• Bulletin of the Korean Chemical Society
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• 제20권4호
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• pp.417-421
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• 1999

The complex, K3[La(TTHA)]5H,O, was prepared and its crystal structure was analyzed by single crystal X-ray diffraction method. In the complex, the La(Ⅲ) ion adopts a ten-coordinate geometry with four nitrogen atoms and six carboxyl oxygen atoms from the same TTHA ligand molecule. Its coordination polyhedron can be described as a distorted bicapped square antiprism. Each [La(TTHA)]3- anion is linked by K+ cations via carboxyl groups of TTHA ligand to form a three dimensional crystal structure. The thermal properties were investigated by TG and DTA techniques in argon atmosphere. The materials resulting from thermal treatment were La(OH)3 and K2O which were identified by powder X-ray diffraction technique.

• 한국섬유공학회:학술대회논문집
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• 한국섬유공학회 1997년도 춘계학술발표회 논문집
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• pp.1-5
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• 1997

• 한국섬유공학회:학술대회논문집
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• 한국섬유공학회 1991년도 제2차 학술발표초록집
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• pp.23-23
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• 1991

• Bulletin of the Korean Chemical Society
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• 제33권10호
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• pp.3317-3320
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• 2012

A novel energetic compound, bifurazano[3,4-b:3',4'-f]furoxano[3'',4''-d] oxacyclohetpatriene (BFFO), was synthesized through special etherification and its structure was determined by single crystal X-ray diffraction. The crystal of $BFFO{\cdot}H_2O$ is monoclinic, space group P2(1)/c with crystal parameters of a = $9.324(4){\AA}$, b = $9.727(4){\AA}$, c = $10.391(4){\AA}$, ${\beta}=106.305(6)^{\circ}$, V = $904.5(6){\AA}^3$, Z = 4, ${\mu}=0.17mm^{-1}$, F(000) = 512 and $D_c=1.866g\;cm^{-3}$. Spectroscopic properties and thermal behaviors of BFFO were studied. BFFO presents good detonation properties.

• International Journal of Industrial Entomology and Biomaterials
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• 제18권2호
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• pp.131-134
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• 2009

The purpose of this study was to establish whether there are differences in the productivity of the same silkworm(Bombyx mori L.) parthenoclones, obtained by two different methods-thermal and combined, as well as to study their genotype structure by several enzyme loci. It was established that all individuals of parthenoclones Joana, Joana(${\downarrow}{\uparrow}$), Pohi and Pohi(${\downarrow}{\uparrow}$), are homozygous by the studied esterase and phosphoglucomutase loci, which substantiated the clones' genetic stability. By comparative analysis of some biological and technological properties, it was found that parthenoclone Pohi(${\downarrow}{\uparrow}$) obtained by low-high temperature activation is characterized by higher values of these properties as compared to parthenoclone Pohi obtained by thermal parthenogenesis. Comparing the two methods of inducing ameiotic parthenogenetic development, we would recommend that parthenoclone Joana is sustained by thermal parthenogenesis, and parthenoclone Pohi-by the combined method (low-high temperature).

• 폴리머
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• 제26권3호
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• pp.344-352
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• 2002

본 연구에서는 두 가지 열잠재성 양이온 촉매인 triphenyl benzyl phosphoinium hexa-fluoroantimonate (TBPH)와 benzyl 2-methylpyrazinium hexafluoroantimonate (BMPH)를 새로이 합성하였다. 그리핀 TBPH 혹은 BMPH 1 phr에 의해 개시되어진 이관능성 에폭시 수지(diglycidylether of bisphenol A, DGEBA)의 열 및 기계적 특성들을 연구하였다. 그 실험적인 결과들로서, 에폭시/TBPH 시스템은 에폭시/BMPH 시스템 보다 더 높은 경화 온도와 임계응력 세기인자 ($K_{IC}$) 값을 보였다. 이것은 TBPH에서 4개의 페닐기의 느린 열확산 속도와 벌크 구조 때문으로 사료된다. 그러나, Coats-Redfern 방법에 의하여 결정된 분해 활성화 에너지는 TBPH의 경우가 더 낮게 나타났다. 이러한 결과는 TBPH의 입체장애에 의해서 끊어진 짧은 사슬 구조가 발달되었기 때문인 것으로 사료된다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.1
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• pp.461-464
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• 2004

In this paper, the elastic epoxy added elastomer having viscoelasticity to existing epoxy was measured thermal, structural properties through TGA(Thermogravimetric Analysis) and FESEM(Field Emission Scanning Electron Microscope). Specimens were made of dumbbell forms by the ratio of 5[phr], 10[phr], 15[phr], and 20[phr] by regulation with elastomer contents. The measurement temperature dimensions of TGA were $0[^{\circ}C]\;to\;800[^{\circ}C]$, and rising temperature was $5[^{\circ}C/min]$. And we observed structure through FESEM at the magnification of 1000times with the voltage of 15[kV] after breaking by quenching specimens. As thermal analysis results, we could know that thermal and structural properties was improved quantity according to decrease of elastomer contents. In general, thermal, structural properties of 15[phr] was excellent among the specimens.

• 한국재료학회지
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• 제16권5호
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• pp.292-296
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• 2006

Effects of rapid thermal annealing of bismuth telluride thin films on their thermoelectric properties were investigated. Films with four different compositions were elaborated by co-sputtering of Bi and Te targets. Rapid thermal treatments in range of $300{\sim}400^{\circ}C$ were carried out during 10 minutes under the reducing atmosphere (Ar with 10% $H_2$). As the temperature of thermal treatment increased, carrier concentrations of films decreased while their mobilities increased. These changes were clearly observed for the films close to the stoichiometric composition. Rapid thermal treatment was found to be effective in improving the thermoelectric properties of $Bi_2Te_3$ films. Recrystallization of $Bi_2Te_3$ phase has caused the enhancement of thermoelectric properties, along with the decrease of the carrier concentration. Maximum values of Seebeck coefficient and power factor were obtained for the films treated at $400^{\circ}C$ (about $-128{\mu}V/K$ and $9{\times}10^{-4}\;W/K^2m$, respectively). With further higher temperature ($500^{\circ}C$), thermoelectric properties deteriorated due to the evaporation of Te element and subsequent disruption of film's structure.

• 폴리머
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• 제39권2호
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• pp.200-209
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• 2015

In this study, the influence of dilauroyl peroxide on mechanical and thermal properties of different polypropylene (PP) matrices was investigated. Polypropylene matrices, different molecular weight isotactic PP containing 0.01, 0.02, 0.04, 0.06, 0.08, and 0.1 wt% of dilauroyl peroxide (DLP) were prepared by using a single-screw extruder. The effect of the visbreaking agent (DLP) on mechanical, physical, thermal and morphological properties of different molecular weight PP had been studied. Mechanical properties (tensile strength at break point, at yield and elongation at break point), melt flow index (MFI), scanning electron microscope (SEM) and differential scanning calorimetric (DSC) analyses of these matrices were examined. Melting ($T_m$) and crystallization ($T_c$) temperatures, crystallinity ratio (%) and enthalpies were determined. The microstructure of isotactic polypropylene matrix was investigated by scanning electron microscopy (SEM). From SEM analysis, it was observed that the surface disorder increased by the increasing amount of DLP. As a result of DSC analyses, the crystallinity ratio of the PP matrices has varied between 1.64-7.27%. Mechanical properties of the matrices have been improved. Particularly, the mechanical tests of PP have given interesting results when compounded with 0.06-0.08 wt% dilauroyl peroxide (DLP). Mechanical properties and thermal decomposition processes were all changed by increasing the amount of DLP in the matrix structure.

• 한국세라믹학회지
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• 제53권3호
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• pp.273-281
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• 2016

This review examines computational simulations of thermoelectric properties, such as electrical conductivity, Seebeck coefficient, and thermal conductivity. With increasing computing power and the development of several efficient simulation codes for electronic structure and transport properties calculations, we can evaluate all the thermoelectric properties within the first-principles calculations with the relaxation time approximation. This review presents the basic principles of electrical and thermal transport equations and how they evaluate properties from the first-principles calculations. As a model case, this review presents results on $Bi_2Te_3$ and Si. Even though there is still an unsolved parameter such as the relaxation time, the effectiveness of the computational simulations on the transport properties will provide much help to experimental scientist researching novel thermoelectric materials.