• Korean Journal of Agricultural Science
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• v.11 no.2
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• pp.315-321
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• 1984

The electrochemical reduction of 0,0-dimethyl-0-(3-methyl-4 -nitrophenyl)-phosphorothioate ($Sumithion^{(R)}$) in acetonitrile solution has been studied by direct current (DC), differential pulse (DP) polarography and cyclic voltammetry methods. The irreversible electron-transfer chemical reaction (EC) mechanism of Sumithion proceeds by six electron-transfer to form radical and reduction of three-step which undergoes single bond of the phosphorus atom & phenoxy group by electron-transfer and protonation cleaved to give p-hydroxyamino-m-cresol and dimethylthiophosphonate as major product.

• Journal of the Korean Society of Safety
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• v.13 no.2
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• pp.109-115
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• 1998

Tri-cresyl phosphate(TCP) was synthesized by reaction of phosphorus chloride with mixed cresol(mixture of m-cresol, p-cresol, and others) in the presence of $AlCl_3$. Some of unwanted products and unreactants colored TCP. In order to separate TCP from these, vaccume distillation was carried twice, but colorless TCP could not be producted. Separation of unwanted materials by 2% NaOH solution was introduced before first and second distillation and optimal separation conditions such as NaOH concentration, mixing volume ratio, mixing time, and rpm were investigated for new batch separation and production of colorless TCP Optimal conditions were 2% NaOH solution, 35% mixing volume ratio of 2% NaOH solution, 1.5 hours of mixing time, and 20 rpm.

• Journal of the Korean Applied Science and Technology
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• v.38 no.3
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• pp.832-839
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• 2021

We tried to investigate the effects of substituent position, temperature, and additives such as NaCl and n-butanol on the solubilizations of cresol isomers by tetradecyltrimethylammonium bromide (TTAB), using the UV-Vis spectrophotometric method. The measured solubilization constants (K_s) values for each cresol isomer increased in the order o-cresolo and ∆H^o values for the solubilizations of cresols were all negative values but the ∆S^o values were all positive values within the measured ranges. The values of ∆G^o increased also with increasing the concentration of n-butanol but decreased with increasing the concentration of NaCl. From these facts, we could conclude that both the enthalpy and entropy changes contribute together for the solubilizations of cresols isomers by cationic surfactant of TTAB and they are solubilized in the polar palisade region or at the surface of micelle.

• Archives of Pharmacal Research
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• v.28 no.7
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• pp.765-769
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• 2005

The essential oil fraction of Ostericum koreanum was analyzed by GC-MS. Inhibiting activities of this oil and its main components were tested by the broth dilution assay and disk diffusion test against one antibiotic-susceptible and two resistant strains of Salmonella enteritidis and S. typhimurium, respectively. The GC-MS analysis revealed thirty-four compounds; the main components were $\alpha$-pinene (41.12%), $\rho$-cresol (17.99%) and 4-methylacetophenone (7.90%). The essential oil of O. koreanum and its main components were significantly effective against the tested antibiotic-susceptible strains as well as against the resistant strains of the two Salmonella species, with MICs (minimum inhibitory concentrations) ranging from 2 mg/mL to 16 mg/mL. The anti-Salmonella effects of the oils were dose-dependent on $M\"{u}ller-Hinton$ agar plates in this experiment. Additionally, checkerboard titer test results demonstrated significant combined effects of streptomycin and O. koreanum oil or cresol, one of the main components of this oil, against the two streptomycin resistant strains of S. typhimurium, with FICIs ranging from 0.12 to 0.37.

• Applied Chemistry for Engineering
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• v.8 no.2
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• pp.308-314
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• 1997

The effects of catalyst and blocking reagents(BR) on the blocking reactions of TDI and MDI in the preparation of polyurethane varnishes have been studied. It was found that certain types of catalysts, such as 1,4-diazabicyclo[2.2.2]octane(DABCO) and tetramethyl guanidine(TMG), were necessary to complete the NCO blocking reactions. Blocking rate of TMG was shown much faster than that of DABCO. Reactivity increased with the increase of TMG concentration, at least to the concentration of 1%. In case of DABCO, the 0.25% concentration of catalyst showed the highest reactivity. In order to study the steric effects of BR on the blocking reactions, phenol, p-cresol, m-cresol, o-cresol, 2,4-xylenol were used as blocking reagents. As expected, BR which has less steric hindrance showed higher reactivity. The increase in BR concentration and reaction temperature increased the productivity of polyurethanes in this reaction system.

• 한국생물공학회:학술대회논문집
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• 2000.04a
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• pp.434-437
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• 2000

Streptomyces setonii(ATCC 39116) is a thermophilic gram-positive soil bacteria which undergoes an ortho-cleavage pathway in the presence of phenol or benzoate as a sole carbon and energy source. The specific activities of catechol-1,2-dioxygenase in S. setonii, a key enzyme in ortho-cleavage pathway, were induced by various aromatic compounds such as benzoate, phenol, m-hy-benzoate, p-hy-benzoate, catechol, o-cresol, m-cresol, p-cresol, benzene, toluene, ethyl-benzene, 2-chloro-phenol, and 4-chloro-phenol, among which the phenol showed the highest inducibility in the presence of 0.01% glucose. More than 0.1% glucose dramatically reduced the specific activities of catechol-1,2-dioxygenase induced by most of the single aromatic compounds tested.

• Journal of Food Hygiene and Safety
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• v.22 no.2
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• pp.110-115
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• 2007

This test was performed to evaluate the skin irritation and sensitization of Creocomplex, disinfectant, Containing 10% 4-chloro-m-cresol, 10% didecyl dimethyl ammonium chloride, and 10% glutaraldehyde. In primary skin irritation test, rabbits were dermally treated with Creocomplex for 24 hrs. The disinfectant did not induce any adverse reactions such as erythema and edema on intact skin sites, but on abraded skin sites, some rabbits showed very slight erythema and edema 24hr after topical application. So, the disinfectant was classified as a practically non-irrifating material based on the score 0.13 of primary irritation index. In the skin sensitization test, guinea pigs were sensitized with intradermal injection of 0.1ml Creocomplex for 24 hr. After 1 week, Creocomplex was treated on the site of injection, and challenged 2 weeks later. Creocomplex did not induce any allergic reactions. Therefore, 10% Creocomplex was graded as a weak material from 0 in both sensitization score· and rate. From results of the present study, it is suggested that 10% Creocomplex does not cause contact irritation and sensitization.

• 한국생물공학회:학술대회논문집
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• 2003.04a
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• pp.382-385
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• 2003

Organic solvent tolerant bacterium, designated as strain BCNU 106 is a gram negative, rod-shaped aerobe and grows on benzene, toluene, ethylbenzene, and xylenes (BTEX) as a sole carbon source. According to 16S rDNA analysis and fatty acid analysis, strain BCNU 106 showed highest similarity to Pseudomonas syringae var. savastanoi (Pseudomonas savastanoi). Strain BCNU 106 was able to utilize toluene, ethylbenzene, both o-, m-, p-xylene , m-cresol and o-cresol. The degradation of o-, m-, p-xylene by strain BCNU 106 is particularly important, since o-xylene is a compound of considerable environmental interest, owing to its recalcitrance; and very few microorganism have been reported to utilize both o-, m-, p-xylene as a sole carbon source.

• Journal of the Korean Society of Tobacco Science
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• v.12 no.2
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• pp.67-75
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• 1990

The pyrolytlc behavior of cocoa powder, a flavorant of tobacco smoking products, was examined by determining its pyrolyzate constituents. Cocoa powder was pyrolyzed of two cigarette smoking conditions'distillation-pyrolysis zone(35$0^{\circ}C$, 55$0^{\circ}C$) and high temperature zone($650^{\circ}C$, 85$0^{\circ}C$). Pyrolyzate was flushed from the tube by NB gas into CS2 trap in dry ice-acetone cooled bath and charcoal tube and its constituents were analyzed by GC/MS. As results, the major components of pyrolyzates were identified as hydrocarbon and phenolic compounds. In addition to these, aldehyde, ketone, pyrazin in very small amount. Component changes were observed with temperature increase; decane, styrene, tridecane, m-cresol,4-ethylphenol were increased while hexadecane, tetradecane were decreased. o-cresol and 2-ethylphenol were constant in amounts despite temperature change.

• Journal of the Korean Applied Science and Technology
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• v.24 no.3
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• pp.309-318
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• 2007

Novolac is widely used as the primary solid component of most photoresists in semiconductor and microelectronic devices. In this study, novolac resins were prepared by condensation of 35% formaldehyde with phenolic compounds such as m-/p-cresol, 2,5-dimethylphenol and bisphenol A in the presence of oxalic acid as catalyst. The average molecular weight $(M_w)$ of these novolac resins has been varied on the changing of mixing ratio of m-/p-cresol/2,5-dimethylphenol/bisphenol A or formaldehyde/phenolic compound. Also, thermal properties of novolac were observed by TGA.