• Journal of Powder Materials
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• v.12 no.5 s.52
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• pp.357-361
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• 2005

Fe-doped skutterudite $CoSb_3$ with a nominal composition of $Fe_{x}Co_{4-x}Sb_{12}(0\;{\le}\;x\;{\le}\;2.5)$ has been synthesized by mechanical alloying (MA) of elemental powders, followed by hot pressing. Phase transformations during mechanical alloying and hot pressing were systematically investigated using XRD. Single phase skutterudite was successfully produced by vacuum hot pressing using as-milled powders without subsequent annealing. However, second phase in the form of marcasite structure $FeSb_2$ was found to exist in case of $x\;{\ge}\;2$, suggesting the solubility limit of Fe with Co in this system. Thermoelectric properties as functions of temperature and Fe contents were evaluated for the hot pressed specimens. Fe substitution up to x=1.5 with Co in $Fe_{x}Co_{4-x}Sb_{12}$ appeared to increase thermoelectric figure of merit (ZT) and the maximum ZT was found to be 0.78 at 525K in this study.

• Korean Journal of Materials Research
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• v.15 no.7
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• pp.453-457
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• 2005

Piezoelectric properties of $Pb(Mn_{1/3}Nb_{2/3})O_3-PbZrO_3-PbTiO_3$ ceramics were investigated with $Al_2O_3$ content $(0.0-1.0 wt\%)$. The constituent phases, microstructure, electromechanical coupling factor, dielectric constant, piezoelectric charge and voltage constants were analyzed. Diffraction peaks for (002) and (200) planes were identified by X-ray diffractometer for all the specimens doped with $Al_2O_3$, indicating the MPB (morphotropic phase boundary) composition of tetragonal structures. The highest sintered density of $7.8 g/cm^3$ was obtained for $0.2wt\%\;Al_2O_3-doped$ specimen. Grain size increased by doping $Al_2O_3$ up to $0.3 wt\%$, and it decreased by more doping. Electromechanical coupling factor, dielectric constant, piezoelectric charge and voltage constants increased by doping $Al_2O_3$ up to $0.2wt\%$, and it decreased by more doping. This might result from the formation of oxygen vacancies due to defects in $O^{2-}$ ion sites and the substitution of $Al^{3+}$ ions.

• Journal of the Korea Institute of Building Construction
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• v.7 no.2 s.24
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• pp.93-98
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• 2007

Waste of Plastic that is waste tile and waste interlocking block result, waste tile and waste interlocking block that execute an experiment to foretell practical use possibility availability as recycled aggregate for concrete giving change in the principal parts rate for coarse aggregate recycled aggregate appeared in the world by available thing to coarse aggregate to rate 10% but necessity that present amount used establishing material application standard that is crushed than uniform application standard to receive entropy of re-fresh concrete quality is judged to be.

• Journal of Korean Dental Science
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• v.5 no.1
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• pp.1-6
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• 2012

Patients with gingival overgrowth are easily seen in dental clinics. Cyclosporin-A (CsA), a widely prescribed immunosuppressant induces gingival overgrowth in up to 35% of patients with medical history of organ transplantation. The immunosuppressant CsA can transform genetic expression of gingival fibroblasts, resulting in gingival overgrowth. Meticulous plaque control is recommended for treatment of gingival overgrowth. Substitution of the drug or surgical procedures such as gingivectomy and periodontal flaps should be considered after re-evaluation. Azithromycin is often recommended as a supplementary drug to reduce this side effect. Recent studies show that tacrolimus can be a more economic, efficient and safe substitute for CsA.

• Journal of the Korean Society of Industry Convergence
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• v.27 no.3
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• pp.619-627
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• 2024

By analyzing the structure of the currently used Lead Tab tape structure, the outermost layer, low-temperature fusion functionalized olefin, was composed of pp base. To determine whether this could be used as the outermost layer of tab tape, the adhesive strength to metal foils such as copper and aluminum was measured and the adhesive strength was compared with commercially available functionalized olefin. When chlorine was grafted onto PP among the PP used in the composition, the average adhesive strength was similar to that of commercially available LT200T and superior to RE140R and LE320V. The maximum adhesive strength exceeded that of LE200T. When it comes to solvents, xylene has been shown to be better than any other. Physical methods such as substitution of other monomers, switching of additives or let-down hardly changed the adhesion of grafted PP, and the selection of PP is an important factor in preparing functional polymers.

• Environmental and Resource Economics Review
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• v.18 no.2
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• pp.345-375
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• 2009

In this paper we examined the impact of mineral resources industry on the national economy and necessity of a mineral resources cycle technology development. For this purpose, the case study on Gagok polymetallic (zinc-lead-copper) mine, which is being re-developed, was carried out to study an anticipated effects of application of the full cycle technology. As a consequences of the study, if we apply the technology to a polymetallic (zinc-lead-cooper) mine, we can expect 55 billion won worth of import-substitution effect. Moreover, if applied to 10 similar mines, we can expect the 10.4% of import-substitution effect of the total imports annually. Also, national competitiveness in value chain of mineral industry will be promoted through the technological advancement in upper stream and the full cycle technology will render a service to the mineral industry to be the country's new growth engine.

• International Journal of Concrete Structures and Materials
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• v.6 no.3
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• pp.145-153
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• 2012

The aim of this study is to explore the possibility of re-cycling a waste material that is now produced in large quantities, while achieving an improvement of the mechanical properties and durability of the mortar. This study examines the mechanical properties and the durability parameters of mortars incorporating plastics bag wastes (PBW) as fine aggregate by substitution of a variable percentage of sand (10, 20, 30 and 40 %). The influence of the PBW on the, compressive and flexural strength, drying shrinkage, fire resistance, sulfuric acid attack and chloride diffusion coefficient of the different mortars, has been investigated and analyzed in comparison to the control mortar. The results showed that the use of PBW enabled to reduce by 18-23 % the compressive strength of mortars containing 10 and 20 % of waste respectively, which remains always close to the reference mortar (made without waste). The replacement of sand by PBW in mortar slows down the penetration of chloride ions, improves the behavior of mortars in acidic medium and improves the sensitivity to cracking. The results of this investigation consolidate the idea of the use of PBW in the field of construction.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.18 no.2
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• pp.185-191
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• 2008

Optimal damping layout of the constrained viscoelastic damping layer on beam is identified with temperatures by using a gradient-based numerical search algorithm. An optimal design problem is defined in order to determine the constrained damping layer configuration. A finite element formulation is introduced to model the constrained layer damping beam. The four-parameter fractional derivative model and the Arrhenius shift factor are used to describe dynamic characteristics of viscoelastic material with respect to frequency and temperature. Frequency-dependent complex-valued eigenvalue problems are solved by using a simple re-substitution algorithm in order to obtain the loss factor of each mode and responses of the structure. The results of the numerical example show that the proposed method can reduce frequency responses of beam at peaks only by reconfiguring the layout of constrained damping layer within a limited weight constraint.

• Mycobiology
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• v.32 no.3
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• pp.119-122
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• 2004

The intergenic spacer(IGS) sequence of Fusarium oxysporum have been reported to provide reliable information concerning intraspecific variation and phylogeny of fungal species. The eleven strains of Fusarium oxysporum and its formae speciales belonging to section Elegans were compared with sequencing analysis. The direct sequencing of partial IGS was carried out using PCR with primer NIGS1(5'-CTTCGCCTCGATTTCCCCAA-3')/NIGS2(5'-TCGTCGCCGACAGTTTTCTG-3') and internal primer NIGS3(5'-TCGAGGATCGATTCGAGG-3')/NIGS4(5'-CCTCGAATCGATCCTCGA-3'). A single PCR product was found for each strain. The PCR fragments were sequenced and revealed a few within species polymorphisms at the sequence level. The size of partial IGS sequencing of F. oxysporum was divided into three groups; $526{\sim}527$ bp including F. o. f. sp. chrysanthemi, cucumerinum, cyclaminis, lycopersici, and fragariae; $514{\sim}516$ bp including F. o. f. sp. lilii, conglutinans, and raphani; 435 bp for F. o. f. sp. cucumerinum from Korea. Sequence analysis of PCR products showed that transitions were more frequent than transversions as well as the average numbers of substitution per site were range 0.41% to 3.54%.

• The Korean Journal of Food And Nutrition
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• v.32 no.4
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• pp.304-311
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• 2019

Ohmic heating is a heating method based on the principle when an electrical current passes through food. Since this method is internal, electrical current damage occurred during heating treatment. The results of ohmic heated starch's external structure, X-ray diffraction, DSC analysis and RVA were differed from those of conventional heating at the same temperature. Several starches changed more rigid by structure re-aggregation. This change in starch was caused by change of physical, chemical, rheological property. The rheology of ohmic heated potato and corn starch of different heated methods were compared with chemically modified starch. After gelatinization, sample starch suspension (2%, 3%) measured flow curves by rheometer. Cross-linked chemically modified starch's shear stress was decreased with degree of substitution reversibly. Ohmic heated more dramatic, at $60^{\circ}C$. Potato starch's shear stress was less than commercial high cross-linked modified starch. Flow curves of potato starches measured at $4^{\circ}C$, $10^{\circ}C$, $20^{\circ}C$. Showed that Ohmic heated potato starch's shear stress ranging between $4^{\circ}C$ and $20^{\circ}C$ was narrower than modified starch. According to this study, ohmic heated potato starch can be used by decreasing viscosity agent like cross-linked modified starch.