Some NASA contributions to human factors engineering: A survey

This survey presents the NASA contributions to the state of the art of human factors engineering, and indicates that these contributions have a variety of applications to nonaerospace activities. Emphasis is placed on contributions relative to man's sensory, motor, decisionmaking, and cognitive behavior and on applications that advance human factors technology

The landing task and pilot acceptance of displays for landing in reduced weather minimums

Landing task and pilot acceptance of displays for landing in reduced weather minim

Carrier-induced ferromagnetism in n-type ZnMnAlO and ZnCoAlO thin films at room temperature

The realization of semiconductors that are ferromagnetic above room temperature will potentially lead to a new generation of spintronic devices with revolutionary electrical and optical properties. Transition temperatures in doped ZnO are high but, particularly for Mn doping, the reported moments have been small. We show that by careful control of both oxygen deficiency and aluminium doping the ferromagnetic moments measured at room temperature in n-type ZnMnO and ZnCoO are close to the ideal values of 5mB and 3mB respectively. Furthermore a clear correlation between the magnetisation per transition metal ion and the ratio of the number of carriers to the number of transition metal donors was established as is expected for carrier induced ferromagnetism for both the Mn and Co doped films. The dependence of the magnetisation on carrier density is similar to that predicted for the transition temperature for a dilute magnetic semiconductor in which the exchange between the transition metal ions is through the free carriers.Comment: 14 pages pd

Spin polarized transport current in n-type co-doped ZnO thin films measured by Andreev spectroscopy

We use point contact Andreev reflection measurements to determine the spin polarization of the transport current in pulse laser deposited thin films of ZnO with 1% Al and with and without 2%Mn. Only films with Mn are ferromagnetic and show spin polarization of the transport current of up to 55 $\pm$ 0.5% at 4.2 K, in sharp contrast to measurements of the nonmagnetic films without Mn where the polarization is consistent with zero. Our results imply strongly that ferromagnetism in these Al doped ZnO films requires the presence of Mn.Comment: Published versio

Socioeconomic inequalities in duration of untreated psychosis : evidence from administrative data in England

Background. Duration of untreated psychosis (DUP) is an important measure of access to care as it predicts prognosis and treatment outcomes. Little is known about potential socioeconomic inequalities in DUP. The aim of this study was to investigate inequalities in DUP associated with socioeconomic deprivation in a national cohort in England. Method. We analysed a cohort of 887 patients with a first-episode in psychosis using the administrative Mental Health Services Dataset in England. We used a Generalised Linear Model to account for non-linearity in DUP and looked at inequalities across the whole distribution of DUP using quantile regression. Results. The median DUP was 22 days (mean = 74 days) with considerable variations between and within the 31 hospital providers. We found evidence of significant inequalities regarding the level of socioeconomic deprivation. Patients living in the second, third, and fourth deprived neighbourhood quintiles faced a 36, 24, and 31 day longer DUP than patients from the least deprived neighbourhoods. Inequalities were more prevalent in higher quantiles of the DUP distribution. Unemployment prolonged DUP by 40 days. Having been in contact with mental health care services prior to the psychosis start significantly reduced the DUP by up to 53 days. Conclusions. Socioeconomic deprivation is an important factor in explaining inequalities in DUP. Policies to improve equitable access to care should particularly focus on preventing very long delays in treatment and target unemployed patients as well as people that have not been in contact with any mental health professional in the past