Intensified processes for FAME production from waste cooking oil: a technological review

This article reviews the intensification of fatty acid methyl esters (FAME) production from waste cooking oil (WCO) using innovative process equipment. In particular, it addresses the intensification of WCO feedstock transformation by transesterification, esterification and hydrolysis reactions. It also discusses catalyst choice and product separation. FAME production can be intensified via the use of a number of process equipment types, including as cavitational reactors, oscillatory baffled reactors, microwave reactors, reactive distillation, static mixers and microstructured reactors. Furthermore, continuous flow equipment that integrate both reaction and separation steps appear to be the best means for intensifying FAME production. Heterogeneous catalysts have also shown to provide attractive results in terms of reaction performance in certain equipment, such as microwave reactors and reactive distillation

Green process for adipic acid synthesis: oxidation by hydrogen peroxide in water micromelusions using Benzalkonium Chloride C12-14 surfactant

Adipic acid was synthesized by the oxidation of cyclohexene using 30% hydrogen peroxide in a microemulsion in the presence of sodium tungstate as catalyst. The proposed green process is environmentally friendly since catalyst and surfactant are recycled and pure adipic acid is produced in high yield (70% to 79%). Microemulsions are used as a “green solvent” and give a better contact between the phases. Alkyldimethylbenzylammonium chloride (C12-C14) was used as a surfactant for the generation of the microemulsion since it enables the use of harmful organic solvents and phase-transfer catalysts to be avoided. Optimised operating conditions (temperature, reaction time, separation process) have been defined and applied to evaluate the industrial practicability. The main interest of the present work is the easy recovery of pure adipic acid and the reuse of the reaction media (surfactant and catalyst). This shows promise for developing a future green industrial process that will enable greenhouse gas emissions (N2O), among others, to be reduced

Gas-liquid mass transfer : influence of sparger location

The performance of three sparger diameters (DS = 0.6D, DS = D, DS = 1.6D) in combination with three positions (below, above or level with the impeller) for gas-liquid dispersion and mass transfer were evaluated in the case of the Rushton turbine and the A315 propeller in up- or down-pumping mode. The results show that the best results in terms of gas handling and mass transfer capacities are obtained for all impellers with the sparger placed below it and with a diameter at least equal to the impeller diameter. For the sparger position below the agitator, the kLa values of the Rushton turbine are greater than those of the A315 propeller, whatever the pumping mode. The A315 propeller in up-pumping mode is, however, more economically efficient in terms of mass transfer. In all cases, the up-pumping mode gives better results than the down-pumping one

Clean synthesis of adipic acid from cyclohexene in microemulsions with stearyl dimethyl benzyl ammonium chloride as surfactant: From the laboratory to bench scale

Adipic acid, HOOC(CH2)4COOH, is a white crystalline solid used primarily in the manufacture of nylon-6,6 polyamide. In industry, adipic acid is mainly produced by oxidation of cyclohexane with air and nitric acidfollowing a homogeneous two-step route. However, this process leads to the formation of nitrous oxide, a greenhouse gas that has to be decomposed. The aim of this study was the development of a clean technology at pilot scale in order to obtain and recover pure adipic acid, and the evaluation of its industrial practicability. Adipic acid was synthesized from cyclohexene and hydrogen peroxide in microemulsions with stearyl dimethyl benzyl ammonium chloride as surfactant. The non-polluting catalyst sodium tungstate, which contains no heavy metal, was used and the reaction conducted under mild conditions (85 C, 8 h). Yields of up to 81% were reached at the 0.14 L scale. However at the end of the reaction the catalyst and the surfactant must be separated and recycled for subsequent cycles. The reuse of the reaction media enabled the conversion to be increased up to 92% but a loss of surfactant and/or catalyst through the cycles progressively reduced the yields. Yields at the bench scale (1.4 L) increased during the two first cycles and then decreased to conversions of between 60% and 70%. Globally the yield is a little lower at bench scale. The results obtained show that the synthesis of adipic acid by a heterogeneous one-step oxidation of cyclohexene in the presence of hydrogen peroxide is an attractive route for developing a future green industrial process

Infra-red lamp panel study and assessment application to thermal vacuum testing of sigma telescope

A research and development program of the Infra-Red Test has been conducted by the French Space Agency (CNES). A choice, after characterization, among several possibilities has been made on the type of methods and facilities for the I.R. test. An application to the Thermal Vacuum Test of the SIGMA Telescope is described

Athletes' Perceptions of the Motivational Climate on Their Teams in Relation to Career Exploration and Athletic Identity

The core mission of the National Collegiate Association of Athletes (NCAA) is to develop individuals as both students and athletes in preparation for life after their collegiate endeavors. The purpose of this study was to examine the relationship between collegiate athletes' perceptions of the climate on their sport teams to their career exploration and engagement, and their athletic identity. Student-athletes (N= 101) in both revenue and nonrevenue sport from various NCAA Division I institutions were administered online surveys assessing their perceptions of the climate on their sport teams, their athletic identity, career exploration, and career engagement. Canonical correlation analysis was employed to examine the relationship between the climate variables (i.e. caring, task, and ego) to athletic identity (AIMS), career self-efficacy (CDSES), and career exploration/engagement (EXPENG). Loadings revealed that perceptions of a high task-involving climate and moderate caring climate were positively associated with athletes' reporting higher athletic identity, career self-efficacy, and career exploration/engagement. Perceptions of an ego-involving climate did not contribute to the canonical relationship, although the variable was negatively associated with career self-efficacy. Results suggest that Division I coaches may want to consider fostering a caring and task-involving team climate for Division I athletes to help them develop as holistic individuals who spend their college years performing at a high level of sport and also preparing for their lives after sport

Interactions in Information Spread

Since the development of writing 5000 years ago, human-generated data gets produced at an ever-increasing pace. Classical archival methods aimed at easing information retrieval. Nowadays, archiving is not enough anymore. The amount of data that gets generated daily is beyond human comprehension, and appeals for new information retrieval strategies. Instead of referencing every single data piece as in traditional archival techniques, a more relevant approach consists in understanding the overall ideas conveyed in data flows. To spot such general tendencies, a precise comprehension of the underlying data generation mechanisms is required. In the rich literature tackling this problem, the question of information interaction remains nearly unexplored. First, we investigate the frequency of such interactions. Building on recent advances made in Stochastic Block Modelling, we explore the role of interactions in several social networks. We find that interactions are rare in these datasets. Then, we wonder how interactions evolve over time. Earlier data pieces should not have an everlasting influence on ulterior data generation mechanisms. We model this using dynamic network inference advances. We conclude that interactions are brief. Finally, we design a framework that jointly models rare and brief interactions based on Dirichlet-Hawkes Processes. We argue that this new class of models fits brief and sparse interaction modelling. We conduct a large-scale application on Reddit and find that interactions play a minor role in this dataset. From a broader perspective, our work results in a collection of highly flexible models and in a rethinking of core concepts of machine learning. Consequently, we open a range of novel perspectives both in terms of real-world applications and in terms of technical contributions to machine learning.Comment: PhD thesis defended on 2022/09/1

Panossas – Les Buissières

Cette première campagne de fouilles extensives menée sur le site des Buissières à Panossas visait à approfondir la connaissance des deux secteurs déjà sondés en 2012 qui concernent, respectivement, un édifice thermal préservé par la végétation d’un bosquet, d’une part, une zone à vocation agricole et artisanale située 150 m plus à l’ouest, d’autre part. Conformément aux prescriptions de la CIRA, elle s’est principalement concentrée sur ce dernier secteur, afin de reconnaître le plan d’un gran..

Veyre-Monton – Site du plateau de Corent

Identifiant de l'opération archéologique : 2005/144 et 2006/112 Date de l'opération : 2006 (FP) Cette deuxième campagne du programme de fouille triannuelle amorcé en 2005 a poursuivi l’exploration des vestiges reconnus l’année dernière au nord du sanctuaire laténien (parcelle ZI 20, propriété de monsieur et madame Favy), dont la fonction précise, l’organisation et la chronologie restaient à préciser (BSR 2005, p. 132-134. Voir également : Vincent Guichard : BSR 1991, p. 44-45 ; BSR 1992, p. 3..