• 대한화학회지
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• 제6권1호
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• pp.77-83
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• 1962

The solubilities of hydrogen bromide and methyl bromide in nitrobenzene and in 1,2,4-trichlorobenzene have been measured in the presence and absence of gallium bromide. When gallium bromide does not exist in the system, the solubilities of HBr and MeBr in nitrobenzene are greater than in 1,2,4-trichlorobenzene, indicating the greater basicity of nitrobenzene than 1,2,4-trichlorobenzene. When there exists gallium bromide in the system, the addition compounds, GaBr3·HBr and GaBr3·CH3Br, have been found to exist in solution. The addition compound of GaBr3·HBr is stable in nitrobenzene but unstable in 1,2,4-trichlorobenzene. On the other hand the addition compound of $GaBr_3{\cdot}CH_3Br$ is unstable in both solvents. All of these unstable addition compounds dissociate into components to large extents according to one of the following equilibria or both: $$GaBr_3{\cdot}RBr{\leftrightarrows}GaBr_3+RBr\;GaBr_3{\cdot}RBr{\leftrightarrows}1}2\;Ga_2Br_6+RBr$.$ where R denotes either hydrogen atom or methyl group.

• 한국표면공학회지
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• 제32권2호
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• pp.83-92
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• 1999

GaN etching was performed using planar inductively coupled $Cl_2$-based plasmas and the effects of main process parameters on the characteristics of the plasmas and their relations to GaN etch rates were studied. Also, the GaN etch mechanism was investigated using a Langmuir probe and optical emission spectroscopy (OES) during the etching, and X-ray photoelectron spectroscopy (XPS) of the etched surfaces. The GaN etch rates increased with the increase of chlorine radical density and ion energy, and a vertical etch profile haying the etch rate close to 4000 $\AA$/min could be obtained. The addition of 10% Ar to $Cl_2$ gas increased the GaN etch rate and the addition of Ar (more than 20%) and HBr generally reduced the GaN etch rate. The GaN etch rate appeared to be more affected by the chemical reaction between Cl radicals and GaN compared to the physical sputtering itself under the sufficient ion bombardments to break GaN bonds.

• 한국축산식품학회지
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• 제34권6호
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• pp.808-814
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• 2014

This study investigated the effect of gum arabic (GA) combined with microbial transglutaminase (TG) on the functional properties of porcine myofibrillar protein (MP). As an indicator of functional property, heat-set gel and emulsion characteristics of MP treated with GA and/or TG were explored under varying NaCl concentrations (0.1-0.6 M). The GA improved thermal gelling ability of MP during thermal processing and after cooling, and concomitantly added TG assisted the formation of viscoelastic MP gel formation. Meanwhile, the addition of GA decreased cooking yield of MP gel at 0.6 M NaCl concentration, and the yield was further decreased by TG addition, mainly attributed by enhancement of protein-protein interactions. Emulsion characteristics indicated that GA had emulsifying ability and the addition of GA increased the emulsification activity index (EAI) of MP-stabilized emulsion. However, GA showed a negative effect on emulsion stability, particularly great drop in the emulsion stability index (ESI) was found in GA treatment at 0.6 M NaCl. Consequently, the results indicated that GA had a potential advantage to form a viscoelastic MP gel. For the practical aspect, the application of GA in meat processing had to be limited to the purposes of texture enhancer such as restructured products, but not low-salt products and emulsion-type meat products.

• 한국전기전자재료학회논문지
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• 제17권7호
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• pp.764-769
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• 2004

In order to reduce operating voltage of the GaN based blue-violet laser diodes, the effect of highly Mg doped GaN layer, which was grown below ohmic contact metals, on contact resistivity as well as operating voltage has been investigated. The addition of the highly Mg doped GaN layer greatly reduced contact resistivity of Pd/Pt/Au ohmic contacts from $5.2 \times {10}^-2 \Omegaㆍ$\textrm{cm}^2$ to 7.5 \times {10}^-4 \Omegaㆍ$\textrm{cm}^2$$. In addition, it also decreased device voltage at 20 mA by more than 3 V. Temperature- dependent sheet resistivity of the highly Mg doped GaN layer suggested that the reduction of the contact resistivity could be attributed to predominant current flow at the interface between the Pd/Pt/Au contacts and p-GaN through a deep level defect band, rather than the valence band.

• Journal of Magnetics
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• 제14권4호
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• pp.150-154
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• 2009

The effect of Ga and, Nb addition on the kinetics and mechanism of the disproportionation of a Nd-Fe-B alloy were investigated by isothermal thermopiezic analysis (TPA) using $Nd_{12.5}Fe_{(81.1-(x+y))}B_{6.4}Ga_xNb_y$ (x=0 and 0.3, y= 0 and 0.2) alloys. The addition of Ga and Nb retarded the disproportionation kinetics of the Nd-Fe-B alloy significantly, and increased the activation energy of the disproportionation reaction. The disproportionation kinetics of the $Nd_{12.5}Fe_{(81.1-(x+y))}B_{6.4}Ga_xNb_y$ alloys measured under an initial hydrogen pressure of 0.02 MPa were fitted to a parabolic rate law. This suggested that during the disproportionation of $Nd_{12.5}Fe_{(81.1-(x+y))}B_{6.4}Ga_xNb_y$ alloys with an initial hydrogen pressure of 0.02 MPa, a continuous disproportionation product is formed and the overall reaction rate is limited by the diffusion of hydrogen atoms (or ions).

• 한국전자파학회논문지
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• 제15권8호
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• pp.752-758
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• 2004

본 논문에서는 MBE로 성장한 AlGaN/InGaN/GaN 에피층으로 제작된 GaN HEMTs의 특성을 분석하였다. 게이트 전극 길이가 0.5 $\mu$m로 제작된 소자는 비교적 평탄한 전류 전달 특성을 나타내었으며 최대 전류 880 mA/mm, 최대 전달정수 156 mS/mm, 그리고 $f_{r}$와 $f_{MAX}$는 각각 17.3 GHz와 28.7 GHz가 측정되었다. 또한 표면 처리되지 않은 AlGaN/InGaN/HEMT의 경우 기존의 AlGaN/GaN HEMT와는 달리 펄스 전류 동작 상태에서 전류 와해 현상(current collapse)이 발생하지 않음이 확인되었다. 이 연구 결과는 InGaN를 채널층으로 사용할 경우 표면에 존재하는 트랩에 의한 전류 와해 현상이 발생하지 않는 고성능, 고출력의 GaN HEMT를 제작할 수 있음을 보여준다....

• 한국표면공학회지
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• 제37권4호
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• pp.191-195
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• 2004

Gallium or sulphur additions in $CuInSe_2$ were prepared using RF magnetron sputtering and pulsed laser deposition respectively. All of the observed thin films shows a chalcopyrite structure with the S and Ga addition increases the favourable (112) peak. The optical absorption coefficients were slightly decreased. The energy band gap of films could be shifted from 1.04 to 1.68 eV by adjusting the mole ratio of S/(S+Se) and Ga/(In+Ga). It is possible to obtain the optimum energy band gap by adding S or Ga solute at a certain ratio in favour of Se and In respectively. It is also necessary to control the ratio of Ga and S additions and to retain a certain portion of In and Se to provide better properties of thin films.

• 한국작물학회지
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• 제45권1호
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• pp.50-54
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• 2000

The elongation of mesocotyl and coleoptile plays important roles in the seedling emergence and stand establishment of dry direct-seeded rice. Experiments were carried out to elucidate the effects of seed-presoaking treatments of GA$_3$ and some inorganic salts on the mesocotyl, and coleoptile elongation of rice. Seed-soaked GA$_3$ promoted the elongation of mesocotyl, but little effect on the coleoptile elongation. The stimulation effects of GA$_3$ were found to be enhanced by addition of CaCl$_2$ However, the sole treatment of CaCl$_2$ showed no stimulating effect on the mesocotyl and coleoptile elongation. Mesocotyl elongation was most prominent in the combined treatments of 50ppm GA$_3$ with 100 mM CaCl$_2$. The synergistic effects of GA$_3$ and CaCl$_2$ on mesocotyl elongation varied with varietal groups. The stimulating effects of GA$_3$ were enhanced significantly by the addition of CaCl$_2$ in japonica varieties, Dongjinbyeo, Ilpumbyeo and Milyang 95, and tall indica variety, Labelle, but not in semidwarf Tongil type varieties, Tongilbyeo, Milyang 23, and Nampungbyeo, and semi-dwarf indica, Short Labelle. The promoting effects of GA$_3$ on the mesocotyl elongation were decreased in proportion to the lowered osmotic potential by PEG 6000 on the contrary to CaCl$_2$ This implies that the synergistic effects of CaCl$_2$ with GA$_3$ on mesocotyl elongation was not caused by osmotic potential lowered by CaCl$_2$ addition but by the salt itself. Salts such as Ca(NO$_3$)$_2$, MgCl$_2$ BaCl$_2$, NaCl, KCl and KNO$_3$ showed the synergistic effects with GA$_3$ on mesocotyl elongation as well. The degree of synergistic effects showed no differences among salts tested, implying that there is no specificity of ions constituting the salts.

• Journal of Korean Society for Atmospheric Environment
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• 제15권E호
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• pp.1-8
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• 1999

Catalytic performance for NOx removal by Ga-incorporated silicates(Ga-silicate; Gallosilicate) with MFI type synthesized by the rapid crystallization method was reported in this study. NOx removal was investigated under the condition of O2 excess(10%), with various hydrocarbons of low concentrations. Effect of H2O(2%) addition was also considered. The result showd that the conversion from NOx to N2 was enhanced on the Ga-silicate compared with the Al-silicate. Furthermore, the performance for NOx conversion on the Ga-silicate increased with addition of water.

• Journal of Magnetics
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• 제18권3호
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• pp.240-244
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• 2013

The influences of Gallium doping on the magnetic microstructures and corrosion behaviors of Nd-Fe-B-Ti-C alloys are investigated. The cooling rate for obtaining fully amorphous structure is raised, and the glassforming ability is improved by the Ga addition. The High Resolution Transmission Electron Microscopy image shows that the ${\alpha}$-Fe and $Fe_3B$ soft magnetic phases become granular surrounded by the $Nd_2Fe_{14}B$ hard magnetic phase. The rms and $({\Delta}{\varphi})_{rms}$ value of Nd-Fe-B-Ti-C nanocomposite alloy thick ribbons in the typical topographic and magnetic force images detected by Magnetic Force Microscopy(MFM) decreases with 0.5 at% Ga addition. The corrosion resistances of $Nd_9Fe_{73}B_{12.6}C_{1.4}Ti_{4-x}Ga_x$ (x = 0, 0.5, 1) alloys are enhanced by the Ga addition. It can be attributed to the formation of more amorphous phases in the Ga doped samples.