Thin-film ZnO charge-trapping memory cell grown in a single ALD step

Cataloged from PDF version of article.A thin-film ZnO-based single-transistor memory cell with a gate stack deposited in a single atomic layer deposition step is demonstrated. Thin-film ZnO is used as channel material and charge-trapping layer for the first time. The extracted mobility and subthreshold slope of the thin-film device are 23 cm2/V · s and 720 mV/dec, respectively. The memory effect is verified by a 2.35-V hysteresis in the Idrain–Vgate curve. Physics-based TCAD simulations show very good agreement with the experimental results providing insight to the charge-trapping physics

Electroluminescence efficiencies of erbium in silicon-based hosts

International audienceWe report on room-temperature 1.5 lm electroluminescence from trivalent erbium (Er3þ) ionsembedded in three different CMOS-compatible silicon-based hosts: SiO2, Si3N4, and SiNx. We showthat although the insertion of either nitrogen or excess silicon helps enhance electrical conductionand reduce the onset voltage for electroluminescence, it drastically decreases the external quantumefficiency of Er3þ ions from 2% in SiO2 to 0.001% and 0.0004% in SiNx and Si3N4, respectively.Furthermore, we present strong evidence that hot carrier injection is significantly more efficient thandefect-assisted conduction for the electrical excitation of Er3þ ions. These results suggest strategiesto optimize the engineering of on-chip electrically excited silicon-based nanophotonic light sources

Overcoming the Challenges Associated with Image-based Mapping of Small Bodies in Preparation for the OSIRIS-REx Mission to (101955) Bennu

The OSIRIS-REx Asteroid Sample Return Mission is the third mission in NASA's New Frontiers Program and is the first U.S. mission to return samples from an asteroid to Earth. The most important decision ahead of the OSIRIS-REx team is the selection of a prime sample-site on the surface of asteroid (101955) Bennu. Mission success hinges on identifying a site that is safe and has regolith that can readily be ingested by the spacecraft's sampling mechanism. To inform this mission-critical decision, the surface of Bennu is mapped using the OSIRIS-REx Camera Suite and the images are used to develop several foundational data products. Acquiring the necessary inputs to these data products requires observational strategies that are defined specifically to overcome the challenges associated with mapping a small irregular body. We present these strategies in the context of assessing candidate sample-sites at Bennu according to a framework of decisions regarding the relative safety, sampleability, and scientific value across the asteroid's surface. To create data products that aid these assessments, we describe the best practices developed by the OSIRIS-REx team for image-based mapping of irregular small bodies. We emphasize the importance of using 3D shape models and the ability to work in body-fixed rectangular coordinates when dealing with planetary surfaces that cannot be uniquely addressed by body-fixed latitude and longitude.Comment: 31 pages, 10 figures, 2 table

Effect of farnesol on structure and composition of staphylococcus epidermidis biofilm matrix

Staphylococcus epidermidis is the most frequent cause of nosocomial sepsis and catheter-related infections in which biofilm formation is considered to be one of the main virulence mechanisms. Moreover, their increased resistance to conventional antibiotic therapy enhances the need to develop new therapeutical agents. Farnesol, a natural sesquiterpenoid present in many essential oils, has been described as impairing bacterial growth. The aim of this study was to evaluate the effect of farnesol on the structure and composition of biofilm matrix of S. epidermidis. Biofilms formed in the presence of farnesol (300 μM) contained less biomass, and displayed notable changes in the composition of the biofilm matrix. Changes in the spacial structure were also verified by confocal scanning laser microscopy (CSLM). The results obtained by the quantification of extracellular polymers and by wheat germ agglutinin (WGA) fluorescent detection of glycoproteins containing β(1→4)-N-acetyl-d-glucosamine support the hypothesis that farnesol causes disruption of the cytoplasmic membrane and consequently release of cellular content.Fernanda Gomes and Pilar Teixeira fully acknowledge the financial support of Fundacao para a Ciencia e Tecnologia (FCT) through the grants SFRH/BD/32126/2006 and SFRH/BPD/26803/2006, respectively

Comparative Morphological Studies on Lyssa in Carnivores and Camels with Special Reference to Its Surgical Resection

The lyssa is a morphologically supporting structure situated along the median plan on the ventral surface of the apex of the tongue in some animals. The present study aimed to describe the morphological differences of the lyssa in carnivores (dog and cat) and camel using conformist macroscopic and microscopic methods as well as evaluation of its surgical resection in the dog and cat. The lyssa is a rod-shaped in dog, strip like structure in cat and ridge-like structure in camel. It showed straight course in dog and helical appearance in cat. In the studied species, the lyssa was formed from adipose tissue intermingled with irregular connective tissue. However, dense striated muscles fibers were seen in the caudal half of the lyssa in dog. Besides, few bundles of longitudinally running muscle fibers were observed in cat and camel. In dog, the lyssa was defined by a coarse sheath of connective tissue, this capsule was ill-defined in cat and absent in camel. In cat, a pyramidal extension of the adipose tissue of the lyssa was attached to intrinsic striated muscle of the tongue. Full function of the tongue could be achieved after surgical resection of lyssa in dogs and cats

Titan's diverse landscapes as evidenced by Cassini RADAR's third and fourth looks at Titan

International audienceCassini's third and fourth radar flybys, T7 and T8, covered diverse terrains in the high southern and equatorial latitudes, respectively. The T7 synthetic aperture radar (SAR) swath is somewhat more straightforward to understand in terms of a progressive poleward descent from a high, dissected, and partly hilly terrain down to a low flat plain with embayments and deposits suggestive of the past or even current presence of hydrocarbon liquids. The T8 swath is dominated by dunes likely made of organic solids, but also contain somewhat enigmatic, probably tectonic, features that may be partly buried or degraded by erosion or relaxation in a thin crust. The dark areas in T7 show no dune morphology, unlike the dark areas in T8, but are radiometrically warm like the dunes. The Huygens landing site lies on the edge of the T8 swath; correlation of the radar and Huygens DISR images allows accurate determination of its coordinates, and indicates that to the north of the landing site sit two large longitudinal dunes. Indeed, had the Huygens probe trajectory been just 10 km north of where it actually was, images of large sand dunes would have been returned in place of the fluvially dissected terrain actually seen?illustrating the strong diversity of Titan's landscapes even at local scales

Early mortality and primary causes of death in mothers of children with ID or ASD: a retrospective cohort study

INTRODUCTION: Mothers of children with intellectual disability or autism spectrum disorder (ASD) have poorer health than other mothers. Yet no research has explored whether this poorer health is reflected in mortality rates or whether certain causes of death are more likely. We aimed to calculate the hazard ratios for death and for the primary causes of death in mothers of children with intellectual disability or ASD compared to other mothers. METHODS: The study population comprised all mothers of live-born children in Western Australia from 1983-2005. We accessed state-wide databases which enabled us to link socio-demographic details, birth dates, diagnoses of intellectual disability or ASD in the children and dates and causes of death for all mothers who had died prior to 2011. Using Cox Regression with death by any cause and death by each of the three primary causes as the event of interest, we calculated hazard ratios for death for mothers of children intellectual disability or ASD compared to other mothers. RESULTS AND DISCUSSION: During the study period, mothers of children with intellectual disability or ASD had more than twice the risk of death. Mothers of children with intellectual disability were 40% more likely to die of cancer; 150% more likely to die of cardiovascular disease and nearly 200% more likely to die from misadventure than other mothers. Due to small numbers, only hazard ratios for cancer were calculated for mothers of children with ASD. These mothers were about 50% more likely to die from cancer than other mothers. Possible causes and implications of our results are discussed. CONCLUSION: Similar studies, pooling data from registries elsewhere, would improve our understanding of factors increasing the mortality of mothers of children with intellectual disability or ASD. This would allow the implementation of informed services and interventions to improve these mothers' longevity

Analysis of Tangential Slot Blowing on F/A-18 Isolated Forebody

The generation of significant side forces and yawing moments on an F/A-18 fuselage through tangential slot blowing is analyzed using computational fluid dynamics. The effects of freestream Mach number, jet exit conditions, jet length, and jet location are studied. The effects of over- and underblowing on force and moment production are analyzed. Non-time-accurate solutions are obtained to determine the steady-state side forces, yawing moments, and surface pressure distributions generated by tangential slot blowing. Time-accurate solutions are obtained to study the force onset time lag of tangential slot blowing. Comparison with available experimental data from full-scale wind-tunnel and subscale wind-tunnel tests are made. This computational analysis complements the experimental results and provides a detailed understanding of the effects of tangential slot blowing on the flowfield about the isolated F/A-18 forebody. Additionally, it extends the slot-blowing database to transonic maneuvering Mach numbers