New Directions in Scanning Electron Microscopy Cathodoluminescence Microcharacterization

The general principles of the low-temperature spectroscopic cathodoluminescence (LTSCL) technique in the scanning electron microscope (SEM) are outlined. CL microscopy and spectroscopy are now being extended in new directions. Analysis of the intrinsic CL from quantum well materials by LTSCL is proving valuable for microcharacterization and such work can be expected to expand rapidly. The main, early CL results in this exciting field are summarized here. In geology, CL microscopy, without spectroscopy, is widely used via electron-beam attachments to light microscopes and the addition of spectral analysis to these studies is overdue. Much CL from minerals and ceramics comes from trace amounts of rare earth or transition metal ions, so the nature of this important type of emission is briefly described. Results on ceramic materials illustrating the advances in the field and the distinctive nature of the rare earth and transition metal ion emission bands are reviewed. The fascinating high Tc superconducting ceramics emit CL and there are a number of papers reporting the emission spectra of these materials, but no theoretical interpretation of the information is yet available. A new factor in the situation is the commercial availability of complete LTSCL systems, removing one of the main obstacles to the adoption of the technique by more laboratories

SEASAT synthetic-aperture radar data user's manual

The SEASAT Synthetic-Aperture Radar (SAR) system, the data processors, the extent of the image data set, and the means by which a user obtains this data are described and the data quality is evaluated. The user is alerted to some potential problems with the existing volume of SEASAT SAR image data, and allows him to modify his use of that data accordingly. Secondly, the manual focuses on the ultimate focuses on the ultimate capabilities of the raw data set and evaluates the potential of this data for processing into accurately located, amplitude-calibrated imagery of high resolution. This allows the user to decide whether his needs require special-purpose data processing of the SAR raw data

Equivalence-based Security for Querying Encrypted Databases: Theory and Application to Privacy Policy Audits

Motivated by the problem of simultaneously preserving confidentiality and usability of data outsourced to third-party clouds, we present two different database encryption schemes that largely hide data but reveal enough information to support a wide-range of relational queries. We provide a security definition for database encryption that captures confidentiality based on a notion of equivalence of databases from the adversary's perspective. As a specific application, we adapt an existing algorithm for finding violations of privacy policies to run on logs encrypted under our schemes and observe low to moderate overheads.Comment: CCS 2015 paper technical report, in progres

The Cathodoluminescence Mode of the Scanning Electron Microscope: A Powerful Microcharacterization Technique

By detecting cathodoluminescence (CL) in a scanning electron microscope (SEM), pan and monochromatic micrographs and CL spectral analyses analogous to x-ray mode point analyses can be obtained. Complete microcharacterization requires alternate examination of both micrographs and spectra. New techniques for near infra-red CL and low-temperatures to produce sharp spectra are of increasing importance. CL emission is due to electron transitions between quantum mechanical states so the radiative defects present can be unambiguously identified at liquid helium temperatures. Strongly luminescent impurities can be detected to below one part in 108. This is 104 times as sensitive as the x-ray mode (electron probe microanalysis). Only luminescent impurities can be detected and quantitative analyses by CL have not yet been attempted. There is a rapidly increasing use of the CL mode for the study of industrially important problems and for the study of the electronic effects of dislocations in semiconductors

Satellite material contaminant optical properties

The Air Force Wright Research and Development Center and the Arnold Engineering Development Center are continuing a program for measuring optical effects of satellite material outgassing products on cryo-optic surfaces. Presented here are infrared (4000 to 700 cm(-1)) transmittance data for contaminant films condensed on a 77 K geranium window. From the transmittance data, the contaminant film refractive and absorptive indices (n, k) were derived using an analytical thin-film interference model with a nonlinear least-squares algorithm. To date 19 materials have been studied with the optical contents determined for 13 of those. The materials include adhesives, paints, composites, films, and lubricants. This program is continuing and properties for other materials will be available in the future

Characteristics of Magnetoplasmas Semiannual Status Report No. 12, May 1 - Oct. 31, 1965

Magnetoplasma characteristics - anomalous diffusion across magnetic field, heat conduction in plasma, cesium plasma generator, and electron velocity distribution function in magnetoplasma

Fatigue and Its Management in the Aviation Industry, with Special Reference to Pilots

Abstract Fatigue is a significant contributing factor that reduces human ability and leads to accidents and threatens the safety of aircraft and human lives. Approximately 70% of fatal accidents that occur in commercial aviation operations are due to human factors. More specifically, crew fatigue contributes to nearly 15 to 20% of the accidents (Akerstedt, 2000). These accidents and incidents are associated with pilot fatigue because of the long duty periods, disruption of circadian rhythms, and inadequate sleep that are common among both commercial and military pilots. Though fatigue is seen in all the disciplines associated with the aviation industry, this paper will discuss only pilot fatigue. Based on the literature examined, this paper first defines fatigue, examines the significance of the problem, discusses what is fatigue, its types and causes, discusses fatigue-related accidents and incidents, examines fatigue in different flight operations and its impact on the wellbeing of pilots, investigates the in-flight and pre-/post-flight countermeasures (both pharmacological and non-pharmacological methods) practiced at present, and discusses the fatigue risk management system (FRMS)—in this it defines FRMS, briefly discusses its history, describes the organizational structure of FRMS, its process, and its operation in the aviation industry, merits and demerits of FRMS, and its future applications. The paper finally concludes with some recommendations for future research/study in this discipline