• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.45 no.2
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• pp.41-45
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• 2013

Extractives of garlic (Allium scorodorpasum) and green pepper (Capsicum annuum L.) were used to prevent and exterminate rice weevils which contaminate stored rice. The extractives exhibited great efficacy against Sitophilus oryzae and Tribolium castaneum by annihilating all the weevils contained in a bottle. Furthermore, kraft paper coated by 5% extractives also displayed good effectiveness against the rice weevils. When rice weevils were stored with rice in a sack made of extractives-coated kraft paper, the number of living insects was sharply decreased according to elapsed time. In particular, 1,4-benzoquinone, which is very harmful to human, was detected from rice contaminated by Sitophilus oryzae and Tribolium castaneum through the analysis of GC/MS.

• Fire Science and Engineering
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• v.29 no.6
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• pp.65-70
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• 2015

This research examines the removal efficiency of benzene, toluene, xylene (BTX) and total volatile organic compounds (TVOCs) by flowing VOCs, which are generated at a petrochemical complex in the Ulsan area, in a sliding arc plasma (SAP) reactor. The SAP reactor process is composed of 5 steps and the analysis was conducted using a BTX detector and TVOC measuring instrument. The removal efficiency of BTX was better at high concentration than at low concentration and the emitted TVOC concentration increased in later steps of the reactor. In addition, the removal efficiency improved, as the flow velocity increased. The maximum permissible concentration of TVOCs in the first step was about 481 ppm and showed over 94.83% efficiency when it was operated in the 2nd step at concentrations beyond 481 ppm. Therefore, there are many factors for improving the removal efficiency of SAP reactors at low concentration and measures should be prepared according to the application method for the various types of industrial reactors.

• Applied Biological Chemistry
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• v.40 no.2
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• pp.144-147
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• 1997

Different isolation methods for the volatile components of Anise(Pimpinella anisum L.) are compared in terms of the difference of components obtained with each analytical procedure. These methods include headspace(purge & trap) sampling procedure, simultaneous distillation extraction(SDE), steam distillation and solvent extraction. Total 43 components were identified by? comparing gas chromatography retention time and mass spectral data. Different isolation techniques result in compositionally different isolates. The headspace(purge & trap) sampling procedure was found to be the best method of choice for a qualitative analysis of the volatile components.

• The Plant Pathology Journal
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• v.32 no.1
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• pp.16-24
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• 2016

In this study, antifungal activity of essential oils of Cymbopogon citratus and Ocimum basilicum and two fungicides Mancozeb and Metalaxyl-Mancozeb in six different concentrations were investigated for controlling three species of Phytophthora, including P. capsici, P. drechsleri and P. melonis on pepper, cucumber and melon under in vitro and greenhouse conditions, respectively. Under the in vitro condition, the median effective concen- tration ($EC_{50}$) values (ppm) of plant essential oils and fungicides were measured. In greenhouse, soil infested with Phytophthora species was treated by adding 50 ml of essential oils and fungicides (100 ppm). Disease severity was determined after 28 days. Among two tested plant essential oils, C. citratus had the lowest $EC_{50}$ values for inhibition of the mycelial growth of P. capsici (31.473), P. melonis (33.097) and P. drechsleri (69.112), respectively. The mean $EC_{50}$ values for Metalaxyl-Mancozeb on these pathogens were 20.87, 20.06 and 17.70, respectively. Chemical analysis of plant essential oils by GC-MS showed that, among 42 compounds identified from C. citratus, two compounds ${\beta}$-geranial (${\alpha}$-citral) (39.16%) and z-citral (30.95%) were the most abundant. Under the greenhouse condition, Metalaxyl-Mancozeb caused the greatest reduction in disease severity, 84.2%, 86.8% and 92.1% on melon, cucumber, and pepper, respectively. The C. citratus essential oil reduced disease severity from 47.4% to 60.5% compared to the untreated control ($p{\leq}0.05$). Essential oils of O. basilicum had the lowest effects on the pathogens under in vitro and greenhouse conditions. These results show that essential oils may contribute to the development of new antifungal agents to protect the crops from Phytophthora diseases.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2005.04a
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• pp.28-30
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• 2005

Because of high population diversity in soil microbial communities, it is difficult to accurately assess the capability of biodegradation of toxicant by microbes in soil and sediment. Identifying biodegradative microorganisms is an important step in designing and analyzing soil bioremediation. To remove non-important noise information, it is necessary to selectively enrich genomes of biodegradative microorganisms fromnon-biodegradative populations. For this purpose, a stable isotope probing (SIP) technique was applied in selectively harvesting the genomes of biphenyl-utilizing bacteria from soil microbial communities. Since many biphenyl-using microorganisms are responsible for aerobic PCB degradation In soil and sediments, biphenyl-utilizing bacteria were chosen as the target organisms. In soil microcosms, 13C-biphenyl was added as a selective carbon source for biphenyl users, According to $13C-CO_2$ analysis by GC-MS, 13C-biphenyl mineralization was detected after a 7-day of incubation. The heavy portion of DNA(13C-DNA) was separated from the light portion of DNA (12C-DNA) using equilibrium density gradient ultracentrifuge. Bacterial community structure in the 13C-DNAsample was analyzed by t-RFLP (terminal restriction fragment length polymorphism) method. The t-RFLP result demonstates that the use of SIP efficiently and selectively enriched the genomes of biphenyl degrading bacteria from non-degradative microbes. Furthermore, the bacterial diversity of biphenyl degrading populations was small enough for environmental genomes tools (metagenomics and DNA microarrays) to be used to detect functional (biphenyl degradation) genes from soil microbial communities, which may provide a significant progress in assessing microbial capability of PCB bioremediation in soil and groundwater.

• Mycobiology
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• v.34 no.4
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• pp.219-229
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• 2006

Seventeen microbial species including 10 fungal taxa, two yeasts and five bacteria, were isolated from freshly prepared orange, guava and banana juices kept in open bottles at room temperature for 7 days. Eight different essential oils, from local herbs, were tested for their antimicrobial activity against these test organisms. The essential oils of Cymbopogon citratus, Ocimum basilicum and Origanum majorana were found to be highly effective against these microorganisms. Aspergillus niger, A. flavus and Saccharomyces cerevisiae, the most prevalent microorganisms in juice, showed the highest resistance against these essential oils. GC-MS analysis showed that while e-citral, a'-myrcene, and z-citral represent the major components (75.1 %) of the essential oil of Cymbopogon citratus; bezynen,l-methyl-4-(2-propenyl), 1,8-cineole and trans-a'-bisabolene were the main components (90.6%) of Ocimum basilicum; whereas 3-cyclohexen-l-0l,4-methyl-l(l-methylethyl)-(CAS), c-terpinene and trans-caryophyllene represent the major components (65.1%) of Origanum majorana. These three essential oils were introduced into juices by two techniques namely, fumigation and direct contact. The former technique showed more fungicidal effect than the latter one against A. flavus, A. niger, and S. cerevisiae. The essential oil of Cymbopogon citratus by comparison to other test oils showed the strongest effect against these fungi with a minimum inhibitory concentration of $1.5\;{\mu}l/ml$ medium and a sublethal concentration of $1.0\;{\mu}l/ml$. The antimicrobial activity of this oil is thermostable at $121^{\circ}C$ for 30 min.

• Journal of Crop Science and Biotechnology
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• v.10 no.1
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• pp.45-49
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• 2007

Silicon is one of the key elements for healthy growth and development in rice crops. We analyzed the effect of silicon(Si) on some growth parameters, plant mineral contents, and bioactive gibberellins in three rice cultivars. Silicon was applied at the rates of 0 kg/0.1ha(control), 40 kg/0.1ha, and 80 kg/0.1ha throughout the course of experiment. Plant growth parameters were enhanced by the application of elevated Si, though plant height and culm length were more favorably affected than the respective dry weights. The plant mineral contents analyzed also increased in treatments where Si was applied without potassium, demonstrating that Si application promotes the absorption of these minerals in rice crops. The endogenous gibberellins measured in our study showed that $GA_1$ is the only bioactive GA form present in rice seedlings. The endogenous $GA_1$ and its precursor $GA_{20}$ contents increased after Si application. However, this increase in endogenous $GA_1$ and $GA_{20}$ contents, and plant growth parameters were different according to the rice cultivars. Our results indicate that Si is a beneficial element in rice nutrition and that different cultivars of Oryza sativa show differential responses to Si nutrition in terms of their growth and development.

• Korean Journal of Environmental Agriculture
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• v.29 no.4
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• pp.388-395
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• 2010

In order to decrease level of an organophosphorus fungicide, tolclofos-methyl, from in situ ginseng cultivating soil, we isolated a tolclofos-methyl degrading bacteria from ginseng cultivating soil samples. The bacterial strain removed tolclofos-methyl around 95% after 3 days incubation with complete liquid media. The strain was identified as Sphingomonas sp. by 16S rDNA sequence comparison, and designated as Sphingomonas sp. 224. Through the GC-MS analysis, Sphingomonas sp. 224 was proposed to have an initiative degradation pathway generating the metabolite such as 2,6-dichloro-4-methyl phenol compound from tolclofos-methyl. In addition, Sphingomonas sp. 224 was confirmed representing the effective degrading capability to tolclofosmethyl in situ soil.

• Journal of the Korean Society of Food Culture
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• v.18 no.1
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• pp.69-74
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• 2003

This study was conducted to find the appropriate fiber for extraction of volatile compounds from Perilla frutescens var. acuta. by solid phase microextraction (SPME). Two SPME fiber, carboxen/polydimethylsiloxane (CAR/PDMS) and polydimethylsiloxane (PDMS) were used to determine the selectivity of the fibers to the different flavor compounds present in the Perilla frutescens var. acuta. Thirty-nine compounds were identified in the volatile compounds extracted by CAR/PDMS fiber, including 6 aldehyde, 1 alcohol, 10 hydrocarbons, 17 terpene hydrocarbons, 2 ketones and 3 benzenes. In PDMS fiber, 3 aldehydes, 2 alcohols, 13 terpene hydrocarbons and 2 miscellaneouses were identified. Perillaldehyde was found to be major volatile flavor component of fresh Perilla frutescens var. acuta. Perillaldehyde and terpene hydrocarbons were more identified in PDMS fiber. These results suggested that the selectivity of PDMS fiber was better than that of CAR/PDMS fiber in Perilla frutescens var. acuta..

• Journal of the Korean Society of Industry Convergence
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• v.7 no.1
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• pp.107-113
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• 2004

Several transition metal complexes, [$M(L)X_2$](M=Pd(II), Ni(II); X=CI, Br) are prepared with aminophosphine ligands such as 1,2-bis{(diphenylphosphino)amino}ethane{$Ph_2PNHCH_2CH_2NHPPh_2$}($L_1$), 1,2-bis{(diphenylphosphino)amino}propane{$Ph_2PNHCH(CH_3)CH_2NHPPh_2$}($L_2$), trans-1,2-bis{(diphenylphosphino)amino}cyclohexane{$Ph_2PNHC_6H_{10}NHPPh_2$}($L_3$) and 1,2-bis{(diphenylphosphino)amino}benzene{$Ph_2PNHC_6H_4NHPPh_2$}($L_4$). The properties of these complexes are characterized by optical spectroscopic methods including UV/vis spectroscopy, CD, IR, $^1H$- and $^{31}P-NMR$ together with conductometer and elemental analysis. All complexes are stable under atmospheric environment. Catalytic reactivity for C-C coupling between [$M(L)X_2$] and Grignard reagents(RMgX; R=phenyl, propyl, buthyl) by thermolysis were investigated utilizing GC/mass, $^1H$- and $^{13}C-NMR$. When mol scale is 1:20 at [$Pd(L)Cl_2$] and Grignard reagents, the high catalytic activity for C-C coupling is apparent. The [$M(L)X_2$](X=Cl, Br) complexes which have strong bond at M-P exhibit high yields for C-C coupling reactions. When the central metal ion is Pd(II), the high catalytic activity for C-C coupling is apparent. The complex coordinated with Br shows higher catalytic activity for C-C coupling reactions compared to Cl.