Indian Gaming: Issues and Prospects

This article explains the evolution of Indian gaming from economic and social perspectives. Many of the political opportunities and threats to Indian gaming are examined, and current and future issues surrounding Indian gaming are further explored

Investigation of Flow Behavior around Corotating Blades in a Double-Spindle Lawn Mower Deck

When the airflow patterns inside a lawn mower deck are understood, the deck can be redesigned to be efficient and have an increased cutting ability. To learn more, a combination of computational and experimental studies was performed to investigate the effects of blade and housing designs on a flow pattern inside a 1.1m wide corotating double-spindle lawn mower deck with side discharge. For the experimental portion of the study, air velocities inside the deck were measured using a laser Doppler velocimetry (LDV) system. A high-speed video camera was used to observe the flow pattern. Furthermore, noise levels were measured using a sound level meter. For the computational fluid dynamics (CFD) work, several arbitrary radial sections of a two-dimensional blade were selected to study flow computations. A three-dimensional, full deck model was also developed for realistic flow analysis. The computational results were then compared with the experimental results.</p

Real-time Measurement of Stress and Damage Evolution During Initial Lithiation of Crystalline Silicon

Crystalline to amorphous phase transformation during initial lithiation in (100) silicon-wafers is studied in an electrochemical cell with lithium metal as the counter and reference electrode. It is demonstrated that severe stress jumps across the phase boundary lead to fracture and damage, which is an essential consideration in designing silicon based anodes for lithium ion batteries. During initial lithiation, a moving phase boundary advances into the wafer starting from the surface facing the lithium electrode, transforming crystalline silicon into amorphous LixSi. The resulting biaxial compressive stress in the amorphous layer is measured in situ and it was observed to be ca. 0.5 GPa. HRTEM images reveal that the crystalline-amorphous phase boundary is very sharp, with a thickness of ~ 1 nm. Upon delithiation, the stress rapidly reverses, becomes tensile and the amorphous layer begins to deform plastically at around 0.5 GPa. With continued delithiation, the yield stress increases in magnitude, culminating in sudden fracture of the amorphous layer into micro-fragments and the cracks extend into the underlying crystalline silicon.Comment: 12 pages, 5 figure

TITAN code development for application to a PWR steam line break accident : final report 1983-1984

Modification of the TITAN computer code which enables it to be applied to a PWR steam line break accident has been accomplished. The code now has the capability of simulating an asymmetric inlet coolant temperature transient by employing different temperature transient forcing functions for different core inlet regions. Up to ten regions of the core can be considered and each region can have at most 50 channels. A total inlet coolant mass flow rate boundary condition option has been added to the code. Flow/coolant temperature transient and control rod transient can be simulated simultaneously by the code as necessary for a steam line break accident simulation. Also, the transient restart capability has been fixed which allows users to change core conditions during a transient calculation for various purposes. All these modifications have been tested by a ten-channel test calculation.Three steam line break accident simulations (YA-1, YA-2, and YA-3) with different pressure forcing functions have been performed. Each simulation included both closed and open-channel calculations. The steady-state results show that a 1-D thermalhydraulic analysis gives accurate results.Case YA-1 employed a pressure forcing function taken from a Yankee Atomic report. No boiling during the whole calculation was observed. Also, no significant difference between closed and open-channel calculations was found.Case YA-2 employed a reduced pressure forcing function with constant pressure after 45 seconds (because of the limitation of W-3 correlation data base). Boiling was observed around 42 seconds after the beginning of the transient. The MCHFR dropped to a value below 6 after boiling. The MCHFR went back to a high value ("30) at 50 seconds for the open-channel calculation while the MCHFR for the closed-channel case still remained below 6. The open-channel model provided a better condition of flow mixing among channels.Case YW-3 had the same pressure forcing function as that of case YA-2 except the pressure kept decreasing after 45 seconds. The MCHFR was about equal for open-and closed-channels. It is concluded that the closed-channel calculations may produce conservative core power values, but the effect on MCHFR is not always conservative

How frequent are close supermassive binary black holes in powerful jet sources?

24 pages, 36 figures. © 2018 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model (https://academic.oup.com/journals/pages/open_access/funder_policies/chorus/standard_publication_model)Supermassive black hole binariesmay be detectable by an upcoming suite of gravitationalwave experiments. Their binary nature can also be revealed by radio jets via a short-period precession driven by the orbital motion as well as the geodetic precession at typically longer periods. We have investigated Karl G. Jansky Very Large Array and Multi-Element Radio Linked Interferometer Network (MERLIN) radio maps of powerful jet sources for morphological evidence of geodetic precession. For perhaps the best-studied source, Cygnus A, we find strong evidence for geodetic precession. Projection effects can enhance precession features, for which we find indications in strongly projected sources. For a complete sample of 33 3CR radio sources, we find strong evidence for jet precession in 24 cases (73 per cent). The morphology of the radio maps suggests that the precession periods are of the order of 10 6- 10 7 yr. We consider different explanations for the morphological features and conclude that geodetic precession is the best explanation. The frequently observed gradual jet angle changes in samples of powerful blazars can be explained by orbital motion. Both observations can be explained simultaneously by postulating that a high fraction of powerful radio sources have subparsec supermassive black hole binaries.We consider complementary evidence and discuss if any jetted supermassive black hole with some indication of precession could be detected as individual gravitational wave source in the near future. This appears unlikely, with the possible exception of M87.Peer reviewedFinal Published versio

Finding Rare AGN: X-ray Number Counts of Chandra Sources in Stripe 82

We present the first results of a wide area X-ray survey within the Sloan Digital Sky Survey (SDSS) Stripe 82, a 300 deg$^2$ region of the sky with a substantial investment in multi-wavelength coverage. We analyzed archival {\it Chandra} observations that cover 7.5 deg$^2$ within Stripe 82 ("Stripe 82 ACX"), reaching 4.5$\sigma$ flux limits of 7.9$\times10^{-16}$, 3.4$\times10^{-15}$ and 1.8$\times10^{-15}$ erg s$^{-1}$ cm$^{-2}$ in the soft (0.5-2 keV), hard (2-7 keV) and full (0.5-7 keV) bands, to find 774, 239 and 1118 X-ray sources, respectively. Three hundred twenty-one sources are detected only in the full band and 9 sources are detected solely in the soft band. Utilizing data products from the {\it Chandra} Source Catalog, we construct independent Log$N$-Log$S$ relationships, detailing the number density of X-ray sources as a function of flux, which show general agreement with previous {\it Chandra} surveys. We compare the luminosity distribution of Stripe 82 ACX with the smaller, deeper CDF-S + E-CDFS surveys and with {\it Chandra}-COSMOS, illustrating the benefit of wide-area surveys in locating high luminosity AGN. We also investigate the differences and similarities of X-ray and optical selection to uncover obscured AGN in the local Universe. Finally, we estimate the population of AGN we expect to find with increased coverage of 100 deg$^2$ or 300 deg$^2$, which will provide unprecedented insight into the high redshift, high luminosity regime of black hole growth currently under-represented in X-ray surveys.Comment: Accepted for publication in MNRAS, 15 pages, 6 Figures, 2 Table

Lensed CMB power spectra from all-sky correlation functions

Weak lensing of the CMB changes the unlensed temperature anisotropy and polarization power spectra. Accounting for the lensing effect will be crucial to obtain accurate parameter constraints from sensitive CMB observations. Methods for computing the lensed power spectra using a low-order perturbative expansion are not good enough for percent-level accuracy. Non-perturbative flat-sky methods are more accurate, but curvature effects change the spectra at the 0.3-1% level. We describe a new, accurate and fast, full-sky correlation-function method for computing the lensing effect on CMB power spectra to better than 0.1% at l<2500 (within the approximation that the lensing potential is linear and Gaussian). We also discuss the effect of non-linear evolution of the gravitational potential on the lensed power spectra. Our fast numerical code is publicly available.Comment: 16 pages, 4 figures. Changes to match PRD version including new section on non-linear corrections. CAMB code available at http://camb.info

Design and Development of a Photodegradable Bottle Cap

The first photodegradable plastic cap for a glass beer bottle was developed and tested. The cap\u27s design is the same as the current plastic, screw-on cap for soda bottles. A photodegradable resin was added to the soda cap plastic to make it photodegradable. Caps with 0%, 10%, and 25% photodegradable additive were made. Tests show that the photodegradable cap meets most of the physical properties required for a beer or a soda cap. A photodegradable cap with 10% degradable additive will cost about three times more than current metal crowns, but only about 10% more than current plastic soda caps. The photodegradable caps can be made on a large scale using the same process as for regular soda caps. 10,000 caps were made for testing