Water confined in nanopores: spontaneous formation of microcavities

Molecular Dynamics simulations of water confined in nanometer sized, hydrophobic channels show that water forms localized cavities for pore diameter ~ 2.0 nm. The cavities present non-spherical shape and lay preferentially adjacent to the confining wall inducing a peculiar form to the liquid exposed surface. The regime of localized cavitation appears to be correlated with the formation of a vapor layer, as predicted by the Lum-Chandler-Weeks theory, implying partial filling of the pore

Interventi normativi per l’emergenza: perché serve una legge nazionale

Molti dei problemi che si pongono all’indomani di una calamità sono i medesimi e la risposta del legislatore (prima) e della gestione commissariale (poi) non sempre riesce a essere adeguata. Dall'analisi svolta sulle ordinanze emanate nel caso del sisma in Emilia del 2012 è possibile tracciare quali siano gli ambiti rilevanti per l'intervento normativo. Si analizzano inoltre alcuni esempi di effetti economici con-seguenti a un terremoto che colpiscono le famiglie anche nella vita quotidiana, come per i mutui, le polizze assicurative o i contratti per servizi relativi a beni perduti a seguito del sisma. Gli Autori propongono l’adozione di una legge generale che individui preventivamente una serie di misure che il Governo possa direttamente attivare in modo immediato all’indomani di disastri naturali, con l'obiettivo di mettere in atto risposte pronte ed efficaci che riducano gli effetti negativi dell'incertezza nel-le decisioni delle famigli

Incremento della tenacità a frattura interlaminare di Modo I e II in CFRP mediante l’uso di nanofibre polimeriche ottenute per elettrofilatura

I CFRP laminati posseggono scarsa capacità di smorzamento delle vibrazioni (damping), simile a quella dei materiali metallici. Questa può essere migliorata incorporando tessuti nanofibrosi polimerici tra i prepreg in fase di produzione. Per valutare l’effetto del nano-rinforzo nei confronti della delaminazione, nel presente lavoro di tesi sono stati prodotti CFRP laminati a matrice epossidica nano-modificati. Le membrane nanofibrose usate per la modifica sono state prodotte per elettrofilatura (electrospinning) di soluzioni polimeriche contenenti varie percentuali di gomma. I tessuti sono stati caratterizzati morfologicamente (analisi SEM), termicamente (analisi DSC) e meccanicamente (prove di trazione). Dai compositi prodotti sono stati ricavati i provini utilizzati per effettuare i test di tenacità a frattura interlaminare (test DCB, Double Cantilever Beam ed ENF, End Notched Flexture) secondo le relative norme (ASTM D5528-13 e ASTM D7905-14 rispettivamente). Le prove DCB (modalità di apertura in Modo I) mostrano che i nanotessuti sono estremamente efficaci nell’ostacolare la delaminazione (effetto che aumenta all’aumentare del tenore di gomma nel nano-rinforzo). I test ENF (modalità di apertura in Modo II) pur non mostrando un altrettanto significativo effetto di rinforzo dimostrano comunque un impatto non negativo sulla prestazione del composito

Docking Manoeuvre Control for CubeSats

Rendezvous and Docking missions of small satellites are opening new scenarios to accomplish unprecedented in-obit operations. These missions impose to win the new technical challenges that enable the possibility to successfully perform complex and safety-critical manoeuvres. The disturbance forces and torques due to the hostile space environment, the uncertainties introduced by the onboard technologies and the safety constraints and reliability requirements lead to select advanced control systems. The paper proposes a control strategy based on Model Predictive Control for trajectory control and Sliding Mode Control for attitude control of the chaser in last meters before the docking. The control performances are verified in a dedicated simulation environment in which a non-linear six Degrees of Freedom and coupled dynamics, uncertainties on sensors and actuators responses are included. A set of 300 Monte Carlo Simulation with this Non-Linear system are carried out, demonstrating the capabilities of the proposed control system to achieve the final docking point with the required accuracy

An empirical standardized soil moisture index for agricultural drought assessment from remotely sensed data

AbstractWe propose a simple, spatially invariant and probabilistic year-round Empirical Standardized Soil Moisture Index (ESSMI) that is designed to classify soil moisture anomalies from harmonized multi-satellite surface data into categories of agricultural drought intensity. The ESSMI is computed by fitting a nonparametric empirical probability density function (ePDF) to historical time-series of soil moisture observations and then transforming it into a normal distribution with a mean of zero and standard deviation of one. Negative standard normal values indicate dry soil conditions, whereas positive values indicate wet soil conditions. Drought intensity is defined as the number of negative standard deviations between the observed soil moisture value and the respective normal climatological conditions. To evaluate the performance of the ESSMI, we fitted the ePDF to the Essential Climate Variable Soil Moisture (ECV SM) v02.0 data values collected in the period between January 1981 and December 2010 at South–Central America, and compared the root-mean-square-errors (RMSE) of residuals with those of beta and normal probability density functions (bPDF and nPDF, respectively). Goodness-of-fit results attained with time-series of ECV SM values averaged at monthly, seasonal, half-yearly and yearly timescales suggest that the ePDF provides triggers of agricultural drought onset and intensity that are more accurate and precise than the bPDF and nPDF. Furthermore, by accurately mapping the occurrence of major drought events over the last three decades, the ESSMI proved to be spatio-temporal consistent and the ECV SM data to provide a well calibrated and homogenized soil moisture climatology for the region. Maize, soybean and wheat crop yields in the region are highly correlated (r>0.82) with cumulative ESSMI values computed during the months of critical crop growing, indicating that the nonparametric index of soil moisture anomalies can be used for agricultural drought assessment

Investigating the Temporal Dynamics of Covert Visual Spatial Attention: Exploitative and Explorative Attentional Mechanisms

This thesis explores how trial and error learning affects attentional processes. Previous research has shown that selective attention tends to be biased towards cues that accurately and consistently predict future events. Paying attention to predictive cues is adaptive because an animal can use the information that these cues convey to predict future events and change their behaviour accordingly. However, some research has shown that selective attention can be biased towards non-predictive, or uncertain, stimuli. Paying attention to non-predictive cues could also be adaptive because it could help establish the true nature of these currently uncertain stimuli. Although selective attention can be driven by both high and low levels of uncertainty, the factors that determine which driving force prevails are not fully understood. This thesis investigates whether time is one such factor. The experiments presented here involved training participants on a categorisation task where some stimuli were predictive (P) of the categorisation response while others were non-predictive (NP). These stimuli were then used as uninformative spatial cues to a target stimulus in a dot probe task. The time course of attention to the cues was investigated by manipulating the stimulus onset asynchrony (SOA) between the cues and the target. Behavioural and electrophysiological (EEG) data were collected. It was hypothesised that P cues would be preferentially processed early in a trial. However, after these cues were processed, we predicted that they would be inhibited, and that this inhibition would bias attention towards the currently NP cue. Experiments 1-3 (Chapter 2) explored the dot probe paradigm by using different stimuli and different dot probe tasks. Using two SOAs (250 and 1200 ms) and an intermixed dot probe and categorisation task, the reaction time (RT) and N2 posterior contralateral (N2pc) results showed that targets that appeared over P cues after short SOAs were easier to process compared to targets that appeared over NP cues. Therefore, P cues were preferentially processed early in a trial. However, no evidence of inhibition of the P cue was found at the longer SOA. Experiments 4-6 (Chapter 3) tested a wider and earlier range of SOAs and included additional behavioural measures (e.g., dot probe errors and premature responding). In these experiments, RTs were faster to targets that appeared over P cues compared to NP cues, and this advantage increased proportionally with SOA. This novel RT interaction suggested that the P cues were being strategically processed. The N2pc results also showed an interaction between predictiveness and SOA, but one that suggested a shift in attention from P to NP cues. The error data indicated that RTs in the localisation version of the dot probe task could be contaminated by a non-attentional response bias towards selecting a response that was congruent with the location of the P cues. Experiments 7-9 (Chapter 4) tested whether participants were strategically or automatically attending to the P and NP cues, and also investigated whether the attentional effects observed in the previous chapters could influence subsequent cue-outcome learning. Blocking the dot probe and categorisation task resulted in the loss of the interaction between predictiveness and SOA on RTs. Instead, the blocked design resulted in a small, but consistent, RT advantage towards the P cues across all SOAs. This suggested that the current task relevance of the cues is an important factor that determines whether they are strategically processed. In the final experiment, different target stimuli were used after short and long SOAs to investigate whether the changes in attention measured via the N2pc could impact subsequent cue-target learning. However, no evidence of biased learning was found. Chapter 5 presents a summary of the results, including meta-analyses of the behavioural data. The idea that time may be an important factor which moderates exploitative and explorative behaviour is discussed further. This discussion pivots around a real-time model that was modified to take attention into account. Ideas for future research are also presented.Thesis (Ph.D.) -- University of Adelaide, School of Psychology, 202

Early impairment of endothelial structure and function in young normal-weight women with polycystic ovary syndrome

The aim of this study was to evaluate the presence of early vascular damage in young normal-weight women with polycystic ovary syndrome (PCOS).Thirty young normal-weight women with PCOS, who had no additional metabolic or cardiovascular diseases, and 30 healthy women (controls) matched for age and body mass index were studied. A complete hormonal assay was performed in each subject. Serum insulin and glucose levels were measured at baseline and after the oral glucose tolerance test. Plasma endothelin-1 levels and serum lipid profile were also assessed. The endothelial function was studied by flow-mediated dilation on the brachial artery, and arterial structure was evaluated by intima-media thickness measurement using Doppler ultrasound of both common carotid arteries.A significant (P < 0.05) difference in flow-mediated dilation (14.3 +/- 1.9% vs. 18.1 +/- 2.0% for PCOS patients and controls, respectively) and in intima-media thickness (0.53 +/- 0.09 mm vs. 0.39 +/- 0.08 mm for PCOS patients and controls, respectively) was found between PCOS and control subjects. Serum endothelin-1 levels were also significantly (P < 0.05) higher in PCOS patients compared with controls (1.1 +/- 0.4 pmol/liter vs. 0.5 +/- 0.2 pmol/liter for PCOS patients and controls, respectively).In conclusion, our data show that young, normal-weight, nondyslipidemic, nonhypertensive women with PCOS have an early impairment of endothelial structure and function

Anti-calcitonin gene-related peptide monoclonal antibodies for the treatment of vestibular migraine: A prospective observational cohort study

Background: Vestibular migraine is considered the most common cause of recurrent vertigo for which specific treatments are missing. Monoclonal antibodies against calcitonin gene-related peptide,, are effective in preventing migraine. Since CGRP is also detected in human cochlear and vestibular organs it may also play a role in vestibular physiology. Methods: This is a prospective observational cohort study, aiming at evaluating the efficacy of erenumab, fremanezumab or galcanezumab for the treatment of fifty vestibular migraine patients. We assessed mean monthly days with headache and dizziness/vestibular symptoms, pain intensity and migraine-related clinical burden occurring for 18 months. Results: Response to treatment was excellent as 45 (90%) patients had at least a 50% reduction in vertigo frequency, 43 (86%) had at least a 50% reduction in headache frequency, and 40 (80%) a MIDAS reduction of at least 50%. Overall, 39 (78%) patients had a concomitant reduction of all three parameters. Mean monthly days with dizziness/vestibular symptoms showed an overall significant decrease from a mean of 10.3 ± 1.9 at baseline to 0.8 ± 0.3 days, difference 9.5 (CI 95% 3.6, 15.4; p < 0.001) after twelve months. Conclusion: We show that anti-CGRP mAbs may be effective in the treatment of Vestibular Migraine. Their use should be encouraged early in the disease course to allow for a better symptom control and quality of life improvement

Visualization of Thermal Effects in Polypropylene-based Composites under Cyclic Bending Tests☆

Abstract The attention of this paper is focused on surface temperature changes which are experienced by thermoplastic composite materials under cyclic bending tests. Such changes are visualized and measured with an infrared imaging device and later analyzed to gain information which, coupled with other mechanical and/or chemical properties, may be exploited for the material characterization. In particular, thermoplastic composites based on a polypropylene matrix, which may be neat, or modified by the addition of a relatively low amount of a specific compatibilizing agent, and reinforced with glass or jute woven fibres are investigated

Contamination of the Environmental Matrices in Agricultural Areas Produced by Industrial Discharges: The Case Study of the Land of the City of Statte (Taranto, Southern Italy)

The diffusion of pollutants in the atmosphere, agricultural soil, irrigation water, crops and food chain can produce potential environmental health risk. The aims of this study are the environmental risk assessment for the aquifers and the estimation of pollutants concentration in the forage for evaluating the risk for human health. The risk analysis was applied in the rural territory of Statte (Taranto, Italy) using an innovative methodology based on the integration of models for estimation of pollutant leaching in the groundwater and for the evaluation of bio-transfer of pollutant in the plant. The model results are in accordance with the experimental values and therefore the proposed methodology allows the evaluation and management of environmental health risks in agricultural areas interested by pollution phenomena generated by industrial plants