Application of local linearization and the transonic equivalence rule to the flow about slender analytic bodies at Mach numbers near 1.0

The local linearization method for axisymmetric flow is combined with the transonic equivalence rule to calculate pressure distribution on slender bodies at free-stream Mach numbers from .8 to 1.2. This is an approximate solution to the transonic flow problem which yields results applicable during the preliminary design stages of a configuration development. The method can be used to determine the aerodynamic loads on parabolic arc bodies having either circular or elliptical cross sections. It is particularly useful in predicting pressure distributions and normal force distributions along the body at small angles of attack. The equations discussed may be extended to include wing-body combinations

V-Mail (Victory Mail) Letter, W. A. Tyson in Tupelo, Mississippi to Major Rollin S. Armstrong, in North Africa, October 30, 1943

This typed V-Mail (Victory Mail) letter, dated October 30, 1943, is written by W. A. Tyson, the pastor of the First Methodist Church in Tupelo, Mississippi, to Major Rollin S. Armstrong from where he is stationed in North Africa. The letter describes Tyson\u27s recent visit with Armstrong\u27s newborn son and encourages the new father.https://scholarsjunction.msstate.edu/mss-armstrong-papers/1053/thumbnail.jp

Aviation Education - Why?

I will outline four areas which I believe encompass the reasons the industry has formed the National Coalition for Aviation Education (NCAE). I\u27ll talk about the confluence of factors which influenced the aviation industry to establish the NCAE and what the organizing associations see as its mission. I\u27ll speak on some of the special needs that NCAE can assist educators in regarding the training and education of young people as well as the existing aviation workforce. I\u27ll look into the need for all of us involved in aviation education to work together to build effective political constituencies at the local, state, and national levels. We need to influence both the public and our governmental decision-makers so that we can revitalize an industry that once dominated world technology and manufacturing, and the hearts, dreams and ambitions of many young people who looked to the stars as their way to future success

Instrumentation of sampling aircraft for measurement of launch vehicle effluents

An aircraft was selected and instrumented to measure effluents emitted from large solid propellant rockets during launch activities. The considerations involved in aircraft selection, sampling probes, and instrumentation are discussed with respect to obtaining valid airborne measurements. Discussions of the data acquisition system used, the instrument power system, and operational sampling procedures are included. Representative measurements obtained from an actual rocket launch monitoring activity are also presented

Psychosocial Mechanisms Underlying Older Black Men’s Health

Objectives: To evaluate the psychosocial mechanisms underlying older Black men's self-rated health, we examined: (a) the individual, cumulative, and collective effects of stressors on health; (b) the direct effects of psychosocial resources on health; and (c) the stress-moderating effects of psychosocial resources. Method: This study is based on a nationally representative sample of Black men aged 51-81 (N = 593) in the Health and Retirement Study (HRS). Ordinary least squares (OLS) regression models of the psychosocial determinants of self-rated health draw on data from the HRS 2010 and 2012 Core datasets and Psychosocial Modules. Results: Each of the six measures of stressors as well as a cumulative measure of stressors are predictive of worse self-rated health. However, when considered collectively, only two stressors (chronic strains and traumatic events) have statistically significant effects. Furthermore, two of the five psychosocial resources examined (mastery and optimism) have statistically significant protective effects, and prayer moderates the harmful effects of traumatic events on self-rated health. Discussion: Conventional measures of stressors and coping resources-originally developed to account for variance in health outcomes among predominantly white samples-may not capture psychosocial factors most salient for older Black men's health. Future research should incorporate psychosocial measures that reflect their unique experiences

Spin-Coupled Local Distortions in Multiferroic Hexagonal HoMnO3

Local structural measurements have been performed on hexagonal HoMnO3 in order to ascertain the specific changes in bond distances which accompany magnetic ordering transitions. The transition from paramagnetic to the antiferromagetic (noncollinear) phase near ~70 K is dominated by changes in the a-b plane Mn-Mn bond distances. The spin rotation transition near ~40 K involves both Mn-Mn and nearest neighbor Ho-Mn interactions while the low temperature transition below 10 K involves all interactions, Mn-Mn, Ho-Mn (nearest and next nearest) and Ho-Ho correlations. These changes in bond distances reveal strong spin-lattice coupling. The similarity in magnitude of the change in J(Mn-Mn) and J(Ho-Mn) enhances the system frustration. The structural changes are interpreted in terms of a model of competing spin order and local structural distortions. Density functional calculations are used to estimate the energies associated with ionic displacements. The calculations also reveal asymmetric polarization of the charge density of Ho, O3 and O4 sites along the z-axis in the ferroelectric phase. This polarization facilitates coupling between Ho atoms on neighboring planes normal to the z-axis.Comment: 8 figure

CRISPR-mediated phage resistance and the ghost of coevolution past

The past is never dead. It's not even pastWilliam Faulkner (1951

Experiments On Delayed Failure During Galvanizing Of Flame-Cut Structural Steels

Cracks have occasionally been found after hot-dip galvanizing of flame-cut structural beams. A project has been completed at CANMET to find the causes of this problem. Experiments have been designed to measure the time-to-failure of notched samples under near-constant load. Cracking during galvanizing is caused by liquid-metal embrittlement, and occurs for critical combinations of stress and susceptible material. Sources of stress are residual stresses including those from flame cutting, and thermal stresses from thermal gradients during hot dipping. Material susceptibility is related primarily to surface hardness, and correlates well with micro-hardness measured at 100 micrometres depth. Remedial measures to eliminate cracking require either reduction of the hardness below a critical level (270 Vickers), or reduction of residual and thermal stresses

My True Heart In Days Of Old

https://digitalcommons.library.umaine.edu/mmb-vp/2246/thumbnail.jp

Classification of image distortions in terms of Petrov types

An observer surrounded by sufficiently small spherical light sources at a fixed distance will see a pattern of elliptical images distributed over the sky, owing to the distortion effect (shearing effect) of the spacetime geometry upon light bundles. In lowest non-trivial order with respect to the distance, this pattern is completely determined by the conformal curvature tensor (Weyl tensor) at the observation event. In this paper we derive formulas that allow to calculate these distortion patterns in terms of the Newman-Penrose formalism. Then we represent the distortion patterns graphically for all Petrov types, and we discuss their dependence on the velocity of the observer.Comment: 22 pages, 8 eps-figures; revised version, parts of Introduction and Conclusions rewritte