Search results for "Instrumentation"
showing 10 items of 4914 documents
Timing performance of the silicon PET insert probe
2010
Simulation indicates that PET image could be improved by upgrading a conventional ring with a probe placed close to the imaged object. In this paper, timing issues related to a PET probe using high-resistivity silicon as a detector material are addressed. The final probe will consist of several (four to eight) 1-mm thick layers of silicon detectors, segmented into 1 x 1 mm(2) pads, each pad equivalent to an independent p + nn+ diode. A proper matching of events in silicon with events of the external ring can be achieved with a good timing resolution. To estimate the timing performance, measurements were performed on a simplified model probe, consisting of a single 1-mm thick detector with 2…
Search for Isovector Valence-Shell Excitations in 140 Nd and 142 Sm via Coulomb excitation reactions of radioactive ion beams
2018
Projectile Coulomb excitation experiments were performed at HIE-ISOLDE at CERN with the radioactive ion beams of 140Nd and 142Sm. Ions with an energy of 4:62 MeV/A were impinging on a 1.45 mg/cm2 thick 208Pb target. The γ-rays depopulating the Coulomb-excited states were recorded by the HPGe-array MINIBALL and scattered particles were detected by a double-sided silicon strip detector. Experimental intensities were used for the determination of electromagnetic transition matrix elements. A preliminary result of the B(M1; 2+3 → 2+1) of 140Nd and an upper limit for the case of 142Sm are revealing the main fragments of the proton-neutron mixed-symmetry 2+1;ms states.
The silver collection of San Gennaro treasure (Neaples): A multivariate statistic approach applied to X-ray fluorescence data
2021
Abstract In this work we report an X-ray fluorescence spectroscopy (XRF) study combined with a multivariate approach allowing to detect compositional differences and similarities among the alloys used in realization of silver collection of San Gennaro items collection. The San Gennaro treasure in Naples (Italy) represents, in fact, one of the most important silver collections in the world. The classification of the collection items is very complex, not only for the large number of objects, but also in consideration that between 1600 and 1700, in Naples, more than 350 laboratories were active, most of them specialized in specific art of work. As a consequence, a given collection object could…
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…
Identifying yeasts using surface enhanced Raman spectroscopy
2019
Made available in DSpace on 2019-10-06T15:40:09Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-07-05 Tekes Academy of Finland Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) The molecular fingerprints of yeasts Saccharomyces cerevisiae, Dekkera bruxellensis, and Wickerhamomyces anomalus (former name Pichia anomala) have been examined using surface-enhanced Raman spectroscopy (SERS) and helium ion microscopy (HIM). The SERS spectra obtained from cell cultures (lysate and non-treated cells) distinguish between these very closely related fungal species. Highly SERS active silver nano-particles suitable for detecting complex biomolecules were fabricated using a simple synt…
Protocol for development of various plants leaves extract in single-pot synthesis of metal nanoparticles
2012
This article is aimed to extend a simple protocol for preparation of various plant leaves extract and their application to green synthesis of the metallic nanoparticles. Five plant leaves extract showed mild reduction and stabilization ability for silver and gold nanoparticles (AgNPs and AuNPs) at room temperature. The particle size range varied from 25 to 42 nm and 21 to 47 nm for AgNPs and AuNPs, respectively. Plant leaves extract-mediated nanoparticles were characterized to confirm the shape, size, crystallinity, and content using different spectroscopic investigations. Differences in stability of nanoparticles at different pH were also measured by zeta potential.
Green and Integrated Wearable Electrochemical Sensor for Chloride Detection in Sweat
2022
Wearable sensors for sweat biomarkers can provide facile analyte capability and monitoring for several diseases. In this work, a green wearable sensor for sweat absorption and chloride sensing is presented. In order to produce a sustainable device, polylactic acid (PLA) was used for both the substrate and the sweat absorption pad fabrication. The sensor material for chloride detection consisted of silver-based reference, working, and counter electrodes obtained from upcycled compact discs. The PLA substrates were prepared by thermal bonding of PLA sheets obtained via a flat die extruder, prototyped in single functional layers via CO2 laser cutting, and bonded via hot-press. The effect of co…
Accuracy of an Affordable Smartphone-Based Teledermoscopy System for Color Measurements in Canine Skin
2020
Quality smartphone cameras and affordable dermatoscopes have enabled teledermoscopy to become a popular medical and veterinary tool for analyzing skin lesions such as melanoma and erythema. However, smartphones acquire images in an unknown RGB color space, which prevents a standardized colorimetric skin analysis. In this work, we supplemented a typical veterinary teledermoscopy system with a conventional color calibration procedure, and we studied two mid-priced smartphones in evaluating native and erythematous canine skin color. In a laboratory setting with the ColorChecker, the teledermoscopy system reached CIELAB-based color differences &Delta
Thermoanalytical studies on phases of D-mannitol
1993
Abstract D-mannitol exists in several polymorphic crystalline forms. The conditions of crystallization are not well-defined, and in some cases mixtures of the different forms are obtained. In the DSC study the different forms melted nearly at the same temperature (166±°C). The heat of fusion of the k form was lower than those of the other forms. With slow heating rate (2 ° C min ) the δ form changed to k between 140 and 165 °C. The crystallization of D-mannitol from the melt gave from one to seven peaks in the DSC between 95 and 126 °C depending on cooling rates and the amounts of sample.
New-stage discharge relationships for free and submerged sluice gates
2012
Abstract The flow movement through a sluice gate is investigated for both free and submerged flow conditions. For free flow condition, the current dimensionless formula, indicated acceptable accuracy; while for submerged flow condition it was modified especially for low submerged condition. In this regard, Buckingham theorem along with the Incomplete Self-Similarity concept was employed and a new stage–discharge relationship was developed accordingly. Also, to achieve a suitable formula for submerged flow condition being accurate in low submergence, the maximum tailwater depth allowing the free flow condition and head loss factor were identified as missing parameters in the functional dimen…