Search results for "Instrumentation"

Dissociation energies of silver clusters Agn+, n=14, 15, 16, 18

2003

A recently developed method to determine dissociation energies has been applied to positively charged silver clusters of size n=14, 15, 16 and 18. The method uses a combination of sequential and single step decays. It requires an uncalibrated thermometer which here is provided by the evaporation rate constants of the product clusters. For this purpose, earlier measurements [J. Chem. Phys. 57 (1998) 2786] are reanalyzed with the new method. The resulting dissociation energies are compared with the liquid drop values and the measured decay rate constants with expected rate constants from detailed balance theory.

TASISpec—A highly efficient multi-coincidence spectrometer for nuclear structure investigations of the heaviest nuclei

2010

TASISpec (TASCA in Small Image mode Spectroscopy) combines composite Ge- and Si-detectors for a new detector setup aimed towards multi-coincidence gamma -ray, X-ray, conversion electron, fission fragment, and a-particle spectroscopy of the heaviest nuclei. It exploits the TASCA separator's unique small image focal mode, i.e. the fact that evaporation residues produced in fusion-evaporation reactions can be focused into an area of less than 3 cm in diameter. This provides the possibility to pack detectors in very close geometry, resulting in an unprecedented detection efficiency of radioactive decays in prompt and delayed coincidence with implanted nuclei. Crown Copyright (C) 2010 Publis…

Dichroic atomic vapor laser lock with multi-gigahertz stabilization range

2016

A dichroic atomic vapor laser lock (DAVLL) system exploiting buffer-gas-filled millimeter-scale vapor cells is presented. This system offers similar stability as achievable with conventional DAVLL system using bulk vapor cells, but has several important advantages. In addition to its compactness, it may provide continuous stabilization in a multi-gigahertz range around the optical transition. This range may be controlled either by changing the temperature of the vapor or by application of a buffer gas under an appropriate pressure. In particular, we experimentally demonstrate the ability of the system to lock the laser frequency between two hyperfine components of the $^{85}$Rb ground state…

Investigation of modern oil paints through a physico-chemical integrated approach. Emblematic cases from Valencia, Spain

2020

Abstract The study and the characterisation of modern and contemporary oil paintings is still a challenging issue, in particular considering the significant changes in paint production across the 19th and 20th centuries. This paper presents the results of the first physico-chemical integrated study of the artistic materials used in six paintings from the School of Art and Higher Design of Valencia (Escola d'Art i Superior de Disseny, EASD-Valencia), artworks created between 1871 and 1943 by four famous Valencian artists: Salustiano Asenso Arozarena, Salvador Abril I Blasco, Enrique Navas Escuriet and Jose Bellver Delmas. A wide range of inorganic and organic compounds was identified through…

Multidisciplinary approach to characterize archaeological materials and status of conservation of the Roman thermae of reggio Calabria Site (Calabria…

2020

This multidisciplinary research focuses on diagnostic investigations to characterize the archaeological materials, as well as the alteration and degradation forms detected at the Roman Thermae of Reggio Calabria (Calabria, South Italy) site. The thermal complex, (dating I–II century B.C.), was built around three main rooms such as the caldarium (hot bath), the tepidarium (warm bath) and the frigidarium (cold bath), all connected to a central room through several entrances. The central hall still preserves a suggestive mosaic floor dating between the II and III century A.D., characterized by geometric motifs and black and white tesserae. Fragments of various archaeological stone materials, s…

The Algorithm of a Game-Based System in the Relation between an Operator and a Technical Object in Management of E-Commerce Logistics Processes with …

2021

Machine learning (ML) is applied in various logistic processes utilizing innovative techniques (e.g., the use of drones for automated delivery in e-commerce). Early challenges showed the insufficient drones’ steering capacity and cognitive gap related to the lack of theoretical foundation for controlling algorithms. The aim of this paper is to present a game-based algorithm of controlling behaviours in the relation between an operator (OP) and a technical object (TO), based on the assumption that the game is logistics-oriented and the algorithm is to support ML applied in e-commerce optimization management. Algebraic methods, including matrices, Lagrange functions, systems of differential e…

Multispectral, Fluorescent and Photoplethysmographic Imaging for Remote Skin Assessment

2017

Optical tissue imaging has several advantages over the routine clinical imaging methods, including non-invasiveness (does not change the structure of tissues), remote operation (avoids infection) and ability to quantify the tissue condition by means of specific image parameters. Dermatologists and other skin experts need compact (preferably pocket-size), self-sustained and easy-to-use imaging devices. The operational principles and designs of ten portable in-vivo skin imaging prototypes developed at the Biophotonics Laboratory of Institute of Atomic Physics and Spectroscopy, University of Latvia during the recent five years are presented in this paper. Four groups of imaging devices are con…

2021

(1) Background: The purpose of this study was to evaluate the day-to-day variability and year-to-year reproducibility of an accelerometer-based algorithm for sit-to-stand (STS) transitions in a free-living environment among community-dwelling older adults. (2) Methods: Free-living thigh-worn accelerometry was recorded for three to seven days in 86 (women n = 55) community-dwelling older adults, on two occasions separated by one year, to evaluate the long-term consistency of free-living behavior. (3) Results: Year-to-year intraclass correlation coefficients (ICC) for the number of STS transitions were 0.79 (95% confidence interval, 0.70–0.86, p < 0.001), for mean angular velocity—0.81 (95…

Coulomb blockade thermometer: Tests and instrumentation

1998

Coulomb blockade thermometry (CBT) provides a simple method for absolute thermometry in every day laboratory use at cryogenic temperatures. CBT has been found insensitive to even high magnetic fields. We review the principles and the operation of CBT and the fabrication of the sensors, and present new data on radiation hardness and stability of the sensors. We describe the instrumentation of CBT in detail. We have developed two signal conditioning units for CBT measurements. One is a modified alternating current resistance bridge, a versatile laboratory instrument operating with a PC computer, and the other one is a simple stand-alone instrument for direct temperature reading. Test results …

A study of the thermal decomposition of amorphous bimetallic CDTA complexes

1989

Abstract The study of the thermal behaviour of a family of bimetallic amorphous MM'(CDTA)· n H 2 O complexes has been performed using TG and DTA. The complexes decompose in three steps: dehydration, ligand pyrolysis and inorganic residue evoluation.