• Journal of Korean Society of Environmental Engineers
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• v.27 no.9
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• pp.1006-1015
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• 2005

We investigated the effect of hydroxyl radicals on the photolysis of triclosan (TCS), which is a potent broad-spectrum antimicrobial agent. TCS degradation during the initial reaction time of 5 min followed a pseudo-first order kinetic model ai all light intensities at a wavelength of 365 nm and at the low light intensities at a wavelength of 254 nm. The photodegradation rate significantly increased with decreasing wavelength and increasing the UV intensities. The activity of hydroxyl radicals was suppressed when methanol was used as the solvent instead of water. An increase in the photon effect was observed when the UV intensity was higher than $5.77{\times}10^{-5}$ einstein $L^{-1}min^{-1}$ at 254 nm, and lower than $1.56{\times}10^{-4}$ einstein $L^{-1}min^{-1}$ at 365 nm. The quantum yield efficiency for the photolysis of TCS was higher at 365 nm than at 254 nm among the above mentioned UV intensities. Dibenzodichloro-p-dioxin (DCDD) and dibenzo-p-dioxin were detected as intermediates at both UV intensities of $1.37{\times}10^{-4}$ and $1.56{\times}10^{-4}$ einstein $L^{-1}min^{-1}$ at 365 nm. Dichlorophenol and phenol were also detected in all cases. Based on our findings, we presented a possible mechanism of TCS photolysis.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.327-327
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• 2017

The effect of different seedling ages and transplanting times on the growth and yield of Indica ${\times}$ Japonica rice for noodle processing was evaluated to develop a high yielding cultivation technology for increasing the competition against the imported foreign rice. Four seedling ages (10-, 20-, 30- and 33-day old) of two Indica ${\times}$ Japonica rice cultivars (cvs. Saemimyeon and Palbangmi) and three transplanting dates (May 20, May 30 and June 9) were used in the study. Our results showed that the growth and rice yield of the two cultivars were significantly affected by the different seedling ages and transplanting times. Dry matter production at the panicle heading of the two rice cultivars were generally higher in the 30-day old seedling than the other seedling age treatments and then gradually decreased as the transplanting time was delayed from May 20 to June 9. Similar high panicle number per square meter were recorded at the 30-day old seedling between May 20-May 30 transplanting times. In contrast, other yield parameters that includes spikelet number per panicle, 1,000-brown rice weight, and ripened grain ratio (except for the June 9 transplanting time of Palbangmi) were not significantly affected. The milled rice yield of Saemimyeon was higher than that of the Palbangmi regardless of seedling ages and it was also the highest at the 30-day old seedling with four seedling ages. The milled rice yield of Saemimyeon was only slightly decreased as the transplanting time was delayed from the May 20 to June 9 but Palbangmi had a significantly lower milled rice yield at June 9 transplanting due to the low ripened grain ratio. The result indicates that the most suitable seedling age for the cultivars tested was at 30-day old seedling for noodle processing rice and recommended transplanting times were between May 20 and May 30 for the high rice yield in the Yeongnam plain area.

• Journal of Radiation Protection and Research
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• v.37 no.2
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• pp.90-95
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• 2012

A radio-tracer experiment was performed in a greenhouse to investigate the effectiveness of the simultaneous application of K and Ca as a countermeasure for reducing the radiocaesium and radiostrontium uptake by rice. Paddy soil (loam of pH 6.5) in soil boxes was spiked with $^{137}Cs$ and $^{85}Sr$, and treated with K and Ca in the forms of KCl and $Ca(OH)_2$, respectively, at agrochemical grades before transplanting. For the seeds of the control plants, soil-to-plant transfer factors (TF, $m^2\;kg^{-1}-dry$) of $^{137}Cs$ and $^{85}Sr$ were $7.4{\times}10^{-5}$ and $2.1{\times}10^{-4}$, respectively, whereas the corresponding values for the straws were $2.6{\times}10^{-4}$ and $2.2{\times}10^{-2}$, respectively. The TF values of $^{137}Cs$ and $^{85}Sr$ kept decreasing as the level of the simultaneous application of K and Ca (K/Ca, $g\;m^{-2}$) increased up to 33.6/322 and 48.0/460, respectively. The maximum rate of the decrease was around 60% for both radionuclides. Nearly 60% reduction in the TF value of $^{85}Sr$ was observed even at the dosage of 33.6/322, which was considered the optimum dosage based on crop productivity as well as reduction in the radiocaesium and radiostrontium uptake by rice. The optimum dosage may depend on various factors so further experiments need to be made for many different conditions.

• Journal of environmental and Sanitary engineering
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• v.4 no.2 s.7
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• pp.47-59
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• 1989

In order to investigate the bacteriological contamination of water in Han river, the survey was carried out in eight reservoirs of Seoul water supply during the period from January to December in 1985. 1. The counts by means of total bacteria in eight reservoirs by standard plate count method were as follows: $7.7\times10^2$ per ml in Paldang reservior, $9.6\times10^3$ per ml in Gueiri, $8.4\times10^4$ per ml in Doogdo, $1.6\times10^6$ per ml in Bogwang, $2.5\times10^6$ per ml in Noryangjin, $2.2\times10^6$per ml in Seon yoo, $5.9\times10^6$ per ml in Yungdeungpo and $1.9\times10^7$per ml in Gayang. 2. The average counts of total coliform in eight reservoirs by MPN method were as follows : $2.4\times10$ per 100 ml in Paldang, $5.6\times10^2$ per 100 ml in Gueiri, $2.3\times10^3$ per 100 ml in Doogdo, $5.1\times10^4$ per 100 ml in Noryang-jin, $1.2\times10^5$ per 100 ml in Bogwang, $6.2\times10^4$ per 100 ml in Seonyoo, $1.1\times10^5$ per 100 ml in Yungdeungpo and $2.8\times10^5$ per 100 ml Gayang. 3. The counts by means of fecal coliform in eight reservoirs by MPN method were as follows : non detection per 100 ml in Paldang, 5.2 per 100 ml in Gueiri, $1.2\times10^2$ per 100 ml in Doogdo, $1.6\times10^3$ per 100ml in Bogwang, $2.0\times10^3$per 100ml in Noryangjin, $6.6\times10^2$ per 100ml in Seonyoo, $1.2\times10^3$ per 100 ml in Yungdeungpo and $2.5\times10^3$per 100 ml in Gayang. 4. The counts by means of fecal streptococci in eight reservoirs by MPN method were as follows: non detection per 100 ml in Paldang and Gueiri, $6.9\times10$ per 100 ml in Doogdo, $3.2\times10^2$ 102 per 100 ml in Bogwang, $2.9\times10^2$ per 100 ml in Noryangjin, $3.0\times10^2$ per 100 ml in Seonyoo, $4.0\times10^2$ per 100 ml in Yungdeungpo and $14\times10^3$ per 100 ml in Gayang. 5. The counts means of pseudomonas aeruginosa in eight reservoirs by MPN method were as follows; non detection per 100 ml in Paldang, 2.4 per 100 ml in Gueiri, $1.5\times10$ per 100 ml in Doogdo, $2.0\times10$ per 100ml in Bogwang,$6.2\times10$ per 100mI in Noryangjin, $2.1\times10$ per 100ml in Seonyoo, $6.4\times10$ per 100mI in Yungdeungpo and $7.1\times10$ per 100ml in Gaynag.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.361-361
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• 2010

The separated quasi-one-dimensional ($7{\times}7$) and ($5{\times}5$) phases on vicinal Si(557) surfaces were successfully realized by changing the crystallographic orientation and thermal treatment conditions. A small change in the crystallographic orientation of the Si(557) surface stabilized the quasi-one-dimensional ($5{\times}5$) phase of a (111) facet on vicinal Si(557) surfaces and made it coexist with a quasi-one-dimensional ($7{\times}7$) phase after an optimal thermal treatment, whereas only the quasi-one-dimensional ($7{\times}7$) phase was stable on the Si(557) surface. Interestingly, this causes the (111) terraces with different widths (L) to prefer only one of the $5{\times}5$ (L=12) and $7{\times}7$ (L=9) phases resulting in long-range order of both phases along the step edge direction, which was observed by scanning tunneling microscopy (STM) and was supported by first principle calculations. In contrast, the quasi-one-dimensional ($5{\times}5$ and ($7{\times}7$) phases were arranged randomly across the step edge direction. The change of surface morphology of vicinal Si(557) surfaces will be discussed with STM images and theoretical calculations by changing crystallographic cutting angles and thermal treatment conditions.

• Journal of Sericultural and Entomological Science
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• v.39 no.2
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• pp.197-202
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• 1997

To hydrolyze silk fibroin was treated with NaOH solution on various concentrations and times. And it was examined that the addition effects of NaHSO3 solution on the solubility and colouring of silk fibroin. As obtained results are as follows; The more increasement of concentration and time of NaOH treatment, the more increasement of solubility but solubility was slight above 3% concentration of NaOH. Fibroin yield was decreased above 3% concentration. This was due to formation of peptide or amino acids below molecular weight 3,000. Most of molecular weight distribution came out to be under 3,000 in 2% concentration and 4hrs of NaOH treatment. The more increasement of adding concentration and 4hrs of NaOH treatment. The more increasement of adding concentration of NaHSO3, the more reduction of solubility but white index of powder increased. In the results of FT-IR spectras of silk fibroin powder obtained by various concentrations of NaHSO3 treatment, the absorbent peak at 3,400 cm-1 which was considered as -CH=N- (azomethine) was disappeared by the more addition of NaHSO3. It showed that absorbent peak of $\beta$-fibroin moved into low temperature region and transferred to $\alpha$- and random coil structure through the DSC experiment. In the results of amino acid analysis, alkali hydrolysis reduced the oxy amino contents acid like serine and tyrosine, but increased the glycine content by the more addition of NaHSO3.

• Journal of the Korean Wood Science and Technology
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• v.48 no.6
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• pp.861-868
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• 2020

The use of polyphenol extracts from radiata pine (Pinus radiata) bark as raw materials for bio-foams was investigated along with the optimal NaOH extraction conditions. The targeted yield of alkaline extracts was 60%, and the targeted pH was 11 to 12. The radiata pine bark was composed of 70% of a 1% NaOH extract, which contained mainly polyphenols, such as proanthocyanidin (PA). As the particle size of the bark decreased, the yield of the 1% NaOH extracts increased from 57 to 87%. A range of NaOH concentrations, liquor ratios, and extraction times were explored to establish an economic polyphenol extraction method. More than 60% of the alkaline extract was extracted, and the pH of the extract was approximately 12 when the optimum extraction conditions were employed, i.e., a liquor to bark ratio of 5:1, a NaOH dosage of 17 to 18% based on the bark weight, and a 1 h extraction time. Following neutralization of the alkaline extract, structural analysis indicated severe structural changes in the PA during the alkaline extraction. Because the alkaline extract was barely soluble in the solvent used for the structural analyses, it is assumed that chemical modification is required to increase the solubility of the alkaline extract for the production of bio-foams.

• Journal of Korean Society of Steel Construction
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• v.16 no.1 s.68
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• pp.113-121
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• 2004

A test program was conducted on full-scale steel moment connections constructed using a T-stiffener. In the T-stiffener connection, the beam-to-column connection was reinforced with the horizontal and vertical element of the T-stiffener to resist moment under severe cyclic loads. A total of five specimens were tested in this study together with a concrete-filled tubular(CFT) column(${\sqsubset}-500{\times}500{\times}12$) and a steel beam($H-506{\times}201{\times}11{\times}19$). For the specimens, the T-stiffener was combined with RBS (also known as "Dog-bone") detail or Horizontal Element Hole(HEH) detail constructed to enhance deformation capacity. The test program showed excellent seismic performance for specimens constructed with an RBS or an HEH. except the specimens had brittle failure of VE. The test results also showed that the connections all developed maximum moments at the face of the column. Such moments were at least 15% and as much as 36% larger than the plastic moment capacity of the beam. based on the actual yield stress of the beam steel.

• Journal of Physiology & Pathology in Korean Medicine
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• v.22 no.3
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• pp.507-515
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• 2008

To make a bibliographical review on the most frequently used prescriptions and herbs in treating the uterine carcinoma. 43 texts in China and 6 texts in Korea published since 1980 were reviewed for this objective. 590 Oriental Herbal Medicine formulas composed of 457 herbs were investigated. The frequency and efficacy of each herb used were statistically analyzed. The most frequently used herbal medicine formulas were Danchisoyosan in hepatic Qi stasis, Sihosogan-tang mixed with Lungeumdaebo-tang in damage of conception and thoroughfare vessel, Danchisoyosangagam in blood heat, Hoangyunhaedok-tang in pattern of retained dampness-heat, Jibapjihang-tang in iver-kidney yin deficiency pattern, Naebohyunhapsamyoungbaekchulsan in spleen-kidney yang deficiency pattern. The herbal medicines most frequently used were; Angelicae gigantis radix(126 times), Phellodendri cortex(91 times), Borneolum(87 times), Glycyrrhizae radix and Paeoniae radix alba(82 times), Realgar and Alumen(80times), Poria(77 times), Astragali radix(75 times), Moschus and Myrrha(74 times), Coicis semen and Olibanum(73 times), Codonopsis pilosulae radix and Scutellaria bardata Don(70 times) etc. The effect of the most frequently used herbs were : heat-clearing medicine(12), blood-circulation and stasis-dispelling medicine(9), tonifying and replenishing medicine(5), ointments(5), heat-clearing and blood-cooling medicine(3) and etc. The most frequently used herbs may be applied in future animal studies and clinical trials. Also this data can be used as a reference in formulating new Oriental Herbal Medicine formulas for uterine carcinoma.

• Journal of Korean Society on Water Environment
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• v.26 no.4
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• pp.648-653
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• 2010

Discharged pollution load for the management of Total Maximum Daily Loads (TMDLs) is calculated on the basis of rainfall data for reference year. Rainfall has an influence on discharged pollution load in unit watershed with combined sewer system. This study reviewed the status of discharged pollution load and rainfall conditions. We also investigated rainfall effects on discharged pollution load by analyzing change of the load in accordance with increase of rainfall. The change ratio of discharged pollution load was 18.6% while inflow load only 5.8% for 5 years from 2004 to 2008 in Daejeon district. The greatest rainfall and rain days were over 2 times than the least during the period. This change in rainfall could have great effect on discharged pollution load. The analysis showed that discharged pollution load increased 2.1 times in case rainfall increased 2 times and 1.2 times in case rain days increased 2 times. Rainfall effects, therefore, should be considered to make resonable evaluation of discharged pollution load in the assessment of annual performances.