• The Korean Journal of Ceramics
• /
• v.2 no.2
• /
• pp.89-94
• /
• 1996

Aluminum and zinc titanium silicate sol-gel films were fabricated for application of waveguide and the effect of additions of ZnO and $Al_2O_3$ to binary titanium silicate films was investigated. During firing, the films are densified as they shrunk and their refractive index increases in the range of 1.58-1.83 depending on the film composition. The attenuation of the waveguides is not sensitive to changes in composition except for zinc titanium silicate waveguides which have substantially higher attenuation. However, the increase in the attenuation with aging of the waveguides depend upon the composition of waveuides. The addition $Al_2O_3$ or the reduced $SiO_2$ content in the composition appears to slow the deterioration of the waveguides due to the formation of more stable bonds and increased acidity on the film surface. Also, the wavelength dependence of the attenuation of the waveguides varies with composition. The attenuation of the waveguides except for the $65SiO_2{\cdot}35TiO_2$ composition are not Rayleigh scatter limited, suggesting the absorption loss of the waveguides due to the effects of residual carbon and structural defects in the films.

• Journal of the Semiconductor & Display Technology
• /
• v.4 no.4 s.13
• /
• pp.1-4
• /
• 2005

The chemical composition and uniaxial compressive stress are varied to observe their effect on the current-voltage characteristics of ZnO based ceramics. The variation of chemical composition produces two kinds of ceramics showing ohmic and nonohmic current-voltage characteristics. The current at a fixed voltage increased with the increase of the compressive stress for both ohmic and nonohmic ceramics. Ceramics showing nonohmic behavior exhibit better reversible return of current-voltage curve when the applied compressive stress is removed from the ceramics than those showing ohmic behavior do. We found an appropriate chemical composition showing linear relation between current and stress at a fixed voltage. The ceramic materials with an appropriate chemical composition can be used as a potential sensing material in pressure sensors.

• Bulletin of the Korean Chemical Society
• /
• v.35 no.5
• /
• pp.1299-1304
• /
• 2014

The electrochemical performance of Li-S cells was investigated in various ternary electrolyte solutions composed of 1,2-dimethoxyethane (DME), tetra(ethylene glycol) dimethyl ether (TGM), and 1,3-dioxolane (DOX). The discharge capacity values and cycle data obtained at each composition were statistically treated with the Minitab program to obtain mixture contour plots, from which the optimal composition of the ternary solvent systems was predicted. The discharge capacities and capacity retention were quite dependent on the electrolyte composition. It was estimated from the contour plots of the capacity at 1.0 C that the discharge capacity sharply increased with a decrease in the TGM content. High capacities greater than 900 mAh/g at 1.0 C were expected for the electrolyte composition with a volume ratio of DME/TGM/DOX = 1/0/1. In contrast, it was predicted from the mixture contour plot of the capacity retention that the cycle performance would significantly increase with an increase in the DME content.

• Journal of the Korean Ceramic Society
• /
• v.50 no.3
• /
• pp.186-194
• /
• 2013

The relationship between composition and properties of enamel glass was investigated by introducing a mixture design. The enamel glass was manufactured by mixing various components under the following constraints: $45{\leq}SiO_2{\leq}55$, $10{\leq}B_2O_3{\leq}18$, $6{\leq}Na_2O{\leq}15$, $1{\leq}Li_2O{\leq}6$, $5{\leq}K_2O{\leq}10$, $0{\leq}TiO_2{\leq}8$, $0{\leq}ZrO_2{\leq}8$, 13.3MO (mol %). A mathematical model for the calculation of some properties of enamel glasses as a function of their composition was developed by the experimental statistical method. The results showed that the proposed model with the experimental measurement were in good agreement and the mixture experimental design was an effective method for optimizing the composition of the enamel glass with respect to its properties.

• Macromolecular Research
• /
• v.16 no.3
• /
• pp.231-237
• /
• 2008

Biodegradable poly($\varepsilon$-caprolactone-co-L-lactide)-b-poly(ethylene glycol) (PCLA-b-PEG) copolymers were synthesized via solution polymerization by varying the feed composition of $\varepsilon$-caprolactone ($\varepsilon$-CL) and L-lactide (LLA) ($\varepsilon$-CL: LLA= 10:0, 7:3, 5:5, 3:7, 0: 10). The feed ratio based on weight is in accordance with the copolymer composition except for the case of $\varepsilon$-CL: LLA=3:7 (C3L7), which was verified by $^1H$-NMR. Two different approaches were used for the exceptional case, which is an extension of the reaction time or the sequential introduction of the monomer. A copolymer composition of $\varepsilon$-CL: LLA=3:7 could be obtained in either case. The chemical microstructure of PCLA-b-PEG was determined using the $^{13}C$-NMR spectra and the effect of the sequential structure on the thermal properties and crystallinity were examined. Despite the same composition ratio of the copolymer, the microstructure can differ according to the reaction conditions.

• Journal of radiological science and technology
• /
• v.41 no.6
• /
• pp.637-641
• /
• 2018

To compare of body composition and backmusclestrength between physical activity group (PAG) and non-physical activity group (Non-PAG). From Jun 14 to July 13 2018, 66 students were divided into PAG (male 20, female 13) and Non-PAG (male 18, female 15) from questionnaires for general characteristics and activity. All participants were measured body composition (Inbody 720, Biospace, Korea) and backmusclestrength (T.K.K. 5402, TAKEI, Japan) after obtaining written informed consent. Statistical analysis was performed by independent t-test and cross-sectional test using SPSS ver. 19.0 (USA). Sex and body mass index were not significant difference between two groups. Exercise was significant difference between PAG and Non-PAG(100% vs. 45.5%, p<0.001), especially running and push-up, sit-up(p<0.001). Body composition was no significant difference between PAG and Non-PAG (p>0.05). Backmusclestrength was significantly higher in PAG than that in N on-PAG (p<0.01). It is suggested that exercise affects to Backmusclestrength.

• Asian-Australasian Journal of Animal Sciences
• /
• v.26 no.8
• /
• pp.1111-1118
• /
• 2013

The objective of this study was to determine the effects of whole linseed supplementation on performances and milk fatty acid composition of dairy cows. Thirty six Holstein Friesian crossbred lactating dairy cows were blocked by milking days first and then stratified random balanced for milk yields and body weight into three groups of 12 cows each. The control group received 300 g of palm oil. The second group was supplemented with 344 g/d of top-dressed whole linseed plus 150 g of palm oil and the third group was supplemented with 688 g/d of top-dressed whole linseed. All cows also received ad libitum grass silage (Brachiaria ruziziensis), had free access to clean water and were individually housed in a free-stall unit and individually fed according to treatments. Residual feeds were collected on 2 consecutive days weekly and at the end of the experiment. Feed samples were pooled to make representative samples for proximate and detergent analyses. Daily milk yields were recorded. Milk samples were collected on 2 consecutive days weekly. Live weights were recorded at the start and at the end of the experiment. Milk samples were taken on d 56 of the experiment and subjected to milk fatty acid composition. The results showed no statistical significant differences in intakes, live weight change, milk yields and milk compositions, however, C18:1, C18:3 and unsaturated FAs were increased while saturated FAs were reduced by whole linseed supplementation. It is recommended that the addition of 300 g/d oil from whole linseed could be beneficial to lactating dairy cows in early lactation.

• Journal of Sensor Science and Technology
• /
• v.21 no.4
• /
• pp.263-269
• /
• 2012

Al doped ZnO(AZO) thin films were deposited at different substrate temperatures by a continuous composition spread(CCS) method. Various compositions of Al doped ZnO thin films deposited at substrate temperatures between 0 and $250^{\circ}C$ were explored to find excellent electrical and optical properties. The AZO thin film deposited at $100^{\circ}C$ had the lowest resistivity, $9{\times}10^{-4}{\Omega}$ cm and its average transmittance at the 400 to 700 nm wavelength region was 92 %. Optimized composition of the AZO thin film which had the lowest resistivity and high transmittance was 3.13 wt% Al doped ZnO.

• Food Science of Animal Resources
• /
• v.33 no.3
• /
• pp.348-355
• /
• 2013

The purpose of this study was to investage the effects of dietary bamboo charcoal on the carcass characteristics and meat quality of fattening pigs. Fifty four crossed pigs of $61.0{\pm}1.0$ kg body weight (BW) were grouped and housed in 6 animals (3 barrows and 3 gilts) per pen and 3 replications per treatment. The basal diet (C) was supplied with 0.3% bamboo charcoal as treatment 1 (T1) and 0.6 % as treatment 2 (T2). The pigs were fed that experimental diet for 42 days, thereafter 10 longissimus dorsi (LD) per treatment were randomly collected at the time the pigs reached an average weight of $110.0{\pm}5.0$ kg. The carcass weight, backfat thickness, and the carcass grade were better (p<0.05) in the pigs fed bamboo charcoal than in C. The crude fat concentration of LD was higher (p<0.05) in T1 than in C. While the composition of stearic acid and arachidonic acid was lower (p<0.05) in treatments than in C, the composition of oleic acid and linoleic acid of treatments was higher (p<0.05) than C. The physico-chemical characteristics, such as meat color and amino acid composition of LD were not affected (p>0.05) by the supplemented bamboo charcoal. In conclusion, dietary supplementation with bamboo charcoal improved the carcass grade and fatty acids composition of pork meat from fattening pigs, where the composition of unsaturated fatty acids was increased, but that of saturated fatty acids was decreased.

• Animal Bioscience
• /
• v.36 no.9
• /
• pp.1314-1326
• /
• 2023

Sheep and goats can efficiently convert low quality forage into high-quality meat which contains specific nutrients and quality traits. Carcass traits and quality attributes of sheep and goat meat depend upon several factors and one of most effective strategies amongst these is feeding regimens. In this review, the major aspects of feeding regimens affecting growth rate, carcass traits and quality attributes of sheep and goat meat are thoroughly discussed, with a particular focus on physical-chemical composition, flavor profile, and fatty acid (FA) profile. Grazing lambs and kids receiving concentrate or under stall-feeding systems had greater average daily gain and carcass yield compared with animals reared on pasture only. However, growth rate was higher in lambs/kids grazing on pastures of improved quality. Moreover, the meat of grazing lambs receiving concentrate had more intense flavor, intramuscular fat (IMF) content, and unhealthy FA composition, but comparable color, tenderness, juiciness, and protein content compared to that of lambs grazed on grass only. In contrast, meat of concentrate-fed lambs had more intense color, greater tenderness and juiciness, IMF and protein contents, and lower flavor linked to meat. Additionally, the meat of kids grazed on concentrate supplementation had higher color coordinates, tenderness, IMF content and unhealthy FA composition, whereas juiciness and flavor protein content were similar. In contrast, kids with concentrate supplementation had superior color coordinates, juiciness, IMF content and unhealthy FA composition, but lower tenderness and flavor intensity compared to pasture-grazed kids. Thus, indoor-finished or supplemented grazing sheep/goats had higher growth rate and carcass quality, higher IMF content and unhealthy FA composition compared to animals grazed on grass only. Finally, supplementation with concentrate increased flavor intensity in lamb meat, and improved color and tenderness in kid meat, whereas indoor-fed sheep/goats had improved color and juiciness as well as reduced flavor compared to pasture-grazed animals.