Inequalities for electron-field correlation functions

I show that there exists a class of inequalities between correlation functions of different orders of a chaotic electron field. These inequalities lead to the antibunching effect and are a consequence of the fact that electrons are fermions -- indistinguishable particles with antisymmetric states. The derivation of the inequalities is based on the known form of the correlation functions for the chaotic state and on the properties of matrices and determinants.Comment: 8 pages Latex2e, 2 eps figure

Study of explosions in the NASA-MSC Vibration and Acoustic Test Facility /VATF/ Final report

Damage potential of titanium alloy pressure spheres relative to spacecraft vibration testin

Correlation Functions and Spin

The k-electron correlation function of a free chaotic electron beam is derived with the spin degree of freedom taken into account. It is shown that it can be expressed with the help of correlation functions for a polarized electron beam of all orders up to k and the degree of spin polarization. The form of the correlation function suggests that if the electron beam is not highly polarized, observing multi-particle correlations should be difficult. The result can be applied also to chaotic photon beams, the degree of spin polarization being replaced by the degree of polarization.Comment: 6 pages, 1 eps figure, accepted to Phys. Rev.

The Effects of Negative Legacies on the Adjustment of Parentally Bereaved Children and Adolescents

This is a report of a qualitative analysis of a sample of bereaved families in which one parent died and in which children scored in the clinical range on the Child Behavior Check List. The purpose of this analysis was to learn more about the lives of these children. They were considered to be at risk of developing emotional and behavioral problems associated with the death. We discovered that many of these “high risk” children had a continuing bond with the deceased that was primarily negative and troubling for them in contrast to a comparison group of children not at risk from the same study. Five types of legacies, not mutually exclusive, were identified: health related, role related, personal qualities, legacy of blame, and an emotional legacy. Coping behavior on the part of the surviving parent seemed to make a difference in whether or not a legacy was experienced as negative

Low-latitude auroras: the magnetic storm of 14–15 May 1921

We review solar/geophysical data relating to the great magnetic storm of 14–15 May 1921, with emphasis on observations of the low-latitude visual aurora. From the reports we have gathered for this event, the lowest geomagnetic latitude of de6nite overhead aurora (coronal form) was 40° and the lowest geomagnetic latitude from which auroras were observed on the poleward horizon in the northern hemisphere was 30°. For comparison, corresponding overhead/low-latitude values of 48°/32° and 41°/20° were reported for the great auroras on 28–29 August and 1–2 September 1859, respectively. However, for the 1921 event, there is a report of aurora from Apia, Samoa, in the southern hemisphere, within 13◦ of the geomagnetic equator. This report by professional observers appears to be credible, based on the aurora description and timing, but is puzzling because of the discrepancy with the lowest latitude of observation in the northern hemisphere and the great implied auroral height (~ 2000 km, assuming overhead aurora at Auckland, New Zealand). We discuss various possibilities that might account for this observation

Low-latitude auroras: the magnetic storm of 14–15 May 1921

We review solar/geophysical data relating to the great magnetic storm of 14–15 May 1921, with emphasis on observations of the low-latitude visual aurora. From the reports we have gathered for this event, the lowest geomagnetic latitude of de6nite overhead aurora (coronal form) was 40° and the lowest geomagnetic latitude from which auroras were observed on the poleward horizon in the northern hemisphere was 30°. For comparison, corresponding overhead/low-latitude values of 48°/32° and 41°/20° were reported for the great auroras on 28–29 August and 1–2 September 1859, respectively. However, for the 1921 event, there is a report of aurora from Apia, Samoa, in the southern hemisphere, within 13◦ of the geomagnetic equator. This report by professional observers appears to be credible, based on the aurora description and timing, but is puzzling because of the discrepancy with the lowest latitude of observation in the northern hemisphere and the great implied auroral height (~ 2000 km, assuming overhead aurora at Auckland, New Zealand). We discuss various possibilities that might account for this observation

Programmable telemetry system Patent

Time division multiplexed telemetry transmitting system controlled by programmed memor

The X-ray luminosity function of AGN at z~3

We combine Lyman-break colour selection with ultradeep (> 200 ks) Chandra X-ray imaging over a survey area of ~0.35 deg^2 to select high redshift AGN. Applying careful corrections for both the optical and X-ray selection functions, the data allow us to make the most accurate determination to date of the faint end of the X-ray luminosity function (XLF) at z~3. Our methodology recovers a number density of X-ray sources at this redshift which is at least as high as previous surveys, demonstrating that it is an effective way of selecting high z AGN. Comparing to results at z=1, we find no evidence that the faint slope of the XLF flattens at high z, but we do find significant (factor ~3.6) negative evolution of the space density of low luminosity AGN. Combining with bright end data from very wide surveys we also see marginal evidence for continued positive evolution of the characteristic break luminosity L*. Our data therefore support models of luminosity-dependent density evolution between z=1 and z=3. A sharp upturn in the the XLF is seen at the very lowest luminosities (Lx < 10^42.5 erg s^-1), most likely due to the contribution of pure X-ray starburst galaxies at very faint fluxes.Comment: 16 pages, 9 figures, accepted for publication in MNRA

Strategic alliances and interfirm knowledge transfer

This paper examines interfirm knowledge transfers within strategic alliances. Using a new measure of changes in alliance partners' technological capabilities, based on the citation patterns of their patent portfolios, we analyze changes in the extent to which partner firms' technological resources ‘overlap’ as a result of alliance participation. This measure allows us to test hypotheses from the literature on interfirm knowledge transfer in alliances, with interesting results: we find support for some elements of this ‘received wisdom’—equity arrangements promote greater knowledge transfer, and ‘absorptive capacity’ helps explain the extent of technological capability transfer, at least in some alliances. But the results also suggest limits to the ‘capabilities acquisition’ view of strategic alliances. Consistent with the argument that alliance activity can promote increased specialization, we find that the capabilities of partner firms become more divergent in a substantial subset of alliances.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/106908/1/4250171108_ftp.pd