• Journal of Aquaculture
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• v.10 no.2
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• pp.113-121
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• 1997

In order to developed the techniques for artificial seedling production of geoduck clam, Panope japonica, various stimulution for spawning induction and hatching condition were studied. Spawning induction by the air day or UV-irradiation stimulus were not effective. Water temperature stimulus was responsed 15.0~25.0% in May and 10.0% in June. But spawning induction by the gonad incision was highest with 15.0~45.0%. Ammonium hydroxide (NH4OH) stimulus adding in seawater were responsed 15.0% at 8/1000N~10/1000N, and ammonium hyhroxide solution injected in the gonads were responsed 5.0~10.0% at 5/100N~7/100N. The highest fertilization and hatching rate at various water temperature were ranged 74.5~89.2% in 11~$17^{\circ}C, \;84.3~89.5%\;in\;8~14^{\circ}C$, respectively. the highest fertilization rate and hatching rate in various salinity were ranged 72.5~88.5% in 25~$35tetperthousand$, 82.7~86.9% in 30~$35tetperthousand$, respectively. The optimum water temperature and salinity for fertilization and hatching to the 11~14$^{\circ}C$ and 30~$35tetperthousand$, respectively.

• Journal of Advanced Marine Engineering and Technology
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• v.8 no.1
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• pp.17-36
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• 1984

Since 1973, the competition on the development of fuel saving type internal combustion engines has become severe by the two times oil shock, and new type engines are reported every several months. Whenever these new type engines are developed, new designs are required and they will be offered in the market after performing the endurance test for a long time. But the engine market is faced with a heavy burden of finance, as the developing of a new engine requires tremendous expenses. For this reason, the computer simulation method has been lately developed to cope with it. The computer simulation method can be available to perform the reasonable research works by the theoretical analysis before carrying out practical experiments. With these processes, the developing expenses are cut down and the period of development is curtailed. The object of this study is the development of simulation computer program for the small naturally aspirated four-stroke diesel engine which is intended to product by the original design of our country. The process of simulation is firstly investigated for the ideal engine cycle, and secondly for the real engine cycle. In the ideal engine cycle, each step of the cycle is simulated by the energy balance according to the first law of thermodynamics, and then the engine performance is calculated. In the real cycle imulation program, the injection rate, the preparation rate and the combustion rate of fuel and the heat transfer through the wall of combustion chamber are considered. In this case, the injection rate is supposed as constant through the crank angle interval of injection and the combustion rate is calculated by the Whitehouse-Way equation and the heat transfer is calculated by the Annand's equation. The simulated values are compared with measured values of the YANMAR NS90(C) engine and Mitsubishi 4D30 engine, and the following conclusions are drawn. 1. The heat loss by the exhaust gas is well agree with each other in the lower load, but the measured value is greater than the calculated value in the higher load. The maximum error rate is about 15% in the full load. 2. The calculated quantity of heat transfer to the cooling water is greater than the measured value. The maximum error rate is about 11.8%. 3. The mean effective pressure, the fuel consumption, the power and the torque are well agree with each other. The maximum error is occurred in the fuel consumption, and its error rate is about 7%. From the above remarks, it may be concluded that the prediction of the engine performance is possibly by using the developed program, although the program needs to reform by adding the simulation of intake and exhaust process and assumping more reliable mechanical efficiency, volumetric efficiency, preparation rate and combustion rate.

• Korean journal of food and cookery science
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• v.31 no.1
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• pp.18-25
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• 2015

This study investigated the baking properties of sorghum with the addition of xylanase or Pentopan, which is a baking additive containing xylanase. The control bread was made with a 30% substitution for wheat flour and the optimum level of enzyme addition was 0.75 mg/g flour for Pentopan and 5 mg/g flour for xylanase. The water binding capacity of wheat flour increased with the addition of sorghum, but decreased with the addition of either xylanase or Pentopan. The resistance of dough increased while extensibility decreased with the addition of sorghum; however, resistance decreased while extensibility increased with the addition of the enzyme. Specific volume of bread decreased significantly with the addition of sorghum. However, the specific volume was significantly recovered with the addition of enzyme. Crumb firmness was higher in the sorghum-added sample, but crumb firmness of the bread decreased with the addition of the enzyme. The crumb firmness of bread with added xylanase decreased significantly in 24 hours. These results demonstrated that adding sorghum with either xylanase or Pentopan that included xylanase increased specific volume and decreased crumb firmness whereas sorghum decreased the quality of fermented bread when added to wheat flour. The firmness rate of fermented bread particularly decreased with the addition of pure xylanase.

• Journal of the East Asian Society of Dietary Life
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• v.23 no.6
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• pp.760-767
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• 2013

This study investigated the quality of noodles containing different amounts of collagen powder. Noodles were prepared at ratios of 1, 3, 5 and 7% collagen power based on flour weight. The water binding capacity of the collagen powder was higher than that of flour. The rate of weight increase and volume increase of the noodles as well as the pH and turbidity of the soups were significantly increased with increasing amounts of collagen powder. The noodles showed decreased L and a values, and increased b values with increasing collagen powder in the flour composite. Hardness, springiness and chewiness of cooked noodles increased significantly with the increase in collagen powder content. cohesiveness and brittleness decreased with increasing amounts of added collagen powder. DPPH radical scavenging activity was improved significantly the addition of the collagen powder. Finally sensory evaluation results indicated that the noodles containing 1, 3% collagen powder had higher quality as compared to the other samples. Overall the results suggest that collagen powder is effective for improving the appearance and texture of noodles.

• Journal of Applied Biological Chemistry
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• v.61 no.4
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• pp.383-389
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• 2018

Degradation of the insecticide O,O-diethyl O-3,5,6-trichloro-2-pyridyl phosphorothioate (chlorpyrifos) in aqueous solution was investigated using iron salts and potassium persulfate during ZVI treatment through a series of batch experiments. The degradation rate of chlorpyrifos increased with increases in the concentrations of iron salts and potassium persulfate in the aqueous system. Ferric chloride was found to be the most effective iron salt for the ZVI-mediated degradation of chlorpyrifos in aqueous solution. Further, the iron salts tested could be arranged in the following order in terms of their effectiveness: $FeCl_3$> $Fe_2(SO_4)_3$> $Fe(NO_3)_3$. The persulfate-ZVI system could significantly degrade chlorpyrifos present in the aqueous medium. This revealed that chlorpyrifos degradation by treatment with $Fe^0$ was promoted on adding ferric chloride and potassium persulfate. The kinetics of the degradation of chlorpyrifos by persulfate-amended $Fe^0$ was higher than that for iron-salt-amended $Fe^0$. This suggests that using a sequential $Fe^0$ reduction-ferric chloride or $Fe^0$ reduction-persulfate process may be an effective strategy to enhance the removal of chlorpyrifos in contaminated water.

• Journal of the Korean Ceramic Society
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• v.46 no.1
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• pp.24-29
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• 2009

The suspension of $Al_2O_3$ which has long-term stability was made by mechanical milling. Thin films were evaluated and made to use as coating materials. A particle size of the suspension manufactured was 98 nm when 2 mt% nitric acid was added. It indicated that viscosity of the suspension is 12 cps and that it had the long-term stability. Thickness which was from 200 nm to 600 nm of the thin films was able to be made by adjusting draw rate and organic additive. Cracks of thin films at room temperature were prevented by adding Ethyl cellulose from 0.5 wt% to 2 wt%. The thin film heated at $500^{\circ}C$ indicated a hydrophilic property against water and an excellent permeability against a visible ray.

• Textile Coloration and Finishing
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• v.4 no.3
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• pp.82-90
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• 1992

To optimize the foam dyeing procedures for polyester and polyester/nylon blended non-woven fabrics, the effects of organic solvents and surfactants were investigated by measuring the foam heights and surface tensions of the foam dyeing solution. The results of the experiments can be summarized as follows: 1) Organic solvents and surfactants (sodium lauryl sulphate: SLS) solution lower the surface tension (ST) of the water, but ST lowering rate of SLS solution is greater than that of solvents. For a 0.25% SLS solution, the minimum surface tension was 30.3 dyne/cm, which is nearly the same value for organic solvents. 2) For 0.25% SLS solutions, additional adding of a 4.0% organic solvent makes the foam height (FH) be its maximum. 3) At 0.6 g/ι dye concentration, incorporation of 0.4% SLS makes the surface tension of the foam solution be its minimum. The foam height did not show any trend due to the dye type. 4) The effect of foam stabilizers (sodium alginate (Alg-Na) and hydroxy ethyl cellulose (HEC)) were also investigated. The foam height of the foaming solution with HEC was greater than that with Alg-Na. The foam stability of the foaming solution with Alg-Na was better than that with HEC.

• Journal of Applied Biological Chemistry
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• v.42 no.1
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• pp.25-28
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• 1999

For investigating the effectiveness of Korean natural zeolite for removal of $NH_4{^+}$ in waste waters containing $NH_4{^+}$ and $Cu^{2+}$, the adsorption of $NH_4{^+}$ and $Cu^{2+}$ by three Korean natural zeolite samples, which contained mordenite and/or clinoptilolite, was measured by adding solutions containing $NH_4{^+}$ and $Cu^{2+}$ or both at a concentration range from 1 to 7 mmol(+)/L of each cation. In the solutions, the zeolite samples adsorbed more amounts of $NH_4{^+}$ than $Cu^{2+}$. By seven successive equilibrations, Korean natural zeolites adsorbed $NH_4{^+}$ corresponding to 23~33% of those cation exchange capacity from the solution containing both $NH_4{^+}$ and $Cu^{2+}$ at 3 mmol(+)/L of each cation. Whereas, the corresponding adsorption of $Cu^{2+}$ was 17-27% of the CEC. Korean natural zeolite exhibited selectivity for $NH_4{^+}$ but not for $Cu^{2+}$. Nevertheless, it using as a soil amendment after removing of $NH_4{^+}$ in waste waters should be carefully controlled on the application rate.

• Carbon letters
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• v.15 no.1
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• pp.38-44
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• 2014

This paper reports the effect of adding reduced graphene oxide (RGO) as a conductive material to the composition of an electrode for capacitive deionization (CDI), a process to remove salt from water using ionic adsorption and desorption driven by external applied voltage. RGO can be synthesized in an inexpensive way by the reduction and exfoliation of GO, and removing the oxygen-containing groups and recovering a conjugated structure. GO powder can be obtained from the modification of Hummers method and reduced into RGO using a thermal method. The physical and electrochemical characteristics of RGO material were evaluated and its desalination performance was tested with a CDI unit cell with a potentiostat and conductivity meter, by varying the applied voltage and feed rate of the salt solution. The performance of RGO was compared to graphite as a conductive material in a CDI electrode. The result showed RGO can increase the capacitance, reduce the equivalent series resistance, and improve the electrosorption capacity of CDI electrode.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.06a
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• pp.519-520
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• 2006

Research was performed to increase the efficiency of a plasma reactor for $H_2$ yield. In the preceding studies $H_2$ was increased by adding Ni as a transitional metal catalyst and $TiO_2$ as a photocatalyst. In these experiments, it was found that distilled water, discharge frequency, and electrode configuration had a significant impact on $H_2$ generation. A substantial amount of hydrogen yield was observed at 2 kHz of discharge frequency and 12 kV of applied voltage. Within this favorable discharge conditions, the weight rate of $TiO_2$ and Ni powders was investigated. Plasma phenomenon was measured by electrical, optical and acoustical devices. It was found that emitted light, electric current and acoustical signals acquired from the discharge demonstrated systematical correlation. Changing the electrode's configuration allowed discharge distribution along the perimeter of the electrode's tip, which increased the density of streamers and plasma energy loadings, as the value of inception voltage for the discharge propagation decreased.