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The CSIR- National Physical Laboratory of India (NPLI) constantly prepares and disseminates Indian Reference Materials (Bharatiya Nirdeshak Dravya; BND®) in various areas. Recently, NPLI has prepared the Indian Reference Material (IRM) of α-Alumina to calibrate the Powder X-Ray Diffractometer (PXRD). In this report, the preparation and certification procedure of α-Alumina (BND 2001) has been examined as an Indian Reference Material that can be utilized as the primary standard for powder X-ray diffraction instruments. The developed IRM was utilized to calibrate PXRD for phase purity. The stability of the prepared α-alumina was studied by using powder X-ray diffractometer. The homogeneity and the particle size of the material were characterized by using scanning electron microscopy. The repeatability of the preparation and pertinent characterization were affirmed using different calibrated instruments. The phase purity of the material was verified by performing a round-robin test, and the related uncertainty estimations were reported in the paper.

Begomoviruses are among the most damaging pathogens causing epidemics in economically important crops particularly in tropical and subtropical regions. During February 2015, 20 samples of Calendula with yellow vein disease were collected from the campus of S. V. Patel University of Agriculture & Technology, Meerut, Uttar Pradesh, India. Total genomic DNA was isolated from the symptomatic and asymptomatic leaf samples and subjected to PCR using coat protein gene specific primer of begomovirus. The PCR amplification of ~770 bp was obtained from the 13 plants out of 20 collected plants. The PCR amplicon from coat protein gene was cloned, sequenced and submitted to GenBank, with accession number KT833850. The sequence data was further analyzed by BLAST analysis and phylogenetic tree was constructed using MEGA5.0 software which revealed close similarity of sequences with coat protein gene (AV1) components of other potato begomoviruses, which are all tentative strains of Tomato Leaf Curl New Delhi Virus (ToLCNDV). The result also indicated that Calendula spp. plants infected with Tomato Leaf Curl New Delhi Virus may act as an alternate host (reservoir) for other economically important plants.

In the present paper, we show that under contractive conditions, the existence of a common fixed point and occasional weak compatibility are equivalent conditions. We also show that contractive conditions employed by Jungck and Rhoades [Fixed point theorems for occasionally weakly compatible mappings, Fixed Point Theory 7(2) (2006) 287–296; Fixed Point Theory 9 (2008) 383–384 (erratum)] do not provide a nontrivial setting for the application of occasional weak compatible mappings. Finally, we improve the results of Jungck and Rhoades by employing a proper setting.