• Korean Journal of Crystallography
• /
• v.3 no.1
• /
• pp.37-43
• /
• 1992

KTiOP04 is a nonlinear optical crystal which is most widely used for frequency doubling of the radiation of Nd : YAG laser. In the experiment, sin ale crystals of KTiOP04 were grown by TSSG technique using 3K2W04·P2O5 flux. Low temperature gradient furnace suitable for KTP single crystal growth was used. Seed crystal was placed at the surface of the solution for the purpose of better observation of the growing crystals and the possibility of diameter control. Solution included 66.7mol% KTiOP04 for all experiments and its saturation temperature was 1020℃. The conditions of single crystal growth were as follows: cooling rate 0.2℃/h, crystal rotation rate 50rpm, c -axis seed. Using these conditions, single crystals up to 23 ×25×25mm3 have been groan from about 100cc solution. We have also observed a change in the crystal growth habit which resulted in the formation of large (201) faces and small (100) faces. And some crystals have (101) faces.

• Proceedings of the Materials Research Society of Korea Conference
• /
• 2010.05a
• /
• pp.5.1-5.1
• /
• 2010

One of the most important environmental problems is global warming. Global warming is caused by increase in the amounts of water vapor, methane, carbon dioxide and other gases being released into the atmosphere as a result of the burning of fossil fuels. It has thus become important to reduce fossil fuel use. Environmentally friendly preparation of functional materials has, therefore, attracted much interest for environmental problems. Furthermore, nature mimetic processes are recently been of great interest as environmentally friendly one. There have been many studies on fabrication of various functional nanocrystals. Among various nanocrystal fabrication techniques, flux growth is an environmentally friendly, very convenient process and can produce functional nanocrystals at temperatures below the melting points of the solutes. Furthermore, this technique is suitable for the synthesis of crystals having an enhedral habit. In flux growth, the constituents of the materials to be crystallized are dissolved in a suitable flux (solvent) and crystal growth occurs as the solution becomes critically supersaturated. The supersaturation is attained by cooling the solution, by evaporation of the solvent or by a transport process in which the solute is made to flow from a hotter to a cooler region. Many kinds of oxide nanocrystals have been grown in our laboratory. For example, zero- (e.g., particle), one- (e.g., whisker and tube) and two-dimensional (e.g., sheet) nanocrystals were successfully grown by flux method. Our flux-growth technique has some industrial and ecological merits because the nanocrystal fabrication temperatures are far below their melting points and because the used reagents are less harmless to human being and the environment.

• Applied Microscopy
• /
• v.45 no.4
• /
• pp.230-235
• /
• 2015

Crystallographic models are effective tools to interpret, calculate and even to predict the preferred crystallographic morphologies of precipitates in various precipitation systems. The present study gives an introduction on the recently developed secondary constrained coincident site lattice (II-CCSL) model. Using the II-CCSL model, the interface matching condition of the ${\beta}-Mg_{17}Al_{12}$ precipitates with ${\alpha}-Mg$ matrix in an aged AZ91 alloy has been analyzed to rationalize the morphologies of the precipitates. The results show that the characteristic crystallographic features of the observed ${\beta}-Mg_{17}Al_{12}$ precipitates, i.e., the habit plane of the ${\beta}-Mg_{17}Al_{12}$ lath with a Burgers orientation relationship (OR) and the growth direction of the ${\beta}-Mg_{17}Al_{12}$ with a Crawley OR exhibit a better lattice matching degree than their vicinal orientations. Moreover, the Crawley OR is preferred to the Burgers OR due to a better lattice match.

• Journal of Pharmaceutical Investigation
• /
• v.18 no.2
• /
• pp.55-59
• /
• 1988

The size of furosemide was reduced by the recrystallization method in order to increase the dissolution rate of the drug. Surfactants or hydrophilic polymers were used to suppress the aggregation in the crystal formation-growth process of microparticles by dispersing action. Dissolution rate of microparticles increased remarkably due to the size reduction of microparticle. The particle size decreased with increasing the concentration of the drug and the dispersing agents, i.e., surfactants or hydrophilic polymers. No polymorphic transition occurred during the microcrystallization process, but the habit of crystal formation was altered in the case of anionic surfactant.

• Journal of Information Technology Services
• /
• v.13 no.2
• /
• pp.19-34
• /
• 2014

As the global smartphones market is growing at a brisk pace, their associated mobile applications are becoming increasingly ubiquitous in our daily life. The growth of mobile application business is explosive. Like other digital contents businesses, illegal downloads of copyrighted mobile applications become major obstacle in the future of the industry. In spite of anti-piracy efforts, the phenomenon has been getting worse. It is necessary to change the focus of current deterrence policies and strategies. This study investigates the factors influencing smartphone applications piracy behavior. For better understanding of illegal behavior, a research model of potential determinants for the piracy behavior is developed and empirically tested via path analysis using structural equation modeling. Findings show that social factors, beliefs concerning benefits from piracy, self-efficacy, and habit have significant effects on attitude toward smartphone application piracy. The result also shows perceived risks and facilitating conditions were not significantly related to their attitude. Implications for research and practice are discussed.

• Culinary science and hospitality research
• /
• v.7 no.1
• /
• pp.181-202
• /
• 2001

Recently there is growing concern regarding the service industry in Korea, especially the food service industry. The form of food service industry has become larger and speciallized by means of either implementing marketing programme in individual companies or the entrepreneurs' possesstion of chain stores. As the food service industry has extended throughout the whole of Korea, It has contributed enormously to the regional economy. These phenomena is based on the following facts; the increase in income level, the fast economy growth and change, rapid reform of social structure, and the change in status of the labor population. To meet these changes and reforms the food service industry in Korea has to form a new ideology that takes into account the interaction with globalization, the phenomena of instant-food consumption habit, a general increase in the those who eat-out, the two faces of luxury, and the blending of domestic extravagance and practicality, especially the influence of imported brands on advance technology and system utility on the economic section and style as a whole.

• Journal of the Korean Ceramic Society
• /
• v.27 no.2
• /
• pp.249-255
• /
• 1990

High Tc Supperconducting thin films were fabricated by rf magnetron sputtering method. We have successfully controlled the compositions of films by adding sintered CuO pellets on YBa2Cu3O7-x single target. High Tc thin films with large grian size and good crystal habit were obtained by rapid thermal annealing process. The films deposited on SrTiO3(100) single crystal substrate indicated the existence of c-axis prefered orientation confirmed by XRD and SEM analysis. The Tc, zero's of sharp resistive transition for rapid annealed films deposited on polycrystalline YSZ substrate and on SrTiO3(100) single crystal substrate were 79K and 88K, respectively.

• Journal of the Korean institute of surface engineering
• /
• v.29 no.6
• /
• pp.857-861
• /
• 1996

The influence of rf-plasma operation on the thin film formation containing small particles for Al-Li alloys mainly have been studied as a function of Ar gas pressure and plasma power by means of a 200kV transmission electron microscope (TEM). Under the non-plasma operation, the transition from continuous thin films to clusters of grape-like small particles occurred at Ar gas pressures above 20Pa. Particles were single crystals with clear crystal habit planes. Under the plasma operation, the influence of gas pressures on the film formation at a plasma power of 5W was also examined. Thin films containing particles below 30Pa and the films containing mainly particles above 40Pa were formed. The prominent change of the average particle size was not recognized. The increase of the plasma powers at 20Pa, which formed particles under non-plasma, suppressed growth of particles, and homogeneous films containing very small particles were fabricated. The electric conductivity showed slight decrease with an increase of plasma power.

• Journal of the Korean Society of Food Culture
• /
• v.1 no.2
• /
• pp.157-162
• /
• 1986

This study was conducted to research on the nutritional status of vegetarian boys high school students, to keep abreast with the international trend of stressing the vegetarian diet, thereby analyzing the degree of the influence of their dietary habit on their growth. The object of the study were 62boys high school students who are lacto-ovo vegetarians, and the author adopted three popular research methods. questionaire physical test and blood test Though vegetarian diet is helpful for the prevention of coronary and heart diesedse of the adults, but it is not enough for the students who are needed lot of protein and calorie.

• Journal of the Korea Safety Management & Science
• /
• v.9 no.4
• /
• pp.113-119
• /
• 2007

Recently, due to economic growth, living environment has been convenient and comfortable and so human activities were decreased. Consequently energy consumption was also decreased. Also the habit of food intake has been changed and the tendency of obesity has been increased. The main objective of this paper is to provide analysis of obesity index of residents in six metropolitan cities. According to analysis of $R\"{o}hrer$ Index, there were significant differences regionally between men and women in metropolitan cities. Through analysis of Drop Value, it was found that there were significant differences regionally between men and women in metropolitan cities on circumferences of chest, waist and buttocks. The result of this research can be utilized in manufacturing and design of uniforms and equipments for safety.