• Carbon letters
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• v.11 no.4
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• pp.279-284
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• 2010

Graphene is one of the most promising materials for many applications. It can be used in a variety of applications not only as a reinforcement material for polymer to obtain a combination of desirable mechanical, electrical, thermal, and barrier properties in the resulting nanocomposite but also as a component in energy storage, fuel cells, solar cells, sensors, and batteries. Recent research at Michigan State University has shown that it is possible to exfoliate natural graphite into graphite nanoplatelets composed entirely of stacks of graphene. The size of the platelets can be controlled from less than 10 nm in thickness and diameters of any size from sub-micron to 15 microns or greater. In this study we have investigated the influence of melt compounding processing on the physical properties of a polyamide 6 (PA6) nanocomposite reinforced with exfoliated graphite nanoplatelets (xGnP). The morphology, electrical conductivity, and mechanical properties of xGnP-PA6 nanocomposite were characterized with electrical microscopy, X-ray diffraction, AC impedance, and mechanical properties. It was found that counter rotation (CNR) twins crew processed xGnP/PA6 nanocomposite had similar mechanical properties with co-rotation (CoR) twin screw processed or with CoR conducted with a screw design modified for nanoparticles (MCoR). Microscopy showed that the CNR processed nanocomposite had better xGnP dispersion than the (CoR) twin screw processed and modified screw (MCoR) processed ones. It was also found that the CNR processed nanocomposite at a given xGnP content showed the lowest graphite X-ray diffraction peak at $26.5^{\circ}$ indicating better xGnP dispersion in the nanocomposite. In addition, it was also found that the electrical conductivity of the CNR processed 12 wt.% xGnP-PA6 nanocomposite is more than ten times higher than the CoR and MCoR processed ones. These results indicate that better dispersion of an xGnP-PA6 nanocomposite is attainable in CNR twins crew processing than conventional CoR processing.

• Korean Journal of Clinical Pharmacy
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• v.9 no.2
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• pp.109-118
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• 1999

The need for and components of a contemporary community pharmacy externship for pharmacy students have not been clearly identified in Korea. Mail survey was performed among 20 college of pharmacy deans and 800 community pharmacists to analyze the current status and develop a consensus regarding major focus area and criteria of community pharmacy externship to be implemented under the separation of dispensary from medical practice in year 2000. Mail survey yielded $80\%\;and\;23.5\%$ response rate for pharmacy school deans and community pharmacists, respectively. Of the 16 pharmacy schools that responded 14 said they have externship program in hospital pharmacy, and only 8 pharmacy schools responded of having externship program for community pharmacy. However, these community pharmacy programs lacked criteria and standard guideline for the externship. The results of survey revealed that community pharmacy externship program for students should be organized and directed toward developing expert knowledge and skills in pharmacy practice activities, clinical services, communications, pharmacy management, and professionalism. Pharmacy practice components should include competencies and skills in computer application, prescription processing, dispensing, pharmaceutical compounding, Narcotics Control Law application, maintenance and provision of drug information, and laws and regulations. Clinical service components should include the ability to identify patient's drug-related problems, provide long-term patient care and appreciate drug therapy services. Communication skills should be taught to effectively express his/her professional opinion, deduce the needs of others, utilize appropriate techniques and media to communicate ideas and conduct a patient interview and to obtain patient drug history. Pharmacy management skills should be taught to be efficient in medical insurance and drug control process. It was found that professionalism, morality, pharmacy practice experience, ability to provide clinical services, collect and provide drug information and regality are important criteria of preceptors. Externship sites should possess the ability to stock various drugs, access and provide diverse pharmacy services and should have private patient counseling area. Most pharmacists agreed that top 200 drugs' generic and brand name, indications, dosage, side effects, and contraindication should be instructed during the externship. It was also found that student and preceptor should be evaluated for their performances during the externship. This information will be incorporated into teaming objectives for students and to develop Academic Extemship Program Guidelines.

• Journal of the Korean Ceramic Society
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• v.38 no.11
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• pp.1067-1074
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• 2001

Four different composition of autoxidation drying type waterborne coatings (WBC-1, WBC-2, WBC-3, WBC-4) were prepared by the compounding of bentonite (BEN) as a water swellable clay and organometallic soaps as a drier with acrylic binder and coating additives. The solution viscosity, solid content, rheological properties and drying rate of WBCs were investigated. Also the thermal stability, the transmittance and the water-resistance of the films casted by WBCs were measured, and the surface topology of WBC films were investigated by the scanning probe microscopy. As WBC-2, WBC-3 and WBC-4 containing BEN showed the thixotropy with the shear rate, the storage stability of WBC was a excellent. When the driers was mixed in the ratio of Mn/Zn/Ba=1/2/3, the dry ability of WBCs showed maximum as 5.0 sec at 60$\^{C}$. The initial decomposition temperature and the transmittance of WBC films containing BEN increased in range of 32.2∼54.7$\^{C}$ and 5.1∼8.6% than the commercial WBC (MC-21W), respectively. The water resistance of WBC films increased in order of MC-21W

• Journal of Intelligence and Information Systems
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• v.12 no.2
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• pp.67-81
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• 2006

While the existing Web focuses on the interface with human users based on HTML, the next generation Web will focus on the interaction among software agents by using XML and XML-based standards and technologies. The inference engine, which will serve as brains of software agents in the next generation Web, should thoroughly understand the Semantic Web, the standard language of the next generation Web. As abasis for the service, the W3C (World Wide Web Consortium) has recommended SWRL (Semantic Web Rule Language) which had been made by compounding OWL (Web Ontology Language) and RuleML (Rule Markup Language). In this research, we develop a backward chaining inference engine SMART-B (SeMantic web Agent Reasoning Tools -Backward chaining inference engine), which uses SWRL and OWL to represent rules and facts respectively. We analyze the requirements for the SWRL-based backward chaining inference and design analgorithm for the backward chaining inference which reflects the traditional backward chaining inference algorithm and the requirements of the next generation Semantic Web. We also implement the backward chaining inference engine and the administrative tools for fact and rule bases into Java components to insure the independence and portability among different platforms under the environment of Ubiquitous Computing.

• Korean Chemical Engineering Research
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• v.46 no.1
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• pp.106-111
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• 2008

Polypropylene (PP)/corn starch master batch (starch-MB)/silicate composites with different corn starch compositions of 10, 20, 30, 40 and 50 were prepared by melt compounding at $200^{\circ}C$, using lab scale Brabender mixer. The content of silicate was fixed at 5 wt%. The composition of starch-MB in composites was confirmed by the existence of hydroxy group and peak intensity in fourier-transform-infrared (FT-IR) spectrum. The thermal properties of the PP/starch-MB/silicate composites were investigated by differential scanning calorimetry (DSC), and thermogravimetric analyzer (TGA). There was no district change in melting temperature, and TGA curve indicates a decrease in degradation temperature with the increase of starch-MB content. The silicate dispersion of the composites was measured by X-ray diffraction (XRD) and transmission electron microscope (TEM). The degree of silicate dispersion in PP/starch-MB/silicate composites depended on the content of starch-MB. There was detectable change in d-spacing and peak intensity of the composite when the content of starch-MB was higher than 20 wt%. The rheological behavior of the composites was explained by both shear thinning effect and elastic property with the starch-MB amount. These effects were remarkable when the content of starch-MB was higher than 20 wt%. These were confirmed by an oscillatory viscometer at $200^{\circ}C$.

• Elastomers and Composites
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• v.39 no.2
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• pp.131-141
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• 2004

The recycling of waste XLPE(crosslinked polyethylene), which is a major source of scraps from high voltage power transmission cables, has been discussed. The waste XLPE scraps were ground into fine powder with various sizes from less than $100{\mu}m$ up to about $1000{\mu}m$ using two types of tailor-made pulverizers. The compounds were prepared in a modular intermeshing co-rotating twin screw extruder at various conditions such as different compositions, types and powder sizes of waste XLPE, screw configurations and various polymer matrices (LDPE, HDPE, PP, PS). The mechanical and rheological properties and the fracture surface or the compounds were investigated. It was found that an improved impact strength was obtained from the compound with white XLPE powder pulverized from the scraps without outer/inner semi-conductive layers. Generally, the impact strength increases with the content of XLPE but decreases with the size of XLPE. Especially for LDPE, the extrusion was possible up to 80 wt% loading of XLPE. Also, the impact strength increases with the number of kneading disc blocks in the given screw configurations. The melt viscosity of the compounds increases with increasing XLPE loading. However, the higher shear thinning behavior of the compounds at common shear rates implies proper processibility of the compounds. In addition, the impact strength for other polymer matrices used increases with XLPE and it is noticeable that the impact strength of PS/XLPE (80/20 wt%) compound was improved twice that of pure PS.

• Journal of Ginseng Research
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• v.27 no.2
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• pp.66-71
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• 2003

We screened preventives (preventers) from natural resources to prevent the rust phenomenon in ginseng roots. We examined that how these influence on the rusty phenomenon and the growth of 2 years old ginsengs treated in the preventers. All treats which was compounding preventers & improvers were so excellent of the ginsengs growth. Especially, the growth of 2 years old ginsengs treated with bio-preventer of ICPE-C105 and ICPE-P107R were increased to 73%, 28% compared with nontreatment, respectively. Though rusty ginseng of rate was emerged 58% in control, preventers ICPE-C 105 and ICPE-P107 were emerged of each 16.7%, 20%. It was affirmed effective of preventer. On the other hands, amounts of ginsenoside treated with preventatives showed to be changed. The total ginsenoside was increased to 71% with treatment ICPE-C105R which is the highest among groups compared to control, and ICPE-P$\_$107/R was increased to 50%. To sum up with total results, it is biotic preventatives (ICPE-C$\_$105/R and ICPE-P$\_$107/R) which we created improve both a high yield of ginseng roots and the inhibition of the rusty phenomenon. phenomenon.

• Journal of Korean Medicine Rehabilitation
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• v.29 no.4
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• pp.101-108
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• 2019

Objectives The purpose of this study is to evaluate the safety of Gunghatang tablet in healthy male volunteers. Methods Single center pharmacokinetics study was carried out in healthy male volunteers. Through the laboratory test, vital sign and adverse event data, safety evaluation was conducted. Total 15 of 16 subjects who met the inclusion criteria were enrolled and three subjects were allocated to waiting group. 12 subjects were allocated by serial number according to registration order. Subjects took the maximum daily dose of the tablet on the second day of hospitalization. For the evaluation of safety, blood samples were collected and vital sign were checked 4 times (screening, before administration, after administration and follow up period) during the trial. All adverse events were recorded and summarized as frequency and percentage. All continuous data were summarized as mean and standard deviation. For comparison of variables between before administration and after administration, data were analyzed by paired T-test or Wilcoxon signed rank test (p<0.05). Results As a result of all data related to vital sign and laboratory test in both group, there were no significant differences associated with the clinical trial drug between pre and post administration. And there was no adverse event associated with the clinical trial drug. Conclusions Gunghatang tablet were found to be safe for healthy male volunteers.

• Journal of the Korean Recycled Construction Resources Institute
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• v.7 no.3
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• pp.243-254
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• 2019

In this study, problems of the waterproofing methods in which water leakage occurs in the upper slab of the underground parking lot of apartment houses and the requirements considering the characteristics of the upper slab, and selected the appropriate performance(proposal) for the composite polyurea process are reviewed. As a result of the study, it is necessary to review performance such as responsiveness to upper slab of the multi-unit underground parking lot that is comprised of (1) crack and behavior responsiveness, (2) surface integrity, (3) vertical watertight stability, (4) pressure layer construction, (5) impact and pressure response and (6) vehicle moving load. As a result of evaluating 5 items corresponding to the requirements for the soft and hard complex polyurea, all of them were found to meet the conditions, and each materials were improved by compounding the materials that had problems when applying a single-ply method, thereby clarifying the advantages and disadvantages of the material property. However, in order to apply to the actual site, additional evaluation on site applicability such as mock-up evaluation should be conducted, and subsequent studies on the applicability of the market through review of economic feasibility and maintenance is required.

• Elastomers and Composites
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• v.38 no.1
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• pp.57-64
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• 2003

Metal oxide(MgO) was added to FKM rubber in order to develop automotive fuel hose which ran show elastic characteristics under extreme condition. Cure characteristics, physical properties, thermal resistance and fuel resistance of FKM compounded rubber with MgO were investigated. MgO was mixed to FKM rubber materials within the range of $0{\sim}20phr$. From the test results of rheological properties and Mooney viscosity, the $t_{s2}$, $T_{c90}$ values increased as the MgO contents increased in FKM rubber compounding. Hardness and 100% modulus of FKM compounded rubber slightly increased, but tensile strength and elongations at break slightly decreased. From the test results of thermal resistance of rubber specimens at 130, 150, and $170^{\circ}C$ for 70 hrs, the changing rate of physical properties was found to be relatively small. Fuel resistance tests were carried out for fuel A, B, C and D at $40^{\circ}C$ for 70hrs, and the results showed that the changing rate in physical properties was found to increase from Fuel A to D, Furthermore thermal properties of FKM compounded rubber containing MgO were also investigated by using TGA/DSC. The optimum mixing ratio of additive to FKM rubber to get the maximum effect on thermal resistance and fuel resistance, within the range of desirable specification for rubber material, was determined to be 6 phr for MgO.