• Korean Journal of Clinical Laboratory Science
• /
• v.56 no.1
• /
• pp.43-51
• /
• 2024

[⁶⁸Ga]Ga-FAPI-04 is a promising radiopharmaceutical that binds specifically to fibroblast activation protein, which is overexpressed in more than 90% of malignant epithelial tumors but not in normal healthy tissue. This study aimed to develop an efficient method for producing ⁶⁸Ga-labelled FAPI-04 using a cassette-based automated synthesizer. [⁶⁸Ga]GaCl₃ was eluted from an Eckert & Ziegler Medical germanium-68/gallium-68 generator using 2.5 mL of 0.1 M HCl. The synthesis of the [⁶⁸Ga]Ga-FAPI-04 was performed using different concentrations of HEPES (1~2.5 M; 4-(2-hydroxyethyl) piperazine-1-ethanesulfonic acid) in 3~10 minutes; amounts of FAPI-04 precursor (5~50 ㎍) and reaction temperature (25℃~100℃) were optimized on the BIKBox^® synthesizer. The labeling efficiency of [⁶⁸Ga]Ga-FAPI-04 was greater than 96% (decay corrected) using 25 ㎍ FAPI-04 synthesized in 10 minutes at 100℃ in 2 M HEPES (pH 3.85), and its stability was greater than 99% at 6 hours. The total synthesis time of [⁶⁸Ga]Ga-FAPI-04 was 32.4 minutes, and the product met all quality control criteria. In this study, we developed and optimized a labeling method using [⁶⁸Ga]Ga-FAPI-04 using a cassette-based synthesizer. The devised method is expected to be useful for supplying [⁶⁸Ga]Ga-FAPI-04 for diagnosis in clinical practice.

• Bulletin of the Korean Chemical Society
• /
• v.26 no.1
• /
• pp.131-135
• /
• 2005

Gallium nitride (GaN) powders and nanowires were prepared by using tris(N,N-dimethyldithiocarbamato)gallium(III) (Ga(DmDTC)$_3$) and tris(N,N-diethyldithiocarbamato)gallium(III) (Ga(DeDTC)$_3$) as new precursors. The GaN powders were obtained by reaction of the complexes with ammonia in the temperature ranging from 500 to 1100 ${^{\circ}C}$. The process of conversion of the complexes to GaN was monitored by their weight loss, XRD, and $^{71}$Ga magic-angle spinning (MAS) NMR spectroscopy. Most likely the complexes decompose to $\gamma$ -Ga$_2$S$_3$ and then turn into GaN via amorphous gallium thionitrides (GaS$_x$N$_y$). The reactivity of Ga(DmDTC)$_3$ with ammonia was a little higher than that of Ga(DeDTC)$_3$. Room-temperature photoluminescence spectra of asprepared GaN powders exhibited the band-edge emission of GaN at 363 nm. GaN nanowires were obtained by nitridation of as-ground $\gamma$ -Ga$_2$S$_3$ powders to GaN powders, followed by sublimation without using templates or catalysts.

• Korean Journal of Environmental Agriculture
• /
• v.42 no.4
• /
• pp.389-395
• /
• 2023

This study evaluated the effects of gibberellic acid (GA₃) on the growth and quality of creeping bentgrass (Agrostis palustris Huds.). Experimental treatments included a No application of fertilizer and GA₃ (NFG) Control [3 N active ingredient (a.i.) g/m²], 0.3GA₃ (GA₃ 0.3 a.i. mg/m²/200 mL), 0.6GA₃ (GA₃ 0.6 a.i. mg/m²/200 mL), 1.2GA₃ (GA₃ 1.2 a.i. mg/m²/200 mL), and 2.4GA₃ (GA₃ 2.4 a.i. mg/m²/200 mL). Additionally, the study included a 1.5N+GA₃ experiment with similar GA₃ treatments combined with 1.5N a.i. g/m² : NFG, Control (3N a.i. g/m²), 1.5N+ 0.3GA₃ (1.5N a.i. g/m²+GA₃ 0.3 a.i. mg/m²/200 mL), 1.5N+0.6GA₃ (1.5N a.i. g/m²+GA₃ 0.6 a.i. mg/m²/200 mL), 1.5N+1.2GA₃ (1.5N a.i. g/m²+GA₃ 1.2 a.i. mg/m²/ 200 mL), and 1.5N+2.4GA₃ (1.5N a.i. g/m²+GA₃ 2.4 a.i. mg/m²/200 mL). Compared to the NFG, turf color index chlorophyll content was not significantly different (p< 0.05). However, shoot length in 1.2GA₃, 2.4GA₃, 1.5N+0.3GA₃, 1.5N+0.6GA₃, 1.5N+1.2GA₃, and 1.5N+2.4GA₃ treatments increased by 0.8%, 10.6%, 5.15%, 8.3%, 13.5 %, and 21.6%, respectively, compared to the control. As compared to the control, clipping yield in 1.5N+1.2GA₃ and 1.5N+2.4GA₃ treatments increased by 7.1% and 14.3 %, respectively. These results indicated that GA₃ application increased shoot length, with the 1.2GA₃ treatment showing shoot length similar to the control (3N a.i. g /m² ).

• Resources Recycling
• /
• v.4 no.3
• /
• pp.10-18
• /
• 1995

Recycling of GaAs scrap which occurs durmg the manufachre of GaAs waters is. therefore, required to solve the environmentalproblcrns caused by arsenic metal and to reutilize gallium which is a expensive metal. A thema-analyticalstudy (thermogravimeg. and derivative thermogravimetry) tor the evaporation behavior of Fa, As from Gak\ulcorner scrap powdersat vacuum atmosphere(2-2.5X 10'mmHg); was primarily performed to identi j the possibility of Ga extraction. Until79YC, the weight change of G d s porvder does not take place, at 800-970C range GaAs vaporizes as the GaAs compound,and over 1WO"C it decamposes mto Ga and As md then As vaporizes rapidly as a result of the difference af vaporprcssure for Ga and As, liquid Ga rcmains eventually.mains eventually.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2012.08a
• /
• pp.289-289
• /
• 2012

Molecular beam epitaxy 방법으로 성장시킨 AlGaAs/GaAs 다중 양자 우물 구조에 대한 라만 산란 연구를 보고한다. InAs 양자점이 성장된 Si 기판 위에 각기 다른 온도에서 두께 약 1 ${\mu}m$의 GaAs 층을 두 단계로 성장시킨 후 그 위에 AlGaAs/GaAs 다중 양자 우물 구조를 성장시켰다. AlGaAs/GaAs 다중 양자 우물 구조의 광학적 특성에 영향을 주는 GaAs 층의 변형력(stress)의 변화를 알기 위해서 시료의 측면으로부터 공간 분해된 라만 산란 실험을 수행하였다. 라만 산란 실험으로부터 AlGaAs/GaAs 다중 양자 우물 구조가 지니는 모든 종류의 광학 포논을 관측하였으며, 두 단계로 성장시킨 GaAs 층에서의 변형력이 Si 기판으로부터 멀어질수록 성장조건의 변화에 따라서 다르게 전개된다는 것을 파악하였다.

• Journal of the Korean Institute of Navigation
• /
• v.16 no.2
• /
• pp.21-27
• /
• 1992

Shortening the lasing wavelength(particularly below infrared ; the visible region) of laser diodes is very attractive because it can provide a wide range of applications in the fields of optical information, measurement, sensor, the development of medical instrument, and optical communication through plastic fibers. According to the recent researches on the field, InGaAsP/GaAs was suggested as a material for red-light laser. In this study, in order to grow InGaAsP/GaAs epitaxial layer on InGaAsP/GaAs by LPE, we used GaP and InP two phase solution technique for 670nm and 780 nm region, respectively. Through the X-ray diffraction measurement for the epitaxial layer grown from the experiments, we found that the lattice mismatch of $In_{0.46}Ga_{0.54}As_{0.07}P_{0.93}$/GaAs and $In_{0.19}Ga_{0.81}As_{0.62}P_{0.38}$/GaAs was about +0.3% and +0.1%, respectively.

• Journal of the Korean Institute of Telematics and Electronics A
• /
• v.31A no.12
• /
• pp.38-43
• /
• 1994

GaAs and AlGaAs layers were grown by Molecular Beam Epitaxy (MBE) to fabricate hith performance GaAs MESFETs. Optimum growth temperatures were found to be 600$^{\circ}C$ from their Hall measurement data. MESFETs with the gate legth of 1${\mu}$m and the gate width of 100.mu.m were fabricated on the MBE-grown GaAs layters which has i-GaAs buffer layer and characterized. Knee volgate and mazimum transconductance of the devices were 1V, 224mS/mm, respectively. Cut-off frequency at on-wafer measuring pattern was measured to be 18 GHz. The MESFET with the 1${\mu}$m -thick i-Al$_{0.3}Ga_{0.7}$As buffer layer between nactive and i-GaAs was fabricated on order to reduce the leakage current which flows through the i-GaAs buffer layer. Its output resistance was 2.26 k${\Omega}$.mm which increased by a factor of 15 compared with the MESFET without i-Al$_{0.3}Ga_{0.7}$As buffer layer.

• Electronics and Telecommunications Trends
• /
• v.38 no.1
• /
• pp.36-45
• /
• 2023

The increasing demand for ultra-high efficiency of compact power conversion systems for electric vehicle applications has brought GaN power semiconductors to the fore due to their low conduction losses and fast switching speed. In particular, the development of materials and core device processes contributed to remarkable results regarding the publication of vertical GaN power devices with high breakdown voltage. This paper reviews recent advances on GaN material technology and vertical GaN power device technology. The GaN material technology covers the latest technological trends and GaN epitaxial growth technology, while the vertical GaN power device technology examines diodes, Trench FETs, JFETs, and FinFETs and reviews the vertical GaN PiN diode technology developed by ETRI.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.37 no.12
• /
• pp.11-17
• /
• 2000

We investigated the growth of InGaN/GaN multiple quantum wells (MQWs) structures which emit blue light. The samples were grown in a low pressure metalorganic chemical vapor deposition system. We examined InGaN/GaN MQWs by varying growth temperatures and thicknesses of InGaN well and GaN barrier layers in MQWs. Especially, the thickness of GaN barrier in InGaN/GaN MQWs was found to severely affect the interfacial abruptness between InGaN well and GaN barrier layers. The higher order satellite peaks in the high resolution x-ray diffraction spectra and the high resolution cross sectional transmission electron microscope image of MQW structrues revealed that the interface between InGaN and GaN layers was very abrupt. Room-temperature photoluminescence spectra also showed a blue emission from InGaN/GaN MQWs at the wavelength of 463.5nm with a narrow full width at half maximum of 72.6meV.

• Journal of the Korean Vacuum Society
• /
• v.2 no.4
• /
• pp.424-432
• /
• 1993

AlGaAs/InGaAs/GaAs pseudomorphic structures have been grown by atmosheric pressure-MOCVD . The Al incorporation efficiency is constant but slightly exceeds the Ga incorporation during the growth of AlGaAs layers at $650^{\circ}C$ . Meanwhile , the In incorporation efficiency is constant but slightly less than the Ga incorporation in InGAAs layers. InGaAs/GaAs QWs were grown and their optical properties were characterized . $\delta$-doped Al0.24Ga0.76As/In0.16 Ga0.84As p-HEMT structures were successfully grown by MOCVD and their transport properties were characterized by Hall effect and SdH measurements. SdH Measurements at 3.7K show clear magnetoresistance oscillations and plateaus in the quantum Hall effect confirming the existence of a two-dimensional electron gas(2DEG) and a parallel conduction through the GaAs buffer layer. The fabricated $1.5\mu\textrm{m}$gatelength p-HEMTs having p-type GaAs in the buffer layer show a high transconductance of 200 mS/mm and a good pinch-off characteristics.