Search results

Water‐related diseases are a human tragedy, resulting in millions of deaths each year, preventing millions more from leading healthy lives, and undermining development efforts by burdening the society with substantial socio‐economic costs. This problem is of great significance in developing countries, where polluted water, water shortages, and unsanitary living conditions prevail. This paper presents a case study on a health‐based socio‐economic assessment of drinking water quality in Lebanon, based on relevant valuation approaches and available country‐specific data. The assessment revealed that the potential health and economic benefits due to water and sanitation improvements can be significant (0.15‐3.35 percent of GDP).

In this study, tests were conducted to investigate the effect of different concretes on the behaviour of reinforced concrete beams with central splices. Five beam specimens were prepared using different concrete mixes in their splice regions. Experimental results indicated that the bond failure of the spliced rebars governed the ultimate flexural behaviour of all specimens, except the one cast with steel fibres. A small increase in flexural strength was found for both the spliced beams cast with high‐strength concrete and steel fibres. Moreover, use of high‐strength concrete and steel fibrous concrete led to a remarkable improvement in the beam's displacement capacity. The effect of pulverised fuel ash on the splice performance was insignificant while the introduction of silica fume caused improvements in loading capacity and ductility.

In the hybrid electricity market consisting of renewable and conventional energy, the generation output of renewable power is uncertain because of its intermittency, and the power market demand is also fluctuant. Meanwhile, there is fierce competition among power producers in the power supply market and retailers in the demand market after deregulation, which increases the difficulty of renewable energy power grid-connection. To promote grid-connection of renewable energy power in the hybrid electricity market, the authors construct different contract decision-making models in the “many-to-many” hybrid power supply chain to explore the pricing strategy of renewable energy power grid-connecting.

Considering the dual-uncertainty of renewable energy power output and electricity market demand, the authors construct different decision-making models of wholesale price contract and revenue-sharing contract to compare and optimize grid-connecting pricing, respectively, to maximize the profits of different participants in the hybrid power supply chain. Besides, the authors set different parameters in the models to explore the influence of competition intensity, government subsidies, etc. on power pricing. Then, a numerical simulation is carried out, they verify the existence of the equilibrium solutions satisfying the supply chain coordination, compare the differences of pricing contracts and further analyze the variation characteristics of optimal contract parameters and their interaction relations.

Revenue-sharing contract can increase the quantity of green power grid-connection and realize benefits Pareto improvement of all parties in hybrid power supply chain. The competition intensity both of power supply and demand market will have an impact on the sharing ratio, and the increase of competition intensity results in a reduction of power supply chain coordination pressure. The power contract price, spot price and selling price have all been reduced with the increase of the sharing ratio, and the price of renewable power is more sensitive to the ratio change. The sharing ratio shows a downward trend with the increase of government green power subsidies.

On the basis of expanding the definition of hybrid power market and the theory of newsvendor model, considering the dual-uncertainty of green power generation output and electricity market demand, this paper builds and compares different contract decision-making models to study the grid-connection pricing strategy of renewable energy power. And as an extension of supply chain structure types and management, the authors build a “many-to-many” power supply chain structure model and analyze the impact of competition intensity among power enterprises and the government subsidy on the power grid-connecting pricing.

The calculation of the crack width is necessary for the design of prestressed concrete (PC) members. The purpose of this paper is to develop a numerical model based on the bond-slip theory to calculate the crack width in PC beams.

Stress calculation method for common reinforcement after beam crack has occurred depends on the difference in the bonding performance between prestressed reinforcement and common reinforcement. A numerical calculation model for determining the crack width in PC beams is developed based on the bond-slip theory, and verified using experimental data. The calculation values obtained by the proposed numerical model and code formulas are compared, and the applicability of the numerical model is evaluated.

The theoretical analysis and experimental results verified that the crack width of PC members calculated based on the bond-slip theory in this study is reasonable. Furthermore, the stress calculation method for the common reinforcement is verified. Compared with the model calculation results obtained in this study, the results obtained from code formulas are more conservative.

The numerical calculation model for crack width proposed in this study can be used by engineers as a reference for calculating the crack width in PC beams to ensure the durability of the PC member.

The purpose of this paper is to investigate the mechanical behavior of textile-reinforced concrete (TRC)-strengthened concrete columns with small eccentricity under chloride-wet-dry cycles.

A total of ten reinforced concrete (RC) columns were constructed and subjected to eccentric compression, and the effects of the slenderness ratio, a variable number of wet-dry cycles and the coupled effect of loading and a chloride environment were analyzed. One of the columns tested was unreinforced, whereas the remaining columns were strengthened laterally with TRC.

The results showed that a reduction in the slenderness ratio was conducive to the improvement of the bearing capacity of the reinforced column; however, the reinforcement effect of TRC tended to decrease with an increasing number of wet-dry cycles, and the coupled effect of loading and a chloride environment significantly degraded the compression performance of TRC-strengthened columns, with the damage becoming more serious with increase in the sustained load ratio.

In the next test, the duration of chloride-wet-dry cycles will be extended. In the same time, to obtain a clearer trend, the authors will also increase the number of specimens to obtain more data for drawing general conclusions.

The originality is to explore the feasibility of using cement-based materials (TRC) as a confinement technique in chloride environment. The investigations demonstrate that TRC has a good reinforcement effect on the concrete columns under chloride-wet-dry cycles. Finally, influence of each parameter is analyzed, which can be used as reference and foundation in actual application.

The partially prestressed concrete beam with unbonded tendon is still an active field of research because of the difficulty in analyzing and understanding its behavior. The finite-element (FE) simulation of such beams using numerical software is very scarce in the literature and therefore this study is taken to demonstrate the modeling aspects of unbonded partially prestressed concrete (UPPSC) beams. This study aims to present the three-dimensional (3-D) nonlinear FE simulations of UPPSC beams subjected to monotonic static loadings using the numerical analysis package ANSYS.

The sensitivity study is carried out with three different mesh densities to obtain the optimum elements that reflect on the load–deflection behavior of numerical models, and the model with optimum element density is used further to model all the UPPSC beams in this study. Three half-symmetry FE model is constructed in ANSYS parametric design language domain with proper boundary conditions at the symmetry plane and support to achieve the same response as that of the full-scale experimental beam available in the literature. The linear and nonlinear material behavior of prestressing tendon and conventional steel reinforcements, concrete and anchorage and loading plates are modeled using link180, solid65 and solid185 elements, respectively. The Newton–Raphson iteration method is used to solve the nonlinear solution of the FE models.

The evolution of concrete cracking at critical loadings, yielding of nonprestressed steel reinforcements, stress increment in the prestressing tendon, stresses in concrete elements and the complete load–deflection behavior of the UPPSC beams are well predicted by the proposed FE model. The maximum discrepancy of ultimate moments and deflections of the validated FE models exhibit 13% and −5%, respectively, in comparison with the experimental results.

The FE analysis of UPPSC beams is done using ANSYS software, which is a versatile tool in contrast to the experimental testing to study the stress increments in the unbonded tendons and assess the complete nonlinear response of partially prestressed concrete beams. The validated numerical model and the techniques presented in this study can be readily used to explore the parametric analysis of UPPSC beams.

The developed model is capable of predicting the strength and nonlinear behavior of UPPSC beams with reasonable accuracy. The load–deflection plot captured by the FE model is corroborated with the experimental data existing in the literature and the FE results exhibit good agreement against the experimentally tested beams, which expresses the practicability of using FE analysis for the nonlinear response of UPPSC beams using ANSYS software.

The current research seeks to investigate the antecedents of customers’ sustainable purchasing behavior from eco-friendly restaurants located in Lebanon. Moreover, it explores the mediating role of purchase intention on the relationships between pro-environmental antecedents and green purchase behavior. Additionally, it examines the moderating role of willingness to pay premium prices for sustainable products.

The questionnaire technique was used to gather data, and the convenience sample technique was used to select 397 restaurants’ customers.

The results revealed a positive effect of customers’ green purchase behavior exerted by environmental concern, purchase intention, and willingness to pay premium prices for sustainable products. Also, the findings adopted a significant mediating role of green purchase intention between pro-environmental antecedents and purchase behavior toward green products.

The current study presents several practical implications for managers and decision-makers. Such as issuing green marketing campaigns on a regular basis to highlight the value of organic food safety, the necessity of using eco-friendly cutlery and the use of renewable energy systems.

This study examined the model pro-environmental antecedents in Lebanon as one of the Middle Eastern developing countries, whereas few studies examined this relationship. Furthermore, this paper contributes by examining the mediating role of green purchase intention.

The purpose of this paper is to offer an assessment of seismic structural vulnerability of a sample of public schools using Lang survey questionnaire. The structural integrity of public schools in Lebanon is a source of deep concern due to their outdated design and deteriorated status, their apparent lack of compliance with seismic design regulations, the unknown status of their safety and stability, their substandard maintenance and their low construction quality. These schools have not undergone any strengthening improvements to enhance their load-carrying capacity or their resistance to earthquake activity.

This paper is based on survey questionnaire illustrating the seismic risk exposure of public schools in Lebanon. It offers an assessment of seismic structural vulnerability of a sample of public schools using Lang survey questionnaire. It stresses the needs of retrofitting of public school buildings to enhance their functional capacities against future destructive earthquakes.

The findings of the survey emphasize the seismic structural vulnerability of the majority of public schools in Lebanon and call for deeper assessment and investigation that involve government officials for strengthening and retrofitting of public school buildings as part of holistic disaster risk-reduction strategy to prevent the induced serious risk to children in the event of a devastating earthquake.

This article should alert school administrators, public leaders and government officials regarding the seismic threats and their subsequent effects on the structural safety of public school buildings in Lebanon. The assessment of seismic structural vulnerability has rarely been performed or even discussed in the Lebanese-related literature.

Civil society organizations (CSOs) in Lebanon are among the most active groups supporting community welfare and advocating for human rights and policy reform. However, these organizations still lack the basic awareness and commitment needed to expand their role in earthquake disaster risk reduction. The purpose of this paper is to shed light on the exposure of Lebanon to destructive earthquakes and to address the urgent need for CSOs to expand its contribution in earthquake disaster risk reduction supporting public awareness programs and strategic mitigation plans.

The paper sets out to alert CSOs about the seismic hazards of Lebanon and offers a discussion for an active engagement role of Lebanese CSOs in future earthquake disaster risk reduction. The focus is to outline a strategy that may facilitate the engagement of CSOs in building the resilience of Lebanese community against destructive earthquakes.

The proposed strategic plan suggests a leading role of Lebanese universities that call for the establishment of a disaster mitigation coalition leading to CSOs active involvement and effective contribution in collaborating with government and private sector to enhance the resilience capacity of the Lebanese community against future earthquake events.

The implication of the paper is beneficial to community leaders of Lebanon because it highlights the importance of direct engagement of CSOs in earthquake disaster risk reduction which has never been previously emphasized, evaluated or even discussed in the Lebanese studies.

The aim of the current study is to recommend and compare the estimates of finite element model (FEM), analytical model, and artificial neural networks (ANN) model for capturing the LCC of FCSC members. A database comprising 325 FCSC columns was constructed from previous studies to propose FEM and ANN models while the analytical model was proposed based on a database of 712 samples and encasing mechanics of steel tube and FRP wraps. The concrete damage plastic model was used for concrete along with bilinear and linear elastic models for steel tube and FRP wraps, respectively. Analytical and ANN models effectively considered the lateral encasing mechanism of FCSC columns for accurate predictions.

The study aimed to compare the prediction accuracy of finite element (FEM), analytical, and artificial neural network (ANN) models for the load-carrying capacity (LCC) of fiber reinforced polymer (FRP)-encased concrete-filled steel tube (CFST) compression members (FCSC). A database of 325 FCSC columns was developed for FEM and ANN models, while the analytical model was based on 712 samples, utilizing encasing mechanics of steel tube and FRP wraps. FEM used a concrete damage plastic model, bilinear steel tube, and linear elastic FRP models. Statistical accuracy was evaluated using MAE, MAPE, R², RMSE, and a 20-index across all models.

Based on the experimental database, the FEM presented the accuracies in the form of statistical parameters MAE = 223.76, MAPE = 285.32, R² = 0.94, RMSE = 210.43 and a20-index = 0.83. The analytical model showed the statistics of MAE = 427.229, MAPE = 283.649, R2 = 0.8149, RMSE = 275.428 and a20-index = 0.73 while ANN models portrayed the predictions with MAE = 195, MAPE = 229.67, R² = 0.981, RMSE = 174 and a20-index = 0.89 for the LCC of FCSC columns.

Although various investigations have already been performed on the prediction of the load-carrying capacity (LCC) of fiber reinforced polymer (FRP)-encased concrete-filled steel tube (CFST) compression members (FCSC) using small and noisy data, none of them compared the accuracy of prediction of different modeling techniques based on a refined large database.