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

• The Korean Journal of Malacology
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• v.27 no.4
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• pp.337-343
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• 2011

In order to know the effects of rearing conditions such as water temperature, salinity, larval stocking density, kinds and amounts of food organism and seedling collection method on seedling production of the brackish water clam, Corbicula japonica, the growth and survival rate of the larvae were investigated at each rearing condition. The shell length of larvae showed faster growth at $24^{\circ}C$ and $27^{\circ}C$, and survival rate showed good results at $18^{\circ}C$ and $21^{\circ}C$. Based on growth and survival rate according to water temperature, the optimal water temperature for larvae rearing was $24^{\circ}C$. At the salinity of more than 3 psu, the growth and survival rate were higher than 0 psu. The optimal salinities for larvae were 6-9 psu. Growth and survival rate of larvae were high at low stocking density and the optimum stocking density of larvae was 10 inds./ml. Daily feeding concentrations of 10,000-20,000 cell/ml of food organisms mixed Pavolva lutheri, Isochrysis galbana and Chaetoceros calcitrans were very effective. Full grown larvae collection from various substratum was significantly higt in sand, especially sand size was less than 0.25 mm.

• Journal of Animal Science and Technology
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• v.45 no.6
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• pp.975-986
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• 2003

Present study was conducted to investigate the effect of the level of concentrates and pasture grazing in 36 autumn born Hanwoo heifers(initial body weight, 119.7${\pm}$25.6kg) for 426d including 195d for a pasture stage. The animals were fed commercial concentrates at a rate of 0.5%(T1), 1.0%(T2), 1.5%(T3) and 2.0%(T4) of body weight, respectively, for pre- and post-pasture. 1. Mean daily gains by treatments were 0.348, 0.403, 0.450 and 0.501kg for T1, T2, T3 and T4, respectively, indicating that increases in concentrates intake was associated with the daily gain of grazing Hanwoo heifers. However, the mean daily gain was the highest for T2 during the pasture stage. 2. TDN intakes per 1kg gain were, on average, 8.61kg for the entire experimental period and 9.22kg for the pasture stage, respectively. In addition, the rate of roughage to concentrate during the entire experimental period was 49.6 to 68.2%(mean 58.5%). 3. Age reached 225 and 250kg of body weight was, on an average, 15.1mo. and 17.6mo., respectively, indicating that increasing the level of concentrates feeding(by 0.5% of body weight) reduced the first pregnancy by 0.9 mo. Ages and body weight for first service were 19.5mo. and 272.2 kg, respectively. Mean pregnant rate of total heads was approximately 52.8%, but appeared to 66.6% for T3 and T4. Therefore, it may be concluded that the optimum level of concentrates for autumn born Hanwoo heifers is 1.8% of body weight for indoor feeding on rice straw-based diet and 1.5% of body weight for a pasture stage, respectively.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.11
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• pp.5628-5636
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• 2012

Effective drying method of sewage sludge is researched in this study. To dry the sludge, chain crusher flash dryer was adopted to remove moisture content in the cell which is mostly responsible for the sludge moisture content. And Pilot plant experiment was conducted in real life sewage treatment plant to study effect and characteristics of operating conditions. Operating variables include sludge feeding rate, rotational speed of chain, process temperature and feed moisture content. As rotational speed of chain increased, product yield of sludge increased, and the performance of the testing system increased. And, as process temperature increased, the sludge drying efficiency increased. It is found that optimum feed moisture content is at 60% which shows the maximum sludge product yield and about 10 moisture content(%) of sludge product. Sludge feed rate showed optimal value, and when the sludge feed rate is exceeded, sludge product yield did not increased but the amount of residue increased. Pilot plant experiment results are as follow. The optimal condition for the rotational speed of chain 1600rpm(max. speed), final sludge discharge temperature $80^{\circ}C$, feed moisture content 60%, and feed rate 60kg/h. When the plant was operated at the optimal conditions, the final product showed fairly good results such as sludge product yield 85.5%, moisture content 11.0% and sludge drying efficiency 81.7%.

• Journal of Aquaculture
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• v.19 no.4
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• pp.225-230
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• 2006

A long-term (26 weeks) feeding experiment was conducted to examine the essentiality and requirement of inositol in diets for olive flounder because no information is available in the species. Five casein-gelatin based semi-purified diets were formulated to contain four different levels of myo-inositol (0, 0+antibiotic, 400, 800, and 1600 mg/kg, designated as M0, M0+, M400, M800, and M1600, respectively). One (M0+) of the control diets contained tetracycline hydrochloride (0.4%, wt/wt) as an antibiotic to inhibit biosynthesis of inositol by micro-organism in intestine of fish. Olive flounder at the early juvenile stage (initial body weight 1.22 g) were randomly distributed into fifteen 35 L tanks (48 fish/tank) and fed with one of the experimental diets (3 replicates per diet). At the end of the feeding trial, the weight gain, feed intake, specific growth rate, and protein efficiency ratio of fish fed diets containing higher levels of myo-inositol (M800 & M1600) were significantly higher than those of fish fed the other diets (P<0.05). Feed conversion ratio, survival, hematocrits, and hemoglobin of fish fed experimental diets were not significantly different among all the fish groups. Whole body compositions of fish were not different except for lipid content. The lipid content was significantly different between M0 and M400 diet groups. These results indicate that juvenile olive flounder requires dietary supplementation of myo-inositol in diets for normal growth and its optimum level seems to be approximately 800 mg myo-inositol/kg diet.

• Fisheries and Aquatic Sciences
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• v.17 no.2
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• pp.255-261
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• 2014

An 8-week feeding trial was conducted to investigate the effects of dietary taurine supplementation on the growth performance of juvenile rock bream, Oplegnathus fasciatus. Triplicate groups of 25 fish averaging $2.72{\pm}0.04$ g ($mean{\pm}SD$) were fed one of six experimental diets prepared by adding taurine at 0%, 0.25%, 0.5%, 1.0%, 1.5% and 3.0% (Control, $Tau_{0.25}$, $Tau_{0.5}$, $Tau_{1.0}$, $Tau_{1.5}$ and $Tau_{3.0}$, respectively). At the end of the feeding trial, the weight gain, specific growth rate and protein efficiency ratio of fish fed the $Tau_{0.5}$, $Tau_{1.0}$ and $Tau_{1.5}$ diets were significantly higher (P < 0.05) than those of fish fed the Control and $Tau_{0.25}$ diets. The feed efficiency of fish fed the $Tau_{0.5}$ diet was significantly higher than that of fish fed the Control, $Tau_{0.25}$ and $Tau_{3.0}$ diets. Fish fed the $Tau_{1.0}$ diet had higher whole-body crude protein content than fish fed the Control diet, while the crude lipid content of fish fed the $Tau_{1.5}$ and $Tau_{3.0}$ diets was significantly lower than that of fish fed the Control and $Tau_{0.25}$ diets. An ANOVA suggested that the optimum level of dietary taurine supplementation to improve growth and reduce the body lipid contents of juvenile rock bream, O. fasciatus, was 0.5%, while a broken line analysis of weight gain indicated a level of 0.62%.

• Resources Recycling
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• v.15 no.1 s.69
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• pp.3-11
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• 2006

Fast pyrolysis of Quercus acutissima was carried out in a fluidized bed pyrolyser and then the physicochemical properities of obtained bio-oil were analyzed using GC/MS. The yields of bio-oil of Quercus acutissima and Larix leptolepis from a fluidized bed pyrolyzer were maximized at $350^{\circ}C\;and\;400^{\circ}C$, respectively. This is due to the difference or cellulose content between the two tree species. Above the optimum temperature, the yields of char and oil decreased as the reaction temperature increased, but the yield of gas-phase and water fraction increased. It is concluded that this phenomenon is occured by secondary pyrolysis in the free board. The feeding rate of the sample in a fluidized bed pyrolyser did not affect the yields and composition of products, because of a sufficient mixing between bed materials and sand.

• Journal of Dairy Science and Biotechnology
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• v.28 no.1
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• pp.53-59
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• 2010

The milk product is one of the major foods which provide calcium for nutritional requirement. In addition to calcium, it supplies diverse nutrients including protein, potassium, vitamin A, vitamin $B_1$, and vitamin $B_2$. Adequate calcium intake throughout lifetime ensures optimum bone density and prevents osteoporosis in old age by reducing loss of bone mineral during growth and aging. The nutritional deficiency of calcium intake and spreading of osteoporosis in Korean population accentuated necessity of adequate calcium intake through milk consumption. Obstruction of milk consumption due to lactose intolerance should be overcome by educational programs for adequate milk consumption and low-lactose milk product developments. Consumption of milk products was reported to prevent high blood pressure in clinical studies and epidemiological investigations. As the feeding of milk increased, the body weight and fat of animal decreased in animal studies. The epidemiological investigations revealed that there was a negative correlation between the amount of milk consumption and the body fat. When calcium was provided as dietary supplement in the clinical trials, the body weight and body fat of subjects decreased. When calcium was particularly supplied as a part of milk, the body weight reduction rate was augmented. Calcium, vitamin D, and conjugated linoleic acid have been reported to exert a role in reducing cancer. The paramount importance of milk in nutrition as a source of calcium and other invaluable nutrients emphasizes consistent supply of milk products to adults as well as adolescents by dairy industry.

• Journal of Welding and Joining
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• v.12 no.4
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• pp.85-101
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• 1994

Effect of Cr, Cu and Ni metal powders addition on the alloyed layer of aluminum alloy (AC2B) has been investigated with the plasma transferred arc (PTA) overlaying process. The overlaying conditions were 125-200A in plasma arc current, 150mm/min in process speed and 5-20g/min in powder feeding rate. Main results obtained are summarized as follows: 1) It was made clear that formation of thick surface alloyed layer on aluminum alloy is possible by PTA overlaying process. 2) The range of optimum alloying conditions were much wider in case of Cu and Ni powder additions than the case of Cr powder addition judging from the surface appearance and the bead macrostructure. 3) Alloyed layer with Cu showed almost the homogeneous microstructure through the whole layer by eutectic reaction. alloyed layers with Cr and Ni showed needle-like and agglomerated microstructures, the structure of which has compound layer in upper zone of bead by peritectic and eutectic-peritectic reactions, respectively. 4) Microconstituents of the alloyed layer were analyzed as A1+CrA $l_{7}$ eutectics, C $r_{2}$al sub 11/, CrA $l_{4}$, C $r_{4}$A $l_{9}$ and C $r_{5}$A $l_{*}$ 8/ for Cr addition, Al+CuA $l_{2}$(.theta.) eutectics and .theta. for Cu addition, and Al+NiA $l_{3}$ eutectics. NiA $l_{3}$, N $i_{2}$A $l_{3}$ and NiAl for Ni addition. 5) Concerning defect of the alloyed layer, many blow holes were seen in Cr and Ni additions although there was lesser in Cu addition. Residual gas contents in blow hole for Cu and Ni alloyed layer were confirmed as mainly $H_{2}$ and a littie of $N_{2}$ Cracking was observed in compound zone of the alloyed layer in case of Cr and Ni addition but not in Cu alloyed layer.r.r.

• KSBB Journal
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• v.11 no.1
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• pp.65-70
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• 1996

Sodium gluconate was produced by neutralization of gluconic acid formed during the submerged culture fermentation of glucose with Aspergillus niger ACM 7. The fermentation characteristics of Aspergillus niger ACM 7 were investigated quantitatively according to the change of the initial glucose concentrations and the initial pHs of fermentation broth. The maximum specific growth rate was estimated to be $0.20hr^{-1}$ at 95g/$\ell$ of initial glucose concentration. The maximum fermentability of sodium gluconate was 95% at the initial glucose concentration of 26g/$\ell$. However, the maximum sodium gluconate productivity was 1.18g/$\ell$/hr when the initial glucose concentration was 110g/$\ell$. The optimum pH was found to be 5.5 for both the cell growth and the sodium gluconate production. With optimized culture conditions, the productivity of sodium gluconate in a fed-batch culture(production fermentor, 16,000$\ell$) increased up to 7.1g/$\ell$/hr.