• Asian-Australasian Journal of Animal Sciences
• /
• v.22 no.6
• /
• pp.843-848
• /
• 2009

This experiment was conducted to compare the effects of oak acorns and corn on broilers growth performance, carcass characteristics and meat fatty acid (FA) composition according to different ages of broilers. Two separate groups of 400 male broilers, reared for six weeks, were fed diets containing 33.5% green oak acorns (GO) and 67% of corn (C), respectively. At day 35, the body weight of the chickens fed the GO diet was 12% lower (p<0.05) compared with controls (C). However, at day 56 birds reached similar final weights. Abdominal adipose tissue (AAT) was 78% higher in the controls compared to those fed the oak acorn-based diet. The total lipids (TL) of thigh muscle were higher in the controls compared to dietary treatment GO (3.1 against 2.5 g/100 g of muscle). There were significant differences in fatty acid (FA) composition of the muscle between two groups. The broilers fed oak acorn exhibited more C18:2, as well as a higher proportion of polyunsaturated fatty acid (PUFA) and PUFA:SFA (saturated fatty acid) ratio than those on the control diet, but no significant differences were observed among groups for the age of birds. There was a higher proportion of linolenic acid in broilers fed the oak acorn compared to the controls (0.8 vs. 0.6%). Furthermore, linolenic acid content decreased with age (p<0.001) in both groups. The results indicated no significant differences in FA with the age of birds. In conclusion, the meat fatty acids provided by the GO diet appeared to improve the nutritional quality preferred by the consumer.

• Research in Plant Disease
• /
• v.10 no.4
• /
• pp.279-284
• /
• 2004

A rust fungus has caused a serious early defoliation of Zanthoxylum schinifolium during growing seasons every year at the plantations located at Hadong and Jinju, Kyeongsangnam-Do in Korea. In order to identify the rust fungus and clarify its life cycle in Korea, aeciospores from Pinus thunbergii were artificially inoculated on the leaves of Z. schinifolium. Uredinial stage was successively formed on the leaves of Z. schinifolium. Based on the artificial inoculation test and on the morphological features of the dried specimens collected from P. thunbergii and Z. schinifolium, this rust fungus was identified as Coleosporium xanthoxyli. Morphological features of aecial and uredinial stages of the species were described. The first symptom of the infection was developed from later June to early July. And leaf infection ratio was 17.8%-58.7% during August at Hadong and Jinju regions of Kyeongsangnam-Do in Korea.

• Journal of the Korean Society of Radiology
• /
• v.3 no.4
• /
• pp.23-28
• /
• 2009

Monochromatic X-ray can make a medical image of high contrast under a low radiation dose and can be easily generated by combining an X-ray tube and a multilayer mirror. A W/C multilayer mirror was optimally designed for a characteristic X-ray generated from a X-ray tube with Mo target. The d-spacing and the thickness ratio in design parameters were determined under the maximum-reflectivity condition. Tolerances for deposition and alignment of the W/C multilayer mirror were calculated. Within a deposition tolerance of 0.2nm and a alignment tolerance of ${\pm}0.01^{\circ}$, 85% of the theoretical peak reflectivity could be achieved. A multilayer mirror can be widely used for making medical images because of generating high fluence monochromatic X-ray.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.5 no.2
• /
• pp.7-16
• /
• 1997

The food waste composting facility of 10 ton/d capacity at Nanjido has been operated successfully since July, 1996. This study was performed to investigate the characteristics of food waste quality, and variation of physicochemical characteristics of feed materials during composting. Food waste with 79% moisture content was used as a substrate. Wood chip was used as a bulking agent. Monitoring results based on VS, TOC, C/N ratio and gas composition indicated that the facility was operated normally under aerobic conditions. Conductivity values during food waste composting were increased. A highly positive correlation (r=1.00) existed between VS and TOC.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.36 no.5
• /
• pp.465-475
• /
• 2012

This study was carried out with two goals. One was the development of a model of a wind turbine blade airfoil and the other was the application of this folding blade. In general, in large-sized (MW) wind turbines, damage is prevented because of the use of a pitch control system. On the other hand, pitch control is not performed in small wind turbines since equipment costs and maintenance costs are high, and therefore, the blade will cause serious damage. The wind turbine proposed in this study does not require maintenance, and the blades do not break during high winds because they are folded in accordance with changes in the wind speed. But generators are not cut-out, while maintaining a constant angle will continue to produce. The focus of this study, the wind turbine is continued by folding blade system in strong winds and gusts without stopping production.

• Asian-Australasian Journal of Animal Sciences
• /
• v.11 no.6
• /
• pp.661-672
• /
• 1998

Two experiments were conducted to examine the effects of a range of concentrations of ruminal fluid ammonia ($NH_3$-N) on forage digestibility, microbial growth efficiency and the mix of microbial species. Urea was either continuously infused directly into the rumen of sheep fed 33.3 glh of oaten chaff (Exp. I) or sprayed onto the oaten chaff (750 g/d) given once daily (Exp. 2). Concentrations of $NH_3$-N increased with incremental addition of urea (p < 0.01). Volatile fatty acids (VFA) concentrations and 24 h in sacco organic matter digestibility in the rumen were higher when supplemental urea was given (p < 0.01). The (C2 + C4) : C3 VFA ratio was lower (p < 0.05) when $NH_3$-N was above 200 mgN/I. The fungal sporangia appearing on oat leaf blades were significantly higher when urea was supplemented, indicating that $NH_3$-N was a growthlimiting nutrient for fungi at levels of $NH_3$-N below 30 mgN/l. The density of protozoa was highest when $NH_3$-N concentrations were adjusted to 30 mgN/I for continuously fed ($4.4{\times}10^5/ml$) and to 168 mgN/1 for once daily feeding ($2.9{\times}10^5/ml$). Thereafter increasing concentrations of $NH_3$-N, were associated with a concomitant decline in protozoal densities. At the concentration of $NH_3$-N above 200 mgN/l, the density of protozoa was similar to the density of protozoa in ruminal fluid of the control sheep ($1.8{\times}10^5/ml$). The efficiency of net microbial protein synthesis in the rumen calculated from purine excretion was 17-47% higher when the level of $NH_3$-N was above 200 mgN/1. The possibilities are that 1) there is less bacterial cell lysis in the rumen because of the concomitant decrease in the protozoal pool and/or 2) microbial growth per se in the rumen is more efficient with increasing $NH_3$-N concentrations.

• Journal of the military operations research society of Korea
• /
• v.33 no.2
• /
• pp.75-86
• /
• 2007

This paper presents the overall valuation framework of the Army Tactical Command Information System(ATCIS) with its empirical data which is developed by the ROK Army in 2005 with its own R&D efforts over the past 10 years. The valuation with the appropriate methods is conducted through the full and relentless support of ROK Army HQs, defense agencies, and related firms. And the results include both qualitative and quantitative values of the ATCIS in perspectives of economic, technical, and defense strength effects. As a result, the development of ATCIS is valued over 1.7291 trillion Won which is over 6.55 times benefit and cost ratio comparing with other country's similar system. The worth of this paper includes the actual framework and methods to apply the valuation of other weapon systems and its preliminary research, defense offset valuation, performance evaluation and others.

• Proceedings of the International Microelectronics And Packaging Society Conference
• /
• 2002.05a
• /
• pp.193-197
• /
• 2002

The tribological properties and van der Waals attractive forces and the thermal stability of films are very important characteristics of highly hydrophobic fluorocarbon (FC) films for the long-term reliability of nano system. The effect of thermal annealing on films and van der Waals attractive forces and friction coefficient of films have been investigate d in this study. It was coated Al wafer which was treated O2 and Ar that ocatfluorocyclobutane ($C_4_{8}$) and Ar were supplied to the CVD chamber in the ratio of 2:3 for deposition of FC Films. Static contact angle and dynamic contact angle were used to characterize FC films. Thickness of films was measured by variable angle spectroscopy ellipsometer (VASE). Nanotribological data was got by atomic force microscopy (AFM) to measure roughness, lateral force microscopy (LFM) to measure friction force, and force vs. distance (FD) curve to evaluate adhesion force. FC films were cured in N2 and vacuum. The film showed the slight changes in its properties after 3 hr annealing. FTIR ATR studies showed the decrease of C-F peak intensity in the spectra as the annealing time increased. A significant decrease of film thickness has been observed. The friction force of Al surface was at least thirty times higher than ones with FC films. The adhesive force of bare Al was greater than 100 nN. After deposit FC films adhesive force was decreased to 40 nN. The adhesive force of films was decreased down to 10 nN after 24 hr annealing. During 24 hr annealing in $N_2$and vacuum at $100^{\circ}C$ film properties were not changed so much.

• Bulletin of the Korean Chemical Society
• /
• v.25 no.11
• /
• pp.1661-1666
• /
• 2004

The reaction of titanium tetraisopropoxide with 2 equiv of N,N-diethyl acetoacetamide affords Ti($O^iPr)_2(CH_3COCHCONEt_2)_2$ (1) as colorless crystals in 80% yield. Compound 1 is characterized by spectroscopic (Mass and $^1H/^{13}C$ NMR) and microanalytical data. Molecular structure of 1 has been determined by a single crystal X-ray diffraction study, which reveals that it is a monomeric, cis-diisopropoxide and contains a six coordinate Ti(IV) atom with a cis($CONEt_2$), trans($COCH_3$) configuration (1a) in a distorted octahedral environment. Variable-temperature $^1H$ NMR spectra of 1 indicate that it exists as an equilibrium mixture of cis, trans (1a) and cis, cis (1b) isomers in a 0.57 : 0.43 ratio at -20$^{\circ}C$ in toluene-$d_8$ solution. Thermal properties of 1 as a MOCVD precursor for titanium dioxide films have been evaluated by thermal gravimetric analysis and vapor pressure measurement. Thin films of pure anatase titanium dioxide (after annealing above 500$^{\circ}C$ under oxygen) have been grown on Si(100) with precursor 1 in the substrate temperature range of 350- 500$^{\circ}$ using a bubbler-based MOCVD method.

• Korean Journal of Materials Research
• /
• v.8 no.10
• /
• pp.879-883
• /
• 1998

In the vacuum casting process for superalloys, molten metal are poured into the heated ceramic mold up to $1000^{\circ}C~1700^{\circ}C$. The mold has to have the high temperature strength during casting and made by hlgh purity alumina. In this sturdy, the mold was made by low purity alumina and changed silica contents intended to have high strength The 7.7wt.% SiOz specimens have 10- 55% higher strength than others in room and high temp. Therefore, the cast mold has been developed in this study for single crystal vacuum cast by controlling the ratio of fused alumina and colloidal silica which are used commercially for conventional casting in industries.