• Journal of Advanced Marine Engineering and Technology
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• 제33권1호
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• pp.90-96
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• 2009

Injection molding process is one of the most important methods to produce plastic parts with high efficiency and low cost. Today, injection molded parts have been increased dramatically the demand for high strength and quality applications. This report investigates that the optimum injection molding condition for minimum of shrinkage. Molding shrinkage is occurred by several reasons such as thermal shrinkage, a hardening process and compressibility. This report concentrate on shrinkage by a hardening process. As Change a holding pressure and holding time, checked deflections of X, Y, Z directions by shrinkage based on same condition. In conclusion, it was found that holding pressure is stronger and holding time is longer, the deflection by shrinkage is smaller because injection molding needs enough time for cooling and high density. The FEM Simulation CAE tool. Moldflow, is used for the analysis of injection molding process.

• Journal of Electrical Engineering and Technology
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• 제8권5호
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• pp.1086-1095
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• 2013

The main issue of parallel three-phase boost converters is reduction of the low- and high frequency circulating currents. Most present technologies concentrate on low frequency circulating current because the circulating current controller cannot mitigate the high frequency circulating current. In this paper, analytical approach of three-phase coupled inductor applied to parallel system becomes an important objective to effectively reduce the low- and high frequency circulating currents. The characteristics of three-phase coupled inductor based on a structure and voltage equations are mathematically derived. The modified voltage equations are then applied to parallel three-phase boost converters to develop averaged models in stationary coordinates and rotating coordinates. Based on the averaged modeling approach, design of the circulating current controller is presented. Simulation and experimental results demonstrate the effectiveness of the analysis and modeling for the parallel three-phase boost converters using three-phase coupled inductor.

• Asian-Australasian Journal of Animal Sciences
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• 제13권2호
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• pp.188-191
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• 2000

Appetite stimulant ether-soluble neutral extract of a high-grain compound feed was separated into four fractions with an open column of silica gel chromatograph using four carrier solutions containing n-pentane and diethyl ether as 100:0 (Fraction A), 90:10 (Fraction B), 75:25 (Fraction C) and 0:100 (Fraction D). The stimulative effects of the fractions were examined by comparing the intake of hay (with or without the fractions) in two-choice test bioassays with cattle. The Fractions A, B and C of the neutral extract stimulated (p<0.05) hay consumption in cattle, whereas Fraction D had no effect on selective feeding when compared with the control fraction. Furthermore, Fractions A, B and C had higher (p<0.05) feeding stimulative indices (FSI) than that of the Fraction D. The results suggest that chemical stimulants to increase palatability of hay are present in the neutral Fractions A, B and C of high-grain concentrate.

• 대한전기학회논문지:시스템및제어부문D
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• 제49권3호
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• pp.95-101
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• 2000

In this paper, an improved method for magnetic inspection to detect surface of a conductor is presented. The presented method is based on the technique of ECP(Electric Current Perturbation), which is to measure the variation of current flow due to defects with a magnetic sensor. The inspection performance is improved by using high frequency current behaviors in order to concentrate the current near the defect and employing the resonant frequency of a search coil as an operating frequency. By analytical results and experiments of the test specimens, the feasibility of the inspection method is shown.

• Asian-Australasian Journal of Animal Sciences
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• 제13권10호
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• pp.1461-1466
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• 2000

The use of the dairy male calf for beef production has been found to be economically unprofitable during the past due to high cost of feeds and relatively low beef price. However, due to current shortage of domestic beef supply and rising beef price, this research aimed to assess feeding methods and costs and returns in raising dairy male calves for beef production under changing economic conditions. Two diets were compared: calves on an optimal feeding level were given milk replacer for 44 d and a concentrate (with ad lib. hay) to 150 kg bodyweight that contained 16% crude protein; those given a sub-optimal diet, more appropriate for smallholder farms, received milk replacer for 30 d and 14% CP concentrate. Twelve pairs of dairy male calves (average age 32 days) of Holstein-Friesian high grades were used, each pair having similar influencing factors such as weight, age, and genotype. Each animal was kept in a separate feeding stall until reaching the final weight of 150 kg. The results from this experiment showed that the differences of traits concerning growth performance and feed efficiency of the animals raised under the two feeding regimes were statistically nonsignificant. The optimal group was just slightly better, but the cost of production of the sub-optimal group was 24 percent lower (4,667 vs. 6,144 baht per animal) and the cost difference was highly significant. The results from this investigation showed that beef production from dairy male calves can be economically viable when sub-optimal feeding method is used and market beef price is at current level.

• Asian-Australasian Journal of Animal Sciences
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• 제19권5호
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• pp.611-616
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• 2006

Genetic parameters for performance traits on 409 bulls and growth and carcass traits on 591 of their steer progeny were estimated in Japanese Black cattle with Gibbs sampling. Traits of bulls included body weight at the start (BWS) and finish (BWF) of test, daily gain (DG), concentrate, roughage and TDN intake, and TDN conversion ratio. Progeny traits were BWS, BWF, DG, rib eye area, marbling score (MSR), dressing percentage and subcutaneous fat thickness (SFT). In bulls, heritabilities were high for BWS (0.50) and BWF (0.63) and moderate for concentrate (0.48) and TDN intake (0.45), while in progeny, the heritability for all the studied traits was moderate to high (ranging from 0.30 to 0.73), highlighting the potential for genetic improvement of these traits. Genetic correlations between TDN intake and growth traits (BWS, BWF and DG) in bulls were highly positive (ranging from 0.77 to 0.94). The weak but negative genetic correlation (-0.20) between MSR and SFT in progeny indicated that improvement of beef marbling without increasing subcutaneous fat deposition could be possible. The estimated genetic correlations of roughage intake of bulls with body weights (BWS and BWF) and MSR of their progeny were moderate (ranging from 0.35 to 0.52). On the basis of the selection for bulls, growth traits and TDN intake correlated positively with SFT (ranging from 0.43 to 0.53) of their progeny, suggesting the necessity of controlling the increase of SFT in selection programs.

• 농업과학연구
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• 제37권1호
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• pp.61-68
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• 2010

Rice bran proteins from different cultivars(Youngan, Sindongjin, Suwon 511) were extracted with Xylanase using orthogonal analysis method and their functional properties were investigated. The optimum extraction conditions, based on protein content in the extract found to be at 1 wt% xylanase, pH 7 and 50:1, solvent to rice bran ratio(v/w %). Nitrogen solubility indices(NSI) of rice bran protein concentrates were shown a minimum value at pH 4 ranged 2~23%, varied with different cultivars and a maximum (NSI${\geq}$90% for all cultivars) at pH 10. As for water adsorption and fat adsorption capacity, rice bran protein concentrates were shown to be better than Na-caseinate and isolated soy protein, respectively. Emulsifying activities were observed high in order of Na-caseinate>Youngan rice bran protein>Shindongjin rice bran protein>Suwon 511 rice bran protein>isolated soy protein. In general, the surface tension of rice bran protein solution($10^{-3}$ wt%, 5 mM bis-tris, pH 7) was increased with increasing concentrations and found a minimum value near pI. On heating, it was decreased slightly with increasing temperatures up to $70^{\circ}C$ and then increased above $80^{\circ}C$. Addition of sodium chloride was made the surface tension decrease. In conclusion, with Xylanase, rice bran protein concentrate can be successfully extracted from the rice bran of different cultivars and the Youngan rice bran protein was thought to have best functionality among rice cultivars tested. It might be used as a milk protein substitute.

• Asian-Australasian Journal of Animal Sciences
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• 제23권10호
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• pp.1386-1398
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• 2010

Soybean contains a high concentration of carbohydrates that consist mainly of non-starch polysaccharides (NSP) and oligosaccharides. The NSP can be divided into insoluble NSP (mainly cellulose) and soluble NSP (composed mainly of pectic polymers, which are partially soluble in water). Monogastric animals do not have the enzymes to hydrolyze these carbohydrates, and thus their digestion occurs by means of bacterial fermentation. The fermentation of soybean carbohydrates produces short chain fatty acids that can be used as an energy source by animals. The utilization efficiency of the carbohydrates is related to the chemical structure, the level of inclusion in the diet, species and age of the animal. In poultry, soluble NSP can increase digesta viscosity, reduce the digestibility of nutrients and depress growth performance. In growing pigs, these effects, in particular the effect on gut viscosity, are often not so obvious. However, in weaning piglets, it is reported that soy oligosaccharides and soluble NSP can cause detrimental effects on intestinal health. In monogastrics, consideration must be given to the anti-nutritive effect of the NSP on nutrient digestion and absorption on one hand, as well as the potential benefits or detriments of intestinal fermentation products to the host. This mirrors the needs for i) increasing efficiency of utilization of fibrous materials in monogastrics, and ii) the maintenance and improvement of animal health in antibiotic-free production systems, on the other hand. For example, ethanol/water extraction removes the low molecular weight carbohydrate fractions, such as the oligosaccharides and part of the soluble pectins, leaving behind the insoluble fraction of the NSP, which is devoid of anti-nutritive activities. The resultant product is a high quality soy protein concentrate. This paper presents the composition and chemical structures of carbohydrates present in soybeans and discusses their nutritive and anti-nutritive effects on digestion and absorption of nutrients in pigs and poultry.

• Asian-Australasian Journal of Animal Sciences
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• 제19권3호
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• pp.368-375
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• 2006

Four rumen-fistulated dairy steers were randomly assigned according to a $4{\times}4$ Latin square design to investigate effects of supplementation levels of sodium dl-malate in concentrates on rumen ecology, ruminal fermentation, nitrogen balance, feed intake and digestibility of nutrients and ruminal microbial protein synthesis. The dietary treatments were cassava concentrate-based, containing sodium dl-malate supplementation at 0, 9, 18 and 27 g/hd/d with urea-treated rice straw (UTS) fed ad libitum. The experiment was conducted for four periods, each period lasting 21 days. Ruminal pH increased with incremental addition of malate (p<0.05). Additionally, molar proportions of propionate were higher in supplemented groups and was highest at 18 g/hd/d of malate supplement (p<0.05). Microbial protein synthesis tended to be higher in dairy steers receiving sodium dl-malate supplements and also was the highest at 18 g/hd/d. Variable bacterial populations, such as amylolytic, proteolytic and cellulolytic species were increased (p<0.05). Furthermore, protozoal populations were decreased significantly (p<0.05), while fungal zoospores were dramatically increased in dairy steers receiving sodium dl-malate supplement (p<0.05). These results suggested that supplementation of concentrate containing a high level of cassava chip at 18 g/hd/d with UTS in dairy steers could improve rumen fermentation efficiency and rumen microbial protein synthesis.

• 자원리싸이클링
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• 제31권6호
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• pp.66-72
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• 2022

국내산 인상흑연정광의 리튬이온전지 소재로서 활용을 위해 고강도 혼합기를 이용하여 구형화 실험 후 건식분급을 진행하여 각 산물에 대한 구형화도와 입도를 분석하였다. 3,000 rpm의 로터속도에서는 정광시료와 산물의 입도와 구형화도의 차이가 관찰되지 않았으나, 로터속도를 6,000 rpm, 10,000 rpm 12,000 rpm으로 조절하여 구형화도 실험을 진행한 결과, 로터속도와 구동시간의 증가에 따라 구형화도는 증가하고 입도는 감소하였다. 로터속도 12,000 rpm에서 10분간 구동한 결과, 구형화도는 0.870으로부터 0.936까지 증가하였다. 구형화실험 후 건식분급을 진행하였을 때 조립자의 구형화도는 0.947까지 증가하였고 SEM 결과에서 구형입자가 확인되어 구형화가 성공적으로 이루어졌다고 판단되었다.