Quantitative strain analysis of the large deformation at the scale of microstructure: comparison between Digital Image Correlation and Microgrid techniques

A comparative study has been carried out to assess the accuracy of the Digital Image Correlation (DIC) technique for the quantification of large strains in the microstructure of an Interstitial Free (IF) steel used in automotive applications. A microgrid technique has been used in this study in order to validate independently the strain measurements obtained with DIC. Microgrids with a pitch of 5 microns were printed on the etched microstructure of the IF steel to measure the local in-plane strain distribution during a tensile test carried out in a Scanning Electron Microscope (SEM). The progressive deformation of the microstructure with microgrids has been recorded throughout the test as a sequence of micrographs and subsequently processed using DIC to quantify the distribution of local strain values. Strain maps obtained with the two techniques have been compared in order to assess the accuracy of the DIC measurements obtained using the natural patterns of the revealed microstructure in the SEM micrographs. The results obtained with the two techniques are qualitatively similar and thus, demonstrate the reliability of DIC applied to microstructures, even after large deformations in excess of 0.7. However, an average error of about 16 % was found in the strain values calculated using DIC

Strain Evolution Measurement at the Microscale of a Dual Phase Steel Using Digital Image Correlation

Digital Image Correlation (DIC) together with in-situ tensile testing has been used to measure in DP1000 steel the evolution of plastic strains at the microstructure scale. Interrupted tensile tests were performed on specially designed samples and scanning-electron micrographs were taken at regular applied strain intervals. Patterns defined by the microstructural features of the material have been used for the correlation carried out using LAVision software. The full field strain maps produced by DIC show a progressive localisation of deformation into bands at about 45o with respect to the loading direction. Plastic strains as high as 130% have been measured within the ferrite phase

Clustering and formation of nano-precipitates in dilute aluminium and magnesium alloys

Abstract A nuclear magnetic resonance (NMR) method is described for monitoring the evolution of nano-scale precipitate structures in dilute aluminium and magnesium-based alloys. Three examples are given of recent work in this field: (i) 63 Cu detection of Guinier -Preston zones (GPZs) and u-phases in Al(Cu), (ii) 27 Al detection of g-phase (Mg 17 Al 12 ) formation in Mg(Al) alloys and (iii) 45 Sc detection of Al 3 Sc formation in Al(Sc) alloys.

Absences from work among healthcare workers: are they related to influenza shot adherence?

BACKGROUND: The coverage for influenza vaccination among healthcare workers (HCWs) is inadequate in many countries despite strong recommendations; is there evidence that influenza vaccination is effective in preventing absenteeism? Aim of the study is to evaluate the influenza vaccination coverage and its effects on absences from work among HCWs of an Italian academic healthcare trust during the 2017-2018 influenza season. METHODS: We performed a retrospective study to identify predictive characteristics for vaccination, and a retrospective cohort study to establish the effect of vaccination on absences among the vaccinated and non-vaccinated cohorts between December 2017 and May 2018. Overall absence rates over the whole observation period and sub-rates over 14-days intervals were calculated; then comparison between the two groups were conducted applying Chi-square test. RESULTS: Influenza vaccination coverage among 4419 HCWs was 14.5%. Age, university degree, medical care area and physician profile were positively associated with vaccine uptake. Globally during influenza season non-vaccinated HCWs lost 2.47/100 person-days of work compared to 1.92/100 person-days of work among vaccinated HCWs (p\u2009<\u20090.001); significant differences in absences rates resulted when focusing on the influenza epidemic peak. CONCLUSIONS: Factors predicting influenza uptake among HCWs were male sex, working within medical care area and being a physician. Absenteeism among HCWs resulted to be negatively correlated with vaccination against influenza. These findings add evidence to the urgent need to implement better influenza vaccination strategies towards HCWs to tackle vaccine hesitancy among professionals

Patient safety culture in Italian out-ofhours primary care service: a national cross-sectional survey study

Background: Out-of-hours (OOH) services in Italy provide &gt;10 million consultations every year. To the authors' knowledge, no data on patient safety culture (PSC) have been reported. Aim: To assess PSC in the Italian OOH setting. Design &amp; setting: National cross-sectional survey using the Safety Attitudes Questionnaire — Ambulatory Version (SAQ-AV). Method: The SAQ-AV was translated into Italian and distributed in a convenience sample of OOH doctors in 2015. Answers were collected anonymously by Qualtrics. Stata (version 14) was used to estimate Cronbach's alpha, perform exploratory and confirmatory factor analysis, correlate items to doctors' characteristics, and to do item descriptive analysis. Results: Overall, 692 OOH doctors were contacted, with a 71% response rate. In the exploratory factor analysis (EFA), four factors were identified: Communication and Safety Climate (14 items); Perceptions of Management (eight items); Workload and Clinical Risk (six items); and Burnout Risk (four items). These four factors accounted for 68% of the total variance (Kaiser-Meyer-Olkin [KMO] statistic = 0.843). Cronbach's alpha ranged from 0.710-0.917. OOH doctors were often dissatisfied with their job; there is insufficient staff to provide optimal care and there is no training or supervision for new personnel and family medicine trainees. Service managers are perceived as distant, with particular issues concerning the communication between managers and OOH doctors. A large proportion of OOH doctors (56.8%) state that they do not receive adequate support. Conclusion: These findings could be useful for informing policies on how to improve PSC in Italian OOH service

Surface defect evolution in hot rolling of high-Si electrical steels

Surface defects on metal strip products can have their root cause created in the hot rolling process by cavities and indents entrapped scale. The initial size and aspect ratio of surface features are critical parameters that determine whether they will be eliminated by the rolling process. The present research investigates the effects of the initial cavity geometry and the evolution mechanisms in a single hot rolling pass for a high-silicon electrical steel substrate. Laboratory hot-rolling experiments were carried out on blocks with open cavities of different geometries machined into the surface. The final geometry of the longitudinal and transversal profiles of the deformed cavities was analysed from metallurgical cross-sections. For a given initial cavity width, the width of the resulting oxide-filled defect is inversely related to the initial depth of the machined cavity. It has also been observed that the depth of defects increases linearly with the original depth to width aspect ratio of the initial cavities. Cavities with a depth of less than 1 mm essentially disappeared after the rolling. The final length is only dependent on its initial length in the rolling direction. The percentage reduction of cross-sectional area of the defects is found to increase with the initial depth and width of the cavities

The Impact of Functional Bars and Adapted Physical Activity on Quality of Life in Chronic Kidney Disease: A Pilot Study

Chronic kidney disease (CKD) represents a public health problem because it is characterized by several comorbidities, including uremic sarcopenia (US), and a poor quality of life. Currently, there are no standardized treatments available to counteract the onset of US but only some possible therapeutic approaches to slow its progression. The aim of this pilot study is to collect descriptive data in order to design a clinical trial based on the power analysis and simple size. The purpose of this pilot study was to evaluate the possible beneficial action induced by the functional anti-inflammatory and antioxidant bars in combination with the adapted physical activity (APA), on the onset and progression of US and other related-CKD comorbidities. We enrolled 21 CKD patients under conservative therapy, divided into four groups: (A) the physical exercise program (PEP), three times a week, in combination with the daily consumption of the two functional bars group; (B) the PEP group; (C) the daily consumption of the two functional bars group; (D) the control group. The duration of the study protocol was 12 weeks. We observed an improvement trend of body composition, blood pressure levels, lipid metabolism, and functional test in A and B groups. These preliminary data would seem to confirm the effectiveness of APA and to demonstrate the additive role of the natural bioactive compound’s assumption in countering US and other CKD comorbidities

Finite element modelling of surface defect evolution during hot rolling of Silicon steel

Surface defects on metal strips can be generated during hot rolling from surface cavities and indents. The size and aspect ratio of the initial surface cavities present before rolling are critical parameters that determine the final configuration of the defect. The propagation of these defect through the full rolling process is detrimental to the surface quality of the end product, in particular for electrical steel where these type of defects may directly affect the magnetic properties of the final product. A finite element model was developed in the present research to simulate the evolution of surface defects in a high-silicon electrical steel subjected to a single pass hot-rolling operation. The surface defects were modelled as predefined cavities with various aspect ratios and a multi-scale approach was used to capture the large local deformation gradients at the vicinity of the initial cavities. A user-defined subroutine was developed to describe the material constitutive behaviour at different strain rates and temperatures based on the Sellars-Tegart model in ABAQUS/standard finite element package. The modelling results were validated by laboratory scale hot rolling experiments with respect to the measured rolling forces and the plastic deformation of the initial cavities. This study shows that buckling of the lateral sides and bulging of the floor of the initial cavities are the main mechanisms involved in the formation of sub-surface defects. The developed model can be used to predict the evolution of surface cavities and to optimise the rolling parameters in order to minimise the detrimental effect of these defects in the final stages of the hot rolling process

Vascular relaxation of canine visceral arteries after ischemia by means of supraceliac aortic cross-clamping followed by reperfusion

<p>Abstract</p> <p>Background</p> <p>The supraceliac aortic cross-clamping can be an option to save patients with hipovolemic shock due to abdominal trauma. However, this maneuver is associated with ischemia/reperfusion (I/R) injury strongly related to oxidative stress and reduction of nitric oxide bioavailability. Moreover, several studies demonstrated impairment in relaxation after I/R, but the time course of I/R necessary to induce vascular dysfunction is still controversial. We investigated whether 60 minutes of ischemia followed by 30 minutes of reperfusion do not change the relaxation of visceral arteries nor the plasma and renal levels of malondialdehyde (MDA) and nitrite plus nitrate (NOx).</p> <p>Methods</p> <p>Male mongrel dogs (n = 27) were randomly allocated in one of the three groups: sham (no clamping, n = 9), ischemia (supraceliac aortic cross-clamping for 60 minutes, n = 9), and I/R (60 minutes of ischemia followed by reperfusion for 30 minutes, n = 9). Relaxation of visceral arteries (celiac trunk, renal and superior mesenteric arteries) was studied in organ chambers. MDA and NOx concentrations were determined using a commercially available kit and an ozone-based chemiluminescence assay, respectively.</p> <p>Results</p> <p>Both acetylcholine and calcium ionophore caused relaxation in endothelium-intact rings and no statistical differences were observed among the three groups. Sodium nitroprusside promoted relaxation in endothelium-denuded rings, and there were no inter-group statistical differences. Both plasma and renal concentrations of MDA and NOx showed no significant difference among the groups.</p> <p>Conclusion</p> <p>Supraceliac aortic cross-clamping for 60 minutes alone and followed by 30 minutes of reperfusion did not impair relaxation of canine visceral arteries nor evoke biochemical alterations in plasma or renal tissue.</p

Broadband Parametric Amplification in DARTWARS

Superconducting parametric amplifiers offer the capability to amplify feeble signals with extremely low levels of added noise, potentially reaching quantum-limited amplification. This characteristic makes them essential components in the realm of high-fidelity quantum computing and serves to propel advancements in the field of quantum sensing. In particular, Traveling-Wave Parametric Amplifiers (TWPAs) may be especially suitable for practical applications due to their multi-Gigahertz amplification bandwidth, a feature lacking in Josephson Parametric Amplifiers (JPAs), despite the latter being a more established technology. This paper presents recent developments of the DARTWARS (Detector Array Readout with Traveling Wave AmplifieRS) project, focusing on the latest prototypes of Kinetic Inductance TWPAs (KITWPAs). The project aims to develop a KITWPA capable of achieving 20 dB of amplification. To enhance the production yield, the first prototypes were fabricated with half the length and expected gain of the final device. In this paper, we present the results of the characterization of one of the half-length prototypes. The measurements revealed an average amplification of approximately 9 dB across a 2 GHz bandwidth for a KITWPA spanning 17 mm in length