• Korean Journal of Food Science and Technology
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• v.41 no.1
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• pp.32-36
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• 2009

The physical properties of freeze-dried Aloe vera gel powders were examined according to the influence of the concentration degrees of the gel solutions as raw materials during freeze-drying. As a pre-treatment prior to freeze-drying, the gel solutions were vacuum-concentrated at three concentration levels (g water/g solids): high (H), 76; medium (M), 119; and low (L), 159. The water contents of the three powder samples were almost the same. For their viscosity measurements, non-Newtonian fluid behavior with shear thinning was observed in samples H and M, whereas Newtonian liquid behavior was found in sample L. In electrical conductivity measurements, sample H showed the highest conductivity upon dissolving the powder in water. For their water sorption isotherms, sample H was analyzed to have the least amount of bound water. Finally, it was determined that the degree of concentration caused only slight differences in the physical properties of freeze-dried Aloe gel powders.

• Carbon letters
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• v.7 no.3
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• pp.166-170
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• 2006

Silicon carbide whiskers ($SiC_w$) having the diameter in the range of 20-80 nm were synthesised from coconut fibres through sol-gel process. The coconut fibres were impregnated with tetraethoxysilane and methyltriethoxysilane derived sol and pyrolyzed at $1400^{\circ}C$ in argon. X-ray of the pyrolyzed samples showed the formation of ${\beta}$-SiC.

• The Journal of Korean Physical Therapy
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• v.18 no.1
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• pp.75-82
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• 2006

Purpose: This study conducted the following experiment to examine transdermal permeation effects or 500 KHz ultrasound with lidocaine HCl. Methods; First, to experiment skin permeation enhancement effects of 500 KHz ultrasound frequency, it produced apparatus and transducer of 500 KHz ultrasound and Franz diffusion cell for skim permenation experiment suitable to purposes of the experiment. Transdermal permeation experiment applied Lidocaine HCL gel to skin of hairless mouse depending on ultrasound frequency and duty cycle and analyzed permeation ratio with HPLC. Results: As a result of fixing lidocaine HCl gel at the same intensity with pulsed mode and continuous mode and comparing transdermal permeation ratio by frequency, transdermal permeation ratio was increased at 500 KHz ultrasound and remarkably increased at continuous ultrasound. It was found that 1 MHz and 500 KHz ultrasound in transdermal permeation experiment enhanced transdermal permeation of lidocaine HCl. In particular, transdermal permeation of 500 KHz using lidocaine HCl gel was highest. Conclusion: However, researches considering various frequencies, intensities and application hours in low frequency areas including 500 KHz ultrasound are needed to increase deep permeation or drugs.

• Elastomers and Composites
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• v.54 no.1
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• pp.30-34
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• 2019

Four different diisocyanates (IPDI; isophorone diisocyanate, HDI; hexamethylene diisocyanate, HMDI; dicyclohexylmethane-4,4'-diisocyanate, and XDI; m-xylylene diisocyanate) were used to prepare polyurethane gel-coats, and the weatherabilities, physical properties, and surface characteristics of the gel-coats were investigated with respect to the chemical structure of the diisocyanates. The weathering test results indicated that all of the diisocyanates used in this study were suitable for use in the preparation of the polyurethane gel-coat. However, the set-to-touch times and physical properties of the polyurethane gel-coat indicated that the cycloaliphatic diisocyanate (IPDI and HMDI) were ideal for the preparation of polyurethane gel-coats.

• Journal of the Korean Academy of Clinical Electrophysiology
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• v.1 no.2
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• pp.11-19
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• 2003

The purpose of this study investigated the anesthetic effects of lidocaine gel by phonophoretic transdermal delivery. The anesthetic effects were evaluated by two aspects as quantitative sensory testing and sensory nerve conduction study. Twelve healthy males(aged $23.25{\pm}2.09$ years) were studied. Exclusion criteria were ; pain, history of sensory disturbances and skin conditions in the areas to be examined. The subjects were divided into two groups; group I(lidocaine gel without ultrasound) and group II(lidocaine gel with ultrasound). The following results were obtained; 1. In changes of tactile threshold and electrical pain threshold, all groups were significantly increased(p<0.05). 2. In changes of electrical pain threshold, it was significantly differenced between the groups(p<0.05). We conclude that the transdermal delivery of lidocaine gel by phonophoresis has a possibility to use for surface anesthesia and the pain control of the superficial tissue.

• Journal of the Korean Academy of Clinical Electrophysiology
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• v.1 no.1
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• pp.17-29
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• 2003

This study was investigated the effects on functional recovery of eccentric exercise-induced muscle damage by phonophoresis transdermal permeation of piroxicam gel and observed the change of amplitude at muscle action potential. Through eccentric exercise-induced muscle damage, performed healthy men and women take eccentric resistance exercise and measured action, potentials. The subjects were divided into three groups of four men each 24 hour, 48 hour, 72 hour. The results of this were as follows: 1. Change of maximal action potential at maximal voluntary contraction : The phonophoresis group was increase more than control group and gel group. 2. Change of average action potential at maximal voluntary contraction : The gel group was increase more than control group and phonophoresis group. 3. Change of maximal action potential at pain subthreshold voluntary contraction : The phonophoresis group was increase more significantly than control group and gel group. 4. Change of average action potential at pain subthreshold voluntary contraction : The phonophoresis group was increase more significantly than control group and gel group. In conclusion, the change of muscle action potential amplitude by eccentric exercise-induced muscle damage showed that the phonophoresis by pulsed ultrasound of piroxicam gel was improved the recovery of muscle function.

• The Journal of Korean Physical Therapy
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• v.12 no.2
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• pp.57-67
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• 2000

The purpose of this study was carried out in five rabbits of 3kg to investigate the change of superficial and deep heats in ultrasound application by coupling media. Temperature measured with thermistor needle at skin. subcutaneous, muscle in before coupling media application, after coupling media application. 2minutes. 5minutes, 7minutes, 10minutes. Coupling media was used gel, glycerin, distilled water. The data was analyzed using spss/pc+and t-test The results were as fallow : 1. With skin. gel was significant temperature change in 2minutes(p<.05). glycerin was significant temperature change in 2minutes(p<.05), 5minutes(p<.05), 7minutes(p<.01), 10minutes(p<.01). distilled water was significant temperature change in post coupling media(p<.05), 2minutes(p<.01). 5minutes(p<.05). 7minutes(p<.01). 10minutes(p<.01). With subcutaneous. gel was no temperature change. glycerin was significant temperature change in 2minutes(p<.05), 5minutes(p<.05), 10minutes(p<.01). distilled water was no temperature change. With muscle. gel was no temperature change. glycerin was significant temperature change in 2minutes(p<.05). 5minutes(p<.05). 7minutes(p<.05). 10minutes( p<.05). distilled water was significant temperature change in 10minutes(p<.05). 2. Superficial heats of skin and subcutaneous was higher temperature change than Deep heats of muscle. 3. Gel. glycerin. distilled Water required minimum treatment 10minutes fur thermal effect. 4. Gel was low temperature change superficial and deep heats. and glycerin was high temperature change superficial and deep heats. This results show that gel is high transmissiveness in the coupling media and glycerin is low transmissiveness in the coupling media.

• Journal of the Korean Ceramic Society
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• v.39 no.2
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• pp.113-119
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• 2002

The effect of ultrasonic radiation is reported for silica-poly(ethylene glycol) system prepared without the solvent using sol-gel processing by varying various parameters such as ultrasonic irradiation time, PEG content and HCl/TEOS molar ratio. The property of sonogel is compared with classic gel which has been prepared with ethanol as a solvent by traditional sol-gel processing. SEM, BET, DTA-TGA, density and Vickers hardness measurements are carried out for analyzing the samples. The gelation time is found strongly dependent on radiation time, PEG content and pH value, and has been discussed on the basis of existing theories. The $SiO_2-10$ & 20 wt% PEG sonogel exhibited superior optical, physical and gel properties as compared to the classic gel, hence, found suitable for device applications. The ultrasonic radiation increased the density and surface area, and also reduced the pore size which is well supported by the shift in the peak of DTA curve. The DTA thermogram was found similar to that of pure silica gel.

• Elastomers and Composites
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• v.54 no.3
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• pp.247-251
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• 2019

Two different urethane acrylates (mono-acrylate and di-acrylate) were used to prepare unsaturated polyester-based hybrid gel-coats. The physical properties and surface characteristics of these gel-coats were investigated on the basis of the content and type of urethane acrylate. The set-to-touch time increased and the physical properties (surface hardness and tensile strength) decreased with an increase in the urethane acrylate content. However, the type of urethane acrylate did not affect these parameters. It was found that the optimal urethane acrylate content for the application of unsaturated polyester-based hybrid gel-coats is ~10 wt%.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.47 no.4
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• pp.347-355
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• 2014

This study examined the effects of additives on the physical properties of surimi made from Antarctic krill Euphausia superba. Krill surimi was prepared from krill meat with an added cryoprotectant (sugar 6%, polyphosphate 0.2%). Krill surimi without additives does not form a gel. In order to enhance the gelling of krill surimi, additives such as soy protein isolate (SPI), guar gum, carrageenan, and wheat starch were examined. Of these, SPI had the highest gel-forming activity, while guar gum, carrageenan, and wheat starch had decreasing gel-forming activity and negative effects on other physical properties as their concentrations were increased. In addition, SPI enhanced the gel strength and physical properties of krill surimi. The fluoride and astaxanthin contents of krill surimi with added SPI were 55.0 mg/kg and 0.8 mg/kg, respectively.