Archaeological Investigation at the Marshall Powder Mill (41HS17), Confederate States of America 1863-1865, Harrison County, Texas: 1994 Season

The Northeast Texas Archeological Society, in conjunction with the East Texas, Dallas, and Tarrant County archeological societies, reinstated archaeological investigations at the Marshall Powder Mill (41HS17) in 1994 following several years of delicate negotiations with the landowner about the value of preserving this archaeological site. The Marshall Powder Mill manufactured gunpowder, small arms and cannon, and refurbished weaponry, and was one of several arsenals that served the Trans-Mississippi Department of the Confederate States of America from 1863 to 1865. None have been thoroughly investigated archaeologically, however, thereby ignoring a major aspect of the Confederacy\u27s war effort, and an important industrial enterprise. Building foundations, earthworks, roads, and an artificial channel race remain essentially undisturbed within the Loop 390 corridor and the privately-owned portions of the site; the eastern one-third of the site has been destroyed by a modern lumber mill. Although the site is listed on the National Register of Historic Places, there is no concerted plan for preservation of this Civil War military-industrial complex. Little historical documentation exists as to the number and types of buildings, their locations, or the activities that were conducted at the Marshall Powder Mill. The single map in the National Archives was captured by Federal troops in 1864, and only indicates a few of the buildings and none of the earthworks. Apparently the Confederates were concerned with security, and the commander, Major George D. Alexander, destroyed or removed all records prior to Federal occupation of the site in 1865. Therefore, the archaeological remains speak the clearest about the Marshall Powder Mill\u27s buildings and their functions, and may be the only sure means of reconstructing the layout and design of the arsenal, as well as ancillary fortifications, buildings, and structures around Marshall that date to the Civil War period

The Hedonic Price Structure of Faculty Compensation at U.S. Colleges and Universities

Economic theory suggests that the variation in academic salaries across institutions in part reflects compensating differences associated with variation in the levels of local quality of life factors such as environmental quality and the provision of local public services. This paper presents an econometric analysis of the hedonic, or implicit price structure, of faculty compensation at U.S. colleges and universities using data from AAUP merged with data on a host of location-specific characteristics. Quality of life factors are found to be important, accounting for between 7 percent and 12.8 percent of total compensation

Radical pair intersystem crossing: Quantum dynamics or incoherent kinetics?

Magnetic field effects on radical pair reactions arise due to the interplay of coherent electron spin dynamics and spin relaxation effects, a rigorous treatment of which requires the solution of the Liouville-von Neumann equation. However, it is often found that simple incoherent kinetic models of the radical pair singlet-triplet intersystem crossing provide an acceptable description of experimental measurements. In this paper we outline the theoretical basis for this incoherent kinetic description, elucidating its connection to exact quantum mechanics. We show in particular how the finite lifetime of the radical pair spin states, as well as any additional spin-state dephasing, leads to incoherent intersystem crossing. We arrive at simple expressions for the radical pair spin state interconversion rates to which the functional form proposed recently by Steiner et al. [J. Phys. Chem. C 122, 11701 (2018)] can be regarded as an approximation. We also test the kinetic master equation against exact quantum dynamical simulations for a model radical pair and for a series of $\text{PTZ}^{\bullet+}\text{-Ph}_\text{n}\text{-PDI}^{\bullet-}$ molecular wires

Quantum diffusion in liquid water from ring polymer molecular dynamics

We have used the ring polymer molecular-dynamics method to study the translational and orientational motions in an extended simple point charge model of liquid water under ambient conditions. We find, in agreement with previous studies, that quantum-mechanical effects increase the self-diffusion coefficient D and decrease the relaxation times around the principal axes of the water molecule by a factor of around 1.5. These results are consistent with a simple Stokes-Einstein picture of the molecular motion and suggest that the main effect of the quantum fluctuations is to decrease the viscosity of the liquid by about a third. We then go on to consider the system-size scaling of the calculated self-diffusion coefficient and show that an appropriate extrapolation to the limit of infinite system size increases D by a further factor of around 1.3 over the value obtained from a simulation of a system containing 216 water molecules. These findings are discussed in light of the widespread use of classical molecular-dynamics simulations of this sort of size to model the dynamics of aqueous systems