494 research outputs found

    Field ion microscope investigations of solid solutions Annual report

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    Ion microscopic studies of solute atoms in solid solution lattice

    Quantitative treatment of the creep of metals by dislocation and rate-process theories

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    An equation for the steady-state rate of creep has been derived by applying the theory of dislocations to the creep of pure metals. The form of this equation is in agreement with empirical equations describing creep rates. The theory was also used to predict the dependence of steady-state rate of creep on physical constants of the material and good agreement was obtained with data in the literature for pure annealed metals. The rate of creep was found to decrease with increasing modulus of rigidity. This relation suggest that one of the requirements for a heat-resisting alloy is that its matrix be a metal that has a high modulus of rigidity and therefore a high modulus of elasticity

    A survey of the behavior of carbon in tungsten as revealed by field-ion microscopy technical report no. 1

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    Behavior of carbon in tungsten as revealed by field-ion microscop

    Sequence of a Brassica campestris Myrosinase Gene

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    Child Anxiety and Depression Symptom Trajectories and Predictors over 15 Months of the Coronavirus Pandemic

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    Repeated measures are required to monitor and map trajectories of mental health symptoms that are sensitive to the changing distal and proximal stressors throughout the coronavirus (COVID-19) pandemic. Understanding symptoms in young children is particularly important given the short- and long-term implications of early-onset internalizing symptoms. This study utilized an intensive longitudinal approach to assess the course and environmental correlates of anxiety and depression symptoms in 133 children, ages 4–11 (Mage = 7.35, SD = 1.03), in the United States during the COVID-19 pandemic. Caregivers completed 48 repeated assessments from April 7, 2020, to June 15, 2021, on child and caregiver mental health symptoms, family functioning, and COVID-19-related environmental changes. Results from a series of multilevel growth models demonstrate that child depression symptoms were highest following initial stay-at-home orders (April 2020) and linearly decreased over time, while child anxiety symptoms were variable over the 15-month period. Caregiver depression symptoms and family conflict significantly predicted levels of child depression symptoms. In contrast, caregiver depression symptoms, caregiver anxiety symptoms, and time spent home quarantining significantly predicted levels of child anxiety symptoms. Results suggest that depression and anxiety symptoms in young children may have unique trajectories over the course of the coronavirus pandemic and highlight symptom-specific risk factors for each symptom
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