• Analytical Science and Technology
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• v.26 no.1
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• pp.19-26
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• 2013

Gibberllic acid ($GA_3$) is one of gibberellins (GAs) that are a class of plant growth hormones that exert profound and diverse effects on plant growth and development. $GA_3$ is essentially non-UV absorbing and is difficult to assay by UV-detector. For effective extraction of gibberellic acid from fruits by using liquid-liquid extraction, optimized pH and extraction solvent were established. The selective and sensitive derivative of $GA_3$ for HPLC/UV-vis was derivatized using phenacyl bromide, and the experimental factors, including reaction time, reaction temperature and amount of derivatizing reagent and base were investigated for the effective synthesis. The derivatized $GA_3$ with phenacyl bromide was effectively analyzed by HPLC/UV-vis. The structure of derivatized $GA_3$ was confirmed by HPLC/ESI-MS. For apple, LOD and LOQ were 0.008 mg/kg and 0.027 mg/kg, respectively. For pear, LOD and LOQ were 0.003 mg/kg, 0.012 mg/kg, respectively. The established method can be applied to more effective analysis of $GA_3$ from plant and food.

• Applied Biological Chemistry
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• v.19 no.1
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• pp.1-23
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• 1976

The female moths of Lepidoptera comprising over 1,000,000 described species possess long-chain unsaturated alcohols or esters as the typical structure of potential sex attractants. In this experiment, various stereoisomers of $C_{16}-unsaturated$ acetates were synthesized for potential sex attractants; e.g., $CH_3(CH_2)_mCH=CH(CH_2)_nOR$ (m=0-12, n=1-13, R=H and $-COCH_3$). Seventeen acetates were spectrometrically examined so that the data would provide a ready catalog of gas chromatography and mass spectrometric data for comparison with natural insect sex attractants. Exclusively cis and trans isomers were obtained by the catalytic and chemical reduction methods, respectively. Commercially available $CH_3(CH_2)_mBr,\;CH_3(CH_2)_mC{\equiv}CH,\;HC{\equiv}C(CH_2)_nOH\;and\;HO(CH_2)_n\;OH$ were used for the synthetic starting material. 1-Alkynes, $CH_3(CH_2)_m\;C{\equiv}CH$ exceeding nine methylene groups did not condense with alkyl dihalides. The yield of coupling products was gradually decreased with increasing the molecular weight of diols. In the coupling reaction of $BrCH_2CH_2$ OTHP with acetylene gas, the tetrahydropyranyl ether of bromohydrin produced undesirable elimination product. In this experiment, it seems that p-toluenesulfonic acid is greatly favoured hydrolyzing agent over dilute sulfuric acid in the hydrolysis of the tetrahydropyranyl ether of long-chain alkynols.

• Journal of the Korean Geographical Society
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• v.45 no.1
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• pp.49-74
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• 2010

Cities are major sources of greenhouse gas emissions but also suitable places for implementing proactive climate mitigation and adaptation strategies. Based on the interdisciplinary review of literature, we categorize the current discussion about urban climate mitigation and adaptation planning, policy and practices into four perspectives - sustainability science, global change science, multilevel governance, and structural engineering. While these four schools of thought have distinct perspectives rooted in different disciplinary lenses, our synthesis of the literature identifies several universal themes that are common to all of the perspectives in the context of combating threats posed by climate change. The Portland case study illustrates that a city can make changes to reduce greenhouse gas emissions and increase adaptive capacity to climate change impacts by implementing smart growth, devising local climate action plans that target emission reductions in various sectors, recognizing the interactions and influences of multiple scales of governance, and supporting the installation of various green infrastructures that contribute to green economy. Furthermore, a university can serve as a hub in this climate mitigation and adaptation arena by connecting various levels of community organizations in both public and private sectors, creating innovative research centers and spatially explicit green infrastructure, designing impact assessments and campus carbon inventories, and engaging students and the larger community through service learning.

• Korean Chemical Engineering Research
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• v.52 no.2
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• pp.214-218
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• 2014

In this study, nanoporous $Cu_3(BTC)_2$ membranes were synthesized on macroporous alumina tube supports by solvothermal method. It is very difficult to prepare uniform and crack-free $Cu_3(BTC)_2$ layer on macroporous alumina support by in situ solvothermal method. In this study, continuous and crack-free $Cu_3(BTC)_2$ tubular membranes could be obtained by in situ solvothermal process after surface modification of alumina support. The surface modification was conducted by spraying Cu precursor solution on the alumina support heated at $200^{\circ}C$. The prepared $Cu_3(BTC)_2$ tubular membranes were characterized by XRD, FE-SEM and gas permeation experiments. $H_2$ permeance through $5{\mu}m$ thick $Cu_3(BTC)_2$ tubular membrane was calculated to be $7.8{\times}10^{-7}mol/s{\cdot}m^2{\cdot}Pa$ by single gas permeation test, with the ideal selectivities of $H_2/N_2=11.94$, and $H_2/CO_2=12.82$.

• Journal of the korean academy of Pediatric Dentistry
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• v.30 no.1
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• pp.124-131
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• 2003

The concentration of nitrous oxide in dental environment has increased especially in pediatric department. In pediatric department frequently met the behavior disordered patients who need the deep sedation. As the deeply sedated patients could not respond well to verbal command, the amount of mouth breathing would be increased especially with mouth prop which backward transposition of mandible. Inhalation of low concentration of nitrous oxide for a long duration has caused various side effects such as spontaneous abortion and inhibition of methionine synthetase activity which is harmful to DNA synthesis. For evaluation of factors of mouth breathing during deep sedation. The author measured the concentration of nitrous oxide in breathing zone by the change of the scavenging methods. One is drain the gas through the tail part of reservoir bag of Jackson Ree's system naturally. Another is scavenge from tail portion of reservoir bag with negative pressure. Last one is scavenge from nasal mask with negative pressure. The nitrous oxide concentration in breathing zone was the lowest in nasal part drainage but high above the recommended concentration of NIOSH. The order of nitrous concentration in breathing zone was: natural drainage, tail part with negative pressure, nasal part with negative pressure. This would reflect the order of resistance of nasal airway and showed the amount of mouth breathing. From the above experiment, the resistance of nasal airway by the increment of gas flow in corrugating tube and reservoir bag would be one of the causative factors of mouth breathing in deeply sedated patients.

• Applied Chemistry for Engineering
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• v.8 no.3
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• pp.543-549
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• 1997

The direct reaction of carbon dioxide($CO_2$) with butane($C_4H_{10}$) to obtain synthesis gas and hydrocarbon compounds have been studied on nickel loaded catalysts. In the reaction of $CO_2$ with $C_4H_{10}$, Ni loaded catalysts showed similar activity with Pt catalyst and Coke deposition on the catalyst was severe by dehydrogenation of butane. The main products were carbon monoxide and hydrogen, when alumina and Y type zeolite were used as a support. Instead, a great deal of aromatic hydrocarbons were obtained on the Ni loaded ZSM-5 catalyst. The conversion of $CO_2$ increased with the increasing molar ratio of $CO_2$/$C_4H_{10}$ on Ni/ZSM-5, Ni/NaY and Ni/alumina catalyst, but the conversion decreased again from the ratio of 2. The value of $CO_2$ conversion was the highest at the 5wt% of Ni loading on ZSM-5 catalyst. A part of cokes deposited on the catalysts diminished when only $CO_2$ gas or water steam flowed into the reactor. The coke deposited on the catalysts was very reactive and it may be an important intermediate for the carbon dioxide reforming reaction.

• Korean Journal of Materials Research
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• v.22 no.5
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• pp.253-258
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• 2012

Activated magnetite ($Fe_3O_{4-{\delta}}$) was applied to reducing $CO_2$ gas emissions to avoid greenhouse effects. Wet and dry methods were developed as a $CO_2$ removal process. One of the typical dry methods is $CO_2$ decomposition using activated magnetite ($Fe_3O_{4-{\delta}}$). Generally, $Fe_3O_{4-{\delta}}$ is manufactured by reduction of $Fe_3O_4$ by $H_2$ gas. This process has an explosion risk. Therefore, a non-explosive process to make $Fe_3O_{4-{\delta}}$ was studied using $FeC_2O_4{\cdot}2H_2O$ and $N_2$. $FeSO_4{\cdot}7H_2O$ and $(NH_4)_2C_2O_4{\cdot}H_2O$ were used as starting materials. So, ${\alpha}-FeC_2O_4{\cdot}2H_2O$ was synthesized by precipitation method. During the calcination process, $FeC_2O_4{\cdot}2H_2O$ was decomposed to $Fe_3O_4$, CO, and $CO_2$. The specific surface area of the activated magnetite varied with the calcination temperature from 15.43 $m^2/g$ to 9.32 $m^2/g$. The densities of $FeC_2O_4{\cdot}2H_2O$ and $Fe_3O_4$ were 2.28 g/$cm^3$ and 5.2 g/$cm^3$, respectively. Also, the $Fe_3O_4$ was reduced to $Fe_3O_{4-{\delta}}$ by CO. From the TGA results in air of the specimen that was calcined at $450^{\circ}C$ for three hours in $N_2$ atmosphere, the ${\delta}$-value of $Fe_3O_{4-{\delta}}$ was estimated. The ${\delta}$-value of $Fe_3O_{4-{\delta}}$ was 0.3170 when the sample was heat treated at $400^{\circ}C$ for 3 hours and 0.6583 when the sample was heat treated at $450^{\circ}C$ for 3 hours. $Fe_3O_{4-{\delta}}$ was oxidized to $Fe_3O_4$ when $Fe_3O_{4-{\delta}}$ was reacted with $CO_2$ because $CO_2$ is decomposed to C and $O_2$.

• Korean Chemical Engineering Research
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• v.43 no.1
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• pp.1-8
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• 2005

In this study, $TiO_2$ powders were prepared by hydro-thermal synthesis with titanium tetra isopropoxide. The prepared $TiO_2$ and the commercial $TiO_2$(P-25, Degussa) were by impregnating $H_2PtCl_6$ solution or the leached solution from the waste catalytic converter of automobile. Modified photocatalysts were analyzed by ICP-AES, UV-DRS, XRD, SEM. And band-gap energy of modified photo-catalyst was found to decreased to 1.76eV and basic structure was changed upon modification by leached solution. Modified photocatalysts were coated on the wallpaper after using mixed solution with adhesive materials(PVC). And then to know the modified photo catalysts tested the reactivity and quantum efficiency in the mixed gas with NO as reactants in the photo catalytic reactor. In the gas phase, photo-catalytic activity of NO was the highest for modified P-25 catalysts(P-25(w)) that P-25(w) was impregnated by leached solution of wasted catalytic converter.

• Clean Technology
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• v.24 no.3
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• pp.239-248
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• 2018

In this study, pervaporation experiments of water, ethanol and IPA (Isopropyl alcohol) single components and water/ethanol, water/IPA mixtures were carried out using zeolite 4A membranes developed by Fine Tech Co. Ltd. Those membranes were fabricated by hydrothermal synthesis (growth in hydrothermal condition) after uniformly dispersing the zeolite seeds on the tubular alumina supports. They have a pore size of about $4{\AA}$ by ion exchange of $Na^+$ to the LTA structure with Si/Al ratio of 1.0, and shows strong hydrophilic property. Physical characteristics of prepared membranes were evaluated by using SEM (surface morphology), porosimetry (macro- or meso- pore analysis), BET (micropore analysis), and load tester (compressive strength). Pervaporation experiments with various temperature and concentration conditions confirmed that the zeolite 4A membrane can selectively separate water from ethanol and IPA. Water/ethanol separation factor was over 3,000 and water/IPA separation factor was over 1,500 (50 : 50 wt%, initial feed concentration). Pervaporation behaviors of single components and binary mixtures were predicted using ACM (activity coefficient model), GMS (generalized Maxwell Stefan) model and DGM (Dusty Gas Model). The adsorption and diffusion coefficients of the zeolite top layer were obtained by parameter estimation using GA (Genetic Algorithm, stochastic optimization method). All the calculations were carried out using MATLAB 2018a version.

• Journal of Microbiology and Biotechnology
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• v.21 no.9
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• pp.893-902
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• 2011

Endophytic fungi are little known for their role in gibberellins (GAs) synthesis and abiotic stress resistance in crop plants. We isolated 10 endophytes from the roots of field-grown soybean and screened their culture filtrates (CF) on the GAs biosynthesis mutant rice line - Waito-C. CF bioassay showed that endophyte GMH-1B significantly promoted the growth of Waito-C compared with controls. GMH-1B was identified as Penicillium minioluteum LHL09 on the basis of ITS regions rDNA sequence homology and phylogenetic analyses. GC/MS-SIM analysis of CF of P. minioluteum revealed the presence of bioactive $GA_4$ and $GA_7$. In endophyte-soybean plant interaction, P. minioluteum association significantly promoted growth characteristics (shoot length, shoot fresh and dry biomasses, chlorophyll content, and leaf area) and nitrogen assimilation, with and without sodium chloride (NaCl)-induced salinity (70 and 140 mM) stress, as compared with control. Field-emission scanning electron microcopy showed active colonization of endophyte with host plants before and after stress treatments. In response to salinity stress, low endogenous abscisic acid and high salicylic acid accumulation in endophyte-associated plants elucidated the stress mitigation by P. minioluteum. The endophytic fungal symbiosis of P. minioluteum also increased the daidzein and genistein contents in the soybean as compared with control plants, under salt stress. Thus, P. minioluteum ameliorated the adverse effects of abiotic salinity stress and rescued soybean plant growth by influencing biosynthesis of the plant's hormones and flavonoids.