• 대한수의학회지
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• 제20권2호
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• pp.93-97
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• 1980

To observe sequential postmortem autolysis in liver of Korean native cattle, liver placed in controlled environment chamber at $23-27.5^{\circ}C$ was treated after various intervals and observed with light microscope. The nuclear fading accompanied by margination of the chromatin in the hepatocytes appeared by 3 to 6 hours, and reduction of the cytoplasmic stainability and haryolisis began at 15 hours after death. Pyknosis of Kupffer's cells was noted by 3 to 20 hours, thereafter followed the decrease in staining of nuclei, but the nuclei were visible until 50 hours after death. Sinusoids and space of Disse were markedly distended at 10 hours, thereafter spaces of Disse were more dilatable than sinusoids. A large number of the erythrocytes in blood vessels were lysed, and the cytoplasmic stainability was largely reduced at 25 hours and nearly disappeared at 40 hours after death.

• Asian-Australasian Journal of Animal Sciences
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• 제26권3호
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• pp.386-393
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• 2013

This experiment was conducted to evaluate anti-Salmonella enteritidis (anti-SE) bacteriophage as feed additives to prevent Salmonella enteritidis in broilers. The experimental diets were formulated for 2 phases feeding trial, and 3 different levels (0.05, 0.1 and 0.2%) of anti-SE bacteriophage were supplemented in basal diet. The basal diet was regarded as the control treatment. A total of 320 1-d-old male broilers (Ross 308) were allotted by randomized complete block (RCB) design in 8 replicates with 10 chicks per pen. All birds were raised on rice hull bedding in ambient controlled environment and free access to feed and water. There were no significant differences in body weight gain, feed intake and feed conversion ratio (FCR) at terminal period among treatments (p>0.05). Relative weights of liver, spleen, abdominal fat and tissue muscle of breast obtained from each anti-SE bacteriophage treatment were similar to control, with a slightly higher value in anti-SE bacteriophage 0.2%. In addition, a numerical difference of glutamic-oxaloacetic transaminase (GOT), glutamic-pyruvic transaminase (GPT) and LDL cholesterol level was observed in the 0.2% anti-SE bacteriophage application even though blood profiles were not significantly affected by supplemented levels of anti-SE bacteriophage (p>0.05). In the result of a 14 d record after Salmonella enteritidis challenge of 160 birds from 4 previous treatments, mortality was linearly decreased with increasing anti-SE bacteriophage level (p<0.05), and Salmonella enteritidis concentration in the cecum was decreased with increasing levels of anti-SE bacteriophage (p<0.05). Based on the results of this study, it is considered that supplementation of 0.2% anti-SE bacteriophage may not cause any negative effect on growth, meat production, and it reduces mortality after Salmonella enteritidis challenge. These results imply to a possible use of anti-SE bacteriophage as an alternative feed additive instead of antibiotics in broilers diet.

• 한국농공학회논문집
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• 제60권3호
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• pp.71-81
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• 2018

$CO_2$ concentration has a significant effect on quality of cold-stored apples. High indoor $CO_2$ concentrations above 10,000 ppm cause the browning of apples and result in economic loss for farmers. The purpose of this study is to evaluate $CO_2$ concentrations and their distribution in a controlled atmosphere (CA) storage and provide better structural designs to improve the $CO_2$ environment using computational fluid dynamics (CFD) simulations. The CFD model was developed for a real CA storage for apples and applied to investigate the effect of changing the inlet and outlet locations and the aspect ratio of the floor of the CA storage on the spatial distributions of $CO_2$ concentration and the browning of the apples. The lowest $CO_2$ concentrations in existing CA storage with a high aspect ratio of the floor were achieved from the combination of the inlet located at the top of the right side and the outlet located at the bottom of the left side. In modified CA storage with a low aspect ratio, the combination of the inlet and outlet located at top and bottom of left side respectively achieved the lowest $CO_2$ concentrations. The proposed case enhanced the storage performance by reducing total browned apples by 3.6% in storage duration of 210 days. This study is expected to reduce the browning damages of apples in CA storage, and thus greatly prevent economic losses.

• 농업생명과학연구
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• 제50권2호
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• pp.175-185
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• 2016

본 연구에서는 UTC 시스템을 대표적인 농업시설인 돈사에 적용하기에 앞서, UTC 제어 시스템 및 프로그램 개발에 따른 돈사 내 적정 사육 환경 유지 및 난방에너지 저감을 위한 기초자료로 활용하고자, 2동의 실험돈사를 제작, UTC 제어 시스템 적용에 따른 실험돈사 내부 온도 변화 및 에너지를 비교, 분석하였다. 제어 시스템은 T1~T4, 총 4점의 온도를 측정 후 프로그램 내 알고리즘에 의해 O1~O5, 총 5개의 출력 신호를 ON/OFF 방식으로 각각 제어하도록 구성하였다. 온도 설정은 실험돈사 내부 온도 28.0℃, UTC 내부 온도 34.0℃로 설정하였고, 측정된 온도와 비교를 통해 출력 신호를 제어하였다. 3일간, 제어 시스템을 가동한 돈사의 경우 최고 온도는 평균 31.8℃로 측정되었다. 같은 시간, 비교돈사의 최고 온도는 평균 36.6℃로 제어 시스템을 가동한 돈사의 내부 온도가 약 4.8℃ 낮은 것으로 나타났다. 또한 제어 프로그램의 가동에 따라 UTC 플레넘 최고 온도는 평균 50.5℃까지 상승한 것으로 나타났다.

• 농약과학회지
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• 제11권1호
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• pp.18-26
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• 2007

콩 검음뿌리썩음병의 방제를 위한 살균제 선발을 위하여 실내 및 온실 검정을 실시하였다. 한천희석법과 96-well microtiter plate법을 이용하여 총 25종의 살균제의 병원균에 대한 생육 억제 효과를 검정하였다. 보호용 살균제 중에서 iminoctadine을 제외한 dithianon, dichlofluanid, mancozeb, captan 등은 한천희석법에서 조사한 병원균의 생육을 억제하는 $EC_{50}$값은 $500{\mu}g\;mL^{-1}$ 이상으로 효과가 매우 낮았지만, 96-well microtiter plate법에서는 4.65, 0.61, 4.64, $0.29{\mu}g\;mL^{-1}$로, 병원균의 포자 발아에 대하여 매우 높은 활성을 보였다. 그러나 ergosterol 생합성을 저해하는 살균제 (EBI) 그룹은 물질에 따라 매우 다른 살균활성을 보였다. Difenconazole의 경우에는 균사생육보다는 포자발아 억제활성이 높았고, prochloraz의 경우에는 균사 생육활성과 포자 발아억제활성이 서로 유사하였다. 이에 비하여 다른 EBI 살균제들은 포자발아보다는 균사생육저해활성이 큰 것으로 나타났다. Carbendazim과 diethofencarb의 혼합제와 dazomet만이 두 가지의 실내 검정법 모두에서 우수한 효과를 보였다. Carbendazim과 diethofencarb의 혼합제를 비롯한 8종의 살균제를 선발하여 온실검정을 실시한 결과, carbendazim과 diethofencarb의 혼합제만이 병원균을 접종하기 2일 전과 후에 토양에 처리하였을 때, 75와 76.7%의 효과를 보였고, tebuconazole은 병원균을 접종하고 2일 후에 관주처리 하였을 때, 83.3%의 효과를 보였다.

• 펄프종이기술
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• 제37권4호통권112호
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• pp.32-37
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• 2005

To Increase the productivity of a paper machine, the maximization of the machine speed is a kind of simple way As the machine speed increases, more intense wet pressing is required to persist the outlet consistency of press part and reduce the water removal of dryer part. With more intense pressing, there are concerns that the quality of paper will be affected. This study was carried out to evaluate the influence of wet-pressing on internal structure of paper, The nip pressure at the first and third nip in triple nip press was controlled. Paper structures, strength properties and pore properties were evaluated. As a result, first nip pressure more strongly influenced the paper structural properties than third nip pressure in triple nip pressing condition. Because of the high water content and low wet-web strength of paper web in first nip, increasing the first nip pressure induced the incipient crushing of wet-web and then caused a potential of web break during the following coating or printing processes.

• 생물환경조절학회지
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• 제3권1호
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• pp.66-71
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• 1994

겨울부터 봄에 걸친 배추의 시설보온재배에서 많이 발생되는 Tipburn현상의 원인을 구명하기 위하여 배추재배 시험구의 토양과 배추의 부위별 무기성분 분석을 했다. 실험결과는 다음과 같다. 1. Tipburn현상의 발생과 토양의 칼슘농도와는 관계가 없었다. 2. 배추부위별 칼슘농도는내엽<중엽<외엽이었고, 내엽맥<중엽맥<뇌엽맥의 순이었다. 3. 이상의 결과로 Tipburn현상의 발생원인은 배추생육의 일정시기에 배추 내엽으로부터 증산작용을 억제시키는 어떤 환경요인에 의해 1차적으로 발생된다고 생각된다.

• Asian-Australasian Journal of Animal Sciences
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• 제21권5호
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• pp.677-684
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• 2008

Accurate estimation of dry matter intake (DMI) is a prerequisite to meet animal performance targets without penalizing animal health and the environment. The objective of the current study was to evaluate some of the existing models in order to predict DMI when lactating dairy cows were offered a total mixed ration containing a high level of concentrates and locally produced agricultural by-products. Six popular models were chosen for DMI prediction (Brown et al., 1977; Rayburn and Fox, 1993; Agriculture Forestry and Fisheries Research Council Secretariat, 1999; National Research Council (NRC), 2001; Cornell Net Carbohydrate and Protein System (CNCPS), Fox et al., 2003; Fuentes-Pila et al., 2003). Databases for DMI comparison were constructed from two different sources: i) 12 commercial farm investigations and ii) a controlled dairy cow experiment. The model evaluation was performed using two different methods: i) linear regression analysis and ii) mean square error prediction analysis. In the commercial farm investigation, DMI predicted by Fuentes-Pila et al. (2003) was the most accurate when compared with the actual mean DMI, whilst the CNCPS prediction showed larger mean bias (difference between mean predicted and mean observed values). Similar results were observed in the controlled dairy cow experiment where the mean bias by Fuentes-Pila et al. (2003) was the smallest of all six chosen models. The more accurate prediction by Fuentes-Pila et al. (2003) could be attributed to the inclusion of dietary factors, particularly fiber as these factors were not considered in some models (i.e. NRC, 2001; CNCPS (Fox et al., 2003)). Linear regression analysis had little meaningful biological significance when evaluating models for prediction of DMI in this study. Further research is required to improve the accuracy of the models, and may recommend more mechanistic approaches to investigate feedstuffs (common to the Asian region), animal genotype, environmental conditions and their interaction, as the majority of the models employed are based on empirical approaches.

• 한국환경농학회지
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• 제42권3호
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• pp.231-238
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• 2023

We analyzed the variations in the CO₂ concentration and temperature between a CO₂-enriched and control greenhouse. We cultivated Alstroemeria 'Hanhera' in the two greenhouses and assessed the growth parameters (stem length, stem thickness, and the number of flowers) and yield. The CO₂-enriched greenhouse had a CO₂ generator that produced CO₂ at rate of 0.36 kg/h and its windows were programmed to open when the temperature exceeded 20℃ and close when it dropped below 15℃. The control greenhouse had no additional CO₂ supplementation, and its windows were programmed to open when the temperature exceeded 20℃ and close at approximately 17:00. In the morning, CO₂ concentration remained above 500 ppm in the CO₂-enriched greenhouse, which was higher than that in the control greenhouse (approximately 370 ppm). The ventilation effect only through the side windows to reduce the temperature in both greenhouses did not appear dynamically. CO₂ supplementation promoted plant growth, resulting in a significant increase in plant yield of over 60% compared to that of the control greenhouse. Our findings suggest that elevated CO₂ concentration in the morning can significantly promote the growth and development of Alstroemeria during the winter.

• 생물환경조절학회지
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• 제21권4호
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• pp.398-403
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• 2012

폐양액 발생을 최소화할 수 있는 배액제로형 수경재배기술 개발을 위하여 토마토 수경재배 시 배액제로 센서를 이용하여 배액을 제로화 또는 최소화하였을 때 표준배액량 처리와 비교하여 근권환경 변화와 토마토의 생육, 수량, 품질 등에 미치는 영향을 구명하였다. 처리별 주당 1일 공급량은 표준배액률 처리가 1.4, 배액제로 1처리가 0.9, 배액제로 2처리가 0.8L이었고, 배액률은 표준배액률 처리가 23.8, 배액제로 1처리가 8.6, 배액제로 2 처리가 3.7%이었다. 표준배액률 처리, 배액제로 1과, 2처리의 함수율과 배지 내 EC는 각각 64.5~88.0%와 $1.5{\sim}3.5dS{\cdot}m^{-1}$, 40.3~76.0%와 $2.5{\sim}4.0dS{\cdot}m^{-1}$, 그리고 56.3~69.0%, $2.7{\sim}3.7dS{\cdot}m^{-1}$이었다. 토마토 생육은 표준배액률 처리에 비해 배액제로 처리에서 엽장, 엽수, 경경은 차이가 없었으나, 초장과 엽폭이 작은 경향을 보였다. 토마토 수량은 표준배액률 처리에 비해 배액제로 처리에서 상품수량이 7.7~12% 적고 1과중이 작았으나, 당도는 반대로 높았고 상품과률은 차이가 없었다.