AdS Black Hole with Phantom Scalar Field

In this paper, we present an AdS black hole solution with Ricci flat horizon in Einstein-phantom scalar theory. The phantom scalar fields just depend on the transverse coordinates $x$ and $y$, and which are parameterized by the parameter $\alpha$. We study the thermodynamics of the AdS phantom black hole. Although its horizon is a Ricci flat Euclidean space, we find that the thermodynamical properties of the black hole solution are qualitatively same as those of AdS Schwarzschild black hole. Namely there exists a minimal temperature, the large black hole is thermodynamically stable , while the smaller one is unstable, so there is a so-called Hawking-Page phase transition between the large black hole and the thermal gas solution in the AdS spacetime in Poincare coordinates. We also calculate the entanglement entropy for a strip geometry dual to the AdS phantom black holes and find that the behavior of the entanglement entropy is qualitatively the same as that of the black hole thermodynamical entropy.Comment: 6 pages, 8 figure

Legendre Invariance and Geometrothermodynamics Description of the 3D Charged-Dilaton Black Hole

We first review Weinhold information geometry and Ruppeiner information geometry of 3D charged-dilaton black hole. Then, we use the Legendre invariant to introduce a 2-dimensional thermodynamic metric in the space of equilibrium states, which becomes singular at those points. According to the analysis of the heat capacities, these points are the places where phase transitions occur. This result is valid for the black hole, therefore, provides a geometrothermodynamics description of black hole phase transitions in terms of curvature singularities

JPSS-1 VIIRS Solar Diffuser Witness Sample BRF Calibration Using a Table-Top Goniometer at NASA GSFC

In support of the prelaunch calibration of the Joint Polar Satellite System-1 (JPSS-1) Visible Infrared Imaging Radiometer Suite (VIIRS), the Bidirectional Reflectance Factor (BRF) and Bidirectional Reflectance Distribution Function (BRDF) of a VIIRS solar diffuser (SD) witness sample were determined using the table-top goniometer (TTG) located in the NASA GSFC Diffuser Calibration Laboratory (DCL). The BRF of the sample was measured for VIIRS bands in the reflected solar wavelength region from 410 nm to 2250 nm. The new TTG was developed to extend the laboratorys BRF and BRDF measurement capability to wavelengths from 1600 to 2250 nm and specifically for the VIIRS M11 band centered at 2250 nm. We show the new features and capabilities of the new scatterometer and present the BRF and BRDF results for the incident/scatter test configuration of 0/45 and for a set of angles representing of the VIIRS on-orbit solar diffuser calibration. The BRF and BRDF results of the SD witness were used to assist in finalizing the set of BRF values of J1 VIIRS SD to be used on-orbit. Comparison of the BRF results between the JPSS-1 VIIRS SD witness sample and the flight SD panel was made by varying different sample clocking orientations and by analyzing the ratio of BRF to total hemispherical reflectance in effort to minimize the uncertainty of the extrapolated flight BRF value at 2250 nm. Furthermore, differences between the prelaunch BRF results and those used in the VIIRS on-orbit BRF lookup table were examined to improve the VIIRS BRF calibration for future missions

JPSS-1 VIIRS Solar Diffuser Witness Sample BRF Calibration Using a Table-Top Goniometer at NASA GSFC

In support of the prelaunch calibration of the Joint Polar Satellite System-1 (JPSS-1) Visible Infrared Imaging Radiometer Suite (VIIRS), the Bidirectional Reflectance Factor (BRF) and Bidirectional Reflectance Distribution Function (BRDF) of a VIIRS solar diffuser (SD) witness sample were determined using the table-top goniometer (TTG) located in the NASA GSFC Diffuser Calibration Laboratory (DCL). The BRF of the sample was measured for VIIRS bands in the reflected solar wavelength region from 410 nm to 2250 nm. The new TTG was developed to extend the laboratorys BRF and BRDF measurement capability to wavelengths from 1600 to 2250 nm and specifically for the VIIRS M11 band centered at 2250 nm. We show the new features and capabilities of the new scatterometer and present the BRF and BRDF results for the incident/scatter test configuration of 0/45 and for a set of angles representing of the VIIRS on-orbit solar diffuser calibration. The BRF and BRDF results of the SD witness were used to assist in finalizing the set of BRF values of J1 VIIRS SD to be used on-orbit. Comparison of the BRF results between the JPSS-1 VIIRS SD witness sample and the flight SD panel was made by varying different sample clocking orientations and by analyzing the ratio of BRF to total hemispherical reflectance in effort to minimize the uncertainty of the extrapolated flight BRF value at 2250 nm. Furthermore, differences between the prelaunch BRF results and those used in the VIIRS on-orbit BRF lookup table were examined to improve the VIIRS BRF calibration for future missions

Spectroscopy of the rotating BTZ black hole via adiabatic invariance

According to Bohr-Sommerfeld quantization rule, an equally spaced horizon area spectrum of a static, spherically symmetric black hole was obtained under an adiabatic invariant action. This method can be extended to the rotating black holes. As an example, we apply this method to the rotating BTZ black hole and obtain the quantized spectrum of the horizon area. It is shown that the area spectrum of the rotating BTZ black hole is equally spaced and irrelevant to the rotating parameter, which is consistent with the Bekenstein conjecture. Specifically, the derivation do not need the quasinormal frequencies and the small angular momentum limit.Comment: 6 pages, 0 figures, to appear in Sci China Ser G-Phys Mech Astron. arXiv admin note: text overlap with arXiv:1106.229

New Hyperspectral BRDF Feature of a Table-Top Goniometer in the Diffuser Calibration Lab at NASA GSFC

A Table-Top Goniometer (TTG) was built in the Diffuser Calibration Lab at NASA GSFC to support solar diffuser (SD) calibrations from 350 nm to 2500 nm. So far, it has been used to complete the BRDF calibration for the J1 VIIRS SD witness sample as an effort to validate its pre-launch calibration made by the instrument vendor. The new hyperspectral BRDF feature of TTG was implemented to improve BRDF measurements with high-efficiency and high-spectral resolution, and to simulate on-orbit calibration scenarios. This enables us to figure out the potential difference of BRDF results from measurements using monochromatic and broadband light sources. The preliminary hyperspectral BRDF measurements of spectralon samples were conducted with the appropriate integration time and pixel averaging using a CCD spectrometer from 200 nm to 1100 nm and a UV enhanced broadband laser-driven plasma lamp source. The comparison of BRDF results from the spectrometer and a Si detector is made to validate the new feature. The details of methodology for realization of the hyperspectral BRDF measurement and the BRDF scale transfer algorithm are described. The short-term stability of light source, and uncertainty components are also discussed

BRDF Measurements using a Large-area Uniform Illumination Scatterometer (LUIS) in Support of NASA Remote Sensing Programs

There are two newly developed scatterometers at the Diffuser Calibration Lab (DCL) NASA GSFC. One of them is a laser/lamp-based table-top scatterometer (TTS) covering the spectral range from 300 nm to 2300 nm with a relative small beam size of 5 to 10 mm in diameter. The spatial non-uniformity of BRDF is requested when a large diffuse sample is measured on TTS. In order to test the BRDF along with spatial non-uniformity, a Large-area Uniform Illumination Scatterometer (LUIS) was built to meet the requirements for different large samples, especially volume diffuse samples. The LUIS system at NASA GSFC is capable of generating a 6” dia. uniform collimated beam using a 16” dia. 2.5 m long telescope, high power LEDs from 340 nm to 1650 nm, and different field-of-view detectors, and applies the same measurement equation as that used in flight. BRDF results of selected white and black diffuse samples measured using LUIS are presented, including surface diffusers and volume diffusers, and compared with those from TTS. Several new capabilities of BRDF measurements of LUIS are also demonstrated. In addition, another approach of BRDF tests for a large-area sample was attempted to simulate a large-area uniform illumination by rastering a 532 nm pencil laser across it. These BRDF results are compared with that from LUIS, showing a good agreement. To extend the spectral coverage of LUIS beyond 2000 nm, a high power SWIR tunable laser is used to generate the large-area uniform collimated light. Some related results will be reported. Also discussed in this presentation are the BRDF validation and uncertainty budget

Food macromolecule based nanodelivery systems for enhancing the bioavailability of polyphenols

Diet polyphenols—primarily categorized into flavonoids (e.g., flavonols, flavones, flavan-3-ols, anthocyanidins, flavanones, and isoflavones) and nonflavonoids (with major subclasses of stilbenes and phenolic acids)—are reported to have health-promoting effects, such as antioxidant, antiinflammatory, anticarcinoma, antimicrobial, antiviral, and cardioprotective properties. However, their applications in functional foods or medicine are limited because of their inefficient systemic delivery and poor oral bioavailability. Epigallocatechin-3-gallate, curcumin, and resveratrol are the well-known representatives of the bioactive diet polyphenols but with poor bioavailability. Food macromolecule based nanoparticles have been fabricated using reassembled proteins, crosslinked polysaccharides, protein–polysaccharide conjugates (complexes), as well as emulsified lipid via safe procedures that could be applied in food. The human gastrointestinal digestion tract is the first place where the food grade macromolecule nanoparticles exert their effects on improving the bioavailability of diet polyphenols, via enhancing their solubility, preventing their degradation in the intestinal environment, elevating the permeation in small intestine, and even increasing their contents in the bloodstream. We contend that the stability and structure behaviors of nanocarriers in the gastrointestinal tract environment and the effects of nanoencapsulation on the metabolism of polyphenols warrant more focused attention in further studies