• Title/Summary/Keyword: Electron Temperature

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Comparative Study on Components and Activities of Sperm Head Plasma Membrane in Active and Hibernating Animals (활동 및 동면동물의 정자 두부 Plasma Membrane의 성분 및 활성에 관한 비교 연구)

  • Oh, Yung-Keun;Ahn, Byung-Sik;Choi, In-Ho;Jung, Noh-Pal;Shin, Hyung-Cheul;Kwak, Byoung-Ju
    • Applied Microscopy
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    • v.29 no.2
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    • pp.241-253
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    • 1999
  • Fertilization pattern of north temperate bats is known to be unique for their sperm storage in the female reproductive tract during hibernation (e.g. Korean greater horseshoe bats). They copulate in fall but their ejaculated spermatozoa survive until the next spring. In another words they can persist to survive during long hibernation under the cold condition $(8\sim13^{\circ}C)$ and are to be fertilized with the ovum ovulated in the next spring, so called delayed fertilization. The present study was designed to observe morphological and functional changes of spermatozoa plasma membrane of the bats, hamsters which are hibernators, and mice which are non-hibernators in the room and the cold (bat-hibernation) temperatures and to confirm influence of the temperature on spermatozoa; survival rate, acrosome reaction rate, protein distribution, $Na^+-K^+-ATPase$ activities and scanning electron microscopic histochemistry. Based on the experimental results obtained in the present study, there were no significant morphological and functional differences in the spermatozoa plasma membrane in both the room and cold (bat-hibernation) temperatures and such an absence of difference suggests that the spermatozoa plasma membrane might play a pertinent role as a protector for consistent fertilization during and after hibernation.

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A Study on Red Tide Monitoring system using Wireless Sensor Network (무선센서네트워크를 이용한 적조모니터링 시스템 구축을 위한 연구)

  • Min Heo;Mo Soo-Jong;Yim Jae-Hong;Kim Ki-Moon
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2006.05a
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    • pp.489-492
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    • 2006
  • Red tide occurred sporadically in early 90s. But It is happening extensively by global warming. So, Airline observation, Red tide buoy development, and Red tide alarm system research is progressing for monitor ring. However, study to early forecast red tide and red tide alarm system did not exist hard. This paper proposed development that design and implementation red tide database of using wireless sensor network. There are GPS, Water Temperature sensor, Oxygen sensor, and Turbidity sensor in each node. And data is stored to red tide database through Ad-hoc network. This data is integrated and analyzed. So, forecast red tide. And red tide database has red tide data that happen at past. This is utilized to comparative analysis data for red tide estimate. Main screen displays position of node and measured value in electron map. Much studies must be backed for this a study. But I think that contribute to analyze red tide data by red tide database construction.

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EXPERIMENTAL STUDY ON THE DISSOLUTION COMPONENTS AND CORROSION PRODUCTS OF SEVERAL AMALGAMS IN ARTIFICIAL SALIVA (인공타액에서 수종 아말감의 부식시 용해성분 및 표면 부식 생성물에 관한 실험적 연구)

  • Cho, Seung-Joo;Lee, Myung-Jong
    • Restorative Dentistry and Endodontics
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    • v.19 no.1
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    • pp.1-26
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    • 1994
  • The purpose of this study was to investigate the dissolution components during corrosion of amalgams and to identify surface corrosion products in the modified Fusayama artificial saliva. Four type of amalgam alloys were used: low copper lathe cut amalgam alloy (Cavex 68), low copper spherical amalgam alloy (Caulk Spherical Alloy), high copper admixed amalgam alloy (Dispersalloy) and high copper single composition amalgam alloy (Tytin). Each amalgam alloy and Hg were triturated according to the manufacturer's direction by means of mechanical amalgamator (Capmaster, S.S.White), and then the triturated mass was inserted into the cylindrical metal mold which was 10mm in diameter and 2.0mm in height and condensed with compression of 150kg/$cm^2$ using oil pressor. The specimens were removed from the mold and stored at room temperature for 7 days and cleansed with distiled water for 30 minutes in an ultrasonic cleaner. The specimens were immersed in the modified Fusayama artificial saliva for the periods of 1 month, 3 months and 6 months. The amounts of Hg, Cu, Sn and Zn dissolved from each amalgam specimen immersed in the artificial saliva for the periods of 1 month, 3 months and 6 months were measured using Inductivity Coupled Plasma Atomic Emission Spectrometry (ICPQ-1000, Shimadzu, Japan) and amount of Ag dissolved from amalgam specimen was measured using Atomic Absorption Spectrophotometry (Atomic Absorption/Flame emission spectrophotometer M-670, Shimadzu, Japan). A surface corrosion products of specimens were analysed using Electron Spectroscopy Chemical Analyser (ESCA PHI-558, PERKIN ELMER, U.S.A.). The secondary image and back scattered image of corroded surface of specimens was observed under the SEM, and the corroded surface of specimens was analysed with the EDX. The following results were obtained. 1. The dissolution amount of Cu was the most in high copper admixed amalgam(Dispersalloy) and the least in high copper single composition amalgam(Tytin). 2. Sn and Zn were dissolved during all the experiment periods, and dissolution amounts were decreased as the time elapsed. 3. Initial surface corrosion products were ZnO and SnO. 4. Corrosion of ${\gamma}$ and ${\gamma}_2$ phase in low copper amalgams was observed and Ag-Cu eutectic alloy phase was corroded in low copper spherical amalgam(Caulk Sperical Alloy). 5. Corrosion of ${\gamma}$ and $\eta$' phase in high copper amalgams was observed and Ag-Cu eutectic alloy phase was corroded in high copper admixed amalgam(Dispersalloy). 6. Sn-Cl was produced in the subsurface of low copper amalgams and high copper admixed amalgam.

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Three-dimensional measurement of electron temperature and plasma density in coplanar AC plasma display panels (면방전 AC-PDP에서의 전자온도와 플라스마 밀도의 3차원 진단)

  • Jeong, S.H.;Moon, M.W.;Park, W.B.;Lee, J.H.;Lim, J.E.;Lee, H.J.;Son, C.G.;Lee, S.B.;Yoo, N.L.;Han, Y.G.;Oh, P.Y.;Ko, B.D.;Jeoung, J.M.;Seo, Yoon-Ho;Cho, Guang-Sup;Choi, Eun-Ha
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2005.05a
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    • pp.139-141
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    • 2005
  • 이번 실험에서는 변방전형 교류 PDP에서의 3차원적인 전자온도와 이온밀도의 측정을 마이크로 랑뮈르 탐침법을 통해 실험적으로 연구하였다. 스테핑 모터에 연결된 마이크로 랑뮈르 탐침은 20um씩 움직이며 탐침에 인가하는 플러스와 마이너스의 직류전압을 통해 I-V곡선을 구할 수 있고 이를 통해서 전자온도와 플라스마 밀도를 구할 수 있다. Ne+Xe(4%) 200Torr의 혼합가스에서 전극의 테두리를 따라(X축) 전자온도 및 플라스마 밀도를 측정한 결과 중앙지점에서와 전극의 경계지역에서 이온밀도는 $7.69{\sim}11.1{\times}10^{11}cm^{-3}$ 까지 측정되었다. 또한 전자온도는 플라스마 밀도와 균형적인 관계에 있다는 것은 주목할 만하다. 전자온도는 전극 사이의 중심에서 가장 적게 1.3 ~ 3.15eV까지 측정되었다. Y축으로 측정했을 경우 이온 밀도와 전자온도는 전극 갭 중앙에서부터 약 80um 떨어진 지점에서 서로 교차하며 증가 및 감소였으며 이온밀도는 $8.3{\sim}11.1{\times}10^{11}cm^{-3}$로 측정되었고 전자온도는 이와 균형적인 관계를 가지고 1.2~1.6eV로 측정되었다. 또한 이러한 특성은 AC PDP 에서 나타나는 줄무늬 현상과 관련이 있는 것으로 보인다. Z축으로 측정했을 경우 약 125um높이에서 가장 높게 측정되었으며 $1.1{\times}10^{12}cm^{-3}$정도로 측정되었다.

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Preparation and Characterization of Zaltoprofen-Loaded Polyoxalate Microspheres for Control Release (방출제어를 위한 잘토프로펜이 함유된 폴리옥살레이트 미립구의 제조와 특성)

  • Kim, Kyoung Hee;Lee, Cheon Jung;Jo, Sun A;Lee, Jung Hwan;Jang, Ji Eun;Lee, Dongwon;Kwon, Soon Yong;Chung, Jin Wha;Khang, Gilson
    • Polymer(Korea)
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    • v.37 no.6
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    • pp.702-710
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    • 2013
  • Zaltoprofen loaded polyoxalate (POX) microspheres were prepared by an emulsion solvent-evaporation/extraction method like oil-in-water (O/W) for sustained release of zaltoprofen. The influence of several preparation parameters such as fabrication temperature, stirring speed, intensity of the sonication, initial drug ratio, molecular weight ($M_w$) of POX, concentration of POX and concentration of emulsifier has been investigated on the zaltoprofen release profiles. Physicochemical properties and morphology of zaltoprofen loaded POX microspheres were investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD), differential scanning calorimeter (DSC) and Fourier transform infrared (FTIR). Through the analyzed results, it was demonstrated that the characteristics of the microspheres greatly affected by the prepared condition. The releases behavior of zaltoprofen was investigated for 10 days in vitro. It was confirmed that the release behavior of zaltoprofen can be controlled by the manufacturing factor of solvent-evaporation/extraction method.

Emission spectroscopic diagnostics of argon arc Plasma in Plasma focus device for advanced lithography light source (차세대 리소그래피 빛샘 발생을 위한 플라스마 집속장치의 아르곤 아크 플라스마의 방출 스펙트럼 진단)

  • Hong, Y.J.;Moon, M.W.;Lee, S.B.;Oh, P.Y.;Song, K.B.;Hong, B.H.;Seo, Y.H.;Yi, W.J.;Shin, H.M.;Choi, E.H.
    • Journal of the Korean Vacuum Society
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    • v.15 no.6
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    • pp.581-586
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    • 2006
  • We have generated the argon plasma in the diode chamber based on the established coaxial electrode type and investigated the emitted visible light for emission spectroscopy. We applied various voltages $2\sim3.5kV$ to the device by 0.5kV, and obtained the emission spectrum data for the focused plasma in the diode chamber on the argon pressure of 330 mTorr. The Ar I and Ar II emission line are observed. The electron temperature and ion density have been measured by the Boltzmann plot and Saha equation from assumption of local thermodynamic equilibrium (LTE) The Ar I and Ar II ion densities have been calculated to be $\sim10^{15}/cc\;and\;~10^{13}/cc$, respectively, from Saha equation.

Formation of MOCVD TiN from a New Precursor (새로운 증착원으로 형성된 MOCVD TiN에 관한 연구)

  • Choe, Jeong-Hwan;Lee, Jae-Gap;Kim, Ji-Yong;Lee, Eun-Gu;Hong, Hae-Nam;Sin, Hyeon-Guk
    • Korean Journal of Materials Research
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    • v.9 no.3
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    • pp.244-250
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    • 1999
  • MOCVD TiN films were prepared from a new TiN precursor, tetrakis(etylmethylamino)titanium (TEMAT) and ammonia. Deposition of TiN films from a single precursor, TEMA T yielded the growth rates of $70 to 1050\AA$/min, depending on the deposition temperature. Furthermore, the excellent bottom coverage of -90% over $0.35\mu\textrm{m}$ contacts was obtained at $275^{\circ}C$. The addition of ammonia to TEMA T lowered the resistivity of as- deposited TiN film to ~ $800\mu\omega-cm$ from $3500~6000\mu\omega-cm$ and improved the stability of TiN film in air. Examination of the films by Auger electron spectroscopy(AES) showed that the oxygen and carbon contents decreased with the addition of ammonia. However, increasing ammonia flow rate decreased the bottom coverage of TiN films over $0.5\mu\textrm{m}$ contacts, probably due to the high sticking coefficient of intermediate species produced from the gas phase reaction of TEMA T and ammonia. Based on the byproduct gases detected by the quadrupole mass spectrometer (QMS), the transammination reaction was proposed to be responsible for TiN deposition. In addition, XPS analysis revealed that the carbon in the films made from TEMA T and ammonia was metallic carbon, suggesting that $\beta$-hydrogen activation process occurs competitively with the transammination reaction.

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Thermal Stability of $\textrm{Fe}_{80-x}\textrm{P}_{10}\textrm{C}_{6}\textrm{B}_{4}\textrm{M}_{x}$(M=Transition Metal) Amorphous Alloys ($\textrm{Fe}_{80-x}\textrm{P}_{10}\textrm{C}_{6}\textrm{B}_{4}\textrm{M}_{x}$(M=Transition Metal) 비정질합금의 열적안정성)

  • Guk, Jin-Seon;Jeon, U-Yong;Jin, Yeong-Cheol;Kim, Sang-Hyeop
    • Korean Journal of Materials Research
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    • v.7 no.3
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    • pp.218-223
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    • 1997
  • At the aim of finding a Fehased amorphous alloy with a wide supercooled liquid region (${\Delta}T_{x}=T_{x}-T_{g}$) before crystallization, the changes in glass transition temperatudfI$T_{g}$ and crystallization temperature ($T_{x}$) by the dissolution of additional M elements were examined for the $Fe_{80}P_{10}C_{6}B_{4}$(x~6at%. M= transition metals) amorphous alloys. The ${\Delta}T_{x}$ value is 27K for the Fe,,,P,,,C,,R, alloy and increases to 40K for the addition of M=4at%Hf, 4at%Ta or 4at%Mo. The increase in ${\Delta}T_{x}$ is due to the increase of $T_{x}$ exceeding the degree in the increase in $T_{g}$. The $T_{g}$ and $T_{x}$ increase with decreasing electron concentration (e/a) from about 7 38 to 7.05. The decrease of e/a also implies the increase in the attractive bonding state between the M elements and other constitutent elements. It is therefore said that $T_{g}$ and $T_{x}$ increase kith increasing attractive bonding force.

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Effect of Precipitator and Quantity on the Formation of Fe3(PO4)2 (Fe3(PO4)2 생성에 미치는 침전제와 첨가량의 영향)

  • An, Suk-Jin;Lee, Sun-Young;Oh, Kyoung-Hwan;Suhr, Dong-Soo
    • Korean Journal of Materials Research
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    • v.21 no.11
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    • pp.587-591
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    • 2011
  • The effect of the precipitator (NaOH, $NH_4OH$) and the amount of the precipitator (150, 200, 250, 300 ml) on the formation of $Fe_3(PO_4)_2$, which is the precursor used for cathode material $LiFePO_4$ in Li-ion rechargeable batteries was investigated by the co-precipitation method. A pure precursor of olivine $LiFePO_4$ was successfully prepared with coprecipitation from an aqueous solution containing trivalent iron ions. The acid solution was prepared by mixing 150 ml $FeSO_4$(1M) and 100 ml $H_3PO_4$(1M). The concentration of the NaOH and $NH_4OH$ solution was 1 M. The reaction temperature (25$^{\circ}C$) and reaction time (30 min) were fixed. Nitrogen gas (500 ml/min) was flowed during the reaction to prevent oxidation of $Fe^{2+}$. Single phase $Fe_3(PO_4)_2$ was formed when 150, 200, 250 and 300 ml NaOH solutions were added and 150, 200 ml $NH_4OH$ solutions were added. However, $Fe_3(PO_4)_2$ and $NH_4FePO_4$ were formed when 250 and 300 ml $NH_4OH$ was added. The morphology of the $Fe_3(PO_4)_2$ changed according to the pH. Plate-like lenticular shaped $Fe_3(PO_4)_2$ formed in the acidic solution below pH 5 and plate-like rhombus shaped $Fe_3(PO_4)_2$ formed around pH 9. For the $NH_4OH$, the pH value after 30 min reaction was higher with the same amount of additions of NaOH and $NH_4OH$. It is believed that the formation mechanism of $Fe_3(PO_4)_2$ is quite different between NaOH and $NH_4OH$. Further investigation on this mechanism is needed. The prepared samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and the pH value was measured by pH-Meter.

Growth of Epitaxial AlN Thin Films on Sapphire Substrates by Plasma-Assisted Molecular Beam Epitaxy (플라즈마분자선에피탁시법을 이용한 사파이어 기판 위 질화알루미늄 박막의 에피탁시 성장)

  • Lee, Hyo-Sung;Han, Seok-Kyu;Lim, Dong-Seok;Shin, Eun-Jung;Lim, Se-Hwan;Hong, Soon-Ku;Jeong, Myoung-Ho;Lee, Jeong-Yong;Yao, Takafumi
    • Korean Journal of Materials Research
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    • v.21 no.11
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    • pp.634-638
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    • 2011
  • We report growth of epitaxial AlN thin films on c-plane sapphire substrates by plasma-assisted molecular beam epitaxy. To achieve two-dimensional growth the substrates were nitrided by nitrogen plasma prior to the AlN growth, which resulted in the formation of a two-dimensional single crystalline AlN layer. The formation of the two-dimensional AlN layer by the nitridation process was confirmed by the observation of streaky reflection high energy electron diffraction (RHEED) patterns. The growth of AlN thin films was performed on the nitrided AlN layer by changing the Al beam flux with the fixed nitrogen flux at 860$^{\circ}C$. The growth mode of AlN films was also affected by the beam flux. By increasing the Al beam flux, two-dimensional growth of AlN films was favored, and a very flat surface with a root mean square roughness of 0.196 nm (for the 2 ${\mu}m$ ${\times}$ 2 ${\mu}m$ area) was obtained. Interestingly, additional diffraction lines were observed for the two-dimensionally grown AlN films, which were probably caused by the Al adlayer, which was similar to a report of Ga adlayer in the two-dimensional growth of GaN. Al droplets were observed in the sample grown with a higher Al beam flux after cooling to room temperature, which resulted from the excessive Al flux.