• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.3
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• pp.576-581
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• 2005

In this paper. the a-Si:H TFT using ferroelectric of $SrTiO_3$ as a gate insulator is fabricated on glass. High k gate dielectric is required for on-current, threshold voltage and breakdown characteristics of TFT Dielectric characteristics of ferroelectric are superior to $SiO_2$ and $Si_3N_4$. Ferroelectric increases on-current and decreases threshold voltage of TFT and also ran improve breakdown characteristics.$SrTiO_4$ thin film is deposited by e-beam evaporation. Deposited films are annealed for 1 hour in N2 ambient at $150^{\circ}C\~600^{\circ}C$. Dielectric constant of ferroelectric is about 60-100 and breakdown field is about IMV/cm. In this paper, the TFT using ferroelectric consisted of double layer gate insulator to minimize the leakage current. a-SiN:H, a-Si:H (n-type a-Si:H) are deposited onto $SrTiO_3$ film to make MFNS(Metal/ferroelectric/a-SiN:H/a-Si:H) by PECVD. In this paper, TFR using ferroelectric has channel length of$8~20{\mu}m$ and channel width of $80~200{\mu}m$. And it shows that drain current is $3.4{\mu}A$at 20 gate voltage, $I_{on}/I_{off}$ is a ratio of $10^5\~10^8,\;and\;V_{th}$ is$4\~5\;volts$, respectively. In the case of TFT without having ferroelectric, it indicates that the drain current is $1.5{\mu}A$ at 20gate voltage and $V_{th}$ is $5\~6$ volts. If properties of the ferroelectric thin film are improved, the performance of TFT using this ferroelectric thin film can be advanced.

• Journal of Sensor Science and Technology
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• v.1 no.1
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• pp.5-12
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• 1992

We have fabricated a-Si:H multilayer for contact-type linear image sensor by means of RF glow discharge decomposition method. The ITO/i-a-Si:H/Al structure has relatively high dark current due to indium diffusion and carrier injection from both electrodes, resulting in low photocurrent to dark current. To suppress the dark current and to enhance interface electric field between ITO and i-a-Si:H film we have fabricated ITO/insulator/i-a-S:H/p-a-S:H/Al multilayer film with blocking structure. The photocurrent of ITO/$SiO_{2}(300{\AA})$/i-a-Si:H/p-a-Si:H($1500{\AA}$)/Al multilayer sensor with 5V bias voltage became saturated at about 20nA under $20{\mu}W/cm^{2}$ light intensity, while the dark current was less than 0.1nA. To increase the light generation efficiency we have adopted ITO/$SiO_{x}N_{y}(300{\AA})$/i-a-Si:H/p-a-Si:H($1500{\AA}$)/Al structure, showing photocurrent of 30nA and dark current of 0.08nA with 5V bias voltage. Also the spectral photosensitivity of the multilayer was enhanced for short wavelength visible region of 560nm, compared with that of the a-Si:H monolayer of 630nm. And its photoresponse time was about 0.3msec with the film homogeneity of 5% deviation.

• Journal of Life Science
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• v.9 no.3
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• pp.289-292
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• 1999

This study was performed to monitor the circulation of various influenza virus strains since influenza is one of the commonest respiratory disease in man, its causative virus has been the subjects of extensive research. The authors investigated the epidemics of influenza in Pusan in 1998. Influenza viruses have been isolated from patients with respiratory disease whose ages range from 1 to 68. Virus isolation from female was higher than male. The isolation of virus was mostly concentrated in December in 1998. The isolated virus showed strong cytopathic effect on MDCK cells and identified as influenza A/Sydney/05/97-like(H3N2) and influenza A/Beijing/262/95-like(H1N1). A negative staining of electron micrograph showed 130 nm with H1N1 in diameter, respectively.

• Journal of the Korean Mathematical Society
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• v.38 no.3
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• pp.595-611
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• 2001

Let Q(n,1) be the set of even unimodular positive definite integral quadratic forms in n-variables. Then n is divisible by 8. For A[X] in Q(n,1), the theta series $\theta$(sub)A(z) = ∑(sub)X∈Z(sup)n e(sup)$\pi$izA[X] (Z∈h (※Equations, See Full-text) the complex upper half plane) is a modular form of weight n/2 for the congruence group Γ$_1$(8) = {$\delta$∈SL$_2$(Z)│$\delta$≡()mod 8} (※Equation, See Full-text). If n$\geq$24 and A[X], B{X} are tow quadratic forms in Q(n,1), the quotient $\theta$(sub)A(z)/$\theta$(sub)B(z) is a modular function for Γ$_1$(8). Since we identify the field of modular functions for Γ$_1$(8) with the function field K(X$_1$(8)) of the modular curve X$_1$(8) = Γ$_1$(8)＼h(sup)* (h(sup)* the extended plane of h) with genus 0, we can express it as a rational function of j(sub) 1,8 over C which is a field generator of K(X$_1$(8)) and defined by j(sub)1,8(z) = $\theta$$_3$(2z)/$\theta$$_3$(4z). Here, $\theta$$_3$ is the classical Jacobi theta series.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.3
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• pp.286-291
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• 2006

We studied possibility of mixing treatment of livestock wastewater and sewage using Phanerochaete chrysosporium PSBL-1. Our study showed that 97.6% of SS and 95% of T-P removal efficiency was achieved when 2 mL BF02(a coagulant) and 100 mL C-210EL(a cationic polymer) were added to the mixture(2:1, v/v) of livestock wastewater and sewage. We studied treatment characteristic of Phanerochaete chrysosporium PSBL-1, after were mixed pretreated wastewater and sewage by dillution ten times about livestock wastewater. The removal efficiency of NBDCOD(non-biodegradable COD), $NH_3-N$ and T-N was increased according to increase of pH. That is, T-N concentration of effluent was satisfied 60 mg/L by drain water waterqulity standard of livestock wastewater public treatment facilities with 35 mg/L from a lapse of five days at pH 6.7, 51 mg/L from a lapse of three days at pH 8 and 33 mg/L from a lapse of one day at pH 10. Moreover $COD_{Mn}$ concentration of effluent was satisfied 40 mg/L by drain water waterqulity standard of livestock wastewater public treatment facilities after a laps of one day at all pH. Organics and nitrogen concentrations of effluent were higher case with addition of V.A.(veratryl alcohol) than case without addition of V.A.(veratryl alcohol). $COD_{Mn}$ concentration of effluent satisfied drain water qulity standard of livestock wastewater public treatment facilities from a lapse of one day, when C/N rate(3:1) of influent was not controled. T-N satisfied that from a lapse of two days, when C/N rate was controled with $4{\sim}6$.

• Bulletin of the Korean Chemical Society
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• v.19 no.6
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• pp.671-676
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• 1998

The formation and dissociation rates of $Ce^{3+}$ Complexes of the 1,4,7,10-tetraaza-13,16-dioxacyclooctadecane-NN', N",N"'-tetraacetic acid (1), 1,4,7,10-tetraaza-13,16-dioxacyclooctadecane-N,N',N",N"'-tetramethylacetic acid (2), and 1,4,7,10-tetraaza-13,16-dioxacyclooctadecane-N,N',N",N"'-tetrapropionic acid (3) have been measured by the use of stopped-flow spectrophotometry. Observations were made at 25.0±0.1 ℃ and at an ionic strength of 0.10 M $NaClO_4$. The complexation of $Ce^{3+}$ ion with 1 and 2 proceeds through the formation of an intermediate complex $(CeH_3L^{2+})^*$ in which the $Ce^{3+}$ ion is incompletely coordinated. This may then lead to be a final product in the rate-determining step. Between pH 4.76 and 5.76, the diprotonated $(H_2L^{2-})$ from is revealed to be a kinetically active species despite of its low concentration. The stability constants $(logK(CeH_3L^{2+}))$ and specific water-assisted rate constants $(k_{OH})$ of intermediate complexes have been determined from the kinetic data. The dissociation reactions of $Ce^{3+}$ complexes of 1, 2, and 3 were investigated with $Cu^{2+}$, ions as a scavenger in acetate buffer. All complexes exhibit acid-independent and acid-catalyzed contributions. The effect of buffer and $Cu^{2+}$ concentration on the dissociation rate has also been investigated. The ligand effect on the dissociation rate of $Ce^{3+}$ complexes is discussed in terms of the side-pendant arms and the chelate ring sizes of the ligands.

• Journal of the Korean Chemical Society
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• v.33 no.3
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• pp.309-314
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• 1989

A kinetic study was carried out for the redox reaction of cis-$[Co(en)_2(N_3)_2]^+$ with Fe(II) in acidic solution by spectrophotometric methods. This redox reaction system have been found to show a third order for overall reaction as the respective first order with respect to reactant cis-$[Co(en)_2(N_3)_2]^+$, Fe(II), and $H^+$ catalyst. The activation parameters, ${\Delta}H^{\neq}$ and ${\Delta}S^{\neq}$, were obtained as 14.2Kcal/mol and -16.7 e.u., respectively. On the basis of the kinetic data, we suggest that the redox reaction system proceeds via inner sphere mechanism. The rate equation derived from the proposed mechanism is in agreement with the observed rate equation.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.32 no.4
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• pp.379-385
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• 1987

A field experiment was conducted to find out the effects of liming (soil pH) and sources of N on the chemical constituents of soil and leaf lamina of burley tobacco. Treatments consisted of liming (nonliming, liming to soil pH 5.5 and 6.5) as the main plot and N sources［compound fertilizer of containing 3.9% $NH_4-N$ and 6.1% $NH_2-N,\;NaNO_3,\;(NH_2)_2CO\;and\;(NH_4)_2SO_4$］as the sub-plot. The soil pH was high in $NaNO_2$ plot, while low in $(NH_4)_2SO_4$. But the differences of Ca concentration in top soil among N sources were not detected. The $NO_3-N$ concentration in top soil was high in high limed and $NaNO_3$ plot. The $NO_3-N$ content of leaf (lamina) at 75 days after transplanting was high in $NaNO_3$ plot and CaO con-tent of leaf at 45 days after transplanting was high in high limed plot. But neither liming nor N source had effect on the contents of total nitrogen, $P_2-O_{5}\;and\;K_2O$ of leaf during growing season. There was no significant differences in total alkaloid and total nitrogen contents of cured leaf (lamina) to liming and N source. But when the source of N was $NaNO_3$, the content of total alkaloid was increased by adding lime. When the source of N was $(NH_4$)_2SO_4$, the content of $K_2O$ in cured leaf was high while CaO was low. But neither liming nor N source had effect on the contents of $P_2-O_{5}$ and MgO in cured leaf.

• Journal of the Korean Magnetic Resonance Society
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• v.20 no.1
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• pp.1-6
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• 2016

The proton NMR line widths and spin-lattice relaxation rates, $T_1^{-1}$, of ferroelectric $LiH_3(SeO_3)_2$, $Li_2SO_4{\cdot}H_2O$, and $LiN_2H_5SO_4$ single crystals were measured as a function of temperature. The line width measurements reveal rigid lattice behavior of all the crystals at low temperatures and line narrowing due to molecular motion at higher temperatures. The temperature dependences of the proton $T_1^{-1}$ for these crystals exhibit maxima, which are attributed to the effects of molecular motion by the Bloembergen - Purcell - Pound theory. The activation energies for the molecular motions of $^1H$ in these crystals were obtained. From these analysis, $^1H$ in $LiH_3(SeO_3)_2$ undergoes molecular motion more easily than $^1H$ in $LiN_2H_5SO_4$ and $Li_2SO_4{\cdot}H_2O$ crystals.

• Bulletin of the Korean Chemical Society
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• v.29 no.10
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• pp.1905-1910
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• 2008

The reaction of 3,14-dimethyl-2,6,13,17-tetraazatetracyclo[16.4.0$0^{1.18}.0^{7.12}$]docosane ($L^1$) with formaldehyde in warm methanol yielded 3,14-dimethyl-2,6,13,17-tetraazatetracyclo[16.4.$1^{2.6}.0^{1.18}.0^{7.12}$]tricosane ($L^7$) containing one 1,3-diazacyclohexane subunit. In methanol, $L^7$ readily reacts with $Cu^{2+}$ ion to form [$CuL^7(H_2O)$]$^{2+}$ which is extremely inert against methanolysis. In the solution containing $Ni^{2+}$ ion, however, $L^7$ reacts with methanol to yield [$NiL^3$]$^{2+}$ ($L^3$ = 2-(methoxymethyl)-5,16-dimethyl-2,6,13,17-tetraazatricyclo[16.4.$0^{1.18}.0^{7.12}$]- docosane), in which one N-$CH_2OCH_3$ pendant arm is appended. The copper(II) complex [$CuL^7(H_2O)$]- $(ClO_4)_2{\cdot}3H_2O\;(I{\cdot}3H_2O)$ has a severely distorted trigonal bipyramidal coordination geometry with a 4-5- 6-5 chelate ring sequence. The crystal structure of [$NiL^3$]$(PF_6)_2{\cdot}2H_2O$ (IIb) shows that the N-$CH_2OCH_3$ pendant arm is not coordinated to the metal ion in the solid state. In various solvents (S), however, the nickel(II) complex exists as a mixture of [$NiL^3$(S)]$^{2+}$, in which the N-$CH_2OCH_3$ group as well as S is coordinated to the metal ion, and [$NiL^3$]^{2+}.