Freestanding nanowires have ultrahigh elastic strain limits (4 to 7%) and yield strengths, but exploiting their intrinsic mechanical properties in bulk composites has proven to be difficult. We ...exploited the intrinsic mechanical properties of nanowires in a phase-transforming matrix based on the concept of elastic and transformation strain matching. By engineering the microstructure and residual stress to couple the true elasticity of Nb nanowires with the pseudoelasticity of a NiTi shape-memory alloy, we developed an in situ composite that possesses a large quasi-linear elastic strain of over 6%, a low Young's modulus of ∼28 gigapascals, and a high yield strength of ∼1.65 gigapascals. Our elastic strain-matching approach allows the exceptional mechanical properties of nanowires to be exploited in bulk materials.
This paper estimates the price and income elasticities of demand for gasoline in China. Our estimates of the intermediate-run price elasticity of gasoline demand range between −0.497 and −0.196, and ...our estimates of the intermediate-run income elasticity of gasoline demand range between 1.01 and 1.05. We also extend previous studies to estimate the vehicle miles traveled (VMT) elasticity and obtain a range from −0.882 to −0.579.
•The price elasticity of demand for gasoline in China is between −0.497 and −0.196.•The income elasticity of demand for gasoline in China is between 1.01 and 1.05.•The price elasticity of demand for VMT in China is between −0.882 and −0.579.
This paper uses annual urban household survey data of Sichuan Province from 2007 to 2009 to estimate the income and price elasticities of residential electricity demand, along with the effects of ...lifestyle-related variables. The empirical results show that in the urban area of Sichuan province, the residential electricity demand is price- and income-inelastic, with price and income elasticities ranging from −0.35 to −0.50 and from 0.14 to 0.33, respectively. Such lifestyle-related variables as demographic variables, dwelling size and holdings of home appliances, are also important determinants of residential electricity demand, especially the latter. These results are robust to a variety of sensitivity tests. The research findings imply that urban residential electricity demand continues to increase with the growth of income. The empirical results have important policy implications for the Multistep Electricity Price, which been adopted in some cities and is expected to be promoted nationwide through the installation of energy-efficient home appliances.
•We estimate price and income elasticities in China using household survey data.•The current study is the first such study in China at this level.•Both price and income are inelastic.•Behavior factors have important impact on electricity consumption.
A size-dependent integral elasticity model is developed for a small-scaled rod in tension based on the nonlocal strain gradient theory. The integral rod model contains a nonlocal parameter and a ...material length scale parameter to incorporate the scaling effects of nonlocal stress and microstructure-dependent strain gradient. In comparison to size-dependent differential models, the developed integral rod model is both self-consistent and well-posed. The governing equations and boundary conditions for the nonlocal strain gradient rod in tension are derived by employing the principle of virtual work. In addition to the classical natural and essential boundary conditions, non-classical natural and essential boundary conditions are present for the integral rod model. The closed-form solutions for predicting the displacement and reduced Young’s modulus are derived for four types of boundary conditions. It is shown explicitly that the integral rod model can exert stiffness-softening and stiffness-hardening effects by considering various values of size-dependent parameters and boundary conditions. It is found that, the developed rods with four different boundary conditions can predict the scaling effects of the Young’s modulus of single-walled carbon nanotube, and the scaling effects are more sensitive to the size-dependent parameters (the material length scale parameter and the nonlocal parameter) in comparison with the non-classical boundary conditions.
We study the residential demand for electricity and gas, working with nationwide household-level data that cover recent years, namely 1997–2007. Our dataset is a mixed panel/multi-year cross-sections ...of dwellings/households in the 50 largest metropolitan areas in the United States as of 2008. We estimate static and dynamic models of electricity and gas demand. We find strong household response to energy prices, both in the short and long term. From the static models, we get estimates of the own price elasticity of electricity demand in the −
0.860 to −
0.667 range, while the own price elasticity of gas demand is −
0.693 to −
0.566. These results are robust to a variety of checks. Contrary to earlier literature (Metcalf and Hassett, 1999; Reiss and White, 2005), we find no evidence of significantly different elasticities across households with electric and gas heat. The price elasticity of electricity demand declines with income, but the magnitude of this effect is small. These results are in sharp contrast to much of the literature on residential energy consumption in the United States, and with the figures used in current government agency practice. Our results suggest that there might be greater potential for policies which affect energy price than may have been previously appreciated.
In this work the problem of the in-plane free vibrations (axial and bending) of a Bernoulli–Euler nanobeam using the mixed local/nonlocal Eringen elasticity theory is studied. The natural frequencies ...of vibration have been analytically obtained solving two uncoupled integro-differential eigenvalue problems, which are properly transformed in differential eigenvalue problems. Different kinds of end supports have been considered, and the influence of both mixture parameter and length scale has been analysed. The results show the softening effect of the Eringen’s nonlocality, which is more pronounced as the local phase fraction decreases.
A large number of papers devoted to the dynamics of Bernoulli–Euler beams considering the fully nonlocal Eringen elasticity theory has been previously published. However, as recently stated by Romano, Barretta, Diaco and de Sciarra (2017), the problem is ill-posed in general, and the existence of a solution is an exception, the rule being non-existence. Nevertheless, the presence of a local term in the constitutive equation, leading to the two-phase formulation, renders the problem well-posed. To the best knowledge of the authors, this is the first time an exact solution is presented for a dynamic problem involving structures with constitutive equations corresponding to nonlocal integral Eringen’s elasticity.
This study examines the short- and long-run price and income elasticities of residential and industrial electricity demand in the European Union between 1996 and 2016. Instrumental variable models ...using the between estimator, as well as dynamic panel models are employed to present robust estimates, and to assess the impact of different methodologies on the reported elasticities. The long-run price elasticity of residential electricity consumption is estimated between −0.53 and −0.56. These elasticities are more inelastic than that of industrial electricity use, which is reported between −0.75 and −1.01. The choice of different econometric methodologies has only moderate impact on the estimates. While long-run residential income elasticity estimates are moderately inelastic and estimated around 0.61, industrial electricity use tends to be closely tied to income, with elasticities between 0.76 and 1.08. Electricity demand in all sectors is highly price and income inelastic in the short run. Additionally, population density, temperatures, and policy measures also influence sectoral electricity use. The above estimates can aid the design of European energy and environmental policy.
•Electricity demand is highly price and income inelastic in the short run.•The long-run price elasticity of industrial electricity use is between −0.75 and −1.01.•The long-run price elasticity of residential electricity use is between −0.53 and −0.56.•Industrial electricity consumption is closely tied to income.
The Baveno VI consensus proposed a dual liver stiffness (LS) by transient elastography threshold of <10 and >15 kPa for excluding and diagnosing compensated advanced chronic liver disease (cACLD) in ...the absence of other clinical signs. Herein, we aimed to validate these criteria in a real-world multicentre study.
We included 5,648 patients (mean age 51 ± 13 years, 53% males) from 10 European liver centres who had a liver biopsy and LS measurement within 6 months. We included patients with chronic hepatitis C (n = 2,913, 52%), non-alcoholic fatty liver disease (NAFLD, n = 1,073, 19%), alcohol-related liver disease (ALD, n = 946, 17%) or chronic hepatitis B (n = 716, 13%). cACLD was defined as fibrosis stage ≥F3.
Overall, 3,606 (66%) and 987 (18%) patients had LS <10 and >15 kPa, respectively, while cACLD was histologically confirmed in 1,772 (31%) patients. The cut-offs of <10 and >15 kPa showed 75% sensitivity and 96% specificity to exclude and diagnose cACLD, respectively. Examining the ROC curve, a more optimal dual cut-off at <7 and >12 kPa, with 91% sensitivity and 92% specificity for excluding and diagnosing cACLD (AUC 0.87; 95% CI 0.86–0.88; p <0.001) was derived. Specifically, for ALD and NAFLD, a low cut-off of 8 kPa can be used (sensitivity=93%). For the unclassified patients, we derived a risk model based on common patient characteristics with better discrimination than LS alone (AUC 0.74 vs. 0.69; p <0.001).
Instead of the Baveno VI proposed <10 and >15 kPa dual cut-offs, we found that the <8 kPa (or <7 kPa for viral hepatitis) and >12 kPa dual cut-offs have better diagnostic accuracy in cACLD.
The term compensated advanced chronic liver disease (cACLD) was introduced in 2015 to describe the spectrum of advanced fibrosis and cirrhosis in asymptomatic patients. It was also suggested that cACLD could be diagnosed or ruled out based on specific liver stiffness values, which can be non-invasively measured by transient elastography. Herein, we assessed the suggested cut-off values and identified alternative values that offered better overall accuracy for diagnosing or ruling out cACLD.
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•cACLD is the spectrum of advanced fibrosis and cirrhosis in asymptomatic patients.•The Baveno VI consensus suggested a dual liver stiffness cut-off to diagnose/rule out cACLD.•Proposed liver stiffness cut-offs of 15 kPa had 75%/96% Se/Sp to rule out/in cACLD.•We showed that liver stiffness cut-offs of 12 kPa are optimal (Se/Sp 91%/92%).•In ALD and NAFLD, a cut-off <8 kPa can be used to rule out cACLD (Se=93%).
The price elasticities demand of electricity, gas, oil fuel, gasoline and steam coal are estimated using household surveys from 1992 to 2014. The analysis uses alternative econometric techniques – ...OLS, SURE, and Quadratic Almost Ideal Demand System (QUAIDS) – the last of which is based on the methodology of Banks, Blundell and Lewbel considering socioeconomic characteristics of the households to account for the difference in demand of energy related goods. It is found that the demands for fuels are price inelastic, and the differences in elasticities between poor and non-poor households are small but statically significant. The income elasticity of demand is generally found to be positive and higher in absolute value than price elasticity, and the differences are greater between poor and non-poor. Consequently, there would be a differentiated reaction of consumers to changes in energy prices according to their poverty status. Steam coal and firewood, each of which could be considered inferior goods, stand as counterexamples in that the income elasticity is found to be negative. The contribution of this study helps policy makers to analyze household welfare when applying changes in energy prices in the face of fiscal and/or energy reforms, such as those Mexico is implementing.
•Detailed analysis of Mexican energy use for poor and non-poor households.•The Income-Expenditure National Survey is used to estimate household elasticities.•Elasticities can inform policy to minimize regressive tax and subsidy impacts.•Carbon (coal) and wood are found to be inferior energy goods.•Transportation fuels and services see rising use with household income.
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