• Elastomers and Composites
• /
• 제31권5호
• /
• pp.327-334
• /
• 1996

A correlative analysis has been carried out to predict the average particle size of rubber dispersed phase In high impact polystyrene manufactured by bulk polymerization. To do the correlation, a mechanistic model suggested previously by the author was used for describing the size of stabilizing particles agitated under the turbulent viscous shear subranges in a prepolymerization reactor, where the rubber particles were assumed to be formed at the time of phase inversion in the reactor. Viscosities required for the model were postulated to describe the overall behavior of butadiene rubber and polystyrene mixture along the wide range of conversion. The good agreement between the model and the experimental data from a plant was quite satisfactory for the prediction of the average rubber particle size of high impact polystyrene.

• 한국약용작물학회지
• /
• 제10권4호
• /
• pp.249-252
• /
• 2002

Several plant growth regulators were examined for on their effect on the in vitro propagation of Kalopanax pictus$(T_{HUNB}.)$ $(N_{AKAI}.)$ on WPM medium. Among the cytokinins tested, BA at $13.32\;{\mu}M$ appeared to be the most effective for multiple axillary shoot formation. Although the addition of $2.89\;{\mu}M\;GA_3$ promoted stem elongation, it produced morphologically abnormal leaves and stems. For rooting of the shoots, $4.9\;{\mu}M$ IBA seemed to be more effective than $2.69\;{\mu}M$ NAA. When the regenerated plants were transferred on artificial mixture containing vermiculite and peat-moss (1 : 1, v/v), 81% of them survived and grew normally.

• International Journal of Internet, Broadcasting and Communication
• /
• 제7권2호
• /
• pp.155-160
• /
• 2015

The objective of this study was to develop the classification method of various organic wastes. Specifically, the effects of proximate composition on the biogas production and degradation rates of agricultural by-production was investigated and a new standards for mixture of various organic wastes based on proximate composition combination was developed. Agricultural by-products (ABPs) with medium total carbohydrate, medium crude protein and low fat contents demonstrated the single step digestion process. ABPs with low total carbohydrate, high crude protein and high fat contents demonstrated the two step digestion process of Diauxic growth. The single ABP (Class No. 15) and the mixed ABPs (Class No. 12+18, 6+12+22, 9+12+18) after 10days showed the similar biogas yield pattern. We can use the classification method for the more ABPs and organic wastes from factory and municipal waste treatment plant for the high efficient biogas production.

• KSBB Journal
• /
• 제27권3호
• /
• pp.157-160
• /
• 2012

When iron oxide magnetic nanoparticles were synthesized by co-precipitation method using aqueous ammonia as reducing agent, the synthesized particles were aggregated and thus precipitation occurred. Using Magnolia kobus leaf extract as reducing agent, spherical nanoparticles of 50~200 nm were synthesized with low yield. By using both Magnolia kobus leaf extract and aqueous ammonia as reducing and stabilizing agents, smaller nanoparticles of 40~120 nm could be synthesized with various shapes. The synthesized magnetic nanoparticles were characterized with field emission transmission electron microscopy (FE-TEM) and scanning electron microscopy (SEM). TEM and SEM images showed that the magnetic nanoparticles are a mixture of triangles, tetragons, rods and spherical structures.

• 대한기계학회논문집B
• /
• 제23권10호
• /
• pp.1274-1284
• /
• 1999

The Regulatory Guide 1.82 recommends an analysis of hydraulic performance for sump of ECCS (Emergency Core Cooing System) when LOCA(Loss of Coolant Accident) occurs in a nuclear power plant. The present study deals with 3-dimensional, unsteady, turbulent and two-phase flow simulation to examine the behavior of mixture of reactor coolant and debris near the floor of containment building in conjunction with appropriate assumptions. The dispersed solid model has been adjusted to the interfacial momentum transfer between reactor coolant and debris. According to the results, the counterclockwiserecirculation zone had been formed in the region between sump and connection aisle about 376 second after LOCA occurs. The debris thickness accumulated on a sump screen periodically increases or decreases up to 2000 second, afterwards its peak decreases.

• Journal of Preventive Medicine and Public Health
• /
• 제18권1호
• /
• pp.149-156
• /
• 1985

By using Factor analysis on the variables relating to the subjective symptoms of total 56 workers, who have exposed to mixture of organic solvents at the musical instrument manufacturing plant, as experinmental group, and 70 workers, who worked in noisy working environment as control group, the study was performed. It was confirmed that the variables found in hematological figures, age specification, occupational history and physical examination have a influential factor on the subjective symptoms of both groups. It was explicated that the ratio of these to total Eigen Values showed 31.1 percent in experimental group and the control group revealed 37.7 percent.

• Natural Product Sciences
• /
• 제9권4호
• /
• pp.270-272
• /
• 2003

The methanol extract of Euphorbia milii exhibited strong inhibitory effect on platelet aggregation in the cource of our search for anti-platelet component from succulent plants. Two components, components 1 and 2 were isolated from this plant. 1 was the mixture of 72% of 1-octacosanol (1a) and 28% of 1-triacontanol (1b), and 2 was identified as ${\beta}-sitosterol$. 2 ($IC_{50}$: $195\;{\mu}M$, and $170\;{\mu}M$ respectively) was about two fold stronger than ASA ($IC_{50}$: $420\;{\mu}M$ and $340\;{\mu}M$ respectively) on both collagen and U46619 induced aggregation, while the effect of 1 to platelets was negligible.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 1986년도 한국자동제어학술회의논문집; 한국과학기술대학, 충남; 17-18 Oct. 1986
• /
• pp.238-243
• /
• 1986

Distillation columns are widely used in almost every chemical plant. The use of multivariable control for such units is attractive because of the strong interactions exhibited between outputs and inputs and the desire to control simultaneously both top and bottom products. In this research design of a robust multivariable controller for distillation column was considered; output feedback controller with proportional and integral modes was designed using pole assignment. The transfer function matrix was obtained by fitting the step response realtions between single input double output pairs of variables. This matrix was then converted to linear time invariant state space model by multivariable realization technique. With the proposed multivariable proportional and integral controller applied to the process, the result of the digital computer simulation showed a good performance of asymtotic tracking. The limited experimental performance of this multivariable control was compared with the result from simulation. It was found that the proposed controller performed satisfactorily for the distillation column which separated binary mixture of methanol and water.

• Journal of Ginseng Research
• /
• 제7권2호
• /
• pp.108-114
• /
• 1983

1. To know the site of saponin synthesis in this plant, 4-years old Panax ginseng C.A. Meyer was administered with 1, 2-l4C-acetate (Na salt, 10 ucilplant) by stem injection and was continued to grow for 3 weeks and the distribution of the radioactivity in leaf, stem and root part was identified. The percentage of radioactivity recovered was about 3.99%. 2. The sliced roots or leaf discs (2g) were bathed in the reaction mixture containing sugar, ATP, NADPH, and the distribution of the radioactivity of the fractions (sugar, saponin, sapogenin) was identified. 3. It seemed that major synthesized saponins in roots and leaves are dial and triol-type, respectively. Although both types of saponins are synthesized in roots, the main saponins seemed to be dial saponins and a significant portion of triol saponins are supplied from leaves through stem.

• 한국펄프종이공학회:학술대회논문집
• /
• 한국펄프종이공학회 2006년도 PAN PACIFIC CONFERENCE vol.1
• /
• pp.37-42
• /
• 2006

The paper discusses the combined use of softwood and eucalyptus kraft pulps in the production of printing and writing papers. Looking for process and paper quality optimization, refining pilot plant trails were carried to identify the effects of refining type (mixed or separate) and intensities (specific edge load), and also furnish composition (amount of each pulp in mixture) on final paper quality and process costs. The basic effects on pulp fibers were evaluated against paper quality properties, such as physical strengths, bulk, vessel picking, opacity and porosity, as well as the interactions with papermaking process, such as estimates of paper machine runnability, paper breaks and industrial refining control. The results show that the furnish composition and the type of refining has a significant effect on properties related with both final paper quality and total costs. The best alternative for printing and writing papers was identified for mixed refining, under the lowest refining intensity, and with the highest dosage of eucalyptus pulp.