• The Research Journal of the Costume Culture
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• v.11 no.6
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• pp.967-971
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• 2003

As the concerns over health increased in 1990's, research and development on the health material were also activated. The development of UV-cut textile became the hot issue, because the damage of W irradiation due to ozone depletion has become widely known. UV-cut effect is determined by the material, the color, the organization and the density of UV-cut fibers. UV-cut effect is very different according to the fibers. Polyester is known to have a better effect. Even in the same textile material, staple fiber has more effect than filament fiber. Different colors have different offsets. Although textiles have the same color, the effects can be different according to the depth of color. PET, PET/cotton blend, nylon and cotton fabrics were ultraviolet cutting finished with padding method using several absorbers. These UV-cut effect can be improved through the processing. Safety of UV-cut textile for the body must be considered future, Until now the figure of the UV-cut effects has been emphasized. There has been no experiment on the human body, although the textiles are directly on the human body. Futhermore there os no safety standard of UV-cut textiles. Therefore every effort will be made to set the standard UV-cut processing is established. The need of UV-cut products will be known to the consumers.

• Composites Research
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• v.23 no.6
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• pp.7-13
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• 2010

Type3 cylinder is a composite pressure vessel fully over-wrapped with carbon/epoxy composite layers over an aluminum liner, which is the most ideal and safe high pressure gas container for CNG vehicles due to the lightweight and the leakage-before-burst characteristics. During service in CNG vehicle, if a fiber cut damage occurs in outer composite layers, it can degrade structural performance, reducing cycling life from the original design life. In this study, finite element modeling and analysis technique for the composite cylinder with fiber-cut crack damage is presented. Because FE analysis of type3 cylinder is path dependant due to plastic deformation of aluminum liner in autofrettage process, method to introduce a crack into FE model affect analysis result. A crack should be introduced after autofrettage in analysis step considering real circumstances where crack occurs during usage in service. For realistic simulation of this situation, FE modeling and analysis technique introducing a crack in the middle of analysis step is presented and the results are compared with usual FE analysis which has initial crack in the model from the beginning of analysis. Proposed analysis technique can be used effectively in the evaluation of influence of damage on composite layers of type3 cylinder and establish inspection criteria of composite cylinder in service.

• Composites Research
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• v.29 no.3
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• pp.111-116
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• 2016

The tilting pad journal bearing for the turbo compressor application has a role to support high speed and heavy loading rotor. White metal has been widely used for the bearing material but the conventional bearing is immediately suspended and induces serious serious damage to the rotor under the unexpected oil cut situation or the insufficient oil film formation. The carbon fiber reinforced composite having high specific stiffness, specific strength and excellent tribological characteristics can solve these seizure problems. In this work, the study on the durability of high thermal resistance carbon fiber/epoxy composite tilting pad journal bearing under oil cut situation was conducted. The material properties of the composite materials including tensile, compressive and interlaminar properties were measured at room and high temperature of oil cut situation. To investigate the possibility of failure of composite tilting pad journal bearing under oil cut situation, the stress distribution of the composite bearing was analyzed via finite element analysis and the Tsai-Wu Failure index was calculated. To verify the failure analysis results, the oil cut tests for the composite tilting pad journal bearing were conducted using industrial test bench.

• KIEE International Transactions on Electrophysics and Applications
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• v.2C no.6
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• pp.309-313
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• 2002

In this paper, we have studied minimization of the kerf-width and surface burning, which occurred after the conventional singulation process of the multi-layer BGA board with copper, polyethylene and epoxy glass fiber. The high thermal energy of a pulsed Nd:YAG laser is used to cut the multi-layer board. The most considerable matter in the laser cutting of the multi-layer BGA boards is their different absorption coefficient to the laser beam and their different heat conductivity. The cut mechanism of a multi-layer BGA board using a 2$^{nd}$ harmonic Nd:YAG laser is the thermal vaporization by high temperature rise based on the Gaussian profile and copper melting point. In this experiment, we found that the sacrifice layer and Na blowing are effective in minimizing the surface burning by the reaction between oxygen in the air and the laser beam. In addition, N2 blowing reduces laser energy loss by debris and suppresses surface oxidation. Also, the beam incidence on the epoxy layer compared to polyimide was much more suitable to reduce damage to polyimide with copper wire for the multi layer BGA singulation. When the polyester double-sided tape is used as a sacrifice layer, surface carbonization becomes less. The SEM, non-contact 3D inspector and high-resolution microscope are used to measure cut line-width and surface morphology.

• Journal of the Korea institute for structural maintenance and inspection
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• v.13 no.1 s.53
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• pp.69-77
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• 2009

An underwater structure is made to put with serious damage state by special environmental factors. If this damage phenomena persist, as for the structure, it is generated a structural serious problem because of the corrosion of a reinforcing bar and the loss of the concrete cut end. Repair work of an underwater structure is very harder than repair work in land, and it is actual that certification about a maintenance effect is uncertain. And the existing repair method is applied to a structure damaged with you without verification of a repair effect by a foreign reward and experience. In this study, a repair method about an underwater structure was proposed and observed a behavior characteristic and interface failure of an specimens. and comparison analyzed an effect of a proposed maintenance method.

• Nutrition Research and Practice
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• v.13 no.3
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• pp.205-213
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• 2019

BACKGROUND/OBJECTIVES: Myocardial infarction (MI) is caused by extensive myocardial damage attributed to the occlusion of coronary arteries. Our previous study in a rat model of ischemia/reperfusion (I/R) demonstrated that administration of arabinoxylan (AX), comprising arabinose and xylose, protects against myocardial injury. In this study, we undertook to investigate whether psyllium seed husk (PSH), a safe dietary fiber containing a high level of AX (> 50%), also imparts protection against myocardial injury in the same rat model. MATERIALS/METHODS: Rats were fed diets supplemented with PSH (1, 10, or 100 mg/kg/d) for 3 d. The rats were then subjected to 30 min ischemia through ligation of the left anterior descending coronary artery, followed by 3 h reperfusion through release of the ligation. The hearts were harvested and cut into four slices. To assess infarct size (IS), an index representing heart damage, the slices were stained with 2,3,5-triphenyltetrazolium chloride (TTC). To elucidate underlying mechanisms, Western blotting was performed for the slices. RESULTS: Supplementation with 10 or 100 mg/kg/d of PSH significantly reduces the IS. PSH supplementation (100 mg/kg/d) tends to reduce caspase-3 generation and increase BCL-2/BAX ratio. PSH supplementation also upregulates the expression of nuclear factor erythroid 2-related factor 2 (NRF2), and its target genes including antioxidant enzymes such as glutathione S-transferase mu 2 (GSTM2) and superoxide dismutase 2 (SOD2). PSH supplementation upregulates some sirtuins ($NAD^+$-dependent deacetylases) including SIRT5 (a mitochondrial sirtuin) and SIRT6 and SIRT7 (nuclear sirtuins). Finally, PSH supplementation upregulates the expression of protein kinase A (PKA), and increases phosphorylated cAMP response element-binding protein (CREB) (pCREB), a target protein of PKA. CONCLUSIONS: The results from this study indicate that PSH consumption reduces myocardial I/R injury in rats by inhibiting the apoptotic cascades through modulation of gene expression of several genes located upstream of apoptosis. Therefore, we believe that PSH can be developed as a functional food that would be beneficial in the prevention of MI.

• Journal of the Korean Society of Industry Convergence
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• v.23 no.5
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• pp.817-823
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• 2020

In recent, the machining of difficult-to-cut materials such as titanium alloys, stainless steel, Inconel, ceramic, glass, and carbon fiber reinforced plastics (CFRP) used in aerospace, automobile, medical industry is actively researched. Abrasive waterjet is a non-traditional processing method in which ultra-high pressure water and abrasive particles are mixed in a mixing chamber and shoot out jet through a nozzle, and removed by erosion due to collision with a material. In particular, the nozzle of the abrasive waterjet is one of the most important parts that affect the machining quality as with a cutting tool in general machining. It is very important to monitor the condition of the nozzle because the workpiece is uncut or the surface quality deteriorates due to wear, expanding of the bore, damage of the nozzle and clogging of the abrasive, etc. Therefore, in this paper, we propose a monitoring system based on Acoustic Emission(AE) sensor that can detect nozzle condition in real time during AWJ processing.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.1
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• pp.205-213
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• 2003

The fiber reinforced composite material is widely used in the multi-industrial field where the weight reduction of the infrastructure is demanded because of their high specific modulus and specific strength. It has two main merits which are to cut down energy by reducing weight and to prevent explosive damage preceding to the sudden bursting which is generated by the pressure leakage condition. Therefore, Pressure vessels using this composite material in comparison with conventional metal vessels can be applied in the field such as defense industry, aerospace industry and rocket motor case where lightweight and the high pressure are demanded. In this paper, for nonlinear finite element analysis of E-glass/epoxy filament winding composite pressure vessel receiving an internal pressure, the standard interpretation model is developed by using the ANSYS, general commercial software, which is verified as the accuracy and useful characteristic of the solution based on Auto LISP and ANSYS APDL. Both the preprocessor for doing exclusive analysis of filament winding composite pressure vessel and postprocessor that simplifies result of analysis have been developed to help the design engineers.

• Journal of Mechanical Science and Technology
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• v.18 no.6
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• pp.904-914
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• 2004

The fiber reinforced composite material is widely used in the multi-industrial field because of their high specific modulus and specific strength. It has two main merits which are to cut down energy by reducing weight and to prevent explosive damage proceeding to the sudden bursting which is generated by the pressure leakage condition. Therefore, Pressure vessels using this composite material can be applied in the field such as defence industry and aerospace industry. In this paper, for nonlinear finite element analysis of E-glass/epoxy filament winding of composite vessel subjected to internal pressure, the standard interpretation model is developed by using the ANSYS with AutoLISP and ANSYS APDL languages, general commercial software, which is verified as useful characteristic of the solution. Among the modules of the system, both the process planning module for carrying out the process planning of filament wound composite pressure vessel and the autofrettage process module for obtaining higher residual stress will minimize trial and error and reduce the period for developing new products. The system can serve as a valuable system for experts and as a dependable training aid for beginners.

• Journal of Korean Society on Water Environment
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• v.24 no.4
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• pp.423-429
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• 2008

Microfiltration (MF) and ultrafiltration (UF) processes for removal of particulate materials (i.e., turbidity, microorganisms and viruses) have been used to produce drinking water with higher quality. As membrane filtration technique has become widely applied for drinking water treatment, the importance of membrane integrity test (MIT) has also been increasingly emphasized. The results of pressure decay test (PDT) were presented in the paper to monitor membrane integrity. In this paper the PDT was carried out with deliberately-defected membrane fibers to evaluate the sensitivity of PDT on membrane fiber damage. Variation of pressure decay rate and removal rate were investigated to evaluate the impact of defection (defection ratio) and pore size of membrane. The membrane integrity could be successfully monitored by the PDT. The pressure decay rate varied from $0.002{\sim}0.189kg_f/cm^2hr$ with the initial pressure ranged from 0.2 to $1.0kg_f/cm^2hr$. Higher initial pressure which provided with higher pressure decay rate was preferred to evaluate the defection of membrane fiber. As for the particle removal rate, the Log Removal Rate (LRV) of kaolin solution decreased significantly from 3.78 to 2.31 when one fiber out of 3,200 fibers was cut. The membranes with different pore size were tested to evaluate virus removal efficiency. The virus removal rate of the MF membrane ($0.1{\mu}m$) was about 30% although the poliovirus was smaller than the pore size of the MF membrane, indicating that the removal rate was much lower than Korea Water Works Association (KWWA) certificate LRV of 1.5.