• Journal of Biosystems Engineering
• /
• v.6 no.2
• /
• pp.33-47
• /
• 1982

To modernize the conventional rice post production technology and reduce grain losses, a transition toward the wet-paddy threshing system has been strongly demanded. The head-feeding type thresher with pneumatic separation has been used dominantly for threshing dried-paddy, but some adverse effects in separation performance for threshing wet-paddy is encounterred. In order to solve the problems, the development of thresher with an additional oscillating sieve to the conventional pneumatic separation has been recommanded. This study was intended to evaluate the separating performance of thresher with oscillating sieve which was attached additionally to the conventional auto-thresher equipped with separation system of blower and suction fan. For different feed rates and rice varieties, wet-and dry-material were tested with threshers attached with and without oscillating sieve. Results of the study are summarized as follows: 1. When the feed rates were 480 and 640 kg/hr, there was no statistically significant difference in power reqirements between the threshers with and without an additional sieve device for both dry-and wet-threshing. However, when the feed rate was 960 kg/hr, power requirements of thresher without sieve were greater for wet-paddy threshing than the thresher with the additional sieve separator by about 20% points. 2. With additional oscillating sieve device, the ratios of total weights of whole grains including grains with branch let and damaged grains to the total output did not show statistical difference among the feed rates. However, with pneumatic separation the ratio was decreased as the level of feed rate increased. 3. The total amount of grains with branchlet (including broken panicle) increased with the moisture content. For both the wet-and dry-material threshing with the additional oscillating sieve, the percent of grains with branchlet to the total output decreased greatly as the feed rate increased. 4. The output of the damaged grains increased as moisture content decreased. Especially, for the dry-paddy threshing, the additional sieve separating device produced more damaged grains than the pneumatic separation at all feed rates. 5. Generally, for dry paddy threshing, the separating performance of the thresher with the additional sieve device was better at all feed rates, showing greater difference with increasing feed rates. 6. Separating losses were greater with the pneumatic than sieve separation for both the wet-and dry-threshing. 7. The overall comparison of separating performance of threshers tested with and without an additional sieve device showed that the former was more effective than the latter for the dry-material threshing. However, for the wet-paddy threshing, the separation performance with a sieve device was better than the pneumatic only when the feed rate was high.

• Asian Journal of Turfgrass Science
• /
• v.21 no.1
• /
• pp.69-79
• /
• 2007

Incorporating herbicides application into a fertilization program has several benefits including saving time and reducing traffics on the lawn. Premixed products of fertilizers and herbicides are commonly known as Weed & Feed in the lawn-care industry. To compare Weed & Feed with separate applications of fertilizers and herbicides on a Kentucky bluegrass (Poa pratensis L.) lawn, a Weed & Feed 28-3-3, containing 0.64% 2,4-D, 0.31% MCPP, and 0.03% dicamba of active ingredients, was used in this study. The first application was in May, with the second in June or Sept. Herbicides in forms of 2,4-D (LV-4, 4EC), MCPP (4EC), and dicamba (Clarity, 4EC) were applied at rates equal to the amounts in Weed & Feed or at half of the rates. The dominant weed in both locations was common dandelion (Taraxacum officinale Weber.) in 2005 and 2004. A secondary weed was Canada thistle (Cirsium arvense (L.) Scop.) in 2004 and broadleaf plantain (Plantago major L.) in 2005. When applied in May and June, fertilizer plus full rate of herbicides treatment achieved 112.3 and 83.7 days of acceptable turf quality in 2004 and 2005, respectively. During the same period, Weed & Feed resulted in 58.7 and 24.3 days of acceptable turf quality, respectively. Our study showed that Weed & Feed was generally as effective in weed control as the same amount of fertilizer plus half rates of herbicides sprayed although results may vary due to the timing of application. Fertilizer plus full rates of herbicides provided the same or better results of weed control than Weed & Feed.

• KSBB Journal
• /
• v.14 no.4
• /
• pp.495-502
• /
• 1999

The optimization of fed-batch yeast fermentation process has been performed using genetic algorithm(GA). Three strategies were designed and applied to obtain the optimal feed rate profiles. Genes in the chromosome (input variables for optimization) included feed rates on fixed time intervals (strategy I), or swiching times $t_s1\;and\;t_s2$, and feed rates on singular arc (strategy II), or feed rates and the length of time interval (strategy III). Strategy III showed the best results for all initial conditions due to efficient utilization of genetic information. Simulation results using GA showed similar or better performance compared with previous results by variational caculus and singular control approach.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.11 no.2
• /
• pp.675-680
• /
• 2010

This study was investigated to complement nitrogen removal of low concentration influent municipal sewage. The following are the results of the effect of Internal Recircularion and Step Feed rates on Treatment efficiency at a BOD low concentration influent municipal sewage. Up to 90.0% of BOD, 87.8% of COD, 71.0% of T-N, 75.3% of T-P were removed on average at a low concentration influent. Whereas BOD and T-P were removed without any relations to Step Feed rates, T-N was influenced. Nitrogen removal efficiencies in 80% of Step Feed rates was 65%, which was caused by the lack of Carbon Source for denitrification. Nitrogen removal efficiency in 40% of Step Feed rates was 58%, which means it was not removed but dischared. Consequently, the efficiency was 73%, 80%, and 78% in 70%, 60% and 50% of Step Feed rates, which was concluded as the best range of Step Feed rates. Nitrogen removal efficiency increased under the condition of Internal Recircularion. At over 150% of Internal Recircularion rate, the efficiencies were not affected any more. It is believed that lots of Recircularion caused inflow of DO to anoxic tank. Therefore, the most appropriate Internal Recircularion rate can be concluded as 50~150%.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1997.10a
• /
• pp.37-42
• /
• 1997

Off-line feed rate scheduling is an advanced methodology to automatically determine optimum feed rates for the optimization of NC code. However, the present feed rate scheduling systems have lim~tations to generate the optimized NC codes because they use the material removal rate or non-generalized cutting force model. In this paper, a feed rate scheduling system based on an improved cutting force model that can predrct cutting forces exactly in general machining was presented. Original blocks of NC code were divided to small ones with the modified feed rates to adjust the peak value of cutting forces to a constant vale. The characteristic of acceleration and deceleration for a given machrne tool was considered when off-line feed rate scheduhng was performed. Software for the NC code optimization was developed and applied to pocket machining simulation.

• Journal of Biosystems Engineering
• /
• v.6 no.1
• /
• pp.60-72
• /
• 1981

This study was carried out to find out the effects of the sheaf size of paddy harvested by the binders on the threshing performance, load characteristics and power requirement of an auto-feed thresher. The results of the study are summarized as follows: 1. The seperating performance of the thresher appeared to be satisfactory for all the sheaf sizes although the amount of rubbishes and empty grains slightly increased with the sheaf size of paddy. 2. There was no significant difference in grain output quality of the thresher among the three sheaf sizes. However, the amount of grains left unthreshed increased with the sheaf size. In the case of the largest sheaf size with the feed rate of 780kg/h, it exceeded the limit set by the national inspection regulations. 3. The position of the feed-chain rail gave a significant effect on the power requirement of the thresher. At the feed rate of 780kg/h, the net power required to convey sheafs through the feed chain was in the range of 0.37 to 0.50 PS for the middle and lowest position of feed-chain rail, and there was no significant difference among the sheaf sizes. At the highest position, however, it appeared that the smallest sheaf required more power than the others. The net power requirements at this position were 1.03, 0.59. 0.65 PS for the smallest, medium and largest sheafs respectively. 4. The torques of both the thresher and the engine shaft increased with the feed rate and were not affected by the sheaf size for the lower two feed rates of 520 and 780kg/h. At the highest feed rate of 1,040 kg/h, however, they were affected by the sheaf size. In this case, the medium sheaf size gave lower values than the others. 5. The variations in the thresher and the engine torque increased with the feed rate and were not affected by the sheaf size for the feed rate of 520kg/h. At the feed rate of 780kg/h, however, they increased with sheaf size. And at the feed rate of 1,040 kg/h, the torque variations increased greatly for all the sheaf sizes due to an over-load operating condition. 6. It appeared that the average and maximum power requirements of the thresher increased with the feed rate. But, there was no significant difference in power requirement among the sheaf sizes for the lower two feed rates. 7. The threshing efficiency of the thresher was in the range of 214-249 kg/ps.h with the feed rates of 520 and 780 kg/h, and it was not affected by both the sheaf size and the feed rate. At the feed rate of 1,040 kg/h, however, it decreased to as low as 171-174 kg/ps.h because of a sudden increase in power requirement. 8. The average power requirements of the engine were slightly higher than those of the thresher due to the slippage of flat belt between the thresher and engine. It appeared that power transmission from the engine to the thresher was maintained properly since slippages were moderately low with the range of 2.78 to 6.51% throughout the tests. 9. The specific fuel consumption of the engine (diesel 8PS) decreased as the feed rate increased. However, there was no significant reduction in specific fuel consumption as the feed rate increased above 780 kg/h.

• Journal of Biosystems Engineering
• /
• v.8 no.2
• /
• pp.39-48
• /
• 1983

This study was performed to obtain the basic data which could be used for the modification of the manual center-burner-type rice-husk furnace into a small scale automatic type for the multi-purpose use in the farm. For this purpose, first, the utilization feasibility of the rice-husk furnace in the farm was analyzed briefly in aspects of available amount of rice-husk for the fuel, annual operation time and replaceble amount of residential heating energy with rice-husk in the farm. For the experiment a prototype furnace geared with an automatic feeding device was fabricated, and feed rate, mold size and chimney height were changed to investigate the combustion efficiency of rice-husk and thermal efficiency of the furnace. Also, optimum and limiting operational factors were observed in each treatments. The results obtained are summarized as follows. 1. If the rice-husk is intensively used for residential heating in the farm for winter season, on an average 51 percent of the total heating energy can be replaced with the rice-husk. Therefore, development of a small scale automatic rice-husk furnace was recognized to be feasible. 2. The operational condition depending on husk-feed rates was very important factor for successive steady burning operation of the given furnace. When the feed-rate was 1.5 kg/hr, the top of the burning zone should be kept at the position about 55 cm from the bottom of the combustion chamber with the periodic removal of ash (termed as steady state position), which was 18 cm above the mold waist. When the feed rates were 2.4 kg/hr and 3.0 kg/hr, the steady state position was at about 4 cm above the mold waist. 3. The mold size affected inflow rate of air into the furnace and consequently CO content in the exhaust gas. The relatively bigger mold gave positive effect on the air-inflow rate. 4. When the husk-feed rates were 1.5 kg/hr, 2.4 kg/hr, 3.0 kg/hr, the combustion efficiencies of the rice-husk were 98.5%, 97.4% and 95.0%, the thermal efficiencies of the furnace were 93.4%, 93.2% and 87.6%, and CO content in the exhaust gas were 1.21%, 1.03%, and 2.43%, respectively. The air-inflow rates were decreased with the increase of feed rates. When the amount of excess air was 30-40%, the CO content in the exhaust gas was at the minimum level. 5. When the chimney height was lowered from 260 cm to 96 cm, the air-inflow rate was slightly decreased, but the average temperature in the combustion chamber, CO content in the exhaust gas and combustion and thermal efficiencies were not changed significantly. 6. The incidental problems associated with the protytype furnace were accumulation of the ash inside the mold, accumulation of the cinder between the outer-drum of the furnace and the combustion chamber wall, and accumulation of the cinder in the chimney.

• Asian-Australasian Journal of Animal Sciences
• /
• v.10 no.3
• /
• pp.260-264
• /
• 1997

This study was conducted with adult cockerels to determine whether dietary RNA affects feed intake and renal weight and function, and if the responses are similar to dietary adenine. Chickens were ad libitum fed a RNA diet (100 g/kg) or an adenine diet (9.1 g/kg) for 14 d and catheterized in right jugular vein, hepatic portal vein and both urethers, and saline together with para-amino hippuric acid and sodium thiosulfate was continuously infused into them to evaluate renal functions. Dietary RNA reduced feed intake and body weight, and dietary adenine increased kidney weight expressed as a proportion of body weight (P < 0.05). Feed intake and body weight on the adenine diet and kidney weight on the RNA diet showed similar though non significant tendencies. No calculi were detected in the kidney in chickens fed either the RNA or adenine diets. Plasma inorganic phosphate (IP), Ca and 1,25 $(OH)_2$ vitamin $D_3$ concentrations were increased by dietary RNA and adenine, although the increases of IP and Ca in adenine-fed chickens were not significant. Uric acid and urea concentrations in the blood plasma were unaffected by dietary RNA or adenine. Both dietary RNA and adenine increased renal blood flow rates 3.5-3.7 fold, renal plasma flow rates 3.4-3.7 fold and glomerular filtration rates (GFR) 2.9-3.0 fold (p < 0.01). Clearance of urea, IP and Ca were also enhanced by dietary RNA, but not by dietary adenine. However, neither RNA nor adenine affected uric acid clearance. Only IP clearance was significantly augmented at the glomerular level by dietary RNA (p < 0.05). Glomerular filtration of uric acid, urea, IP and Ca and reabsorption of urea, IP and Ca at the renal tubule were increased by dietary RNA and adenine (p < 0.05), whereas tubular secretion of uric acid was decreased by both dietary treatments. It is concluded that dietary adenine is effective in changing renal function and P and Ca metabolism in chickens.

• 한국기계연구소 소보
• /
• s.18
• /
• pp.29-35
• /
• 1988

When low sliding velocities in the boundary lubrication range are operating, irregular movements frequently occur which are a result of the stick-slip phenomenon. Such slide motions are undesirable in precision machine tools, particularly with feed back systems used in numerical and adaptive control machine tools. Accordingly, this paper reports analytical and experimental studies in the stick-slip characteristic of machine tool feeding system. The main conclusions of this study are as follows; The tendency towards stick-slip effects may be reduced by; 1). Reducing the drop in friction coefficient in the Stribeck curve(on the rising part of the friction characteristic at higher sliding speeds, the system is stable all the time) 2). Reducing the transition velocity by the use of a higher viscosity lubricating oil. 3). Increasing the stiffness(Damping)and reducing normal load(Sliding mass) Therefore, the Critical velocity is decided from the above conclusions and in designing of machine tool, feed rates(sliding velocity)must be design the more than critical velocity.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.48 no.4
• /
• pp.466-473
• /
• 2015

The juvenile red variant of the sea cucumber Stichopus japonicus is distributed worldwide. It is a valuable food source in Korea, China, and Japan. Major issues in farming the juvenile red variant sea cucumber include growth rates and disease resistance. In recent years, studies have focused on feed additives to enhance immune system and health. In this study, we used a common diet (CD), a nutritional diet (ND; mixed nutritional supplements), and an immunity diet (ID; mixed probiotics, spirulina, and levan) and compared the growth rates and immunity of juvenile red variant sea cucumbers fed the experimental diets for 12 weeks. The growth and survival rates in the ID group were significantly increased (P>0.05). This suggests that the feed additives positively influenced immunity and growth in the ID group. However, the immune activity was exhibit a stabilizing effect, and further investigation of immune effects is required.