Articles written in Bulletin of Materials Science
Volume 34 Issue 2 April 2011 pp 311-321
AA7020 Al–Mg–Zn, a medium strength aluminium alloy, is used in welded structures in military and aerospace applications. As it may be subjected to extremes of environmental exposures, including high pressure liquid hydrogen, it could suffer hydrogen embrittlement. Hydrogen susceptibility of alloy AA7020 was evaluated by slow strain-rate tensile testing, and delayed failure testing of hydrogen-charged specimens of air-cooled, duplexaged, and water-quenched duplex agedmaterials. The resistance to hydrogen embrittlement of the alloy was found to be in the order of air-cooled duplex aged alloy > as-received (T6 condition) > water quenched duplex aged material.
Volume 35 Issue 7 December 2012 pp 1165-1171
Pure phase of magnesium titanate (MgTiO3) was obtained at 1100°C by both the conventional solid-state method as well as by the flux method starting from hexahydrated magnesium nitrate and titanium dioxide as the reactants. MgTiO3 doped with Na or K was also prepared by the solid-state route. Na and K doped compositions led to monophasic MgTiO3 below 5 mol% dopant concentration while biphasic mixture of MgTiO3 (major phase) and MgTi2O5 (minor phase) were obtained at higher dopant concentration. The dielectric constant and dielectric loss of MgTiO3 were found to be almost the same irrespective of the preparative method. MgTiO3 doped with 5 mol % of Na and K ions displayed optimum dielectric properties.
Volume 36 Issue 1 February 2013 pp 175-182
The aim of the present study is to develop cross-linked chitosan (CH) films that can release drug over an extended period of time and that too in a controlled manner. A solution of different percentages of CH, is prepared in 1% lactic acid, followed by addition of citalopram (CTP) and then reacted with increasing amounts of glutaraldehyde (GL) to obtain films with different cross-linking densities. Prepared films are characterized for their physical and mechanical properties. The films are then subjected to
Volume 38 Issue 6 October 2015 pp 1639-1643
The optical parameters including the refractive index (𝑛) and thermo-optic coefficient, TOC (d𝑛/d𝑇), the dielectric constant (𝜀) and its variation with temperature, and the thermal volume expansion coefficient (𝛽) and its variation with temperature of chitosan–alizarin yellow GG (CS–AY GG) complex were examined. The dn/dT and 𝜀- values for the polymer derivative were in the range −2.5 × 10−4 to 1.2 × 10−4° C−1 and 2.2 to 2.3, respectively. The dn/dT values were larger than that of inorganic glasses such as zinc silicate glass (5.5 × 10−6° C−1) and borosilicate glass (4.1 × 10−6° C−1) and were larger than that of organic polymers such as polystyrene (−1.23 × 10−4 ° C−1) and PMMA (−1.20 × 10−4 ° C−1). The 𝜀-values are lower than optically estimated 𝜀-values of conventional polymer (3.00), aliphatic polyimide (2.5) and semi-aromatic polyamide (2.83). The obtained results of chitosan derivative are expected to be useful for optical switching and optical waveguide areas for devices of biomedical applications.
Volume 44, 2021
Continuous Article Publishing mode
Prof. Subi Jacob George — Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bengaluru
Chemical Sciences 2020
Prof. Surajit Dhara — School of Physics, University of Hyderabad, Hyderabad
Physical Sciences 2020
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