Transient photodarkening induced by a nanosecond pulsed laser in amorphous and liquid As2Se3: fractal characteristics in relaxation dynamics

Journal of Materials Science: Materials in Electronics - Both amorphous and liquid As2Se3 exhibit fast decrease of optical transmittance under a nanosecond pulsed laser excitation. This...     

The effect of gear oil viscosity and friction reducer type on transmission efficiency

The effects of gear oil viscosity and friction reducer type on transmission efficiency have been investigated using the manual transmission and hypoid rear axle of a typical Japanese car. A reduction in the viscosity of the oil improved the efficiency of the manual transmission but led to positive and negative effects in the rear axle, depending upon operating conditions. The effect of the friction reducer varied according to the type of EP additive used, indicating the necessity of preliminary investigations of compatibility with EP additives before adding friction reducers to gear oils.     

Characterization of Light-Enhanced Respiration in Cyanobacteria

In eukaryotic algae, respiratory O₂ uptake is enhanced after illumination, which is called light-enhanced respiration (LER). It is likely stimulated by an increase in respiratory substrates produced during photosynthetic CO₂ assimilation and function in keeping the metabolic and redox homeostasis in the light in eukaryotic cells, based on the interactions among the cytosol, chloroplasts, and mitochondria. Here, we first characterize LER in photosynthetic prokaryote cyanobacteria, in which respiration and photosynthesis share their metabolisms and electron transport chains in one cell. From the physiological analysis, the cyanobacterium Synechocystis sp. PCC 6803 performs LER, similar to eukaryotic algae, which shows a capacity comparable to the net photosynthetic O₂ evolution rate. Although the respiratory and photosynthetic electron transports share the interchain, LER was uncoupled from photosynthetic electron transport. Mutant analyses demonstrated that LER is motivated by the substrates directly provided by photosynthetic CO₂ assimilation, but not by glycogen. Further, the light-dependent activation of LER was observed even with exogenously added glucose, implying a regulatory mechanism for LER in addition to the substrate amounts. Finally, we discuss the physiological significance of the large capacity of LER in cyanobacteria and eukaryotic algae compared to those in plants that normally show less LER.     

Control of Structural Distortions in Transition‐Metal Oxide Films through Oxygen Displacement at the Heterointerface

Structural distortions in the oxygen octahedral network in transition‐metal oxides play crucial roles in yielding a broad spectrum of functional properties, and precise control of such distortions is a key for developing future oxide‐based electronics. Here, it is shown that the displacement of apical oxygen atom shared between the octahedra at the heterointerface is a determining parameter for these distortions and consequently for control of structural and electronic phases of a strained oxide film. The present analysis by complementary annular dark‐ and bright‐field imaging in aberration‐corrected scanning transmission electron microscopy reveals that structural phase differences in strained monoclinic and tetragonal SrRuO₃ films grown on GdScO₃ substrates result from relaxation of the octahedral tilt, associated with changes in the in‐plane displacement of the apical oxygen atom at the heterointerface. It is further demonstrated that octahedral distortions and magnetrotransport properties of the SrRuO₃ films can be controlled by interface engineering of the oxygen displacement. This provides a further degree of freedom for manipulating structural and electronic properties in strained films, allowing the design of novel oxide‐based heterostructures.     

Controllable Magnetic Proximity Effect and Charge Transfer in 2D Semiconductor and Double-Layered Perovskite Manganese Oxide van der Waals Heterostructure

Optically generated excitonic states (excitons and trions) in transition metal dichalcogenides are highly sensitive to the electronic and magnetic properties of the materials underneath. Modulation and control of the excitonic states in a novel van der Waals (vdW) heterostructure of monolayer MoSe₂ on double-layered perovskite Mn oxide ((La_0.8Nd_0.2)_1.2Sr_1.8Mn₂O₇) is demonstrated, wherein the Mn oxide transforms from a paramagnetic insulator to a ferromagnetic metal. A discontinuous change in the exciton photoluminescence intensity via dielectric screening is observed. Further, a relatively high trion intensity is discovered due to the charge transfer from metallic Mn oxide under the Curie temperature. Moreover, the vdW heterostructures with an ultrathin h-BN spacer layer demonstrate enhanced valley splitting and polarization of excitonic states due to the proximity effect of the ferromagnetic spins of Mn oxide. The controllable h-BN thickness in vdW heterostructures reveals a several-nanometer-long scale of charge transfer as well as a magnetic proximity effect. The vdW heterostructure allows modulation and control of the excitonic states via dielectric screening, charge carriers, and magnetic spins.     

Provitamin A carotenoid intake and carotid artery plaques: the Atherosclerosis Risk in Communities Study

Clara cell protein is a 16-17 kDa protein (CC16) secreted by Clara cells in the bronchiolar lining fluid of the lung. In order to investigate the potential of this protein as a pulmonary marker in animals, CC16 was isolated from rat bronchoalveolar lavage fluid (BALF) and a sensitive latex immunoassay applicable to both rat and mouse CC16 was developed. The pattern of CC16 concentrations in rat biological fluids determined by the immunoassay was consistent with the hypothesis of a passive diffusion of the protein across the bronchoalveolar/blood barriers showing a difference of more than 5,000 fold between the concentration in the epithelial lining fluid (mean, 140 mg x L(-1)) and that in serum (20 microg x L(-1)) or urine (3 microg x L(-1)). In BALF, the CC16 concentration averaged 5,500 microg x L(-1) and was of the same magnitude as that determined on lung and trachea homogenates. CC16 was also detectable in amniotic fluid with a mean value of 800 microg x L(-1) before delivery. Damage of Clara cells produced by methylcyclopentadienyl manganese tricarbonyl resulted in a significant decrease of CC16 in BALF but did not affect the serum levels of the protein. The nephrotoxicant sodium chromate by contrast had no influence on the CC16 content of BALF but markedly increased CC16 levels in both serum and urine as a result of impaired glomerular filtration and tubular reabsorption, respectively. In conclusion, mouse or rat Clara cell protein of 16-17 kDa can easily be quantified, not only in bronchoalveolar lavage fluid, but also in extrapulmonary fluids such as serum or urine. Thus, in rodents, Clara cell protein of 16-17 kDa follows the same metabolic pathway as in humans, diffusing from the respiratory tract into serum where it is eliminated by the kidneys. This serum Clara cell protein of 16-17 kDa may be useful as a peripheral marker of events taking place in the respiratory tract.     

Reassuring evacuation guidance with mobile terminal communication and RFID system in absence of power supply

In this paper, we propose a method which aims to allow people inside a building to evacuate when a disaster occurs. In particular, it is very difficult for them to evacuate safely in blackout conditions with servers down. In the proposed method, passive RFID tags are placed on the walls of the building and each evacuee carries a mobile terminal that is battery‐powered and equipped with an RFID reader‐writer. This device finds evacuation routes based on the information from passive RFID tags touched by the evacuee. The method identifies safety of evacuation routes from the movement of people who have evacuated safely. Mobile terminal communication and RFID tags achieve sharing of information on safe routes among many evacuees. An experiment was conducted, letting people evacuate by two routes in an actual building, and giving about half of them mobile terminals. We easured the increases in the blood pressure and heart rates of the evacuees before and after the evacuation. In both routes, the rates of increase of these two characteristics in the evacuees with terminals were smaller than those in the evacuees without terminals, demonstrating that the proposed method provides assurance to evacuees. © 2011 Wiley Periodicals, Inc. Electr Eng Jpn, 177(2): 19–31, 2011; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/eej.21165     

Preparation of Zn doped Cu(In,Ga)Se2 thin films by physical vapor deposition for solar cells

Cu(In,Ga)Se₂ (CIGS) surface was modified with Zn doping using vacuum evaporation. Substrate temperatures and exposure times during the Zn evaporation were changed to control a distribution of Zn in the CIGS films. Diffusion of Zn in the CIGS films was observed at the substrate temperature of over 200°C. The diffusion depth of Zn increases with increasing the exposure time at the substrate temperature of 300°C. Solar cells were fabricated using the Zn doped CIGS films. A distribution of the efficiencies decreases with increasing the exposure time of Zn vapor. The doping of Zn at the film surface improved reproducibility of a high fill factor and efficiency. A solar cell fabricated using the CIGS film modified with Zn doping showed an efficiency of 14.8%.