• Kyungpook Mathematical Journal
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• v.48 no.1
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• pp.15-24
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• 2008

Let $N{\geq}1$ and p > 1. Let ${\Omega}$ be a domain of $\mathbb{R}^N$. In this article we shall establish Kato's inequalities for quasilinear degenerate elliptic operators of the form $A_pu$ = divA(x,$\nabla$u) for $u{\in}K_p({\Omega})$, ), where $K_p({\Omega})$ is an admissible class and $A(x,\xi)\;:\;{\Omega}{\times}\mathbb{R}^N{\rightarrow}\mathbb{R}^N$ is a mapping satisfying some structural conditions. If p = 2 for example, then we have $K_2({\Omega})\;= \;\{u\;{\in}\;L_{loc}^1({\Omega})\;:\;\partial_ju,\;\partial_{j,k}^2u\;{\in}\;L_{loc}^1({\Omega})\;for\;j,k\;=\;1,2,{\cdots},N\}$. Then we shall prove that $A_p{\mid}u{\mid}\;\geq$ (sgn u) $A_pu$ and $A_pu^+\;\geq\;(sgn^+u)^{p-1}\;A_pu$ in D'(${\Omega}$) with $u\;\in\;K_p({\Omega})$. These inequalities are called Kato's inequalities provided that p = 2. The class of operators $A_p$ contains the so-called p-harmonic operators $L_p\;=\;div(\mid{{\nabla}u{\mid}^{p-2}{\nabla}u)$ for $A(x,\xi)={\mid}\xi{\mid}^{p-2}\xi$.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.28A no.1
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• pp.30-39
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• 1991

The influence of physical parameters (Al mole fraction, thickness, doping concentration) in the window and emitter on the efficiency characteristics of heteroface p-$Al_{x}Ga_{1-x}As/p-GaAs/n-GaAs/n^{+}$-GaAs solar cell is investigated. The maximum efficiency theoretically calculated in this device is obtained when a thickness of the window is in a range of (400-1000))$\AA$and a thickness/doping concentration of the emitter is in a range of (0.5-0.8)$\mu$m/(1-7)${\times}10^{17}cm^{-3}$, respectively. Also is the efficiency improved according to the increase of Al mole fraction in the indirect gap window(0.41${\le}x{\le}1.0$). The optimum designed heteroface cell with an area of 0.165cm$^2$fabricated using MOCVD exhibits an active area conversion efficiency of 17%, having a short circuit current density of 21.2mA/cm\ulcorner an open circuit voltage of 0.94V, and a fill factor of 0.75 under ELH-100mW/cm$^2$illumination.

• Bulletin of the Korean Mathematical Society
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• v.46 no.2
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• pp.311-319
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• 2009

Let H be a Hilbert space which is the direct sum of five closed subspaces $X_0,\;X_1,\;X_2,\;X_3$ and $X_4$ with $X_1,\;X_2,\;X_3$ of finite dimension. Let J be a $C^{1,1}$ functional defined on H with J(0) = 0. We show the existence of at least four nontrivial critical points when the sublevels of J (the torus with three holes and sphere) link and the functional J satisfies sup-inf variational inequality on the linking subspaces, and the functional J satisfies $(P.S.)^*_c$ condition and $f|X_0{\otimes}X_4$ has no critical point with level c. For the proof of main theorem we use the nonsmooth version of the classical deformation lemma and the limit relative category theory.

• Journal of the Korean Vacuum Society
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• v.9 no.4
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• pp.353-359
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• 2000

$(Bi_{0.15}Sb_{0.85})_2Te_3$ and $(Bi_{1-x}Sb_x)_2Te_3$ thermoelectric thin films were prepared by magnetron sputtering process, and their thermoelectric characteristics were investigated with variation of the sputtering condition and the $Sb_2Te_3$ content. The $(Bi_{0.15}Sb_{0.85})_2Te_3$ film, deposited by DC sputtering at $300^{\circ}C$ with rotating the Corning glass substrate at 10 rpm, was fully crystallized to $(Bi,Sb)_2Te_3$ phase with c-axis preferred orientation. This $(Bi_{0.15}Sb_{0.85})_2Te_3$ film exhibited the Seebeck coefficient of 185 $\mu$V/K which was higher than the values of other $(Bi_{0.15}Sb_{0.85})_2Te_3$ films fabricated with different sputtering conditions. With increasing the $Sb_2Te_3$ content, the Seebeck coefficient and electrical resistivity of p-type $(Bi_{1-x}Sb_x)_2Te_3$ (0.77$\leq$x$\leq$1.0) film were lowered. Among p-type $(Bi_{1-x}Sb_x)_2Te_3$ films, a maximum power factor of $0.79{\times}10^{-3}W/K^2-m$ was obtained at (Bi_{0.05}Sb_{0.95})_2Te_3$ composition..

• Journal of the Korean Vacuum Society
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• v.15 no.5
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• pp.527-533
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• 2006

Spinel $LiNi_xMn_{2-x}O_4$ thin films were synthesized up to x = 0.9 by a sol-gel method employing spin-coating. The Ni-substituted films were found to maintain cubic structure at low x but to exhibit tetragonal structure for $x{\geq}0.6$. Such cubic-tetragonal phase transition indicates that $Ni^{3+}(d7)$ ions with low-spin $(t_{2g}^6,e_g^1)$ state occupy the octahedral sites of the compound, thus being subject to the Jahn-Teller distortion. By x-ray photoelectron spectroscopy both $Ni^{2+}$ and $Ni^{3+}$ ions were detected. Optical properties of the $LiNi_xMn_{2-x}O_4$ films were investigated by spectroscopic ellipsometry (SE) in the visible?ultraviolet range. The measured dielectric function spectra by SE mainly consist of broad absorption structures attributed to charge-transfer (CT) transitions, $O^{2-}(2p){\rightarrow}Mn^{4+}(3d)$ for 1.9 $(t_{2g})$ and $2.8{\sim}3.0$ eV $(e_g)$ structures and $O^{2-}(2p){\rightarrow}Mn^{3+}(3d)$ for 2.3 $(t_{2g})$ and $3.4{\sim}3.6$ eV $(e_g)$ structures. Also, sharp absorption structures were observed at about 1.6, 1.7, and 1.9 eV, interpreted as due to d-d crystal-field transitions within the octahedral $Mn^{3+}$ ion. The strengths of these absorption structures are reduced by the Ni substitution. Rapid reduction of the CT transition strength involving the eg states for x = 0.6 is attributed to the reduced wavefunction overlap between the $e_g$ and the $O^{2-}(2p)$ states due to the tetragonal extension of the lattice constant by the Jahn-Teller effect.

• Applied Microscopy
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• v.42 no.1
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• pp.27-33
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• 2012

Transient receptor potential ankyrin 1 (TRPA1), responding to noxious cold (${\leq}17^{\circ}C$) and pungent compounds, is implicated in nociception, but little is known about the coexpression of TRPA1 and other channels or receptors involved in the nociception in craniofacial regions. To address this issue, we characterized the TRPA1-immunopositive (+) neurons in the rat trigeminal ganglion (TG) and investigated their colocalization with other proteins known to be expressed in nociceptive neurons, such as transient receptor potential vanilloid (TRPV1) and $P2X_3$ receptor, using light microscopic immunofluorescence labeling method with TRPA1 and TRPV1 or $P2X_3$ antisera. The majority of TRPA1+ neurons costained for TRPV1 (TRPV1+/TRPA1+; 58.8%, 328/558) and 41.2% only expressed TRPA1 but not TRPV1. The TRPV1+/TRPA1+ neurons were small and medium sized. In addition, we investigated the colocalization of TRPA1 with $P2X_3$, a nonselective cation channel activated by ATP that may be released in the extracellular space as a result of tissue damage and inflammation. Among all TRPA1+ TG neurons, 26.1% (310/1186) costained for $P2X_3$, whereas 73.9% (876/1186) of TRPA1+ neurons did not coexpress $P2X_3$. $P2X_3$+/TRPA1+ neurons were predominantly small and medium sized. These results suggest that TRPA1+ neurons coexpressing TRPV1 or $P2X_3$ are involved in specific roles in the transmission and processing of orofacial nociceptive information by noxious cold, heat, and inflammation.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.1 no.2
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• pp.33-40
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• 2000

The present invention relates to a absorption rotor for removed VOC(volatile organic compound) and humidity in semiconductor clean room system. A absorption rotor medium is made by NaX zeolite and TS-1 zeolite formed on a honeycomb matrix of ceramic papers. The crystallization of NaX zeolite was hydrothermal reaction, and NaX zeolite crystals of a uniform particle size of 5$\mu$m were synthesized that NaX zeolite seed crystals (2~3$\mu$m) added in a batch composition at levels of 3~15 wt$\%$. The seeding resulted in an increase in the fraction of large crystals compared with unseeded batches and successfully led to a uniform NaX zeolite crystal. The microporous zeolite-type titanosilicate(TS-1) was synthesized by different of the reactant solution pH. The pH range of reactant solution has been changed from 10.0 to 11.5 TS-1 zeolite (ETS-10), having a large pore(8~10 $\AA$), was synthesized at 10.4 of pH, since TS-1 zeolite (ETS-4), having a small pore(3~5$\AA$), was synthesized at 11.5 of pH.

• Journal of the Korean Ceramic Society
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• v.36 no.1
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• pp.50-54
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• 1999

We have measured the x-ray photoemission spectroscopy of cation deficient La0.970Mn0.970O3 as a function of temperature. Detailed results on the chemical shifts and changes in Mn 2p and Lp 3d core levels due to variation of temperature have been obtained. The Mn 2p 3/2 and 1/2 main peaks and La 3d core spectrum shift to lower binding energy levels with increasing temperature. This XPS behavior is correlated with the strength of localization of Mn3+. The Jahn-Teller effect due to Mn3+ besides the conventional random potential effects is likely to localize charge carriers in La-.970Mn0.970O3.

• Proceedings of the KIEE Conference
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• 1988.11a
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• pp.168-171
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• 1988

The p-n homo junction diode of the III-V ternary alloy semiconductor $In_{1-x}Ga_xP$ : S grown by the temperature gradient solution (TGS) was fabricated by Zn-diffusion, and it's characteristics was investigated. The carrier concentration of $In_{1-x}Ga_xP$ doped with sulfur, 0.5 mol %, was $1{\times}10^{17}cm^{-3}$ and the mobility was varied with the composition. In the case that the diffusion time was constant as 30 minutes. The temperature dependence of diffusion coefficient was decreased from D= $4.2{\times}10^{-5}$ exp (-1.74/$k_{B}T$) to D= $2.5{\times}10^{-5}$ exp (-3.272/$k_{B}T$) with increasing of composition $\times$ from 0.43 to 0.98. The major peak of E.L spectrum was due to D-A pair recombination and the peak intensity was increased with the increasing of input current. And the E.L intensity was decreased with the increasing temperature, and shift to the long wavelength. The luminescence efficiencies measured at $5^{\circ}C$, atmosphere temperature, was decreased from $2.6{\times}10^{-4}$% to $9.49{\times}10^{-6}$ % with increasing of composition it from 0.39, direct transition region, to 0.98, indirect transition region.

• Journal of applied mathematics & informatics
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• v.30 no.1_2
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• pp.15-26
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• 2012

Some oscillation results are presented for the second-order neutral dynamic equation of mixed type on a time scale unbounded above $$\(r(t)[x(t)+p_1(t)x(t-{\tau}_1)+p_2(t)x(t+{\tau}_2)]^{\Delta}\)^{\Delta}+q_1(t)x(t-{\tau}_3)+q_2(t)x(t+{\tau}_4)=0.$$ These criteria can be applied when $\mathbb{T}=\mathbb{R}$, $\mathbb{T}=h{\mathbb{Z}}$ and $\mathbb{T}=\mathbb{P}_{a,b}$. Two examples are also provided to illustrate the main results.