CuO/WO3 and Pt/WO3 nanocatalysts for efficient pollutant degradation using visible light irradiation

CuO/WO3 and Pt/WO3 nanocatalysts with a nanorod morphology were used for photodegradation of organic compounds using visible light irradiation. Both nanocatalysts were prepared using flame assisted spray pyrolysis method (FASP). The prepared nanocatalysts were mechanically stable during the agitation treatment for the photodegradation test due to good interconnection between WO3 and co-catalysts. The enhancement of photocatalytic activity was observed after the addition of CuO and Pt as co-catalysts. The addition of CuO would change the morphology of WO3 from nanorods to cubic. The optimal concentration of the CuO addition was 0.33 wt.%. A low Pt concentration (0.12 wt.%) was required for optimal photocatalytic activity of the Pt/WO3 nanocomposite. The addition of Pt affected neither the morphology nor the crystallite structure of WO3

Synthesis of uniformly porous NiO/ZrO2 particles

Porous NiO–ZrO2 particles were successfully synthesized using a spray-drying method with polystyrene latex (PSL: 400 nm) as a template and starting materials that included NiO powder (7 nm) and ZrO2 sol (1.2 nm). Porous particles with an average diameter of 4.5 µm and nearly spherical, narrow pores with an average size of ∼300 nm were obtained from the precursor at a pH of 3.7. The Brunauer, Emmett and Teller (BET) surface area of the prepared particles was relatively high—about 27 m2/g. When the solution pH was increased to 9.7, the particle morphology became completely spherical, indicating that the morphology of prepared particles can be controlled by adjusting the pH. Calcinations at 900 and 1200 °C were carried out to estimate the thermal stability of the prepared particles, which had shrinkage of less than 36%. The existence of these pores means that various applications, such as electrodes and catalysts, will be possible for the prepared particles

Point-Focusing Electromagnetic-Acoustic Transducer for Crack Inspection

Stress corrosion cracking in stainless-steel pipes is a critical failure in atomic power plants and chemical plants. In ultrasonic testing, piezoelectric transducers are generally used, in which reproducibility of amplitude measurements is not necessarily high because of effects of coupling materials and contacting conditions between the transducers and specimens. Comparing to the transducers, an electromagnetic acoustic transducer (EMAT) requires no coupling materials and is less sensitive to the contacting conditions, making the reproducibility higher. However, lower signal to noise (S/N) ratio has been a disadvantage. For increasing the S/N ratio, we developed a point-focusing EMAT (PF-EMAT) [1]. It generated shear-vertical (SV) waves from concentric line sources on a top surface of a specimen. Coil configuration of the EMAT was designed so that the SV waves were accumulated in phase at a focal point on the bottom surface, which increased the S/N ratio and improved the spatial resolution. We have designed PF-EMATs operated at different frequencies, and applied to artificially fabricated defects on stainless steel specimens. In this presentation, we show the results, and discuss availability of the PF-EMAT to crack inspection

Decolorization of beads-milled TiO2 nanoparticles suspension in an organic solvent

In this paper, a new method is proposed for the decolorization of a yellow-hued suspension of rutile TiO2 nanoparticles in an organic solvent (diethylene glycol dimethylether). The presence of color has always been undesirable in a suspension of nanoparticles filler used for industrial needs, particularly for optical applications. A colorless suspension was achieved by irradiating well-dispersed TiO2 nanoparticles in an organic solvent with UV-light (λ = 254 nm) for 5 h. TiO2 nanoparticles of 1 and 5 wt.% were dispersed using a beads mill method. Trimethoxytrifluor(propyl) silane was used as a dispersant to achieve stability. The effect of the UV-light irradiation on the TiO2 nanosuspension was investigated by means of a Fourier transform nuclear magnetic resonance analyzer (FT-NMR). The dispersant was partially desorbed due to the interaction of UV light and the TiO2/dispersant complex. Thus, an enhanced transparency and the absence of color were obtained for well-dispersed TiO2 nanoparticles in an organic solvent

Decolorization of beads-milled TiO2 nanoparticles suspension in an organic solvent

In this paper, a new method is proposed for the decolorization of a yellow-hued suspension of rutile TiO2 nanoparticles in an organic solvent (diethylene glycol dimethylether). The presence of color has always been undesirable in a suspension of nanoparticles filler used for industrial needs, particularly for optical applications. A colorless suspension was achieved by irradiating well-dispersed TiO2 nanoparticles in an organic sol- vent with UV-light (k = 254 nm) for 5 h. TiO2 nanoparticles of 1 and 5 wt.% were dispersed using a beads mill method. Trimethoxytrifluor(propyl) silane was used as a dispersant to achieve stability. The effect of the UV-light irradiation on the TiO2 nanosuspension was investigated by means of a Fourier transform nuclear magnetic resonance analyzer (FT-NMR). The dispersant was partially desorbed due to the inter- action of UV light and the TiO2/dispersant complex. Thus, an enhanced transparency and the absence of color were obtained for well-dispersed TiO2 nanoparticles in an organic solvent. � 2010 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved

Transient nature of graphene quantum dot formation via a hydrothermal reaction

A facile, economic and environmentally friendly one-step approach for the preparation of highly luminescent graphene quantum dots (GQDs) was developed using a hydrothermal reaction between citric acid and urea. Unlike previous reports, we focused on the effect of the transient nature of GQD formation on the photoluminescence (PL) properties and molecular structure changes of the products. We found that the GQDs have an optimum reaction time and require an effective precursor to achieve excellent luminescent properties. The PL, ultraviolet-visible (UV-vis) absorption, zeta potential, and nuclear magnetic resonance (NMR) analyses of the GQDs prepared at various reaction times revealed that the molecular structures responsible for the luminescence of the GQDs are aggregates or condensation products of citric acid amides. We found that urea addition to the precursor drastically enhances the PL intensity of the GQDs, and it is 40 times higher than those prepared using the pure citric acid precursor. Additionally, a GQDs–polyvinyl alcohol composite achieved an excellent quantum yield (QY) of 43.6%.This work was supported by JSPS KAKENHI Grant numbers 26709061 and 24656413. We thank Dr Eishi Tanabe from the Hiroshima Prefectural Institute of Industrial Science and Technology for helping with TEM analyses, and Drs Naoya Tochio and Junichi Kakimura from Hiroshima University for NMR analyses

Effect of Fuels on the Physicochemical Properties and Photocatalytic Activity of Bismuth Oxide, Synthesized using Solution Combustion Method

The potential of bismuth oxide (Bi2O3) as a photocatalyst, due to its a wide band gap (2.3-3.3 eV), was successfully synthesized using the solution combustion method with several fuels: urea, glycine, and citric acid. The synthesis was started by dissolving bismuth nitrate pentahydrate in nitric acid and then adding the fuel. The solution formed was heated for 8 h at 300°C. After heating, calcination was carried out for 4 h at 700°C. The resulting three products were in a yellow powder form. Fourier Transform InfraRed (FTIR) spectra of the samples confirmed that Bi2O3 had formed, as indicated by the functional groups of Bi-O-Bi observed at approximately 830–850 cm-1 and Bi-O at 1380 cm-1. X-ray diffractograms indicated that Bi2O3 synthesized using urea and glycine fuels was present in the mixed phases of ?-Bi2O3 at 2? of 27.7, 33.3, 27.2 and ?-Bi2O3 at 2? of 30.5, 41.8, 45.5, based on the Joint Committee on Powder Diffraction Standards (JCPDS) database 41-1449 and 27-0050, respectively. However, Bi2O3 produced by citric acid fuel comprised only ?-Bi2O3. Furthermore, different fuels produced different crystallite product sizes; urea generated the smallest crystallite, followed by glycine and citric acid. Additionally, the photocatalytic activity on the degradation of methyl orange of Bi2O3 synthesized using urea fuel exhibited better photocatalytic activity than the other products, with degradation rate constants of 4.38×10-5 s-1, 3.38×10-5 s-1, 2.33×10-5 s-1 for bismuth oxide synthesized by urea, glycine, and citric acid, respectively

Novel Oral Derivative UD-017, a Highly Selective CDK7 Inhibitor, Exhibits Anticancer Activity by Inducing Cell-Cycle Arrest and Apoptosis in Human Colorectal Cancer

Objective: This study aimed to investigate the anticancer profile of a new cyclin-dependent kinase 7 (CDK7) inhibitor, UD-017, by examining its mechanism of action using HCT-116 colorectal cancer cells. Methods: The anticancer properties of UD-017 were assessed using several assays, including in vitro kinase, proliferation, and apoptosis assays, western blot analysis, and an in vivo xenograft mouse model. Results: UD-017 significantly inhibited CDK7 activity (IC50 = 16 nM) with high selectivity in an in vitro kinase assay testing a panel of over 300 proteins and lipid kinases. UD-017 also inhibited the growth of HCT-116 cells (GI50 = 19 nM) and inhibited the phosphorylation of various downstream mediators of CDK7 signaling. In cell cycle and apoptosis assays using HCT-116 cells, UD-017 increased the number of cells in both G1 and G2/M phases and induced apoptosis. In vivo, UD-017 inhibited tumor growth in an HCT-116 xenograft mouse model by 33%, 64%, and 88% at doses of 25, 50, and 100 mg/kg, respectively, with clear dose-dependency. Co-administration of 5-FU and 50 mg/kg UD-017 had a strong synergistic effect, as reflected in the complete inhibition of tumor growth. Conclusion: CDK7 may play a major role in colorectal cancer growth by regulating the cell cycle and apoptosis. UD-017 is a promising candidate therapeutic agent for the treatment of cancer involving CDK7 signaling

The ASTRO-H X-ray Observatory

The joint JAXA/NASA ASTRO-H mission is the sixth in a series of highly successful X-ray missions initiated by the Institute of Space and Astronautical Science (ISAS). ASTRO-H will investigate the physics of the high-energy universe via a suite of four instruments, covering a very wide energy range, from 0.3 keV to 600 keV. These instruments include a high-resolution, high-throughput spectrometer sensitive over 0.3-2 keV with high spectral resolution of Delta E < 7 eV, enabled by a micro-calorimeter array located in the focal plane of thin-foil X-ray optics; hard X-ray imaging spectrometers covering 5-80 keV, located in the focal plane of multilayer-coated, focusing hard X-ray mirrors; a wide-field imaging spectrometer sensitive over 0.4-12 keV, with an X-ray CCD camera in the focal plane of a soft X-ray telescope; and a non-focusing Compton-camera type soft gamma-ray detector, sensitive in the 40-600 keV band. The simultaneous broad bandpass, coupled with high spectral resolution, will enable the pursuit of a wide variety of important science themes.Comment: 22 pages, 17 figures, Proceedings of the SPIE Astronomical Instrumentation "Space Telescopes and Instrumentation 2012: Ultraviolet to Gamma Ray