• Journal of the Korean institute of surface engineering
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• v.18 no.3
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• pp.95-104
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• 1985

A study has been made of preferred orientation, crose sectional microstructure, surface morphology and mechanical properties of copper foils fabricated by electrodeposition on 304 stainless steel plate from copper sulfate baths for high speed plating. The preferred orientation of the copper foils changed from the [110] to the [111] to ture with decreasing bath temperature and increasing cathode current density. The foils with the [110] texture had the field oriented texture type structure and the surface of many asperities grooved approximately perpendicular to the subtrate. A specimen with the [111]+[311] texture had the lower strength than one with the [10] texture, if they were obtained under similar electrolysis conditions.

• Proceedings of the Materials Research Society of Korea Conference
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• 2012.05a
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• pp.95.1-95.1
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• 2012

Very High Temperature gas cooler Reactor (VHTR) has been considered as one of the most promising nuclear reactor because of many advantages including high inherent safety to avoid environmental pollution, high thermal efficiency and the role of secondary energy source. The TRISO coated fuel particles used in VHTR are composed of 4 layers as OPyC, SiC, IPyC and buffer PyC. The significance of CVD-SiC coatings used in tri-isotropic(TRISO) nuclear coated fuel particles is to maintain the strength of the whole particle. Various methods have been proposed to evaluate the mechanical properties of CVD-SiC film at room temperature. However, few works have been attempted to characterize properties of CVD-SiC film at high temperature. In this study, micro tensile system was newly developed for mechanical characterization of SiC thin film at elevated temperature. Two kinds of CVD-SiC films were prepared for micro tensile test. SiC-A had [111]-preferred orientation, while SiC-B had [220]-preferred orientation. The free silicon was co-deposited in SiC-B coating layer. The fracture strength of two different CVD-SiC films was characterized up to $1000^{\circ}C$.The strength of SiC-B film decreased with temperature. This result can be explained by free silicon, observed in SiC-B along the columnar boundaries by TEM. The presence of free silicon causes strength degradation. Also, larger Weibull-modulus was measured. The new method can be used for thin film material at high temperature.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.7 no.2
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• pp.255-262
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• 2003

In this paper, an investigation on the ZnO film deposition using radio-frequency magnetic sputtering techniques on aluminum bottom electrode for film bulk acoustic wave resonator (FBAR) filter applications and the temperature effects on the ZnO film growth is presented. The investigation on how much impact the actual process temperature may have on the crystal growth is more meaningful if it is considered that the piezoelectricity property of ZnO films plays a dominant role in determining the resonance characteristics of FBAR devices and the piezoelectricity is determined by the degree of the c-axis preferred orientation of the deposited ZnO films. In this experiment, it was found that the growth of ZnO crystals has a strong dependence on the deposition temperature ranged from room temperature to $350^{\circ}C$ regardless of the RF powers applied and there exist 3 temperature regions divided by 2 critical temperatures according to the degree of the c-axis preferred orientation. Overall, below $200^{\circ}C$, ZnO deposition results in columnar grains with a highly preferred c-axis orientation. With this ZnO film, a multilayered FBAR structure could be realized successfully.

• Journal of the Korean Ceramic Society
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• v.39 no.12
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• pp.1171-1176
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• 2002

The growth characteristics on the MgO thin films prepared by the e-beam evaporation method have been investigated. We observed the film of preferred orientation and surface morphology with various parameters such as substrate temperature, deposition rate on Si(100) and slide glass respectively. Consequently, it was shown that MgO(111) preferred orientation films can be obtained as the deposition rate was increased on Si(100) substrate. MgO(220) peak was found as the substrate temperature was increased. Whereas, in case of slide glass the orientation is changed from (200) to (111) by substrate temperature. Also we investigated the relationship between the film characteristics and the orientation of MgO thin films.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.29 no.9
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• pp.1-9
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• 2015

The aim of this study is to deduce color temperature and illuminance by conducting the preference & affective evaluation consequent on illuminance change of ambient light in case of the lighting method of ambient light mixed with task light in time of reading which is visual work action among the action in learning space. As a result of the prior survey on preferred lighting method in time of the act of reading targeting 20 experts before doing evaluation, the method of lighting mixed with ambient light and task light was found to be the highest. Such a result is analyzed to be attributable to the fact that the less the difference in illuminance of nearby space and work surface because of the mixed method of lighting, the less the glare, which makes a reader feels easy and concentrate on reading. On the basis of descriptive statistics of evaluation results and impact analysis by category, this study recommends the application of combinations of ambient light illuminance ranging from 40lx to 100lx with color temperature of 5500~6000K in case of the method of lighting mixed with general light and task light.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.04b
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• pp.101-104
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• 2004

In this study AlN/Al thin films were prepared at various conditions, such as $N_2$ gas flow rate $[N_2/(N_2+Ar)]$ from 0.6 to 0.9, a substrate temperature ranging from room temperature to $300^{\circ}C$ and working pressure 1mTorr. We estimated crystallographic characteristics and c-axis preferred orientations of AlN/Al thin films as function of Al electrode surface roughfness. The optimal processing conditions for Al electrode were found at substrate temperature of $300^{\circ}C$, sputtering power of 100W and a working pressure of 2mTorr. In these conditions, we obtained the c-axis preferred orientation of $AlN/Al/SiO_2/Si$ thin film about 4 degree.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.44 no.6
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• pp.658-664
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• 2011

Rotifers of the genus Brachionus are commonly used as a live food for larval fish, and rotifers of different sizes are preferred according the mouth size of the fish. Rotifer species vary in size, and individual size can depend on the temperature and salinity of the rearing environment. We investigated the effects of temperature and salinity for two species, B. plicatilis (250-300 ${\mu}m$) and B. rotundiformis (100-220 ${\mu}m$). Two strains of B. plicatilis (CCUMP 36 and 48) and two strains of B. rotundiformis (CCUMP 51 and 56) were received from the Culture Collection of Useful Marine Plankton (CCUMP) at Pukyong National University and cultured with the green alga, Nannochloris oculata (KMMCC 16) from the Korea Marine Microalgal Culture Center (KMMCC). The growth and size of rotifers were examined at three water temperatures ($16^{\circ}C$, $24^{\circ}C$, $32^{\circ}C$) and four salinities (20 psu, 25 psu, 30 psu, 35 psu) under continuous light (40 ${\mu}molm^{-2}s^{-1}$). The maximum density and growth rate of B. rotundiformis were greater than those of B. plicatilis. The lorica length of B. plicatilis ranged from 215.4 to 269.7 ${\mu}m$ and from 154.9 to 206.6 ${\mu}m$ for B. rotundiformis, depending on strain, temperature and salinity. Rotifers were smaller when cultured at high temperatures, regardless of salinity. B. rotundiformis preferred higher salinity than B. plicatilis. The results demonstrated that the size of rotifers could be controlled to some extent by temperature and salinity.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1998.06a
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• pp.325-329
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• 1998

In this paper, the (Sr$_{1-x}$ Ca$_{x}$)TiO$_3$(SCT) thin films were deposited at various substrate temperature using RF magnetron sputtering method on optimized Pt-coated electrodes (Pt/TiN/SiO$_2$/Si). An influence of substrate temperature and annealing temperature on the structural and dielectric properties are investigated. The substrate temperature changed from 100[$^{\circ}C$] to 500[$^{\circ}C$] and crystalline SCT thin films were deposited abode 400[$^{\circ}C$]. All thin films had (111) preferred orientation, the (100) oriented films were obtained at the substrate temperature above 400[$^{\circ}C$]. The dielectric constant changes almost linearly in the temperature region of -80~+90[$^{\circ}C$], the temperature characteristics of the dielectric loss exhibited a stable value within 0.1, then not affected by substitutional contents. The capacitance characteristics appears a stable value within $\pm$5[%].

• Fashion & Textile Research Journal
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• v.22 no.6
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• pp.844-852
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• 2020

This study is to understand the preferences of pilots, flight engineers and crew who work in the same aircraft but are exposed to different working environments and perform different mission operations in order to develop an ergonomic flight jacket. Based on a preliminary investigation, a survey of 107 pilots and 36 flight engineers and crew was conducted. The results are as follows; Pilots can control the temperature inside the cockpit, so they are less exposed to the cold when working, while flight engineers and crew are exposed to the cold more because they have many external tasks. The reason for the problem of the current flight jacket was a difference in ranking between two groups, but the highest ranking was poor dimensional suitability due to the habit of wearing layers of clothing. As a result of preferred design, there were significant differences between groups in the item of overall style. Pilots preferred a bomber jacket style(P:68.2%, E&C:44.4%), on the other hand, flight engineers and crew preferred a field jacket style(P:26.2%, E&C:55.6%)(p<.01). They preferred a stand collar(P:71.0%, E&C:86.1%), a fastener slider for a front fastening(P:62.6%, E&C:61.1%), fastener tape cuffs(P:54.2%, E&C:47.2%), a jacket with a softshell(P:86.9%, E&C:83.3%), fleece as softshell material(P:88.8%, E&C:69.4%), and fastener sliders as a attaching method(P:69.2%, E&C:61.1%). A hem fastening will be selected differently according to the overall style of outshell. Additionally, they preferred more than 5ea pockets(P:51.4%, E&C:44.4%), fastener sliders as pocket's fastenings(P:48.6%, E&C:61.1%), armpit ventilations(P:62.9%, E&C:58.5%). The results of above will be considered to design an ergonomic flight jacket.

• Journal of the Korean Ceramic Society
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• v.52 no.6
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• pp.441-448
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• 2015

Silicon carbide (SiC) coatings for tri-isotropic (TRISO) nuclear fuel particles were fabricated using a chemical vapor deposition (CVD) process onto graphite. A micro-tensile-testing system was developed for the mechanical characterization of SiC coatings at high temperatures. The fracture strength of the SiC coatings was characterized by the developed micro-tensile test in the range of $25^{\circ}C$ to $1000^{\circ}C$. Two types of CVD-SiC films were prepared for the micro-tensile test. SiC-A exhibited a large grain size (0.4 ~ 0.6 m) and the [111] preferred orientation, while SiC-B had a small grain size (0.2 ~ 0.3 mm) and the [220] preferred orientation. Free silicon (Si) was co-deposited onto SiC-B, and stacking faults also existed in the SiC-B structure. The fracture strengths of the CVD-SiC coatings, as measured by the high-temperature micro-tensile test, decreased with the testing temperature. The high-temperature fracture strengths of CVD-SiC coatings were related to the microstructure and defects of the CVD-SiC coatings.