• Korean Journal of Poultry Science
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• v.32 no.2
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• pp.81-87
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• 2005

A study was carried out to examine the effects of dietary kaolin on the performance, feed and nutrient efficiency, meat quality and feeding environment using 200 day-old growing ducts. Four replicates of 10 birds each was assigned to diets containing 0(C), 1 (T1), 2(T2), 3(T3) and $4(T4)\%$ of kaolin. Body weight gain in T1 and T2 were higher than in $C(p<0.05)$ whereas weight gain in T3 and T4 were not significantly different from the control. Feed intake and feed conversion ratio tended to increased as the level of dietary kaolin increased, but without significant differences among treatments. Mortality of growing ducks during 6 week period was not significantly different among treatments. Dressing percentage was highest in T1 and lowest in T4 $(p<0.05)$. The utilizability of nutrients except for crude fat Increased$(p<0.05)$, as the level of dietary kaolin increased. Moisture content and $NH_3$ gas emission of excreta was not significantly influenced by dietary kaolin. $H_2S$ gas emission of excreta in T2, T3 and T4 was lower compare to that in C and $T1(p<0.05)$. Cholesterol content in breast and thigh meat was not different among treatments. Values for pH, WHC, TBARS, POV and Cooking loss of breast and thigh meat were not significantly different or did not show any trend among treatments.

• Korean Journal of Poultry Science
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• v.37 no.2
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• pp.145-150
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• 2010

This study was conducted to evaluate effects of dietary Agariemycetes on egg quality and fecal noxious gas concentration in laying hens. A total of two hundred forty laying hens were randomly allocated to four treatments with five replicates of twelve chicks per pen. The experiment lasted 42 days with a 7-day adjustment period. Dietary treatments were as follows: 1) CON (basal diet), 2) A1 (basal diet + Agariemycetes 0.1%), 3) A3 (basal diet + Agariemycetes 0.3%) and 4) A5 (basal diet + Agariemycetes 0.5%). There was no significant difference in egg production and egg weight between CON and Agariemycetes treatments. During the second week of the experiment, eggshell breaking strength was higher in A3 and A5 treatments than that in CON treatment (P<0.05). Besides, eggshell breaking strength in P5 treatment was higher when compared with that in CON treatment (P<0.05) in the sixth week. During the second week of the experiment, eggshell thickness was higher in Agariemycetes treatments than CON treatment (P<0.05). Also, A5 treatment was higher than other treatments in the fourth week of the experiment (P<0.05). At the end of the second week, yolk color unit in A5 treatment was lower compared with CON treatment (P<0.05). During the fourth week of the experiment, CON treatment was higher than A3 treatment (P<0.05). During the second week of the experiment, Haugh unit in A3 treatment was greater than that in CON treatment (P<0.05). At the end of six weeks, Haugh unit in CON treatment was lower than other treatments (P<0.05). Fecal ammonia and hydrogen sulfide were increased in Agariemycetes treatments when compared with CON treatment (P<0.05). Compared with CON and A5 treatments, fecal mercaptans was higher than in other treatments in first of the experiment (P<0.05). In conclusion, this study indicated that the addition of Agariemycetes in the diet improved the egg quality and decreased the feacal noxious gas concentration in laying hens.

• Applied Chemistry for Engineering
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• v.24 no.4
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• pp.423-427
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• 2013

This research was carried out to identify the characteristics of the wastewater from coke oven gas (COG) purification process of the coke plant, and derive optimal operating conditions for the treatment of wastewater. The coke plant wastewater contains highly concentrated $S^{-2}$ and $SCN^-$ that are harmful to microorganisms, and their concentrations were 6.8~11.2 mg/L and 190~320 mg/L, respectively. When the $S^{-2}$ ion concentration was lower than 10 mg/L, $SV_{30}$ of active sludge was 280~ 340 mL and the sludge sedimentation velocity was very fast. But, when the $S^{-2}$ ion concentration was higher than 15 mg/L, $SV_{30}$ of the active sludge was 560~680 mL and the sludge sedimentation velocity was very slow. Also when the $SCN^-$ ion concentration was lower than 300 mg/L, $SV_{30}$ of the active sludge was 245~320 mL and the sludge sedimentation velocity was very fast. But, when the $SCN^-$ ion concentration was higher than 400 mg/L, $SV_{30}$ of the active sludge was 470~ 567 mL and the sludge sedimentation velocity was slow. To treat the wastewater generated by COG purification process of the coke plant effectively and to maintain microorganism activities in good conditions, the ion concentration of $S^{-2}$ and $SCN^-$ should be lower than 15 mg/L and 400 mg/L, respectively.

• Explosives and Blasting
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• v.26 no.2
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• pp.64-76
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• 2008

Bulk Emulsion blasts using mechanized charging system, which is generally used in foreign countries, have recently introduced and gradually increased in Korea. The Bulk Emulsion are safe and able to increase the charging density for improvement of fragmentation and advancement especially in tunneling, and minimizing environmental problem. Because of less toxic gas generation, the explosives are called, namely ech-friendly products. There are two kinds of Bulk Emulsion; one is for open cut and the other is for tunneling. According to features of blast sites and its purpose, the compositions are different, but the principle is the same. In this study, trial blasts using Bulk Emulsion for tunneling had executed at 10 sites in Korea. The major result of the major job-sites is the following. First of all, compared with cartridge explosive, Bulk Emulsion was able to increase its charging density up to $35{\sim}60%$, to decrease the blast holes to approximately $10{\sim}30%$ down, and the advancement was improved up to $8{\sim}20%$ and also 30% up in its fragmentation. Toxic gas production after cartridge blasting showed 34.44ppm of its CO. Bulk Emulsion, however, showed 20.13ppm, which was 58.45% production of the cartridge explosive, and NOx was below 2ppm. The mechanized charging system of Bulk Emulsion should be applied to large sized tunnel blasting, long advanced tunnel which can secure the advancement of over $4{\sim}5m$, and the sites required finishing rapidly.

• Resources Recycling
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• v.18 no.4
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• pp.14-23
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• 2009

In terms of resources recycling and resolving waste disposal problems, it is very important to recover precious metals like Au, Ag and Pd and valuable metals like Cu, Sn and Ni from the scraps of waste electrical and electronic equipment(WEEE) that consists of detective electrical and electronic parts discarded during manufacturing electrical and electronic equipments and waste electrical and electronic parts generated during disassembling them. In general, the scraps of WEEE are composed of various metals and alloys as well as refractory oxides and plastic components. Precious and valuable metals from the scraps of WEEE can be recovered by gas-phase-volatilization, hydrometallurgical, or pyrometallurgical processes. However, the gas-phase-volatilization and hydrometallurgical processes have been suggested but not yet commercialized. At the present time, most of the commercial plants for recovering precious and valuable metals from the scraps of WEEE adopt pyrometallurgical processes. Therefore, in this paper, the technical and environmental aspects on the important pyrometallurgical processes through literature survey are reviewed, and the scale-up result of a new pyrometallurgical process for recovering the precious and valuable metals contained in the scraps of WEEE using waste copper slag is presented.

• Fire Science and Engineering
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• v.29 no.2
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• pp.73-78
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• 2015

Fire in the risk management subject belongs to high risk disaster which accompanies personnel and materiel loss. So, management of disaster and safety is required to include fire prevention activities, fire risk prediction and investment of safety management expense. Combustion toxicity is required by gas toxicity test (KS F 2271), to minimize human damage. In this study, gas toxicity test were experimented with regard to urethane sample (Depth 5~25 mm) to obtain basic data. Fire effluent exposing to experimental animal were analyzed by FT-IR (Fourier transform infrared spectroscopy). Combustion toxicity index Lethal Fractional Effective Dose ($L_{FED}$) of ISO 13344 was calculated. According to the result of calculating Lethal Concentration 50% ($LC_{50}$) based on $L_{FED}$, $LC_{50}$ of urethane sample containing certain level of fire load is confirmed as $118{\sim}129g/m^3$. Through this study, applicability of this method was confirmed for fire risk assessment. This method can provide information to predict human damage by toxicity combustion gas for securing safety.

• Journal of the Korean Recycled Construction Resources Institute
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• v.8 no.3
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• pp.286-293
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• 2020

In this study, we tried to verify the correlation of the amount of combustible industrial by-products, household waste used as fuels on cement sintering process and the amount of NOx, and CO, harmful components in the exhaust gas. The analysis uses coal as natural fuel, soft plastics (plastics with properties that tend to be scattered by wind, such as vinyls), hard plastics (plastics with properties that are not scattered by wind, such as PETs, wate rubbers), and reclaimed oils as alternative fuels. Utilizing the response surface analysis (RSM) technique using the process data of 2019, such as the fuel input and combustion temperature of a domestic A cement manufacturer's sintering facilities as independent variables, and the NOx, and CO emissions to the stack as dependent variables. Correlation was analyzed. As a result, it was confirmed that the impact on the emission material differs for each waste. In particular, it was analyzed that the hard plastics increase the CO emission but have an excellent effect of reducing NOx.

• Resources Recycling
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• v.22 no.3
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• pp.91-99
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• 2013

Steel industry which has been accomplishes the base of our country economy, automobile and electronic industry are taking charge of the role, whose electroplating is important. Large amount of wastewater and various metal salts, including hazardous materials was generated from the electroplating pre-treatment, plating, washing and post-plating. Currently, the general wastewater follows in the environmental law and neutralization after controlling, sludge where the various metal is mixed reclaims below multiple regulative and trust it is controlling. The sludge which includes the gas price metal reclaims in the field and trust it controls. a reclamation price of land it is insufficient but and the control expense holds plentifully and it loses the gas price metal which is valuable. Consequently, The research regarding to recover a gas price metal actively from this waste water, it is advanced. A new method to recover valuable metals from electroplating wastewater synthesis of metal sulfides using topical methods utilizing iron oxidizing bacteria, reagent of sulfides and solvent extraction using an organic solvent, such as the development of the law to recover these metals and metal sulfides of wastewater using selective recovery have been studied. By using these wastewater treatment method under frequency above 95%, it has been obtained the valuable metal from the wastewater, where the metal ion of Fe, Cu, Zn and Ni complexes was mixed. As we discuss the wastewater, which has been discharged from electroplating process, it is important and will be applied to the resources of metal in the urban mine.

• Clean Technology
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• v.25 no.2
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• pp.153-160
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• 2019

As air pollution becomes more serious due to the increased number of diesel vessel operations, ship regulations on harmful emissions strengthen. Therefore, the development of a diesel exhaust after-treatment system for ships is required, and the higher the flow uniformity of the exhaust treatment system, the higher the treatment efficiency. With the computer software ANSYS Fluent, pressure drop and flow uniformity were used in this study to simulate flow rate with and without a baffle in both a Diesel Oxidation Catalyst (DOC) and Diesel Particulate Filter (DPF) system. The system pressure drop was found to be 38 to 40 mbar in the existing system condition, and the flow uniformity was approximately 84 to 92% at the inlet and outlet of the DOC. When the baffle was installed inside the system, the pressure increased and the flow uniformity was lowered due to an increase in flow rate. When the exhaust gas flow was reduced by 50% from $7,548kg\;h^{-1}$ to $3,772kg\;h^{-1}$, the flow uniformity at the inlet and outlet of the DOC increased by approximately 1 to 3% due to the low flow rate. In the case of DPF, the flow uniformity of exhaust gas was 98 to 99% because the uneven flow proceeded after uniformly flowing from the DOC.

• Journal of the Korean Institute of Gas
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• v.23 no.4
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• pp.1-9
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• 2019

Large-scale industrial boilers operating at high temperature and high pressure, have a large amount of water, and a large amount of energy is released at the time of explosion. Currently, most industrial boilers use gas fuel such as LNG and LPG, etc. and fuel exists in the same space as equipment, so there is a high possibility of secondary damage such as fire or explosion in the event of a boiler accident. Both special care and management are required to operate the very dangerous equipment that causes casualty 2.51 per accident. For boilers of a certain size or more, the Korea Energy Agency conducts inspections in accordance with the Energy Usage Rationalization Act, KS, and public notice of the Ministry of Industry, Trade and Resources. In this research, based on the results of the inspection, the hazard factorss are configured, and a questionnaire is conducted to the inspector, the equipment manager, the maintenance person, and the person in charge of the manufacturer. We analyzed the results by using AHP (Analytic Hierarchy Process). As a result of analysis, generally recognized hazard factorss are not good management, measurement failure, specification failure, water leak, leak analysis, but connection, welding, scale, and corrosion, etc. are relatively less important. It is judged that the adverse factors that are recognized to be highly important among all groups and careers are already well managed, but less important and adverse factors should be well managed to ensure that the safe usage of the boiler.