• Title/Summary/Keyword: Differential reaction

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Sensibility Evaluation on the Correlated Color Temperature in White LED Lighting (백색 LED 조명의 색온도에 관한 감성평가)

  • Jee, Soon-Duk;Lee, Sang-Hyuk;Choi, Kyoung-Jae;Park, Joung-Kyu;Kim, Chang-Hae
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.22 no.4
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    • pp.1-12
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    • 2008
  • The aim of this study is to investigate the sensitivity evaluation of human beings in reacting to the correlated color temperature of the optical properties of white LED lighting. For the sake of this study, white light-emitting diode modules have been fabricated their correlated color temperature have been measured, test cabinets for the sensitivity evaluation have been constructed with the white LED modules, and their sensitivity reactions on the test cabinets have been evaluated and analyzed. The sensitivity reaction has been evaluated by the semantic differential method with 15 selected questions, and the reliability and the content validity of their lighting have been analyzed to 3 factors which foe the activity as the first factor, the stability as the second one, the potency as the third one, respectively. For the data analysis on the sensitivity reaction, the dependent variable is the score of the sensitivity evaluation and the independent one is the correlated color temperature of the test module. The results of this study is as follows: In the case of the sensitive evaluation on the activity and the potency in the white LED lighting compared with the fluorescent lamp, the subjects have made higher mark on $MA_3$ with 8,300[K], and in the factor of the stability, they have made higher mark on $MA_1$ with 3,800[K].

The Effect of Functional Group Position of the Piperidine Derivatives on the CO2 Absorption Characteristics in the (H2O-Piperidine-CO2) System ((H2O-Piperidine-CO2) system에서 piperidine 유도체의 작용기 위치에 따른 이산화탄소 흡수특성 연구)

  • Choi, Jeong Ho;Yun, Soung Hee;Kim, Yeong Eun;Yoon, Yeo Il;Nam, Sung Chan
    • Korean Chemical Engineering Research
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    • v.53 no.1
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    • pp.57-63
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    • 2015
  • Absorption characteristics of 2-methylpiperidine (2MPD), 3-methylpiperidine (3MPD) and 4-methylpiperidine (4MPD) absorbents were studied by a vapor-liquid equilibrium (VLE) apparatus and a differential reaction calorimeter (DRC). Using a VLE apparatus, the $CO_2$ loading capacity of each absorbent was estimated. After reaching the absorption equilibrium, nuclear magnetic resonance spectroscopy (NMR) had been conducted to characterize the species distribution of the ($H_2O$-piperidine-$CO_2$) system. Using a DRC, the reaction of heat was confirmed in accordance with the absorption capacity. The unique characteristics of 2MPD, 3MPD and 4MPD absorbents appeared by the position of methyl group. The 2MPD possessing the methyl group at the ortho position showed its hindrance effect during the absorption process; however, piperidine derivatives possessing the meta position and para position did not show its characteristics in $H_2O$-piperidine-$CO_2$ system.

Determination of the Langmuir and Temkin Adsorption Isotherms of H for the Cathodic H2 Evolution Reaction at a Pt/KOH Solution Interface Using the Phase-Shift Method

  • Chun Jang-H.;Jeon Sang-K.;Chun Jin-Y.
    • Journal of the Korean Electrochemical Society
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    • v.9 no.1
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    • pp.19-28
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    • 2006
  • The phase-shift method for determining the Langmuir, Frumkin, and Temkin adsorption isotherms ($\theta_H\;vs.\;E$) of H for the cathodic $H_2$ evolution reaction (HER) at a Pt/0.1 M KOH solution interface has been proposed and verified using cyclic voltammetric, differential pulse voltammetric, and electrochemical impedance techniques. At the Pt/0.1 M KOH solution interface, the Langmuir and Temkin adsorption isotherms ($\theta_H\;vs.\;E$), the equilibrium constants ($K_H=2.9X10^{-4}mol^{-1}$ for the Langmuir and $K_H=2.9X10^{-3}\exp(-4.6\theta_H)mol^{-1}$ for the Temkin adsorption isotherm), the interaction parameters (g=0 far the Langmuir and g=4.6 for the Temkin adsorption isotherm), the rate of change of the standard free energy of $\theta_H\;with\;\theta_H$ (r=11.4 kJ $mol^{-1}$ for g=4.6), and the standard free energies (${\Delta}G_{ads}^{\circ}=20.2kJ\;mol^{-1}$ for $k_H=2.9\times10^{-4}mol^{-1}$, i.e., the Langmuir adsorption isotherm, and $16.7<{\Delta}G_\theta^{\circ}<23.6kJ\;mol^{-1}$ for $K_H=2.9\times10^{-3}\exp(-4.6\theta_H)mol^{-1}$ and $0.2<\theta_H<0.8$, i.e., the Temkin adsorption isotherm) of H for the cathodic HER are determined using the phase-shift method. At intermediate values of $\theta_H$, i.e., $0.2<\theta_H<0.8$, the Temkin adsorption isotherm ($\theta_H\;vs.\;E$) corresponding to the Langmuir adsorption isotherm ($\theta_H\;vs.\;E$), and vice versa, is readily determined using the constant conversion factors. The phase-shift method and constant conversion factors are useful and effective for determining the Langmuir, Frumkin, and Temkin adsorption isotherms of intermediates for sequential reactions and related electrode kinetic and thermodynamic data at electrode catalyst interfaces.

An Introduction to Kinetic Monte Carlo Methods for Nano-scale Diffusion Process Modeling (나노 스케일 확산 공정 모사를 위한 동력학적 몬테칼로 소개)

  • Hwang, Chi-Ok;Seo, Ji-Hyun;Kwon, Oh-Seob;Kim, Ki-Dong;Won, Tae-Young
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.41 no.6
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    • pp.25-31
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    • 2004
  • In this paper, we introduce kinetic Monte Carlo (kMC) methods for simulating diffusion process in nano-scale device fabrication. At first, we review kMC theory and backgrounds and give a simple point defect diffusion process modeling in thermal annealing after ion (electron) implantation into Si crystalline substrate to help understand kinetic Monte Carlo methods. kMC is a kind of Monte Carlo but can simulate time evolution of diffusion process through Poisson probabilistic process. In kMC diffusion process, instead of. solving differential reaction-diffusion equations via conventional finite difference or element methods, it is based on a series of chemical reaction (between atoms and/or defects) or diffusion events according to event rates of all possible events. Every event has its own event rate and time evolution of semiconductor diffusion process is directly simulated. Those event rates can be derived either directly from molecular dynamics (MD) or first-principles (ab-initio) calculations, or from experimental data.

Classification of Potato Virus Y Strains based on Reactions of Differential Plants (감자바이러스 Y 계통분류를 위한 판별 식물)

  • Park E. K.;Choi J. K.
    • Korean journal of applied entomology
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    • v.23 no.4 s.61
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    • pp.203-208
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    • 1984
  • Four varieties of tobacco, Nicotiana tabacum var. NC 2326. NC 95, NC 744 and Havana. and two plant species, Physalis floridana Rydb., N. repanda Wild. were used for classification of ten isolates of potato virus Y(PVY) obtained Iron potato or tabacco plants showing various symptoms. Each of the 10 isolates could be distinguished by the host reactions showing necrosis, vein banding and/or mottling, or no symptom on these hosts. Five isolates of PVY, PVY-VN, PVY-N, PVY-NSNR, PVY-Chile, and PVY-Argentina, showed necrotic symptom on NC 2326, but others showed vein handing and/or mottling symptom. On NC95, each of the isolates tested showed similar symptons as on NC2326, except necrotic symptom by the isolate PVY-MSNR. Havana showed mottling reaction to the PVY-NSNR, PVY-MSNR, PVY-MSMR, PVY-VB, and necrosis to PVY-Chile, PVY-Argentina, but showed no symptom to the others. NC744 showed mottling symptom to the PVY-MSNR and PVY-MSMR, necrosis to the PVY-Chile and PVY-Argentina, and no symptom to the others. On N. repanda, necrotic reaction to PVY-Argentina. no symptom to PVY-VN and PVY-C, and nettling to others were observed.

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The Study on the Properties of Polypropylene/Nylon6 with Various Compatibilizers (Polypropylene/Nylon6 블렌드에서 이종의 상용화제에 따른 물성연구)

  • Kim, H.C.;Lee, K.Y.;Kim, H.I.
    • Applied Chemistry for Engineering
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    • v.10 no.4
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    • pp.497-501
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    • 1999
  • The changes of properties were studied for the polypropylene(PP)/Nylon6 blends containing different kinds of compatibilizer made by either reactive extrusion of solution reaction. The compatibilizers were PP grafted with maleic anhydride (MAH) made by reactive extrusion and solution reaction. The grafted MAH contents were 0.3 wt %, and 2.7 wt %, respectively. The composition of the PP/nylon6 blend was fixed at 75/25 by weight. Blending was carried out with twin-screw extruder (L/D=30, ${\psi}=30$) at 300 rpm. As the content of PP-g-MAH was increased, the crystallization peak of Nylon6 decreased gradually then finally disappeared. Disappearance of crystallization peak of Nylon6 was mostly affected by grafted MAH content rather than the preparation method and the amount of compatibilizer. The portion of Nylon6 that could not crystallize in its normal crystallization temperature crystallized together with PP at the crystallization temperature of PP. So called concurrent crystallization was observed. Meanwhile two more peaks were observed during heating cycle. One was exothermic peak at $193^{\circ}C$ near to crystallization temperature of Nylon6, the other was endothermic peak at $215^{\circ}C$ that was $5^{\circ}C$ lower than normal endothermic peak of Nylon6. To analyze the peaks, nylon6 was annealed in the differential scanning calorimeter. As a result, the peak at $193^{\circ}C$ was crystallization peak of imperfect crystalline of Nylon6 and the other peak at $215^{\circ}C$ was melting peak of imperfect crystalline of nylon6.

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Serological Diagnosis of Human Sparganosis by means of micro-ELISA (효소면역측정법을 이용한 스파르가눔증의 혈청학적 진단)

  • Hyuck Kim;Suk-Il Kim;Seung-Yull Cho
    • Parasites, Hosts and Diseases
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    • v.22 no.2
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    • pp.223-228
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    • 1984
  • Seven cases of surgically proven sparganosis were serologically tested by means of microELISA for their specific IgG antibody levels. For that purpose, crude saline extract of spargana from snake, Natrix tigrina lateralis was prepared and used as antigen. The sparganosis sera were also tested with Paragonimus and Cysticercus antigens to observe the cross reactivity. A total of 71 sera from normal control, ectopic and pulmonary paragonimiasis, clonorchiasis, cysticerCOSIS and Taenia saginata cases were also included. Except for one case of old calcified infection, all of 6 human sparganosis showed higher serum levels of specific IgG antibody when the differential point of positive reaction was set at the absorbance value of 0.25 (the sensitivity being 85.7%). In control and other helminthic infections, all except 3 cases of T. saginata infection showed negative reaction to sparganum antigen (the specificity being 90.7%). None of sparganosis cases showed cress reactivity to Paragonimus and Cysticercus antigens. Undiluted cerebrospinal l1uid also showed high levels of antibody when central nervous system was invaded. The serologic diagnosis by means of micro ELISA could be a useful tool in epidemiological study of human sparganosis in susceptible population, as well as in individual diagnosis.

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The Differential Effects of Plyometric Training and Weight Training on Muscular Power, Agility and Maximal Muscular Strength of the Male and Female High-school Throwers (고등학교 투척선수들의 plyometric training과 weight training이 순발력, 민첩성 및 최대 근력에 미치는 영향)

  • Kim, Hyung-Don;Kim, Duk-Jung;Kwak, Yi-Sub
    • Journal of Life Science
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    • v.19 no.12
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    • pp.1821-1828
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    • 2009
  • The purpose of this research was to investigate how the plyometric training and weight training program, applied in the field for exercise performance of throwing players, influenced improvement of athletic abilities, including agility, maximum muscular power, and strength. After implementing plyometric training and weight training to 21 high school throwing players for 10 weeks, we designed the next step. The 21 subjects were divided into two groups - women's group and men's group. All subjects were tested to determine agility using sidestep, burpee test, reaction time, lower body power and strength using standing long jump, standing jump, 30 m running, squats and leg presses. Additionally, isokinetic strength was measured using Cybex isokinetic dynamometer. The results showed that both groups demonstrated improvement in the standing long jump, standing jump and 30 m running after training. Particularly, the women's group indicated better improvement. Second, women's groups showed higher improvement in the sidestep and burpee test. However, in the reaction time test, the men's group indicated better improvement. Third, both groups showed better improvement in squats and leg presses after training. Particularly, the women's group indicated better improvement. Fourth, in the left and right side extension torque and flexion torque at a velocity of $60^{\circ}$/sec, both groups showed better improvement after training. In the left side extension peak torque, the men's group showed higher improvement, but the women's group showed higher improvement in the left side flexion and extension peak torque. Fifth, both groups showed better improvement in bench pressing and back strength after training. Particularly, the women's group indicated higher improvement.

Process Parameters on Quality Characteristics of Jacopever (Sebastes schlegeli Hilgendorf) under Treatment of Hydrostatic Pressure (고압처리 공정변수가 조피볼락의 초기 품질특성에 미치는 영향)

  • Kim, Min-Ji;Lee, Soo-Jeong;Kim, Chong-Tai
    • The Korean Journal of Food And Nutrition
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    • v.29 no.3
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    • pp.371-381
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    • 2016
  • The present study investigated the effects of processing parameters such as time (10, 20, 30, 40 min), pressure (25, 50, 75, 100 MPa), and the salinity of brine (0~10%(w/v)) on jacopever (Sebastes schlegeli Hilgendorf) in order to establish optimization of the three factors using a high hydrostatic pressure (HHP) machine. To do so, it analyzed the quality characteristics of volatile basic nitrogen (VBN), trimethylamine (TMA), total bacterial counts, dynamic viscoelasticities, and differential scanning calorimetry (DSC) properties. First, when the time increased to 40 mins, by 10 min intervals, the total bacterial counts in HHP groups under $25^{\circ}C$, 100 MPa, and 4%(w/v) brine were significantly decreased except for the first 10 min in comparison to the control group. In regards to DSC properties, the onset temperature ($T_O$) of the first endothermal curve was significantly reduced. Second, when the pressure level increased up to 100 MPa by 25 MPa increments, the total bacterial counts in the HHP samples significantly decreased for 20 min at 50 MPa or higher. As the pressure increased, G', G" and the slope of tan ${\delta}$ decreased (except for 50 MPa). Third, in regards to the salinities of brine, when the HHP processing was treated at 100 MPa, $25^{\circ}C$ for 20 min, the total bacterial counts of all the HHP groups significantly decreased in comparison to those of the control group. A significant difference was found in the enthalpy of the second endothermic curve in the 6~10%(w/v) (except 7%(w/v)) HHP groups. Therefore, the salinity of the immersion water under the HHP condition was appropriate when it was lower than 6%(w/v). The present study demonstrated that the optimum parameter condition according to/under the condition of the microbial inhibition and economic effects using an HHP would be the reaction time for 20 min, reaction pressure at 100 MPa, and the salinity of 4%(w/v) brine.

Electrochemical Studies on the Lanthanides (란탄족 원소의 전기화학적 환원에 관한 연구 (제 1 보))

  • Park, Jong Min;Gang, Sam U;Do, Lee Mi;Han, Yang Su;Son, Byeong Chan
    • Journal of the Korean Chemical Society
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    • v.34 no.6
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    • pp.561-568
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    • 1990
  • Voltammetric behavior of some light lanthanide ions (La$^{3+}$, Pr$^{3+}$, Nd$^{3+}$, Sm$^{3+}$, and Eu$^{3+}$) in various supporting electrolytes has been investigated by several electrochemical techniques. The peak potentials and the peak currents, their dependency on the concentration, temperature and pH effects, the reversibility of the electrode reactions are described. The reduction of La$^{3+}$, Pr$^{3+}$ and Nd$^{3+}$ in 0.1 M lithium chloride proceeds by a three-electron change directly to the metallic state (Ln$^{3+}$ + 3e- → Ln$^0$) and charge transfer is totally irreversible. However, the reduction of Sm$^{3+}$ in 0.1 M tetramethylammonium iodide and Eu$^{3+}$ in 0.1 M lithium chloride proceeds in two stages (Ln$^{3+}$ + e- → Ln$^{2+}$ and Ln$^{2+}$ + 2e- → Ln$^0$). At pH values lower than ca.4 the hydrated lanthanide species (Ln(OH)$^{2+}$) reduced before the lanthanide ions (Ln$^{3+}$) due to the catalytic effect of hydrogen ions, and peak current increase with in the order Eu$^{3+}$ < Sm$^{3+}$ < Nd$^{3+}$ < Pr$^{3+}$ < La$^{3+}$ in differential pulse polarography. Some representative plots of $i_{pc}V^{-1/2} (proportional to current function) vs. V show considerable influence of hydrogen ion/lanthanide ion concentration in cyclic voltammetry. It is shown that a reaction of lanthanide ions with proton and/or water and catalytic reaction is enhanced at lower pH and at decreased lanthanide ion concentration.

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