Standalone, battery powered radiation monitors for accelerator electronics

A technical description of the design of a new type of radiation monitors is given. The key point in the design is the low power consumption inferior to 17 mW in radiation sensing mode and inferior to 0.3 mW in standby mode. The radiation monitors can operate without any external power or signal cabling and measure and store radiation data for a maximum period of 800 days. To read the radiation data, a standard PC can be connected via a USB interface to the device at any time. Only a few seconds are required to read out a single monitor. This makes it possible to survey a large network of monitoring devices in a short period of time, for example during a stop of the accelerator

Finite strains fully coupled analysis of a horizontal wellbore drilled through a porous rock formation

Wellbore instability, in particular in deep perforations, continues to be one of the major problem in the oil and gas industry, that can dramatically increase production costs. Eventual instabilities may be prevented supporting temporarily the wellbore with mud circulation. If instability may occur, the value of the mud pressure needs to be sufficiently high to prevent compressional failure, but it should also be lower than a critical value that would cause tensile failure and unintentional hydraulic fracturing. Predicting faithfully the stress distribution around a borehole, and moreover the yielding and failure zones, is a challenging but fundamental task, essential to estimate the correct mud pressure and hence to prevent instabilities and sand production. This study focuses on quantifying the pressure distribution, stress field and plastic zones around a horizontal borehole drilled at great depth through a highly porous rock formation. The perforation of a wellbore in a saturated porous material is a coupled problem, which involves deformations of the solid phase and simultaneous diffusion of the fluid phase. A fully coupled finite element method is adopted, considering both material non linearity (elastoplasticity) and geometric nonlinearity (finite deformations) in the solid matrix, resulting in a so called u−p formulation. The variation of porosity and permeability, as consequence of the finite deformations of the solid matrix, is taken into account. The model adopts an elastoplastic constitutive law characterized by two yield surfaces, that is able to capture the dilatant and compactant plastic mechanism. The simulations investigate the quasi-static transient phenomenon associated with the perforation, until the steady state condition is reached. The model describes the evolution of the stress and pressure distribution, and moreover the propagation of the plastic zones around the borehole. The work demonstrates the capability of the finite deformations coupled approach to simulate the whole process, giving an instrument to determine the stability and sand production of the wellbore

Thyroid ultrasonography reporting: consensus of Italian Thyroid Association (AIT), Italian Society of Endocrinology (SIE), Italian Society of Ultrasonography in Medicine and Biology (SIUMB) and Ultrasound Chapter of Italian Society of Medical Radiology (SIRM)

Thyroid ultrasonography (US) is the gold standard for thyroid imaging and its widespread use is due to an optimal spatial resolution for superficial anatomic structures, a low cost and the lack of health risks. Thyroid US is a pivotal tool for the diagnosis and follow-up of autoimmune thyroid diseases, for assessing nodule size and echostructure and defining the risk of malignancy in thyroid nodules. The main limitation of US is the poor reproducibility, due to the variable experience of the operators and the different performance and settings of the equipments. Aim of this consensus statement is to standardize the report of thyroid US through the definition of common minimum requirements and a correct terminology. US patterns of autoimmune thyroid diseases are defined. US signs of malignancy in thyroid nodules are classified and scored in each nodule. We also propose a simplified nodule risk stratification, based on the predictive value of each US sign, classified and scored according to the strength of association with malignancy, but also to the estimated reproducibility among different operators

Thyroid nodules treated with percutaneous radiofrequency thermal ablation: a comparative study

Percutaneous radiofrequency thermal ablation (RTA) was reported as an effective tool for the management of thyroid nodules (TNs). The aim of this study was to investigate the effects of RTA and to establish whether they were treatment-related by comparison with a matched, untreated control group