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Purpose: The purpose of this study is to investigate the physical, chemical and thermal characteristics of paraffin-blended fuels to determine their suitability as fuel in hybrid rockets. Design/methodology/approach: Wax fuels are viable and efficient alternatives to conventional rocket fuels, having excellent structural strength and thermal and mechanical properties. The authors report a study of the morphological, chemical and thermal properties of paraffin wax with and without additives for use as fuels in hybrid rockets. Scanning electron microscopy, X-ray diffraction and Fourier transform infrared spectroscopy were used for the morphological and chemical characterizations of the fuel blends. The thermal stability and combustion characteristics were assessed under an atmosphere of nitrogen by the simultaneous application of thermogravimetry and differential scanning calorimetry techniques. Findings: The melting temperatures for pure paraffin and other formulations were around 61°C as seen in differential scanning calorimetry experiments. Variations in the compositions of monoesters, n-alkanes, fatty acids, carboxylic acids methyl and hydroxyl esters in the fuel samples were assessed using Fourier transform infrared spectroscopy. The assessment criterion was chosen as the relative content of carbonyl groups, and the ratio of the stretching vibration of the C–C bonds to the deformation vibration of the aliphatic carbon–hydrogen bonds was taken as the basis for the quantitative calibration. The crystal phases identified by X-ray diffraction were used to identify nonlinear chemicals and alkane lengths. Scanning electron microscopy validated homogeneity in the paraffin-blended samples. Originality/value: This study presents the thermal stability and other relevant characteristics of fuel formulations comprising unconventional blends. [ABSTRACT FROM AUTHOR]

Purpose: This paper aims to determine the regression rate using wax fuels for three different grain configurations and find a suitable grain port design for hybrid rocket application. Design/methodology/approach: The design methodology of this work includes different grain port designs and subsequent selection of solid fuels for a suitable hybrid rocket application. A square, a cylindrical and a five-point star grained were designed and prepared using paraffin and beeswax fuels. They were tested in a laboratory-scale rocket with gaseous oxygen to study the effectiveness of solid fuels on these grain structures. The regression rate by static fire testing of these wax fuels was analyzed. Findings: Beeswax performance is better than that of paraffin wax fuel for all three designs, and the five-slotted star fuel port grain attained the best performance. Beeswax fuel attained an average regression rate ≈of 1.35 mm/s as a function of oxidizer mass flux Gox ≈ 111.8 kg/m2 s and for paraffin wax 1.199 mm/s at Gox ≈ 121 kg/m2 s with gaseous oxygen. The local regression rates of fuels increased in the range of 0.93–1.194 mm/s at oxidizer mass flux range of 98–131 kg/m2 s for cylindrical grain, 0.99–1.21 mm/s at oxidizer mass flux range of 96–129 kg/m2s for square grain and 1.12–1.35 mm/s at oxidizer mass flux range of 91–126 kg/m2 s for a star grain. A complete set of the regression rate formulas is obtained for all three-grain designs as a function of oxidizer flux rate. Research limitations/implications: The experiment has been performed for a lower chamber pressure up to 10 bar. Originality/value: Different grain configurations were designed according to the required dimension of the combustion chamber, injector and exhaust nozzle of the design of a lab-scale hybrid rocket, and input parameters were selected and analyzed. [ABSTRACT FROM AUTHOR]

In this work the variation of mechanical properties like tensile, impact and chemical resistance properties of randomly oriented sisal/glass fibre reinforced hybrid composites with different fibre ratios (50:50,45:55,40:60,30:70) was studied. Hand lay up method is used for making the composites with epoxy resin. The result shows that increase in chemical, impact properties of composites with increase in fibre loading. Also it was observed that significant improvement in tensile properties of hybrid composites by alkali treatment. [ABSTRACT FROM AUTHOR]

In the present study, we evaluated the effect of biochanin A (BCA) on high-fat diet (HFD)-induced obesity cardiomyopathy. BCA (10 mg/kg body weight) was administered to HFD-induced obese rats for 30 days, and its effect on anthropometrical, morphological, plasma cardiac, and inflammatory biomarkers, along with cardiac lipid profiles was assessed. Supplementation of HFD to rats significantly increased body mass index, obesity index parameters, and cardiac lipid profile along with notable oxidative stress and inflammation. Additionally, BCA treatment in obese rats demonstrated a superior therapeutic action by restoring the altered parameters to almost normal levels. Simultaneously, BCA increased the activities and mRNA expressions of enzymatic antioxidants by upregulating the Nrf-2 pathway and inhibiting the NF-κB cascade. BCA may attenuate obesity and its associated cardiomyopathy by suppressing oxidative stress and inflammation through activation of the Nrf-2 pathway and inhibition of NF-κB activation. [ABSTRACT FROM AUTHOR]