Vikram Sarabhai Space Centre

About: Vikram Sarabhai Space Centre is a facility organization based out in Thiruvananthapuram, India. It is known for research contribution in the topics: Aerosol & Ultimate tensile strength. The organization has 2092 authors who have published 3058 publications receiving 47975 citations. The organization is also known as: VSSC.

Development of polyimide–nanosilica filled EPDM based light rocket motor insulator compound: Influence of polyimide–nanosilica loading on thermal, ablation, and mechanical properties

Abstract: Thermal protection materials are necessary to protect structural components of launch vehicles during lift-off of launching system. The present study deals with the development of a novel thermally protected light rocket motor insulator compound (RMIC) of polyimide–silica filled EPDM nanocomposites. The insulation compound prepared for the studies comprised of aromatic polyimide and nanosilica particles. The addition of these materials in rocket insulator compound enhanced the multifunctional thermal and insulation characteristics. EPDM when grafted with maleic anhydride, contributed polarity in the non-polar EPDM matrix. Nanosilica contributes specifically better erosion resistance. SEM and TEM micrograph of EPDM nanocomposites exhibits good dispersion of nanosilica in polyimide–EPDM matrix. Nanocomposite formation was characterised by FTIR. Density, co-efficient of thermal expansion, thermal conductivity, ablation rate, specific heat, maximum thermal degradation, char yield and mechanical properties of the RMIC have been measured. This developmental study may find wide scope for commercial exploitation.

Aerosol black carbon over Bay of Bengal observed from an island location, Port Blair: Temporal features and long-range transport

Abstract: [1] Extensive measurements of the mass concentration of aerosol black carbon (BC) made for about 18 months during 2002–2003 from an island location, Port Blair, in the Bay of Bengal are used to characterize its temporal variations, mass mixing ratio, and association to air mass types. Significantly high concentrations (∼2.4 μg m−3) occur during prevalence of continental air mass, when it also depicts a high mass-mixing ratio (∼6.5%) to the composite aerosols. Diurnal variations show a nighttime peak and afternoon low, similar to those seen over the mainland, but weaker. Over the years, the concentrations are high during the September to April period, decrease rapidly (by a factor of >3) and continue to do so during the summer monsoon months (June to August). Back trajectory analyses reveal five potential advection pathways, which are seasonal in nature and have a strong influence on the BC concentrations over the island. Concentrations increase significantly, irrespective of air mass types, when the trajectories have long tracks close to and over land areas. The possible implications of the findings on radiative forcing are discussed.

The Cadmium Zinc Telluride Imager on AstroSat

Abstract: The Cadmium Zinc Telluride Imager (CZTI) is a high energy, wide-field imaging instrument on AstroSat. CZTI’s namesake Cadmium Zinc Telluride detectors cover an energy range from 20 keV to $$>200$$ keV, with 11% energy resolution at 60 keV. The coded aperture mask attains an angular resolution of 17 $$^\prime $$ over a 4.6 $$^\circ $$ $$\times $$ 4.6 $$^\circ $$ (FWHM) field-of-view. CZTI functions as an open detector above 100 keV, continuously sensitive to GRBs and other transients in about 30% of the sky. The pixellated detectors are sensitive to polarization above $$\sim $$ 100 keV, with exciting possibilities for polarization studies of transients and bright persistent sources. In this paper, we provide details of the complete CZTI instrument, detectors, coded aperture mask, mechanical and electronic configuration, as well as data and products.