• Journal of Physiology & Pathology in Korean Medicine
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• v.23 no.6
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• pp.1261-1266
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• 2009

The wrinkle is a typical sign showing aging. These days lots of people want to have a young and healthy appearance and many medical doctors are studying about wrinkle cure. In fact a young face without wrinkle looks more healthy and energetic. Therefore the wrinkle cure is important at the point of medical view. This research is an investigation of several studies about wrinkle cure using acupuncture needle. We have to consider the problem of the whole body which is related 12 meridians and meridian muscles as well as topical skin and tissues. There are three parts affecting wrinkle formation and cure. The first is a meridian and meridian muscle, the second is a local muscle and fascia on the head and neck, the third is a local skin structure. There are three kinds of method to cure the wrinkle locally. The first one is the perpendicular treatment of acupuncture, called the microneedle therapy, the process of this method is that lots of microneedles stab in the skin to dermis. The second one is the transverse treatment of acupuncture. The process of this method is that an acupuncture needle inserts just under the wrinkle skin. The third one is the incision treatment of acupuncture, called subcision, the process of this method is to cut the fibrous band which connect from the facial muscle to SMS(superficial musculoaponeurotic system) using cuttable needle. The hematoma after treatment let a collagen increase.

• Applied Chemistry for Engineering
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• v.2 no.4
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• pp.356-362
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• 1991

The physico-mechanical properties of NR/BR blend were measured, and the results were interpreted in terms of the crosslink density with cure system. The cure rate, maximum torque and crosslink density increase with the content and ratio of curative for cure system. Hardness, 300 % tensile modulus, rebound and wear resistance increase with crosslink density of the vulcanizate but heat build-up and tan $\delta$ at $60^{\circ}C$ decrease. It is expected that semi-EV(efficient vulcanization) cure system is appropriate for application in tire tread of truck/bus in which load bearing property is impotant.

• Polymer(Korea)
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• v.25 no.2
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• pp.177-185
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• 2001

In this work, the cure kinetics and rheological properties of difunctional epoxy(diglycidylether of bisphenol A, DGEBA)/polysulfone (PSF) blends were investigated using differential scanning calorimeter and rheometer. From the DSC results of the blends, the temperature of the exothermic peak and cure activation energy (E) using a half-width method were increased with increasing the PSF content to neat epoxy resin up to 30 wt%. However, a marginal decrease in the blend system was shown in E. The conversion ($\alpha$) and conversion rate (d$\alpha$/dt) were decreased as the content of PSF increases. Rheological properties of the blend system were investigated under isothermal condition using a rheometer. Cross-linking activation energy (E$_{c}$) was determined from the Arrhenius equation based on gel time and curing temperature. As a result, the E$_{c}$ showed a similar behavior with E which could be resulted from high viscosity of PSF and the phase separation between DGEBA and PSF.PSF.f PSF and the phase separation between DGEBA and PSF.PSF.

• Elastomers and Composites
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• v.34 no.1
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• pp.11-19
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• 1999

Rebound, storage and loss modulus, and tan ${\delta}$ were investigated on cured rubbers with various ratios of sulfur to accelerator and the volume fraction of carbon black in the cured rubbers. The rebound was increased as the sulfur to accelerator ratio and the volume fraction of carbon black decreased. The storage modulus decreased as the loading of carbon black and the strain increased regardless of the cure systems. The network structure formed by filler-filler interaction was destroyed above 6% strain regardless of the loading of carbon black, because constant storage modulus was shown at the higher strain than 3% for $40{\sim}50phr$ loading of carbon black and at the higher strain than 6% for 60 phr and above loading of carbon black. Little effect on loss modulus was found at the low loading of carbon black, but the peak of loss modulus was shown at 1% strain as the loading of carbon black was increased. Tan ${\delta}$ increased as the loading of carbon black and the strain were increased regardless of the cure system, and maximum tan ${\delta}$ was shown at 2% strain regardless of the loading of carbon black.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1998.06a
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• pp.227-230
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• 1998

The effects of post curing conditions on thermal properties of alumina filled epoxy resin system DGEBA/MDA/SN were investigated. As the post curing time increased at 15$0^{\circ}C$, the glass transition temperature increased from 121 to 124, slightly. As the heating rate increased, high thermal decomposing temperature (T$_{d}$) and most decomposing temperature (T$_{p}$) increased. For the case of post-cured system at 15$0^{\circ}C$ for 4 days showed lower values than virgin system. At the post curing condition the system must have been thermally degraded.ded.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.38 no.1 s.113
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• pp.1-8
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• 2006

To overcome troubles in strength and process of linerboard caused by raw materials, a neutral sizing which is usual in fine paper making can be considered. A new sizing agent is necessary to show good performance in a system with high conductivity and COD. In this study, fast cure type AKD was examined as a new sizing agent and compared with conventional AKD. The effects of fixing agent addition and drying condition were also investigated. Fast cure type AKD which has a higher cationicity showed better sizing degree than conventional AKD in spite of low addition level and no curing treatment. And when fixing agent of sufficient amount was added, sizing degree was improved for both AKDs. High cationicity is a crucial factor for neutral sizing of linerboard for obtaining fast and stable sizing degree. Drying with temperature over $100^{\circ}$ was desirable for developing sizing degree.

• Elastomers and Composites
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• v.31 no.1
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• pp.33-42
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• 1996

NR, NBR, and CR rubber were prepared by mixing filler in various ratios. Their vulcanization characteristics and thermal properties were studied. Vulcanization characteristics were investigated using cure curve that had been obtained from oscillating disk rheometer study. The Arrhenius law is known to describe the relationship between cure time and temperature of most elastomers. Curing could be done by the addition of sulfur, peroxides, and proper acceleratores. The optimum cure time that affects desirable values of modulus and tensile strength of the vulcanizate is taken as t90 as measured by a rheometer. Rubbers were cured in the rheometer at temperatures ranging from $130^{\circ}C\;to\;180^{\circ}C$ in order to check the validity of the curing system used. A linear relationship between ln(ts2) and ln(t90) was found for all elastomers. The term sensitivity has been used to describe the relationship between a change of ts2 to the corresponding change of t90 due to an increment of temperature. This is related to the formula of the compound.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.11a
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• pp.652-655
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• 2010

BBU attached to the 155mm is the weapon system for the extension of range through the reduction of base drag. This research focus on the development of inhibitor formulation changing cure agent from DDI to IPDI. Development process is as follows. First, the formulation test about basic property Second, the study on the application of process. Third, the tests for the quality and aging properties. The test results are satisfied with the all of the requirments. In results, this research is contributed to the stable manufacturing in the instability of supplying of cure agent.

• Korea-Australia Rheology Journal
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• v.21 no.2
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• pp.91-102
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• 2009

This paper describes an extension of viscoelastic Group Interaction Modelling (GIM) to predict the relaxation response of linear, branched and cross-linked structures. This model is incorporated into a Monte Carlo percolation grid simulation used to generate the topological structure during the isothermal cure of a gel, so enabling the chemorheological response to be predicted at any point during the cure. The model results are compared to experimental data for an epoxy-amine systems and good agreement is observed. The viscoelastic model predicts the same exponent power-law behaviour of the loss and storage moduli as a function of frequency and predicts the cross-over in the loss tangent at the percolation condition for gelation. The model also predicts the peak in the loss tangent which occurs when the glass transition temperature surpasses the isothermal cure temperature and the system vitrifies.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2001.10a
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• pp.43-48
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• 2001

To overcome the disadvantages of conventional excavation technology, various trenchless (or excavation free, or no-dig) repair-reinforcement technologies have been developed and tried. But trenchless technologies so fat developed have some brawbacks such as high cost and inconvenience of operation. In this study, a repairing-reinforcing process for underground pipes with glass fiber fabric polymer composites using VARTM(Vacuum Assisted Resin Transfer Molding) has been developed. The developed process requires shorter operation time and lower cost with smaller and simpler operating equipments than those of the conventional trenchless technologies. For the reliable operation of the developed method, a simple method to apply pressure and vacuum to the reinforcement was devised and flexible mold technology was tried. Also, resin filling and cure status during RTM process were monitored with a commercial dielectrometry cure monitoring system, LACOMCURE. From the investigation, it has been found that the developed repairing-reinforcing technology with appropriate process variables and on-line cure monitoring has many advantages over conventional methods.