• Title/Summary/Keyword: reaction characteristics

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A study on the characteristics of ozone generation using photochemical reaction lamp (광화학 램프를 이용한 오존발생 특성 연구)

  • Woo, Sung-Hun;Lee, Sang-Keun;Lee, Kwang-Sik
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 2004.11a
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    • pp.321-323
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    • 2004
  • In this paper, We have designed and manufactured a photochemical reaction lamp type ozonizer system which was performed a role of preservation of oriental herbal medicine. This paper describes preliminary discussions on the characteristics of ozone concentration and discharge parameters according to number of turn-on lamp.

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A Study on recycling of waste concrete for ${PO}_4^{3-}$-P removal contained in livestock wastewater (축산폐수에 함유된 ${PO}_4^{3-}$-P의 제거를 위한 폐콘크리트의 재활용에 관한 연구)

  • 김은호;박진식;성낙창;이영형;신남철;전기일
    • Journal of Environmental Science International
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    • v.8 no.2
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    • pp.227-231
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    • 1999
  • This study was conducted to investigate the removal characteristics of $PO_4^{3-}-P$ contained in livestock wastewater using waste concrete. With small particle size, increased dosage and temperature of water, $PO_4^{3-}-P$ was well removed by waste concrete.$PO_4^{3-}-P$ was removed by adsorption reaction in low pH of the primary phase, but the crystallization reaction predominated for increasing pH with passed time. As a result of adapting the adsorption isotherm equation, $PO_4^{3-}-P$ removal was more affected by the crystallization reaction than the adsorption reaction. In the SEM micrograph, there was no evident change on the waste concreter surface. Particle size was plate-phase before reaction but appeared a dense form to progress in the crystallization reaction.

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Preparation of Hexagonal Boron Nitride from Boron Oxide and Sodium Amide (산화붕소의 소듐아미드로부터 육방정 질화붕소의 합성)

  • 손영국;장윤식;오기동
    • Journal of the Korean Ceramic Society
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    • v.27 no.7
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    • pp.869-876
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    • 1990
  • Hexagonal boron nitride was synthesized from boron oxide and sodium amide in ammonia gas stream. The reaction mechanisms and characteristics of as synthesized boron nitride was investigated by means of TG, DTA, IR, XRD, SEM and PSA. The results are ; 1) hexagonal boron nitride was synthesized from reactions at temperatures above 40$0^{\circ}C$ 2) Sodium metaborate was present as by-product after reaction so that the reaction mechanism is reduced as follows : 2B2O3+3NaNH2longrightarrowBN+3NaBO2+2NH3. 3) boron nitride obtained at the reaction temperature below 40$0^{\circ}C$ is found to have random layer strudcture but the structure transits to ordered layer structure rapidly with increasing reaction temperature, showing separation of (101) differaction line from (10)band in XRD pattern of the reaction product at 50$0^{\circ}C$.

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Vibration Control of a Single-Link Flexible Manipulator Using Reaction Moment Estimator (반력모멘트 추정기를 이용한 단일 링크 유연 조작기의 진동제어)

  • Shin, Hocheol;Han, Sangsoo;Kim, Seungho
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.15 no.2 s.95
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    • pp.169-175
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    • 2005
  • In this paper, a novel vibration control scheme for a single-link flexible manipulator system without using a vibration feedback sensor is proposed. In order to achieve the vibration information of the flexible link, a reaction moment estimator based on the dynamic characteristics of the flexible manipulator is proposed. While the manipulator is maneuvering the reaction moment is reciprocally acting on the flexible link and the hub inertia due to the vibration of the link. A sliding mode controller based on the equivalent rigid body dynamics corresponding to the proposed flexible manipulator is then augmented with the reaction moment estimator to realize a decentralized control system. The reaction moment estimator is implemented via the first order low pass filter. The performance of the proposed control scheme is verified by computer simulation and experiment.

Characteristics of Borosilicate Glass Incorporated Mortar for Improve Neutron Shielding Capability (중성자 차폐능 향상을 위한 붕규산유리 혼입 모르타르의 특성 분석)

  • Jang, Bo-Kil;Kim, Ji-Hyun;Chung, Chul-Woo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2017.11a
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    • pp.155-156
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    • 2017
  • Borosilicate glass was incorporated to improve the neutron shielding capability of concrete. Boron is a typical neutron shielding material, and it is contained in borosilicate glass. However, borosilicate glass causes alkali-silica reaction, which damages the concrete. Therefore, studied to reduce the expansion due to alkali-silica reaction and to improve the neuton shielding capability. The measurement of the expansion due to the alkali-silica reaction was based on ASTM C 1260. Experimental results show that the expansion due to alkali-silica reaction is reduced when borosilicate glass powder incorporated. In addition, the neutron shielding capability was significantly improved when the fine aggregate replaced with borosilicate glass.

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Impact Fracture and Shear Strength Characteristics on Interfacial Reaction Layer of Nb/MoSi2 Laminate Composite

  • Lee, Sang-Pill;Yoon, Han-Ki;Park, Won-Jo
    • International Journal of Ocean Engineering and Technology Speciallssue:Selected Papers
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    • v.3 no.1
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    • pp.35-39
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    • 2000
  • The present study dealt with the relationships among the interfacial shear strength, the thickness of interfacial reaction layer and the impact value of $Nb/MoSi_2$ laminate composites. In addition, the tensile test was conducted to evaluate the fracture strain of $Nb/MoSi_2$ laminate composites. To change the thickness of the reaction layer, $Nb/MoSi_2$ laminate composites alternating sintered MoSi2 layers and Nb foils were fabricated as the parameter of hot press temperature. It has been found that the growth of the reaction layer increases the interfacial shear strength and decreases the impact value by localizing a plastic deformation of Nb foil. There also exist appropriate shear strength and the thickness of the reaction layer, which are capable of maximizing the fracture energy of $Nb/MoSi_2$.

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A Study of Child Emotion Regulation by the Cluster of Mother's Reaction to Children's Negative Emotion (아동의 부정적 정서표현에 대한 어머니 반응 유형의 군집에 따른 아동의 정서조절 능력 차이 검증)

  • Kim, Jiyoun;Oh, Ji-Hyun
    • Korean Journal of Childcare and Education
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    • v.13 no.3
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    • pp.39-54
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    • 2017
  • Objective: The purpose of this study was to examine natural groupings of the sub-factors of mother's reaction to children's negative emotions. The natural groupings were as follows; the emotion-coaching-reaction, the emotion-minimizing-reaction and oversensitive reaction. In addition, this paper also investigated individual differences in children's emotion regulation by clusters of sub-factors of mother's reaction to children's negative emotions. Methods: The subjects of this study consisted of 318 children. The data were analyzed using cluster analysis and one-way ANOVA. Results: The results suggested four proper clusters, according to the characteristics of mother's reaction to children's negative emotions. Cluster 1 was categorized as 'child centered-emotion coaching', cluster 2 was categorized as 'oversensitive-emotion coaching comorbid', cluster 3 was categorized as 'acception-emotion minimizing confused' and cluster 4 was categorized as 'emotion minimizing-unsupporting.' Additionally, the differences between Emotion regulations in each cluster showed distinct points of interest. In terms of the maladaptive emotion regulation, cluster 3 showed the highest level followed by cluster 4. And cluster 1 and 2 showed the lowest level. Conclusion/Implications: The results of this study helped to find a deeper understanding of the operation of specific clusters of mother's reaction to children's negative emotion and children's emotion regulation.

The Comparison of Bunsen Reaction With Phase Separation in Sulfur-lodine Thermochemical Hydrogen Production Process (황-요오드 열화학 수소 제조 공정에서 분젠 반응과 상 분리 비고)

  • Lee, Kwang-Jin;Ahn, Sueng-Hyuk;Kim, Young-Ho;Park, Chu-Sik;Bae, Ki-Kwang
    • Transactions of the Korean hydrogen and new energy society
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    • v.19 no.2
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    • pp.111-117
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    • 2008
  • A Bunsen reaction section is a primary stage of Sulfur-iodine thermochemical hydrogen production cycle. This section is important, because it decides the efficiency of next stages. In order to produce hydrogen very efficiently, the characteristics of Bunsen reaction were investigated via two experimental methods. The one is a phase separation of $H_2SO_4-HI-H_2O-I_2$ mixture system, and the other is a direct Bunsen reaction. The characteristics of each method were investigated and compared. As the result of this study, the amount of HI and $I_2$ in $H_2SO_4$ phase via Bunsen reaction was more decreased than that via $H_2SO_4-HI-H_2O-I_2$ mixture system with increasing $I_2$ concentration. However, the amount of $H_2SO_4$ in $HI_x$ phase via Bunsen reaction was remarkably increased with increasing $I_2$ concentration, while that via $H_2SO_4-HI-H_2O-I_2$ mixture system was decreased. On the other hand, the range of initial composition which is able to separate into two liquid phases without $I_2$ solidification was almost alike.

The Effect of Supportive Nursing on the Stress Reaction of Breast Cancer Patients Undergoing Chemotherapy (지지적 간호중재가 암화학요법을 받고 있는 유방암 환자의 스트레스 반응에 미치는 영향)

  • 박점희
    • Journal of Korean Academy of Nursing
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    • v.27 no.4
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    • pp.912-922
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    • 1997
  • The purpose of this study was to examine the effect of supportive nursing on stress reaction of breast cancer patients undergoing chemotherapy. The nonequivalent control group pre-test/post-test design was used for this experimental study. The subjects were 32 patients who were receiving chemotherapy after mastectomies at K hospital in Taegu from June, 1994 to June 1995. Among 32 subjects, 16 were placed in the experimental group and 16 in the control group. The experimental and control groups were tested for general characteristics, trait anxiety, health locus of control, family support, state anxiety, hopelessness, physical stress, and anxiety behavior. Collected data was analized by means of a chisquare test and a t-test for the comparative analysis of the general characteristics and homogeneity of subjects. ANOVA, and MANOVA were used for testing the hypothesis. Reliability of the tools were analyzed using the Pearson Correlation coefficient. The results of this study were as follows : 1. The hypothesis : The stress reaction of the experimental group which took supportive nursing was lower than the stress reaction of the control group : this was supported statistically. The main variable influenced in stress reaction was hopelessness. Supportive nursing for breast cancer patients, who are receiving chemotherapy, was especially effective in the reduction of hopelessness compared to state anxiety, physical stress, and anxiety behavior. 2. An analysis of the difference on stress reaction, according to the frequency of supportive nursing between the control and experimental group, showed the level of hopelessness of the experimental group was lower than the control group after four supportive meeting sessions. But there was no statistical difference in state anxiety, physical stress, and anxiety behavior. In conclusion, this study supported utilization of supportive care as well as demonstrating the effectiveness of the System-Developmental Stress Model developed by Chrisman and Riehl-Sisca.

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