Solar thermal plant impact analysis and requirements definition

Progress on a continuing study comprising of ten tasks directed at defining impact and requirements for solar thermal power systems (SPS), 1 to 10 MWe each in capacity, installed during 1985 through year 2000 in a utility or a nonutility load in the United States is summarized. The point focus distributed receiver (PFDR) solar power systems are emphasized. Tasks 1 through 4, completed to date, include the development of a comprehensive data base on SPS configurations, their performance, cost, availability, and potential applications; user loads, regional characteristics, and an analytic methodology that incorporates the generally accepted utility financial planning methods and several unique modifications to treat the significant and specific characteristics of solar power systems deployed in either central or distributed power generation modes, are discussed

Understanding the radio emission geometry of PSR B0329+54

We have analyzed high-quality single pulse data of PSR B0329+54 at 325 MHz and 606 MHz to study the structure of the emission beam. Using the window-threshold technique, which is suitable for detecting weak emission components, we have detected 4 additional emission components in the pulse window. Three of these are new components and the fourth is a confirmation of a recently proposed component. Hence PSR B0329+54 is now known to have 9 emission components - the highest among all known pulsars. The distribution of the pulse components around the central core component indicates that the emission beam consists of four nested cones. The asymmetry in the location of the conal components in the leading versus trailing parts of the profile is interpreted as being due to aberration and retardation in the pulsar magnetosphere. These measurements allow us to determine the precise location of the 4 conal rings of emission. We find that the successive outer cones are emitted at higher altitudes in the magnetosphere. Further, for any given cone, the emission height at the lower frequency is found to be more than that at the higher frequency. The inferred heights range from ~160 km to ~1150 km. The set of ``active'' field lines, from which most of the conal radiation appears to originate, are found to be confined to a region located within ~0.5 to ~0.6 of the polar cap radius. We discuss the implications of our new findings on our understanding of the pulsar emission geometry and its impact on the emission mechanisms.Comment: 20 pages, 5 figures. Accepted for Astrophysical Journa

Odd-particle systems in the shell model Monte Carlo: circumventing a sign problem

We introduce a novel method within the shell model Monte Carlo approach to calculate the ground-state energy of a finite-size system with an odd number of particles by using the asymptotic behavior of the imaginary-time single-particle Green's functions. The method circumvents the sign problem that originates from the projection on an odd number of particles and has hampered direct application of the shell model Monte Carlo method to odd-particle systems. We apply this method to calculate pairing gaps of nuclei in the iron region. Our results are in good agreement with experimental pairing gaps

Discovery of a remarkable subpulse drift pattern in PSR B0818-41

We report the discovery of a remarkable subpulse drift pattern in the relatively less studied wide profile pulsar, B0818-41, using high sensitivity GMRT observations. We find simultaneous occurrence of three drift regions with two different drift rates: an inner region with steeper apparent drift rate flanked on each side by a region of slower apparent drift rate. Furthermore, these closely spaced drift bands always maintain a constant phase relationship. Though these drift regions have significantly different values for the measured P2, the measured P3 value is the same and equal to 18.3 P1. We interpret the unique drift pattern of this pulsar as being created by the intersection of our line of sight (LOS) with two conal rings on the polar cap of a fairly aligned rotator (inclination angle alpha ~ 11 deg), with an ``inner'' LOS geometry (impact angle beta ~ -5.4 deg). We argue that both the rings have the same values for the carousel rotation periodicity P4 and the number of sparks Nsp. We find that Nsp is 19-21 and show that it is very likely that, P4 is the same as the measured P3, making it a truly unique pulsar. We present results from simulations of the radiation pattern using the inferred parameters, that support our interpretations and reproduce the average profile as well as the observed features in the drift pattern quite well.Comment: 5 pages and 7 figures, Accepted for publication in MNRAS Letter

Explore parameter sensitivities and model calibration in a locally coupled environment

A locally coupled Single Column Model (SCM) was used for sensitivity analysis and model calibration. The sensitivity analysis was used to identify 32 land-surface parameters which appeared to be more or less sensitive in the locally coupled environment. The multi-objective sensitive analysis shows that the land surface-atmosphere interactions could have significant influences on the model parameter sensitivities. The calibration results suggest that it is crucial to include both land-surface and atmospheric parameters in the calibration of a coupled land surface model

All spherically symmetric charged anisotropic solutions for compact star

In the present paper we develop an algorithm for all spherically symmetric anisotropic charged fluid distribution. Considering a new source function $\nu(r)$ we find out a set of solutions which is physically well behaved and represent compact stellar models. A detailed study specifically shows that the models actually correspond to strange stars in terms of their mass and radius. In this connection we investigate about several physical properties like energy conditions, stability, mass-radius ratio, electric charge content, anisotropic nature and surface redshift through graphical plots and mathematical calculations. All the features from these studies are in excellent agreement with the already available evidences in theory as well as observations.Comment: 28 pages, 15 figures, major changes in the text. arXiv admin note: text overlap with arXiv:1408.5126 by other author