Moderate or Intense Low-oxygen Dilution (MILD) combustion which known as a combustion under highly preheated and diluted condition is a relatively new combustion regime including many differences in ...comparison with the traditional one. Among many distinguished disparities between combustion modeling of conventional and MILD ones, turbulent-chemistry interaction modeling is an open field of study. Current knowledge on modeling this combustion regime shows that the eddy dissipation concept (EDC) model could be successfully used for modeling of this combustion regime. In this paper, it has been tried to propose some guidelines to modify the semi-empirical constants of the original EDC model for MILD combustion. In this way a parametric study of the EDC model constants for a nonpremixed MILD burner is done in terms of accuracy of prediction while the responses of the model to its constants are focused on the basis of physical arguments. Burner of Dally et al. (JHC) is modeled using the RANS approach in a 2D axisymmetric computational domain for different oxygen levels and fuel jet Reynolds numbers when a reduced detail chemical mechanism of DRM-22 is used to represent the chemical mechanism. Moreover using a well-stirred–reactor analysis and extracting the chemical reactions pathways, discussions are completed. Results show that reducing the CD2 constant which leads to a decrease in time scale and volume fraction constants of the model would improve the performance of the model for MILD condition. Prediction of flame lift-off and minor OH species has been improved by changing default model constants of Cτ and Cγ to around 0.0893 and 1.0, respectively, especially for lower oxygen levels. Indeed reaction pathway analysis and dimension of reaction zone showed that reducing scales of the defined reactor in the EDC model (i.e. fine structure) to the Kolmogrov or smaller scales might push the reactions inside each structure toward the non-equilibrium condition and enlargement of overall reaction zone and make the EDC model more compatible with MILD combustion characteristics. Reduction in the length and time scales of the fine structure led to improvement in Temperature, OH, and CO profiles inside of MILD region of the JHC burner, although for CO, disagreement is still considerable. Considering error analysis of five checked parameters (i.e. H2O, CO2, OH, CO, and temperature) at both MILD and conventional regions of the JHC burner may conduct us toward that the defaults setting of the model still works reasonably on the whole when it is used at both regions.
Understanding the nexus CO2 emissions and economic growth helps economies in formulating energy policies and developing energy resources in sustainable ways. Although during recent years, numerous of ...the previous studies have been very thoroughly investigated the nexus between economic growth and CO2 emissions, there is a lack of research regarding the qualitative systematic review and meta-analysis in these areas. The main purpose of this review paper is to present the comprehensive overview of the relationship between CO2 emissions and economic growth. In this regard, the Web of Science database has been chosen and a qualitative systematic and meta-analysis method which called “Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA)” has been proposed. Therefore, a review of 175 published articles appearing in 55 scholarly international journals between 1995 and 2017 has been achieved to reach a broad review of the nexus between economic growth and CO2 emissions with other indicators. Consequently, the selected articles have been categorized by the author name, the year of publication, data duration, types of techniques, data analysis method, the name of indicators, country, scope (individual country and multi-countries), journals, results, and outcome in which they appeared. The results of this paper demonstrated that the nexus between CO2 emissions and economic growth gives reasons for policy options that have to reduce emissions by imposing limiting factors on economic growth as well. Given the fact that bidirectional causality exists, as far as economic growth increases or decreases, further CO2 emissions are stimulated in higher or lower levels and consequently, a potential reduction of the emissions should have an adverse influence on economic growth.
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•A review of 175 articles dealing with CO2 and economic growth during 2 recent decades was performed.•These papers were obtained from 55 journals refereed at WoS database.•Qualitative systematic and meta-analysis method called “PRISMA” was applied.•Articles have been categorized by author, techniques, countries, data analysis, results, etc.•The bidirectional causality exists between economic growth and CO2 emission trends.
This study analyzes the effects of innovation-driven (ID) on a company’s new product innovation performance using knowledge-based theory. Furthermore, it explores absorptive capacity’s (ACAP) ...intermediary effect on ID and new product innovation performance (NPIP). Hierarchical multiple regression was used for hypothesis verification using data from 350 Chinese high-tech companies. The findings reveal that innovation affects NPIP, and the relationships are intermediated by ACAP. However, market volatility (MV) negatively moderates the relationship between ID and ACAP. According to these results, it can be concluded that the market and technology information acquired by a company must be digested, absorbed, and converted into useful knowledge to achieve organizational goals. This study offers implications for the development of high-tech companies in China and worldwide in the area of new product innovation.
The Eddy Dissipation Concept (EDC) combustion model, in comparison with some other combustion models, has drawn attention, especially for the Moderate or Intense low oxygen Dilution (MILD) ...combustion. The original formulation of the EDC combustion model is not developed for the MILD combustion regime, and a revision of the model could be considered. In this study, the effect of the characteristic frequency on the EDC combustion model has been investigated, and some parametric studies on the ratios of length and time scales of the fine structures to the Kolmogorov scales have been performed. Results revealed that finding optimum model constants for all combustion field with a wide range of Damköhler numbers seems to be complicated. The variations in scales ratio of fine structure to the Kolmogorov eddies shows different consequence at low and high Damköhler number combustion regions which leads to a conclusion on difficulties for EDC model global optimization. As a solution, a localized modulation method based on some local variables such as the turbulence Reynolds number and Damköhler number has been developed and applied on the Adelaide Jet in Hot Coflow(JHC) and Delft Jet in Hot Coflow (DJHC), and in addition in supplementary material on Sandia/TUD piloted flame and Sydney bluff-body burners. These burners demonstrate combustion regimes with both low and high Damköhler numbers. Results have shown the better performance of the local approach in the simulation of the burners. The improvement is more perceptible at the sections far from the inlet, where Damköhler number is increased, in comparison with the standard (default) EDC model. The average of deviations from the measurements is decreased by more than 10% and even more by a decrement in oxidizer oxygen level.
The main goal of green supply chain management is to minimize the injurious ecological impacts in all activities and phases of a supply chain. Evaluating the suppliers and selecting the best one ...based on environmental criteria can facilitate us to reach the objective of green supply chain management. As the assessment generally consists of various alternatives over different criteria, green supplier selection is regarded as a multi-criteria decision-making problem. Hesitant fuzzy set, which is an extension of fuzzy set, is an effective tool to handle the vagueness in such a way that hesitant and flawed information by allowing the degree of belongingness for a green supplier selection over the evaluation criteria. In this paper, an integrated method is developed based on Weighted Aggregated Sum Product Assessment (WASPAS) approach to solve the multi-criteria decision-making problems with hesitant fuzzy information. This method is based on hesitant fuzzy operators, some improvement in the conventional WASPAS approach and a procedure for calculating the criteria weights. To calculate the criteria and decision expert weights, we propose new information measures for hesitant fuzzy sets and combine entropy and divergence measures for criteria weights, while we use similarity measure for decision expert weights. Since the uncertainty is an inevitable feature of multi-criteria decision-making problems, the developed approach can be a useful tool for uncertain multi-criteria decision-making atmosphere. Next, a green supplier selection problem is taken to show the usefulness of the developed approach in real-life decision-making problems. The results of this study found that the most significant criteria for green supplier selection were management commitment (0.3119), environmental management system (0.2259) and green product (0.2010). Also, we demonstrate a sensitivity analysis over different parameter values and sets of criteria weight to illustrate the stability of the developed method. Finally, the outcome developed approach with existing approaches is compared to validate the developed method.
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•A novel method based on WASPAS approach is developed with HFSs.•Various information measures are proposed for calculating experts and criteria weights.•The modifications of the WASPAS approach, HF-operators and criteria weights assessment process are implemented.•The developed method is implemented for a green supplier selection problem.
Based on the data of Chinese A-share listed companies from 2011 to 2019, this paper uses the multiple regression method to explore the relationship between environmental information disclosure and ...corporate innovation, which is divided into exploratory innovation and exploitative innovation according to heterogeneity and investigates the impact of media attention on the relationship. The results show that: (1) Environmental information disclosure significantly promotes corporate innovation. (2) Environmental information disclosure promotes exploratory innovation more significantly than exploitative innovation. (3) Media attention has an “inverted U-shaped” regulating effect on the relationship between environmental information disclosure and corporate innovation. This study is expected to guide enterprises to scientifically carry out environmental information disclosure activities and direct the media to play its role in information dissemination and external corporate governance. Additionally, it can provide new ideas for corporate innovation.
Energy consumption by direct-driven electric in-wheel motors is massively crucial for optimized power management. Commercial electric vehicles invariably demand higher power contents because of the ...surface state and operating conditions. Gaussian process regression (GPR) models have been used to gain an underlying mapping between the inputs, such as speed, and the output in terms of electric power. This article presents a new method of modifying the isotropic kernel function with an automatic relevance determination (ARD) that brings about highly relevant input features to enhance the estimation precision and robustness. A well-equipped electric wheel-based system in a controlled testing environment is utilized to assess the proposed technique's effectiveness. The obtained results indicate that the proposed framework with Matern32 and Matern52 invariably denote better performance than standard GPR methods with exponential kernels, subjected to noise and various traveling speeds during all tested scenarios.
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