In this study, laser-ablated nanoparticles were produced by laser ablation of a copper target in deionized water by the increased first harmonic of Nd:YAG laser and the influence of the subsequent ...annealing temperature on the structural and optical properties of produced nanoparticles was studied. Also, the annealing temperature influence on the photocatalytic reduction of aqueous Cr(VI) ion with the nanoparticles was investigated. Its X-ray diffraction (XRD) results indicate that the laser-ablated nanoparticles are completely oxidized into CuO nanoparticles by annealing and by increasing the temperature from 400 to 800°C, the mean crystallite size of nanoparticles increased from 11 to 90 nm, and the bandgap decreased from 1.2 to 1.9 eV. The bandgap increased with a size reduction due to the quantum confinement effect. The morphological analysis by field-emission scanning electron microscope and transmission electron microscope confirm that spherical-shaped CuO nanoparticles are formed and the size of particles increased with the increase in the annealing temperature. The photocatalytic activity results of nanoparticles show maximum Cr(VI) reduction for nanoparticles annealed at 600°C. The decrease as the temperature of annealing rises is associated with the surface area reduction and the temperature reduce is attributed to the expansion of the bandgap.
Smart grids (SGs) have a central role in the development of the global power sector. Cost-benefit analyses and environmental impact assessments are used to support policy on the deployment of SG ...systems and technologies. However, the conflicting and widely varying estimates of costs, benefits, greenhouse gas (GHG) emission reduction, and energy savings in literature leave policy makers struggling with how to advise regarding SG deployment. Identifying the causes for the wide variation of individual estimates in the literature is crucial if evaluations are to be used in decision-making. This paper (i) summarizes and compares the methodologies used for economic and environmental evaluation of SGs (ii) identifies the sources of variation in estimates across studies, and (iii) point to gap in research on economic and environmental analyses of SG systems. Seventeen studies (nine articles and eight reports published between 2000 and 2015) addressing the economic costs versus benefits, energy efficiency, and GHG emissions of SGs were systematically searched, located, selected, and reviewed. Their methods and data were subsequently extracted and analysed. The results show that no standardized method currently exists for assessing the economic and environmental impacts of SG systems. The costs varied between 0.03 and 1143M€/yr, while the benefits ranged from 0.04 to 804M€/yr, suggesting that SG systems do not result in cost savings The primary energy savings ranged from 0.03 to 0.95MJ/kWh, whereas the GHG emission reduction ranged from 10 to 180gCO2/kWh, depending on the country grid mix and the system boundary of the SG system considered. The findings demonstrate that although SG systems are energy efficient and reduce GHG emissions, investments in SG systems may not yield any benefits. Standardizing some methodologies and assumptions such as discount rates, time horizon and scrutinizing some key input data will result in more consistent estimates of costs and benefits, GHG emission reduction, and energy savings.
Abstract
This research is an attempt to identify the most important dimensions of vocational education and training (VET) on empowering rural women, a topic that has received less attention. The ...present study is a quantitative, non-experimental, applied, survey research, whose statistical population includes rural women and girls who participated in VET classes. The research tool was a researcher-designed questionnaire. The reliability and validity of the research tool using a pilot test and calculating Cronbach’s alpha, AVE, and CR coefficients were shown to indicate the high capability of the research tool to collect data. The results showed that among the four dimensions of VET, the role of content and educator was more than other dimensions and these dimensions of training had improved the economic empowerment of rural women, which was often at the lowest level. The conceptual framework presented can be used as a guide to achieving sustainable development goals of the millennium; and should be considered at the national and international levels. The paper makes an impact on the growing body of knowledge by emphasizing on more important dimensions of education; which can be effective for the empowerment of women, especially in the economic dimension. In the existing studies on empowering rural women, none of them examined the effect of all different components of education on women’s overall empowerment, which are among the innovations of the present study and should be considered in future planning.
In this paper, an automated adaptive remeshing procedure is presented for simulation of arbitrary shape crack growth in a 2D finite element mesh. The Zienkiewicz–Zhu error estimator is employed in ...conjunction with a modified SPR technique based on the recovery of gradients using analytical crack-tip fields in order to obtain more accurate estimation of errors. The optimization of crack-tip singular finite element size is achieved through the adaptive mesh strategy. Finally, several numerical examples are illustrated to demonstrate the effectiveness, robustness and accuracy of computational algorithm in calculation of fracture parameters and prediction of crack path pattern.
In this paper, the three-dimensional automatic adaptive mesh refinement is presented in modeling the crack propagation based on the modified superconvergent patch recovery technique. The technique is ...developed for the mixed mode fracture analysis of different fracture specimens. The stress intensity factors are calculated at the crack tip region and the crack propagation is determined by applying a proper crack growth criterion. An automatic adaptive mesh refinement is employed on the basis of modified superconvergent patch recovery (MSPR) technique to simulate the crack growth by applying the asymptotic crack tip solution and using the collapsed quarter-point singular tetrahedral elements at the crack tip region. A-posteriori error estimator is used based on the Zienkiewicz–Zhu method to estimate the error of fracture parameters and predict the crack path pattern. Finally, the efficiency and accuracy of proposed computational algorithm is demonstrated by several numerical examples.
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•Laser ablation of copper target in H2O2 solution with 1064 nm wavelength of a Ce:Nd:YAG pulsed laser.•Investigation of the composition and morphology of the samples synthesized with ...different laser pulse energies and in different concentrations of H2O2 solution.•Synthesis of Cu/CuO flake-like nanostructures with band gap in visible region and its extension by changing the synthesis parameters such as laser pulse energy and concentration of H2O2 solution.•The CuO to Cu ratio content of the synthesized samples increased with increasing H2O2 concentration.
Laser ablation of copper targets using Ce:Nd:YAG laser with pulses of 1064 nm wavelengths at 10 ns pulse width and with different laser pulse energies and in different concentrations of H2O2 solution is investigated experimentally. Cu/CuO flake-like nanostructures with visible band gap and the extension of its light absorption by changing the synthesis parameters such as laser pulse energy and concentration of H2O2 solution were observed.
Characterization and comparison of the obtained suspensions are exploited by X-ray diffraction (XRD), UV–vis spectroscopy and field emission scanning electron microscopy (FE-SEM). The XRD analysis data show that in 10 vol% H2O2 solution CuO phase has been synthesized, while with decreasing the H2O2 concentration, Cu phase is also observed. The mean crystallite sizes of CuO were estimated using XRD patterns and were between 2.1 and 3.3 nm. The comparison of the UV–visible absorption spectra indicates that with decreasing pulse energy and decreasing H2O2 concentration up to 5 vol% the band gap of nanoparticles increased from 2.19 eV to 2.34 eV, which is accordant with the quantum confinement effect. FESEM image of all the synthesized samples illustrate the formation of flake-like nanostructure with the thickness of about 12–15 nm.
The goal of this survey study was to understand pastoralist attitudes toward sustainable integrated rangeland management (SIRM) in Tehran province, Iran. Using multi-stage stratified random sampling, ...1280 pastoralists participated in the study. Data were collected using a researcher-made questionnaire. A panel of experts approved the content validity and Cronbach's alpha coefficient was used to test the reliability of the questionnaire. Results revealed that most of the pastoralists held a positive attitude toward teamwork and collaborative behavior. Moreover, regression analysis indicated that education level, attitudes toward other pastoralists, teamwork and collaboration with administrative officials, significantly affected pastoralist attitudes toward SIRM. Furthermore, path analysis showed that attitudes to other pastoralists indirectly affects attitudes toward SIRM and collaboration with administrative officials. This study concluded that if sustainable rangeland management is a goal, human factors should be considered as a key element.
► Pastoralists have positive attitudes toward sustainable integrated rangeland management (SIRM). ► Policy makers should take ‘human factor’ into consideration when designing effective SIRM. ► Administrative officials should start with those pastoralists who have already experienced integrated programs. ► Practitioners should begin with those pastoralists who are more positive about teamwork.
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