Search results for "Solid"
showing 10 items of 3575 documents
Hyper-reticulated calixarene polymers: a new example of entirely synthetic nanosponge materials
2018
New calixarene-based nanosponges (CaNSs), i.e., hyper-reticulated polymers constituted by calixarene monomer units joined by means of bis(1,2,3-trialzolyl)alkyl linkers, were synthesized, characterized and subjected to preliminary tests to assess their supramolecular absorption abilities towards a set of suitable organic guests, selected as pollutant models. The synthesis was accomplished by means of a CuAAC reaction between a tetrakis(propargyloxy)calix[4]arene and an alkyl diazide. The formation of the polymeric network was assessed by means of FTIR and 13C{1H} CP-MAS solid-state NMR techniques, whereas morphological characterization was provided by SEM microghaphy. The materials were pro…
Oligarchies and Client Systems in Rural communities in the South of the Crown of Aragón (13th to 15th Centuries)
2010
Studies of late medieval Hispanic client systems generally focus on networks of noble power, to the exclusion of the peasantry. This is doubtless in part because the peasantry has traditionally been considered to represent a largely homogenous social group defined in opposition to the feudal nobility, whose members defended common interests. However, the last few years have witnessed a profusion of studies into the rural, or peasant, elites of Western Europe during the late medieval and modern periods, and these highlight not only significant disparities between the economic status of those and that of the remainder of the peasantry, but also their employment of specific power-mechanisms in…
Analysis of Contact Traces of Cannabis by In-Tube Solid-Phase Microextraction Coupled to Nanoliquid Chromatography
2018
Because of its inherent qualities, in-tube solid-phase microextraction (IT-SPME) coupled on-line to nanoliquid chromatography (nanoLC) can be a very powerful tool to address the new challenges of analytical laboratories such as the analysis of traces of complex samples. This is the case of the detection of contact traces of drugs, especially cannabis. The main difficulties encountered in the analysis of traces of cannabis plants on surfaces are the low amount of sample available (typically <
Synthetic Inhibitors of Cell Adhesion: A Glycopeptide from E-Selectin Ligand 1 (ESL-1) with the Arabino Sialyl Lewisx Structure
2001
Particularly selective methods are required for the synthesis of arabino sialyl Lewisx glycopeptides owing to the acid-labile β-arabinopyranoside bond. It is important for the inhibition of cell adhesion that the arabino sialyl Lewisx glycopeptide 1, which contains the Gly 672 -Asp 681 sequence of the E-selectin Ligand 1 (ESL-1), binds ten times more strongly than sialyl Lewisx to E-selectin, although it is monovalent and does not contain L-fucose, which is considered essential.
Tecnica Co.Di per la produzione di cartilagine solida umana
2015
Abstract English Tissue or organ transplantation is severely limited by the problems of donor shortage and immune rejection from the patients. The cartilage defects are difficult to reconstruct. In head and neck surgery, as in septal reconstruction, auricular reconstruction for injury or malformation, in laryngotracheal reconstruction, surgeons harvest autologous cartilage from a donor site (of the patient) in order to reconstruct the defect. Today's current therapies to reconstruct cartilage defects involve the use of autologous cartilage grafts or biocompatible implants, but these seem inadequate to restore form and function, have many limits and are related with many complications. Due t…
Catacomba di Villagrazia di Carini. La galleria XII: indagini archeologiche e problemi della conservazione
2017
The archaeological research in the southeastern area of the Early Christian catacombs of Villagrazia di Carini has been ongoing since 2000 to the present, but in 2014 the structural problems occurred during the excavation of the cubicles X13 and X15 have showed that this sector of the cemetery was cut into a tuff stone bench less compact and durable than the rest of the catacomb. Similarly, the excavation in the corridor XII has provided new informations about the serious effects of the physico-chemical changes that occurred here, over the centuries, by the action of the environmental factors and the continued infiltrations of water from the above ground. The risk of a collapse that would m…
Solid-state compatibility of Ca:LaNbO4 with perovskite cathodes: Evidences from X-ray microspectroscopy
2022
The solid-state compatibility between calcium-doped lanthanum niobate and three perovskite cathode materials was investigated using two X-ray microbeam techniques, micro X-ray fluorescence and micro X-ray absorption spectroscopy. The cathode powders (lanthanum strontium ferrite, either cobalt or copper-doped, and lanthanum strontium cobaltite) in contact with the dense electrolyte pellet were annealed at 1150 degrees C for 12-144 h to simulate the effect of thermal stresses due to fabrication and long-term operation. As a result, several interdiffusion phenomena were then observed on the bilayer cross-sections: in particular, the chemical state and coordination environment of calcium, iron,…
Definition of the chalcogen bond (IUPAC Recommendations 2019)
2019
Abstract This recommendation proposes a definition for the term “chalcogen bond”; it is recommended the term is used to designate the specific subset of inter- and intramolecular interactions formed by chalcogen atoms wherein the Group 16 element is the electrophilic site.
Correlation of wood-based components and dewatering properties of waste activated sludge from pulp and paper industry.
2010
Large amounts of wet sludge are produced annually in municipal and industrial wastewater treatment. Already in pulp and paper industry, more than ten million tons of primary sludge, waste activated sludge, and de-inking sludge is generated. Waste activated sludge contains large quantities of bound water, which is difficult to dewater. Low water content would be a matter of high calorific value in incineration but it also has effects on the volume and the quality of the matter to be handled in sludge disposal. In this research waste activated sludges from different pulp and paper mills were chemically characterised and dewatered. Correlations of chemical composition and dewatering properties…
Influence of Sodium on the Structure and HDS Activity of Co–Mo Catalysts Supported ON Silica and Aluminosilicate
2000
Abstract Structural changes and catalytic performances of hydrodesulfurization (HDS) Co–Mo catalysts, supported on amorphous aluminosilicate (ASA) and amorphous SiO 2 were investigated as a function of the amount of sodium ions added to the supports. The catalysts were prepared according to the incipient wet impregnation method using (NH 4 ) 6 Mo 7 O 24 as molybdenum precursor and CoCl 2 or Co(NO 3 ) 2 as cobalt precursor. Structural and morphological characterisations of the materials were performed with X-ray diffraction (XRD) and surface area measurements (BET). In the case of the ASA-supported catalysts, increasing the amount of sodium resulted in a gradual decrease of the catalyst surf…