Novel Nanoparticle-Assisted Room-Temperature Synthesis of Methyl Esters from <i>Aloe vera</i> Seed Oil

<i>Aloe vera</i> has been used as a cosmetic and medical remedy since ancient times and has gained increasing popularity in recent years. Despite its widespread use, reports on biodiesel from <i>Aloe vera</i> seeds are lacking. The present investigation reports the fatty acid composition of <i>Aloe vera</i> seed oil (AVSO) and addresses the feasibility of using AVSO as a source of biodiesel. A novel ecofriendly catalyst was developed using triacetin as a model. Interestingly, the room-temperature conversion of AVSO and other nonedible oils to methyl esters could be achieved using this novel catalytic system consisting of ethylene diamine in the presence of nickel nanoparticles (NiNPs). The metal core, capping agent, and amine concomitantly contribute to make the system an effective catalyst

Dark matter profiles and annihilation in dwarf spheroidal galaxies: Prospectives for present and futureγ-ray observatories - I. The classical dwarf spheroidal galaxies

Due to their large dynamical mass-to-light ratios, dwarf spheroidal galaxies (dSphs) are promising targets for the indirect detection of dark matter (DM) in γ-rays. We examine their detectability by present and future γ-ray observatories. The key innovative features of our analysis are as follows: (i) we take into account the angular size of the dSphs; while nearby objects have higher γ-ray flux, their larger angular extent can make them less attractive targets for background-dominated instruments; (ii) we derive DM profiles and the astrophysical J-factor (which parametrizes the expected γ-ray flux, independently of the choice of DM particle model) for the classical dSphs directly from photometric and kinematic data. We assume very little about the DM profile, modelling this as a smooth split-power-law distribution, with and without subclumps; (iii) we use a Markov chain Monte Carlo technique to marginalize over unknown parameters and determine the sensitivity of our derived J-factors to both model and measurement uncertainties; and (iv) we use simulated DM profiles to demonstrate that our J-factor determinations recover the correct solution within our quoted uncertainties