Sharif Digital Repository

To attain superior energy density concurrently with high power density, high-performance supercapacitors have been developed. Herein an innovative strategy has been adopted to fabricate unique binder-free electrodes composed of a unique porous structure of binary metal carbonate hydroxide nanomace-decorated hydrothermal porous carbon spheres (PCSs). Hierarchical nickel-cobalt carbonate hydroxide (NiCOCH) nanomaces, directly grown on PCSs, are used as positive electrodes for supercapacitors fabrication. Furthermore, Fe2O3@PCS composites, having benefits of highly reversible redox reaction in the negative potential window and highly porous structure, are employed as the negative electrode in... 

To attain superior energy density concurrently with high power density, high-performance supercapacitors have been developed. Herein an innovative strategy has been adopted to fabricate unique binder-free electrodes composed of a unique porous structure of binary metal carbonate hydroxide nanomace-decorated hydrothermal porous carbon spheres (PCSs). Hierarchical nickel-cobalt carbonate hydroxide (NiCOCH) nanomaces, directly grown on PCSs, are used as positive electrodes for supercapacitors fabrication. Furthermore, Fe2O3@PCS composites, having benefits of highly reversible redox reaction in the negative potential window and highly porous structure, are employed as the negative electrode in... 

Context: Software testing is a pivotal activity in the development of high-quality software. As software is evolving through its life cycle, the need for a fault-revealing criterion assessing the effectiveness of the test suite grows. Over the years, researchers have proposed coverage-based criteria, including statement and branch coverage, to solve this issue. In literature, the effectiveness of such criteria is attested in terms of their correlations with the mutation score. Objective: In this paper, we aim at proposing a coverage-based criterion named statement frequency coverage, which outperforms statement and branch coverage in terms of correlation with mutation score. Method: To this... 

Context: Software testing is a pivotal activity in the development of high-quality software. As software is evolving through its life cycle, the need for a fault-revealing criterion assessing the effectiveness of the test suite grows. Over the years, researchers have proposed coverage-based criteria, including statement and branch coverage, to solve this issue. In literature, the effectiveness of such criteria is attested in terms of their correlations with the mutation score. Objective: In this paper, we aim at proposing a coverage-based criterion named statement frequency coverage, which outperforms statement and branch coverage in terms of correlation with mutation score. Method: To this... 

Developing a computational model for studying tribological performance is essential for computing accurate life cycle of various materials. Caused by the existence of complicated and nonlinear interactions between material surfaces, exact modeling of wear behavior is very difficult. Artificial intelligence (AI) can be used in distinguishing similar patterns in experimental data and predictive modeling of a certain material’s wear behavior. In this paper, artificial neural networks (ANNs) approach, adaptive neural-based fuzzy inference system (ANFIS) technique, and fuzzy clustering method (FCM) are used to develop a simple, accurate, and applicable model for predicting the wear behavior of... 

The aim of this study is to evaluate the sustainability of two actual wastewater treatment plants using the eco-efficiency index based on emergy and life cycle analysis. The life cycle analysis is used for environmental investigation to estimate the eco-efficiency index. Moreover, the emergy theory indicating the input and output flows of the ecosystem are applied to assess the sustainability considering ecosystem services. Two treatment plants are studied in the city of Mashhad in Iran. The potential for sustainability improvement of plants is analyzed in some scenarios including the production of agricultural compost from sludge, 10% reduction of energy consumption, and 10% reduction of... 

This study presents a comprehensive framework for evaluating renewable and non-renewable power plants' performance using the Life Cycle Analysis (LCA) and emergy analysis. The emergy analysis is used to consider the free ecosystem services in the sustainability of the systems as a supplement to the LCA. The results indicate that the wind and photovoltaic power plants have the best performance in terms of the LCA analysis, while the wind and combined cycle power plants have the highest emergy sustainability index. The best scenario is chosen under a two-objective optimization problem, including the single score and emergy sustainability as objective functions. Here, the wind power plant is... 

This study presents a comprehensive framework for evaluating renewable and non-renewable power plants' performance using the Life Cycle Analysis (LCA) and emergy analysis. The emergy analysis is used to consider the free ecosystem services in the sustainability of the systems as a supplement to the LCA. The results indicate that the wind and photovoltaic power plants have the best performance in terms of the LCA analysis, while the wind and combined cycle power plants have the highest emergy sustainability index. The best scenario is chosen under a two-objective optimization problem, including the single score and emergy sustainability as objective functions. Here, the wind power plant is... 

Purpose: Dams require high-volume of construction materials and operations over the life cycle. This paper aims to select a proper type of dam structure that can significantly contribute to the sustainability of dam projects. Design/methodology/approach: This research proposes a complementary fuel consumption and carbon dioxide (CO2) emission assessment method for the alternate dam structure types to assist decision-makers in selecting sustainable choices. Related equations are developed for two common earthen and rock-fill dam structures types in Iran. These equations are then successfully applied to two real dam project cases where the significance of the achieved results are assessed and... 

Purpose: Dams require high-volume of construction materials and operations over the life cycle. This paper aims to select a proper type of dam structure that can significantly contribute to the sustainability of dam projects. Design/methodology/approach: This research proposes a complementary fuel consumption and carbon dioxide (CO2) emission assessment method for the alternate dam structure types to assist decision-makers in selecting sustainable choices. Related equations are developed for two common earthen and rock-fill dam structures types in Iran. These equations are then successfully applied to two real dam project cases where the significance of the achieved results are assessed and... 

OMG's Model Driven Architecture (MDA) has deeply influenced modern-day software development, not only by providing promising means for automating the software process, but also through revitalizing the role of modeling in software development, the importance of which had been neglected during the recent euphoria over lightweight development methods. However, MDA's need to remain reasonably abstract means that it is more a software development approach rather than a standalone methodology, and therefore needs methodology support to be practically useful. Several MDA-based methodologies exist today, yet the need remains for the definition of an instantiable MDA-based development process. We... 

Despite the great promise of hybrid solar-wind-biomass energy systems to power future sustainable cities, complexities associated with their optimal planning and design limit their wide-scale implementation. This study provides a novel systematic framework to identify optimal hybrid renewable solutions for urban areas at neighborhood scales. In particular, we examine the role of economies of scale in the techno-economic feasibility and environmental performance of hybrid renewable systems. For demonstration, we assess the impact of the economics of scale (at the neighborhood scales of 1/500, 1/250, and 1/100 of the city's electrical load) on the life-cycle costs of optimal hybrid renewable... 

Significant energy subsidies are believed to be the main factor that has resulted in high energy intensities of Iranian industries. The Subsidy Reform Act of 2010 was directed at modifying energy consumption pattern and fostering energy efficiency enhancement. This study aims at analyzing the effect of energy subsidy reform on promoting energy efficiency in six energy intensive industries of Iran. In order to do so, the energy efficiency practices that have not been adopted after the implementation of the first phase of energy subsidy reform are investigated. Data analysis reveals that if financially interesting investments are determined as those with payback periods less than three years,... 

A new design methodology based on the total value of structures is introduced. This methodology, namely Value Based Design of structures (VBD), uses the advantages of Endurance Time (ET) method. While prescriptive and earlier generations of performance based design approaches commonly try to find structures with the least initial cost, a design approach to directly incorporate the concept of value in design procedure has been formulated here. Reduced computational effort in ET analysis provides the prerequisites to practical use of optimization algorithms in seismic design. A genetic algorithm is used with the objective of minimizing total cost of the building during its lifespan. ET method... 

In this research, application of the Endurance Time (ET) method in performance-based design of structures with and without consideration of uncertainties is investigated and a practical optimum design procedure is proposed. The ET method is used as an analytical assessment tool because of its capabilities in response estimation with an affordable computational demand. In the first step of the proposed method, ET analysis is implemented in a multi-objective optimum design procedure in order to achieve a set of Pareto optimal designs. Optimization is conducted with respect to initial cost and expected life cycle cost using a deterministic approach. For each design alternative the median... 

Computational cost is one of the major obstacles for detailed risk analysis of structures. This paper puts forward a methodology for efficient probabilistic seismic loss assessment of structures using the Endurance Time (ET) analysis and the first-order reliability method (FORM). The ET analysis efficiently yields the structural responses for a continuous range of intensities through a single response-history analysis. Taking advantage of this property of ET, FORM is employed to estimate the annual rate of exceedance for the loss components. The proposed approach is an amalgamation of two analysis approaches, ET and FORM, that significantly lower the computational costs. This makes it... 

Agent-oriented software methodologies have found their way to become one of the most important issues of software development. The diversity of existing methodologies and the variety of newly arriving ones have arisen the question of which methodology is best in the context of a special problem, so the need for evaluating and comparing methodologies is becoming more important everyday. On the other hand evaluating methodologies can reveal their strengths and shortcomings which lead to an improvement in development of the next generation of agent-oriented methodologies. In this paper, we are going to introduce an approach for evaluating methodologies via the evaluation of their lifecycle... 

The paper presents the experimental and analytical model analysis of a steel-girder arch bridge. The field test is carried out by ambient vibration testing under traffic excitations. Both the peak picking method in the frequency domain and the stochastic subspace identification method in the time domain are used for the output-only model identification. A good agreement in identified frequencies has been found between the two methods. It is further demonstrated that the stochastic subspace method provides better mode shapes. The three-dimensional finite element models are constructed and an analytical model analysis is then performed to generate natural frequencies and mode shapes in the... 

In recent years, increasing attention has been paid to the use of renewable energy sources in building sector. The ground source heat pumps are a promising alternative for heating and cooling applications. Despite the high coefficients of performance and significant environmental benefits, their performance may deteriorate over the long-term operation if the annual ground loads are not well balanced. An appropriate solution is the use of hybrid ground source heat pump system through which some portion of the thermal loads can be offset by supplemental components. The aim of this study is to assess the feasibility of a solar-assisted ground source heat pump system for heating a detached house... 

In recent years, increasing attention has been paid to the use of renewable energy sources in building sector. The ground source heat pumps are a promising alternative for heating and cooling applications. Despite the high coefficients of performance and significant environmental benefits, their performance may deteriorate over the long-term operation if the annual ground loads are not well balanced. An appropriate solution is the use of hybrid ground source heat pump system through which some portion of the thermal loads can be offset by supplemental components. The aim of this study is to assess the feasibility of a solar-assisted ground source heat pump system for heating a detached house...