• Research in Plant Disease
• /
• v.8 no.2
• /
• pp.124-130
• /
• 2002

In 1998, a pathogen isolated from infected onions was identified as Aspergillus niger. At 3$0^{\circ}C$, A. niger AnYD-1 showed the best mycelial growth, spore germination, and high pathogenicity to onions. In spite of the weak inhibitory effect of flusilazole and hexaconazole on the mycelial growth on PDA, they showed the specific inhibitory activity against the formation of spores in the vapour phase. With flusilazole and hexaconazole, the effects of the solvent, the applied concentration and the incubating temperature on the activities inhibiting the spore formation were confirmed. Their inhibitory effect on the spore formation in vapour phase was excellent by solving them with dimethylsulfoxide and dimethylformamide among tested solvents, and applying them at high temperature such as 30~35$^{\circ}C$.

• Applied Chemistry for Engineering
• /
• v.8 no.6
• /
• pp.967-972
• /
• 1997

Recovery of aromatics in extract phase which was obtained by batch equilibrium extraction between light cycle oil(LCO) and dimethylsulfoxide(DMSO) solution as solvent was investigated by re-extraction. To select the most suitable re-extraction solvent for recovery of aromatics in extract phase, distribution equilibrium was measured between extract phase and solvents. The solvents used were benzene(B), toluene(T), m-Xylene(mX), n-hexane(Hx) and n-hexane(Hx) and n-Octane(Ot). From the distribution coefficients and yields of aromatics, Hx seemed to be the most suitable. Furthermore, effects of operation parameters for re-extraction of aromatics in the extract phase were studied by batch equilibrium re-extracion with Hx as solvent. Yields of aromatics were found to increase with increasing solvent/feed (extract phase) mass ratio(S/F), while distribution coefficients of aromatics were fixed irrespective of S/F used. Operating temperature did not affect distribution coefficients and yields of aromatics. Distibution coefficients and yields of naphthalene group(carbon numer : 10~12) increased with increasing cabon number. Mass transfer rates of aromatics were also measured with a batch stirred vessel.

• Polymer(Korea)
• /
• v.26 no.4
• /
• pp.535-542
• /
• 2002

We have prepared the surfactant-free nanoparticles of poly(DL-lactide-co-glycolide) (PLGA) by dialysis method and their physicochemical properties such as particle size and drug contents were investigated against various solvent. The size of PLGA nanoparticles prepared by using dimethylacetamide (DMAc), dimethylformamide (DMF), and dimethylsulfoxide (DMSO) was smaller than that from acetone. Also, the order of drug contents was DMAc>DMF>DMSO=acetone. These phenomena could be expected from the fact that solvent affects the size of nanoparticles and drug contents. The PLGA nanoparticles have a good spherical shapes as observed from scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Also, surfactant-free nanoparticles entrapping norfloxacin (NFx) have a good drug loading capacity without free-drug on the surface of nanoparticles confirmed by the analysis of X-ray powder diffraction. Release kinetics of NFx used as a model drug was governed not only by drug contents but also by particle size. Also, the biodegradation rate of PLGA nanoparticles prepared from DMF was faster than that prepared from acetone, indicating that the biodegradation of PLGA nanoparticles is size-dependent.

• Journal of the Korean Chemical Society
• /
• v.24 no.3
• /
• pp.209-217
• /
• 1980

The relative viscosities and osmotic coefficients of solutions of urea, 1,3-dimethyl-urea(DMU), acetamide(AA), and propionamide (PA) in dimethylsulfoxide(DMSO), water, methanol, and in ethanol have been measured at 25 and $45^{\circ}$C by viscometry and osmometry. Viscosity increment in nonaqueous solutions decreased with increasing of the partial molal volumes of the solutes, but in aqueous solution the result was inversed. Viscosity increment of aqueous solution was smaller than that of aqueous DMU solution, but that of nonaqueous urea solution was larger than that of DMU. Amides, however, showed similar viscosity increment in any solvent.Osmotic coefficients of aqueous solution of urea were larger than those of DMU. In the nonaqueous solutions urea exhibited larger deviation from Raoult's law than DMU. The results indicated that urea molecules break water-structure in water, self-associate in DMSO, and showed larger solute-solvent interaction in alcohols than DMU. It can be also confirmed that amides break alcohol structure to a greater extent than any other solutes.

• Journal of the Korean Chemical Society
• /
• v.47 no.6
• /
• pp.608-613
• /
• 2003

In order to remove particles on surface of post-oxide CMP wafer, new cleaning solution was prepared by mixing with DHF (Diluted HF), nonionic surfactant PAAE (Polyoxyethylene Alkyl Aryl Ether), DMSO (Dimethylsulfoxide) and D.I.W.. Silicone wafers were intentionally contaminated by silica, alumina and PSL (polystylene latex) which had different zeta potentials in cleaning solution. This cleaning solution under megasonic irradiation could remove particles and metals simultaneously at room temperature in contrast to traditional AMP (mixture of $NH_4OH,\;H_2O_2$ and D.I.W) without any side effects such as increasing of microroughness, metal line corrosion and deposition of organic contaminants. This suggests that this cleaning solution would be useful future application with copper CMP in brush cleaning process as well as traditional post CMP cleaning process.

• Journal of the Korean Chemical Society
• /
• v.50 no.4
• /
• pp.307-314
• /
• 2006

The redox characteristics of 2-ketohydrazono-3-phenyl-5-substituted-2,3-dihydro-1,3,4-thiadiazoles and its derivatives (1a-h) has been investigated in nonaqueous solvents such as 1,2-dichloroethane (DCE), dichloromethane (DCM), acetonitrile (AN), tetrahydrofuran (THF), and dimethylsulfoxide (DMSO) containing 0.1 mol.dm-3 tetra n-butylammonium perchlorate (TBAP) as supporting electrolyte at platinum ectrode. Through controlled potential electrolysis, the oxidation and reduction products of the investigated compounds can be separated and indentified. The redox mechanism is suggested and proved. It was found that all the investigated compounds are oxidized in two irreversible one-electron processes following the well known pattern of EC-mechanism. On the other hand, these compounds are reduced in a single two electron or in a successive two one electron processes following the well known pattern of EEC-mechanism according to the nature of the substituent

• Membrane Journal
• /
• v.26 no.3
• /
• pp.212-219
• /
• 2016

The alumina hollow fiber membranes were prepared by spinning and sintering a polymer solution containing suspended alumina powders. For determine pore structure of hollow fiber membranes formed by different solvent-nonsolvent interaction rate, dimethylsulfoxide (DMSO), dimethylacetamide (DMAc), triethylphosphite (TEP) were prepared in dope solution by solvent, polyethersulfone (PESf) and polyvinylpyrrolidone (PVP) were used as a polymer binder and additive. The pore structure of hollow fiber membranes was characterized using scanning electron microscope (SEM). The alumina hollow fiber membranes prepared by DMSO, DMAc were had the asymmetric structure mixed sponge-like and finger-like morphology, while TEP solvent were had single sponge-like structure. The prepared hollow fiber membranes were analyzed gas permeation and mechanical strength experiment also. The hollow fiber membrane having single sponge-like structure was had high gas permeation performance. On the contrary to this, more finger-like morphology was less gas permeation performance.

• Journal of the Korean Chemical Society
• /
• v.28 no.6
• /
• pp.349-354
• /
• 1984

The relative viscosities and the osmotic coefficients of alkaline metal iodides (NaI, KI, RbI, CsI) in methanol, ethanol, dimethylsulfoxide (DMSO), and sulfolane (TMS) have been measured by Ubbelohde viscometer and vapor pressure osmometry at 45 ∼ $120^{\circ}C.$ The order of A and B coefficients in viscosity for alkaline metal iodides are MeOH > EtOH > TMS > DMSO, and TMS > EtOH > DMSO > MeOH. dB/dT values for the alkaline metal iodides are in the order of NaI > KI > RbI > CsI in the protic solvents, while those for the aprotic solvents are in the reverse order. The order of the osmotic coefficients for the alkaline metal iodides is EtOH > DMSO > MeOH > TMS.

• Archives of Pharmacal Research
• /
• v.4 no.1
• /
• pp.9-17
• /
• 1981

A simple, accurate and specific NMR procedure is described for the determination of amplicilin and cloxacillin mixtures in injection dosage form and capsules. The solvent was dimethysulfoxde $d_{6}$ and maleic acid was the internal standard. By integrating the peak at 2.68 ppm and 4.57 ppm, cloxacillin and ampicillin could be determined respectively. The relative proton ratio of ampicillin trihydrate and cloxacillin were 1.038 and 0.950. The coefficents of variation of amplicillin trihydrate and cloxacillin in a few commerical preparation were 1.55 % (n =9), 2.69 % (n =15).

• KSBB Journal
• /
• v.15 no.3
• /
• pp.313-317
• /
• 2000

In this paper enantioselective production of levofloxacin by porcine liver esterase was investigated, To enhance the produc0-tivity various factors which affect the enzyme activity and the enantioselectivity were optimized, In terms of temperature and pH 45$^{\circ}C$ and 4.8 were found to be the best conditions for enzyme reaction. Addition of ofloxacin butyl ester the substrate at the concentration of 5 g/L was desirable to avoid the product inhibition and the activity of porcine liver esterase was maintained up to 72 hours.In addition to enhance the availability of substrate effect of solvent was also examined. It was found that the application of 5% (v/v) of acetone acetonitrile and dimethylsulfoxide did not increase the conversion of substrate and the presence of 5%(v/v) butanol inhibited the enzyme activity significantly.