• Korean Journal of Materials Research
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• v.13 no.3
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• pp.150-154
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• 2003

Amorphous carbon nitride films were deposited on Si(001) substrates by a plasma enhanced chemical vapor deposition technique (PECVD) using $CH_4$and $N_2$as reaction gases. The growth and film properties were investigated while the gas ratio and the working pressure were changed systematically. At 1 Torr working pressure, an increase in the $N_2$partial pressure results in a significant increase of the deposition rate as well as an apparent presence of C ≡N bonding, while little affecting the microstructure and amorphus nature of the films. In the case of changing the working pressure at a fixed $N_2$partial pressure of 98%, a film grown at a medium pressure of $1${\times}$10^{-2}$ Torr shows the most prominent C=N bonding nature and photoluminescent property.

• Journal of the Korean Society for Heat Treatment
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• v.14 no.6
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• pp.345-349
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• 2001

This study has investigated the effect of thermal stability and mechanical property of $Fe_{80-X}P_{10}C_6B_4M_X$(X=2, 4, 6, M=transition metal) amorphous alloys fabricated by the melt-spun process. The glass transition temperature($T_g$), crystallization temperature($T_x$) and hardness increase with decreasing electron concentration (e/a) from about 7.38 to 7.18. The decrease of e/a implies the increase in the attractive bonding state between the M elements and other constituent element. The decrease in a/e leads to the enhancement of the attractive bonding state among the constituent elements which is favorable for the increase in $T_g$, $T_x$ and hardness.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.42 no.2
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• pp.41-45
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• 2010

This study was performed to evaluate the effect of paper property changes by internal addition of surface strength agent on printability. Advances in printing technique has required the development of paper qualities in many aspects. Basically paper structure is composed of hydrogen bonds which induce many problems in high speed printing machine because of weak bonding strength. One of the important printing problems is surface picking when mechanical pulp or recycled pulp are used. It was caused by the ink-stained blanket in printing process because accumulations of pollutant in white water and other elements which are bonded weakly or do not have hydrogen bonds. Debris at paper surface adheres to blanket which deteriorates printing efficiency and causes various problems. To complement these problems, Pennocel 5137 of polysaccharide structure was used as an agent to improve paper's surface property, strength and printability. Paper surface picking was analyzed by RI-1 test. As the dosage amount increased tensile strength, fiber bonding strength and ZDT strength were improved. Further more formation, smoothness and surface picking resistance were improved. It was confirmed that when adding polysaccharide structure polymers to improve surface strength such as surface picking resistance, it was also possible to improve tensile strength, fiber bonding strength, formation and smoothness.

• The Research Journal of the Costume Culture
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• v.25 no.4
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• pp.448-457
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• 2017

This study aims to analyze the changes in the mechanical properties of interlock fabrics knitted with three types of fibers (i.e., cotton, wool, and polyester) by bonding fusible interlinings with varying deniers (i.e., 10D, 20D, and 30D) for a 3D virtual try-on system. We experimented with four properties and thicknesses of twelve specimens of interlining bonded knitted fabrics including face fabrics and interlinings. The results showed that the tensile property changed values (i.e., LT increased, and WT and RT decreased) according to the denier of interlinings; however, the change was slight. On the other hand, the bending property increased significantly as the denier of the interlining increased on both the wale and the course. Among shearing properties, the value of G increased as the denier of the interlining increased on both the wale and the weft; however, 2HG decreased. Additionally, changes in the compression property varied according to the fibers and the denier of the interlinings. The thickness of the knitted fabrics increased or decreased slightly by bonding the interlining. based on these results, we conclude that the 3D virtual system users need to reflect these numerical changes of interlock fabrics by bonding interlinings when they perform fitting tasks on the screen to accurately express the to accurately express the manufacturing conditions of the real garment.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 1996.04a
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• pp.73-87
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• 1996

The outer-most electrons of metal atoms and the remining valence electrons of any molecular atoms make three dimensional crystallizing $\pi$-bondings. The electrons on the $\pi$-bonding orbital rotate clockwise or counter-clockwise and they then make electro-magnetic waves between atoms on the orbital because electron move between plus charged ions. The three dimensional crystallizing $\pi$-bonding orbitals are quantum-mechanically modeled by a cyclic Kronig-Penny Model and energy band structures are analyzed with their potential barrier thickness. The waves generated between plus charged ions are the particular $\pi$-far infrared rays, which have dual properties between material and electro-magnetic waves and can be measured not by modern electro-magnetic tester but biosensor such as finger's force tester. Because the $\pi$-rays can be modulated with electro-magnetic waves it can be applied for harmful electro-magnetic wave killers. Because the $\pi$-rays make new three dimensional crystallizing $\pi$-bonding orbitals in the material the food and drink can be transformed into a helpful physical constitutional property for human health. Distinction between crystalline and amorphous metals is possible because very strong crystalline $\pi$-bonding orbitals can not easily be transformed into another. The $\pi$-rays can also be applied for biofunctional diagnostics and therapy. Gravitational field is one of the electro-magnetic fields. And also magnetic field and gravitational force field make charge's movement. ($\times$ = q, : magnetic field, : force field, q: plus charge, : velocity field)

• Composites Research
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• v.36 no.4
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• pp.246-252
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• 2023

A secondary barrier made of glass fiber reinforced composites has been installed infinitely using automatic bonding machine(ABM) in membrane type LNG cargo containment system (CCS). At the same time, significant thermal stress due to cryogenic heat shrinkage has occurred in the composite on the non-bonding area between the adhesive fixation at both ends. There have been studies from the perspective of structural safety evaluation taking this into account, but none that have analyzed mechanical property taking an prolonged length into account. In this study, 2-parameter Weibull distribution statistical analysis was used to standardize reliable mechanical property for actual length, taking into account the composite's brittle fracture of ceramic material with wide fracture strength dispersion. Related experimental data were obtained by performing uniaxial tensile tests at specific temperatures below cryogenic condition considering LNG environment. As a result, the mechanical strength increased about 1.5 times compared to -20℃ at -70℃ and initial non-linear behavior of fiber stretched was suppressed. As the temperature decreased until the cryogenic, the mechanical strength continued to increase due to cold brittleness. The suggested mechanical property in this study would be employed to secure reliable analysis support material property when assessing the safety of secondary barrier's structures.

• Restorative Dentistry and Endodontics
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• v.23 no.1
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• pp.413-423
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• 1998

Dental ceramics exhibit excellent esthetic property, compressive strength, chemical durability, biocompatibility and translucency. This study evaluated the shear bond strength of composite resin to the new heat-pressed ceramic material (IPS-Empress System) depending on the surface treatments and bonding agents. The surface treatments were etching with 4.0% hydrofluoric acid, application of silane, and the combination of the two methods. Composite resin was bonded to ceramic with four kinds of dentin bonding agents(All-Bond 2, Heliobond, Scotch bond Multi-purpose and Tenure bonding agents). The ceramic specimen bonded with composite resin was mounted in the testing jig, and the universal testing machine(Zwick 020, Germany) was used to measure the shear bond strength with the cross head speed of 0.5 mm/min. The results obtained were as follows 1. The mean shear bond strength of the specimens of which the ceramic surface was treated with the combination of hydrofluoric acid and silane before bonding composite resin was significantly higher than those of the other surface treatment groups(p<0.05). 2. In the case of All-Bond 2 and Scotchbond Multi-purpose bonding agent group, the surface treatment methods did not influenced significantly on the shear bond(p>0.05). 3. Of the four bonding agents tested, the shear bond strength of Heliobond was significantly lower than those of other bonding agents regardless of the surface treatment methods(p<0.05). 4. The highest shear bond strength($12.55{\pm}1.92$ MPa) was obtained with Scotchbond Multipurpose preceded by the ceramic surface treatment with the combination of 4% hydrofluoric acid and silane.

• Macromolecular Research
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• v.16 no.5
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• pp.399-403
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• 2008

Monodisperse, micron-sized, hybrid particles having a core-shell structure were prepared by coating the surface of poly(methyl methacrylate)(PMMA) microspheres with silica and by copolymerizing acrylamide (AAm) to supply the hydrogen bonding effect by means of the amide groups. Tetraethoxysilane (TEOS) was then slowly dropped onto the medium under certain conditions. Because of the hydrogen bonding between the amide of the PMMA particles and the hydroxyl group of the hydrolyzed silanol, a silica shell was generated on the PMMA core particles. The morphology of the hybrid particles was investigated with transmission (TEM) and scanning (SEM) electron microscopy as a function of the medium conditions and the amount of TEOS. Improved thermal properties were observed by TGA analysis.

• Korean Journal of Materials Research
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• v.15 no.4
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• pp.240-245
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• 2005

An oxygen free copper was severely deformed by accumulative roll-bonding (ARB) process for improvement of its mechanical properties. Two copper sheets 1 m thick, 30 mm wide and 300 m long are first degreased and wire-brushed for sound bonding. The sheets are then stacked to each other, and roll-bonded by about $50\%$ reduction rolling without lubrication at ambient temperature. The bonded sheet is then cut to the two pieces of same dimensions and the same procedure was repeated to the sheets up to eight cycles $(\varepsilon-6.4)$. TEM observation revealed that ultrafine grains were developed after the third cycle, and their size was slightly increased at higher cycles. Tensile strength of the copper increased with the strain at low strain levels, but it hardly increased from 3 cycles $(\varepsilon>2.4)$ due to occurrence of dynamic recovery, even if the imposed strain increased.

• Transactions of Materials Processing
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• v.27 no.5
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• pp.267-275
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• 2018

The clad sheet material is produced by a roll-bonding process of one or more materials with different properties. Good formability of clad sheet material is an essential property in to deform a clad metal sheet into a part or component. Performance of the clad sheet material largely depends on interfacial bond strength between different materials. In this study, interfacial bond strength of STS/Al clad sheet was analyzed by varying experimental parameters using a blanking process. Experimental parameters are the punching speed, clearance, and stacking order of plate materials. In addition, blanking test results were compared with bond strengths measured by the T-peel test, that analyzes interface bonding strength of the standard clad sheet. The blanking process was analyzed by the finite element method under the sticking condition of interface of different materials, and experimental results and analysis results were compared.