System Planning Corporation

About: System Planning Corporation is a company organization based out in Arlington, Virginia, United States. It is known for research contribution in the topics: Container (abstract data type) & Shearlet. The organization has 56 authors who have published 100 publications receiving 3372 citations.

Stellar Diameters and Temperatures. II. Main-sequence K- and M-stars

Abstract: We present interferometric angular diameter measurements of 21 low-mass, K- and M-dwarfs made with the CHARA Array. This sample is enhanced by adding a collection of radius measurements published in the literature to form a total data set of 33 K-M-dwarfs with diameters measured to better than 5%. We use these data in combination with the Hipparcos parallax and new measurements of the star's bolometric flux to compute absolute luminosities, linear radii, and effective temperatures for the stars. We develop empirical relations for ~K0 to M4 main-sequence stars that link the stellar temperature, radius, and luminosity to the observed (B – V), (V – R), (V – I), (V – J), (V – H), and (V – K) broadband color index and stellar metallicity [Fe/H]. These relations are valid for metallicities ranging from [Fe/H] = –0.5 to +0.1 dex and are accurate to ~2%, ~5%, and ~4% for temperature, radius, and luminosity, respectively. Our results show that it is necessary to use metallicity-dependent transformations in order to properly convert colors into stellar temperatures, radii, and luminosities. Alternatively, we find no sensitivity to metallicity on relations we construct to the global properties of a star omitting color information, e.g., temperature-radius and temperature-luminosity. Thus, we are able to empirically quantify to what order the star's observed color index is impacted by the stellar iron abundance. In addition to the empirical relations, we also provide a representative look-up table via stellar spectral classifications using this collection of data. Robust examinations of single star temperatures and radii compared to evolutionary model predictions on the luminosity-temperature and luminosity-radius planes reveal that models overestimate the temperatures of stars with surface temperatures <5000 K by ~3%, and underestimate the radii of stars with radii <0.7 R_☉ by ~5%. These conclusions additionally suggest that the models over account for the effects that the stellar metallicity may have on the astrophysical properties of an object. By comparing the interferometrically measured radii for the single star population to those of eclipsing binaries, we find that for a given mass, single and binary star radii are indistinguishable. However, we also find that for a given radius, the literature temperatures for binary stars are systematically lower compared to our interferometrically derived temperatures of single stars by ~200 to 300 K. The nature of this offset is dependent on the validation of binary star temperatures, where bringing all measurements to a uniform and correctly calibrated temperature scale is needed to identify any influence stellar activity may have on the physical properties of a star. Lastly, we present an empirically determined H-R diagram using fundamental properties presented here in combination with those in Boyajian et al. for a total of 74 nearby, main-sequence, A- to M-type stars, and define regions of habitability for the potential existence of sub-stellar mass companions in each system.

System and method for providing container security

Abstract: A system for monitoring the contents of a closed container is provided. The system includes a sensing system for monitoring the contents of the container; a signal receiving element for receiving sensor data from the sensing system; a control element for analyzing received sensor data; a first transceiver element for receiving signals containing sensor data from within the container and for transmitting those signals outside of the container; and a satellite transceiver element for receiving signals from the first transceiver element and for forwarding the received signals via satellite uplink to a remote location.

Protective structure for an immersion pyrometer

Abstract: An immersion pyrometer having an outer casing comprising a mixture of graphite and a refractory metal oxide for contact with molten metal, an inner sheath enclosed by said outer casing, said inner sheath comprising a closed end metal tube wherein the closed end is in heat transfer contact with said outer casing, and a thermocouple within said inner sheath.

Immersion pyrometer with protective structure for sidewall use

Abstract: Temperature sensing apparatus for use in the sidewall or bottom of a vessel for containing molten metal. A temperature sensing element is mounted within a sheath which is provided with a sacrificial coating to protect the sheath from premature oxidation such as may occur during a gas-flame pre-heat cycle. The sheath which is being protected against premature oxidation by the sacrificial coating is a composite of a closed end metal tube and a plurality of porous cermet layers of aluminum oxide-chromium oxide-molybdenum with the concentration of molybdenum decreasing in proceeding from the inner cermet layer to the outer cermet layer. The outer cermet layer of the sheath is covered by a ceramic layer of aluminum oxide. The sacrificial coating consists of a layer of zirconium oxide in combination with and covered by a layer of fibrous alumina. The sacrificial coating is typically destroyed by the end of a pre-heat cycle.