• 대한환경공학회지
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• 제31권4호
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• pp.263-271
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• 2009

본 연구는 Y 정수장 혼화지의 응집효율을 향상시킬 목적으로 혼화지에서 생성되는 플럭을 실시간 온라인으로 평가하였다. 플럭크기를 평가하는 장비로는 온라인으로 플럭을 연속적으로 평가할 수 있는 응집플럭성장측정장치(iPDA)를 사용하였다. 플럭크기를 평가하기 위해 유기고분자 응집제인 폴리아민, 무기응집제 주입량, 원수의 탁도, pH같은 여러 가지 인자를 변수로 적용하였다. 현장실험 기간 동안 사용된 응집제는 폴리염화알루미늄(PACl)이었고, 응집보조재로 폴리아민이 사용되었다. 현장 테스트 기간 동안 원수의 탁도는 25~140 NTU 범위, pH는 7~9이었다. 원수의 탁도가 증가할수록 생성되는 플럭의 크기도 증가 하여 침전속도에 영향을 미쳤다. 회귀선분석으로 부터 FSI (Floc size index)와 탁도 T 값과의 관계식을 다음과 같이 얻었다. FSI = 0.9388logT - 0.3214 ($R^2$ = 0.8040, T : Turbidity) 또한 보조제로 사용된 폴리아민도 플럭크기값에 큰 영향을 주었고, 색도제거제로 사용된 활성탄(PAC)도 그 자체 입자로 작용하여 응집플럭크기 값에 영향을 상당히 주는 것으로 나타났다. 고탁도인 경우 FSI는 [PACl]과 [PAC]함수로 다음과 같은 식을 유도할 수 있었으며 $R^2$ = 0.9050이었다. FSI = $0.0407[T]^{0.324}[PACI]^{0.769}[PAC]^{0.178}$ [PACl] = PACl 주입농도, [PAC] = 활성탄 주입농도 상대적 응집속도 ${\Delta}FST/{\Delta}T$ 값은 응집제의 주입량보다는 활성탄의 주입량이 더 큰 영향을 주었다. 본 연구과정에서 활성탄주입량이 응집속도에 미치는 영향은 응집제의 주입농도가 미치는 것보다 ${\Delta}FST/{\Delta}T$ 값이 1.41 배 큰 것으로 나타났다. 본 연구에서 연구한 결과 플럭크기값 FSI는 여러 가지 영향인자에 상당한 영향을 받는 것으로 분석되었고, 집혼화 효율향상에 유익한 데이터를 얻을 수 있었다.

• 한국미생물·생명공학회지
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• 제44권2호
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• pp.140-144
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• 2016

사람의 분변으로부터 분리한 Bacteroides stericoris HJ-15로부터 chondroitinase ABC 유전자를 클로닝하였다. 클로닝한 chondroitinase ABC 유전자는 3,090 bp, 1,029 아미노산으로 구성되어 있었다. B. stercoris chondroitinase ABC 유전자는 이미 보고된 chondroitinase ABC 유전자들과 호몰로지가 없었으나, 아미노산서열에서는 82% 호몰로지를 보였다. T7 promoter를 가진 pET-26b+ expression vector에 클로닝한 chondroitinase ABC 유전자를 Escherichia coli BL21 (DE3)에서 발현하여 정제한 재조합 chondroitinase ABC는 chondroitin sulfate A, B 및 C를 모두 분해하였다.

• 한국세라믹학회지
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• 제34권9호
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• pp.915-920
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• 1997

Tetragonal ZrO2 polycrystal (TZP), consisted of 90.24 mol% ZrO2-5.31 mol% Y2O3-4.45 mol% Nb2O5, were prepared using hot-press and mechanical properties and high-temperature degradation were investigated. The specimen, hot-pressed for 1 h at 140$0^{\circ}C$ in Ar atmosphere, exhibited flexural strength of 1010 MPa and fracture toughness of 7.5 MPam1/2 and experienced no low-temperature degradation below 40$0^{\circ}C$. However, as aged for 100h at temperatures higher than 40$0^{\circ}C$, TZP was suffered by high-temperature degradation due to an extensive cavitation caused by the oxidation of carbon. XPS observation revealed that the carbon incorporated in TZPs during hot-pressing exists as either an ether-type CO or a carbonyl-type C=O. Despite of the high-temperature degradation of t-ZrO2 co-doped with Y2O3 and Nb2O5, its flexural strength and fracture toughness were superior to those of the commercial 3 mol% Y2O3-TZP hot-pressed under the identical condition as determined before and after the aging treatments.

• 대한기계학회논문집A
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• 제27권5호
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• pp.750-757
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• 2003

In order to determine creep stress intensity limit of high-temperature components, the usefulness of the creep work and time equation, defined as W$\_$c/t$\^$p/ = B(where W$\_$c/ = $\sigma$$\varepsilon$ is the total creep work done during creep, and p and B are constants), was investigated using the experimental data. For this Purpose, the creep tests for generating 1.0% strain for commercial type i16 stainless steel were conducted with different stresses; 160 MPa, 150 MPa, 145 MPa, 140 MPa and 135 MPa at 593$^{\circ}C$. The plots of log W$\_$c/ - log t showed a good linear relation up to 10$\^$5/ hr, and the results of the creep work-time relation for p, B and stress intensity values showed good agreement to those of isochronous stress-strain curves (ISSC) presented in ASME BPV NH. The relation can be simply obtained with only several short-term 1% strain data without ISSC which can be obtained by long-term creep data. Particularly, this relation is useful in estimating stress intensity limit for new and emerging class of high-temperature creeping materials.

• 대한한의학회지
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• 제20권2호
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• pp.128-140
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• 1999

To evaluate the antitumor activity, antimetastatic and immunomodulatory effects of samryongbakchulsankamibang(SBSK) studies were done experimentally, In cytotoxicity against P388, A549. SK-OV-3, B16-F10 and SK-MEL-2. concentration inhibiting cell growth up to below 40% of control was recognized at $10^{-3}g/ml$ of SBSK. In Inhibitory effect on activity of DNA topoisomerase I. the $IC_{50}$ was shown $200-400{\mu}g/ml$ of SBSK. The T/C was 154% in SBSK-treated group in S-180 bearing ICR mice, The concentration inhibiting adhesion of A549 and B16-F10 to complex extracellular matrix up to below 30% of control was recognized at $5{\times}10^{-4}$, $1{\times}10^{-3}\;g/ml$ of SBSK. In pumonary colonization assay with B16-BL/6, a number of colonies in the lungs were decreased significantly in SBSK-treated group as compared with control group, In hematological changes in B16-BL/6 injected C57BL/6, numbers of WBC and platelet were not changed significantly in SBSK-treated groups, In CAM and in vitro neovascularization assay, angiogenesis was inhibited significantly in SBSK-treated group as compared with control group. From above results it was concluded that SBSK could be usefully applied for the prevention and treatment of cancer.

• 환경위생공학
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• 제15권3호
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• pp.31-36
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• 2000

Conventional membrane systems was difficults to treatment for the swine waste water. Technological advances in membrane filtration systems have created opportunity for the swine wastewater to treat effluent streams in order to meet stricter environmental constraints. "Vibratory Shear Enhanced Processing(VSEP)" developed by new logic international makes it possible to filter effluent streams without the fouling problem exhibited by conventional membrane systems. Various kinds of waste water occurred to and swine wastewater experiment with "VSEP" set up conventional reverse osmosis membrane (ACM-4, ESPA, BW-30). The results were as followes : Treatment efficiency for the input COD(From $332mg/{\ell}$ to $4,968mg/{\ell}$) was 98%. Treatment efficiency for the input SS(From $140mg/{\ell}$ to $4,040mg/{\ell}$) was 100%(All together). Treatment efficiency for the input T-N(From $155mg/{\ell}$ to $934mg/{\ell}$) was 97%~99.8%. Treatment efficiency for the input T-P(From $28.6mg/{\ell}$ to $132mg/{\ell}$) was 99.7% and up. ESPA membrane excels three types of reverse osmosis membranes applied VSEP in removal efficiency.

• 여성건강간호학회지
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• 제22권4호
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• pp.233-240
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• 2016

Purpose: The purpose of this study was to investigate factors which effect clinical nurses' exhaustion. Methods: This research was conducted targeting 140 clinical nurses. Data were collected from 18 September to 30 September 2015. Data were analyzed using the program SPSS/WIN 18.0. Descriptive statistics, t-test, ANOVA, Pearson correlation coefficient, and Stepwise multiple regression analysis were used. Results: Burnout was significantly different by age (F=7.99, p=.001), marital status (t=8.69, p=.004), department area (F=7.65, p<.001), frequency of night work in a month (F=7.65, p=<.001), and clinical career (F=3.68, p=.028). There was positive correlations between menstrual attitudes of participants and premenstrual syndrome (r=34, p<.001), menstrual attitudes and stress (r=.40, p<.001), and menstrual attitudes and burnout (r=.16, p=.031). There were positive correlations between premenstrual syndrome and stress (r=.46, p<.001), between premenstrual syndrome and burnout (r=.35, p<.001), and between stress and burnout (r=.36, p<.001). Factors influencing burnout were premenstrual syndrome (${\beta}=.335$) and age (${\beta}=.216$), with an explanatory power of 18.0%. Conclusion: There is a need to develop and apply program for reducing clinical nurses' pre-menstrual syndrome. In addition, policies are needed to allow for menstruation leave, thereby making it legal.

• 전자공학회논문지B
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• 제31B권10호
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• pp.140-148
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• 1994

본 논문에서는 입력영상에 존재하는 복수 패턴을 한번의 패스(pass)로 인식할 수 있는 변형된 네오코그니트론을 제안한다. 변형된 네오코그니트론은 특징을 추출하는 S세포층 및 V세포층과 패턴의 크기, 이동, 회전 등 변형에 덜 민감하게 하는 C세포층으로 구성된 계층적 신경망이다. S세포와 V세포들은 DCC(don't care condition)을 적용하여 영상에 존재하는 모든 패턴에 대한 특징을 추출하는 역할을 하며, S세포와 C세포는 추출된 패턴에 대한 위치정보도 함께 가진다. 위치정보는 추출된 특징들이 서로 간섭을 받지 않고 올바른 특징만이 추출되도록 하는 데 이용된다. 제안한 방법은 피드백이 존재하는 선택적 주의 방법과는 달리 단일패스로 인식이 가능하므로 인식시간이 짧으며, DCC와 위치정보를 이용하므로 서로 접촉되어 있는 복수 패턴의 인식도 가능하다.

• 한국물환경학회지
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• 제21권2호
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• pp.132-140
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• 2005

The pilot test of a new alternative for small wastewater treatment system has been conducted for two years. It consists of a hybrid bioreactor and the expert system including the process control logic, PLC system, and HMI for the process automation. In order to monitor and remote control its status, the real-time data was transferred from the on-site control center to the central station via a wireless local area network. More efficient and stable performances were observed at automatic operating mode compared with the manual. On an average, COD, SS, T-N and T-P concentrations in the effluent from the hybrid bioreactor were less than 14, 7, 12 and 0.9 mg/L, respectively. According to the result from pilot tests, the quality of treated wastewater with sand filtration was enough to be utilized again.

• 한국인쇄학회지
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• 제20권2호
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• pp.131-140
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• 2002

Chemically amplified deep UV(CA-DUV) resists are typically based on a combination of an acid labile polymer and a photoacid generator(PAG) but acid amplification type photoresist is formulated by addition of the acid amplifiers to chemically amplified resist system(CAPs). We developed acid amplifiers base on cyclohexanediol such as 1-methacryloyloxy-4-tosyloxy cyclohexane(MTC) and poly(MTC$_{10}$-co-tBMA$_{90}$)(P-1) to enhance photosensitivity. P-1 is a copolymer of tert-butyl methacrylate and MTC as a positive working photoresist based on polymeric acid amplifier in order to enhance photosensitivity and simplify the process of fomulating a photoresist. P-1 exhibited 2X higher photosensitivity compared with PtBMA. The acid amplifiers showed reasonable thermal stability for resist processing temperature and higher photosensitivity compared with chemically amplified resist.