1,052 research outputs found
ASPECTS OF THE ENERGETICS AND THE MECHANICS OF HUMAN LOCOMOTION
The relationship between the mechanical work performed by the muscles during locomotion and the corresponding metabolic energy consumption is still not completely understood beside the methodological problems and the inherent assumptions in the calculation of both mechanical work and metabolic energy it seems that many factors can affect this relationship. They can be of very different nature depending on muscle structure and composition, body dimension. kinetic and kinematic parameters. The analysis of the mechanical work, in terms of its two component, external work !that done to lift and to accelerate the centre of mass at each step) and internal work (that of accelerating the limbs relative to the body centre of mass), together with the measurement of the metabolic energy consumption, appears a useful approach to better understand the determinants of many characteristics of human locomotion. The relevance of the external and of the internal work has been inferred by altering them separately in particular conditions as in uphill and downhill walking and running or in loaded locomotion (adding 'weight to the trunk or to the limbs).Optimization processes that seem to set the normal speed of walking of unrestrained subjects, the speed of spontaneous transition from walking to running. the frequency freely adopted at a given gait and speed seem better explained on these bases Yet, from the results so far obtained, it appears that neither mechanical work and energy cost are the sole determinants of many aspects of human locomotion
Role and Management of a Head and Neck Department during the COVID-19 Outbreak in Lombardy
The recent Italian outbreak of coronavirus disease 2019 led to an unprecedented burden on our health care system. Despite head and neck\u2013otolaryngology not being a front-line specialty in dealing with this disease, our department had to face several specific issues. Despite a massive reallocation of resources in the hospital, we managed to keep the service active, improving safety measures for our personnel, specifically during common otolaryngologic maneuvers known to produce aerosols. Furthermore, we strived to maintain our teaching role, giving residents an inclusive role in managing the response to the emergency state, and we progressively integrated our inactive specialists into other service rotations to relieve front-line colleagues\u2019 burden. Specific issues and management decisions are discussed in detail in the article
Orbital medial wall fractures: Purely endoscopic endonasal repair with polyethylene implants
Our technique couples the stronger support granted by non-resorbable materials and the minimal invasiveness of the endoscopic approach without the need for long-term nasal packing
Self-consistent simulation of plasma scenarios for ITER using a combination of 1.5D transport codes and free-boundary equilibrium codes
Self-consistent transport simulation of ITER scenarios is a very important
tool for the exploration of the operational space and for scenario
optimisation. It also provides an assessment of the compatibility of developed
scenarios (which include fast transient events) with machine constraints, in
particular with the poloidal field (PF) coil system, heating and current drive
(H&CD), fuelling and particle and energy exhaust systems. This paper discusses
results of predictive modelling of all reference ITER scenarios and variants
using two suite of linked transport and equilibrium codes. The first suite
consisting of the 1.5D core/2D SOL code JINTRAC [1] and the free boundary
equilibrium evolution code CREATE-NL [2,3], was mainly used to simulate the
inductive D-T reference Scenario-2 with fusion gain Q=10 and its variants in H,
D and He (including ITER scenarios with reduced current and toroidal field).
The second suite of codes was used mainly for the modelling of hybrid and
steady state ITER scenarios. It combines the 1.5D core transport code CRONOS
[4] and the free boundary equilibrium evolution code DINA-CH [5].Comment: 23 pages, 18 figure
Risk perception and media in shaping protective behaviors: insights from the early phase of COVID-19 Italian outbreak
In the absence of target treatments or vaccination, the SARS-CoV-2 pandemic can be impeded by effectively implementing containment measures and behaviors. This relies on individuals’ adoption of protective behaviors, their perceived risk, and the use and trust of information sources. During a health emergency, receiving timely and accurate information enables individuals to take appropriate actions to protect themselves, shaping their risk perception. Italy was the first western country plagued by COVID-19 and one of the most affected in the early phase. During this period, we surveyed 2,223 Italians before the national lockdown. A quarter of the sample perceived COVID-19 less threatening than flu and would not vaccinate, if a vaccine was available. Besides, most people perceived containment measures, based on social distancing or wearing masks, not useful. This perceived utility was related to COVID-19 threat perception and efficacy beliefs. All these measures were associated with the use of media and their truthfulness: participants declared to mainly use the Internet, while health organizations’ websites were the most trusted. Although social networks were frequently used, they were rated lower for trustfulness. Our data differ from those obtained in other community samples, suggesting the relevance to explore changes across different countries and during the different phases of the pandemic. Understanding these phenomena, and how people access the media, may contribute to improve the efficacy of containment measures, tailoring specific policies and health communications
Modelling of 3D fields due to ferritic inserts and test blanket modules in toroidal geometry at ITER
Computations in toroidal geometry are systematically performed for the plasma response to 3D magnetic perturbations produced by ferritic inserts (FIs) and test blanket modules (TBMs) for four ITER plasma scenarios: the 15 MA baseline, the 12.5 MA hybrid, the 9 MA steady state, and the 7.5 MA half-field helium plasma. Due to the broad toroidal spectrum of the FI and TBM fields, the plasma response for all the n = 1-6 field components are computed and compared. The plasma response is found to be weak for the high-n (n > 4) components. The response is not globally sensitive to the toroidal plasma flow speed, as long as the latter is not reduced by an order of magnitude. This is essentially due to the strong screening effect occurring at a finite flow, as predicted for ITER plasmas. The ITER error field correction coils (EFCC) are used to compensate the n = 1 field errors produced by FIs and TBMs for the baseline scenario for the purpose of avoiding mode locking. It is found that the middle row of the EFCC, with a suitable toroidal phase for the coil current, can provide the best correction of these field errors, according to various optimisation criteria. On the other hand, even without correction, it is predicted that these n = 1 field errors will not cause substantial flow damping for the 15 MA baseline scenario
Dielectric diamond window for the ITER EC H&CD Upper Launcher: design, analysis and qualification
- …