• Korean Journal of Materials Research
• /
• v.13 no.1
• /
• pp.59-63
• /
• 2003

The microstructural characteristics of $Al_2$$O_3$/Cu composites hot-pressed at different temperatures for atmosphere switching from $H_2$to Ar have been studied. When the composite atmosphere was switched at $1000^{\circ}C$ it led to more homogeneous microstructure than when the atmosphere was switched at $1450^{\circ}C$. The strong sensitivity of Cu to atmosphere, especially the oxygen content in the atmosphere, was found to be responsible for the observed change, based upon the interfacial phenomena related to the formation of $CuAlO_2$. The practical implication of these results is that an optimum processing condition for the design of homogeneous microstructure and stable properties can be established.

• Journal of the Korean Ceramic Society
• /
• v.31 no.10
• /
• pp.1176-1180
• /
• 1994

The sliding wear behavior of the plasma-sprayed zirconia containing 3 mol% yttria was investigated after the annealing at room temperature to 80$0^{\circ}C$ in various concentrations of humid atmosphere as laboratory, humid, dry argon atmosphere. Both of the friction coefficient and the wear loss increased with increasing temperature up to 80$0^{\circ}C$. Surface morphology of the worn samples changed with annealing temperature. The change of monoclinic/tetragonal (m/t) x-ray peak intensity ratio effected the wear behavior. The m/t ratio had maximum value at 20$0^{\circ}C$ and decreased with increased temperature in laboratory and humid atmosphere. In argon atmosphere the m/t ratio had no maximum value and decreased with increasing temperature. At all the annealing temperature humid atmosphere had more the m/t ratio value than any other atmosphere. The change of toughness was showed the inversed result of m/t ratio change. The results indicated that the resudial stress which was induced by the different amount of phase transformation takes a detrimental role in wear behavior.

• Journal of Institute of Control, Robotics and Systems
• /
• v.6 no.10
• /
• pp.936-941
• /
• 2000

Advanced space transportation systems, such as the National Aerospace Plane or an Orbital Transfer Vehicle, have atmospheric maneuvering capabilities. For such vehicles the use of aeroassisted orbital transfer from a high Earth orbit to a low Earth orbit, with unpowered flight in the atmosphere, has the potential for significant fuel savings compared to exoatmospheric Hohmann transfer. However, to exploit the fuel savings that can be achieved by using the Earths atmosphere to reduce the vehicles energy, a guidance law is required, and it must be able to handle large unpredictable fluctuations in atmospheric density, on the order of ${\pm}$50% relative to the 1962 US Standard Atmosphere. In this paper aeroassisted orbital transfer is considered as a differential game, with Nature controlling the atmosphere density to yield a worst case (min-max fuel required) atmosphere, from which the guaranteed playable set boundary are achieved. Inside the playable set, it is guaranteed that the vehicle achieves the optimal atmospheric exit condition for the minimum fuel consumption regardless of the atmospheric density variations.

• Journal of Urban Science
• /
• v.9 no.1
• /
• pp.91-108
• /
• 2020

The purpose of this study is to study how Peter Zumthor construct an atmosphere throughout the process of his architecture. Peter Zumthor revels the atmosphere through his architecture works in architectural language. The beholders recognize the architectural ambience of Peter Zumthor through their various physical senses and reaction. Peter Zumthor placed a delicate attention on how to build and use of the material in order to encourage them to recognize the intended atmosphere, causing the atmosphere to the particular beholders.

• Journal of the East Asian Society of Dietary Life
• /
• v.4 no.1
• /
• pp.95-104
• /
• 1994

This study was carried out to investigate the effect of sub-atmosphere on the fermentation and heat treatment after fermentation of Kimchi. When the results from the conditions of atmosphere and under-atmosphere were compared, the growth of lactic acid bacteria was increased but the growth of aerobic bacteria was decreased under 560mmHg and 360mmHg. The number of total microorganism was decreased and simultaneously damaged to the tissue of Kimchi under 0mmHg. Kimchi fermented under 560mmHg and 360mmHg had longer storage duration than that of atmosphere. Among the several conditions, the result of heat treatment under 460-260mmHg was the best. the treatment for 4 minutes at 80$^{\circ}C$, 2 minutes at 100$^{\circ}C$, and 1 minute at 120$^{\circ}C$ was good in tissue states and storage.

• Journal of Ginseng Research
• /
• v.19 no.3
• /
• pp.260-266
• /
• 1995

Fifteen free fatty acids including myristic acid were isolated and identified from red ginseng processed from CA and MA stored fresh ginseng. Linoleic acid (80%) and palmitic acid (10.5%) content were the major components accounting for more than 90% of the total free fatty acid. The contents of free and identified fatty acids were not greatly changed in all the treatments. Especially when preservative was treated, the change of free fatty acid was quite stable over the control. Each fraction of neutral, glyco- and phospholipid was constant in terms of quantities before and after the treatment. Key words Controlled atmosphere, modified atmosphere, fresh ginseng, red ginseng, fatty acid.

• Hwankyungkyoyuk
• /
• v.23 no.2
• /
• pp.16-31
• /
• 2010

The purpose of this study was to investigate the influence of the integrated atmosphere environmental education program on environmental attitudes for 5th graders in elementary school. The major results of this study were as follows. First, the developed atmosphere environmental education program had a positive effect on environmental attitudes of elementary students. Second, it also had a positive effect on their interest and desire of atmosphere environment issues. Third, it had a positive correlation among the 3 subdomains of cognitive, affective and behavioral. In conclusion, the atmosphere environmental education program is more directly effective than lectures on environment following the curriculum to improve students' attitudes toward environment. Therefore, it is required that more systematic research should be done linking with teaching and learning methods, as a follow-up activity.

• Journal of the Korean Society for Heat Treatment
• /
• v.7 no.2
• /
• pp.111-117
• /
• 1994

Effect of rapidly solidfid 6.5wt%Si-Fe alloy annealed in the sulfur atmosphere were studied. The ribbons Which were showed with random structure at the received state, were developed into(110) texture in the heat treatment of the vacuum atmosphere, into (100)texture in the sulfur atmosphere. After the ribbon was continuously annealed in the vacuum atmosphere for 3 min. at $1100^{\circ}C$, and sulfur atmosphere for 1hr at $1175^{\circ}C$, grain size of (100)plane was grew to 4-8mm and the coercive force was decreased to 2-4A/m remarkably.

• Atmosphere
• /
• v.15 no.3
• /
• pp.149-153
• /
• 2005

A balloon-borne Optical Particle Counter (hereafter "OPC Sonde"), which was developed by the atmospheric research group of Nagoya University, is used for getting the information of vertical profile of particle size and concentration in Anmyeon ($36^{\circ}32^{\prime}N$ $126^{\circ}19^{\prime}E$) on 18 March 2005. A range of five different particle sizes is shown in the vertical profile of aerosol number density estimated from the OPC Sonde. It was found that small size particles have vertically larger aerosol number density than relatively big ones. For all size ranges the vertical aerosol number density shows a decreased pattern as the altitude becomes higher. The aerosol number density of $0.3{\sim}0.5{\mu}m$, $0.5{\sim}0.8{\mu}m$, $0.8{\sim}1.2{\mu}m$ size ranges at the 10km height, which is the tropopause approximately, are $1,000,000ea/m^3$, $100,000ea/m^3$, $10,000ea/m^3$ respectively. The data of OPC Sonde are also compared with the data of PM10 $\beta$-ray) and Micro Pulse Lidar which are operating at Korea Global Atmosphere Watch Observatory in Anmyeon.

• Korean Journal of Food Science and Technology
• /
• v.13 no.1
• /
• pp.25-29
• /
• 1981

Harvested asparagus, Viking variety, was stored in normal and controlled atmosphere with and without ‘Butts in water’ to extend shelf life of fresh asparagus. Controlled atmosphere storage significantly reduced bacterial soft rot of asparagus. When asparagus was stored in controlled atmosphere in combination with ‘Butts in water’, asparagus spears could be stored over 3 weeks without noticeable soft rot. Texture of stored asparagus, as measured by Instron and fiber analysis, became tougher as the storage time was extended. Increase of fiber content in asparagus was significantly reduced by controlled atmosphere storage and fiber content actually decreased in asparagus stored in controlled atmosphere in combination with ‘Butts in water’. Asparagus stored in controlled atmosphere had markedly less chlorophyll destruction than that in normal atmosphere. Reflectance color values of stored asparagus were closely associated with chlorophyll content in asparagus. Considering all quality factors of stored asparagus, controlled atmosphere in combination with ‘Butts in water’ was the best storage method to maintain overall quality of harvested asparagus over 3 weeks.