Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 21
Filtrar
Más filtros












Base de datos
Intervalo de año de publicación
1.
Heliyon ; 10(1): e23196, 2024 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-38163242

RESUMEN

Face masks can filter droplets containing viruses and bacteria minimizing the transmission and spread of respiratory pathogens but are also an indirect source of microbes transmission. A novel antibacterial and antiviral Ag-coated polypropylene surgical mask obtained through the in situ and one-step deposition of metallic silver nanoparticles, synthesized by silver mirror reaction combined with sonication or agitation methods, is proposed in this study. SEM analysis shows Ag nanoparticles fused together in a continuous and dense layer for the coating obtained by sonication, whereas individual Ag nanoparticles around 150 nm were obtained combining the silver mirror reaction with agitation. EDX, XRD and XPS confirm the presence of metallic Ag in both coatings and also oxidized Ag in samples by agitation. A higher amount of Ag nanoparticles is deposited on samples by sonication, as calculated by TGA. Further, both coatings are biocompatible and show antibacterial properties: coating by sonication caused 24 % and 40 % of bacterial reduction while coating by agitation 48 % and 96 % against S. aureus and E. coli, respectively. At 1 min of contact with SARS-CoV-2, the coating by agitation has an antiviral capacity of 75 % against 24 % of the one by sonication. At 1 h, both coatings achieve 100 % of viral inhibition. Nonetheless, larger samples could be produced only through the silver mirror reaction combined with agitation, preserving the integrity of the mask. In conclusion, the silver-coated mask produced by silver mirror reaction combined with agitation is scalable, has excellent physico-chemical characteristics as well as significant biological properties, with higher antimicrobial activities, providing additional protection and preventing the indirect transmission of pathogens.

2.
Materials (Basel) ; 17(1)2024 Jan 03.
Artículo en Inglés | MEDLINE | ID: mdl-38204107

RESUMEN

The mechanical properties of a defect-free laser melting (PBF-LB) deposit of an AISI 316L steel alloy were assessed by means of an instrumented indentation test (IIT), at both the macro- and nano-scales. The inherent non-equilibrium microstructure of the alloy was chemically homogenous and consisted of equiaxed grains and large-elongated grains (under the optical microscope) with irregular outlines composed of a much finer internal cell structure (under the scanning electron microscope). Berkovich and Vickers indenters were used to assess the indentation properties across individual grains (nano) and over multiple grains (macro), respectively. The nano-indentation over the X-Y plane revealed nearly constant indentation modulus across an individual grain but variable on average within different grains whose value depended on the relative orientation of the individual grain. The macro-indentation test was conducted to analyze the tensile-like properties of the polycrystalline SS 316L alloy over the X-Y and Y-Z planes. The macro-indentation test provided a reliable estimate of the ultimate tensile strength (UTS-like) of the alloy. Other indentation properties gave inconsistent results, and a post factum analysis was, therefore, conducted, by means of a new approach, to account for the presence of residual stresses. The already existing indentation data were supplemented with new repeated indentation tests to conduct a detailed analysis of the relaxation ability of compressive and tensile residual stresses. The developed methodology allows the effect of residual stresses and the reliability of measured macro-indentation properties to be examined as a function of a small group of indentation parameters.

3.
Sci Adv ; 9(48): eadi3728, 2023 12.
Artículo en Inglés | MEDLINE | ID: mdl-38019920

RESUMEN

Barrel cortex integrates contra- and ipsilateral whiskers' inputs. While contralateral inputs depend on the thalamocortical innervation, ipsilateral ones are thought to rely on callosal axons. These are more abundant in the barrel cortex region bordering with S2 and containing the row A-whiskers representation, the row lying nearest to the facial midline. Here, we ask what role this callosal axonal arrangement plays in ipsilateral tactile signaling. We found that novel object exploration with ipsilateral whiskers confines c-Fos expression within the highly callosal subregion. Targeting this area with in vivo patch-clamp recordings revealed neurons with uniquely strong ipsilateral responses dependent on the corpus callosum, as assessed by tetrodotoxin silencing and by optogenetic activation of the contralateral hemisphere. Still, in this area, stimulation of contra- or ipsilateral row A-whiskers evoked an indistinguishable response in some neurons, mostly located in layers 5/6, indicating their involvement in the midline representation of the whiskers' sensory space.


Asunto(s)
Corteza Cerebral , Cuerpo Calloso , Cuerpo Calloso/fisiología , Neuronas/fisiología , Axones , Tacto/fisiología
4.
Eur J Radiol ; 165: 110917, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37327548

RESUMEN

PURPOSE: In this study we investigate how patients perceive the interaction between artificial intelligence (AI) and radiologists by designing a survey. METHOD: We created a survey focused on the application of Artificial Intelligence in radiology which consisted of 20 questions distributed in three sections:Only completed questionnaires were considered for analysis. RESULTS: 2119 subjects completed the survey. Among them, 1216 respondents were over 60 years old, showing interest in AI even though they were not digital natives. Although >45% of the respondents reported a high level of education, only 3% said they were AI experts. 87% of respondents favored using AI to support diagnosis but would like to be informed. Only 10% would consult another specialist if their doctor used AI support. Most respondents (76%) said they would not feel comfortable if the diagnosis was made by the AI alone, highlighting the importance of the physician's role in the emotional management of the patient. Finally, 36% of respondents were willing to discuss the topic further in a focus group. CONCLUSION: Patients' perception of the use of AI in radiology was positive, although still strictly linked to the supervision of the radiologist. Respondents showed interest and willingness to learn more about AI in the medical field, confirming how patients' confidence in AI technology and its acceptance is central to its widespread use in clinical practice.


Asunto(s)
Inteligencia Artificial , Radiología , Humanos , Persona de Mediana Edad , Radiólogos , Radiología/educación , Encuestas y Cuestionarios , Radiografía
5.
Materials (Basel) ; 16(10)2023 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-37241376

RESUMEN

The microstructure and tensile behavior of two heavy section castings that had chemical compositions typical of GJS400 were investigated. Conventional metallography, fractography, and micro-Computer Tomography (µ-CT) were employed, enabling the quantification of the volume fractions of eutectic cells with degenerated Chunky Graphite (CHG), which was identified as the major defect in the castings. The Voce equation approach was exploited to evaluate the tensile behaviors of the defective castings for integrity assessment. The results demonstrated that the Defects-Driven Plasticity (DDP) phenomenon, which refers to an unexpected regular plastic behavior related to defects and metallurgical discontinuities, was consistent with the observed tensile behavior. This resulted in a linearity of Voce parameters in the Matrix Assessment Diagram (MAD), which contradicts the physical meaning of the Voce equation. The findings suggest that the defects, such as CHG, contribute to the linear distribution of Voce parameters in the MAD. Furthermore, it is reported that the linearity in the MAD of Voce parameters for a defective casting is equivalent to the existence of a pivotal point in the differential data of the tensile strain hardening data. This pivotal point was exploited to propose a new material quality index assessing the integrity of castings.

6.
Sensors (Basel) ; 23(3)2023 Jan 18.
Artículo en Inglés | MEDLINE | ID: mdl-36772163

RESUMEN

This paper presents the technical development and subsequent testing of a Real-Time Locating System based on Ultra-Wideband signals, with the aim to appraise its potential implementation in a real industrial case. The system relies on a commercial Radio Indoor Positioning System, called Qorvo MDEK1001, which makes use of UWB RF technology to determine the position of RF-tags placed on an item of interest, which in turn is located in an area covered by specific fixed antennas (anchors). Testing sessions were carried out both in an Italian laboratory and in a real industrial environment, to determine the best configurations according to some selected performance indicators. The results support the adoption of the proposed solution in industrial environments to track assets and work in progress. Moreover, most importantly, the solution developed is cheap in nature: indeed, normally tracking solutions involve a huge investment, quite often not affordable above all by small-, medium- and micro-sized enterprises. The proposed low-cost solution instead, as demonstrated by the economic assessment completing the work, justifies the feasibility of the investment. Hence, results of this paper ultimately constitute a guidance for those practitioners who intend to adopt a similar system in their business.

7.
Sustain Futur ; 4: 100093, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-37522104

RESUMEN

One of the main issues addressed by the recent COVID-19 pandemic which affected the whole world is the availability of Personal Protective Equipment (PPE) (e.g., face masks, white coats, or disposable gloves). This issue impacts on sustainability from different perspectives, such as more generated waste or environmental pollution, both for manufacturing and disposal, or more inequalities deriving from who can afford and access PPE and who cannot, since many shortages were recorded during the pandemic as well as fluctuating unit prices. Moreover, quite often PPE intended for single use are improperly used more times, thus generating a biological risk of infection. In an attempt to propose an innovative solution to face this problem, in this paper the re-design of an oven originally intended for food purposes is presented, with the aim of operating a thermal sanitization of PPE. The machinery and its components are detailed, together with physical and microbiological tests performed on non-woven PPE to assess the effect of treatment on mechanical properties and viral load. The pilot machinery turned out to be effective in destroying a bovine coronavirus at 95 °C and thus reducing contaminating risk in one hour without compromising the main properties of PPE, opening perspectives for the commercialization of the solution in the near future.

8.
Materials (Basel) ; 14(6)2021 Mar 18.
Artículo en Inglés | MEDLINE | ID: mdl-33803669

RESUMEN

In this paper, the best laser powder bed fusion (L-PBF) printing conditions for FeSi steels with two different Si content (3.0% and 6.5%) are defined. Results show very strict processing window parameters, following a lack of fusion porosity at low specific energy values and keyhole porosity in correspondence with high specific energy values. The obtained microstructure consists of grains with epitaxial growth starting from the grains already solidified in the underling layer. This allows the continuous growth of the columnar grains, directed parallel to the built direction of the component. The magnetic behaviour of FeSi6.5 samples, although the performances found do not still fully reach those of the best commercial electrical steels (used to manufacture magnetic cores of electrical machines and other similar magnetic components), appears to be quite promising. An improvement of the printing process to obtain thin sheets with increased Si content, less than 0.5 mm thick, with accurate geometry and robust structures, can result to an interesting technology for specific application where complex geometries and sophisticated shapes are required, avoiding mechanical machining processes for electrical steel with high silicon content.

9.
Materials (Basel) ; 14(7)2021 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-33916243

RESUMEN

FIMEC (flat-top cylinder indenter for mechanical characterisation) is an instrumented indentation test employing a cylindrical punch. It has been used to determine the mechanical properties of metallic materials in several applications of industrial interest. This work briefly describes the technique and the theory of indentation with a flat-ended punch. The flat indentation of metals has been investigated through experimental tests, and an equation has been derived to calculate the yield stress from the experimental data in deep indentation. The approach is supported by many data on various metals and alloys. Some selected case studies are presented in the paper: (i) crank manufacturing through pin squeeze casting; (ii) the evaluation of the local mechanical properties in a carter of complex geometry; (iii) the qualification of Al billets for extrusion; (iv) stress-relaxation tests on CuCrZr heat sinks; (v) the characterization of thick W coatings on CuCrZr alloy; (vi) the measure of the local mechanical properties of the molten-zone (MZ) and the heat-affected zone (HAZ) in welded joints. The case studies demonstrate the great versatility of the FIMEC test which provides information not available by employing conventional experimental techniques such as tensile, bending, and hardness tests. On the basis of theoretical knowledge and large amount of experimental data, FIMEC has become a mature technique for application on a large scale in industrial practice.

10.
Aging Clin Exp Res ; 33(12): 3183-3189, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-33905104

RESUMEN

BACKGROUND: Inadequate osteoporosis education can make patients ill-informed concerning preventive and therapeutic interventions and creates misconceptions and unnecessary concerns about the disease. AIM: Our study aimed to assess whether patients referred to the DXA exam by their general practitioner are informed about risk factors for osteoporosis, comparing patients who received a diagnosis of osteoporosis before the exam with those without this diagnosis. METHODS: An observational single-center study was performed among patients who were referred to the DXA exam at the Osteoporosis Service of Marche Nord Hospital (Fano, Italy) between April and July 2019. Socio-demographic and clinical characteristics, awareness of suffering from osteoporosis, femoral and lumbar spine T-score and bone mineral density, risk of fracture and the I-FOOQ score were assessed. RESULTS: A pilot study was carried out to validate the questionnaire in the Italian language (alpha-Cronbach 0.75). After that, a sample of 128 patients was enrolled (response rate 93.3%). Mean age was 66 ± 10.6 years, 95.6% were women. Overall, I-FOOQ mean score was 12 ± 3.5. Age, educational level, menopausal age, body mass index, femoral T-score were not associated with a better knowledge (p > 0.05). A comparison between who know to suffer from osteoporosis and others found no differences (12.2 ± 3.4 and 12 ± 3.5, respectively, p = 0.772). Effect of walking, recommended calcium intake, and familiar predisposition are the less known topics. CONCLUSION: Patients who undergo the DXA exam are poorly informed about risk factors for osteoporosis, independently of age, education, bone mineral density and risk of fracture. Knowing to suffer from osteoporosis does not increase the likelihood to be informed. It is mandatory to improve the education that is provided to the patients, as there are effective non-pharmacological interventions to prevent and treat osteoporosis.


Asunto(s)
Osteoporosis , Absorciometría de Fotón , Anciano , Densidad Ósea , Femenino , Humanos , Vértebras Lumbares , Osteoporosis/diagnóstico por imagen , Proyectos Piloto , Encuestas y Cuestionarios
11.
Waste Manag ; 125: 132-144, 2021 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-33684664

RESUMEN

The 2030 Agenda of the United Nations includes the objective of setting up sustainable production patterns by pursuing several Sustainable Development Goals. Among them, the "Responsible production and consumption" is a key topic in the food production and is strictly connected with the "Climate action"; the crucial point, however, is how to jointly act on all these aspects and apply them in practice. The waste yearly produced in the food chain represent both an ethical, economic and environmental issue. In particular, as far as the recovery of packaged food waste from retailers is concerned, the valorisation of the wasted meat is an extremely relevant issue. Pet food industries could be interested in valorising this waste fraction to replace meat coming from slaughters in their product recipes. This article evaluates the environmental impact of valorising meat fraction from packaged food waste to produce two different recipes of high quality pet food, called Natura and Pâté. A life cycle assessment of the current scenario (traditional pet food production and landfilling of packaged food waste) and of a new one (pet food production using meat fraction from packaged food waste) is carried out applying the ReCiPe 2016 method of impact assessment. Real data have been taken from retailers and pet food manufacturer. The production of pet food using the meat fraction from packaged food waste generates on average lower environmental impacts if compared to the traditional process, in terms of GWP (-56.40%), water consumption (-22.62%), land use (-87.50%) and fossil resource scarcity (-21.78%). Benefits are interesting even if considering the production of Pâté (-14.66%), for which the traditional production process makes use of some slaughter by-products. The proposed industrial process is demonstrated to be sustainable from an environmental point of view and appears to be in line with Sustainable Development Goals (SDGs) 2, 12 and 13.


Asunto(s)
Eliminación de Residuos , Industria de Alimentos , Industrias , Carne , Embalaje de Productos
12.
Elife ; 102021 02 18.
Artículo en Inglés | MEDLINE | ID: mdl-33599609

RESUMEN

Behavioral studies differentiate the rodent dorsal striatum (DS) into lateral and medial regions; however, anatomical evidence suggests that it is a unified structure. To understand striatal dynamics and basal ganglia functions, it is essential to clarify the circuitry that supports this behavioral-based segregation. Here, we show that the mouse DS is made of two non-overlapping functional circuits divided by a boundary. Combining in vivo optopatch-clamp and extracellular recordings of spontaneous and evoked sensory activity, we demonstrate different coupling of lateral and medial striatum to the cortex together with an independent integration of the spontaneous activity, due to particular corticostriatal connectivity and local attributes of each region. Additionally, we show differences in slow and fast oscillations and in the electrophysiological properties between striatonigral and striatopallidal neurons. In summary, these results demonstrate that the rodent DS is segregated in two neuronal circuits, in homology with the caudate and putamen nuclei of primates.


Asunto(s)
Ganglios Basales/fisiología , Corteza Cerebral/fisiología , Cuerpo Estriado/fisiología , Vías Nerviosas/fisiología , Neuronas/fisiología , Animales , Femenino , Masculino , Ratones
13.
Materials (Basel) ; 13(9)2020 May 05.
Artículo en Inglés | MEDLINE | ID: mdl-32380713

RESUMEN

Tungsten carbide-cobalt (WC-Co) composites are a class of advanced materials that have unique properties, such as wear resistance, hardness, strength, fracture-toughness and both high temperature and chemical stability. It is well known that the local indentation properties (i.e., nano- and micro-hardness) of the single crystal WC particles dispersed in such composite materials are highly anisotropic. In this paper, the nanoindentation response of the WC grains of a compact, full-density, sintered WC-10Co composite material has been investigated as a function of the crystal orientation. Our nanoindentation survey has shown that the nanohardness was distributed according to a bimodal function. This function was post-processed using the unique features of the finite mixture modelling theory. The combination of electron backscattered diffraction (EBSD) and statistical analysis has made it possible to identify the orientation of the WC crystal and the distinct association of the inherent nanoindentation properties, even for a small set (67) of nanoindentations. The proposed approach has proved to be faster than the already existing ones and just as reliable, and it has confirmed the previous findings concerning the relationship between crystal orientation and indentation properties, but with a significant reduction of the experimental data.

14.
J Mech Behav Biomed Mater ; 106: 103724, 2020 06.
Artículo en Inglés | MEDLINE | ID: mdl-32250950

RESUMEN

Despite the great potential of Mg and its alloys as material for biodegradable implants, their low resistance to the simultaneous action of corrosion and mechanical stresses in the human body have hampered their use. Stress Corrosion Cracking has been reported as one of the most critical failure modes to overcome to allow such materials to be clinically applied. Thus, in this paper we investigate the effect of Equal Channel Angular Pressing (ECAP) on the Stress Corrosion Cracking (SCC) susceptibility of the AZ31 Mg alloy. To do so, AZ31 alloy has been subjected to 1, 2 and 4 passes of ECAP, and the samples so obtained have then been tested by means Slow Strain Rate Tests (SSRTs) in Simulated Body Fluid (SBF) at 37 °C. Samples subjected to one pass of ECAP are shown to be less susceptible to SCC compared to the material in the as-received condition, while further ECAP processing (2 and 4 passes) are found to worsen the SCC susceptibility. To understand the different SCC susceptibilities shown by the differently ECAPed samples, microstructural analyses, potentiodynamic polarization curves, hydrogen evolution experiments and Scanning Electron Microscopy (SEM) analyses of the fracture surfaces were carried out. The improved corrosion resistance of the samples subjected to 1 pass of ECAP compared to the samples in the as received condition (due to a finer grain size) and to the samples subjected to 2 and 4 passes (due to a more favourable texture evolution) represents the reason of their reduced SCC susceptibility.


Asunto(s)
Líquidos Corporales , Magnesio , Aleaciones , Corrosión , Humanos
15.
Materials (Basel) ; 12(19)2019 Sep 27.
Artículo en Inglés | MEDLINE | ID: mdl-31569629

RESUMEN

Element clustering and structural features of liquid lead-bismuth eutectic (LBE) alloy have been investigated up to 720 °C by means of high temperature X-ray diffraction (HT-XRD), X-ray Photoemission Spectroscopy (XPS) and Scanning Photoemission Microscopy (SPEM) at the Elettra synchrotron in Trieste. The short-range order in liquid metal after melting corresponds to the cuboctahedral atomic arrangement and progressively evolves towards the icosahedral one as temperature increases. Such process, that involve a negative expansion of the alloy, is mainly connected to the reduction of atom distance in Pb-Pb pairs which takes place from 350 °C to 520 °C. On an atomic scale, it is observed a change of the relative number of Bi-Bi, Pb-Pb, and Pb-Bi pairs. The Pb-Bi pairs are detected only at a temperature above ~350 °C, and its fraction progressively increases, giving rise to a more homogeneous distribution of the elements. SPEM results showed evidence that the process of chemical homogenization on an atomic scale is preceded and accompanied by homogenization on micro-scale. Clusters rich of Bi and Pb, which are observed after melting, progressively dissolve as temperature increases: Only a few residuals remain at 350 °C, and no more clusters are detected a 520 °C.

16.
Sci Rep ; 8(1): 14265, 2018 09 24.
Artículo en Inglés | MEDLINE | ID: mdl-30250230

RESUMEN

The voluntary control of movement is often tested by using the countermanding, or stop-signal task that sporadically requires the suppression of a movement in response to an incoming stop-signal. Neurophysiological recordings in monkeys engaged in the countermanding task have shown that dorsal premotor cortex (PMd) is implicated in movement control. An open question is whether and how the perceptual demands inherent the stop-signal affects inhibitory performance and their underlying neuronal correlates. To this aim we recorded multi-unit activity (MUA) from the PMd of two male monkeys performing a countermanding task in which the salience of the stop-signals was modulated. Consistently to what has been observed in humans, we found that less salient stimuli worsened the inhibitory performance. At the neuronal level, these behavioral results were subtended by the following modulations: when the stop-signal was not noticeable compared to the salient condition the preparatory neuronal activity in PMd started to be affected later and with a less sharp dynamic. This neuronal pattern is probably the consequence of a less efficient inhibitory command useful to interrupt the neural dynamic that supports movement generation in PMd.


Asunto(s)
Conducta Animal/fisiología , Corteza Motora/fisiología , Neuronas/fisiología , Desempeño Psicomotor/fisiología , Animales , Fijación Ocular/fisiología , Humanos , Macaca mulatta/fisiología , Movimiento/fisiología , Inhibición Neural/fisiología , Estimulación Luminosa , Tiempo de Reacción
17.
Materials (Basel) ; 10(9)2017 Sep 05.
Artículo en Inglés | MEDLINE | ID: mdl-28872620

RESUMEN

Electron Beam (EB) welding has been used to realize seams on 2 mm-thick plates of directionally solidified (DS) IN792 superalloy. The first part of this work evidenced the importance of pre-heating the workpiece to avoid the formation of long cracks in the seam. The comparison of different pre-heating temperatures (PHT) and pass speeds (v) allowed the identification of optimal process parameters, namely PHT = 300 °C and v = 2.5 m/min. The microstructural features of the melted zone (MZ); the heat affected zone (HAZ), and base material (BM) were investigated by optical microscopy (OM), scanning electron microscopy (SEM), energy dispersion spectroscopy (EDS), electron back-scattered diffraction (EBSD), X-ray diffraction (XRD), and micro-hardness tests. In the as-welded condition; the structure of directionally oriented grains was completely lost in MZ. The γ' phase in MZ consisted of small (20-40 nm) round shaped particles and its total amount depended on both PHT and welding pass speed, whereas in HAZ, it was the same BM. Even if the amount of γ' phase in MZ was lower than that of the as-received material, the nanometric size of the particles induced an increase in hardness. EDS examinations did not show relevant composition changes in the γ' and γ phases. Post-welding heat treatments (PWHT) at 700 and 750 °C for two hours were performed on the best samples. After PWHTs, the amount of the ordered phase increased, and the effect was more pronounced at 750 °C, while the size of γ' particles in MZ remained almost the same. The hardness profiles measured across the joints showed an upward shift, but peak-valley height was a little lower, indicating more homogeneous features in the different zones.

18.
Exp Brain Res ; 235(7): 2203-2214, 2017 07.
Artículo en Inglés | MEDLINE | ID: mdl-28439628

RESUMEN

We investigated how the ability to suppress an impending movement is affected by the visual salience of the stop-signal in a reaching countermanding task. We found that when the stop-signal was easy to detect, stop performance was better than when the stop-signal was difficult to detect. In an exploratory analysis, we also found that the change in salience of the stop-signal can have an effect on the speed of response in trials following the stop-signal. This effect occurred together with strategic slowing down after an error in inhibiting was committed and together with a repetition priming effect due to the stop-signal presented in the previous trial. Our results suggest the need to investigate more in depth the afferent processing stage of the inhibitory control of movement and how task demands can affect its functioning.


Asunto(s)
Inhibición Psicológica , Movimiento/fisiología , Inhibición Neural/fisiología , Desempeño Psicomotor/fisiología , Percepción Visual/fisiología , Adulto , Análisis de Varianza , Movimientos Oculares/fisiología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estimulación Luminosa , Tiempo de Reacción/fisiología
19.
Appl Ergon ; 41(2): 211-24, 2010 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-19286165

RESUMEN

This paper describes the field tests on a driving simulator carried out to validate the algorithms and the correlations of dynamic parameters, specifically driving task demand and drivers' distraction, able to predict drivers' intentions. These parameters belong to the driver's model developed by AIDE (Adaptive Integrated Driver-vehicle InterfacE) European Integrated Project. Drivers' behavioural data have been collected from the simulator tests to model and validate these parameters using machine learning techniques, specifically the adaptive neuro fuzzy inference systems (ANFIS) and the artificial neural network (ANN). Two models of task demand and distraction have been developed, one for each adopted technique. The paper provides an overview of the driver's model, the description of the task demand and distraction modelling and the tests conducted for the validation of these parameters. A test comparing predicted and expected outcomes of the modelled parameters for each machine learning technique has been carried out: for distraction, in particular, promising results (low prediction errors) have been obtained by adopting an artificial neural network.


Asunto(s)
Algoritmos , Inteligencia Artificial , Conducción de Automóvil , Modelos Teóricos , Investigación , Adulto , Atención , Simulación por Computador , Lógica Difusa , Humanos
20.
Ann N Y Acad Sci ; 1161: 407-15, 2009 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-19426334

RESUMEN

The solidification of two binary alloys, In-10Sn and Sn-13Pb, has been investigated by X-ray diffractometry (XRD) at high temperatures. The high-temperature X-ray camera, which was mounted on a diffractometer, had a sample holder suitable for molten metals and operated in a controlled Ar atmosphere. Melts were cooled down slowly and XRD spectra were recorded step by step in order to monitor the structural evolution of the liquid prior to and during solidification. Temperature was kept constant while the XRD data were collected. The radial distribution functions (RDFs) were then determined from the spectra for each temperature. Experiments showed that atomic clusters form in the melt immediately before the appearance of the first solid. The experimental problems encountered in real-time monitoring of phase transformations involving liquid metals were looked at. To avoid convective motion in the liquid and to arrive at the best possible experimental conditions, we discussed the possibility of carrying out these studies at the reduced gravity found on the International Space Station.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...