614 research outputs found

    Process hazard and operability analysis of BPCS and SIS malicious manipulations by POROS 2.0

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    The increasing interconnectivity with external networks and the higher reliance on digital systems make the facilities of the chemical, process, and Oil&Gas industry more vulnerable to cyber-attacks. These attacks have the potential of causing events with severe consequences on property, people, and the surrounding environment such as major event scenarios. The application of the currently available methodologies for cyber risk identification to complex plants with a large number of units may be demanding and cumbersome. The present study proposes an updated methodology, named POROS 2.0, that allows reducing time and effort in application by limiting the scope of the analysis to relevant cybersecurity scenarios. The latter are identified by investigating the potential escalation of consequences propagating among process and/or utility nodes of the manipulations of BPCS and SIS, similar to what is done in the HazOp technique in the safety domain. POROS 2.0 was demonstrated by the application to a case study addressing a fixed offshore platform for gas exploitation

    Canine substitution of a missing maxillary lateral incisor in an orthodontic re-treatment case: Long term follow up

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    Abstract Introduction: This case report describes the orthodontic re-treatment of a case with a severely compromised maxillary lateral incisor requiring removal and canine substitution. The treatment included creative asymmetric treatment mechanics and a careful management of anchorage. Case Presentation: Pre-treatment, post treatment and 5 years follow-up records are shown. The treatment outcomes proved to be stable at the follow-up with acceptable aesthetic and functional results. Conclusion: Through careful management of anchorage it was possible to successfully use asymmetric treatment mechanics to achieve a good functional occlusion

    Processing and Communication Delays in EWS: On the Performance of the Earthcloud Prototype

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    A Seismic Alert System (SAS), also called Earthquake Warning System (EWS) or Earthquake Early Warning System (EEW or EEWS), represents one of the most important measures that can be taken to prevent and minimize earthquake damage. These systems are mainly used to detect P-waves and the faster seismic waves and to subsequently trigger an alarm about the incoming S-waves, the slower and most dangerous seismic waves. In some cases, distributed systems are also able to alert some locations before the impending P-waves strike them. This paper presents Earthcloud, a cloud-based SAS that aims to provide all the former capabilities while retaining financial accessibility. Earthcloud first results, generated from four months of data acquisition, are compared with those coming from other systems. In particular, the paper focuses on processing and communication delays, showing how the Earthcloud new detection strategy may minimize delays. Although a thorough test campaign with more sensor nodes is needed to assess performance reliably, especially for highly dense urban scenarios, initial results are promising, with total latencies for Earthcloud always kept under the 1-second mark, despite being at the expense of solid magnitude estimation

    Kinetic Generation of Whistler Waves in the Turbulent Magnetosheath

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    The Earth's magnetosheath (MSH) is governed by numerous physical processes which shape the particle velocity distributions and contribute to the heating of the plasma. Among them are whistler waves which can interact with electrons. We investigate whistler waves detected in the quasi-parallel MSH by NASA's Magnetospheric Multiscale mission. We find that the whistler waves occur even in regions that are predicted stable to wave growth by electron temperature anisotropy. Whistlers are observed in ion-scale magnetic minima and are associated with electrons having butterfly-shaped pitch-angle distributions. We investigate in detail one example and, with the support of modeling by the linear numerical dispersion solver Waves in Homogeneous, Anisotropic, Multicomponent Plasmas, we demonstrate that the butterfly distribution is unstable to the observed whistler waves. We conclude that the observed waves are generated locally. The result emphasizes the importance of considering complete 3D particle distribution functions, and not only the temperature anisotropy, when studying plasma wave instabilities.Peer reviewe

    A new proposal: A digital flow for the construction of a haas-inspired rapid maxillary expander (HIRME)

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    Maxillary expansion is a common orthodontic treatment used for the correction of posterior crossbite resulting from reduced maxillary width. Transverse maxillomandibular discrepancies are a major cause of several malocclusions and may be corrected in dierent manners; in particular, the rapid maxillary expansion (RME) performed in the early mixed dentition has now become a routine procedure in orthodontic practice. The aim of this study is to propose a procedure that reduces the patient cooperation as well as the lab work required in preparing a customized Haas-inspired rapid maxillary expander (HIRME) that can be anchored to deciduous teeth and can be utilized in mixed dentition with tubes on the molars and hooks and brackets on the canines. This article thus presents an expander that is completely digitally developed, from the first moment of taking the impression with an optical scanner to the final solidification phase by the use of a 3D printer. This digital flow takes place in a CAD environment and it starts with the creation of the appliance on the optical impression; this design is then exported as an stl extension and is sent to the print service to obtain a solid model of the device through a laser sintering process. This "rough" device goes through a post-processing procedure; finally, a commercial expansion screw is laser-welded. This expander has all the advantages of a cast-metal Haas-type RME that rests on deciduous teeth; moreover, it has the characteristic of being developed with a completely digitized and individualized process, for the mouth of the young patient, as well as being made completely of cobalt-chrome, thus ensuring greater adaptability and stability in the patient's mouth

    an experimental investigation into the operation of an electrically heated tobacco system

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    Abstract An experimental investigation of the thermal processes taking place in the tobacco substrate of a recently developed multicomponent electrically heated tobacco product (EHTP) that is part of an electrically heated tobacco system (EHTS – also referred to as the Tobacco Heating System 2.2) was carried out. Temperature profiles in the tobacco substrate of the EHTP were characterized using thermocouples positioned at different distances from the heater surface. The average maximum temperature of the tobacco measured 0.2 mm from the heater's surface wa

    New insights into the pathogenesis of bullous pemphigoid: 2019 update

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    There are several lines of evidence indicating that the physiopathological bases of bullous pemphigoid (BP), the most common subepidermal autoimmune bullous disease, are hallmarked by the production of autoantibodies directed against the hemidesmosomal anchoring proteins BP180 and BP230. In contrast to the robustness of the latter assumption, the multifaceted complexity of upstream and downstream mechanisms implied in the pathogenesis of BP remains an area of intense speculation. So far, an imbalance between T regulatory cells and autoreactive T helper (Th) cells has been regarded as the main pathogenic factor triggering the autoimmune response in BP patients. However, the contributory role of signaling pathways fostering the B cell stimulation, such as Toll-like receptor activation, as well as that of ancillary inflammatory mechanisms responsible for blister formation, such as Th17 axis stimulation and the activation of the coagulation cascade, are still a matter of debate. In the same way, the pathomechanisms implied in the loss of dermal-epidermal adhesion secondary to autoantibodies binding are not fully understood. Herein, we review in detail the current concepts and controversies on the complex pathogenesis of BP, shedding light on the most recent theories emerging from the literature

    2D Reconstruction of Magnetotail Electron Diffusion Region Measured by MMS

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    Models for collisionless magnetic reconnection in near-Earth space are distinctly characterized as 2D or 3D. In 2D kinetic models, the frozen-in law for the electron fluid is usually broken by laminar dynamics involving structures set by the electron orbit size, while in 3D models the width of the electron diffusion region is broadened by turbulent effects. We present an analysis of in situ spacecraft observations from the Earth's magnetotail of a fortuitous encounter with an active reconnection region, mapping the observations onto a 2D spatial domain. While the event likely was perturbed by low-frequency 3D dynamics, the structure of the electron diffusion region remains consistent with results from a 2D kinetic simulation. As such, the event represents a unique validation of 2D kinetic, and laminar reconnection models.Peer reviewe
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