• Journal of Sensor Science and Technology
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• v.14 no.4
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• pp.258-264
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• 2005

Li+-ion conducting ($Li_{3}PO_{4}$) thin films with thickness of $0.3{\mu}m$, $0.65{\mu}$, $1.2{\mu}$ were deposited on $Al_{2}O_{3}$ substrate at room temperature by thermal evaporation. They were sintered at $700^{\circ}C$ and $800^{\circ}C$ for 2 hours, respectively. Reference electrode and sensing electrode were printed on Au-electrode by silk printing method. The EMF and the ${\Delta}EMF$/dec were increased with increasing the electrolyte thickness and sintering temperature. The sample sintered at $800^{\circ}C$ was shown a good response and recovery characteristics more than those sintered at $700^{\circ}C$. The Nernst's slop of 75 mV per decade was obtained at operating temperature of $500^{\circ}C$.

• Bulletin of the Korean Chemical Society
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• v.14 no.1
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• pp.101-107
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• 1993

Ab initio calculations are carried out at the 6-311G$^{**}$ level for the $C_{2v}$ interactions of Be and Li atoms with acetylene molecule. The main contribution to the deep minima on the $^3B_2\;BeC_2H_2\;and\;^2B_2 LiC_2H_2$ potential energy curves is the b_2\;(2p(3b_2)-l{\pi}_g^*(4b_2))$ interaction, the $a_1\;(2s(6a_1)-I{\pi}_u(5a_1))$ interaction playing a relatively minor role. The exo deflection of the C-H bonds is basically favored, as in the $b_2$ interaction, due to steric crowding between the metal and H atoms, but the strong in-phase orbital interaction, or mixing, of the $a_1$ symmetry hydrogen orbital with the $5a'_1,\;6a'_1,\;and\;7a'_1$ orbitals can cause a small endo deflection in the repulsive complexes. The Be complex is more stable than the Li complex due to the double occupancy of the 2s orbital in Be. The stability and structure of the $MC_2H_2$ complexes are in general determined by the occupancy of the singly occupied frontier orbitals.

• Korean Journal of Optics and Photonics
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• v.14 no.6
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• pp.657-662
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• 2003

Optimum Hamming apodized acousto-optic 2${\times}$2 add/drop multiplexers, using SiO$_2$ film loaded acoustic waveguide with angular offset to the Ti:LiNbO$_3$ waveguide, were fabricated. The four-port device consists of two input waveguides, a polarization beam splitter (PBS), two polarization conversion/acoustooptic tuning waveguide sections, a second PBS and two output waveguides. Insertion loss <7.1 ㏈ has been obtained and side-lobe of -19 ㏈ for -32 ㎽ RF driving power has been realized. Add/drop performance has been confirmed and a linear tuning rate of 8.1 nm/MHz and a 3 ㏈ spectral width of -1.5 nm were demonstrated.

• IEMEK Journal of Embedded Systems and Applications
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• v.14 no.1
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• pp.1-9
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• 2019

In this paper, we propose a method of generating a 2D gray image from LiDAR 3D reflection intensity. The proposed method uses the Fully Convolutional Network (FCN) to generate the gray image from 2D reflection intensity which is projected from LiDAR 3D intensity. Both encoder and decoder of FCN are configured with several convolution blocks in the symmetric fashion. Each convolution block consists of a convolution layer with $3{\times}3$ filter, batch normalization layer and activation function. The performance of the proposed method architecture is empirically evaluated by varying depths of convolution blocks. The well-known KITTI data set for various scenarios is used for training and performance evaluation. The simulation results show that the proposed method produces the improvements of 8.56 dB in peak signal-to-noise ratio and 0.33 in structural similarity index measure compared with conventional interpolation methods such as inverse distance weighted and nearest neighbor. The proposed method can be possibly used as an assistance tool in the night-time driving system for autonomous vehicles.

• Journal of Wind Energy
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• v.14 no.4
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• pp.87-97
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• 2023

Due to the limitations of onshore wind power, the wind power industry is currently transitioning to offshore wind power. There has been active research on the development of a floating LiDAR system (FLS) that is easy to install at a low cost. The Carbon Trust published a commercialization roadmap for FLS in 2013, and an updated version was released in 2018, taking into account industry experience. The roadmap divides the development maturity of FLS into three stages: Stage 1 (prototype), Stage 2 (pre-commercialization), and Stage 3 (commercialization), each of which requires availability and accuracy assessment. The results must meet the requirements of the Key Performance Index (KPI) for each stage. Therefore, when developing FLS, the motion compensation algorithm of the FLS is essential because the LiDAR can produce incorrect measurements of wind speed and direction due to the six degrees of freedom in motion. In this study, we implemented the FLS motion compensation algorithm developed by Nassif, F.B. et al. and validated it using data provided by Fraunhofer. In conclusion, the results showed that the determination coefficients of wind speed and wind direction were improved compared to those obtained from the met mast.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.24 no.1
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• pp.16-22
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• 2012

Experimental investigations were carried out to examine the heat and mass transfer characteristics of LiCl aqueous solution for a plate heat exchanger type dehumidifier. Cooling dehumidification was adopted vertical type heat exchanger. Also non woven fabric is attached surface of the heat exchanger for spreadability of LiCl aqueous solution. Mass flow-rate of LiCl aqueous solution and concentration were selected as experimental conditions. Also, In this study, the effects of relative humidity of process air and velocity were investigated experimentally. As a result of heat transfer coefficient and mass transfer coefficient of were increased film reynolds number increased. heat transfer coefficient and mass transfer coefficient of LiCl aqueous solution were 0.14~0.24 kW/$m2^{\circ}C$ and $1.3{\times}10-63{\sim}6.2{\times}10-6$ m/s respectively.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07b
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• pp.541-544
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• 2002

In this study, a new LTCC material using $ZnWO_4$-LiF system was attempted with respect to use as a capacitor layer in Front-End Module. Pure $ZnWO_4$ must be sintered above $1050^{\circ}C$ in order to obtain up to 98% of full density. It's measured dielectric constant, quality factor, and temperature coefficient of resonant frequency were 15.5, 74380GHz, and $-70ppm/^{\circ}C$, respectively. LiF addition resulted in an liquid phase formation at $810^{\circ}C$ due to interaction between $ZnWO_4$ and LiF. Therefore $ZnWO_4$ with 0.5~1.5wt% LiF could be densified at $850^{\circ}C$. Addition of LiF slightly lowered the dielectric constant from 15.5 to 14.2~15. In the given LiF addition range, the sintering shrinkage increased with increasing LiF content. $Q{\times}fo$ value, however, decreased with increasing LiF content(or increasing densification). This is originated from the interaction between the liquid phase and $ZnWO_4$ and inhomogeneity of grain morphology.

• Journal of the Korean Ceramic Society
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• v.35 no.5
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• pp.451-457
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• 1998

$Li_2$$ZrO_3$ powder which is one of the candidates of breeding materials for the fusion reactor was syn-thesized by a precipitation-combustion process. Although precipitates from the reaction between zirconium nitrate and citric acid were existed in a precursor solution. $Li_2$$ZrO_3$ could easily be obtained by using the mixed fuel of urea and citric acid in stoichiometric composition. The phases of as-synthesized powder con-sisted of $Li_2$$ZrO_3$ and small amounts of $Li_6$$Zr_2O_3$ and $Li_2$$ZrO_3$ The latter phases disappeared after the cal-cination at $1100^{\circ}C$ for 2 h. The primary particle size and the specific surface area of as-synthesized powders were smaller than 20nm and 10-14 $M^2$/g, respectively. The primary particle size of the precipitation-combustion synthesized powders was affected by the size of precipitates present in a precursor solution.

• Progress in Superconductivity
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• v.14 no.1
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• pp.11-16
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• 2012

Based on fully self-consistent dynamical mean field theory (DMFT) method, we investigate electronic structure and Fermi surface nesting property of LiFeAs and NaFeAs, focusing on the correlation effect of iron 3d orbital. For LiFeAs, good nesting property by density functional theory (DFT) method is much suppressed by DFT+DMFT method due to the orbital-dependent renormalization magnitude. NaFeAs shows a similar behavior, but a better nesting is obtained than LiFeAs from DFT+DMFT Fermi surfaces. Our result is consistent with the observed superconducting (spin density wave) ground state of LiFeAs (NaFeAs).

• Resources Recycling
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• v.32 no.1
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• pp.42-49
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• 2023

The glass ceramic secondary resource containing Li-Al-Si is used in inductor, fireproof glass, and transparent cookware and accounts for 14% of the total consumption of Li, which is the second most widely used after Li-ion batteries. Therefore, new Li resources should be explored when the demand for Li is exploding, and extensive research on Li recovery is needed. Herein, we recovered Li from fireproof Li-Al-Si glass ceramic, which is a new secondary resource containing Li. The fireproof glass among all Li-Al-Si glass ceramics was used as raw material that contained 1.5% Li, 9.4% Al, and 28.9% Si. The process for recovering Li from the fireproof glass was divided into two parts: (1) calcium salt roasting and (2) water leaching. In calcium salt roasting, a sample of fireproof glass was crushed and ground below 325 mesh. The leaching efficiency was compared based on the presence or absence of heat treatment of the fireproof glass. Moreover, the leaching rates based on the input ratios of calcium salt, Li-Al-Si glass, and ceramics and the leaching process based on calcium salt roasting temperatures were compared. In water leaching, the leaching and recovery rates of Li based on different temperatures, times, solid-liquid ratios, and number of continuous leaching stages were compared. The results revealed that fireproof glass ceramics containing Li-Al-Si should be heat treated to change phase to beta-type spodumene. CaCO₃ salt should be added at a ratio of 6:1 with glass ceramics containing Li-Al-Si, and then leached 4 times or more to achieve a recovery efficiency of Li over 98% from a solution containing 200 mg/L of Li.