• Journal of Advanced Marine Engineering and Technology
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• v.32 no.7
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• pp.1080-1088
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• 2008

This paper addresses some concerns faced by the shipping industry nowadays. Initially, the environmental issues were resolved and stricter regulations are now being implemented with regards to the exhaust gas, specifically nitrogen oxides (NOx) and sulfur oxides (SOx), emitted from ships. Secondly, with the increasing and unstable cost of fuel oils in the world market, it has become almost a necessity to explore on a new alternative fuel. Hence, this study was conducted. An experiment was carried-out on a fishing survey vessel with the main engine (M/E) and generator engine (G/E) operated on expensive marine gas oil (MGO). During the experiment, two pre-refinery systems were installed and different fuel oil samples were employed for the M/E and the G/E. Furthermore, the NOx emission and soot concentration were monitored and verified. The results confirmed the compatibility of some fuel oil types to the engines and meeting the emission standards. MDO, MF15 and Bunker A can be used in place of MGO for the engines(M/E, G/E).

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.5
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• pp.684-689
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• 2006

The present study examined the effects of Tween 80 on the attachment and hydrolytic activity of a cellulase enzyme against ball-milled cellulose (BMC), using the whole component (native CBH I) and the catalysis module (core CBH I) of carbohydrolase I purified from Trichoderma viride (Meicelase, Meiji Seika, Tokyo, Japan). The effects were evaluated as protein concentrations in the supernatant after mixing enzyme and substrate with Tween 80 at room temperature. Tween 80 decreased the adsorption of native CBH I and core CBH I onto BMC (p<0.001) and increased the amount of reducing sugars released from BMC by native CBH I (p<0.001). However, Tween 80 did not enhance the hydrolytic activity of core CBH I. Observations using SEM revealed that Tween 80 caused cellulose filter paper to swell and enhanced surface cracks and filaments caused by native CBH I but not by core CBH I. These results suggested that Tween 80 decreases enzyme adsorption to its substrate but enhances enzymatic activity.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.05b
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• pp.173-176
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• 2004

The piezoelectric ceramics for AE sensor piezoelectric devices are desirable to possess higher resonance vibrations. The compositions of $0.9Pb(Zr_xTi_{1-x})O_3-0.1Pb(Mn_{1/3}Nb_{1/3}Sb_{1/3})O_3$ (PZT-PMNS) in this work are selected for obtaining especially large electromechanical coupling factor, high mechanical quality factor and high Curie temperature. This ceramic has higher piezoelectric activity and higher electromechanical coupling factor, but the ceramic has lower Curie temperature. The piezoelectric and dielectric characteristics of PZT-PMNS ternary system are investigated as functions of $Ti^{2+}$, $Zi^{2+}$ mol rate. As the results, MPB(morphotropic phase boundary) in this piezoelectric ceramic is x=0.522. Resonance vibrations of PZT ceramics are investigated as ball-bearing drop test. For the use of AE sensor that driving with pre-amplifier, filter circuit after packed this ceramic and an elastic body.

• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.337-341
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• 2001

A new method to extract gold from pyrite roster cinder, which combines ultra-fine-grinding with resin-in-pulp, has been studied in this paper. Compared with traditional leaching technology, it can short leaching time, avoid complex filter process, lower sodium cyanide consumption and increase gold recovery by 35%. During leaching, aluminium oxide ball was used as stirred medium, hydrogen peroxide as leaching aid and sodium hexametaphosphate as grinding aid. With the high efficiency and chemistry effect of ultra-fine-grinding, the leaching process was developed and the gold leaching rate may reach 88%. With AM-2 Б resin as abosorber and sulfocarbamide (TU) as eluent, gold was recovered from cyanide pulp by resin-in-pulp. AM-2 Б resin has good adsorbability in cyanide solution(pH=10). It was easy to elude gold from the loaded resin with 0.1㏖/L cholhydric acid and 1㏖/L sulfocabamide. The effect of contact time, temperature and acidity etc. on the gold absorption had been examined with static methods. The results showed that the adsorption and desorption of gold could both reach over 98%. The effects of flow rate of solution on dynamic adsorption and elution of gold had been examined with dynamic methods. Breakthrough curve and elution curve had been drawn in this paper. A mild condition was determined through a number of experiments: leaching time 2 hours, liquid solid ratio 4:1, sodium cyanide 3kg/t, hydrogen peroxide 0.05%, sodium hexametaphosphate 0.05%; adsorption time 30 minutes, temperature 10-3$0^{\circ}C$, resin($m\ell$) solid(g) ratio 1:10, eluent resin ratio 10-20:1, velocity of eluent $1.5m\ell$/min. Under the mild condition, the gold recovery may reach 85%.

• Journal of Animal Environmental Science
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• v.9 no.2
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• pp.93-102
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• 2003

This study designed and constructed an experimental column far adhesion efficiency test and conducted experiment to investigate the offensive odor adhesion efficiency of filter bed materials. The offensive odor adhesion experiment was conducted using mixture of high physical adhesion efficiency material, and the fixity of deodorization microorganism of selected filter bed material was tested using ammonia exclude microorganism A4-­2 and sulfur oxidation microorganism S5­-5.2 those were cultured at the Agricultural Chemical Department of Chungnam National University, and deodorization efficiency of selected filter bed material mixture was tested. Following are summary of these tests results. 1. Amount of elimination of the offensive odor gas of ammonia and hydrogen sulfide per unit volume was 0.054 and 0.016$\ell/\textrm{cm}^3$ in rice hull, 0.01 and 0.004 $\ell/\textrm{cm}^3$ in rice straw 0.158 and 0.01 $\ell/\textrm{cm}^3$ in coconut, 0.014 and 0.02$\ell/\textrm{cm}^3$ perlite, 0.004 and 0.003$\ell/\textrm{cm}^3$ in high road ball, and 0.112 and 0.015 $\ell/\textrm{cm}^3$ in chaff of pine, respectively. 2. Amount of elimination of offensive odor gas of ammonia and hydrogen sulfide per unit volume was 0.045 and 0.014$\ell/\textrm{cm}^3$ in mixture 1, 0.079 and 0.016$\ell/\textrm{cm}^3$ in mixture 2, 0.123 and 0.017 $\ell/\textrm{cm}^3$ in mixture 3, 0.031 and 0.015$\ell/\textrm{cm}^3$ in mixture 4, 0.055 and 0.016$\ell/\textrm{cm}^3$ in mixture 5, and 0.111 and 0.020$\ell/\textrm{cm}^3$ in mixture 6, respectively. 3. The offensive odor elimination microorganism inoculated to mixture of chaff of pine(70%) and perlite(30%) showed the elimination efficiency of 99.06% and 96.61% against the ammonia and hydrogen sulfide, respectively, during 24 hours period.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.18 no.1
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• pp.5-9
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• 2008

Cordierite has a very low thermal expansion coefficient, but has problem that it has a weak mechanical strength and is apt to be attacked by acid such as sulfur for using as a diesel particulate filter support. The physical properties of $ZrTiO_4$ modified with $SiO_2,\;Al_2O_3$, MoOx, $Cr_2O_3\;and\;Nb_2O_5$ were investigated with XRD, SEM, UTM and thermal expansion, etc. in this paper. $ZrTiO_4$ powder was synthesized as a monoclinic structure with processes that starting materials of $TiO_2\;and\;ZrO_2$ were mixed with ball mill and calcined above $1240^{\circ}C$ for 3 hr. Additive modified $ZrTiO_4$ specimens for flexural strength and thermal expansion measurement were obtained by mixing $ZrTiO_4$ powder with additives, pressing and firing at $1300^{\circ}C$ for 3 hr. The porosity of additive modified $ZrTiO_4$ decreased monotonically with increasing additive content by 5 wt% regardless of additive types and saturated for further increase of additive by 10wt. The flexural strength of $Al_2O_3$ (5, 10 wt%) modified $ZrTiO_4$ shows a large increase, but that of other additives modified $ZrTiO_4$ decreased. The thermal expansion coefficient of additive modified $ZrTiO_4$ except $Nb_2O_5$ decreased continuously with the content of additive. In particular, the lowest thermal expansion coefficient of $ZrTiO_4$ was obtained for the additive of $SiO_2$.