Search results for "Silo"

Hettangian ammonites from the old iron mine of Beauregard (Thoste, Côte-d’Or, France).

2012

The ammonite fauna of the old iron mine of Beauregard is reviewed. Only nine specimens from this locality are presently known. They are housed in the collections of the “Musée de Semur-en-Auxois”, of the “Muséum national d’Histoire naturelle” (Paris) and of the “Ecole Nationale Supérieuredes Mines” (Claude Bernard University, Lyon 1). The age, or possibly the ages, of these ammonites remain to precise in a coarsely defined time-span including the upper part of the early Hettangian and the middle Hettangian (pro parte?). These fossils, usually finely preserved, were collected during the nineteenth century thanks to intensive mining in the Thoste-Beauregard area. They are illustrated uniforml…

Search for Production of Invisible Final States in Single-Photon Decays of Υ(1S)

2010

We search for single-photon decays of the Upsilon(1S) resonance, Upsilon->gamma+invisible, where the invisible state is either a particle of definite mass, such as a light Higgs boson A0, or a pair of dark matter particles, chi chi-bar. Both A0 and chi are assumed to have zero spin. We tag Upsilon(1S) decays with a dipion transition Upsilon(2S)->pi+pi-Upsilon(1S) and look for events with a single energetic photon and significant missing energy. We find no evidence for such processes in the mass range m_A0<=9.2 GeV and m_chi<=4.5 GeV in the sample of 98e6 Upsilon(2S) decays collected with the BaBar detector and set stringent limits on new physics models that contain light dark ma…

Innovations in endodontic filling materials

2012

One of the goals of endodontic treatment is to achieve a complete, tridimensional, hermetic sealing of the root canal system to prevent the entry of microorganisms or their products through both the coronal and apical pathways. Gutta-percha is the most widely used material for root canal filling and despite its numerous properties, such as biocompatibility and thermoplasticity, it has however an important limit: the lack of adhesion to the canal walls. Attempts to address this problem have been made over the years by using endodontic cements capable of bonding to canal dentine but their tendency to resorption in time can compromise the quality of treatment. The first step towards a real adh…

n-3 PUFAs modulate T-cell activation via protein kinase C-α and -ε and the NF-κB signaling pathway

2005

We elucidated the mechanisms of action of two n-3 PUFAs, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), in Jurkat T-cells. Both DHA and EPA were principally incorporated into phospholipids in the following order: phosphatidylcholine < phosphatidylethanolamine < phosphatidylinositol/phosphatidylserine. Furthermore, two isoforms of phospholipase A(2) (i.e., calcium-dependent and calcium-independent) were implicated in the release of DHA and EPA, respectively, during activation of these cells. The two fatty acids inhibited the phorbol 12-myristate 13-acetate (PMA)-induced plasma membrane translocation of protein kinase C (PKC)-alpha and -epsilon. The two n-3 PUFAs also inhibited t…

ORMOSIL thin films: Tuning mechanical properties via a nanochemistry approach

2006

The mechanical properties (hardness and elastic modulus) of organically modified silicate thin films can be finely tuned by varying the degree of alkylation and thus the fraction of six- and four-membered siloxane rings in the organosilica matrix. This opens the way to large tunability of parameters that are of crucial practical importance for films that are finding increasing application in numerous fields ranging from microelectronics to chemical sensing.

Prediction of compound channel secondary flows using anisotropic turbulence models

2014

Unsteady turbulence in plane channel flow

2011

Abstract Direct numerical simulations were conducted for oscillating flow with zero time mean (reciprocating flow) in a plane channel subject to a harmonic forcing term of varying amplitude and frequency. The results confirmed the existence of four flow regimes (laminar, “disturbed laminar”, intermittently turbulent, and fully turbulent) depending on the above parameters. The flow behaviour was found to depend on the complex interplay of mean and turbulence quantities, as described by the closed loop formed by the streamwise Reynolds-averaged momentum equation in conjunction with the exact transport equations for the turbulent (Reynolds) stresses. A crucial role in this loop appeared to be …

A vorticity based aeroacoustic prediction for the noise emission of a low-speed turbulent internal flow

2003

Abstract Turbulent internal flows are known to generate intense noise as well as surface pressure fluctuations. Numerically predicting the noise emission near the prescribed boundaries requires that the sound-generating turbulent flow be adequately represented and described. The k – e method provides a promising tool for obtaining the unsteady characteristics of a realistic turbulent flow interacting with a rectangular flat plate undergoing “ground effect”. The far-field acoustic calculation is facilitated by the Kambe model (from Lighthill’s theory) and an original post-processor has been developed to determine the far-field spectra and the source term characteristics. In pre-processed tur…

Il principio del non refoulement tra controllo dell'accesso al territorio dell'Unione europea e protezione dei diritti umani

2020

Nonostante il non-refoulement sia un principio cardine del diritto internazionale dei rifugiati, il suo preciso ambito di applicazione e l’esatta individuazione degli obblighi a carico degli Stati sono oggetto di incertezza per la tensione costante tra due opposte tendenze. In quanto espressione di un valore umanitario fondamentale, sono fiorite interpretazioni estensive, ma, in quanto limite al potere sovrano dello Stato di regolare l’accesso al territorio, sono emerse tendenze di segno restrittivo. L’articolo presenta la politica comune di asilo come sottoposta alla stessa tensione e ne descrive per grandi linee gli aspetti che costituiscono un ampliamento della protezione offerta dal dir…

Gold nanoparticles grown on a hydrophobic and texturally tunable PDMS-like framework

2021

Mesoporous silicas are among the most suitable high-surface area solids to support small-sized metal clusters and nanoparticles. Unfortunately, the instability of silica in water constitutes a serious impediment for its widespread use and large implementation as a catalytic support for fine chemical synthesis and for biomass upgrading in the context of biorefineries. While end cupping silanols provides a way for delaying framework degradation, further investigations are needed to design more robust, water-resistant supports. Prompted by the success of polydimethylsiloxane (PDMS) in surface coating and water-repellent technologies, we herein explore the transformation of triethoxysilyl-funct…