LTA structures and materials technology

The state-of-the-art concerning structures and materials technology is reviewed. It is shown that many present materials developments resulting from balloon and aircraft research programs can be applied to new concepts in LTA vehicles. Both buoyant and semi-buoyant vehicles utilize similar approaches to solving structural problems and could involve pressurized non-rigid and unpressurized rigid structures. System designs common to both and vital to structural integrity include much of the past technology as well. Further research is needed in determination of structural loads, especially in future design concepts

Dynamics of structural defects and plasticity: models and numerical implementation for dynamical problems

We report the plasticity model with explicit description of kinetics of the material defects (dislocations, grain boundaries). This method becomes especially effective for computation of the dynamical deformation of materials at high strain rates because it allows for a simple accounting of the strain rate effects. The equation system is written out and discussed; its implementation is demonstrated for the problem of the plastic flow localization

Current developments lighter than air systems

Lighter than air aircraft (LTA) developments and research in the United States and other countries are reviewed. The emphasis in the U.S. is on VTOL airships capable of heavy lift, and on long endurance types for coastal maritime patrol. Design concepts include hybrids which combine heavier than air and LTA components and characteristics. Research programs are concentrated on aerodynamics, flight dynamics, and control of hybrid types

What Communities Can Do to Rein In Payday Lending: Strategies for Successful Local Ordinance Campaigns through a Texas Lens

Because New Mexico has one of the highest consumer usage rates and highest concentrations of payday and title loan shops in the nation,2 we thought it would be an ideal place to measure the public’s knowledge of and interest in these ubiquitous loans. We also measured knowledge of interest rate caps in the context of credit cards, as a point of comparison. Our data are consistent with that of previous studies showing that the general public overwhelmingly supports interest rate caps both in general and for certain types of loans. More uniquely, we also found that many consumers are unaware that there are no interest rate caps on many forms of consumer loans. These data are useful in explaining why consumers do not do more to change the law on interest rate caps

Analysis of thin-film structures with nuclear backscattering and x-ray diffraction

Backscattering of MeV ^(4)He ions and Seemann-Bohlin x-ray diffraction techniques have been used to study silicide formation on Si and SiO_2 covered with evaporated metal films. Backscattering techniques provide information on the composition of thin-film structures as a function of depth. The glancing-angle x-ray technique provides identification of phases and structural information. Examples are given of V on Si and on SiO_2 to illustrate the major features of these analysis techniques. We also give a general review of recent studies of silicide formation

The Brief Mood Introspection Scale (BMIS)

The BMIS scale is an open-source mood scale consisting of 16 mood-adjectives to which a person responds (e.g., Are you happy ?). The scale can yield measures of overall pleasant-unpleasant mood, arousal-calm mood, and it also can be scored according to positive-tired and negative-calm mood

Dust capture and long-lived density enhancements triggered by vortices in 2D protoplanetary disks

We study dust capture by vortices and its long-term consequences in global two-fluid inviscid disk simulations using a new polar grid code RoSSBi. We perform the longest integrations so far, several hundred disk orbits, at the highest resolution attainable in global simulations of disks with dust, namely 2048x4096 grid points. This allows to study the dust evolution well beyond vortex dissipation. We vary a wide range of parameters, most notably the dust-to-gas ratio in the initial setup varies in the range $10^{-3}$ to $0.1$. Irrespective of the initial dust-to-gas ratio we find rapid concentration of the dust inside vortices, reaching dust-to-gas ratios of order unity inside the vortex. We present an analytical model that describes very well the dust capture process inside vortices, finding consistent results for all dust-to-gas ratios. A vortex streaming instability develops which causes invariably vortex destruction. After vortex dissipation large-scale dust-rings encompassing a disk annulus form in most cases, which sustain very high dust concentration, approaching ratios of order unity. The rings are long lived lasting as long as the duration of the simulations. They also develop a streaming instability, which manifests itself in eddies at various scales within which the dust forms compact high density clumps. Such clumps would be unstable to gravitational collapse in absence of strong dissipation by viscous forces. When vortices are particularly long lived, rings do not form but dust clumps inside vortices become then long lived features and would likely undergo collapse by gravitational instability. Rings encompass almost an Earth mass of solid material, while even larger masses of dust do accumulate inside vortices in the earlier stage. We argue that rapid planetesimal formation would occur in the dust clumps inside the vortices as well as in the post-vortex ring.Comment: Preprint version, submitted to the Astrophysical Journal. Due to size constraints on ArXiv, some plots are at low resolution JPEG

Near-bottom seismic profiling: High lateral variability, anomalous amplitudes, and estimates of attenuation

For almost a decade the Marine Physical Laboratory of Scripps Institution of Oceanography has been conducting near‐bottom geophysical surveys involving quantitative seismic profiling. Operating initially at 4 kHz and more recently at 6 kHz, this system has provided a wealth of fine scale quantitative data on the acoustic properties of ocean sediments. Over lateral distances of a few meters, 7‐dB changes in overall reflected energy as well as 10‐dB changes from individual reflectors have been observed. Anomalously high amplitudes from deep reflectors have been commonly observed, suggesting that multilayer interference is prevalent in records from such pulsed cw profilers. This conclusion is supported by results from sediment core physical property work and related convolution modeling, as well as by the significant differences observed between 4‐ and 6‐kHz profiles. In general, however, lateral consistency has been adequate in most areas surveyed to permit good estimates of acoustic attenuation from returns from dipping reflectors and sediment wedges

Onboard sampling of the rockfish and lingcod commerical passenger fishing vessel industry in northern and central California, January through December 1995

The Central California Marine Sport Fish Project has been collecting angler catch data on board Commercial Passenger Fishing Vessels (CPFVs) fishing for rockfish or lingcod since 1987. The program depends on the voluntary cooperation of CPFV owners and operators. This fifth report in a series presents data collected in 1995, refers to historical data from 1987 to 1994, and documents trends in species composition, angler effort, catch per unit effort (CPUE), and, for selected species, mean length, and length frequency. Angler catches on board central and northern California CPFVs were sampled from 12 ports, ranging from Fort Bragg in the north to Port San Luis (Avila Beach) in the south. Technicians observed a total of 1829 anglers fishing on 218 CPFV trips. These observed anglers caught 26,197 fish of which samplers determined 22,888 were kept. Over 62% of these fish were caught at Monterey or Morro Bay area ports. Only 18 of 55 species comprised at least one percent of the catch. The top ten species in order of abundance were yellowtail, blue, olive, and rosy rockfishes, lingcod, and canary, widow, gopher, starry, and vermilion rockfishes. Blue and yellowtail rockfishes together comprised approximately 47% of the observed catch. Overall, rockfishes represented 35 species or 64% of the 55 identified species. By number, rockfishes comprised 91.9 % of the observed catch. All CPUE and length data collected since 1987 were partitioned into six location groups for each port area, based on a combination of location, bottom depth, and distance from the nearest port. This allowed examination of indicator trends without potential biases due to non-random trip selection or ontogenetic changes in depth distribution for certain rockfishes. Results indicate that the two primary species in the northern and central California CPFV fishery, blue and yellowtail rockfishes (accounting for 47% of all observed fish in 1995), are in reasonably good condition with no steady declines in either average catch per angler hour or mean length during the last 8 years. The primary species of concern are mainly shallow-water species impacted by a recently expanded commercial hook-and-line fishery or deep-water species (chilipepper and bocaccio) which are fished intensively by the commercial industry and have experienced recent statewide stock declines. Estimated total rockfish catch, adjusted by logbook compliance rates and on board sampling data, has declined significantly in all port areas since 1992. This is largely attributable to increased recreational fishing effort for salmon as well as coast-wide stock declines in several important commercially fished species. (112pp.