• Journal of the Korean Chemical Society
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• v.5 no.1
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• pp.15-17
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• 1961

A ninhydrin positive substance(formed during germination of Mung Bean) which on a 2-dimensional chromatography(BuOH-HAc, and$ PhOH-NH_2$ gave a spot above glutamic acid was isolated by cutting out the appropriate spot on the paper and extracting the paper with water. Hydrolysis of this substance with $2N H_2SO_4\;or\;3N\;HCl\;at\;120^{\circ}C$ for 15 hours gave the spot of mainly glutamic acid, alanine and very faint of glycine and cysteine on a paper chromatography. It is suggested that the reaction of ${\gamma}$-glutamyl-cysteinecyl-glycine + L-alanine in the presence of ${\gamma}$-glutamyle transferase ${\rightarrow}$ ${\gamma}$-glutamyl-alanine + cysteinyl-glycine, takes place in germinated Mung Bean.

• Journal of the Korea Institute of Military Science and Technology
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• v.8 no.2 s.21
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• pp.77-87
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• 2005

The thermomechanical characteristics were evaluated for 17-4PH stainless steel widely used in supersonic airframe subjected to both aerodynamic loading and heating. The thermomechanical tests were conducted under both elevated temperature and rapid heating condition from $1^{\circ}C/sec\;to\;28^{\circ}C/sec$. The thermomechanical behaviors under rapid heating were compared with those of elevated temperature after 1/2 hour exposure in terms of yield stress to investigate the influence of heating rates. A heating rate-yield temperature parameter was suggested for rapid heating based on time-temperature parameters, and master yield stress curve was obtained by using these parameters. The experimental results and methodology from this study can be used as basic engineering data when designing supersonic vehicle structures subjected to aerodynamic loading and severe heating environment.

• Microbiology and Biotechnology Letters
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• v.17 no.5
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• pp.407-411
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• 1989

Extracellular neutral pretense of Streptomyces rimosus producing oxytetracycline was purified by ammonium sulfate fractionation, DEAE Sephadex A-50 chromatography and Sephadex G-100 gel filteration, and was showed single band on the cathodic gel electrophoresis. The optimum pH and temperature of the enzyme were pH 8.0 and 6$0^{\circ}C$, respectively. The enzyme was activated about 80% in the presence of Co$^{2+}$ ion, and strongly inhibited by Hg$^{2+}$, Fe$^{2+}$ and chelatig agent, EDTA. Molecular weight of the enzyme was estimated to be 12, 000. The Km value of the enzyme of casein as a substrate was 2.7$\times$10$^{-4}$M.

• Bulletin of the Korean Chemical Society
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• v.15 no.6
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• pp.432-436
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• 1994

Monomeric rhodium and iridium-diaryltetrazene complexes $Cp^*$M(RNN=NNR)($Cp^*$=1,2,3,4,5-pentamethylcyclope ntadienyl; M=Rh, Ir; R=Ph, 4-tolyl) have been synthesized from [$Cp^*MCl_2]_2$(M=Rh, Ir) and 2 equiv. of $[Li(THF)_x]_2(RN_4$R) in benzene. We have determined the crystal structure of (${\eta}^5$-pentamethylcyclopentadienyl)diphenyltetrazene iridium by using graphite-monochromated Mo-$K_a$ radiation. The compound was crystallized in the monoclinic space group $P2_{1/c}$ with a=13.781(3), b=9.035(l), c=17.699(3) ${\AA}$, and ${\beta}=111.93(l)^{\circ}$. An X-ray crystal structure of complex 1 showed a short N(2)-N(3) distance ($1.265 {\AA}$) consistent with the valence tautomer A with Ir(III) rather than Ir(I). All complexes are highly colored and decompose on irradiation at 254 nm. Electrochemical studies show that complex 1 displays a quasi-reversible reduction.

• KSBB Journal
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• v.17 no.2
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• pp.169-175
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• 2002

A lactic acid bacterial isolate Lactobacillus ssp. SCU-M which produces exopolysaccharide was identified and its cultural Condition was investigated. The optimum Conditions for exopolysaccharide(EPS) Production Of Lactobacillus ssp. SCU-M were 37$\^{C}$, pH 6.5, using medium composed of 1.5% galactose, 1.0% yeast extract, 0.25% peptone, 0.15% MgSO$_4$, 0.15% K$_2$HPO$_4$ and 0.1% tween 80 in distilled water. The EPS concentration after 48 hours at the Initial pH 6.5, 37$\^{C}$ in a flask culture was 1,680 mg/ℓ.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.17 no.1
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• pp.76-81
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• 2024

Recently, agricultural methods are changing from experience-based agriculture to data-based agriculture. Changes in agricultural production due to the 4th Industrial Revolution are largely occurring in three areas: smart sensing and monitoring, smart analysis and planning, and smart control. In order to realize open-field smart agriculture, information on the physical and chemical properties of soil is essential. Conventional physicochemical measurements are conducted in a laboratory after collecting samples, which consumes a lot of cost, labor, and time, so they are quickly measured in the field. Measurement technology that can do this is urgently needed. In addition, a soil analysis system that can be carried and moved by the measurer and used in Korea's rice fields, fields, and facility houses is needed. To solve this problem, our goal is to develop and commercialize software that can collect soil samples and analyze the information. In this study, basic soil composition measurement was conducted using soil composition measurement sensors consisting of hardness measurement and electrode sensors. Through future research, we plan to develop a system that applies soil sampling using a CCD camera, ultrasonic sensor, and sampler. Therefore, we implemented a sensor and soil analysis UI that can measure and analyze the soil condition in real time, such as hardness measurement display using a load cell and moisture, PH, and EC measurement display using conductivity.

• Macromolecular Research
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• v.17 no.4
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• pp.221-226
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• 2009

The present study firstly describes the synthesis of novel, thermo-latent initiators based on xanthenyl phosphonium salts with different counter anions and phosphine moieties and secondly examines their efficiency in the bulk polymerization of glycidyl phenyl ether(GPE). The polymerization was performed with phosphonium salt initiators($I_{SbF6}$, $I_{PF6}$, $I_{AsF6}$ and $I_{BF4}$) at ambient temperature to $200^{\circ}C$ for 1 h. The order of initiator activity was $I_{SbF6}>I_{PF6}>I_{AsF6}>I_{BF4}$. To examine the effect of the phosphine moiety on the initiator activity, polymerization was carried out with $I_{SbF6}(Ph_{3}P)$ and $II_{SbF6}(Bu_{3}P)$ at ambient temperature to $170^{\circ}C$ for 1 h. The order of reactivity was $I_{SbF6}>II_{SbF6}$. In general, the conversion percentage increased with increasing polymerization temperature. The thermal stability of these salts was measured by thermo gravimetric analysis(TGA). The solubility of phosphonium salts in various organic solvents and epoxy monomers was also investigated.

• Microbiology and Biotechnology Letters
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• v.17 no.5
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• pp.524-528
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• 1989

A $\beta$-Galactosidase producing strain, Alkalophilic Bacillus sp, YS-309, has been isolated from soil sample. The strain was capable of producing large amount of intracellular $\beta$-galactosidase in the alkaline media rather than in the neutral media. The preferable medium composition has been determined to be as follows: 0.5% lactose, 0.5% yeast extract, 0.5% soybean meal, 0.1% KH$_2$PO$_4$, 0.02% MgSO$_4$7$H_2O$ 0,0.6% Na$_2$CO$_3$ (pH 9.9). The enzyme was produced by lactose or IPTG as in-ducer. But both Enzyme synthesis and cellular growth were decreased when lactose was added at the higher concentrations than 1.5% (v/v).

• Journal of Ginseng Research
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• v.6 no.1
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• pp.17-24
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• 1982

This studies were conducted to investigate the changes of saponin pattern, pH and organic acid contents of malt wort added ginseng components during alcoholic fermentation by Sacch. uvarum. The results are as follows. Saponin patterns of fermented wort were same as that of the non- fermented wort, but the weight of former was decreased comparing to that of the latter. pH value of fermented wort contained 0.1∼0.5% of ginseng extract were almost same as that of control(PH 4.23). Lactate, pyruvate, succinate and fumarate, pyroglutarate and citrate contents of the fermented wort were increased by the addition of ginseng extract and pyruvate content, particularly, was increased from 28.4 to 214mg/100 ml while that of control was 33.2mg/100m1. Citrate content of fermented wort contained ginseng saponin was almost same as control (37. 5mg/100m1) . But pyruvate content was tower 4-8.6mg/100m1 than that of control(33.2mg/100m1) .

• Current Research on Agriculture and Life Sciences
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• v.1
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• pp.85-93
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• 1983

Total annual water requirements for agricultural use are exceedingly large. In many areas of the country, particularly in the arid regions, irrigation water requirements comprise the bulk of the total developed water supply. On the other hand, we are, at present, poorly prepared to evaluate the hazards of many substances in the water phase of the agricultural environments. This study is to survey the water quality phase of agricultural conditions and to give some ideas to prevent disasters from the environmental hazards such as PH, Electric Conductivity, BOD, DO, Cu, Pb, and Cd. In the analysed results, mean PH was 6.5 to 7.8, maximum EC was $200{\mu}{\Omega}/cm$ at $25^{\circ}C$, the maximum BOD was less than 10 ppm (standard value), the DO was 4.2 to 12.0 mg/L (standard value is more than 2.0 mg/L) and the Cu, Pb, Cd were estimated in scope of safety value respectively. Especially BOD is gradually closed with the hazardous point in the few places. At present, the hazardous environmental conditions originated from the municipal sewage, industrial waste, and human and domestic animals excrements etc. have to strongly be improved much better than before.