Modeling the Retention Probability of Black Holes in Globular Clusters: Kicks and Rates

We simulate black hole binary interactions to examine the probability of mergers and black hole growth and gravitational radiation signals using a specific initial distribution of masses for black holes in globular clusters and a simple semi-analytic formalism for dynamical interactions. We include 3-body recoil and the latest results in numerical relativity for gravitational radiation recoil. It is found that while 99% of binaries are ejected from low metallicity, low mass clusters; metal rich massive clusters retain 5% of their binaries. An interesting fraction of the ejected binaries, especially those from high mass, high metallicity systems, merge on timescales short enough to be gravitational radiation sources during their mergers with rates approaching those expected for galactic field black hole binaries. While the merger rates are comparable, the much larger mass of these binaries and their localization will make them appealing targets for advanced LIGO. We single out two possible Milky Way clusters (NGC 6441 and NGC 6388) as having the properties for a good probability of retention

The Advanced Technology Large Aperture Space Telescope (ATLAST): Science Drivers, Technology Developments, and Synergies with Other Future Facilities

The Advanced Technology Large-Aperture Space Telescope (ATLAST) is a concept for an 8-meter to 16-meter UVOIR space observatory for launch in the 2025-2030 era. ATLAST will allow astronomers to answer fundamental questions at the forefront of modern astrophysics, including "Is there life elsewhere in the Galaxy?" We present a range of science drivers that define the main performance requirements for ATLAST (8 to 16 milliarcsec angular resolution, diffraction limited imaging at 0.5 m wavelength, minimum collecting area of 45 square meters, high sensitivity to light wavelengths from 0.1 m to 2.4 m, high stability in wavefront sensing and control). We will also discuss the synergy between ATLAST and other anticipated future facilities (e.g., TMT, EELT, ALMA) and the priorities for technology development that will enable the construction for a cost that is comparable to current generation observatory-class space missions

Extraction of Stevioside from Stevia Rebaudiana Leaves Using Cellulase

Stevioside is a diterpene glycoside present in Stevia Rebaudiana leaves that has the ability to sweeten at rated between 70 to 350 times than sucrose (0.4% w/v). It has no calorific value. Unlike many low calorie sweeteners, stevioside is stable at high temperature. The objective of this research is to extract stevioside from stevia rebaudiana leaves by using cellulase from Aspergillus Niger. Acetate buffer and ethanol were used as a medium for enzyme and as a solvent, respectively. In this present study, the enzymatic extraction of stevioside from stevia rebaudiana leaves was carried out using cellulase with various parameters that affect the production of stevioside such as concentration of enzyme, incubation time and temperature. Cellulase was observed to give the highest stevioside yield (16230 ± 0.3 μg/ml) at 40oC. This indicated that the maximum temperature for cellulase activity was 40oC. The results signify that the enzymatic extraction method is an alternative to solvent based stevioside extraction, based on its higher efficiency. Thus, it can be concluded that the extraction of stevioside from Stevia rebaudiana leaves using cellulase can be maximized under the maximum conditions for the cellulase activity where the used of solvent can be minimized in degrading the cell wall Together with the maximum heat and correct combination of the solvent used, a new and efficient way of extracting high yield of stevioside can be obtained

Student-Athletes at an Historically Black University (HBU): Examining the Relationship Between Student-Engagement on Campus and Career Situation Awareness

The purpose of this exploratory study was to examine the relationship between student-athletes’ engagement experiences on campus and their career situation awareness at an historically Black university (HBU) in the Southeastern United States with NCAA Division I affiliation. Data was obtained from a sample (n = 118) of female (n= 45) and male (n = 73) student-athletes using measures from the revised versions of the Student-Athlete Experiences Inventory (SAEI) and the Student-Athlete Career Situation Inventory (SACSI). One-way ANOVA, Pearson product-moment correlation tests, and t-tests were employed to analyze gender, race, year classification, and sport played effects. Following data analysis, three key findings were identified. First, HBCUs are likely to provide socially enriching environments for minority student-athletes of both genders that promote career confidence; particularly for Black, female student-athletes. Second, in an HBCU context, White student-athletes may not be as academically involved in university life when compared to their minority counterparts. Third, the use of the library for academic purposes and engagement in socially enriching experiences may have diminishing effects on female student-athletes’ sport identities. Implications and future research recommendations are discussed. To better validate and improve the generalizability, future research should conduct similar studies that employ data from multiple HBCUs

The Cost of U.S. Forest-Based Carbon Sequestration

Examines the economic and climate impacts of storing carbon in forests over long periods of time. Investigates the potential for incorporating land-use changes into climate policy

BVRI Light Curves for 29 Type Ia Supernovae

BVRI light curves are presented for 27 Type Ia supernovae discovered during the course of the Calan/Tololo Survey and for two other SNe Ia observed during the same period. Estimates of the maximum light magnitudes in the B, V, and I bands and the initial decline rate parameter m15(B) are also given.Comment: 17 pages, figures and tables are not included (contact first author if needed), to appear in the Astronomical Journa

The Advanced Technology Large Aperture Space Telescope (ATLAST): Science Drivers and Technology Developments

The Advanced Technology Large-Aperture Space Telescope (ATLAST) is a concept for an 8-meter to 16-meter UVOIR space observatory for launch in the 2025-2030 era. ATLAST will allow astronomers to answer fundamental questions at the forefront of modern astrophysics, including "Is there life elsewhere in the Galaxy?" We present a range of science drivers and the resulting performance requirements for ATLAST (8 to 16 milliarcsecond angular resolution, diffraction limited imaging at 0.5 m wavelength, minimum collecting area of 45 square meters, high sensitivity to light wavelengths from 0.1 m to 2.4 m, high stability in wavefront sensing and control). We also discuss the priorities for technology development needed to enable the construction of ATLAST for a cost that is comparable to current generation observatory-class space missions. Keywords: Advanced Technology Large-Aperture Space Telescope (ATLAST); ultraviolet/optical space telescopes; astrophysics; astrobiology; technology development

The Effect of a Steel Core upon the Electrical Characteristics of Large Stranded Aluminum Conductors

No abstract