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The most important rheological parameter for lubricants is viscosity as it also affects the tribological properties like friction between interacting surfaces and wear. This research intends to study the relationship between viscosity and temperature at different shear rates for multiple grades of three different categories of lubricants used for different applications viz. L1: MG20W50 (engine oil), L2: SAE20W50 (engine oil), L3: MC20W50 (mineral engine oil), L4: EP90 (gear oil), and L5: DXTIII (steering fluid). Constant high dynamic viscosity, shear stress, and low compressibility at different temperatures in multigrade as well as single grade industrial oil will help to maintain the surface film over the period of time and hence the reduction in wear. The dynamic viscosity of these chosen samples has been measured experimentally in temperature range of 20 to 50 ∘ C. The measurements have been extended to observe the dependence of shear rate, time, and temperature on the dynamic viscosity. All the samples are observed to behave like Newtonian fluids in the entire temperature range of study. Further, all samples seem to obey the Arrhenius relationship with temperature. Shear stress shows linear variation with shear rate exhibiting uniform viscosity which is substantiated by almost no variation in dynamic viscosity with shear rate for value above 5 per second.

The demand for broad-band antennas has been increased in the recent years. They find to be extensively used in high frequency and high speed data communication. The factors affecting the bandwidth of the microstrip antenna is discussed in this paper. There are two main parameter responsible for the broadening of the antenna. One is the height of the dielectric substrate and another one is the width of the patch.  In this paper, we study the performance characteristics of rectangular patch antenna with variable thickness of the substrate and width of the patch. One of the parameter is varied keeping the other fixed and the characteristic effects on resonant frequency, band width and gain are studied.

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In the present paper, a temperature-dependent equation of state (EOS) of condensed matter is discussed, which is capable of predicting the high-pressure and high-temperature behaviour of solids and liquids. The EOS can be used to obtain the volume compression, the isothermal bulk modulus and its first pressure derivative, the thermal expansion coefficient and the Anderson-Grüneisen parameter, together with other thermodynamic properties as functions of pressure at different temperatures. The present EOS has been applied for Au, Mo and W and liquid Hg. Good agreement between theory and experiment is observed.

Facile one-pot hydrothermal synthesis of nanorice-like TiO 2 for an efficient dye-sensitized solar cell (DSSC) ABSTRACT. Highly crystalline TiO 2 powder consisting of morphologically rice-like nanoparticles is synthesized by a simple hydrothermal process using a premixture of titanium isopropoxide, ethanol and aqueous ammonia. An efficient mechanism decoupling hydrolysis and condensation promotes the formation of a rice-like morphology. As the average particle size and BET properties of nanorice-like TiO 2 were found to be quite similar to a commercially available TiO 2 (Degussa P25), their photoelectric properties were compared as a DSSC electrode. Under 1 sun irradiation the photovoltaic efficiency of nanorice-like TiO 2 was measured to be c. 20% higher in contrast to the mediocre efficiency (~5.45%) of P25. We suggest that together with a generally exploited reference, such nanorice-like TiO 2 could also be adopted as a model material for various applications.

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