for $NO_x$, reduction with propene was investigated. The pressure drop of a 2 mm porous beads filter was less than that of a 1 mm porous beads filter and the difference in pressure drop between these two increased as the flow rate increased. The catalytic activity of $Pt/{\gamma}-alumina$ washcoated on the porous bead was tested with varying Pt loading $(0.005{\sim}0.1g/cm^3),\;C_3H_6/NO$ mole ratio $(0.5{\sim}8)$, space velocity $(20,000{\sim}30,000h^{-1})$ and oxygen contents (1 and 8). Pt loading of $0.04g/cm^3$ showed the highest activity for $NO_x$ conversion. The $De-NO_x$, test was operated in the temperature range of $200{\sim}400^{\circ}C$ and the best operation temperature of the catalytic filter is about $250^{\circ}C$. As the C/N ratio increased, increase of the $NO_x$, conversion might result from the increase in exhaustion of the amount of oxygen by the reduction of hydrocarbon. $NO_x$ conversion at $20,000h^{-1}$ of space velocity shows a maximum 34% higher conversion than that at $30,000h^{-1}$. On condition that $O_2$ was 5%, space velocity was $20,000h^{-1}$ and the C/N ratio was 8, the $NO_x$ conversion exhibited a maximum of 40% at $250^{\circ}C$.

• 한국식품영양학회지
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• 제3권1호
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• pp.57-68
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• 1990

In order to obtain the fundamental informations on cellulase of Trichoderma viride QM 9414 for its production and utilization, some physico-chemical properties of the enzyme were reviewed. When T. viride QM 9414 was cultured on wheat bran medium, filter paper-disintegrating and carboxymethyl cellulose-saccharifying activity were increased with the cell growth, and thereafter CMC-saccharifying activity was kept on almost the same leved while filter-paper disintegrating activity was decreased sharply. And B-glucosidase was formed maximally on the late stationary phase of growth. The crude cellulase of cell-free extracts was purified by (NH4)2SO4 fractionation, Sephadex-G 200 column chromatography and DEAE Sephadex A-50 column chromatography. Filter paper-disintegrating, CMC-saccharifying and B-glucosidase activity were purified 10-fold, 47-fold and 38-fold, respectively. The crude enzyme was proved to be a complex of three different enzyme proteins which were showing filter paper-disintegrating, CMC-saccharifying and B-glucosidase activity. The optimal pH of the three enzyme components was alike pH 4.0, and the optimal temperature for CMC-saccharifying, filter paper-disintegrating and B-glucosidase activity were 4$0^{\circ}C$, 45$^{\circ}C$ and 5$0^{\circ}C$ respectively. The Km and Vmax values of CMC saccharifying activity for CMC were 0.485% and 3.10, and the Km and Vmax vallues of B-glucosidase for PNPG were 0.944$\times$10-3M and 0.097, respectively. The Km and Vmax values of filter paper-disintegrating activity for Avicel were determined to be 0.09% and 0.178, respectively. B-Glucosidase activity was competitively inhibited by glucose, and the Ki value for this enzyme was 3.54$\times$10-3M, CMC saccharifying activity was found to be greatly inhibited by cellobiose.