Search results for "amber"

Study of passive sampling of polycyclic aromatic hydrocarbons in gas phase using Amberlite XAD resins as filling materials of semipermeable membranes

2013

Abstract In this work, a study was performed to evaluate the use of Amberlite XAD resins (XAD-2, XAD-4 and XAD-16), for the first time, as filling materials for low-density polyethylene membranes, which will be inserted as passive samplers for polycyclic aromatic hydrocarbons (PAHs) in gas phase. The use of samplers deployed for 48 h evidenced a relative capability to retain the compounds under study. A detailed study was performed to evaluate the recovery of analytes from the sampler through microwave-assisted extraction by using acetonitrile. A clean-up step using alumina-C18 cartridges was necessary before determination of the PAHs by high performance liquid chromatography with fluoresce…

High-performance liquid chromatographic determination of sumatriptan after in vitro transdermal diffusion studies.

2004

A simple, accurate, precise and rapid HPLC method with UV detection has been validated in order to determine the in vitro transdermal absorption of sumatriptan succinate. The HPLC method is a modification of that described by Nozal et al. [M.J. Nozal, J.L. Bernal, L. Toribio, M.T. Martin, F.J. Diez, J. Pharm. Biomed. Anal. 30 (2002) 285-291]. Separation was carried out on a 250 mm Kromasil C18 column at room temperature. The detector response, at 282.7 nm, was found to be linear in a concentration range between 0.145 and 145 microM. The limit of detection (LOD) was 0.019 microM and the limit of quantification (LOQ) was 0.145 microM.

Insights into the compositional evolution of crustal magmatic systems from coupled petrological-geodynamical models

2020

Funding was provided by the VAMOS Research Center, University of Mainz (Germany) and by the ERC Consolidator Grant MAGMA (project #771143). The evolution of crustal magmatic systems is incompletely understood, as most studies are limited either by their temporal or spatial resolution. Exposed plutonic rocks represent the final stage of a long-term evolution punctuated by several magmatic events with different chemistry and generated under different mechanical conditions. Although the final state can be easily described, the nature of each magmatic pulse is more difficult to retrieve. This study presents a new method to investigate the compositional evolution of plutonic systems while consid…

Intrusion of granitic magma into the continental crust facilitated by magma pulsing and dike‐diapir interactions: Numerical simulations

2016

The never-ending story of geologically ancient DNA: was the model plantArabidopsisthe source of Miocene Dominican amber?

2013

Studies characterizing geologically ancient DNA in plants are rare, and all have reportedly obtained plastid DNA sequences from Miocene fossils in a remarkable state of preservation. Recently, a group made the extraordinary claim of having amplified a geologically ancient Miocene plastid DNA fragment (the rbcL gene) from Dominican amber nuggets, and the organismal source of this DNA was identified as Hymenaea protera (Fabaceae), the plant that produced the fossilized Dominican amber. Assuming that the Miocene sequence is error-free, reanalysis of the sequence indicates it is probably a technical artifact or an rbcL pseudogene. Furthermore, BLAST similarity searches and phylogenetic analyses…

209 New Fricke gel with high sensitivity and low diffusion for 3D-MRI dosimetry

2018

Purpose Fricke gel (FG) dosimeters are good candidates for 3D dose assessment in biological materials. Their effective atomic number and density are similar to those of soft tissue. In view of their chemical and morphological characteristics, FG serve as dosimeters and as phantoms at the same time. FG dosimeters are obtained by incorporating an acidic aqueous solution of ferrous ions Fe2+ into a gel matrix. In order to address the limitations of gels based on natural matrices, we have studied FG produced with a matrix of poly-vinyl alcohol (PVA) cross-linked with glutaraldehyde (GTA). Materials and methods The proposed gel contains 10% w/v of PVA and GTA of 1%w/v. A common formulation agaro…

L’analisi strutturale e le fasi

2019

The X13-X13.1 is one of the most considerable cubicles in the catacomb. It consists of a quadrangular funerary chamber preceded by a short dromos placed along the gallery X. The tombs are several and of different types: arcosolia for adults and children, lithic sarcophagi, pavimental graves ("formae"), and very interesting areas for ritual "refrigerium" The archaeological investigations and the structural date indicate that the duplex cubicle is the result of different phases of development, and that it was used by a numerous and wealthy family group for several generations, by the end of the fourth/beginning of the fifth to the seventh/eighth century, as it seems also indicated by the pott…

Premessa al volume: Il cubicolo X13 nella catacomba di Villagrazia di Carini. Indagini preliminari e interventi di consolidamento 2016-2019

2019

This book is dedicated to the archaeological excavations and to the consolidation of the structures of cubicle X13 in the catacomb of Villagrazia di Carini (PA). In 2015 the interesting funerary chamber was seriously damaged by the collapse of the ceiling; from 2016 to 2019, the realization of the recovery and restoration project by the Pontificia Commissione di Archeologia Sacra has been the occasion for the study of the rock-cut architectures and of the structural characteristics of the cubicle, one of the most remarkable private funerary spaces in the Early Christian and byzantine cemetery of Carini.

Los oficiales y subalternos de la Real Audiencia de Mallorca (1716-1808)

2019

The objective of this work is to know the organic structure of the officers and subordinates of the Royal Court of Majorca during the 18th century, which was the essence of the high judicial administration insular. Because of that, we approached through these relatively extensive professionals, with the description of their functions, who they were and how they obtained their charges. The article ends with an epilogue dedicated to the enlargement of the Royal Court with the creation of the second chamber during the reformist stage of Charles III to improve the high judicial administration insular.

Near-intrinsic energy resolution for 30-662 keV gamma rays in a high pressure xenon electroluminescent TPC

2013

We present the design, data and results from the NEXT prototype for Double Beta and Dark Matter (NEXT-DBDM) detector, a high-pressure gaseous natural xenon electroluminescent time projection chamber (TPC) that was built at the Lawrence Berkeley National Laboratory. It is a prototype of the planned NEXT-100 Xe-136 neutrino-less double beta decay (0 nu beta beta) experiment with the main objectives of demonstrating near-intrinsic energy resolution at energies up to 662 keV and of optimizing the NEXT-100 detector design and operating parameters. Energy resolutions of similar to 1% FWHM for 662 keV gamma rays were obtained at 10 and 15 atm and similar to 5% FWHM for 30 keV fluorescence xenon X-…