Search results for "pulse"
showing 10 items of 1508 documents
Direct Measurement of Mammographic X-Ray Spectra with a Digital CdTe Detection System
2012
In this work we present a detection system, based on a CdTe detector and an innovative digital pulse processing (DPP) system, for high-rate X-ray spectroscopy in mammography (1–30 keV). The DPP system performs a height and shape analysis of the detector pulses, sampled and digitized by a 14-bit, 100 MHz ADC. We show the results of the characterization of the detection system both at low and high photon counting rates by using monoenergetic X-ray sources and a nonclinical X-ray tube. The detection system exhibits excellent performance up to 830 kcps with an energy resolution of 4.5% FWHM at 22.1 keV. Direct measurements of clinical molybdenum X-ray spectra were carried out by using a pinhole…
Instrumentation for time-of-flight elastic recoil detection analysis
2016
Time-of-flight elastic recoil detection is an ion beam based method to analyze the elemental composition of thin film samples at different depths. In order to improve the mass resolution and to enable kinematic correction a position sensitive gas ionization chamber energy detector was constructed. This detector along with pre-existing timing detectors were connected to a modern fully digitizing data acquisition setup. This thesis describes the design of these instruments, including all aspects from the mechanical design of the gas ionization detector to the algorithm and software development of the digitizing acquisition setup. The performance of the system has been studied with measurements …
Clinical evaluation of automated capillary refill time estimation in dogs and cats
2019
In this study, we clinically evaluated a pulse oximeter-based device for automated capillary refill time (CRT) estimation in dogs and cats. CRT can reveal conditions like shock or anemia in dogs and cats. However, visual CRT estimation has low repeatability, and the available optical systems for automated estimation are not suitable for pets. We evaluated a custom-made portable CRT measuring device on various measurement sites of 12 dogs and 11 cats with parallel visual CRT estimation on the gum by treating veterinarian. The capillary refill was also recorded by a video camera for reference. The visual and video procedures were moderately correlated with the coefficient of 0.61; visual CRT …
Stieltjes Differential Inclusions with Periodic Boundary Conditions without Upper Semicontinuity
2021
We are studying first order differential inclusions with periodic boundary conditions where the Stieltjes derivative with respect to a left-continuous non-decreasing function replaces the classical derivative. The involved set-valued mapping is not assumed to have compact and convex values, nor to be upper semicontinuous concerning the second argument everywhere, as in other related works. A condition involving the contingent derivative relative to the non-decreasing function (recently introduced and applied to initial value problems by R.L. Pouso, I.M. Marquez Albes, and J. Rodriguez-Lopez) is imposed on the set where the upper semicontinuity and the assumption to have compact convex value…
Innovative extraction and separation technologies to improve the recovery of microalgae nutrients and bioactive compounds with potential beneficial e…
2023
Las microalgas son ricas en una gran variedad de compuestos bioactivos, que incluyen proteínas, polifenoles, polisacáridos, pigmentos, minerales, vitaminas, etc., que pueden utilizarse o separarse directamente para obtener componentes de mayor valor. La extracción y la separación son pasos clave en la obtención y posterior procesamiento de los productos relacionados con las microalgas, representando las tecnologías innovadoras de procesado una estrategia innovadora y eficiente para mejorar la calidad de estos productos. Actualmente, las microalgas y sus compuestos (nutrientes, compuestos bioactivos, etc.) se utilizan como alimento y también con finalidades desde el punto de vista de salud, …
Measurements of cardiac Pre-Ejection period using a combo PPG-ECG system
2015
The extraction of biomedical parameters, for early disease detection, is assuming today an ever increasing and fundamental importance. In particular, in the cardiologic field, the preejection period (PEP) is the duration of the iso-volumetric left ventricle contraction until the aortic valve opening. This parameter is a non-constant additive delay, which rapidly changes in response to stress, emotion and physical effort. To estimate this period, several wearable electronics devices have been developed in literature, and among them the Impedance Cardiogram equipment is the most used. However, these systems are often expensive and bulky. In this paper, we propose a cost-effective and easy to …
Optically pumped Cs magnetometers enabling a high-sensitivity search for the neutron electric dipole moment
2020
An array of 16 laser-pumped scalar Cs magnetometers was part of the neutron electric dipole moment (nEDM) experiment taking data at the Paul Scherrer Institute in 2015 and 2016. It was deployed to measure the gradients of the experiment's magnetic field and to monitor their temporal evolution. The originality of the array lies in its compact design, in which a single near-infrared diode laser drives all magnetometers that are located in a high-vacuum chamber, with a selection of the sensors mounted on a high-voltage electrode. We describe details of the Cs sensors' construction and modes of operation, emphasizing the accuracy and sensitivity of the magnetic-field readout. We present two app…
Non-linear interactions of femtosecond laser pulses with graphene : photo-oxidation, imaging and photodynamics
2017
This thesis presents a study focused on interactions of femtosecond laser pulses with graphene, a one atom thick carbon membrane. Graphene, which exhibits exceptional electronic and optoelectronic properties, could provide considerable advantage over current silicon-based electronics. Graphene alone, being semi-metal, is not sufficient for electronic applications, but requires modification. For this, a set of methods for modifying and measuring the properties of graphene was developed. With the perspective of making graphene a suitable component for electronics, optoelectronics or photonics, ultrashort laser pulses were used for drawing patterns on graphene. The procedure modifies graphene …
Radiation engineered nanogels as platforms for medical diagnostics and therapeutic nanodevices
2015
A scalable, single step, synthetic approach for the manufacture of biocompatible, functionalized microgels and nanogels has been developed. Pulsed EB irradiation of PVP aqueous solutions, at relatively low energies per pulse and doses within the sterilization dose range, has led to a variety of ‘as-born’ sterile, functional nanostructures that exhibit a combination of favourable properties which make them suitable as biomedical nanocarriers. Reactive functional groups have been generated by graft copolymerization of functional acrylic monomers. These groups can be used to attach fluorescent probes to the NPs, to bioconjugate ligands of specific cell receptors and to incorporate therapeutics…
Aortic pulse wave velocity in children with migraine: a case control study
2018
Background: Migraine has been associated with increased risk of cardiovascular (CV) accident like angina and myocardial infarction(1) . Vascular changes in migraineur traditionally may prevail in cranial blood district, but more likely it is a generalized vascular phenomenon.(2) Previous studies showed an increased aortic pulse wave velocity (aPWV), a direct measure of aortic stiffness and an independent predictor of stroke and CV disease, in young and middle-aged migraineurs(3) Here we hypothesized that, if associated with the pathogenetic bases of the disease, increased aPWV should be appreciable also in migraineurs children. Materials and Methods: : We studied 10 children with migraine w…