Research in large adaptive antenna arrays

The feasibility of microwave holographic imaging of targets near the earth using a large random conformal array on the earth's surface and illumination by a CW source on a geostationary satellite is investigated. A geometrical formulation for the illuminator-target-array relationship is applied to the calculation of signal levels resulting from L-band illumination supplied by a satellite similar to ATS-6. The relations between direct and reflected signals are analyzed and the composite resultant signal seen at each antenna element is described. Processing techniques for developing directional beam formation as well as SNR enhancement are developed. The angular resolution and focusing characteristics of a large array covering an approximately circular area on the ground are determined. The necessary relations are developed between the achievable SNR and the size and number of elements in the array. Numerical results are presented for possible air traffic surveillance system. Finally, a simple phase correlation experiment is defined that can establish how large an array may be constructed

Random sampling adaptively focusing synthetic aperture radar

A high resolution narrow angle of view imaging radar system is considered that employs an airborne synthetic aperture of 600 meters operating at X-band to produce a beamwidth of approximately 0.05 mr. This system differs from a conventional SAR in that only a smaller number of wavefront samples, spaced randomly over the aperture are processed, and adaptive beamforming with open loop scanning is used. As a result, the processing requirements are reduced to within the capability of present day small computer technology, and the tolerance on flight stability is loosened by about 100:1. The system is described and initial analysis and evaluation results are presented

Conceptual design of thermal energy storage systems for near term electric utility applications. Volume 2: Appendices - screening of concepts

Volume 2 of this 2 volume report is represented. This volume contains three appendices: (1) bibliography and cross references; (2) taxonomy - proponents and sources; and (3) concept definitions

Conceptual design of thermal energy storage systems for near term electric utility applications. Volume 1: Screening of concepts

Over forty thermal energy storage (TES) concepts gathered from the literature and personal contacts were studied for their suitability for the electric utility application of storing energy off-peak discharge during peak hours. Twelve selections were derived from the concepts for screening; they used as storage media high temperature water (HTW), hot oil, molten salts, and packed beds of solids such as rock. HTW required pressure containment by prestressed cast-iron or concrete vessels, or lined underground cavities. Both steam generation from storage and feedwater heating from storage were studied. Four choices were made for further study during the project. Economic comparison by electric utility standard cost practices, and near-term availability (low technical risk) were principal criteria but suitability for utility use, conservation potential, and environmental hazards were considered

Job Management and Task Bundling

High Performance Computing is often performed on scarce and shared computing resources. To ensure computers are used to their full capacity, administrators often incentivize large workloads that are not possible on smaller systems. Measurements in Lattice QCD frequently do not scale to machine-size workloads. By bundling tasks together we can create large jobs suitable for gigantic partitions. We discuss METAQ and mpi_jm, software developed to dynamically group computational tasks together, that can intelligently backfill to consume idle time without substantial changes to users' current workflows or executables.Comment: 8 pages, 3 figures, LATTICE 2017 proceeding

Public Health Considerations of Launching Nuclear Waste to the Sun

The article discusses the public health aspects of disposing of radioactive nuclear waste by launching it to the sun. Disposing of radioactive nuclear waste by launching it to the sun remove the threats of exposure from leakage of a storage facility. The high temperatures will incinerate and consume all matter prior to its reaching the sun\u27s corona

Study of large adaptive arrays for space technology applications

The research in large adaptive antenna arrays for space technology applications is reported. Specifically two tasks were considered. The first was a system design study for accurate determination of the positions and the frequencies of sources radiating from the earth's surface that could be used for the rapid location of people or vehicles in distress. This system design study led to a nonrigid array about 8 km in size with means for locating the array element positions, receiving signals from the earth and determining the source locations and frequencies of the transmitting sources. It is concluded that this system design is feasible, and satisfies the desired objectives. The second task was an experiment to determine the largest earthbound array which could simulate a spaceborne experiment. It was determined that an 800 ft array would perform indistinguishably in both locations and it is estimated that one several times larger also would serve satisfactorily. In addition the power density spectrum of the phase difference fluctuations across a large array was measured. It was found that the spectrum falls off approximately as f to the minus 5/2 power

General practitioners knowledge of breastfeeding management: A review of the literature

Breastmilk and breastfeeding are known to have significant advantages and benefits over the use of artificial formula for infants and young children[1-4]. These benefits are reflected in the increased costs related to preventable illnesses as well as the actual costs of artificial formulas[5]. Both the World Health Organization[3] and the National Health and Medical Research Council[1] Guidelines recommend exclusive breastfeeding for the first six months of a baby's life, with the gradual introduction of appropriate, complementary foods and continuing to breastfeed for two or more years. Pregnant and breastfeeding women seek support from a variety of sources, and in particular, health professionals. The medical practitioner or general practitioner (GP) is commonly the first health professional women encounter during pregnancy. The GP will continue to provide care for mother and then mother and baby after discharge from hospital. This literature review seeks to determine what is known about medical practitioners' attitudes to and levels of knowledge about, breastfeeding and human lactation. The review also considers how they initially learn and then maintain their knowledge once in general practic