• 자원리싸이클링
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• 제17권6호
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• pp.79-88
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• 2008

본 연구는 폐 주석의 리싸이클링을 통한 고기능성 주석 산화물 나노 분말의 대량제조 기술개발을 위한 전 단계 연구로서 주석 염화물 용액을 원료로 하여 분무열분해 반응에 의하여 평균입도 50nm 이하의 주석 산화물 분말을 제조하였으며 반응온도의 변화에 따른 생성 입자들의 특성 변화를 파악하였다. 열분해 반응온도가 $800^{\circ}C$로부터 $850^{\circ}C$로 증가함에 따라 형성된 입자들의 평균입도는 20 nm로부터 30 nm로 증가하였다. 또한 XRD 피크의 강도도 증가하였으며 비표면적은 1/2 정도로 크게 감소하였다. 반응온도 $900^{\circ}C$의 경우에는 액적 형태는 평균입도 30 nm 정도의 나노 입자들로 구성되어 있는 반면 독립된 입자들의 경우에는 평균입도가 $80{\sim}100\;nm$로 현저하게 증가 하였으며 입자 표면이 더욱 치밀화되어 있었다. 또한 XRD 피크 강도도 현저히 증가하였으며 비표면적은 현저하게 감소하였다. 반응온도 $950^{\circ}C$의 경우에는 액적 형태의 비율 및 크기가 현저히 감소하였으며 대부분의 입자들은 독립된 형태를 유지하고 있었으며 평균입도는 약 70 nm로 $900^{\circ}C$의 경우보다 오히려 감소하였다. 또한 XRD 피크의 강도도 $900^{\circ}C$의 경우에 비하여 현저히 감소하였으며 비표면적은 2배 정도 크게 증가하였다.

• 한국재난정보학회 논문집
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• 제8권1호
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• pp.1-9
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• 2012

현대사회의 정보화는 컴퓨터와 인터넷을 통해 대량의 정보를 생산 교류하므로 새로운 커뮤니케이션 방식을 탄생시키고 있다. 과거 피동적 방식의 일방적 정보흐름이 능동적 상호작용 방식으로 진화하여 정보생산자와 정보소비자의 구별을 약회시키고 있으며, 온라인상의 인적관계를 강화시키는 Social Networking Service의 사회구조로 발전하고 있다. 따라서 정보의 확산은 사회적 네트워크 구조를 긴밀하게 작용시킴으로 사회적 갈등을 불러일으키는 하나의 요인으로도 작용하기도 하고, 제도와 환경, 개인의 문화적 적응이 과학 기술의 빠른 발전 속도를 따라가지 못함으로 갈등과 혼란을 초래하기도 한다. 이에 본 논문은 정보화 사회의 특성과 진화과정을 살펴보면서 정보화의 파장으로서 사회적 위험요인을 살펴보고 이에 대한 민간시큐리티의 역할을 모색해 보고자 한다. 정보화 사회는 시간과 공간의 영역을 축소시켜 인간생활의 편리성과 간편성을 가져다 준 반면, 비대면성과 익명성이라는 특성으로 인해 많은 사회적 부작용도 발생시키고 있다. 이에 국가차원의 제도적 대책 마련이 이루어지고 있지만 개인생활보호를 위한 민간차원의 보호장치는 아직 논의되지 않고 있다. 주문자 방식의 개인의 생명과 재산을 보호하는 민간시큐리티가 이를 담당해야 할 것이다.

• Asian-Australasian Journal of Animal Sciences
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• 제27권1호
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• pp.101-114
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• 2014

While there are persistent rumors that the consumption of goat meat dishes increases blood pressure, there is no scientific evidence to support this. Two experiments were conducted to clarify whether or not blood pressure increases in conjunction with the consumption of goat meat dishes. In experiment 1, 24 Dahl/Iwai rats (15 weeks old, body weight $309.3{\pm}11.1$ g) were evenly separated into 4 groups. The control group (CP) was fed a diet containing 20% chicken and 0.3% salt on a dry matter basis. The goat meat group (GM) was fed a diet containing 20% goat meat and 0.3% salt. The goat meat/salt group (GS) was fed a diet containing 20% goat meant and 3% to 4% salt. The Okinawan mugwort (Artemisia Princeps Pampan)/salt group (GY) was fed a diet containing 20% goat meat, 3% to 4% salt and 5% of freeze-dried mugwort powder. The experiment 1 ran for a period of 14 weeks during which time the blood pressure of the animals was recorded. The GS, and GY groups consumed significantly more water (p<0.01) than the CP and GM groups despite the fact that their diet consumption levels were similar. The body weight of animals in the CP, GM, and GS groups was similar while the animals in the GY group were significantly smaller (p<0.01). The blood pressure in the GM group was virtually the same as the CP group throughout the course of the experiment. In contrast, while the blood pressure of the animals in the GS and GY group from 15 to 19 weeks old was the same as the CP group, their blood pressures were significantly higher (p<0.01) after 20 weeks of age. The GY group tended to have lower blood pressure than the GS group. In experiment 2, in order to clarify whether or not the increase in blood pressure in the GS group and the GY group in experiment 1 was caused by an excessive intake of salt, the effects on blood pressure of a reduction of salt in diet were investigated. When amount of salt in the diet of the GS and GY group was reduced from 4% to 0.3%, the animal's blood pressure returned to normotensive. These results indicate that, as in the case of chicken consumption, prolonged consumption of goat meat does not cause increased blood pressure, rather the large amount of salt used in the preparation of goat meat dishes is responsible for the increase in blood pressure.

• Asian-Australasian Journal of Animal Sciences
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• 제16권7호
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• pp.1020-1024
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• 2003

Five barrows (average initial body weight 58.6 kg) were used to determine the apparent ileal digestibilities of amino acids, DM, N and energy in various soybean meal, rapeseed meal and coconut meal in finishing pigs. Dietary treatments included 1) KSBM (Korean soybean meal), 2) CSBM (Chinese soybean meal), 3) ASBM (Argentine soybean meal), 4) RSM (Rapeseed meal), and 5) CNM (Coconut meal). The diets were corn starch-based and formulated so that each protein source provided the same amount of total ME (3,490 kcal/kg), CP (15.70%), lysine (1.00%), Ca (0.80%) and P (0.60%). Protein content of the KSBM was higher than the CSBM and ASBM, with all values similar to those expected, and protein content of the CNM was lower than that of the SBM preparation and RSM. Apparent ileal digestibilities of histidine, lysine, threonine, alanine, asparatic acid, cystine, glutamic acid and serine were greater for the KSBM, CSBM, ASBM and RSM than for the CNM (p<0.05). Also, the apparent ileal digestibilities of methionine, leucine, phenylalanine, valine and tyrosine were greater for the KSBM than for the CSBM, ASBM, RSM and CNM (p<0.05). Overall, the apparent ileal digestibilities of total essential amino acids were greater for the KSBM than for the CSBM, ASBM, RSM and CNM (p<0.05), and the apparent ileal digestibilities of total non essential amino acids were greater for the KSBM, CSBM, ASBM and RSM than for the CNM (p<0.05). No difference (p>0.05) in apparent digestibility of DM at the small intestine was observed among the treatments. However, the apparent digestibility of DM at the total tract was greater for the KSBM than for the CSBM, ASBM, RSM and CNM (p<0.05). Also, apparent digestibilities of N and digestible energy at the small intestine and total tract were greater for the KSBM than for the RSM and CNM (p<0.05). In conclusion, nutrient digestibility values of SBM preparations and RSM were relatively high compared to CNM.

• Asian-Australasian Journal of Animal Sciences
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• 제31권3호
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• pp.403-409
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• 2018

Objective: The present study was conducted to investigate the effects of a lipid-coated zinc oxide (ZnO) supplement Shield Zn (SZ) at the sub-pharmacological concentration on intestinal morphology and gene expression in weanling pigs, with an aim to gain insights into the mechanism of actions for SZ. Methods: Forty 22-day-old weanling pigs were fed a nursery diet supplemented with 100 or 2,500 mg Zn/kg with uncoated ZnO (negative control [NC] or positive control [PC], respectively), 100, 200, or 400 mg Zn/kg with SZ for 14 days and their intestinal tissues were taken for histological and molecular biological examinations. The villus height (VH) and crypt depth (CD) of the intestinal mucosa were measured microscopically following preparation of the tissue specimen; expression of the genes associated with growth and immune function was determined using the real-time quantitative polymerase chain reaction. Results: There was no difference in daily gain, gain:feed, and diarrhea score between the SZ group and either of NC and PC. The VH and VH:CD ratio were less for the SZ group vs NC in the jejunum and duodenum, respectively (p<0.05). The jejunal mucosal mRNA levels of insulin-like growth factor (IGF-I) and interleukin (IL)-10 regressed and tended to regress (p = 0.053) on the SZ concentration with a positive coefficient, respectively, whereas the IL-6 mRNA level regressed on the SZ concentration with a negative coefficient. The mRNA levels of IGF-I, zonula occludens protein-1, tumor necrosis $factor-{\alpha}$, IL-6, and IL-10 did not differ between the SZ group and either of NC and PC; the occludin and transforming growth $factor-{\beta}1$ mRNA levels were lower for the SZ group than for PC. Conclusion: The present results are interpreted to suggest that dietary ZnO provided by SZ may play a role in intestinal mucosal growth and immune function by modulating the expression of IGF-I, IL-6, and IL-10 genes.

• Corrosion Science and Technology
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• 제12권1호
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• pp.1-6
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• 2013

Recently Digital TV industry has drastically been moving the illuminating system, which causes an obvious product change from PDP and LCD to LED model to provide high-definition image. Due to strong competition in the digital industry, TV manufacturers make a great efforts to reduce production cost by using low-priced materials such as steels instead of aluminum and plastic etc. In this paper we have developed a new low-priced electrogalvanized steel sheet, which has a black resin composite layer, to substitute conventional high-priced PCM steel and plastic mold for rear cover panel in the digital TV. The black resin composite was prepared by mechanical dispersion of the mixture solution that consists of high solid polyester resin, melamine hardener, black pigment, micronized silica paste, polyacrylate texturing particle and miscellaneous additives. The composite solution was coated on the steel sheet using roll coater followed by induction furnace curing and cooling. Although the coated layer has a half thickness compared to the conventional PCM steels having $23{\mu}m$ thickness, it exhibits excellent quality for the usage of rear cover panel. The new steel sheet was applied to test products to get quality certification from worldwide electronic appliance customers. Detailed discussion provides in this paper including preparation of composite solution, roll coating technology, induction curing technology and quality evaluation from customers.

• 디지털융복합연구
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• 제13권8호
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• pp.21-31
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• 2015

최근 음성인식기술의 향상은 세계를 새로운 구비문화의 시대로 이끌 것이다. 그것은 문자를 기반으로 하는 존재하지 않았던 말문화의 시대이며 문화적 혁명이 될 수 있다. 본 연구는 언어와 문자의 기반에 뿌리를 두고 인간을 탐구하는 인문학의 입장에서 이러한 말과 글의 상보적 관계가 야기할 수 있는 미래의 문화적 문제에 대응하는 것을 목표로 한다. 이를 위해 먼저 최근 변화되고 있는 글문화에서 말문화의 양상을 논의하고, 음성인식기술의 변화에 대해 점검한 이후, 그것이 야기할 수 있는 문화적 변동의 가능성과 문제성을 논의하게 될 것이다. 이에 대한 예상 가능성으로는 말하기와 쓰기의 상보성, 사적 문화의 공적문화로의 확대, 동시적 병행성의 가능성 등을 논하고, 문제점으로는 음성의 새로운 기호화 필요성, 생활세계로의 확대에 대한 준비, 그리고 한국문화의 글로벌 기업 종속에 저항해야 할 필요성들을 논의하였다. 본 연구는 새로운 음성인식기술과 문화변동의 가능성에 대한 단초적 연구로서, 이후 구체적이고 세분화된 후속연구들을 여는데 유용하게 활용될 수 있을 것으로 기대한다.

• 농업과학연구
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• 제24권1호
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• pp.94-107
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• 1997

Producing organic farm products is one of the high-payoff farming practices considering the rapid increase of consumer's purchasing power. The purpose of this study is to identify the optimal organic farming system in relation to farm income. To cope with the above objectives, present farming conditions and profitability of 15 farmers producing organic products including rice and leaf vegetables as lettuse and cabbage were surveyed in Hongsung and Ahsan Gun, Chungnam Province. Based on the surveyed data, maximization of organic farm income were analyzed under the constrained conditions such as limited monthly labour inputs and competitive use of land by Linear Programming Model. The results of this study can be summarized as follows. 1. In the profitability analysis of 15 farmers producing organic products, rice farmers could earn their farm income more than that of conventional farmers by 50%. On the other hand, the controlled lettuce farmers could get more about 100% than that of it. But the controlled cabbage farm could get more about 40% of it. These organic farm products were saled at high prices comparing with the prices of conventional farm products by 170% ~ 230% even though the crop yields produced by organic materials had decreased. 2. According to the labor requirement of the organically produced crops, rice cultivation was needed more labour inputs than the conventional farming method by 130%. On the other hand lettuce and cabbage could saved labour requirement by 40% and 80% of those respectively. Especially for the rice cultivation concern, higher labor requirement was due to the activities as organic fertilization, soil preparation and pest and weed controll, etc. 3. With the surveyed data from farmers who produced farm commodities, L.P. analysis was implemented to find out the optimul farming system and the maximum income. According to the results of L.P. analysis, 58% of total farm income could get more than the conventional farming system In the case of rice cultivation, one ha of paddy was recommendable to save more labour inputs than the controlled leaf vegetables such as lettuse and cabbage. However, in the controlled leaf vegatables, only 73% of total upland equivalent to 0.3 ha should be cultivated under the condition of labor shortage as the restricted 4 workers. And increasing the size of hogs raising should be recommened to achieve self-sufficiency of organic fertilizer. As pointed out the possibility of organic farming, present farmers producing organic farm products could be able to maximize their income by expanding organic farm size with regard to all conditions of our organic industry. Of course, there are many difficulties in the course of developing organic agriculture. So Government should effort to support the development of our organic agriculture considering the various aspects of production, marketing, Quality certification of organic produces.

• Asian-Australasian Journal of Animal Sciences
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• 제30권9호
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• pp.1285-1291
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• 2017

Objective: A trial was conducted from 11 to 42 d post-hatch to investigate the effectiveness of the supplementation of a multiple-enzyme preparation (Natuzyme Plus) in a wheat-based diet on digesta viscosity, pH and microbial population, villus morphology, feed passage time, nutrient retention, carcass characteristics, blood lipid parameters and growth performance of broiler chickens. Methods: Three hundreds 10-d-old male Ross 308 chicks were allocated to three diets with five replicates of 20 birds per replicate. Dietary treatments were i) a wheat-based diet (W), ii) W+Natuzyme Plus (WN; 500 mg/kg of the diet), and iii) a corn-based diet (C). Results: Birds fed on the C diet had higher average daily gain (ADG, p<0.01), villus height (VH, p<0.01), total tract apparent retention (TTAR) of nitrogen (NT, p<0.01) and ether extract (EE, p<0.01), nitrogen-corrected apparent metabolizable energy ($AME_n$, p<0.05), relative weight (RW, % of body weight) of carcass (p<0.05), blood concentration of triglyceride (TG, on d 40 [p<0.01]), total cholesterol (TC, on d 22 [p<0.05]) and low density lipoprotein (LDL, on d 22 [p<0.01] and 40 [p<0.05]), and also lower feed conversion ratio (FCR, p<0.01), digesta viscosity (p<0.01), count of coliforms (p<0.01) and Escherichia coli (p<0.01) and epithelium thickness (ET, p<0.05) than those fed on the W diet. ADG, FCR, VH, ET, TTAR of NT and EE, RW of carcass, blood concentration of TG (on d 40), TC (on d 22) and LDL (on d 22 and 40) values of the WN diet did not show a significant (p>0.05) difference compared to those of the C diet. Compared to those of the W diet, the WN diet showed the higher count of Lactobacilli and lower count of coliforms (p<0.01) and digesta viscosity (p<0.01). Conclusion: In general, the results of this study showed that Natuzyme Plus supplementation in a wheat-based diet can be appropriate to achieve a comparable growth performance in broiler chickens to those given the C diet probably through improving digesta viscosity, VH, ET, TTAR of NT and EE, $AME_n$, count of Lactobacilli and coliforms.

• 공업화학
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• 제10권7호
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• pp.1028-1034
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• 1999

p-Xylene을 용매로 사용하고, 몇 가지 다른 종류의 촉매를 사용하여 직접 축중합에 의해 직쇄형 폴리락트산 합성 실험을 하였다. 그 중 우수한 활성을 보인 촉매는 주석(Tin)계 촉매이었다. 촉매의 양과 용매의 양을 변화시켜 중합반응을 한 결과, 촉매 0.2g (0.5 wt % 모노머), 용매 100 mL 수준에서 보다 높은 분자량의 중합체를 얻을 수 있었으며, 이때 대수점성도 ${\eta}_{inh}$는 0.72 dL/g(중량평균분자량(GPC)=70500)이었다. 직접중합 반응 시스템에서 분자량을 더욱 향상시키기 위해 branching 모노머로서 다가알콜인 dipentaerythritol(dipet) 또는 pentaerythritol(pet)을 소량 도입하여 스타형 폴리락트산을 합성하였으며, 직쇄형에 비해 분자량 분포가 좁고, 향상된 분자량(최고 ${\eta}_{inh}$ = 1.14, ${\bar{Mw}}$ = 143,200)을 얻을 수 있었다. Dipet의 함량이 0.05~0.2 wt %일 때 보다 높은 분자량의 폴리락트산을 얻을 수 있었으며, 얻어진 중합체의 열적성질은 직쇄형에 비해 큰 차이가 없었다. 얻어진 고분자량의 중합체로부터 투명하고 강인한 필름을 성형할 수 있었다.