• Resources Recycling
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• v.15 no.4 s.72
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• pp.44-51
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• 2006

Most electric arc furnace dust (EAFD) treatment processes to recover zinc from EAFD employ carbon as a reducing agent for the zinc oxide in the EAFD. In the present work, the reduction reaction of zinc oxide with carbon in the present of iron oxide was kinetically studied. The experiments were carried out at temperatures between 1173 K and 1373 K under nitrogen atmosphere using a weight-loss technique. From the experimental results, it was concluded that adding the proper amount of iron oxide to the reactant accelerates the reaction rate of zinc oxide with carbon. This is because iron oxide in the reduction reaction of zinc oxide with carbon promotes the carbon gasification reaction. The spherical shrinking core model for a surface chemical reaction control was found to be useful in describing kinetics of the reaction over the entire temperature range. The reaction has an activation energy of 53 kcal/mol (224 kJ/mol) for ZnO-C reaction system, an activation energy of 42 kcal/mol (175 kJ/mol) for $ZnO-Fe_{2}O_{3}-C$ reaction system, and an activation energy of 44 kcal/mol (184 kJ/mol) for ZnO-mill scale-C reaction system.

• Women's Health Nursing
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• v.23 no.1
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• pp.33-41
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• 2017

Purpose: The purpose of this study was to investigate the effect of aroma inhalation therapy on stress, anxiety, depression, and an autonomic nervous system reaction in high-risk hospitalized pregnant women. Methods: A quasiexperimental study used a non-equivalent control group non-synchronized design. Fifty high-risk hospitalized pregnant women were selected as participants on delivery room and maternity ward at university hospital. Twenty-five were selected for the experimental group while 25 were assigned to a control group. Neroli essential oil was used for aroma therapy and was already identified as not being hazard to pregnant women. It provided emotional stability from previous study. The participants inhaled Neroli 2 minutes, 3 times (9 am to 10 am, 4 pm to 5 pm, just before sleep) a day. A total of 15 sessions were held from the day of the preliminary investigation. Pre and post written survey and measuring an autonomic nervous system reaction were collected from both groups. Results: The data were analyzed by $x^2$ test, t-test, and paired t-test. There was a statistically significant difference in stress (t=-3.98, p<.001) between the experimental group and the control group. Conclusion: These findings indicate that aroma inhalation therapy is effective as a nursing intervention for the stress relief of hospitalized high-risk pregnant women.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.16 no.3
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• pp.188-196
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• 2016

For the balancing control of a one-wheel mobile robot, CMG (Control Moment Gyro) can be used as a gyroscopic actuator. Balancing control has to be done in the roll angle direction by an induced gyroscopic motion. Since the dedicated CMG cannot produce the rolling motion of the body directly, the yawing motion with the help of the frictional reaction can be used. The dynamic uncertainties including the chattering of the control input, disturbances, and vibration during the flipping control of the high rotating flywheel, however, cause ill effect on the balancing performance and even lead to the instability of the system. Fuzzy compensation is introduced as an auxiliary control method to prevent the robot from the failure due to leaning aside of the flywheel. Simulation studies are conducted to see the feasibility of the proposed control method. In addition, experimental studies are conducted for the verification of the proposed control.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.7
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• pp.1123-1130
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• 2017

This paper deals with the dynamic surface control based tracking control for a drone equipped with a 2-DOF manipulator. First, the dynamics of drone and 2-DOF manipulator are derived separately. And we obtain the combined model of a drone equipped with a manipulator considering the inertia and the reactive torque generated by a manipulator. Second, a dynamic surface control based attitude and altitude control method is presented. Also, multiple sliding mode control based position control method is presented. The system stability and convergence of tracking errors are proven using Lyapunov stability theory. Finally, the simulation results are given to verify the effectiveness of the proposed control method.

• The Journal of Pediatrics of Korean Medicine
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• v.34 no.1
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• pp.37-47
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• 2020

Objectives After inducing dermatitis in 6-week-old mice, we tried to find out the effects of recovery in the damaged skin by administering genistein and palmitoylethanolamide (PEA) Methods The 6-week-old mice were divided into the control group (Ctrl), dermatitis causing group (AcDE), genistein-administered group after the onset of dermatitis (GsT), and PEA-administered group after the onset of dermatitis (PEAT). Seven mice were assigned to each group. Changes in the skin barrier were observed after three days of administration following the onset of dermatitis. Results In the GsT and PEAT, there was less skin damage compared to the AcDE, and the lowest skin damage showed in the GsT. The intensity of CB1 and CB2 expression was increased by 64% (CB1) and 39% (CB2) in the GsT, and 38% (CB1) and 28% (CB2) in the PEAT compared to the AcDE. The E-catherin positive reaction was decreased in the AcDE, while the E-catherin positive reaction was increased in the GsT (76%) and PEAT (34%). The p-JNK positive reaction was increased in the AcDE, while the p-JNK positive reaction was decreased in the GsT (60%) and PEAT (39%). Toxic Hepatopathy was not observed in the liver tissue of Genistein administered 3OGsT, and PEA administered 3OPEAT. Conclusions Genistein has recovery effect on dermatitis damage through active induction of the endocannabin system (ECS).

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.32 no.4
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• pp.95-100
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• 2004

This paper represents the development of a CLS(Control Loading System) for a target a airplane (KT-1) with mechanical linkage reversible flight control system. The system is composed of mechanical frame, controller, sensing part to measure the force from the stick, driving system generating the reaction forces. The DS1103 DSP(Digital Signal Processor) of the dSpace Corp. was used as the controller. The control algorithm of the CLS and the operational environment including monitoring software and evaluation tools are described. The evaluation of the system was conducted according to the requirement specification. The results of the test were analyzed by comparing with the actual data of the target airplane.

• Applied Science and Convergence Technology
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• v.23 no.1
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• pp.14-26
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• 2014

Copper is an important component from coin metal to electronic wire, integrated circuit, and to lithium battery. Copper oxides, mainly including $Cu_2O$ and CuO, are important semiconductors for the wide applications in solar cell, catalysis, lithium-ion battery, and sensor. Due to their low cost, low toxicity, and easy synthesis, copper oxides have received much research interest in recent year. Herein, we review the crystallization of copper oxides by designing various chemical reaction routes, for example, the synthesis of $Cu_2O$ by reduction route, the oxidation of copper to $Cu_2O$ or CuO, the chemical transformation of $Cu_2O$ to CuO, the chemical precipitation of CuO. In the designed reaction system, ligands, pH, inorganic ions, temperature were used to control both chemical reactions and the crystallization processes, which finally determined the phases, morphologies and sizes of copper oxides. Furthermore, copper oxides with different structures as electrode materials for lithium-ion batteries were also reviewed. This review presents a simple route to study the reaction-crystallization-performance relationship of Cu-based materials, which can be extended to other inorganic oxides.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07b
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• pp.670-673
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• 2002

Powder synthesis using the alkoxy precursor technique exhibits processing flexibility not available in traditional high temperature solid-state reaction. With proper process control, impurities can be reduced to very low levels. The major distinction of the present work lies in the method of accomplishing the hydrolysis reaction. In the present case, water is not added to the system. Instead the metal alkoxide/alcohol solution is heated to a temperature at which water is formed through dehydration of the alcohol solvent, causing precipitation of the corresponding metal oxide (hydroxide). The present method provides a means of producing amorphous alumina.

• Proceedings of the Korea Concrete Institute Conference
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• 1998.10b
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• pp.883-887
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• 1998

Hydration is the main reason for the growth of the material properties. A exact parameter to control the chemical and physical process is not the time, but the degree of hydration. Therefore, it is reasonable that development all material properties should be formulated in terms of degree of hydration. Mathematical formulation of degree of hydration is based on combination of reaction rate functions. The effect of moisture conditions as well as temperature on the rate of reaction is considered in the degree of hydration model. This effect is subdivided into two contributions: water shortage and water distribution. The former is associated with the effect of on the progress of hydration. The water needed for progress of hydration do not exist and there is not enough space for the reaction products to form. The latter is associated with the effect of free capillary water distribution in the pore system. Physically absorption layer does not contribute to progress of hydration and only free water is available for further hydration.

• Journal of Environmental Health Sciences
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• v.30 no.2
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• pp.79-83
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• 2004

The oxidative degradation of BPA with laccase from Trametes versiclor was conducted in a closed, temperature controlled system containing acetate buffer for pH control. The effects of medium pH, buffer concentration, temperature and mediator on degradation of BPA were investigated. The inactivation of the enzyme by temperature and reaction product was also studied. The optimal pH for BPA degradation showed about 5. Buffer concentration did not affect BPA degradation. On the other hand, the enzyme stability was higher at low concentration buffer(25 mM). Temperature rise increased the degradation rate of BPA up to 45$^{\circ}C$. The valuable mediator of laccase for BPA was ABTS. Elevated temperature and reaction product irreversibly inactivated the enzyme.