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Copper oxide in layered tin oxide with intracrystalline microporosity for oxidative imination of toluene and p-xylene
No full textHomoepitaxial layered structure of tin oxide, SnO2 containing low amount of copper oxide, CuO (named as CuOSnO2) was found to convert toluene and p-xylene into value-added compounds. The CuO-SnO2 with microporous channels and expanded lattice planes allowed the high diffusion of toluene and p-xylene. Such characteristics features made the oxidative coupling of toluene and p-xylene with various amines resulting in different imines with good yield (70-92%) within 12 h. The reaction proceeded with the selective transformation from toluene to benzaldehyde and its condensation with amines at 120degree celsius in presence of H2O2 as oxidant. Theoretical investigations were done to understand to know the thermodynamic feasibility of the reaction. The same study also suggested the involvement of weak supramolecular forces like cation (Sn4+)-pi interactions in stabilizing the intermediate state during the course of the reaction. The thermally stable CuO-SnO2 catalysts with moderate to strong basic sites appeared as a suitable recyclable catalyst for the oxidative imination raction
Application of Emergency Response Difficulty Coefficient Developed by Tokyo Metropolitan Government for Seismic Community Risk Assessment to Korea
No full textThe extent of damage to a community from an earthquake depends on the existing road infrastructure and space for disaster response activities. The Bureau of Urban Development of the Tokyo Metropolitan Government has assessed the seismic vulnerability and risk to communities, and announced the results approximately every five years since 1975. The present study investigates the assessment methods used last three times by focusing on the emergency response difficulty coefficient. The methods are then applied to a community in the Republic of Korea as a pilot. Subsequently, it is observed that the results of application in Korea are similar to those in the Tokyo Metropolitan city
DFT-study supported synergistic electrochemical supercapacitor performance of Bi2MoS6 nanosheets
No full textSynergistic electrochemical performance of the bismuth molybdenum sulphide (Bi2MoS6, BMS) nanosheets can be beneficial for fast ion exchange kinetics in electrolyte solution for energy storage performance. Bismuth sulphide (Bi2S3, BS), molybdenum sulphide (MoS2, MS), and BMS electrode materials of different morphologies are grown on stainless-steel (SS) conducting substrate using a wet chemical process. A 0 - 1 V operating potential window vs. Ag/AgCl has been utilized for half-cell analysis wherein, 947.4 F g- 1 specific capacitance is obtained for BMS nanosheet-like electrode at 0.6 Ag-1 current density with nearly 97 % stability which is better than BS and MS electrode materials. Full understanding of synergistic effect i.e., enhancement of electrochemical properties, has clearly been revealed by applying ab-initio theoretical calculations using density functional theory. The values of power density and energy density of the as-constructed symmetric supercapacitor device by using BMS electrode are respectively found to be 1130 Wkg- 1 and 85 Whkg- 1. A panel of forty-two LEDs coupled in series has been powered through symmetric device to demonstrating the practical application of the asprepared nanosheet-type BMS electrode material for commercial feasibility
Halogen-Free Donor Polymers Based on Dicyanobenzotriazole with Low Energy Loss and High Efficiency in Organic Solar Cells
No full textHalogenation of organic semiconductors is an efficient strategy for improving the performance of organic solar cells (OSCs), while the introduction of halogens usually involves complex synthetic process and serious environment pollution problems. Herein, three halogen-free ternary copolymer donors (PCNx, x = 3, 4, 5) based on electron-withdrawing dicyanobenzotriazole are reported. When blended with the Y6, PCN3 with strong interchain interactions results in appropriate crystallinity and thermodynamic miscibility of the blend film. Grazing-incidence wide-angle X-ray scattering measurements indicate that PCN3 has more ordered arrangement and stronger pi-pi stacking than previous PCN2. Fourier-transform photocurrent spectroscopy and external quantum efficiency of electroluminescence measurements show that PCN3-based OSCs have lower energy loss than PCN2, which leads to their higher open-circuit voltage (0.873 V). The device based on PCN3 reaches power conversion efficiency (PCE) of 15.33% in binary OSCs, one of the highest values for OSCs with halogen-free donor polymers. The PCE of 17.80% and 18.10% are obtained in PM6:PCN3:Y6 and PM6:PCN3:BTP-eC9 ternary devices, much higher than those of PM6:Y6 (16.31%) and PM6:BTP-eC9 (17.33%) devices. Additionally, this ternary OSCs exhibit superior stability compared to binary host system. This work gives a promising path for halogen-free donor polymers to achieve low energy loss and high PCE
A review on metal-organic frameworks for the removal of hazardous environmental contaminants
No full textEfficient elimination of hazardous organic and inorganic pollutants, remains a difficult task from the ecological viewpoint because of their deleterious impact on the environment and living organism. Highly porous metal???organic frameworks (MOF), are emerging as a potential material in the field of capturing various types of hazardous organic and inorganic pollutants. This article addresses the performance of various modified MOF to remove various toxic contaminants, including dyes, pesticides, pharmaceutical products, heavy metals, radioactive metals, and toxic gases (NH3, COx, NOx, SO2, and VOCs). Because of the poor water stability of MOF, pre- and post-synthetic functionalization and modification of MOF have also been studied. Aspects pertain to the interaction mechanisms between selected pollutant and MOF-based composite are comprehensively described. The adsorption characteristic of numerous MOF-based composites are examined and compared with those of other commonly used adsorbents. Still, further research into the actual viability and usability of MOF as adsorbents on a commercial scale is required. For more efficient and practicable application of MOF, some expected and unobserved aspects were also presented as the prospects and challenges to instill the significant enhancement in mitigating various contaminants. Despite the existence of drawbacks and difficulties related to the usage of MOF, these materials are irrefutably beneficial for the confiscation of contaminants from the environment. ?? 2022 Elsevier B.V
Torque coil-based, highly-flexible photoacoustic and ultrasonic mini-probe for use in the instrument channel of a clinical video endoscope
No full textThis will present the first in vivo demonstration of an optical-resolution photoacoustic and ultrasonic mini-probe embodied in a highly-flexible form based on a torque toil to provide co-registered images through the standard instrument channel of a clinical video endoscope. Although there was an anticipation that photoacoustic endoscopy could make a significant contribution to gastrointestinal endoscopy and thus there were multiple reports demonstrating sufficient probe miniaturization smaller than the channel sizes, no actual in vivo image acquisition has yet been reported thus far. In this study, through an instrument channel, we acquired the first in vivo photoacoustic and ultrasonic endoscopic images from the esophagogastric junction of a swine
Transurethral photoacoustic and ultrasonic endoscopic probe developed for bladder cancer diagnosis
No full textMinimally-invasive imaging application of photoacoustic (optoacoustic) tomography (PAT) has been mainly focused on gastrointestinal endoscopy or the imaging of cardiovascular and reproductive systems, such as uterus, ovary, and prostate, in relation to the diagnosis of atherosclerotic plaques (e.g., plaques building up in a coronary artery) and the cancers developed in the mentioned core reproductive systems. However, related miniature probe technology could also make a considerable contribution to the diagnosis and post-treatment follow-ups of urinary diseases because PAT can provide unique anatomical, functional, and molecular information, which is not possible with conventional methods. Among related clinical issues, development of a new diagnostic paradigm for the early detection of bladder cancer is urgently needed because this cancer is known very aggressive and lethal if it is found after stage 2 (T2). In this study, we developed a 2.8 mm outer diameter, transurethral photoacoustic and ultrasonic endoscopic probe to contribute to the early diagnosis of bladder cancer. From a live rabbit, we have successfully acquired the first high-resolution 3D vasculature map distributed over an area more than 80% of the bladder wall, which we believe it is a completely new type of image information never acquired from a vertebrate level urinary system before
Topological charge-dependent motion of the emergent magnetic monopole in soft magnetic elements
No full textUnderstanding of Active Sites and Interconversion of Pd and PdO during CH4 Oxidation
No full textPd-based catalysts are widely used in the oxidation of CH4 and have a significant impact on global warming. However, understanding their active sites remains controversial, because interconversion between Pd and PdO occurs consecutively during the reaction. Understanding the intrinsic active sites under reaction conditions is critical for developing highly active and selective catalysts. In this study, we demonstrated that partially oxidized palladium (PdOx) on the surface plays an important role for CH4 oxidation. Regardless of whether the initial state of Pd corresponds to oxides or metallic clusters, the topmost surface is PdOx, which is formed during CH4 oxidation. A quantitative analysis using CO titration, diffuse reflectance infrared Fourier-transform spectroscopy, X-ray diffraction, and scanning transmission electron microscopy demonstrated that a surface PdO layer was formed on top of the metallic Pd clusters during the CH4 oxidation reaction. Furthermore, the time-on-stream test of CH4 oxidation revealed that the presence of the PdO layer on top of the metallic Pd clusters improves the catalytic activity. Our periodic density functional theory (DFT) calculations with a PdOx slab and nanoparticle models aided the elucidation of the structure of the experimental PdO particles, as well as the experimental C-O bands. The DFT results also revealed the formation of a PdO layer on the metallic Pd clusters. This study helps achieve a fundamental understanding of the active sites of Pd and PdO for CH4 oxidation and provides insights into the development of active and durable Pd-based catalysts through molecular-level design