Search results for "Head"
showing 10 items of 1640 documents
Radiation dose in non-dental cone beam CT applications: a systematic review.
2018
Background: Radiation-induced health risks are broadly questioned in the literature. As cone beam computed tomography (CBCT) is increasingly used in non-dental examinations, its effective dose needs to be known. This study aimed to review the published evidence on effective dose of non-dental CBCT for diagnostic use by focusing on dosimetry system used to estimate dose. Materials and methods: A systematic review of the literature was performed on 12 November 2017. All the literature up to this date was included. The PubMed and web of science databases were searched. Studies were screened for inclusion based on defined inclusion and exclusion criteria according to the preferred reporting ite…
CT AND MRI OF THYROGLOSSAL DUCT CYST
2015
Aims and objectives Methods and materials Results Conclusion Personal information References
Stimulation of the sphenopalatine ganglion in intractable cluster headache: expert consensus on patient selection and standards of care.
2014
Context and overview Chronic cluster headache (CCH) is a debilitating headache disorder with a significant impairment of the patients' lives. Within the past decade, various invasive neuromodulatory approaches have been proposed for the treatment of CCH refractory to standard preventive drug, but only very few randomized controlled studies exist in the field of neuromodulation for the treatment of drug-refractory headaches. Based on the prominent role of the cranial parasympathetic system in acute cluster headache attacks, high-frequency sphenopalatine ganglion (SPG) stimulation has been shown to abort ongoing attacks in some patients in a first small study. As preventive effects of SPG-sti…
Improving angle stability by switching shunt reactors in mixed overhead cable lines. An Italian 400 kV case study
2019
Stringent environmental constraints make the construction of new transmission overhead lines more and more difficult. Alternatively, today it is possible to use cable lines for high (HV) and extra-high (EHV) voltage systems. The configuration of the so-called mixed lines can create some problems in the operation of the electrical system, both during steady-state and transient conditions. In particular, the system stability is one of the main concerns when analyzing the dynamic response of power systems. In this paper, the study of angular stability of a system containing a mixed line is presented: a specific control logic applied to the shunt reactors of the mixed line is proposed as improv…
Methodologies for the Exploitation of Existing Energy Corridors. GIS Analysis and DTR Applications
2018
The exploitation of power lines currently in operation has now become a common practice among electric system operators. The construction of new power lines requires taking economic, political and social problems into consideration. This paper considers two methodologies adopted by the Italian Transmission System Operator (TSO), Terna S.p.A.: Dynamic Thermal Rating (DTR) and Laser Imaging Detection and Ranging-Geographic Information System (L-GIS). DTR systems dynamically calculate the real transport capacity of a power line. The L-GIS system allows, after the geo-referencing of the power line, the management of any interference between the line and the nearby obstacles, permitting the opti…
The nationality of companies in French law
2012
The development of international economic relations and the construction of an integrated European area, both from an economic and a political point of view, has revived the debate on the nationality of trading companies. The question is not so much whether trading companies have a nationality on an equal footing with natural persons – solutions have long been accepted by international doctrine and jurisprudence – but rather to determine how this notion has evolved and adapted to the constraints on the one hand, of a globalized market economy and, on the other hand, of European Union law which overturns the traditionally accepted solutions of nationality of trading companies into the legal …
An experimental investigation on two different methods for swirl induction in a multivalve engine
2005
This paper describes an experimental investigation aimed at comparing the swirl effect induced by unbalancing the mass flow through the two intake ports of a multivalve engine head using two different methods: the first one reduced the curtain area of one of the intake valves [different lifts (DL) method]; the second one adopted a sluice-gate-shaped valve, installed upstream of the intake valves [swirl control valve (SCV) method] in order to cause a pressure drop. A steady-flow test rig (equipped with instrumentation for the discharge coefficient and swirl intensity measurement) was realized in order to compare and evaluate the results of both methods and determine their respective validit…
The Migration Crisis: An Introduction
2020
In 2015, the EU and its member states struggled to coordinate, communicate, and cooperate on the migration crisis as the chapters in this section show. Schilde and Wallace Goodman point out that while border security contains examples of deeper integration, asylum management policy has followed the scenarios of breaking down and muddling through. All the authors highlight the Dublin convention as particularly ill-devised and thus paving the way for the refugee crisis. Bosilca finds evidence for breaking down in addition to minimal reforms of border security policy that constitute muddling through. Crawford argues that the migration crisis provides evidence both of muddling through and headi…
FPGA-based concurrent watchdog for real-time control systems
2003
A straightforward and efficient implementation of a custom concurrent watchdog processor for real-time control systems is presented. Emphasis is given to the techniques used for on-line checking the main processor activity without adding overhead, and to the advantages of a field programmable gate array implementation.
Examination of the fetal brain by transabdominal three-dimensional ultrasound: potential for routine neurosonographic studies
2006
Objective To evaluate the role of transabdominal three-dimensional (3D) ultrasound in the assessment of the fetal brain and its potential for routine neurosonographic studies. Methods We studied prospectively 202 consecutive fetuses between 16 and 24 weeks' gestation. A 3D ultrasound volume of the fetal head was acquired transabdominally. The entire brain anatomy was later analyzed using the multiplanar images by a sonologist who was expert in neonatal cranial sonography. The quality of the conventional planes obtained (coronal, sagittal and axial, at different levels) and the ability of the 3D multiplanar neuroscan to visualize properly the major anatomical structures of the brain were eva…