• Journal of Pharmaceutical Investigation
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• 제32권2호
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• pp.95-101
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• 2002

Matrix tablets of nifedipine (NP) were prepared with Eudragit, diluent (lactose or Ca. phosphate) and Mg. stearate employing two different preparation methods (wet granulation and direct compression) to develop its sustained-release dosage forms. The effects of various formulation factors on the dissolution rate of the drug were investigated. Dissolution test was studied in pH 6.8 phosphate buffer containing 1% sodium lauryl sulfate using the paddle method. Formulation factors were the type and content of Eudragit, the type of diluent and the tablet preparation method. The optimum formula of NP matrix tablet, which resulted in a similar dissolution profile to that from Adalat Oros used as a reference, was 30 mg NP, 10% Eudragit RS, 2% Mg. stearate and an adequate quantity of lactose to yield 500 mg weight using the wet granulation method.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권2호
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• pp.1703-1705
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• 2007

Before the ultra-violet glue encapsulation, the research evaporated LiF thin film on device surface to be the extra packaging layer for improving the lifetime of organic light-emitting diode. The formula of UV glue was specially developed. We found 100 nm LiF is the optimum thickness. The best lifetime obtained by using LiF and special UV glue is 2.4 times longer than those by commercial UV glue.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• 제3B권1호
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• pp.23-31
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• 2003

A novel 3D shape optimization algorithm is presented for electromagnetic devices carry-ing eddy current. The algorithm integrates the 3D finite element performance analysis and the steepest descent method with design sensitivity and mesh relocation method. For the design sensitivity formula, the adjoint variable vector is defined in complex form based on the 3D finite element method for eddy current problems. A new 3D mesh relocation method is also proposed using the deformation theory of the elastic body under stress to renew the mesh as the shape changes. The design sensitivity f3r the sur-face nodal points is also systematically converted into that for the design variables for the parameterized optimization application. The proposed algorithm is applied to the optimum design of the tank shield model of the transformer and the effectiveness is proved.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 C
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• pp.1829-1831
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• 2001

A novel multi-section power divider configuration is proposed to obtain wide-band frequency performance up to microwave frequency region. Design procedures for the proposed microwave broadband power divider are composed of a planar multi-section three-ports hybrid and a waveguide transformer design procedures. The multi-section power divider is based on design theory of the optimum quarter-wave transformer. Furthermore, in order to obtain the broadband isolation performance between the two adjacent output ports, the odd mode equivalent circuit should be matched by using the lossy element such as resistor. The derived design formula for calculating these odd mode matching elements is based on the singly terminated filter design theory. The waveguide transformer section is designed to suppress the propagation of the higher order modes such as waveguide modes due to employing the metallic electric wall. Simulation and experiment show excellent performance of multi section power divider.

• 한국유체기계학회 논문집
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• 제10권4호
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• pp.15-20
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• 2007

In order to control and balance axial thrust of turbo machine, many types of balancing devices are used but most of them are complicated and sometimes cause troubles. In this study, a very simple device of using shallow grooves mounted on a casing wall, known as "J-Groove", is proposed and studied experimentally and theoretically. The result shows that 70% of axial thrust in an industrial 4-stage centrifugal pump can be reduced at the best efficiency point. Moreover, the analytical method of "interfered gap flow" is established and a simple formula which can determine the optimum dimension of groove and its location is proposed.

• Journal of the Korean Wood Science and Technology
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• 제37권2호
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• pp.128-136
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• 2009

Curved glued laminated timber (glulam) is rapidly coming into the domestic modern timber frame buildings and predominant in building construction. The radial stress is frequently occurred in curved beams and is a critical design parameter in curved glulam. Three models, Wilson equation, Exact solution and Approximation equation were introduced to determine the radial stress of curved glulam under pure bending condition. It is obvious that radial stress distribution between small radius and large radius was different due to slight change of neutral plane location to center line. If the beam design with extremely small radius, it should be considered to determine the exact location of maximum radial stress. The current standard KSF 3021 was reviewed and would be considered some adjustment determining the optimum radius in curved glulam. Current design principle is that the stress factor is given by the curvature term only in constant depth of the beam, but like tapered or small radius of beams, the stress factor by Wilson equation was underestimated. So current design formula should be considered to improvement for characterizing the radial stress factor under pure bending condition.

• 한국식품영양학회지
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• 제23권1호
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• pp.8-14
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• 2010

This study was carried out to develop an optimum baking formula and baking process for a new bread raw material with added Cordyceps militaris powder, which has been known to prevent various adult diseases and cancers. The rheological properities of dough made from Cordyceps militaris powder-wheat flour with 0, 1, 2, and 3% Cordyceps militaris powder added-were investigated. A farinogram showed that the water absorption and weakness value of dough increased with added Cordyceps militaris powder, but development time and dough stability were decreased. An extensogram showed that resistance to extension was increased in bread with 1% Cordyceps militaris powder, but decreased in bread with 2% and, 3% powder. Extensibility decreased fermentation progressed. An amylogram showed that gelatinization point was increased but maximum viscosity was decreased with added Cordyceps militaris powder. With increased amounts of powder dough volume during fermentation was reduced. The change in pH values of dough after mixing, fermentation, and proofing decreased with increased amounts of added powder.

• Biomolecules & Therapeutics
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• 제5권4호
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• pp.357-363
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• 1997

The effects of formulation variables of topical lotion on the skin permeation of ketoprofen were evaluated using excised rat skins. The formulation variables were the amounts of poloxamer 407, drug and ethanol, and penetration enhancers. The Keshary-Chien diffusion cells were used for the diffusion study. The flux of ketoprofen linearly decreased as the concentration of poloxamer increased from 5% to 15% in the preparation, and linearly increased as the amount of drug increased. Penetration enhancers such as fatty acids and fatty alcohols showed markedly enhancing effects at the level of 5%. Among them, the highest flux was shown in linolenic acid. From these results, optimum formula containing 3% ketoprofen, 5% poloxamer 407, 40% ethanol and 5% linolenic acid having the flux of 537.6 $\mu$g/$\textrm{cm}^2$/hr were noted.

• Journal of Pharmaceutical Investigation
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• 제18권1호
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• pp.31-41
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• 1988

Computer optimization technique was applied to obtain the optimum formula of o/w type ointment vehicle containing sodium lauryl sulfate and 1-methyl-2-pyrrolidinone (MP). In order to determine the feasibility of optimizing a vehicle composition with the aid of computer, the amounts of sodium lauryl sulfate $(X_1)$, salicylic acid $(X_2)$, and MP $(X_3)$ were selected as the independent variables for the solubility and the absorption rates of salicylic acid (dependent variables). The experimental values of absorption rates agreed well with the calculation values obtained from the polynomial regression analysis, and the contour charts drawn by computer were useful in optimization process.

• 공업화학
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• 제5권2호
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• pp.209-214
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• 1994

Mono alkyl glycerides have bean obtained in good yield by enzyme catalyst from soybean oil. The reaction was carried out in an oil rich microemulsion formula. Best results were obtained with sodium bis(2-ethyl hexyl) sulfo succinate(AOT), isooctane as hydrocarbon component and buffer of pH 7. The enzyme used was a 1,3-specific lipase which leaves the 2-position intact. However, the 2-monoglyceride formed slowly undergoes long chain acyl migration to 1-mono-glyceride. Optimal reaction time at $35^{\circ}C$ reaction temperature was found to be three hour.