The present work ascertains the feasibility of oil residue treatment for stabilizing wind-blown sand dunes. Various combinations of natural collapsible saline from the Jandaq desert of Iran and oil residue from distil...The present work ascertains the feasibility of oil residue treatment for stabilizing wind-blown sand dunes. Various combinations of natural collapsible saline from the Jandaq desert of Iran and oil residue from distillation towers of Iranian refineries were tested in laboratory experiments. Stabilized sands were evaluated in terms of geotechnical properties, permeability, and oil retention characteristics(i.e. bonding mechanisms, leaching and migrating behaviour of oil residue from the stabilized sands). Since the presence of oil residue in soils can pose an environmental threat, the optimum retention capacity of the stabilized sands is of critical concern. Relative to sand that was not augmented with oil residue, specimens made of 7% oil residues had the highest compressive strength, significantly higher cohesion and load bearing capacity, and considerably lower permeability. The effect of distilled water, saline water and municipal sewage on prepared specimens were also evaluated.展开更多
This study provides the first systematic evaluation of image resolution’s effect (50-300 PPI, pixels per inch) on UAV (unmanned aerial vehicle)-based digital close-range photogrammetry accuracy in civil engineering a...This study provides the first systematic evaluation of image resolution’s effect (50-300 PPI, pixels per inch) on UAV (unmanned aerial vehicle)-based digital close-range photogrammetry accuracy in civil engineering applications, such as infrastructure monitoring and heritage preservation. Using a high-resolution UAV with a 20 MP (MegaPixels) sensor, four images of a brick wall test field were captured and processed in Agisoft Metashape, with resolutions compared against Leica T2002 theodolite measurements (1.0 mm accuracy). Advanced statistical methods (ANOVA (analysis of variance), Tukey tests, Monte Carlo simulations) and ground control points validated the results. Accuracy improved from 25 mm at 50 PPI to 5 mm at 150 PPI (p < 0.01), plateauing at 4 mm beyond 200 PPI, while 150 PPI reduced processing time by 62% compared to 300 PPI. Unlike prior studies, this research uniquely isolates resolution effects in a controlled civil engineering context, offering a novel 150 PPI threshold that balances precision and efficiency. This threshold supports Saudi Vision 2030’s smart infrastructure goals for megaprojects like NEOM, providing a scalable framework for global applications. Future research should leverage deep learning to optimize resolutions in dynamic environments.展开更多
The present study investigates the engineering properties of submerged organic silt(orSi)stabilized with F-class fly ash(FA),with and without the addition of an activator(CaO).The utilization of F-class FA for soil im...The present study investigates the engineering properties of submerged organic silt(orSi)stabilized with F-class fly ash(FA),with and without the addition of an activator(CaO).The utilization of F-class FA for soil improvement is an important aspect of sustainable and environmentally-conscious geotechnical engineering when marginal usage of lime and concrete is of great interest to engineers and societies.Currently,discussion is predominantly focused on the positive aspects of using the F-class FA,with a paucity of emphasis on the negative aspects.To explore these features more thoroughly,a series of strength and compressibility tests was conducted.The sample preparation and curing methodology were chosen to replicate the in situ conditions where soil is surcharged and submerged in water.It was found that the incorporation of F-class FA without an activator reduces the undrained shear strength of submerged orSi by about 20%–25%and permanently prevents any thixotropic strength restoration.An increase in undrained shear strength is observed when lime(3%–6%)is added to the soil–FA mixture or when only lime(in the same amount of 3%–6%)is used.Consequently,F-class FA can be successfully used as a filler for slurries with minimum lime content in soil mixing methods.The F-class FA(with or without an activator)shifts the so-called“creep delay”in time,consequently reducing the total creep settlements.The shift of“creep delay”is more considerable for orSi stabilized with lime or with FA and lime as an activator,than for orSi stabilized with pure F-class FA.展开更多
PM_(1.0),particulate matter with an aerodynamic diameter smaller than 1.0μm,can adversely affect human health.However,fewer stations are capable of measuring PM_(1.0) concentrations than PM2.5 and PM10 concentrations...PM_(1.0),particulate matter with an aerodynamic diameter smaller than 1.0μm,can adversely affect human health.However,fewer stations are capable of measuring PM_(1.0) concentrations than PM2.5 and PM10 concentrations in real time(i.e.,only 9 locations for PM_(1.0) vs.623 locations for PM2.5 or PM10)in South Korea,making it impossible to conduct a nationwide health risk analysis of PM_(1.0).Thus,this study aimed to develop a PM_(1.0) prediction model using a random forest algorithm based on PM_(1.0) data from the nine measurement stations and various environmental input factors.Cross validation,in which the model was trained in eight stations and tested in the remaining station,achieved an average R^(2) of 0.913.The high R^(2) value achieved undermutually exclusive training and test locations in the cross validation can be ascribed to the fact that all the locations had similar relationships between PM_(1.0) and the input factors,which were captured by our model.Moreover,results of feature importance analysis showed that PM2.5 and PM10 concentrations were the two most important input features in predicting PM_(1.0) concentration.Finally,the model was used to estimate the PM_(1.0) concentrations in 623 locations,where input factors such as PM2.5 and PM10 can be obtained.Based on the augmented profile,we identified Seoul and Ansan to be PM_(1.0) concentration hotspots.These regions are large cities or the center of anthropogenic and industrial activities.The proposed model and the augmented PM_(1.0) profiles can be used for large epidemiological studies to understand the health impacts of PM_(1.0).展开更多
Laboratory scale model of DMMBF （dual mixed media biofilter） were designed and installed in AI-Mustansiriya University Environmental Hydraulic Lab. Experiments were conducted using two mixed layers through PVR colum...Laboratory scale model of DMMBF （dual mixed media biofilter） were designed and installed in AI-Mustansiriya University Environmental Hydraulic Lab. Experiments were conducted using two mixed layers through PVR column--2.2 m height and 300 mm diameter. The first mixed media filter of depth 640mm mixed of sand, rice husk and granular activated carbon. The percentage volume mix is 1：1：1. While the other mixed media of depth 740 mm, consisting of coal, crash porcelinaite, rock and granite with equally percentage volume. Fifty samples were collected during the experiments, which was spread over a period of forty two weeks. The obtained results indicate that when the flow loading raised from 0.15 L/min to 2.7 L/rain, the removal efficiency of BOD decreased 8%-11%, and the removal efficiency of COD deceased 3%-4%, while the removal efficiency of turbidity increased with the decreasing of hydraulic loading. The results showed that the removal efficiency of turbidity is more than 95% at the lower discharge （0.15 L/min）. Therefore, infiltration should be conservatively designed using low loading rates.展开更多
Strategic assessments are a landscape scale assessment and unlike project-by-project assessments which look at individual actions, they can consider a much broader set of issues;for example, a large urban growth area ...Strategic assessments are a landscape scale assessment and unlike project-by-project assessments which look at individual actions, they can consider a much broader set of issues;for example, a large urban growth area that will be developed over many years or a fire management policy across a broad landscape. Wetlands are important and effective ecosystems for biodiversity protection and improving environmental conditions. Bird watching as tourism and ecotourism activity is a complex process which it is compatible with conservation of wetlands and other aquatic zones. In this research, combination of SWOT analysis and FAHP method base on strategic fuzzy assessment are used for bird watch zoning in Bazangan Lake. By making internal and external matrix for SWOT factors, existing condition was in competitive strategies (ST) in the study area. Offered strategies in this condition were environment restoration to increase in environment resilience against hazards (natural and human), avoiding of land use and land cover changes and presence of ecotourism responsibly especially Bird watching. The sensitivity analysis results did not show any difference within the results of the present study and it was suitable and valid to use for similar situations. Base on the presented medium and short term strategies, it needed to have a short time training program to inform and empower local communities to wetlands partnership management by sharing them in the getting benefits in Bazangan Lake. By using the preferred frame in this study, decision makers can plan for each lake, dam and wetland and determine the best areas for tourist activities like bird watching. Conservation, protection and restoration of environment with its wildlife are guaranteed by using fuzzy assessment to provide reasonable strategies.展开更多
Unit stream power is the most important and dominant parameter for the determination of transport rate of sand,gravel,and hyper-concentrated sediment with wash load.Minimum energy dissipation rate theory,or its simpli...Unit stream power is the most important and dominant parameter for the determination of transport rate of sand,gravel,and hyper-concentrated sediment with wash load.Minimum energy dissipation rate theory,or its simplified minimum unit stream power and minimum stream power theories,can provide engineers the needed theoretical basis for river morphology and river engineering studies.The Generalized Sediment Transport model for Alluvial River Simulation computer mode series have been developed based on the above theories.The computer model series have been successfully applied in many countries.Examples will be used to illustrate the applications of the computer models to solving a wide range of river morphology and river engineering problems.展开更多
Environmental catalysis has drawn a great deal ofattention due to its clean ways to produce useful chemicals or carry out some chemical processes.Photocatalysis and electrocatalysis play important roles in these field...Environmental catalysis has drawn a great deal ofattention due to its clean ways to produce useful chemicals or carry out some chemical processes.Photocatalysis and electrocatalysis play important roles in these fields.They can decompose and remove organic pollutants from the aqueous environment,and prepare some fine chemicals.Moreover,they also can carry out some important reactions,such as 02 reduction reaction(ORR),O2 evolution reaction(OER),H2 evolution reaction(HER),CO2 reduction reaction(C02 RR),and N2 fixation(NRR).For catalytic reactions,it is the key to develop high-performance catalysts to meet the demand fortargeted reactions.In recentyears,two-dimensional(2 D) materials have attracted great interest in environmental catalysis due to their unique layered structures,which offer us to make use of their electronic and structural characteristics.Great progress has been made so far,including graphene,black phosphorus,oxides,layered double hydroxides(LDHs),chalcogenides,bismuth-based layered compounds,MXenes,metal organic frameworks(MOFs),covalent organic frameworks(COFs),and others.This content drives us to invite many famous groups in these fields to write the roadmap on two-dimensional nanomaterials for environmental catalysis.We hope that this roadmap can give the useful guidance to researchers in future researches,and provide the research directions.展开更多
KM （knowledge management） has in the recent past been promoted as a means of harnessing and utilising intellectual resources and to improve innovation, business performance and client satisfaction within the constru...KM （knowledge management） has in the recent past been promoted as a means of harnessing and utilising intellectual resources and to improve innovation, business performance and client satisfaction within the construction industry. However, there has been no attempt to ascertain the required level of KM within any given firm. The study reported in this paper aimed at establishing a general equation for assessing a firm’s required level of KM. Through literature review and a questionnaire survey, a total of 22 key indicators of KM were established. The interaction and effects of the key indicators against turnover and employee base were established, yielding an elliptic paraboloid fitted graph over which desirability could be calculated. It was observed that there is a continuous relationship among the firm’s turnover, employee base and the identified key indicators. In practice, firms have different combinations of the employee base and turnover. The derived equation fits well with the different combinations. Firms can, through the use of such equations, determine the level of effort and investment required to implement KM.展开更多
Grapes are the main reason why the grapevine (Vitis vinifera L.) is cultivated. However, climate, soil conditions, vegetation and anthropogenic effects on the soil greatly affect grapevine production. The organoleptic...Grapes are the main reason why the grapevine (Vitis vinifera L.) is cultivated. However, climate, soil conditions, vegetation and anthropogenic effects on the soil greatly affect grapevine production. The organoleptic properties of grape-derived products, such as wine, are influenced by these factors, which are becoming increasingly popular in Africa. Thus, grapevines, which are commonly grown in warm regions, are acclimatized in Africa using grapevine varieties that can adjust to tropical conditions. This study, which was carried out in 2019, aimed to promote grapevine cultivation in Côte d’Ivoire by examining the influence of pedoclimatic factors on the agro-physiological characteristics of grapevines. In Côte d’Ivoire, there were four distinct agro-ecological zones (North, South, Southeast and West) where three grapevine varieties, Bequignol, Muscat Rouge and Aleatico, were grown. Grapevine plants could grow robustly in morpho-physiological ways because the soils had sufficient fertility, as revealed by the analysis of experimental sites. Grapevine varieties have successfully adapted to different terroirs, with the exception of Muscat Rouge, which only displayed favorable morphological characteristics in the Man zone (West). Regardless of the grape variety, the regions with the best grapevine-growing conditions were Man (West), followed by Aboisso (Southeast). Consequently, grapevine development was less favorable in Korhogo (North) and Abidjan (South) zones. Thus, the cultivation of grapevine varieties in Côte d’Ivoire was greatly influenced by terroir.展开更多
The paper aims to provide insight on the level of energy consumption and carbon emission per each sector.The municipality of Roskovec is located in the south part of Albania and has a total population of 32,990 inhabi...The paper aims to provide insight on the level of energy consumption and carbon emission per each sector.The municipality of Roskovec is located in the south part of Albania and has a total population of 32,990 inhabitants.The total area of the municipality is 118 km2.The research contributes in identifying the main source of emissions and categorizes them according their weight.The methodology used in the reseach is based on the IPCC(Intergovernmental Panel on Climate Change)methodology by considering the activity and the emission factors.In line with the methodology,the study has considered the main sectors building,transport,waste and agriculture.The municipality of Roskovec has in total 42 municipal objects including kindergardens,municipality buildings,cultural buildings etc.The main results show that the transport sector accounts the highest part of the energy consumption and GHG(greenhouse gas)emissions with the a total 51 GW energy consumption or 13,212 ton-CO_(2).The second sector after the transport is the building sector with 45.5 GW followed by waste and waste water.Based on the existing data,the municipality shall work in the replacement of the existing caris with electrical ones and secondly invest in building renovation of the private and public sector.展开更多
Bromate(BrO_(3)^(−))is a toxic disinfection byproduct frequently formed during ozonation in water treatment processes and is classified as a potential human carcinogen.Its effective removal from drinking water is ther...Bromate(BrO_(3)^(−))is a toxic disinfection byproduct frequently formed during ozonation in water treatment processes and is classified as a potential human carcinogen.Its effective removal from drinking water is therefore a pressing concern for public health and environmental safety.This study investigated the removal of BrO_(3)^(−)from water using the synthesized zeolite imidazolate framework(ZIF)-67 and ZIF-67/graphene oxide(GO)nanocomposites through a comparative approach.The morphology,composition,and crystallinity of both ZIFs were characterized.The effects of four independent parameters(initial BrO_(3)^(−)concentration,pH,adsorbent dose,and contact time)on BrO_(3)^(−)removal efficiency were examined.A strong correlation was observed between experimental and predicted values.GO enhanced BrO_(3)^(−)removal not only through synergistic interactions with ZIF-67 but also by improving dispersion and providing additional functional groups that facilitate electrostatic interactions and adsorption.The Box-Behnken design was employed to evaluate both individual and interactive effects of the parameters on BrO_(3)^(−)removal,achieving an optimum removal efficiency of approximately 99.6%using 1.5 g/L of ZIF-67/GO at a pH value of 4 with an initial BrO_(3)^(−)concentration of 2 mg/L.The optimization process was further supported by desirability analysis.The BrO_(3)^(−)removal mechanisms are primarily attributed to porosity,electrostatic interactions,and adsorption onto active sites.Compared to ZIF-67 alone,ZIF-67/GO demonstrated superior anion removal efficiency,highlighting its potential for water treatment applications.展开更多
This paper addresses the problem of a viscoelastic Euler-Bernoulli beam under the influence of a constant velocity moving mass and different types of appendages.Four types of boundary conditions are considered:pinned-...This paper addresses the problem of a viscoelastic Euler-Bernoulli beam under the influence of a constant velocity moving mass and different types of appendages.Four types of boundary conditions are considered:pinned-pinned,fixed-pinned,fixed-free(or cantilever),and fixed-fixed.Appendages considered include lumped masses,dampers,and springs.The modal decomposition method is employed to derive the equation of motion of the beam,for which an analytical closed-form expression of the dynamic vibration response is generated.The proposed method enables the study of the effect of a single appendage or a combination of the three types of appendages on the non-dimensional dynamic response of the beam.Numerical examples are presented to illustrate the effects of these appendages and compare them to the reference cases of a beam with no appendages.The results demonstrate the importance of considering these parameters in the design of structures.The proposed method is compared to other techniques in the literature and found to be advantageous due to its direct approach.The method also offers a versatile tool for investigating various configurations,aiding in engineering design and structural analysis for which establishing a precise prediction of beam vibrations is crucial.展开更多
The removal of arsenic from water is essential for the protection of public health. To investigate the adsorption capabilities of laterite, sandstone, and shale for the removal of arsenic from aqueous solutions, colum...The removal of arsenic from water is essential for the protection of public health. To investigate the adsorption capabilities of laterite, sandstone, and shale for the removal of arsenic from aqueous solutions, column experiments were conducted. In this study, raw materials and heat-treated (calcined) materials were examined. The experiments assessed the influence of various parameters, including initial concentration, bed depth, and the effects of heat treatment. The findings revealed that the breakthrough curves were influenced by the initial concentration of arsenic, the depth of the bed, and the type of material used. For an initial arsenic concentration of 5 mg/L, columns containing 85 cm of calcined laterite, sandstone, and shale produced volumes of 7460 ml (1492 min), 3510 ml (702 min), and 4400 ml (880 min) of water with arsenic levels below 0.01 mg/L, respectively. These calcined materials demonstrate significant potential for the effective removal of arsenic from water.展开更多
Effects of polycarboxylate type admixture（PCA）on calcium monocarboaluminate hydrate（AFmc）formation in hydrated cement paste containing limestone filler（LF）are investigated by the Fourier transform infrared spect...Effects of polycarboxylate type admixture（PCA）on calcium monocarboaluminate hydrate（AFmc）formation in hydrated cement paste containing limestone filler（LF）are investigated by the Fourier transform infrared spectroscopy（FTIR）,the scanning electron microscopy（SEM）,the derivative thermogravimetric（DTG）analysis and the adsorption amount measurement.Experimental results indicate that AFmc forms during the initial hydration period of cement as early as 15 min.It is found that PCA accelerates the early age AFmc formation and enhances cement hydration by promoting C4AF hydration at the early age,and,as a consequence,the iron associated AFmc phase forms more readily.The phenomenon is not observed when PCA is replaced by a naphthalene formaldehyde sulphonate condensate water reducer.Compatibility between PCA and cement is modified due to the presence of AFmc along with ettringite（AFt）,which results in a less adsorption amount of PCA on the surface of cement minerals.As a kind of high-range water reducer,PCA may be the preferred choice for concrete containing LF.展开更多
This study aims to investigate the possibility of using biopolymer(environmental friendly material) to enhance the mechanical behaviors of collapsible soil.Two types of biopolymers were(xanthan gum and guar gum) used ...This study aims to investigate the possibility of using biopolymer(environmental friendly material) to enhance the mechanical behaviors of collapsible soil.Two types of biopolymers were(xanthan gum and guar gum) used in this study due to their stable behaviors under severe conditions and their availability with reasonable prices.The experimental program focused on three major soil properties,i.e.compaction characterizations,collapsible potential and shear parameters.These three properties are essential in process of soil improvement.Different biopolymer concentrations were used in this study and the experimental program was performed at two curing periods(soon after mixing the soil with the biopolymer and after one week curing time).Shear parameters were measured for the treated specimens under both soaked and unsoaked conditions,while a collapsible potential test was performed under different mixing conditions(wet mix and dry mix).A numerical model was built to predict the behavior of the treated collapsible soil after and before water immersing.The results indicated that the ability of both xanthan gum and guar gum can be used as improvement materials for collapsible soil treatment.The collapsible potential has been reduced from 9%to 1%after mixing the soil with 2%biopolymer concentration in the wet case.After one week curing,the cohesion has been increased from 8.5 kPa to105 kPa by increasing the xanthan gum concentration from zero to 2%,leading to an overall improvement in soil shear strength.It also proves that the guar gum is superior to the xanthan gum.The shear strength of soil can be increased by about 30%when using the guar gum in comparison with the xanthan gum at the same conditions;however,the collapsible potential of soil material will be reduced by about 20%.展开更多
A wet catalytic oxidation at room temperature was investigated with solution containing ferric, ferrous and cupric ions for H2S removal. The experiments were carried out in a two step process, and the results obtained...A wet catalytic oxidation at room temperature was investigated with solution containing ferric, ferrous and cupric ions for H2S removal. The experiments were carried out in a two step process, and the results obtained show that the removal efficiency of H2S can always reach 100% in a 300 mm scrubbing column with four sieve plates, and the regeneration of ferric ions in 200 mm bubble column can match the consumed ferric species in absorption. Removal of H2S, production of elemental sulfur and regeneration of ferric, cupric ions can all be accomplished at the same time. No raw material is consumed except O2 in flue gas or air, the process has no secondary pollution and no problem of catalyst degradation and congestion.展开更多
Fenton and ozone treatment was investigated at laboratory scale for the degradation of aqueous solutions of nitrobenzene （NB）. Effects of reactants concentration （O3, H2O2, and Fe（Ⅱ））, temperature, and pH on NB...Fenton and ozone treatment was investigated at laboratory scale for the degradation of aqueous solutions of nitrobenzene （NB）. Effects of reactants concentration （O3, H2O2, and Fe（Ⅱ））, temperature, and pH on NB degradation were monitored. Reaction kinetic of these processes was also assessed. A rapid reaction took place for Fenton process at higher initial concentration of H2O2, higher temperatures, and more acidic conditions （pH 3）. Similarly, ozonation reaction exhibited rapid rates for higher ozone dose, higher temperatures, and more basic conditions （pH 11）. Complete NB degradation in 65 min was achieved using Fenton process. The conditions of complete elimination of 100 mg/L of initial NB concentration, were 250 mg/L of H202 concentration, pH 3, and 10 mg/L of Fe（Ⅱ） concentration. Under these conditions, 55% organic carbon elimination was achieved. Total organic carbon mineralization was attained in 240 rain reaction time by Fenton process with 900 mg/L of H202 concentration, and 30 mg/L of Fe（Ⅱ） concentration. Fenton reaction showed a pseudo-first order kinetic; the reaction rate constant was ranged from 0.0226 to 0.0658 min^-1. Complete NB degradation was also achieved for an ozone dose of the order of 2.5 g/L. The ozonation was studied at different ozone doses, different initial pH （7-11） and at different temperatures （15-35℃）. NB ozonation kinetic was represented by a bi-molecular kinetic model which was reduced to pseudo-first order kinetic. The pseudo-first order reaction rate constant was determined to increase at 20℃ from 0.004 to 0.020 min^-1 as the used ozone increased from 0.4 to 1.9 g/L.展开更多
Welding is a vital component of several industries such as automotive,aerospace,robotics,and construction.Without welding,these industries utilize aluminum alloys for the manufacturing of many components or systems.Ho...Welding is a vital component of several industries such as automotive,aerospace,robotics,and construction.Without welding,these industries utilize aluminum alloys for the manufacturing of many components or systems.However,fusion welding of aluminum alloys is challenging due to several factors,including the presence of non-heat-treatable alloys,porosity,solidification,and liquation of cracks.Many manufacturers adopt conventional in-air friction stir welding(FSW)to weld metallic alloys and dissimilar materials.Many researchers reported the drawbacks of this traditional in-air FSW technique in welding metallic and polymeric materials in general and aluminum alloys and aluminum matrix composites in specific.A number of FSW techniques were developed recently,such as underwater friction stir welding(UFSW),vibrational friction-stir welding(VFSW),and others,for welding of aluminum alloy joints to overcome the issues of welding using conventional FSW.Therefore,the main objective of this review is to summarize the recent trends in FSW process of aluminum alloys and aluminum metal matrix composites(Al MMCs).Also,it discusses the effect of welding parameters of the traditional and state-of-the-art developed FSW techniques on the welding quality and strength of aluminum alloys and Al MMCs.Comparison among the techniques and advantages and limitations of each are considered.The review suggests that VFSW is a viable option for welding aluminum joints due to its energy efficiency,economic cost,and versatile modifications that can be employed based on the application.This review also illustrated that significantly less attention has been paid to FSW of Al-MMCs and considerable attention is demanded to produce qualified joint.展开更多
文摘The present work ascertains the feasibility of oil residue treatment for stabilizing wind-blown sand dunes. Various combinations of natural collapsible saline from the Jandaq desert of Iran and oil residue from distillation towers of Iranian refineries were tested in laboratory experiments. Stabilized sands were evaluated in terms of geotechnical properties, permeability, and oil retention characteristics(i.e. bonding mechanisms, leaching and migrating behaviour of oil residue from the stabilized sands). Since the presence of oil residue in soils can pose an environmental threat, the optimum retention capacity of the stabilized sands is of critical concern. Relative to sand that was not augmented with oil residue, specimens made of 7% oil residues had the highest compressive strength, significantly higher cohesion and load bearing capacity, and considerably lower permeability. The effect of distilled water, saline water and municipal sewage on prepared specimens were also evaluated.
文摘This study provides the first systematic evaluation of image resolution’s effect (50-300 PPI, pixels per inch) on UAV (unmanned aerial vehicle)-based digital close-range photogrammetry accuracy in civil engineering applications, such as infrastructure monitoring and heritage preservation. Using a high-resolution UAV with a 20 MP (MegaPixels) sensor, four images of a brick wall test field were captured and processed in Agisoft Metashape, with resolutions compared against Leica T2002 theodolite measurements (1.0 mm accuracy). Advanced statistical methods (ANOVA (analysis of variance), Tukey tests, Monte Carlo simulations) and ground control points validated the results. Accuracy improved from 25 mm at 50 PPI to 5 mm at 150 PPI (p < 0.01), plateauing at 4 mm beyond 200 PPI, while 150 PPI reduced processing time by 62% compared to 300 PPI. Unlike prior studies, this research uniquely isolates resolution effects in a controlled civil engineering context, offering a novel 150 PPI threshold that balances precision and efficiency. This threshold supports Saudi Vision 2030’s smart infrastructure goals for megaprojects like NEOM, providing a scalable framework for global applications. Future research should leverage deep learning to optimize resolutions in dynamic environments.
基金supported by the Polish National Science Center(Grant No.2022/06/X/ST10/00320)received by Witold Tisler.
文摘The present study investigates the engineering properties of submerged organic silt(orSi)stabilized with F-class fly ash(FA),with and without the addition of an activator(CaO).The utilization of F-class FA for soil improvement is an important aspect of sustainable and environmentally-conscious geotechnical engineering when marginal usage of lime and concrete is of great interest to engineers and societies.Currently,discussion is predominantly focused on the positive aspects of using the F-class FA,with a paucity of emphasis on the negative aspects.To explore these features more thoroughly,a series of strength and compressibility tests was conducted.The sample preparation and curing methodology were chosen to replicate the in situ conditions where soil is surcharged and submerged in water.It was found that the incorporation of F-class FA without an activator reduces the undrained shear strength of submerged orSi by about 20%–25%and permanently prevents any thixotropic strength restoration.An increase in undrained shear strength is observed when lime(3%–6%)is added to the soil–FA mixture or when only lime(in the same amount of 3%–6%)is used.Consequently,F-class FA can be successfully used as a filler for slurries with minimum lime content in soil mixing methods.The F-class FA(with or without an activator)shifts the so-called“creep delay”in time,consequently reducing the total creep settlements.The shift of“creep delay”is more considerable for orSi stabilized with lime or with FA and lime as an activator,than for orSi stabilized with pure F-class FA.
基金supported by the Fine Particle Research Initiative in East Asia Considering National Differences Project through the National Research Foundation of Korea(NRF)funded by the Ministry of Science and ICT(No.NRF-2023M3G1A1090660)supported by a grant from the National Institute of Environmental Research(NIER),funded by the Ministry of Environment of the Republic of Korea(No.NIER-2023-04-02-056).
文摘PM_(1.0),particulate matter with an aerodynamic diameter smaller than 1.0μm,can adversely affect human health.However,fewer stations are capable of measuring PM_(1.0) concentrations than PM2.5 and PM10 concentrations in real time(i.e.,only 9 locations for PM_(1.0) vs.623 locations for PM2.5 or PM10)in South Korea,making it impossible to conduct a nationwide health risk analysis of PM_(1.0).Thus,this study aimed to develop a PM_(1.0) prediction model using a random forest algorithm based on PM_(1.0) data from the nine measurement stations and various environmental input factors.Cross validation,in which the model was trained in eight stations and tested in the remaining station,achieved an average R^(2) of 0.913.The high R^(2) value achieved undermutually exclusive training and test locations in the cross validation can be ascribed to the fact that all the locations had similar relationships between PM_(1.0) and the input factors,which were captured by our model.Moreover,results of feature importance analysis showed that PM2.5 and PM10 concentrations were the two most important input features in predicting PM_(1.0) concentration.Finally,the model was used to estimate the PM_(1.0) concentrations in 623 locations,where input factors such as PM2.5 and PM10 can be obtained.Based on the augmented profile,we identified Seoul and Ansan to be PM_(1.0) concentration hotspots.These regions are large cities or the center of anthropogenic and industrial activities.The proposed model and the augmented PM_(1.0) profiles can be used for large epidemiological studies to understand the health impacts of PM_(1.0).
文摘Laboratory scale model of DMMBF （dual mixed media biofilter） were designed and installed in AI-Mustansiriya University Environmental Hydraulic Lab. Experiments were conducted using two mixed layers through PVR column--2.2 m height and 300 mm diameter. The first mixed media filter of depth 640mm mixed of sand, rice husk and granular activated carbon. The percentage volume mix is 1：1：1. While the other mixed media of depth 740 mm, consisting of coal, crash porcelinaite, rock and granite with equally percentage volume. Fifty samples were collected during the experiments, which was spread over a period of forty two weeks. The obtained results indicate that when the flow loading raised from 0.15 L/min to 2.7 L/rain, the removal efficiency of BOD decreased 8%-11%, and the removal efficiency of COD deceased 3%-4%, while the removal efficiency of turbidity increased with the decreasing of hydraulic loading. The results showed that the removal efficiency of turbidity is more than 95% at the lower discharge （0.15 L/min）. Therefore, infiltration should be conservatively designed using low loading rates.
文摘Strategic assessments are a landscape scale assessment and unlike project-by-project assessments which look at individual actions, they can consider a much broader set of issues;for example, a large urban growth area that will be developed over many years or a fire management policy across a broad landscape. Wetlands are important and effective ecosystems for biodiversity protection and improving environmental conditions. Bird watching as tourism and ecotourism activity is a complex process which it is compatible with conservation of wetlands and other aquatic zones. In this research, combination of SWOT analysis and FAHP method base on strategic fuzzy assessment are used for bird watch zoning in Bazangan Lake. By making internal and external matrix for SWOT factors, existing condition was in competitive strategies (ST) in the study area. Offered strategies in this condition were environment restoration to increase in environment resilience against hazards (natural and human), avoiding of land use and land cover changes and presence of ecotourism responsibly especially Bird watching. The sensitivity analysis results did not show any difference within the results of the present study and it was suitable and valid to use for similar situations. Base on the presented medium and short term strategies, it needed to have a short time training program to inform and empower local communities to wetlands partnership management by sharing them in the getting benefits in Bazangan Lake. By using the preferred frame in this study, decision makers can plan for each lake, dam and wetland and determine the best areas for tourist activities like bird watching. Conservation, protection and restoration of environment with its wildlife are guaranteed by using fuzzy assessment to provide reasonable strategies.
文摘Unit stream power is the most important and dominant parameter for the determination of transport rate of sand,gravel,and hyper-concentrated sediment with wash load.Minimum energy dissipation rate theory,or its simplified minimum unit stream power and minimum stream power theories,can provide engineers the needed theoretical basis for river morphology and river engineering studies.The Generalized Sediment Transport model for Alluvial River Simulation computer mode series have been developed based on the above theories.The computer model series have been successfully applied in many countries.Examples will be used to illustrate the applications of the computer models to solving a wide range of river morphology and river engineering problems.
基金the National Natural Science Foundation of China (Nos. 21603129 & 20871167)National Natural Science Foundation of Shanxi Province (No. 201601D202021)the Foundation of State Key Laboratory of Coal Conversion (No. J1819-903) for the financial support
文摘Environmental catalysis has drawn a great deal ofattention due to its clean ways to produce useful chemicals or carry out some chemical processes.Photocatalysis and electrocatalysis play important roles in these fields.They can decompose and remove organic pollutants from the aqueous environment,and prepare some fine chemicals.Moreover,they also can carry out some important reactions,such as 02 reduction reaction(ORR),O2 evolution reaction(OER),H2 evolution reaction(HER),CO2 reduction reaction(C02 RR),and N2 fixation(NRR).For catalytic reactions,it is the key to develop high-performance catalysts to meet the demand fortargeted reactions.In recentyears,two-dimensional(2 D) materials have attracted great interest in environmental catalysis due to their unique layered structures,which offer us to make use of their electronic and structural characteristics.Great progress has been made so far,including graphene,black phosphorus,oxides,layered double hydroxides(LDHs),chalcogenides,bismuth-based layered compounds,MXenes,metal organic frameworks(MOFs),covalent organic frameworks(COFs),and others.This content drives us to invite many famous groups in these fields to write the roadmap on two-dimensional nanomaterials for environmental catalysis.We hope that this roadmap can give the useful guidance to researchers in future researches,and provide the research directions.
文摘KM （knowledge management） has in the recent past been promoted as a means of harnessing and utilising intellectual resources and to improve innovation, business performance and client satisfaction within the construction industry. However, there has been no attempt to ascertain the required level of KM within any given firm. The study reported in this paper aimed at establishing a general equation for assessing a firm’s required level of KM. Through literature review and a questionnaire survey, a total of 22 key indicators of KM were established. The interaction and effects of the key indicators against turnover and employee base were established, yielding an elliptic paraboloid fitted graph over which desirability could be calculated. It was observed that there is a continuous relationship among the firm’s turnover, employee base and the identified key indicators. In practice, firms have different combinations of the employee base and turnover. The derived equation fits well with the different combinations. Firms can, through the use of such equations, determine the level of effort and investment required to implement KM.
文摘Grapes are the main reason why the grapevine (Vitis vinifera L.) is cultivated. However, climate, soil conditions, vegetation and anthropogenic effects on the soil greatly affect grapevine production. The organoleptic properties of grape-derived products, such as wine, are influenced by these factors, which are becoming increasingly popular in Africa. Thus, grapevines, which are commonly grown in warm regions, are acclimatized in Africa using grapevine varieties that can adjust to tropical conditions. This study, which was carried out in 2019, aimed to promote grapevine cultivation in Côte d’Ivoire by examining the influence of pedoclimatic factors on the agro-physiological characteristics of grapevines. In Côte d’Ivoire, there were four distinct agro-ecological zones (North, South, Southeast and West) where three grapevine varieties, Bequignol, Muscat Rouge and Aleatico, were grown. Grapevine plants could grow robustly in morpho-physiological ways because the soils had sufficient fertility, as revealed by the analysis of experimental sites. Grapevine varieties have successfully adapted to different terroirs, with the exception of Muscat Rouge, which only displayed favorable morphological characteristics in the Man zone (West). Regardless of the grape variety, the regions with the best grapevine-growing conditions were Man (West), followed by Aboisso (Southeast). Consequently, grapevine development was less favorable in Korhogo (North) and Abidjan (South) zones. Thus, the cultivation of grapevine varieties in Côte d’Ivoire was greatly influenced by terroir.
文摘The paper aims to provide insight on the level of energy consumption and carbon emission per each sector.The municipality of Roskovec is located in the south part of Albania and has a total population of 32,990 inhabitants.The total area of the municipality is 118 km2.The research contributes in identifying the main source of emissions and categorizes them according their weight.The methodology used in the reseach is based on the IPCC(Intergovernmental Panel on Climate Change)methodology by considering the activity and the emission factors.In line with the methodology,the study has considered the main sectors building,transport,waste and agriculture.The municipality of Roskovec has in total 42 municipal objects including kindergardens,municipality buildings,cultural buildings etc.The main results show that the transport sector accounts the highest part of the energy consumption and GHG(greenhouse gas)emissions with the a total 51 GW energy consumption or 13,212 ton-CO_(2).The second sector after the transport is the building sector with 45.5 GW followed by waste and waste water.Based on the existing data,the municipality shall work in the replacement of the existing caris with electrical ones and secondly invest in building renovation of the private and public sector.
文摘Bromate(BrO_(3)^(−))is a toxic disinfection byproduct frequently formed during ozonation in water treatment processes and is classified as a potential human carcinogen.Its effective removal from drinking water is therefore a pressing concern for public health and environmental safety.This study investigated the removal of BrO_(3)^(−)from water using the synthesized zeolite imidazolate framework(ZIF)-67 and ZIF-67/graphene oxide(GO)nanocomposites through a comparative approach.The morphology,composition,and crystallinity of both ZIFs were characterized.The effects of four independent parameters(initial BrO_(3)^(−)concentration,pH,adsorbent dose,and contact time)on BrO_(3)^(−)removal efficiency were examined.A strong correlation was observed between experimental and predicted values.GO enhanced BrO_(3)^(−)removal not only through synergistic interactions with ZIF-67 but also by improving dispersion and providing additional functional groups that facilitate electrostatic interactions and adsorption.The Box-Behnken design was employed to evaluate both individual and interactive effects of the parameters on BrO_(3)^(−)removal,achieving an optimum removal efficiency of approximately 99.6%using 1.5 g/L of ZIF-67/GO at a pH value of 4 with an initial BrO_(3)^(−)concentration of 2 mg/L.The optimization process was further supported by desirability analysis.The BrO_(3)^(−)removal mechanisms are primarily attributed to porosity,electrostatic interactions,and adsorption onto active sites.Compared to ZIF-67 alone,ZIF-67/GO demonstrated superior anion removal efficiency,highlighting its potential for water treatment applications.
文摘This paper addresses the problem of a viscoelastic Euler-Bernoulli beam under the influence of a constant velocity moving mass and different types of appendages.Four types of boundary conditions are considered:pinned-pinned,fixed-pinned,fixed-free(or cantilever),and fixed-fixed.Appendages considered include lumped masses,dampers,and springs.The modal decomposition method is employed to derive the equation of motion of the beam,for which an analytical closed-form expression of the dynamic vibration response is generated.The proposed method enables the study of the effect of a single appendage or a combination of the three types of appendages on the non-dimensional dynamic response of the beam.Numerical examples are presented to illustrate the effects of these appendages and compare them to the reference cases of a beam with no appendages.The results demonstrate the importance of considering these parameters in the design of structures.The proposed method is compared to other techniques in the literature and found to be advantageous due to its direct approach.The method also offers a versatile tool for investigating various configurations,aiding in engineering design and structural analysis for which establishing a precise prediction of beam vibrations is crucial.
文摘The removal of arsenic from water is essential for the protection of public health. To investigate the adsorption capabilities of laterite, sandstone, and shale for the removal of arsenic from aqueous solutions, column experiments were conducted. In this study, raw materials and heat-treated (calcined) materials were examined. The experiments assessed the influence of various parameters, including initial concentration, bed depth, and the effects of heat treatment. The findings revealed that the breakthrough curves were influenced by the initial concentration of arsenic, the depth of the bed, and the type of material used. For an initial arsenic concentration of 5 mg/L, columns containing 85 cm of calcined laterite, sandstone, and shale produced volumes of 7460 ml (1492 min), 3510 ml (702 min), and 4400 ml (880 min) of water with arsenic levels below 0.01 mg/L, respectively. These calcined materials demonstrate significant potential for the effective removal of arsenic from water.
基金The Natural Science Foundation of Jiangsu Province(No.BK2009712)the National Construction Research Project(No.2009-K4-9)
文摘Effects of polycarboxylate type admixture（PCA）on calcium monocarboaluminate hydrate（AFmc）formation in hydrated cement paste containing limestone filler（LF）are investigated by the Fourier transform infrared spectroscopy（FTIR）,the scanning electron microscopy（SEM）,the derivative thermogravimetric（DTG）analysis and the adsorption amount measurement.Experimental results indicate that AFmc forms during the initial hydration period of cement as early as 15 min.It is found that PCA accelerates the early age AFmc formation and enhances cement hydration by promoting C4AF hydration at the early age,and,as a consequence,the iron associated AFmc phase forms more readily.The phenomenon is not observed when PCA is replaced by a naphthalene formaldehyde sulphonate condensate water reducer.Compatibility between PCA and cement is modified due to the presence of AFmc along with ettringite（AFt）,which results in a less adsorption amount of PCA on the surface of cement minerals.As a kind of high-range water reducer,PCA may be the preferred choice for concrete containing LF.
文摘This study aims to investigate the possibility of using biopolymer(environmental friendly material) to enhance the mechanical behaviors of collapsible soil.Two types of biopolymers were(xanthan gum and guar gum) used in this study due to their stable behaviors under severe conditions and their availability with reasonable prices.The experimental program focused on three major soil properties,i.e.compaction characterizations,collapsible potential and shear parameters.These three properties are essential in process of soil improvement.Different biopolymer concentrations were used in this study and the experimental program was performed at two curing periods(soon after mixing the soil with the biopolymer and after one week curing time).Shear parameters were measured for the treated specimens under both soaked and unsoaked conditions,while a collapsible potential test was performed under different mixing conditions(wet mix and dry mix).A numerical model was built to predict the behavior of the treated collapsible soil after and before water immersing.The results indicated that the ability of both xanthan gum and guar gum can be used as improvement materials for collapsible soil treatment.The collapsible potential has been reduced from 9%to 1%after mixing the soil with 2%biopolymer concentration in the wet case.After one week curing,the cohesion has been increased from 8.5 kPa to105 kPa by increasing the xanthan gum concentration from zero to 2%,leading to an overall improvement in soil shear strength.It also proves that the guar gum is superior to the xanthan gum.The shear strength of soil can be increased by about 30%when using the guar gum in comparison with the xanthan gum at the same conditions;however,the collapsible potential of soil material will be reduced by about 20%.
文摘A wet catalytic oxidation at room temperature was investigated with solution containing ferric, ferrous and cupric ions for H2S removal. The experiments were carried out in a two step process, and the results obtained show that the removal efficiency of H2S can always reach 100% in a 300 mm scrubbing column with four sieve plates, and the regeneration of ferric ions in 200 mm bubble column can match the consumed ferric species in absorption. Removal of H2S, production of elemental sulfur and regeneration of ferric, cupric ions can all be accomplished at the same time. No raw material is consumed except O2 in flue gas or air, the process has no secondary pollution and no problem of catalyst degradation and congestion.
文摘Fenton and ozone treatment was investigated at laboratory scale for the degradation of aqueous solutions of nitrobenzene （NB）. Effects of reactants concentration （O3, H2O2, and Fe（Ⅱ））, temperature, and pH on NB degradation were monitored. Reaction kinetic of these processes was also assessed. A rapid reaction took place for Fenton process at higher initial concentration of H2O2, higher temperatures, and more acidic conditions （pH 3）. Similarly, ozonation reaction exhibited rapid rates for higher ozone dose, higher temperatures, and more basic conditions （pH 11）. Complete NB degradation in 65 min was achieved using Fenton process. The conditions of complete elimination of 100 mg/L of initial NB concentration, were 250 mg/L of H202 concentration, pH 3, and 10 mg/L of Fe（Ⅱ） concentration. Under these conditions, 55% organic carbon elimination was achieved. Total organic carbon mineralization was attained in 240 rain reaction time by Fenton process with 900 mg/L of H202 concentration, and 30 mg/L of Fe（Ⅱ） concentration. Fenton reaction showed a pseudo-first order kinetic; the reaction rate constant was ranged from 0.0226 to 0.0658 min^-1. Complete NB degradation was also achieved for an ozone dose of the order of 2.5 g/L. The ozonation was studied at different ozone doses, different initial pH （7-11） and at different temperatures （15-35℃）. NB ozonation kinetic was represented by a bi-molecular kinetic model which was reduced to pseudo-first order kinetic. The pseudo-first order reaction rate constant was determined to increase at 20℃ from 0.004 to 0.020 min^-1 as the used ozone increased from 0.4 to 1.9 g/L.
基金United Arab Emirates University (UAEU), Al-Ain, UAE, and Sultan Qaboos University (SQU), Muscat, Sultanate of Oman, for providing research support through a collaborative research project (UAEU: 31N270)。
文摘Welding is a vital component of several industries such as automotive,aerospace,robotics,and construction.Without welding,these industries utilize aluminum alloys for the manufacturing of many components or systems.However,fusion welding of aluminum alloys is challenging due to several factors,including the presence of non-heat-treatable alloys,porosity,solidification,and liquation of cracks.Many manufacturers adopt conventional in-air friction stir welding(FSW)to weld metallic alloys and dissimilar materials.Many researchers reported the drawbacks of this traditional in-air FSW technique in welding metallic and polymeric materials in general and aluminum alloys and aluminum matrix composites in specific.A number of FSW techniques were developed recently,such as underwater friction stir welding(UFSW),vibrational friction-stir welding(VFSW),and others,for welding of aluminum alloy joints to overcome the issues of welding using conventional FSW.Therefore,the main objective of this review is to summarize the recent trends in FSW process of aluminum alloys and aluminum metal matrix composites(Al MMCs).Also,it discusses the effect of welding parameters of the traditional and state-of-the-art developed FSW techniques on the welding quality and strength of aluminum alloys and Al MMCs.Comparison among the techniques and advantages and limitations of each are considered.The review suggests that VFSW is a viable option for welding aluminum joints due to its energy efficiency,economic cost,and versatile modifications that can be employed based on the application.This review also illustrated that significantly less attention has been paid to FSW of Al-MMCs and considerable attention is demanded to produce qualified joint.
