Adapting Global Service-Learning Project and Community Partnership Outcomes Using a “Tele-engineering” Approach in Response to the COVID-19 Pandemic

The Water Supply in Developing Countries (WSDC) service-learning course at Purdue University has fostered a strong partnership with the La Vega region in the Dominican Republic since 2012. During this time, an interdisciplinary group of engineering and science students has helped design drinking water treatment systems and the group has developed water, sanitation, and health (WASH) education materials. These WASH education and water safety approaches often have been conducted in person in the past. However, with the state of the COVID-19 pandemic and the inability to travel in the fall and spring semesters of the 2020–2021 academic year, the students have been exploring (1) the impact of the pandemic on the community schools in the La Vega province, (2) the impact of the pandemic on the current water treatment systems, and (3) possible solutions to implement a “virtual installation” of a water treatment system at our newest partner school in the community of Desecho. The coronavirus pandemic has ushered in a new way that we may approach our service-learning experiences in the future. More specifically, in the future, it may be more effective to serve as a “virtual consulting firm” of engineers and consultants, rather than builders, for the implementation and design of the water treatment systems. In this way, we may facilitate a partnership that fosters community agency and solution-based approaches to technical issues are led by local community members

Tailoring 3-component photoinitiating systems for use as efficient photopolymerizable holographic material

8 pagesInternational audienceTo enhance the efficiency of photopolymerizable systems as holographic recording materials, the use of 3-component photoinitiating systems was explored. In order to get more insight into the hologram formation, gratings' recording curves were compared to those of monomer conversion obtained by RTFTIR spectroscopy. This work outlines the differences between the photoinitiating systems. A holographic 3-component recording material giving rise to thick phase holograms with both high diffraction yield and high rate of formation is highlighted

Photocyclic initiating system for free radical photopolymerization studied through holographic recording

International audienceThis paper discusses the efficiency of photocyclic initiating system (PCIS) based on a pyrromethene dye (EMP), an amine as electron donor (NPG) and an iodonium salt as electron acceptor (I250) under homogenous irradiation and holographic recording. It is shown that the PCIS is more efficient than the corresponding two component systems. This high efficiency is due to a photocyclic reaction that takes places during the irradiation, inducing the recovery of the dye in the ground state and the formation of two initiating radicals. The beneficial effect on the rate of grating formation and on the diffraction efficiency is clearly noticed. At high irradiation time, the fast polymerization observed with EMP-NPG-I250 even induces the polymerization in the dark fringes leading to a decrease of the holographic diffraction efficiency. This confirms the high performance of the photoinitiating system which can be used in holographic recording provided that the irradiation dose could be controlled

Photopolymérisation et modulation d'indice de réfraction en holographie

5 pagesNational audienceLes systèmes ici mis en œuvre en tant que support d'enregistrement holographique reposent sur la mise en commun des compétences, d'une part, du LPIM dans le domaine des photoamorceurs et des supports d'enregistrement holographique, et celles, d'autre part, du laboratoire Foton. Les systèmes photoamorceurs considérés sont composés de trois éléments : un colorant et deux co-amorceurs (un donneur d'électron et un accepteur d'électron). Le système SFH+-NPG-ClHABI est, après optimisation des formulations, celui qui conduit aux meilleures performances holographiques, tant du point de vue rendement final de diffraction que de la vitesse de formation du réseau, tout en se stabilisant rapidement à son maximum

Optimisation de nouveaux systèmes photoamorceurs de polymérisation pour le stockage d'informations par holographie

2 pagesNational audienceDifférents systèmes photoamorceurs mettant en jeu trois composants et destinés à la polymérisation d'un mélange d'acrylates sont ici optimisés en tant que support pour le stockage d'informations par holographie. Ces matériaux donnent naissance à des réseaux de phase épais, fonctionnant en transmission. L'étude basée sur l'enregistrement de réseaux sinusoïdaux sous forme d'une modulation d'indice de réfraction a permis de comparer les systèmes 3-composants aux 2-composants correspondants, les premiers étant plus performants d'un point de vue photochimique (vitesse et taux de polymérisation élevés). L'optimisation des matériaux a conduit à des rendements de diffraction corrigés dans l'ordre 1 supérieurs à 90%

Optimization of a photopolymerizable material based on a photocyclic initiating system using holographic recording

9 pagesInternational audienceA set of photoinitiating systems (PIS) for free radical photopolymerization was studied using time-resolved spectroscopic experiments, real-time FTIR and holographic recording. It is shown that the efficiency of the photoinitiating system can be drastically increased when a redox additive is added to the conventional dye/coinitiator system by virtue of photocyclic behaviour. The homogeneous photopolymerization process was found to reach a fast vitrification, limiting the conversion at about 55%. By contrast, holographic recording underlines the differences in photoinitiating system reactivity, allowing diffraction efficiencies close to unity for the most reactive PIS

Continuous Flow Metathesis for Direct Valorization of Food Waste: An Example of Cocoa Butter Triglyceride.

The direct chemical conversion of cocoa butter triglycerides, a material available as a postmanufacture waste stream from the food industry, to 1-decene by way of ethenolysis is reported. The conversion of the raw waste material was made possible by use of 1 mol % of the [RuCl2(iBu-phoban)2(3-phenylindenyl)] catalyst. The process has been investigated in both batch and flow conditions, where the latter approach employs a Teflon AF-2400 tube-in-tube gas-liquid membrane contactor to deliver ethylene to the reaction system. These preliminary studies culminate in a continuous processing system, which maintained a constant output over a 150 min period tested.The ERC (Advanced Investigator Award-FUNCAT to S.P.N.) and EPSRC are gratefully acknowledged for support (S.V.L., D.L.B., Award No. EP/K009494/1). Umicore AG is acknowledged for their generous gift of materials. S.P.N. is a Royal Society Wolfson Research Merit Award holder.This is the final version of the article. It first appeared from ACS via http://dx.doi.org/10.1021/acssuschemeng.5b00397

Holography, reconstructing by light thanks to a photostructurable medium

During holographic recording, interference patterns produced by a reference beam and the light waves scattered by the object are stored by building-up of refractive index variations or relief profiles in the photosensitive medium. Early holograms used silver halide photographic emulsions as the recording medium. Being able to memorize an incident complex fringe pattern with small features at the submicrometer scale, different polymeric media are also successfully usable. All this optimizing work generated different applications

Mystery of fatal 'staggering disease' unravelled: novel rustrela virus causes severe meningoencephalomyelitis in domestic cats

‘Staggering disease’ is a neurological disease entity considered a threat to European domestic cats (Felis catus) for almost five decades. However, its aetiology has remained obscure. Rustrela virus (RusV), a relative of rubella virus, has recently been shown to be associated with encephalitis in a broad range of mammalian hosts. Here, we report the detection of RusV RNA and antigen by metagenomic sequencing, RT-qPCR, in-situ hybridization and immunohistochemistry in brain tissues of 27 out of 29 cats with non-suppurative meningoencephalomyelitis and clinical signs compatible with’staggering disease’ from Sweden, Austria, and Germany, but not in non-affected control cats. Screening of possible reservoir hosts in Sweden revealed RusV infection in wood mice (Apodemus sylvaticus). Our work indicates that RusV is the long-sought cause of feline ‘staggering disease’. Given its reported broad host spectrum and considerable geographic range, RusV may be the aetiological agent of neuropathologies in further mammals, possibly even including humans

Leukotriene B-4-Neutrophil Elastase Axis Drives Neutrophil Reverse Transendothelial Cell Migration In Vivo

This work was supported by generous funds from the Wellcome Trust (098291/Z/12/Z to S.N.). T.C. was supported by the ERC (ENDHORET). The work was also supported in part by funds from the William Harvey Research Foundation