sound quality analysis of the powertrain booming noise in a diesel passenger car

Abstract Among many noises which can be heard inside a car, the booming noise caused by powertrain excitation is usually considered as one of the very annoying acoustic features that affect the interior sound quality of a car. This work presents results coming from an experimental analysis carried out on a Diesel passenger car in order to evaluate the interior booming sensation related with the engine rotation and firing. Tests were performed in acceleration conditions on the vehicle installed at the chassis dynamometer, by measuring noise at the driver and passengers' positions inside cabin. A waterfall analysis was firstly carried out to see the spectral and temporal pattern of recorded time-varying sounds. In particular, the change of sound level related to the fundamental frequency of engine firing and its harmonics was assessed as a function of engine revolution per minute at each microphone location. Acquired data were properly post-processed for sound quality analysis as well, in order to have information about the degree of booming sensation in the accelerating car and to quantify the level of annoyance perceived by each car's occupant. The analysis allowed to identify the vehicle operating conditions as well as the locations inside cabin that make the passengers more exposed to the booming phenomenon. The obtained results represent a useful starting basis for selecting the most appropriate noise and vibration control strategies in vehicle sound quality optimization process

Automotive Materials: An Experimental Investigation of an Engine Bay Acoustic Performances

Abstract In this work an extensively experimental analysis aimed to verify the sound insulation properties of the engine bay of a commercial passenger car is carried out, evaluating the possibility to adopt different sound absorbing materials, to be applied under engine cover nylon skin, in the place of commonly used polyurethane foams. Experimental tests were performed on the vehicle at different stationary operating conditions, employing typical pressure microphones for far field measurements, according to the related prescribed standards. A limited number of materials has been initially selected through a preliminary analysis, and then employed for creating different engine cover configurations, which were subsequently tested in real engine operating conditions. For a good understanding of the obtained results, an experimental investigation through an innovative in situ impedance method aimed to assess acoustic properties of each considered material has been also performed. Among all the tested materials, only one able to ensure better acoustic performance at mid and high frequencies with respect to the already existing cover configuration, has been finally identified, after considering other selection criteria such as an adequate high temperature resistance and the most cost-effective solution. Future analyses will regard investigations on the use of additional materials, for solving problem in attenuating engine noise also at low frequencies

Genome-wide haplotype association study identifies the FRMD4A gene as a risk locus for Alzheimer's disease

Recently, several genome-wide association studies (GWASs) have led to the discovery of nine new loci of genetic susceptibility in Alzheimer's disease (AD). However, the landscape of the AD genetic susceptibility is far away to be complete and in addition to single-SNP (single-nucleotide polymorphism) analyses as performed in conventional GWAS, complementary strategies need to be applied to overcome limitations inherent to this type of approaches. We performed a genome-wide haplotype association (GWHA) study in the EADI1 study (n=2025 AD cases and 5328 controls) by applying a sliding-windows approach. After exclusion of loci already known to be involved in AD (APOE, BIN1 and CR1), 91 regions with suggestive haplotype effects were identified. In a second step, we attempted to replicate the best suggestive haplotype associations in the GERAD1 consortium (2820 AD cases and 6356 controls) and observed that 9 of them showed nominal association. In a third step, we tested relevant haplotype associations in a combined analysis of five additional case-control studies (5093 AD cases and 4061 controls). We consistently replicated the association of a haplotype within FRMD4A on Chr.10p13 in all the data set analyzed (OR: 1.68; 95% CI: (1.43-1.96); P=1.1 × 10 -10). We finally searched for association between SNPs within the FRMD4A locus and Aβ plasma concentrations in three independent non-demented populations (n=2579). We reported that polymorphisms were associated with plasma Aβ42/Aβ40 ratio (best signal, P=5.4 × 10 -7). In conclusion, combining both GWHA study and a conservative three-stage replication approach, we characterised FRMD4A as a new genetic risk factor of AD

Repositioning of the global epicentre of non-optimal cholesterol

High blood cholesterol is typically considered a feature of wealthy western countries1,2. However, dietary and behavioural determinants of blood cholesterol are changing rapidly throughout the world3 and countries are using lipid-lowering medications at varying rates. These changes can have distinct effects on the levels of high-density lipoprotein (HDL) cholesterol and non-HDL cholesterol, which have different effects on human health4,5. However, the trends of HDL and non-HDL cholesterol levels over time have not been previously reported in a global analysis. Here we pooled 1,127 population-based studies that measured blood lipids in 102.6 million individuals aged 18 years and older to estimate trends from 1980 to 2018 in mean total, non-HDL and HDL cholesterol levels for 200 countries. Globally, there was little change in total or non-HDL cholesterol from 1980 to 2018. This was a net effect of increases in low- and middle-income countries, especially in east and southeast Asia, and decreases in high-income western countries, especially those in northwestern Europe, and in central and eastern Europe. As a result, countries with the highest level of non-HDL cholesterol—which is a marker of cardiovascular risk—changed from those in western Europe such as Belgium, Finland, Greenland, Iceland, Norway, Sweden, Switzerland and Malta in 1980 to those in Asia and the Pacific, such as Tokelau, Malaysia, The Philippines and Thailand. In 2017, high non-HDL cholesterol was responsible for an estimated 3.9 million (95% credible interval 3.7 million–4.2 million) worldwide deaths, half of which occurred in east, southeast and south Asia. The global repositioning of lipid-related risk, with non-optimal cholesterol shifting from a distinct feature of high-income countries in northwestern Europe, north America and Australasia to one that affects countries in east and southeast Asia and Oceania should motivate the use of population-based policies and personal interventions to improve nutrition and enhance access to treatment throughout the world.</p

A century of trends in adult human height

Being taller is associated with enhanced longevity, and higher education and earnings. We reanalysed 1472 population-based studies, with measurement of height on more than 18.6 million participants to estimate mean height for people born between 1896 and 1996 in 200 countries. The largest gain in adult height over the past century has occurred in South Korean women and Iranian men, who became 20.2 cm (95% credible interval 17.5-22.7) and 16.5 cm (13.3-19.7) taller, respectively. In contrast, there was little change in adult height in some sub-Saharan African countries and in South Asia over the century of analysis. The tallest people over these 100 years are men born in the Netherlands in the last quarter of 20th century, whose average heights surpassed 182.5 cm, and the shortest were women born in Guatemala in 1896 (140.3 cm; 135.8-144.8). The height differential between the tallest and shortest populations was 19-20 cm a century ago, and has remained the same for women and increased for men a century later despite substantial changes in the ranking of countries

Repositioning of the global epicentre of non-optimal cholesterol

High blood cholesterol is typically considered a feature of wealthy western countries1,2. However, dietary and behavioural determinants of blood cholesterol are changing rapidly throughout the world3 and countries are using lipid-lowering medications at varying rates. These changes can have distinct effects on the levels of high-density lipoprotein (HDL) cholesterol and non-HDL cholesterol, which have different effects on human health4,5. However, the trends of HDL and non-HDL cholesterol levels over time have not been previously reported in a global analysis. Here we pooled 1,127 population-based studies that measured blood lipids in 102.6 million individuals aged 18 years and older to estimate trends from 1980 to 2018 in mean total, non-HDL and HDL cholesterol levels for 200 countries. Globally, there was little change in total or non-HDL cholesterol from 1980 to 2018. This was a net effect of increases in low- and middle-income countries, especially in east and southeast Asia, and decreases in high-income western countries, especially those in northwestern Europe, and in central and eastern Europe. As a result, countries with the highest level of non-HDL cholesterol�which is a marker of cardiovascular risk�changed from those in western Europe such as Belgium, Finland, Greenland, Iceland, Norway, Sweden, Switzerland and Malta in 1980 to those in Asia and the Pacific, such as Tokelau, Malaysia, The Philippines and Thailand. In 2017, high non-HDL cholesterol was responsible for an estimated 3.9 million (95 credible interval 3.7 million�4.2 million) worldwide deaths, half of which occurred in east, southeast and south Asia. The global repositioning of lipid-related risk, with non-optimal cholesterol shifting from a distinct feature of high-income countries in northwestern Europe, north America and Australasia to one that affects countries in east and southeast Asia and Oceania should motivate the use of population-based policies and personal interventions to improve nutrition and enhance access to treatment throughout the world. © 2020, The Author(s), under exclusive licence to Springer Nature Limited

Rising rural body-mass index is the main driver of the global obesity epidemic in adults

Body-mass index (BMI) has increased steadily in most countries in parallel with a rise in the proportion of the population who live in cities 1,2 . This has led to a widely reported view that urbanization is one of the most important drivers of the global rise in obesity 3�6 . Here we use 2,009 population-based studies, with measurements of height and weight in more than 112 million adults, to report national, regional and global trends in mean BMI segregated by place of residence (a rural or urban area) from 1985 to 2017. We show that, contrary to the dominant paradigm, more than 55 of the global rise in mean BMI from 1985 to 2017�and more than 80 in some low- and middle-income regions�was due to increases in BMI in rural areas. This large contribution stems from the fact that, with the exception of women in sub-Saharan Africa, BMI is increasing at the same rate or faster in rural areas than in cities in low- and middle-income regions. These trends have in turn resulted in a closing�and in some countries reversal�of the gap in BMI between urban and rural areas in low- and middle-income countries, especially for women. In high-income and industrialized countries, we noted a persistently higher rural BMI, especially for women. There is an urgent need for an integrated approach to rural nutrition that enhances financial and physical access to healthy foods, to avoid replacing the rural undernutrition disadvantage in poor countries with a more general malnutrition disadvantage that entails excessive consumption of low-quality calories. © 2019, The Author(s)

Sound quality analysis of the powertrain booming noise in a Diesel passenger car

Abstract Among many noises which can be heard inside a car, the booming noise caused by powertrain excitation is usually considered as one of the very annoying acoustic features that affect the interior sound quality of a car. This work presents results coming from an experimental analysis carried out on a Diesel passenger car in order to evaluate the interior booming sensation related with the engine rotation and firing. Tests were performed in acceleration conditions on the vehicle installed at the chassis dynamometer, by measuring noise at the driver and passengers' positions inside cabin. A waterfall analysis was firstly carried out to see the spectral and temporal pattern of recorded time-varying sounds. In particular, the change of sound level related to the fundamental frequency of engine firing and its harmonics was assessed as a function of engine revolution per minute at each microphone location. Acquired data were properly post-processed for sound quality analysis as well, in order to have information about the degree of booming sensation in the accelerating car and to quantify the level of annoyance perceived by each car's occupant. The analysis allowed to identify the vehicle operating conditions as well as the locations inside cabin that make the passengers more exposed to the booming phenomenon. The obtained results represent a useful starting basis for selecting the most appropriate noise and vibration control strategies in vehicle sound quality optimization process

Antimicrobial efficacy and release kinetics of thymol from zein films.

A comprehensive study on thymol loaded zein films is presented in this work. In particular, the antimicrobial efficacy of developed active zein films was tested against three different spoilage microorganisms (cells and spores of Bacillus cereus, Candida lusitaniae and Pseudomonas spp.) and one GRAS (Generally recognized as safe) microbial strain (Streptococcus thermophilus). Results show that the films are effective against the selected spoilage food borne microorganisms, without compromising the growth of S. thermophilus. Release tests were also run at 25 C to investigate the thymol release mechanism. Results show that the Fick’s Second Law satisfactorily describes the release kinetic. Moreover, it was also found that the thymol diffusion coefficient does not depend to a great extent on the thymol concentration. On the other hand, thymol sorption isotherm in zein showed an upward concavity as in the case of low molecular weight compound sorption in polymeric matrix. Finally, antimicrobial effectiveness of developed active film as compared to thymol directly added to the inoculated growing medium was assessed on Pseudomonas spp. by comparing results obtained from direct addiction of thymol to that obtained from released thymol. Results show that differences are negligible