• Asian-Australasian Journal of Animal Sciences
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• v.24 no.8
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• pp.1136-1141
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• 2011

Effect of dietary essential oils on growth, feed utilization and meat yields of white leg shrimp L. vannamei was investigated. White shrimp fry weighing 0.62 g were kept in one of 12 tanks (75 head/500 L holding tank) in a closed recirculation system. Four experimental diets, a commercial diet (control), phytoncide oil (PO), oregano oil (OO) and fermented garlic liquid (GL) were fed for 16 weeks. The mean water quality values for the whole experimental period were $27.8{\pm}1^{\circ}C$, $7.6{\pm}0.3$, $15.5{\pm}0.3$ g/L and $6.1{\pm}0.3$ mg/L for water temperature, pH, salinity and dissolved oxygen, respectively. At the end of the trial, 10 shrimp per tank were randomly sampled and meat yields (%) were evaluated after peeling the shell and removing the head. After a 16 week feeding trial, final weight of shrimp ranged from 21.9 g to 23.6 g. Feed conversion was not significantly different among groups (p>0.05), which was the lowest (1.95) in the control and highest (2.30) in the PO. Specific growth rate was also not significantly different (p>0.05) and ranged from 3.18% to 3.25%. Average daily gain of 0.2 g was obtained in all treatments. Mortality varied from 35.1% for control to 44.9% for OO. Meat yields maintained constant at 52.1% for control to 53.0% for PO. The study suggested that natural essential oils could not exert any improvement in growth performance, mortality and meat yields of white leg shrimp.

• Membrane Journal
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• v.23 no.2
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• pp.170-175
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• 2013

Poly (vinyl alcohol) (PVA) solution containing the glutaraldehyde (GA) as a crosslinking agent was coated onto the polyacrylonitrile (PAN) hollow fiber membrane as the supporter. Pervaporation experiments were carried out to characterize the prepared PVA/PAN composite membrane for water-isopropyl alcohol mixture. The flux and separation factor were measured at 30, 50, $90^{\circ}C$ for the feed mixture of aqueous 85 wt% IPA solution with varying the reaction temperature and composition of coating solutions. Typically the flux showed 1,870 $g/m^2{\cdot}hr$ at $90^{\circ}C$ feed mixture and the coating concentration of 3.5 wt% and the highest separation factor of 804 was obtained at $30^{\circ}C$ feed mixture and the coating concentration of 7 wt% as well.

• Journal of Korean Society on Water Environment
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• v.31 no.3
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• pp.235-240
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• 2015

To evaluate the unit load generation and discharge, pig cage test was conducted. Feed intake, drink amount, and urine generation increased growth stage (heavy weight) of the pig more great. However, the sum of the urine and manure did not show a significant difference in the growth stages of pigs. Because of the limit of the experiment, e.g., research period, high pigpen temperature, breed-related stress and etc., it could not be derived the results of the four seasons. Therefore, in order to generalize the results, the feed intakes were calibrated using a NRC (National Research and nutritional requirements of pigs from the Commission) standards. The finalized unit load generation and generation amounts of manure and urine were estimated at BOD 104.1 g/head/d, T-N 21.2 g/head/d, T-P 4.9 g/head/d, manure 0.96 L/d, urine 1.66 L/d with consideration of revised feed intake. Compare to the former research results of MOE (Ministry of Environment, 1999) and NIAS (National Institute of Animal Science, 2008), the generation amounts of manure and urine were similar to the NIAS's values. In case of unit load generation, BOD and T-N were almost similar in all of them. However, the T-P unit load generation of MOE was more difference, e.g., 2.5 times high, compare to this study.

• Journal of Aquaculture
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• v.12 no.1
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• pp.25-30
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• 1999

This study was carried out to produce the seedling of the larvae and juveniles of pale chup, Zacco platypus (Cyprinidae) in terms of artificial hatching, feeding behavior and growth rates. The total lengths of the newly hatched larvae were 7.6~8.2mm (mean: 7.97mm). The hatched larvae rose to the surface 3 days after hatching. The larvae were fed Daphnia, rotifer, Artemia and powdered feed. Hatching experiments were conducted in jar incubators under the different water temperature conditions, $20~32^{\circ}C$. The highest hatching rate was at $26^{\circ}C$ after 47 hours. Jar incubators was the highest hatching rate (89%), and cage and Californian incubators were useful and relatively high hatching rates (>89%). The size of the larvae 50 days after hatching were 30.0mm (25.6~32.0mm). As the water temperatures was increased, the growth rate of the larvae was also increased. Especially, the growth rates were favorable over $26^{\circ}C$, but survival was the worst at $32^{\circ}C$. This species was quick to accept assorted feed after hatching. The assorted feeds for flounder and rockfish better than that of carp in reference to growth rate.

• Membrane Journal
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• v.26 no.3
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• pp.197-204
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• 2016

The objective of this work was to investigate the performance of pervaporation process for recovery of ester compounds from model aqueous solutions and how the fluxes of esters and water were affected by changes in feed concentration and temperature. The flux of ethyl acetate (EA), propyl acetate (PA), ethyl propionate (EP), butyl acetate (BA), and ethyl butyrate (EB) increased with an increase in feed concentration from 0.15 wt% to 0.60 wt%, and increased with temperature change from $30^{\circ}C$ to $50^{\circ}C$. The flux of esters (EA, PA, EP, BA, and EB) was in order of (EA) < (PA, EP) < (BA, EB). This result meant that the flux strongly depended on affinity between esters and membrane surface; EA is the least hydrophobic because it has one hydrophobic function group ($-CH_2-$), (PA, EP) have two ($-CH_2-$), and (BA, EB) are the most hydrophobic because these have three ($-CH_2-$). As well as such an influence of hydrophobicity of ester molecules on ester flux, the influence of hydrophobicity of membrane surface on ester flux needs further investigation. With increase in temperature, water flux of aqueous EA, PA, EP, BA, and EB solution increased. However, water flux of aqueous ester solutions did not change appreciably with increase in concentration. This experimental results may be used as fundamental data for pervaporation (PV) to improve the aroma recovery process as an alternative to thermal evaporation and distillation processes.

• Korean Journal of Environmental Agriculture
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• v.27 no.4
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• pp.441-446
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• 2008

This study was conducted to determine the effect of heat stress on laying hen performance during summer. A total of 180 Hyline-brown layers, 98 days of age, were housed in a enclosed house. The daily maximum temperature in the house was ranged $26{\sim}36^{\circ}C$. The egg production was markedly fallen than other days when daily maximum temperature in the layer house became more than $33^{\circ}C$. As water intake and feed intake increased to $490\;mL\;bird^{-1}\;day^{-1}$ and $240\;g\;bird^{-1}\;day^{-1}$, the egg production soared. But it was hardly increased more than them. Based on these results, layer house roof should be amply insulated to improve the egg production of layers. If not insulated, the shade curtain should be installed above roof and cool water sprayed before and after 2 p.m. And layers should be provided cool drinking water of about $15^{\circ}C$ in the day time.

• Journal of Aquaculture
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• v.17 no.4
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• pp.240-245
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• 2004

Two experiments were conducted to study the effect of temperature on growth and survival of yearling sea bass, Lateolabrax japonicus reared from 3$^{\circ}C$ to 33$^{\circ}C$. In the I st experiment, we used yearlings fish averaging 19.2$\pm$0.2 cm/fish (Mean$\pm$S.E.M.) of total length (TL) and 67.0$\pm$1.8 g/fish (Mean$\pm$S.E.M.) of body weight (BW), and we cultured the fish at 3, 6, 9, 12 and 17$^{\circ}C$ for 90 days. In the 2nd experiment, the experimental fish averaging 24.9$\pm$0.1 cm/fish (Mean$\pm$S.E.M) of TL and I 46.4$\pm$3.0 g/fish (Mean$\pm$S.E.M) of BW were reared at 21,24,27,30 and 33$^{\circ}C$ for 90 days. During these experiments, we measured food intake, feed efficiency, survival and growth (TL and BW) in the both experiments. Although food intake of the yearling increased with the temperature, the feed efficiency was only enhanced within the temperature range, from 21 to 27$^{\circ}C$. Growth of yearling was normal within the temperature range from 17 to 3$0^{\circ}C$, but it was stoped or reduced in other temperatures. Survival rate was significantly reduced in 3$^{\circ}C$ from the 1st experiment and in 30 and 33$^{\circ}C$ from the 2nd experiment, but there was no significant difference among other groups.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2003.10a
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• pp.24-29
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• 2003

Deep sea water has cold temperature, abundant nutrients and minerals, and good water quality that is pathogen-free and stable. Compared with surface water, deep sea water contains more nutrition salt, such as nitrogen and phosphor. Moreover, if has the good balance of minerals. Because of the ability of the spray drying process to produce a free-flowing power considering of spherical particles with a well-defined size distribution and the rapid drying times for heat-sensitive material, spray drying is attractive for a wide range of applications spray drying is a unique unit operation in which powders are produced from a liquid feed in a single processing step. Key component of the process are atomizer, spray chamber. Design of spray chamber should be based on the atomizer type, the production rate, and the particle size required. Because of the complex processes taking place during spray drying, traditional design method are based on pilot-plant tests and empirical scale-up rules. Modern technique such as CFD have a role to play in design and troubleshooting.

• Applied Chemistry for Engineering
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• v.16 no.1
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• pp.61-67
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• 2005

Zeolite membranes show better thermal, mechanical, chemical stabilities than polymer membranes. Water was separated from water/ethanol mixtures by pervaporation using the NaA and the NaY zeolite membranes synthesized in our laboratory. The effects of concentration of ethanol at the feed side and temperature were studied on the permeation flux and separation factor of water. The separation factors obtained with the NaA zeolite membrane was found to be 1000 times higher than those obtained with the NaY. However, the water flux through the NaA zeolite membrane was observed to be lower than 1/2 of that through the NaY zeolite membrane.

• Environmental Engineering Research
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• v.24 no.3
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• pp.404-411
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• 2019

In this study, we designed a data-driven model to predict chlorophyll-a using M5P model tree and extreme learning machine (ELM). The Juksan weir in the Youngsan River has high chlorophyll-a, which is the primary indicator of algal bloom every year. Short-term algal bloom prediction is important for environmental management and ecological assessment. Two models were developed and evaluated for short-term algal bloom prediction. M5P is a classification and regression-analysis-based method, and ELM is a feed-forward neural network with fast learning using the least square estimate for regression. The dataset used in this study includes water temperature, rainfall, solar radiation, total nitrogen, total phosphorus, N/P ratio, and chlorophyll-a, which were collected on a daily basis from January 2013 to December 2016. The M5P model showed that the prediction model after one day had the highest performance power and dropped off rapidly starting with predictions after three days. Comparing the performance power of the ELM model with the M5P model, it was found that the performance power of the 1-7 d chlorophyll-a prediction model was higher. Moreover, in a period of rapidly increasing algal blooms, the ELM model showed higher accuracy than the M5P model.