Search results for "conversion"

A cluster of cuticle protein genes of Drosophila melanogaster at 65A: sequence, structure and evolution

1997

0016-6731 (Print) Journal Article Research Support, Non-U.S. Gov't Research Support, U.S. Gov't, Non-P.H.S.; A 36-kb genomic DNA segment of the Drosophila melanogaster genome containing 12 clustered cuticle genes has been mapped and partially sequenced. The cluster maps at 65A 5-6 on the left arm of the third chromosome, in agreement with the previously determined location of a putative cluster encompassing the genes for the third instar larval cuticle proteins LCP5, LCP6 and LCP8. This cluster is the largest cuticle gene cluster discovered to date and shows a number of surprising features that explain in part the genetic complexity of the LCP5, LCP6 and LCP8 loci. The genes encoding LCP5 a…

All-Optical Fiber Hanbury Brown & Twiss Interferometer to study 1300 nm single photon emission of a metamorphic InAs Quantum Dot

2016

[EN] New optical fiber based spectroscopic tools open the possibility to develop more robust and efficient characterization experiments. Spectral filtering and light reflection have been used to produce compact and versatile fiber based optical cavities and sensors. Moreover, these technologies would be also suitable to study N-photon correlations, where high collection efficiency and frequency tunability is desirable. We demonstrated single photon emission of a single quantum dot emitting at 1300 nm, using a Fiber Bragg Grating for wavelength filtering and InGaAs Avalanche Photodiodes operated in Geiger mode for single photon detection. As we do not observe any significant fine structure s…

Design of a knowledge and management system for starch bioconversion

2011

Abstract In this paper a knowledge acquisition and management system (KAMS) which allows the collection, analysis, ordering and storage of informations generated at starch liquefaction was developed. KAMS was structured on three levels: PostgreSQL as a backend, D2RQ as middle tier and Seaside as frontend. The system was used to store knowledge about the liquefaction process with the goal to be used as a decision support system in chosing the condition for this operation. The tests had shown that the implemented KAMS provides support for: Distributed acquisition of the scientific data generated by the researchers; Structured data storage; Support for the generation and storage of knowledge o…

Conversion of carbohydrates into 5-HMF in Deep Eutectic Solvents under mild reaction conditions

Perovskite CH3NH3PbI3–XClx Solar Cells. Experimental Study of Initial Degradation Kinetics and Fill Factor Spectral Dependence

2021

The main drawback of the methylammonium lead halide perovskite solar cells is their degradation in ambient atmosphere. To investigate ambient-air-induced cell degradation, spec-tral dependencies of open-circuit voltage (VOC), fill factor (FF) and the power conversion effi-ciency (PCE) have been acquired (for the first time reported in literature). Our custom-made measurement system allowed us to perform measurements of the above-mentioned entities in situ directly in vacuum during and after thermal deposition of the elec-trode. We also studied how these parameters in vacuum changed after cell exposure to ambient air for 85 min (50 nm top electrode) and for 180 min (100 nm top Ag electrode).…

A didactic experiment and model of a flat-plate solar collector

2011

We report on an experiment performed with a home-made flat-plate solar collector, carried out together with high-school students. To explain the experimental results, we propose a model that describes the heating process of the solar collector. The model accounts quantitatively for the experimental data. We suggest that solar-energy topics should be included in school programmes to give students the opportunity to gain experience with solar energy and increase their awareness of the benefits that can be obtained from this remarkable and renewable energy source.

Upconversion nanoparticles with a strong acid-resistant capping

2016

Water-dispersible upconversion nanoparticles (β-NaYF:Yb,Er, UCNP) coated with a thin shell of a biocompatible copolymer comprising 2-hydroxyethylmethacrylate (HEMA) and 2-acrylamido-2-methyl-1-propanesulphonsulphonic acid (AMPS), which we will term COP, have been prepared by multidentate grafting. This capping is remarkably resistant to strong acidic conditions as low as pH 2. The additional functionality of the smart UCNP@COP nanosystem has been proved by its association to a well-known photosensitizer (namely, methylene blue, MB). The green-to-red emission ratio of the UC@COP@MB nanohybrid exhibits excellent linear dependence in the 7 to 2 pH range as a consequence of the release of the d…

Fluorinated Heterocyclic Compounds− The First Example of an Irreversible Ring-Degenerate Rearrangement on Five-Membered Heterocycles by Attack of an …

2004

The reactions of 5-perfluoroalkyl-1,2,4-oxadiazoles 3 with hydroxylamine in DMF give the regioisomeric 3-perfluoroalkyl-1,2,4-oxadiazoles 4 in excellent yields. This process is the first example of ring-degenerate rearrangement (RDR) occurring on five-membered heterocycles by attack of an external bidentate nucleophile, which replaces two heteroatoms of the ring. We suggest that an ANRORC-like mechanism occurs in which the addition of the nucleophilic nitrogen atom (NH2OH) on the C(5) atom of 3 is followed by ring opening and irreversible ring-degenerate closure by attack of the nucleophilic oxygen atom (=NOH) on the C(3) atom of the original ring, realizing an elegant and efficient synthes…

Emploi public, emploi privé : la difficile conversion des titulaies de thèse

1998

International audience; Les titulaires de thèse continuent de bénéficier d'une insertion relativement favorable. La plupart deviennent enseignants, chercheurs ou ingénieurs après 3 ans de vie active. Pourtant, leur nombre a fortement augmenté depuis 1989, comme celui de l'ensemble des sortants de l'enseignement supérieur. Ceux qui ne peuvent prétendre à un poste dans l'enseignement supérieur ou la recherche doivent réorienter leur projet professionnel pour espérer se faire une place dans le secteur privé. Ils sont toutefois concurrencés par les diplômés des écoles d'ingénieurs lors de leur recrutement en entreprise. Les docteurs doivent alors tirer profit de leur spécialisation et des liens…

Electro-optical characterization of ruthenium-based dye sensitized solar cells: A study of light soaking, ageing and temperature effects

2017

Abstract In this work, we report on the electro-optical characterization of Dye Sensitized Solar Cells (DSSCs) which use ruthenium complexes as sensitizers. In particular, several kinds of measurements have been performed to study the electrical performances and the efficiency levels of the cells at different operating conditions. In detail, the measurements have been conducted at varying temperatures and hours of light soaking. Our results show that the short circuit current density J SC , the open circuit voltage V OC and the conversion efficiency η increase with the hours of light soaking, while they decrease with temperature. A thorough investigation on the light soaking process at the …