Sprag solenoid brake

Operation of solenoid braking mechanism is discussed. Illustrations of construction of the brake are provided. Device is used for braking low or medium speed shaft rotations and produces approximately ten times braking torque of similar solenoid brakes

Development of a Data Acquisition System for Common Velocity Anemometers

The objective of this project was to develop a software package that would allow more efficient, accurate, and easier use of wind tunnel data. The software was to receive an analog signal from an array of hot wire anemometers, convert the signal to a digital format, and then process the raw data, converting it into values of properties which have practical value to the user. Unfortunately, due to scheduling conflicts, this project never left the software development stage. The user interface was successfully designed. The signal conversion portion of the package was not completed and the package was never tested

Testing Methods of Surficial Sinkhole Identification Using Remotely Sensed Data

Nearly a quarter of all people rely on karst aquifers for drinking water. In the United States, the Safe Water Drinking Act requires a complete assessment of public water systems\u27 vulnerabilities to contamination. As part of that assessment, watershed boundaries must be delineated, while recharge and supply locations identified. In the context of karst aquifers, surficial karst features, such as sinkholes, can act as a point source of direct recharge to karst aquifers and create vulnerabilities to critical drinking water sources. Historical methods of locating these features are inefficient and depend on basic field investigations, resulting in a clear need for advanced identification methods. To this end, this study focuses on developing more efficient identification methods that use remotely sensed data to locate and map surficial karst features that may require protection. Satellite and unmanned aerial vehicle (UAV) data were used to explore the resolution needed to identify surficial karst feature signatures and the most promising methods for analyzing these data. This study\u27s data included red, green, blue, and near-infrared reflectance rasters, thermal mosaics, and digital surface and terrain models. Spectral and thermal properties were used to filter data that could include karst features. Additionally, digital elevation models were used to explore multiple smoothing methods, image differencing, edge detection, terrain curvature, sink location, and watershed delineation. Findings from the different methods were compared to known karst feature locations. Data with a resolution between 0.5 and 2.5 meters per pixel were found to be ideal for most methods tested. However, vegetation removal, followed by a simple interpolation to fill these areas, created data analysis problems and highlighted the need for other data products, such as LiDAR, that provide accurate elevations of terrain shrouded by vegetation. In the end, it was found that edge detection, mapping curvature, and locating of low points (or sinks) via DEM analyses are all promising methods. It was concluded that by combining multiple methods, detailed digital terrain models could accurately locate many surficial karst features

Realistic Vertical Atmospheric Profiles and Effects from Limited Surface Observations

The ability to accurately describe the atmospheric conditions around us is not only important to the Air Force, but to anyone involved in signal propagation. The programs currently utilized to describe the atmosphere take into account a variety of measures. The LEEDR (Laser Environmental Effects Definition and Reference) program in particular, allows the user to select a location, aerosol and molecular effects model, numerous cloud and precipitation events, as well as other features. Even with the control that the user has, the output that the program provides can vary from actual conditions on a day to day basis. This is due to LEEDR‟s dependence on averaged climatological data. In order to make the output more specific for deterministic conditions, two additions to the LEEDR program have been proposed. The incorporation of calculated or measured ground level characteristics will allow the program to extrapolate data from scenario-specific anchor points, leading to a more realistic depiction of conditions below the boundary layer for the scenario of interest. After making this modification to the LEEDR program, differences were observed in several of the output variables throughout the boundary layer. Also, after interpolating sounding data from a location near the LEEDR site to model ground level conditions, LEEDR was able to more accurately model upper air measurements. In addition, a Correlated-k band model has been developed to augment the line-by-line LEEDR calculation in order to reduce the computation time required to describe atmospheric transmission bands of the spectrum. This allows the implementation of fast calculating path radiance computations. As a stand-alone module, the Correlated-k method is able to calculate transmission for the band interval studied, assuming a homogeneous atmosphere on average, 170% faster than the current transmission method in LEEDR

The Migration of Amphibian Primordial Germ Cells in the Chick Embryo

A fibrous band of extracellular materials on the chick embryo area pellucida/area opaca border is a preferential migratory pathway for chick embryo primordial germ cells (PGC). This band contains fibronectin, collagen Type I and sulphated glycosaminoglycans. It is known that PGCs from Xenopus laevis interact with fibronectin as they undergo migration in the embryo from their site of origin to the gonads. To establish whether this pathway is species specific in chick embryos it was decided to transplant PGC from Xenopus laevis embryos stage 48 on to chick embryos stage 4 fibrous band. Their rapid migration on this extracellular matrix and their subsequent re-orientation of the basement membrane has been studied by scanning electron microscopy

DYNAMICS OF THERMOREGULATION IN NEWBORN BABIES

This paper presents a simple mathematical model of the thermoregulation system of newborn babies. The parameters of this model are estimated from in vivo measurements with a specially constructed research incubator. The results of fourteen experiments are presented. They can be used in the design and evaluation of commercial incubators

Panel Discussion: Ethical Issues for Applications of Lucid Dreaming

A panel discussion featuring Joseph Dane, University of Virginia; P. Eric Craig, Center for Existential Studies and Human Services; Morton Schatzman, St. Thomas’ Hospital, London