• Animal Bioscience
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• 제34권6호
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• pp.1022-1028
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• 2021

Objective: Supplemental nitrate is known to be an effective tool to mitigate methane emission by ruminants. Based on theoretical considerations, supplemental nitrate can improve but also deteriorate the growth performance. The overall effect of supplemental nitrate on growth performance, however, is not yet known. The objective of the current study was therefore to evaluate the effect of a higher dose of NO3- on overall growth performance when feeding either Pangola grass hay or rice straw. Methods: Thirty-two crossbred, 3-month-old Thai native×Anglo-Nubian crossbred male goats were used. The experiment had a 2×2 factorial design with an experimental period of 60 days. Eight goats were randomly allocated to each dietary treatment, i.e. a ration containing either Pangola hay (Digitaria eriantha Steud) or rice straw (Oryza Sativa) as a source of roughage, supplemented with a concentrate containing either 3.2% or 4.8% potassium nitrate. The rations were formulated to be isonitrogenous. The animals were weighed at the start of the experiment and at days 30 and 60. Feces were collected during the last five days of each 30-day period. Results: High-nitrate increased overall DM intake by approximately 3%, irrespective the source of roughage, but only the goats fed a rice straw-based ration responded with an increase in body weight (BW). Thus, the overall feed conversion ratio (kg feed/kg BW gain) was influenced by roughage source ×nitrate and decreased by almost 60% when the goats were fed rice straw in combination with a high versus a low dietary nitrate content. The digestibility of macronutrients was only affected by the source of roughage and the digestibility of organic matter, crude protein, and neutral detergent fibre was greater when the goats were fed Pangola hay. Conclusion: It was concluded that the replacement of soybean meal by nitrate improves the growth performance of meat goats fed rations based on rice straw, but not Pangola hay.

• 비교문화연구
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• 제29권
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• pp.25-53
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• 2012

The attitude of observer in the painting of history is to exclude a prejudice and a subjective view of an artist and to introduce a photograph, which is a record of objectivity, in the process of painting. Its ultimate intent is to redescribe the fact of an event's image intactly without any prejudice and to represent the event as a proven evidence that it was. The representation of history based on fact had already been conceived in imagination of renowned artists such as Francisco Goya or $Th{\acute{e}}odore$ $G{\acute{e}}ricault$ even before cameras were invented. What they portrayed was their own truth of reality which is gained through their observation, not a history that have corresponded to political ideologies, for all reliance on a limited tool of representation, painting. Furthermore, history was necessary for 19th century impressionism artists to be represented under proven fact in a neutral perspective excluding all subjective prejudice, not based on the representation with imagination. Edouard Manet in particular reconstited an instant moment on the basis of real proof of photograph without personal prejudice or opinion as if today's photojournalism. The catastrophic series by Andy Warhol and the photographic painting by Gerhard Richter show another role of painting in the realm of art, each of them implying information distortion and abuse by current media and intentional deformation toward history as Manet's painting of history. Today, the representation of an historical event that we experience in the era of the Internet and social networks having a great deal of information already came to be the exclusive property of the cutting edge mass media. Nevertheless, the attitude of observer which is realistic and contemplative in the realm of art is the crucial point in terms of artists' act as ever.

• 농업과학연구
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• 제46권3호
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• pp.569-577
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• 2019

The current experiment was conducted to compare nutrient utilization in the aged laying hens with different eggshell strengths or different intensities of brown eggshell color. Two metabolic trials with 96-week-old Hy-Line Brown laying hens were conducted. Twelve hens with a strong eggshell strength (SES) and 12 hens with a weak eggshell strength (WES) were selected and used in the first experiment, whereas 12 hens with dark brown eggshells (DBE) and 12 hens with light brown eggshells (LBE) were selected and used in the second experiment. All hens were fed a common commercial layer diet. Diets included chromic oxide as an indigestible marker to determine the apparent total tract retention (ATTR) of the gross energy (GE), dry matter, acid-hydrolyzed ether extract, nitrogen, neutral detergent fiber, acid detergent fiber, ash, and minerals. The results indicate that the ATTR of Ca in the aged laying hens with SES (59.7%) was greater (p < 0.05) than in the aged laying hens with WES (48.6%). However, the ATTR of the GE and other nutrients was not different between the hens with SES or WES. There were no differences in the ATTR of GE and nutrients between the hens with DBE or LBE. In conclusion, aged laying hens with SES have a greater ability to utilize dietary Ca than those with WES, indicating that the extent of dietary Ca utilization determines the eggshell strength of aged laying hens. However, nutrient utilization in diets may have little impact on eggshell brown coloration in aged laying hens.

• 한국축산식품학회지
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• 제38권6호
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• pp.1226-1236
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• 2018

Ovotransferrin (OTF) is a well-known protein of the transferrin family with strong iron chelating activity, resulting in its antimicrobial activity. Furthermore, OTF is known to have antioxidant, anticancer, and antihypertensive activities. However, there have been few studies about the immune-enhancing activity of OTF. In current study, we investigated the immune-enhancing activity of OTF using the murine macrophage cells in vitro. The effect of OTF on production of pro-inflammatory mediators and cytokines were determined using Griess assay and quantitative real-time PCR. Using Neutral Red uptake assay, we confirmed the effect of OTF on phagocytic activity of macrophages. Ovotransferrin significantly increased the production of nitric oxide (NO) and secretion of inducible nitric oxide synthase (iNOS) mRNA with no cytotoxic activity. Ovotransferrin (2 mg/mL) stimulated NO production up to $31.9{\pm}3.5{\mu}M$. Ovotransferrin significantly increased the mRNA expression levels of pro-inflammatory cytokines which are tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$), Interleukin-$1{\beta}$ (IL-$1{\beta}$), and IL-6: OTF (2 mg/mL) treatment increased the secretion of mRNA for TNF-${\alpha}$, IL-$1{\beta}$, and IL-6 by 22.20-, 37.91-, and 6.17-fold of the negative control, respectively. The phagocytic activity of macrophages was also increased by OTF treatment significantly compared with negative control. Also, OTF treatment increased phosphorylation level of MAPK signaling pathways. These results indicated that OTF has immune-enhancing activity by activating RAW 264.7 macrophages via MAPK pathways.

• 한국의상디자인학회지
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• 제23권1호
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• pp.129-142
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• 2021

This study aims to identify the perception of New-Hanbok one-piece dresses that female consumers have purchased and to analyze the design preference based on design types and brands. Analysis was conducted on New-Hanbok brand websites, and additional research was carried out through a survey of 402 women in their 20s and older. The survey consisted of 36 questions, which were divided into categories including pattern, color, material, and recognition of the one-piece dress. The research results are as follows. First, the preferred design form of the New-Hanbok one-piece dress was long length, medium fit, princess line, round git, rectangular git, regular width git, V neckline, regular width dongjeong, front closing with a wide overlap of the chest are a, narrow goreum, a skirt part with moderate crease spacing and number of pleats, A-line skirt silhouette, long and narrow sleeves, diagonal shoulder line, and a cuff at the end of each sleeve. Second, the preferred colors of the New-Hanbok one-piece dress were bright, neutral, or light and were predominately monochromatic Third, the preferred fabric conveyed a contemporary atmosphere through its print pattern. The most favored fabric material was cotton. Through this study, more systematic design development research should be carried out focusing on the current situation and identifying problems, thereby improving traditional culture.

• Corrosion Science and Technology
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• 제21권3호
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• pp.209-220
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• 2022

Erosion-corrosion behaviors of Hadfield steel under a neutral aqueous environment with fine SiO₂ particles were examined and compared with those of conventional carbon steel. A range of electrochemical experiments (potentiodynamic polarization, linear polarization, and impedance), immersion test, and slurry pot test (i.e., erosion-corrosion test) were performed. Results showed that the Hadfield steel composed of austenitic matrix with (Fe,Mn)-based carbide had lower corrosion potential and higher corrosion current density than carbon steel with a typical ferrite/pearlite structure. In addition, pipe forming increased total corrosion rates (i.e., pure corrosion and erosion-enhanced corrosion rates). Nevertheless, the erosion-corrosion rate of Hadfield steel was much smaller. Morphological observation showed that local damage in the form of a crater by erosion-corrosion was more noticeable in carbon steel. The higher resistance of Hadfield steel to erosion-corrosion was attributed to its lower total erosion rates (i.e., pure erosion and corrosion-enhanced erosion rates) highly depending on surface hardness. This study suggests that Hadfield steel with higher resistances to flowing erosion-corrosion in an aqueous environment can be applied widely to various industrial fields.

• 전기화학회지
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• 제25권1호
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• pp.22-31
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• 2022

Carbon nanomaterials are considered to be the materials of choice for the fabrication of electrochemical energy storage devices due to their stability, cost-effectiveness, well-established processing techniques, and superior performance compared to other active materials. In the present work, reduced graphene oxide (rGO) has been synthesized and used for the fabrication of a symmetric supercapacitor. The electrochemical performance of the fabricated supercapacitors with three different aqueous electrolytes namely 0.5 M H₂SO₄, 0.5 M H₃PO₄, and 1.0M Na₂SO₄ have been compared and analyzed. Among the three electrolytes, the highest areal specific capacitance of 14 mF/cm² was calculated at a scan rate of 5 mV/s observed with 0.5M H₃PO₄ electrolyte. The results were also confirmed from the charge/discharge results where the supercapacitor with 0.5M H₃PO₄ electrolyte delivered a specific capacitance of 11 mF/cm² at a current density of 0.16 mA/cm². In order to assess the stability of the supercapacitor with different electrolytes, the cells were subjected to continuous charge/discharge cycling and it was observed that acidic electrolytes showed excellent cyclic stability with no appreciable drop in specific capacitance as compared to the neutral electrolyte.

• 우주기술과 응용
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• 제3권3호
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• pp.239-256
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• 2023

지구 전리권은 고층대기의 일부가 이온화되어 전파에 영향을 주는 플라즈마 상태로 존재하는 영역으로 통신과 관련하여 실생활에 직접적으로 영향을 주어 오랜 기간 연구되어온 분야이다. 고도에 따라 전자밀도를 이루는 주된 이온에 따라 D-층, E-층, F-층으로 구분되며, 전자 밀도에 비해 중성대기 밀도가 매우 커서 그 영향을 고려한 플라즈마로 기술되어야 한다. 또한 태양에서 시작되어 지표면에 이르는 영역까지 전리권 외부의 영향이 직접적으로 반영되는 영역으로 복잡하고 다양한 영역의 연구가 연관되는 분야이다. 본 논문에서는 지구 고층대기가 이온화되어 전리권을 형성하는 과정을 설명하고 중·저위도 전리권의 특성에 대해 소개하였다. 또한 현재까지 전리권과 관련하여 국내 연구자들이 참여한 연구를 소개하고 향후 전리권 연구 분야의 교류 활성화에 활용되기를 기대한다.

• 수면정신생리
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• 제20권2호
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• pp.75-81
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• 2013

목 적 : 혐오 자극에 대한 뇌의 기능적 영상 연구에 있어서 기능적 자기공명영상, 양전자방출단층촬영 등의 연구는 많이 진행되어 있으나 저해상 전자기 단층촬영(low resolution brain electromagnetic tomography) 분석을 이용한 연구는 거의 없다. 본 연구의 목적은 피험자들에게 시각적 혐오자극을 준 후 나타나는 대뇌 피질의 활성변화를 저해상 전자기 단층촬영을 이용하여 파악하고자 하는 것이다. 방 법 : 총 45명($27.1{\pm}2.6$세)의 건강한 젊은 성인남녀가 연구에 참여하였다. 국제정서사진체계를 사용하여 중립자극에서 4장, 신체훼손과 관련된 혐오자극에서 4장의 사진을 뽑아 피험자들에게 각 30초간 보여주면서 뇌파를 측정하였다. 저해상 전자기 단층촬영분석을 시행하여 중립자극에 대비해 혐오자극에서의 변화된 전류밀도를 비교 분석하였다. 결 과 : 혐오시각 자극을 받는 동안 피험자 모두 불쾌감, 놀람, 스트레스를 받았다고 보고하였다. 저해상 전자기 단층촬영 분석상 세타파에서 좌측 전두엽의 위이마이랑(BA10)과 중간이마이랑(BA10, 11) 영역에서 유의미한 전류밀도의 감소를 보이는 복셀 클러스터가 관찰되었다. 이 복셀 클러스터는 총 11개의 복셀로 구성되어 있으며 유의미한 전류밀도(p<0.05)의 감소를 나타내는 t값의 임계값은 -1.984이었다. 남녀 간의 혐오 반응 정도에 유의미한 차이는 없었다. 결 론 : 이 연구의 결과인 시각 혐오자극에 의한 배외측 전전두엽의 활성은 혐오 정서의 조절과 관여되어 있을 것으로 생각된다.

• 한국농림기상학회지
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• 제25권1호
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• pp.1-16
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• 2023

기후변화에 관한 정부간 협의체(IPCC)가 2050년까지 전지구적으로 탄소중립(Carbon Neutrality) 사회로의 전환을 강조함에 따라 한국, 일본, 유럽 등 주요국들은 탄소중립 목표를 선언하였다. 농업분야는 탄소 흡수가 가능한 분야이며, 2021년 11월 영국에서 개최된 기후변화협약 당사국총회(COP 26)에서 기후변화 논의를 위한 농업의 역할을 강조하면서 그 중요성이 높아졌다. 그러나 농업분야의 온실가스 감축 사업은 국내 상황을 고려한 모니터링이 제대로 이루어지지 않고 있으며, 사업 프로그램 이행에 대한 효과나 근거를 정량적으로 평가할 수 있는 체계가 마련되지 않아 농업 현장에서의 적용이 원활히 이루어지지 않는 실정이다. 그러므로 농업분야 온실가스 감축을 위한 정책 설계, 시행 및 모니터링을 원활하게 하기 위해 기존 정책의 현황을 이해하고 개선이 필요한 사항을 검토하기 위한 선험적인 연구가 필요하다. 본 연구의 목적은 농업분야에서 우리나라 온실가스 감축정책 현황 진단 및 정책 추진의 방해 요인을 파악하기 위해 반구조화 인터뷰 방식을 적용해 이해관계자들의 의견을 검토하는 것이다. 반구조화 인터뷰를 진행한 결과, 본 연구는 농업부문 온실가스 감축정책의 추진을 저해하는 요인들을 데이터 및 기술, 금융, 제도 및 인식의 4가지 유형에 따라 제시하였다. 또한 일부 이해관계자들은 기술의 데이터 확보, 효과 검증을 위한 체계를 마련, 인센티브 지급 및 홍보 등 본 연구에서 제시한 시사점을 종합적으로 고려할 수 있는 방안으로서 시범사업 추진이 도움이 될 수 있음을 강조하였다. 본 연구는 구체적인 결론을 도출하기보다는 온실가스 감축정책 추진 현황을 진단하고 검토하는 탐색적 연구의 성격을 가지며, 향후 면접 응답자를 충분히 확보하고 그룹별 표본 수를 균형 있게 조정하여 추가 분석을 실시한다면 본 연구는 유용한 기초자료로 활용될 수 있을 것이다.