• Asian-Australasian Journal of Animal Sciences
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• 제23권7호
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• pp.952-959
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• 2010

This study was conducted to evaluate growth, behavior and carcass traits of fattening Hanwoo (Korean native cattle) steers managed in different group sizes. A total of 48 animals, 6 months of age, were allocated to one of three group sizes and the experiment was conducted from 12 to 30 months of age. Groups were balanced for weight and the group sizes consisted of 4, 8, or 12 steers which were named 4sG, 8sG and 12sG, respectively. When animals were 12 months of age, initial fasted body weight (BW, $304.51{\pm}12.40\;kg$) was measured. All animals were housed at a constant space allowance of $8.82\;m^2$ per animal, and a feeder and drinker were provided per 4 animals. The whole fattening stage was divided into three phases: phase I (from 12 to 18 month of age), phase II (from 19 to 24 month of age), and phase III (from 25 to 30 month of age). Steers managed in 12sG showed low (p<0.05) growth rate and feed conversion rate (FCR) in phase I and phase II when compared to other treatment groups. However, this difference was not observed for the whole fattening phase (p>0.05). Steers managed in 4sG had a thick (p<0.05) ultrasound back fat thickness at 15 and 18 months of age. However, group size had no effect on meat yield and quality traits of area and marbling score. Animals managed in 8sG yielded a better meat grade of "A" than the "B" grade in other treatment group sizes. Lean color, fat color, firmness and maturity scores did not differ among group sizes. Hanwoo steers housed under 12sG spent less time on eating concentrate, relevant higher eating rate, less frequency of allogrooming, and more time on walking (p<0.05). It could be concluded that a large group size retarded growth rate and back fat thickness in the fattening stage, which was mainly focused on 15 and 18 months of age.

• 대한기계학회논문집B
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• 제35권7호
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• pp.749-755
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• 2011

현재 상용되고 있는 CNG(Compressed Natural Gas) 엔진에서 천연가스 조성만 변경했을 때 엔진성능 변화를 실험적으로 규명하였다. 실험에 사용된 엔진은 6606 cc, 희박 연소, 공기 과급기가 장착된 타입이며, 점화 시기는 발열량 10454 kcal/$Nm^3$의 가스에 최적화하여 고정시켰다. 실험결과 LNG 발열량이 10454 kcal/$Nm^3$에서 9811 kcal/$Nm^3$과 9523 kcal/$Nm^3$으로 낮아질 때 출력의 경우 평균 3.2, 3.4 %(공연비 미 제어시 3.4, 4.7 %) 각각 낮아지고 열효율은 평균 1.1, 1.5 % 포인트(공연비 미 제어시 1.5, 2.1 % 포인트) 낮아지는 것으로 관찰되었다. 배가스의 경우, 발열량 저하에 따라 이산화탄소, 일산화탄소, 질소산화물의 배출 농도는 모두 감소하는 것으로 나타났으나 THC(Total Hydrocarbon)의 경우에는 일정한 경향이 보이지 않았고 변화량은 크지 않았다.

• 공업화학
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• 제5권5호
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• pp.808-818
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• 1994

Ru/${\gamma}$-$Al_2O_3$와 Ru/$CeO_2$-${\gamma}$-$Al_2O_3$를 사용하여 Ru담지 촉매의 반응성과 열적노화현상에 미치는 Ce의 영향을 연구하였다. $^{129}Xe$-NMR과 수소흡착법을 사용하여 촉매특성을 검토하였으며, 모사 자동차 배기가스를 사용하여 과농, 양론 및 희박조건에서의 CO, HC 및 $NO_x$ 전환율을 측정하였다. 새촉매와 노화촉매 모두 Ru/$CeO_2$-${\gamma}$-$Al_2O_3$가 Ru/${\gamma}$-$Al_2O_3$보다 세 가지 오염물질에 대한 전환율이 높았다. $^{129}Xe$-NMR과 수소흡착에 의하면 Ce을 첨가하여도 열적노화현상을 억제할 수 없었다. 그러나 673K에서 열적노화시킨 경우 Ru/${\gamma}$-$Al_2O_3$의 반응성은 새촉매보다 작았으나 Ru/$CeO_2$-${\gamma}$-$Al_2O_3$의 반응성은 오히려 컸다. 이것은 열적 노화과정에서 Ru/Ce 사이의 계면에 아마도 새로운 활성점이 만들어지기 때문이 아닌가 사료된다. 또한, Ru금속에 미치는 Ce같은 양이온 효과를 좀더 정량적으로 구하기 위하여 Ca, Ba, La, Y, Ce 등의 양이온을 교환한 Y-제올라이트에 Ru을 담지시킨 모델 촉매의 열적노화 정도를 $^{129}Xe$-NMR과 EXAFS로 연구한 결과 이들 양이온이 Ru의 열적 노화성에 거의 영향을 미치지 못하는 것을 관찰하였다.

• 근관절건강학회지
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• 제1권1호
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• pp.1-30
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• 1994

Rheumatoid arthritis is a chronic systematic disease with unpredictable course of exacerbation and remission, characterized by pain, joint deformity and reduced activity by joint limitation. The growing public awareness of the need for health management of chronic illnesses, provides impetus for nursing to demonstrate social effectiveness by active nursing intervention in this vast area in general, and with rheumatoid condition in particular. However, nursing interventions to date have not demonstrated its active participation in the management of chronic conditions. Nursing intervention for the patients having rheumatoid arthritis is one such area that needs to be studied intensively and to demonstrate their effectiveness empirically. The purposes of this study were two fold : first, to develop a comprehensive program that was intensified with therapeutic joint exercises in water, self-help group activities and utilization of self-efficacy promoting strategies : and secondly, to determine the effect of aquatic exercise program on pain, physiological changes and quality of life in the rheumatoid arthritis patients. Thirty five female subjects participating in this study were selected from outpatients in the Rheumatism Center, Hanyang University hospital. The period of data collection was from December, 1992 to March, 1993 in seoul and Taejeon. Subjects in Taejeon were assigned to the experimental group. The comprehensive aquatic exercise program for the experimental group was carried out three times a week for 6 weeks in regular swimming pool. Subjects in Seoul did not participated in the program, and treated as the control group. Data were analyzed with repeated measure MANCOVA, t-test, ANCOVA, percentage of change, Kruskal-Wallis 1-Way ANOVA using SPSS $PC^+$ program. Results were obtained as follows : 1) Scores on Korean pain scale, Numeric pain score, and RAI score of the experimental group were significantly lower than those of the control group (t=2.11, p=0.022 ; F=4.40, p=0.044 : t=3.10, p=0.002). 2) There was significant improvement in the physiological parameters (higher joint movement parameters, F=15.64, p=0.024 ; higher lean body mass, percentage of change=+12.2, lower body weight, t=1.01, p=0.026 : lower ESR, t=1.69, p=0.001) in the experimental group compaired with subjects In the control group. 3) There was significant improvement in the specific self-efficacy score through the comprehensive aquatic exercise program(t=2.73, p=0.011), but not in the general self- efficacy score(t=0.62, p=0.113). 4) The quality of life failed to show significant improvement in the experimental group as compaired with the control group (F=3.69, p=0.064). 5) In the experimental group, findings from additional analysis showed no significant difference in the specific self-efficacy between those who continued to aquatic exercise after completing 6 week program and those who stopped (X2=0.086, p=0.690). Therefore, adherence to aquatic exercise program for 6 weeks seem to be affected mainly by self-help group activities. An indepth study to delve into articulation of mechanisms affecting the effect of aquatic exercise program be recommended. A further study is necessary to determine the difference in the effect of group and individual aquatic exercise program, to assess factors affecting adherence to exercise for an extended length of time.