Theory of the thermally-stimulated-current transport peak. Application to a dispersive transport case

13 págs.; 6 figs.Thermally-stimulated-current (TSC) technique consists of heating a dielectric, with excess carriers having been introduced. The current flowing under the effect of applied electric field is then recorded as a function of increasing temperature. The current maximum obtained is called a >transport TSC peak> if it appears due to thermally activated transport of carriers initially generated at one electrode and collected at the other. In this paper the transport of carriers, controlled by multiple trapping, is studied when the temperature of the system is increased linearly with time. The general equations for current density in a TSC experiment are obtained and are applied for the cases of a single trap and an exponential trap distribution. The condition for a TSC current maximum, initial rise of current, and partial heating technique are studied in detail. The properties of the transport TSC peak differ considerably from those of the classical TSC; the position of the current maximum and activation energy found from partial heating at the maximum depend on the field applied and on sample thickness. It is also found that there exists a correlation between the transport TSC peak and time-of-flight signal, and the transport parameters found from TSC (activation energy of mobility, parameter of dispersion ±, etc.) correspond to those of the time of flight measurements. The critical trap criterion and concepts of lifetime and transit time are extended to the general case of nonisothermal transport. © 1981 The American Physical Society.Peer Reviewe

La autoridad del romano Pontífice según Melchor Cano

El trabajo que ahora se muestra a los ojos del lector consiste en un resumen de la tesis doctoral que elaboré y presenté —hace algunos años— en la Facultad de Teología de la Universidad de Navarra. Su contenido pretende contribuir al esfuerzo que, de un tiempo a esta parte, viene realizando el Departamento de Historia de la Teología de la mencionada Facultad, para poner de relieve el importante papel que desarrolla la escuela Teológica Salmantina del siglo XVI en la historia de la Teología. Brilla en ella con luz propia la figura teológica de Melchor Cano, autor del importante tratado De Locis Theologicis —objeto de numerosas ediciones— y de otras obras que, en buena parte, permanecen sorprendentemente aún inéditas en manuscritos. La gran talla del teólogo salmantino y el atractivo del tema que estudia en el libro sexto de dicho tratado, la autoridad del Romano Pontífice, fueron los motivos que me indujeron a abordar esta tarea. Y he de reconocer que ha sido apasionante, tanto el meterse de lleno en la riqueza de su pensamiento, como el manejar un escrito de gran calidad literaria por el empleo del latín humanístico que Cano hace en este tratado

Profiling the propagation of error from PPG to HRV features in a wearable physiological-monitoring device

This is the final version. Available on open access from IET via the DOI in this recordWearable physiological monitors are becoming increasingly commonplace in the consumer domain, but in literature there exists no substantive studies of their performance when measuring the physiology of ambulatory patients. In this Letter, the authors investigate the reliability of the heart-rate (HR) sensor in an exemplar 'wearable' wrist-worn monitoring system (the Microsoft Band 2); their experiments quantify the propagation of error from (i) the photoplethysmogram (PPG) acquired by pulse oximetry, to (ii) estimation of HR, and (iii) subsequent calculation of HR variability (HRV) features. Their experiments confirm that motion artefacts account for the majority of this error, and show that the unreliable portions of HR data can be removed, using the accelerometer sensor from the wearable device. The experiments further show that acquired signals contain noise with substantial energy in the high-frequency band, and that this contributes to subsequent variability in standard HRV features often used in clinical practice. The authors finally show that the conventional use of long-duration windows of data is not needed to perform accurate estimation of time-domain HRV features

Relationship between sensory analysis and Near Infrared Spectroscopy in common beans

Postprint (published version

ComeHere: Exploiting ethereum for secure sharing of health-care data

The problem of protecting sensitive data like medical records, and enabling the access only to authorized entities is currently a challenge. Current solutions often require trusting some centralized entity which is in charge of managing the data. The disruptive technology of blockchains may offer the possibility to change the current scenario and give to the users the control on their personal data. In this paper we propose ComeHere, a system able to store medical records and to exploit the blockchain technology to control and track the access right transfer on the blockchain. The paper shows the current status of the project, presents a preliminary proof-of-concept implementation and discusses the future improvements of the system, and some critical issues which are still open.Engineering and Physical Sciences Research Council (EPSRC)BioBeats Group Lt

I feel it in my finger: Measurement device affects cardiac interoceptive accuracy

This is the final version. Available on open access from Elsevier via the DOI in this recordIn recent years, measures of cardiac interoceptive accuracy have been heavily scrutinised. The focus has been on potentially confounding physiological and psychological factors; little research has examined whether the device used to record objective heartbeats may influence cardiac interoceptive accuracy. The present studies assessed whether the device employed influences heartbeat counting (HCT) accuracy and the location from which heartbeats are perceived. In Study One, participants completed the HCT using a hard-clip finger pulse oximeter, electrocardiogram (ECG) and a smartphone application. In Study Two, an ECG, hard-clip and soft-clip oximeter were compared. Moderate-strong correlations were observed across devices, however, mean HCT accuracy and confidence varied as a function of device. Increased sensation in the finger when using a hard-clip pulse oximeter was related to increased accuracy relative to ECG. Results suggest that the device employed can influence HCT performance, and argue against comparing, or combining, scores obtained using different devices.Economic and Social Research Council (ESRC)Baily Thomas TrustFonds de Recherche Québec – Sant