• Asian-Australasian Journal of Animal Sciences
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• 제5권4호
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• pp.699-707
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• 1992

Three goats were fed with $^{15}N$-labelled rice straw to study the characteristics of digestion, assimilation, metabolism and excretion of C and N compounds from rice straw. It was shown that the amount of $^{15}N$ assimilated into the bodies of the two slaughtered goats accounted for 38.5 and 23.6% of the total amount of $^{15}N$ ingestion in the experimental diet by each goat. The $^{15}N$ excreted via the feces and urine for the three goats accounted for 34.8, 33.2 and 33.9% of the total amount of $^{15}N$ ingested in the feed of the 3 goats. The recoveries of $^{15}N$ from the two slaughtered goats were 73.3 and 57.5%, with the corresponding rates of $^{15}N$ loss 26.7 and 42.5% respectively. The amino acids digestibilities were 68.7 and 54.0%, while the digestibilities of carbohydrates were 74.8 and 67.7% respectively for goats 1 and 3.

• 유기물자원화
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• 제6권1호
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• pp.13-20
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• 1998

고농도 유기폐수인 양돈 폐수에 광합성 미생물(Rhodospirillum rubrum N-1)을 접종하고 여기에 공기를 160 mL/min 주입함으로써 양돈분뇨의 악취제거 효과를 조사하였다. 7일 동안 1일 간격으로 이화학적 변화를 검토하였다. 검토 결과 Biochemical Oxygen Demand (BOD) 20,000ppm인 양돈폐수의 경우 호기적 조건과, Rhodospirillum rubrum N-1 접종한 경우 volatile fatty acids(VFAs)의 제거율이 87.0%였으며, BOD제거율 54.6%, $PO_4-P$는 54.5%의 감소를 보였고, PH, $NH_3$ 등은 증가하는 경향을 나타내었다. T-N, T-P, $NO_3-N$, $NO_2-N$, $H_2S-N$, mercaptane 등은 별다른 증감율을 보이지 않고 일정하게 나타났다.

• 한국응용과학기술학회지
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• 제21권2호
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• pp.148-155
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• 2004

Response surface analysis was used to study dietary ratios of n-3/n-6 fatty acid and P/S to minimize plasma triglycerides, total cholesterol and LDL ${\cdot}$ VLDL-C levels and maximize plasma HDL ${\cdot}$ C levels of rats. Because the dietary components were not statistically independent, they were studied in combinations of two variables. The two-variable combinations were the most useful in locating the desired maximum or minimum plasma triglycerides, total cholesterol and LDL ${\cdot}$ VLDL-C response in terms of the proportions of the dietary components. Response surface contours and three dimensional plots were developed for each plasma lipid response. The contours and three dimensional plots were used to help determine those combinations of the dietary fatty acid ratios that would produce the desired minimum or maximum lpid responses. The statistical analyses indicated that the minimized plasma cholesterol response levels could be attained with a diet consisting of 2.26 n-3/n-6 fatty acid and 2.15 P/S ratios.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2022년도 추계학술대회
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• pp.229-230
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• 2022

미래환경에 부합하는 스마트 항로표지는 다양한 정보를 생성하고, 다양한 방식으로 제공될 것이다. 해양 이용자에게 적절한 서비스제공을 위해 관리자는 언제든지 항로표지를 확인하고, 원하는 형식으로 자료를 확인할 수 있어야 한다. 또한 미래의 항로표지가 적절히 관리되기 위해서는 항로표지사고의 원인을 파악하고, 재발 방지를 위해 노력해야 할 것이다. 이를 본 연구에서는 항로표지사고에 대하여 원인 7종과 사고종류를 11종으로 구분하여 제시하였다.

• 한국초지조사료학회지
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• 제36권3호
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• pp.215-222
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• 2016

Nitrogen (N) fertilizer management is one of the important aspects of economic production of sorghums in sustainable agriculture. The aim of the study was to evaluate the effects of different N application rates and its split N application methods on productivity, growth characteristics, N accumulation, N use efficiency (NUE), and feed value of Sorghum ${\times}$ Sudangrass hybrids. Treatments consisted of five N application rates (0, 150, 200, 250, and $300kg\;ha^{-1}$) and two split N application methods (40% in basal N, 30% at the growing stage, and 30% after the first harvest vs. 50% in basal N and 50% after the first harvest). Plant height, leaf width, and stem diameter were increased ($p{\leq}0.05$) with increasing N fertility rates at each harvest. Chlorophyll content (expressed as SPAD values) was the highest at a rate of $300\;kg\;N\;ha^{-1)$ (first harvest, 46.32; second harvest, 33.09). It was the lowest at zero N (first harvest, 21.56; second harvest, 18.5). Total N, N uptake, and NUE were increased with higher N rates. Split N application had little effect on total N, amount of N uptake, or NUE. Total dry matter yields were the highest ($21,715\;kg\;ha^{-1}$) at a rate of $300\;kg\;N\;ha^{-1}$. It was the lowest ($10,054\;kg\;ha^{-1}$) at zero N. Our results suggest that more than $300\;kg\;N\;ha^{-1}$ can improve dry matter yield to be above 116% compared to zero N, thus enhancing the agronomic characters of sorghums. However, no significant effect had been found for split N application. Further work is needed to determine the optimal N levels and the effect of split N application rates.

• 한국미생물학회:학술대회논문집
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• 한국미생물학회 2001년도 추계학술대회
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• pp.113-120
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• 2001

The production of microcystins from Microcystis aeruginosa was investigated in a P-limited continuous culture and a batch culture. The microcystin content of M aeruginosa was higher at a lower $\mu$, whereas the microcystin (MC)-producing rate was linearly proportional to $\mu$. The ratios of the MC-producing rate to the C-fixation rate were higher at a lower $\mu$. Consequently, increases in the microcystin content per dry weight along with the production of the more toxic form, MC-LR, were both observed under more P-limited conditions. The microcystin content of M. aeruginosa exhibited a high correlation with the total N content regardless of N-fixed or P-fixed culture. The microcystin concentration was investigated from spring to autumn in 1999 in the Daechung Reservoir, Korea. The dominant species in the algal blooming season was Microcystis. When the microcystin concentration exceeded about 100 ng $1^{-1}$ the ratio of particulate to dissolved total nitrogen (TN) or total phosphorus (TP) interestingly converged at a value of 0.6. The microcystin concentration was lower than 50 ng $1^{-1}$ at a particulate N:P ratio below 8, whereas the microcystin concentration varied quite substantially from 50 ng $1^{-1}$ to 250 ng $1^{-1}$ at a particulate N:P ratio> 8.

• 대한두경부종양학회지
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• 제14권1호
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• pp.88-93
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• 1998

In order to review the clinicopathologic characteristics of the thyroid cancer associated with benign thyroid disease, we evaluated 47 patients treated between January, 1993 and September, 1997 at the Chonnam National University Hospital. In those period, we had operated a total of 690 thyroidectomy of which 320 were diagnosed as thyroid cancer. Forty three(91.4%)occurred in women and four(8.5%)occurred in men. The mean age at operation was 46.7years(range, 15 to 76 years). Forty three of the 47 cancers(91.4%) were papillary carcinomas while 4(8.5%)were follicular. Twenty four of the 47 patients (51%) were occult thyroid carcinomas measured less than 1 cm in diameter. The concurrent benign disease were nodular goiter(n=17), Hashimoto's thyroiditis(n=16), follicular adenoma(n=10), Graves' disease(n=2) and diffuse hyperplasia(n=2). Thirty one patients were diagnosed by preoperative FNAC and they underwent total thyroidectomy. Three were diagnosed by frozen section examination at the time of operation. Among them, one underwent total thyroidectomy and two underwent subtotal thyroidectomy. Eight cases revealed lymph node metastases and 2 cases extended to surrounding muscles. In conclusion, concurrent thyroid cancers and benign thyroid disease are not uncommon and a regular ultrasonic follow-up with selective aspiration cytologic examination is recommaned to enhance their diagnostic accuracy.

• 한국농공학회논문집
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• 제46권1호
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• pp.99-105
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• 2004

The present agricultural water quality standards are set by a policy goal. This is intended for water quality management of public water resources, but not for the use of water resources. These standards were not determined by considering the influence of water quality on the safety of agricultural produce and the growth, yield and quality of agricultural crops. Thus, this study was carried out to investigate the influence of irrigation water quality on the growth, yield, and grain quality of rice and acquire fundamental knowledges to set up irrigation water quality standards. The pot experiment was conducted with 4 treatments using irrigation waters with various total nitrogen concentrations (control, 1, 5, 10, 20mg/L) and replicated four times with randomized block design. The results of this study showed that plant height, number of tiller, plant dry weight, the uptake of N, P, and K, and rice protein contents tended to increase as the T-N concentration in irrigation water was increased. In addition, grain yield at T-N 20 mg/L was significantly higher than in the control, but the percentage of head rice was slightly lower due to the increase of green kernel and white belly/core kernel.

• 한국수산과학회지
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• 제56권5호
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• pp.676-683
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• 2023

The development of the egg, larvae, and juveniles of Acheilognathus macropterus from the Wicheon stream of Nakdonggang River was investigated for early life history characteristics. The fish used in the study were collected from Wicheon stream located in Bian-myeon, Uiseong-gun, Gyeongsangbuk-do. The fertilized egg was 1.88±0.09 mm (n=30) in long diameter and 1.34±0.06 mm (n=30) in short diameter. After fertilization at a water temperature of 20℃, the egg took 31 h and 40 min to hatch. Newly hatched larvae had an average total length of 3.92±0.13 mm (n=30) and possessed a yolk sac the mouth and anus were not developed. Twenty days after hatching, the postflexion larvae had an average total length of 8.08±0.29 mm (n=30), with the tail tip fully bent at 45° and began feeding. Thirty-three days after hatching, the number of fin stems reached an integer with an average total length of 15.0±1.08 mm (n=30). In this study, differences in the egg size, hatching time, melanophore development period, and distribution location were confirmed between A. macropterus and allied species.

• Asian-Australasian Journal of Animal Sciences
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• 제19권11호
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• pp.1623-1631
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• 2006

The objective of this study was to evaluate the effect of protein and energy on goats fed oil palm fronds (OPF) as roughages. Twenty-four male Saanen goats aged between 7 and 8 months and weighing $23.4{\pm}1.6kg$ were used in a $2{\times}3$ factorial design. Factors were three levels of urea (3%, 4% or 5%) and two levels of energy (low energy (LE) or high energy (HE)). On average, all parameters measured, including dry matter intake (DMI), nutrient digestibility, digestible nutrient intakes, ruminal ammonia-N ($NH_3$-N), ruminal total volatile fatty acid (total VFA) and individual VFA concentrations (mM/L), microbial N supply, P/E ratio and N retention were higher for HE compared to LE diets. Significant (p<0.05) interactions were found between levels of urea and energy for nonstructural carbohydrate (NSC) and energy (DE) digestibilities, ruminal $NH_3$-N and total VFA concentrations. HE diets had higher N absorption and retention than LE diets. Interactions between urea and energy for plasma urea nitrogen (PUN), heat production (HP), and urine and faeces N excretion were significantly lower (p<0.05) for the HE diets than those recorded for the LE diets. The results indicated that supplementation of energy enhanced utilization of urea and resulted in higher animal performance as a consequence of improved ruminal fermentation, microbial yield and N balance. However, the optimal level of urea supplementation remained at 3% in the HE diet.