• Archives of Plastic Surgery
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• v.32 no.5
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• pp.656-659
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• 2005

Plantar corn is a circumscribed and sharply demarcated hard mass of traumatic hyperkeratosis, which has a central core impacting the dermis deeply and causes pain while walking. The cause of the corn is the mechanical stress to the skin induced by several causative factors; extrinsic(tight shoes) or intrinsic(bony prominence), or combined(the claw toe). We found 7 cases of patients with a painful recurrent plantar corn which had an epidermal cyst under its lesion. These corns and cysts were excised totally and there was no recurrence in all cases during two to four months follow-up period. We think that an epidermal cyst may be another intrinsic factor for the development of a plantar corn. So, an epidermal cyst should be considered once in a recurrent plantar corn to be recalcitrant against popular treatments.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.26 no.6_spc
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• pp.667-673
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• 2016

Canister with composite sandwich panel has been suggested owing to its higher stiffness and strength over a weight for square shaped canisters. The pyro shock induced by a short time explosion inside a canister is generally considered to be the most severe source of load affecting on the entire structure. Therefore, in this study, the approach and modeling method to identify the effect of pyro shock on canister with composite sandwich panel in a numerical way were mainly discussed. Moreover, the verification was implemented through comparison with test results.

• CELLMED
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• v.12 no.4
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• pp.16.1-16.2
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• 2022

Treatment of patients with pain is directed at relieving pain and restoring function. Heat therapy has been used as a pain treatment. The mean temperatures were 40 and 41℃. Our device, Dr.Pakk heats special silicone to 41℃ with far-infrared rays and attaches it to the painful knee using a vacuum to show the effect. The core technology of the Dr.Pakk is that deep heat is generated when the heat is transmitted deeply by attaching it to the skin. In our experience, Dr.Pakk can be especially effective for knee pain.

• Journal of the Korean Electrochemical Society
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• v.4 no.3
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• pp.104-108
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• 2001

Naphthalene derived mesophase pitch WP) was spun into short fibers by using melt-blown technology. The pitch fibers oxidative stabilization were carried out heating rates of $2^{\circ}C/min,\;5^{\circ}C/min\;and\; 10^{\circ}/min$. The heating rate was a key factor to maximate the capacity of the Li-ion secondary battery through controlling the morphology of the graphitized fiber. The diameters of the melt-blown fibers prepared were in the range of $4{\mu}m\~16{\mu}m$ with functions of air jet speed, air temperature and the temperature of the nozzle. The graphitized fibers of $10{\mu}m$ diameters showed various morphological structure with heating rate of the stabilization. Radial, radial-random and skin-core cross-sectional structure of the fibers were observed at the respective heating rate of $2^{\circ}C/min\;5^{\circ}C/min\;and\;10^{\circ}C/min$. Most crystalline structure of graphite was obtained from the fiber stabilized at heating rate of $10^{\circ}C/min$ exhibiting the best anode performance with 400 mAh/g of capacitance and $96.8\%$ of charge/discharge efficiency.

• Membrane Journal
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• v.25 no.6
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• pp.530-537
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• 2015

Photovoltaic (PV) modules are environmentally energy conversion devices to generate electricity via photovoltaic effect of semiconductors from solar energy. One of key elements in PV modules is "Backsheet," a multilayered barrier film, which determines their lifetime and energy conversion efficiency. The representative Backsheet is composed of chemically resistant poly(vinyl fluoride) (PVF) and cheap poly(ethylene terephthalate) (PET) films used as core and skin materials, respectively. PVF film is too expensive to satisfy the market requirements to Backsheet materials with production cost as low as possible. The promising alternatives to PVF-based Backsheet are hydrocarbon Backsheets employing semi-crystalline PET films instead of PVF film. It is, however, necessary to provide improved barrier property to water vapor to the PET films, since PET films are suffering from hydrolytic decomposition. In this study, a polyurethane adhesive with reduced water vapor permeation behavior is developed via a homogeneous distribution of hydrophobic silica nanoparticles. The modified adhesive is expected to retard the hydrolysis of PET films located in the core and inner skin. To clarify the efficacy of the proposed concept, the mechanical properties and electrochemical PV performances of the Backsheet are compared with those of a Backsheet employing the polyurethane adhesive without the silica nanoparticles, after the exposure under standard temperature and humidity conditions.

• Journal of Animal Environmental Science
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• v.18 no.2
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• pp.95-98
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• 2012

A normal body temperature data base for cattle was established to utilize for automatic monitoring of abnormal body condition of cattle by using sensor network and radio frequency identification technology. Three castrated Holstein cattle (mean body weight: $318{\pm}12kg$) were employed for body temperature measurement. Animals were adapted at the stanchion barn over 2 weeks, and 4 places (skins of ear, neck, head and subcutaneous tissue of neck) of body temperatures were continuously measured through thermocouples and recorder devices for 9 days. All places of body temperatures were fluctuated throughout the day and showed a cyclic pattern, with higher temperature in day time and lower temperature in nigh time. Normal subcutaneous tissue temperature (core temperature) in a day was ranged from $36.1^{\circ}C$ to $38.2^{\circ}C$. Skin temperatures were varied largely with environmental temperature change. Ear, head and neck temperatures varied with $36.3{\sim}28.5^{\circ}C$, $36.1{\sim}28.0^{\circ}C$ and $35.0{\sim}28.2^{\circ}C$, respectively. In this study, we established a basic data base for normal body temperature in cattle. For more effective data base, it would be needed further study.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.1
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• pp.666-671
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• 2018

A honeycomb panel is a plate made by attaching two surface plateson eitherside of a honeycomb core. The honeycomb plate hasexcellent specific strength and energy absorption and is suitable for use in regions where good impact resistance is required. Recently, with the increasing the need for a lightweight design to facilitate transportation, numerous studies have been conducted using aluminum honeycomb plates as body materials for vehicles such as automobiles and high-speed trains. In addition, honeycomb plates have excellent sound deadening properties, as well as excellent heat insulation and durability. Savings in weight using lightweight materials such as aluminum alloy for honeycomb panel's skin can lead to increase fuel economy and reduction in air pollution. In this study, in order to improve the design technology of the honeycomb plate material, the manufacturing technology of the aluminum honeycomb core and honeycomb plate material and various mechanical properties of the honeycomb plate were evaluated. From the results, it was found that the design of the manufacturing process of the aluminum honeycomb plate, as well as itsproduction and characteristics, were improved. The resulting excellent energy absorption capability of the honeycomb plate was due to the repetitive core buckling, indicating that the higher the compressive strength, the higher the strength per bonded area.

• Composites Research
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• v.12 no.6
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• pp.74-82
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• 1999

The static and fatigue characteristics of polyurethane foam cored sandwich structures are investigated. Three types of the specimens with the glass fabric faces and the polyurethane foam core are used; non-stitched. stitched, and stiffened sandwich specimen. Especially additional structural reinforcements with the twisted polyester and glass fiber for thickness direction are made to stitched sandwich structure panel to minimize the delamination of structure which is stitched the upper and lower faces through the core and the resin is impregnated Into stitched fiber with the characteristics of low viscosity of resin at resin flow temperature and cured together with during the curing process. Bending strength of stitched specimen which is 50 mm $50{\times}50{\;}mm$ pitched is improved by 50 % as com-pared with non-stitched specimen and stiffened specimen is improved 10 times more than non-stitched structure. After fatigue testing of $10^6$cycles by 20% of ultimate load under monotonic load, the bending fatigue strength of non-stitched specimen is decreased by 27% of monotonic bending strength, 39% for stitched structure and 20% for stiffened specimen. To verify the aging effect of polyurethane form core, Ultrasonic C-scanning equipment is used to detect the damage of skin laminate alone after fatigue test. From results of UT C-scan images, there is no defect that can be damaged occurred during fatigue test. It is concluded that the decrease of bending strength for foam cored sandwich specimen is caused by the decrease of stiffness due to the aging of polyurethane foam core during fatigue cycles.

• Journal of the Korea Institute of Building Construction
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• v.20 no.5
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• pp.417-423
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• 2020

In order to reduce cooling and heating, which is 40% of the energy consumption of buildings, it is important to improve the insulation of the skin. In order to improve the existing insulation, research is being conducted to apply a vacuum insulation panel(VIP) to buildings. However, VIP cannot be repaired, so we considered the metal vacuum insulation panel. Since the core of the metal vacuum pressure and have low thermal conductivity, foam concrete is adopted. However, preliminary experiments confirmed that the time to reach 0.001torr differs depending on the amount and nature of the bubbles. This effect is determined by the type of foaming agent and the density of the bubble slurry, the vacuum delivery time is determined to be the optimum foam concrete conditions are necessary. Therfore, this study aims to present basic data applicable to core materials by measuring vacuum delivery time and thermal conductivity change according to the foaming agent type and foam slurry density of foam large concrete which is core material of metal vacuum insulation panel. Experimental results and analysis show that compressive strength can be used regardless of the type of foam, In terms of thermal conductivity, it is stable to use vegetable foaming agents at 0.9g/㎤ or less. In terms of the vacuum delivery time, the foaming agent appeared similar regardless of the type of foaming agent, but it is considered suitable to use vegetable foaming agent based on compressive strength and thermal conductivity.

• Fashion & Textile Research Journal
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• v.6 no.4
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• pp.515-521
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• 2004

The Purpose of this study was to investigate the effect of body fat on thermophysiological responses and subjective sensations under hot environment. Fifteen female college students volunteered as subjects. Subjects were organized into three groups - low body fat group(L group : less than 20% of body fat), medium body fat group(M group : 20%~30% of body fat) and high body fat group(H group : More than 30% of Body fat). The experiment was carried out in a climate chamber of $32^{\circ}C$, 60%RH with the repeat of having 'Exercise' and 'Rest' period. The results of this study are as follows ; Rectal temperature maintained higher in M group and L group than in H group in the period of exercise 1. High body fat was so effective in keeping the core temperature, it seems that as was usually the case in cold environment. The mean skin temperature was the lowest value in H group but the ratio of mean skin temperature change was clearly high value in H group. The above facts indicated that thermophysiological response occurs rapidly in H group. Blood pressure, pulse rate and metabolic rate of H group showed the highest values and those of L group showed the lowest value in all period of experiment. Effective of sweating rate was higher in H group than other groups. In subjective sensations, The H group felt more pleasant and comfortable than M group. With these results in mind, people of H group responses more actively for thermal regulation in a hot environment, and these leads H group to feel more pleasant and comfortable.