Pioneer Venus Orbiter Measurements of Solar EUV Flux During Solar Cycles 21 and 22     

K. K. Mahajan  Hari Om Upadhyay  N. K. Sethi  W. R. Hoegy  W. D. Pesnell  L. H. Brace 《Solar physics》1998,177(1-2):203-216

The Pioneer Venus Orbiter (PVO) had on board the electron temperature probe experiment which measured temperature and concentration of electrons in the ionosphere of Venus. When the probe was outside the Venus ionosphere and was in the solar wind, the probe current was entirely due to solar photons striking the probe surface. This probe thus measured integrated solar EUV flux (Ipe) over a 13-year period from January 1979 to December 1991, thereby covering the declining phase of solar cycle 21 and the rising phase of solar cycle 22. In this paper, we examine the behavior of Ipe translated to the solar longitude of Earth (to be called EIpe) during the two solar cycles. We find that total EUV flux changed by about 60% during solar cycle 21 and by about 100% in solar cycle 22. We also compare this flux with other solar activity indicators such as F_10.7 , Lα, and the solar magnetic field. We find that while the daily values of EIpe are highly correlated with F_10.7 (correlation coefficient 0.87), there is a large scatter in EIpe for any value of this Earth-based index. A comparison of EIpe with SME and UARS SOLSTICE Lα measurements taken during the same period shows that EIpe tracks Lα quite faithfully with a correlation coefficient of 0.94. Similar comparison with the solar magnetic field (Bs) shows that EIpe correlates better with Bs than with F_10.7 . We also compare EIpe with total solar irradiance measured during the same period.  相似文献   

Temporal MODIS data for identification of wheat crop using noise clustering soft classification approach   总被引：1，自引：0，他引：1  

Priyadarshi Upadhyay  S.K. Ghosh  Anil Kumar 《国际地球制图》2016,31(3):278-295

In this study, temporal MODIS-Terra MOD13Q1 data have been used for identification of wheat crop uniquely, using the noise clustering (NC) soft classification approach. This research also optimises the selection of date combination and vegetation index for classification of wheat crop. First, a separability analysis is used to optimise the date combination for each case of number of dates and vegetation index. Then, these scenes have undergone for NC soft classification. The resolution parameter (δ) was optimised for the NC classifier and found to be a value of 1.6 × 10⁴ for wheat crop identification. Classified outputs were analysed by receiver operating characteristics (ROC) analysis for sub-pixel detection. Highest area under the ROC curve was found for soil-adjusted vegetation index corresponding to the three different phenological stages data sets. From this study, the data sets corresponding to the Sowing, Flowering and Maturity phenological stages of wheat crop were found more suitable to identify it uniquely.  相似文献   

Focal mechanism solutions and dynamic parameters of earthquakes in the eastern Himalayas and northern Burma     

S. K. Upadhyay  V. K. Ahuja  V. Sri Ram 《Tectonophysics》1983,93(3-4)

Focal-mechanism solutions of four earthquakes in the eastern Himalayas and northern Burma are determined using the first motion of compressional waves. Two possible solutions thus obtained for each event reveal steeply dipping fault with predominantly strike-slip motion. The stress directions inferred from the focal mechanism solutions are interpreted in the light of predictions of the plate tectonics theory, viz., the underthrusting of the Indian plate in the Burma region in an easterly direction.Dynamic parameters (seismic moment, apparent stress and average dislocations) are obtained using the corrected spectra of Love waves. The earthquakes are found to possess low seismic moment and apparent stress values. A comparison of these estimates with values for intraplate earthquakes is given. It is suggested that these earthquake might be a consequence of a nonhomogeneous rupture process.  相似文献   

Non-linear laminar flow into well partially penetrating a porous aquifer of finite thickness     

K. K. Upadhyay 《Pure and Applied Geophysics》1977,115(3):631-638

In steady state condition, non-linear laminar flow of fluid into a well partially penetrating a porous aquifer of finite thickness is considered. The influence of such a flow on discharge and its dependence on related physical quantities are investigated. It is observed that the discharge into the well decreases as the depth of the well is decreased and the region of non-linear laminar flow is widened, which is quite obvious from physical considerations. As a particular case, result for a fully penetrating well has been deduced.  相似文献   

Mesoproterozoic rift-related alkaline magmatism at Elchuru, Prakasam Alkaline Province, SE India   总被引：6，自引：0，他引：6  

D. Upadhyay  M.M. Raith  K. Mezger  K. Hammerschmidt 《Lithos》2006,89(3-4):447-477

The Elchuru alkaline complex in the Prakasam igneous province represents one occurrence of several alkaline bodies within the craton–Eastern Ghats Belt contact zone in Peninsular India. Nepheline syenites and associated mafic rocks intruded the cratonic crust at ≈1321 Ma and were deformed–metamorphosed to amphibolite facies condition during Pan-African times. Trace element compositions and Sr, Nd and Pb isotopic systematics indicate that the alkaline magma was derived from an enriched mantle source in the sub-continental lithosphere. The adjacent crusts of the Eastern Dharwar craton and the Eastern Ghats Belt were not involved either as source or as contaminants. The enriched mantle source was at least 1.9–2.1 Ga old as seen from the depleted mantle model ages of the rocks. The primary parent magma was a basanitic liquid that fractionated ferrokaersutite and clinopyroxene in the mantle, lowering the density sufficiently for the residual melt to intrude the crust. Magmatic differentiation in the suite can be explained by a two stage fractional crystallization model involving the removal of amphibole, clinopyroxene, allanite, titanite, apatite and zircon. The rift-related intra-continental setting of the complex indicates that alkaline magmatism represents the manifestation of a Mesoproterozoic continental breakup. Rifting along the cratonic margin may have led to the formation of several cratogenic basins (e.g., Chattisgarh basin, Indravati basin etc.) where stable shelf-type sediments could have been deposited on the passive margin during the Proterozoic. It could also have opened an ocean where some of the sediments of the Eastern Ghats Province may have been deposited.  相似文献   

Intrusion age, geochemistry and metamorphic conditions of a quartz-monzosyenite intrusion at the craton–Eastern Ghats Belt contact near Jojuru, India     

D. Upadhyay  M.M. Raith 《Gondwana Research》2006,10(3-4):267-276

The boundary between the Archean cratons and the Eastern Ghats Belt in peninsular India represents a rifted Mesoproterozoic continental margin which was overprinted by a Pan-African collisional event associated with the westward thrusting of the Eastern Ghats granulites over the cratonic foreland. The contact zone contains a number of deformed and metamorphosed nepheline syenite complexes of rift-related geochemical affinities. In addition to the nepheline-bearing rocks, metamorphosed quartz-bearing monzosyenitic bodies can also be identified along the suture in the region between the Godavari-Pranhita graben and the Prakasam Igneous Province. One such occurrence at Jojuru near Kondapalle is geochemically comparable to the nepheline syenites and furnishes a weighted mean concordant U–Th–Pb SHRIMP zircon age of 1263 ± 23 Ma (2σ), which provides a lower age bracket for the rift-related magmatic activity. The original igneous mineral assemblage in the monzosyenite was partially replaced by the formation of coronitic garnet during the Pan-African metamorphism of the rocks. P–T estimates of garnet corona formation at the interface between clinopyroxene–orthopyroxene–ilmenite clusters and plagioclase indicate mid to upper amphibolite facies condition (5.5–7.0 kbar and 600–700 °C) during the thrust induced deformation and metamorphism associated with the Pan-African collisional tectonics.  相似文献   

Assessment of Ground Water Quality with Respect to Bacteriological Contamination in Bhavnagar,Gujarat, India          下载免费PDF全文

Mittal Patel  Krushnakant Baxi  Paras Dayma  Devang Upadhyay  Navalsang Parmar  Soumya Haldar  Bhavanath Jha 《洁净——土壤、空气、水》2014,42(10):1351-1362

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An investigation on tolerance and accumulation of a facultative marine fungus <Emphasis Type="Italic">Aspergillus flavus</Emphasis> to pentavalent arsenic     

Anjana K. Vala  Vipul Davariya  R. V. Upadhyay 《中国海洋大学学报(英文版)》2010,9(1):65-67

Tolerance of a facultative marine fungus Aspergillus flavus towards As (V) was tested. Luxuriant growth of the test isolate was observed in culture media with As (V) concentrations of 25 mg L⁻¹ and 50 mg L⁻¹, indicating its tolerance to the metal. Accumulation rate of arsenic was always higher when exposed to As (V) at 50 mg L⁻¹ than at 25 mg L⁻¹. The study reveals Aspergillus flavus as a promising candidate for environmental bioremediation. Arsenic contents (mg g⁻¹) in the fungus when exposed to 50 mg L⁻¹ As (V) were measured as 11.1773, 4.0983, and 8.0000 mg g⁻¹ on day 3, 6 and 9, respectively. The highest content was observed initially, i.e. on day 3, followed by a decline and a rise again. These results provide baseline information for further explorations regarding the exploitation of the fungus for arsenic removal.  相似文献   

Mapping of Cropping System for the Indo-Gangetic Plain Using Multi-Date SPOT NDVI-VGT Data     

Sushma Panigrahy  Gargi Upadhyay  Shibendu Shankar Ray  Jai S. Parihar 《Journal of the Indian Society of Remote Sensing》2010,38(4):627-632

The present study has been carried out to delineate the existing cropping systems in the Indo-Gangetic Plains (IGP) using 10 day composite SPOT VEGETATION (VGT) NDVI data acquired over a crop year (June–May). Results showed that it is feasible to identify the major crops like rice, wheat, sugarcane, potato, and cotton in the dominant growing areas with good accuracy. Double cropping pattern is the most prevalent. Rice-wheat, sugarcane based, cotton-wheat, rice-potato, rice-rice, maize/millet-wheat are some of the major rotations followed. Rice-wheat is the dominant rotation accounting for around 40% of the net sown area. Triple crop rotations was less than 5% of the area and observed in some parts of Uttar Pradesh, Bihar and West Bengal. Single crop rotation of rice-fallow is significant only in West Bengal.  相似文献   

A preliminary report of microfossils (Foraminiferida) from the Jurassic sediments of Jajiya Member,Jaisalmer Formation,Western Rajasthan     

A. Talib  Gagnesh Upadhyay  M. Haseen 《Journal of the Geological Society of India》2012,79(4):422-423

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