• Title/Summary/Keyword: Electron Heating

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Effects of Setting on the Gelation Characteristics of Frozen Mackerel Surimi Prepared by Alkaline Washing under Reduced Pressure (Setting조건이 감압 알칼리수세하여 제조한 고등어 냉동 Surimi의 Gel화 특성에 미치는 영향)

  • Park, Hyung-Sun;Park, Sang-Woo;Yang, Seung-Taek
    • Korean Journal of Food Science and Technology
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    • v.30 no.5
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    • pp.1152-1157
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    • 1998
  • In this study, an attempt was made to obtain the optimum setting condition of frozen mackerel surimi prepared from alkaline washing under atmospheric, 660 and 560 mmHg pressure. Mackerel surimi were incubated at 15, 25, 35 and $45^{\circ}C$ for 2, 4, 6, 8 and 10 hr, respectively, followed by heating at $90^{\circ}C$ for 25 min to be cooked gel. The qualities of surimi gels were examined by analyzing the transglutaminase (TGase) activity, gel strength and scanning electron microscopy (SEM). For the preparation of mackerel surimi gel, optimum condition of setting was incubation at $35^{\circ}C$ for 6 hr.

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Development of High Density Inductively Coupled Plasma Sources for SiH4/O2/Ar Discharge (고밀도 유도 결합 플라즈마 장치의 SiH4/O2/Ar 방전에 대한 공간 평균 시뮬레이터 개발)

  • Bae, S.H.;Kwon, D.C.;Yoon, N.S.
    • Journal of the Korean Vacuum Society
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    • v.17 no.5
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    • pp.426-434
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    • 2008
  • A space averaged $SiH_4/O_2/Ar$ simulator for the high density inductively coupled plasma sources for $SiH_4/O_2/Ar$ discharge is developed. The developed simulator uses space averaged fluid equations for electrons, positive ions, negative ions, neutral species, and radicals in $SiH_4/O_2/Ar$ plasma discharge, and the electron heating model including the anomalous skin effect. Using the developed simulator, the dependency of the density of charged particles, neutral particles, and radicals, the electron temperature, the plasma resistance, and the power absorption coefficient for the RF power and pressure is calculated.

Low Temperature Synthesis and Characterization of Sol-gel TiO2 Layers

  • Jin, Sook-Young;Reddy, A.S.;Park, Jong-Hyurk;Park, Jeong-Young
    • Proceedings of the Korean Vacuum Society Conference
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    • 2011.08a
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    • pp.353-353
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    • 2011
  • Titanium dioxide is a suitable material for industrial use at present and in the future because titanium dioxide has efficient photoactivity, good stability and low cost [1]. Among the three phases (anatase, rutile, brookite) of titanium dioxide, the anatase form is particularly photocatalytically active under ultraviolet (UV) light. In fabrication of photocatalytic devices based on catalytic nanodiodes [2], it is challenging to obtain a photocatalytically active TiO2 thin film that can be prepared at low temperature (< 200$^{\circ}C$). Here, we present the synthesis of a titanium dioxide film using TiO2 nanoparticles and sol-gel methods. Titanium tetra-isopropoxide was used as the precursor and alcohol as the solvent. Titanium dioxide thin films were made using spin coating. The change of atomic structure was monitored after heating the thin film at 200$^{\circ}C$ and at 350$^{\circ}C$. The prepared samples have been characterized by X-ray diffraction (XRD), scanning electron microcopy, X-ray photoelectron spectroscopy, transmission electron microscopy, ultraviolet-visible spectroscopy (UV-vis), and ellipsometry. XRD spectra show an anatase phase at low temperature, 200$^{\circ}C$. UV-vis confirms the anatase phase band gap energy (3.2 eV) when using the photocatalyst. TEM images reveal crystallization of the titanium dioxide at 200$^{\circ}C$. We will discuss the switching behavior of the Pt /sol-gel TiO2 /Pt layers that can be a new type of resistive random-access memory.

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Electrical and Optical Properties of Vacuum-Evaporated CdS Films for the Window Layer of $CdS/CuInSe_2$ Solar Cells. ($CdS/CuInSe_2$태양전지의 Window Layer로 쓰이는 CdS박막의 진공증착법에 따른 전기적.광학적 성질)

  • Nam, Hee-Dong;Lee, Byung-Ha;Park, Sung
    • Korean Journal of Crystallography
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    • v.8 no.2
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    • pp.105-110
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    • 1997
  • 1μm-CdS films for a window layer of CdS/CuInSe2 solar cell have been prepared by vacuum of 1x10-3 mTorr. Source and substrate temperature ranges were used 800-1100'C and 50-200℃ respectively. Structural, electircal and optical properties of CdS films have been investigated by X-ray diffractometer (XRD), scanning electron microscopy (SSEM), electrical resistivity, the Hall measurement and optical transmission spectra. Electrical resistivity and optical transmission of the CdS films decreased with the increase in CdS source temperature without substrate heating. All the films had hexagonal structure and strong texture with (002) orientation of grain normal to the substrate glass. CdS films evaporated at 1000℃ were the highest electrical conductivity of 0.9(S/cm). Electrical resistivity and optical transmission at the substrate temperature of 100℃ were 40(Ω,cm) and 80% respectively.

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Extreme Enhancements in GPS TEC on 8 and 10 November 2004

  • Chung, Jong-Kyun;Jee, Gun-Hwa;Kim, Eo-Jin;Kim, Yong-Ha;Cho, Jung-Ho
    • Bulletin of the Korean Space Science Society
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    • 2010.04a
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    • pp.30.2-30.2
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    • 2010
  • It is a mistaken impression that the midlatitude ionosphere was a very stable region with well-known morphology and physical mechanism. However, the large disturbances of midlatitude ionospheric contents in response to global thermospheric changes during geomagnetic storms are reported in recent studies using global GPS TEC map and space-born thermospheric UV images, and its importance get higher with the increasing application areas of space navigation systems and radio communication which are mostly used in the midlatitudes. Positive and negative storm phases are used to describe increase and decrease of ionospheric electron density. Negative storms result generally from the enhanced loss rate of electron density according to the neutral composition changes which are initiated by Joule heating in high-latitudes during geomagnetic storms. In contrast, positive ionospheric storms have not been well understood because of rare measurements to explain the mechanisms. The large enhancements of ground-based GPS TEC in Korea were observed on 8 and 10 November 2004. The positive ionospheric storm was continued except for dawn on 8 November, and its maximum value is ~65 TECU of ~3 times compared with the monthly mean TEC values. The other positive phase on 10 November begin to occur in day sector and lasted for more than 6 hours. The O/N2 ratios from GUVI/TIMED satellite show ~1.2 in northern hemisphere and ~0.3 in southern hemisphere of the northeast Asian sector on 8 and 10 November. We suggest the asymmetric features of O/N2 ratios in the Northeast Asian sector may play an important role in the measured GPS TEC enhancements in Korea because global thermospheric wind circulation can globally change the chemical composition during geomagnetic storms.

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Preparation of Hybrid Carbon from Conducting Polymer-Coconut Shell Composites and Their Electrochemical Properties (코코넛 껍질-전도성 고분자 복합소재로부터 탄소 소재의 제조 및 전기화학적 특성 분석)

  • Jeongeun Park;Subin Shin;Yewon Yoon;Jiwon Park;Joonwon Bae
    • Applied Chemistry for Engineering
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    • v.35 no.1
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    • pp.37-41
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    • 2024
  • The coconut shell, a by-product of popular tropical fruit, is a promising material due to its interesting properties. The preparation of the composite consisted of conducting polymer and coconut shell using a simple wet method, and subsequent carbonization produced a carbonized material under a controlled carbonization cycle. In addition, its electrochemical performance as an anode in lithium-ion batteries was also investigated. The appearance of the obtained materials was observed with a scanning electron microscope. The internal structure of the carbon derived from the coconut shell under a controlled heating profile was analyzed using a Raman spectroscope. A simple electrical measurement based on the ohmic relationship showed that the carbonized product has a significant electrical conductivity. The application of the carbonized product as anode in a lithium-ion battery was tested using half-cell charge/discharge experiments. This article provides important information for future research regarding the recycling of fruit shells and food waste.

Influences of the Irradiation of Intense Pulsed ion Beam (IPIB) on the Surface of Ni$_3$Al Base Alloy IC6

  • Le, X.Y.;Yan, S.;Zhao, W.J.;Han, B.H.;Wang, Y.G.;Xue, J.M.;Zhang, H.T.
    • Journal of Korean Vacuum Science & Technology
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    • v.6 no.2
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    • pp.92-96
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    • 2002
  • In this paper, we treated the Ni$_3$Al based alloy samples with intense pulsed ion beams (IPIB) at the beam parameters of 250KV acceleration voltage, 100 - 200 A/cm$^2$ current density and 60 u pulse duration. We simulated the thermal-mechanical process near the surface of Ni$_3$Al based alloy with our STEIPIB codes. The surface morphology and the cross-section microstructures of samples were observed with SEM, the composition of the sample surface layer was determined by X-ray Energy Dispersive Spectrometry (XEDS) and the microstructure on the surface was observed by Transmission Electron Microscope (TEM). The results show that heating rate increases with the current density of IPIB and cooling rate reached highest value less than 150 A/cm$^2$. The irradiation of IPIB induced the segregation of Mo and adequate beam parameter can improve anti-oxidation properly of IC6 alloy. Some craters come from extraneous debris and liquid droplets, and some maybe due to the melting of the intersection region of interphase. Increasing the pulse number enlarges average size of craters and decreases number density of craters.

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Assessment of Bacteria Removal Using Silver Ion Absorbed Ceramic Filter

  • Kim, Woo-Hang;Smith, James
    • Journal of Environmental Science International
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    • v.21 no.8
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    • pp.901-907
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    • 2012
  • The objective of this study was to evaluate bacteria removal ability of the metallic silver which was baked silver ion impregnated ceramic filter at heating condition. Silver leaking from baked ceramic filter was tested to sustain bacteria removal for a long time. Silver impregnated ceramic filter could remove E. coli completely at $10^{12}$ MPN/100ml to $10^{13}$ MPN/100ml of influent. However, ceramic filter without silver did not remove E. coli completely under the same condition. After baking, the silver impregnated ceramic filter almost didn't leak out the silver ion from filter. Photo of TEM (Transmission Electron Microscopy) showed that absorbed silver ions remained in ceramic filter after baking process and most of silver were less than 10 nm. According to the increase in the amount of silver in the ceramic filter, removal efficiencies of E. coli were increased but turbidity removal was decreased. It can be accounted that increased removal efficiency of E. coli was from disinfection of silver that is in the ceramic filter. Simulated concentrations of bacteria agree well with the observed experimental effluent concentration data. Moreover, first-order decay coefficients increased to 0.0034/min after silver was added in the ceramic filter. Increase of first-order decay coefficient proves that silver-added ceramic filter can remove bacteria easily.

Studies on the Processing Properties and Interactions Between Porcine Blood Proteins and Waxy Rice Starch During Making Porcine Blood Cake

  • Lin, Chin-Wen;Yang, Jeng-Huh;Chu, Hsien-Pin;Su, Ho-Ping;Chen, Hsiao-Ling;Huang, Chia-Cheong
    • Asian-Australasian Journal of Animal Sciences
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    • v.14 no.3
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    • pp.358-364
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    • 2001
  • The physiochemical properties and interactions between porcine blood and waxy rice were determined. Addition of calcium chloride (0.15%) improved acceptability of blood cake and increased the gelatinization degree of waxy rice. The water-holding capacity of porcine blood gel (blood/water=60/40, v/v), extent of absorption and gelatinization of waxy rice, and scanning electron microscopy showed that blood protein matrix and waxy rice are competitors for holding water in the cooking procedure. Non-haem iron content increased linearly (R=0.95) when heating temperature rose. The presence of blood proteins caused increasing of peak temperature (Tp) of gelatinization in differential scanning calorimetric thermal gram, The microstnlcture of plasma proteins and haemoglobin appeared continuous changes, and interacted with surface of waxy rice flour in terms of network and mosaic form, respectively. The electrophoretic patterns revealed an interaction between plasma proteins and waxy rice glutelin and haemoglobin when heated could be found at temperatures above $60^{\circ}C$.

플라즈마 도핑 후 급속열처리법을 이용한 n+/p 얕은 접합 형성

  • Do, Seung-U;Seo, Yeong-Ho;Lee, Jae-Seong;Lee, Yong-Hyeon
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2009.11a
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    • pp.50-50
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    • 2009
  • In this paper, the plasma doping is performed on p-type wafers using $PH_3$ gas(10 %) diluted with He gas(90 %). The wafer is placed in the plasma generated with 200 W and a negative DC bias (1 kV) is applied to the substrate for 60 sec under no substrate heating. the flow rate of the diluted $PH_3$ gas and the process pressure are 100 sccm and 10 mTorr, respectively. In order to diffuse and activate the dopant, annealing process such as rapid thermal annealing (RTA) is performed. RTA process is performed either in $N_2$, $O_2$ or $O_2+N_2$ ambient at $900{\sim}950^{\circ}C$ for 10 sec. The sheet resistance is measured using four point probe. The shallow n+/p doping profiles are investigated using secondary ion mass spectromtry (SIMS). The analysis of crystalline defect is also done using transmission electron microscopy (TEM) and double crystal X-ray diffraction (DXRD).

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