• R S Rane

Articles written in Pramana – Journal of Physics

• Einstein–Rosen inflationary Universe in general relativity

Einstein–Rosen inflationary Universe is investigated in the presence of mass-less scalar field with a flat potential. To get an inflationary Universe, we have considered a flat region in which the potential V is constant. Some physical properties of the model are discussed.

• Bianchi type-I massive string magnetized barotropic perfect ﬂuid cosmological model in bimetric theory

Bianchi type-I massive string cosmological model for perfect ﬂuid distribution in the presence of magnetic ﬁeld is investigated in Rosen’s [Gen. Relativ. Gravit. 4, 435 (1973)] bimetric theory of gravitation. To obtain the deterministic model in terms of cosmic time, we have used the condition $A = (B C)^n$, where n is a constant, between the metric potentials. The magnetic ﬁeld is due to the electric current produced along the 𝑥-axis with inﬁnite electrical conductivity. Some physical and geometrical properties of the exhibited model are discussed and studied.

• Influence of argon plasma treatment on polyethersulphone surface

Polyethersulphone (PES) was modified to improve the hydrophilicity of its surface, which in turn helps in improving its adhesive property. The modified PES surface was characterized by contact angle measurement, X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM) and Vicker’s microhardness measurement. The contact angles of the modified PES reduces from $49^{\circ}$ to $10^{\circ}$ for water. The surface free energy (SFE) calculated from measured contact angles increases from 66.3 to 79.5 mJ/m2 with the increase in plasma treatment time. The increase in SFE after plasma treatment is attributed to the functionalization of the polymer surface with hydrophilic groups. The XPS analysis shows that the ratio of O/C increases from 0.177 to 0.277 for modified PES polymer. AFM shows that the average surface roughness increases from 6.9 nm to 23.7 nm due to the increase in plasma treatment time. The microhardness of the film also increases with plasma treatment.

• # Pramana – Journal of Physics

Current Issue
Volume 93 | Issue 6
December 2019

• # Editorial Note on Continuous Article Publication

Posted on July 25, 2019