• Microbiology and Biotechnology Letters
• /
• v.9 no.4
• /
• pp.231-236
• /
• 1981

Studies were made on the optimal conditions of sterilization for Streptococcus pyogenes treated with heat. The results were as follows: The optimal temperature on growth of Streptococcus pyogenes was 37$^{\circ}C$ and mean generation time was 20 minutes in the logarithmic growth phase. The suspension of Streptococcus pyogenes, adjusted to pH 6-9 and treated with heat at 5$0^{\circ}C$, showed logarithmic death rate. Specific death rate constant(k) values at pH 6-9 were 0.1448, 0.1194. 0.1273 and 0.1707 minute$^{-1}$ , respectively.

• Journal of the Korean Chemical Society
• /
• v.39 no.11
• /
• pp.869-877
• /
• 1995

Carbonation process of Jung sun slake lime$(Sr(OH)_2=0.053 wt%)$ suspension with $CO_2$ gas at 30∼80$^{\circ}C$ has been studied to investigate the formation process of aragonite. The reaction temperature at above $50^{\circ}C$, rhombic nuclei of $SrCO_3$ has been grown with the interaction of $CO_3^{2-}$(aq) which is profitable to growth the nuclei at the liquid film of gas-liquid interface to form pillar aragonite crystal. At $40^{\circ}C$, the controlling of concentration of $CO_2$(aq) at the beginning of the reaction has been made the nuclei to growth to be an aragonite crystal. Addition of some $Sr(OH)_2$ to Yi Lee slake lime $(Sr(OH)_2=0.011 wt%)$ suspension and controlling the concentration of $OH^-$(aq) and $CO_2$(aq), the carbonation reaction produced pillar aragonite crystal with the short side of 0.1∼0.2 ${\mu}m$ and long side of 1∼2 ${\mu}m.$

• Korean Journal of Plant Resources
• /
• v.22 no.4
• /
• pp.337-342
• /
• 2009

Present studies were conducted to evaluate the effects of medium strength(MS and Hyponex), carbon sources and their concentrations, agar concentrations, and inoculation amounts on prothallus propagation of Pterdium aquilinum var. latiusculum(Desv.) Underw. ex Hell in vitro. The optimum MS medium strength for prothallus propagation was 2MS concentration. Phosphate source was most effective for prothallus growth of P. aquilinum var. latisculum. The addition of 1% sucrose or glucose to MS medium promoted prothallus multiplication. Growth of prothallus was not affected by agar concentration. Propagation of homogenized prothallus was vigorous even in liquid medium. Chopped gametophytes(100 and 200 mg) were inoculated on 250 ml ${\Delta}$flask with 100 mL of 2MS concentration medium and suspension culture was done at 100 rpm for 22 days. After 20 days, prothallus multiplication slowed down, so 100 mg of chopped prothalli is recommended for initial inoculation, since initial amount of inoculum did not affect subsequent prothallus multiplication. Consequently after 20 days of suspension culture, prothallus should be subcultured or transplanted outside of growing vessels.

• Bulletin of the Korean Chemical Society
• /
• v.26 no.7
• /
• pp.1083-1089
• /
• 2005

Most experimental studies available in the literature on filtration are based on observed average zeta potential of particles (usually 10 measurements). However, analyses of data using the average zeta potential alone can lead to misleading and erroneous conclusions about the attachment behavior because of the variation of particle zeta potentials and the heterogeneous distribution of the collector surface charge. To study characteristics of zeta potential, zeta potential distributions (ZPDs) of silica particles under 9 different chemical conditions were investigated. Contrary to many researchers’ assumptions, most of the ZPDs of silica particles were broad. The solids concentration removal was better near the isoelectric point (IEP) as many researchers have noticed, thus proper destabilization of particles is very important to achieve better particle removal in particle separation processes. While, the mean zeta potential of silica particles at a given coagulant dose was a function of particle concentration; the amount of needed coagulant for particle destabilization was proportional to the total surface charge area of particles in the suspension.

• Journal of Pharmaceutical Investigation
• /
• v.20 no.3
• /
• pp.145-152
• /
• 1990

Zirconium pyrithione complex was prepared by reaction of sodium-pyrithione solution and zirconyl chloride solution. The physico-chemical properties of the complex was examined by means of IR, XRD, DSC and NMR. And the stability of Zr-complex was investigated on the basis of accelerated stability analysis under conditions of temp. elevation, UV radiation and pH dependence. The result indicates that the ratio of the ligand to metal in Zr-pyrithione complex was determined 4:1, and its stability constant was $4.643{\times}10^4$. The rate order of decomposition of the complex was apparent first-order reaction of which rate constant and the decomposition rate was not only accelerated by effect of heat and UV radiation but was catalyzed by specific acid-base catalysis considered the pH dependence for the hydrolysis of the complex and the suspension was most stable over the range pH 4-8 indicating that solvent catalysis is the primary made of reaction in this region.

• Korean Journal of Pharmacognosy
• /
• v.15 no.1
• /
• pp.39-42
• /
• 1984

To examine stability and a separate quantitative method of a mixed preparation of lactic acid bacteria, a capsule containing Lactobacillus acidophilus, Lactobacillus bulgaricus and Streptococcus thermophilus was suspended and diluted in sterile water. After the diluted suspension was spread on three media of tryptone glucose extract agar, MRS agar and MRS-sucrose agar, their colonies appeared and were counted. The viable counts exceeded the minimum number of the three bacteria and showed that the mixed preparation was stable at least for 18 months. The results also showed that a separate quantitation of viable cells of the each strain was feasible.

• Journal of the Korean Society for Precision Engineering
• /
• v.12 no.6
• /
• pp.137-144
• /
• 1995

The purpose of this study is to obtain a foundation data for chassis design and road noise reduction of automobiles. Using the combination of the automobile, radial tires and instrumentation equipment, experimental investigation was carried out to examine the characteris- tics of the structural vibration of tire as the key to obtaining the effective parameters for reducing road noise. From the results of this studies it has been confirmed that the specific ranges of natural frequency of tire exciting the suspension and chassis system. And the tire, axle and chassis natural frequency of automobile govern the road noise. Results show that material properties of tire and experimental condition are major parameter for shifting of tire natural frequency. These results would be utilized as basic materials for the design of chassis design with papametric study, which enables a designer of an automobile to foresee the influence of the various design factors or operating conditions.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.15 no.4 s.97
• /
• pp.375-381
• /
• 2005

The purpose of this study is to obtain a foundation data for chassis design and road noise reduction of automobiles. Using the combination of the automobile, radial tires and instrumentation equipment, experimental investigation were carried out to examine the characteristics of the structural vibration of tire as the key to obtaining the effective parameters for reducing road noise. From the results of experimental studies it has been confirmed that the existence of important frequency ranges, which were attributable to the suspension and chassis system. The tire, axle and chassis natural frequency of automobile govern the road noise. Results that material property of tire and experimental condition are parameter for shifting of tire natural frequency, which enables a designer of an automobile to foresee the influence of the various design factors on the road noise.

• Korean Journal of Microbiology
• /
• v.5 no.1
• /
• pp.1-6
• /
• 1967

The environmental effects on radio-sensitivities of Lactobacillus and Saccharomyces cerevisiae were studied; Liquid suspensions of Lactobacillus and yeast were gamma-irradiated under various conditions; temperatures, hydrogen ion concentrations, amino acids and vitamins were treated seperately with variations of concentrations. (shown in figures) It is found that simultaneous heat treatment is effective to sterilize microorganisms than pre after treatment, and concentration of hydrogen ion does not affect the lethalty of yeast but or Lactobacilli was affect at the range of pH. 5.0 to 7.0. Ascorbic acid, thiamin and pyridoxine were protective dependently against lethal action of gamma-ray and its protective effects increase with the increasings of concentrations. Glutamic acid, aspartic acid, tyrosine and phenylalanine were proved to be protective for both strains at 0.1 between 1.0 percent. It can be suggested that industrial sterilizing doses of irradiation by gamma-ray for food should be applied more than those dose of saline or buffer suspension, because natural food stuffs are rich of vitamins and amino acids.

• Korean Journal of Weed Science
• /
• v.14 no.1
• /
• pp.28-33
• /
• 1994

This study was conducted to investigate the efficacy of weed control by pyributicarb{O-[3-tert-butylphenyl] N-[6-methoxy-2-pyridyl]-N-methyl thiocarbamate}/bensulfuron-methyl{methyl 2-[[[[[[4, 6-dimethoxypyrimidin-2-yl] amino] carbonyl] amino] sulfonyl] methyl] benzoate} SC and oxadiazon{5-tert-butyl-3-[2,4-dichloro-5-isopropoxyphenyl]-1,3,4-oxadiazol-2(3)-one}/bensulfuron-methyl SC, and to develope weed control methods for paddy rice. There was little difference between suspension concentrate and granule of pyributicarb/bensulfuron-methyl and oxadiazon/bensulfuron-methyl combination in the effect of weed control. Pyributicarb/bensulfuron-methyl SC and oxadiazon/bensulfuron-methyl SC were diffused from the point of application to 6m. Pyributicarb/bensulfuron-methyl SC applied on water surface from irrigation inlet and in paddy water from dike controlled more than 90% of weeds. Pyributicarb/bensulfuron-methyl SC was precipitated about 1-2cm per 1 hour after dripping on water surface. The efficacy of weed control by pyributicarb/bensulfuron-methyl SC was higher in 0-1cm than in 6-7cm standing water depth.