Lime-fly ash loess is composed of fly ash, lime and loess. It is a new material in subgrade backfill. Main factors to influence the strength of lime-fly ash loess are age, amount of fly ash and lime, ratio of fly ash ...Lime-fly ash loess is composed of fly ash, lime and loess. It is a new material in subgrade backfill. Main factors to influence the strength of lime-fly ash loess are age, amount of fly ash and lime, ratio of fly ash to lime (1:K), and moisture content. In order to observe the effect of each factor influencing the strength of lime-fly ash loess and find out the relationship between each other, this paper adopted orthogonal test design to conduct unconfined compression tests. The result shows that 90d strength can be considered to calculate the strength of lime-fly ash loess in practice. And the most important factor to influence the 90d strength of lime-fly ash loess is the amount of fly ash and lime, the second is moisture content, and then is the ratio of fly ash to lime (1:K). These achievements are significant to the design and application of lime-fly ash loess in subgrade construction of loess areas.展开更多
Recycling rare earth elements(REEs)from waste is necessary for an environmentally sustainable reuse and wastewater management approach.Na-A zeolite was synthesized from coal fly ash(CFA)and applied for Ce^(3+)adsorpti...Recycling rare earth elements(REEs)from waste is necessary for an environmentally sustainable reuse and wastewater management approach.Na-A zeolite was synthesized from coal fly ash(CFA)and applied for Ce^(3+)adsorption.Fourier transform infrared(FTIR)spectra show peaks at 790,500 and 467 cm^(-1),which are bond vibrations of Si-O-Si,Si with Al-O and Si-O-.The surface area is 15.88 m^(2)/g,with a pore size of 2.14 nm.SEM images show a cubic shape,which indicates the formation of zeolite.Field emission and energy disperse spectroscopy(EDS)shows the formation of Si,Al,Na,and O.Na-A zeolite was applied for Ce^(3+)adsorption.The optimum conditions for Ce^(3+)adsorption are 50 ppm concentration,360 min,and pH 6.The maximum adsorption capacity is 176.49 mg/g.Based on the results,it is found that the adsorption of Ce^(3+)by Na-A zeolite is pseudo-second-order.The desorption test using HNO_(3) is more effective than using HCl and H_(2)SO_(4).A desorption efficiency of 97.22%is obtained at 4 cycles.Adsorption test using real sample wastewater demonstrates an adsorption efficiency of 83.35%.展开更多
Three types of activators such as sodium hydroxide,calcium oxide and triethanolamine(TEA)are used to establish different activation environments to address the problems associated with the process of activating fly as...Three types of activators such as sodium hydroxide,calcium oxide and triethanolamine(TEA)are used to establish different activation environments to address the problems associated with the process of activating fly ash paste.We conducted mechanical tests and numerical simulations to understand the evolution of microstructure,and used environmental scanning electron microscopy(ESEM)and energy dispersive spectroscopy(EDS)techniques to analyze the microenvironments of the samples.The mechanical properties of fly ash paste under different activation conditions and the changes in the microstructure and composition were investigated.The results revealed that under conditions of low NaOH content(1%-3%),the strength of the sample increased significantly.When the content exceeded 4%,the rate of increase in strength decreased.Based on the results,the optimal NaOH content was identified,which was about 4%.A good activation effect,especially for short-term activation(3-7 d),was achieved using TEA under high doping conditions.The activation effect was poor for long-term strength after 28 days.The CaO content did not significantly affect the degree of activation achieved.The maximum effect was exerted when the content of CaO was 2%.The virtual cement and concrete testing laboratory(VCCTL)was used to simulate the hydration process,and the results revealed that the use of the three types of activators accelerated the formation of Ca(OH)_(2) in the system.The activators also corroded the surface of the fly ash particles,resulting in a pozzolanic reaction.The active substances in fly ash were released efficiently,and hydration was realized.The pores were filled with hydration products,and the microstructure changed to form a new frame of paste filling that helped improve the strength of fly ash paste.展开更多
In order to study the characteristics of pure fly ash-based geopolymer concrete(PFGC)conveniently,we used a machine learning method that can quantify the perception of characteristics to predict its compressive streng...In order to study the characteristics of pure fly ash-based geopolymer concrete(PFGC)conveniently,we used a machine learning method that can quantify the perception of characteristics to predict its compressive strength.In this study,505 groups of data were collected,and a new database of compressive strength of PFGC was constructed.In order to establish an accurate prediction model of compressive strength,five different types of machine learning networks were used for comparative analysis.The five machine learning models all showed good compressive strength prediction performance on PFGC.Among them,R2,MSE,RMSE and MAE of decision tree model(DT)are 0.99,1.58,1.25,and 0.25,respectively.While R2,MSE,RMSE and MAE of random forest model(RF)are 0.97,5.17,2.27 and 1.38,respectively.The two models have high prediction accuracy and outstanding generalization ability.In order to enhance the interpretability of model decision-making,we used importance ranking to obtain the perception of machine learning model to 13 variables.These 13 variables include chemical composition of fly ash(SiO_(2)/Al_(2)O_(3),Si/Al),the ratio of alkaline liquid to the binder,curing temperature,curing durations inside oven,fly ash dosage,fine aggregate dosage,coarse aggregate dosage,extra water dosage and sodium hydroxide dosage.Curing temperature,specimen ages and curing durations inside oven have the greatest influence on the prediction results,indicating that curing conditions have more prominent influence on the compressive strength of PFGC than ordinary Portland cement concrete.The importance of curing conditions of PFGC even exceeds that of the concrete mix proportion,due to the low reactivity of pure fly ash.展开更多
BACKGROUND Hepatocellular carcinoma(HCC)has been a pervasive malignancy throughout the world with elevated mortality.Efficient therapeutic targets are beneficial to treat and predict the disease.Currently,the exact mo...BACKGROUND Hepatocellular carcinoma(HCC)has been a pervasive malignancy throughout the world with elevated mortality.Efficient therapeutic targets are beneficial to treat and predict the disease.Currently,the exact molecular mechanisms leading to the progression of HCC are still unclear.Research has shown that the microRNA-142-3p level decreases in HCC,whereas bioinformatics analysis of the cancer genome atlas database shows the ASH1L expression increased among liver tumor tissues.In this paper,we will explore the effects and mechanisms of microRNA-142-3p and ASH1L affect the prognosis of HCC patients and HCC cell bioactivity,and the association between them.AIM To investigate the effects and mechanisms of microRNA-142-3p and ASH1L on the HCC cell bioactivity and prognosis of HCC patients.METHODS In this study,we grouped HCC patients according to their immunohistochemistry results of ASH1L with pathological tissues,and retrospectively analyzed the prognosis of HCC patients.Furthermore,explored the roles and mechanisms of microRNA-142-3p and ASH1L by cellular and animal experiments,which involved the following experimental methods:Immunohistochemical staining,western blot,quantitative real-time-polymerase chain reaction,flow cytometric analysis,tumor xenografts in nude mice,etc.The statistical methods involved in this study contained t-test,one-way analysis of variance,theχ^(2)test,the Kaplan-Meier approach and the log-rank test.RESULTS In this study,we found that HCC patients with high expression of ASH1L possess a more recurrence rate as well as a decreased overall survival rate.ASH1L promotes the tumorigenicity of HCC and microRNA-142-3p exhibits reduced expression in HCC tissues and interacts with ASH1L through targeting the ASH1L 3′untranslated region.Furthermore,microRNA-142-3p promotes apoptosis and inhibits proliferation,invasion,and migration of HCC cell lines in vitro via ASH1L.For the exploration mechanism,we found ASH1L may promote an immunosuppressive microenvironment in HCC and ASH1L affects the expression of the cell junction protein zonula occludens-1,which is potentially relevant to the immune system.CONCLUSION Loss function of microRNA-142-3p induces cancer progression and immune evasion through upregulation of ASH1L in HCC.Both microRNA-142-3p and ASH1L can feature as new biomarker for HCC in the future.展开更多
In order to adjust some properties of cement grout or concrete,some mineral admixtures are usually added in the preparation.Admixtures can reduce the cement consumption and save the cost,and also adjust the workabilit...In order to adjust some properties of cement grout or concrete,some mineral admixtures are usually added in the preparation.Admixtures can reduce the cement consumption and save the cost,and also adjust the workability of the material,improve the strength and durability of the cement stone,or reduce hydration heat of the composite cement.At present,the content of fly ash or slag is generally less than 50%among the composite cementitious materials that have been studied more,but there is little research on composite cementitious materials with large mineral admixture.In this paper,XRD,SEM,and adiabatic temperature rise tests were used to discuss hydration products and mechanism of composite cement grout with 90%content of fly ash and slag.The results show that the hydration of the composite cement grout is an alkali-activated hydration reaction,and the hydration products are mainly amorphous substances such as hydrated calcium silicate or hydrated calcium aluminate gel.The hydration reaction temperature rise is much lower than that of ordinary cement grout,and the time of the temperature peak is significantly delayed.展开更多
Microwave-curing and mechanical grinding of fly ash have both beenadopted as effective methods for improving the early-age strength of alkali-activated fly ash(AAFA)binders.This study combined these two approaches by ...Microwave-curing and mechanical grinding of fly ash have both beenadopted as effective methods for improving the early-age strength of alkali-activated fly ash(AAFA)binders.This study combined these two approaches by synthesizing AAFA using original,medium-fine,and ultrafine fly ash as precursors,and then specimens were cured with a five-stage temperature-controlled microwave.The compressive strength results indicate that the original AAFA develops the highest strength initially during microwave-curing,reaching 28 MPa at stage 2.Medium-fine AAFA exhibits the highest strength of 60 MPa when cured to stage 4-I,which is 26%higher than the peak strength of original AAFA.It is attributed to the significant rise in their specific surface area,which accelerates the dissolution of Si and Al from the precursor and facilitates the subsequent formation of N-A-S-H gels.Additionally,nanoscale zeolite crystals formed as secondary products fill the tiny gaps between amorphous products,thereby significantly improving their microstructure.In contrast,ultrafine fly ash,primarily composed of fragmented particles,necessitated a substantial amount of water,which adversely affects the absorption efficiency for microwave of AAFA specimens.Thus,ultrafine AAFA specimens consistently exhibit the lowest compressive strength.Specifically,at the end of curing,the compressive strength of these three specimens with microwave-curing is approximately 32%,59%,and 172%higher than that of the steam-cured sample,respectively.These findings demonstrate the compatibility of microwave-curing and fly ash refinement in enhancing the early compressive strength development of AAFA.展开更多
This study was part of the framework that contributed not only to the improvement of thermal comfort in housing but also to the decarbonization of the construction and building materials industry. For this purpose, te...This study was part of the framework that contributed not only to the improvement of thermal comfort in housing but also to the decarbonization of the construction and building materials industry. For this purpose, terracotta brick seems to meet these needs. Thus, the objective of this work was to evaluate the influence of the incorporation of coal fly ash from a thermal power plant on the physical and mechanical properties of fired bricks from grey clay in the Thicky area of Senegal. The coal fly ash was incorporated into the raw clay material in proportions of 0, 5, 10, and 15 % by weight. These two raw materials were first characterized by X-ray fluorescence spectroscopy (XRF). The XRF analyses showed that the most abundant oxides in clay were SiO2 (55.034%) and Fe2O3 (10.155%). In coal fly ash, SiO2 (38.574%) is predominant. The ash also contained Al2O3 (7.717%) and alicano-earthy melting oxides such as CaO (9.271%) and MgO (7.298%) etc. These melting oxides were necessary to facilitate the formation of the liquid phase when baking platelets. The latter, when burned at a temperature of 880°C, were characterized by determining the number of physico-mechanical parameters, such as linear shrinkage during cooking, water absorption, fire loss and compressive strength. A Hierarchical Ascending Classification of these different parameters was performed and three classes were obtained. Class 1 with better compressive strength (6.358 MPa), was in sample A (5%). Class 2 consisted of sample D (reference) and had a higher plasticity index (28.51%) and water absorption rate (11.19%). Finally, class 3, which included samples B (10%) and C (15%), had very high shrinkage and fire losses compared to other platelets. These results highlighted the possibility of using up to 5% of the coal fly ash in the production of new fired bricks with good performance.展开更多
The use of organic fertilizers is less expensive and advantageous for both the development of the plant and the sanitation of the environment. This is why this investigation aims to promote the ash from emptying of oi...The use of organic fertilizers is less expensive and advantageous for both the development of the plant and the sanitation of the environment. This is why this investigation aims to promote the ash from emptying of oil mill boilers as a source of organic fertilization in the production of palm bunches. To do this, different doses of oil mill boiler emptying ash were tested on oil palms in production. The results showed that the oil palms responded favorably regardless of the dose of oil mill boiler emptying ash. Thus, the comparison of the different doses Tv1 (1 kg), Tv2 (1.5 kg), Tv3 (2 kg), Tv4 (3 kg), Tv5 (4 kg), Tv6 (5 kg) and Tv7 (7 kg) showed that the high doses led to an increase in the weight of the bunches. Better still, the Tv6 treatment at a dose of 5 kg/tree proved to be optimal for good production of palm bunches with a gain of 73.9% compared to the treatment without oil mill boiler emptying ash (absolute control).展开更多
Municipal solid waste incineration fly ash(MSWI)is considered as one of the hazardous wastes and requires to be well disposed to reduce the contaminant to the environment.Reference to the production of coal fly ash(FA...Municipal solid waste incineration fly ash(MSWI)is considered as one of the hazardous wastes and requires to be well disposed to reduce the contaminant to the environment.Reference to the production of coal fly ash(FA)bricks,MSWI and FA were utilized to prepare autoclaved MSWI-FA block samples.Ultrasonic-assisted hydrothermal synthesis technology was used for production to explore the effect of ultrasonic pre-treatment.Compressive strength,dry density,and water absorption tests were conducted to determine the optimal ultrasonic parameters.Ultrasonic pre-treating mechanisms were investigated by SEM,FT-IR,particle size analysis,and BET.Furthermore,the micro-analyses of block samples were conducted.The heavy metal leaching concentration was studied to assess the environmental safety.The experimental results show that the ultrasonic pre-treating time,water bath temperature,and ultrasonic power of 3 h,30℃,and 840 W are the optimal,under which the compressive strength,dry density,and water absorption were 8.14 MPa,1417.48 kg/m^(3),and 0.38,respectively.It is shown that ultrasound destroys the surface structure of raw materials and smaller FA particles embed into MSWI.The particle size distribution of pre-treated raw materials mixture is wider and total pore volume is decreased by 6.3%.During hydrothermal processing,more Al-substituted tobermorite crystals are generated,which is the main source of higher strength and smaller pore volume of prepared block samples.The solidification/stabilization rates of Cu,Pb,and Zn increased by 30.77%,4.76%,and 35.29%,respectively.This study shows a feasible way to utilize MSWI as raw material for construction.展开更多
[Objectives]To explore the effects of mixed humus soil and straw ash substrate on rhizosphere bacterial community and growth of hot pepper.[Methods]In this pot experiment,high-throughput sequencing was conducted to an...[Objectives]To explore the effects of mixed humus soil and straw ash substrate on rhizosphere bacterial community and growth of hot pepper.[Methods]In this pot experiment,high-throughput sequencing was conducted to analyze bacterial communities in the rhizosphere soil of pepper plants treated with four different HA proportions.[Results]Pepper seedlings exhibited optimal growth in the 6:4(w/w)HA substrate.Bacterial structure and composition varied with the HA proportion.The relative abundance of the Proteobacteria phylum(ranging from 48.37%to 60.40%)was the highest across all treatments.Correlation analysis indicated that certain bacterial communities were closely related to the availability of soil nutrients and enzymatic activities.[Conclusions]This study elucidates the impact of HA proportion on rhizosphere bacterial communities and plant growth,laying a foundation for understanding the application of different mixed substrates and their effects on soil microbiology.展开更多
Over the last decades,huge amounts of ash residues have been generated worldwide leading to increasing demand for viable recycling technologies.Magnetic separation is considered a promising option for sustainable mana...Over the last decades,huge amounts of ash residues have been generated worldwide leading to increasing demand for viable recycling technologies.Magnetic separation is considered a promising option for sustainable management of these wastes.The present paper aims to review the recent advances in magnetic separation of ash residues to convert these waste materials into valuable commodities,minimizing negative environmental impact and in compliance with the circular economy requirements.Emphasis is placed on single magnetic separation techniques,multi-step separation procedures,and implementation of the magnetic separation in more complex separation schemes(in combination with particle-size fractionation,flotation,electrostatic separation,density(sink-float)separation,etc.)Novel and special approaches are mentioned as well(using organic solvents,selective magnetic coating,separation supported by thermal treatment or chlorination,methods for removal of non-magnetic components,magnetic separation applied on solubilized/precipitated compounds etc.).It discusses the latest literature results on the magnetospheres’morphology,chemical and mineral composition,and elemental leachability.Particular attention is paid to the utilization perspectives of the magnetic fractions and the non-magnetic residues.Based on the existing research status,the paper also provides concluding remarks highlighting the most promising trends.Current limitations indicating suggestions for future research(including insights on how existing approaches could be further improved)are mentioned as well.展开更多
Coke is the only solid charge component in the lower part of the blast furnace,and its strength is crucial to its production.Si and Al are the two most abundant elements in coke ash.The influences of these oxides on t...Coke is the only solid charge component in the lower part of the blast furnace,and its strength is crucial to its production.Si and Al are the two most abundant elements in coke ash.The influences of these oxides on the tensile strength of the coke matrix were studied by splitting tests.According to the Weibull analysis,with increasing Si and Al oxide concentrations,the fracture stress range of the coke widened,the upper and lower limits decreased,the probability of fracture under the same stress conditions increased,and the randomness and dispersion of strength increased.These results can be attributed to the inhibitory effect of ash during coal pyrolysis.Ash impedes the growth and contact of mesophase,leading to a decrease in graphitic carbon structures and an increase in edge carbon and aliphatic carbon structures in the resulting coke.Consequently,the overall ordering of the carbon structure is reduced.Moreover,SiO_(2)and Al_(2)O_(3)promoted the development of coke pores,thinned the coke pore wall,and significantly increased the proportion of large pores(>500μm).Moreover,Al_(2)O_(3)had more significant influences on the coke strength,carbon structure and stomatal ratio than SiO_(2).In addition,the position where the ash particles bonded to the carbon matrix easily produced cracks and holes,and the sharp edge of the matrix was likely to produce stress concentration points when subjected to an external force,leading to structural damage.Therefore,controlling the concentration of ash could effectively reduce the number of structural defects inside coke,which is conducive to improving the strength.展开更多
This study examines how ball milling parameters,specifically rotational speeds(20,40,and 60 r/min)in dry and wet condi-tions,affect the development of mullite/5wt%nano-fly ash coatings on AISI 410 steel,focusing on th...This study examines how ball milling parameters,specifically rotational speeds(20,40,and 60 r/min)in dry and wet condi-tions,affect the development of mullite/5wt%nano-fly ash coatings on AISI 410 steel,focusing on their impact on feedstock powders and plasma-sprayed coatings.Optimized milling parameters at 60 r/min under wet conditions yielded high-quality feedstock powders with a particle size of 14μm and limited size distribution.Coatings produced from wet-milled powders demonstrated a higher deposition effi-ciency(35%)due to their smaller,uniformly distributed particles,which enhanced melting during the spraying process.These coatings also exhibited significantly lower porosity(7.9%),resulting in denser structures with superior mechanical properties,including a hardness of HV_(1)647,fracture toughness of 1.41 MPa·m^(0.5),and a smoother surface finish with a roughness(R_(a))of 6.1μm.Residual stress analysis showed that wet-milled coatings had higher residual stresses,reaching up to 165.95 MPa,compared to dry-milled coatings.This increase is attributed to finer particle sizes and rapid thermal cycling during deposition,which intensified tensile stresses within the coating.These results highlight the importance of optimizing milling parameters to enhance coating performance and process efficiency.展开更多
The cement-fly ash composite expansive stable grout was prepared to deal with the problems of poor stability and volume shrinkage of ordinary cement grout,and the effects of fly ash ratio and water-binder ratio on the...The cement-fly ash composite expansive stable grout was prepared to deal with the problems of poor stability and volume shrinkage of ordinary cement grout,and the effects of fly ash ratio and water-binder ratio on the properties of the grout and its consolidation were analyzed.In addition,the mineral composition and microstructural characteristics of grout consolidation with different mixing ratios were investigated.The experimental results indicate that fly ash and the increase of water-binder ratio reduce the strength of the grout consolidation,and increase the fluidity,bleeding rate,and setting time of the composite grout.However,the magnitude of the fly ash-induced strength reduction decreases with time.And the effect of fly ash on the setting time and compressive strength becomes more significant with the water-binder ratio.The later expansion performance of grout consolidation(after 7-42 d)is improved by fly ash.But the expansibility of consolidation with fly ash decreases at the early curing stage,and the reduction amplitude of expansion rate is smaller and the reduction age is shorter with the water-binder ratio increase.Fly ash improves the corrosion resistance performance of grout consolidation,and the corrosion resistance coefficient rises first and then falls with the fly ash ratio.And for 0.6:1 water-binder ratio,the corrosion resistance coefficient of the samples mixed with fly ash are greater than 100%.XRD and SEM show that fly ash inhibited the formation of ettringite in the early stage,which is unfavorable to the expansion of the slurry,and with the increase of age,this effect gradually weakened.展开更多
The Ordovician-Silurian transition was marked by extensive volcanic activity globally.In South China,intensive volcanism was documented by abundant ash layers in strata,but the origins and tectonic settings of these a...The Ordovician-Silurian transition was marked by extensive volcanic activity globally.In South China,intensive volcanism was documented by abundant ash layers in strata,but the origins and tectonic settings of these ashes remain controversial.This study presents the stratigraphic distribution of volcanic ash layers,zircon trace element and Hf isotope data from the Wanhe Section in the southwestern Yangtze Shelf,providing insights into the tectonic setting and the origin of the parent magmas.The results suggest that volcanic ashes in the southwestern Yangtze Shelf primarily originated from arc magmatism in the Wuyi-Yunkai Orogen,with a mixed source from mantle and crust.The findings corroborate the hypothesis that the Late Ordovician–Silurian Wuyi-Yunkai Orogen in South China represents a collisional orogenic belt.展开更多
The effects of various fly ash(FA)contents on the durability and mechanical properties of recycled fine aggregate high ductility cementitious composites(RFA-HDCC)prepared with recycled fine aggregates(RFA)to fully rep...The effects of various fly ash(FA)contents on the durability and mechanical properties of recycled fine aggregate high ductility cementitious composites(RFA-HDCC)prepared with recycled fine aggregates(RFA)to fully replace natural fine aggregates was investigated.The results indicated that a 50% FA content significantly increased the compressive strength of RFA-HDCC by 13.93%.However,a?further increase in FA content led to a drastic decrease.The increased fly ash content substantially reduced the flexural and tensile strength;however,it markedly increased the matrix strain capacity,resulting in a 53.73% increase in the peak strain when FA was raised to 70%.Regarding durability,the increase in FA content negatively affected the chloride ion permeability and carbonation resistance.However,the increase in FA content initially improved the frost resistance of RFA-HDCC,peaking at 50% FA and deteriorating at 60% and 70% FA content.展开更多
The effects of isocyanate(IA)incorporation on the toughness and volume stability of AAFS were systematically investigated.Various IA dosages were introduced into AAFS,and their influence on mechanical properties,micro...The effects of isocyanate(IA)incorporation on the toughness and volume stability of AAFS were systematically investigated.Various IA dosages were introduced into AAFS,and their influence on mechanical properties,microstructure,and shrinkage behavior was evaluated.The experimental results indicate that,with the incorporation of 5%IA,the 28-day compressive strength reaches 48.6 MPa,the 56-day drying shrinkage decreases by 35.91%,and minimal cracking is observed in the ring test.Microstructural analyses using SEM,XRD,and FTIR reveal that IA reacts with water to form urethane and biuret,which crosslinks into a durable network structure.This network fills pores,reducing internal stresses and improving both toughness and volume stability.These findings offer new insights into optimizing alkali-activated materials for construction applications and provide a potential pathway for the development of more durable and stable geopolymers.展开更多
文摘Lime-fly ash loess is composed of fly ash, lime and loess. It is a new material in subgrade backfill. Main factors to influence the strength of lime-fly ash loess are age, amount of fly ash and lime, ratio of fly ash to lime (1:K), and moisture content. In order to observe the effect of each factor influencing the strength of lime-fly ash loess and find out the relationship between each other, this paper adopted orthogonal test design to conduct unconfined compression tests. The result shows that 90d strength can be considered to calculate the strength of lime-fly ash loess in practice. And the most important factor to influence the 90d strength of lime-fly ash loess is the amount of fly ash and lime, the second is moisture content, and then is the ratio of fly ash to lime (1:K). These achievements are significant to the design and application of lime-fly ash loess in subgrade construction of loess areas.
基金Project supported by Rumah Program 2023 and Net Zero Emission Program(1507/Ⅱ.7/HK.01.00/6/2023)a research facility from the National Research and Innovation Agency of Republic of Indonesia。
文摘Recycling rare earth elements(REEs)from waste is necessary for an environmentally sustainable reuse and wastewater management approach.Na-A zeolite was synthesized from coal fly ash(CFA)and applied for Ce^(3+)adsorption.Fourier transform infrared(FTIR)spectra show peaks at 790,500 and 467 cm^(-1),which are bond vibrations of Si-O-Si,Si with Al-O and Si-O-.The surface area is 15.88 m^(2)/g,with a pore size of 2.14 nm.SEM images show a cubic shape,which indicates the formation of zeolite.Field emission and energy disperse spectroscopy(EDS)shows the formation of Si,Al,Na,and O.Na-A zeolite was applied for Ce^(3+)adsorption.The optimum conditions for Ce^(3+)adsorption are 50 ppm concentration,360 min,and pH 6.The maximum adsorption capacity is 176.49 mg/g.Based on the results,it is found that the adsorption of Ce^(3+)by Na-A zeolite is pseudo-second-order.The desorption test using HNO_(3) is more effective than using HCl and H_(2)SO_(4).A desorption efficiency of 97.22%is obtained at 4 cycles.Adsorption test using real sample wastewater demonstrates an adsorption efficiency of 83.35%.
基金Supported by Yunnan Major Scientific and Technological Projects(No.202403AA080001)National Natural Science Foundation of China(No.52074137)Yunnan Fundamental Research Projects(No.202201AT070151)。
文摘Three types of activators such as sodium hydroxide,calcium oxide and triethanolamine(TEA)are used to establish different activation environments to address the problems associated with the process of activating fly ash paste.We conducted mechanical tests and numerical simulations to understand the evolution of microstructure,and used environmental scanning electron microscopy(ESEM)and energy dispersive spectroscopy(EDS)techniques to analyze the microenvironments of the samples.The mechanical properties of fly ash paste under different activation conditions and the changes in the microstructure and composition were investigated.The results revealed that under conditions of low NaOH content(1%-3%),the strength of the sample increased significantly.When the content exceeded 4%,the rate of increase in strength decreased.Based on the results,the optimal NaOH content was identified,which was about 4%.A good activation effect,especially for short-term activation(3-7 d),was achieved using TEA under high doping conditions.The activation effect was poor for long-term strength after 28 days.The CaO content did not significantly affect the degree of activation achieved.The maximum effect was exerted when the content of CaO was 2%.The virtual cement and concrete testing laboratory(VCCTL)was used to simulate the hydration process,and the results revealed that the use of the three types of activators accelerated the formation of Ca(OH)_(2) in the system.The activators also corroded the surface of the fly ash particles,resulting in a pozzolanic reaction.The active substances in fly ash were released efficiently,and hydration was realized.The pores were filled with hydration products,and the microstructure changed to form a new frame of paste filling that helped improve the strength of fly ash paste.
基金Funded by the Natural Science Foundation of China(No.52109168)。
文摘In order to study the characteristics of pure fly ash-based geopolymer concrete(PFGC)conveniently,we used a machine learning method that can quantify the perception of characteristics to predict its compressive strength.In this study,505 groups of data were collected,and a new database of compressive strength of PFGC was constructed.In order to establish an accurate prediction model of compressive strength,five different types of machine learning networks were used for comparative analysis.The five machine learning models all showed good compressive strength prediction performance on PFGC.Among them,R2,MSE,RMSE and MAE of decision tree model(DT)are 0.99,1.58,1.25,and 0.25,respectively.While R2,MSE,RMSE and MAE of random forest model(RF)are 0.97,5.17,2.27 and 1.38,respectively.The two models have high prediction accuracy and outstanding generalization ability.In order to enhance the interpretability of model decision-making,we used importance ranking to obtain the perception of machine learning model to 13 variables.These 13 variables include chemical composition of fly ash(SiO_(2)/Al_(2)O_(3),Si/Al),the ratio of alkaline liquid to the binder,curing temperature,curing durations inside oven,fly ash dosage,fine aggregate dosage,coarse aggregate dosage,extra water dosage and sodium hydroxide dosage.Curing temperature,specimen ages and curing durations inside oven have the greatest influence on the prediction results,indicating that curing conditions have more prominent influence on the compressive strength of PFGC than ordinary Portland cement concrete.The importance of curing conditions of PFGC even exceeds that of the concrete mix proportion,due to the low reactivity of pure fly ash.
基金Supported by the Haihe Laboratory of Cell Ecosystem Innovation Fund,No.22HHXBJC00001the Key Discipline Special Project of Tianjin Municipal Health Commission,No.TJWJ2022XK016.
文摘BACKGROUND Hepatocellular carcinoma(HCC)has been a pervasive malignancy throughout the world with elevated mortality.Efficient therapeutic targets are beneficial to treat and predict the disease.Currently,the exact molecular mechanisms leading to the progression of HCC are still unclear.Research has shown that the microRNA-142-3p level decreases in HCC,whereas bioinformatics analysis of the cancer genome atlas database shows the ASH1L expression increased among liver tumor tissues.In this paper,we will explore the effects and mechanisms of microRNA-142-3p and ASH1L affect the prognosis of HCC patients and HCC cell bioactivity,and the association between them.AIM To investigate the effects and mechanisms of microRNA-142-3p and ASH1L on the HCC cell bioactivity and prognosis of HCC patients.METHODS In this study,we grouped HCC patients according to their immunohistochemistry results of ASH1L with pathological tissues,and retrospectively analyzed the prognosis of HCC patients.Furthermore,explored the roles and mechanisms of microRNA-142-3p and ASH1L by cellular and animal experiments,which involved the following experimental methods:Immunohistochemical staining,western blot,quantitative real-time-polymerase chain reaction,flow cytometric analysis,tumor xenografts in nude mice,etc.The statistical methods involved in this study contained t-test,one-way analysis of variance,theχ^(2)test,the Kaplan-Meier approach and the log-rank test.RESULTS In this study,we found that HCC patients with high expression of ASH1L possess a more recurrence rate as well as a decreased overall survival rate.ASH1L promotes the tumorigenicity of HCC and microRNA-142-3p exhibits reduced expression in HCC tissues and interacts with ASH1L through targeting the ASH1L 3′untranslated region.Furthermore,microRNA-142-3p promotes apoptosis and inhibits proliferation,invasion,and migration of HCC cell lines in vitro via ASH1L.For the exploration mechanism,we found ASH1L may promote an immunosuppressive microenvironment in HCC and ASH1L affects the expression of the cell junction protein zonula occludens-1,which is potentially relevant to the immune system.CONCLUSION Loss function of microRNA-142-3p induces cancer progression and immune evasion through upregulation of ASH1L in HCC.Both microRNA-142-3p and ASH1L can feature as new biomarker for HCC in the future.
文摘In order to adjust some properties of cement grout or concrete,some mineral admixtures are usually added in the preparation.Admixtures can reduce the cement consumption and save the cost,and also adjust the workability of the material,improve the strength and durability of the cement stone,or reduce hydration heat of the composite cement.At present,the content of fly ash or slag is generally less than 50%among the composite cementitious materials that have been studied more,but there is little research on composite cementitious materials with large mineral admixture.In this paper,XRD,SEM,and adiabatic temperature rise tests were used to discuss hydration products and mechanism of composite cement grout with 90%content of fly ash and slag.The results show that the hydration of the composite cement grout is an alkali-activated hydration reaction,and the hydration products are mainly amorphous substances such as hydrated calcium silicate or hydrated calcium aluminate gel.The hydration reaction temperature rise is much lower than that of ordinary cement grout,and the time of the temperature peak is significantly delayed.
文摘Microwave-curing and mechanical grinding of fly ash have both beenadopted as effective methods for improving the early-age strength of alkali-activated fly ash(AAFA)binders.This study combined these two approaches by synthesizing AAFA using original,medium-fine,and ultrafine fly ash as precursors,and then specimens were cured with a five-stage temperature-controlled microwave.The compressive strength results indicate that the original AAFA develops the highest strength initially during microwave-curing,reaching 28 MPa at stage 2.Medium-fine AAFA exhibits the highest strength of 60 MPa when cured to stage 4-I,which is 26%higher than the peak strength of original AAFA.It is attributed to the significant rise in their specific surface area,which accelerates the dissolution of Si and Al from the precursor and facilitates the subsequent formation of N-A-S-H gels.Additionally,nanoscale zeolite crystals formed as secondary products fill the tiny gaps between amorphous products,thereby significantly improving their microstructure.In contrast,ultrafine fly ash,primarily composed of fragmented particles,necessitated a substantial amount of water,which adversely affects the absorption efficiency for microwave of AAFA specimens.Thus,ultrafine AAFA specimens consistently exhibit the lowest compressive strength.Specifically,at the end of curing,the compressive strength of these three specimens with microwave-curing is approximately 32%,59%,and 172%higher than that of the steam-cured sample,respectively.These findings demonstrate the compatibility of microwave-curing and fly ash refinement in enhancing the early compressive strength development of AAFA.
文摘This study was part of the framework that contributed not only to the improvement of thermal comfort in housing but also to the decarbonization of the construction and building materials industry. For this purpose, terracotta brick seems to meet these needs. Thus, the objective of this work was to evaluate the influence of the incorporation of coal fly ash from a thermal power plant on the physical and mechanical properties of fired bricks from grey clay in the Thicky area of Senegal. The coal fly ash was incorporated into the raw clay material in proportions of 0, 5, 10, and 15 % by weight. These two raw materials were first characterized by X-ray fluorescence spectroscopy (XRF). The XRF analyses showed that the most abundant oxides in clay were SiO2 (55.034%) and Fe2O3 (10.155%). In coal fly ash, SiO2 (38.574%) is predominant. The ash also contained Al2O3 (7.717%) and alicano-earthy melting oxides such as CaO (9.271%) and MgO (7.298%) etc. These melting oxides were necessary to facilitate the formation of the liquid phase when baking platelets. The latter, when burned at a temperature of 880°C, were characterized by determining the number of physico-mechanical parameters, such as linear shrinkage during cooking, water absorption, fire loss and compressive strength. A Hierarchical Ascending Classification of these different parameters was performed and three classes were obtained. Class 1 with better compressive strength (6.358 MPa), was in sample A (5%). Class 2 consisted of sample D (reference) and had a higher plasticity index (28.51%) and water absorption rate (11.19%). Finally, class 3, which included samples B (10%) and C (15%), had very high shrinkage and fire losses compared to other platelets. These results highlighted the possibility of using up to 5% of the coal fly ash in the production of new fired bricks with good performance.
文摘The use of organic fertilizers is less expensive and advantageous for both the development of the plant and the sanitation of the environment. This is why this investigation aims to promote the ash from emptying of oil mill boilers as a source of organic fertilization in the production of palm bunches. To do this, different doses of oil mill boiler emptying ash were tested on oil palms in production. The results showed that the oil palms responded favorably regardless of the dose of oil mill boiler emptying ash. Thus, the comparison of the different doses Tv1 (1 kg), Tv2 (1.5 kg), Tv3 (2 kg), Tv4 (3 kg), Tv5 (4 kg), Tv6 (5 kg) and Tv7 (7 kg) showed that the high doses led to an increase in the weight of the bunches. Better still, the Tv6 treatment at a dose of 5 kg/tree proved to be optimal for good production of palm bunches with a gain of 73.9% compared to the treatment without oil mill boiler emptying ash (absolute control).
基金Funded by the National Natural Science Foundation of China(No.52178241)the National Key Research and Development Program of China during the Fourteenth Five-Year Plan Period(No.2021YFB3802001)+1 种基金the Shanghai Science and Technology Innovation Action Plan(No.23D21201401)the Key Research and Development of the Shaanxi Province of China(No.2022GY-163)。
文摘Municipal solid waste incineration fly ash(MSWI)is considered as one of the hazardous wastes and requires to be well disposed to reduce the contaminant to the environment.Reference to the production of coal fly ash(FA)bricks,MSWI and FA were utilized to prepare autoclaved MSWI-FA block samples.Ultrasonic-assisted hydrothermal synthesis technology was used for production to explore the effect of ultrasonic pre-treatment.Compressive strength,dry density,and water absorption tests were conducted to determine the optimal ultrasonic parameters.Ultrasonic pre-treating mechanisms were investigated by SEM,FT-IR,particle size analysis,and BET.Furthermore,the micro-analyses of block samples were conducted.The heavy metal leaching concentration was studied to assess the environmental safety.The experimental results show that the ultrasonic pre-treating time,water bath temperature,and ultrasonic power of 3 h,30℃,and 840 W are the optimal,under which the compressive strength,dry density,and water absorption were 8.14 MPa,1417.48 kg/m^(3),and 0.38,respectively.It is shown that ultrasound destroys the surface structure of raw materials and smaller FA particles embed into MSWI.The particle size distribution of pre-treated raw materials mixture is wider and total pore volume is decreased by 6.3%.During hydrothermal processing,more Al-substituted tobermorite crystals are generated,which is the main source of higher strength and smaller pore volume of prepared block samples.The solidification/stabilization rates of Cu,Pb,and Zn increased by 30.77%,4.76%,and 35.29%,respectively.This study shows a feasible way to utilize MSWI as raw material for construction.
文摘[Objectives]To explore the effects of mixed humus soil and straw ash substrate on rhizosphere bacterial community and growth of hot pepper.[Methods]In this pot experiment,high-throughput sequencing was conducted to analyze bacterial communities in the rhizosphere soil of pepper plants treated with four different HA proportions.[Results]Pepper seedlings exhibited optimal growth in the 6:4(w/w)HA substrate.Bacterial structure and composition varied with the HA proportion.The relative abundance of the Proteobacteria phylum(ranging from 48.37%to 60.40%)was the highest across all treatments.Correlation analysis indicated that certain bacterial communities were closely related to the availability of soil nutrients and enzymatic activities.[Conclusions]This study elucidates the impact of HA proportion on rhizosphere bacterial communities and plant growth,laying a foundation for understanding the application of different mixed substrates and their effects on soil microbiology.
基金the financial support of the European Union under the REFRESH-Research Excellence for Region Sustainability and High-tech Industries project number CZ.10.03.01/00/22_003/0000048 via the Operational Programme Just Transition and SGS projects 2022/68 and 2023/034.
文摘Over the last decades,huge amounts of ash residues have been generated worldwide leading to increasing demand for viable recycling technologies.Magnetic separation is considered a promising option for sustainable management of these wastes.The present paper aims to review the recent advances in magnetic separation of ash residues to convert these waste materials into valuable commodities,minimizing negative environmental impact and in compliance with the circular economy requirements.Emphasis is placed on single magnetic separation techniques,multi-step separation procedures,and implementation of the magnetic separation in more complex separation schemes(in combination with particle-size fractionation,flotation,electrostatic separation,density(sink-float)separation,etc.)Novel and special approaches are mentioned as well(using organic solvents,selective magnetic coating,separation supported by thermal treatment or chlorination,methods for removal of non-magnetic components,magnetic separation applied on solubilized/precipitated compounds etc.).It discusses the latest literature results on the magnetospheres’morphology,chemical and mineral composition,and elemental leachability.Particular attention is paid to the utilization perspectives of the magnetic fractions and the non-magnetic residues.Based on the existing research status,the paper also provides concluding remarks highlighting the most promising trends.Current limitations indicating suggestions for future research(including insights on how existing approaches could be further improved)are mentioned as well.
基金supported by the National Natural Science Foundation of China(No.51974212)the China Baowu Low Carbon Metallurgy Innovation Foundation(No.BWLCF202116)+2 种基金the Science and Technology Major Project of Wuhan(No.2023020302020572)the Postdoctor Project of Hubei Province(No.2024HBBHCXA074)the Foundation of Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education(No.FMRUlab23-04).
文摘Coke is the only solid charge component in the lower part of the blast furnace,and its strength is crucial to its production.Si and Al are the two most abundant elements in coke ash.The influences of these oxides on the tensile strength of the coke matrix were studied by splitting tests.According to the Weibull analysis,with increasing Si and Al oxide concentrations,the fracture stress range of the coke widened,the upper and lower limits decreased,the probability of fracture under the same stress conditions increased,and the randomness and dispersion of strength increased.These results can be attributed to the inhibitory effect of ash during coal pyrolysis.Ash impedes the growth and contact of mesophase,leading to a decrease in graphitic carbon structures and an increase in edge carbon and aliphatic carbon structures in the resulting coke.Consequently,the overall ordering of the carbon structure is reduced.Moreover,SiO_(2)and Al_(2)O_(3)promoted the development of coke pores,thinned the coke pore wall,and significantly increased the proportion of large pores(>500μm).Moreover,Al_(2)O_(3)had more significant influences on the coke strength,carbon structure and stomatal ratio than SiO_(2).In addition,the position where the ash particles bonded to the carbon matrix easily produced cracks and holes,and the sharp edge of the matrix was likely to produce stress concentration points when subjected to an external force,leading to structural damage.Therefore,controlling the concentration of ash could effectively reduce the number of structural defects inside coke,which is conducive to improving the strength.
基金financially supported by the King Mongkut’s University of Technology North Bangkok(KMUTNB),Thailand(No.KMUTNB-63-KNOW-039)the Electricity Generating Authority of Thailand(No.64-N201000-11-IO.SS03N3008589)the Program Management Unit for Human Resources&Institutional Development,Research and Innovation(No.B13F660125).
文摘This study examines how ball milling parameters,specifically rotational speeds(20,40,and 60 r/min)in dry and wet condi-tions,affect the development of mullite/5wt%nano-fly ash coatings on AISI 410 steel,focusing on their impact on feedstock powders and plasma-sprayed coatings.Optimized milling parameters at 60 r/min under wet conditions yielded high-quality feedstock powders with a particle size of 14μm and limited size distribution.Coatings produced from wet-milled powders demonstrated a higher deposition effi-ciency(35%)due to their smaller,uniformly distributed particles,which enhanced melting during the spraying process.These coatings also exhibited significantly lower porosity(7.9%),resulting in denser structures with superior mechanical properties,including a hardness of HV_(1)647,fracture toughness of 1.41 MPa·m^(0.5),and a smoother surface finish with a roughness(R_(a))of 6.1μm.Residual stress analysis showed that wet-milled coatings had higher residual stresses,reaching up to 165.95 MPa,compared to dry-milled coatings.This increase is attributed to finer particle sizes and rapid thermal cycling during deposition,which intensified tensile stresses within the coating.These results highlight the importance of optimizing milling parameters to enhance coating performance and process efficiency.
基金Funded by the National Natural Science Foundation of China(No.51979153)the Yunnan Key Research and Development Program(No.202103AA080016)。
文摘The cement-fly ash composite expansive stable grout was prepared to deal with the problems of poor stability and volume shrinkage of ordinary cement grout,and the effects of fly ash ratio and water-binder ratio on the properties of the grout and its consolidation were analyzed.In addition,the mineral composition and microstructural characteristics of grout consolidation with different mixing ratios were investigated.The experimental results indicate that fly ash and the increase of water-binder ratio reduce the strength of the grout consolidation,and increase the fluidity,bleeding rate,and setting time of the composite grout.However,the magnitude of the fly ash-induced strength reduction decreases with time.And the effect of fly ash on the setting time and compressive strength becomes more significant with the water-binder ratio.The later expansion performance of grout consolidation(after 7-42 d)is improved by fly ash.But the expansibility of consolidation with fly ash decreases at the early curing stage,and the reduction amplitude of expansion rate is smaller and the reduction age is shorter with the water-binder ratio increase.Fly ash improves the corrosion resistance performance of grout consolidation,and the corrosion resistance coefficient rises first and then falls with the fly ash ratio.And for 0.6:1 water-binder ratio,the corrosion resistance coefficient of the samples mixed with fly ash are greater than 100%.XRD and SEM show that fly ash inhibited the formation of ettringite in the early stage,which is unfavorable to the expansion of the slurry,and with the increase of age,this effect gradually weakened.
基金funded by the National Natural Science Foundation of China(Nos.42222209 and 42488201)the State Scholarship Fund.
文摘The Ordovician-Silurian transition was marked by extensive volcanic activity globally.In South China,intensive volcanism was documented by abundant ash layers in strata,but the origins and tectonic settings of these ashes remain controversial.This study presents the stratigraphic distribution of volcanic ash layers,zircon trace element and Hf isotope data from the Wanhe Section in the southwestern Yangtze Shelf,providing insights into the tectonic setting and the origin of the parent magmas.The results suggest that volcanic ashes in the southwestern Yangtze Shelf primarily originated from arc magmatism in the Wuyi-Yunkai Orogen,with a mixed source from mantle and crust.The findings corroborate the hypothesis that the Late Ordovician–Silurian Wuyi-Yunkai Orogen in South China represents a collisional orogenic belt.
基金Funded by the Natural Science Foundation of Jiangsu Province(No.BK20220626)Postgraduate Research&Practice Innovation Program of Jiangsu Province(No.KYCX24_3174)Taizhou Science and Technology Support Programme(Social Development)Directive Project(No.TS202432)。
文摘The effects of various fly ash(FA)contents on the durability and mechanical properties of recycled fine aggregate high ductility cementitious composites(RFA-HDCC)prepared with recycled fine aggregates(RFA)to fully replace natural fine aggregates was investigated.The results indicated that a 50% FA content significantly increased the compressive strength of RFA-HDCC by 13.93%.However,a?further increase in FA content led to a drastic decrease.The increased fly ash content substantially reduced the flexural and tensile strength;however,it markedly increased the matrix strain capacity,resulting in a 53.73% increase in the peak strain when FA was raised to 70%.Regarding durability,the increase in FA content negatively affected the chloride ion permeability and carbonation resistance.However,the increase in FA content initially improved the frost resistance of RFA-HDCC,peaking at 50% FA and deteriorating at 60% and 70% FA content.
基金Funded by the National Key R&D Program of China(No.2022YFC3803400)。
文摘The effects of isocyanate(IA)incorporation on the toughness and volume stability of AAFS were systematically investigated.Various IA dosages were introduced into AAFS,and their influence on mechanical properties,microstructure,and shrinkage behavior was evaluated.The experimental results indicate that,with the incorporation of 5%IA,the 28-day compressive strength reaches 48.6 MPa,the 56-day drying shrinkage decreases by 35.91%,and minimal cracking is observed in the ring test.Microstructural analyses using SEM,XRD,and FTIR reveal that IA reacts with water to form urethane and biuret,which crosslinks into a durable network structure.This network fills pores,reducing internal stresses and improving both toughness and volume stability.These findings offer new insights into optimizing alkali-activated materials for construction applications and provide a potential pathway for the development of more durable and stable geopolymers.
