Elemental and Chemical Phase Analyses of Ras-Family Ayurvedic Medicinal Products.

Fifteen Ayurvedic medicines of Ras-family (herbo-mineral-metallic preparations) from three reputed manufactures were analysed for elemental quantification and their chemical phase identification using the energy-dispersive (ED) and wavelength-dispersive (WD) X-ray fluorescence (XRF) techniques, and powder X-ray diffraction (XRD) technique, respectively. The low-Z elements C, H, N, S and O constituting a major portion of these medicines were also determined by CHNSO analyser and further used as input for XRF analyses. The elements of concern, Hg, Pb and As, are identified in different medicine products with disquiet concentration values (maximum concentration values range ~ 4-10%) and that too with substantial variations in the products from different manufacturers. These elements are identified mainly in the cinnabar (α-HgS)/metacinnabar (ß-HgS), litharge (PbO) and alacranite (As4S4) phases in different medicines. Keeping in view the high concentration of chemicals of the Hg, Pb and As elements in the Ras-family medicines, it is vitally required to investigate their bioaccessibility and surmise the associated toxicological aspects. It is suggested that the formation of the bioaccessible toxic chemical forms of the Hg, Pb and As elements be avoided during preparation of the mineral ingredients or these soluble chemical forms be removed at suitable stage of the preparation. In view of large variations observed for the Hg, Pb and As based ingredients in the Ras family Ayurvedic medicine products from different manufacturers, adequate quality control mechanisms and production regulations are recommended.

Measurement of large angle Rayleigh scattering cross sections for 39.5, 40.1 and 45.4keV photons in elements with 26 ≤ Z ≤ 83.

The present work reports Rayleigh scattering cross section measurements for the 39.5keV (Sm- Kα2), 40.1keV (Sm-Kα1) and 45.4keV (Sm-Kß1,3) X-ray photons in 35 elements with 26 ≤ Z ≤ 83 at backward angle of 139°. The scattering measurements were performed in reflection mode geometrical set up involving a secondary photon source consisting of Samarium (62Sm) target excited by the 59.54keV γ-rays from the 241Am radioactive source. The scattered photons were detected using a low energy germanium (LEGe) detector. The product of detector efficiency, intensity of incident photons and other geometrical factors were determined by measuring the K X-ray yields from targets with 47 ≤ Z ≤ 59 and knowledge of the respective K X-ray fluorescence cross sections. The measured cross sections are compared with the theoretical cross sections based on the modified form factor (MF) formalisms and the second-order S-matrix approach. The experimental results demonstrate large deviations from the MF values for the elements with K shell binding energy (BK) in vicinity of the incident photon energy (Ein), which smooth out with inclusion of the anomalous scattering factors (ASFs). The S-matrix values, in general, agree with the measured cross sections for all the elements under investigation.

Fabrication and characterization of carbon-backed thin 208Pb targets.

Thin carbon-backed isotopically enriched 208Pb targets were required for our experiment aimed to study the reaction dynamics for 48Ti + 208Pb system, populating the near super-heavy nucleus 256Rf, through mass-energy correlation of the fission fragments. Purity and thickness of the targets are of utmost importance in such studies as these factors have strong influence on the measurement accuracy of mass and energy distribution of fission fragments. 208Pb targets with thickness ranging from 60 µg/cm2 to 250 µg/cm2 have been fabricated in high vacuum environment using physical vapor deposition method. Important points in the method are as follows: •208Pb was deposited using resistive heating method, whereas carbon (backing foil) deposition was performed by using the electron beam bombardment technique.•Different characterization techniques such as Particle Induced X-ray Emission (PIXE), Energy Dispersive X-Ray Fluorescence (EDXRF) and Rutherford Backscattering Spectrometry (RBS) were used to assert the purity and thickness of the targets.•These targets have successfully been used to accomplish our experimental objectives.