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Using calculations based on first principles, we demonstrate that the preferred interface in singles LiFePO<sub>4</sub> particles depends both on the particle size and morphology.
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This special issue aims to explore critical elements of the overall design, user experience, and resulting solutions related to using pervasive computing technologies to inform our understanding of the dynamics of ourselves and our ecosystem, community, and urban landscapes. This issue not only explores pervasive technologies but also reviews practical solutions for improving citizens' health, wellbeing, and everyday lives. Careful attention is also paid to the interplay of social media within this landscape of pervasive analytics and citizen science.
Objective: Delayed onset posttraumatic stress disorder (PTSD) refers to PTSD that develops at least 6 months after the traumatic event. This study aimed to index the features of patients who develop delayed-onset PTSD. Method: This study investigated delayed onset PTSD by prospectively assessing 103 motor vehicle accident survivors within 1 month of the motor vehicle accident for acute stress disorder, and subsequently assessing them for PTSD 6 months post-accident, and 2 years post-accident. Patients were initially assessed for symptoms of traumatic stress, anxiety, depression, and resting heart rate. Results: Five patients displayed PTSD 2 years post-trauma without meeting PTSD criteria 6 months posttrauma. Delayed onset cases were characterized by elevated psychopathology scores and resting heart rate levels within the initial month and elevated psychopathology 6 months posttrauma. Conclusions: These findings suggest that cases of delayed onset PTSD suffer subsyndromal levels of posttraumatic stress prior to the diagnosis of PTSD. These findings challenge the notion of PTSD developing after a period without symptoms.
Rh(111). Ethanol and acetaldehyde are formed from CO + H{sub 2} by parallel routes on Rh catalysts which do not contain interacting supports or oxide promoters; i.e., the two compounds result from CO insertion into different metal-hydrocarbon bonds. Aldehydes decarbonylate via {alpha}-CH scission to form acyl, followed by C-C scission to release an alkyl ligand; this ligand undergoes hydrogenation and dehydrogenation steps. Alcohols form surface alkoxides, but these do not dehydrogenate further to the aldehydes, they release CO + H{sub 2} but no volatile hydrocarbon. These results indicate that {beta}-CH scissors to form a surface oxametallacycle intermediate; supporting evidence is spresented for this intermediate. Chemistry of alcohols blocked to different extends at the {beta}-position was also studied; complete blocking (CF{sub 3}CH{sub 2}OH) forces the reaction to follow the aldehyde-acyl path, while partial substitution at the {beta} position (branched alcohols) favors the oxametallacycle pathway. (DLC)
NGC 4395 is one of the least luminous and nearest known type 1 Seyfert\ngalaxies, and it also lacks a bulge. We present an HST I-band image of its\nnuclear region and Keck high-resolution (8 km/s) echelle spectra containing the\nCa II near-infrared triplet. In addition to the unresolved point source, there\nis a nuclear star cluster of size r ~ 3.9 pc; the upper limit on its velocity\ndispersion is only 30 km/s. We thus derive an upper limit of 6.2x10^6 solar\nmasses for the mass of the compact nucleus. Based on the amount of spatially\nresolved light in the HST image, a sizable fraction of this is likely to reside\nin stars. Hence, this estimate sets a stringent upper limit on the mass of the\ncentral black hole. We argue, from other lines of evidence, that the true mass\nof the black hole is likely to be 10^4-10^5 solar masses. Although the black\nhole is much less massive than those thought to exist in classical active\ngalactic nuclei, its accretion rate of L_bol/L_Edd ~ 2x10^-2 to 2x10^-3 is\nconsistent with the mass-luminosity relation obeyed by classical AGNs. This may\nexplain why NGC 4395 has a high-excitation (Seyfert) emission-line spectrum;\nactive galaxies having low-ionization spectra seem to accrete at significantly\nlower rates. NGC 4395, a pure disk galaxy, demonstrates that supermassive black\nholes are not associated exclusively with bulges.\n
Silicon-based microelectromechanical systems (MEMS) have been a prominent material platform since micromachining technologies were adapted from the microelectronics industry. Fatigue-induced drift and other degradation of MEMS are critical considerations for a wide range of circuit, sensor, and display technologies. The first objective of this chapter is to provide a review of what is currently known about the fracture and high cycle fatigue behavior of silicon structural films. The second objective is to review the fracture mechanics-based design methodologies that ensure reliable MEMS in safety-critical applications.
Hydrogen Peroxide (H 2 O 2 ) is one of many reactive oxygen species (ROS) that plays vital roles in intracellular signaling and stress processes, but its transient nature has made deciphering its roles in transcellular signaling a significant challenge. We have designed boronate caged small‐molecule probes bearing a fluoromethylene pendant group that serves as a latent quinone methide source that can undergo a tandem activity‐based sensing and biomolecule labeling reaction cascade to produce a spatially localized fluorescence signal upon exposure to H 2 O 2 . This strategy enables us to capture and record spatial information on ROS fluxes and has enabled us to move beyond studying intracellular H 2 O 2 signaling to identifying and mapping cell‐to‐cell H 2 O 2 communication in a microglia‐neuron co‐culture cell model, where selective activation of microglia for ROS production increases H 2 O 2 in nearby neurons.
The electrochemistry of pure aluminum and six alloys containing elements such as Ga, In, Tl, Mg, and Mn in at temperatures of 25°, 50°, and 80°C is reported. Alloy electrodissolution and hydrogen evolution were explored separately by delineating the current/voltage curves for the anodic and cathodic partial reactions using the technique described in Part II of this series (1). Aluminum is shown to be a passive metal in concentrated potassium hydroxide solution, at least at 25° and 50°C, with the active‐to‐passive transition being evident at the lowest temperature. At potentials more positive than the open‐circuit value, aluminum dissolves in the transpassive mode yielding a nearly linear current/voltage curve. The minor alloying elements (particularly Ga, In, Tl, Mn, and Mg) passivate aluminum by forming a protective layer on the base aluminum. Activation of the alloy occurs by the oxidation of this layer to form soluble products; in those alloys containing gallium the oxidation of Ga to appears to determine the critical activation potential . The alloying elements also inhibit hydrogen evolution, partly by decreasing the exchange current density but also by modifying the Tafel constant. The kinetic data for hydrogen evolution have been used to estimate surface coverages of the alloying elements as a function of potential and temperature.
