• Journal of the Korean Society of Environmental Restoration Technology
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• v.9 no.6
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• pp.162-167
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• 2006

The urban stream includes the channel and sandbars. The sandbar plays a key role in the riparian ecosystem. For birds and insects the sandbar offers a small strip of habitat and fish and other fauna feed in the boundary of sandbar where eddies occur. So, it is important habitat and source for the flow of energy, matter and organisms through the landscape and act as ecotone between the terrestrial and stream corridors. However, the sandbar changes continuously by the natural process. Thus, it is necessary to measure the shape and area of the sandbar accurately for the efficient urban stream management for the amenity of urban residents and stream protection. The study site is Yangjae Stream where the first natural-style urban stream restoration projected was impelemented by the support of Ministry of Education in Korea. The measurement was taken by the beacon Differential Global Positioning System (DGPS) and the data were stored and analyzed using ArcView Geographic Information System (GIS) program. Therefore, the purpose of this study is to measure the change of sandbars in the urban stream after concentrated stormwater during summer.

• Asian-Australasian Journal of Animal Sciences
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• v.33 no.2
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• pp.305-312
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• 2020

Objective: The present trial was conducted to determine the influence of different dietary fatty acid (omega-3 and omega-6) sources on reproductive performance of female broiler breeders and growth performance and carcass traits of their progeny. Methods: Two hundred and twenty, 25 weeks old Ross-308 male (20) and female (200) broiler breeders were used in the experiment for the period of 6 weeks. All birds were randomly divided into four dietary treatments (containing 2% soybean oil, 2% sunflower oil, 2% flaxseed oil, and 2% fish oil) each with five replicates of one male and ten females. Throughout this experiment hatching performance of broiler breeders, progeny growth performance and carcass parameters were recorded. Results: The results showed that the inclusion of different fatty acid sources in female broiler breeders diet had no significant effects (p>0.05) on number of fertile eggs, post-hatch mortality, and fertility rate. The soybean oil supplemented group had significantly (p<0.05) higher late embryonic mortality compared to other three treatments. Conclusion: It was concluded that inclusion of 2% of different sources of omega-3 and omega-6 fatty acids (especially 2% flax seed oil) in broiler breeders' diet can reduce late embryonic mortality. The other reproductive characteristics of parents and growth and carcass characteristics of progeny remained unaltered by dietary sources of omega-3 and omega-6 fatty acids.

• Journal of Microbiology and Biotechnology
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• v.1 no.3
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• pp.212-219
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• 1991

Four species of yeast, Saccharomyces cerevisiae, Candida utilis, Saccharomycopsis flbuligera, and Schwanniomyces castellii were evaluated for their ability to bioconvert potato processing waste water into microbial protein and the resulting single-cell proteins were evaluated as protein sources for rainbow trout, using in vitro analyses. The studies indicated that Schwanniomyces castellii, which utilizes starch dircetly and converts it into cell mass efficiently, was suitable for the bioconversion. In the single-stage continuous bioconversion, the yield S. castellii cell mass, which contained approximately 37% protein, was 77%, at dilution rate 0.25 $h^{-1}$. Reduction of total carbohydrate was 81%. During batch fermentations, cell mass yield was about 72% and total carbohydrate reduction was 81%. Among the yeasts tested, S. castellii possessed the most fragile cell wall and had a favorable amino acid profile for salmonid fish; protein score of 86% (Met). In an in vitro pepsin digestibility test 80% digestibility (23~38% above control) was observed when cells were pre-heated in a steam bath for 30 min. Results presented should be regarded as being preliminary in nature because they were derived from single experiments.

• Journal of Environmental Policy
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• v.3 no.1
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• pp.95-117
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• 2004

This study was conducted to estimate nitrogen discharge from Korea (southern part of Korean peninsula) as NPS(non-point source) by mass balance approach; input and output analyses of nitrogen using existing data available. The material flow was sectored into three different activities; agricultural (raising crop and animals), human and natural activities in forest and urban areas. Atmospheric deposition, biological nitrogen fixation, inorganic fertilizers and manures applied, animal feed and imported foodstuffs such as crops, meat and fish were the inputs in this study, while ammonia volatilization, denitrification, human and animal waste generation, crop and meat production, and discharge into river to ocean were the outputs. The estimated total nitrogen input was $1,194.5{\times}10^3$ tons N/year and the river discharge was 408 to $422{\times}10^3$ tons N/year, of which 66 to 71% was from NPS. In detail, the estimated NPS discharges were respectively $8,274\;kg\;N/km^2$/year from agricultural area, $730\;kg\;N/km^2$/year from forest and $7,657\;kg\;N/km^2$/year from the other land areas such as urban and industrial area.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.49 no.2
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• pp.146-153
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• 2016

A feeding experiment was conducted to determine the nutritional value of various dietary protein sources without a vitamin premix supplementation in juvenile black rockfish, Sebastes schlegeli. Diets containing similar quantities of lipid and carbohydrate with 50% crude protein from fish meal (FM)/soybean meal (SBM)/corn gluten meal (CGM), FM only, casein/gelatin, high FM/low casein and low FM/high casein were fed to rockfish along with a commercial rockfish diet. The diet containing only 65.6% FM and the commercial rockfish diet produced significantly greater weight gain (WG) and feed efficiency (FE) than all other semipurified diets (SPDs); the economical diet with 52.8% FM, 10% SBM and 5% CGM produced lower WG than the diet containing FM and commercial rockfish diet, but FE and survival were similar both diets. Intermediate responses were observed for rockfish fed the SPD containing 32.8% FM and 27.4% casein, while SPDs containing 10% FM and 41.8% casein and 38.5% casein and 10% gelatin yielded the lowest WG and FE. Some differences in tissue indices and body composition of rockfish were induced by the diets containing various protein sources and levels without the vitamin premix supplementation.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.36 no.5
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• pp.458-462
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• 2003

This study was to survey proper condition of nitrate removal by hydraulic retention time (HRT) and measured growth of black rockfish (Sebastes schlegeli) and giant croaker (Nibea japonica) in the seawater recirculating culture system designed for nitrate removal. Nitrate conversion to nitrogen at 8 hr-HRT was higher than 16 hr-HRT, amounting to $32.2\;g/m^3/day$ in the seawater recirculating culture system. The removal efficiency of nitrate improved when dissolved oxygen was situated less than 0.5 mg/L. Daily growth rate (DGR) and feed efficiency (FE) of S. schlegeli with mean body weight of 108 g in 8 hr-HRT were significantly higher values than those in 4 hr-HRT (P<0.05). The DGR and FE of N. japonica with mean body weight of 12 g in added carbon system showed not differing in the values from N. japonica in control system (P>0.05).

• International Journal of Industrial Entomology and Biomaterials
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• v.21 no.2
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• pp.185-187
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• 2010

Most studies of the black soldier fly, Hermitia illucens, widely distributed throughout Southeast Asia and America focused on the use of larvae for recycling various organic materials and feed for fish and livestock. To recognize the instars of the soldier fly's larvae, we examined the number of exuviae originated from each larva from 1st instar to pupa. The weight and the head capsule width of the black soldier fly larvae also confirmed that the black soldier fly was passed through 6th instars. In addition, we found that the black soldier fly larvae had a well developed mandibular-maxillary complex, similar to those reported from the larvae of scavengers including Odontomyia cincta, Neopachygaster maculicornis, Ptecticus brunettii and Stratiomys ruficornis.

• Fisheries and Aquatic Sciences
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• v.12 no.1
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• pp.49-53
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• 2009

We conducted a histological analysis to investigate the influence of nutritional changes on melano-macrophages (MMs) accumulation in the kidney of sub-adult rock bream (Oplegnathus fasciatus). Four experimental groups were established (initial control, control, fed and starved), and fed commercial feed amounting to 1-3% of their body weight for 2 weeks prior to initiation of experiments. Kidney MMs with dark brown pigment were randomly observed in the kidneys of starved fish, increasing rapidly after 4 weeks, while deposition levels remained low throughout the experiment in the control and fed groups. These results suggest that catabolic tissue breakdown is a major factor contributing to the formation of pigments within MMs. Results also suggest that the degree of MMs deposition in the kidney can be used as alternative indicators in identifying starvation in wild and cultured rock bream.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.47 no.6
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• pp.840-846
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• 2014

This study investigated growth and hematological changes in parrotfish Oplegnathus fasciatus (~200 g/fish) reared under different total ammonia nitrogen (TAN) concentrations (0, 4, or 8 mg/L) for 6 weeks. Survival rates of parrotfish in all experimental groups did not significantly differ, as they were all ~100%. Although specific growth rate (SGR), weight gain, and daily feed intake in the high TAN concentration group (TAN8) were significantly lower than in the other two groups, there was no significant difference between the TAN4 group and the control group, (TAN0), indicating that parrotfish have a strong resistance to ammonia toxicity. As for temporal changes of the major blood components, cortisol increased as a result of stress caused by the high ammonia concentration in the TAN8 group. For this reason, the concentrations of energy sources such as glucose and total cholesterol were reduced. However, there was little difference among all experimental groups in concentrations of liver function glutamic oxaloacetic transaminase (GOT) and glutamic pyruvic transaminase (GPT), and nutrient factors, such as total protein and albumin.

• Environmental Engineering Research
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• v.19 no.3
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• pp.293-298
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• 2014

An anaerobic photosynthetic treatment process utilizing purple non-sulfur photosynthetic bacteria (PNSB) was applied to the recovery of organic carbon from food processing wastewater. PNSB cells, by-product from the treatment, have high nutrition such as proteins and vitamins which are a good alternative for fish feed. Effects of light source on performance of anaerobic photosynthetic process were investigated in this study. Two bench-scale photo-bioreactors were lighted with infrared light emitting diodes (LEDs) and tungsten lamps covered with infrared transmitting filter, respectively, aiming to supply infrared light for photosynthetic bacteria growth. The photo-bioreactors were operated to treat noodle-processing wastewater for 323 days. Hydraulic retention time (HRT) was set as 6 days. Organic removals in the photo-bioreactor lighted with infrared LEDs (91%-95%) was found higher than those in photo-bioreactor with tungsten lamps with filter (79%-83%). Biomass production in a 150 L bench-scale photo-bioreactor was comparable to a 8 L small-scale photo-bioreactor in previous study, due to improvement of light supply efficiency. Application of infrared LEDs could achieve higher treatment performance with advantages in energy efficiency and wavelength specifity.