• Asian-Australasian Journal of Animal Sciences
• /
• v.27 no.11
• /
• pp.1652-1662
• /
• 2014

The present study investigated the optimum blending condition of protected fat, choline and yeast culture for lowering of rumen temperature. The Box Benken experimental design, a fractional factorial arrangement, and response surface methodology were employed. The optimum blending condition was determined using the rumen simulated in vitro fermentation. An additive formulated on the optimum condition contained 50% of protected fat, 25% of yeast culture, 5% of choline, 7% of organic zinc, 6.5% of cinnamon, and 6.5% of stevioside. The feed additive was supplemented at a rate of 0.1% of diet (orchard grass:concentrate, 3:7) and compared with a control which had no additive. The treatment resulted in lower volatile fatty acid (VFA) concentration and biogas than the control. To investigate the effect of the optimized additive and feed energy levels on rumen and rectal temperatures, four rumen cannulated Hanwoo (Korean native beef breed) steers were in a $4{\times}4$ Latin square design. Energy levels were varied to low and high by altering the ratio of forage to concentrate in diet: low energy (6:4) and high energy (4:6). The additive was added at a rate of 0.1% of the diet. The following parameters were measured; feed intake, rumen and rectal temperatures, ruminal pH and VFA concentration. This study was conducted in an environmentally controlled house with temperature set at $30^{\circ}C$ and relative humidity levels of 70%. Steers were housed individually in raised crates to facilitate collection of urine and feces. The adaptation period was for 14 days, 2 days for sampling and 7 days for resting the animals. The additive significantly reduced both rumen (p<0.01) and rectal temperatures (p<0.001) without depressed feed intake. There were interactions (p<0.01) between energy level and additive on ruminal temperature. Neither additive nor energy level had an effect on total VFA concentration. The additive however, significantly increased (p<0.01) propionate and subsequently had lower acetate:propionate (A/P) ratios than non-additive supplementation. High concentrate diets had significantly lower pH. Interactions between energy and additive were observed (p<0.01) in ammonia nitrogen production. Supplementation of diets with the additive resulted in lower rumen and rectal temperatures, hence the additive showed promise in alleviating undesirable effects of heat stress in cattle.

• Membrane Journal
• /
• v.1 no.1
• /
• pp.34-43
• /
• 1991

The relationships between affinity of membranes and optimum operation conditions were investigated in the pervaporation of water(1)/ethanol(2) mixture through cellulose acetate(CA) membranes having more affinity to water and silicone rubber(SR) membranes having more affinity to ethanol. CA and SR membranes were prepared and amount of sorption, sorption selectivity, pervaporation separation factor and pervaporation rate in both of membranes were determined and compared. The effects of downstream pressure were analyzed using Thompson diagram and the sorption and pervaporation characteristics with composition of feed and operation temperature were examined in terms of affinity, activity coefficient, plasticizing effect and activation energy of individual species. In the separation of water through CA membranes, high performance of both pervaporation separation factor (water to ethanol, $[\alpha^2_1]_{PV}$) and pervaporation rate was obtained in the conditions of low downstream pressure, middle range of feed concentration and high temperature. In the separation of ethanol through SR membranes, pervaporation separation factor(ethanol to water, $[\alpha^2_1]_{PV}$) increased with downstream pressure and decreased with concentration of ethanol in feed and operation temperature, while pervaporation rate showed opposite trends to those of ($[\alpha^2_1]_{PV}$).

• Asian-Australasian Journal of Animal Sciences
• /
• v.13 no.5
• /
• pp.681-685
• /
• 2000

A computer software was developed in our laboratory to automatically control the pigs environment by the image analysis system (IAS), which monitors and analyzes the pig's behavior and feeds the results back to the computer hardware. Three feeding trials were conducted with growing pigs ($L{\times}Y$) to test the effectiveness of the IAS under various seasons. In all three trials, the open-sided conventional pens with half-slatted floor were used as controls; for the IAS treatment, fully-slatted floors were used in the windowless pens. Experiment 1 was conducted in the winter for 30 d with 24 growing pigs. There were two treatments (Conventional vs. IAS), and three pens (replicates) per treatment. During the growing period, the feed efficiency was significantly (p<0.05) improved by the IAS. In addition, the pigs reared under the IAS during the growing period displayed better growth rate during the finishing period than did the pigs reared under the conventional conditions. Experiment 2 was conducted in the summer for 30 d with 24 growing pigs. The experimental design was the same as Experiment 1. During the finishing period, all the pigs were kept in conventional open-sided pens until their market weights to evaluate their carcass characteristics. During the growing period, the growth rate and feed efficiency of the pigs in the IAS was better than those of the control pigs. In addition, various carcass characteristics were significantly improved by the IAS rearing during the growing period. Experiment 3 was conducted with 30 growing pigs for 30 d in the spring. The experimental design was the same as Experiment 1. No difference was found in growing performance between the control and IAS pigs. It could be concluded that the IAS is effective in providing optimum conditions for the growing pigs in summer and winter seasons. In addition, providing an optimum environment during the growing period results in improved growth rate, feed efficiency, and carcass qualities for the finishing pigs.

• International Journal of Precision Engineering and Manufacturing
• /
• v.9 no.2
• /
• pp.3-7
• /
• 2008

Vibratory conveyors are widely used in industry to transport granular materials and products. A theoretical point mass model for vibratory conveying was studied. The results agreed well with experimental observations. The model theory included the resting, sliding and flight states of the material. Each state was considered separately when determining the equations of motion. For the coefficients of restitution, values of zero for the normal component and 0.8 for the tangential component were found to be appropriate for modeling the collisions of the granular particles with the conveying surface. The vibration angle had a large influence on the mode and rate of transport. There was an optimum vibration angle for a given set of conditions. The optimum vibration angle decreased and was better defined as the coefficient of friction increased. The results suggest the existence of an optimum dimensionless track acceleration (throw number), which does not support general industrial practice in which the track acceleration is limited when the feed cycle becomes erratic and unstable.

• Journal of Biosystems Engineering
• /
• v.30 no.1 s.108
• /
• pp.8-16
• /
• 2005

The extrusion-cooking condition on Cordyceps pruinosa was designed using twin-screw extruder. Response surface methodology (RSM) was used to investigate extrusion-cooking using a central composition design with varying die temperature $(114-146^{\circ}C)$, feed moisture $(22-38\%)$, feed rate (4-14 ka/h) and screw speed (120-280 rpm). System parameters (die pressure and specific mechanical energy (SME)) and extrudate parameters (density and water solubility index (WSI)) were statically analyzed using RSH. Die pressure was significantly affected by temperature, moisture contents and feed rate. SM was affected by screw speed and feed rate. When die temperature is $130^{\circ}C$ and moisture content $25\%$, the optimum pressure is shown. SME is about 20 Wh/kg, when feed rate is $10\~12kg/min$ and screw speed $200\~250rpm$. WSI was affected by temperature and moisture contents. Density was not affected by any factor. WSI increases by $7\%$ from about $23\%$ to about $30\%$, as temperature is raised from $120^{\circ}C\;to\;140^{\circ}C$. The WSI of Cordyceps pruinosa pulverized after extruding (PE) is about $26.97\%$ higher than that of raw material and $10\%$ higher than that of pulverized after drying (PD). The content of unsaturated fatty acid were not significantly different in PD and PE. Anti-oxidative activity of PE was 1.67-2.2 times higher than that of PD in Cordyceps pruinosa using 1- dipheny1-2-picrylhydrazyl method (DPPH).

• Membrane and Water Treatment
• /
• v.4 no.4
• /
• pp.277-291
• /
• 2013

The transport and recovery of Levafix brilliant red E-4BA and Levafix brilliant red E-6BA were investigated using polytetrafluoroethylene (PTFE) fiber based supported liquid membrane containing tetra butyl ammonium bromide (TBAB) in coconut oil as a carrier. The influencing parameters studied are: pH of the feed solution, concentration of dye in the feed solution, extractant concentration, and various kind of stripping agent, rate of stirring, time of transport, reusability of membrane and stability of membrane. Increase in TBAB concentration inside the membrane enhances the flux with its maximum value at $1.553{\times}10^{-4}$ M TBAB. Further increase in the concentration of TBAB leads to decreased rate of transport due to increase in viscosity of membrane liquid. The optimum conditions for dye transport are: pH of feed ($7{\pm}0.1$), $1.553{\times}10^{-4}$ M extractant concentration, 350 rpm for stirring, $4.9{\times}10^{-1}$ M potassium hydrogen phthalate as a stripping solution, the time of transport 6 h. It was noticed that flux values were increased with increasing dye concentration in the feed phase. Applying this study to textile wastewater, dyes were transported up to 98% in 6 h. This recovery technique is rewarding to environment and economic.

• Journal of the Korean Ceramic Society
• /
• v.27 no.8
• /
• pp.1050-1054
• /
• 1990

Rutile(TiO2) single crystals were grown by FZ method. Feed rod was sintered in the longitudinal tube-shaped furnace at 135$0^{\circ}C$ and optimum growth condition was growth rate 5-8mm/hr, rotation rate 30-40rpm. When crystal was growing, atomosphere was oxidized condition, and grown single crystal was annealed at 110$0^{\circ}C$. The rutile single crystals were oriented to [001] direction and color change of single crystals were related to atmosphere, and difference of electric conductivity and resistance was due to the fact above.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.48 no.3
• /
• pp.308-313
• /
• 2015

A $3{\times}3$ factorial study was conducted to investigate the effects of dietary protein and lipid levels on the growth, feed utilization and innate immunity of red seabream Pagrus major. Nine diets consisting of three protein levels (42%, 46% and 50% crude protein) and three lipid levels (10%, 14% and 18% crude lipid) were formulated. Triplicate groups of red seabream were fed the experimental diets to apparent satiation (5-6 times a day, from 08:00 to 18:00 h at 2-h intervals) for 10 weeks. At the end of the feeding trial, the weight gain and specific growth rate of fish fed P46L14 (46% protein and 14% lipid), P50L10 (50% protein and 10% lipid) and P50L14 (50% protein and 14% lipid) were significantly (P<0.05) higher than those of fish fed P42L18 (42% protein and 18% lipid). The feed conversion ratios (FCR) of the fish were affected by dietary lipid levels (P<0.039), but not dietary protein levels. The FCR tended to increase with increasing dietary lipid levels from 10% to 18% with the 46% and 50% protein levels. The weight gain, protein efficiency ratio, specific growth rate, feed intake and survival of fish were not affected by either dietary protein or lipid levels. Myeloperoxidase activity in the group fed P50L14 (50% protein and 14% lipid) was significantly higher than that in the group fed P42L10 (42% protein and 10% lipid) or P50L18 (50% protein and 18% lipid). However, the myeloperoxidase activity of fish was not affected by either dietary protein or lipid level. The fish fed P46L14 (46% protein and 14% lipid) and P46L18 (46% protein and 18% lipid) showed significantly higher superoxide dismutase activity than did the fish fed P46L10 (46% protein and 10% lipid), P50L10 (50% protein and 10% lipid) of P50L18 (50% protein and 18% lipid). In conclusion, the optimum protein and lipid levels for the growth and feed utilization of juvenile red seabream were 46% and 14%, respectively, and the optimum dietary protein to energy ratio was 27.4 g/MJ.

• Membrane and Water Treatment
• /
• v.3 no.4
• /
• pp.243-252
• /
• 2012

Tri-n-butyl phosphate (TBP) was used as carrier for the transport of Golden yellow and Cibacron LSG dyes through a hexane bulk liquid membrane. The transport efficiency of dyes by TBP was investigated under various experimental conditions such as pH of the feed phase (dyes solution), concentration of the receiving phase (NaOH solution), concentration of TBP in membrane, rate of stirring, effect of transport time, type of solvent, dye concentration in feed phase, effect of temperature.. The maximum transport dyes occurs at ratio of 1:1 TBP-hexane At pH 3.0 0.1 (feed phase) the transport dyes decreased. At high stirring speed (300 rpm) the dyes transport from the feed phase to the strip phase was completed within 60 minutes at $27^{\circ}C$. Under optimum conditions: Feed phase 100 mg/L dyes solution at pH 1.0 0.1, receiving phase 0.1 mol/L NaOH solution, membrane phase 1:1 TBP-hexane , Stirring speed 300 rpm and temperature $27^{\circ}C$, the proposed liquid membrane was applied to recover the textile effluent.

• Transactions of the Korean Society of Machine Tool Engineers
• /
• v.17 no.2
• /
• pp.71-76
• /
• 2008

Micro end-milling is one of effective technology that is able to do ultra-precision machining while increasing the productivity and has wide application field. But selection of machining condition is very difficult because of complicated machining mechanism. Therefore this study was carried out to select working factors to get the optimum surface roughness. Machining condition are depth of cut, feed rate and spindle revolution. The result of this study showed that Surface roughness was affected, in the other of depth of cut, spindle revolution, feed rate. And this study provided an regression equation relating surface roughness to working factors through Regression Analysis and determination coefficient of regression equation had a satisfactory reliability of 79%.