Theoretical studies in support of the 3M-vapor transport (PVTOS-) experiments

Results are reported for a preliminary theoretical study of the coupled mass-, momentum-, and heat-transfer conditions expected within small ampoules used to grow oriented organic solid (OS-) films, by physical vapor transport (PVT) in microgravity environments. It is show that previous studies made restrictive assumptions (e.g., smallness of delta T/T, equality of molecular diffusivities) not valid under PVTOS conditions, whereas the important phenomena of sidewall gas creep, Soret transport of the organic vapor, and large vapor phase supersaturations associated with the large prevailing temperature gradients were not previously considered. Rational estimates are made of the molecular transport properties relevant to copper-phthalocyanine monomeric vapor in a gas mixture containing H2(g) and Xe(g). Efficient numerical methods have been developed and are outlined/illustrated here to making steady axisymmetric gas flow calculations within such ampoules, allowing for realistic realistic delta T/T(sub)w-values, and even corrections to Navier-Stokes-Fourier 'closure' for the governing continuum differential equations. High priority follow-on studies are outlined based on these new results

Trials and tribulations : what happens when historians enter the courtroom

In recent years, historians have been brought into legal cases in unprecedented numbers. As the courts have tried to adjudicate responsibility for environmental and occupational diseases, history has played an increasingly central role in decisions that affect the cases themselves and in social policy regarding risk. In suits over tobacco-related diseases, asbestosis, radiation, and other toxic substances, more historians of technology and science, social history, and public health are being sought to provide testimony aimed at assessing responsibility for damages that have arisen years--sometimes decades--after exposure. Here, Rosner traces the use of historians as experts in litigation

Shift in weak phase γ\gamma due to CP asymmetries in DD decays to two pseudoscalar mesons

A difference of several tenths of a percent has been observed between the direct CP asymmetries of $D^0\to K^+K^-$ and $D^0\to \pi^+\pi^-$. It has been noted recently that CP asymmetries in such singly-Cabibbo-suppressed (SCS) decays can affect the determination of the weak phase $\gamma$ using the Gronau-London-Wyler method of comparing rates for $B^+ \to D K^+$ and $B^- \to D K^-$, where $D$ is a superposition of $D^0$ and \od decaying to a CP eigenstate. Using an analysis of the CP asymmetries in SCS decays based on a $c \to u$ penguin amplitude with standard model weak phase but enhanced by CP-conserving strong interactions, we estimate typical shifts in $\gamma$ of several degrees and pinpoint measurements which would reduce uncertainties to an acceptable level.Comment: 15 pages, 3 figures, submitted to Phys. Rev. D. More text and references adde

Measuring Strong and Weak Phases in Time-Independent B Decays

Flavor SU(3) symmetry implies certain relations among $B$-decay amplitudes to $\pi\pi$, $\pi K$ and $K {\bar K}$ final states, when annihilation-like diagrams are neglected. Using three triangle relations, we show how to measure the weak CKM phases $\alpha$ and $\gamma$ using time-independent rate measurements only. In addition, one obtains all the strong final-state phases and the magnitudes of individual terms describing tree (spectator), color-suppressed and penguin diagrams. Many independent measurements of these quantities can be made with this method, which helps to eliminate possible discrete ambiguities and to estimate the size of SU(3)-breaking effects.Comment: 2 figures available from the authors upon request, 12 pages,UdeM-LPN-TH-94-19

Seeking common ground : a history of labor and Blue Cross

In recent years, voluntary health insurance costs have become a major source of friction in labor-management negotiations. What was once a "fringe" has led to job actions, strikes, and intensive bargaining. We examine the history of labor's participation in New York Blue Cross from the 1930s to the recent past and show that labor's participation in the plan was crucial to Blue Cross's success in the plan's early decades. By the late 1950s, serious tensions developed over rate increases and the participation of labor in Blue Cross governance. Ultimately, the issue was one of the control over what was provided by the plans and who would pay for the costs of care. We posit that labor was never able to achieve an important role in the control of the third-party payer, and in the antilabor environment of the 1980s this proved detrimental to labor's interests

Within-ring movement of free water in dehydrating Norway spruce sapwood visualized by neutron radiography

This study is a first approach to visualize moisture distribution and movement between annual rings during sapwood drying by neutron imaging (NI). While Norway spruce [Picea abies (L.) Karst.] sapwood beams were allowed to dehydrate on a balance at ambient conditions, NI was performed in 1-10 min time steps. From NI raw files, radial dimensional changes were calculated during dehydration and transmission profiles were drawn for different relative moisture content (MC) steps from full saturation until equilibrium moisture content. The NI technique proved to be a useful tool to visualize the movement of free water within, and between, annual rings. Removal of free water in the middle part of the wood beam did not proceed continuously from the surface to the central part, but was strongly influenced by wood anatomy. Water is removed from earlywood during early stages of dehydration and later, at higher moisture loss (<50% MC), from the main latewood parts. It is therefore concluded that the radial dimensional changes measured at moderate moisture loss are not only caused by cell wall shrinkage of the outer wood parts located beneath the wood surface, but a result of elastic deformation of earlywood tracheids under the influence of negative hydrostatic pressure

Spin-Orbit and Tensor Forces in Heavy-quark Light-quark Mesons: Implications of the New Ds state at 2.32 GeV

We consider the spectroscopy of heavy-quark light-quark mesons with a simple model based on the non-relativistic reduction of vector and scalar exchange between fermions. Four forces are induced: the spin-orbit forces on the light and heavy quark spins, the tensor force, and a spin-spin force. If the vector force is Coulombic, the spin-spin force is a contact interaction, and the tensor force and spin-orbit force on the heavy quark to order $1/m_1m_2$ are directly proportional. As a result, just two independent parameters characterize these perturbations. The measurement of the masses of three p-wave states suffices to predict the mass of the fourth. This technique is applied to the $D_s$ system, where the newly discovered state at 2.32 GeV provides the third measured level, and to the $D$ system. The mixing of the two $J^P=1^+$ p-wave states is reflected in their widths and provides additional constraints. The resulting picture is at odds with previous expectations and raises new puzzles.Comment: 6 pages, 1 figur