• Korean Journal of Fisheries and Aquatic Sciences
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• v.47 no.4
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• pp.399-405
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• 2014

We investigated the effects of feeding rate on the growth performance, blood components, and histology of growing olive flounder Paralichthys olivaceus. Optimum feeding rate (initial fish mean weight : $316.7{\pm}6.18g$) was determined under the optimum water temperature. Two replicated groups of fish were fed a commercial diet at rates of 0%, 0.4%, 0.6%, and 0.8% of body weight (BW) per day, and to satiation. Feeding trial was conducted using a flow-through system with 10 1.2-metric ton aquaria receiving filtered seawater at $21-24^{\circ}C$ for 3 weeks. Weight gain (WG) and specific growth rate (SGR) were significantly higher in fish fed to satiation (1.0% BW/day) than in those in other treatments. These parameters were negative and significantly lower in the starved fish than in fish fed the experimental diet at all feeding rates. There were no significant differences in WG and SGR among fish fed at 0.4%, 0.6%, and 0.8% BW/day. Hematocrit and hemoglobin in fish fed to satiation were significantly lower than those in other treatments. Histological changes of fish fed at 0.6% BW/day indicated that this group was in the best condition; differences were not found in tissues of fish fed at 0%, 0.6% and 1.0% BW/day. Broken-line regression analysis of weight gain showed that the optimum feeding rate of olive flounder weighing 317 g was 0.99% BW per day at the optimum water temperature.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.47 no.3
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• pp.234-240
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• 2014

We investigated the effects of feeding rate on the growth performance, blood components, and histology of growing olive flounder Paralichthys olivaceus. We determined the optimum feeding rate (initial fish mean weight of $240{\pm}10.9$ g) at the optimum water temperature. Two replicated groups of fish were fed a commercial diet at rates of 0%, 0.5%, 0.75%, and 1.0% body weight (BW) per day, and to satiation. Feeding trial was conducted using a flow-through system with 10 1.2-metric ton aquaria receiving filtered seawater at $19-21^{\circ}C$ for three weeks. Weight gain (WG) for fish fed to satiation was significantly higher than that of unfed fish and fish fed at 0.5% and 0.75% BW per day. The WG of fish fed at 1.0% BW per day was significantly higher than that of unfed fish and of fish fed at 0.5% BW per day. However, there were no significant differences in WG between fish fed at 0.5% BW per day and those fed at 0.75% BW per day, between fish fed at 0.75% BW per day and those fed at 1.0% BW per day, and between fish fed at 1.0% BW per day and those fed to satiation. The specific growth rates of fish fed at 1.0% BW per day and those fed to satiation were significantly higher than those of unfed fish and of fish fed at 0.5% BW per day. Broken-line regression analysis of weight gain showed that the optimum feeding rate of olive flounder weighing 240 g was 1.09% BW per day at the optimum water temperature.

• Computers and Concrete
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• v.34 no.2
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• pp.213-230
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• 2024

The use of waste tires and industrial wastes such as fly ash (FA) and ground granulated blast furnace slag (GGBS) in concrete is an important issue in terms of sustainability. In this study, the effect of parameters affecting the physical, mechanical and microstructural properties of FA/GGBS-based geopolymer concretes with waste rubber fiber was investigated. For this purpose, the effects of rubber fiber percentage (0.6%, 0.9%, 1.2%), binder (75FA25GGBS, 50FA50GGBS, 25FA75GGBS) and curing temperature (75 ℃, 90 ℃ and 105 ℃) were investigated. The Taguchi-Grey Relational Analysis (TGRA) method was used to obtain optimum parameter levels of rubber fiber geopolymer concrete (RFGC). The slump, fresh and hardened density, compressive strength, flexural strength, static and dynamic modulus of elasticity, ultrasonic pulse velocity (UPV) tests and scanning electron microscopy (SEM) analysis were performed on the produced concretes. The analysis of variance (ANOVA) method was used to statistically determine the effects of the parameters on the experimental results. A confirmation test was performed to test the accuracy of the optimum values found by the TGRA method. With the increase of GGBS percentage, the compressive strength of RFGC increased up to 196%. The increase in rubber fiber percentage and curing temperature adversely affected the mechanical properties of RFGC. As a result of TGRA, the optimum value was found to be A1B3C1. ANOVA results showed that the most effective parameter on the experimental results was the binder with 99% contribution percentage. It is understood from the SEM images that the optimum concrete had a denser microstructure and less capillary cracks and voids. For this study, the use of the TGRA method in multiple optimization has proven to provide very useful and reliable results. In cases where many factors are effective on its strength and durability, such as geopolymer concrete, using the TGRA method allows for finding the optimum value of the parameters by saving both time and cost.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.44 no.4
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• pp.345-351
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• 2011

Two feeding trials were conducted to investigate the optimum feeding rates in juvenile olive founder Paralichthys olivaceus fed practical expanded pellet(EP) containing 58.1% crude protein, 10.7% crude lipid, and 10.8% ash at low and high water temperatures. In the first experiment, triplicate groups of 15 fish with average weight of 7.7 g were fed at one of seven feeding rates(0, 1, 1.5, 2, 2.25, or 2.5% of body weight/day or to satiation) for 4 weeks at low water temperature. In the second experiment, quadruplicate groups of 20 fish with average weight of 5.5 g were fed at one of eight feeding rates(0, 3, 3.5, 4, 4.25, 4.5, or 4.75% of body weight/day or to satiation) for 4 weeks at high water temperature. Based on growth performance, we estimated that the optimum feeding rates for juvenile olive flounder were 1.97-2.51% and 4.82-6.36% of body weight/day at low and high water temperatures, respectively.

• Journal of Environmental Science International
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• v.7 no.1
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• pp.96-103
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• 1998

To study the optimum conditions of composting with industrial wastewater sludge, the variations of temperature and $CO_2$ generation amount during the composting periods were investigated. The conditions were that industrial wastewater added to bulking agents such as sawdust and rice hull was used, and differently treated with microorganism seeding or not, initial C/N ratios, air flow rate and initial moisture contents, respectively. The results were summarized as follows : Seeding 5% of microorganism was higher the temperature than not seeding. And using sawdust as bulking agents, and adjusting 30~40 of Initial C/N ratio, 200ml/l.min. of k flow rate and 67~68% moisture contents were higher the temperature than any other conditions. Seeding 5% of microorganisms was higher $CO_2$ generation amount than not seeding. And that was much in the order of 7~40, 30~34 and 22~23 of initial C/N ratio. Judging from the results, it should be considered that the optimum conditions in the composting of industrial wastewater sludge were seeding of 5% microorganisms, and adjusting 30~34 of Initial C/N ratio, 200ml/l min. of air flow rate and 67~68% of Intitial moisture contents. The contents of inorganic matters and C/N ratio during the composting periods at optimum condition were a little Increased. and heavy metals contents after composting were lower than standard for fortllizer.

• Journal of Mechanical Science and Technology
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• v.20 no.12
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• pp.2203-2208
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• 2006

Both 1-D and 2-D analytic methods are used for a rectangular fin optimization. Optimum heat loss is taken as 98% of the maximum heat loss. Temperature profile using 2-D analytic method and relative error of temperature along the fin length between 1-D and 2-D analytic methods are presented. Increasing rate of the optimum heat loss with the variation of Biot number and decreasing rate of that with the variation of the fin base length are listed. Optimum fin tip length using 2-D analytic method and relative error of that between 1-D and 2-D analytic methods are presented as a function of Biot numbers ratio.

• Textile Coloration and Finishing
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• v.18 no.5 s.90
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• pp.22-29
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• 2006

The purpose of this study was to investigate the dyeability and antibacterial activity on wool fabric dyed with cochineal at variable dyeing conditions. Al, Cr, Fe, Cu and Sn were used as mordants and adsorption was compared with different mordanting methods. The optimum dyeing conditions of wool fabrics were dyeing concentration 2.0%(o.w.s), dyeing temperature $60^{\circ}C$, pH 3 and dyeing time 30 minutes. The pre-mordanting method was preferred for Al and Cr, and the post-mordanting one was preferred for Cu, Sn and Fe to achieve better dyeing. The optimum mordanting conditions of wool fabrics dyed with cochineal were mordanting concentration of 1%(o.w.s), mordanting temperature $60^{\circ}C$, and dyeing time 30 minutes. Wool fabrics dyed with cochineal showed a little antibacterial activity, but it was increased by Cu and Sn mordanting. The light fastness and perspiration fastness of wool fabric treated with cochineal were improved by mordanting.

• Journal of Microbiology and Biotechnology
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• v.14 no.6
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• pp.1196-1199
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• 2004

A bacterium, isolated from rabbit's waste and identified as Cellulomonas sp., had cellulase and thermostable $\alpha$-amylase activity when grown on wheat bran. Maximum activity of thermostable $\alpha$-amylase was obtained by adding $3\%$ soluble starch. However, soybean oil (1 ml $1^{-1}$) could increase the production of $\alpha$-amylase and cellulase in 'wheat bran. The $\alpha$-amylase was characterized by making a . demonstration of optimum activity at $90^{\circ}C$ and pH 6- 9, with soluble starch as a substrate. The effect of ions on the activity and the stability of this enzyme were investigated. This strain secreted carboxymethyl cellulase (CMCase), cellobiase ($\beta$­glucosidase), and filter paperase (Fpase) during growth on wheat bran. Carboxymethy1cellulase, cellobiase, and Fpase activities had pH optima of 6, 5.5, and 6, respectively. CMCase and cellobiase activities both had an optimum temperature of $50^{\circ}C$, whereas Fpase had an optimum temperature of $45^{\circ}C$.

• Journal of environmental and Sanitary engineering
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• v.14 no.2
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• pp.90-95
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• 1999

The study on the fermented feeds production of garbages have been conducted to determine the optimum operation condition. The process variables considered for this study were initial air flow rate and temperature control. The results showed that optimum air requirement was $4{\ell}-air/min{\cdot}kg-$ garbages on dry weight basis which is equal to $0.8{\ell}-air/min{\cdot}kg-$ garbages on the basis of 80% moisture content. The optimum initial temperature control in the reactor was $40^{\circ}C$. Crude fiber content of fermented final byproducts were higher than feedstuffs standard for pig breeding and consequently final byproducts had to mix with single-component feed.

• Transactions of Materials Processing
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• v.6 no.5
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• pp.425-434
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• 1997

A superplastic material, aluminum-lithium alloy 8090, was examined with uniaxial tensile tests to investigate its thermomechanical behavior. The tests were carried out at the strain rate ranging from $2X10^4 to 1X10^2$ and at the temperature from 48$0^{\circ}C$ to 54$0^{\circ}C$. The experiments produced force-dis-placement curves which were converted to stress-strain curves. From the curves, the optimum conditions of superplastic forming were obtained by deteriming the strain rate sensitivety, the optimum strain rate, and the strength coefficient for various forming temperatures.