Test of nuclear level density inputs for Hauser-Feshbach model calculations

The energy spectra of neutrons, protons, and alpha-particles have been measured from the d+59Co and 3He+58Fe reactions leading to the same compound nucleus, 61$Ni. The experimental cross sections have been compared to Hauser-Feshbach model calculations using different input level density models. None of them have been found to agree with experiment. It manifests the serious problem with available level density parameterizations especially those based on neutron resonance spacings and density of discrete levels. New level densities and corresponding Fermi-gas parameters have been obtained for reaction product nuclei such as 60Ni,60Co, and 57Fe

Interview with W. T. Dub Massey

In his April 27th, 1981 interview with Phil O’Quinn, W.T. Massey recollects his involvement in the Civil Rights Movement as one of the Friendship 9 protestors and non-violent activists. Massey retells the preparation and events leading up to the sit-in at McCrory’s lunch counter. Massey also shares the negative effects he experienced with his involvement as an activist and leader in the Civil Rights Movement, in particular, his arrest from the McCrory’s sit-in. Massey concludes his interview with advice and hope for the black community. This interview was conducted for inclusion into the Louise Pettus Archives and Special Collections Oral History Program.https://digitalcommons.winthrop.edu/oralhistoryprogram/1154/thumbnail.jp

Coordinated design of coding and modulation systems

The joint optimization of the coding and modulation systems employed in telemetry systems was investigated. Emphasis was placed on formulating inner and outer coding standards used by the Goddard Spaceflight Center. Convolutional codes were found that are nearly optimum for use with Viterbi decoding in the inner coding of concatenated coding systems. A convolutional code, the unit-memory code, was discovered and is ideal for inner system usage because of its byte-oriented structure. Simulations of sequential decoding on the deep-space channel were carried out to compare directly various convolutional codes that are proposed for use in deep-space systems

Subaru Suprime-Cam Weak Lensing Survey over 33 deg^2

Under the currently popular CDM model, mass plays the major role in evolution of large scale structure of the universe. In order to examine the paradigm based on observations, it ould be ideal to use purely mass selected object catalog. Weak lensing surveys enable a blind search of cluster scale objects, and thus could provide such catalogs. We are working on a weak lensing survey using Subaru Prime Focus Camera (Suprime-Cam). In this note, we introduce our survey strategy, and the status as well as the performance of Suprime-Cam as a weak lensing surveyor

Oxygen-rich dust production in IC 10

We report the detection of oxygen-rich circumstellar envelopes in stars of the nearby (700 kpc) starburst galaxy IC 10. The star formation history and the chemical environment of this galaxy makes it an ideal target to observe dust production by high-mass stars in a low-metallicity environment. The goal of this study is to identify oxygen-rich stars in IC 10 and to constrain their nature between asymptotic giant branch stars (AGBs), red supergiants (RSGs), and other infrared bright sources. We examine the mass-loss rate of the stars and compare to results obtained for the Magellanic Clouds. Our objectives are to (1) assess whether RSGs can be significant dust producers in IC 10, and (2), solve the discrepancy between the star formation history of IC 10 and the relatively low number of RSGs detected in the optical. We search for silicate dust in emission by using the spectral map observed with the Infrared Spectrograph on board the Spitzer Space Telescope. The optical (UBVRI) and infrared (JHK, Spitzer/IRAC and Spitzer/MIPS) photometry is used to assert the membership of the stars to IC 10 and disentangle between AGBs and RSGs. Radiative models are used to infer mass-loss rates and stellar luminosities. The luminosity and colors of at least 9 silicate emission sources are consistent with stars within IC 10. Furthermore, the photometry of 2 of these sources is consistent with RSGs. We derive dust mass-loss rates similar to the values found in the Magellanic Clouds. Accounting for the sample completeness, RSGs are not important contributors to the dust mass budget in IC 10.Comment: Accepted for publication in A&

Intrinsic and extrinsic geometries of a tidally deformed black hole

A description of the event horizon of a perturbed Schwarzschild black hole is provided in terms of the intrinsic and extrinsic geometries of the null hypersurface. This description relies on a Gauss-Codazzi theory of null hypersurfaces embedded in spacetime, which extends the standard theory of spacelike and timelike hypersurfaces involving the first and second fundamental forms. We show that the intrinsic geometry of the event horizon is invariant under a reparameterization of the null generators, and that the extrinsic geometry depends on the parameterization. Stated differently, we show that while the extrinsic geometry depends on the choice of gauge, the intrinsic geometry is gauge invariant. We apply the formalism to solutions to the vacuum field equations that describe a tidally deformed black hole. In a first instance we consider a slowly-varying, quadrupolar tidal field imposed on the black hole, and in a second instance we examine the tide raised during a close parabolic encounter between the black hole and a small orbiting body.Comment: 27 pages, 4 figure

Tripod Deployment: YR160825 to YR160913, PC-ADP and LISST, Clay Bank, York River Virginia

Dataset consists of burst data collected as part of a tripod deployment. The tripod included the following instruments: Pulse-coherent Acoustic Doppler Profiler (PCADP), Sequoia LISST, two HOBOs

Resistivity, Magnetic Susceptibility and Sediment Characterization of the York River Estuary in Support of the Empirical Investigation of the Factors Influencing Marine Applications of EMI (Year 2 of SERDP Project MR-2409) Final Report.

Vessel and personnel support was provided for a series of cruises to three salinity regimes along the York River. Data and samples from a standard suite of hydrographic and sedimentological measurements, as well as electrical resistivity and magnetic susceptibility, were collected and analyzed for each location. These cruises provided opportunities to obtain information that is being used to quantify the unique marine contributions to the early time TEM noise, including conductivity variations in the water and variability in bottom sediment properties in real marine environments, for use in the parallel modeling and electromagnetic-induction sensor work ongoing in the same project. Data collected during Year 1 of this project were used to select the appropriate locations to provide a range of conductivity and sediment conditions