• Journal of the Korean Society of Industry Convergence
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• v.4 no.4
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• pp.413-418
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• 2001

The change of crystalline structure and mechanical properties of drawn PP filaments which was treated by tensioned and non-tensioned annealing was investigated. Measurements were carried out with XRD for crystallite size, density gradient tube for crystallinity. and UTM for mechanical properties. Tensioend and non-tensioned annealing were carried out $80^{\circ}C$, $100^{\circ}C$, $120^{\circ}C$: for 10min., 30min., 60min, in oil bath. It was found that the crystallinity and crystallite size of (110) plane of samples were increased with increasing of annealed temperature and time. Also crystallinity and crystallite size of samples which was tensioned annealing were larger than those of non-tensioned annealed samples. Initial modulus and tensile strength of tensioned annealed samples were higher than non-tensioned annealed samples, But elongation of tensioned annealed samples was lower than non-tensioned annealed samples.

• 한국정보디스플레이학회:학술대회논문집
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• 2002.08a
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• pp.670-673
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• 2002

We have investigated the catalyst effect on the growth and structure of CNTs using thermal chemical vapor deposition. The respective growth rate of CNTs shows that the performance of catalysts is in the order of nickel (Ni)>cobalt (Co)>iron (Fe). The average diameter of CNTs follows the sequence of Fe, Co, and Ni catalysts. The structure of CNTs reveals almost same morphology regardless of catalyst but the crystallinity of CNTs is largely dependent on catalyst. The crystallinity of CNTs synthesized from Fe catalyst is higher than that from Ni or Co catalyst. We demonstrate that the growth rate, the diameter, and the crystallinity of CNTs can be manipulated by selecting the catalysts.

• Journal of the Korean Wood Science and Technology
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• v.21 no.4
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• pp.73-78
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• 1993

Crystal structure of tension, opposite and lateral wood of Platanus orientalis L. were analysed in some aspects of crystallinity index, crystallite size, d-spacing of (200) and (004), and integrated intensity ratios with X-ray diffraction method. Crystallinity index and crystallite width in tension wood appeared somewhat larger than opposite or lateral wood. However, d-spacing and integrated intensity ratios were nearly identical irrespective of tension, opposite, and lateral wood.

• Journal of the Korean Society of Clothing and Textiles
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• v.27 no.9_10
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• pp.1144-1152
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• 2003

Kenaf has been cultivated in Jeju Island. After being harvested at 105 DAP(day after planting) and separated from kenaf stalks , decorticated kenaf basts were treated with different concentration/temperature/time combinations in order to do chemical rotting. The following fiber properties were compared; rotting effects, colors, crystallinity, molecular structures, dyeabilities, and non-cellulose contents such as pectins, lignins, & hemicellulose. The best results of chemical rotting were obtained from the specimens treated with low concentration/ low temperature/short time. Their colors were bright yellow. The lumens of specimens diminished with the affect of NaOH. The structures of chemically rotted kenaf fibers were cellulose 1. The degree of crystallinity of chemically retted kenaf fibers were very high. Non-cellulose content, especially hemicellulose, was low in the specimens treated with the high NaOH concentration. Dyeabilities of kenaf fibers were higher among the specimens without the non-cellulose content than those with the non-cellulose content.

• Journal of the Korean institute of surface engineering
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• v.37 no.3
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• pp.164-168
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• 2004

Polycrystalline silicon thin films were deposited by inductively coupled plasma (ICP) assisted magnetron sputtering using a gas mixture of Ar and $H_2$ on a glass substrate at $250^{\circ}C$. At constant Ar mass flow rate of 10 sccm, the working pressure was changed between 10mTorr and 70mTorr with changing $H_2$ flow rate. The effects of RF power applied to ICP coil and $Ar/H_2$ gas mixing ratio on the properties of the deposited Si films were investigated. The crystallinity was evaluated by both X-ray diffraction and Raman spectroscopy. From the results of Raman spectroscopy, the crystallinity was improved as hydrogen mixing ratio was increased up to$ Ar/H_2$=10/16 sccm; the maximum crystalline fraction was 74% at this condition. When RF power applied to ICP coil was increased, the crystallinity was also increased around 78%. In order to investigate the surface roughness of the deposited films, Atomic Force Microscopy was used.

• Advanced Composite Materials
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• v.18 no.3
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• pp.287-295
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• 2009

$\beta$-Tricalcium phosphate ($\beta$-TCP) particles reinforced bioresorbable plastics poly-L-lactide (PLLA) composites were prepared by injection molding. The nominal weight ratio of $\beta$-TCP was selected as 5, 10 and 15%. In order to clarify effects of the PLLA crystallinity on the mechanical properties, the specimens were heat treated isothermally. Results of differential scanning calorimetry indicated that the PLLA crystallinity increased with increasing heat treatment temperature. Bending and compressive tests were conducted on the specimen with different $\beta$-TCP contents and crystallinities. The results show that the bending and compressive moduli increased with increasing $\beta$-TCP contents and crystallinity. On the other hand, bending strength decreased with increasing $\beta$-TCP contents. Maximum bending strength was obtained at the heat treatment of $70^{\circ}C$ for 24 h, whereas compressive 0.2% proof strength increased with increasing heat treatment temperature. This difference is attributed to the difference in the microscopic damages.

• Journal of Electrochemical Science and Technology
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• v.8 no.1
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• pp.69-76
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• 2017

Crystallization of one-dimensional porous tin oxide during the anodic oxidation of tin at ambient temperatures is reported. Remarkable crystallinity is achieved when a substrate with a high elastic modulus (e.g., silicon) is used and the tin coating on it is very thin. It is suggested that the compressive stress applied to the anodic tin oxide during the anodization process is the key factor affecting the degree of crystallinity. The measured value of the stress generated during anodization matches well with the range of the most favorable theoretical pressure (stress) for crystallization.

• Journal of the Korean Ceramic Society
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• v.29 no.10
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• pp.779-784
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• 1992

In producing cordierite glass-ceramics by sintering, following experiments were conducted in order to determine the optimum heat-treatment schedule for high-crystallinity and dense sintered body. The glass composition of 11.67MgO-29.46Al2O3-52.88SiO2-5P2O5-1B2O3 (wt%) was selected on the basis of the early experiment. The 3-step heat treatment schedule was determined by the results of DTA, Dilatometric measurement and high-temperature XRD, where the particle-size-controlled glass powder was used. The degree of densification and the crystallinity were evaluated by the measurement of the bulk density and X-ray scattering intensity. The specimen fired with the optimum conditions showed ${\alpha}$-cordierite phase, relative density ∼98%, crystallinity ∼92%, thermal expansion coefficient ∼30${\times}$10-7/$^{\circ}C$, dielectric constant ∼5.5 and resistivity ∼1.0${\times}$1012 {{{{ OMEGA }}cm, respectively.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.43 no.4
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• pp.601-606
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• 1994

This paper describes the effect of elongation on electrical properties and molecular structrue of high density polyethylene. Thin polyethylene films films obtained dy roll elongation after extruded at 220$^{\circ}C$ and elongated to draw rations of 16. Crystallinity of polyethylene films was measured by X-Ray diffraction and electrical properties were estimated by conductivity and TSC(Thermal Simulated Current). It was foung that the crystallinity increases and the electrical conductivity decreases as the elongation increases. The elongation dependence of electrical conductivity may be explained by the trap density. Thus, the control of polymer structure and crystallinity makes its properties better and can be applicated in order to get more active properties.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.11 no.10
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• pp.809-814
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• 1998

In this study, the metastable state diamond thin films have been deposited on Si substrates from methand-hydrogen and oxygen mixture usin gMicrowave Plasma Enhanced Chemical Vapor Deposition (MWPCVD) method. effects experimental parameters MWPCVD including methan concentrations, oxygen additions, operating pressure, deposition time on the growth rate and crystallinity were investigated. diamond thin film was synthesized under the following conditions: methane concentration of 0.5%(0.5sccm)∼5%(5sccm). oxygen concentration of 0∼80%(2.4sccm). operating pressure of 30Torr∼ 70Torr, deposition time of 1∼32hr. SEM, WRD, and Raman spectroscopy were employed to analyse the growth rate and morphology, crystallinity and prefered growth direction, and relative amounts of diamond and non=diamond phases respectively.