• 한국세라믹학회지
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• 제59권
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• pp.338-349
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• 2020

Large scale with high-purity hexagonal aluminum nitride nanoparticles (AlN NPs) was synthesized using DC thermal plasma arc discharge method (TPAD). Argon gas was used as the plasma forming gas, while ammonia (NH₃) gas was used as the reactive gas, which was fed into the reactor at a constant flow rate of 5 LPM. In order to optimize the process for high yield, the experiments were carried out at various plasma input powers, such as 1.5, 3.0, and 4.5 kW. Following the optimization, to examine the influence of using pure nitrogen gas, an experiment was also carried out in the nitrogen ambience. The phase identification and structural determination of the synthesized NPs were carried out using XRD and Raman spectroscopic analyses. While the morphology, particle size, and elemental compositions of the synthesized NPs were observed from SEM, HRTEM, XPS, and EDX analyses. The photoluminescence response was confirmed from the PL spectrum. The PL emission peaks observed around 440 nm (2.8 eV) and 601 nm (2.07 eV), respectively, which correspond to the UV blue and red band emissions of both AlN and Al/AlN NPs. The results show that the synthesized nano-AlN NPs exhibit excellent crystallinity with a high yield of approximately 210 g/h. The current plasma technology can be regarded as a perfect potential process for developing nano-AlN powders with improved efficiency.

• 연구논문집
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• 통권23호
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• pp.93-107
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• 1993

The chemistry and performance characteristics of the EBDS process have been introduced, in which experimental results from laboratory, test plant, and pilot plant studies agree very well and can be understood from detailed kinetic models. The parametric dependencies of the NOx and $SO_2$, removal yields on the input conditions have been discussed and formulated quantitatively. The process is best suited for flue gas with high $SO_2$, loadings. The operation conditions, such as dose, ammonia, and water additions, can be adjusted fast upon load changes. The process works waste water free and the major product is a mixture of ammonium nitrate and sulfate that can be used as fertilizer. The up-date results show that the EBDS technology is safe and competitive with other already well-established technologies. Due to these interesting features, the electron beam process has gained much international recognition. Demonstration units of 100MW have been proposed in the United States and Japan. Further pilot plants are under construction in Poland and China, countries that make abundant use of highsulfur coal. Additional research activities are under way to further improve the energy efficiency of process, and accelerator prices have been decreasing during the past 10 years. So the EBDS process has a good chance to start a new generation of emission-control technology.

• 한국입자에어로졸학회지
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• 제7권3호
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• pp.87-97
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• 2011

In this study, we organized the test results obtained from the performance tests for the CA certificated air cleaners which had been commercially available in Korea since 2003, and analyzed the correlation among the test parameters such as flow rate, particle collection efficiency, clean air delivery rate (CADR), ozone emission, odor removal efficiency and noise level etc. The noise level of 267 air cleaners were increased as concentrated at the 45, 50, 55 dB, which are the required noise level for CA certification according to flow rate, and ozone emissions from the CA air cleaners were significantly lower than the requirement limit, 50 ppb for 24 hour operation. The average particle collection efficiency and odor removal efficiency were 89.3 and 80.8%, approximately 20% higher than the requirement of CA certification, regardless of flow rates. The particle removal performance of an air cleaner was clearly discriminated by its CADR, and the CADR was obtained with a simple calculation: 0.79 x flow rate. The low differentiation of gas removal performance of air cleaners by the current CA gas test method was improved by 3.2, 751.3, 13.4 times for ammonia, acetic acid, respectively, by adopting the CADR concept and the real time measurement method, FTIR, for gas removal performance test.

• Asian-Australasian Journal of Animal Sciences
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• 제20권8호
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• pp.1196-1200
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• 2007

Eight feeds (mixture of wheat straw and oil seed cakes in 3:1 ratio) were evaluated for methane emission and fermentation pattern with buffalo rumen liquor as inoculum in an in vitro gas production test. The cakes tested were groundnut cake (GNC), soybean cake (SBC), mustard seed cake (MSC), cotton seed cake (CSC), karanj seed cake expeller extracted (KCEE), karanj seed cake solvent extracted (KCSE), caster bean cake expeller extracted (CBCEE) and caster bean cake solvent extracted (CBCSE). The gas production (ml/g dry matter) was significantly higher with SBC and MSC followed by CSC, GNC, KCSE, KCEE, CBCSE and was the lowest with CBCEE. Methane emission was significantly lower with KCEE, KCSE, CBCEE, CBCSE (20.32- 22.43 ml/g DM) than that with SBC, GNC, CSC (27.34-31.14 ml/g DM). Mustard seed cake was in-between the two groups of oil cakes in methane production. In vitro true digestibility was highest with SBC followed by GNC, CSC, MSC, KCSE, KCEE, CBCSE and CECEE. Ammonia nitrogen level was positively correlated with the amount of protein present in the cake. Total holotrich protozoa were significantly higher with SBC, whereas, large spirotrich protozoa tended to be lower than with other cakes. The counts of small spirotrich and total protozoa were similar with all the cakes. Total volatile fatty acid production and acetate to propionate ratio were significantly higher with SBC and significantly lower with KCEE as compared to the other cakes. Among the conventional oil cakes tested in the present experiment (GNC, SBC, MSC and CSC), mustard seed cake-based feed produced the minimum methane without affecting other fermentation characteristics adversely.

• 대한환경공학회지
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• 제34권8호
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• pp.541-548
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• 2012

본 연구에서는 생활폐기물 자동집하시설에서의 악취물질 배출특성을 파악하고자 2개소(A시설, B시설)의 시설을 선정하여 공기관로 내의 이송가스와 최종배출가스를 대상으로 복합악취와 22종의 지정악취물질을 조사하였다. 생활폐기물 자동집하시설에서 배출되는 주된 악취물질은 암모니아, 황 화합물, 아세트알데하이드이었으며, 악취처리공정의 종류에 따라 최종배출구의 악취 배출특성이 상이하였다. 이송가스를 대상으로 한 악취기여도 평가에서는 A시설의 경우, 디메틸설파이드 26%, 아세트알데하이드 18%, 메틸머캅탄 14%의 악취기여도를 보였으며, B시설의 경우에는 메틸머캅탄 56%, 황화수소와 디메틸설파이드가 각각 15%이었다.

• Asian-Australasian Journal of Animal Sciences
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• 제33권4호
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• pp.597-604
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• 2020

Objective: This study was conducted to investigate the effect of zinc aspartic acid chelate (Zn-ASP) on growth performance, nutrient digestibility, blood profiles, fecal microbial and fecal gas emission in growing pigs. Methods: A total of 160 crossbred ([Landrace×Yorkshire]×Duroc) growing pigs with an initial body weight (BW) of 25.56±2.22 kg were used in a 6-wk trial. Pigs were randomly allocated into 1 of 4 treatments according to their sex and BW (8 replicates with 2 gilts and 3 barrows per replication pen). Treatments were as follows: i) CON, basal diet, ii) TRT1, CON+0.1% Zn-ASP, iii) TRT2, CON+0.2% Zn-ASP, and iv) TRT3, CON+0.3% Zn-ASP. Pens were assigned in a randomized complete block design to compensate for known position effects in the experimental facility. Results: In the current study, BW, average daily gain, and gain:feed ratio showed significant improvement as dietary Zn-ASP increased (p<0.05) in growing pigs. Apparent total tract digestibility (ATTD) of dry matter was increased linearly (p<0.05) in pigs fed with Zn-ASP diets. A linear effect (p<0.05) was detected for the Zn concentration in blood with the increasing levels of Zn-ASP supplementation. Lactic acid bacteria and coliform bacteria were affected linearly (p<0.05) in pigs fed with Zn-ASP diets. However, no significant differences were observed in the ATTD of nitrogen, energy and Zn. And dietary Zn-ASP supplementation did not affect fecal ammonia, hydrogen sulfide and total mercaptans emissions in growing pigs. Conclusion: In conclusion, dietary supplementation with Zn-ASP of diet exerted beneficial effects on the growth performance, nutrient digestibility, blood profiles and fecal microbes in growing pigs.

• 한국초지조사료학회지
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• 제33권3호
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• pp.197-205
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• 2013

An in vitro study was conducted to determine the effects of defaunation (removal of protozoa) and forage sources (rice straw, ryegrass and tall fescue) on ruminal fermentation characteristics, methane ($CH_4$) production and degradation by rumen microbes. Sodium lauryl sulfate, as a defaunation reagent, was added into the mixed culture solution to remove ruminal protozoa at a concentration of 0.375 mg/ml. Pure cellulose (0.64 g, Sigma, C8002) and three forage sources were incubated in the bottle of culture solution of mixed rumen microbes (faunation) or defaunation for up to 24 h. The concentration of ammonia-N was high under condition of defaunation compared to that from faunation in all incubations (p<0.001). Total VFA concentration was increased at 3, 6 and 12 h (p<0.05~p<0.01) but was decreased at 24 h incubation (p<0.001) under condition of defaunation. Defaunation decreased acetate (p<0.001) and butyrate (p<0.001) proportions at 6, 12 and 24 h incubation times, but increased propionate (p<0.001) proportion at all incubation times for forages. Effective degradability of dry matter was decreased by defaunation (p<0.001). Defaunation not only decreased total gas (p<0.001) and $CO_2$ (p<0.01~0.001) production at 12 and 24 h incubations, but reduced $CH_4$ production (p<0.001) at all incubation times for all forages. The $CH_4$ production, regardless of defaunation, in order of forage sources were rice straw > tall fescue > ryegrass > cellulose (p<0.001) up to 24 h incubation.

• 농업생명과학연구
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• 제51권4호
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• pp.97-109
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• 2017

본 시험은 항염에 효과가 있다고 알려진 식물 추출물의 첨가가 반추위 발효와 메탄 생성에 미치는 영향을 알아보기 위해 in vitro 실험을 수행하였다. 항염과 항산화 효과가 있는 산뽕나무, 뽕나무, 예덕나무, 오동나무, 방아풀과 은행나무 6종을 선발하였다. 반추위액과 McDougall buffer 혼합액 15mL과 티모시 0.3g, 각각의 추출물을 기질의 5%로 넣고 $39^{\circ}C$에서 3, 9, 12, 24, 48 그리고 72시간 배양하였다. 항염 효과가 있는 식물 추출물의 첨가는 반추위 발효 성상(pH, 건물소화율, Glucose 농도, 암모니아 농도, 단백질 농도, 미생물 성장량, 휘발성지방산)에는 영향을 미치지 않았다. 총 가스 발생량은 각기 다른 양상을 보였으며, 이산화탄소 발생량은 48시간대에서 예덕나무와 방아풀에서 대조구에 비해 유의적(p<0.05)으로 높았다. 또한 메탄 발생량은 배양 초기에는 대조구보다 첨가구에서 유의적(p<0.05)으로 감소하였으나, 발효가 진행될수록 대조구에 비해 첨가구에서 더 많은 메탄이 발생하였다. Polyphenol과 flavonoid는 은행나무 추출물구에서 가장 높았다. 본 시험의 결과에서 항염에 효과가 있는 식물 추출물을 in vitro 반추위 배양액에 첨가하였을 때, 반추위 발효에는 영향을 미치지 않았고, 메탄은 초기 발효에 저감 효과가 있는 것으로 사료된다.

• Journal of Animal Science and Technology
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• 제45권4호
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• pp.551-558
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• 2003

본 시험은 쑥(Artemisia montana Pampan) 분말을 이유자돈 사료에 0%, 0.5%, 1.0% 및 2.0% 수준으로 대체하여 급여할 경우 증체량, 사료섭취량, 사료요구율, 영양소 소화율 및 분의 유해가스 발생량에 미치는 영향과 적정 첨가수준을 구명하기 위하여 4처리, 4반복, 반복당 7두로서 총 112두를 공시하여 4주간 사양시험을 실시하였다. 0${\sim}$14일령 동안의 일당증체량, 사료섭취량 및 사료요구율은 쑥분말 1.0% 첨가구와 2.0% 첨가구에서 개선되는 경향을 나타내었고 15${\sim}$28일령 동안의 일당증체량과 사료요구율은 처리간의 유의차가 없었으나 사료섭취량은 대조구에 비해 쑥분말 1.0% 첨가구가 증가하였고(P<0.05) 쑥분말 0.5% 첨가구와 2.0% 첨가구는 다소 증가하는 경향만 나타냈다. 한편, 전 기간 동안의 일당증체량은 대조구에 비해 쑥분말 1.0% 첨가구와 2.0% 첨가구가 증가하는 경향을 보였고 사료섭취량은 모든 쑥분말 첨가구에서 증가하는 경향을 보여서 사료요구율은 쑥분말 1.0% 첨가구와 2.0% 첨가구에서 개선되는 경향을 나타냈다. 영양소 소화율에 있어서 건물 소화율은 대조구에 비해 모든 쑥분말 첨가구에서 증가하는 경향을, 조단백질 소화율은 쑥분말 1.0% 첨가구에서 증가(P<0.05), 인 소화율은 쑥분말 2.0% 첨가구에서 증가(P<0.05)한 것으로 나타났다. 질소와 인 배설량은 대조구에 비해 쑥분말 2.0% 첨가구에서 감소하였고(P〈0.05) 쑥분말 0.5% 첨가구와 1.0% 첨가구에서는 감소하는 경향만을 나타냈다. 분의 유해가스 발생량에 있어서 $NH_3$ 발생량은 48시간 발효시에 대조구에 비해 모든 쑥분말 첨가구들에서 뚜렷하게 감소하였고(P<0.05) $H_2S$ 발생량은 전반적으로 쑥분말 첨가구들에서 감소하는 경향을 보였다. 이상의 결과를 종합해 보면 이유자돈 사료에 쑥분말을 1.0${\sim}$2.0% 수준으로 첨가하여 급여하는 것이 생산성 향상과 유해가스 발생량 감소에 효과가 있는 것으로 사료된다.

• 한국토양비료학회지
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• 제31권1호
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• pp.77-84
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• 1998

퇴비화 과정 중 암모니아 발생을 억제하기 위한 생물학적 방법으로서 고온성 암모니아 내성균인 TAT112, TAT117, TAT119균주의 배양액을 첨가하여 돈분의 퇴비화를 실시하면서 암모니아 발생과 미생물의 밀도변화를 조사한 결과는 다음과 같다. 대조구를 비롯한 모든 처리구의 퇴비화는 전형적인 퇴비화 과정에서 나타나는 결과와 일치하였으며 퇴비화 과정중 포집된 응결수와 6N 황산의 질소함량는 무첨가구인 대조구가 2.72g인데 반하여 TAT112 첨가구는 1.90g으로 낮았으나 다른 첨가구는 높았다. 또한 1일 1회 측정한 배출되는 암모니아 가스의 농도는 고온을 유지하는 동안에는 고온성 암모니아 내성균을 첨가한 처리구가 대조구보다 낮았으나 온도가 내려가는 시기에 TAT112처리구를 제외한 첨가구는 대조구의 최고 기록보다 높은 농도를 기록하였다. 초기, 뒤집은 시기, 말기의 미생물 밀도를 조사한 결과 고온성 암모니아 내성균의 밀도는 균주 첨가구 모두가 대조구에 비해 모든 기간에 걸쳐 높은 밀도를 유지하였다. 반면 고온성 세균의 밀도는 초기 대조구가 다른 처리구에 비해 현저히 낮았으나 뒤집은 시기, 말기에는 다른 처리구와 비슷한 수준을 유지하였다. 한편, 중온성 암모니아 내성균의 밀도는 초기에 모든 처리구가 동일하였으나 뒤집은 시기에는 대조구와 TAT112 첨가구가 TAT 117 첨가구와 TAT119 첨가구 보다 약 10배 정도 높게 관찰되었고 말기에는 다시 모든 처리에서 비슷한 수준을 나타냈다.