Search results for "MINOS"

Stability of Halloysite, Imogolite, and Boron Nitride Nanotubes in Solvent Media

2018

Inorganic nanotubes are attracting the interest of many scientists and researchers, due to their excellent application potential in different fields. Among them, halloysite and imogolite, two naturally-occurring aluminosilicate mineral clays, as well as boron nitride nanotubes have gained attention for their proper shapes and features. Above all, it is important to reach highly stable dispersion in water or organic media, in order to exploit the features of this kind of nanoparticles and to expand their applications. This review is focused on the structural and morphological features, performances, and ratios of inorganic nanotubes, considering the main strategies to prepare homogeneous col…

ECS-3: A Crystalline Hybrid Organic-Inorganic Aluminosilicate with Open Porosity

2011

Sepiolite-Hydrogels: Synthesis by Ultrasound Irradiation and Their Use for the Preparation of Functional Clay-Based Nanoarchitectured Materials.

2021

International audience; Sepiolite and palygorskite fibrous clay minerals are 1D silicates featuring unique textural and structural characteristics useful in diverse applications, and in particular as rheological additives. Here we report on the ability of grinded sepiolite to generate highly viscous and stable hydrogels by sonomechanical irradiation (ultrasounds). Adequate drying of such hydrogels leads to low-density xerogels that show extensive fiber disaggregation compared to the starting sepiolite-whose fibers are agglomerated as bundles. Upon re-dispersion in water under high-speed shear, these xerogels show comparable rheological properties to commercially available defibrillated sepi…

‘Maya chemistry’ of organic–inorganic hybrid materials: isomerization, cyclicization and redox tuning of organic dyes attached to porous silicates

2013

[EN] Association of indigo and lapachol dyes to aluminosilicate clays yields polyfunctional organic – inorganic hybrid materials forming Maya Blue-like systems. Upon partial removing of clay's zeolitic water by moderate thermal treatment, abundant isomerization, cyclicization and oxidation reactions occur defining a‘ Maya chemistry whose complexity could explain the versatile use of such materials in the pre-Columbian cultures and permits the preparation of polyfunctional materials potentially usable for therapeutic and catalytic purposes.

Trace metal partitioning in Fe–Mn nodules from Sicilian soils, Italy

2001

Concentrations of 20 elements (Mn, Fe, Na, Mg, Al, K, Ca, V, Co, Ni, Cu, Zn, Rb, Sr, Cd, Cs, Ba, La, Ce, Pb) were determined in 18 Fe–Mn nodules from two alfisols, which are subject to periodic waterlogging. The nodules are significantly enriched in most trace metals relative to the host soil, with Mn, Co, Ce, Pb, Ba, Cd, Ni more enriched than Fe, V, La, Cu, Sr, Zn. Cesium and rubidium show poor or no enrichment in the nodules, consistent with their aluminosilicate affiliation. Scanning electron microscopy (SEM) examination and energy dispersive X-ray spectrometer (EDS) microprobe analysis have shown different microstructures (an undifferentiated fabric and a distinctive Fe–Mn banded struct…

Asymmetric Allylation/Pauson-Khand Reaction: A Simple Entry to Polycyclic Amines. Application to the Synthesis of Aminosteroid Analogues

2014

Asymmetric allylation of o-iodoarylsulfinylimines has been achieved in high diastereoselectivities. The thus-obtained o-iodoarylhomoallylic sulfinamides participate in a subsequent Sonogashira coupling followed by a diastereoselective intramolecular Pauson-Khand reaction. In this way, tricyclic amines showing a unique benzo-fused indenyl backbone were obtained. The methodology has been applied to the synthesis of amino steroid analogues.

Physics with Antiprotons at the Future GSI Facility

2003

Recently GSI presented the plans for a major new international research facility (http://www.gsi.de/GSI-future/). Highly luminous secondary beams with excellent quality encompassing the production of antiprotons will be delivered. In a High Energy Storage Ring (HESR) with a bending power of 50 Tm antiprotons will be cooled either stochastically or by electrons. The envisaged limits are a momentum range of 1.5 to 15 GeV/c and a luminosity of 2 × 1032 cm-2 s-1. Four major physical research goals can be addressed: high precision charmonium spectroscopy, medium effects of open and hidden charm, the search for glueballs and hybrids, and the production of hypernuclei.

Complete Measurement of the Λ Electromagnetic Form Factors.

2019

The exclusive process e+e−→ΛΛ¯, with Λ→pπ− and Λ¯→p¯π+, has been studied at s=2.396 GeV for measurement of the timelike Λ electric and magnetic form factors, GE and GM. A data sample, corresponding to an integrated luminosity of 66.9 pb−1, was collected with the BESIII detector for this purpose. A multidimensional analysis with a complete decomposition of the spin structure of the reaction enables a determination of the modulus of the ratio R=|GE/GM| and, for the first time for any baryon, the relative phase ΔΦ=ΦE−ΦM. The resulting values are R=0.96±0.14(stat)±0.02(syst) and ΔΦ=37°±12°(stat)±6°(syst), respectively. These are obtained using the recently established and most precise value of …

Chemical modification of halloysite nanotubes for controlled loading and release.

2020

Clay minerals have been used for medical purposes from ancient times. Among them, the halloysite nanotube, an aluminosilicate of the kaolin group, is an emerging nanomaterial which possesses peculiar chemical characteristics. By means of suitable modifications, such as supramolecular functionalization or covalent modifications, it is possible to obtain novel nanomaterials with tunable properties for several applications. In this context the covalent grafting of suitable organic moieties on the external surface or in the halloysite lumen has been exploited to improve the loading and release of several biologically active molecules. The resulting hybrid nanomaterials have been applied as drug…

Precision Measurement of the Mass and Lifetime of the Ξ[0 over b] Baryon

2014

Using a proton-proton collision data sample corresponding to an integrated luminosity of 3 fb$^{-1}$ collected by LHCb at center-of-mass energies of 7 and 8 TeV, about 3800 $\Xi_b^0\to\Xi_c^+\pi^-$, $\Xi_c^+\to pK^-\pi^+$ signal decays are reconstructed. From this sample, the first measurement of the $\Xi_b^0$ baryon lifetime is made, relative to that of the $\Lambda_b^0$ baryon. The mass differences $M(\Xi_b^0)-M(\Lambda_b^0)$ and $M(\Xi_c^+)-M(\Lambda_c^+)$ are also measured with precision more than four times better than the current world averages. The resulting values are $\frac{\tau_{\Xi_b^0}}{\tau_{\Lambda_b^0}} = 1.006\pm0.018\pm0.010$, $M(\Xi_b^0) - M(\Lambda_b^0) = 172.44\pm0.39\pm…