Synthesis and characterization of zeolite A from crushed particles of aluminoborosilicate glass used in LCD panels

AbstractWe tried to synthesize zeolite from the sand-like particles of crushed LCD panel glass collected from discarded electronics devices. In the previous study, zeolite A was synthesized using fine glass particles of <10μm. Acid treatment was found effective toward synthesizing single phase zeolite A. Using sand-like coarse glass particles, of which the internal-core consists of glass and the surficial shell transforms into zeolite, we investigated the effect of acid-treatment by evaluating the surface of the coarse glass particles. Under acid-treatment, components other than Si eluted from the glass. The elution amounts were several percent of the total glass mass. After acid-treatment, the surface of the glass particle was discovered to be covered in a thin layer of poor components other than Si and a relatively rich quantity of Si, by scanning electron microscopy and energy dispersive spectrum analysis. The synthesized zeolite A increased the longer the acid-treatment time, which suggest the thin layer increased. When the concentration of the acid solution decreased, glass components other than Si dissolved well, and the synthesized zeolite A increased as a result. This indicates that the Si-rich layer is necessary for preferential synthesis of zeolite A from crushed particles of aluminoborosilicate glass

Imparting CO₂ reduction selectivity to ZnGa₂O₄ photocatalysts by crystallization from hetero nano assembly of amorphous-like metal hydroxides

Imparting an enhanced CO₂ reduction selectivity to ZnGa₂O₄ photocatalysts has been demonstrated by controlled crystallization from interdispersed nanoparticles of zinc and gallium hydroxides. The hydroxide precursor in which Zn(II) and Ga(III) are homogeneously interdispersed was prepared through an epoxide-driven sol–gel reaction. ZnGa₂O₄ obtained by a heat-treatment exhibits a higher surface basicity and an enhanced affinity for CO₂ molecules than previously-reported standard ZnGa₂O₄. The enhanced affinity for CO₂ molecules of the resultant ZnGa₂O₄ leads to highly-selective CO evolution in CO₂ photo-reduction with H₂O reductants. The present scheme is promising to achieve desirable surface chemistry on metal oxide photocatalysts

Pre-clinical medical student cardiac point-of-care ultrasound curriculum based on the American Society of Echocardiography recommendations : a pilot and feasibility study

Background: Cardiac point-of-care ultrasound (POCUS) training has been integrated into medical school curricula. However, there is no standardized cardiac POCUS training method for medical students. To address this issue, the American Society of Echocardiography (ASE) proposed a framework for medical student cardiac POCUS training. The objective of this pilot study was to develop a medical student cardiac POCUS curriculum with test scoring systems and test the curriculum feasibility for a future definitive study. Methods: Based on the ASE-recommended framework, we developed a cardiac POCUS curriculum consisting of a pre-training online module and hands-on training with a hand-held ultrasound (Butterfly iQ, Butterfly Network Inc., Guilford, CT, USA). The curriculum learning effects were assessed with a 10-point maximum skill test and a 40-point maximum knowledge test at pre-, immediate post-, and 8-week post-training. To determine the curriculum feasibility, we planned to recruit 6 pre-clinical medical students. We semi-quantitatively evaluated the curriculum feasibility in terms of recruitment rate, follow-up rate 8 weeks after training, instructional design of the curriculum, the effect size (ES) of the test score improvements, and participant satisfaction. To gather validity evidence of the skill test, interrater and test-retest reliability of 3 blinded raters were assessed. Results: Six pre-clinical medical students participated in the curriculum. The recruitment rate was 100% (6/6 students) and the follow-up rate 8 weeks after training was 100% (6/6). ESs of skill and knowledge test score differences between pre- and immediate post-, and between pre- and 8-week post-training were large. The students reported high satisfaction with the curriculum. Both interrater and test-retest reliability of the skill test were excellent. Conclusions: This pilot study confirmed the curriculum design as feasible with instructional design modifications including the hands-on training group size, content of the cardiac POCUS lecture, hands-on teaching instructions, and hand-held ultrasound usage. Based on the pilot study findings, we plan to conduct the definitive study with the primary outcome of long-term skill retention 8 weeks after initial training. The definitive study has been registered in ClinicalTrials.gov (Identifier: NCT04083924)

Synthesis and Evaluation of Olivine Material Coated with Carbon

Lithium iron phosphate, LiFePO4, was synthesized by hydrothermal process and subsequently coated with carbon by the thermal decomposition of acetylene gas. The products were characterized by XRD, SEM, and TG-DTA. As-synthesized LiFePO4 was submicron sized plate-like particle. After heating at various temperature in nitrogen atmosphere, the particle size and the crystalline sizes were grown with increasing the heating temperature. Above 700°C, the grain growth was remarkably. Carbon coating temperature was set at 500-600°C because of fine particle and good crystallinity. As a carbon raw material, acetylene gas was flowing to the as-synthesized LiFePO4 in nitrogen atmosphere, and the LiFePO4/C composite was obtained. TG curves showed weight loss above 500°C, which was thought to be associated with carbon layer composition

Effect of High Magnetic Field on Ferrite Materials Obtained by Calcination of Layered Double Hydroxide

In this paper, the effect of high magnetic field on the development of property were investigated by calcination of MgFe-LDH (CO3) as a precursor of ferrite material under applied field of 10T. Obtained products were identified by X-ray diffraction analysis (XRD) and their microstructures were observed using scanning electron microscopy (SEM). Furthermore, their magnetic properties were evaluated by a superconducting quantum interference device (SQUID). It was observed that the particle size of mixed oxide prepared by calcination under 10T was homogeneous and small. Saturation magnetization of mixed oxide synthesized under 10T was higher than that of zero field. Therefore, it was found that calcination due to imposition of high magnetic field affected phase transition to mixed oxide and provided enhancement of its property. [doi:10.2320/matertrans.MI200710