Testing Lin's social capital theory in an informal African urban economy

In order to test Lin's social capital theory in an informal African urban economy, this paper outlines an approach articulated around the notion of 'ego-centred network'. We used an original dataset collected in Bobo-Dioulasso (Burkina Faso) to evaluate how member attributes in entrepreneurs' networks tend to influence their economic outcomes. The instrument of multiple name generators provides a vast amount of information that can be used to compute quantitative measures of the composition of networks. We show that the proportion of members with a high social status have no significant positive impact on economic outcomes, contrary to more approachable individuals

Synthesis of Monoglycerides by Esterification of Oleic Acid with Glycerol in Heterogeneous Catalytic Process Using Tin–Organic Framework Catalyst

INGENIERIE+TLE:DFASelective synthesis of monoglycerides by esterification of glycerol with fatty acids is a difficult reaction because of immiscibility of reagents and the formation of di- and tri-glyceride by-products. In this work a heterogeneous catalytic process was conceived in which the reactant mixture was homogenized using tert-butanol solvent. Candidate catalysts were screened in the reaction of oleic acid with glycerol. While under such reaction conditions zeolites were rather inactive, metal-organic frameworks and, especially, tin-organic frameworks were found promising. A tin-organic framework (Sn-EOF) was most active and achieved a parts per thousand yen98 % monoglyceride selectivity at 40 % conversion in catalyzing esterification of oleic acid with glycerol at a low reaction temperature of 150 A degrees C. Leaching of tin from Sn-EOF catalyst was suppressed by limiting the amount of oleic acid in the starting mixture. Characterization of the acid sites of Sn-EOF by pyridine-chemisorption and FTIR revealed Lewis acidity to be responsible for the catalytic activity

A 16 hr Transit of Kepler-167 e Observed by the Ground-based Unistellar Telescope Network

More than 5000 exoplanets have been confirmed and among them almost 4000 were discovered by the transit method. However, few transiting exoplanets have an orbital period greater than 100 days. Here we report a transit detection of Kepler-167 e, a “Jupiter analog” exoplanet orbiting a K4 star with a period of 1071 days, using the Unistellar ground-based telescope network. From 2021 November 18 to 20, citizen astronomers located in nine different countries gathered 43 observations, covering the 16 hr long transit. Using a nested sampling approach to combine and fit the observations, we detected the midtransit time to be UTC 2021 November 19 17:20:51 with a 1σ uncertainty of 9.8 minutes, making it the longest-period planet to ever have its transit detected from the ground. This is the fourth transit detection of Kepler-167 e, but the first made from the ground. This timing measurement refines the orbit and keeps the ephemeris up to date without requiring space telescopes. Observations like this demonstrate the capabilities of coordinated networks of small telescopes to identify and characterize planets with long orbital periods. © 2022. The Author(s). Published by the American Astronomical Society.Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]