Electrodeposition and anodization of Al-TiO2 composite coatings for enhanced photocatalytic activity

In this study, we investigated the feasibility of a new process for the fabrication of Al-based composite coatings containing TiO₂ particles with high photocatalytic activity. In the first step of this process, Al-TiO₂ composite coatings were electrodeposited in a dimethyl sulfone-aluminum chloride bath with suspended TiO₂ particles yielding Al-matrix composite coatings with uniformly dispersed TiO₂ particles. Subsequently, the electrodeposited Al-TiO₂ composite coatings were anodized in oxalic aqueous solution. Through this anodization step, the Al matrix was converted into an alumina layer with many nanopores extending from the surface of the coating toward the substrate. As a consequence, a porous alumina layer supporting TiO₂ particles was formed. The photocatalytic activity of the anodized composite coatings was confirmed to be higher than that of the as-deposited coatings

High-susceptibility of photosynthesis to photoinhibition in the tropical plant Ficus microcarpa L. f. cv. Golden Leaves

BACKGROUND: The tropical plant Ficus microcarpa L. f. cv. Golden Leaves (GL) is a high-light sensitive tropical fig tree in which sun-leaves are yellow and shade-leaves are green. We compared the response of photosynthetic activities to strong light between GL and its wild-type (WT, Ficus microcarpa L. f.). RESULTS: Field measurements of maximum photosystem II (PSII) efficiency (F(v)/F(m)) of intact sun-leaves in GL showed that photo synthetic activity was severely photoinhibited during the daytime (F(v)/F(m) = 0.46) and subsequently recovered in the evening (F(v)/F(m) = 0.76). In contrast, WT did not show any substantial changes of F(v)/F(m) values throughout the day (between 0.82 and 0.78). Light dependency of the CO(2) assimilation rate in detached shade-leaves of GL showed a response similar to that in WT, suggesting no substantial difference in photosynthetic performance between them. Several indicators of photoinhibition, including declines in PSII reaction center protein (D1) content, F(v)/F(m) value, and O(2) evolution and CO(2) assimilation rates, all indicated that GL is much more susceptible to photoinhibition than WT. Kinetics of PAM chlorophyll a fluorescence revealed that nonphotochemical quenching (NPQ) capacity of GL was lower than that of WT. CONCLUSION: We conclude that the photosynthetic apparatus of GL is more highly susceptible to photoinhibition than that of WT

Long-duration nano-second single pulse lasers for observation of spectra from bulk liquids at high hydrostatic pressures

AbstractThe influence of laser pulse duration on the spectral emissions observed from bulk ionic solutions has been investigated for hydrostatic pressures between 0.1 and 30MPa. Transient pressure, shadowgraph imaging and spectroscopic measurements were performed for single pulses of duration 20 and 150ns. The transient pressure measurements show that for hydrostatic pressures up to 30MPa, propagation of the high-pressure shockwave generated by the focused laser causes the local pressure to reduce below ambient levels during the time frame that spectroscopic measurements can be made. The pressure impulse and subsequent reduction in pressure are larger, with the latter lasting longer for the 150ns pulse compared to a 20ns pulse of the same energy. The 150ns pulse generates larger cavities with significant enhancement of the spectral emissions observed compared to the 20ns duration pulse for pressures up to 30MPa. The results demonstrate that laser-induced breakdown using a long ns duration pulse offers an advantage over conventional, short ns duration pulses for the analysis of bulk ionic solutions at hydrostatic pressures between 0.1 and 30MPa

Development of a deep-sea laser-induced breakdown spectrometer for in situ multi-element chemical analysis

Spectroscopy is emerging as a technique that can expand the envelope of modern oceanographic sensors. The selectivity of spectroscopic techniques enables a single instrument to measure multiple components of the marine environment and can form the basis for versatile tools to perform in situ geochemical analysis. We have developed a deep-sea laser-induced breakdown spectrometer (ChemiCam) and successfully deployed the instrument from a remotely operated vehicle (ROV) to perform in situ multi-element analysis of both seawater and mineral deposits at depths of over 1000 m. The instrument consists of a long-nanosecond duration pulse-laser, a spectrometer and a high-speed camera. Power supply, instrument control and signal telemetry are provided through a ROV tether. The instrument has two modes of operation. In the first mode, the laser is focused directly into seawater and spectroscopic measurements of seawater composition are performed. In the second mode, a fiber-optic cable assembly is used to make spectroscopic measurements of mineral deposits. In this mode the laser is fired through a 4 m long fiber-optic cable and is focused onto the target’s surface using an optical head and a linear stage that can be held by a ROV manipulator. In this paper, we describe the instrument and the methods developed to process its measurements. Exemplary measurements of both seawater and mineral deposits made during deployments of the device at an active hydrothermal vent field in the Okinawa trough are presented. Through integration with platforms such as underwater vehicles, drilling systems and subsea observatories, it is hoped that this technology can contribute to more efficient scientific surveys of the deep-sea environment

Second moment of the Husimi distribution as a measure of complexity of quantum states

We propose the second moment of the Husimi distribution as a measure of complexity of quantum states. The inverse of this quantity represents the effective volume in phase space occupied by the Husimi distribution, and has a good correspondence with chaoticity of classical system. Its properties are similar to the classical entropy proposed by Wehrl, but it is much easier to calculate numerically. We calculate this quantity in the quartic oscillator model, and show that it works well as a measure of chaoticity of quantum states.Comment: 25 pages, 10 figures. to appear in PR

Moments of generalized Husimi distributions and complexity of many-body quantum states

We consider generalized Husimi distributions for many-body systems, and show that their moments are good measures of complexity of many-body quantum states. Our construction of the Husimi distribution is based on the coherent state of the single-particle transformation group. Then the coherent states are independent-particle states, and, at the same time, the most localized states in the Husimi representation. Therefore delocalization of the Husimi distribution, which can be measured by the moments, is a sign of many-body correlation (entanglement). Since the delocalization of the Husimi distribution is also related to chaoticity of the dynamics, it suggests a relation between entanglement and chaos. Our definition of the Husimi distribution can be applied not only to the systems of distinguishable particles, but also to those of identical particles, i.e., fermions and bosons. We derive an algebraic formula to evaluate the moments of the Husimi distribution.Comment: published version, 33 pages, 7 figre

Effects of 3 MeV Proton Irradiation on Superconductivity and CDW in 2H-NbSe2 Single Crystals

Interplay between superconductivity and charge-density wave (CDW) in 2H-NbSe2 single crystals irradiated by 3 MeV protons is studied. Both Tc and TCDW are found to decrease monotonically with the increase in irradiation dose. This behavior is different from electron-irradiated NbSe2, where TCDW is suppressed monotonically with the increase in dose, while Tc shows an initial enhancement before it starts to decrease. We attempt to explain this difference based on the negative pressure effect which has been reported in our previous study on NbSe2 irradiated by heavy ions

Mizoribine Suppresses the Progression of Experimental Peritoneal Fibrosis in a Rat Model

Background/Aims: Peritoneal fibrosis is a serious complication of peritoneal dialysis (PD). It has been reported that administration of mizoribine, an effective immunosuppressant, ameliorated renal fibrosis in a rat model of unilateral ureteral obstruction. We therefore examined the effects of mizoribine in an experimental model of peritoneal fibrosis. Methods: 24 rats were given a daily intraperitoneal injection of chlorhexidine gluconate and ethanol dissolved in saline. The rats were divided into three groups (n = 8 per group) that received either vehicle or mizoribine at a dose of 2 or 8 mg/kg once a day. 28 days after the start of the treatments the rats were sacrificed and peritoneal tissue samples collected. Macrophage infiltration (ED1), myofibroblast accumulation (alpha-smooth muscle actin (SMA)) and expression of type III collagen, transforming growth factor (TGF)-beta and monocyte chemotactic protein-1 (MCP-1) were examined by immunohistochemistry. Results: Mizoribine significantly suppressed submesothelial zone thickening and reduced macrophage infiltration. Mizoribine also reduced collagen III+ area and decreased the number of alpha-SMA(+), TGF-beta(+) and MCP-1(+) cells. The magnitude of the changes observed was dose-dependent. Conclusion: The administration of mizoribine prevented the progression of peritoneal fibrosis in this rat model. Mizoribine may represent a novel therapy for peritoneal sclerosis in patients undergoing long-term PD