• Membrane Journal
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• v.17 no.1
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• pp.67-79
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• 2007

Uniform microcapsules containing ionic model drugs were prepared by controlling various conditions of emulsification procedure using a lab-scale membrane emulsification system with a SPG (Shirasu porous glass) tubular membrane. We observed the effects of various emulsification parameters [concentration and molecular weight of polycaprolatone (PCL) polymer, transmembrane pressure and emulsifier concentration in disperse phase and continuous phase, stirring speed] on the mean size and size ditribution of microcapsules containing lidocaine hydrochloride (cationic drug), sodium salicylate (nonionic drug) and 4-acetaminophen (anionic drug) used as a model drugs. Also, release characteristics of a model drugs from PCL microcapsules were investigated. Controlling membrane emulsification parameters, uniform PCL microcapsules with about $5\;{\mu}m$ of the mean size were finally prepared. The release rate and the burst effect of microcapsules were decreased in condition of the acidic solution, but it was increased in condition of the base solution.

• The Transactions of the Korea Information Processing Society
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• v.3 no.1
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• pp.191-199
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• 1996

In this paper, We assume that the closed computer system model composed of multiprocessor system is analyzed by BCMP queueing network theory with priority levels. In this system that contains terminals, processors and I/O devices, We show maximum throughput and the number of active terminals in the optimum multiprogramming levels. It is compared the performance with the other. In the result, it is obtained the optimum number of processors and active terminals. Therefore, the system model consisted of the optimum number of processor and multiprogramming level m is analyzed by the servers with a priority level. Each server is applied to the type of server which is characterized terminal, processor I/O device etc.. This model is analyzed by the server with a probability ditribution. Ideal state is proposed by the modeling for priority levels. Finally, we try to increase the performance in overload system.

• The Korean Journal of Pesticide Science
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• v.4 no.2
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• pp.44-49
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• 2000

Objective of this study was to determine the Si distribution and extent of control of powdery mildew diseases of cucumber(Cucumis sativus L.). The distribution of silicon in the leaf epidermis of cucumber plants grown in hydroponic nutrient solutions supplemented with soluble silicates was examined using scanning electron microscopy and energy dispersive X-ray analysis. The silicate absorbed from nutrient solution was translocated into cucumber leaves, and accumulated mainly in the cells surrounding the base of trichome hairs. Base cells surrounding the trichomes also had high levels of Si, Ca, and K. Si levels in the epidermal cells for low Si treatment were not detectable except in the trichome bases. Hyphal lengths of powdery mildew occurring on cucumber leaves cultivated in medium with high concentration of silicate were remarkably shorter than those of cucumber leaves cultivated with low concentration of silicate. There was a negative correlation between hyphal length of S. fuliginea and silicate concentrations.

• Journal of Chest Surgery
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• v.2 no.1
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• pp.41-49
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• 1969

The authors made a clinical study of 80 cases of empyema who were diagnosed and treated at department of chest surgery, St. Mary`s Hospital, Chatholic Medical College, during the period of May.l964 through April.1969 and compared the empyema of infant and children with that of adults. 1. In age and sex ditribution, infant was 6 cases, childhood 22 cases and adult 52 cases. The ratio of male to female was 2.2:1. There`s a little difference in infant-childhood but prominence of males over females in adults was being 3. 3:1, in its ratio. 2. The cardinal symptoms were cough [61.3%], fever [60.0%] and dyspnea [52.8%]. The leukocytosis were observed in 83.7% of all cases, 96.2% of infant-childhood and 76.9% of adults. The hemoglobin level showed subnormal in 82.1% of infant-childhood and in 55.8% of adults. 3. Most frequent lesion to predisposing factor of empyema was pneumonia [43.7%],being prominent in infants children [64.3%] to that of adult 4. The Pathogenic organism by culture in 75 cases of empyema were staphylococuss [48%], streptococuss[9.3%], Gram[-] bacilli [9.3%], Klebsiella[2.7%], pneumococcus[4.0%], E. coli [5.4%] and no growth 21.3% in over all. Among the cases of empyema. staphlocal origin was 62.9% in infant-childfood and 39.6% adults. 5. Staphylococci were most susceptible to erythromycin [86. 1%], Kanamycin [75.0%], albamycin [61.7%] and neomycin [52.8%] but most resistant to penicillin, Chtoramphenicol and terramycin. 6. In the treatment of empyema, of 53 cases were closed thoracotomy drainage and the remainder of cases by open thoracotomy, decortication, thoracoplasty and pleuropneumonectomy. we could attain favourable results by only the closed thoracotomy in infant-childhood, 28 cases. 7. The mortality rate was 6.3% in over all; adult 3 cases, infant and children 2 cases. 3 cases of these, were due to staphylococcal infection.

• Journal of the Korean Applied Science and Technology
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• v.29 no.1
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• pp.122-128
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• 2012

The influences of fluorescence, scattering, and flocculation in turbid material by light scattering of L-aspartic acid, preservative and emulsifier were interpreted for the scattered fluorescence intensity and wavelength. They have been studied the molecular properties by the spectroscopy of laser induced fluorescence (LIF) and flocculation. The effects of optical properties in scattering media have been found by the optical parameters(${\mu}_s$, ${\mu}_a$, ${\mu}_t$). Flocculation is an important step in many solid-liquid separation processes and is widely used. When two particles approach each other, interactions of several colloid particles can come into play which may have major effect on the flocculation and LIF process. The values of scattering coefficient ${\mu}_s$ are large by means of the increasing scattering of scatterer, The values have been found that the slope decays exponentially as a function of concentration from laser source to detector by our experimental result. It may also aid in designing the best model for oil chemistry, bio-pharmaceutical products, laser medicine and application of medical engineering on LIF and coagulation in particle transport mode.

• Journal of the Korean Geographical Society
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• v.36 no.1
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• pp.52-65
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• 2001

Between 1985 and 1997 the diffusion of private passenger cars first occurred in major cities such as Seoul, Busan, Daegu and the satellite cities of the capital city that enjoyed high incomes and advanced service industries and then it gradually expanded to industrial and major provincial cities while posting a downturn in the major cities. Factor contrbuting to this phenomenon most significantly was the rate of employment in the financial insurance, real estate, and business service sectors in 1985 and 1990. The most ingluential factor in 1997 was the rate of employment in agriculture, hunting, forestry, and fishery. When measured against 1991 as a yardstick, the spatiotemporal ditribution rate of private passenger cars was highly between 1985 and 1990 in Seoul's satellite cities and major regional cities, showing a large inter-regional gap in terms of diffusion rate. The period from 1991 to 1997 showed a high rate of diffusion in cities within the capital region as well as in major regional cities, but inter-regional diffusion rate became similar. Key factors responsible for regional types of the diffusion were {1}the rate of employment in the service industrier and income in the major citier, and (2)the geogtaphic distamce between counties and Seoul plus the size of population in the county regions.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.6 no.1_2
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• pp.20-26
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• 1973

Authors have investigated the monthly distribution of vibrio flora in sea water, mud, fish and shellfish in the public beaches at the suburbs of Busan in order to determine the possible origins of food poisoning. The results are summarized as follows: 1. The monthly distribution shows that V. parahaemolyticus occurs from May to November and V. alginelyticus all the year round. 2. A total of 40 strains of Vibrio flora were isolated from 40 sea water samples, 25 strains from 40 mud samples, If strains from 88 shellfish samples, and 3 strains from 30 fish samples. 3. More strains were isolated from the samples collected at Yongho and Suyeong that at the other localities. 4. A total of 80 strains of Vibrio flora, isolated from 198 samples, were divided into two groups : V. perahaemolyticus with 20 strains and V. alginelyticus 60 strains.

• Korean Journal of Materials Research
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• v.3 no.6
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• pp.645-651
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• 1993

The growth of semi-insulating(SI) high resistant undoped GaAs epilayer has been studied to solve the problems ocurring when GaAs IC is fabricated by the widely used ion implantation directly into the SI GaAs substrate. The EPD ditribution of the SI substrates has been examined, and the suitability of the buffer layers grown by MOCVD and MBE, respectively, has been tested for IC fabrication through leakage current measurement. IJngated FET has been fabricated on the SI epilayer and leakage current through the buffer layer has been measured. In the case of MOCVD grown 1$\mu\textrm{m}$-thick buffer layer, the leakage current is as small as about 270nA/mm, and this value does not affect the pinch-off of FET. In this case, the epilayer quality is affected by the substrate defects because the leakage current distribution is coincided with the EPD distribution of the SI substrate. The 2$\mu\textrm{m}$-thick buffer layer grown by MBE, however, has the better quality, and shows the lower leakage current(40nA/mrn) and higher uniformity.

• Elastomers and Composites
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• v.48 no.2
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• pp.172-179
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• 2013

Impact modifier reinforced polymers are frequently used. In this study, Izod impact test has been simulated to analyze the mechanism of impact reinforcement of Nylon6 which contains impact modifier. The modeling of rubber particles added to Nylon6 as an impact modifier has been attempted. Based on the modeling, simulation of Izod impact test has been performed to observe the distribution and direction of stress at the cross-section of impact specimen. Three computer simulation models for Nylon6 were investigated. Those were without impact modifier, containing impact modifier without surface treatment, and containing impact modifier with surface treatment in the Nylon6. Simulation results showed that the stress which originated at the notch surface propergated to the inside of specimen round a impact modifier. In addition to that, impact modifier reinforced Nylon6 specimen showed low stress ditribution in the cross-section specially at notch surface. Principal stress in perpendicular direction to crack was also lowered in impact modifier reinforced Nylon6. These enhanced impact resistance reduced and crack propergations. Through this study it was realized that the computer simulation can be utilized to investigate the property enhacement of composite materials.

• Journal of Conservation Science
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• v.6 no.1 s.7
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• pp.15-30
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• 1997

The chamical and physical properties of the fragments of an ancient pottery such as earthenware, gliazed pottery and celadon excavated in Chonnam province has been investigated by X-ray diffraction inductively coupled plasma spectroscopy(ICP), thermal mechanical analysis(TMA). Glazed pottery fragments of Chonnam province are cotaining Fe2O3 $4\~7\%$ by the analyis of ICP, firing temperature range was presumed to $1100-1150^{\circ}C$ by TMA. Celadon fragments of Chonnam province are containing Fe2O3 $2\~3\%$ by the analyis of ICP, firing temperature range was presumed to $1140\~1200^{\circ}C$ by TMA. The charateristics in the trace element composition of an ancient pottery of Chonnam provinceis are similar, it is an reflection of similar geological charateristics. The charateristic elements of Chonnam provincical ancient pottery were Rb, Sr, V, Zr, Y, Nd, Sc, La, Ce, Nb, Sm, Eu, Dy and Yb of the analyzed 21 trace elements. By Fe2O3-Zn ditribution diagram, potteries excavated in Yong-am, celadons excavated in Haenam, Kangjin, Buan and glazed pottery excavated in Hae-nam are grouped into the same class.