• Journal of Pharmaceutical Investigation
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• v.31 no.4
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• pp.225-232
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• 2001

The present study was carried out to observe the effect of liposome dispersed gel formulation (Lipogel) on topical delivery of ascorbyl palmitate (AsP). Neutral and negatively charged MLV liposomes containing AsP were prepared with dimyristoylphosphadtidylcholine (DMPC) and dicetyl phosphate (DCP), and dispersed to poloxamer gel matrix. In the hydrolysis study in rat's skin homogenates, AsP hydrolyzed to ascorbic acid (AsA) according to the first-order kinetics with the rate constant of $2.46{\times}10^{-2}\;min^{-1}$. In the passive skin penetration study using Franz diffusion cell, lipogel systems exhibited the greater values in the flux $(J_s)$ and the amount penetrated $(Q_p)$ compared to control hydrogels containing diethyleneglycol monoethyl ether $(Transcutol^{\circledR})$ as a solubilizing agent and a penetration enhancer for AsP. The total amount penetrated $(Q_{Total})$, which is expressed as a summation of $Q_P\;and\;Q_L$, for lipogel system was about 1.4 times higher in average than that of control hydrogel. However the amount localized in the skin $(Q_L)$ was similar in both formulations. As a result, lipogel system enhanced the skin penetration of AsP, possibly due to the increase in local concentration of AsP by preferential adsorption of liposome to the skin and the enhancing effect of phospholipid in liposome composition. Moreover it was expected that the penetrated AsP would generate AsA during skin penetration by the skin esterase. In conclusion, lipogel formulation was considered as a good candidate for topical delivery of AsP.

• Journal of Welding and Joining
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• v.26 no.4
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• pp.44-49
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• 2008

Generally, wear plate is steel plate having improved surface contact strength and impact strength by surface hardening which is welded using materials with good corrosion resistance, wear resistance and thermal resistance property. CFP GMAW(Compound Filler Plate Gas Metal Arc Welding) is the cladding method using GMAW with the CFP, which is bound with waterglass, on the substrate. It has advantages of reducing compound powder loss, uniform penetration, and preventing hardness decrease. To develope mass production technique of CFP GMAW process for production of high quality wear plate, the method for controling shallow penetration and increasing productivity is required. In this study, twin torch method applied to CFP GMAW process for increasing productivity. And the method was developed by controling penetration control, CFP dry time, gas formation flux and water glass concentration. As a result, applying twin torch method to CFP GMAW process was possible and high quality wide bead could be made without overlap joint.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.2
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• pp.300-307
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• 2002

Partial penetration welding joint is defined as groove welds welded from one side, without steel backing or groove welds welded from both sides but without back gouging. So it has an unwelded portion at the root of the weld. Study of partial penetration weldment fracture behavior includes residual stress analysis and fracture analysis. The J-integral loses its path independency in residual stress field. Therefore, it is necessary to introduce a new J-integral, J, which is defined including the effect of plastic deformation and thermal strain. In this study, theoretical formulation and program were developed for the evaluation of J-integral for the crack tip located in the weldment. Evaluations of fracture behavior were performed for partial penetration multi-pass weldment of 25.4mm thick plate by J-integral. From a point of fracture in partial penetration multi-pass welding, it seemed to be better to control root face smaller than 6.35mm.

• Computers and Concrete
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• v.13 no.1
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• pp.17-30
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• 2014

This research presents the effect of various ground pozzolanic materials in blended cement concrete on the strength and chloride penetration resistance. An experimental investigation dealing with concrete incorporating ground fly ash (GFA), ground bottom ash (GBA) and ground rice husk ash (GRHA). The concretes were mixed by replacing each pozzolan to Ordinary Portland cement at levels of 0%, 10%, 20% and 40% by weight of binder. Three different water to cement ratios (0.35, 0.48 and 0.62) were used and type F superplasticizer was added to keep the required slump. Compressive strength and chloride permeability were determined at the ages of 28, 60, and 90 days. Furthermore, using this experimental database, linear and nonlinear multiple regression techniques were developed to construct a mathematical model of chloride permeability in concretes. Experimental results indicated that the incorporation of GFA, GBA and GRHA as a partial cement replacement significantly improved compressive strength and chloride penetration resistance. The chloride penetration of blended concrete continuously decreases with an increase in pozzolan content up to 40% of cement replacement and yields the highest reduction in the chloride permeability. Compressive strength of concretes incorporating with these pozzolans was obviously higher than those of the control concretes at all ages. In addition, the nonlinear technique gives a higher degree of accuracy than the linear regression based on statistical parameters and provides fairly reasonable absolute fraction of variance ($R^2$) of 0.974 and 0.960 for the charge passed and chloride penetration depth, respectively.

• Restorative Dentistry and Endodontics
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• v.6 no.1
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• pp.141-147
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• 1980

The sealing effect of a few cavity liners upon the dentinal tubule were studied in vitro. The materials employed in this study were Silcot (SP$\'{E}$CIALIT$\'{E}$S SEPTODONT, M.-T. GENDRAULT, Pharmacien), Hypo-Cal(Ellman Dental Mfg.Co.Inc.), Cavity Lining(De Trey), and Copaute(Harry J. Bosworth Co.). Freshly extracted human teeth were devided into 5 groups by age-under twenty, twenties, thirties, forties, and over fifty. Class V cavities were prepared routinely. The cavity walls of eight teeth of each group were lined by Silcot, Copalite, Cavity Lining, and Hypo-Cal. Remaining eight were not lined as a control. These specimens were immersed in dye solution (2 gm eosin Y to 800 cc distilled water) for 48 hours to allow maximum dye penetration into dentinal tubules. Each specimen was sectioned longitudinally including Class V cavity floor under water spray. Dye penetration into dentinal tubules were examined and following results were obtained. 1. Liners used on this study showed more or less dye penetration into dentinal tubules. But compared with the teeth without lining, the dye penetration of lined specimens were decreased. 2. Of these liners tested, Silcot was the most effective sealer upon the dentinal tubules. Copalite was the moderate sealer and Cavity Lining showed a tendency similar to Copalite. Hypo-Cal revealed the greatest dye penetration. 3. As the age was increased, the more the dye penetration into the dentinal tubules was decreased.

• Geomechanics and Engineering
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• v.13 no.6
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• pp.1027-1044
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• 2017

Membrane penetration is the most important factor influencing the measurement of volume change for triaxial consolidated-drained shear test for coarse-grained soil. The effective pressure p, average particle size $d_{50}$, thickness $t_m$ and elastic modulus $E_m$ of membrane, contact area between membrane and soil $A_m$ as well as the initial void ratio e are the major factors influencing membrane penetration. According to the membrane deformation model given by Kramer and Sivaneswaran, an analytical solution of the membrane penetration considering the initial void ratio is deduced using the energy conservation law. The basic equations from theory of plates and shells and the elastic mechanics are employed during the derivation. To verify the presented solution, isotropic consolidation tests of a coarse-grained soil are performed by using the method of embedding different diameter of iron rods in the triaxial samples, and volume changes due to membrane penetration are obtained. The predictions from presented solution and previous analytical solutions are compared with the test results. It is found that the prediction from presented analytical solution agrees well with the test results.

• Korean Journal of Veterinary Service
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• v.26 no.4
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• pp.329-337
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• 2003

The functional role of the cumulus cells on sperm penetration and polyspermy during in vitro fertilization was examined. The penetration rate was significantly higher(p<0.01) in oocytes with(61%) than without(25%) cumulus cells. No significant differences, however, was observed in polyspermy. When the hyaluronidase was supplemented to the fertilization medium with different concentrations, penetration rates in oocytes with cumulus cells were higher than oocytes without cumulus cells at 0(61 vs 34% ; p<0.05), 0.01(56 vs 35% ; p<0.05), 0.1(66 vs 30% ; p<0.05) and 1.0 mg/$m\ell$(39 vs 27%). On the other hand, the polyspermy rates were lower oocytes without than with cumulus cells, and had a tendency to decrease with high concentrations of hyaluronidase. In another experiment, the penetration and polyspermy rates had a tendency to increase as time of sperm-oocytes culture was prolonged. At 16 and 20hrs after insemination, the penetration rates were significantly higher(p<0.05) in oocytes with(48 and 62% for 16 and 20hrs) than without(25 and 31% for 16 and 20hrs) cumulus cells in medium with hyaluronidase. However, the polyspermy rates were significantly(p<0.05) lower in oocytes without(3 and 16%) than with(37 and 48%) cumulus cells at 16 and 20hrs after insemination. In cumulus-free oocytes inseminated in medium with or without hyaluronidase at different concentrations of cumulus cells, the penetration rates were significantly(p<0.05) higher in medium with than without hyaluronidase at different concentrations of cumulus cells. The proportions of polyspermy were lower in medium without than with hyaluronidase at 0 (10 vs 0%), 10$^2$(25 vs 0%), 10$^4$(24 vs 14%) and 10$\^$6/(29 vs 10% ; p<0.05) cumulus cells/ml. These results suggest the advantage of culture in medium with cumulus cells and denuded oocytes to inhibit polyspermy with no decrease in the penetration rates during the fertilization in vitro in the porcine.

• Restorative Dentistry and Endodontics
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• v.48 no.1
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• pp.1.1-1.11
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• 2023

Objectives: This study evaluated the dentinal penetration depth of 2.5% sodium hypochlorite (NaOCl) in root canals with and without preparation and different irrigant activation protocols. Materials and Methods: Sixty-three bovine mandibular incisors were randomly allocated to 6 groups (n = 10): G1, preparation + conventional needle irrigation (CNI); G2, preparation + passive ultrasonic irrigation (PUI); G3, preparation + Odous Clean (OC); G4, no preparation + CNI; G5, no preparation + PUI; G6, no preparation + OC; and CG (negative control; n = 3). Samples were filled with crystal violet for 72 hours. Irrigant activation was performed. Samples were sectioned perpendicularly along the long axis, 3 mm and 7 mm from the apex. Images of the root thirds of each block were captured with a stereomicroscope and analyzed with an image analysis software. One-way analysis of variance, followed by the Tukey post hoc test, and the Student's t-test were used for data analysis, with a significance level of 5%. Results: The NaOCl penetration depth was similar when preparation was performed, regardless of the method of irrigation activation (p > 0.05). In the groups without preparation, G6 showed greater NaOCl penetration depth (p < 0.05). The groups without preparation had a greater NaOCl penetration depth than those with preparation (p = 0.0019). Conclusions: The NaOCl penetration depth was similar in groups with root canal preparation. Without root canal preparation, OC allowed deeper NaOCl penetration. The groups without preparation had greater NaOCl penetration than those undergoing root canal preparation.

• Journal of the korean academy of Pediatric Dentistry
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• v.26 no.2
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• pp.416-426
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• 1999

The objective of this study is to confirm the effect of dentine bonding primer application on penetration of sealant. Extracted permanent molars were used to compare penetration success rate of control group (sealant application only) and experimental groups (sealant application after applying the primers of $Scotchbond^{TM}$ Multi-Purpose system and $All-Bond^{(R)}$ 2 system). The following results were obtained: 1. The experimental groups using the primers showed increased sealant penetration success rate to the base of fissure when compared to control group but there was no statistically significant differences(p>0.05). 2. The depth, width and 'depth/width' value of fissure had statistically significant effect on sealant penetration success rate(p<0.05). 3. The penetration success rate decreased about 0.9 times as the depth of fissure increased every $25{\mu}m$, and increased about 1.1 times as the width of the fissure orifice increased every $25{\mu}m$ and decreased about 0.6 times as the 'depth/width' value increased every 1. From the above results, it can be concluded that assure morphology had a great effect on sealant penetration and for better penetration, use of dentine bonding primer can be helpful but it needs more study in clinical bases.

• Journal of Welding and Joining
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• v.20 no.1
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• pp.62-68
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• 2002

This study investigated the feasibility of penetration depth measurement using infrared temperature sensing on the weld surface. The detection point was optimized by FEM analysis in the laser keyhole welding. The profile of the weld surface temperature was measured using infrared detector array. Surface temperature behind the weld pool is proportional or exponentially proportional to penetration depth and bead width. From the results, the monitoring device of surface temperature using infrared detector array was applicable fur real time penetration depth control.