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

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

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

Evaluation of morphometric characteristics and watershed prioritization of Bhadar basin of Saurashtra region, Gujarat

Morphometric analysis is one of the important aspects of quantitative geomorphology which is primarily used to study the geometrical aspects of the landforms. The study was undertaken with the objectives of evaluating morphometric characteristic and prioritizing the watersheds of Bhadar basin based on its morphometric characteristics.&nbsp; Linear, relief and aerial aspects were calculated for watershed characterization. The watersheds were ranked on the basis of high values of linear parameters and low values of shape parameters. A total of 16 watersheds 5G1B1, 5G1B2, 5G1B3, 5G1B4, 5G1B5, 5G1B6, 5G1B7, 5G1B8, 5G1B9, 5G1B10, 5G1B11, 5G1B12, 5G1B13, 5G1B14, 5G1B15 and 5G1B16 were identified in the Bhadar basin and morphometric characteristic of each watershed was determined. Highest priority indicated the greater degree of erosion in the particular watershed and it therefore priority should be given in applying soil conservation measures. It was concluded that the watershed 5G1B15 should be given highest priority because of higher erosion problems over other watersheds of Bhadar basin while 5G1B4 should be given the least priority

Evaluation of Antitumor Activity of Cuscuta Reflexa Roxb (Cuscutaceae) Against Ehrlich Ascites Carcinoma in Swiss Albino Mice

Purpose: The aim of this study was to investigate the antitumor effect of the chloroform and ethanol extract of the whole plant of Cuscuta reflexa Roxb. (Cuscutaceae) in Swiss albino mice against Ehrlich Ascites Carcinoma (EAC) cell line.Methods: The antitumor activity of the chloroform and ethanol extracts of Cuscuta reflexa was evaluated against Ehrlich ascites carcinoma (EAC) tumor in mice at doses of 200 and 400 mg/kg body weight orally, respectively, while acute oral toxicity studies were performed to determine the safety of the extracts. Briefly, the EAC cells were injected (i.p.) into ninty six mice (divided into 6 numerically equal groups), and after a one-day incubation period, the extracts were administered to the mice daily for 16 days. On day 21, six animals in each group were sacrificed for observation of antitumor activity and the remaining animals were observed to determine host the life span. Antitumor effect was determined by evaluating tumor volume, viable and nonviable tumor cell count and hematological parameters of the host. The standard antitumor used was 5-fluorouracil.Results: Administration of the extracts resulted in a significant (p < 0.05) decrease in tumor volume and viable cell count, but increased non-viable cell count and mean survival time, thereby increasing the life span of the tumor-bearing mice. Restoration of hematological parameters - red blood cells (RBC), hemoglobin, white blood cells (WBC) and lymphocyte count - to normal levels in extract-treated mice was also observed.Conclusion: The results suggest that the chloroform and ethanol extracts of C. reflexa exhibit significant antitumor activity in EAC-bearing mice that is comparable to that of the reference standard, 5-fluorouracil.Keywords: Cuscuta reflexa, Ehrlich ascites carcinoma, 5-Fluorouracil, Tumor volume, Viable cell count

Naked strong curvature singularities in Szekeres space-times

We investigate the occurrence and nature of naked singularities in the Szekeres space-times. These space-times represent irrotational dust. They do not have any Killing vectors and they are generalisations of the Tolman-Bondi-Lemaitre space-times. It is shown that in these space-times there exist naked singularities that satisfy both the limiting focusing condition and the strong limiting focusing condition. The implications of this result for the cosmic censorship hypothesis are discussed.Comment: latex, 9 page

Profiling a decade of information systems frontiers’ research

This article analyses the first ten years of research published in the Information Systems Frontiers (ISF) from 1999 to 2008. The analysis of the published material includes examining variables such as most productive authors, citation analysis, universities associated with the most publications, geographic diversity, authors’ backgrounds and research methods. The keyword analysis suggests that ISF research has evolved from establishing concepts and domain of information systems (IS), technology and management to contemporary issues such as outsourcing, web services and security. The analysis presented in this paper has identified intellectually significant studies that have contributed to the development and accumulation of intellectual wealth of ISF. The analysis has also identified authors published in other journals whose work largely shaped and guided the researchers published in ISF. This research has implications for researchers, journal editors, and research institutions

Field of a Radiation Distributuion

General relativistic spherically symmetric matter field with a vanishing stress energy scalar is analyzed. Procedure for generating exact solutions of the field equations for such matter distributions is given. It is further pointed out that all such type I spherically symmetric fields with distinct eignvalues in the radial two space can be treated as a mixture of isotropic and directed radiations. Various classes of exact solutions are given. Junction conditions for such a matter field to the possible exterior solutions are also discussed.Comment: Latex file, 13 pages, no figures. Accepted for publication in Phys. Rev.

The final fate of spherical inhomogeneous dust collapse II: Initial data and causal structure of singularity

Further to results in [9], pointing out the role of initial density and velocity distributions towards determining the final outcome of spherical dust collapse, the causal structure of singularity is examined here in terms of evolution of the apparent horizon. We also bring out several related features which throw some useful light towards understanding the nature of this singularity, including the behaviour of geodesic families coming out and some aspects related to the stability of singularity.Comment: Latex file, uses epsf.sty, 15 pages and 3 eps figures. Paragraph on role of smooth functions rewritten. Four references added. To appear in Classical & Quantum Gravit

Physical nature of the central singularity in spherical collapse

We examine here the nature of the central singularity forming in the spherically symmetric collapse of a dust cloud and it is shown that this is always a strong curvature singularity where gravitational tidal forces diverge powerfully. An important consequence is that the nature of the naked singularity forming in the dust collapse turns out to be stable against the perturbations in the initial data from which the collapse commences.Comment: Latex file, 11 pages, 2 figures, Updated version to match the published version in PR