497 research outputs found
Improving a pavement-watering method on the basis of pavement surface temperature measurements
Pavement-watering has been studied since the 1990's and is currently
considered a promising tool for urban heat island reduction and climate change
adaptation. However, possible future water resource availability problems
require that water consumption be optimized. Although pavement heat flux can be
studied to improve pavement-watering methods (frequency and water consumption),
these measurements are costly and require invasive construction work to install
appropriate sensors in a dense urban environment. Therefore, we analyzed
infrared camera measurements of pavement surface temperatures in search of
alternative information relevant to this goal. Firstly, surface temperature
reductions of up to 4{\textdegree}C during shading and 13{\textdegree}C during
insolation were found. Secondly, the infrared camera successfully detected
temperature spikes indicative of surface drying and can therefore be used to
optimize the watering frequency. Measurements made every 5 min or less are
recommended to minimize relevant data loss. Finally, if the water retaining
capacity of the studied pavement is known, optimization of total water
consumption is possible on the sole basis of surface temperature measurements.Comment: Published in Urban Climat
Dexipm-Grapevine: a multicriteria assessment tool of the sustainability for grapevine farming systems
The development of innovative farming systems to reach new goals of agricultural sustainability needs new methods for efficiency assessment. DEXiPM-Grapevine© is a multicriteria assessment tool for overall sustainability of grapevine farming systems adapted from DEXiPM arable crops (Pelzer et al, 2012). DEXiPM-Grapevine© was implemented during the European PURE Project 2012-2015 (Integrated Pest Management (IPM) solutions in agriculture) in order to assess and compare various innovative grapevine systems. This model includes 65 basic attributes describing the cropping system, which are then combined into 97 aggregated attributes, designed to assess the economic, social and environmental performances. This model is based on expert knowledge and agricultural surveys, to define thresholds of classes for each attribute and the weighting of the aggregations. A guide helps users to adjust these parameter specific features due to local context. We tested DEXiPM-Grapevine© on innovative grapevine systems, designed with low pesticides use, and experimented at field scale in the French EcoViti Network. We made bothex ante and ex post analyses of experimented systems in order to sort them and to adjust their strategies. Three main strategies ofpesticide reduction are explored: (i) IPM, (ii) alternative products, organic and biocontrol approach, (iii) pesticide-free cropping systems based on new grapevine mildew resistant varieties. Seven prototypes are tested on INRA experimental farms in Angers(Loire Valley, center of France), Bordeaux (Atlantic region), and Montpellier (Mediterranean region). The first DEXiPMGrapevine© assessments show a high environmental performance of innovative biocontrol strategies, and new resistant varieties.However, IPM strategies have the best overall sustainability with better economic and social assessments. DEXiPM-Grapevine©supports the analysis of performances and helps to identify the strengths/weaknesses of the tested prototypes. This tool can be used for ex ante assessment to guide the designing of cropping systems. It can also enable to re-adjust the prototypes after fieldexperimentations. A third use for farmers' advisors is to help producers to modify their farming systems to enhance the sustainability of their farm
Electrode cleanliness impact on the surface treatment of fluoropolymer films for a long-lasting plasma process
A dielectric barrier discharge in a continuous process configuration is used to coat the surface of polymer films. The effect of the growth of a coating layer on top of the uncovered electrode with regards to the physicochemical properties of the film treatment is studied. Plasma electrical parameters such as power density (W.cmâ2) and voltage (kV) are monitored during a typical cycle, which is comprised between two electrode cleanings. In addition, the surface energy and chemistry are determined at chosen time-points of the process by contact angle measurements with two liquids and X-ray photoelectron spectroscopy (XPS). Based on these analyses, no major modification of the coated polymer physicochemical properties was attributed to the deposition of an organic layer on top of the bare electrodes after the equivalent of 1 h of continuous treatment
Corps-à -corps dans le travail éducatif auprÚs des personnes en situation de handicap avec déficience intellectuelle
Partant dâune enquĂȘte menĂ©e auprĂšs dâĂ©ducateurs et Ă©ducatrices qui travaillent dans des institutions socio-Ă©ducatives en Suisse romande, cet article analyse le « corps Ă corps » entre les professionnel·le·s et les personnes avec une dĂ©ficience intellectuelle. Ă partir dâobservations et dâentretiens rĂ©alisĂ©s avec le personnel Ă©ducatif, les auteur·e·s mettent en Ă©vidence la dimension active du corps au travail (lâaction de toucher), la dimension affective ou Ă©motionnelle (ĂȘtre touché·e), mais Ă©galement la dimension passive du travail (se faire toucher). Ă travers le prisme de la sexualisation, du soin et de la contention, lâanalyse de la dimension passive du travail permet de pointer les enjeux relatifs Ă la professionnalitĂ© des Ă©quipes Ă©ducatives.Based on a survey of educators working at socio-educational institutions in French-speaking Switzerland, the article analyses the close physical relationships between professionals and people with an intellectual disability. Using observations and educator interviews, the authors highlight the active dimensions associated with this kind of work - physicality (the act of touching) and emotionality (the act of being touched) â as well as its passive dimension (the act of wanting to be touched). This latter dimension, addressed through the prism of sexualisation, care and physical restraint, reveals issues related to educational teamsâ professionality.A partir de una encuesta realizada a educadores y educadoras que trabajan en instituciones socio educativas en RomandĂa, este artĂculo analiza el contacto fĂsico entre profesionales y alumnos con discapacidad intelectual. A partir de observaciones y entrevistas del personal educativo, los autores evidencian la dimensiĂłn activa del cuerpo en el trabajo (la acciĂłn de tocar), la dimensiĂłn afectiva o emocional (ser tocado), asĂ como la dimensiĂłn pasiva del trabajo (dejarse tocar). A travĂ©s del prisma de la sexualizaciĂłn, del cuidado y de contenciĂłn, analizar la dimensiĂłn pasiva del trabajo permite apuntalar los retos relativos al profesionalismo de los equipos educativos
Characterization of argon dielectric barrier discharges applied to ethyl lactate plasma polymerization
The influence of the input voltage frequency (35 and 150 kHz), interelectrode gap (1 and
2mm) and precursor concentration (250, 350, and 450 ppm) on the electron temperature (Te),
number density of metastable Ar atoms (n(Arm)), and discharge current density (proportional
to the electron density ne) is studied in an argon-ethyl lactate dielectric barrier discharge
(DBD). An argon-ammonia Penning mixture is also considered as reference. These results
are correlated to the chemistry (XPS, IR) and topography (AFM) of the ethyl-lactate-based
plasma polymer coatings. Low Te values from 0.3 to 0.5 eV were obtained for all discharges.
This observation, in addition to resemblances with the ArâNH3 mixture, suggested that the
ionization kinetics of ethyl lactate-based discharges is driven by Penning reactions. Among
the investigated parameters, the dissipated power obtained through changes of the excitation
frequency had the largest impact on both the coatings properties and the discharge behavior
Photoswitchable single-walled carbon nanotubes for super-resolution microscopy in the near-infrared
The design of single-molecule photoswitchable emitters was the first milestone toward the advent of single-molecule localization microscopy, setting a new paradigm in the field of optical imaging. Several photoswitchable emitters have been developed, but they all fluoresce in the visible or far-red ranges, missing the desirable near-infrared window where biological tissues are most transparent. Moreover, photocontrol of individual emitters in the near-infrared would be highly desirable for elementary optical molecular switches or information storage elements since most communication data transfer protocols are established in this spectral range. Here, we introduce a type of hybrid nanomaterials consisting of single-wall carbon nanotubes covalently functionalized with photoswitching molecules that are used to control the intrinsic luminescence of the single nanotubes in the near-infrared (beyond 1 ÎŒm). Through the control of photoswitching, we demonstrate super-localization imaging of nanotubes unresolved by diffraction-limited microscopy
Measurement of the Cooling Efficiency of Pavement-watering as an Urban Heat Island Mitigation Technique
The Paris region (Ăle-de-France) was amongst the hardest hit by the August 2003 heat wave, due in part to subsequent amplification of its urban heat island. This has created high heat-wave awareness in climate change adaptation studies for the city of Paris. Over the summer of 2013, pavement watering was studied experimentally in two locations as a climate change adaptation method. Pavement watering was found to lower pavement surface temperatures by several degrees for several hours after watering, while also strongly reducing its cooling rate a few hours before and after sunset. Heat flux and storage at a depth of 5 cm in the pavement were also found to have been significantly reduced, especially during direct sunlight exposure, but also when the pavement was in the shade. Uninterrupted watering appears necessary during direct sunlight exposure of the pavement to maximize efficiency
Polymer Chain Generation for Coarse-Grained Models Using Radical-Like Polymerization
International audienceThis paper presents major improvements in the efficiency of the so-called Radical-Like Polymerization (RLP) algorithm proposed in âPolymer chain generation for coarse-grained models using radical-like polymerizationâ [J. Chem. Phys. 128 (2008)]. Three enhancements are detailed in this paper: (1) the capture radius of a radical is enlarged to increase the probability of finding a neighboring monomer; (2) between each growth step, equilibration is now performed with increasing the relaxation time depending on the actual chain size; (3) the RLP algorithm is now fully parallelized and proposed as a âfixâ within the âLammpsâ molecular dynamics simulation suite
A prototyping method for the re-design of intensive perennial systems: the case of vineyards in France
The results of our re-design and experimentation of grapevine agrosystem, as well as on the other crops (Lançon et al., 2007 and Wery & Langeveld, 2010) show promising perspectives of the prototyping method to achieve high goals for performance and innovation. The complexity of the grapevine agrosystem (ie the number of technical interventions and their potential interactions) requires a strong systemic approach at the interface between the technical and biophysical dimensions of cropping systems (Rapidel et al., 2009). The approach must implement agro-ecological processes to greatly limit inputs. It also required a high innovation and significant changes in the grapevine agrosystem genetics, structure and management. Our results point out the need to re-design grapevine systems from the crop plantation with new varieties, new training systems and with intercrops aiming to improve ecosystem services and maintain a very high level of sustainability criteria
Thrombin modifies growth, proliferation and apoptosis of human colon organoids: a protease-activated receptor 1- and protease-activated receptor 4-dependent mechanism
International audienceExperimental Approach: Crypts were isolated from human colonic resections and cultured for 6 days, forming human colon organoids. Cultured organoids were exposed to 10 and 50 mU·mLâ1 of thrombin, in the presence or not of proteaseâactivated receptor (PAR) antagonists. Organoid morphology, metabolism, proliferation and apoptosis were followed.Key Results: Thrombin favoured organoid maturation leading to a decreased number of immature cystic structures and a concomitant increased number of larger structures releasing cell debris and apoptotic cells. The size of budding structures, metabolic activity and proliferation were significantly reduced in organoid cultures exposed to thrombin, while apoptosis was dramatically increased. Both PAR1 and PAR4 antagonists inhibited apoptosis regardless of thrombin doses. Thrombinâinduced inhibition of proliferation and metabolic activity were reversed by PAR4 antagonist for thrombin's lowest dose and by PAR1 antagonist for thrombin's highest dose.Conclusions and Implications: Overall, our data suggest that the presence of thrombin in the vicinity of human colon epithelial cells favours their maturation at the expense of their regenerative capacities. Our data point to thrombin and its two receptors PAR1 and PAR4 as potential molecular targets for epithelial repair therapies
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