• Korean Chemical Engineering Research
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• 제57권1호
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• pp.78-84
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• 2019

최근 지속 가능형 에너지로 바이오 부탄올(bio-butanol)에 관한 연구가 활발히 진행되고 있으나, 이의 상업화에는 저렴한 바이오메스 개발 및 경제적 분리 방법 등 선결해야 할 문제들이 있다. 전통적인 ABE 바이오부탄올 발효공정은 아세톤, 부탄올, 에탄올과 함께 유기산(organic acid)과 같은 부산물을 생성한다. 따라서 이들의 상호분리를 위해 아세톤, 부탄올, 에탄올 및 아세틱 산에 대한 상평형 데이터 등은 많이 발표되었으나, 탄소수가 큰 유기산에 대한 상평형 및 혼합물성 데이터는 매우 부족한 실정이다. 따라서 본 연구는 $C_3-C_6$ 유기산 조합의 이성분계 혼합물에 대한 고-액 상평형과 혼합물성으로 과잉부피($V^E$), 굴절율 편차(${\Delta}R$) 그리고 점도 편차(${\Delta}v$)를 298.15 K에서 실험적으로 측정하였다. 측정된 고-액 상평형 데이터는 NRTL, UNIQUAC식을 이용하여 상관시켰으며 RMSD, 0.5 K이하로 잘 상관되었다. 또한 동일 이성분계 혼합물에 대한 $V^E$, ${\Delta}R$ 및 ${\Delta}v$의 혼합물성 데이터는 Redlich-Kister 다항식을 이용해 매개변수를 상관하였으며 약 0.004 이하의 표준편차로 잘 상관됨을 확인하였다.

• Asian Journal of Atmospheric Environment
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• 제12권2호
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• pp.178-191
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• 2018

The concentrations and chemical compositions of volatile organic compounds (VOCs), including volatile fatty acids, phenols, indoles, aldehydes, and ketones, which are the main organic compounds generated by swine, were investigated in July and October 2016 and January 2017. In addition, the emission rates and annual emissions of these components from the swine shed were estimated. The concentrations of VOCs in the swine shed averaged $511.3{\mu}g\;m^{-3}$ in summer, $315.5{\mu}g\;m^{-3}$ in fall and $218.6{\mu}g\;m^{-3}$ in winter. Acetone, acetic acid, propionic acid, and butyric acid were the predominant components of the VOCs, accounting for 80-88% of the total VOCs. The hourly variations of VOC concentrations in the swine shed in fall and winter suggest that the VOC concentrations were related to the ventilation rate of the swine shed, the activity of the swine, and the temperature in the swine shed. Accordingly, the emission rates of VOCs from the swine shed were $1-2{\times}10^3{\mu}g(h\;kg-swine)^{-1}$.

• Preventive Nutrition and Food Science
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• 제16권2호
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• pp.165-173
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• 2011

Five types of meju were prepared from 100% defatted soybean (DFSG0), a mixture of 90% DFS and 10% glasswort (DFSG1), a mixture of 80% DFS and 20% glasswort (DFSG2), a mixture of 70% DFS and 30% glasswort (DFSG3), and a mixture of 60% DFS and 40% glasswort (DFSG4). Five types of kanjang were separately prepared from the 5 types of meju by ripening in brine for 6 months. The contents of certain minerals (Mg, Ca, Fe, Mn, and Zn), organic acids (citric acid, malic acid) and the antioxidative effects in the kanjang were increased in proportion to the glasswort content in the meju. However, the free amino acid contents in the kanjang were reduced in proportion to the glasswort content in the meju. DFSG1- and DFSG2-kanjang did not show distinct differences from DFSG0-kanjang based on aroma, flavor, and taste that were compared simply by panel tests. The bacterial and fungal community in the fermented meju and kanjang was not affected by the addition of glasswort to the meju-making process. Bacteria belonging to the Lactobacillus and Bacillus genera and the Lactobacillus family predominated, and yeasts belonging to the Saccharomyces genus and fungi belonging to the Aspergillus genus predominated in the fermented meju and kanjang. In conclusion, the glasswort was a supplement that nutritionally improved the kanjang (except for free amino acid contents) but didn't influence the growth of microorganisms that are responsible for the fermentation of meju and kanjang.

• 한국세라믹학회지
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• 제31권9호
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• pp.1076-1086
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• 1994

This study covers synthetic effect of the various hydrothermal treatments on formation of artificially made kaolinite mineral. The hydrothermal treatment includes the temperature treatment with time duration, addition of seeds, particle size of the starting material used, pH variation and the different types of organic acids. A colloidal silica and alumina sol which are commercially available are used for this study. A colloidal silica and alumina sol are mixed by the atomic ratio of Al/Si = 1, based on the theoretical kaolinite composition and calcined at $600^{\circ}C$ for 8 hours duration. It was found that the kaolinitic clay mineral was well developed; thereby, the different patterns of crystalline mineral are appeared. Spherical type as a crystal form was distinctively formed at the temperature of 20$0^{\circ}C$ to 25$0^{\circ}C$ with short duration time, while platy type as a crystal was highly yielded at 300~35$0^{\circ}C$. Moreover, by adding more than 20 wt% of seed as the natural kaolinitic clay to the starting material is widely distributed and developed when 2 ${\mu}{\textrm}{m}$ or less particle size of the starting material is used; also, when they are heat-treated at the temperature of 25$0^{\circ}C$ with 5 hours duration. With respect of the effect of pH variation on formation of the synthetic kaolinite minerals, the crystalline minerals are highly yielded at less than pH 2 and gradually diminished at more than pH9. Regarding to the effect of different acids on development of the kaolinite mineral, the organic acids with high chelating capacity produces good formation of crystalline minerals; whereas, amine radical-(NH2) is not an effective agent to generate the crystalline minerals.

• 한국유기농업학회지
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• 제28권4호
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• pp.579-589
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• 2020

고추역병 다발생 포장에서 녹비작물인 호밀재배에 따른 토양환경 변화와 고추역병 경감 효과를 조사하였다. 토양 물리성을 분석한 결과에서는 호밀재배에서 용적밀도와 공극률이 증가하였다. 또한, 토양 삼상의 분포는 고상에서는 관행재배와 차이가 없었으나, 기상은 관행재배 보다 증가하고 액상은 감소하였다. 토양 내 인지질 지방산을 추출하여 지표 지방산으로 분석한 미생물 군락의 상대밀도는 호밀재배에서 유의성 있게 증가하였으며, 호기성균/혐기성균의 비율의 비율도 호밀재배에서 높게 나타났다. 환경스트레스 지표인 포화지방산/불포화지방산 비율과 cyclo-지방산/전구체 비율은 호밀재배가 관행재배 보다 낮아 토양환경이 개선 된 것으로 나타났다. 호밀재배에 따른 고추역병의 경감효과를 조사한 결과 호밀재배가 관행재배 보다 30.7% 낮은 발병률을 나타냈다. 이상의 결과를 요약해볼 때, 고추역병 다발생 포장에서 녹비작물인 호밀재배는 토양환경을 개선하고 고추역병 발병을 감소시킬 것으로 사료된다.

• KSBB Journal
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• 제20권6호
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• pp.447-452
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• 2005

본 연구에서는 과일 폐액으로부터 고정화 세포를 이용하여 수소생산을 위한 배양조건을 조사하였다. 각종 과일 폐액 중에 수박 폐액에서 환원당의 함량이 가장 높았으며, 수소생산량은 2319.2 mL/L이었다. 고정화 물질 sodium alginate의 농도와 크기에 따른 수소생산성 효과는 검토범위 내에서는 적었다. 고정화된 비드의 내부 관찰에서 세포가 왕성하게 생육하고 있음을 확인했다. 대사의 효소물질로 이용될 수 있는 각종 아미노산의 첨가는 종류에 관계없이 수소생산성에 영향을 거의 미치지 않았다. 금속이온 $FeSO_4$를 첨가한 결과 최적 농도는 1.2 g/L이고, 1.3배의 수소생산 증가를 나타났다. 수소생산정지 후 배양액의 유기산은 lactic acid와 butyic acid가 가장 많았다.

• Asian-Australasian Journal of Animal Sciences
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• 제29권7호
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• pp.987-997
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• 2016

The objective of the study was to compare the carcass characteristics, meat quality, and blood parameters of slow and fast grown female broiler chickens fed in organic or conventional production system. The two genotypes tested were medium slow-growing chickens (SG, Hubbard Red JA) and commercial fast-growing chickens (FG, Ross 308). Both genotypes (each represented by 400 chickens) were divided into two sub-groups fed either organic (O) or conventional (C) systems. Chickens of each genotype and system were raised in a semi environmentally controlled poultry house until 21 d of age and were assigned to 5 pens of 40 chickens each. Then, O system chickens were transferred into an open-side poultry house with an outdoor run. At 81 d of age, 10 female chickens from each genotype and from each production system (n = 40) were randomly chosen to provide material for analysis, and were weighed and brought to the slaughterhouse to assess carcass characteristics and meat quality. The blood parameters were determined by using 5 female chickens from each genotype and from each production system (n = 20). FG had the higher live weight, along with carcass, breast, and thigh-drumstick weights compared to SG (p<0.05). FG had the higher breast yield, whereas SG had the higher thigh-drumstick yield (p<0.05). The O system resulted in a higher amount of abdominal fat (p<0.05). In addition, the O system values were higher for dry matter, crude ash, crude protein, and $pH^{15}$ values in breast meat, and for crude ash, crude protein, and $pH^{15}$ values in drumstick meat (p<0.05). In addition, total saturated fatty acids, total mono-unsaturated fatty acids, and total omega 3 were significantly higher in the O system than in the C system. Thus, the O system showed a positive advantage compared to the C system regarding female chicken meat quality, primarily within the ash, protein, and total omega 3 fatty acid profiles. In conclusion, the present study indicated that the main factor affecting the carcass characteristics of female chickens was genotype, whereas the organic system contributed to enhanced meat quality. These findings provide a better understanding of the relative roles of genotype and production systems in female broiler characteristics, and might aid producers in designing their facilities to optimize yield and quality while maintaining acceptable animal welfare standards.

• 한국식품영양과학회지
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• 제26권6호
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• pp.1140-1146
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• 1997

Storage stability of ginger paste product was investigated from the standpoint of the inhibition of nonenzymatic browning and loss of gingerol contents. For the experimentations, control, 0.04% of N-acetyl-L-cysteine in ginger paste(NAcCys), and combination treatment of NAcCys, 0.92 of water activity and 6.30 of pH in ginger paste (mixed treatment) were stored at 3$0^{\circ}C$ for 40 days and analyzed for browning and gingerol contents. In addition the changes in sugars, organic acids, ascorbic acids, amino acids, and sensory quality were determined. The results revealed that the mixed treatment agent was effective in preventing both nonenzymatic browning and loss of gingerol contents. The inhibition by combination treatment might be resulted from the control of radical formations by sulfhydryl groups of NAcCys and the increase of diffusion resistance in lower water activity. Browning development and total gingerol contents were found to be correlated to some physicochemical characteristics of ginger paste; that is, browning development to amino acid and color value in sensory evaluation, and total gingerol contents to flavor in sensory evaluation.

• International Journal of Air-Conditioning and Refrigeration
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• 제16권3호
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• pp.89-99
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• 2008

Indoor ozone has received attention because of its well-documented adverse effects on health. In addition to the inherently harmful effects of ozone, it can also initiate a series of reactions that generate potentially irritating oxidation products, including free radicals, aldehydes, organic acids and secondary organic aerosols (SOA). Especially, ozone reacts actively with terpene. The overarching goal of this work was to better understand ozone and terpene distributions within rooms. Towards this end, the paper has two parts. The first describes the development of a cylindrical test chamber that can be used to obtain the second order rate constant $(k_b)$ for the bi-molecular chemical reaction of ozone and terpene in the air phase. The second consists of model room experiments coupled with Computational Fluid Dynamics (CFD) analysis of the experimental scenarios to obtain ozone and terpene distributions in various turbulent flow fields. The results of CFD predictions were in reasonable agreement with the experimental measurements.

• 한국식품영양학회지
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• 제12권2호
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• pp.204-208
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• 1999

In order to obtain data for use of algin in drink making process solution properties of algin have been investigated at various condition of algin concentration temperature pH and various food additives. At same revolution velosity viscosities of algin were increased as algin concentration raised. Algin solution showed dilatnat type flow in concentration of 0.25% to 0.4% but pseudoplastic type flow in above 0.5% showed dilatant type flow in concentration of 0.25% to 0.4% but pseudoplastic type folw in above 0.5% A maximum viscosity of algin was observed at pH 5.5 and its viscosities were also decreased as the tem-perature increased and heating at 8$0^{\circ}C$ above. Organic acids affected on the viscosity of algin with pH dependently and gel formed in pH below 3.0 Sweetners have no effect to the viscosity of algin. How-ever addition of NaCl and KCL upto 1.0% decreased a little its viscosity and CACl2 MgCl2 and FeCl3 increased the viscosity of algin Glutamic acid decreased the viscosity of algin.