Influence of texture on tyre road noise spectra in rubberized pavements

Abstract Road traffic noise is the most common source of environmental pollution in urban areas and therefore, the study of noise mitigation actions is fundamental for urban planning. The main source of road traffic noise is tyre/road interaction; thus, the use of low noise road surfaces represents an optimal solution for its mitigation. Several studies tried to find a correlation between road texture and broadband noise data, trying to provide guidelines for the development of acoustically optimised road surfaces. The present work studies the correlation between road texture and tyre/road noise from an experimental point of view, by analysing texture and noise spectra on ten different road surfaces. Tyre deformation has also been addressed by analysing two already existing tyre envelopment algorithms. The first algorithm, proposed by Von Meier and based on the limitation of the second order derivative of the profile signal, shows poor correlation with high frequency noise, while the second algorithm, based on a novel method proposed by Sandberg and Goubert and called indenter method, enhances correlation with low frequency noise and preserves information at higher frequencies. Correlation patterns show that rolling noise can be separated in three main contributions: low, middle and high frequency noise. Finally, experimental tyre/road noise and enveloped texture data obtained with the indenter algorithm have been used to elaborate a linear model that relates low and high frequency noise to texture one-third octave bands. This model deepens knowledge on tyre/road interaction

modelling of acoustic ageing of rubberized pavements

Abstract Tyre-road noise is the most important source of traffic noise in the mid-to-high speed range. The use of low noise road surfaces represents an ideal solution to mitigate traffic noise, because it directly affects the source, generating a widespread benefit for all the dwellings near the road and decreasing the number of people annoyed. More knowledge about long-term acoustic performance is required to promote the use of low noise road surfaces as mitigation action. In fact, as for a traditional road surface, the acoustic properties of low noise surfaces worsen over time: only by knowing the initial noise reduction and its time evolution, public administrations can design their application and related maintenance plans. In this work, an innovative approach was used to investigate and model acoustic ageing of some rubberized road surfaces surveyed for several years. This type of quiet pavements represents an efficient road surface technology in terms of traffic noise reduction. A new regression model was applied to estimate the acoustic ageing of the investigated pavements, considering the complex interacting system composed of three main elements: pavement type, traffic loads and climatic conditions

modelling the acoustic performance of newly laid low noise pavements

Abstract Road traffic in urban contexts produces noise mainly by the interaction of tyres with pavement surface and, therefore, the use of low-noise surfaces represents the best solution since they aim to mitigate the source. Moreover, in urban contexts it is often the only viable solution, together with a careful traffic planning. The main challenge in their adoption as noise mitigation actions is to be able to forecast the acoustical performances that the new road surface will be able to offer. In the UE, the new Green Public Procurement requires experimental verification of noise performance compliance: the designer must declare the acoustical performance of the proposed low-noise pavement and, a few months after the laying, the actual performance of the road surface must be tested using the Close Proximity Method (CPX). Due to the importance of being able to forecast CPX levels, the present work reports a novel way to model CPX broadband levels of newly laid low-noise road surfaces using only data available to the designer before the laying or easily obtained through coring tests, such as grading curve, fractal dimension, asphalt binder content, air voids, voids in mineral aggregates. Two models were elaborated, using two different frequency separations for tyre/road noise. The first model separates low and high frequency contributions, while the second one also considers noise around 1 kHz separately, using a three-band model. Both models are capable of forecasting the acoustic performance of newly laid low-noise road surfaces, using different road mixture parameters at different frequency ranges. The three band model shows a lower RMSE

evaluation of tyre road noise and texture interaction on rubberised and conventional pavements using cpx and profiling measurements

Road traffic noise is the most common source of environmental pollution in urban areas, and therefore, the study of noise mitigation actions is fundamental for urban planning. The use of low noise ..

Biofabrication of bundles of poly(lactic acid)-collagen blends mimicking the fascicles of the human Achille tendon

Electrospinning is a promising technique for the production of scaffolds aimed at the regeneration of soft tissues. The aim of this work was to develop electrospun bundles mimicking the architecture and mechanical properties of the fascicles of the human Achille tendon. Two different blends of poly(L-lactic acid) (PLLA) and collagen (Coll) were tested, PLLA/Coll-75/25 and PLLA/Coll-50/50, and compared with bundles of pure PLLA. First, a complete physico-chemical characterization was performed on non-woven mats made of randomly arranged fibers. The presence of collagen in the fibers was assessed by thermogravimetric analysis, differential scanning calorimetry and water contact angle measurements. The collagen release in phosphate buffer solution (PBS) was evaluated for 14 days: results showed that collagen loss was about 50% for PLLA/Coll-75/25 and 70% for PLLA/Coll-50/50. In the bundles, the individual fibers had a diameter of 0.48 ±0.14 μm (PLLA), 0.31 ±0.09 μm (PLLA/Coll-75/25), 0.33 ±0.08 μm (PLLA/Coll-50/50), whereas bundle diameter was in the range 300-500 μm for all samples. Monotonic tensile tests were performed to measure the mechanical properties of PLLA bundles (as-spun) and of PLLA/Coll-75/25 and PLLA/Coll-50/50 bundles (as-spun, and after 48 h, 7 days and 14 days in PBS). The most promising material was the PLLA/Coll-75/25 blend with a Young modulus of 98.6 ±12.4 MPa (as-spun) and 205.1 ±73.0 MPa (after 14 days in PBS). Its failure stress was 14.2 ±0.7 MPa (as-spun) and 6.8 ±0.6 MPa (after 14 days in PBS). Pure PLLA withstood slightly lower stress than the PLLA/Coll-75/25 while PLLA/Coll-50/50 had a brittle behavior. Human-derived tenocytes were used for cellular tests. A good cell adhesion and viability after 14 day culture was observed. This study has therefore demonstrated the feasibility of fabricating electrospun bundles with multiscale structure and mechanical properties similar to the human tendon

TOWARDS THE DEVELOPMENT OF BENCH TESTING FOR LOWER-LIMB PROSTHETIC SOCKETS FOR SPORT APPLICATIONS

Prosthetic sockets are the bespoken part of lower-limb prostheses. Knowledge about the mechanical properties of sockets is essential to ensure patient safety and comply with current medical device regulations. This includes sockets designed for sport activities. Unfortunately, the literature is extremely limited and contradictory as described in a recent systematic review. The aim of this study was to initiate a research activity aiming to design a mechanical bench system for socket testing and perform a comparative analysis of the ultimate strength of alternative socket layups. Results highlight substantial differences in the maximum loading at failure, stressing the importance of increasing the knowledge about socket mechanical properties to support prosthetists provide reliable and safe products to patients and athletes

The skeletal effect of post-natal treatment with N-acetylcysteine in a diastrophic dysplasia mouse model

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Dasabuvir and Ombitasvir/Paritaprevir/Ritonavir with or without Ribavirin in Patients with HIV-HCV Coinfection. Real Life Interim Analysis of an Italian Multicentre Compassionate Use Program

Background and Aims: An HCV cure is now possible in a large proportion of HIV-HCV patient. We present real life results of a compassionate use program promoted by SIMIT (Infectious and Tropical Diseases Italian Society) of Dasabuvir and Ombitasvir/Paritaprevir/Ritonavir ± Ribavirin for 12 weeks in 213 HIV-HCV genotype 1 patients. Data on efficacy and tolerability of this strategy in HIV patients have been reported until now only in 43 non cirrhotic HIV subjects

Antigene MYCN Silencing by BGA002 Inhibits SCLC Progression Blocking mTOR Pathway and Overcomes Multidrug Resistance

: Small-cell lung cancer (SCLC) is the most aggressive lung cancer type, and is associated with smoking, low survival rate due to high vascularization, metastasis and drug resistance. Alterations in MYC family members are biomarkers of poor prognosis for a large number of SCLC. In particular, MYCN alterations define SCLC cases with immunotherapy failure. MYCN has a highly restricted pattern of expression in normal cells and is an ideal target for cancer therapy but is undruggable by traditional approaches. We propose an innovative approach to MYCN inhibition by an MYCN-specific antigene-PNA oligonucleotide (BGA002)-as a new precision medicine for MYCN-related SCLC. We found that BGA002 profoundly and specifically inhibited MYCN expression in SCLC cells, leading to cell-growth inhibition and apoptosis, while also overcoming multidrug resistance. These effects are driven by mTOR pathway block in concomitance with autophagy reactivation, thus avoiding the side effects of targeting mTOR in healthy cells. Moreover, we identified an MYCN-related SCLC gene signature comprehending CNTFR, DLX5 and TNFAIP3, that was reverted by BGA002. Finally, systemic treatment with BGA002 significantly increased survival in MYCN-amplified SCLC mouse models, including in a multidrug-resistant model in which tumor vascularization was also eliminated. These findings warrant the clinical testing of BGA002 in MYCN-related SCLC

The banking-industry relationship in Italy: large national banks and small local banks compared (1913-1936)

Using a large dataset of Italian joint-stock companies, this article analyses the networks of corporate interlocks of the major universal banks and twenty most ‘central’ local banks in a critical period of Italian industrialisation. The networks of the two types of banks were largely independent, with universal banks being affiliated principally to larger concerns in electricity, transport and storage, and financials; and local banks to riskier, younger and smaller firms in light manufacturing. The article then explores whether the bank-industry relationship in Italy reflected the hegemony of banks and followed a bank-control model. Our analysis does not support that view. It rather indicates that interlocking directorates were driven principally by a convergence of interests between banks (monitoring customers) and industrial firms (interested in tapping capital and credit flows), with the latter exerting a slightly higher influence over the former. This significantly differentiates Italy from Germany and the USA, where banks had a more dominant position in the corporate system