• Journal of Pharmaceutical Investigation
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• v.40 no.spc
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• pp.113-118
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• 2010

Pharmaceutical technology has primarily focused on the development of the best dosage forms depending on the route of administration. The design of dosage forms is greatly influenced by the route of administration. Due to a variety of advantages such as avoidance of first-pass effect, abundant blood supply and easy access to the absorption site, the oral cavity has frequently been selected as a site for drug delivery. Since the oral cavity is relatively unique from the anatomical and physiological viewpoint, one should always consider these conditions when designing the drug delivery systems for the oral cavity. In this regard, the current review paper was prepared to summarize the essential features of the drug delivery systems utilized in the oral cavity, along with the introduction of various dosage forms developed to date.

• Restorative Dentistry and Endodontics
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• v.25 no.1
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• pp.91-108
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• 2000

Most of cervical abrasion and erosion lesions show gingival margin where the cavosurface angle is on cementum or dentin. Composite resin restoration of cervical lesion shrink toward enamel margin due to polymerization contraction. This shrinkage has clinical problem such as microleakage and secondary caries. Several methods to diminish contraction stress of composite resin restoration, such as modifying cavity form and building up restorations in several increments have been attempted. The purpose of this study was to compare polymerization contraction stress of composite resin in Class V cavity subjected to cavity forms and placement methods. In this study, finite element model of 5 types of Class V cavity was developed on computer tomogram of maxillary central incisor. The types are : 1) Box cavity 2) Box cavity with incisal bevel 3) V shape cavity 4) V shape cavity with incisal bevel 5) Saucer shape cavity. The placement methods are 1) Incisal first oblique incremental curing 2) Bulk curing. An FEM based program for light activated polymerization is not available. For simulation of curing dynamics, time dependent transient thermal conduction analysis was conducted on each cavity and each placement method. For simulation of polymerization shrinkage, thermal stress analysis was performed with each cavity and each placement method. The time-temperature dependent volume shrinkage rate, elastic modulus, and Poisson's ratio were determined in thermal conduction data. The results were as follows : 1. With all five Class V cavifies, the highest Von Mises stress at the composite-tooth interface occurred at gingival margin. 2. With box cavity, V shape cavity and saucer cavity, Von Mises stress at gingival margin of V shape cavity was lower than the others. And that of box cavity was lower than that of saucer cavity. 3. Preparing bevel at incisal cavosurface margin decreased the rate of stress development in early polymerization stage. 4. Preparing bevel at incisal cavosurface margin of V shape cavity increased the Von Mises stress at gingival margin, but decreased at incisal margin. 5. At incisal margin, stress development by bulk curing method was rapid at early stage. Stress development by first increment of incremental curing method was also rapid but lower than that by bulk curing method, however after second increment curing final stress was the same for two placement methods. 6. At gingival margin, stress development by incremental curing method was suddenly rapid at early stage of second increment curing, but final stress was the same for two placement methods.

• Proceedings of the KSME Conference
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• 2002.08a
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• pp.775-778
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• 2002

In order to analyse the mechanism of a flow tone around a cavity, the correlations between the flow in the cavity and the boundary layer flow in front of the cavity are studied experimentally in this paper. The instability In the boundary layer forms the vortex at the front edge of the cavity and the flow tone is occurred by the vortex breakdown at the rear edge of the cavity Therefore, the boundary layer measurement is important in the cavity flow control. We measure the velocity of the boundary layer at the entrance of the cavity using hot-wire anemometry and the flow tone around the cavity by microphone. The boundary layer characteristic is changed by the various angle of the flap on the front edge of the cavity, while it is less influenced by the ratio of length and depth of the cavity.

• Restorative Dentistry and Endodontics
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• v.12 no.2
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• pp.83-90
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• 1987

Composite resins has been widely used in dental clinics because of esthetic restoration. The aim of this study was to assess the effects of the cavity designs on the compressive stress of resin restoration. So, the author made the standardized specimen of four types (Type of speciemen are width 1.5mm, depth 2mm, width 1.5mm, depth 3mm, width 2mm, depth 2mm, width 2mm, depth 3mm). The compressive strength was measured by universal testing machine (Tong Kwang Co.) The results indicating following; 1. There was a statistic significance of compressive strength between four cavity forms. 2. There was no difference of significance of compressive strength between two resins. 3. There was a significance of compressive strength between depth 3mm width 1.5mm and depth 3mm width 2mm.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.17 no.12
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• pp.1223-1229
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• 2007

Flow traveling over a cavity opening forms a vortex due to unstable shear layer and induces an aerodynamic pressure excitation from the diffusion of the vortex convecting out of the trailing edge of the opening. The interaction between the excitation force and the cavity response sustains resonance in the resonator(cavity) and locked-in vortex shedding at the leading edge of the opening. The aerodynamic excitation force can be described from the diffusion of the vortex over the trailing edge and the level of its diffusivity is related to the strength of vorticity seeded at the leading edge. In this study, the control scheme of the internal pressure oscillation was proposed from regulating the vorticity at the leading edge by use of an oscillating spoiler. It was found that the relative motion between the spoiler and the air mass at the cavity opening influenced vorticity strength and the control was achieved by direct feedback of the cavity pressure fluctuation to the actuator.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.11a
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• pp.196-199
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• 2005

Flow traveling over a cavity opening forms a vortex due to unstable shear layer and induces an aerodynamic pressure excitation from the diffusion of the vortex convecting out of the trailing edge of the opening. The interaction between the excitation force and the cavity response sustains resonance in the resonator(cavity) and locked-in vortex shedding at the leading edge of the opening. The aerodynamic excitation force can be described from the diffusion of the vortex over the trailing edge and the level of its diffusivity is related to the strength of vorticity seeded at the loading edge. In this study, the control scheme of the internal pressure oscillation was proposed from regulating the vorticity at the leading edge by use of an oscillating spoiler. It was found that the relative motion between the spoiler and the air mass at the cavity opening influenced vorticity strength and the control was achieved by direct feedback of the cavity pressure fluctuation to the actuator.

• Applied Microscopy
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• v.46 no.1
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• pp.51-57
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• 2016

The histology and anatomy of the olfactory organ in Luciogobius guttatus was investigated using a light microscopy and scanning electron microscopy. The paired olfactory organs in the dorsal part of the snout are situated in between the upper lip and the eyes. They consist of two nostrils, one anterior and the other posterior openings, and a single olfactory cavity. The anterior nostril, an incurrent opening, forms a short tubular structure from the skin. The posterior nostril, an excurrent opening, forms a circular structure opened to the exterior. The distributional pattern of the sensory epithelium is a continuous type. The sensory epithelium with numerous-motile cilia is made up of receptor cells, supporting cells, basal cells, and mucous cells. In contrast, the non-sensory epithelium is comprised of stratified epithelial cells and two types of mucous cells, acidic and neutral cells. The cilia number of the receptor cell is in range of 3 to 4 units. Such results in L. guttatus may reflect its ecological habit and microhabitat in the tidal zone with a periodic tide.

• Proceedings of the KIEE Conference
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• 1998.07g
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• pp.2518-2520
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• 1998

Silicon can be reactive ion etched (RIE) either isotropically or anisotropically. In this paper, a new micromachining technology combining these two etching characteristics is proposed. In the proposed method, the fabrication steps are as follows. First. a polysilicon layer, which is used as the bottom electrode, is deposited on the silicon wafer and patterned. Then the silicon substrate is etched anisotropically to a few micrometer depth that forms a cavity. Then an PECVD oxide layer is deposited to passivate the cavity side walls. The oxide layers at the top and bottom faces are removed while the passivation layers of the side walls are left. Then the substrate is etched again but in an isotropic etch condition to form a round trench with a larger radius than the anisotropic cavity. Then a sacrificial PECVD oxide layer is deposited and patterned. Then a polysilicon structural layer is deposited and patterned. This polysilicon layer forms a pivot structure of a rocker-arm. Finally, oxide sacrificial layers are etched away. This new micromachining technology is quite simpler than conventional method to fabricate joint structures, and the devices that are fabricated using this technology do not require a flexing structure for motion.

• Journal of the Korean GEO-environmental Society
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• v.14 no.12
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• pp.43-52
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• 2013

Limestone typically forms large caverns such as reticular caverns or limestone caves, and also forms sinkhole and doline. These caverns cause different settlement when constructing roads, dams, etc. because the foundation cannot sustain the upper structures. So it is necessary to reinforce foundation such as cavern filling method, etc. In this study, ground reinforcement for structure foundation was carried out using CGS method in limestone cavity area and evaluation of reinforcement effect from engineering viewpoint was conducted through the field test. Among others, boring test was carried out to identify the ground structure and engineering characteristics. After CGS reinforcement, boring test was conducted for supplementary verification, and with reinforcement core taken during boring test, rock test was carried out to identify the physical properties of reinforcement material. After applying CGS method, rock test of the typical specimen, among reinforcement cores, taken from boring test was carried out and physical properties of the reinforcement was identified. As a result of compressive test of core sample, material inside the cavity was filled properly, indicating compressive strength of 12.2~19.2(MPa) which was evaluated acceptable. Thus the limestone cavity proved to have been reinforced successfully.

• Korean Journal of Clinical Laboratory Science
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• v.45 no.4
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• pp.144-148
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• 2013

Candida spp. are yeast form fungi, which cause an opportunistic infections in a immune suppressed patients however it is a normal flora of the respiratory system, the gastrointestinal system, and the urogenital system of healthy person. It is investigated that the distribution of Candida spp. cause an oral disease from oral cavity of healthy people and also identified Candia dubliniensis. Distribution and identification of the yeast form fungi in oral cavities of healthy people was investigated by an automatic identifier, VITEK2 system. We found 21 strains of Candida albicans, 3 strains of Candida famata, one strain of Candida tropicalis, Candida haemulonii, Candida krusei, and Candida dubliniensis. In addition, one strain of Cryptococcus spp., Saccharomyces spp., and two unknown strains were isolated. Candida dubliniensis which forms a mass by more than 2 chlamydospores was isolated from a healthy person for the first time. Candida dubliniensis was not grown at $42^{\circ}C$ whereas Candida albicans was grown well. It is known that Candida dubliniencis was isolated in AIDS while it is found in healthy people from this study, which will be helpful to investigate the distribution of Candida spp.