The asphalt pavement industry is transforming because of the growing influence of artificial intelligence and industrial digitization.As a result of this shift,there is a stronger emphasis on advanced statistical appr...The asphalt pavement industry is transforming because of the growing influence of artificial intelligence and industrial digitization.As a result of this shift,there is a stronger emphasis on advanced statistical approaches like optimization tools like response surface methodology(RSM)and machine learning(ML)techniques.The goal of this paper is to provide a scientometric and systematic review of the application of RSM and ML applications in data-driven approaches such as optimizing,modeling,and predicting asphalt pavement performance to achieve sustainable asphalt pavements in support of numerous sustainable development goals(SDGs).These include Goals 9(sustainable infrastructure),11(urban resilience),12(sustainable construction strategies),13(climate action through optimized materials),and 17(multidisciplinary interaction).A thorough search of the ScienceDirect,Web of Science,and Scopus databases from 2010 to 2023 yielded 1249 relevant records,with 125 studies closely examined.Over the last thirteen years,there has been significant research growth in RSM and ML applications,particularly in ML-based pavement optimization.The study shows that the topic has a global presence,with notable contributions from Asia,North America,Europe,and other continents.Researchers have concentrated on utilizing sophisticated ML models such as support vector machines(SVM),artificial neural networks(ANN),and Bayesian networks for prediction.Also,the integration of RSM and ML provides a faster and more efficient method for analyzing large datasets to optimize asphalt pavement performance variables.Key contributors include the United States,China,and Malaysia,with global efforts focused on sustainable materials and approaches to reduce impact on the environment.Furthermore,the review demonstrates the integrated use of RSM and ML as transformative tools for improving sustainability,which contributes significantly to SDGs 9,11,12,13,and 17.Providing valuable insights for future research and guiding decision-making for soft computing applications for asphalt pavement projects.展开更多
One of the largest known megafloods on earth resulted from a glacier dam-break,which occurred during the Late Quaternary in the Altai Mountains in Southern Siberia.Computational modeling is one of the viable approache...One of the largest known megafloods on earth resulted from a glacier dam-break,which occurred during the Late Quaternary in the Altai Mountains in Southern Siberia.Computational modeling is one of the viable approaches to enhancing the understanding of the flood events.The computational domain of this flood is over 9460 km2 and about 3.784 × 106 cells are involved as a 50 m × 50 m mesh is used,which necessitates a computationally efficient model.Here the Open MP(Open Multiprocessing) technique is adopted to parallelize the code of a coupled 2D hydrodynamic and sediment transport model.It is shown that the computational efficiency is enhanced by over 80% due to the parallelization.The floods over both fixed and mobile beds are well reproduced with specified discharge hydrographs at the dam site.Qualitatively,backwater effects during the flood are resolved at the bifurcation between the Chuja and Katun rivers.Quantitatively,the computed maximum stage and thalweg are physically consistent with the field data of the bars and deposits.The effects of sediment transport and morphological evolution on the flood are considerable.Sensitivity analyses indicate that the impact of the peak discharge is significant,whilst those of the Manningroughness,medium sediment size and shape of the inlet discharge hydrograph are marginal.展开更多
An emergy-based environmental accounting of Mongolia is presented based on the data from 1995 to 2012. By calculating natural and economic inputs and a series of emergy indicators, this paper discusses Mongolia＇s res...An emergy-based environmental accounting of Mongolia is presented based on the data from 1995 to 2012. By calculating natural and economic inputs and a series of emergy indicators, this paper discusses Mongolia＇s resource use structure, economic situation, trade status and societal sustainability. The results show that the total emergy use for Mongolia changed from 2.83×10^22 sej in 1995 to 4.96×10^22 sej in 2012, representing a 75% increase over the 18 years of this study, yet its emergy per capita remains one of the lowest in the world （1.74× 10^16 sej/capita）. The emergy money ratio （EMR） of Mongolia during 1995-2012 decreased from 1.99×10^13 sej/USD to 7.75×10^12 sej/USD, which indicates that the power of a dollar for purchasing real wealth in Mongolia was declining, while the relatively high absolute values compared to its trading partners and even the world average EMR suggests that Mongolia is continuing a trade disadvantage. Mongolia＇s emergy exchange ratio is increasingly less than one to the point that in 2012 the ratio was 0.3 suggesting that the exported emergy was over 3.3 times greater than the imported emergy. The growing dependence on imports and the dramatic increase in exports suggests that Mongolia＇s economy is increas- ingly vulnerable to downturns in the world economy.展开更多
The interactions of cnoidal waves with a submerged quartercircular breakwater are investigated by a ReynoldsAveraged Navier–Stokes(RANS) flow solver with a Volume of Fluid(VOF) surface capturing scheme(RANSVOF) model...The interactions of cnoidal waves with a submerged quartercircular breakwater are investigated by a ReynoldsAveraged Navier–Stokes(RANS) flow solver with a Volume of Fluid(VOF) surface capturing scheme(RANSVOF) model. The vertical variation of the instantaneous velocity indicates that flow separation occurs at the boundary layer near the breakwater. The temporal evolution of the velocity and vorticity fields demonstrates vortex generation and shedding around the submerged quartercircular breakwater due to the flow separation. An empirical relationship between the vortex intensity and a few hydrodynamic parameters is proposed based on parametric analysis. In addition, the instantaneous and time-averaged vorticity fields reveal a pair of vortices of opposite signs at the breakwater which are expected to have significant effect on sediment entrainment, suspension, and transportation,therefore, scour on the leeside of the breakwater.展开更多
Influenced by weather, the estuaries and bays often exhibit recurring oscillations in flow and water level similar to astronomical tides. The weather impact however is less regular than tides and more difficult to pre...Influenced by weather, the estuaries and bays often exhibit recurring oscillations in flow and water level similar to astronomical tides. The weather impact however is less regular than tides and more difficult to predict. The spectrum of weather induced motions in estuaries and bays is mostly at the low-frequency end with time scales longer than those of diurnal tides. The repeated weather impact produces meteorological tide: the recurring flood and ebb and flushing of the estuaries and bays but at lower frequencies than those of tides. The variation in weather conditions is quasi-periodic and of large scale nature(~1000-3000 km) because of the alternating low-and high-atmospheric pressure systems of extra-tropical cyclones and anti-cyclones and associated fronts. By examining 40 years of data between Jan. 1, 1977 and Dec. 31, 2016, we identified 1648 frontal events(averaging ~41.2±4.7 per year)influencing the northern Gulf of Mexico for time periods in the spring, fall and winter. The late spring and summer months(May, Jun, July, and August) were not included in the calculation because of much weaker activities involving synoptic weather systems with fronts during these months. It is found that the number of frontal events reached the maximum in Jan. and Dec. while the minimum occurred in April and Sept. It is found that there is an increasing trend of number of fronts over the 40-year period. Our data show that the low pass filtered water level,velocity, and vorticity(velocity shear) all vary in response to the weather and appear as the meteorological tide. The particle excursions of meteorological tides are much larger than those from the astronomical tides. In addition, the irregular nature of the meteorological tide makes the inward flux and outward flux asymmetric in general and thus it has a significant implication to dispersion and transport of waterborne materials. A scaling analysis shows that the meteorological tide generally reaches quasi-steady state;and as a result, a regression model is established which can be very useful for predicting the weather produced quasi-periodic motions.展开更多
Concrete slabs are widely used in modern railways to increase the inherent resilient quality of the tracks,provide safe and smooth rides,and reduce the maintenance frequency.In this paper,the elastic performance of a ...Concrete slabs are widely used in modern railways to increase the inherent resilient quality of the tracks,provide safe and smooth rides,and reduce the maintenance frequency.In this paper,the elastic performance of a novel slab trackform for high-speed railways is investigated using three-dimensional finite element modelling in Abaqus.It is then compared to the performance of a ballasted track.First,slab and ballasted track models are developed to replicate the full-scale testing of track sections.Once the models are calibrated with the experimental results,the novel slab model is developed and compared against the calibrated slab track results.The slab and ballasted track models are then extended to create linear dynamic models,considering the track geodynamics,and simulating train passages at various speeds,for which the Ledsgard documented case was used to validate the models.Trains travelling at low and high speeds are analysed to investigate the track deflections and the wave propagation in the soil,considering the issues associated with critical speeds.Various train loading methods are discussed,and the most practical approach is retained and described.Moreover,correlations are made between the geotechnical parameters of modern high-speed rail and conventional standards.It is found that considering the same ground condition,the slab track deflections are considerably smaller than those of the ballasted track at high speeds,while they show similar behaviour at low speeds.展开更多
Pollution by polycyclic aromatic hydrocarbons（PAHs） is widespread due to tmsuitable disposal of industrial waste. They are mostly defined as priority pollutants by environmental protection authorities worldwide. Phe...Pollution by polycyclic aromatic hydrocarbons（PAHs） is widespread due to tmsuitable disposal of industrial waste. They are mostly defined as priority pollutants by environmental protection authorities worldwide. Phenanthrene, a typical PAH, was selected as the target in this paper. The PAH-degrading mixed culture, named ZM, was collected from a petroleum contaminated river bed. This culture was injected into phenanthrene solutions at different concentrations to quantify the biodegradation process. Results show near-complete removal of phenanthrene in three days of biodegradation if the initial phenanthrene concentration is low. When the initial concentration is high, the removal rate is increased but 20%-40% of the phenanthrene remains at the end of the experiment. The biomass shows a peak on the third day due to the combined effects of microbial growth and decay. Another peak is evident for cases with a high initial concentration, possibly due to production of an intermediate metabolite. The pH generally decreased during biodegradation because of the production of organic acid. Two phenomenological models were designed to simulate the phenanthrene biodegradation and biomass growth. A relatively simple model that does not consider the intermediate metabolite and its inhibition of phenanthrene biodegradation cannot fit the observed data. A modified Monod model that considered an intermediate metabolite （organic acid） and its inhibiting reversal effect reasonably depicts the experimental results.展开更多
The goals of this study are to assess the viability of waste tire-derived char(WTDC)as a sustainable,low-cost fine aggregate surrogate material for asphalt mixtures and to develop the statistically coupled neural netw...The goals of this study are to assess the viability of waste tire-derived char(WTDC)as a sustainable,low-cost fine aggregate surrogate material for asphalt mixtures and to develop the statistically coupled neural network(SCNN)model for predicting volumetric and Marshall properties of asphalt mixtures modified with WTDC.The study is based on experimental data acquired from laboratory volumetric and Marshall properties testing on WTDCmodified asphalt mixtures(WTDC-MAM).The input variables comprised waste tire char content and asphalt binder content.The output variables comprised mixture unit weight,total voids,voids filled with asphalt,Marshall stability,and flow.Statistical coupled neural networks were utilized to predict the volumetric and Marshall properties of asphalt mixtures.For predictive modeling,the SCNN model is employed,incorporating a three-layer neural network and preprocessing techniques to enhance accuracy and reliability.The optimal network architecture,using the collected dataset,was a 2:6:5 structure,and the neural network was trained with 60%of the data,whereas the other 20%was used for cross-validation and testing respectively.The network employed a hyperbolic tangent(tanh)activation function and a feed-forward backpropagation.According to the results,the network model could accurately predict the volumetric and Marshall properties.The predicted accuracy of SCNN was found to be as high value>98%and low prediction errors for both volumetric and Marshall properties.This study demonstrates WTDC's potential as a low-cost,sustainable aggregate replacement.The SCNN-based predictive model proves its efficiency and versatility and promotes sustainable practices.展开更多
Dear Editor,Pinus sylvestris L.is one of the most popular and predominant tree species in Central Europe and Scandinavia.Its cultivation depends on atmospheric conditions,soil fertility,use of fertilizers,and individu...Dear Editor,Pinus sylvestris L.is one of the most popular and predominant tree species in Central Europe and Scandinavia.Its cultivation depends on atmospheric conditions,soil fertility,use of fertilizers,and individual characteristics of the trees.Pinus sylvestris L.wood,roots,and needles are used for energy production.Pi-展开更多
This work has examined the effects of pH on the treatment efficiency and biomass production rate of water hyacinth ponds (WHP) treating domestic wastewater. Experiments were carried out outdoor in WHP, working under b...This work has examined the effects of pH on the treatment efficiency and biomass production rate of water hyacinth ponds (WHP) treating domestic wastewater. Experiments were carried out outdoor in WHP, working under batch and subtropical environmental conditions, using pre-treated sewage with pH varying from 5 to 9. It was observed that the plants regulated the pH of the medium to within 6.4 to 7.1 during the treatment processes independently of influent wastewater pH ranges. This adjustment reduced the treatment performances and the biomass production in ponds, the alkaline conditions in ponds being less favorable to the activities of the plants. The optimal removal and biomass production was achieved with influent pH of 7 lying in the above interval. So the optimum influent pH for the growth of plants and the removal of nutrients and organic matters in WHP is within pH 6.4 to pH 7.1.展开更多
Geothermal heat pumps （GHPs） are an attractive proposition for renewable energy worldwide as it uses energy naturally stored in the earth. The Earth is a very resourceful form of energy, using the natural solar ener...Geothermal heat pumps （GHPs） are an attractive proposition for renewable energy worldwide as it uses energy naturally stored in the earth. The Earth is a very resourceful form of energy, using the natural solar energy collection and heat storage capabilities as an infinite heat source/heat sink at the base of permeable pavements, which can provide excellent temperature gradients for GHP＇s. Experimental rigs were setup up at The University of Edinbttrgh for a combined permeable pavement and GHP system. At the base of a pavement structure （approximately 1 meter） below the ground＇s surface, temperatures are constant of 10℃ in the U.K all year round. The GHP performance efficiency was analysed by the coefficient of performance （COP） in a heating cycle and the energy efficiency ratio （EER） in a cooling cycle. The mean COP and EER for both systems averaged between 2-4.5 and 3-5 respectively. The combined GHP and pavement structure operated at an optimum efficiency for both heating and cooling cycles and has shown to be unaffected by higher summer or lower winter temperatures. This hybrid system is an attractive renewable energy technology and has additional environmental benefits such as urban runoff reuse and recycling.展开更多
The structural dynamic response reconstruction technology can extract unmeasured information from limited measured data,significantly impacting vibration control,load identification,parameter identification,fault diag...The structural dynamic response reconstruction technology can extract unmeasured information from limited measured data,significantly impacting vibration control,load identification,parameter identification,fault diagnosis,and related fields.This paper proposes a dynamic response reconstruction method based on the Kalman filter,which simultaneously identifies external excitation and reconstructs dynamic responses at unmeasured positions.The weighted least squares method determines the load weighting matrix for excitation identification,while the minimum variance unbiased estimation determines the Kalman filter gain.The excitation prediction Kalman filter is constructed through time,excitation,and measurement updates.Subsequently,the response at the target point is reconstructed using the state vector,observation matrix,and excitation influence matrix obtained through the excitation prediction Kalman filter algorithm.An algorithm for reconstructing responses in continuous system using the excitation prediction Kalman filtering algorithm in modal space is derived.The proposed structural dynamic response reconstruction method evaluates the response reconstruction and the load identification performance under various load types and errors through simulation examples.Results demonstrate the accurate excitation identification under different load conditions and simultaneous reconstruction of target point responses,verifying the feasibility and reliability of the proposed method.展开更多
There are many issues surrounding the performance of critical assets on high-speed ballasted railway lines.At assets like switch & crossings and bridge transitions high track forces can be produced resulting in hi...There are many issues surrounding the performance of critical assets on high-speed ballasted railway lines.At assets like switch & crossings and bridge transitions high track forces can be produced resulting in higher ballast settlements and hence track misalignments.The latter result in higher track forces and hence more settlement,leading to the need for increased track maintenance to ensure comfort and safety.Current technologies for solving issues like ballast movement under high-speed loading regimes are limited.However,a technique that has been well used across the UK and now increasingly overseas to stabilise and reinforce ballasted railway tracks is the application of in-situ polyurethane polymers,termed XiTRACK.This paper discusses how this technique can be used to solve these types of long-standing issues and presents actual polymer application profiles at two typical critical sites,namely a junction and a transition onto concrete slab-track.展开更多
There is an increasing interest in understanding ambient bioaerosols due to their roles both in health and in climate. Here, we deployed an Ultraviolet Aerodynamic Particle Sizer to monitor viable （fluorescent） bioa...There is an increasing interest in understanding ambient bioaerosols due to their roles both in health and in climate. Here, we deployed an Ultraviolet Aerodynamic Particle Sizer to monitor viable （fluorescent） bioaerosol concentration levels at city centers （highly polluted） and their corresponding suburbs （near pristine） （total 40 locations） in 11 provinces featuring different climate zones in China between July 16 and 28, 2013. The concentration levels of viable bioaerosol particles （BioPM） of 〉0.5 μm were measured, and corresponding percentages of BioPM% （biological fraction of total PM） and BioPM2.5% （biological fraction of PM2.5） in particulate matter （PM） and BioPM, respectively, were determined. For some key cities, indoor viable bioaerosol levels were also obtained. In addition, bacterial structures of the air samples collected across these monitoring locations were studied using pyrosequencing. BioPM concentration levels ranged from 2.1 ×10^4 to 2.4 × 10^5/m3 for city centers [BioPM% = 6.4 % （4-6.3 %）] and 0.5 × 10^4 to 4.7 × 10^5/m3 for suburbs [BioPM% = 10 % （4-8.7 %）]. Distinctive bioaerosol size distribution patterns were observed for different climate zones, e.g., some had fluorescence peaks at 3 μm, while the majority had peaks at 1 μm. Ambient bacterial aerosol community structures were also found different for different geophysical locations. Results suggest that there was a poor overall relationship between PM and BioPM across 40 monitoring locations （R2= 0.081, two-tailed P value = 0.07435）. Generally, city centers had higher PM concentrations than suburbs, but not BioPM and BioPM%. Indoor bioaerosol levels were found at least tenfold higher than those corresponding outdoors. Bacillus was observed to dominate the bacterial aerosol community in the air sample.展开更多
This paper focuses on understanding and evaluating the dynamic effect of the heavy-haul train system on the seismic performance of a long-span railway bridge. A systematic study on the effect of heavy-haul trains on b...This paper focuses on understanding and evaluating the dynamic effect of the heavy-haul train system on the seismic performance of a long-span railway bridge. A systematic study on the effect of heavy-haul trains on bridge seismic response has been conducted, considering the influence of vehicle modeling strategies and dynamic characteristics of the seismic waves. For this purpose, the performance of a long-span cable-stayed railway bridge is assessed with stationary trains atop it, where the heavy-haul vehicles are modeled in two different ways: the multi-rigid body model with suspension system and additional mass model. Comparison of the bridge response in the presence or absence of the train system has been conducted, and the vehicle loading situation, which includes full-load and no-load, is also discussed. The result shows that during the earthquake, the peak moment of the main girder and peak stress of stay cables increase by 80% and by 40% in the presence of fully loaded heavy-haul trains, respectively. At the same time, a considerable decrease appears in the peak acceleration of the main girder. This proves the existence of the damping effect of the heavy-haul train system, and this effect is more obvious for the fully loaded vehicles. Finally, this paper proposes an efficient vehicle modeling method with 2 degrees of freedom(DOF) for simplifying the treatment of the train system in bridge seismic checking.展开更多
The aim of this study is to identify the influence of the dip angle of a pre-existing macrocrack on the lifetime and ultimate deformation of rock-like material. Prediction of lifetime has been studied for three groups...The aim of this study is to identify the influence of the dip angle of a pre-existing macrocrack on the lifetime and ultimate deformation of rock-like material. Prediction of lifetime has been studied for three groups of specimens under axial static compressive load levels. The specimens were investigated from 65% to 85% of UCS(uniaxial compressive strength) at an interval of 10% of UCS for the groups of specimens with a single modelled open flaw with a dip angle to the loading direction of 30°(first group), at an interval of 5% of UCS increment for the groups of specimens with single(second group), and double sequential open flaws with a dip angle to the loading direction of 60°(third group). This study shows that crack propagation in specimens with a single flaw follows the same sequences. At first, wing cracks appear, and then shear crack develops from the existing wing cracks. Shear cracking is responsible for specimen failure in all three groups. A slip is expected in specimens from the third group which connects two individual modelled open flaws. The moment of the slip is noticed as a characteristic rise in the axial deformation at a constant load level. It is also observed that axial deformation versus time follows the same pattern, irrespective of local geometry. Specimens from the first group exhibit higher axial deformation under different load levels in comparison with the specimens from the second and third groups.展开更多
It is important to understand how ballistic materials respond to impact from projectiles such that informed decisions can be made in the design process of protective armour systems. Ballistic testing is a standards-ba...It is important to understand how ballistic materials respond to impact from projectiles such that informed decisions can be made in the design process of protective armour systems. Ballistic testing is a standards-based process where materials are tested to determine whether they meet protection, safety and performance criteria. For the V50ballistic test, projectiles are fired at different velocities to determine a key design parameter known as the ballistic limit velocity(BLV), the velocity above which projectiles perforate the target. These tests, however, are destructive by nature and as such there can be considerable associated costs, especially when studying complex armour materials and systems. This study proposes a unique solution to the problem using a recent class of machine learning system known as the Generative Adversarial Network(GAN). The GAN can be used to generate new ballistic samples as opposed to performing additional destructive experiments. A GAN network architecture is tested and trained on three different ballistic data sets, and their performance is compared. The trained networks were able to successfully produce ballistic curves with an overall RMSE of between 10 and 20 % and predicted the V50BLV in each case with an error of less than 5 %. The results demonstrate that it is possible to train generative networks on a limited number of ballistic samples and use the trained network to generate many new samples representative of the data that it was trained on. The paper spotlights the benefits that generative networks can bring to ballistic applications and provides an alternative to expensive testing during the early stages of the design process.展开更多
Rivers often witness non-uniform bed load sedim ent transport. For a long tim e, non-uniform bed load transport has been assum ed to be at capacity regime determined exclusively by local flow. Yet whether the capacity...Rivers often witness non-uniform bed load sedim ent transport. For a long tim e, non-uniform bed load transport has been assum ed to be at capacity regime determined exclusively by local flow. Yet whether the capacity assumption for non-uniform bed load transport is justified remains poorly understood. Here, the relative time scale of non-uniform bed load transport is evaluated and non-capacity and capacity models are compared for both aggradation and degradation cases with observed data. As characterized by its relative time scale, the adaptation of non-uniform bed load to capacity regime should be fulfilled quickly. However, changes in the flow and sedim ent inputs from upstream or tributaries hinder the adaptation. Also, the adaptation to capacity regime is size dependent, the finer the sediment size the slower the adaptation is, and vice versa. It is shown that the capacity model may entail considerable errors compared to the non-capacity model. For modelling of non-uniform bed load, non-capacity modelling is recommended, in which the temporal and spatial scales required for adaptation are explicitly appreciated.展开更多
Using a revised version of a previously published expert classification system, a database of potential Sustainable Flood Retention Basins has been developed for Scotland. The research shows that the majority of small...Using a revised version of a previously published expert classification system, a database of potential Sustainable Flood Retention Basins has been developed for Scotland. The research shows that the majority of small and former （often old） drinking water reservoirs are kept full and their spillways are continuously in operation. Utilising some of the available capacity to contribute to flood control could significantly reduce the costs of complying with the European Union Flood Directive. Furthermore, the application of a previously developed classification model for Baden in Germany for the Scottish data set showed a lower diversity for basins in Scotland due to less developed infrastructure. The classification system appears to be robust and has the potential, with minor modifications, to be applied across Europe. The principle value of this approach is a clear and unambiguous categorisation, based on standard variables, which can help to promote communication and understanding between stakeholders.展开更多
Nanotechnology is a field of research with objects up to 100 nm in size. Nanomaterials belong to a wide area in the field of material engineering. These include nanolayers, nanoslabs, nanopores, nanotubes, nanofibers,...Nanotechnology is a field of research with objects up to 100 nm in size. Nanomaterials belong to a wide area in the field of material engineering. These include nanolayers, nanoslabs, nanopores, nanotubes, nanofibers, nanoparticles and quantum dots. Nanostructures are characterized by special properties due to their nanometric dimensions. The natural properties of nanostructures allow their wide application in various industries. The paper presents an overview of the application and significance of nanostructures in fuel cell technology, with particular emphasis on nanocatalysts. The article includes the classification of nanomaterials, new hybrid nanostructures, types of surface modification, division by area of application, with particular emphasis on nanomaterials in the advanced energy system. The design and operation of fuel cells and the role of nanoparticles have been described taking into account existing solutions to reduce generator costs. The high price of low temperature fuel cells depends on the number of nanoparticles used. The article describes the risk associated with using products at the nano scale. Higher concentrations of these extremely active materials can be dangerous and can cause ecological problems and harm natural ecosystems.展开更多
文摘The asphalt pavement industry is transforming because of the growing influence of artificial intelligence and industrial digitization.As a result of this shift,there is a stronger emphasis on advanced statistical approaches like optimization tools like response surface methodology(RSM)and machine learning(ML)techniques.The goal of this paper is to provide a scientometric and systematic review of the application of RSM and ML applications in data-driven approaches such as optimizing,modeling,and predicting asphalt pavement performance to achieve sustainable asphalt pavements in support of numerous sustainable development goals(SDGs).These include Goals 9(sustainable infrastructure),11(urban resilience),12(sustainable construction strategies),13(climate action through optimized materials),and 17(multidisciplinary interaction).A thorough search of the ScienceDirect,Web of Science,and Scopus databases from 2010 to 2023 yielded 1249 relevant records,with 125 studies closely examined.Over the last thirteen years,there has been significant research growth in RSM and ML applications,particularly in ML-based pavement optimization.The study shows that the topic has a global presence,with notable contributions from Asia,North America,Europe,and other continents.Researchers have concentrated on utilizing sophisticated ML models such as support vector machines(SVM),artificial neural networks(ANN),and Bayesian networks for prediction.Also,the integration of RSM and ML provides a faster and more efficient method for analyzing large datasets to optimize asphalt pavement performance variables.Key contributors include the United States,China,and Malaysia,with global efforts focused on sustainable materials and approaches to reduce impact on the environment.Furthermore,the review demonstrates the integrated use of RSM and ML as transformative tools for improving sustainability,which contributes significantly to SDGs 9,11,12,13,and 17.Providing valuable insights for future research and guiding decision-making for soft computing applications for asphalt pavement projects.
基金funded by Natural Science Foundation of China (Grants No. 11172217 and 11432015)National Key Basic Research and Development Program (i.e., 973 Program) of China (Grant No. 2007CB714106)
文摘One of the largest known megafloods on earth resulted from a glacier dam-break,which occurred during the Late Quaternary in the Altai Mountains in Southern Siberia.Computational modeling is one of the viable approaches to enhancing the understanding of the flood events.The computational domain of this flood is over 9460 km2 and about 3.784 × 106 cells are involved as a 50 m × 50 m mesh is used,which necessitates a computationally efficient model.Here the Open MP(Open Multiprocessing) technique is adopted to parallelize the code of a coupled 2D hydrodynamic and sediment transport model.It is shown that the computational efficiency is enhanced by over 80% due to the parallelization.The floods over both fixed and mobile beds are well reproduced with specified discharge hydrographs at the dam site.Qualitatively,backwater effects during the flood are resolved at the bifurcation between the Chuja and Katun rivers.Quantitatively,the computed maximum stage and thalweg are physically consistent with the field data of the bars and deposits.The effects of sediment transport and morphological evolution on the flood are considerable.Sensitivity analyses indicate that the impact of the peak discharge is significant,whilst those of the Manningroughness,medium sediment size and shape of the inlet discharge hydrograph are marginal.
基金Chinese Academy of Sciences President’s International Fellowship Initiative,No.2016VBA043(BM)China Scholarship Council and Michigan State University,No.NN-X-09-AM-55G(LH)
文摘An emergy-based environmental accounting of Mongolia is presented based on the data from 1995 to 2012. By calculating natural and economic inputs and a series of emergy indicators, this paper discusses Mongolia＇s resource use structure, economic situation, trade status and societal sustainability. The results show that the total emergy use for Mongolia changed from 2.83×10^22 sej in 1995 to 4.96×10^22 sej in 2012, representing a 75% increase over the 18 years of this study, yet its emergy per capita remains one of the lowest in the world （1.74× 10^16 sej/capita）. The emergy money ratio （EMR） of Mongolia during 1995-2012 decreased from 1.99×10^13 sej/USD to 7.75×10^12 sej/USD, which indicates that the power of a dollar for purchasing real wealth in Mongolia was declining, while the relatively high absolute values compared to its trading partners and even the world average EMR suggests that Mongolia is continuing a trade disadvantage. Mongolia＇s emergy exchange ratio is increasingly less than one to the point that in 2012 the ratio was 0.3 suggesting that the exported emergy was over 3.3 times greater than the imported emergy. The growing dependence on imports and the dramatic increase in exports suggests that Mongolia＇s economy is increas- ingly vulnerable to downturns in the world economy.
基金financially supported by the National Natural Science Foundation of China(Grant Nos.51509178 and 51509177)the Natural Science Foundation of Tianjin City(Grant No.14JCYBJC22100)the Natural Science Foundation of Tianjin Education Commission(Grant No.2017KJ046)
文摘The interactions of cnoidal waves with a submerged quartercircular breakwater are investigated by a ReynoldsAveraged Navier–Stokes(RANS) flow solver with a Volume of Fluid(VOF) surface capturing scheme(RANSVOF) model. The vertical variation of the instantaneous velocity indicates that flow separation occurs at the boundary layer near the breakwater. The temporal evolution of the velocity and vorticity fields demonstrates vortex generation and shedding around the submerged quartercircular breakwater due to the flow separation. An empirical relationship between the vortex intensity and a few hydrodynamic parameters is proposed based on parametric analysis. In addition, the instantaneous and time-averaged vorticity fields reveal a pair of vortices of opposite signs at the breakwater which are expected to have significant effect on sediment entrainment, suspension, and transportation,therefore, scour on the leeside of the breakwater.
基金The research was financially supported by the National Science Foundation and Natural Environment Research Council(Grant Nos.NSF-NERC 1736713 and NSF-NERC 1737274)Bureau of Ocean Energy Management(Grant No.M15AC000015)NOAA-NOS-IOOS-2016-2004378,through the Northern Gulf Institute by NOAA’s Office of Ocean and Atmospheric Research.
文摘Influenced by weather, the estuaries and bays often exhibit recurring oscillations in flow and water level similar to astronomical tides. The weather impact however is less regular than tides and more difficult to predict. The spectrum of weather induced motions in estuaries and bays is mostly at the low-frequency end with time scales longer than those of diurnal tides. The repeated weather impact produces meteorological tide: the recurring flood and ebb and flushing of the estuaries and bays but at lower frequencies than those of tides. The variation in weather conditions is quasi-periodic and of large scale nature(~1000-3000 km) because of the alternating low-and high-atmospheric pressure systems of extra-tropical cyclones and anti-cyclones and associated fronts. By examining 40 years of data between Jan. 1, 1977 and Dec. 31, 2016, we identified 1648 frontal events(averaging ~41.2±4.7 per year)influencing the northern Gulf of Mexico for time periods in the spring, fall and winter. The late spring and summer months(May, Jun, July, and August) were not included in the calculation because of much weaker activities involving synoptic weather systems with fronts during these months. It is found that the number of frontal events reached the maximum in Jan. and Dec. while the minimum occurred in April and Sept. It is found that there is an increasing trend of number of fronts over the 40-year period. Our data show that the low pass filtered water level,velocity, and vorticity(velocity shear) all vary in response to the weather and appear as the meteorological tide. The particle excursions of meteorological tides are much larger than those from the astronomical tides. In addition, the irregular nature of the meteorological tide makes the inward flux and outward flux asymmetric in general and thus it has a significant implication to dispersion and transport of waterborne materials. A scaling analysis shows that the meteorological tide generally reaches quasi-steady state;and as a result, a regression model is established which can be very useful for predicting the weather produced quasi-periodic motions.
基金Engineering and Physical Sciences Research Council (EPSRC) is also acknowledged for funding this work under Grant Number EP/N009207/1.
文摘Concrete slabs are widely used in modern railways to increase the inherent resilient quality of the tracks,provide safe and smooth rides,and reduce the maintenance frequency.In this paper,the elastic performance of a novel slab trackform for high-speed railways is investigated using three-dimensional finite element modelling in Abaqus.It is then compared to the performance of a ballasted track.First,slab and ballasted track models are developed to replicate the full-scale testing of track sections.Once the models are calibrated with the experimental results,the novel slab model is developed and compared against the calibrated slab track results.The slab and ballasted track models are then extended to create linear dynamic models,considering the track geodynamics,and simulating train passages at various speeds,for which the Ledsgard documented case was used to validate the models.Trains travelling at low and high speeds are analysed to investigate the track deflections and the wave propagation in the soil,considering the issues associated with critical speeds.Various train loading methods are discussed,and the most practical approach is retained and described.Moreover,correlations are made between the geotechnical parameters of modern high-speed rail and conventional standards.It is found that considering the same ground condition,the slab track deflections are considerably smaller than those of the ballasted track at high speeds,while they show similar behaviour at low speeds.
基金The National Natural Science Foundation of China （No. 50178040） the Royal Society of UK and the Hi-Tech Research and Development Program（863） of China（No. 2003AA601080）
文摘Pollution by polycyclic aromatic hydrocarbons（PAHs） is widespread due to tmsuitable disposal of industrial waste. They are mostly defined as priority pollutants by environmental protection authorities worldwide. Phenanthrene, a typical PAH, was selected as the target in this paper. The PAH-degrading mixed culture, named ZM, was collected from a petroleum contaminated river bed. This culture was injected into phenanthrene solutions at different concentrations to quantify the biodegradation process. Results show near-complete removal of phenanthrene in three days of biodegradation if the initial phenanthrene concentration is low. When the initial concentration is high, the removal rate is increased but 20%-40% of the phenanthrene remains at the end of the experiment. The biomass shows a peak on the third day due to the combined effects of microbial growth and decay. Another peak is evident for cases with a high initial concentration, possibly due to production of an intermediate metabolite. The pH generally decreased during biodegradation because of the production of organic acid. Two phenomenological models were designed to simulate the phenanthrene biodegradation and biomass growth. A relatively simple model that does not consider the intermediate metabolite and its inhibition of phenanthrene biodegradation cannot fit the observed data. A modified Monod model that considered an intermediate metabolite （organic acid） and its inhibiting reversal effect reasonably depicts the experimental results.
基金the University of Teknologi PETRONAS(UTP),Malaysia,and Ahmadu Bello University,Nigeria,for their vital help and availability of laboratory facilities that allowed this work to be conducted successfully.
文摘The goals of this study are to assess the viability of waste tire-derived char(WTDC)as a sustainable,low-cost fine aggregate surrogate material for asphalt mixtures and to develop the statistically coupled neural network(SCNN)model for predicting volumetric and Marshall properties of asphalt mixtures modified with WTDC.The study is based on experimental data acquired from laboratory volumetric and Marshall properties testing on WTDCmodified asphalt mixtures(WTDC-MAM).The input variables comprised waste tire char content and asphalt binder content.The output variables comprised mixture unit weight,total voids,voids filled with asphalt,Marshall stability,and flow.Statistical coupled neural networks were utilized to predict the volumetric and Marshall properties of asphalt mixtures.For predictive modeling,the SCNN model is employed,incorporating a three-layer neural network and preprocessing techniques to enhance accuracy and reliability.The optimal network architecture,using the collected dataset,was a 2:6:5 structure,and the neural network was trained with 60%of the data,whereas the other 20%was used for cross-validation and testing respectively.The network employed a hyperbolic tangent(tanh)activation function and a feed-forward backpropagation.According to the results,the network model could accurately predict the volumetric and Marshall properties.The predicted accuracy of SCNN was found to be as high value>98%and low prediction errors for both volumetric and Marshall properties.This study demonstrates WTDC's potential as a low-cost,sustainable aggregate replacement.The SCNN-based predictive model proves its efficiency and versatility and promotes sustainable practices.
文摘Dear Editor,Pinus sylvestris L.is one of the most popular and predominant tree species in Central Europe and Scandinavia.Its cultivation depends on atmospheric conditions,soil fertility,use of fertilizers,and individual characteristics of the trees.Pinus sylvestris L.wood,roots,and needles are used for energy production.Pi-
文摘This work has examined the effects of pH on the treatment efficiency and biomass production rate of water hyacinth ponds (WHP) treating domestic wastewater. Experiments were carried out outdoor in WHP, working under batch and subtropical environmental conditions, using pre-treated sewage with pH varying from 5 to 9. It was observed that the plants regulated the pH of the medium to within 6.4 to 7.1 during the treatment processes independently of influent wastewater pH ranges. This adjustment reduced the treatment performances and the biomass production in ponds, the alkaline conditions in ponds being less favorable to the activities of the plants. The optimal removal and biomass production was achieved with influent pH of 7 lying in the above interval. So the optimum influent pH for the growth of plants and the removal of nutrients and organic matters in WHP is within pH 6.4 to pH 7.1.
文摘Geothermal heat pumps （GHPs） are an attractive proposition for renewable energy worldwide as it uses energy naturally stored in the earth. The Earth is a very resourceful form of energy, using the natural solar energy collection and heat storage capabilities as an infinite heat source/heat sink at the base of permeable pavements, which can provide excellent temperature gradients for GHP＇s. Experimental rigs were setup up at The University of Edinbttrgh for a combined permeable pavement and GHP system. At the base of a pavement structure （approximately 1 meter） below the ground＇s surface, temperatures are constant of 10℃ in the U.K all year round. The GHP performance efficiency was analysed by the coefficient of performance （COP） in a heating cycle and the energy efficiency ratio （EER） in a cooling cycle. The mean COP and EER for both systems averaged between 2-4.5 and 3-5 respectively. The combined GHP and pavement structure operated at an optimum efficiency for both heating and cooling cycles and has shown to be unaffected by higher summer or lower winter temperatures. This hybrid system is an attractive renewable energy technology and has additional environmental benefits such as urban runoff reuse and recycling.
基金supported by the National Natural Science Foundation of China(Nos.12372066,U23B6009,52171261)the Aeronautical Science Fund(No.20240013052002)the Qing Lan Project。
文摘The structural dynamic response reconstruction technology can extract unmeasured information from limited measured data,significantly impacting vibration control,load identification,parameter identification,fault diagnosis,and related fields.This paper proposes a dynamic response reconstruction method based on the Kalman filter,which simultaneously identifies external excitation and reconstructs dynamic responses at unmeasured positions.The weighted least squares method determines the load weighting matrix for excitation identification,while the minimum variance unbiased estimation determines the Kalman filter gain.The excitation prediction Kalman filter is constructed through time,excitation,and measurement updates.Subsequently,the response at the target point is reconstructed using the state vector,observation matrix,and excitation influence matrix obtained through the excitation prediction Kalman filter algorithm.An algorithm for reconstructing responses in continuous system using the excitation prediction Kalman filtering algorithm in modal space is derived.The proposed structural dynamic response reconstruction method evaluates the response reconstruction and the load identification performance under various load types and errors through simulation examples.Results demonstrate the accurate excitation identification under different load conditions and simultaneous reconstruction of target point responses,verifying the feasibility and reliability of the proposed method.
基金Project (No. EP/H027262/1) partially supported by the Engineering and Physical Sciences Research Council,UK
文摘There are many issues surrounding the performance of critical assets on high-speed ballasted railway lines.At assets like switch & crossings and bridge transitions high track forces can be produced resulting in higher ballast settlements and hence track misalignments.The latter result in higher track forces and hence more settlement,leading to the need for increased track maintenance to ensure comfort and safety.Current technologies for solving issues like ballast movement under high-speed loading regimes are limited.However,a technique that has been well used across the UK and now increasingly overseas to stabilise and reinforce ballasted railway tracks is the application of in-situ polyurethane polymers,termed XiTRACK.This paper discusses how this technique can be used to solve these types of long-standing issues and presents actual polymer application profiles at two typical critical sites,namely a junction and a transition onto concrete slab-track.
基金supported by the National Natural Science Foundation of China(21277007,21477003,and 41121004)the Ministry of Science and Technology of China(2015DFG92040,2015CB553401)Ministry of Education(20130001110044)
文摘There is an increasing interest in understanding ambient bioaerosols due to their roles both in health and in climate. Here, we deployed an Ultraviolet Aerodynamic Particle Sizer to monitor viable （fluorescent） bioaerosol concentration levels at city centers （highly polluted） and their corresponding suburbs （near pristine） （total 40 locations） in 11 provinces featuring different climate zones in China between July 16 and 28, 2013. The concentration levels of viable bioaerosol particles （BioPM） of 〉0.5 μm were measured, and corresponding percentages of BioPM% （biological fraction of total PM） and BioPM2.5% （biological fraction of PM2.5） in particulate matter （PM） and BioPM, respectively, were determined. For some key cities, indoor viable bioaerosol levels were also obtained. In addition, bacterial structures of the air samples collected across these monitoring locations were studied using pyrosequencing. BioPM concentration levels ranged from 2.1 ×10^4 to 2.4 × 10^5/m3 for city centers [BioPM% = 6.4 % （4-6.3 %）] and 0.5 × 10^4 to 4.7 × 10^5/m3 for suburbs [BioPM% = 10 % （4-8.7 %）]. Distinctive bioaerosol size distribution patterns were observed for different climate zones, e.g., some had fluorescence peaks at 3 μm, while the majority had peaks at 1 μm. Ambient bacterial aerosol community structures were also found different for different geophysical locations. Results suggest that there was a poor overall relationship between PM and BioPM across 40 monitoring locations （R2= 0.081, two-tailed P value = 0.07435）. Generally, city centers had higher PM concentrations than suburbs, but not BioPM and BioPM%. Indoor bioaerosol levels were found at least tenfold higher than those corresponding outdoors. Bacillus was observed to dominate the bacterial aerosol community in the air sample.
基金Project(51678576) supported by the National Natural Science Foundation of ChinaProject(2017YFB1201204) supported by the National Key R&D Program of China。
文摘This paper focuses on understanding and evaluating the dynamic effect of the heavy-haul train system on the seismic performance of a long-span railway bridge. A systematic study on the effect of heavy-haul trains on bridge seismic response has been conducted, considering the influence of vehicle modeling strategies and dynamic characteristics of the seismic waves. For this purpose, the performance of a long-span cable-stayed railway bridge is assessed with stationary trains atop it, where the heavy-haul vehicles are modeled in two different ways: the multi-rigid body model with suspension system and additional mass model. Comparison of the bridge response in the presence or absence of the train system has been conducted, and the vehicle loading situation, which includes full-load and no-load, is also discussed. The result shows that during the earthquake, the peak moment of the main girder and peak stress of stay cables increase by 80% and by 40% in the presence of fully loaded heavy-haul trains, respectively. At the same time, a considerable decrease appears in the peak acceleration of the main girder. This proves the existence of the damping effect of the heavy-haul train system, and this effect is more obvious for the fully loaded vehicles. Finally, this paper proposes an efficient vehicle modeling method with 2 degrees of freedom(DOF) for simplifying the treatment of the train system in bridge seismic checking.
文摘The aim of this study is to identify the influence of the dip angle of a pre-existing macrocrack on the lifetime and ultimate deformation of rock-like material. Prediction of lifetime has been studied for three groups of specimens under axial static compressive load levels. The specimens were investigated from 65% to 85% of UCS(uniaxial compressive strength) at an interval of 10% of UCS for the groups of specimens with a single modelled open flaw with a dip angle to the loading direction of 30°(first group), at an interval of 5% of UCS increment for the groups of specimens with single(second group), and double sequential open flaws with a dip angle to the loading direction of 60°(third group). This study shows that crack propagation in specimens with a single flaw follows the same sequences. At first, wing cracks appear, and then shear crack develops from the existing wing cracks. Shear cracking is responsible for specimen failure in all three groups. A slip is expected in specimens from the third group which connects two individual modelled open flaws. The moment of the slip is noticed as a characteristic rise in the axial deformation at a constant load level. It is also observed that axial deformation versus time follows the same pattern, irrespective of local geometry. Specimens from the first group exhibit higher axial deformation under different load levels in comparison with the specimens from the second and third groups.
基金supported by the Engineering and Physical Sciences Research Council [grant number: EP/N509644/1]。
文摘It is important to understand how ballistic materials respond to impact from projectiles such that informed decisions can be made in the design process of protective armour systems. Ballistic testing is a standards-based process where materials are tested to determine whether they meet protection, safety and performance criteria. For the V50ballistic test, projectiles are fired at different velocities to determine a key design parameter known as the ballistic limit velocity(BLV), the velocity above which projectiles perforate the target. These tests, however, are destructive by nature and as such there can be considerable associated costs, especially when studying complex armour materials and systems. This study proposes a unique solution to the problem using a recent class of machine learning system known as the Generative Adversarial Network(GAN). The GAN can be used to generate new ballistic samples as opposed to performing additional destructive experiments. A GAN network architecture is tested and trained on three different ballistic data sets, and their performance is compared. The trained networks were able to successfully produce ballistic curves with an overall RMSE of between 10 and 20 % and predicted the V50BLV in each case with an error of less than 5 %. The results demonstrate that it is possible to train generative networks on a limited number of ballistic samples and use the trained network to generate many new samples representative of the data that it was trained on. The paper spotlights the benefits that generative networks can bring to ballistic applications and provides an alternative to expensive testing during the early stages of the design process.
基金funded by the N atural Science Foundation of China (G rants No. 11172217, 51279144 and 11432015)Chinese Academy of Sciences (G rant No. KZZDEW -05-01-03)
文摘Rivers often witness non-uniform bed load sedim ent transport. For a long tim e, non-uniform bed load transport has been assum ed to be at capacity regime determined exclusively by local flow. Yet whether the capacity assumption for non-uniform bed load transport is justified remains poorly understood. Here, the relative time scale of non-uniform bed load transport is evaluated and non-capacity and capacity models are compared for both aggradation and degradation cases with observed data. As characterized by its relative time scale, the adaptation of non-uniform bed load to capacity regime should be fulfilled quickly. However, changes in the flow and sedim ent inputs from upstream or tributaries hinder the adaptation. Also, the adaptation to capacity regime is size dependent, the finer the sediment size the slower the adaptation is, and vice versa. It is shown that the capacity model may entail considerable errors compared to the non-capacity model. For modelling of non-uniform bed load, non-capacity modelling is recommended, in which the temporal and spatial scales required for adaptation are explicitly appreciated.
基金The European Regional Development Fund Interreg IVB 2007-2013 North Sea Region Programme funded the research project Sustainable Flood Retention Basins to Control Flooding and Diffuse Pollution, which is part of the Strategic Alliance for Water Management Actions consortium.
文摘Using a revised version of a previously published expert classification system, a database of potential Sustainable Flood Retention Basins has been developed for Scotland. The research shows that the majority of small and former （often old） drinking water reservoirs are kept full and their spillways are continuously in operation. Utilising some of the available capacity to contribute to flood control could significantly reduce the costs of complying with the European Union Flood Directive. Furthermore, the application of a previously developed classification model for Baden in Germany for the Scottish data set showed a lower diversity for basins in Scotland due to less developed infrastructure. The classification system appears to be robust and has the potential, with minor modifications, to be applied across Europe. The principle value of this approach is a clear and unambiguous categorisation, based on standard variables, which can help to promote communication and understanding between stakeholders.
文摘Nanotechnology is a field of research with objects up to 100 nm in size. Nanomaterials belong to a wide area in the field of material engineering. These include nanolayers, nanoslabs, nanopores, nanotubes, nanofibers, nanoparticles and quantum dots. Nanostructures are characterized by special properties due to their nanometric dimensions. The natural properties of nanostructures allow their wide application in various industries. The paper presents an overview of the application and significance of nanostructures in fuel cell technology, with particular emphasis on nanocatalysts. The article includes the classification of nanomaterials, new hybrid nanostructures, types of surface modification, division by area of application, with particular emphasis on nanomaterials in the advanced energy system. The design and operation of fuel cells and the role of nanoparticles have been described taking into account existing solutions to reduce generator costs. The high price of low temperature fuel cells depends on the number of nanoparticles used. The article describes the risk associated with using products at the nano scale. Higher concentrations of these extremely active materials can be dangerous and can cause ecological problems and harm natural ecosystems.
