• Journal of Korean Society of Forest Science
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• v.99 no.3
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• pp.292-297
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• 2010

This study was carried out to provide preliminary data to purify contaminated sites by nickel (Ni). After rooted cuttings of Salix reichardtii had been grown in Ni solution (hydroponic culture), pH changes in the solution and the accumulated Ni amount in plant parts were measured and analyzed. When the Ni concentration was low enough for S. reichardtii cuttings to grow well, the pH value of the solution decreased considerably. As the Ni concentration got higher, the plant growth got poorer and the pH value decreased slowly. Roots accumulated the highest Ni amount. Leaves and stems followed after. When stems were older, the accumulated Ni amount was lower. more Ni was accumulated in the plant parts which had more flexible tissue and live cells. As the Ni concentration in solution got higher up to 50.0 ${\mu}mol$/L, so did the Ni accumulation in the plant parts. However, the plant individuals nearly died and the Ni accumulation tended to drop when the Ni concentration in solution was 100.0 ${\mu}mol$/L. The rooted cuttings of S. reichardtii grew poorer as the Ni concentration in solution got higher. The plants in solution with 100.0 ${\mu}mol$/L of Ni were practically dead in four weeks.

• Journal of Korean Home Economics Education Association
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• v.31 no.3
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• pp.117-134
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• 2019

This study aims to explore the effects of the parenting education program for high-school maladjusted students. To this purpose, a parenting education program for adolescents developed by the Ministry of Gender Equality and Family(MOGEF) was applied to ten high-school maladjusted students in an alternative(Dae-an) class in Jeju. Findings from class observations and interviews with participants are as follows. First, students with school maladjustment recognized importance and necessity of positive self-concepts and had an opportunity for self-growth through parenting education program. Second, students with school maladjustment obtained understanding about their family of origin and confidence for forming their future families. Third, advance learning about meanings and roles of being a parent provided students with opportunities to know importance of responsible sexual behavior. Fourth, practices of basic care with a replica of a new-born baby enhanced participation and concentration level of students with school maladjustment which became extremely effective in obtaining necessary knowledge for the basic care. Fifth, information provision for parent roles according to children's different developmental levels let students recognize that parent's roles change as their children grow and opened a way to grasp the need of parent education. Sixth, education and repetitive practices on reflective listening helped students enhance communication skills which entailed expanding their human relations. Seventh, passing-down of emotion and understanding on child abuse allowed students recognize risks of child abuse as well as the importance and need of skills for controlling emotion. This study sheds lights on the feasibility and effectiveness of a parenting education program for maladjusted or vulnerable students as an effective program for school drop-out prevention.

• Clinical and Experimental Reproductive Medicine
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• v.26 no.1
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• pp.75-81
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• 1999

The beneficial effect of glucose and phosphate ions in culture medium on the development of human embryos in vitro has not been fully elucidated. The purpose of this study was to evaluate the influence of fertilization and culture of embryos in glucose/phosphate-free m-TALP medium on pregnancy rates in IVF-ET program. The patients in 244 IVF-ET cycles received GnRH agonist + HMG regimens. A does of 10,000 IU HCG was administered when two or more dominent follicles reached 18mm in diameter. Thirty-six hours after HCG, oocytes were recovered transvaginally using ultrasound guidance. Aspirated oocytes were matured for 4 to 6 h in TCM-199 supplemented with 10% follicular fluid (FF). Insemination was carried out with 50,000 motile spermatozoa in TCM-199 + 10% FF or m-TALP + 5% FF + 5% fetal cord serum (FCS) according to experimental design. After 6 h, oocytes were washed 3 to 4 times and cultured in each fresh medium. After 20 h, oocytes were freed from cumulus/corona cells and examined for the presence of pronuclei. Fertilized oocytes were transferred into each co-culture drops and cultured for further incubation. On day 3, embryo transfer was performed with grade 1 and 2 embryos. Monolayers for co-culture of embryos were prepared by plating $1{\times}10^5$ cumulus cells/ml in 10ul drop of TCM-199 + 10% FF or m-TALP + 5% FF + 5% FCS media 24 h prior to the onset of co-culture. Development to 4 to 16 cell stage was observed at 70x magnification following two days of incubation. Pregnancy was confirmed by detecting increasing serum ${\beta}$-hCG concentrations for 11 days following embryo transfer. Data were analyzed by ${\chi}^2$-test. Oocytes from 244 IVF-ET cycles were randomized. The number of cycles and mean age of patients were 97 and 147, 31.3 yrs and 31.2 yrs for TCM-199 (control) and m-TALP groups, respectively. The mean number of retrieved oocytes/cycle, fertilization rates, number of embryos transferred/ET and pregnancy rates were 11.1 and 10.3, 65.1% and 67.3%, 4.1 and 4.7, 28.9% and 43.8% for TCM-199 and m-TALP groups, respectively. Differences in the pregnancy rates were found between control and m-TALP groups (p<0.05). The pregnancy rate of patients divided according to maternal age groups of ${\leq}30$, 31-35, $36{\leq}$ were 44.4% and 49.0%, 26.1% and 41.3%, 29.2% and 41.2% for control and m-TALP groups, respectively. These data indicate that culture of human embryos in glucose/phosphate-free m-TALP medium improves pregnancy rates.

• Journal of the Korean Society for Railway
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• v.14 no.4
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• pp.313-319
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• 2011

In a modern society, various type of transportation modes are utilized, among them the subway system is the one of the main transportation mode which more than 7.21 million people ride a day in Seoul. Due to the increased interests on the indoor air quality (IAQ) of underground facilities, public concerns on IAQ of subway system are increasing also. Platform screen door (PSD) recently installed at the whole stations of Seoul subway and tunnel washing-out appeared to be effective in reducing particulate matters in the platform and tunnel. However there has not been any attempt to improve IAQ of subway cabin inside. Most technologies for removing airborne particulate matters are known to be difficult to adopt on the subway cabin due to the problem of maintenance cost. Therefore, the object of this study is a practical development of cabin air cleaning system which can reduce the concentration of airborne particles and harmful gases at the same time. In this paper, we focused on the development of particle removing system utilizing a roll-filter for increasing operating time of air filter. The prototype of system was designed and manufactured based on the numerical prediction results. For rollfilter device, 5 candidate filter materials were tested in point of particle collection efficiency and pressure drop. It was found that the electrically charged filter material showed the highest performance among them.

• Elastomers and Composites
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• v.39 no.1
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• pp.12-22
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• 2004

The plasma surface modification of natural rubber vulcanizate was carried out using chlorodifluoromethane in a radio-frequency (13.56 MHz) electrodeless bell type plasma reactor. The modification was qualitatively assessed by Fourier transform infrared spectroscopy. The frictional force of the plasma-treated surface was found to decrease with the time of plasma treatment. An increase in the surface polarity, as evidenced by the decrease in contact angle of a sessile drop of water and ethylene glycol on the natural rubber vulcanizate surface, was noted with the plasma modification. In the case of similar plasma treatment of glass surface, only a reduction in the polarity was observed. The use of geometric and harmonic mean methods was found to be useful to evaluate the London dispersive and specific components of surface free energy. Irrespective of the method used for evaluation, an increasing trend in the surface free energy was noted with increasing plasma treatment time. However, the harmonic mean method yielded comparatively higher values of surface free energy than the geometric mean method. The plasma surface modification was found to vary the frictional coefficient by influencing the interfacial, hysteresis and viscous components of friction in opposing dual manners.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.44 no.2
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• pp.201-210
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• 2018

In this study, we formulated oil-in-water emulsion composition for skin care products containing jadeite powder which is well known as far-infrared radiating material. Jadeite powder could sustain stable dispersion in aqueous solvents over a month and this helped mixing it high content in oil-in-water emulsion formulation. To identify the effect of jadeite as a far-infrared radiator materials relating to the skin surface temperature change, we applied emulsion formulation containing 2 weight percent jadeite powder onto facial skin surface and blank formulation together and analyzed surface temperature with thermo-vision. Our results showed that the temperature difference between jadeite powder formulation applied region and blank formulation reached to 1.5 ~ 2.0 degree Celsius. We also performed same test with nephrite powder and titanium dioxide powder but only jadeite powder containing formulation showed significant skin temperature change. To elucidate main cause of heat energy transfer, we tested heat radiation, energy dispersive spectrometer analysis and measured far infrared radiance emissivity, diffuse reflectance spectra and water evaporation rate. We found out jadeite powder could retard water evaporation effectively from the skin surface and resist temperature drop down. This is because of the innate chemical composition and surface structure of jadeite, which can bind with water molecules to form hydrogen bonds. It is concluded that we can develop novel skin care products for moisturizing and thermos with jadeite powder.

• The Journal of Sustainable Design and Educational Environment Research
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• v.17 no.2
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• pp.1-10
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• 2018

Due to the sudden drop in the number of students currently, Korea is facing a turning point in the urgent need to revise the school acceptance plan policy. Especially, in the case of the decrease of the number of students, the reckless establishment of a school in a certain area has an adverse effect of further reducing the number of students in the nearby school. The purpose of this study is to provide basic data on the appropriate scale policy through the correlation between the opening school year and the number of enrolled students in 19 out of 1,179 schools. The results of the linear regression analysis are as follows : First, in 19 cities nationwide, 17 cities except Suwon city and Anyang city had a hypothesis that 'the number of new school students is more than the number of existing school students'. Second, not only the results of the analysis of 1,179 schools in Korea, but also the results of regional analysis showed a hypothesis. Third, there are many small schools and oversized schools in the national city. It is necessary to establish an appropriate school policy.

• Tuberculosis and Respiratory Diseases
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• v.38 no.2
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• pp.135-142
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• 1991

We reviewed 15 cases of mesothelioma of the pleura, of which three cases were localized benign form and 12 cases were malignant diffuse form. The tumors were distributed equally in both sexes, and occured most commonly in fifth to seventh decades. The history of exposure to asbestos was present in only one case. The chief complaints were mainly chest pain and dyspnea. Associated symptoms were cough, sputum, hemoptysis, weight loss, anorexia, chill. On physical examination, unilateral, decreased breathing sound was main feature. The simple chest radiograph showed masses in all localized mesotheliomas (100%) and in 2 diffuse mesotheliomas (17%). 8 cases of diffuse mesotheliomas (67%) showed unilateral pleural effusions. Pleural effusions were mainly bloody (67%), and almost all were exudates. In all localized mesotheliomas, final diagnosis was made by open thoracotomy. In diffuse mesotheliomas, final diagnosis was made by open thoracotomy in 7 cases, chest wall mass biopsy in 2 cases, thoracoscopic biopsy in 1 case, pleural biopsy in 1 case, and pleural biopsy combined with axillary lymph node biopsy in 1 case. Localized mesotheliomas were treated by simple excision with good prognosis. In diffuse mesotheliomas, surgical treatment (pleuropneumonectomy, pleurectomy), chemotherapy, or radiotherapy, alone or in combination, were used with dismal prognosis. The prognostic factors were not found due to the small number of cases, incomplete follow up, and early drop out.

• Korean Journal of Food Science and Technology
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• v.38 no.2
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• pp.249-255
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• 2006

The optimum culture conditions for the ice nucleating activity and the cell growth of Xanthomonas translucens KCTC 2751 were investigated. The optimum initial pH and temperature for the cell growth and the ice nucleating activity were 6.5 and $25^{\circ}C$, respectively. The optimum culture medium for the ice nucleating activity was composed of 1.0% maltose, 1.4% yeast extract, 0.8% digested of gelatin, and 0.03% KCI in distilled water. Freezing operations carried out on distilled water showed that the degrees of supercooling were $-7.90^{\circ}C$ without ice nucleators, $-1.56^{\circ}C$ with silver iodide as a commercial ice nucleator, and $-1.36^{\circ}C$ when Xanthomonas translucens KCTC 2751 were added. During progressive freeze-concentration assays, the addition of Xanthomonas translucens KCTC 2751 led to lower saccharose concentrations in the crystals, while the cells led to higher saccharose concetrations in the concentrated phase.

• Membrane Journal
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• v.8 no.4
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• pp.203-209
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• 1998

The cutting oil emulsion microfiltration was carried out on dead-end call and crossflow systems equipped with 0.22 $\mu$m GVHP Millipore and 0.2 m stainless steel Mott microfiltration membranes, respectivdy. The oil drop size in the emulsion was varied from 0.07 to 0.22 $\mu$m. Cake filtration(CFM) and standard pore blocking models(SPBM) were applied to predict the permeation flux. The permeation fluxes of 0.01 vol% oil emulsion followed CFM for dead-end system very well under the condition of 400 rpm and below 100 kPa. The SPBM was, however, suitable for the permeation flux at 400 rpm and above 150 kPa. The oil layer on the membrane surface was destroyed and reproduced repeatedly as operating pressure was suddenly changed from 60 to 200 kPa, and then returned to 60 kPa. Also, we estimated the critical entry pressure(CEP) which is changed from CFM to SPBM, and CEP for dead-end system was around 100 kPa. The CEP increased from around 100 to 150 kPa for the crossflow system as the oil concentration increased from 0.01 to 0.03 vol% when Reynolds number was 7080.