• Proceedings of the Korea Concrete Institute Conference
• /
• 1999.10a
• /
• pp.303-306
• /
• 1999

For the purpose of Military means, explosion proof concrete, which protect the structures from the damage due to the explosion of bomb and maintain its shape, is required to develop. Therefore, in this paper, mechanical and explosionproof properties of concrete are tested under various steel fiber contents and member size. According to the experimental results, compressive, tensile and flexural strength go up with the increase of fiber contents. Energy bearing capacities is higher with the increase of fiber contents. Especially, it is confirmed that slurry infiltrated fiber concrete (SIFCON) gains in high strength and has high energy bearing capacities. SIFCON is expected to apply in the construction of explosion proof structures.

• Proceedings of the Korean Society For Composite Materials Conference
• /
• 2001.05a
• /
• pp.254-257
• /
• 2001

An intensity-based optical fiber vibration sensor is applied to detect and evaluate damages and fiber failure of composites. The optical fiber vibration sensor is constructed by placing two cleaved fiber end, one of which is cantilevered in a hollow glass tube. The movement of the cantilevered section lags behind the rest of the sensor in response to an applied vibration and the amount of light coupled between the two fibers is thereby modulated. Vibration characteristics of the optical fiber vibration sensor are investigated. Surface mounted optical fiber vibration sensor is used in tensile and indentation test. Experimental results show that the optical fiber sensor can detect damages and fiber failure of composites correctly.

• Proceedings of the Korean Society For Composite Materials Conference
• /
• 2002.05a
• /
• pp.151-154
• /
• 2002

The durability of two kinds of CFRP plates, carbon/UP and carbon/V, was studied under severe environmental conditions. Immersion into the chemical solutions and accelerated weathering were executed on the CFRP plates and the weight change under each condition was measured. After those treatments, the plates were tested by tensile testing machine to measure the mechanical properties and observed by SEM to find the damage behaviour of the surface. Comparing the virgin plates and the chemically exposed plates, both plates show severe deterioration of the mechanical properties. But, the plates subjected to alkali solution show much larger reduction than those of acidic solution and carbon/V has better chemical resistance than carbon/UP. The material properties of CFRP plate exposed to the weathering were deteriorated linearly proportional to the exposure time.

• Journal of the Korean Ceramic Society
• /
• v.43 no.7 s.290
• /
• pp.415-420
• /
• 2006

The residual stresses in the interface region of the Thermal Barrier Coating (TBC)/Thermally Grown Oxide (TGO)/Bond Coat (BC) were calculated on the TBC-coated superalloy samples using a Finite Element Method (FEM). It was found that the stress distribution of the interface boundary was dependent upon mainly the geometrical shape or its aspect ratio and the thickness of TGO layer, which was formed by growth and swelling behavior of oxide layer. Maximum compressive residual stress in the TBC/TGO interface is higher than that of the TGO/bond coat interface, and the tensile stress had nothing to do with change of an aspect ratio. The compressive residual stresses in the TBC/TGO and TGO/bond coat interface region increased gradually with the TGO growth.

• Journal of the Korea Institute of Building Construction
• /
• v.7 no.1 s.23
• /
• pp.85-90
• /
• 2007

According as industry develops rapidly, problem of resources exhaustion and environmental pollution is appearing. Way to use construction waste that is development of new compound material and Industry product is required. Limestone powder that is Industry product is $CaCO_3$. and vicosity is promotion effect because there is no damage to hydration of cement and powder is very thin and water tightness increases. This research purposed to analyze concrete property changing limestone fineness. According as the limestone powdered replacement ratio increases, slump and unit capacity mass increased, and the air content decreased according as the replacement ratio increases. Compressive strength and tensile strength decreased according as the limestone powder replacement ratio increases.

• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.33 no.2
• /
• pp.81-86
• /
• 2001

The functions of food packaging are not only prevention from physical damage and loss during carrying and transportation, but also extension of shelf-life by adding antimicrobial substrate in packaging materials. Consumption of active packaging is gradually increasing. With different dosage of potassium sorbate(P.S.), the food preservative agent, antimicrobial papers were made by internal and external application of starch. The antimicrobial action of the paper was analyzed by the halo test and the shake flask method. The mechanical properties and strength were also measured. Antimicrobial papers adding P.S. showed higher values in tensile index than adding starch. The antimicrobial paper using starch showed similar microbe decreasing rate as that using P.S. Though microbe decreasing rate was 21.9%, it showed possibility to make antimicrobial paper using food preservative.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2004.05a
• /
• pp.364-367
• /
• 2004

The purpose of this study is to investigate quality of recycled fine aggregate manufactured by drying manufacturing system which is the manufacture method of high quality recycled fine aggregate, and to analyze on the fresh, hardened and durability properties of recycled concrete using it. Therefore it is to present the fundamental data for structural application of recycled concrete. The results of this study are as follows; Quality of recycled fine aggregate by drying manufacturing system is improved, and compressive and tensile strength of recycled concrete using high quality recycled fine aggregate are similar to those of normal concrete. But, durability such as carbonation, salt damage and dry shrinkage show decreased somewhat.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.23 no.7
• /
• pp.987-997
• /
• 1999

The purpose of this study was finding out the appropriate cleaning method for buried fabrics from old tombs focusing on the conservation of textiles. Cleaning effects and physical properties change depending on cleaning method have been analysed, The following results were obtained from this study : 1. Wet cleaning showed better effect on the cleaning of fabrics compared to solvent cleaning which meant more water-soluble soils existed than oily soils. 2. All the cleaning methods used did not cause any distorsion or shrinkage to the fabrics because fabrics had been stabilized for a long time 3. Addition of detergent to cleaning system decreased the friction of fiber during cleaning rocess so that the damage of fabrics could be minimized., 4. Ironing is an undesirable process because heat remarkably weakened fibers.

• Journal of Sericultural and Entomological Science
• /
• v.38 no.2
• /
• pp.168-174
• /
• 1996

Dyeing on silk with vat dyes which shows good color fastness at strong alkaline conditions were newly examined. The optimum conditions of dyeing bath to prevent the damage on the tensile strength and elongation were sodium hydroxide(NaOH) 10g/l, sodium hydrosulfite(Na2S2O4) 20~22 g/l, for 30 min at 5$0^{\circ}C$. The color yield of silk fabrics was increase according to the concentration of NaOH and Na2S2O4, but decreased at higher concentration than that of NaOH 10g/l and Na2S2O4 22g/l. The vat dyeings showed excellent color fastness against washing and light, compared with the conventional dyeings.

• Journal of Ocean Engineering and Technology
• /
• v.7 no.2
• /
• pp.103-113
• /
• 1993

X-ray diffraction analysis technique was used for the fatigue damage analysis and fatigue life prediction in Al 7075-T651 alloy. The tensile test, fatigue strength and fatigue crack propagation test with change of stress ratio were carried out. As a result, half-value breadth was increased with the plastic deformation in the specimen increasint at all test conditions. In particular, half-value breadth at the surface of the specimens fractured by fatigue was increased as stress intensity factor range and effective stress intensity factor range were increased. In addition, the good relationship between half-value breadty and diffraction pattern was shown.