Determination of the REE in Geological Reference Materials DTS-1 (Dunite) and PCC-1 (Peridotite) by Ultrasonic and Microconcentric Desolvating Nebulisation ICP-MS     

Jinesh C. Jain  M. Paul Field  Clive R. Neal  James C. Ely  Robert M. Sherrell 《Geostandards and Geoanalytical Research》2000,24(1):65-72

Inductively coupled plasma-mass spectrometry is well suited for the precise, accurate and rapid determination of rare earth elements in most geological samples. However, determination of rare earth elements in certain mantle-derived materials, without applying preconcentration techniques, remains problematical due to low natural concentrations (generally < 1 ng g⁻¹). Consequently, USGS reference materials DTS-1 (a dunite) and PCC-1 (a partially serpentinized harzburgite) have only suggested rather than recommended values for the rare earth elements in reference material compilations. We compared results obtained using two ICP-MS instruments: a U-5000AT ultrasonic nebuliser coupled to a PQ2+ quadrupole ICP-MS and an ELEMENT sector field ICP-MS equipped with a MCN-6000 microconcentric desolvating nebuliser, with the suggested literature values for these two reference materials. Precision and accuracy of analytical methods employed by both instruments were demonstrated by excellent relative standard deviations (< 2%) and inter-laboratory agreement (< 5%) for numerous analyses of BHVO-1 and BIR-1, which are well established with rare earth elements contents at the μg g⁻¹ level. Repeat analyses of DTS-1 and PCC-1 at each laboratory indicate that each method is generally precise to better than 5% at sub-g g⁻¹ levels. Furthermore, values from both instruments generally agree to within 10%. Our DTS-1 and PCC-1 values agree reasonably well with selected data reported in the literature (except for Ce and Sm in DTS-1) but exhibit poorer agreement with reported compilation values. With the demonstrated level of precision and accuracy, we contend that these new values for DTS-1 and PCC-1, generated by two different instruments, are the best estimates of the true whole-rock composition of these samples reported to date.  相似文献   

Interpolation of wave heights   总被引：1，自引：0，他引：1  

M. C. Deo  N. Kiran Kumar 《Ocean Engineering》2000,27(9)

Remote sensing of waves often necessitates presentation of data in the form of wave height values grouped over large time intervals. This restricts their use to long-term applications only. This paper describes how such data can be made suitable for short-term usage in the field. Weekly mean significant wave heights were derived from their monthly mean observations with the help of different alternative techniques. These include model-free neural network schemes as well as model-based statistical and numerical methods. Superiority of neural networks was noted when the estimations were compared with corresponding observations. The network was trained using three different training algorithms, viz., error back propagation, conjugate gradient and cascade correlation. The technique of cascade correlation took minimum training time and showed better coefficient of correlation between observations and network output.  相似文献   

Empirical estimate of p-mode frequency shift for solar cycle 23     

Jain  Kiran  Tripathy  S.C.  Bhatnagar  A.  Kumar  Brajesh 《Solar physics》2000,192(1-2):487-494

We have obtained empirical relations between the p-mode frequency shift and the change in solar activity indices. The empirical relations are determined on the basis of frequencies obtained from BBSO and GONG stations during solar cycle 22. These relations are applied to estimate the change in mean frequency for the cycle 21 and 23. A remarkable agreement between the calculated and observed frequency shifts for the ascending phase of cycle 23, indicates that the derived relations are independent of epoch and do not change significantly from cycle to cycle. We propose that these relations could be used to estimate the shift in p-mode frequencies for past, present and future solar activity cycles, if the solar activity index is known. The maximum frequency shift for cycle 23 is estimated to be 265±90 nHz, corresponding to a predicted maximum smoothed sunspot number 118.1±35.  相似文献   

The statistics of weak lensing at small angular scales: probability distribution function     

Dipak Munshi  Bhuvnesh Jain 《Monthly notices of the Royal Astronomical Society》2000,318(1):109-123

Weak gravitational lensing surveys have the potential to probe mass density fluctuation in the Universe directly. Recent studies have shown that it is possible to model the statistics of the convergence field at small angular scales by modelling the statistics of the underlying density field in the highly non-linear regime. We propose a new method to model the complete probability distribution function of the convergence field as a function of smoothing angle and source redshift. The model relies on a hierarchical ansatz for the behaviour of higher order correlations of the density field. We compare our results with ray-tracing simulations and find very good agreement over a range of smoothing angles. Whereas the density probability distribution function is not sensitive to the cosmological model, the probability distribution function for the convergence can be used to constrain both the power spectrum and cosmological parameters.  相似文献   

Constraints on dark energy models from galaxy clusters with multiple arcs     

Massimo Meneghetti  Bhuvnesh Jain  Matthias Bartelmann  Klaus Dolag 《Monthly notices of the Royal Astronomical Society》2005,362(4):1301-1310

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Some expanding and shearing viscous fluid cosmological models in general relativity     

Raj Bali  Deepak Raj Jain 《Astrophysics and Space Science》1988,141(2):207-216

Two cylindrically-symmetric cosmological models representing viscous fluid distributions when free-gravitational field of typeD where coefficient of shear viscosity is assumed to be proportional to the rate of expansion, are obtained. The behaviour of the models in the absence of viscosity and other physical properties are also discussed.  相似文献   

Cometes surattensis Burm. var. Ambajiensis Bedi and Madala as an indicator of copper-lead-zinc mineralization     

M. Ravi Kiran  S.J. Bedi 《Journal of Geochemical Exploration》1984,20(1):47-53

A new variety of Cometes surattensis Burm. has been reported and is confined in its distribution to only the Ambamata (Cu-Pb-Zn) mineralized area. Geobotanical and biogeochemical studies suggest that this plant is an indicator of Cu-Pb-Zn mineralization.  相似文献   

Seasonal and annual trends of carbonaceous species of PM<Subscript>10</Subscript> over a megacity Delhi,India during 2010–2017     

S. K. Sharma  T. K. Mandal  A. Sharma  Saraswati  Srishti Jain 《Journal of Atmospheric Chemistry》2018,75(3):305-318

PM₁₀ samples were collected to characterize the seasonal and annual trends of carbonaceous content in PM₁₀ at an urban site of megacity Delhi, India from January 2010 to December 2017. Organic carbon (OC) and elemental carbon (EC) concentrations were quantified by thermal-optical transmission (TOT) method of PM₁₀ samples collected at Delhi. The average concentrations of PM₁₀, OC, EC and TCA (total carbonaceous aerosol) were 222?±?87 (range: 48.2–583.8 μg m^?3), 25.6?±?14.0 (range: 4.2–82.5 μg m^?3), 8.7?±?5.8 (range: 0.8–35.6 μg m^?3) and 54.7?±?30.6 μg m^?3 (range: 8.4–175.2 μg m^?3), respectively during entire sampling period. The average secondary organic carbon (SOC) concentration ranged from 2.5–9.1 μg m^?3 in PM₁₀, accounting from 14 to 28% of total OC mass concentration of PM₁₀. Significant seasonal variations were recorded in concentrations of PM₁₀, OC, EC and TCA with maxima during winter and minima during monsoon seasons. In the present study, the positive linear trend between OC and EC were recorded during winter (R²?=?0.53), summer (R²?=?0.59) and monsoon (R²?=?0.78) seasons. This behaviour suggests the contribution of similar sources and common atmospheric processes in both the fractions. OC/EC weight ratio suggested that vehicular emissions, fossil fuel combustion and biomass burning could be the major sources of carbonaceous aerosols of PM₁₀ at the megacity Delhi, India. Trajectory analysis indicates that the air mass approches to the sampling site is mainly from Indo Gangetic plain (IGP) region (Uttar Pradesh, Haryana and Punjab etc.), Thar desert, Afghanistan, Pakistan and surrounding areas.  相似文献   

Remote sensing application for property tax evaluation     

Sadhana Jain 《International Journal of Applied Earth Observation and Geoinformation》2008

This paper presents a study for linking remotely sensed data with property tax related issues. First, it discusses the key attributes required for property taxation and evaluates the capabilities of remote sensing technology to measure these attributes accurately at parcel level. Next, it presents a detailed case study of six representative wards of different characteristics in Dehradun, India, that illustrates how measurements of several of these attributes supported by field survey can be combined to address the issues related to property taxation. Information derived for various factors quantifies the property taxation contributed by an average dwelling unit of the different income groups. Results show that the property tax calculated in different wards varies between 55% for the high-income group, 32% for the middle-income group, 12% for the low-income group and 1% for squatter units. The study concludes that higher spatial resolution satellite data and integrates social survey helps to assess the socio-economic status of the population for tax contribution purposes.  相似文献   

Discussion of "Evaluation of Ultraviolet (UV)-Oxidation Treatment Methods", by Evan K. Nyer and Paul Bitter, Ground Water Monitoring Review, v. 11, no. 1, pp. 88, Winter 1991.     

Dr.  Kiran Kumar Topudurti 《Ground Water Monitoring & Remediation》1991,11(2):190-191

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