Search results for " Structural"
showing 10 items of 1751 documents
Experimental Evidence of Leaks in Elastic Pipes
2016
Several studies have been carried out in recent decades to establish a relationship between total head and leaks. In literature, the leakage governing equations have been analysed in light of pipe materials, water head, leak dimension or shape. Most of these contributions questioned the classical Torricelli equation, demonstrating through experimental evidence that the classical orifice law can give unsatisfactory results. Nevertheless, starting from the Torricelli equation, other exponential or linear governing equations have been proposed as mathematical models able to reproduce the leakages in water distribution systems (WDSs). To investigate the validity of the proposed governing equati…
Channels through Which Human Capital Inequality Influences Economic Growth
2011
This paper empirically investigates the theoretical predictions of some of the channels through which human capital inequality may discourage investment and growth. In a cross section of countries over the period 1960–2000, findings reveal that, all other things being equal, a greater degree of human capital inequality increases fertility rates and reduces life expectancy, which in turn hampers the accumulation rates of human capital. This effect is reinforced in the countries where individuals find it difficult to access credit. Extensive sensitivity analyses show that the results are robust across specifications and are not driven by atypical observations, endogenous regressors, or unobse…
Six-years-long effects of the Italian policies for photovoltaics on the pay-back period of grid-connected PV systems installed in urban contexts
2017
Abstract In this study the discounted pay-back (DPB) period of rooftop photovoltaic (PV) systems installed in urban contexts was investigated during the course of time with the aim of evaluating the effects of the different supporting policies enacted by the Italian government. The profitability of the investment in three Italian cities was observed from June 2010 to May 2016 by means of an exhaustive economic analysis based on the study of the variation of the costs and benefits during the lifetime of the investment. The analysis considered the disbursements for the PV system devices, maintenance and management, insurance, and wear of PV panels and inverters. Other significant parameters, …
Urban morphology detection and it's linking with land surface temperature: A case study for Tehran Metropolis, Iran
2021
Abstract Expansion of urban areas and alteration of natural land cover exacerbate the local climate change. To find out the effect of land cover changes on the local climate, in this study, the Local Climate Zone (LCZ) concept was utilized to detect urban morphology in Tehran Metropolis. LCZ and Land Surface Temperature (LST) can be identified and classified based on available remote sensing products. Firstly, LCZ maps of Tehran metropolis were extracted using Landsat imagery, and secondly, relationships between LCZ and LST were explored for three years (1990, 2004, and 2018). We found that Tehran urban structure has 13 LCZs based on imagery from Landsat 5 and 14 LCZs based on images for La…
Waterfront Redevelopment in Post-America’s Cup Valencia: Some Insights from a Survey to Local Residents
2018
AbstractWaterfront renewal is a recurrent event in the life of many cities around the world. Traditionally, planners and geographers have focused on this phenomenon analyzing the ongoing relationsh...
Expectations and the term premium as time varying leading indicators of US economic activity
2009
This paper investigates the growth predictive properties of the expectation-related and term premium components of the US term spread. Results suggest that although the predictive power of two components has greater predictive power compared to the simple spread, it has a time-varying nature. The expectations-related term is positive and statistically significant up to the end of the 80s becoming insignificant afterwards. The term-premium estimates are positive and significant for a brief period in the 70s, turn insignificant after the 80s, except in short intervals at the beginning of the 90s and the 2000s, when they turn negative.
Comparison of numerical modelling techniques for impact investigation on a wind turbine blade
2019
Wind turbine blades are exposed to numerous impact risks throughout their lifetimes. The impact risks range from bird collisions during operation to impacts with surrounding structures at the time of transportation and installation. Impact loads on the fibre composite blades can induce several complex, simultaneously interacting and visually undetectable damage modes and have a high potential to reduce the local and global blade stiffness. An assessment of such impact-induced damages is therefore necessary and usually involves high computational costs using numerical procedures, especially when analysing large composite components. To minimise this computational expense, different numerical…
Numerical investigation of rain droplet impact on offshore wind turbine blades under different rainfall conditions: A parametric study
2020
The leading edge of a fiber composite wind turbine blade (WTB) is prone to erosion damages due to repeated rain droplet impact during its service life. Such damages are critical to the blade's aerodynamic as well as structural performance, ultimately resulting in substantial repair costs. An effective design of a coating material for WTB is necessary and its analysis must include variables associated with erosive rain droplets such as (1) droplet diameter, (2) impact velocity, and (3) droplet impact angle. The present paper develops and validates a coupled fluid structure interaction (FSI) computational model for simulating rain droplet impact on WTBs, where the structure domain is modelled…
Optimizing the Sampling Area across an Old-Growth Forest via UAV-Borne Laser Scanning, GNSS, and Radial Surveying
2022
Aboveground biomass, volume, and basal area are among the most important structural attributes in forestry. Direct measurements are cost-intensive and time-consuming, especially for old-growth forests exhibiting a complex structure over a rugged topography. We defined a methodology to optimize the plot size and the (total) sampling area, allowing for structural attributes with a tolerable error to be estimated. The plot size was assessed by analyzing the semivariogram of a CHM model derived via UAV laser scanning, while the sampling area was based on the calculation of the absolute relative error as a function of allometric relationships. The allometric relationships allowed the structural …
Uncertainty analysis of life cycle assessment of asphalt surfacings
2023
The Life Cycle Assessment (LCA) of asphalt pavements are associated with significant uncertainty resulting from variability in the quantity and impact of individual components, the quality of data for each component, and variability of asphalt durability. This study presents a framework to quantify and incorporate the uncertainty of LCA and asphalt durability data into LCA of asphalt surfacings. The suggested framework includes: estimating the uncertainty of asphalt production processes by the pedigree matrix method, conducting a deterministic LCA, applying Monte Carlo Simulation (MCS) to estimate the probability density functions (PDFs) of the considered impacts using the uncertainty data,…