• Asian-Australasian Journal of Animal Sciences
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• 제23권8호
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• pp.1028-1033
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• 2010

The effects of delta-aminolevulinic acid (DALA) or chito-oligosaccharide (COS) in layer diets on production performance, egg quality and hematological characteristics were investigated in this 8-week trial. Two hundred and seventy 27-week-old (Hy-Line brown) layers were randomly assigned to 5 treatments with 9 replications per treatment. Dietary treatments were i) Control (basal diet); ii) DALA1 (basal diet+DALA 2 mg/kg); iii) DALA2 (basal diet+DALA 4 mg/kg); iv) COS1 (basal diet+COS 100 mg/kg) and v) COS2 (basal diet+COS 200 mg/kg). In this study, no significant difference was observed in feed intake and egg shell quality (eggshell breaking strength and egg shell thickness) among treatments. The inclusion of DALA increased egg production during the first 4 weeks. Egg weight was increased in both DALA (quadratic, p<0.05) and COS (linear, p<0.05) treatments compared with the control treatment. Laying hens fed the DALA treatment had an increased yolk color unit (quadratic, p<0.05) and haugh unit (linear, p<0.05) compared with the control group. Similarly, these characteristics were also affected by COS treatments, with both values being linearly increased (p<0.05) in COS treatments compared with the control treatment. Additionally, birds fed DALA treatments significantly increased (quadratic, p<0.05) the number of RBC, WBC and lymphocytes compared with the control treatment. Dietary DALA supplementation linearly increased (p<0.05) the serum iron concentration at the end of the 8th week. The inclusion of COS increased (linear, p<0.05) the concentration of RBC, WBC and lymphocytes compared with the control treatment. In conclusion, dietary DALA at the lower dosage (2 mg/kg) could exert better effects in laying hens than higher dosage (4 mg/kg). Birds fed DALA supplemented diet had an increased iron availability, egg weight, eggshell quality and immunity. Moreover, the inclusion of COS (200 mg/kg) can increase egg weight, eggshell quality and immunity in laying hens. Therefore, both the utilization of COS and DALA could be considered as a new strategy for optimizing egg quality and health condition of laying hens.

• 자원ㆍ환경경제연구
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• 제10권2호
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• pp.173-216
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• 2001

We compare impacts of different $CO_2$ abatement mechanisms using a CGE model. Focus is on the way the tradable permits are initially distributed for emissions trading, namely auction and grandfathering. For three major energy consuming industries (basic chemical, iron & steel and electricity) in Korea, emissions trading is clearly superior to individual $CO_2$ abatement, but auction and grandfathering show somewhat different patterns of impact. We show that depending on how the government uses the revenue from permit auction, auction may be preferable to grandfathering.

• 한국철도학회논문집
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• 제8권6호
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• pp.581-585
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• 2005

In this study, the environmental impacts of a bogie in the electric motor unit(EMU) were evaluated quantitatively using simplified life cycle assessment(S_LCA). Target was the bogie and life cycle inventory(LCI) database for the bogie was established. The software used for simplified LCA was PASS. Environmental impacts with the parts of the bogie were dependent on their weight significantly. Among impact categories, abiotic resource depletion(ARD) and global warming(GW) were shown dominantly. Global warming was occurred mainly due to the emission of CO₂released from energy consumption and abiotic resource depletion was caused mostly by the consumption of iron ore for the manufacturing of steel. Therefore, the environmental impacts of the bogie could be reduced by the light-weighting of EMU and the improvement of energy efficiency.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2002년도 ICCAS
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• pp.69.6-69
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• 2002

The optimal byproduct gas supply system was developed for the optimal management of the byproduct gases in the iron and steel making process based on EXCEL environment. It supplies optimal byproduct gas distribution result as well as analysis including expected electricity generation, holder level change, amount of oil consumption, energy distribution to each boiler, and efficiency of energy resource. To reflect the changing environment of the plant such as maintenance, the system was developed to easily change the optimization model for changing configuration of the system. To verify the performance of the system , case studies for various situation was performed with the developed system, a...

• 자원리싸이클링
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• 제25권4호
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• pp.23-31
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• 2016

양양철광산 선광 부산물(폐석, 광미)의 폐기물공정시험기준에 의한 중금속용출량은 환경기준값 보다 낮아 유해성이 없으므로 그 자체를 물질전환법에 의해 순환자원화 하는 데는 문제가 없다. 선광 광미를 시멘트 부원료로 사용할 경우에는 시멘트 품질안정성 차원에서 전 알카리($R_2O$)함량이 포틀랜드 시멘트(KS L 5201) 품질 기준치인 0.6%를 초과하지 않도록 광미 첨가량을 3%이하로 사용하는 것이 좋다고 판단된다. 재활용 점토벽돌(KS I 3013) 1종 규격에 부합되는 비소성 에코벽돌은 무기결합제의 15%를 광미로 그리고 일반잔골재의 100%를 철광산 폐석으로 대체하여 제조 가능하였다. 이처럼 선광 부산물을 시멘트 부원료 및 비소성 에코벽돌로 순환자원화함으로서 광미 적치장의 축소 및 유지관리비용 절감 그리고 에너지 사용 및 $CO_2$ 발생 절감으로 환경적 효과 및 경제적 효과를 동시에 얻을 수 있을 것이다.

• Geomechanics and Engineering
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• 제14권5호
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• pp.439-451
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• 2018

The stress path characteristics of surrounding rock in the formation of gob were analysed and the unloading was solved. Taking Chengchao Iron Mine as the engineering background, the model for analysing the instability of deep gob was established based on the mechanism of stress relief in deep mining. The energy evolution law was investigated by introducing the local energy release rate index (LERR), and the energy criterion of instability of surrounding rock was established based on the cusp catastrophe theory. The results showed that the evolution equation of the local energy release energy of the surrounding rock was quartic function with one unknown and the release rate increased gradually during the mining. The calculation results showed that the gob was stable. The LERR per unit volume of the bottom structure was relatively smaller, which mean the stability was better. The LERR distribution showed that there was main energy release in the horizontal direction and energy concentration in the vertical direction which meet the characteristics of deep mining. In summary, this model could effectively calculate the stability of surrounding rock in the formation of gob. The LERR could reflect the dynamic process of energy release, transfer and dissipation which provided an important reference for the study of the stability of deep mined out area.

• 자원ㆍ환경경제연구
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• 제14권1호
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• pp.221-235
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• 2005

본 연구는 비재생자원 수입국이 자원수입시 부과할 적정관세의 동태적 구조를 분석하고 있다. 지금까지 비재생자원 수입국이 자원수입시 부과할 적정관세의 동태적 구조를 분석한 선행연구들에 의하면 자원 수입국은 자국의 경제적 후생을 증대하기 위해서 수입 초기에 부과하기로 결정한 관세를 일관되게 부과하기보다는 각 시점별로 서로 다른 관세를 부과할 것을 제안하고 있다. 그러나 본 연구는 효율적인 관세모형을 설정하여 상태변수인 자원스톡과 연관된 공동상태변수가 희소성 효과와 비용 효과로 분리되는 속성을 지니고 있음을 규명하였다. 본 연구는 이 결과를 바탕으로 선행연구들이 제안한 관세 부과방식의 이론적 오류를 지적하고, 자원 수입국이 비재생자원수입시 동태적으로 일관된 관세를 부과하는 것이 자국의 경제적 후생을 증대할 수 있음을 보이고 있다.

• 한국식품조리과학회지
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• 제24권2호
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• pp.188-197
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• 2008

This study was carried out to determine the optimal cooking conditions for various rice cultivars (Ilpoom, Saechucheong, Sindongjin, and Sura-top rice) using trial preparations with different soaking times (0, 30, and l20min) and cooking equipment (electric pressure cookers, electric cookers, gas pressure cookers, iron pots, and stone pots). In adddition, the texture and sensory characteristics of the rice prepared with the electric pressure cookers, gas pressure cookers, and stone pots were analyed. The results showed that the moisture, amylose and physicochemical compositions of the four rice varieties were similar. According to RVA, the Sura, cultivar had generally high viscosity, and the Ilpoom, cultivar presented the highest hot and peak viscosities. Saechucung had the highest initial gelatinizing temperature and Sindongjin showed the greatest setback. The optimal amounts of added water as well as heating conditons were dependent on the rice varieties, soaking times, and cooking equipment. A longer soaking time reduced the hardness of the cooked rice, amount of added water, and the heating time. The pressure cooking equipment provided the best cooked rice texture, reduced the affect of the soaking time, and decreased the heating time. In general, all the variaties of cooked rice had high overall acceptability, which tended to increase when the rice was soaked for 30min prior to cooking, had a 1.2-fold amount of water to rice added, and was cooked in the pressure equipment.

• 자원ㆍ환경경제연구
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• 제15권4호
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• pp.643-672
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• 2006

본 연구는 한국의 산업별 독성물질 배출량을 이용하여 산업별 인체유해도를 측정한 것이다. 분석에 이용된 자료는 146종의 인체유해화학물질 배출량과 2000년도 산업연관표이다. 분석결과, 총배출 강도가 높은 산업의 순위는 목재나무제품펄프종이(1.1632) >유기화학기초제품(0.9750) >기타화학제품(0.9620) >플라스틱제품(0.3804) >합성수지 및 합성고무(0.3412) >선박 및 기타 수송장비(0.3275) 등이다. 또한 인체발암지수는 산업 전체가 $11.86198{\times}10^3$(이미지참조)이며, 산업 평균이 $0.26360{\times}10^3$(이미지참조)으로 계산되었다. 인체유해도가 높은 산업의 순위를 보면, 자동차 및 부문품(7.85033) >선철 및 강반성품(4.57409) >철강 1차 제품(4.36668) >선박 및 기타 수송장비(3.43293) >무기화학기초제품(2.64379) 등이다. 총배출강도나 인체유해도 등은 인체유해 화학물질 감축을 위한 수요 및 산업 정책을 전개할 때, 규제산업의 우선순위를 결정하는 근거가 될 수 있다.

• Journal of Microbiology and Biotechnology
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• 제25권6호
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• pp.880-886
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• 2015

Bacterial heme was produced from a genetic-engineered Escherichia coli via the porphyrin pathway and it was useful as an iron resource for animal feed. The amount of the E. coli-synthesized heme, however, was only few milligrams in a culture broth and it was not enough for industrial applications. To analyze heme biosynthetic pathways, an engineered E. coli artificially overexpressing ALA synthase (hemA from Rhodobacter sphaeroides) and pantothenate kinase (coaA gene from self geneome) was constructed as a bacterial heme-producing strain, and both the transcription levels of pathway genes and the intermediates concentrations were determined from batch and continuous cultures. Transcription levels of the pathway genes were not significantly changed among the tested conditions. Intracellular intermediate concentrations indicated that aminolevulinic acid (ALA) and coenzyme A (CoA) were enhanced by the hemA-coaA co-expression. Intracellular coproporphyrinogen I and protoporphyrin IX accumulation suggested that the bottleneck steps in the heme biosynthetic pathway could be the spontaneous conversion of HMB to coproporphyrinogen I and the limited conversion of protoporphyrin IX to heme, respectively. A strategy to increase the conversion of ALA to heme is discussed based on the results.