• Applied Chemistry for Engineering
• /
• v.16 no.1
• /
• pp.1-8
• /
• 2005

Electrorheological (ER) fluids, typically composed of particles having higher dielectric constant or electric conductivity than that of suspending fluids with a low viscosity, undergo dramatic, reversible changes when exposed to an external electric field. Among various electroactive materials, we put our efforts on inorganic materials including zeolite, MCM-41, MCM-41/polyaniline composite and SBA-15/polyaniline composites. Their preparation and ER characteristics are introduced.

• Korean Chemical Engineering Research
• /
• v.44 no.2
• /
• pp.172-178
• /
• 2006

Mesoporous silicate materials have been used as adsorbents for the removal of heavy metals from water by introducing functional groups such as thiol and amine. In this research, it was investigated whether surfactants used as templating agents in synthetic processes can act as adsorption sites for heavy metals. Three mesoporous silicates-SBA-15, MCM-41, and HMS were synthesized using, respectively, block copolymer, hexadecyltrimethylammoniumbromide (HDTMA), and dodecyamine as surfactants. X-ray diffraction and $N_2$ gas adsorption analysis confirmed that the mesoporous silicates were well prepared and FT-IR spectra resulted in the existence of the surfactants in as-synthesized mesoporous silicates and the removal of surfactants after calcination. The interactions between $Pb^{2+}$ ions and the mesoporous silicate materials with/without surfactants were observed. In adsorption kinetic experiments, it revealed that the calcined mesoporous silicates and the surfactant-loaded SBA-15 almost had no adsorption capacity for $Pb^{2+}$ ions. In contrast, the surfactant-loaded MCM-41 and HMS showed, respectively, the adsorption capacities of 26.60 and 115.16 mg/g which were acquired through the fits of adsorption kinetic data to the pseudo second order kinetic model. The adsorption capacities were comparable to those of other mesoporous adsorbents for heavy metals.

• Journal of Life Science
• /
• v.16 no.6
• /
• pp.1014-1028
• /
• 2006

This study attempted to investigate the developmental alterations of the cerebral cortex. The effects of EGEE on the developmental cerebral cortex in the prenatal, postnatal and adults were examined by lectin histochemical methods. To investigate the change of sugar residues of glycoconjugates, biotinylated lectins(DBA, SBA, PNA, BSL-1, RCA-1, sWGA, UEA-1, Con A and LCA) were detected with by IHC using ABC kit. In the case of injection of EGEE, the reactions to Con A and LCA were shown in binding phase in the cerebral cortex commonly, and the reactions to PNA, RCA-1 and LCA were shown partially, the number of lectins to be shown reaction were decreased, and there were no reactions to DBA, SBA, BSL-1, RCA-1 and UEA-1. The reaction to Con A was similar to control group during developmental phases. The reaction to LCA was increased in the fetal, suckling, and weanning phases compared with control group. But there were no reactions to SBA and sWGA, the reaction to PNA was decreased in the frontal and occipital cortex and no reaction to sWGA in the fetal phase. There were no reactions to sWGA and PNA in the suckling phase and, no reaction to PNA and sWGA. The reaction to Con A was decreased in the frontal, parietal and occipital cortexes and, the reaction to LCA was decreased in the frontal and occipital cortexes in adult phase. As the results, the effects of EGEE, environmental hormone on the each part of cerebral cortex have shown differences. But, It had deep effect on the differentiation and growth in the cerebral cortex pathologically. In particular, the effect was severe in suckling phase. $Galactosyl-({\beta}-1,3)-N-acetyl-D-galactosamine$,${\beta}-N-acetyl-D-galactosamine$ and ${\beta}-N-acetyl-D-glucosamine$ were decreased while ${\alpha}-D-mannose$ and ${\alpha}-D-glucose$ were increased. It affected the sugar metabloism, and it was severe in fetal and suckling phases.

• Clean Technology
• /
• v.16 no.2
• /
• pp.95-102
• /
• 2010

Sulfonic acid (-SO3H) functionalized mesoporous silica containing HMS, SBA 15(S15), MCM 41(M41) were synthesized by post-synthesis and co-condensation method. Their catalytic performance is tested by dehydration reaction of D-xylose to furfural. As a result, good conversion and selectivity was obtained using water as an environmentally friendly solvent. Additionally, increased amounts of sulfuric acid in catalysts resulted in improved conversion of D-xylose. All of the acid-functionalized mesoporous silica showed higher selectivity than other solid acids such as ${\gamma}-Al_{2}O_{3}$ and zeolite.

• Perspectives in Nursing Science
• /
• v.15 no.2
• /
• pp.49-69
• /
• 2018

Purpose: The purpose of this study was to derive contextual indicators of medical provider quality and assess their relative importance along with the individual utilization of antenatal care (ANC) and institutional births with a skilled birth attendant (SBA) in India using a multilevel framework. Methods: The 2015~2016 Demographic and Health Survey (DHS) from India was used to assess the outcomes of neonatal, infant, and under-five child mortality. The final analytic sample included 182,980 children across 28,283 communities, 640 districts, and 36 states and union territories. The contextual indicators of medical provider quality for districts and states were derived from the individual-level number of ANC visits (<4 or ${\geq}4$) and institutional delivery with SBA. A series of random effects logistic regression models were estimated with a stepwise addition of predictor variables. Results: About half of the mothers (47.3%) had attended ${\geq}4$ ANC visits and 75.8% delivered in institutional settings with SBAs. Based on ANC visits, 276~281 districts (43.1~43.9%) and 13~16 states (36.5~44.4%) were classified as "low" quality areas, whereas 268~285 districts (41.9~44.5%) and 8~9 states (22.2~25.0%) were classified as "low" quality areas based on institutional delivery with SBAs. Conditional on a comprehensive set of covariates, the individual use of both ANC and SBA were significantly associated with all mortality outcomes (OR: 1.17, 95% CI: 1.08, 1.26, and OR: 1.10, 95% CI: 1.02, 1.19, respectively, for under-five child mortality) and remained robust even after adjusting for contextual indicators of medical provider quality. Districts and states with low quality were associated with 57~61% and 27~43% higher odds of under-five child mortality, respectively. Conclusion: When simultaneously considered, district- and state-level provider quality mattered more than individual access to care for all mortality outcomes in India. Further investigations are needed to assess the importance of improving the quality of health service delivery at higher levels to prevent unnecessary child deaths in developing countries.

• Applied Chemistry for Engineering
• /
• v.16 no.5
• /
• pp.719-723
• /
• 2005

Organic-inorganic hybrid mesoporous materials were prepared by co-condensation of organosilanes with tetraethyl orthosilicate (TEOS) or 1,2-bis(triethoxysilyl) ethane (BTSE). Their removal capability of volatile organic compounds (VOCs) in the air was evaluated and compared with that of inorganic hydrophilic mesoporous material, SBA-15 that was prepared with TEOS only. It was found that the increased hydrophobicity of mesoporous materials due to the presence of organic group, could enhance the VOCs removal by adsorption in the air. An organic-inorganic hybrid material prepared by the co-condensation of BTSE/phenyl triethoxysilane (90/10 by weight) was a typical example of superior adsorbent. It was also observed that these organic-inorganic hybrid materials can be utilized as absorbents for the removal of oil dispersed in water.

• Bulletin of the Korean Chemical Society
• /
• v.32 no.9
• /
• pp.3274-3280
• /
• 2011

Monodispersed porous NiO and $Co_3O_4$ microcapsules with a hollow core were synthesized using SBA-16 silica sol and PS as a hard template. The porous hollow microcapsules were characterized by XRD, TEM and $N_2$ adsorption/desorption analysis. After $H_2$ reduction of metal oxide microspheres, they were conducted as an active catalyst in the reduction of chiral butylronitrile and cyanobenzene. The mesoporous metals having a hollow structure showed a higher activity than a nonporous metal powder and an impregnated metal on the carbon support.

• Journal of the Korean Society for Precision Engineering
• /
• v.16 no.2 s.95
• /
• pp.201-210
• /
• 1999

One of the major limitations of productivity and quality in metal cutting is the machining accuracy of machine tools. The machining accuracy is affected by geometric and thermal errors of the machine tools. Therefore, a key requirement for improving te machining accuracy and product quality is to reduce the geometric and thermal errors of machine tools. This study models geometric error for error analysis and develops on-machine measurement system by which the volumetric erors are measured. The geometric error is modeled using form shaping function(FSF) which is defined as the mathematical relationship between form shaping motion of machine tool and machined surface. The constant terms included in the error model are found from the measurement results of on-machine measurement system. The developed on-machine measurement system consists of the spherical ball artifact (SBA), the touch probe unit with a star type stylus, the thermal data logger and the personal computer. Experiments, performed with the developed measurement system, show that the system provides a high measuring accuracy, with repeatability of ${\pm}2{\mu}m$ in X, Y and Z directions.

• Journal of Information Technology and Architecture
• /
• v.9 no.3
• /
• pp.233-241
• /
• 2012

Architecture framework (AF) is a guideline to define components needed to develop and operate enterprise architecture (EA), and to define relationships among the components. There are many architecture frameworks to operate EA of governments and businesses such as Zachman framework, DoDAF, TOGAF, FEAF, and TEAF. DoDAF is the most representative AF to support the development of the EA in the military domain. DoDAF is composed of eight viewpoints and 40 views that are affiliated with the viewpoints. To develop an AF for a specific goal, system architects decide a set of views. Furthermore, they determine data that are needed for a view modeling. However, views and data in DoDAF are structurally inter-related explicitly and/or implicitly. So, developing an AF for a specific goal is going to be a project to be carried out over a long haul. To reduce the burden of its development, in this paper, we develop ONT-SAF (Ontology for DoDAF) that can infer inter-relationships like referential and transitive relationships and the sequences among the views. Furthermore, to promote reusability and consistency of the views and the data within an AF, we adopt the view-data separation strategy. ONT-DAT contains classes like 'viewpoint', 'view', 'data', 'expression method', and 'reference model', and 11 properties including 'hasView.' To prove the effectiveness of ONT-SAF, we perform a case study.