Photon redshift and the appearance of a naked singularity

In this paper we analyze the redshift as observed by an external observer receiving photons which terminate in the past at the naked singularity formed in a Tolman-Bondi dust collapse. Within the context of models considered here it is shown that photons emitted from a weak curvature naked singularity are always finitely redshifted to an external observer. Certain cases of strong curvature naked singularities, including the self-similar one, where the photons are infinitely redshifted are also pointed out.Comment: Latex file, 14 pages, no figures, one change in the reference. Accepted for publication in Phys. Rev.

Efficiency of Indian Banking Industry in the Post-Reform Era

One of the major objectives of Indian banking sector reforms was to encourage operational self-sufficiency, flexibility and competition in the system and to increase the banking standards in India to the international best practices. The second phase of reforms began in 1997 with aim to reorganization measures, human capital development, technological up-gradation, structural development which helped them for achieving universal benchmarks in terms of prudential norms and pre-eminent practices. This paper seeks to determine the impact of various market and regulatory initiatives on efficiency improvements of Indian banks. Efficiency of firm is measured in terms of its relative performance that is, efficiency of a firm relative to the efficiencies of firms in a sample. Data Envelopment Analysis (DEA) has used to identify banks that are on the output frontier given the various inputs at their disposal. The present study is confined only to the Constant-Return-to-Scale (CRS) assumption of decision making units (DMUs). Variable returns to scale (VRS) assumption for estimating the efficiency was not attempted. It was found from the results that national banks, new private banks and foreign banks have showed high efficiency over a period time than remaining banks.

Analysis of curtailment at The Geysers geothermal Field, California

Geothermal energy has traditionally been viewed as a baseload energy source, but the rapid growth of intermittent renewable energy has led to a need for more flexibility in power generation to avoid mandatory curtailment imposed by grid operators. This study of curtailment at The Geysers provides insights into the magnitude, duration, frequency, temporal and spatial distribution, and potential causes of curtailment events between 2013 and 2018. Annual levels of curtailment range during this period from 9 to 47 GW h, representing 0.15 to 0.81 % of the net generation. Most curtailments occurred at the power plants connected to a lower capacity transmission line and may result from transmission constriction. There is a clear link between negative pricing and economic curtailment, especially when solar production is higher. Economic curtailment events tend to be only a few hours and vary in magnitude up to almost 300 MW, whereas transmission-related curtailment events can be up to several weeks in duration. It is likely that curtailment of geothermal power will be an increasing concern, and could be mitigated by flexible generation strategies and increases in energy storage. It is critical to know the nature of curtailment events so that flexible generation options can be assessed properly

Null Geodesic Expansion in Spherical Gravitational Collapse

We derive an expression for the expansion of outgoing null geodesics in spherical dust collapse and compute the limiting value of the expansion in the approach to singularity formation. An analogous expression is derived for the spherical collapse of a general form of matter. We argue on the basis of these results that the covered as well as the naked singularity solutions arising in spherical dust collapse are stable under small changes in the equation of state.Comment: 10 pages, Latex File, No figure

Editorial

The special issue “Emerging Aerospace Technologies in Aerodynamics, Propulsion, and Materials” is published which covers the aerospace domain covering aerodynamics, propulsion, and materials used for aeronautical and aerospace domains. In this issue, the authors have focused on the articles related to experimental and computational work related to aircraft performance, aircraft stability and control, materials, and some other important areas. Most of the papers are based on Project Based Learning which is one of the research-oriented teaching-learning processes recently introduced in National Education Policy 2020 by the Government of India

Nature of genetic control of the length and number of elongated internodes in deepwater rice under non-flooded condition

Inheritance of total length and number of elongated internodes in some varities of deepwater rice were studied in a 7 X 7 diallel (excluding reciprocals) by a procedure that does not require flooding. Estimates of combining ability and genetic component analysis showed highly significant additive and non-additive gene effects with preponderance of additive type. The high estimate of narrow sense heritability further supported the importance of additive gene effects. lalmagna and IR40905-11-3-1-5-2-21 were not always the best combiners. The significance of the gene distribution indicated the presence of gene asymmetry. The average degree of dominance was 8.83 for both total length and number of elongated internodes indicating partial dominance

Anthelmintic Activity of a Polyherbal Preparation

The present study was done with the aim to investigate the anthelmintic activity of polyherbal formulation containing herbs Thespesia populnea (bark), Terminalia alata (bark), Clematis triloba (roots) and Ceratophyllum demersum (leaves) using adult earthworm Pheritima posthuma. The aqueous and ethanolic extract of the crude drug of different concentration were tested which involve determination of paralysis time and time to kill the worms. Piperazine citrate was used as standard and it was found that the PHF ethanolic extract activity is higher than PHF aqueous extract

Calcined Phosphate Fertilizer from Jhamarkotra Secondary Phosphate Ore and Rock Phosphate Beneficiation Plant Bulk Circuit Tail

The secondary phosphate ore of RSMML 's Jhamarkotra rock phosphate mines have high iron content that renders it unsuitable for manufacturing of phosphatic fertilizers like SSP,DAP and phosphoric acid. This paper explores the feasibility of utilizing the secondary phosphate ore by thermal treatment, which involves calcination as well as fusion. The calcined and fused products both have good citrate solubility and thus have a potential to be used as a citrate soluble phosphatic fertilizer. This paper also deals some phosphate resources which are added during thermal treatment. These additives not only assist in the fusion and calcination but also improves soil fertility. These are more beneficial to the soil. Calcined dolomite tailing among these has a potential to be utilized as citrate soluble phosphate rich magnesium fertilize

Utilization of Nano Technology in Reducing Moisture Content of Phosphate Cake at RSMML Rock Phosphate Beneficiation Plant

After the induction of High Pressure Grinding Rolls at rock Phosphate Beneficiation Plant, The belt Drum Filters (BDF's) performance rapidly deteriorated. This was mainly attributed to fine grinding i.e., about 85% < 25 microns. The phosphate cake produced by BDF was sloppy and posed problems in handling and transportation. The sloppier the product the more inefficient in loading and transportat-ion'. Thus the most daunting task was to reduce moisture content of phosphate cake from about 22% to 13-15%. This paper discusses the most critical role played by nano-technology in tackling this problem

Advancements in UAVs-A review

ABSTRACT: Present decade has been observed that Unmanned Aerial Vehicles(UAVs) are occupying the sky to accomplish different missions. They became the popular area of interest due to their growing utility and relative cost. Increased demand of UAVs allowing the researchers for the optimized UAV as a major area of interest. They are providing new and better opportunities to cellular networks. UAV industry is undergoing a huge amount of advancements in it such as in navigation system, privacy and security ,mission management system, power system communication system etc. this article mainly focuses on the advancements regarding privacy and security of UAVs ,mission management system. The motivation behind the development of strategies for defending the breaches caused by data protection and public safety them are examined. This study gives an overview about past and how the present usage of UAVs is optimized by implementing the defense techniques. The major six criteria implemented to defend socio-technical concerns are explained. Few countries which adapted these regulations are discussed briefly .Ensuring security of the UAV system is studied considering physical security and cyber security as major aspects. The study also provides the techniques to defend these security threats. on Mission planning and mission management