Development of welding techniques and filler metals for high strength aluminum alloys second quarterly report, 1 oct. - 31 dec. 1964

Welding techniques and filler metals for high strength aluminum alloys evaluated by bulge test progra

Electrostatic electron cyclotron instabilities near the upper hybrid layer due to electron ring distributions

A theoretical study is presented of the electrostatic electron cyclotron instability involving Bernstein modes in a magnetized plasma. The presence of a tenuous thermal ring distribution in a Maxwellian plasma decreases the frequency of the upper hybrid branch of the electron Bernstein mode until it merges with the nearest lower branch with a resulting instability. The instability occurs when the upper hybrid frequency is somewhat above the third, fourth, and higher electron cyclotron harmonics, and gives rise to a narrow spectrum of waves around the electron cyclotron harmonic nearest to the upper hybrid frequency. For a tenuous cold ring distribution together with a Maxwellian distribution an instability can take place also near the second electron cyclotron harmonic. Noise-free Vlasov simulations are used to assess the theoretical linear growth-rates and frequency spectra, and to study the nonlinear evolution of the instability. The relevance of the results to laboratory and ionospheric heating experiments is discussed

Social and emotional components of book reading between caregivers and their toddlers in a high-risk sample

In this collective case study of caregiver behaviors with their toddlers, two-minute videotaped reading interactions were analyzed using a constant comparative method. Twenty-four caregiver—toddler dyads from a high-risk sample of children prenatally exposed to cocaine were selected from a larger sample because they represented the extremes of expressive language scores on the Reynell Expressive Language Quotient at 36 months, one year after the reading interactions. Caregivers in the high-scoring group shared control of the book and discourse, were ‘in tune’ with the child’s needs and abilities, and answered their own questions to the children. This was in contrast to the behaviors of caregivers of the low-scoring children, who appeared unaware of the child’s developmental needs in the interaction, particularly in their ability to respond to the questions posed. Implications of the results for future research on caregiver reading with young children are discussed

Profiles of Temperament and Perfectionism in High Ability College Students

Different physical, mental, and motivational outcomes for perfectionistic strivings and perfectionistic concerns indicate that individuals have different experiences of perfectionism. Although research has focused on parenting practices as a factor related to these differences, little research has examined the impact of temperamental differences on perfectionism. In the current study, 434 high ability undergraduate students completed perfectionism, adult temperament, and personality measures. Latent class analysis that examined the patterns among the relationships between self-oriented perfectionism, socially prescribed perfectionism, and four dimensions of adult temperament (negative affect, effortful control, extraversion, orienting sensitivity) revealed three distinct subgroups. Although the largest subgroup demonstrated patterns consistent with prior research on perfectionism (e.g., perfectionism associated with negative affect), two other subgroups revealed separate patterns that were inconsistent with prior research (e.g., one subgroup had negative relationships between negative affect and both types of perfectionism). Our results demonstrate that temperament may play an important role in explaining the heterogeneity among perfectionists

Integrative, In Silico and Comparative Analysis of Breast Cancer Secretome Highlights Invasive-Ductal-Carcinoma-Grade Progression Biomarkers

Funding: This research was funded by NHS Grampian Endowment Fund grant number NER11101 Acknowledgments: The authors would like to thank the NHS Grampian Breast Cancer Endowment Fund body for supporting the publication of the present manuscript and funding publication fees.Peer reviewedPublisher PD

Development of welding techniques and filler metals for high strength aluminum alloys Annual summary report, 27 Jun. 1964 - 27 Jun. 1965

Welding techniques and filler metals for high strength aluminum alloy

Water Entry of a Simple Harmonic Oscillator

When a blunt body impacts an air-water interface, large hydrodynamic forces often arise, a phenomenon many of us have unfortunately experienced in a failed dive or "belly flop." Beyond assessing risk to biological divers, an understanding and methods for remediation of such slamming forces are critical to the design of numerous engineered naval and aerospace structures. Herein we systematically investigate the role of impactor elasticity on the resultant structural loads in perhaps the simplest possible scenario: the water entry of a simple harmonic oscillator. Contrary to conventional intuition, we find that "softening" the impactor does not always reduce the peak impact force, but may also increase the force as compared to a fully rigid counterpart. Through our combined experimental and theoretical investigation, we demonstrate that the transition from force reduction to force amplification is delineated by a critical "hydroelastic" factor that relates the hydrodynamic and elastic timescales of the problem