• Journal of the Korean Society of Industry Convergence
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• v.9 no.2
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• pp.141-145
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• 2006

In case of sense case manufactured by method of outage capacity, sensitivity is declined by outside effect and method of the photo electricity has a problem in transmission. therefore, packing case of composite sense should be developed to improve such a problem about influence of outside environment and its property evaluation has been performed. Mechanical property and result of analysis & test evaluation of Mat'l on aluminum die-casting(ADC 12type) Mat'l developed are as following. Tensile test piece, No. 4 of KS B 0801, has been applied to mechanical property test of Mat'l and It has been tested by method of metal mat'l tensile test(KS B 0802 : 2003). It can be found that physical property to KS(Korea Standard) is excellent. and homogeneous mechanical property appears. Test of Mat'l analysis has been performed by using OE Spectrometer, according to ASTM E 1251 : 1994 regulation. Consequently, good and homogeneous component contents classified by element to standard, except for Fe, have been obtained with coordination of Fe content as below 1.3% from composition standard of Aluminum Die-casting.

• Journal of the Korean Ceramic Society
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• v.30 no.6
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• pp.492-498
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• 1993

The pretreatment condition for uniform distribution of SiC whisker in A2O3-SiCw composites has been determined and the mechanical properties of the composites with various whisker contents have been measured. Good dispersion of the whisker can be obtained in a solution of pH=10.45 by ball milling and ultrasonic treatment. The relative density of hot pressed composites decreases with the whisker content up to 40vol%, but is found to be satisfactory, over 98% for all samples. The mechanical property of the composites is sensitive to the whisker dispersion. Uniform distributjion of the whisker is critical in order to guarantee good mechanical property.The samples containing 20~30vol% whisker show the best mechanical property within the studied range.

• Elastomers and Composites
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• v.52 no.1
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• pp.1-8
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• 2017

Hydrolysis resistance and mechanical property changes of polyketone (POK)/glass fiber (GF) composites were investigated for GF concentrations varying between 30 and 50%. The hydrolysis resistance of GF filled POK and polyamide66 (PA66, hydrolysis resistant grade) composites were compared. As shown by the experimental results, increasing the immersion time of the composites in a monoethylene glycol (MEG)/water solution at $120^{\circ}C$ had no impact or resulted in slightly decreased mechanical properties such as the tensile strength, tensile modulus, and strain at break in case of POK composites, whereas the mechanical properties of PA66 composites showed a significant drop. Increasing GF concentrations increased the tensile strength, tensile modulus, flexural strength, and flexural modulus of POK composites; however, impact strength did not show significant changes. Hydrolysis mechanisms of POK and PA66 are discussed.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.33 no.3
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• pp.196-200
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• 2009

Lithium niobate ($LN:LiNbO_3$) is a compound of niobium, lithium and oxygen. The characteristics of LN are piezoelectricity, ferroelectricity and photoelectricity, and which is widely used in surface acoustic wave (SAW). To manufacture LN devices, the LN surface should be a smooth surface and defect-free because of optical property, but the LN material is processed difficult b traditional processes such as grinding and mechanical polishing (MP) because of its brittleness. To decrease defects, chemical mechanical polishing (CMP) was applied to the LN wafer. In this study, the suitable parameters such as down force and relative velocity, were investigated for the LN CMP process To improve roughness, the LN CMP was performed using the parameters that were the highest removal rate among process parameters. And, evaluation of optical property was performed by the optical reflectance.

• Fashion & Textile Research Journal
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• v.12 no.4
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• pp.494-499
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• 2010

Knitted fabrics are very popular for their numerous advantages such as greater comfort, attractive garment appearance, better fit on the body, etc. In this study, we investigated the mechanical properties and abrasion property of warp knitted fabrics for footwear which treated with several softeners to improve abrasion resistance. The antistatic softener among the various softeners showed high improvement in abrasion resistance. Among the mechanical properties with treating conditions, WT (tensile energy), G (shear stiffness), B (bending rigidity) increased as treating timeincreased. But the other mechanical properties were little changed with treating concentration.

• Fashion & Textile Research Journal
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• v.19 no.2
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• pp.240-248
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• 2017

This study compares general jacquard fabrics and jacquard fabrics with optical fiber on mechanical properties, sensibility and preference evaluation of fabric for the blind. The analysis also assesses the effect of optical fiber in the evaluation and identifies those best suited for consumers. The mechanical properties of jacquard fabrics were measured by the KES-FB system. Sensibility and the preference of the jacquard fabric for the blind were rated on tactile sensation by women experts in their 20's and 30's. It was found that the optical fiber in jacquard fabric affected the change of mechanical properties as well as sensibility and preference. Jacquard fabric with optical fiber were softer and more transformable, while the fabrics had lower recover property by shear force and compression as well as more violent unevenness. Jacquard fabrics were also classified into three hand factors of surface property, resilience and weightiness. There were significant differences on surface property perceptions and weightiness, hand and blind preferences by optical fiber. Jacquard fabrics that contained optical fiber were not preferred by the blind because they were perceived to be uneven and heavy. Those, that were smooth and light, were preferred for jacquard fabric; in addition, fabrics preferred by the blind had good compression.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.20 no.9
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• pp.3015-3029
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• 1996

The notion of effective transport property of a heterogeneous medium implies that the medium is large enough that the ergodic theorem holds and local fluctuation of the property can be neglected. In case that the medium is not large enough compared to its characteristic microstructure length scale, the effective property fluctuates and differs from the value of the medium being large enough. As a representative transport phenomenon, diffusion was considered and the fluctuation of varying effective diffusion property, diffusion coarseness $C_k$, was defined as a quantifying parameter. Scaled effective diffusion property, $^*$>/k$_1$ and $C_k$ were computed for the two phase random media consisting of matrix of diffusion coefficient k$_1$ and spheres of diffusion coefficient k$_2$. Numerical simulations were performed by use of the so-called first passage time technique and data were collected for existing microstructure models of hard spheres(HS), overlapping spheres(OS) and penetrable concentric shells(PCS).

• Journal of the Korean Society of Clothing and Textiles
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• v.19 no.4
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• pp.671-683
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• 1995

This paper described the changes of mechanical KES values after fusing 4 different (in weave & density) wool face fabrics with 3 different (in weave & extensibility) fusible interlining. The fusing condition was 15$0^{\circ}C$, 4kg.f/cm2 The results of the study were as follows: (1) After fusing, KES mechanical value of B, 2HB, G, 2HGS, WC increased, where as LT, WT werent't changed so much and EM, RT decreased. It means after fusing extensibility and recovery property were decreased and volume and stiffness were increased. (2) Within the limits of this investigation, tensile property seemed to be more influenced by the characteristics of face fabrics, and bending property nil by the effect of adhesive penetration and shear and compression property did by complex of the characteristics of face fabrics and interlining and the effect of adhesive penetration.

• Proceedings of the Korean Fiber Society Conference
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• 1998.10a
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• pp.33-36
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• 1998

Segmented block copolyetheresters defined as copolymers having sequences of alternating polyester hard blocks and polyether soft blocks create labile physical cross-links upon crystallization of hard polyester blocks Since the nature of the physical interlocking is a crystallite formed exclusively from the crystallizable hard segment, the hard segment content (HSC) and hard segment length (HSL) will play an important role in determining the properties such as mechanical property and dynamic mechanical property. (omitted)

• Applied Chemistry for Engineering
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• v.24 no.2
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• pp.138-143
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• 2013

This paper studied the possibility to predict a mechanical property variation from changes in created carbonyl bands by irradiating the surface of high-density polyethylene with short-wavelength ultraviolet radiation of 254 nm to induce a fast chemical degradation. The meaning of this study lies in checking whether a mechanical property change with the same chemical property as the induced optical deterioration is caused by using a UVC lamp with high photon energy instead of optical deterioration via xenon arc light source and outdoor exposure test via natural sunlight requiring a long time. The mechanical strength of high-density polyethylene checked by a tensile test and a creep destruction test showed a similar tendency with CI changes. In particular, the yield strength and elongation had a close relationship with the exposure time to ultraviolet radiation. Accordingly, this paper presented a method to grasp the mechanical property change outdoors requiring a long time more fast through the relationship between the mechanical property change and the carbonyl index using a UVC lamp causing the fast surface degradation.