Tactical Air Power Controversies in Normandy: A Question of Doctrine

The history of tactical air power in the battle of Normandy has been fraught with both misunderstanding and contradiction. Largely ignored by the army-centric historians who have written the histories of the campaign, it has been asserted on the one hand that Allied air power was overwhelming and on the other that the system for controlling it was cumbersome and ineffective. On the face of it, at least, there would appear to be some tension between those two schools of thought. Which is more accurate? In order to examine that question, it is important to begin with an understanding of the doctrine for tactical air power—the contemporary doctrine of the time—and disputes about both that doctrine and the role of air power in the campaign. What emerges is that there is enough blame to go around for all parties—and enough credit. In truth, the doctrine of the time was under-developed, and this simply reflected some of the larger doctrinal weaknesses of the Western Allies’ militaries

Managing a Farm in the Corn Borer Area

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Trends in office internal gains and the impact on space heating and cooling demands

Internal gains from occupants, equipment and lighting contribute a significant proportion of the heat gains in an office space. Looking at trends in Generation-Y, it appears there are two diverging paths for future ICT demand: one where energy demand is carefully regulated and the other where productivity enhancers such as multiple monitors and media walls causes an explosion of energy demand within the space. These internal gains scenarios were simulated on a variety of different building archetypes to test their influence on the space heating and cooling demand. It was demonstrated that in offices with a high quality facade, internal gains are the dominant factor. As a case study, it was shown that natural ventilation is only possible when the ICT demand is carefully regulated

High performance thermoplastics: A review of neat resin and composite properties

A review was made of the principal thermoplastics used to fabricate high performance composites. Neat resin tensile and fracture toughness properties, glass transition temperatures (Tg), crystalline melt temperatures (Tm) and approximate processing conditions are presented. Mechanical properties of carbon fiber composites made from many of these thermoplastics are given, including flexural, longitudinal tensile, transverse tensile and in-plane shear properties as well as short beam shear and compressive strengths and interlaminar fracture toughness. Attractive features and problems involved in the use of thermo-plastics as matrices for high performance composites are discussed

Pulsar Spin--Velocity Alignment: Further Results and Discussion

The reported alignment between the projected spin-axes and proper motion directions of pulsars is revisited in the light of new data from Jodrell Bank and Effelsberg. The present investigation uses 54 pulsars, the largest to date sample of pulsars with proper-motion and absolute polarisation, to study this effect. Our study has found strong evidence for pulsar spin-velocity alignment, excluding that those two vectors are completely uncorrelated, with >99% confidence. Although we cannot exclude the possibility of orthogonal spin-velocity configurations, comparison of the data with simulations shows that the scenario of aligned vectors is more likely than that of the orthogonal case. Moreover, we have determined the spread of velocities that a spin-aligned and spin-orthogonal distribution of kicks must have to produce the observed distribution of spin-velocity angle offsets. If the observed distribution of spin-velocity offset angles is the result of spin-aligned kicks, then we find that the distribution of kick-velocity directions must be broad with {\sigma}_v~30\degree if the orthogonal-kick scenario is assumed, then the velocity distribution is much narrower with {\sigma}_v<10\degree. Finally, in contrast to previous studies, we have performed robustness tests on our data, in order to determine whether our conclusions are the result of a statistical and/or systematic bias. The conclusion of a correlation between the spin and velocity vectors is independent of a bias introduced by subsets in the total sample. Moreover, we estimate that the observed alignment is robust to within 10% systematic uncertainties on the determination of the spin-axis direction from polarisation data.Comment: 20 pages, 7 figures, 1 Table, accepted in MNRA

Competing Magnetic Fluctuations in Iron Pnictide Superconductors: Role of Ferromagnetic Spin Correlations Revealed by NMR

In the iron pnictide superconductors, theoretical calculations have consistently shown enhancements of the static magnetic susceptibility at both the stripe-type antiferromagnetic (AFM) and in-plane ferromagnetic (FM) wavevectors. However, the possible existence of FM fluctuations has not yet been examined from a microscopic point of view. Here, using $^{75}$As NMR data, we provide clear evidence for the existence of FM spin correlations in both the hole- and electron-doped BaFe$_2$As$_2$ families of iron-pnictide superconductors. These FM fluctuations appear to compete with superconductivity and are thus a crucial ingredient to understanding the variability of $T_{\rm c}$ and the shape of the superconducting dome in these and other iron-pnictide families.Comment: 5 pages, 4 figures, accepted for publication in Phys. Rev. Let

Destined for (Un)Happiness: Does Childhood Predict Adult Life Satisfaction?

In this paper we address the question of how much of adult life satisfaction is predicted by childhood traits, parental characteristics and family socioeconomic status. Given the current focus of many national governments on measuring population well-being, and renewed focus on effective policy interventions to aid disadvantaged children, we study a cohort of children born in a particular week in 1958 in Britain who have been repeatedly surveyed for 50 years. Importantly, at four points in their adult lives this cohort has been asked about their life satisfaction (at ages 33, 42, 46, and 50). A substantive finding is that characteristics of the child and family at birth predict no more than 1.2% of the variance in average adult life satisfaction. A comprehensive set of child and family characteristics at ages 7, 11 and 16 increases the predictive power to only 2.8%, 4.3% and 6.8%, respectively. We find that the conventional measures of family socioeconomic status, in the form of parental education, occupational class and family income, are not strong predictors of adult life satisfaction. However, we find robust evidence that non-cognitive skills as measured by childhood behavioural-emotional problems, and social maladjustment, are powerful predictors of whether a child grows up to be a satisfied adult. We also find that some aspects of personality are important predictors. Adding contemporaneous adulthood variables for health and socio-economic status increases the predictability of average life satisfaction to 15.6%, while adding long-lags of life satisfaction increases the predictive power to a maximum of 35.5%. Repeating our analyses using data from the 1970 British Cohort Study confirms our main findings. Overall, the results presented in the paper point to average adult life satisfaction not being strongly predictable from a wide-range of childhood and family characteristics by age 16, which implies that there is high equality of opportunity to live a satisfied life, at least for individuals born in Britain in 1958 and 1970.childhood, socioeconomic status, life satisfaction, non-cognitive, cognitive

Mental Health and Labour Market Participation: Evidence from IV Panel Data Models

A large body of empirical research links mental health and labour market outcomes; however, there are few studies that effectively control for the two-way causality between work and health and the existence of unobserved individual characteristics that might jointly determine health and labour market outcomes. In this study, we estimate the effect of mental health on labour market participation using various models, including instrumental variable models that exploit individual variation observed in panel data. We find robust evidence that a reduction in mental health has a substantial negative impact on the probability of actively participating in the labour market. We calculate that a one standard deviation decrease in mental health decreases the probability of participation by around 17 percentage points. This effect is larger for females and for older individuals. We therefore provide robust evidence that there are substantial costs due to the lost productivity resulting from poor mental health.measurement error, mental health, labour market participation, causality