• Journal of The Korean Society of Grassland and Forage Science
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• v.10 no.3
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• pp.141-146
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• 1990

Changes in dry matter yield, crude components, nutrients uptake($P_2O_5$, $K_2O$, CaO, MgO) and sulphur containing amino acid(cysteine, methionine) of orchardgrass(Dacty1is glomerata. L) and alfalfa(A4edicago sativa. L) by gypsum application(as sulphur source, 0, 2. 5, 10, 20kg SIlOa) were investigated to understand the effect of sulphur on herbage production in pasture, which was established in 1987 as means of hand broadcasting. The effect of gypsum on dry matter yield at different cutting times during growing seasons has not been found both in orchardgrass and in alfalfa, but in respect to annual total dry matter yield there were increment in herbage yield (P<0.05) of alfalfa at 5, 10, 20kg SIlOa in 1989 and the amounts of sulphur taken up in herbage slightly increased according to the rates of gypsum application. Maximum apparent recovery of sulphur was 7.55% at 2kg SIlOa in orchardgrass and was 17.8% at 5kg S/lOa in alfalfa. There were no any great differences in the content of crude components of both species and this trend was similar with the mineral contents of orchardgrass. But in alfalfa, the amounts of $K_2O$, CaO, and $P_2O_5$ taken up were increased by gypsum application and the increment in the amounts of minerals taken up in herbage at 20kg SIlOa were 14.9 of $K_2O$, 9.1 of CaO, and 2.5kgIlOa of $P_2O_5$ as compared to those of at untreated plot. Cysteine and methionine were not influenced by gypsum applicaton not only in orchardgrass but also cysteine in alfalfa, however, the content of methionine in alfalfa was slightly increased at 2, 5, lOkg SIlOa and at 20kg SIlOa was reverse.

• Membrane and Water Treatment
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• v.6 no.4
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• pp.263-276
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• 2015

This paper deals with the influence of chemical oxygen demand to nitrogen ratio ((COD/N) ratio) on the performance of an membrane bioreactor. We aim at establishing relations between COD/N ratio, organisms' distribution and sludge properties (specific resistance to filtration (SRF) and membrane fouling). It is also essential to define new criteria to characterize the autotrophic microorganisms, as the measurements of apparent removal rates of ammonium seem irrelevant to characterize their specific activity. Two experiments (A and B) have been carried on a 30 L lab scale membrane bioreactor with low COD/N ratio (2.3 and 1.5). The obtained results clearly indicate the role of the COD/N ratio on the biomass distribution and performance of the membrane bioreactor. New specific criteria for characterising the autotrophic microorganisms activity, is also defined as the ratio of maximum ammonium rate to the specific oxygen uptake rate in the endogenous state for autotrophic bacteria which seem to be constant whatever the operating conditions are. They are about 24.5 to 23.8 $gN-NH_4{^+}/gO_2$, for run A and B, respectively. Moreover, the filterability of the biological suspension appear significantly lower, specific resistance to filtration and membrane fouling rate are less than $10^{14}m^{-2}$ and $0.07\;10^{12}m^{-1}.d^{-1}$ respectively, than in conventional MBR confirming the adv < antage of the membrane bioreactor functioning under low COD/N ratio.

• Journal of Korean Society on Water Environment
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• v.20 no.3
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• pp.197-205
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• 2004

Batch test methods have developed for a long time to measure kinetic and stoichiometric parameters which are required to perform steady state design and mathematical modelling of activated sludge processes. However, at various So/Xo ratios, abnormal behaviors of ordinary heterotrophic organism in batch tests have been reported in many researches. Thus, in this research, abnormal behaviors of heterotrophs in batch tests were investigated at various So/Xo conditions by measuring and interpreting oxygen utilization rate. As So/Xo ratio increased, the calculated values of maximum specific growth rates, ${\mu}_{H,max}$ and $K_{MP,max}$, increased. However, at a certain point of So/Xo (around 10mgCOD/mgMLAVSS), ${\mu}_{H,max}$ and $K_{MP,max}$ values started to decrease. According to this observation, three prominent behaviours of heterotrophs were identified at various So/Xo conditions. (1) At low So/Xo region (below 5 mgCOD/mgMLAVSS), the oxygen utilization rate of heterotrophs in batch tests were almost stable and consequently yielded lower maximum specific growth rate. (2) At high So/Xo region (up to 5~10 mgCOD/mgMLAVSS), oxygen utilization rate incresed sharply with time and indicated more upward curvature than the predicted OUR with conventional activated sludge model, which consists of single hetetrotrophs group. Thus, in this region, competition model of two organisms, fast-grower and slow-grower, seemed to be appropriate. (3) At extremely high So/Xo region (over 10mgCOD/mgMLAVSS), significant oxygen utilization rate was still observed even after depletion of readily biodegradable COD. This might be caused by retarded utilization of intermediates which were generated by self inhibition mechanism in the process of RBCOD uptake.

• The Journal of the Korean bone and joint tumor society
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• v.20 no.2
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• pp.66-73
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• 2014

Purpose: Various diagnostic imaging modalities have been used to evaluate the effect of neoadjuvant chemotherapy for osteosarcoma early and noninvasively. We evaluated the effectiveness of imaging studies of plain radiographs and positron-emission tomography/computed tomography (PET/CT) in predicting neoadjuvant chemotherapy effect for osteosarcoma and tried to establish a general principle in interpretation of PET/CT parameters. Materials and Methods: Eighteen patients who underwent two cycles of neoadjuvant chemotherapy and surgical excision for osteosarcoma were enrolled. There were 13 males and 5 females, with a median age of 19 (11-63) years. Fifteen patients of 18 had the American Joint Committe on Cancer (AJCC) stage IIB. They had plain radiographs and PET/CT before and after neoadjuvant chemotherapy. The resected tumor specimens were pathologically examined to determine histological response grade using a conventional mapping method. Statistical analysis was performed to evaluate the correlation between histopathological necrosis rate, and radiographic finding category, post-chemotherapy maximum standardized uptake value (SUVmax), average standardized uptake value and metabolic tumor volume (MTV) as well as reduction rates of them. Results: Eight patients were good responders to neoadjuvant chemotherapy based on histological evaluation. Median SUVmax reduction rate was 73 (23-77) % in good responders and 42 (-32-76) % in poor responders. Median MTV reduction rate was 93.5 (62-99) % in good responders and 46 (-81-100) % in poor responders. While radiographic finding category was not different according to histological response (p=1.0), SUVmax reduction rate was significantly different (p=0.041). Difference in MTV reduction rates approached statistical significance as well (p=0.071). Conclusion: While radiographic finding category was not reliable to assess neoadjuvant chemotherapy effect for osteosarcoma, reduction rate of SUVmax was a useful indicator in this study. As parameters of PET/CT can be influenced by various factors of settings, different centers have to make an effort to establish their own standard of judgement with reference of previous studies.

• Radiation Oncology Journal
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• v.36 no.4
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• pp.295-303
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• 2018

Purpose: We evaluated prognostic value of the 8th edition of the American Joint Committee on Cancer/International Union for Cancer Control (AJCC/UICC) staging system for nasopharyngeal cancer and investigated whether tumor volume/metabolic information refined prognostication of anatomy based staging system. Materials and Methods: One hundred thirty-three patients with nasopharyngeal cancer who were staged with magnetic resonance imaging (MRI) and treated with intensity-modulated radiotherapy (IMRT) between 2004 and 2013 were reviewed. Multivariate analyses were performed to evaluate prognostic value of the 8th edition of the AJCC/UICC staging system and other factors including gross tumor volume and maximum standardized uptake value of primary tumor (GTV-T and SUV-T). Results: Median follow-up period was 63 months. In multivariate analysis for overall survival (OS), stage group (stage I-II vs. III-IVA) was the only significant prognostic factor. However, 5-year OS rates were not significantly different between stage I and II (100% vs. 96.2%), and between stage III and IVA (80.1% vs. 71.7%). Although SUV-T and GTV-T were not significant prognostic factors in multivariate analysis, those improved prognostication of stage group. The 5-year OS rates were significantly different between stage I-II, III-IV (SUV-T ≤ 16), and III-IV (SUV-T > 16) (97.2% vs. 78% vs. 53.8%), and between stage I, II-IV (GTV-T ≤ 33 mL), and II-IV (GTV-T > 33 mL) (100% vs. 87.3% vs. 66.7%). Conclusion: Current anatomy based staging system has limitations on prognostication for nasopharyngeal cancer despite the most accurate assessment of tumor extent by MRI. Tumor volume/metabolic information seem to improve prognostication of current anatomy based staging system, and further studies are needed to confirm its clinical significance.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.29 no.2
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• pp.230-237
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• 1996

The objective of the present study is to evaluate organic removal efficiencies, nitrogen removal efficiencies, kinetic constant, sludge production rates, oxygen requirements, and optimum treatment renditions for recycling water treatment of aquaculture by using a trickling filter process. When the loading rates were $0.500\~0.082kg\;COD/m^3/day$ and $0.271\~0.044kg\;NH_4^+-N/m^3/day$, SCOD and ammonia removal efficiencies were $74.5\~84.0\%$ and $43.7\~61.8\%$, respectively. The maximum removal rate of ammonia was 119.5 mg/L/day. Observed cell yield coefficient in the trickling filter reactor was 0.572 kg VSS/kg $BOD_{rem}$. When the hydraulic loading rate was $6.712\~40.341m^3/m^2/day$, oxygen uptake rate was $1.33\~7.22\;mg\;O_2/L/hr$.

• Journal of Korean Society of Forest Science
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• v.90 no.5
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• pp.600-607
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• 2001

This study was conducted to estimate the capability of Populus alba ${\times}$ glandulosa and Betula schmidtii for the uptake of Pb from the lead-contaminated soil and their tolerance to lead. Rooted cuttings in the former species and germinated seedlings in the latter species were planted in pots and irrigated with Pb-containing water for 60 days. In both tree species, growth inhibition was observed in 800, and 1,500ppm of $Pb(NO_3)_2$. Most Pb was accumulated in plant roots and only a small portion was transported to the shoots. The translocation rates of Pb for B. schmidtii and P. alba ${\times}$ glandulosa were 1.6-2.6% and 1.2-1.6%, respectively. The maximum Pb content accumulated in shoots was 468.0mg/kg d.w. in P. alba ${\times}$ glandulosa, and 602.0mg/kg d.w. in B. schmidtii. Although tolerance to lead was generally higher in B. schmidtii than P. alba ${\times}$ glandulosa, the highest tolerance to lead was observed in P. alba ${\times}$ glandulosa clone, 72-16. Finally, we discussed the applicability of P. alba ${\times}$ glandulosa and B. schmidtii for phytoextraction based on their Pb uptake ability, high biomass production, and easiness in large-scale cultivation.

• Korean Journal of Soil Science and Fertilizer
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• v.17 no.3
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• pp.218-223
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• 1984

In order to analyze the effects of percolation rate on the growth and yield of rice plants in paddy soils, pot (1a/2000) experiments were carried out. The soil used was highly concentrated with various salts in the horticulture area under vinyl house cultivation, and Samgang variety of Japanica rice was planted. With the increasing rates of percolation, $SiO_2$ and $Ca^{2+}$ were more leached out from soils than supplied by irrigation while $K^+$ and $NH_4{^+}$ were more supplied to soils than leached out. The root activity in the late growth stage was higher in the percolation pots than in the non-percolation pots. Amounts of nutrient uptake of T-N, $P_2O_5$, $K_2O$ and MgO were increased gradually with the increase of percolation rate, but that of $SiO_2$ was maximum at 10mm per day. The percolation rate of 5~10mm per day was considered to be the optimum condition for obtaining more than 95% of relative yield in rice cultivation.

• Membrane Journal
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• v.25 no.5
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• pp.406-414
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• 2015

In this study, partially fluorinated cation exchange membranes were prepared by direct sulfonation of Poly(VDF-co-hexafluoropropylene) copolymers (PVDF-co-HFP) followed by a casting method for application in the Membrane capacitive deionization (MCDI). The structure of sulfonated PVDF-co-HFP (SPVDF) was confirmed by Fourier-transform infrared (FT-IR) and $^1H$ Nuclear magnetic resonance ($^1H$ NMR) analysis. For quantitative analysis of the chemical composition, the X-ray Photoelectron Spectroscopy (XPS) was used. The membrane properties such as water uptake, ion exchange capacity and electrical resistance were measured. It was suggested that the optimum direct sulfonation condition of PVDF-co-HFP ion exchange membranes was $60^{\circ}C$ and 7 hours for temperature and duration of sulfonation, respectively. The water uptake of the SPVDF ion exchange membrane was 21.5%. The ion exchange capacity and electrical resistance were 0.89 meq/g and $3.70{\Omega}{\cdot}cm^2$, respectively. It was investigated that if it is feasible to apply these membranes in MCDI at various cell potentials (0.9~1.5 V) and initial flow rates (10~40 mL/min). In the MCDI process, the maximum salt removal rate was 62.5% in repeated absorption-desorption cycles.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.15 no.1
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• pp.16-24
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• 2010

Utilization of dissolved organic phosphorus (DOP) and alkaline phosphatase (APase) activity by Skeletonema costatum, Chaetoceros didymus, Alexandrium tamarense and Heterosigma akashiwo under the phosphorus deficient condition were examined in the laboratory. S. costatum, C. didymus, A. tamarense and H. akashiwo could make use of phosphomonoester and nucleotide compounds for the growth of them as a phosphorus source. APase activity of S. costatum, C. didymus, A. tamarense and H. akashiwo began to be activated at dissolved inorganic phosphorus (DIP) concentrations less than $0.30\;{\mu}M$, $0.33\;{\mu}M$, $2.04\;{\mu}M$ and $0.63\;{\mu}M$ respectively, and their maximum APase activity were $0.01\;pmol\;cell^{-1}\;hr^{-1}$, $0.11\;pmol\;cell^{-1}\;hr^{-1}$, $1.63\;pmol\;cell^{-1}\;hr^{-1}$ and $0.19\;pmol\;cell^{-1}\;hr^{-1}$, respectively. Although each phytoplankton species displayed different APase activity for DOP utilization, their maximum APase activities were higher than maximum phosphorus uptake rates, inferring that these species might be able to keep growing under DIP-limited conditions thought utilizing effectively the hydrolized product of DOP. This result also implies that utilization of DOP might contribute to not only the growth of red tide forming phytoplankton but also the interspecific competition among phytoplankton species in coastal environments.