Analysis of aircraft spectrometer data with logarithmic residuals

Spectra from airborne systems must be analyzed in terms of their mineral-related absorption features. Methods for removing backgrounds and extracting these features one at a time from reflectance spectra are discussed. Methods for converting radiance spectra into a form similar to reflectance spectra so that the feature extraction procedures can be implemented on aircraft spectrometer data are also discussed

A study of the mechanism of chemical reactivity of nitrogen tetroxide with titanium alloys Quarterly report, 1 Oct. - 31 Dec. 1967

Corrosion test of titanium alloys with nitrogen tetroxid

Chiral discrimination in optical binding

The laser-induced intermolecular force that exists between two or more particles in the presence of an electromagnetic field is commonly termed “optical binding.” Distinct from the single-particle forces that are at play in optical trapping at the molecular level, the phenomenon of optical binding is a manifestation of the coupling between optically induced dipole moments in neutral particles. In other, more widely known areas of optics, there are many examples of chiral discrimination—signifying the different response a chiral material has to the handedness of an optical input. In the present analysis, extending previous work on chiral discrimination in optical binding, a mechanism is identified using a quantum electrodynamical approach. It is shown that the optical binding force between a pair of chiral molecules can be significantly discriminatory in nature, depending upon both the handedness of the interacting particles and the polarization of the incident light, and it is typically several orders of magnitude larger than previously reported

Strong D* -> D+pi and B* -> B+pi couplings

We compute g_{D* D pi} and g_{B* B pi} using a framework in which all elements are constrained by Dyson-Schwinger equation studies of QCD, and therefore incorporates a consistent, direct and simultaneous description of light- and heavy-quarks and the states they may constitute. We link these couplings with the heavy-light-meson leptonic decay constants, and thereby obtain g_{D* D pi}=15.9+2.1/-1.0 and g_{B* B pi}=30.0+3.2/-1.4. From the latter we infer \hat-g_B=0.37+0.04/-0.02. A comparison between g_{D* D pi} and g_{B* B pi} indicates that when the c-quark is a system's heaviest constituent, Lambda_{QCD}/m_c-corrections are not under good control.Comment: 5 pages, 1 table, 2 figure

Mental Health Care Consumption and Outcomes: Considering Preventative Strategies Across Race and Class

In previous work (Richman 2007), we found that even under conditions of equal insurance coverage and access to mental healthcare providers, whites and high-income individuals consume more outpatient mental health services than nonwhites and low-income individuals. We follow-up that study to determine (1) whether nonwhite and low-income individuals obtain medical substitutes to mental healthcare, and (2) whether disparate consumption leads to disparate health outcomes. We find that nonwhites and low-income individuals are more likely than their white and high-income counterparts to obtain mental health care from general practitioners over mental healthcare providers, and nearly twice as likely not to follow up with a mental health provider after hospitalization with a mental health diagnosis. We further are unable to find any evidence that this leads to adverse health outcomes. These findings echo concern expressed in Richman (2007) that low-income and nonwhite individuals might be paying for health services that primarily benefit their white and more affluent coworkers

Coarse-grained interaction potentials for polyaromatic hydrocarbons

Using Kohn-Sham density functional theory (KS-DFT), we have studied the interaction between various polyaromatic hydrocarbon molecules. The systems range from mono-cyclic benzene up to hexabenzocoronene (hbc). For several conventional exchange-correlation functionals potential energy curves of interaction of the $\pi$-$\pi$ stacking hbc dimer are reported. It is found that all pure local density or generalized gradient approximated functionals yield qualitatively incorrect predictions regarding structure and interaction. Inclusion of a non-local, atom-centered correction to the KS-Hamiltonian enables quantitative predictions. The computed potential energy surfaces of interaction yield parameters for a coarse-grained potential, which can be employed to study discotic liquid-crystalline mesophases of derived polyaromatic macromolecules

What to Choose? The Value of Label Claims to Produce Consumers

This paper addresses three key empirical questions related to health, nutrient, and process claims on front-label packaging; namely, 1) How do consumers value alternative claims on product and process-based attributes for fresh produce; 2) Are these values additively separable; and 3) To what degree is there heterogeneity between consumers on these values? We use a hypothetical choice experiment on red leaf lettuce attribute bundles, and estimate several logit models (MNL and ML) that provide estimates of marginal utilities (and with the inclusion of varying prices, marginal values) of various attributes related to general health claims, specific nutrition and health claims, certification logos related to health and nutrition currently found in the marketplace, as well as certified organic claims (relative to the conventional reference group). The results showed that consumers do distinguish between competing claims and logos, though the impacts are not always as expected, likely due to the information set used at the time of the choice. We found some evidence of attribute bundling between the health claims and the familiar Five-a-day program logo, and between organic production and a claim regarding vitamin C content. Finally, we found that use of the unconditional distributions (relative to the conditional)in a ML model overstates the degree of preference heterogeneity across the sample and overstates the magnitude of the marginal effects of the random parameters. This may create misleading impressions regarding the existence and size of specialized niche markets, the response of consumers to varying health, nutrition, or process claims, and/or the response of consumers to the introduction of new products with these (or similar) claims.Consumer/Household Economics, Demand and Price Analysis,

Highly Efficient Modeling of Dynamic Coronal Loops

Observational and theoretical evidence suggests that coronal heating is impulsive and occurs on very small cross-field spatial scales. A single coronal loop could contain a hundred or more individual strands that are heated quasi-independently by nanoflares. It is therefore an enormous undertaking to model an entire active region or the global corona. Three-dimensional MHD codes have inadequate spatial resolution, and 1D hydro codes are too slow to simulate the many thousands of elemental strands that must be treated in a reasonable representation. Fortunately, thermal conduction and flows tend to smooth out plasma gradients along the magnetic field, so "0D models" are an acceptable alternative. We have developed a highly efficient model called Enthalpy-Based Thermal Evolution of Loops (EBTEL) that accurately describes the evolution of the average temperature, pressure, and density along a coronal strand. It improves significantly upon earlier models of this type--in accuracy, flexibility, and capability. It treats both slowly varying and highly impulsive coronal heating; it provides the differential emission measure distribution, DEM(T), at the transition region footpoints; and there are options for heat flux saturation and nonthermal electron beam heating. EBTEL gives excellent agreement with far more sophisticated 1D hydro simulations despite using four orders of magnitude less computing time. It promises to be a powerful new tool for solar and stellar studies.Comment: 34 pages, 8 figures, accepted by Astrophysical Journal (minor revisions of original submitted version