A REVIEW OF THE MATHEMATICAL FORMULATION OF THE PROBLEM OF INELASTIC NEUTRON SCATTERING BY POLYCRYSTALLINE MATERIAL

A self-contained development of the formulation of the problem of inelastic neutron scattering by crystals is presented. Although nearly all of the methods and results used in the discussion have appeared in a variety of previously published papers, additional mathematical details are given here which were found to aid in understanding the final results. (auth

Strength increase as a factor in the performance of a gymnastic skill

The purpose of this study was to determine whether or not an increase in abdominal and shoulder strength were factors in the performance of the skin-the-cat skill on the high uneven parallel bar in gymnastics, to devise two exercise programs (prescribed exercise and apparatus exercise) for developing abdominal and shoulder strength and to determine if one program was superior to the other in terms of effectiveness and efficiency in developing strength and in resulting successful performance of the skill. The cable tensiometer was the instrument selected to assess strength measures. Subjects for the study were college women enrolled in gymnastic classes at The University of North Carolina at Greensboro during the second semester of the 1966-67 academic year. The subjects were students who were unable to perform the skin-the-cat skill prior to the beginning of the study. The subjects were equated into two separate groups with each being assigned to follow one of the devised exercise programs. Each program involved a maximum time of ten minutes of exercise two days per week for a period of five weeks

Automated Inspection Device for Explosive Charge in Shells - AIDECS

Certain defects in the explosive charge of an artillery shell can cause the projectile to explode prematurely in the barrel of the launcher from which it is fired. The sensitivity of the radiographic technique presently used is limited by the large influence of the steel shell casing on the transmitted radiation. A filmless radiometric technique utilizing the basic radiation principle of Compton scattering, which will detect cavities in the explosive filler with minimal interference from the steel casing, has been identified and tested. By scanning the shell with a beam of radiation and observing the Compton scattering through a unique collimating system, it has been possible to detect voids as small as 1/16 inch in cross section. The hardware consists of the source, beam collimator, detector collimator, and a large plastic scintillator detector system. The projectile is inserted into the beam path and moved through a fixed scanning pattern by a mechanical handling system. The scanning sequence is computer contra ll ed and results in a threedimensional data matrix giving a direct representation of density within the projectile. Voids are identified and classified by computer analysis, and shell acceptability decisions are automatically generated. An engineering prototype system is currently being assembled and tested. (A production prototype conceptual design is concurrently under development.) This new technique will replace an existing film radiography inspection procedure and eliminate the need for human interpretation of the defects, while providing more consistent and reliable inspections at lower costs

Study of the influence of physical, chemical and biological conditions that influence the deterioration and protection of Underwater Cultural Heritage

Two wrecks related to the Battle of Trafalgar (1805) were studied. Following the guidelines of the UNESCO-2001 Convention for the Protection of the Underwater Cultural Heritage, a holistic and interdisciplinary approach based on the development of four of the thirty-six Rules of this international agreement was applied. A non-destructive survey technique was developed to obtain information from the scattered cannons and anchors without altering their condition (Rule 4). The work performed provided information about the origin of both wrecks, the Fougueux and the Bucentaure, two ships of the line of the French Navy, and allowed to characterize the state of conservation at each site without jeopardizing their future conservation in the marine environment. In addition, measurements of the main physical, chemical and biological variables allowed correlating the conservation status at each site with the marine environmental conditions (Rule 15). Thus, in Fougueux shipwreck large iron objects are corroding at a higher rate (between 0.180 and 0.246 mmpy) due to high sediment remobilization and transport induced by waves at this site, causing damage by direct mechanical effect on metallic material and by removing the layer of corrosion products developed on the artefacts. Meanwhile artillery on Bucentaure site, covered with thick layers of biological concretion, is well preserved, with lower corrosion rates (0.073 to 0.126 mmpy), and archaeological information is guaranteed. Finally, the effectiveness of the cathodic protection as a temporary measure for in situ conservation (Rule 1) was evaluated on a cannon. The use of a sacrificial anode after 9 months reduced the average corrosion rate (from 0.103 to 0.064 mmpy) and the percent of corrosion rate in 37.9%. These results are very useful for developing a decision making system of the Site Management Program, based on predictive models of artefacts permanence and risk factors in the marine environment (Rule 25)

Supplemental Information 3: Raw data from this study

Although the existence of coral-reef habitats at depths to 165 m in tropical regions has been known for decades, the richness, diversity, and ecological importance of mesophotic coral ecosystems (MCEs) has only recently become widely acknowledged. During an interdisciplinary effort spanning more than two decades, we characterized the most expansive MCEs ever recorded, with vast macroalgal communities and areas of 100% coral cover between depths of 50–90 m extending for tens of km2 in the Hawaiian Archipelago. We used a variety of sensors and techniques to establish geophysical characteristics. Biodiversity patterns were established from visual and video observations and collected specimens obtained from submersible, remotely operated vehicles and mixed-gas SCUBA and rebreather dives. Population dynamics based on age, growth and fecundity estimates of selected fish species were obtained from laser-videogrammetry, specimens, and otolith preparations. Trophic dynamics were determined using carbon and nitrogen stable isotopic analyses on more than 750 reef fishes. MCEs are associated with clear water and suitable substrate. In comparison to shallow reefs in the Hawaiian Archipelago, inhabitants of MCEs have lower total diversity, harbor new and unique species, and have higher rates of endemism in fishes. Fish species present in shallow and mesophotic depths have similar population and trophic (except benthic invertivores) structures and high genetic connectivity with lower fecundity at mesophotic depths. MCEs in Hawai‘i are widespread but associated with specific geophysical characteristics. High genetic, ecological and trophic connectivity establish the potential for MCEs to serve as refugia for some species, but our results question the premise that MCEs are more resilient than shallow reefs. We found that endemism within MCEs increases with depth, and our results do not support suggestions of a global faunal break at 60 m. Our findings enhance the scientific foundations for conservation and management of MCEs, and provide a template for future interdisciplinary research on MCEs worldwide

Stable ptychographic phase retrieval via lost subspace completion.

In this paper, we consider a special case of the phase retrieval problem called ptychography. Its is a popular technique of imaging, based on local illuminations of a specimen and further reconstruction from the far field diffraction patterns. The stability and success of the recovery process is heavily based on the choice of the illumination function commonly called a window. It describes the distribution of the light along the measured region. While for some windows the conditioning can be controlled, many important classes of windows, such as Gaussian windows, were not covered. We present a subspace completion method, which allows for a well-conditioned reconstruction for a much wider choice of windows, including Gaussian windows

DISCUSSION OF AN ACTIVATION METHOD FOR MEASURING THE RATIO OF Usup238sup 238 ABSORPTION TO Usup235sup 235 FISSION IN A REACTOR

The theory is presented in detail of an activation method for measuring the ratio of U/sup 238/ absorptions to U/sup 235/ fissions in a nuclear reactor. The origin of the activities is discussed, the equations are given for interpretation of the measurements, and the expected counting rates are computed for a typical experiment in the EGCR. (auth

A Rapid Ecological Assessment (REA) Quantitative Survey Method for Benthic Algae Using Photoquadrats with Scuba

The challenge of assessing seldom-visited, benthic substrates has created the need for a method to describe benthic communities quickly and efficiently. Macroscale rapid ecological assessments (REAs) of algal assemblages provide managers of coral reefs and other benthic ecosystems with the fundamental descriptive data necessary for continued yearly monitoring studies. The high cost of monitoring marine communities, especially remote sites, coupled with the time limitations imposed by scuba, require that statistically valid data be collected as quickly as possible. A photoquadrat method using a digital camera, computer software for photographic analysis, and minimal data collection in the field was compared with the conventional method of point-intersect (grid) quadrats in estimating percentage cover in subtidal benthic communities. In timed studies, photoquadrats yielded twice the number of quadrats (and an almost infinite number of data points) as conventional methods, provided permanent historical records of each site, and minimized observer bias by having only one observer identifying algae in the field. However, photoquadrats required more post-collection computer analyses of digital photographs than conventional methods. In the manual method, observer bias in algal identification can occur depending on the degree of experience of individual divers. On the other hand, photoquadrats rely on one observer in the field and one observer in the laboratory, standardizing algal identification. Overall, photoquadrats do not yield the finer resolution in diversity that was found using point-intersect quadrats but do provide a more precise estimate of percentage cover of the abundant species, as well as establishing a permanent visual record in the time allowed by work with other teams