• Geomechanics and Engineering
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• 제25권4호
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• pp.267-273
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• 2021

In this work, we compare the analytical solutions with the numerical solutions for photothermal interactions in semiconductor medium containing cylindrical cavity. This paper is devoted to a study of the photothermal interactions in semiconductor medium in the context of the coupled photo-thermal model. The basic equations are formulated in the domain of Laplace transform and the eigenvalue scheme are used to get the analytical solutions. The numerical solution is obtained by using the implicit finite difference method (IFDM). A comparison between the analytical solution and the numerical solutions are obtained. It is found that the implicit finite difference method (IFDM) is applicable, simple and efficient for such problems.

• Journal of Pharmaceutical Investigation
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• 제23권3호
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• pp.155-163
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• 1993

Inclusion complexation of 1,7,21,27-tetraaza[7.1.7.1]paracyclophane (CPM 55) with 2,7-dihydroxynaphthalene (2,7-DHN) or 1,3-dihydroxynaphthalene (1,3-DHN) in pD 1.17 $DCl-D_2O$ solution was investigated by $^1H$ nuclear magnetic resonance spectroscopy (NMR) using 4,4'-dimethylaminodiphenylmethane (ACM 11) as an acyclic analog of CPM 55. In CPM 55-naphthalene derivative complex, alkyl protons located in the cavity of CPM 55 were shown to be subjected to anisotropic shielding and protons of naphthalene moiety shifted remarkably to upfield. However, in ACM 11-naphthalene derivative systems, chemical shifts for protons of both DHN compounds were not significant. The remarkable chemical shift changes suggested that the naphthalene moiety of 2,7-DHN or 1,3-DHN was included in the hydrophobic cavity of CPM 55 in aqueous solution. From the continuous variation plots of induced chemical shifts of 2,7-DHN, it was found that 2,7-DHN was included in the cavity of CPM 55 at 1:1 molar stoichiometry. Both computer simulation of a inclusion complex and strong upfield chemical shift changes of 2,7-DHN protons supported the conformation of pseudoaxial inclusion as the presumed geometry of the host-guest complex.

• 대한기계학회논문집B
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• 제30권4호
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• pp.337-342
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• 2006

Natural convection flows in a cubical air-filled cavity that has one pair of opposing faces isothermal at different temperatures, $T_h\;and\;T_c$, respectively, the remaining four faces having a linear variation from $T_c\;to\;T_h$ are numerically simulated by a solution code(PowerCFD) using unstructured cell-centered method. Special attention is paid to three-dimensional flow and thermal characteristics according to the variation of inclination angle $\theta$ of the isothermal faces from horizontal: namely $\theta=0^{\circ},\;15^{\circ},\;30^{\circ},\;45^{\circ},\;50^{\circ},\;60^{\circ},\;75^{\circ}\;and\;90^{\circ}$. Comparisons of the average Nusselt number at the cold face are made with experimental benchmark results found in the literature. It is demonstrated that the average Nusselt number at the cold face has a maximum value around the inclination angle of $50^{\circ}$. It is also found that the code is capable of producing accurately the nature of the laminar convection in a cubical air-filled cavity with differentially heated walls.

• 소성∙가공
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• 제15권1호
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• pp.42-46
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• 2006

For mass production, usually injection mold has multi-cavity which is filled through geometrical balanced runner system. Despite geometrical balanced runner system, filling imbalances between cavity to cavity have always been observed. These filling imbalances are one of the most significant factors to affect quality of plastic parts. Filling imbalances are results from non-symmetrical shear rate distribution within melt when it flows through tile runner system. It has been possible to decrease filling imbalance by optimizing processing conditions, but it has not completely eliminated this phenomenon during injection molding processing. This paper presents a solution for these filling imbalances by using Runner Core pin (RC pin). The Runner Core pin which is developed in this study creates a symmetrical shear distribution within runner. As a result of using Runner Core pin, a remarkable improvement in reducing filling imbalances was confirmed.

• 터널과지하공간
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• 제12권3호
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• pp.171-178
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• 2002

본 연구에서는 마제형터널 주변에 공동이 존재하는 경우에 대해 동적해석을 수행함으로써 터널주변의 공동이 터널의 동적거동에 미치는 영향을 검토하였다. 이를 위해 반무한 평면상에서 터널의 동적응답해석을 수행할 수 있는 해석기법을 개발하였다. 먼저 주파수 영역에서의 다층 반무한 지반내에서의 동적 기본해를 유도하였고 이를 경계요소에 적용하였다. 외부영역을 모형화한 경계요소를 내부영역의 유한요소와 조합하여 반무한 영역에서의 터널구조의 동적응답을 구할 수 있도록 하였다. 개발된 기법의 검증을 위하여 단층 및 다층 반무한 구조계에 대해 Ricker 파형을 이용한 동적해석을 수행하여 기존의 해석결과와 비교하였고, 개발된 기법을 이용하여 석회암층에 있는 터널에 대해 공동의 유무 및 터널과의 이격거리에 따른 터널의 동적거동을 고찰하였다.

• Restorative Dentistry and Endodontics
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• 제6권1호
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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.

• 대한간호학회지
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• 제45권1호
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• pp.46-53
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• 2015

Purpose: This study was conducted to examine the effect of oral care with an aroma solution on oral status and oral cavity microorganism growth in elderly patients with stroke. Methods: A non-equivalent control group, with a pretest-posttest design was used in this study. The participants were assigned to the experimental group (n=30) that received oral care with an aroma solution or the control group (n=31) that received 0.9% saline solution. To identify the effect of the experimental treatments, objective/subjective assessments of oral status and oral cavity microorganism growth were performed using the oral assessment guide, oral perception guide, and oral swab culture. Data were analyzed using Chi-square test, Fisher's exact test, and t-test with the SPSS version 21.0 program. Results: The objective oral status was significantly lower in the experimental group than in the control group (t= -3.64, p<.001). There was no significant difference between the subjective oral status of the experimental group and control groups (t= -1.24, p=.109). Oral microorganism growth was significantly lower in the experimental group than in the control group (t= -7.39, p<.001). Conclusion: These findings indicate that special mouth care using an aroma solution could be an effective oral health nursing intervention for elderly patients with stroke.

• Geomechanics and Engineering
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• 제13권6호
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• pp.907-928
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• 2017

The effects of seepage force and out-of-plane stress on cavity contracting and tunnel opening was investigated in this study. The generalized Hoek-Brown (H-B) failure criterion and non-associated flow rule were adopted. Because of the complex solution of pore pressure in an arbitrary direction, only the pore pressure through the radial direction was assumed in this paper. In order to investigate the effect of out-of-plane stress and seepage force on the cavity contraction and circular tunnel opening, three cases of the out-of-plane stress being the minor, intermediate, or major principal stress are assumed separately. A method of plane strain problem is adopted to obtain the stress and strain for cavity contracting and circular tunnel opening for three cases, respectively, that incorporated the effects of seepage force. The proposed solutions were validated by the published results and the correction is verified. Several cases were analyzed, and parameter studies were conducted to highlight the effects of seepage force, H-B constants, and out-of-plane stress on stress, displacement, and plastic radius with the numerical method. The proposed method may be used to address the complex problems of cavity contraction and tunnel opening in rock mass.

• Applied Microscopy
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• 제30권2호
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• pp.113-119
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• 2000

Lipophilic glandular trichomes form secretory vesicles that accumulate in a distended noncellular secretory cavity . Imidazole-buffered osmium tetroxide solution was used to visualize unsaturated lipids in glands of Cannabis sativa. This method of staining revealed two kinds of secretory vesicles in the cavity of glands. Some smaller and rounded vesicles in the secretory cavity and secretory cells were positively stained with the imidazole, and they appeared electron-dense. The other type of vesicles which have bigger sizes more or less were not reacted, however, they appeared transparent. A high contrast of the cuticles which cover the gland was also strongly reacted with that processing. Those result suggest that the dark vesicles in the cavity may contribute to enlarge the subcuticular wall and cuticle when contents of these vesicles are dispersed into wall.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.706-709
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• 2005

Despite geometrical balanced runner system, filling imbalances between cavity to cavity have always been observed in multi-cavity injection mold. These filling imbalances are results from non-symmetrical shear rate distribution within melt as it flows through the runner system. It has been possible to decrease filling imbalance by optimizing processing conditions, but it has not completely eliminated this phenomenon during the injection molding processing. This paper presents a solution of these filling imbalances by using runner core pin which creates a symmetrical shear distribution within runner and the effects on filling imbalance when modifying a shape of runner core pin. As a result of using runner core pin, a remarkable improvement in reducing filling imbalance was confirmed. In addition we investigated how filling imbalances were affected by shape of runner core pin.