• Applied Biological Chemistry
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• v.51 no.3
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• pp.233-237
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• 2008

The essential oil was obtained from the aerial part of Rhododendon mucronulatum Turcz. var. ciliatum Nakai by steam distillation, samples were collected by headspace (HS) and solid-phase microextraction (SPME) methods, and the compositions of the oil were analyzed by gas chromatography-mass spectrometry (GC-MS). Nineteen constituents were identified from the essential oil: 15 carbohydrates, 3 alcohols, and 1 acetates. Major constituents were 2-${\beta}$-pinene (16.1%), camphene (11.9%), ${\delta}$-3-carene (11.4%), d,l-limonene (9.5%), and ${\gamma}$-terpinene (9.5%). By SPME extraction, seventeen constituents were identified: 13 hydrocarbons, 1 alcohol, 1 nitrogen-containing compound, 1 acetate, and 1 amine. Major constituents of the SPME-extracted sample were cam phene (19.6%), 2-${\beta}$-pinene (18.0%), ${\delta}$-3-carene (17.4%), trimethyl hydrazine (9.7%), ${\gamma}$-terpinene (8.5%), and d,l-limonene (5.5%). By HS extraction, thirteen constituents were identified: 11 hydrocarbons, 1 alcohol, and 1 nitrogen-containing compound. Major constituents of the HS-extracted sample were camphene (25.8%), ${\delta}$-3-carene (24.8%), 2-${\beta}$-pinene (20.2%), d,l-limonene (5.4%), tricyclene (5.1%) and trimethyl hydrazine (4.6%). The fragrance of the essential oil was coniferous, balsamic, and woody, and the $IC_{50}$ value of the essential oil was 0.030 ${\mu}g/mg$ in MTT assay using UaCaT keratinocyte cell line.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.16 no.2
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• pp.197-206
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• 2003

A three-dimensional (3-D) method of analysis is presented for determining the free vibration frequencies and mode shapes of solid and hollow hemispherical shells of revolution of arbitrary wall thickness having arbitrary constraints on their boundaries. Unlike conventional shell theories, which are mathematically two-dimensional (2-D), the present method is based upon the 3-D dynamic equations of elasticity. Displacement components μ/sub Φ/, μ/sub z/, and μ/sub θ/ in the meridional, normal, and circumferential directions, respectively, are taken to be sinusoidal in time, periodic in θ, and algebraic polynomials in the Φ and z directions. Potential (strain) and kinetic energies of the hemispherical shells are formulated, and the Ritz method is used to solve the eigenvalue problem, thus yielding upper bound values of the frequencies obtained by minimizing the frequencies. As the degree of the polynomials is increased, frequencies converge to the exact values. Novel numerical results are presented for solid and hollow hemispheres with linear thickness variation. The effect on frequencies of a small axial conical hole is also discussed. Comparisons are made for the frequencies of completely free, thick hemispherical shells with uniform thickness from the present 3-D Ritz solutions and other 3-D finite element ones.

• Coupled systems mechanics
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• v.11 no.5
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• pp.439-458
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• 2022

Over-coating is one of the most popular engineering practices to strengthen Reinforced Concrete (RC) structures, due to the relative quickness and ease of construction. It consists of an external coat bonded to the outer surface of the structural RC element, either by the use of chemical adhesives, mechanical anchor bolts or simply mortar injection. In contrast to these constructive advantages, the numerical estimation of the bearing capacity of the strengthened reinforced concrete element is still complicated, not only for the complexity of modelling a flexible membrane or plate attached to a quasi-rigid solid, but also for the difficulties that raise of simulating any potential delamination between both materials. For these reasons, the standard engineering calculations used in the practice remain very approximated and clumsy. In this work, we propose the formulation of a new 2D solid-layer finite element capable to link a solid body with a flexible thin layer, as it were the "skin" of the body, allowing the potential delamination between both materials. In numerical terms, this "skin" element is intended to work as a transitional region between a solid body (modelled with a classical formulation of a standard quadrilateral four-nodes element) and a flexible coat layer (modelled with cubic beam element), dealing with the incompatibility of Degrees-Of-Freedom between them (two DOF for the solid and three DOF for the beam). The aim of the solid-layer element is to simplify the mesh construction of the strengthened RC element being aware of two aspects: a) to prevent the inappropriate use of very small solid elements to simulate the coat; b) to improve the numerical estimation of the real bearing capacity of the strengthened element when the coat is attached or detached from the solid body.

• Coupled systems mechanics
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• v.12 no.6
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• pp.481-501
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• 2023

Over-coating is one of the most popular engineering practices to strengthen Reinforced Concrete (RC) structures, due to the relative quickness and ease of construction. It consists of an external coat bonded to the outer surface of the structural RC element, either by the use of chemical adhesives, mechanical anchor bolts or simply mortar injection. In contrast to these constructive advantages, the numerical estimation of the bearing capacity of the strengthened reinforced concrete element is still complicated, not only for the complexity of modelling a flexible membrane or plate attached to a quasi-rigid solid, but also for the difficulties that raise of simulating any potential delamination between both materials. For these reasons, the standard engineering calculations used in the practice remain very approximated and clumsy. In this work, we propose the formulation of a new 2D solid-layer finite element capable to link a solid body with a flexible thin layer, as it were the "skin" of the body, allowing the potential delamination between both materials. In numerical terms, this "skin" element is intended to work as a transitional region between a solid body (modelled with a classical formulation of a standard quadrilateral four-nodes element) and a flexible coat layer (modelled with cubic beam element), dealing with the incompatibility of Degrees-OfFreedom between them (two DOF for the solid and three DOF for the beam). The aim of the solid-layer element is to simplify the mesh construction of the strengthened RC element being aware of two aspects: a) to prevent the inappropriate use of very small solid elements to simulate the coat; b) to improve the numerical estimation of the real bearing capacity of the strengthened element when the coat is attached or detached from the solid body.

• Journal of Biomedical Engineering Research
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• v.21 no.3 s.61
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• pp.225-231
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• 2000

The Delaunay triangulation. which is one of the surface rendering methods. have been evaluated as a good algorithm which can solve the geometrical connection problems and make high quality images. However this method also have the problem that is the 'non-solid' connection between slices. In this paper, we proposed a new method for the Delaunay triangulation for the surface rendering from 2D medical images in the PC environment. The proposed method was designed to eliminate 'non-solid' tetrahedra. which had no correspondence to the geometric closeness, and used elimination algorithm with modified External Voronoi Skeleton path. This method enabled us to eliminate 'non-solid' tetrahedra without affecting other regions. Thus we could effectively reconstruct the complex shaped objects which were compactly connected with tetrahedra.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.2170-2174
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• 2005

Selective Laser Sintering (SLS) is a useful rapid prototyping technique for the manufacture of three dimensional (3D) solid objects directly from a scanning data. A new approach called a Selective Multi-Laser Sintering (SMLS) system has been developed at Korea Institute Machinery & Materials (KIMM) as an industrial type SFFS. This SMLS machine is built with a frame, heaters, nitrogen supply part, laser system. This system uses the dual laser and 3D scanner made in $Solutionix^{TM}$ to improve the precision and speed for large objects. The three-dimensional solid objects are made of polyamide powder. The investigation on each part of SMLS system is performed to determine the proper theirs design and the effect of experimental parameters on making the 3D objects. The temperature of the system has a great influence on sintering the polymer. Because the stability of the powder temperature prevents the deformation of each layer, the controls of the temperature in both the system and the powders are very important during the process. Therefore, we simulated the temperature distribution of build room using the temperature analysis with ANSYS program. Selected radiant heater is used to raise temperature of powder to melting point temperature. The laser parameters such as scan spacing, scan speed, laser power and laser delay time affect the production the 3D objects too. The combination of the slow scan speed and the high laser power shows the good results without the layer curling. The work is under way to evaluate the effect of experimental parameters on process and to produce the various objects. We are going to experiment continuously to improve the size accuracy and surface roughness.

• Journal of Magnetics
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• v.17 no.4
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• pp.265-270
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• 2012

We report improved low-field magnetoresistance (LFMR) effects of the $La_{0.7}Sr_{0.3}Mn_{1+d}O_3-Mn_3O_4$ composite films with the nominal composition of $La_{0.7}Sr_{0.3}MnO_3$(LSMO)-50 mol% $Mn_3O_4$. The composite films were fabricated by ex-situ solid phase crystallization (SPC) of amorphous films at the annealing temperature region of $900-1100^{\circ}C$ for 2 h in a pure oxygen atmosphere. The amorphous films were deposited on polycrystalline $BaZrO_3$ (poly-BZO) substrates by dc-magnetron sputtering at room temperature. The Curie temperatures ($T_C$) of all composite films were insignificantly altered in the range of 368-372 K. The highest LFMR value of 1.29 % in 0.5 kOe with the maximum dMR/dH value of $37.4%kOe^{-1}$ at 300 K was obtained from 900 nm-thick composite film annealed at $1100^{\circ}C$. The improved LFMR properties of the composite films are attributed to effective spin-dependent scattering at the $La_{0.7}Sr_{0.3}Mn_{1+d}O_3$ grain boundaries sharpened by adjacent chemically compatible $Mn_3O_4$ grains.

• Biomolecules & Therapeutics
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• v.23 no.4
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• pp.379-385
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• 2015

The eye irritation potential of drug candidates or pharmaceutical ingredients should be evaluated if there is a possibility of ocular exposure. Traditionally, the ocular irritation has been evaluated by the rabbit Draize test. However, rabbit eyes are more sensitive to irritants than human eyes, therefore substantial level of false positives are unavoidable. To resolve this species difference, several three-dimensional human corneal epithelial (HCE) models have been developed as alternative eye irritation test methods. Recently, we introduced a new HCE model, MCTT HCE$^{TM}$ which is reconstructed with non-transformed human corneal cells from limbal tissues. Here, we examined if MCTT HCE$^{TM}$ can be employed to evaluate eye irritation potential of solid substances. Through optimization of washing method and exposure time, treatment time was established as 10 min and washing procedure was set up as 4 times of washing with 10 mL of PBS and shaking in 30 mL of PBS in a beaker. With the established eye irritation test protocol, 11 solid substances (5 non-irritants, 6 irritants) were evaluated which demonstrated an excellent predictive capacity (100% accuracy, 100% specificity and 100% sensitivity). We also compared the performance of our test method with rabbit Draize test results and in vitro cytotoxicity test with 2D human corneal epithelial cell lines.

• Asian-Australasian Journal of Animal Sciences
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• v.33 no.4
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• pp.568-578
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• 2020

Objective: The objective of this study was to investigate effects of supplementation of culture media from solid-state fermented Isaria cicadae (I. cicadae) on performance, serum biochemical parameters, serum immune indexes, antioxidant capacity and meat quality of broiler chickens. Methods: A total of 648 Arbor Acres male broiler chickens(1 d; average body weight, 42.93±0.47 g) were randomly assigned to 6 treatments, each with six replicates and 18 broiler chickens per replicate. Broiler chickens were fed phase I (d 1 to 21) and phase II (d 22 to 42) diets. The phase I diets were corn and soybean-meal based diets supplemented with 0%, 2%, 4%, 6%, 8%, or 10% culture media from solid-state fermented I. cicadae respectively. The phase II diets were corn and soybean-meal based diets supplemented with 0%, 1.33%, 2.67%, 4.00%, 5.32%, or 6.67% culture media from solid-state fermented I. cicadae respectively. Results: In phase I, the broiler chickens with the supplementation of culture media had increased body weight gain and feed intake (linear and quadratic, p<0.05) with increasing inclusion of culture media. The levels of serum total antioxidant capacity (T-AOC), glutathione (GSH) and superoxide dismutase (SOD) increased linearly (p<0.05). In phase II, levels of serum T-AOC and interleukin-1β increased linearly (p<0.05), and GSH increased (p<0.05). In the kidney, GSH and glutathione peroxidase (GSH-Px) concentrations increased (linear and quadratic, p<0.05) and SOD concentration increased linearly (p<0.05). Compared to the control, shear force and drip loss of breast muscle decreased (linear and quadratic, p<0.05). Drip loss of leg muscle decreased linearly and quadratically (p<0.05). Conclusion: Dietary supplementation of culture media from solid-state fermented I.cicadae which was enriched in both wheat and residual bioactive components of I. cicadae enhanced the growth performance of broiler chickens. It also improved body anti-oxidative status and contributed to improve broiler meat quality.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.2 no.1
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• pp.76-85
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• 1992

${\beta}-$Ag_2S$(high temperature phase) was grown by solid/vapour reaction growth based on solid -state electrochemisty. In S/V growth, one of the reactants, silver ion, is supplied to the growth surface through the solid $Ag_2S$ from one side and the other reactants, surfur, is transported in the phase of vapour from the other side. With the sufficient supply of S vapour, the growth rate increased as increasing $T_d$(decomposition temperature of $Ag_2S$) and ${\Delta}T$ between $T_d$ and $T_g$(temperature of growth surface). At low S vapour pressure, growth rate decreased with decreased vapour pressure and ${\beta}-$Ag_2S$ was grown in the form of whisker, when Ag+ion is sufficiently supplied. The measured values of electronic conductivity of ${\beta}-$Ag_2S$ showed that electronic conductivity of the poly crystal was larger than that of single crystal.