• Journal of Korea Foundry Society
• /
• v.7 no.2
• /
• pp.122-132
• /
• 1987

Full mold casting process is a new technique offering numerous advantages and promising possibilities. The present study is aimed to bring out the results of experiments carried out to study the effect of pattern coatings on the solidification of 99.5% pure aluminum plate-shaped castings in the various sand molds and the thermal behavior of the molds. The results of the investigation indicate that (i) with increase in pattern coating thickness, the relative chilling power decreases gradually for silica and increases for zircon coating, and (ii) the application of a pattern coating significantly reduces the maximum interface temperature by the mold which is more pronounced in the case of thinner mold wall. The investigation also indicates that Chvorinov's rule is not found to be valid for the casting in the full mold, with or without pattern coating. Therefore in full mold process, the pattern coating thickness will be a very important parameter in the study of thermal behavior.

• Journal of the Korean Society for Precision Engineering
• /
• v.29 no.10
• /
• pp.1144-1148
• /
• 2012

Process conditions for generating nano patterns handle different process according to the pattern characteristics, and different process data according to patterns in questions. To efficiently find optimal process conditions for generating nano patterns, process data by experiment is needed consideration of the pattern characteristics concerning the equipment. In particular, coating methods of a cylindrical mold differ from it of a flat plate because of viscosity of coating materials. Also the coating thickness affects nano process and pattern line width. So coating method of coating thickness for cylindrical mold is very important on nano pattern generating. In this study, a method is proposed for coating Photo Resist through the spray in order to coat cylindrical mold and measuring the thickness of coating using measuring tip considering the size of cylindrical mold because there is no method in the existing SEM. The proposed method is applied to a real printed electronics system to verify its accuracy and efficiency.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 1995.11a
• /
• pp.273-276
• /
• 1995

In this paper, the response characteristics of organic gases were investigated by using quartz crystal microbalance(Q.C.M) with different coating materials. The method for pattern was discussed in order to develope gas sensing system using neural network and pattern recognition. we analyzed the response characteristics by the area of frequency shift, which mean affinities of gases for coating material. The results shows that the Parameter made by the area of frequency shift has possibility to be used for pattern recognition and neural network. we found that each gas had different decrease pattern for coating material.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.11 no.6
• /
• pp.183-188
• /
• 2012

This study was carried out to design the spray nozzle tip for airless spray coating. Airless spray coating is the process of coating an object with a liquid spray of paint or other fluid. The nozzle tip controls the fluid flow rate and creates back pressure in the system. The nozzle tip also defines the spray pattern by the size and shape of the orifice. The spray pattern of nozzle tip was investigated numerically using ANSYS CFX ver. 14.0. It was observed that performance result of designed nozzle tip was correspond well, compared with that of GARCO nozzle tip.

• Journal of Ocean Engineering and Technology
• /
• v.28 no.2
• /
• pp.177-184
• /
• 2014

Heavy duty coating is playing an important role in the field of heavy industry in the development of the shipbuilding and plant industries. Heavy duty coating has the very important function of protecting steel under serious corrosive conditions. The airless tip used for heavy duty coating is an essential part that determines the spray pattern of the paint. This research investigated the injection properties of three airless tips(numbers 521, 523, and 525) by using particle image velocimetry(PIV). The velocity and turbulent intensity according to pressure change with each tip type were investigated by using PIV. If the pressure is greater, the turbulent intensity becomes stronger and the break up of particles becomes bigger as the tip number gets smaller. The velocity is the fastest in the center and decreases in the radial direction.

• Journal of information and communication convergence engineering
• /
• v.10 no.3
• /
• pp.295-299
• /
• 2012

Defect generation during organic bottom anti-reflective coating (BARC) in the photo lithography process is closely related to humidity control in the BARC coating unit. Defects are related to the water component due to the humidity and act as a blocking material for the etching process, resulting in an extreme pattern bridging in the subsequent BARC etching process of the poly etch step. In this paper, the lower limit for the humidity that should be stringently controlled for to prevent defect generation during BARC coating is proposed. Various images of defects are inspected using various inspection tools utilizing optical and electron beams. The mechanism for defect generation only in the specific BARC coating step is analyzed and explained. The BARC defect-induced gate pattern bridging mechanism in the lithography process is also well explained in this paper.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2012.05a
• /
• pp.581-582
• /
• 2012

• The Journal of Internal Korean Medicine
• /
• v.42 no.6
• /
• pp.1199-1210
• /
• 2021

Objectives: The aim of this study was to analyze the correlation between patterns determined by pattern identification of functional dyspepsia (FD) and tongue features, including tongue coating and tooth marks, in FD patients. Methods: We reviewed the clinical records of 68 FD patients who visited the Department of Digestive Diseases of Kyung Hee University Korean Medicine Hospital from September 1, 2020 to August 31, 2021. The subjects were evaluated with a computerized tongue image acquisition system (CTIS) and by pattern identification of FD. Measurement included the percentage of tongue coating, tooth mark levels, and pattern scores. Results: Statistically significant negative correlations were noted between the scores of the pattern of 'spleen and stomach deficiency and cold' (SSDC) and the percentage of tongue coating in whole, center, and root of the tongue body. However, no other patterns were correlated with any parameter measured by CTIS. No significant difference was noted in the percentage of tongue coating and the tooth mark level between the patterns. Conclusions: This study demonstrated that the pattern of SSDC was significantly associated with the percentage of tongue coating. We suggest that the percentage of tongue coating could be a useful indicator for identifying the degree of patterning of SSDC in patients with FD.

• Journal of Korea Foundry Society
• /
• v.17 no.6
• /
• pp.569-576
• /
• 1997

Coating materials for Evaporative Pattern Casting (EPC) process have been developed to investigate the effect of refractories on coating material properties. Three types of developed and one foreign coating materials were used. The former designated as A, B, C and the latter named S.K. The refractory of coating material A is spherical shape of zirconia, and the ones of B, C and S.K. is flake shape of mica. Strength, permeability at room and elevated temperature, anti-sand attachability and carbon residuary were evaluated at each coating materials. Permeability measurement device for elevated temperature was also designed. The zirconia type of coating material had excellent permeability, on the other hand the mica type had good strength and anti-sand attachability. It was found that the refractories were not broken during casting, so permeability indicated same trend at both room and elevated temperature. Based on results, coating material contained small size of mica which is designated as B has the best combination for cast iron.

• Journal of the Korean Ceramic Society
• /
• v.35 no.12
• /
• pp.1257-1265
• /
• 1998

Hertzian contact tests were used to investigate the evolution of fracturedamage in the coating layer as functions of contact load and coating thickness by studying crack patterns in porcelain on glass-infiltrated alumina bilayer system conceived to simulate the crown structure of a tooth. Cone cracks initiated at the coating top surface without delamination at interface and crack propagation to substrate. Preferentially the cracks made multi-cracks at the coating top surface rather than proceeding to interface. The cracks were highly stabilized with wide ranges between the loads to initiate first cracking and to cause final failure im-plying damage-tolerant capability. Finite element modelling was used to evaluate the stress distribution. Maximum tensile stress were responsible for the cracking at the coating layer and had a profound influence on the crack pattern and fracture damage in the layered structure materials.