• 상하수도학회지
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• 제27권6호
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• pp.703-709
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• 2013

Among many microalgae cultivation types, heterotrophic culture with low cost carbon sources and energy saving culture method is crucial. A result of estimating the effects of pH on wastewater treatment using heterotrophic growing microalgae Chlorella sorokiniana shows that there was no difference in microalgae growth amount and nitrogen, phosphorus removal rate by wide range of pH(5 ~ 9). From pH 5 to 9, total nitrogen, phosphorous and glucose removal rates were 10.5 mg-N/L/d, 2 mg-P/L/d, 800 ~ 1000 mg/L respectively. This study reveals that C. sorokiniana cannot metabolite glycerol heterotrophically, however, glucose and acetate were proper carbon sources for growth and T-N, T-P and TOC removal. This research highlights the potential of heterotrophic microalgal growth with wastewater treatment plant with wide range of pH and carbon sources.

• 한국환경과학회지
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• 제27권11호
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• pp.1117-1127
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• 2018

This study was carried out to gather basic data for the purpose of proposing a plan to improve the water quality and conserve the aquatic ecosystem of the Singu Agricultural Reservoir in Korea. The water quality, sediment composition, benthic macroinvertebrate distribution, and fish distribution in the Singu Reservoir were analyzed; the reservoir is located close to farmlands, forests, villages, and livestock breeding areas. The results of the water quality analysis are as follows: 5.8~7.8 mg/L for dissolved oxygen, 13.1~20.7 mg/L for chemical oxygen demand, 14.4~18.8 mg/L for suspended solid, 0.96~1.70 mg/L for total nitrogen, 0.07~0.11 mg/L for total phosphorous, and $41.9{\sim}49.8{\mu}g/L$ for $chlorophyll-{\alpha}$. In total, 75 benthic macroinvertebrate specimens belonging to 4 classes, 7 orders, 14 families, and 17 species were recorded. The ecological scores of the benthic macroinvertebrate communities ranged from 11 to 23. Fish specimens recorded belonged to two families and four species. The dominant fish species were Carassius auratus and Pseudorasbora parva, both of which are water-pollutant tolerant species.

• Journal of Animal Science and Technology
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• 제57권7호
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• pp.26.1-26.5
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• 2015

Background: Rice bran is a by-product of the rice-milling process, which remains largely underutilized; however, efficient processing treatments may improve its feeding value for chickens. This is of great economic and environmental importance, as this can lower the production costs, and offer an opportunity for valorization of a low-quality agricultural by-product, to a high-value feed source. Methods: This experiment was conducted to study the effect of extruded rice bran on performance and phosphorous (P) bioavailability in broiler chickens. In a completely randomized design, 200 seven-day-old broilers (Cobb 500) were allotted to five treatments with five replicates per treatment and 8 chicks per replicate, and fed with their respective diet during the starter (8 to 21 days) and grower (22 to 42 days) periods. Diets were a basal corn-soybean based diet (T1), or diets containing 20 % rice bran (T2), 30 % rice bran (T3), 20 % extruded rice bran (T4), or 30 % extruded rice bran (T5). Results: Birds feeding on T4 and T5 diets had a higher body weight gain and lower feed-to-gain ratio compared to those feeding on T2 and T3 diets (p < 0.05). Birds receiving diets containing extruded rice bran had higher total P availability and tibia ash content, as compared with those receiving diets containing un-extruded rice bran (p < 0.05). Relative weight of the pancreas was higher in birds receiving T2 and T3 diets. Conclusions: The results confirmed the beneficial effect of extrusion treatment of rice bran on performance and P availability in broilers. Up to 30 % extruded rice bran may be included in the broiler diet without apparent adverse effects on the performance.

• 대한영양사협회학술지
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• 제7권4호
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• pp.349-360
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• 2001

The purpose of this study was to investigate the nutritional status of school lunch supported students and to provide fundamental data for improving their health. In order to do that, we collected the data for 59 school lunch supported students and 71 not supported students in an elementary school in the Taegu Metropolitan city area. The survey was conducted from February 10 to April 30, 2000. The results are as follows; In relation to their body composition(BMI, Fatmass, Percent Body Fat, Mid-upper Arm Muscle Circumference, Mid-upper Arm Circumference), the school lunch supported students' value was lower than that of the not supported students. In relation to food intake according to the food groups, the school lunch supported students' intake of animal food(p<0.05) and total food(p<0.01)was significantly lower than that of the other students. The average intake of energy for both school lunch supported students and not supported students was below the RDA. Also, it was significantly lower than that of the school lunch supported students in relation to the other students(p<0.05). For protein, calcium, phosphorous, and riboflavin, the school lunch supported students' intake was significantly lower than that of the students who were not supported(p<0.05, p<0.05, p<0.05, p<0.05). There are the classification in relation to the nutrient intake in relation to the RDA standards for that of the school lunch supported students. The criteria used for this study was calorie intake, protein, and niacin. The classifications are for groups below 75%, between 75%～100%, and 100%. The nutrients for which the students were deficient( below 75%) of the RDA were iron, calcium, riboflavin, vitamin C, thiamin, calorie, niacin, vitamin A, protein, and phosphorous in the above order.

• 한국재료학회지
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• 제23권7호
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• pp.392-398
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• 2013

A two-pass differential speed rolling(DSR) was applied to a deoxidized low-phosphorous copper alloy sheet in order to form a homogeneous microstructure. Copper alloy with a thickness of 3 mm was rolled to 75 % reduction by two-pass rolling at $150^{\circ}C$ without lubrication at a differential speed ratio of 2.0:1. In order to introduce uniform shear strain into the copper alloy sheet, the second rolling was performed after turning the sample by $180^{\circ}$ on the transverse direction axis. Conventional rolling(CR), in which the rotating speeds of the upper roll and lower roll are identical to each other, was also performed by two-pass rolling under a total rolling reduction of 75 %, for comparison. The shear strain introduced by the conventional rolling showed positive values at positions of the upper roll side and negative values at positions of the lower roll side. However, samples processed by the DSR showed zero or positive values at all positions. {100}//ND texture was primarily developed near the surface and center of thickness for the CR, while {110}//ND texture was primarily developed for the DSR. The difference in misorientation distribution of grain boundary between the upper roll side surface and center regions was very small in the CR, while it was large in the DSR. The grain size was smallest in the upper roll side region for both the CR and the DSR. The hardness showed homogeneous distribution in the thickness direction in both CR and DSR. The average hardness was larger in CR than in DSR.

• Elastomers and Composites
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• 제42권3호
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• pp.177-185
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• 2007

유기화된 montmorillonite(O-MMT)와 인을 포함하는 polyamic acid(PPAA)를 용액 블렌딩하여 PAA/organoclay 나노 복합체를 제조하였다. 이들 나노 복합체들의 연구를 위하여 FT-IR, DSC, TGA, PCFC, SEM 그리고 XRD를 이용하였다. 나노복합체들의 제조확인은 FT-IR과 XRD 분석을 통하여 확인하였다. SEM 사진들은 O-MMT가 매트릭스 고분자에 비교적 고르게 분산되어 있음을 보여 주었고, XRD 결과를 통하여 O-MMT가 intercalation 되었음을 확인하였다. O-MMT/PPAA 나노복합체들의 열안정성 및 난연성은 순수한 PAA 보다 크게 높았으며, O-MMT/PPAA-0.2, 0.4, 0.6 복합체들의 열방출 용량과 총열방출 값들은 인의 함량 증가와 함께 감소하였다. 본 연구에서 제조된 나노복합체 필름들이 화재안전재료로서 사용될 수 있는 잠재성을 가지고 있음을 확인하였다.

• Journal of Ecology and Environment
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• 제46권3호
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• pp.204-217
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• 2022

Background: Increasing land demands for food production have led to biodiversity loss and land degradation in the Madhupur Sal forest. Reforestation activities such as agroforestry and woodlot plantation support the conservation of diversity, restoration of forest and prevention of soil erosion in degraded natural Sal forest. Knowing about these reforestation activities, this study is needed to compare the species composition, richness, and soil nutrients of these two plantation activities to the natural Sal forest in the degraded Madhupur Sal forest in Bangladesh. Results: The analysis showed that in between the reforestation activities, the highest Shannon-Wiener index (1.79), evenness (0.60) and Simpson's index (0.79) were found in the agroforestry site compared to the woodlot plantation site. On the contrary, the highest species richness (n = 14), tree basal area (19.56 m² ha^-1), Margalef's index (1.96) were recorded in woodlot plantation than in the agroforestry site. We observed that at 0-15 cm depth, soil organic matter (2.39%), total nitrogen (0.14%), available phosphorous (62.67 ㎍ g^-1) and exchangeable potassium (0.36 meq/100 g) in agroforestry plots were significantly higher compared to other forest sites. At topsoil (15-30 cm depth), soil organic matter (1.67%) and available phosphorous (21.09 ㎍ g^-1) were found to be higher in agroforestry site. Conclusions: Both reforestation approaches improved soil function, although woodlot plantation had the higher species richness. Therefore, plantation activities by the sustainable implementation of these two practices are the best alternative to restore the biodiversity, richness and conserve soil fertility in the Madhupur Sal forest of Bangladesh.

• 한국물환경학회지
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• 제33권4호
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• pp.434-440
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• 2017

In order to understand the characteristics of phosphorus in the paddy field, this study analyzed $PO_4-P$ and T-P concentrations of irrigation water, flooding water, and runoff from 2008 to 2010. The variation of phosphorous form within hydrologic cycle around the rice paddy field was investigated using the ratio of $PO_4-P$ to TP. In addition, the correlation between pH, EC, and DO in flooding water was analyzed and the factors affecting phosphorus form in paddy field were investigated. The concentration of T-P in flooding water was high during the survey period, and the concentration of T-P in runoff was assumed to be decreased by dilution due to irrigation and rainfall. On the other hand, the ratio of $PO_4-P$ to T-P was lower in flooding water than those of irrigation water and runoff, which was interpreted to be due to the fact that the phosphorus fertilizer was applied in the paddy field but the adsorption was rapidly occurred to the paddy field by the soil. The similar proportions of $PO_4-P$ to T-P in flooding water and runoff suggest that the form of phosphorus outflowed from the paddy is influenced by the form of phosphorus in the flooding water of paddy field. In addition, DO concentration in flooding water showed negative correlation with the concentrations of $PO_4-P$ and T-P. The effort to survey frequent irrigation water quality data is required for the analysis of phosphorus behavior in the paddy water system since concentration of phosphorous and DO in irrigation water would influence rhe form of phosphorous in flooding water and subsequent runoff.

• 한국가축번식학회지
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• 제23권2호
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• pp.175-180
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• 1999

본 실험은 한우 번식장애우와 저수태우의 혈액 성분 및 성선호르몬(estrogen과 progesterone)의 농도를 비교 분석하여 번식우의 기초적인 생리지표를 확립시키는데 있다. 본 실험의 결과를 요약하면 다음과 같다. 1. 저수태 한우와 번식장애우 혈중 albumin, BUN, Ca, cholesterol, creatine, glucose, phosphorous, total protein 및 triglyceride 함량은 3.28$\pm$0.05 와 3.27$\pm$0.04 g/㎗, 11.07$\pm$0.61와 12.69$\pm$0.88 mg/㎗, 9.98$\pm$0.10와 9.56$\pm$0.11mg/㎗, 105.75$\pm$3.57와 126.78$\pm$5.66 mg/㎗, 1.62$\pm$0.05와 1.65$\pm$0.09 mg/㎗, 67.46$\pm$3.07와 76.97$\pm$3.76 mg/㎗, 6.13$\pm$0.36 와 6.11$\pm$0.26 mg/㎗, 5.82$\pm$0.08와 6.18$\pm$0.08 g/㎗ 및 12.82$\pm$1.46와 15.19$\pm$1.61 mg/㎗으로 나타났다. 2. 혈청의 중요한 성분중 하나인 요소태 질소, 칼슘 및 인의 함량이 번식 장애우와 저수태우의 경우 정상우보다 다소 높은 경향을 나타냈으며, 특히 콜레스테롤의 함량이 번식 장애우와 저수태우의 경우 정상우의 약 2배정도 현저히 높은 성적을 나타냈다. 3. 발정주기중 혈액내 progesterone 수준은 임신우와 비임신우에서 수정후 18일까지는 비슷한 수준(6.55$\pm$0.17, 5.46$\pm$0.18 ng/$m\ell$)을 보였으나 그 후 임신우에서는 점차 증가하였고 비임신우에서는 발정일 (0.18$\pm$0.03 ng/$m\ell$)에 급감하였다. 4. 번식 장애우와 저수태우의 혈중 estrogen과 progesterone 함량은 각각 57.42$\pm$5.03, 56.76$\pm$8.73 pg/$m\ell$과 6.26$\pm$0.83 ng/$m\ell$, 9.41$\pm$1.85 ng/$m\ell$으로서, 혈중 progesterone 농도가 정상우의 황체기 수준으로 유지되어 발정발현과 수태가 억제되는 것으로 나타났다.

• 한국환경복원기술학회지
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• 제9권2호
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• pp.23-32
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• 2006

Total suspended solids (TSS), five-day biochemical oxygen demand ($BOD_5$), total nitrogen (T-N), and total phosphorous (T-P) concentrations around and under a floating island were examined from October 2002 to September 2003. The island was installed in July 2002 on the surface of an agricultural irrigation reservoir located in the southern part of the Korean Peninsula. It was composed of six polyethylene panels. Each panel was 2 m (length) ${\times}$ 1 m (width) ${\times}$ 0.02 m (thick) and had about thirty-two holes each with a diameter of eight centimeters, through which plant roots grew down into the water. Coconut fibers of nine-centimeters in height were placed on the panel, which sustained plants rhizomes and roots. Both the fibers and the panel were raped with polyethylene wire mashes. About thirty irises (Iris pseudoacorus) were planted into the fibers of each panel. The concentrations of TSS, $BOD_5$, T-N and T-P below the island during the iris-growing season averaged 9.70, 2.59, 3.61 and 0.14 mg/L, respectively and those around it averaged 9.99, 2.83, 4.07 and 0.16 mg/L, respectively. The average concentrations of TSS, $BOD_5$, T-N and T-P below it during the iris non-growing season were 8.68, 2.37, 3.25 and 0.14 mg/L, respectively and those near it were 8.76, 2.43, 3.34 and 0.15 mg/L, respectively. At a significance level of ${\alpha}$=0.05, $BOD_5$, T-N and T-P concentrations under the island during the iris-growing season were significantly low when compared with those around it except TSS. No differences in TSS, $BOD_5$, T-N and T-P concentrations between around and near it were found at a significance level of ${\alpha}$=0.05 during the iris non-growing season. The removal of $BOD_5$, T-N, and T-P during the growing season were significantly high when compared with those during the non-growing season. TSS abatement of the floating island was very low during both the growing and non-growing seasons. The island's reductions of $BOD_5$, T-N and T-P were good during the growing season, especially T-N and T-P, which have been considered as primary pollutant sources causing the water quality degradation of reservoirs. The removal of T-N and T-P was primarily attributed to the absorption of nitrogen and phosphorous by the irises during the growing season.