• 한국초지조사료학회지
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• 제5권3호
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• pp.200-206
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• 1985

유지(由地)의 경사도(傾斜度)($10^{\circ},\;20^{\circ},\;30^{\circ}$) 및 3 요소(要素)($N-P_2O_5-K_2O$)의 시용수준(施用水準)(0-0-0, 14-10-10, 28-25-25, 42-40-40kg/10a)이 겉뿌림 산지초지(山地草地)(orchardgrass, tall fescue, redtop, ladino clover 혼파(混播)의 조성(造成), 생산성(生産性), 식생(植生) 및 목초품질등(牧草品質等)에 미치는 영향(影響)을 구명(究明)하였다. 본고(本稿)에서는 토양(土壤)의 화학적(化學的) 특성(特性), 목초(牧草)의 양분함량(養分含量)과 비료(肥料)의 이용효율에 관(關)하여 검토(檢討)하였다. 1. 2년(年) 시험후(試驗后) 토양(土壤)의 화학적(化學的) 특성변화(特性變化)를 보면, 경사도(傾斜度)가 증가(增加)함에 따라서 pH, 치환성(置換性) Mg, Na함량(含量), 염기포화도(鹽基飽和度)가 낮아지고, OM, 유효$P_2O_5$함량(含量) 증가경향(增加傾向)을 보였으나, Ca함량(含量) 및 $K/\sqrt{Ca+Mg}$ 당양비(當量比) 변화(變化)는 뚜렷하지 않았다. 3. 요소(要素) 시용수준(施用水準)이 증가(增加)함에 따라서 pH, 치환성(置換性) Ca, Mg, 염기포화도(鹽基飽和度)가 낮아지고, 유효 $P_2O_5$함량(含量), 치환성(置換性) K 함량(含量), $K/\sqrt{Ca+Mg}$ 당양비(當量比)는 증가(增加)하는 경향(傾向)을 보였다. 2. 목초중(牧草中) 무기양분(無機養分)의 함량변화특성(含量變化特性)을 보면 경사도(傾斜度)가 증가(增加)함에 따라서 혼파목초중(混播牧草中) 화본과목초(禾本科牧草) 및 잡초(雜草)의 양분함량변화(養分含量變化)는 뚜렷하지 않았으나 두과목초(荳科牧草)는 급경사지(急傾斜地)에서 N, K 및 Mg 함량(含量)이 매우 낮았으며 이는 수량감소(收量減少)와 연관(聯關)된 것으로 보인다. Mg함량(含量)은 모든 초종(草種)이 기준함량(基準含量)에 크게 부족(不足)하였다. 3. 3요소수준(要素水準)이 증가(增加)함에 따라서 화본과목초(禾本科牧草)는 N, K, Na함량(含量)은 증가(增加)하고, Mg 및 Ca함량(含量)은 감소(減少)되었고, P 함량(含量)은 무비구(無肥區)보다 증가(增加)하였으나 시용수준간(施用水準間)에는 차이(差異)가 없었다. 두과목초(荳科牧草)에서는 K함량(含量)은 미약(微弱)하게 증가(增加)되었고, Mg함량(含量)은 감소(減少)되었으며, N, Ca 및 Na함량(含量)은 뚜렷한 변화(變化)가 없었다. 반면에 잡초(雜草)에서는 N함량(含量)의 미약(微弱)한 증가외(增加外)에는 변화(變化)가 뚜렷하지 않았다. 혼합목초(混合牧草)의 특성(特性)을 보면 일반적(一般的)으로 N, K 함량(含量)은 증가(增加)하고 Ca, Mg함량(含量)은 감소(減少)되며, P, Na함량변화(含量變化)는 경미(輕微)하였다. 4. 3요소(要素)의 이용율(利用率)은 경사도(傾斜度)가 증가(增加)할수록, 3요소시용수준(要素施用水準)이 증가(增加)할수록 낮아졌으며 K>N>P 순(順)으로 높았다. 3요소(要素) 혼합시비효율은 경사도(傾斜度) 및 3 요소수준(要素水準)이 증가(增加)할수록 낮아졌으나, 3요소(要素)를 혼합(混合)한 흡수시비효율은 경사도간(傾斜度間)에는 차이(差異)가 없었으나 시비수준(施肥水準)이 증가(增加)함에 따라서 다소 감소(減少)되는 경향(傾向)을 보였다.

• 자원리싸이클링
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• 제19권1호
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• pp.21-26
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• 2010

본 연구에서는 마이크로웨이브 열탄소환원에 의한 제철 슬래그의 Fe 회수를 위한 기초연구로서, CaO-$SiO_2$-FeO계 슬래그의 열탄소환원 반응에 미치는 가스 분위기(질소 및 대기분위기) 및 탄소 첨가량의 영향을 살펴보았다. 실험결과, 질소 분위기에 비하여 대기 분위기에서 반응 시 최고 도달 온도 및 환원률이 증가하고, 대기 분위기에서는 탄소 당량 증가에 따라 최고 도달 온도 및 환원률이 증가하는 경향을 나타내었다. 대기 중 탄소 당량($C_{eq}$)이 5인 조건에서 최고 온도는 1800K에 도달하였으며 약 90%의 철회수율을 얻을 수 있었고, 탄소 당량이 5 이상 증가할 경우 최고 온도 및 환원율의 변화는 크지 않음을 알 수 있었다.

• 한국초지조사료학회지
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• 제10권3호
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• pp.141-146
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• 1990

Changes in dry matter yield, crude components, nutrients uptake($P_2O_5$, $K_2O$, CaO, MgO) and sulphur containing amino acid(cysteine, methionine) of orchardgrass(Dacty1is glomerata. L) and alfalfa(A4edicago sativa. L) by gypsum application(as sulphur source, 0, 2. 5, 10, 20kg SIlOa) were investigated to understand the effect of sulphur on herbage production in pasture, which was established in 1987 as means of hand broadcasting. The effect of gypsum on dry matter yield at different cutting times during growing seasons has not been found both in orchardgrass and in alfalfa, but in respect to annual total dry matter yield there were increment in herbage yield (P<0.05) of alfalfa at 5, 10, 20kg SIlOa in 1989 and the amounts of sulphur taken up in herbage slightly increased according to the rates of gypsum application. Maximum apparent recovery of sulphur was 7.55% at 2kg SIlOa in orchardgrass and was 17.8% at 5kg S/lOa in alfalfa. There were no any great differences in the content of crude components of both species and this trend was similar with the mineral contents of orchardgrass. But in alfalfa, the amounts of $K_2O$, CaO, and $P_2O_5$ taken up were increased by gypsum application and the increment in the amounts of minerals taken up in herbage at 20kg SIlOa were 14.9 of $K_2O$, 9.1 of CaO, and 2.5kgIlOa of $P_2O_5$ as compared to those of at untreated plot. Cysteine and methionine were not influenced by gypsum applicaton not only in orchardgrass but also cysteine in alfalfa, however, the content of methionine in alfalfa was slightly increased at 2, 5, lOkg SIlOa and at 20kg SIlOa was reverse.

• International Journal of Concrete Structures and Materials
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• 제5권2호
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• pp.133-137
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• 2011

In this study, a physical and chemical properties analysis was conducted for PCSP to evaluate properties of its materials and, for comparison purpose, was also conducted for CSP. The result of experiment confirmed improvement of iron recovery rate due to introduction of rapid water-cooling equipment and greater density of exterior and interior structure through SEM observation and porosity measurement. Also, SEM, XRD and DSC-TGA analysis showed that content of f-CaO in PCSP was minuscule so it was decided that problems of material stability including f-CaO-caused bulging failure, which has been problematic, can be solved.

• 자원리싸이클링
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• 제13권3호
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• pp.27-36
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• 2004

수소화 반응용 니켈 폐촉매를 배소하여 산화니켈을 회수한 다음, 회수한 산화니켈을 산처리하고 침전법으로 Kieselguhr에 담지 된 니켈 촉매로 재생시켰다. 폐촉매의 배소 조건이 니켈산화물의 회수에 미치는 영향을 조사하였다. 니켈 폐촉매의 재생 과정에서 $1,000^{\circ}C$의 온도에서 배소 하였을 경우에 대부분 니켈산화물로 회수할 수 있었다. 산화니켈을 산처리하여 얻은 질산니켈을 사용하여 Kieselguhr에 담지 된 니켈 촉매를 제조하였다. 이때 조촉매의 첨가, 침전 조건 및 환원 조건 등이 재생된 촉매의 식물성 오일의 수소화 반응 성능에 미치는 영향을 조사하였다. 알카리 금속인 CaO와 희토류 금속인 $Ce_2$$O_3$를 조촉매로 첨가했을 때 수소화 반응의 활성이 증가하였다.

• 한국자원리싸이클링학회:학술대회논문집
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• 한국자원리싸이클링학회 2006년도 춘계임시총회 및 제27회 학술발표대회
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• pp.78-85
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• 2006

In textile industries, waste effluent containing zinc is generated during the manufacture of rayon yarn from the wood pulp or cotton linters. Due to the strict environmental regulations and the presence of toxic metallic and other constituents, the discharge of industrial effluents in the sewage or disposal of solid sludge as landfill is restricted. Before recycling of zinc as zinc sulphate solution to the spinning-bath of the rayon manufacturing plant the zinc sulphate solution must be free from calcium, which is deleterious to the process as gypsum precipitates with the increase in concentration and forms scale in the bath. In the present work an attempt has been made to develop a process following solvent extraction technique using thiophosphinic extractants, Cyanex 272 and 302 modified with isodecanol and diluted in kerosene to recover zinc from rayon effluent. Various process parameters viz. extraction of zinc from different concentration of solution, distribution ratio, selective extraction, O/A ratio on extraction and stripping from the loaded organic, complex formation in the organic phase etc. have been studied to see the feasibility of the process. The extractant Cyanex 302 has been found selective for the recovery of 99.99% of zinc from the effluent above equilibrium pH 3.4 maintaining the O/A ratio of 1/30 leaving all the calcium in the raffinate. It selectively extracted zinc in the form of complex $[R_{2}Zn.3RH]_{org}$ and retained all the calcium in the aqueous raffinate. The zinc from the loaded Cyanex 302 can be stripped with 10% sulphuric acid at even O/A ratio of 10 without affecting the stripping efficiency. The stripped solution thus obtained could be recycled in the spinning bath of the rayon plant. The raffinate obtained after the recovery of zinc could be disposed safely without affacting environment.

• 한국초전도저온공학회:학술대회논문집
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• 한국초전도저온공학회 1999년도 제1회 학술대회논문집(KIASC 1st conference 99)
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• pp.3-9
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• 1999

The grain morphology, the changes in morphology and Jc with the thermo-mechanical treatment (TMT) history, the field dependence of Jc and the nature of intergranular bonding were studied in $T_{10.8}$$Pb_{.2}$$Bi_{0.2}$$Sr_{1.8}$$Ba_{0.2}$$Ca_{2.2}$$Cu_{3}$$O_{z}$/Ag tapes. As a result, incorporation of intermediate rolling during the final heat-treatment resulted in of plate-like TI-1223 grains, and thus enhanced Jc. Jc's near 2.5$\times$104 A/cm2 at 77 K and 0 T were obtained in just rolled tapes with an excellent reproducibility. The high Jc's seem to grain-connectivity easy recovery of excellent grain-connectivity during final heat-treatment after inter -mediate rolling, probably due to retarded T1 evaporation and excessive Ca content in the present composition. The strong field dependence of Jc even in low fields, however, indicated that there still existed significant weak-links and the degree of directional grain-alignment was far from the desired one. The intergranular binding in the tapes seemed to be mainly dominated by SIS junctions.

• The Korean Journal of Physiology
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• 제23권2호
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• pp.351-361
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• 1989

The contraction of renal arterial strip by no.epineph.me (NE) or 40 mM $K^+$ were Significantly attenuated after histamine $(10^{-5}\;M)-induced$ contraction. The mechanisms of this phenomenon were investigated in the helical strips of isolated renal artery with the measurement of isometric tension. The arterial strip was immersed in the tris-buffered Tyrode's solution which was equilibrated with 100% $O_2\;at\;35^{\circ}C$. The contraction was induced by NE or 40 mM $K^+$ during the recovery from the histamine-induced contraction which lasted for 15 minutes. The contraction by NE was also attenuated in the $Ca^{2+}-free$ Tyrode's solution and the increase of contraction by addition of 2 mM $Ca^{2+}$ was attenuated as well. This attenuation phenomenon was not observed in the presence of low concentration $(3{\times}10^{-7}\;M)$ of histamine. This attenuation was not affected by destruction of endothelium, pretreatment with papaverine or propranolol. This attenuation was partially inhibited by pretreatment of ouabain or in low $K^+(0.5 mM)$ Tyrode's solution. But the attenuation in the $Ca^{2+}-free$ Tyrode's solution was not inhibited. Furthermore this attenuation was completely blocked by pretreatment of djphenhydramine $(H_1-receptor blocker)$ and potentiated by pretreatment of cimetidine $(H_2-receptor\;blocker)$. This attenuation Phenomenon was disappeared after recovery of 1 hour. From the above results, it is suggested that the attenuation phenomenon may be resulted partially from the activation of $Na^+-K^+$ exchange pump and partially from the depletion of intracellular $Ca^{2+}$ pool after the histamine-induced contraction mediated through $H_1-receptor$ function.

• Journal of Korean Neurosurgical Society
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• 제29권9호
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• pp.1161-1170
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• 2000

Objective : The transverse hippocampal slice is one of the most commonly studied in vitro models of mammalian brain physiology. However, despite its broad usage, there has been no standardization of slice preparation techniques or recording condition. It is well known that variations in recording conditions can result in profound different effects to neuronal responses. Evoked field potentials, recorded extracellularly, were used to investigate the effects of variations in hippocampal slice preparation protocol on hypoxia responses of CA1 neurones. Material & Methods : Before hypoxic injury, hippocampal slices were incubated for 4 hours. During incubation period, the slices were placed in a incubation chamber($21^{\circ}C$) for recovery from preparation injury and then transferred to recording chamber($34^{\circ}C$) for more recovery and baseline electric recording with current stimulation(0.1Hz). Various time periods in incubation chamber and recording chamber were applied to each experimental group(group 1=60min : 180min, group 2=90min : 150min, group 3=180min : 60min, time in incubation chamber : time in recording chamber) before 10 min hypoxia produced by replacing 95% $O_2$+5% $CO_2$ mixed gas to 95% $N_2$+5% $CO_2$ gas. Calcium, Magnesium ions and several drugs effecting on glutamate receptor also were studied. Recoveries from hypoxic injury of hippocampal slices were estimated by percent recovery of population spike(PS). Statistic analysis of study were performed using paired t-test. Results : The percent recovery of PS after 10min hypoxia was considerably enhanced by increasing the period of current stimulation during incubation period before hypoxic injury. Temperature effect on the result of this experiment was also studied(group 4) but the result from this showed no statistic significance. Low magnesium ion concentration of artificial CSF(Mg-free aCSF) during incubation period enhanced the recovery of PS but low calcium (calcium-free) and high magnesium ion concentration(2mM) reduced it after hypoxic injury. L-glutamate($100{\mu}M$) and AP-5($50{\mu}M$) had no effect on the recovery of PS but CNQX($10{\mu}M$) in artificial CSF during incubation period markedly enhanced the recovery of PS. Co-treatment of AP-5($50{\mu}M$), CNQX($10{\mu}M$) and high magnesium concentration(2mM) enhanced recovery of PS in immediate following period of hypoxic injury but the effect of cotreatment after then decayed rapidly and lost statistic significance. Conclusions : Judging from above results, the condition of baseline recording is important in observing the recovery of population spike after hypoxia, and the time and the condition should be controled more strictly to obtain reliable results.

• 자원리싸이클링
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• 제7권2호
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• pp.39-45
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• 1998

LD 제강 더스트를 제철원료로 LD 전로 제강 슬래그를 용제로 하고 폐타이어에 의해 제조한 건류탄을 환원제로 사용하여 반사로에서 환원 실험하여 배합비, 온도 및 반응시간 변화에 따른 환원율 및 철 회수율의 영향을 조사하여 다음과 같은 결과를 얻을 수 있었다. 1) $1300^{\circ}C$에서 1시간 동안 환원실험한 결과 탈아연율(removal rate of zinc)이 97%이상이며 잔사중의 Zn은 0.1~0.2%이었다. 2)페렛트 중에 LD 스래그 15~20%, 폐타이어 건류탄 4.1~6.7% 함유된 시료를 대기압, $1350^{\circ}C$에서 3시간동안 환원실험한 결과 선철의 회수율은 89.3~92%이었다. 3)환원제련시에 집진장치에서 회수한 더스튼 Zn 60%의 조산화아연이었다. 4) 회수한 선철의 성분은 Fe 96%, C 1.6%, P 0.08%, S 0.05%이었다. 5) 환원시에 생성한 슬래그의 조성은 $Ca_2Al_2SiO_7$, 8CaO $5SiO_2$ 및 $Na_3Ca_6(PO_4)_5$가 확인되었다.