• Journal of the Korean Chemical Society
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• v.24 no.6
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• pp.413-420
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• 1980

Die Geschwindigkeitskonstanten der Solvolyse-Reaktionen von 9-Chlormethylanthracen wurden bei verschiedenen Temperaturen in unterschiedlichen binadren Losungsmittelgemischen (Wasser/Aceton, Wasser/Acetonitril, Wasser/Methanol, Wasser/Athanol) mit Hilfe der Leitfahigkeitsmeßungen bestimmt. Die Aktivierungsparameter $E_a$, ${\Delta}H^{\neq}$ und ${\Delta}S^{\neq}$ wurden berechnet. Die Meßergebnisse deuten darauf hin, daß die Solvolyse von 9-Chlormethylanthracen in protonischen Losungsmitteln schneller ablauft als in aprotonischen Losungsmitteln; in den Meßreihen mit protonsichen bzw. mit aprotonischen Losungsmitteln steigt die Reaktionsgeschwindigkeit mit der Zunahme der Dielektrizitatskonstanten des Losungsmittels an, und die Aktivierungsparameter nehmen mit steigendem Wassergehalt zu. Es wurde festgestellt, daß die Reaktion nach einem $S_N1$-Mechanismus ablauft. Die experimentellen Daten deuten darauf hin, daß Wasser einerseits als Nucleophil und andererseits als allgemeine Base am Reaktionsmechanismus beteiligt ist.

• The korean journal of orthodontics
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• v.10 no.1
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• pp.37-43
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• 1980

This study was undertaken to assess the effects of demethylchlortetracycline on bone growth of mandibular symphyseal region in rats. Demethylchlortetracycline at 30mg/kg body weight, respectively, were daily administered by mouth to the sewen female rats from 10th day of pregnancy to 13th day. Thirty six new-born rats from these experimental animals were used for histological examination at 1, 5, 10, 15, 20, 25 and 30 days. All these new-born rats were killed by an overdose of ether. Mandibular bodies were removed and fixed in $10\%$ neutral formalin,. Carney and aceton. Specimens were embedded, sectioned and stained with H-E, Van Gieson, PAS and prepared for alkaline phosphatase. The results were as follows; 1. Until erupting of incisors, hyaline cartilage was located in relatively large symphyseal space, but bone trabeculae of ossifying area at incisal side were arranged irregularly in experimental group. 2. During this period, PAS reaction was moderately positive, but alkaline phosphatase reaction was slightly positive. 3. By erupting or incisors, symphyseal space appeared narrower like control group, but alkaline phosphatase reaction tended to slow down. 4. By erupting of molars, symphyseal space appeared muck narrower, and cartilane plate was reduced and aealed off like control group. Alkaline phosphatase reaction tended to slow down severely.

• Microbiology and Biotechnology Letters
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• v.2 no.2
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• pp.111-117
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• 1974

Studies were carried out on the practical use of Naringinase and some chracteristics of Naringin solublizing enzme which might hydrolyae naringin to purunin. Obtained results were as follows. 1. Selected strain for Naringinase producing was identified to be Aspergillus niger S-1 and its naringinase was applied to chinese citron processing to remove the bitter taste. 2. Of the naringinase, naringin solubilizing enzyme was purified on a DEAE-Sephadex A-50 column and crystalized from acetone and ammonium sulfate. 3. Hydrolized naringin which has higher solubility rather than naringin or naringenin were identified by thin layer chromatography. 4. Hydrolyzed naringin and naringin were separatly determinated by ethylacetate extraction and this result was compared with sensory test.

• Korean Journal of Microbiology
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• v.9 no.4
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• pp.163-168
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• 1971

Neutral protease which was obtained from a genus of Aspergilli as the crystal form were investigated for their purification and properties. The results of biochemical and enzymatic studies for their purification and properties in this enzyme were as follows. 1) On the wheat media containing 70%-water and $CaCo_{3}$, Aspergilus oryzae S.H.W. 131 is satisfactorily grown under the basic optimum conditions temperature $27^{\circ}C$- $30^{\circ}C$at relative humidity 100% for three days. 2) The enzyme solution extracted with water is successively purified through the passing on column of Asmti-177N for decolorization of it. And ion exchanger such as DEAAE Sphadex A-50 or Shepadex G-100 and fraction collector is necessary for the sepearte treatments of this enzyme. After washing it with organic solvents as aceton-EtOH, etc., it should be dried on the vacuum dryer at $40^{\circ}C$) The protease activity is determined by the amounts of amino acids, tyrosine. 4) The optimum pH of neutral protease is 6.0-8.0. 5) In effectively decomposing with this neutral protease, the optimum temperature is $35^{\circ}C$. 6) It is interesting that the amounts of metal ion affects the activity of neutral protease. For examples, if it were treated with manganic ion, its activity would be more effective than any other that.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.687-687
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• 2013

In rearpoint contact solar cell and the PERC (passivated emitter rear contact) type cell, surfaces were passivated by SiO2 or Al2O3 to increase solar cell efficiency. Therefore, we have investigated the effect of surface passivation for crystalline silicon solarcell using mass-production atomic layer deposited (ALD) Al2O3. The patttern which consists of cylinders with 100um diameter and 5um height was formed by PR patterning on Si (100) substrate and then Al2O3 of about 10nm and 20nm thickness was deposited by ALD. The pattern in 10 nm Al2O3 film was removed by dipping in aceton solution for about 10 min but the pattern in 20 nm Al2O3 film was not. The influences of process temperature and heat treatment were investigated using microwave photoconductance decay (PCD) and Quasi-Steady-State photoconductance (QSSPC). The solar cell process used in this work combines the advantage of using the applicability of a selective deposition associated with a ALD passivation and the use of low-cost screen print for the contacts formation.

• Journal of the Korean Applied Science and Technology
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• v.10 no.1
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• pp.67-74
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• 1993

1, 2-Isopropylidene glycerol produced by ketalyzation of glycerol with aceton was esterified with long chain fatty acids in the presence of a Mucor miehei lipase to obtain 1, 2-isopropylidene 3-long chain acyl glycerol. To determine optimal conditions for the esterification reaction, esterification was proceeded as a reversible second-order reaction in various parameters that are enzyme/substrate ratio 0.096g/g at reaction temperatures ranged from $25^{\circ}C$ to $70^{\circ}C$. The order of reaction rate of fatty acids were lauric acid, myristic acid, oleic acid, and stearic acid. The range of their activation energies were from 7.8 to 11.4 (kcal/mol) and that of entropies of activation which have negative values were from 42.8 to 52.5(e.u.).

• Journal of the Korean Chemical Society
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• v.39 no.3
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• pp.191-197
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• 1995

The reactions of [${Mo(NO)_2Cl_2}_n$] with unidentate ligands in $CH_2Cl_2$ solvent afforded monomeric complexes [$Mo(NO)_2L_2Cl_2$]. $[Mo(NO)_2L_4](ClO_4)_2$ was obtained by reaction of unidentate with $[Mo(NO)_2L_2Cl_2]$ in aceton solvent. 4-Dimethylaminopyridine(dmap), pyridine(py), and isoquinoline(isoq) were used as coordinating ligands. These dinitrosylmolybdenum complexes are prepared and characterized by elemental analysis, $^1H$ NMR, infrared, and UV-Visible spectroscopy. The infrared spectra indicate that the NO groups occupy cis-positions of the octahedral.

• The Korean Journal of Mycology
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• v.11 no.1
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• pp.23-26
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• 1983

Aspergillus ustus was cultured in the salts media contained dextran (2%). Then the cultured liquid media were filtrated and concentrated up to 10 folds by evaporation, and then purified by means of acetone precipitation, of a repeated chromatography on the columns of DEAE-Ccellulose, Biogel P-150, and Sephadex G-200. Total proteins in the initial culture filtrate were 38,500mg, but the final amounts of proteins were 172mg. The specific activity of the protein in the culture filtrate was $1,340\;{\mu}moles$ products per minute per mg protein, but the final specific activity of the protein was $2,448\;{\mu}\;moles$ products per minute per mg protein. The final yields remained about 30% of the initial.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.24 no.3
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• pp.353-358
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• 2014

Purpose: This study was conducted to evaluate desorption efficiency and storage stability on activated carbon acquired form domestic market. Materials: Mixture of acetone, benzene, normal hexane and toluene was injected on four types of charcoal 100 mg. After overnight, charcoal was desorbed by carbon disulfide $1m{\ell}$ and analyzed by gas chromatography with flame ionization detector. Results: Desorption efficiency of benzene, normal hexane and toluene in charcoal tubes were 95% ~ 105%. But desorption efficiency of acetone in charcoal tubes was below 75% and different from types of charcoal. The more injected amount of acetone on charcoal showed higher desorption efficiency. Acetone injected on charcoal tubes migrated from front section into back section after 10 days storage at room temperature. Conclusions: Desorption efficiency and storage stability of activated carbon acquired from domestic market was good for benzene, normal hexane and toluene. The activated carbon acquired from domestic market has ability to be used as sampling media.

• Analytical Science and Technology
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• v.6 no.1
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• pp.83-92
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• 1993

The electrochemical behaviors of lanthanide ion(La and Nd) and lanthanide complexes with 2, 2, 6, 6-tetramethyl-3, 5-heptanedione(THD), sym-hydroxydibenzo-16-crown-5(HD16C5) and sym-dibenzo-16-crown-5-oxyacetic acid(D16C5A) ligands in acton solution have been investigated by the use of cyclic voltammetry and direct current polarography. The peak potential and peak current, their dependency on the concentration, temperature, the reversibility of the eleotrode reactions are described. The reduction of the lanthanide ions and complexes in 0.05 M TEAP proceeded one-electron step in first step and one two-electron step in second step. These reduction step was irreversible and the reduction current was diffusion controlled. Macrovcyclic crown ethers, sym-hydroxydibenzo-16-crown-5(HD16C5) and sym-dibenzo-16-crown-5-oxyacetic acid(D16C5A), were prepared from 1, 5-bis-(2-hydroxyphenoxy)-3-oxapentane with epichlorohydrin. The voltammetric behaviors of Ln(III)-HD16C5 and Ln-D16C5A complexes in aceton solution have been investigated by the voltammetric method. The composition and stability constants of lanthanide complexes were determined.