67 research outputs found

    Radiation-induced hydrogen transfer in metals

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    The paper presents processes of hydrogen (deuterium) diffusion and release from hydrogen-saturated condensed matters in atomic, molecular and ionized states under the influence of the electron beam and X-ray radiation in the pre-threshold region. The dependence is described between the hydrogen isotope release intensity and the current density and the electron beam energy affecting sample, hydrogen concentration in the material volume and time of radiation exposure to the sample. The energy distribution of the emitted positive ions of hydrogen isotopes is investigated herein. Mechanisms of radiation-induced hydrogen transfer in condensed matters are suggested

    When the Ideal Meets the Feasible: Constructing a Protocol for Developmental Assessment at Early School-Age

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    Objective: To describe development of a methodology for an outcome study of children born following in-vitro fertilization or spontaneously-conceived, as a model for defining normal and below-normal development of school-age children for research purposes.Study Design: The main issues addressed were defining the major health and developmental domains to be investigated, selection of age-appropriate validated instruments, considering time constraints to maximize compliance, and budgetary limitations. The final protocol included a half-hour structured telephone interview with mothers of all 759 children and a 2-h developmental assessment of 294 of them. Each of the instruments and recruiting methods are described in terms of the abovementioned considerations.Results: Almost all of the mothers who agreed to be interviewed completed it within the half-hour allotted; however only about half of those who agreed to bring the child for the developmental assessment actually did so. The entire examination battery, assessing cognitive ability, executive functions, attention, and learning skills, was completed by almost all 294 children. There was a significant degree of agreement between the maternal report of the child's reading, writing and arithmetic skills and the in-person examination, as well as regarding the child's weight and height measurements.Conclusion: The findings lend support for a low-budget study, relying on telephone interviews. However, limitations such as the validity of maternal report and recall bias must be taken into consideration

    Cross-Effects in Microgravity Flows

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    Film growth by chemical/physical vapor deposition is a process of considerable interest in microgravity experiments. The absence of natural convection should allow better control of film growth processes but, in highly non-isothermal ampoules, thermal slip (creep) can become a matter of significant concern. The reported research is a theoretical and experimental investigation of the flow of gas/vapor mixtures under non-continuum conditions. The Boltzmann equation has been solved for a monatomic gas under non-condensing conditions and the various phenomenological coefficients have been computed. Computations for realistic potentials as well as for velocity and creep slip have been completed and the creep slip has been found to be dependent on the type of gas confirming the accuracy of previous variational results. The variational technique has been extended and planar flows calculated via the Burnett solutions. Velocity, diffusion and creep slips have been computed for gas mixtures and previously unknown dependencies of the creep slip on the mixture properties have been observed. Also for gas mixtures, an integral representation of the linearized Boltzmann operator has been developed for use in numerical and variational calculations for all intermolecular force laws. Two, two-bulb capillary systems have been designed, built and tested for the measurements of cross-flows; one of glass for isothermal measurements and one of stainless steel for non-isothermal measurements. Extensive data have been collected for Ar-He and N2-He mixtures at a variety of pressures and mole ratios. Viscosity, velocity slip coefficients and tangential momentum accommodation coefficients have been obtained from measurements with a spinning rotor gauge via a new theory that has been formulated for the spinning rotor gauge in the slip regime. The FIDAP fluid dynamics code has been applied to condensing flows in ampoules in the continuum regime and agreement obtained with the earlier work of Duval

    Fetal brain growth and infant autistic traits

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    Background: Structural differences exist in the brains of autistic individuals. To date only a few studies have explored the relationship between fetal brain growth and later infant autistic traits, and some have used fetal head circumference (HC) as a proxy for brain development. These findings have been inconsistent. Here we investigate whether fetal subregional brain measurements correlate with autistic traits in toddlers. Methods: A total of 219 singleton pregnancies (104 males and 115 females) were recruited at the Rosie Hospital, Cambridge, UK. 2D ultrasound was performed at 12-, 20- and between 26 and 30 weeks of pregnancy, measuring head circumference (HC), ventricular atrium (VA) and transcerebellar diameter (TCD). A total of 179 infants were followed up at 18–20 months of age and completed the quantitative checklist for autism in toddlers (Q-CHAT) to measure autistic traits. Results: Q-CHAT scores at 18–20 months of age were positively associated with TCD size at 20 weeks and with HC at 28 weeks, in univariate analyses, and in multiple regression models which controlled for sex, maternal age and birth weight. Limitations: Due to the nature and location of the study, ascertainment bias could also have contributed to the recruitment of volunteer mothers with a higher than typical range of autistic traits and/or with a significant interest in the neurodevelopment of their children. Conclusion: Prenatal brain growth is associated with toddler autistic traits and this can be ascertained via ultrasound starting at 20 weeks gestation

    STRUCTURE AND PROPERTIES OF V90Cо10 MEMBRANE ALLOY

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    Vanadium-based alloys having bcc structure are promising materials for hydrogen separation due to their relatively high hydrogen permeability and low cost in comparison with palladium alloys. Bulk and surface characteristics of the V90Co10 membrane alloy was examined by XRD, SEM, and X-ray photoelectron spectroscopy, confocal scanning microscopy, respectively.Исследование выполнено при финансовой поддержке РФФИ в рамках научного проекта № 16-38-00759мол_а. Работа выполнена с использованием оборудования ЦКП “Урал-М” и НОЦ НАНОТЕХ УрФУ

    Elevated Levels of the Vesicular Monoamine Transporter and a Novel Repetitive Behavior in the Drosophila Model of Fragile X Syndrome

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    Fragile X Syndrome (FXS) is characterized by mental impairment and autism in humans, and it often features hyperactivity and repetitive behaviors. The mechanisms for the disease, however, remain poorly understood. Here we report that the dfmr1 mutant in the Drosophila model of FXS grooms excessively, which may be regulated differentially by two signaling pathways. Blocking metabotropic glutamate receptor signaling enhances grooming in dfmr1 mutant flies, whereas blocking the vesicular monoamine transporter (VMAT) suppresses excessive grooming. dfmr1 mutant flies also exhibit elevated levels of VMAT mRNA and protein. These results suggest that enhanced monoamine signaling correlates with repetitive behaviors and hyperactivity associated with FXS

    Les restes humains du volcan de La Denise près du Puy-en-Velay, Haute-Loire

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    Gabis Renée V. Les restes humains du volcan de La Denise près du Puy-en-Velay, Haute-Loire. In: Bulletins et Mémoires de la Société d'anthropologie de Paris, X° Série. Tome 8 fascicule 5-6, 1957. pp. 205-243
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