Search results for "InP"

Quantum collision models: Open system dynamics from repeated interactions

2022

We present an extensive introduction to quantum collision models (CMs), also known as repeated interactions schemes: a class of microscopic system-bath models for investigating open quantum systems dynamics whose use is currently spreading in a number of research areas. Through dedicated sections and a pedagogical approach, we discuss the CMs definition and general properties, their use for the derivation of master equations, their connection with quantum trajectories, their application in non-equilibrium quantum thermodynamics, their non-Markovian generalizations, their emergence from conventional system-bath microscopic models and link to the input-output formalism. The state of the art o…

Collision models in quantum optics

2017

AbstractQuantum collision models (CMs) provide advantageous case studies for investigating major issues in open quantum systems theory, and especially quantum non-Markovianity. After reviewing their general definition and distinctive features, we illustrate the emergence of a CM in a familiar quantum optics scenario. This task is carried out by highlighting the close connection between the well-known input-output formalism and CMs. Within this quantum optics framework, usual assumptions in the CMs’ literature - such as considering a bath of noninteracting yet initially correlated ancillas - have a clear physical origin.

Pervasive body sensing: Implanted RFID tags for vascular monitoring

2010

Beside the common logistic usages of the Radio Frequency Identification (RFID) technology, one of the most innovative and promising applications is the possibility to process the backscattering signals to detect additional information about the target, such as its state and its evolution, without any specific embedded sensor or local power supply. The rationale of this idea lies in the clear dependence of the tag's input impedance and reflectivity on the physical and geometrical features of a real target. When the object where the tag is attached on undergoes some changes along with the time, the tag's electrical features also change and these variations can be remotely detected by the read…

Factors associated with influenza vaccination of hospitalized elderly patients in Spain

2016

Vaccination of the elderly is an important factor in limiting the impact of influenza in the com- munity. The aim of this study was to investigate the factors associated with influenza vacci- nation coverage in hospitalized patients aged 65 years hospitalized due to causes unrelated to influenza in Spain. We carried out a cross-sectional study. Bivariate analysis was performed comparing vaccinated and unvaccinated patients, taking in to account sociodemographic variables and medical risk conditions. Multivariate analysis was per- formed using multilevel regression models. We included 1038 patients: 602 (58%) had received the influenza vaccine in the 2013 - 14 season. Three or more general p…

Nonlinear Optical Characterization of InP@ZnS Core-Shell Colloidal Quantum Dots Using 532 nm, 10 ns Pulses

2021

InP@ZnS core-shell colloidal quantum dots (CQDs) were synthesized and characterized using the z-scan technique. The nonlinear refraction and nonlinear absorption coefficients (γ = −2 × 10−12 cm2 W−1, β = 4 × 10−8 cm W−1) of these CQDs were determined using 10 ns, 532 nm pulses. The saturable absorption (β = −1.4 × 10−9 cm W−1, Isat = 3.7 × 108 W cm−2) in the 3.5 nm CQDs dominated at small intensities of the probe pulses (I ≤ 7 × 107 W cm−2) followed by reverse saturable absorption at higher laser intensities. We report the optical limiting studies using these CQDs showing the suppression of propagated nanosecond radiation in the intensity range of 8 × 107–2 × 109 W cm−2. The role of nonline…

Zirconium–hafnium and rare earth element signatures discriminating the effect of atmospheric fallout from hydrothermal input in volcanic lake water

2016

The geochemical behaviour of Rare Earth Elements, Zr and Hf was investigated in the thermal waters of Nevado del Ruiz volcano system. A wide range of pH, between 1.0 and 8.8, characterizes these fluids. The acidicwaters are sulphate dominatedwith different Cl/SO4 ratios. The important role of the pH and the ionic complexes for the distribution of REE, Zr a nd Hf in the aqueous phase was evidenced. The pH rules the precipitation of authigenic Fe and Al oxyhydroxides producing changes in REE, Zr, Hf amounts and strong anomalies of Cerium. The precipitation of alunite and jarosite removes LREE from the solution, changing the REE distribution in acidic waters. Y-Ho and Zr-Hf (twin pairs) have a…

Nanoscale etching of III-V semiconductors in acidic hydrogen peroxide solution: GaAs and InP, a striking contrast in surface chemistry

2019

In this study of nanoscale etching for state-of-the-art device technology, the importance of surface chemistry, in particular the nature of the surface oxide, is demonstrated for two III-V materials. Striking differences in etching kinetics were found for GaAs and InP in sulphuric and hydrochloric acidic solutions containing hydrogen peroxide. Under similar conditions, etching of GaAs was much faster, while the dependence of the etch rate on pH, and on H2O2 and acid concentrations also differed markedly for the two semiconductors. Surface analysis techniques provided information on the product layer present after etching: strongly non-stoichiometric porous (hydr)oxides on GaAs and a thin st…

Artificial Ground Motions and Nonlinear Response of RC Structures

2020

The selection of seismic inputs for nonlinear dynamic analysis is widely debated, mainly focusing on the advantages and disadvantages provided by the choice of natural, simulated, or artificial records. This work proves the differences in the structural behavior of RC buildings when using accelerograms with different levels of stationarity. Initially, nonlinear response under three sets of accelerograms equivalent in terms of pseudo acceleration spectrum is evaluated and compared. Then, the results of incremental dynamic analyses are compared by the statistical point of view considering different levels of irregularity for the reference structure.

REGIONAL DEVELOPMENT PLANNING STRATEGY: DESIGNING A DYNAMIC INTEGRATED MODEL FRAMEWORK FOR THE SICILY REGION

Over the past decades, Sicily Region has experienced periods of stagnation, recession and sporadic slow economic growth, lagging always behind the national performance. As a consequence of globalization and deregulation, the relevance of regions in national economies has changed considerably in the last decades. Recognizing the importance of the Sicily region in the development process at national level, the purpose of the research is to further explore the dynamics governing the behaviour of the regional economic system. The goal is achieved by the use of simulation modelling: a model framework for the regional economic system is designed by integrating the System Dynamics (SD) methodology…

Pattern of in-hospital changes in drug use in the older people from 2010 to 2016

2017

Purpose: To assess the pattern of in-hospital changes in drug use in older patients from 2010 to 2016. Methods: People aged 65 years or more acutely hospitalized in those internal medicine and geriatric wards that did continuously participate to the REgistro POliterapie Società Italiana di Medicina Interna register from 2010 to 2016 were selected. Drugs use were categorized as 0 to 1 drug (very low drug use), 2 to 4 drugs (low drug use), 5 to 9 drugs (polypharmacy), and 10 or more drugs (excessive polypharmacy). To assess whether or not prevalence of patients in relation to drug use distribution changed overtime, adjusted prevalence ratios (PRs) was estimated with log-binomial regression mo…