TEOS AND TIME: THE INLFUENCE OF APPLICATION SCHEDULES ON THE EFFECTIVENESS OF ETHYL SILICATE BASED CONSOLIDANTS

An investigation was carried out at KIK-IRPA on the application modalities of ethyl silicate based products aiming at understanding the influence of time between successive applications on the pore structure and on the final strengthening effect of stones. Samples of Maastrichter lime stone were treated with different formulations and dilutions. The number of treatments varied from one to three with an interval between successive treatments ranging from one day to three weeks. Mercury porosity measurements, polymerized product content and hardness profiles obtained by a drilling resistance measurement system (DRMS) were used to evaluate the consolidating properties. Noticeable differences in pore blocking and in overall hardness were observed in samples that were treated at one day intervals and those treated at three week intervals. The strengthening effect alsoseems to vary with the type of formulation

A middle Triassic back-stepping carbonate platform in the Dolomites (Italy): sequence stratigraphy and biochronostratigraphy

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Advances in the ERETIC Method for the Quantification of In-Vivo 1H and 31P Spectra

Absolute quantification is a desirable tool to determine metabolite changes. Calibration with ERETIC (Electric REference To access In vivo Concentrations) has proven to be an accurate method for the assessment of absolute concentration in spectra. In this work, we present a new implementation of ERETIC on a clinical scanner using a low-power transmit channel, thus permitting simultaneous use of proton decoupling and nuclear Overhauser enhancement with the high-power RF channel of the system during the acquisition of 31P or 13C spectra. Stability of the ERETIC signal is demonstrated. Also, ERETIC was for the first time applied to in-vivo 1H measurements

An RF-Over-Fiber System for Reliable Signal Injection in ERETIC Spectroscopy

We present an optical link used to transmit a reference signal in spectroscopy (ERETIC method). The optical link has the peculiarity to be safety and inexpensive since it is made of only a low noise preamplifier, a high speed LED, polymer optical fiber and a photodiode. The reference signal is generated outside the MR room, it travels along the optical fiber, enters the scanner room’s Faraday shield through a waveguide and is injected into a birdcage coil by inductive coupling. The link is shown to be reliable and stable over time consenting so, good fidelity quantitative measurements of metabolite concentrations

In-vivo measurement of absolute metabolite concentrations using the ERETIC method

Absolute quantification is an indispensable tool to precisely determine metabolite changes. Calibration with ERETIC (Electric REference To access In vivo Concentrations), whereby a synthetic reference signal is injected during the acquisition of spectra, was used to determine quantitative in-vivo metabolite concentrations in volunteers. Brain 1H MRS spectra were acquired and cross-validated against the internal water reference method. The results of both calibration techniques were in good agreement in healthy tissue. In addition, the ERETIC setup was perfected by substitution of the electrical by an optical signal transmission line to eliminate fluctuations of the ERETIC signal intensity due to parasitic coupling

New constrain for the Ladinian-Carnian boundary in the Southern Alps: suggestions for a global correlations

The Ladinian-Carnian boundary interval is represented in many localities of the Southern Alps (Northern Italy) by continuous and expanded basinal successions. The boundary interval is best exposed in Badia and Cordevole valleys (Dolomites); there, the Stuores Wiesen section has been indicated as a possible GSSP site for the Carnian stage (Broglio Loriga et al., 1999). The purpose of this study is to critically review the potential of Stuores Wiesen as a GSSP candidate, in the light of new data and interpretations that have arisen in the last eight years (e.g., Manco et al., 2004; Mietto et al., 2004)