• 한국정보디스플레이학회:학술대회논문집
• /
• 2006.08a
• /
• pp.655-659
• /
• 2006

This paper presents a novel electrostatic drop-on-demand inkjet device featured by a MEMS fabricated pole-type and hole-type nozzle with tube shaped orifice and investigates the feasibility of applying the inkjet device to display fabrication process. The electric voltage signal applied to the ring shaped upper electrode plate, against the hole-shaped ground or pole-shaped ground, referred here pole-type and hole-type nozzle respectively, allows ejection of small droplet to take place: That is, a tiny droplet is taken away from the peak of the mountain shaped liquid meniscus formed at the nozzle orifice. It is verified experimentally that the use of the pole type nozzle allows a stable and sustainable micro-dripping mode of droplet ejection for a wider range of applied voltages and of liquid viscosities. This demonstrates a feasibility of electrostatic drop-on-demand inkjet device as a disruptive alternative to conventional print heads such as thermal bubble or piezoelectric inkjet heads.

• Fashion & Textile Research Journal
• /
• v.6 no.4
• /
• pp.433-439
• /
• 2004

Hanji costumes has four aspects that allow the creator or artist to create many variations. The pictorial effects of Hanji costumes are produced through variations in the dyes and brushes used for its application. The amount of water and texture of the Hanji mixture also influences the Hanji clothing. This effect was expressed using a dry brush technique, a dripping technique, India inks, and fragments from other Hanji works. A second aspect of Hanji clothing is the coloring effect in the Hanji costumes. The coloring is due to the fibers in the preparation mixture and the uniqueness of the dyes. The Hanji clothing was dyed various colors and patterns by dip dyeing, block dyeing, silk screens, digital printing. The third aspect of Hanji imagination in clothing is the decorative details. The details in Hanji clothing can be seen using frills, pleats, tucks and ribbons. The last variation of Hanji clothing can be expressed through crafting techniques. These techniques are the quality of paper string, cuts in the paper and paste ingredients. With Hanji cloth, it is possible to plait, roll, and crample into other flexible & useful materials.

• Proceedings of the KSME Conference
• /
• 2000.11b
• /
• pp.738-744
• /
• 2000

The breakup behaviors of impinging droplet on a hot surface are studied experimentally. The droplets are produced by the dripping method and the breakup behaviors of liquid droplet are recorded by photographs. Experimental conditions are, droplet diameter di : 2.5, 3.2 [mm], weber number : $30{\sim}140$, surface temperature : $28^{\circ}C(room\;temperature){\sim}450^{\circ}C$. Water is used to liquid. As weber number of droplet increases, a liquid sheet, which is formed after the impingement on a hot surface, is disintergrated by the dynamical effect. But at low weber number, it has effected by thermodynamical effect. The breakup behaviors of droplet are divided into three patterns with weber number and surface temperature, non-disintegration, transition and disintegration region. Further, these boundary values are affected by the hot surface temperature and weber number. SMD of breakup droplets are calculated in according to surface temperatures and weber number. The minium SMD of breakup droplets are observed at weber number 65.49, temperature $250^{\circ}C$ and weber number 99.08, temperature $350^{\circ}C$.

• Fire Science and Engineering
• /
• v.13 no.2
• /
• pp.3-11
• /
• 1999

New examination of a predictive model for the ISO 9705 room-corner test have been m made for materials studied by L S Fire Laboratories, Italy. The ISO 9705 test subjects wall a and ceiling mounted materials to a comer ignition source of 100 kW for a duration of 10 m minutes; if flashover does not occur this is followed by 300 kW for another 10 minutes. The m materials that did not stay in place during combustion because of melting, dripping, or d distorting were simulated by an adjustment to the material's total available energy. For m mat려als that remain in place the simulation model appears to do well in its prl어ictions. A l large-s떠Ie room test results 뾰 compar벼 with the m여el’s prediction also.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.24 no.8
• /
• pp.1085-1096
• /
• 2000

An experimental study was performed to examine the heat and mass transfer characteristics of $LiBr-H_2O$ solution flowing over a single horizontal tube with the water vapor absorption. Effects of the flow rate and the temperature of the solution at the top of the tube, the absorber pressure and the drainage pattern were considered. The absorption rate depends highly on the absorber pressure at the low flow rate condition while on the solution inlet temperature at the high flow rate condition. Also, when the flow rate is low, the absorption performance with the sheet flow drainage appeared to be higher than that with the dripping/jet drainage. However, at the high flow rate condition, the case became reversed. The liquid film became wavy with the higher absorption rate. The waves were more probable to form with the lower flow rate and temperature of the solution, and with the higher absorber pressure.

• Transactions of the Society of Information Storage Systems
• /
• v.1 no.1
• /
• pp.108-114
• /
• 2005

The generation of fine relics of suspensions is a significant interest as it holds the key to the fabrication of electronic devices. These processes offer opportunities for miniaturization of multilayer circuits, for production of functionally graded materials, ordered composites and far small complex-shaped components. Some novel printing methods of depositing ceramic and metal droplets were suggested in recent years. In an electro-hydrodynamic printing, the metallic capillary nozzle can be raised to several kilovolts with respect to the infinite ground plate or pin-type electrode positioned a few millimeters from the nozzle tip. Depending on the electrical and physical properties of the liquid, for a given geometry, it Is possible to generate droplets in any one of three modes, dripping, cone-jet and multi-jet. In this experiment, an alumina suspension flowing through a nozzle was subjected to electro-hydrodynamic printing using pin-type electrodes in the cone-jet mode at different applied voltages. The pin-type electrodes of 1, 100, 1000${\mu}m$ in diameter were used to form fine ceramic patterns onto the substrates. Various feature sizes with applied voltages and electrode diameters were measured. The feature sizes increased with the electrode diameter and applied voltages. The feature size was as fine as $30 {\mu}m$.

• The Korean Journal of Pain
• /
• v.8 no.1
• /
• pp.156-158
• /
• 1995

Total spinal anesthesia is a well documented serious life threatening complication which results from an attempted spinal or epidural analgesia. We had an accidental total spinal anesthesia associated with a cranial nerve paralysis and an eventual unconsciousness during epidural analgesia. A 45-year-old female with an uterine myoma was scheduled for a total abdominal hysterectomy under the epidural analgesia. A lumbar tapping for the epidural analgesia was performed in a sitting position at a level between $L_{3-4}$, using a 18 gauge Tuohy needle. Using the "Loss of Resistance" technique to identify the epidural space, the first attempt failed; however, the second attempt with the same level and the technique was successful. The epidural space was identified erroneously. However, fluid was dripping very slowly through the needle, which we thought was the fluid from the normal saline which was injected from the outside to identify the space. Then 20 ml of 2% lidocaine was administered into the epidural space. Shortly after the spinal injection of lidocaine, many signs of total spinal anesthesia could be clearly observed, accompanied by the following progressing signs of intracrainal nerve paralysis: phrenic nerve, vagus nerve, glossopharyngeal nerve and trigeminal nerve in that order. Then female was intubated and her respiration was controlled without delay. The scheduled operation was carried out uneventfully for 2 hours and 20 minutes. The patient recovered gradually in th4e reverse order four hours from that time.

• The Research Journal of the Costume Culture
• /
• v.10 no.5
• /
• pp.578-589
• /
• 2002

The purpose of this research was to analyze the residual water retention and to determine the number and species of microorganisms from the wet cotton fabrics in dehydration and drying process during washing. The drying rates of terrycloth and interlock knit under the rainy seasons were measured according to the dehydration and hanging methods, layers of fabric and pre-treatment agents. Microorganisms were isolated from the dried terrycloth by pure culture, and were identified by Biolog system. The results are as follow: The initial water retention of fabrics after dehydration decreased in the order of dripping>centrifuge>squeezing method, which affected the drying rate. The drying rates were faster by increasing surface area of fabrics. There was no significant difference in drying rate among the fabrics pre-treated with detergent, or fabric softener, or cationic surfactants such as Cetyltrimethylammonium bromide(CTAB) and Benzalkonium chloride(BC). Puedomonas aureginosa was found in the fabrics treated with a powder-type detergent. On the other side, there was no growth of microorganism in the fabrics treated with a liquid-type detergent (containing antibacterial agent), CTAB and BC.

• Journal of ILASS-Korea
• /
• v.10 no.2
• /
• pp.18-31
• /
• 2005

This study was performed to explore the liquid breakup and atomization characteristics for the classification of drop formation mode and background of uniform droplets generation in electrohydrodynmaic atomization according to the change of experimental parameters such as nozzle material (stainless steel. teflon). fluid flow rate, applied electrical field and intensity, and frequency. In results, from the classification map of drop formation modes according to the variation of applied AC voltage and frequency at a stainless nozzle, the droplet size was smaller than the outer diameter of the nozzle tip relatively in the spindle mode. The transition points became clearly to be moved toward the high applied voltage by rising the applied AC frequency beyond 450Hz. Also the droplet radius can be observed quite small in the frequency bandwidth of $350{\sim}450Hz$. The droplet radiuses decrease as the applied voltage increases for a fixed applied AC frequency within the range from 50Hz to 400Hz Over 400Hz, the relation between the power intensity and the droplet size was not consistent with a continuous mechanism of liquid breakup. Thus, it is showed that the droplet size distribution using the teflon nozzle was analogous to the results of stainless steel, but the droplet size was bigger than that of stainless steel relatively in case of a teflon nozzle.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.56 no.8
• /
• pp.1445-1449
• /
• 2007

This paper presents the DOD (Drop-On-Demand) characteristic using the electrostatic field induced inkjet printing system. In order to achieve the DOD characteristic of electrostatic field induced inkjet printing, applied the bias voltage of 1.4 kV and the pulse voltage of $2.0\;kV\;{\sim}\;2.7\;kV$ using high voltage pulse generator. Electrostatic field induced droplet ejection is directly observed using a high-speed camera and for investigated DOD characteristic, CNT ink used. The electrostatic field induced inkjet head system has DOD characteristic using pulse generator which can be applied pulse voltage. The bias voltage has a good condition which form meniscus and has micro dripping mode for small size micro droplet. Also, the droplet size decreases with increasing the applied pulse voltage. This paper shows DOD characteristic at electrostatic field induced inkjet head system, Therefore. electrostatic DOD inkjet head system will be applied industrial area comparing conventional electrostatic inkjet head system.