Search results for "Electron microscope"
showing 10 items of 784 documents
Microscopic findings and soil genetic “indicators” in support of pedoarchaeological studies
2015
Archaeologists use historical artefacts and archaeological records to reconstruct the communities that produced them and the environment in which they lived. Soil protects our buried or damaged heritage of archaeological and historic remains from depletion, damage, and any disturbance. Here are presented some preliminary results obtained in the framework of the FP7 Project "MEditerranean MOntainous LAndscapes: an historical approach to cultural Heritage based on traditional agrosystems (MEMOLA)" where ancient soils horizons are themselves archaeological records. In order to implement the MEMOLA archaeological study and to identify soil genetic "indicators", two integrated approaches were us…
Graphite-supported TiO2 for 4-nitrophenol degradation in a photoelectrocatalytic reactor
2009
WOS: 000274769500044
Poly lactic acid based foams prepared via thermally induced phase separation (TIPS): A method to tune the crystallinity
2012
Blends of Poly-L-Lactic Acid (PLLA) with two Poly-Lactic Acid (PLA) in different proportions (90/10 and 70/30) were utilized in order to produce biodegradable and biocompatible scaffolds for soft tissue engineering applications. The scaffolds were produced via thermally induced phase separation (TIPS) starting from ternary systems where dioxane was the solvent and water the non-solvent. Morphology was evaluated by Scanning Electron Microscopy (average pore size and interconnection). Moreover a DSC analysis was carried out on the as-obtained scaffold in order to obtain information about theirs thermal properties (enthalpy of melt and crystallization). The results showed that is possible to p…
Role of SH-Groups and S-S Bridges in the Main Subunit (1/12 Molecule) of Spirographis Spallanzanii Chlorocruorin
1986
In all species of annelids described, the extracellular hemoglobins show (by electron microscopy) the same quaternary structure constituted by twelve identical subunits. The fine structure of the 1/12 subunit is not well resolved and several models have been proposed for it (2).
Preliminary studies on nanocomposite based on high quality Silicon Carbide nanofibers
2012
Nanocomposites are nowadays the most promising new materials due to their unique properties (such as high mechanical strength, chemical and thermal resistance). The nanocomposite matrix is blended with a nanostructured filler. In this study, Silicon Carbide nanofibers (NFSiC) and their bundles were tested as a reinforcement of two epoxy resins: EPIKOTE 828 and EL 20. PAP-4 (33 phr) and P-900 (40 phr) were used as hardeners in the two cases, respectively. Several samples were prepared in the range between 0.1 and 5 % wt for both types of resins and fillers (NFSiC and NFSiC bundles). Mechanical and electrical properties were tested. The fillers were obtained using a new simple, fast, low-cost…
Porous silicon based photoluminescence immunosensor for rapid and highly-sensitive detection of Ochratoxin A.
2017
A rapid and low cost photoluminescence (PL) immunosensor for the determination of low concentrations of Ochratoxin A (OTA) has been developed. This immunosensor was based on porous silicon (PSi) and modified by antibodies against OTA (anti-OTA). PSi layer was fabricated by metal-assisted chemical etching (MACE) procedure. Main structural parameters (pore size, layer thickness, morphology and nanograins size) and composition of PSi were investigated by means of X-Ray diffraction (XRD), scanning electron microscopy (SEM) and Raman spectroscopy. PL-spectroscopy of PSi was performed at room temperature and showed a wide emission band centered at 680 ± 20nm. Protein A was covalently immobilized …
The adaptation of mechanically softened gutta-percha to the canal walls in the presence or absence of smear layer: a scanning electron microscopic st…
1995
Summary The objective of this study was to compare the adaptation of mechanically softened gutta-percha to the root canal wall in the presence and absence of smear layer. The root canals of 20 freshly extracted human maxillary incisors were cleaned and shaped. Prior to obturation, 10 root canals were irrigated with 20 ml of 50% citric acid followed by 20 ml of 5.25% sodium hypochlorite. All canals were obturated with mechanical compaction of gutta-percha and AH-26 sealer. After 72h, each tooth was fractured in half. Scanning electron microscopy demonstrated that the sealer had formed a continuous layer in contact with the canal walls, becoming progressively thinner towards the apex. The sea…
Nylon-Supported Plasmonic Assay Based on the Aggregation of Silver Nanoparticles: In Situ Determination of Hydrogen Sulfide-like Compounds in Breath …
2019
A procedure for supporting silver nanoparticles (AgNPs) on nylon is proposed. Besides, the membrane has been developed as a solid-phase colorimetric plasmonic sensor for volatile sulfide compounds (VSCs) like H2S, CH3SH, and (CH3)2S. AgNP behavior in the membrane has been studied by UV-vis diffuse reflectance spectrometry, Raman spectrometry, High-resolution transmission electron microscopy (HR-TEM), and Scanning electron microscopy (SEM). The sensor responded by changing its color from yellow in absence of VSCs to several orange/brown colors in the function of VSC concentration as occurs in solution; an increase in the hydrodynamic diameter, estimated by both asymmetrical flow field-flow f…
Synthesis and optical characterization of Er-doped bismuth titanate nanoparticles grown by sol-gel hydrothermal method
2017
Abstract The Er 3+ -doped bismuth titanate (Bi 4 Ti 3 O 12 , BIT) nanoparticles were synthesized by a combined sol–gel and hydrothermal method under a partial oxygen pressure of 30 bar. The composition and morphology were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and Raman scattering. They showed pure and homogeneous spherical BIT nanoparticles with a size below the 30 nm. The incorporation of Er ions showed a strong decrease in the lattice parameters, as well as averaged particle size. The photoluminescence up-conversion (excitation wavelength =1480 nm) showed an enhancement of the infrared emission (980 nm) as Er concentration increased, achieving a maxi…
Polymer-based materials modified with magnetite nanoparticles for enrichment of phospholipids
2018
[EN] A polymeric material modified with magnetic nanoparticles (MNPs) has been synthesized and evaluated as sorbent both for solid-phase extraction (SPE) and dispersive magnetic solid-phase extraction (MSPE) of phospholipids (PLs) in human milk samples. The synthesized sorbent was characterized by scanning electron microscopy and its iron content was also determined. Several experimental variables that affect the extraction performance (e.g. loading solvent, breakthrough volume and loading capacity) were investigated and a comparison between conventional SPE and MSPE modalities was done. The proposed method was satisfactorily applied to the analysis of PLs in human milk fat extracts in diff…