196,457 research outputs found
Durando: ¿novador o renovador?
No full textM. A. Michel sostiene que Durando no se opone propiamente a Santo Tomás en la explicación de la identidad del cuerpo mortal y del resucitado. A lo más, Durando pone el acento más fuerte en admitir que en algunos casos, Dios tendrá que suplir totalmente el defecto de materia. En este sentido, se pretende demostrar si Durando está definitivamente opuesto o no a Santo Tomás en este último asunto
Ultra-Low Power Discrete-Time Readout for CMOS Radiation Sensors
No full textThis paper presents the design of a discrete time front-end electronics for CMOS radiation sensors with a power consumption of 11 nW/pixel. The architecture is inspired by the DRAM sensing techniques and it is suitable for small pixel readout. The design is implemented in a 110 nm CMOS technology and consists of a discrete time binary front-end composed by a source follower input stage, an inverting discriminator with offset compensation and a digital buffer.
The work is carried out in the framework of the ARCADIA collaboration, which aims to develop fully-depleted monolithic CMOS sensor with low noise, fast charge collection and low power readout, compatible with standard fabrication processes.
The first prototype of the discrete-time front-end is implemented in a 2x2 mm matrix composed by 4 sectors of 6 columns of 24 50 m pitch pixels.
Simulations show a power density below 1 mW/cm for a frame rate of 10 KHz. The circuit performance have been simulated with systematic and random process variation Monte Carlo simulations
Multi-body numerical simulation of the distribution drive system in an internal combustion engine
No full textV clanku je predstaven vyvoj metodiky pro vypocet dynamiky mechanismu motoroveho rozvodu. Vyuzity jsou techniky simulaci
vicehmotovych soustav; pouzit byl software AVL/Tycon. Objektem vyzkumu byl vliv pracovnfho rezimu motoru na dynamiku
retezoveho rozvodu s jednim (SOHC) a dvema (DOHC) vackovymi hndeli v hiave motoru. Analyza obsahuje dukaz, ze retezovy
prevod zavadi (di'ky kinematickemu zaberu) vysokou frekvenci s velmi malou amplitudou v porovnani s harmonickymi frekvencemi
od externi sil. Metodika umozhuje urdt zati'zeni vstupni'ho a pomocnych hridelu, zatizeni na strukturu motoru indukovane pres
operne a napmaci kladky. Diky tomu se predstavena metodika stava vyznamnym nastrojem pro predvidani zatizeni; a navic
umoznuje i detailni vypocet trecich ztrat v jednotlivych castech retezoveho rozvodu.The purpose of the present work is the development of a methodology to study the dynamic behavior of the drive distribution
system, based on the techniques of multi-body numerical simulation using AVL/Tycon code. Chain drive systems with both
single cam shaft (SOHC) and double cam shaft (DOHC) are studied to investigate how the dynamic behavior varies with the
engine working rate. The analysis includes evidence that the chain transmissions introduce a high frequency due to kinematic
engagement (polygon effect), with a very low amplitude with regard to the harmonics of external forces. The methodology permits
the evaluation of the loads on the drive shaft, on the distribution shafts, and loads acting on the engine structure through the
supports and constraint points. It represents an important forecasting tool; moreover, it also permits the detailed calculation of
the friction lost in the interaction between the chain components
Effetti osservati sulla salute umana.
No full textSono stati riportati in letteratura una serie di case report e di casi aneddotici che descrivono effetti avversi sulla salute umana attribuiti al gruppo delle palitossine (PLTX) e/o ad alcuni analoghi strutturali, a seguito di esposizioni attraverso varie vie. I segni e sintomi registrati indicano l’insorgenza di effetti locali al sito di contatto, generalmente riconducibili a reazioni di carattere irritativo e infiammatorio, ai quali in alcuni casi si aggiunge una sintomatologia sistemica. Gli scenari espositivi più rilevanti associati ad attività ricreative prevedono un contatto diretto durante la balneazione, attraverso la cute e le mucose, con le tossine disciolte in acqua e/o con le specie algali produttrici. Alcune segnalazioni di effetti avversi su addetti e hobbisti coinvolti nella pulizia di acquari e il ritrovamento di livelli non trascurabili di PLTX in coralli da acquario indicano che anche tali categorie sono da considerarsi a rischio. L’altro scenario da considerare prevede l’inalazione di aerosol di acqua marina durante fioriture di Ostreopsis spp., prodotto a seguito di movimenti forzati dell’acqua marina per specifiche attività (es. nel caso di attività sportive in acque contaminate) e/o in concomitanza di condizioni meteoclimatiche favorevoli (es. vento forte e mareggiate). Quest’ultima via di esposizione coinvolge quindi non solo i ‘bagnanti’ propriamente detti ma anche soggetti che sostano in prossimità della spiaggia e/o sul lungomare.
A queste vie di esposizione si aggiunge quella orale, associata sia all’ingestione involontaria di acqua durante attività ricreative (es. durante il nuoto) che al consumo di prodotti ittici contaminati. Le PLTX possono, infatti, accumularsi nei molluschi marini eduli, nei crostacei e nei pesci: sindromi di avvelenamento talvolta letali, note col nome di clupeotoxismo, sono state descritte in regioni tropicali anche se spesso l’identificazione della tossina è risultata incompleta o mancante e, in questi casi, l’attribuzione dell’avvelenamento all’ingestione di PLTX (relazione causa-effetto) è stata fatta sulla base del quadro clinico, dell’anamnesi e dell’ingestione di alimenti di origine marina. Nonostante alcuni prodotti ittici, quali sardine, acciughe e granchi, parte integrante della dieta mediterranea, possano accumulare PLTX in alte concentrazioni e rappresentino quindi l’anello della catena alimentare attraverso cui l’uomo è potenzialmente esposto, finora non sono stati riportati nel bacino del Mediterraneo effetti associati all’ingestione di prodotti ittici contaminati dalle tossine prodotte da Ostreopsis cf. ovata
The diagnosis of latent tuberculosis infection (Ltbi): Currently available tests, future developments, and perspectives to eliminate tuberculosis (tb)
No full textIntroduction: Despite great efforts, tuberculosis (TB) is still a major public health threat worldwide. For decades, TB control programs have focused almost exclusively on infectious TB active cases. However, it is evident that this strategy alone cannot achieve TB elimination. To achieve this objective a comprehensive strategy directed toward integrated latent tuberculosis infection (LTBI) management is needed. Recently it has been recognized that LTBI is not a stable condition but rather a spectrum of infections (e.g., intermittent, transient or progressive) which may lead to incipient, then subclinical, and finally active TB disease. Aim: Provide an overview of current available LTBI diagnostic test including updates, future developments and perspectives. Results: There is currently no test for the direct identification of live MT infection in humans. The diagnosis of LTBI is indirect and relies on the detection of an immune response against MT antigens, assuming that the immune response has developed after a contact with the biological agent. Tuberculin skin test (TST) and interferon gamma release assays (IGRAs) are the main diagnostic tools for LTBI, however, both present strengths and limitations. The most ancient diagnostic test (TST) can be associated with several technical errors, has limited positive predictive value, is being influenced by BCG vaccination and several conditions can reduce the skin reactivity. Notwithstanding these limitations, prompt identification of TST conversion, should orientate indications for preventive therapy of LTBI. IGRAs have superior specificity, are not af-fected by M. bovis, BCG vaccination and other environmental mycobacteria. However, they present some logistical and organisational constraints and are more expensive. Currently, the WHO guidelines recommend that either a TST or an IGRA can be used to detect LTBI in high-income and upper middle-income countries with estimated TB incidences less than 100 per 100,000 population. Two skin tests (C-TB and Diaskintest), using only two specific M. tuberculosis antigens (ESAT-6 and CFP-10) instead of the tuberculin solution, have recently been developed but, to date, none of these tests is available on the European market. Conclusion: Early identification and treatment of individuals with LTBI is an important priority for TB control in specific groups at risk within the population: this is of crucial meaning in recently infected cases both at the community level and in some occupational settings. Currently there is no gold standard test for LTBI: an improved understanding of the available tests is needed to develop better tools for diagnosing LTBI and predicting progression to clinical active disease
Efecto de la separación materna temprana sobre la activación de estructuras nerviosas que regulan la respuesta de estrés crónico en ratas tratadas con tianeptina
No full textFil: Trujillo, Verónica. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Laboratorio de Fisiología Animal; Argentina.Fil: Durando, Patricia E. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Laboratorio de Fisiología Animal; Argentina.Fil: Suárez, Marta M. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Laboratorio de Fisiología Animal; Argentina.El estrés crónico puede producir la desregulación del eje hipotálamo‐hipofiso‐adrenal (HHA) y del sistema de recompensa que
controla la conducta hedónica. Además, eventos de la vida temprana pueden generar alteraciones persistentes en circuitos
neuronales que controlan la respuesta de estrés y la conducta emocional en el adulto.Fil: Trujillo, Verónica. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Laboratorio de Fisiología Animal; Argentina.Fil: Durando, Patricia E. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Laboratorio de Fisiología Animal; Argentina.Fil: Suárez, Marta M. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Laboratorio de Fisiología Animal; Argentina.Bioquímica y Biología Molecular (ídem 3.1.10
FINITE ELEMENT SIMULATION OF MULTILAYER METAL CYLINDER HEAD GASKETS
No full textABAQUS gasket elements are an efficient and flexible tool to study gasket applications. Nevertheless the usage of the ABAQUS gasket elements is not limited to gasket analysis,
but it provides an effective improvement in structural analysis. The results point out that both the predicted contact pressure and the predicted stress distribution depend on the mesh
topology. Several combinations of mesh dimension and topology are investigated. The purpose is the definition of a calculation methodology and the demonstration of the
application potentiality. Complex models analysis highlights that the set methodology constitutes a very effective tool for the design and optimization of gasket, cylinder head and
cylinder block. At last a particular case is studied and a structural improvement to resolve the problem of the low seal was obtained by FEM; the modifications were introduced in the
layout and the test on the modified component confirmed the calculation previsions. The qualitative and quantitative indications provided by the calculation are confirmed by the
experimental results, whether in condition of cold assembly (color film paper approach) or in condition of hot working (test to motor bench)
MISURE ACUSTICHE - “Sound in air” all’INRiM - Riferibilità metrologica delle misure acustiche
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