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The escalating issue of global climate change necessitates urgent measures to reduce carbon emissions globally. Within this context, the construction industry emerges as a critical sector to address given its high energy consumption, substantial CO2 emissions, and low utilization rate. Therefore, it is pivotal to foster energy conservation and reduce emissions in this sector. To this end, this paper delineates two primary objectives: (1) identifying optimal research methodologies and index parameters for evaluating carbon emission efficiency in the construction industry, and (2) assessing the variance in carbon emission efficiency at disparate stages and regions. Leveraging the Malmquist index, we scrutinize the carbon emission data from 30 Chinese provinces spanning from 2010 to 2019. Our findings indicate a geographical dichotomy in China’s construction industry’s carbon emission efficiency—lower in the west and higher in the east. Additionally, this study delves into the distinguishing features of emission efficiency alterations across regions, the main influencing factors, and avenues for enhancement. Subsequently, it proposes policy recommendations tailored to the unique attributes of various regions and the overarching framework.

For decades, the prediction of bank failure has been a popular topic in credit risk and banking studies. Statistical and machine learning methods have been working well in predicting the probability of bankruptcy for different time horizons prior to the failure. In recent years, bank efficiency has attracted much interest from academic circles, where low productivity or efficiency in banks has been regarded as a potential reason for failure. It is generally believed that low efficiency implies low-quality management of the organisation, which may lead to bad performance in the competitive financial markets. Previous papers linking efficiency measures calculated by Data Envelopment Analysis (DEA) to bank failure prediction have been limited to cross sectional analyses. A dynamic analysis with the updated samples is therefore recommended for bankruptcy prediction. This paper proposes a nonparametric method, Malmquist DEA with Worst Practice Frontier, to dynamically assess the bankruptcy risk of banks over multiple periods. A total sample of 4426 US banks over a period of 15 years (2002–2016), covering the subprime financial crisis, is used to empirically test the model. A static model is used as the benchmark, and we introduce more extensions for comparisons of predictive performance. Results of the comparisons and robustness tests show that Malmquist DEA is a useful tool not only for estimating productivity growth but also to give early warnings of the potential collapse of banks. The extended DEA models with various reference sets and orientations also show strong predictive power.

Dynamic simulation of mechanical systems can be performed using a multibody system dynamics approach. The approach allows to account systems of other physical nature, such as hydraulic actuators. In such systems, the nonlinearity and numerical stiffness introduced by the friction model of the hydraulic cylinders can be an important aspect to consider in the modeling because it can lead to poor computational efficiency. This paper couples various friction models of a hydraulic cylinder with the equations of motion of a hydraulically actuated multibody system in a monolithic framework. To this end, two static friction models, the Bengisu–Akay model and Brown–McPhee model, and two dynamic friction models, the LuGre model and modified LuGre model, are considered in this work. A hydraulically actuated four-bar mechanism is exemplified as a case study. The four modeling approaches are compared based on the work cycle, friction force, energy balance, and numerical efficiency. It is concluded that the Brown–McPhee approach is numerically the most efficient approach and it is well able to describe usual friction characteristics in dynamic simulation of hydraulically actuated multibody systems.

Structural defects in graphene are inevitable during the production process, which have remarkable impacts on the mechanical properties of graphene and further affect the properties of nanocomposite reinforced by graphene. In this work, a bottom-up multiscale approach is employed to investigate the nonlinear dynamics of defective graphene reinforced composite plates from the material properties of nanocomposites to the dynamic behavior of macro-composite plates. The molecular modeling and simulation are conducted by molecular dynamics (MD) to evaluate the effective mechanical properties of pristine graphene, vacancy defective graphene, Stone–Wales defective graphene, poly (methyl methacrylate) (PMMA) and graphene/PMMA composites reinforced by different graphene configurations at the nano-scale. Meanwhile, the fracture mechanism and interfacial interaction energy between graphene and PMMA matrix during the deformation process are examined to explore the enhancement mechanism of nanocomposites. The efficiency parameters are derived by incorporating the MD results and the extended Halpin–Tsai micromechanics model to capture the heterogeneity of nanocomposite at the nano-scale as well as the continuum scale, and then the effective material properties considering the effect of defect, temperature and pressure are substituted into the nonlinear dynamics of functionally graded graphene reinforced composite (FG-GRC) plates at the macro-scale. The governing equations of motion for FG-GRC plates under the aerodynamic pressure are derived based on the third-order shear deformation theory, von-Karman nonlinear strain–displacement relation and Hamilton’s principle. The aerodynamic pressure acting on the surface of the plate consists of two parts, one is the static pressure, and the other is the disturbed air flow. Furthermore, Galerkin method and the fourth-order Runge–Kutta method are exploited to discrete and solve the governing equations of motion. The bifurcation, time history and phase diagrams of FG-GRC plates are obtained to analyze the dynamic characteristics of the plates. This study reveals the nonlinear dynamic characteristics of graphene/PMMA composite plate, which contributes to the prediction of dynamic response of composite structure in the aerospace field.

In the present study, credible analytical and numerical models are developed in order to explain the apparent discrepancies in the ratios of static and dynamic deformation models for assessing the quality of mechanical efficiency of transport structures in Central Europe. Through of experience, authors specifically deal with the comparison of two commonly used methods: the dynamic load plate test, known as the lightweight dynamic test and the static plate load test. This paper presents the relevant correlation dependency of the most commonly used quantification characteristics in earthworks quality control. Their correlation was obtained by applying the static theory of impact to earthworks quality control, which allows for the application of several quality control methods, in line with other member states of the European Union, specifically with regard to constructions under various boundary conditions (climate, soil moisture of the specified layer). According to an analysis of the results of comparisons of static and dynamic load tests, analytical and numerical models of the subsoil formed by soils and uncemented structural materials, respectively, the linear calculation usually used in the conditions of Central Europe does not have universal validity. Rather than relying on the analytical and FEM models for the soil, the authors have determined that the above dependence is a power dependence.

Carbon emissions from the logistics industry have been rising year after year. Correct handling of the relationship between economic development and environmental protection is of great significance to the implementation of green logistics, which is an important component of China’s strategy for strong transportation. This paper focuses on the evaluation of the carbon emissions efficiency of logistics industry from a new strong transportation strategy perspective. A super-efficiency slack-based measurement (Super-SBM) model and Malmquist index are combined to evaluate the static and dynamic carbon emissions efficiency of the logistics industry. The results indicate that compared with the SBM model, the Super-SBM model can more effectively measure the carbon emissions efficiency of the logistics industry. Pilot regions for the strong transportation strategy were divided into two categories, namely regions with slow carbon emission growth rates but high efficiency, and regions with high carbon emission growth rates but low efficiency. Some policy recommendations from the strong transportation strategy perspective were proposed to improve the carbon emissions efficiency of the logistics industry, especially for the second category of pilot regions. This study is expected to provide a basis for decision-making for efficient emissions reduction measures and policies, and to encourage the pilot regions to take the lead in achieving the goal of China’s strategy for transportation.

In this research, to investigate the impact of the guide vanes on the flow analysis in the axial pump, unsteady numerical turbulence field simulations with and without guide vanes are simulated using the model of standard κ–ε turbulence with the technique of sliding mesh (SM). The numerical results are firstly validated and compared with experimental outcomes. Different detailed information data regarding flow analysis, for instance, static, dynamic, total pressures, turbulent kinetic energy, shear stress, and velocity magnitude are qualitatively analysed. Then pressure at varying regions in the pump is qualitatively investigated under different operating conditions. The results have shown that the flow field and performance of the pump are highly affected by adding the guide vane to the axial impeller. The impeller with guide vane can lead to enhance the pump performance. Moreover, results show that the pressure, kinetic energy, shear stress, and velocity are increased by adding a guide vane to the axial impeller. This study will provide good information and guidance to enhance and improve the axial flow pump design operation.

For reducing fossil fuel demand and its environmental damages in Iran, the UN suggests removal of fossil fuel subsidies in this developing country which has the largest amount of energy subsidies in the world within 2010s. This research investigates the effectiveness of subsidy removal as a price policy in reducing the consumption of diesel which has the highest share in the total fossil fuel demand portfolio. The novelty of this research is that it compares the effects of price policy and energy efficiency on reducing diesel demand and improving sustainability to reveal which one is a more effective policy. To this aim, our study employs dynamic model, static model and error-correction model for estimating the diesel demand elasticities during 1976–2017. The results show that the diesel demand responds to changes in energy efficiency substantially, while it responds to changes in price slightly. Based on our findings, energy efficiency is about 30 times more effective than the price policy on reduction of diesel demand and improvement of the sustainable development pillars including economy, environment and social (health). A 10% improvement in energy efficiency at the first year of the studied period could reduce more than 87 billion liters of diesel consumption, 3 billion tons of CO2 emissions and 65 thousand deaths from the air pollution during the period. Therefore, the strategists should improve the technology especially the efficiency of energy-consuming utilities like cars, rather than increasing the price and removal of subsidy, to reduce diesel demand and improve sustainability.

Water is a strategic and basic resource for industrial development. The efficient use of water resources is of great significance for the sustainable development of the economy and society. Dynamic SBM model could overcome the shortcomings of static models and reflect inter-temporal efficiency levels. The kernel density curve is used to fit the distribution pattern of industrial water use efficiency and describe its dynamic evolution. Empirical results show that from 2013 to 2017, under the meta-frontier, the industrial water use efficiency values of Beijing, Tianjin, Shandong, Inner Mongolia, and Shaanxi are all 1, and industrial water use efficiency is high, while the industrial water use efficiency values of Sichuan, Guizhou, Anhui, and other provinces are below 0.3, reflecting the low industrial water use efficiency. From 2013 to 2015, China’s industrial water use efficiency generally shows a downward trend but begins to rise in the next 2 years. The kernel density curve generally exhibits a bimodal distribution trend and evolves from a “spike shape” to a “broad peak shape”.

Airframe–propulsion integration concepts that use boundary-layer ingestion (BLI) have the potential to reduce aircraft fuel burn. One concept that has been recently explored is NASA’s STARC-ABL aircraft configuration, which offers the potential for fuel burn reduction by using a turboelectric propulsion system with an aft-mounted electrically driven BLI propulsor. So far, attempts to quantify this potential fuel burn reduction have not considered the full coupling between the aerodynamic and propulsive performance. To address the need for a more careful quantification of the aeropropulsive benefit of the STARC-ABL concept, we run a series of design optimisations based on a fully coupled aeropropulsive model. A 1D thermodynamic cycle analysis is coupled to a Reynolds-averaged Navier–Stokes simulation to model the aft propulsor at a cruise condition and the effects variation in propulsor design on overall performance. A series of design optimisation studies are performed to minimise the required cruise power, assuming different relative sizes of the BLI propulsor. The design variables consist of the fan pressure ratio, static pressure at the fan face, and 311 variables that control the shape of both the nacelle and the fuselage. The power required by the BLI propulsor is compared with a podded configuration. The results show that the BLI configuration offers 6–9% reduction in required power at cruise, depending on assumptions made about the efficiency of power transmission system between the under-wing engines and the aft propulsor. Additionally, the results indicate that the power transmission efficiency directly affects the relative size of the under-wing engines and the aft propulsor. This design optimisation, based on computational fluid dynamics, is shown to be essential to evaluate current BLI concepts and provides a powerful tool for the design of future concepts.