• Textile Coloration and Finishing
• /
• v.7 no.1
• /
• pp.10-22
• /
• 1995

Cellulosic fabrics, i.e. rayon, polynosic, and linen were treated with liquid ammonia at -33.4$^{\circ}C$. The fine structures, bending properties, tensile strength, wrinkle recoveries, and dyeing properties of the treated fabrics were studied. Dyeing was carried out with two direct dyes, C. I. Direct Red 2 and Blue 1. The liquid ammonia treatment for three fabrics brought about the transition of crystal lattices and the decrease of crystallinity; transforming cellulose I structure of original linen to cellulose I and III structure, and cellulose II structure of original rayon and polynosic to cellulose II and III structure. Moisture regain of liquid ammonia- treated polynosic and linen was higher than that for untreated, and water absorbency of liquid ammonia-traeated fabrics was all lower than that of untreated. Also, bending properties of treated fabrics were not improved compared with those of untreated ones. The rayon treated with liquid ammonia was increased not only the apparent diffusion coefficient and the rate of dyeing but also equilibrium dye adsortion, whereas polynosic and linen were increased only equilibrium dye adsortion. It is suggested that the pore sizes of liquid ammonia-treated rayon, polynosic, and linen are much smaller than that of liquid ammonia-treated cotton.

• Journal of ILASS-Korea
• /
• v.18 no.1
• /
• pp.44-54
• /
• 2013

An experimental study was performed to investigate the liquid jet breakup of a circular nozzle and elliptical nozzles. Furthermore Numerical simulation was attempted to investigate the internal flow structure in the circular and elliptical nozzles. This study showed that the disintegration characteristics of the liquid jet of elliptical nozzles were much different from those of the circular nozzle. The liquid jet issued from the elliptical nozzles became more unstable at the same injection pressure. Surface breakup was observed at the jet issued from the elliptical nozzles with the increase of injection pressure. The disintegration of the liquid jet of elliptical nozzles was related with the internal flow structure which is revealed from the numerical simulation.

• Proceedings of the Earthquake Engineering Society of Korea Conference
• /
• 1999.10a
• /
• pp.99-106
• /
• 1999

In this study a base-isolated liquid storage tank subjected to seismic ground motion is numerically simulated on frequency , domain considering three-dimensional liquid-structure-soil interaction. A hybrid formulation which combines the versatility of finite elements for tank structure and the efficiency of boundary elements for liquid and soil region is adopted for efficient modeling. The base-isolation system using the effective stiffness and damping ratio is also included in this formulation. in order to demonstrate the accuracy and validity of the developed solution the numerical results were compared with the reference solutions in each interaction problem. The effects of the liquid filling ratio and the stiffness of base-isolation system on the behavior of the liquid storage tanks are analyzed.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2004.08a
• /
• pp.1229-1232
• /
• 2004

The ratio of optimized concentration on optical characteristics for phase-separated composite organic films (PSCOF) liquid crystal display is 30% of pre-polymer (NOA65) and 70% of ferroelectric liquid crystal (Felix). The layer structure in ferroelectric liquid crystal cell made by 30% NOA65 and 70% Felix materials is tilt-bookshelf layer structure. The angle of tilt-bookshelf structure are 17$^{\circ}$, 12$^{\circ}$ which are almost same of tilt angle of ferroelectric liquid crystal in Sm $C^{\ast}$ phase. We know that this result is from compensating the layer buckling. In this paper, we will discuss the effect of layer structure in PSCOF cell on ratio of concentration between pre-polymer and liquid crystal by x-ray measurements. We believe that technology of PSCOF is a good solution to solve the problems of align-defect and mechanical shock for future TV application and plastic LCD.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.28 no.11
• /
• pp.1656-1663
• /
• 2004

As the structures become larger, higher and more complicated, the demand for safety level has increased. In recent years, TLD(Tuned Liquid Damper) proved to be a successful control tool for reducing structural vibrations. For this reason, the influence of some key parameters of the U-type TLD on the dynamic response is studied. And simple and effectively developed learning control logic is used to control vibration of U type Tuned Liquid Damper system. The purpose of this paper is design optimal control system to deal with unknown errors from non linearity and variation that cost modeling difficulty in complex structure and is followed with the desired behavior. Finally this hybrid control method applied to U type Tuned Liquid Damper structure gives the benefit from better performance of precision and stability of the structure by reducing vibration effect. This research leads to safety design in various structure to robust unspecified foreign disturbances such as windy-load and earthquake.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 1996.05a
• /
• pp.232-234
• /
• 1996

We have investigated the effect of molecular structure of polymer of rubbed polyimide (PI) films for surface liquid crystal alignment. To obtain surface alignment effect of Polymer molecular structure, we measured the polar (out of plane-tilt) anchoring strength and surface ordering of 5CB on rubbed PI surfaces. We have found that the polar anchoring strength of 5CB is depend on the polymer molecular structure of these unidirectionally rubbed PI surfaces.

• Journal of the Earthquake Engineering Society of Korea
• /
• v.26 no.5
• /
• pp.203-209
• /
• 2022

A simplified method for earthquake response analysis of a rectangular liquid storage tank is proposed with fluid-structure interaction considered. In order to simplify the complex three-dimensional structural behavior of a rectangular liquid storage tank, it is assumed that structural deformation does not occur in the plane parallel to the direction in which the earthquake ground motion is applied but in the plane perpendicular to the direction. The structural deformation is approximated by combining the natural modes of the simple beam and the cantilever beam. The hydrodynamic pressure, the structure's mass and stiffness, and the hydrodynamic pressure's added mass are derived by applying the Rayleigh-Ritz method. The natural frequency, structural deformation, pressure, effective mode mass, and effective mode height of the rectangular liquid storage tank are obtained. The structural displacement, hydrodynamic pressure, base shear, and overturning moment are calculated. The seismic response analysis of an example rectangular liquid storage tank is performed using the proposed simplified approach, and its accuracy is verified by comparing the results with the reference solution by the finite element method. Existing seismic design codes based on the hydrodynamic pressure in rigid liquid storage tanks are observed to produce results with significant errors that cannot be ignored.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.42 no.3
• /
• pp.297-302
• /
• 2016

In this study, we prepared liquid crystal emulsions composed of $C_{12-20}$ alkyl glucoside, $C_{14-22}$ alcohol, and behenyl alcohol and performed structure analysis using various analytical equipment. First, as an important characteristic of liquid crystal emulsions, maltese cross patterns and multi-layer structure were observed by a polarized microscope and cryo-SEM. Also, formation of liquid crystal phase was confirmed by DSC and multi-layer lamellar structure having an interlayer spacing approximately $305{\AA}$ was confirmed by small angle x-ray scattering (SAXS). The alkyl chain arrangement formed orthorhombic structure of a lamellar structure of the liquid crystal emulsion was confirmed by wide angle x-ray scattering (WAXS). These results suggest that information on the various physical properties obtained through the research of liquid crystal emulsion structure is expected to be widely used in cosmetics development in the future.

• Journal of the Korean Chemical Society
• /
• v.8 no.4
• /
• pp.179-182
• /
• 1964

The partition function of liquid ammonia was developed by applying the modified significant structure theory of liquid.$^5$ The molar volume, vapor pressure, vaporization entropy were calculated over a wide temperature range. The critical properties for the liquid were also calculated. And surface tensions of the liquid were calculated in a similar manner developed for water by Chang and Pak.$^{10}$ The results show good agreement with experimental observations.

• Earthquakes and Structures
• /
• v.15 no.2
• /
• pp.133-144
• /
• 2018

To study the effectiveness of sliding isolation in a CRLSS (concrete rectangular liquid-storage structure) and develop a reasonable limiting-device method, dynamic responses of non-isolation, sliding isolation with spring limiting-devices and sliding isolation with steel bar limiting-devices are comparatively studied by shaking table test. The seismic response reduction advantage of sliding isolation for concrete liquid-storage structures is discussed, and the effect of the limiting-device type on system dynamic responses is analyzed. The results show that the dynamic responses of sliding isolation CRLSS with steel bar-limiting devices are significantly smaller than that of sliding isolation CRLSS with spring-limiting devices. The structure acceleration and liquid sloshing wave height are greatly influenced by spring-limiting devices. The acceleration of the structure in this case is close to or greater than that of a non-isolated structure. Liquid sloshing shows stronger nonlinear characteristics. On the other hand, sliding isolation with steel bar-limiting devices has a good control effect on the structural dynamic response and the liquid sloshing height simultaneously. Thus, a limiting device is an important factor affecting the seismic response reduction effect of sliding isolation. To take full advantage of sliding isolation in a concrete liquid-storage structure, a reasonable design of the limiting device is particularly important.