Countering Asymmetrical Warfare in the 21st Century; Strategic Insights, v. 7 issue 3 (July 2008)

This article appeared in Strategic Insights, v.7 issue 3 (July 2008)Approved for public release; distribution is unlimited

Commensurability oscillations due to pinned and drifting orbits in a two-dimensional lateral surface superlattice

We have simulated conduction in a two-dimensional electron gas subject to a weak two-dimensional periodic potential, $V_x \cos(2\pi x/a) + V_y \cos(2\pi y/a)$. The usual commensurability oscillations in $\rho_{xx}(B)$ are seen with $V_x$ alone. An increase of $V_y$ suppresses these oscillations, rather than introducing the additional oscillations in $\rho_{yy}(B)$ expected from previous perturbation theories. We show that this behavior arises from drift of the guiding center of cyclotron motion along contours of an effective potential. Periodic modulation in the magnetic field can be treated in the same way.Comment: 3 pages text, 4 eps figures, revte

The Limits of Sovereignty: Property Confiscation in the Union and the Confederacy During the Civil War

Property and the Law in the Confederacy Among the thousands of political and military histories of the Civil War, its battles, leaders, soldiers, nurses, plantation wives, horses, weapons, blockade-runners, spies, new technologies, slave narratives, railroads, photographers, mapmakers, and...

Modeling the Random Component of Manufacturing Yield of Integrated Circuits.

A model is created for the number of integrated circuits that are good from each wafer on which they are fabricated. The goal is to separate the random or common cause loss from the systematic or special loss. The random loss from this type of process is modeled so that false alarms indicating systematic loss are less likely to occur and so that the structure of the systematic loss can be determined

Deterministic Domain Wall Motion Orthogonal To Current Flow Due To Spin Orbit Torque.

Spin-polarized electrons can move a ferromagnetic domain wall through the transfer of spin angular momentum when current flows in a magnetic nanowire. Such current induced control of a domain wall is of significant interest due to its potential application for low power ultra high-density data storage. In previous reports, it has been observed that the motion of the domain wall always happens parallel to the current flow - either in the same or opposite direction depending on the specific nature of the interaction. In contrast, here we demonstrate deterministic control of a ferromagnetic domain wall orthogonal to current flow by exploiting the spin orbit torque in a perpendicularly polarized Ta/CoFeB/MgO heterostructure in presence of an in-plane magnetic field. Reversing the polarity of either the current flow or the in-plane field is found to reverse the direction of the domain wall motion. Notably, such orthogonal motion with respect to current flow is not possible from traditional spin transfer torque driven domain wall propagation even in presence of an external magnetic field. Therefore the domain wall motion happens purely due to spin orbit torque. These results represent a completely new degree of freedom in current induced control of a ferromagnetic domain wall

Experimental Line Parameters of the b^(1)Σ^(+)_g ← X^(3)Σ^(-)_g Band of Oxygen Isotopologues at 760 nm Using Frequency-Stabilized Cavity Ring-Down Spectroscopy

Positions, intensities, self-broadened widths, and collisional narrowing coefficients of the oxygen isotopologues ^(16)O^(18)O, ^(16)O^(17)O, ^(17)O^(18)O, and ^(18)O^(18)O have been measured for the b^(1)Σg + ← X^(3)Σg − (0,0) band using frequency-stabilized cavity ring-down spectroscopy. Line positions of 156 P-branch transitions were referenced against the hyperfine components of the ^(39)K D_1 (4s ^(2)S_(1/2) → 4p ^(2)P_(1/2)) and D_2 (4s ^(2)S_(1/2) → 4p ^(2)P_(3/2)) transitions, yielding precisions of ~0.00005 cm^(−1) and absolute accuracies of 0.00030 cm^(−1) or better. New excited b^(1)Σg + state molecular constants are reported for all four isotopologues. The measured line intensities of the ^(16)O^(18)O isotopologue are within 2% of the values currently assumed in molecular databases. However, the line intensities of the ^(16)O^(17)O isotopologue show a systematic, J-dependent offset between our results and the databases. Self-broadening half-widths for the various isotopologues are internally consistent to within 2%. This is the first comprehensive study of the line intensities and shapes for the ^(17)O^(18)O or ^(18)O_2 isotopologues of the b^(1)Σg + ← X^(3)Σg − (0,0) band of O_2. The ^(16)O_2, ^(16)O^(18)O, and ^(16)O^(17)O line parameters for the oxygen A-band have been extensively revised in the HITRAN 2008 database using results from the present study

Posttraumatic Stress Disorder and Health-Related Quality of Life among a Sample of Treatment- and Pension-Seeking Deployed Canadian Forces Peacekeeping Veterans

Objectives: To examine the health-related quality of life (HRQOL) in deployed Canadian Forces peacekeeping veterans, addressing associations with posttraumatic stress disorder (PTSD), and depression severity. Methods: Participants (n = 125) were consecutive male veterans who were referred for a psychiatric assessment. Instruments administered included the Clinician-Administered PTSD Scale, Hamilton Depression Scale, Short-Form-36 Health Survey, and sociodemographic characteristics. Results: Mental HRQOL was significantly lower for peacekeepers with, than without, PTSD. Using univariate analyses, PTSD and depression severity were each significantly negatively related to mental HRQOL. In sequential regression analyses controlling for age, we found that PTSD and depression severity significantly predicted both mental and physical HRQOL. Conclusions: Veterans with PTSD have significant impairments in mental and physical HRQOL. This information is useful for clinicians and Veterans Affairs administrators working with the newer generation of veterans, as it stresses the importance of including measures of quality of life in the psychiatric evaluation of veterans to better address their rehabilitation need