• Journal of the Korean Wood Science and Technology
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• v.30 no.2
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• pp.172-179
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• 2002

In this study, two materials treated with a flame retardant were examined for their fire resistance. The first, MDF (medium density fiberboard) was overlaid by an oak sliced veneer, which was either treated by soaking in a 6wt.% solution of flame retardant chemicals (pentabromine-chlorinated paraffin) or non-treated and then was coated with either a flame retardant polyurethane coating or with a common polyurethane coating. The second material, Pinus koraiensis penal was either treated by a spray treatment using a flame retardant solution or non-treated and then was coated with either a flame retardant polyurethane coating or with a common polyurethane coating. Pentabromine-chorinated paraffin chemicals were added (6 part of urethane resin) as the flame retardant chemicals in the polyurethane coatings. In the fire resistance test, the th𝜃(℃·min) decreased with the flame retardant treatment or/and the flame retardant coatings, compared to the untreated sample Weight loss (%) decreased with the flame retardant treatment or/and the flame retardant coatings. The ignition time (sec.) increased and the residual flame time (sec.) decreased with the flame retardant treatment or/and flame retardant coatings. Therefore, the flame retardant treatment or/and flame retardant polyurethane coatings have excellent incombustibility.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.29 no.1
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• pp.25-30
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• 1984

Rice seedlings were raised in seedling box for rice transplanter at the temperatures of 32$^{\circ}C$ (day/1$0^{\circ}C$(night) and $25^{\circ}C$/1$0^{\circ}C$ in a phytotron. The endosperm materials were consumed more rapidly at the high temperature (32/1$0^{\circ}C$) than at the low temperature (25/1$0^{\circ}C$) and thus the leaf development was proloted at the high temperature for 15 days from the sowing. But at 35 days after sowing more leaves were developed at the low temperature than the high temperature. The short cotyledon length(5mm) before sowing was more available for the leaf development than the long cotyledon(20mm) because the endosperm materials of the former were consumed slowly. The residual of 10% endsoperm materials, when seedling age was of 2.0 to 2.1, promoted the regrowth of seedlings after machine transplanting.

• Animal Bioscience
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• v.37 no.2
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• pp.173-183
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• 2024

Objective: This study aimed to evaluate whether the methane (CH₄) to carbon dioxide (CO₂) ratio (CH₄/CO₂) and methane-related traits obtained by the sniffer method can be used as indicators for genetic selection of Holstein cows with lower CH₄ emissions. Methods: The sniffer method was used to simultaneously measure the concentrations of CH₄ and CO₂ during milking in each milking box of the automatic milking system to obtain CH₄/CO₂. Methane-related traits, which included CH₄ emissions, CH₄ per energy-corrected milk, methane conversion factor (MCF), and residual CH₄, were calculated. First, we investigated the impact of the model with and without body weight (BW) on the lactation stage and parity for predicting methane-related traits using a first on-farm dataset (Farm 1; 400 records for 74 Holstein cows). Second, we estimated the genetic parameters for CH₄/CO₂ and methane-related traits using a second on-farm dataset (Farm 2; 520 records for 182 Holstein cows). Third, we compared the repeatability and environmental effects on these traits in both farm datasets. Results: The data from Farm 1 revealed that MCF can be reliably evaluated during the lactation stage and parity, even when BW is excluded from the model. Farm 2 data revealed low heritability and moderate repeatability for CH₄/CO₂ (0.12 and 0.46, respectively) and MCF (0.13 and 0.38, respectively). In addition, the estimated genetic correlation of milk yield with CH₄/CO₂ was low (0.07) and that with MCF was moderate (-0.53). The on-farm data indicated that CH₄/CO₂ and MCF could be evaluated consistently during the lactation stage and parity with moderate repeatability on both farms. Conclusion: This study demonstrated the on-farm applicability of the sniffer method for selecting cows with low CH₄ emissions.

• Korean Journal of Microbiology
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• v.47 no.2
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• pp.137-142
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• 2011

$TiO_2$-coated bamboo activated carbon has been prepared and utilized under UV irradiation as a pretreatment method for an effective biodegradation of the recalcitrant polyaromatic hydrocarbons (PAHs). The anatase $TiO_2$ was successfully coated on the bamboo activated carbon (AC) and it showed the highest photoactivity against methylene blue. In the absence of the PAHs-degrading bacteria PAHs having low molecular weight (i.e., naphthalene, acenaphthylene, acenaphthene, and fluorene) were degraded by 9.8, 76.2, 74.1, and 40.5%, respectively. Higher molecular weight PAHs, however, maintained high residual concentrations of PAHs (400-1,000 ${\mu}g$/L) after the same treatment. On the other hand, the overall concentrations of PAHs became lower than 340 ${\mu}g$/L when the pretreated PAHs were subjected to biodegradation by a PAH-degrading consortium for a week. Herein, phenanthrene, anthracene, fluoranthene, and pyrene were removed by 29.3, 61.4, 27.0, and 44.3%, respectively, indicating the facilitated potential biodegradation of PAHs. Activated carbon coated with $TiO_2$ appeared to inhibit growth of PAH degraders on the surface of AC, indicating planktonic degraders were dominantly involved in the PAH biodegradation in presence of the $TiO_2$-coated bamboo AC. It was proposed that an effective remediation technology for the recalcitrant PAHs could be developed when an optimum pretreatment process is further established.

• Journal of Applied Biological Chemistry
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• v.55 no.4
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• pp.253-261
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• 2012

Dioxin contamination on agroproducts is one of the most important issue in food safety. Herein, we measured concentration of 17 dioxins polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) and 14 dioxin like-polychlorinated biphenyls (DL-PCBs) in the main grain (rice and barley) that were produced in Korea. The 36 rice samples were collected from rice processing complex at eight provinces, and the average concentrations of each province were ranged from 2.98 pg/g wet weight (w.w) to 4.98 pg/g w.w. as total PCDD/Fs and DL-PCBs. The seven barley samples were collected from Jeon-nam and Jeon-buk provinces, and their average total concentrations of PCDD/Fs and DL-PCBs were 3.00 pg/g w.w. and 3.24 pg/g w.w. respectively. The residual amounts and toxic equivalent (TEQ) of DL-PCBs in rice and barley were higher than PCDD/Fs. The average total TEQ of rice and barley were 0.0056 pg-TEQ/g and 0.0092 pg-TEQ/g on lower bound estimation respectively. Estimated daily intake of dioxins from rice and barley were calculated 1.03 pg-TEQ/day/person and 0.0534 pg-TEQ/day/person respectively. These were estimated 0.46% and 0.03% of Korean TDI based on 55 kg body weight.

• Korean Journal of Food Science and Technology
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• v.28 no.5
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• pp.841-849
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• 1996

Quality changes in carrot during storage were studied to investigate the efficiency, cooling properties and the washing and storage effects of hydrocooling method. As a result of plotting the nondimensionalized carrot temperature versus cooling time, its cooling rate coefficient was shown $-0.0171min^{-1}{\sim}-0.0121min^{-1}\;(R^{2}=0.99{\sim}0.95)$, and $-0.141min^{-1}{\sim}-0.0038min^{-1}\;(R^{2}=0.98{\sim}0.92)$ in package condition7. Rate of weight loss and change in moisture content of carrot were not significantly different by treatment conditions during storage at $5^{\circ}C$. During storage at $15^{\circ}C$, however, weight loss of hydrocooled carrot was lower than that of non-treated carrot from the 30th to 40th day. Especially, PE was more effective than tray for packaging hydrocooled carrots. Carrot pretreated wish sterilizing agent, packed with PE vinyl film and with residual water removed after hydrocooling showed a lower decaying-rate than any other carrots. Changes in Hunter L and b values of hydrocooled carrot were slower than those of non-treated one. The carotenoids contents of stored carrot $(0.736{\sim}0.780mg%)$ decreased to $9{\sim}43%$ after 40 days of storage at $5^{\circ}C$ and before 20 days of storage at $15^{\circ}C$. It could be presumed that the addition of sterilizing agent reduced the initial level of overall microbial and coliform counts and their growth rate during storage.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.22 no.5
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• pp.266-280
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• 1989

Gonadal maturation of the Korean pomfrets, Pampus echinogaster (Basilewsky) and Pampus argenteus (Euphrasen) were histologically investigated based on the samples captured in the East China Sea from January 1987 to December 1988. Gonadosomatic index (GSI) of P. echinogaster began to increase from March, and reached maximum between May and July. It began to decrease from July and reached mini-mum between August and February. P. argenteus had a similar cycle, however, P. argenteus has higher values in April than P. echinogaster. Hepatosomatic index (HSI) were positively related to GSI. HIS of P. echinogaster and P. argenteus reached maximum in $April\~July$ and $April\~August$, respectively, Fatness coefficient of two Pampus species were low in the summer, and high in the winter. Ovary is of saccular structure, and testis is of lobular structure. From February, the early oocyte (ca. $100\mu$ in diameter grows) rapidly at the germinal epithelium of ovarian sacs. From March to April the oocytes grew up to cu $400\~500\mu$ in diameter. At this stage, the yolk globules are accumulated rapidly in the cytoplasmic layer. From May, the oocytes roached ca. $650\~850\mu$ in diameter, and they are spawned in $May\~July$. After spawning the residual follicles and remained ripe eggs degenerate. From February, spermatogonia grows into spermatocyte on the epithelium of the testicular lobuli. From May, spermatozoa appeared and spawning occurs. After spawning, the epithelium is thickened and the remained spermatozoa degenerate. Annual reproductive cycle of two Pampus species could be divided into four successive stages: Growing stage ($March\~April$), Mature stage ($April\~May$), Ripe and spent stage ($June\~July$) and Recovery and resting stage ($August\~January$). Absolute fecundity of P. echinogaster was $9,441\~135,294$, and that of P. argenteus was $50,678\~221,894$. Absolute fecundity of two Pampus species were positively related to body length and total weight. Relative fecundity was positively related to body length, while it was reversely related to total weight. The increasing rate of absolute fecundity of P. echinogaster was lower than P. argenteus. In P. echinogaster half of female and male reached first maturity at body length of $15.0\~$17.9cm and $12.0\~14.9cm$, respectively. All of females and males reached first maturity at body length of $18.0\~20.9cm$ and $21.0\~23.9cm, respectively. In P. argenteus all of females and males reached first maturity at body length of 18.6cm and 16.7cm$, respectively.

• Childhood Kidney Diseases
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• v.11 no.2
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• pp.255-263
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• 2007

Purpose : A single center cross sectional retrospective study was performed to compare the outcomes of different peritoneal dialysis(PD) modalities in Korean children. Methods : Among children dialyzed with PD between the year 2004 and 2007, 35 children had reliable data on PD adequacy after 3 to 15 months of dialysis. Subjects were grouped by their modalities; 17, 13 and 5 children were on continuous ambulatory PD(CAPD), continuous cyclic PD(CCPD) and nightly intermittent PD(NIPD), respectively. Body weight and height, number of patients taking anti-hypertensives and laboratory data including biochemical and hemoglobin levels were compared. Dialysis adequacy including weekly Kt/Vurea, creatinine clearance (Ccr) and daily water removal were also compared. Patients were sub-grouped by their peritoneal permeability characteristics. Results : The percentage of patients taking anti-hypertensives, monthly change in Z-scores of body weight and height and laboratory data did not differ among the groups. Patients on CAPD and CCPD showed similar dialysis adequacies. Weekly dialytic Ccr was significantly lower in the NIPD group compared to the others. But total Ccr was not different when residual renal function was added. Weekly dialytic Ccr by CAPD was significantly higher than that of CCPD in low and low-average transporters. Conclusion : We propose that modality can be selected flexibly according to the patients' preferences. And peritoneal permeability characteristics provide valuable information for adjusting PD prescriptions in ultrafiltration failure or in inadequate dialysis. Further study of other clinical performance measures should be performed to clarify the comparable outcomes in different PD modalities.

• Journal of Animal Science and Technology
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• v.46 no.4
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• pp.509-516
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• 2004

This study is to investigate the amount of biased estimates for heritability and genetic correlation according to data structure on marbling scores in Korean cattle. Breeding population with 5 generations were simulated by way of selection for carcass weight, Longissimus muscle area and latent values of marbling scores and random mating. Latent variables of marbling scores were categorized into five by the thresholds of 0, I, 2, and 3 SD(DSI) or seven by the thresholds of -2, -1, 0,1I, 2, and 3 SD(DS2). Variance components and genetic pararneters(Heritabilities and Genetic correlations) were estimated by restricted maximum likelihood on multivariate linear mixed animal models and by Gibbs sampling algorithms on multivariate threshold mixed animal models in DS1 and DS2. Simulation was performed for 10 replicates and averages and empirical standard deviation were calculated. Using REML, heritabilitis of marbling score were under-estimated as 0.315 and 0.462 on DS1 and DS2, respectively, with comparison of the pararneter(0.500). Otherwise, using Gibbs sampling in the multivariate threshold animal models, these estimates did not significantly differ to the parameter. Residual correlations of marbling score to other traits were reduced with comparing the parameters when using REML algorithm with assuming linear and normal distribution. This would be due to loss of information and therefore, reduced variation on marbling score. As concluding, genetic variation of marbling would be well defined if liability concepts were adopted on marbling score and implemented threshold mixed model on genetic parameter estimation in Korean cattle.

• Korean Journal of Food Science and Technology
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• v.27 no.4
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• pp.537-545
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• 1995

Quality changes of lettuce were studied during storage to investigate the efficiency, cooling properties and the washing and storage effects of immersion-type hydrocooling. As a result of plotting the nondimensionalized lettuce temperature versus cooling time, its cooling rate coefficient was shown to be $-0.365\;min^{-1}{\sim}-0.255\;min^{-1}\;(R^2=0.99{\sim}0.88)$. Rate of weight loss was not significantly (p>0.05) different between lettuces with various treatment conditions during storage at $5^{\circ}C$. However, during storage at $15^{\circ}C$, weight loss of hydrocooled lettuce was lower than that of non-treated lettuce after from 10 to 15 days. Especially, The lettuce packed with PE was more effective than that packed with try in terms of packing condition after hydrocooling. Lettuce pretreated with sterilizing agent, packed with PE vinyl film, removed residual water after hydrocooling had lower decaying rate than any other lettuces. Changes of L and b values in hydrocooled lettuce were slower than those of non-treated one. During changes of chlorophyll content, the initial value, $115.7{\sim}147.3\;mg%$ was decreased to $50{\sim}60%$ after 25 days of storage at $5^{\circ}C$ and within 15 days of storage at $15^{\circ}C$. It could be presumed that the addition of sterilizing agent reduced the initial level of overall total and coliform count and its growth rate during storage. The respiration rate of hydrocooled lettuce at $5^{\circ}C$ was $23.95\;mg{\cdot}CO_2/kg\;hr$, which is 10% of those of non-treated lettuce.