Annihilation of NMSSM neutralinos in the Sun and neutrino telescope limits

We investigate neutralino dark matter in the framework of NMSSM performing a scan over its parameter space and calculating neutralino capture and annihilation rates in the Sun. We discuss the prospects of searches for neutralino dark matter in neutrino experiments depending on neutralino content and its main annihilation channel. We recalculate the upper limits on neutralino-proton elastic cross sections directly from neutrino telescopes upper bounds on annihilation rates in the Sun. This procedure has advantages as compared with corresponding recalcalations from the limits on muon flux, namely, it is independent on details of the experiment and the recalculation coefficients are universal for any kind of WIMP dark matter models. We derive 90% c.l. upper limits on neutralino-proton cross sections from the results of the Baksan Underground Scintillator Telescope.Comment: 28 pages, 16 figures, accepted for publication in JCAP, references adde

Fuzzy optimization of the esterification conditions in biodiesel production using karanja oil as feedstock

Current biodiesel production remains unsustainable and costly because of the use of refined edible oils as feedstock. The use of non-edible oils such as Karanja oil would contribute to making biodiesel production more economically competitive because of its availability and low cost. Many studies have performed optimization techniques on biodiesel production which only includes local optimization of operating variables without consideration of cost. This paper performs a case study on the esterification conditions in biodiesel production from Karanja oil which utilizes fuzzy optimization in the multiobjective decision-making process to determine optimized values for the conversion of the free fatty acid (FFA) content in Karanja oil with its cumulative uncertainty error (YQ) and its corresponding total operating cost (CT). This paper also incorporates cumulative uncertainty into the variables and an operating cost equation which is both essential in studying the economic feasibility of the process. The operating variables include the methanol-to-oil ratio, catalyst loading, reaction time, and duty cycle. The Pareto front was generated from the objective functions to determine the boundary limits for YQ and CT. Results indicated an overall satisfaction level of 64.68% for conversion and cost. The optimal conditions of the variables were 5:1 for molar ratio, 0.85 wt% for catalyst loading, 79% for duty cycle, and 89.35 min for reaction time. These conditions yielded a YQ of 68% and a total operating cost of USD 0.12 per liter of Karanja oil esterified. Comparison with previous literature showed a conversion that was 13.51% lower but at a cost that was 24.86% cheaper