• Journal of Korean Society of Environmental Engineers
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• v.35 no.6
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• pp.394-399
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• 2013

The recalcitrant hairs which are accumulated in the U-trap equipped to prevent the stench from the drainage produce the phenomenon of blocking the flow of water through the home drainage pathway. The chemical dissolution solutions commercially manufactured are excessively poured into U-trap to solve this blocking problem. In this study, the specially designed instrument was developed for the experiments to cut and crush the hairs of which main component are the recalcitrant keratin proteins. The performance of the instrument for cutting and crushing hairs was investigated using experimental methods. The cutting and weighing method was used in order to obtain the average length of a large amount of hairs cut by instrument. This method is relatively simple to measure the weight of cutting hairs to obtain the average length of the fibers, the values of average length showed not greater tolerances. Also the average cutting number was defined to evaluate the performance of the cutting and crushing instruments designed for this study. We were able to apply these evaluation methods to provide the criteria to obtain the optimal structure of instrument and proper operation time in the given experimental conditions. These experimental methods and results will provide the good example to design and to analyze the various device that can be used for cutting the fibers. The cutting and crushing instrument developed in this study showed the effective abilities to cutting the hairs. The general using the cuttting and crushing instrument at every home would be helpful to prevent water environmental pollution.

• Analytical Science and Technology
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• v.23 no.3
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• pp.240-246
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• 2010

A technique for the determination of trace Cu(II) in various real samples by FAAS after the column preconcentration onto p-dichlorobenzene-SA adsorbent, which is microcrystalline p-dichlorobenzene loaded with salicylaldoxime (SA) has been developed. Several experimental conditions such as pH of the sample solution, the amount of chelating agent salicylaldoxime, the amount of adsorbent p-dichlorobenzene-SA, and flow rate of sample solution were optimized. The interfering effects of various concomitant ions were investigated. $CN^-$ interfered more seriously than any other ions. However, the interference by $1\;{\mu}g\;mL^{-1}\;CN^-$ could be overcome completely by controlling the concentration of Ni(II) to $20\;{\mu}g\;mL^{-1}$. The linear range, correlation coefficient ($R^2$) and detection limit obtained by this technique were $3.0\sim100\;ng\;mL^{-1}$, 0.9901, and $3.1\;ng\;mL^{-1}$, respectively. For validating this technique, the aqueous samples (wastewater, reservoir water and stream water) and the food samples (orange juice, fresh egg and skim milk) were used. Recovery yields of 93~104% were obtained. These measured mean values were not differents from ICP-MS data at 95% confidence level. The good results were obtained from the experiments using the rice flour certified reference material (CRM) sample. Based on the experimental results, it was found that this technique could be applied to the preconcentration and determination of Cu(II) for various real samples.

• Microbiology and Biotechnology Letters
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• v.26 no.1
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• pp.15-22
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• 1998

The dnrF gene, responsible for conversion of aklavinone to $\varepsilon$-rhodomycinone via C-11 hydroxylation, was mapped in the daunorubicin gene cluster of Streptomyces peucetius subsp. caesius ATCC 27952, close to drrAB, one of the anthracycline resistance genes. To characterize the enzymatic properties of the aklavinone 11-hydroxylase, the dnrF gene was overexpressed in Escherchia coli. The pET-22(+) plasmid which has the T7 promoter under the control of lacUV5 gene was used for the overexpression of the dnrF gene, and the recombinant plasmid pET213 that contains the dnrF gene linked to the T7 promoter of pET-22b(+) was introduced into the E. coli BL2l. When the expression of the dnrF gene was induced by IPTG at the final concentration of 1 mM, the induced protein could be detected in SDS-PAGE only in insoluble precipitate. The insoluble protein was electroeluted from the gel and used for the preparation of antiserum in mice. Various culture conditions were tested to maximize the expression of the aklavinone 11-hydroxylase in soluble form. The enzymatic activity was checked by the bioconversion experiment, and the protein was confirmed by the SDS-PAGE and the Western blot analysis. From the analysis of the data, it was concluded that the culture induced with IPTG at the final concentration of 0.02 mM at 37$^{\circ}C$ yielded the best productivity of active form of enzyme.

• Proceedings of the Korea Water Resources Association Conference
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• 2007.05a
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• pp.433-437
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• 2007

최근 환경부에서는 낙동강 유역의 오염총량관리제도의 시행에 따라 이제까지의 배출구 수질기준으로부터 총량수질기준을 통한 수질관리를 실시하고 있다. 오염총량관리를 실행하기 위해서는 주요지천 및 폐수처리장에서의 수질개선 및 비점오염원 관리가 선행되어야 하는데 이를 효율적으로 제어하기 위해서 낙동강 유역에 적합한 최적 수질해석 모델의 개발이 요구되는 상황이다. 수질모델의 가장 큰 목적은 유역으로부터 발생한 오염물이 하천으로 유입되었을 때 하천 수질 및 생태계의 수학적 표현을 통해 장래의 수질을 예측하고, 예측된 결과에 따라 합리적인 수질관리대책을 수립하는 것이다. 낙동강은 대표적인 수지상 하천망의 형태로서 댐 방류량 및 지류유입량은 본류 수계에 직접적인 영향을 미치며, 수질해석의 기본이 되는 수리계산에 매우 중요한 변수가 된다. 또한 대구, 구미, 왜관, 김천 등에서의 오염부하가 금호강, 남강 등의 주요 지류를 통하여 본류부로 유입되고 있으며, 하류부 칠서, 원동, 매리, 물금 등에서는 대량의 하천수를 취수하여 부산, 울산, 마산, 창원 지역 등의 생활 및 공업용수의 원수로 사용하고 있다. 다시 말해서 댐 방류량, 낙동강 하구언의 수위조절, 지류 유입량, 비점원 유입량 등 계산영역 경계에서의 비정상상태의 수리조건과 수질관리 계획에 의해 일률적으로 오염이 부하되는 정상상태의 수질조건이 공존하고 있는 실정이다. 본 연구에서는 낙동강 유역에 적합한 동적 수질모델을 개발하였다. 본 연구에서 개발된 수치모형은 갈수저수조건 및 불규칙한 하도단면을 반영하고, 동적 상태의 댐 방류량, 낙동강 하구언의 수위조절 영향, 지류 유입량 등 다양한 하천조건에서 발생하는 동적 흐름을 안정적으로 해석하여 낙동강 수질해석의 신뢰도를 향상시킴으로서 낙동강에 유입된 오염물질이 수계에 미치는 영향을 정확히 분석하고자 하였다. 동적수질해석에 의한 모의결과는 유량의 경우 상류부분은 모의치와 실측치가 잘 일치하지만, 중류 이후 지류의 유입이 많아지면서 지류의 변화를 정확히 입력하지 못해 모의치와 실측치의 차이가 발생한다. BOD의 경우는 수질이 양호한 상류지역은 모의치와 실측치가 잘 일치하지만, 오염원의 유입이 많은 중류지역부터는 실측치와 차이를 나타내다가 하류지역에서 다시 비교적 일치함을 알 수 있다. TN의 경우는 전반적으로 실측치보다 높게 모의되었고, TP는 전반적으로 실측치와 비교하여 잘 모의되었다. 본 연구에서 구축한 동적 수리해석모형 및 동적 수질해석모형은 낙동강 유역에 대해 유량 및 수질 등의 실제 하천의 경향에 비교적 잘 반영하므로 오염물총량규제에 따른 합리적인 하천 수질관리대책을 수립하는데 크게 기여할 수 있을 것으로 기대된다.

• Analytical Science and Technology
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• v.15 no.3
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• pp.236-242
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• 2002

A method was investigated to determine the thickness of coating on steel sheet using rf glow discharge atomic emission spectrometer. The RF gas-jet boosted glow discharge has such salient feature as good pleasure stability and high sputtering efficiency that it was possible to determine the thickness of silicon resin film on zinc electroplated steel. The erosion speed variation is dependent on discharge power, gas flow rate and discharge pressure. therefore determine discharge condition to measure the thickness of coating on steels. The fundamental studies have been carried out to investigate an optimum condition for in-depth analysis and composition of zinc coating on steel. In this study, the calibration curve for thickness determination of silicon resin film was found to be linear in the range of $1000{\sim}3500mg/m^2$ film thickness. The developed rf gas-jet boosted glow discharge was applied to the analysis of zinc coating and silicon resin film on steel made by RIST.

• Korean Journal of Food Science and Technology
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• v.19 no.6
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• pp.499-505
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• 1987

The functional properties of lupin seed protein concentrate (LPC) were examined and compared to those of soybean protein isolate (SPI) and Na-caseinate. LPC-50, of which protein level was 50%, was prepared by a two phase solvent (hexane: alcohol: water= 10:7:3) extraction method. LPC-70 was made from LPC-50 by removing the fractions solubilized by carbohydrate decomposing enzymes. The solubilities of LPC-50 and LPC-70 were similar to that of of SPI but slightly higher at pH 4-5, and less susceptible to the added salt. The apparent viscosity of LPC increased exponentially as the concentration increased over 6% level, and the change was similar to that of Na-caseinate. LPC showed strong pseudoplastic non-Newtonean flow behavior, which was similar to that of SPI The emulsifying capasity of LPC-70 was similar to that of SPI when salt was added. The foaming capacity of LPC was comparable to that of SPI. LPC showed high oil and water absorption capacities, which increased as the protein level was elevated. LPC-70 showed the highest oil absorption capacity of all the samples tested.

• Korean Chemical Engineering Research
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• v.50 no.1
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• pp.11-17
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• 2012

Disinfection of Escherichia coli (E. coli) in drinking water was investigated by using $TiO_2$ and $TiO_2-SiO_2$ based photocatalyst prepared by sol-gel method. The disinfection test was carried out in an annular flow reactor with circulating sterile water containing the photocatalysts powder under UV-A irradiation. The disinfection activity was proportional to the anatase`s intensity of crystalline peak of the $TiO_2$ photocatalysts. 100% disinfection of E.coli without endotoxin was achieved with $TiO_2$ coated photocatalytic system under UV-A irradiation within 2 h. However, toxic endotoxine was exist in the disinfection of E.colithe under UV-C irradiation even though 100% disinfection of E.colithe within 30 min, which suggest that $TiO_2$ coated photocatalytic system with UV-A is useful tool for the disinfection of E.coli in drinking water.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.2
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• pp.177-183
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• 2005

The effluent quality is directly affected by the separation of biological solids in a final clarifier because the majority of discharged $BOD_5$ and SS are virtually dependent on the results of biological solids in the sedimentation tank effluent. If a final clarifier is effectively designed and operated, the desired goal of clarification for wastewater can be achieved together with the cost reduction in the treatment of wastewater. To this end flow characteristics and the removal efficiency of SS are numerically investigated especially by the change of the inlet position and the installation of baffle to improve the performance of a rectangular final clarifier. The 2-D computer program developed in a rectangular coordinates has been successfully validated against experimental residence time distribution(RTD) curves obtained by tracing radio-isotope. The lowering of the inlet position weakens the density current and induces the settling of SS in the front zone of a clarifier. Thus the decreased traveling distance of the sludge increases the removal efficiency of SS in the effluent. The inlet baffle installed in the front region of clarifier prevents the short circuiting flow and induces to flow into the dense underflow, which eventually improves the effluent quality. In the case of lower inlet position, however, installation of baffle results in degradation of effluent quality. Consequently it is strongly recommended that in-depth numerical study be performed in advance for optimizing a clarifier design and retrofitting to improve effluent quality in a final clarifier.

• Korean Journal of Food Science and Technology
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• v.27 no.4
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• pp.582-592
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• 1995

To measure rheological properties of the starch dough, an Extrusion Capillary Viscometer(ECV) cell was self-made and attached to Instron machine(Model 1140). Apparent viscosities of corn and waxy corn starch doughs were measured and their gelatinization degrees were determined by enzymatic analysis. When corn and waxy corn starch doughs with $36{\sim}52%$ moisture content were heated at $60{\sim}100^{\circ}C$, come-up time of the cold point of doughs decreased from 220 sec to 140 sec with increased in the moisture content. In the measurement range of $36{\sim}52%$ moisture content and $60{\sim}100^{\circ}C$ heating temperature, both corn and waxy corn starch doughs showed pseudoplastic flow behaviors. At the same shear rate, both shear stress and viscosity of starch dough decreased as the moisture content increased. At the moisture content above 44%, the shear stress and viscosity of starch dough decreased as the heating temperature increased from $60^{\circ}C\;to\;70^{\circ}C$, but increased as the heating temperature increased from $80^{\circ}C\;to\;100^{\circ}C$. When the moisture content increased and heating temperature, the gelatinization degree of starch dough increased from about 10% to about 62%. The gelatinization degree of waxy corn starch dough was $15{\sim}20%$ higher than that of corn starch dough under the same gelatinization conditions. The effects of moisture content on the viscosity of starch dough were examined by Arrhenius equation. As the moisture content increased, viscosity of starch dough decreased. But the effect of moisture content was greater in the range of $80{\sim}100^{\circ}C$ than in the range of $60{\sim}70^{\circ}C$ heating temperature.

• Journal of Korean Society of Forest Science
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• v.85 no.2
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• pp.210-224
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• 1996

The SLODSVAT consists of interrelated submodels that simulate : the transfer of radiation, water vapour, sensible heat, carbon dioxide and momentum in two canopy layers determined by environmental conditions and ecophysiological properties of the vegetation ; uptake and storage of water in the "root-stem-leaf" system of plants ; interception of rainfall by the canopy layers and infiltration and storage of rain water in the four soil layers. A comparison of the results of modeling experiments and field micro-climatic observations in a spruce forest(Picea abies [L].Karst) in the Soiling hills(Germany) shows, that the SLODSVAT can describe and simulate the short-term(diurnal) as well as the long-term(seasonal) variability of water vapour and sensible heat fluxes adequately to natural processes under different environmental conditions. It proves that it is possible to estimate and predict the transpiration and evapotranspiration rates for spruce forest ecosystems on the patch and landscape scales for one vegetation period, if certain meteorological, botanical and hydrological information for the structure of the atmospheric boundary layer, the canopy and the soil are available.