Search results for "Pore"
showing 10 items of 929 documents
Discussion on “Experimental Deformation of Opalinus Clay at Elevated Temperature and Pressure Conditions: Mechanical Properties and the Influence of …
2021
AbstractThe testing procedure and results on saturated samples of Opalinus Clay in the work of Schuster et al. (Rock Mech Rock Eng https://doi.org/10.1007/s00603-021-02474-3, 2021) were conducted and presented using strain rates two to four orders of magnitudes higher than the rates needed to allow pore pressure equilibrium in the material, both in drained and undrained conditions. This leads to an erroneous estimation of the mechanical properties in saturated conditions. We discuss this aspect in the context of shale testing. We also discuss the effect of drying-induced fissuring on the mechanical properties of geomaterials tested in dry conditions.
The Permeable Concrete: A Low Energy Consumption Solution for Deep Draining Trenches
2018
The reduction of pore water pressures is one of the very effective measures to improve the stability conditions of marginally stable water-bearing slopes or to stabilise landslides. For this purpose the trench drains have been used long since. Like filling material of deep trenches the permeable concrete can be effectively employed. It presents relatively high hydraulic conductivity, filtering capacity in order to prevent the internal erosion of the soil in which the trench drain is installed, enough residual hydraulic conductivity after possible clogging, sufficient shear strength after a short curing time to avoid the instabilisation of adjacent previously built panels or piles. Results o…
Predictors of surgical outcomes of minimally invasive right colectomy: the MERCY study
2022
PURPOSE: The optimal approach for minimally invasive (MIS) right colectomy remains under debate. This study aimed to describe surgical trends in the treatment of nonmetastatic right colon cancer and to identify predictors of short-term surgical outcomes. METHODS: A retrospective multicenter cohort study of Minimally-invasivE surgery for oncologic Right ColectomY (MERCY) was conducted on patients who underwent laparoscopic or robotic right colectomy between 2014 and 2020. Classification tree approach was used to describe the extracorporeal (EA) or intracorporeal (IA) anastomosis choice. Mixed-model regressions were used to identify patient- and surgery-related factors predictive of postopera…
Qualité et efficience de l'école primaire française : éléments de comparaisons spatiales et temporelles
2008
08001 - 20 p.; Document de travail de l'IREDU 2008-01; L'objectif principal de ce texte est de présenter des éléments factuels sur les résultats de l'école primaire française. Notre réflexion portera sur deux dimensions complémentaires, à savoir la qualité et l'efficience, celles-ci seront examinées dans une double perspective comparative (temporelle et spatiale). Dans une première partie, nous mobiliserons les données des enquêtes internationales pour apprécier les résultats des élèves français et leur évolution dans le temps sur ces 15 dernières années. La seconde partie sera consacrée aux coûts de l'enseignement primaire et plusieurs aspects seront abordés. Dans un premier temps, l'évolu…
Synthesis of large-pore ordered mesoporous silicas containing aminopropyl groups
2005
Ordered mesoporous silicas with large-pore diameters incorporating aminopropyl groups in variable quantity have been synthesized via the co-condensation of tetraethyl orthosilicate (TEOS) and 3-tert-butyloxycarbonylaminopropyltriethoxysilane templated with nonionic surfactant P123 under acidic conditions. The deprotection of amino groups was then quantitatively achieved either by thermal treatment or acid hydrolysis followed by Et3N treatment, both routes leading to exactly the same materials. We showed that the free amino centers are fully accessible, by using the condensation of the amine function with benzaldehyde.
Refrigeration bound of heat-producing cylinders by superfluid helium
2019
In this paper we go ahead in our studies on refrigeration of nanosystems by superfluid helium, as an appealing subject for future applications to computers or astronautical precision nanodevices. We first recall the effective thermal conductivity in laminar counterflow superfluid helium through arrays of mutually parallel cylinders and we discuss the conditions for the appearance of quantum turbulence around the heat-producing cylinders. We then consider the cooling of an array of heat-producing cylindrical nanosystems by means of superfluid-helium counterflow. We discuss the upper bound on heat removal set by avoidance of quantum turbulence and avoidance of phase transition to normal He I,…
Staphylococcal α-toxin: the role of the N-terminus in formation of the heptameric pore — a fluorescence study1This work contains parts of the M.D. th…
1997
Staphylococcus aureus alpha-toxin forms heptameric pores on eukaryotic cell membranes. Assembly of the heptamer precedes formation of the transmembrane pore. The latter event depends on a conformational change that drives a centrally located stretch of 15 amino acid residues into the lipid bilayer. A second region of the molecule that has been implicated in the pre-pore to pore transition is the far N-terminus. Here, we used fluorescently labeled single cysteine replacement mutants to analyze the functional role of the far N-terminus of alpha-toxin. Pyrene attached to mutants S3C, I5C and 17C forms excimers within the toxin pore complex. This indicates that the distance of adjacent N-termin…
One dimensional consolidation of Opalinus Clay from shallow depth
2017
First experimental results on Opalinus Clay from shallow depth (< 30 m depth) are presented and compared to results on cores from Mont Terri Underground Rock Laboratory (~ 300 m depth). Samples were tested in one dimensional condition using an advanced experimental technique. The samples from the two sites show similar properties in terms of geotechnical characterization and one dimensional compressibility/swelling indexes, despite the different source depths.
Educare alla corporeità a scuola
2022
In ambito educativo, il corpo viene considerato un importante elemento attraverso cui l’individuo costruisce il suo modo di essere e impara ad abitare e conoscere il mondo (Gamelli, 2019). Dal momento che il corpo è ciò che ci mette in relazione con noi stessi, con gli altri e col mondo, diviene fondamentale che la scuola focalizzi il proprio intervento didattico con l’intenzionalità pedagogica e formativa di valorizzare la corporeità invece di limitarla attraverso una didattica scolastica mortificante e inibente (Collacchioni, 2016). L’educazione al corpo e al movimento, soprattutto nella Scuola Primaria, dovrebbe costituire una “componente strutturale e ineliminabile del più generale proc…
La modelización usando corporeización en la Enseñanza de las Ciencias
2017
En este trabajo proponemos la corporeización como herramienta didáctica para enseñar modelos y conceptos en diferentes conceptos básicos de la física y la química que aparecen a lo largo de cursos generales y específicos de ciencia. Presentamos una propuesta de diez modelizaciones con corporeización de fenómenos a escala microscópica y macroscópica y mostramos los resultados de un análisis cualitativo de un proceso de corporeización según el esquema de trabajo general. Los resultados muestran la sencillez con la que se discuten conceptos aparentemente complejos y cómo se alcanza la comprensión de la idea aceptada científicamente a partir de la propia modelización de los alumnos. Estos resul…