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Andaman padauk (Pterocarpus dalbergioides Roxb.) is an important endemic tree species of the Andaman Islands, India, belonging to the family Fabaceae. We studied the seed microstructures which provide information on the physiological features of germination (i.e. factors responsible for the resumption of growth of embryo). Seed anatomy/morphostructures revealed information on its germination physiology (for ex situconservation), dormancy barriers and further taxonomical classification. The seed samples were examined under a scanning electron microscope (SEM) and Fourier-transform infrared spectroscopy (FTIR) was used to study the chemical composition of the seeds. In the SEM images, seed thickness of the parenchyma layer was about 53.16 μm, while that of the osteosclereids (OH) and macrosclereids (MH) layers was 23.95 and 84.68 μm respectively. The size of OS cells had a length of 25.81–34.56 μm; diameter 12.14–16.5 μm and width 7.97–12.60 μm. FTIR spectra of padauk seed assignments were used to determine the probable chromophoric groups that are likely to be present in the seeds. Various functional groups such as N–H, O–H, C–H, C=O, C–O were identified in the seeds. The results indicate the presence of carbohydrates, amino acids, amides, esters, ethers, phenols, proteins and fats in the padauk seeds. These observations would be helpful in correlating several aspects of seed germination/dormancy physiology of this endemic species, which has applications in ex situ conservation. [ABSTRACT FROM AUTHOR]

We report a state-of-the-art cathodoluminescence (CL) facility attached to a high-resolution scanning electron microscope (HRSEM), installed recently at the Saha Institute of Nuclear Physics, Kolkata for the study of opto-electronic properties of nanostructured materials. In this note, we present the technical details of such a CL-SEM facility along with some experimental results. We also demonstrate that the high spatial resolution spectroscopy and imaging capability of a CL-SEM system can be utilized as an ideal tool for nanophotonic research. [ABSTRACT FROM AUTHOR]

The scanning electron microscope (SEM) study of microtextures in quartz grains in India is still in infancy and restricted mostly to the placer or beach sediments. SEM study of micromorphology of quartz grains from Late Pleistocene-Holocene sediments in Uttarkashi district, Uttarakhand, has been taken up for understanding the depositional environment. In the Netal section the quartz grain micromorphological studies indicate basal part of a valley glacier environment or remnant glacial lake, as the quartz grains are angular with high silica deposition besides other imprints of glacial origin. In the Shiror section the sediment appears to be part of the glacial till. The present study provides a new approach to the much needed palaeoenvironmental evaluation of the Himalayan Quaternary sediments on a nanoscale. [ABSTRACT FROM AUTHOR]

During an inter-tidal zone exploration in the Gulf of Khambhat region, a large number of glazed and nonglazed sherds were recovered along with stone anchors dating back to the late medieval period. Four representative specimens were analysed for elemental oxides using scanning electron microscope and energy dispersive spectrum. The results indicate that silicon oxide content of the glazed sherds varies between ∼73 and 77%, forming three-fourths of the total composition, while it ranges from 42 to 47.5% in non-glazed sherds. Its content is more than half that in the ordinary sherds. It is difficult to understand the origin of these sherds on the basis of chemical analysis, as this study focuses only on the Gogha area. Therefore, similar studies from different regions in the Gulf of Khambhat will help to understand the origin and divergence in the manufacturing techniques used. [ABSTRACT FROM AUTHOR]