• 한국식품과학회지
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• 제27권2호
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• pp.205-209
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• 1995

국내에서 생산된 정제 대두유의 열, 산화 안정성을 향상시키고 풍미, 물성의 개량과 이용도를 높이기 위하여 수소첨가에 의한 식용경화 대두유 제조시 반응 조건을 달리하여 주요 지방산 조성, 옥소가 및 trans 이성체의 생성에 미치는 영향을 조사하였다. $180^{\circ}C$의 반응조건에서 trans 산의 생성은 압력 $3.0{\;}kg/cm^{2}H_{2}$에서 $0.5{\;}kg/cm^{2}H_{2}$에서 보다 6.2배 증가하였고 linolenic acid는 감소하였다. 그러나 경화온도 $200^{\circ}C$의 경우 압력 $0.5{\;}kg/cm^{2}H_{2}$에서 $3.0{\;}kg/cm^{2}H_{2}$보다 trans 이성체 생성이 4.6%가 많았으며, linolenic acid, linoleic acid함량은 각각 0.51%, 2.5%가 감소하였다. 경화온도 $180^{\circ}C$, 압력 $3.0{\;}kg/cm^{2}H_{2}$와 sulphur 4 ppm을 첨가한 조건에서 옥소가와 linolenic acid가 감소하여 유리하였으나, trans 이성체의 생성이 가장 많아 불량하였다. 그러나 경화온도 $200^{\circ}C$, 압력 $0.5kg/cm^{2}H_{2}$와 $3.0kg/cm^{2}H_{2}$의 조건하에서 trans 이성체의 생성이 비교적 적게 생성되었고, 옥소가와 linolenic acid도 감소되어 최적 조건이라 생각된다.

• 자연과학논문집
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• 제5권2호
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• pp.63-73
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• 1992

There are many methods of obtaining butadiene described in the literature. In the america it is produced largely from petroleum gases, i.e., by catalytic dehydrogenation of butene of butene-butane mixtures. Butadiene can be recovered from the $C_4$ residue of an olefin plant by distilling off a fraction containing most of the butadiene, catalytically hydrogenating the higher acetylenes to olefins and separating the product from other olefins and isobutane by extraction. Also it can be obtained by cracking naphtha and light oil. Among the individual dienes of commercial importance, 1, 3-butadiene is of first importance. It is used primarily for the production of polymers.In the present paper, it was investigated for a effect of the formation and the growth inhibition of popped corn polymer in butadiene extraction unit. As a result of study, inhibitors, $NaNO_2$ and TBC were good effective for inhibition of the formation and growth in popcorn polymer. The rational formula of popcorn polymer obtained was $(C_4H_6)_x$.

• 한국분말재료학회지
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• 제17권5호
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• pp.385-389
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• 2010

Titanium powders have been usually produced by de-hydrogenating treatment in vacuum with titanium hydride ($TiH_2$) powders prepared by milling of hydrogenated sponge titanium, $TiH_x$. The higher stoichiometry of x in $TiH_x$, whose maximum value is 2, is achieved, crushing behavior is easier. $TiH_x$ powder can be, therefore, easy to manufactured leading to obtain higher recovery factor of it. In addition, contamination of the powder can also minimized by the decrease of milling time. In this study, the hydrogenation behavior of sponge titanium was studied to find the maximum stoichiometry. The maximum stoichiometry in hydride formation of sponge titanium could be obtained at $750^{\circ}C$ for 2 hrs leading to the formation of $TiH_{{\sim}1.99}$ and the treating temperatures lower or higher than $750^{\circ}C$ caused the poor stoichiometries by the low hydrogen diffusivity and un-stability of $TiH_x$, respectively. Such experimental behavior was compared with thermodynamically calculated one. The hydrogenated $TiH_{1.99}$ sponge was fully ball-milled under -325 Mesh and the purity of pure titanium powders obtained by de-hydrogenation was about 99.6%.

• Asian-Australasian Journal of Animal Sciences
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• 제16권12호
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• pp.1743-1748
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• 2003

The effect of pH on the fermentation characteristics and the formation of cis-9, trans-11 conjugated linoleic acid (CLA) and trans-11 octadecenoic acid by mixed ruminal bacteria was examined in vitro when incubated with linseed or rapeseed. Concentrate (1%, w/v) with ground linseed (0.6%, w/v) or rapeseed (0.5%, w/v) was added to 600 ml mixed solution of strained rumen fluid with artificial saliva (1:1, v/v), and was incubated anaerobically for 12 h at $39^{\circ}C$. The pH of culture solution was maintained at level close to 4.5, 5.3, 6.1 and 6.9 with 30% $H_2SO_4$ or 30% NaOH solution. pH increment resulted in increases of ammonia and total volatile fatty acid (VFA) concentration in culture solutions containing both oilseeds. Fermentation did not proceeded at pH 4.5. Molar proportion of acetate decreased but that of propionate increased as pH increased when incubated with oilseeds. While the hydrogenating process was very slow at the pH range of 4.5 to 5.3, rapid hydrogenation was found from the culture solutions of pH 6.1 and 6.9 when incubated with linseed or rapeseed. As pH in culture solution of linseed or rapeseed increases proportions of oleic acid (cis-9 $C_{18:1}$) and trans-11 octadecenoic acid increased but those of linoleic acid and linolenic acid decreased. The CLA proportion increased with pH in culture solution containing rapeseed but CLA was mostly not detected from the incubation of linseed.

• 한국축산식품학회지
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• 제24권3호
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• pp.303-309
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• 2004

Conjugated linoleic acid (CLA) is currently under intensive investigation due to its health benefits. A great deal of interest has been paid to the possible health-promoting roles of CLA, but there are not many studies available on the mechanism of CLA production by ruminal microorganisms. CLA is produced as an intermediate of the characteristic biohydrogenation process of linoleic acid(LA) in the rumen and its production has direct relationship to numerous environmental factors including particle association, substrate concentration, forage-to-grain ratio, pH, ionopore, bacterial cell density, etc. Some of these factors were known to affect hydrogenating activities of Butyrivibrio fibrisolvens A38 which is an active rumen bacterium in CLA production. Dairy cow is a main source of CLA, and its level could be increased by dietary manipulation changing the physiological environment of rumen bacteria such as B. fibrisolvens A38. Therefore, the effects of various factors on. ruminal biohydrogenation should be carefully considered to optimize not only CLA production, but also other fatty acid metabolism, both of which are directly affecting nutritional quality and functionality of dairy products. In this review, the relationship between various environmental factors and ruminal CLA production is discussed focusing on the CLA production of B. fibrisolvens A38.

• 대한화학회지
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• 제66권5호
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• pp.349-361
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• 2022

Because hydrotreating (HDT) of FCC gasoline is one of the important processes used to prepare such gasoline for blending, the development of a catalyst for this process is of great interest. Currently, the industrial HDT of FCC gasoline consists of two stages and the creation of a new catalyst for one-stage HDT will make this process more efficient. Recently, our group has developed the CoMo/Al₂O₃-ASA catalyst and studied the influence of Si/Al ratio on the target reactions of HDT process. Despite the high selectivity and activity, the catalyst with ASA is not applicable in industry because of its low strength. The present work moves forward to study the influence of the ASA content in the catalyst support and clarify the possibility to develop the catalyst that combines high activity and selectivity in HDT reactions with successful performance. Here we show that the CoMo catalyst with ASA/Al₂O₃ molar ratio 1/1 in the support is the best combination for FCC gasoline hydrotreatment due to exceptional properties of the catalyst composition.

• Korean Chemical Engineering Research
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• 제44권4호
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• pp.363-368
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• 2006

$C_9$-알데히드를 수소화하여 $C_9$-알콜을 제조하는 공정에 사용하기 위한 최적의 촉매를 선정하고, $C_9$-알콜의 수율을 극대화하기 위한 운전 조건을 확립하기 위한 실험을 수행하였다. 구리 전구체로 acetate를 사용하고 침전제로 $Na_2CO_3$를 사용하여 제조한 $CuO/ZnO/Al_2O_3$(60:30:10 wt％) 촉매의 표면적 및 구리 비표면적이 가장 우수하였으며 $C_9$-알데히드 수소화 반응에서도 가장 우수한 성능을 보였다. 최적화된 촉매를 장착한 trickle bed 반응기를 사용하여 $175^{\circ}C$, 800 psi, $WHSV=3hr^{-1}$의 조건에서 94.1 wt％의 $C_9$-알콜 수율을 얻었다. 알데히드의 수소화 반응에 사용되는 다른 촉매들과 비교한 결과 Ni/kieselghur 촉매와 유사한 성능을 보였으며 $Cu-Ni-Cr-Na/Al_2O_3$ 촉매 및 $Ni-Mo/Al_2O_3$ 촉매의 경우보다 우수한 성능을 보이는 것을 확인하였다. 장기 촉매 테스트를 통해서 촉매의 안정성을 확인한 결과 약 72시간 이후에는 고비점 부산물의 생성량 증가로 인하여 $C_9$-알콜의 수율이 약간씩 감소하였다.