• Food Science and Biotechnology
• /
• v.18 no.3
• /
• pp.700-705
• /
• 2009

In this study, the volatile compounds in 9 commercial fermented soybean pastes were extracted and analyzed by headspace-solid phase microextraction (HS-SPME) and gas chromatography-mass spectrometry (GC-MS), respectively. A total of 63 volatile components, including 21 esters, 7 alcohols, 7 acids, 8 pyrazines, 5 volatile phenols, 3 ketones, 6 aldehydes, and 6 miscellaneous compounds, were identified. Esters, acids, and pyrazines were the largest groups among the quantified volatiles. About 50% of the total quantified volatile material was contributed by 5 compounds in 9 soybean paste samples; ethyl hexadecanoate, acetic acid, butanoic acid, 2/3-methyl butanoic acid, and tetramethyl-pyrazine. Three samples (CJW, SIN, and HAE) made by Aspergillus oryzae inoculation showed similar volatile patterns as shown in principal component analyses to GC-MS data sets, which showed higher levels in ethyl esters and 2-methoxy-4-vinylphenol. Traditional fermented soybean pastes showed overall higher levels in pyrazines and acids contents.

• Membrane Journal
• /
• v.2 no.1
• /
• pp.1-20
• /
• 1992

Classical membrane processes like microfiltration (MF), ultrafiltration (UF) and reverse osmosis (RO) are being applied in the last years more frequently in environmental and effluent process problems. Newer technologies and developments like pervaporation (PV) and gas sepaxation (GS) recently found commercial applications in the treatment of waste waters and gas streams. The incentive here is either the clean-up from organic components to comply with federal emission regulations or the recovery of the organics for economical reasons. Processes still in their development stage are combinations of chemical reactions with membrane processes to separate and treat $SO_x$ and $NO_x$ laden waste gas streams in the clean-up of stack-gases. In this paper we will first give a short overview of the more recent developments in MF, UF and RO. This is followed by a closer look on newer technologies applied in environmental problems. The applications looked at are the recovery of organic components from solvent laden gas streams and the separation of organic volatiles from aqueous waste waters via pervaporation. Technical solutions, the advantages and disadvantages of the processes and. where possible, cost estimations will be presented.

• Proceedings of the KIEE Conference
• /
• 2005.07c
• /
• pp.2271-2273
• /
• 2005

The cyclic aging for 14days is performed in order to remove the large amount of the volatiles contained in freshly manufactured cable. And the accelerated water treeing test(AWTT) is performed to accelerate the occurance of the water tree in the dielectric of XLPE. In this paper, we examined the AC breakdown voltage characteristics of the 22.9kV power cable before and after the cyclic aging for 14days and the AWTT. As the result, the AC breakdown voltage of the TR CNCV-W power cable is higher than that of CNCV-W and FR CNCO-W power cable.

• Proceedings of the KIEE Conference
• /
• 2005.07c
• /
• pp.2274-2276
• /
• 2005

Cyclic aging for 14days is performed to remove the large amount of the volatiles found in freshly manufactured cable. In this paper, we examined lightning impulse characteristics of power cable before and after cyclic aging for 14days. As the result, the breakdown voltage after aging was lower than that before aging, but the breakdown voltage after aging was higher than that before aging in TR CNCV-W $60mm^2$ power cable.

• Journal of the Korea Furniture Society
• /
• v.13 no.2
• /
• pp.29-38
• /
• 2002

Five type boxes, which are from brick, wood panel, charcoal-packed wood panel, plywood panel and charcoal-packed plywood panel, were prepared. Relationship of preservation characteristic of strawberry and change of relative humidity in the boxes were measured. Physical properties and industrial analysis of white charcoal used were also investigated. Physical Properties and industrial analysis showed that charcoal had: 1) $0.62-0.79g/cm^3$ of density, zero of refining degree and 8.6-9.4 of pH; and 2) 1.0-3.0% of moisture content, 1.9-2.9% of ash content, 3.9-5.0 of volatiles and 89.2-93.2% of fixed carbon, indicating high quality. During the experimental period, relative humidity was highest in the brick box and lowest in the charcoal-packed plywood panel box. Weight loss of strawberry was greatest in charcoal-packed wood Panel box and very little in brick box. In the boxes with charcoal, strawberry was preserved for 6 days without mold, but in brick box it was covered with mold in 3 days. From these results, it is suggested that charcoal-packed wood panel can be used for better ecomaterial.

• 한국연소학회:학술대회논문집
• /
• 2015.12a
• /
• pp.69-72
• /
• 2015

Computational fluid dynamics (CFD) modeling of large-scale coal-fired boilers requires a complicated set of flow, heat transfer and combustion process models based on different degrees of simplification. This study investigates the influence of coal devolatilization, char conversion and turbulent gas reaction models in CFD for a tangential-firing boiler at 500MWe capacity. Devolatilization model is found out not significant on the overall results, when the kinetic rates and the composition of volatiles were varied. In contrast, the turbulence mixing rate influenced significantly on the gas reaction rates, temperature, and heat transfer rate on the wall. The influence of char conversion by the unreacted core shrinking model (UCSM) and the 1st-order global rate model was not significant, but the unburned carbon concentration was predicted in details by the UCSM. Overall, the effects of the selected models were found similar with previous study for a wall-firing boiler.

• Journal of Korea Foundry Society
• /
• v.3 no.2
• /
• pp.100-105
• /
• 1983

The mechanism of coal-dust action on inhibiting burn-on of Sand to iron castings was taken in consideration by means of casting test and thermal decomposition test. To compare the ability of inhibiting sand burn-on, test castings were produced in green sand moulds added three different coal-rusts. And quantitative determination of lustrous carbon and volatiles production for coal-dust samples were performed.The lustrous carbon production was in good agreement with the casting test result. But total voltiles production was relatively inefficient on hibiting sand burn-on to test castings.The lustrous carbon theory can be given to explain the mechanism which coal-dust inhibits sand burn-on to iron castings.

• The Plant Pathology Journal
• /
• v.36 no.3
• /
• pp.193-203
• /
• 2020

Volatile compounds (VOCs) are not only media for communication within a species but also effective tools for sender to manipulate behavior and physiology of receiver species. Although the influence of VOCs on the interactions among organisms is evident, types of VOCs and specific mechanisms through which VOCs work during such interactions are only beginning to become clear. Here, we review the fungal volatile compounds (FVOCs) and their impacts on different recipient organisms from perspective of distinct lifestyles of the filamentous fungi. Particularly, we discuss the possibility that different lifestyles are intimately associated with an ability to produce a repertoire of FVOCs in fungi. The FVOCs discussed here have been identified and analyzed as relevant signals under a range of experimental settings. However, mechanistic insight into how specific interactions are mediated by such FVOCs at the molecular levels, amidst complex community of microbes and plants, requires further testing. Experimental designs and advanced technologies that attempt to address this question will facilitate our understanding and applications of FVOCs to agriculture and ecosystem management.

• Journal of Life Science
• /
• v.7 no.4
• /
• pp.309-315
• /
• 1997

The fermented black tea with tea fungus (FBTF) was prepared by culturing tea fungus biomass in black tea with 10% sucrose (BT) at 30$\circ$ for 14 days. The flavor quality of FBTF was investigated by sensory and chemical analysis, and the results were compared with BT. The data of sensory analysis indicated that fruity, wine-like, sharp-pungent, and vinegar-like flavor notes were increase, while earthy note was reduced during fermentation. GC-MS analysis of volatile compounds collected from FBTF and BT by Tenax trap showed that linalool, liinalool oxide other flavor compounds known as black tea flavor compounds were disappeared. Some major flavor compounds produced during fermentation were acetic acid, ethanol, limonene, $\alpha$-terpineol, and these volatiles may be attributed to the flavor of characteristic FBTF. Biosynthetic pathway for the formation of limonene and $\alpha$-terpineol are proposed through mevalonic acid pathway using acetic acid as precusor and/or through transformation of linalool and linalool oxide.

• Mycobiology
• /
• v.49 no.3
• /
• pp.201-212
• /
• 2021

Truffles are the fruiting bodies of ascomycete fungi that form underground. Truffles are globally valued, culturally celebrated as aphrodisiacs, and highly sought-after delicacies in the culinary world. For centuries, naturalists have speculated about their mode of formation, and in cultures surrounding the Mediterranean Sea, many species have been prized as a delectable food source. Truffle fruiting bodies form underground and emit a variety of volatile organic compounds (VOCs). Truffle volatiles are believed to have evolved to attract animals that disperse their spores. The main VOCs identified from truffles include sulfur compounds, such as dimethyl sulfide (DMS) and dimethyl disulfide (DMDS); in addition, 1-octen-3-ol and 2-methyl-1-propanol have been found in most truffle species. Humans use pigs and dogs trained to detect truffle VOCs in order to find these prized subterranean macrofungi. Truffles have pharmacological potential, but until more reliable cultivation methods become available their high price means they are unlikely to see widespread use as medicinals.