The design and development of solar dryers are crucial in regions with abundant solar energy,such as Bhopal,India,where seasonal variations significantly impact the efficiency of drying processes.The paper is focused ...The design and development of solar dryers are crucial in regions with abundant solar energy,such as Bhopal,India,where seasonal variations significantly impact the efficiency of drying processes.The paper is focused on employing a comprehensive mathematical model to predict the dryer’s performance in drying the materials such as banana slices.To enhance this model,Hyper Tuned Swarm Optimization with Gradient Tree(HT_SOGT)was utilized to accurately predict and determine the optimal size of the dryer dimensions considering various mathematical calculations for material drying.The predictive model considered the influence of seasonal fluctuations,ensuring an efficient drying process with an objective function to optimize the drying time of an average of 7 hrs throughout the year.Across all recorded ambient temperatures(ranging from 16.985○C to 31.4○C),the outlet temperature of the solar dryer is consistently higher,ranging from 39.085○C to 66.2○C.The results show that the optimized dryer design,based on HT_SOGT modelling,significantly improves drying efficiency of the materials across varying conditions,making it suitable for sustainable applications in agriculture and food processing industries in the Bhopal region.展开更多
The dynamics of the drying process of polymer solutions are important for the development of coatings and films.In the present work,digital holographic microscopy(DHM)was performed to capture the drying dynamics of po...The dynamics of the drying process of polymer solutions are important for the development of coatings and films.In the present work,digital holographic microscopy(DHM)was performed to capture the drying dynamics of poly(ethylene oxide)(PEO)droplets using a gold nanoparticle tracer,where the heterogeneous flow field in different regions was illustrated.This demonstrates that the gold nanoparticles at either the center or the edge regions of the droplet exhibit anisotropic kinematic behavior.At early stage,Marangoni backflow causes gold nanoparticles to move towards the edge firstly,and the circles back towards the droplet center after arriving the contact line with a sudden increase in z axis for 10.4μm,indicating the scale of the upward-moving microscopic flow vortices.This phenomenon does not occur in water droplets in the absence of polymers.The gold nanoparticles underwent Brownian-like motion at the center of the PEO droplet or water droplet owing to the low perturbation of the flow field.At the late stage of pinning of the PEO droplets,the motion showed multiple reverses in the direction of the gold nanoparticles,indicating the complexity of the flow field.This study enhances the understanding of the drying dynamics of polymer solution droplets and offers valuable insights into the fabrication of surface materials.展开更多
Purpose–Severe scarcity of natural river sand(RS),exacerbated by environmental protection policies and extraction constraints,has significantly impacted aggregate supply for railway concrete.While manufactured sand(M...Purpose–Severe scarcity of natural river sand(RS),exacerbated by environmental protection policies and extraction constraints,has significantly impacted aggregate supply for railway concrete.While manufactured sand(MS)offers a substitute for RS in railway applications,its widespread adoption in high-strength railway prestressed structures is challenged by lack of drying shrinkage and creep research data on concrete.Design/methodology/approach–High-strength manufactured sand concrete(MSC)was prepared using MS with varying lithologies and stone powder contents.Its drying shrinkage and creep behaviors were evaluated in accordance with the Chinese standard GB/T 50082.The deformation mechanism was analyzed by combining nano-scratch testing.Findings–Compared to RS concrete,MSC from all tested lithologies showed higher drying shrinkage but lower creep deformation.The drying shrinkage rose steadily with increased stone powder content,while the creep strain displayed a distinct non-linear trend,decreasing first before rising.To prepare low-deformation MSC,select high-strength MS and limit stone powder content not greater 10%.Nano-scratch tests indicated that harder MS particles suppress microcracking at the interfacial transition zone(ITZ),improving the creep resistance.The predictive models for drying shrinkage and creep were also developed by incorporating coefficients for stone powder and lithology effects.Originality/value–These findings serve as a foundation for the application of MSC in railway prestressed structures,offering both theoretical and practical guidance.展开更多
Côte d’Ivoire has been the world’s leading producer of cocoa beans for several decades. Apart from this production performance, the quality of the beans, which are mainly exported to the major chocolate-making ...Côte d’Ivoire has been the world’s leading producer of cocoa beans for several decades. Apart from this production performance, the quality of the beans, which are mainly exported to the major chocolate-making countries, presents a quality problem to the point of suffering a discount on the international market. One of these quality problems is the content of ochratoxin A, a mycotoxin produced by fungi. Finally, to verify the level of contamination in beans produced in Côte d’Ivoire, a study was carried out. It consisted of collecting information on fermentation and drying times (The two major post-harvest operations) and collecting beans, which were analyzed by electrophoresis using the High Performance Liquid Chromatography (HPLC) method. The results obtained show ochratoxin A contents of between 0.05 µg/kg and 0.17 µg/kg. The general level of contamination is therefore very low and below the tolerable limit which is 2 µg/kg. In addition, the correlative study between the fermentation and drying times of the beans revealed no significant influence (p < 0.01) of the duration of these operations on the level of ochratoxin A contamination. Major contamination can occur after post-harvest activities carried out by producers. This is certainly due to the development of fungi responsible for the production of ochratoxin A during the period of storage and marketing of cocoa beans in conditions of high humidity in storage enclosures. Producers need to be made more aware of the need to ensure that cocoa beans are properly dried and stored in dry areas to avoid moisture build-up, which is a source of mould growth and ochratoxin A production.展开更多
To study the effects of fine-aggregates on the drying-shrinkage properties of concrete,two types of manufactured-sand and one type of natural sand(excluding<75μm particles)were selected for tests,and nine sets of ...To study the effects of fine-aggregates on the drying-shrinkage properties of concrete,two types of manufactured-sand and one type of natural sand(excluding<75μm particles)were selected for tests,and nine sets of concrete drying shrinkage tests were designed with three strength grade(C30,C40,and C50)as variables.By observing the drying-shrinkage deformation of the specimens over 360 days,the effects of fine-aggregate properties on the drying shrinkage properties of concrete of different strength grades were analyzed and a prediction model was developed.Compared with natural sand concrete,the development of drying shrinkage of manufactured-sand concrete exhibits the phenomenon of advancement.The apparent density of the fine-aggregate and the strength grade are the two main factors affecting the limit value of the drying shrinkage of concrete.With a reduction in the water absorption or apparent density of the fine-aggregate or the strength grade of concrete prepared using the same fine-aggregate,the prediction accuracy of the existing models decreases.According to the GL 2000 model,two coefficients-and-were introduced to propose a prediction model for the drying shrinkage of fine-aggregate concrete,which is applicable to different strength grades.展开更多
The aim of this paper was to characterize through experiment the moisture and temperature kinetic behavior of Eucalyptus gomphocephala wood samples using microwave heating(MWH)in two scenarios:intermittently and conti...The aim of this paper was to characterize through experiment the moisture and temperature kinetic behavior of Eucalyptus gomphocephala wood samples using microwave heating(MWH)in two scenarios:intermittently and continuously.The mechanical properties and surface appearance of the heated samples were also investigated.Continuous and intermittent microwave drying kinetic experiments were conducted at a frequency of 2.45 GHz using a microwave laboratory oven at 300,500,and 1000 watts.Drying rate curves indicated three distinct phases of MWH.Increasing the microwave power with a shorter drying time led to rapid increases in internal temperature and water evaporation rates of the heated samples.Mechanical results indicated that samples heated under continuous MW(Microwave)power at 300 watts had a modulus of rupture(MOR)and modulus of elasticity(MOE)in three static bending tests higher than 29%and 36%,respectively,than samples heated at 1000 watts.Intermittent microwave heating(IMWH)of samples at 300 and 1000 watts produced the highest MOR and MOE values of 31%and 51%,respectively,unlike those heated under continuous microwave heating(CMWH).External qualitative observation showed that samples heated at high microwave power had severe surface checks.These defects were missing when using IMWH.An analysis of variance(ANOVA)showed that mechanical properties were linked to both microwave power level and the heating scenario,except for MOR in axial compression under CMWH.展开更多
Drying operations are of grave importance to realize the reduction and utilization of sewage sludge resources,but the conventional thermal evaporation drying(TED)technology presents challenges due to the need for a la...Drying operations are of grave importance to realize the reduction and utilization of sewage sludge resources,but the conventional thermal evaporation drying(TED)technology presents challenges due to the need for a large amount of thermal energy to conquer the phase-change latent heat of moisture.Herein,we report a non-phase change technology based on particle high-speed self-rotation in a cyclone for fast,low-temperature drying of viscous sludge with high-moisture contents.Dispersed phase medium(DPM)is introduced into the cyclone self-rotation drying(CSRD)reactor to enhance the dispersion of the viscous sludge.The effects of carrier gas temperature,feeding rate,size,and proportion of DPM particles in the drying process are systematically examined.Under optimal operating conditions,the weighted content of moisture in the viscous sludge could be reduced from 80%to 15.01%in less than 5 s,achieving a high drying efficiency of 95.79%.Theoretical calculations also reveal that 89.26%of the moisture is removed through non-phase change pathway,contributing to a 522-fold increase in the drying rate of CSRD compared to TED technology.This investigation presents a sustainable effective approach for high moisture viscous sludge treatment with low energy consumption and carbon emissions.展开更多
The effect of a storage system on drying time and estimation of drying parameters of cocoa beans using an indirect solar dryer with a sensible heat energy storage system (stones which act as both absorber and heat sto...The effect of a storage system on drying time and estimation of drying parameters of cocoa beans using an indirect solar dryer with a sensible heat energy storage system (stones which act as both absorber and heat storage media) is the main subject of this article. This dryer, which uses stones as storage material and is made of wood and plywood, was used to dry a quantity of 5 kg of fermented cocoa beans. The drying parameters for the drying curves and the drying efficiency of cocoa beans were established and studied. The drying curves were modelled from semi-empirical models. The results showed that the moisture of cocoa beans decreased from 60% to 7% in wet basis. With a solar collector and drying efficiency of 40% and 34%, respectively. And this with a maximum average difference temperature between the drying air and the ambient temperature of 13.25˚C day or night. The best concordances are obtained with R2 values of 0.9983, 0.9843, 0.9813 and 0.9837 respectively from the models of Hii, Jena and Das, Demir et al. and Alibas.展开更多
As a typical sedimentary soft rock,mudstone has the characteristics of being easily softened and disintegrated under the effect of wetting and drying(WD).The first cycle of WD plays an important role in the entire WD ...As a typical sedimentary soft rock,mudstone has the characteristics of being easily softened and disintegrated under the effect of wetting and drying(WD).The first cycle of WD plays an important role in the entire WD cycles.X-ray micro-computed tomography(micro-CT)was used as a non-destructive tool to quantitatively analyze microstructural changes of the mudstone due to the first cycle of WD.The test results show that WD leads to an increase of pore volume and pore connectivity in the mudstone.The porosity and fractal dimension of each slice of mudstone not only increase in value,but also in fluctuation amplitude.The pattern of variation in the frequency distribution of the equivalent radii of connected,isolated pores and pore throats in mudstone under WD effect satisfies the Gaussian distribution.Under the effect of WD,pores and pore throats with relatively small sizes increase the most.The sphericity of the pores in mudstones is positively correlated with the pore radius.The WD effect transforms the originally angular and flat pores into round and regular pores.This paper can provide a reference for the study of the deterioration and catastrophic mechanisms of mudstone under wetting and drying cycles.展开更多
Soil microorganisms and labile soil organic carbon(SOC)fractions are essential factors affecting greenhouse gas(GHG)emissions in paddy fields.However,the effects of labile SOC fractions and microorganisms on GHG emiss...Soil microorganisms and labile soil organic carbon(SOC)fractions are essential factors affecting greenhouse gas(GHG)emissions in paddy fields.However,the effects of labile SOC fractions and microorganisms on GHG emissions from flooding to drying after organic fertilizer replacing for chemical fertilizer remain unclear.Here,a long-term experiment was conducted with four treatments:chemical fertilization only(control),organic fertilizer substituting 25%of chemical N fertilizer(NM1),50%of chemical N fertilizer(NM2),and NM2combined with crop straw(NMS).GHG emissions were monitored,and soil samples were collected to determine labile SOC fractions and microorganisms.Results revealed the GHG emissions in the NM2 significantly increased by 196.88%from flooding to drying,mainly due to the higher CO_(2) emissions.The GHG emissions per kg of C input in NMS was the lowest with the value of 9.17.From flooding to drying,organic fertilizer application significantly increased the readily oxidizable organic carbon(ROC)contents and C lability;the NM2 and NMS dramatically increased the SOC and non-readily oxidizable organic carbon(NROC).The bacterial communities showed significant differences among different treatments in the flooding,while the significant difference was only found between the NMS and other treatments in the drying.From flooding to drying,changing soil moisture conditions causes C fractions and microbial communities to jointly affect carbon emissions,and the NMS promoted carbon sequestration and mitigated GHG emissions.Our findings highlight the importance of the labile SOC fractions and microorganisms linked to GHG emissions in paddy fields.展开更多
Onsite sanitation offers a sustainable alternative to centralized wastewater treatment;however,effective faecal sludge management is crucial for safe disposal and resource recovery.Among emerging treatment solutions,s...Onsite sanitation offers a sustainable alternative to centralized wastewater treatment;however,effective faecal sludge management is crucial for safe disposal and resource recovery.Among emerging treatment solutions,solar thermal drying holds significant promise to reduce sludge moisture content and enhance handling.Despite this potential,its application remains limited,with important knowledge gaps,particularly concerning the drying kinetics under different environmental and operational conditions.This study aims to fill these gaps by investigating the solar thermal drying behaviour of faecal sludge from ventilated improved pit latrines(VIPs)and urine-diverting dry toilets(UDs),with a specific focus on how air temperature and velocity influence drying performance.A bench-scale solar drying apparatus was used to investigate thin-layer sludge drying kinetics under controlled airflow conditions.The drying experiments were conducted at varying air temperatures(ambient,40℃,and 80℃)and velocities(0,0.5,and 1 m/s),where heated air was supplied via an electric resistance heater.Key drying parameters-including drying rate,critical moisture content,effective moisture diffusivity,and activation energy-were determined.Results showed that drying proceeded through a constant-rate period followed by a falling-rate period,with the critical moisture content ranging from 1.41 to 1.78 g/g db.Higher temperatures and airflow reduced the duration of the constant-rate phase,increased drying rates(0.31–0.99 g/g·min·m^(2)),and enhanced moisture diffusivity(4.56×10^(−9) to 1.52×10^(−8) m^(2)/s).Activation energy decreased with increased airflow,suggesting reduced temperature sensitivity.Thermal efficiency ranged from 14.6%to 35.1%,with solar energy contributing 73%–95% of total input.VIP sludge dried faster than UD sludge,which showed signs of surface crusting that limited moisture transfer.This research offers valuable insights into solar drying design and operation,providing scientific evidence to improve faecal sludge treatment strategies in decentralized sanitation systems.展开更多
Alternate wetting and soil drying irrigation(AWD)technique is crucial in infuencing grain quality in rice(Oryza sativa L.).Lipids are the third most abundant constituents in rice grains,after starch and proteins,and a...Alternate wetting and soil drying irrigation(AWD)technique is crucial in infuencing grain quality in rice(Oryza sativa L.).Lipids are the third most abundant constituents in rice grains,after starch and proteins,and are closely related to grain quality.However,it remains unclear about the changes in lipids profling under different AWD regimes.This study set up three irrigation regimes including conventional irrigation(CI),alternate wetting and moderate soil drying irrigation(AWMD),and alternate wetting and severe soil drying irrigation(AWSD).It explored lipidome changes in milled rice of Yangdao 6(YD6)using the untargeted lipidomics approach and analyzed rice cooking and eating quality.The results identifed seven lipid classes,55 lipid subclasses,and 1,086 lipid molecular species.Compared with the CI regime,the AWMD regime mainly altered lipid subclasses consisting of triglyceride(TG),ceramide(Cer),diglyceride(DG),bis-methyl lysophosphatidic acid(BisMePA),phosphocholine(PC),phosphoethanolamine(PE),monogalactosyldiacylglycerol(MGDG),and digalactosyl diglyceride(DGDG)in milled rice and improved cooking and eating quality of rice;in contrast,the AWSD regime distinctly changed lipid subclasses like TG,Cer,DG,PC,PE,hexosylceramide(Hex1Cer),DGDG,and BisMePA and degraded cooking and eating quality of rice.Specifcally,AWMD most signifcantly altered the expressions of lipid molecules,including DGDG(18:0_18:2),DGDG(16:0_14:0),PC(33:1),Cer(t17:0_26:0),and Cer(t17:0_16:0);AWSD most obviously influenced the expressions of TG(6:0_14:0_18:3),PC(41:1),TG(19:1_18:4_18:4),Hex1Cer(d18:2_24:0+O),and Hex1Cer(d18:2_24:1).These 10 altered lipid molecules in milled rice can be preferentially used for investigating their relationships with grain quality in rice.展开更多
The heating area of the material is large and the thermal efficiency is high,but it is n ecessary to control the suitable drying temperature ofdiffere nt medici nal materials to preserve the effective in gredients.D i...The heating area of the material is large and the thermal efficiency is high,but it is n ecessary to control the suitable drying temperature ofdiffere nt medici nal materials to preserve the effective in gredients.D iff ere nt kinds of Chinese medicine need different drying conditions to fulfill good drying requirements.Natural drying in the shade is one of the traditional drying methods,which takes a long time and is easily affected by the weather.The water volatilizes slowly.It is prone to mildew and discoloration during the drying process.However,it can better preserve the volatile oil components of Chinese medicine.The hot-air drying machine has lower requirements.The medicinal materials have a large heating area and high thermal efficiency,but it is necessary to control the appropriate drying temperature of different medicinal materials in order to preserve the active ingredients of the medicinal materials;it is not suitable for medicinal materials that stick and bind easily.The microwave drying method possesses superiority in drying some valuable medicinal materials such as Ren she n(Radix et Rhizoma Ginseng)and Lurong(Co「nu Cervi Pantotrichum),and the effective ingredients are preserved at a high degree;it can also achieve the purpose of killing enzymes and protecting glycosides and have a good bactericidal effect,but it is not suitable for Chinese medicines containing heat-sensitive ingredients,because it will destroy most of the proteins,amino acids,and peptides of Chinese medicine and result in the loss of efficacy.The far-infrared drying method is suitable for drying thin-layer medicinal materials and is friendly to the environment.Freeze-drying can preserve the active ingredients very well and greatly retain the efficacy,but it has obvious limitations in preserving some Chinese medicinal materials that need to kill enzymes and protect glycosides;besides,the cost is relatively high and the drying time is long.展开更多
This study is an extension of the previous work done with ARS-680 Environmental Chamber. Drying is a complex operation that demands much energy and time. Drying is essentially important for preservation of ginger rhiz...This study is an extension of the previous work done with ARS-680 Environmental Chamber. Drying is a complex operation that demands much energy and time. Drying is essentially important for preservation of ginger rhizome. Drying of ginger was modeled, and then the effective diffusion coefficient and activation energy were determined. For this purpose, the experiments were done at six levels of varied temperatures: 10°C, 20°C, 30°C, 40°C, 50°C and 60°C. The values of effective diffusion coefficients obtained in this work for the variously treated ginger rhizomes closely agreed with the average effective diffusion coefficients of other notable authors who determined the drying kinetics and convective heat transfer coefficients of ginger slices.展开更多
The significant demand for high quality food has motivated us to adopt appropriate processing methods to improve the food nutritional quality and flavors.In this study,the effects of five drying methods,namely,pulsed ...The significant demand for high quality food has motivated us to adopt appropriate processing methods to improve the food nutritional quality and flavors.In this study,the effects of five drying methods,namely,pulsed vacuum drying(PVD),freeze drying(FD),infrared drying(IRD),hot-air drying(HAD)and sun drying(SD)on free amino acids(FAAs),α-dicarbonyl compounds(α-DCs)and volatile compounds(VOCs)in rape bee pollen(RBP)were determined.The results showed that FD significantly released the essential amino acids(EAAs)compared with fresh samples while SD caused the highest loss.Glucosone was the dominantα-DCs in RBP and the highest loss was observed after PVD.Aldehydes were the dominant volatiles of RBP and SD samples contained more new volatile substances(especially aldehydes)than the other four drying methods.Comprehensively,FD and PVD would be potential methods to effectively reduce the quality deterioration of RBP in the drying process.展开更多
Experiments were conducted to evaluate the healing of drying cracks in air-dried bentonite-sand blocks after hydration and swelling in groundwater,providing justifications to simplify the protection of blocks prior to...Experiments were conducted to evaluate the healing of drying cracks in air-dried bentonite-sand blocks after hydration and swelling in groundwater,providing justifications to simplify the protection of blocks prior to installation in a high-level radioactive waste repository.Synthetic groundwater was prepared to represent the geochemistry of Beishan groundwater,and was used to hydrate the blocks during the swelling pressure and swelling strain measurements,as Beishan is the most promising site for China's repository.Healing of the surface cracks was recorded by photography,and healing of the internal cracks was visualized by CT images and hydraulic conductivity of air-dried blocks.The results indicate that the maximum swelling pressure and swelling strain are primarily affected by the geochemistry of Beishan groundwater,but not affected by the drying cracks.The maximum swelling pressure and swelling strain of air-dried blocks are comparable to or even higher than the pressure and strain of fresh blocks.The maximum swelling pressure measured in strong(i.e.high ion strength)Beishan groundwater was 44%of the pressure measured in deionized(DI)water,and the maximum swelling strain was reduced to 23%of the strain measured in DI water.Nevertheless,the remained swelling of the blocks hydrated in strong Beishan groundwater was sufficient to heal the surface and internal drying cracks,as demonstrated by the pictures of surface cracks and CT images.The hydraulic conductivity of the air-dried block permeated with strong groundwater was comparable(3.7×higher)to the hydraulic conductivity of the fresh block,indicating the self-healing of drying cracks after hydration and swelling in groundwater.A simplified method of protecting the block with plastic wraps before installation is recommended,since the remained swelling of the block hydrated in Beishan groundwater is sufficient to heal the drying cracks.展开更多
Lysine content is a criterion of the nutritional quality of rice.Understanding the process of lysine biosynthesis in early-flowering superior grain(SG)and late-flowering inferior grain(IG)of rice would advance breedin...Lysine content is a criterion of the nutritional quality of rice.Understanding the process of lysine biosynthesis in early-flowering superior grain(SG)and late-flowering inferior grain(IG)of rice would advance breeding and cultivation to improve nutritional quality.However,little information is available on differences in lysine anabolism between SG and IG and the underlying mechanism,and whether and how irrigation regimes affect lysine anabolism in these grains.A japonica rice cultivar was grown in the field and two irrigation regimes,continuous flooding(CF)and wetting alternating with partial drying(WAPD),were imposed from heading to the mature stage.Lysine content and activities of key enzymes of lysine biosynthesis,and levels of brassinosteroids(BRs)were lower in the IG than in the SG at the early grainfilling stage but higher at middle and late grain-filling stages.WAPD increased activities of these key enzymes,BR levels,and contents of lysine and total amino acids in IG,but not SG relative to CF.Application of 2,4-epibrassinolide to rice panicles in CF during early grain filling reproduced the effects of WAPD,but neither treatment altered the activities of enzymes responsible for lysine catabolism in either SG or IG.WAPD and elevated BR levels during grain filling increased lysine biosynthesis in IG.Improvement in lysine biosynthesis in rice should focus on IG.展开更多
Appropriate drying process with optimized controlling of drying parameters plays a vital role in the improvement of the quality and performance of propellant products.However,few research on solvent transport dynamics...Appropriate drying process with optimized controlling of drying parameters plays a vital role in the improvement of the quality and performance of propellant products.However,few research on solvent transport dynamics within NC-based propellants was reported,and its effect on the evolution of mechanical properties was not interpreted yet.This study is conducted to gain a comprehensive understanding of hot-air drying for NC-based propellants and clarify the effect of temperature on solvent transport behavior and further the change of mechanical properties during drying.The drying kinetic curves show the drying time required is decreased but the steady solvent content is increased and the drying rate is obviously increased with the increase of hot-air temperatures,indicating hot-air temperatures have a significant effect on drying kinetics.A modified drying model was established,and results show it is more appropriate to describe solvent transport behavior within NC-based propellants.Moreover,two linear equations were established to exhibit the relationship between solvent content and its effect on the change of tensile properties,and the decrease of residual solvent content causes an obvious increase of tensile strength and tensile modulus of propellant products,indicating its mechanical properties can be partly improved by adjustment of residual solvent content.The outcomes can be used to clarify solvent transport mechanisms and optimize drying process parameters of double-based gun propellants.展开更多
Heat and mass transport through evaporation or drying processes occur in many applications such as food processing,pharmaceutical products,solar-driven vapor generation,textile design,and electronic cigarettes.In this...Heat and mass transport through evaporation or drying processes occur in many applications such as food processing,pharmaceutical products,solar-driven vapor generation,textile design,and electronic cigarettes.In this paper,the transport of water from a fresh potato considered as a wet porous media with laminar convective dry air fluid flow governed by Darcy’s law in two-dimensional is highlighted.Governing equations of mass conservation,momentumconservation,multiphase fluid flowin porousmedia,heat transfer,and transport of participating fluids and gases through evaporation from liquid to gaseous phase are solved simultaneously.In this model,the variable is block locations,the object function is changing water saturation inside the porous medium and the constraint is the constant mass of porous material.It shows that there is an optimal configuration for the purpose of water removal from the specimen.The results are compared with experimental and analyticalmethods Benchmark.Then for the purpose of configuration optimization,multi-agent reinforcement learning(MARL)is used while multiple porous blocks are considered as agents that transfer their moisture content with the environment in a real-world scenario.MARL has been tested and validated with previous conventional effective optimization simulations and its superiority proved.Our study examines and proposes an effective method for validating and testing multiagent reinforcement learning models and methods using a multiagent simulation.展开更多
Drying shrinkage is an important factor affecting the durability of alkali-activated materials.The drying shrinkage of alkali-activated carbon steel slag and the effect of silica fume substitution were studied.The dry...Drying shrinkage is an important factor affecting the durability of alkali-activated materials.The drying shrinkage of alkali-activated carbon steel slag and the effect of silica fume substitution were studied.The drying shrinkage test lasted for 300 d.The compressive strength,flexural strength,Vickers hardness,mass recovery and drying shrinkage recovery of the samples after drying shrinkage were tested.The hydration products and microstructure were characterized by X-ray diffraction,mercury intrusion porosimetry,thermogravimetry–differential thermogravimetry,and scanning electron microscopy–energy dispersive spectroscopy.The results show that although the chemical expansion compensates for the drying shrinkage in 42 d,the drying shrinkage increases continuously within 300 d.Silica fume affects drying shrinkage by refining pore size and increasing matrix microhardness.Solid surface tension and capillary pressure are the driving forces for drying shrinkage in the early and middle to late stages,respectively.The evolution of drying shrinkage is also influenced by chemical expansion,matrix microhardness and macropore collapse.展开更多
文摘The design and development of solar dryers are crucial in regions with abundant solar energy,such as Bhopal,India,where seasonal variations significantly impact the efficiency of drying processes.The paper is focused on employing a comprehensive mathematical model to predict the dryer’s performance in drying the materials such as banana slices.To enhance this model,Hyper Tuned Swarm Optimization with Gradient Tree(HT_SOGT)was utilized to accurately predict and determine the optimal size of the dryer dimensions considering various mathematical calculations for material drying.The predictive model considered the influence of seasonal fluctuations,ensuring an efficient drying process with an objective function to optimize the drying time of an average of 7 hrs throughout the year.Across all recorded ambient temperatures(ranging from 16.985○C to 31.4○C),the outlet temperature of the solar dryer is consistently higher,ranging from 39.085○C to 66.2○C.The results show that the optimized dryer design,based on HT_SOGT modelling,significantly improves drying efficiency of the materials across varying conditions,making it suitable for sustainable applications in agriculture and food processing industries in the Bhopal region.
基金supported by the Key-Area Research and Development Program of Guangdong Province(No.2023B0101200006)Guangdong Basic and Applied Basic Research Foundation(No.2024A1515011926)+1 种基金Fund of Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates,Guangzhou 510640,China(South China University of Technology)(No.2023B1212060003)State Key Laboratory of Applied Microbiology Southern China(No.SKLAM008-2022)。
文摘The dynamics of the drying process of polymer solutions are important for the development of coatings and films.In the present work,digital holographic microscopy(DHM)was performed to capture the drying dynamics of poly(ethylene oxide)(PEO)droplets using a gold nanoparticle tracer,where the heterogeneous flow field in different regions was illustrated.This demonstrates that the gold nanoparticles at either the center or the edge regions of the droplet exhibit anisotropic kinematic behavior.At early stage,Marangoni backflow causes gold nanoparticles to move towards the edge firstly,and the circles back towards the droplet center after arriving the contact line with a sudden increase in z axis for 10.4μm,indicating the scale of the upward-moving microscopic flow vortices.This phenomenon does not occur in water droplets in the absence of polymers.The gold nanoparticles underwent Brownian-like motion at the center of the PEO droplet or water droplet owing to the low perturbation of the flow field.At the late stage of pinning of the PEO droplets,the motion showed multiple reverses in the direction of the gold nanoparticles,indicating the complexity of the flow field.This study enhances the understanding of the drying dynamics of polymer solution droplets and offers valuable insights into the fabrication of surface materials.
基金supported by National Natural Science Foundation of China(award no.52408309)National Natural Science Foundation of China(award no.52438002).
文摘Purpose–Severe scarcity of natural river sand(RS),exacerbated by environmental protection policies and extraction constraints,has significantly impacted aggregate supply for railway concrete.While manufactured sand(MS)offers a substitute for RS in railway applications,its widespread adoption in high-strength railway prestressed structures is challenged by lack of drying shrinkage and creep research data on concrete.Design/methodology/approach–High-strength manufactured sand concrete(MSC)was prepared using MS with varying lithologies and stone powder contents.Its drying shrinkage and creep behaviors were evaluated in accordance with the Chinese standard GB/T 50082.The deformation mechanism was analyzed by combining nano-scratch testing.Findings–Compared to RS concrete,MSC from all tested lithologies showed higher drying shrinkage but lower creep deformation.The drying shrinkage rose steadily with increased stone powder content,while the creep strain displayed a distinct non-linear trend,decreasing first before rising.To prepare low-deformation MSC,select high-strength MS and limit stone powder content not greater 10%.Nano-scratch tests indicated that harder MS particles suppress microcracking at the interfacial transition zone(ITZ),improving the creep resistance.The predictive models for drying shrinkage and creep were also developed by incorporating coefficients for stone powder and lithology effects.Originality/value–These findings serve as a foundation for the application of MSC in railway prestressed structures,offering both theoretical and practical guidance.
文摘Côte d’Ivoire has been the world’s leading producer of cocoa beans for several decades. Apart from this production performance, the quality of the beans, which are mainly exported to the major chocolate-making countries, presents a quality problem to the point of suffering a discount on the international market. One of these quality problems is the content of ochratoxin A, a mycotoxin produced by fungi. Finally, to verify the level of contamination in beans produced in Côte d’Ivoire, a study was carried out. It consisted of collecting information on fermentation and drying times (The two major post-harvest operations) and collecting beans, which were analyzed by electrophoresis using the High Performance Liquid Chromatography (HPLC) method. The results obtained show ochratoxin A contents of between 0.05 µg/kg and 0.17 µg/kg. The general level of contamination is therefore very low and below the tolerable limit which is 2 µg/kg. In addition, the correlative study between the fermentation and drying times of the beans revealed no significant influence (p < 0.01) of the duration of these operations on the level of ochratoxin A contamination. Major contamination can occur after post-harvest activities carried out by producers. This is certainly due to the development of fungi responsible for the production of ochratoxin A during the period of storage and marketing of cocoa beans in conditions of high humidity in storage enclosures. Producers need to be made more aware of the need to ensure that cocoa beans are properly dried and stored in dry areas to avoid moisture build-up, which is a source of mould growth and ochratoxin A production.
基金Funded by the National Natural Science Foundation of China project(Nos.52108219 and U21A20150)the Lanzhou University of Technology Hongliu Outstanding Young Talent Program,China(No.04-062407)the Research on Quality Control Technology of High-performance Concrete Prepared by Manufactured Sand(No.2020Y21)。
文摘To study the effects of fine-aggregates on the drying-shrinkage properties of concrete,two types of manufactured-sand and one type of natural sand(excluding<75μm particles)were selected for tests,and nine sets of concrete drying shrinkage tests were designed with three strength grade(C30,C40,and C50)as variables.By observing the drying-shrinkage deformation of the specimens over 360 days,the effects of fine-aggregate properties on the drying shrinkage properties of concrete of different strength grades were analyzed and a prediction model was developed.Compared with natural sand concrete,the development of drying shrinkage of manufactured-sand concrete exhibits the phenomenon of advancement.The apparent density of the fine-aggregate and the strength grade are the two main factors affecting the limit value of the drying shrinkage of concrete.With a reduction in the water absorption or apparent density of the fine-aggregate or the strength grade of concrete prepared using the same fine-aggregate,the prediction accuracy of the existing models decreases.According to the GL 2000 model,two coefficients-and-were introduced to propose a prediction model for the drying shrinkage of fine-aggregate concrete,which is applicable to different strength grades.
文摘The aim of this paper was to characterize through experiment the moisture and temperature kinetic behavior of Eucalyptus gomphocephala wood samples using microwave heating(MWH)in two scenarios:intermittently and continuously.The mechanical properties and surface appearance of the heated samples were also investigated.Continuous and intermittent microwave drying kinetic experiments were conducted at a frequency of 2.45 GHz using a microwave laboratory oven at 300,500,and 1000 watts.Drying rate curves indicated three distinct phases of MWH.Increasing the microwave power with a shorter drying time led to rapid increases in internal temperature and water evaporation rates of the heated samples.Mechanical results indicated that samples heated under continuous MW(Microwave)power at 300 watts had a modulus of rupture(MOR)and modulus of elasticity(MOE)in three static bending tests higher than 29%and 36%,respectively,than samples heated at 1000 watts.Intermittent microwave heating(IMWH)of samples at 300 and 1000 watts produced the highest MOR and MOE values of 31%and 51%,respectively,unlike those heated under continuous microwave heating(CMWH).External qualitative observation showed that samples heated at high microwave power had severe surface checks.These defects were missing when using IMWH.An analysis of variance(ANOVA)showed that mechanical properties were linked to both microwave power level and the heating scenario,except for MOR in axial compression under CMWH.
基金supported by the National Key Research and Development Program of China(2019YFA0705800)the National Natural Science Foundation of China(52030001)the Science&Technology Commission of Shanghai Municipality(20dz1207600).
文摘Drying operations are of grave importance to realize the reduction and utilization of sewage sludge resources,but the conventional thermal evaporation drying(TED)technology presents challenges due to the need for a large amount of thermal energy to conquer the phase-change latent heat of moisture.Herein,we report a non-phase change technology based on particle high-speed self-rotation in a cyclone for fast,low-temperature drying of viscous sludge with high-moisture contents.Dispersed phase medium(DPM)is introduced into the cyclone self-rotation drying(CSRD)reactor to enhance the dispersion of the viscous sludge.The effects of carrier gas temperature,feeding rate,size,and proportion of DPM particles in the drying process are systematically examined.Under optimal operating conditions,the weighted content of moisture in the viscous sludge could be reduced from 80%to 15.01%in less than 5 s,achieving a high drying efficiency of 95.79%.Theoretical calculations also reveal that 89.26%of the moisture is removed through non-phase change pathway,contributing to a 522-fold increase in the drying rate of CSRD compared to TED technology.This investigation presents a sustainable effective approach for high moisture viscous sludge treatment with low energy consumption and carbon emissions.
文摘The effect of a storage system on drying time and estimation of drying parameters of cocoa beans using an indirect solar dryer with a sensible heat energy storage system (stones which act as both absorber and heat storage media) is the main subject of this article. This dryer, which uses stones as storage material and is made of wood and plywood, was used to dry a quantity of 5 kg of fermented cocoa beans. The drying parameters for the drying curves and the drying efficiency of cocoa beans were established and studied. The drying curves were modelled from semi-empirical models. The results showed that the moisture of cocoa beans decreased from 60% to 7% in wet basis. With a solar collector and drying efficiency of 40% and 34%, respectively. And this with a maximum average difference temperature between the drying air and the ambient temperature of 13.25˚C day or night. The best concordances are obtained with R2 values of 0.9983, 0.9843, 0.9813 and 0.9837 respectively from the models of Hii, Jena and Das, Demir et al. and Alibas.
基金Project(41877240)supported by the National Natural Science Foundation of China。
文摘As a typical sedimentary soft rock,mudstone has the characteristics of being easily softened and disintegrated under the effect of wetting and drying(WD).The first cycle of WD plays an important role in the entire WD cycles.X-ray micro-computed tomography(micro-CT)was used as a non-destructive tool to quantitatively analyze microstructural changes of the mudstone due to the first cycle of WD.The test results show that WD leads to an increase of pore volume and pore connectivity in the mudstone.The porosity and fractal dimension of each slice of mudstone not only increase in value,but also in fluctuation amplitude.The pattern of variation in the frequency distribution of the equivalent radii of connected,isolated pores and pore throats in mudstone under WD effect satisfies the Gaussian distribution.Under the effect of WD,pores and pore throats with relatively small sizes increase the most.The sphericity of the pores in mudstones is positively correlated with the pore radius.The WD effect transforms the originally angular and flat pores into round and regular pores.This paper can provide a reference for the study of the deterioration and catastrophic mechanisms of mudstone under wetting and drying cycles.
基金the support of the National Natural Science Foundation of China(No.42107247)the National Key Research and Development Project(No.2022YFD1901605)+1 种基金the Natural Science Foundation of Sichuan Province(Nos.2025YFHZ0142 and 2024NSFSC0800)the Tobacco Science Foundation of Sichuan Province(No.SCYC202407)。
文摘Soil microorganisms and labile soil organic carbon(SOC)fractions are essential factors affecting greenhouse gas(GHG)emissions in paddy fields.However,the effects of labile SOC fractions and microorganisms on GHG emissions from flooding to drying after organic fertilizer replacing for chemical fertilizer remain unclear.Here,a long-term experiment was conducted with four treatments:chemical fertilization only(control),organic fertilizer substituting 25%of chemical N fertilizer(NM1),50%of chemical N fertilizer(NM2),and NM2combined with crop straw(NMS).GHG emissions were monitored,and soil samples were collected to determine labile SOC fractions and microorganisms.Results revealed the GHG emissions in the NM2 significantly increased by 196.88%from flooding to drying,mainly due to the higher CO_(2) emissions.The GHG emissions per kg of C input in NMS was the lowest with the value of 9.17.From flooding to drying,organic fertilizer application significantly increased the readily oxidizable organic carbon(ROC)contents and C lability;the NM2 and NMS dramatically increased the SOC and non-readily oxidizable organic carbon(NROC).The bacterial communities showed significant differences among different treatments in the flooding,while the significant difference was only found between the NMS and other treatments in the drying.From flooding to drying,changing soil moisture conditions causes C fractions and microbial communities to jointly affect carbon emissions,and the NMS promoted carbon sequestration and mitigated GHG emissions.Our findings highlight the importance of the labile SOC fractions and microorganisms linked to GHG emissions in paddy fields.
基金funded by the Water Research Commission through the grant K5/2582 and the Gates Foundation through the grant OPP1170678.
文摘Onsite sanitation offers a sustainable alternative to centralized wastewater treatment;however,effective faecal sludge management is crucial for safe disposal and resource recovery.Among emerging treatment solutions,solar thermal drying holds significant promise to reduce sludge moisture content and enhance handling.Despite this potential,its application remains limited,with important knowledge gaps,particularly concerning the drying kinetics under different environmental and operational conditions.This study aims to fill these gaps by investigating the solar thermal drying behaviour of faecal sludge from ventilated improved pit latrines(VIPs)and urine-diverting dry toilets(UDs),with a specific focus on how air temperature and velocity influence drying performance.A bench-scale solar drying apparatus was used to investigate thin-layer sludge drying kinetics under controlled airflow conditions.The drying experiments were conducted at varying air temperatures(ambient,40℃,and 80℃)and velocities(0,0.5,and 1 m/s),where heated air was supplied via an electric resistance heater.Key drying parameters-including drying rate,critical moisture content,effective moisture diffusivity,and activation energy-were determined.Results showed that drying proceeded through a constant-rate period followed by a falling-rate period,with the critical moisture content ranging from 1.41 to 1.78 g/g db.Higher temperatures and airflow reduced the duration of the constant-rate phase,increased drying rates(0.31–0.99 g/g·min·m^(2)),and enhanced moisture diffusivity(4.56×10^(−9) to 1.52×10^(−8) m^(2)/s).Activation energy decreased with increased airflow,suggesting reduced temperature sensitivity.Thermal efficiency ranged from 14.6%to 35.1%,with solar energy contributing 73%–95% of total input.VIP sludge dried faster than UD sludge,which showed signs of surface crusting that limited moisture transfer.This research offers valuable insights into solar drying design and operation,providing scientific evidence to improve faecal sludge treatment strategies in decentralized sanitation systems.
基金supported by the Natural Science Foundation of Jiangsu Province,China(BK20241931 and BK20221371)the National Natural Science Foundation of China(32071943 and 32372214)the National Key Research and Development Program of China(2022YFD2300304)。
文摘Alternate wetting and soil drying irrigation(AWD)technique is crucial in infuencing grain quality in rice(Oryza sativa L.).Lipids are the third most abundant constituents in rice grains,after starch and proteins,and are closely related to grain quality.However,it remains unclear about the changes in lipids profling under different AWD regimes.This study set up three irrigation regimes including conventional irrigation(CI),alternate wetting and moderate soil drying irrigation(AWMD),and alternate wetting and severe soil drying irrigation(AWSD).It explored lipidome changes in milled rice of Yangdao 6(YD6)using the untargeted lipidomics approach and analyzed rice cooking and eating quality.The results identifed seven lipid classes,55 lipid subclasses,and 1,086 lipid molecular species.Compared with the CI regime,the AWMD regime mainly altered lipid subclasses consisting of triglyceride(TG),ceramide(Cer),diglyceride(DG),bis-methyl lysophosphatidic acid(BisMePA),phosphocholine(PC),phosphoethanolamine(PE),monogalactosyldiacylglycerol(MGDG),and digalactosyl diglyceride(DGDG)in milled rice and improved cooking and eating quality of rice;in contrast,the AWSD regime distinctly changed lipid subclasses like TG,Cer,DG,PC,PE,hexosylceramide(Hex1Cer),DGDG,and BisMePA and degraded cooking and eating quality of rice.Specifcally,AWMD most signifcantly altered the expressions of lipid molecules,including DGDG(18:0_18:2),DGDG(16:0_14:0),PC(33:1),Cer(t17:0_26:0),and Cer(t17:0_16:0);AWSD most obviously influenced the expressions of TG(6:0_14:0_18:3),PC(41:1),TG(19:1_18:4_18:4),Hex1Cer(d18:2_24:0+O),and Hex1Cer(d18:2_24:1).These 10 altered lipid molecules in milled rice can be preferentially used for investigating their relationships with grain quality in rice.
文摘The heating area of the material is large and the thermal efficiency is high,but it is n ecessary to control the suitable drying temperature ofdiffere nt medici nal materials to preserve the effective in gredients.D iff ere nt kinds of Chinese medicine need different drying conditions to fulfill good drying requirements.Natural drying in the shade is one of the traditional drying methods,which takes a long time and is easily affected by the weather.The water volatilizes slowly.It is prone to mildew and discoloration during the drying process.However,it can better preserve the volatile oil components of Chinese medicine.The hot-air drying machine has lower requirements.The medicinal materials have a large heating area and high thermal efficiency,but it is necessary to control the appropriate drying temperature of different medicinal materials in order to preserve the active ingredients of the medicinal materials;it is not suitable for medicinal materials that stick and bind easily.The microwave drying method possesses superiority in drying some valuable medicinal materials such as Ren she n(Radix et Rhizoma Ginseng)and Lurong(Co「nu Cervi Pantotrichum),and the effective ingredients are preserved at a high degree;it can also achieve the purpose of killing enzymes and protecting glycosides and have a good bactericidal effect,but it is not suitable for Chinese medicines containing heat-sensitive ingredients,because it will destroy most of the proteins,amino acids,and peptides of Chinese medicine and result in the loss of efficacy.The far-infrared drying method is suitable for drying thin-layer medicinal materials and is friendly to the environment.Freeze-drying can preserve the active ingredients very well and greatly retain the efficacy,but it has obvious limitations in preserving some Chinese medicinal materials that need to kill enzymes and protect glycosides;besides,the cost is relatively high and the drying time is long.
文摘This study is an extension of the previous work done with ARS-680 Environmental Chamber. Drying is a complex operation that demands much energy and time. Drying is essentially important for preservation of ginger rhizome. Drying of ginger was modeled, and then the effective diffusion coefficient and activation energy were determined. For this purpose, the experiments were done at six levels of varied temperatures: 10°C, 20°C, 30°C, 40°C, 50°C and 60°C. The values of effective diffusion coefficients obtained in this work for the variously treated ginger rhizomes closely agreed with the average effective diffusion coefficients of other notable authors who determined the drying kinetics and convective heat transfer coefficients of ginger slices.
基金supported by National Natural Science Foundation of China(Nos.31871861 and 31501548)The Apicultural Industry Technology System(NCYTI-43-KXJ17)The Science and Technology Innovation Project of Chinese Academy of Agricultural Sciences(CAAS-ASTIP-2015-IAR)。
文摘The significant demand for high quality food has motivated us to adopt appropriate processing methods to improve the food nutritional quality and flavors.In this study,the effects of five drying methods,namely,pulsed vacuum drying(PVD),freeze drying(FD),infrared drying(IRD),hot-air drying(HAD)and sun drying(SD)on free amino acids(FAAs),α-dicarbonyl compounds(α-DCs)and volatile compounds(VOCs)in rape bee pollen(RBP)were determined.The results showed that FD significantly released the essential amino acids(EAAs)compared with fresh samples while SD caused the highest loss.Glucosone was the dominantα-DCs in RBP and the highest loss was observed after PVD.Aldehydes were the dominant volatiles of RBP and SD samples contained more new volatile substances(especially aldehydes)than the other four drying methods.Comprehensively,FD and PVD would be potential methods to effectively reduce the quality deterioration of RBP in the drying process.
基金supported by the National Natural Science Foundation of China(Grant No.41972265)the Fundamental Research Funds for the Central Universities(Grant No.lzujbky-2021-57)+1 种基金the Gansu Province Science Foundation(Grant No.20JR10RA492)Special thanks to the Environmental Research and Education Foundation for supporting the first author(Y.Tan)through a fellowship for his study at the University of Wisconsin-Madison.
文摘Experiments were conducted to evaluate the healing of drying cracks in air-dried bentonite-sand blocks after hydration and swelling in groundwater,providing justifications to simplify the protection of blocks prior to installation in a high-level radioactive waste repository.Synthetic groundwater was prepared to represent the geochemistry of Beishan groundwater,and was used to hydrate the blocks during the swelling pressure and swelling strain measurements,as Beishan is the most promising site for China's repository.Healing of the surface cracks was recorded by photography,and healing of the internal cracks was visualized by CT images and hydraulic conductivity of air-dried blocks.The results indicate that the maximum swelling pressure and swelling strain are primarily affected by the geochemistry of Beishan groundwater,but not affected by the drying cracks.The maximum swelling pressure and swelling strain of air-dried blocks are comparable to or even higher than the pressure and strain of fresh blocks.The maximum swelling pressure measured in strong(i.e.high ion strength)Beishan groundwater was 44%of the pressure measured in deionized(DI)water,and the maximum swelling strain was reduced to 23%of the strain measured in DI water.Nevertheless,the remained swelling of the blocks hydrated in strong Beishan groundwater was sufficient to heal the surface and internal drying cracks,as demonstrated by the pictures of surface cracks and CT images.The hydraulic conductivity of the air-dried block permeated with strong groundwater was comparable(3.7×higher)to the hydraulic conductivity of the fresh block,indicating the self-healing of drying cracks after hydration and swelling in groundwater.A simplified method of protecting the block with plastic wraps before installation is recommended,since the remained swelling of the block hydrated in Beishan groundwater is sufficient to heal the drying cracks.
基金This work was supported by the National Natural Science Foundation of China(32071943,32272198).
文摘Lysine content is a criterion of the nutritional quality of rice.Understanding the process of lysine biosynthesis in early-flowering superior grain(SG)and late-flowering inferior grain(IG)of rice would advance breeding and cultivation to improve nutritional quality.However,little information is available on differences in lysine anabolism between SG and IG and the underlying mechanism,and whether and how irrigation regimes affect lysine anabolism in these grains.A japonica rice cultivar was grown in the field and two irrigation regimes,continuous flooding(CF)and wetting alternating with partial drying(WAPD),were imposed from heading to the mature stage.Lysine content and activities of key enzymes of lysine biosynthesis,and levels of brassinosteroids(BRs)were lower in the IG than in the SG at the early grainfilling stage but higher at middle and late grain-filling stages.WAPD increased activities of these key enzymes,BR levels,and contents of lysine and total amino acids in IG,but not SG relative to CF.Application of 2,4-epibrassinolide to rice panicles in CF during early grain filling reproduced the effects of WAPD,but neither treatment altered the activities of enzymes responsible for lysine catabolism in either SG or IG.WAPD and elevated BR levels during grain filling increased lysine biosynthesis in IG.Improvement in lysine biosynthesis in rice should focus on IG.
基金the National Natural Science Foundation of China(Grant No.22075146).
文摘Appropriate drying process with optimized controlling of drying parameters plays a vital role in the improvement of the quality and performance of propellant products.However,few research on solvent transport dynamics within NC-based propellants was reported,and its effect on the evolution of mechanical properties was not interpreted yet.This study is conducted to gain a comprehensive understanding of hot-air drying for NC-based propellants and clarify the effect of temperature on solvent transport behavior and further the change of mechanical properties during drying.The drying kinetic curves show the drying time required is decreased but the steady solvent content is increased and the drying rate is obviously increased with the increase of hot-air temperatures,indicating hot-air temperatures have a significant effect on drying kinetics.A modified drying model was established,and results show it is more appropriate to describe solvent transport behavior within NC-based propellants.Moreover,two linear equations were established to exhibit the relationship between solvent content and its effect on the change of tensile properties,and the decrease of residual solvent content causes an obvious increase of tensile strength and tensile modulus of propellant products,indicating its mechanical properties can be partly improved by adjustment of residual solvent content.The outcomes can be used to clarify solvent transport mechanisms and optimize drying process parameters of double-based gun propellants.
文摘Heat and mass transport through evaporation or drying processes occur in many applications such as food processing,pharmaceutical products,solar-driven vapor generation,textile design,and electronic cigarettes.In this paper,the transport of water from a fresh potato considered as a wet porous media with laminar convective dry air fluid flow governed by Darcy’s law in two-dimensional is highlighted.Governing equations of mass conservation,momentumconservation,multiphase fluid flowin porousmedia,heat transfer,and transport of participating fluids and gases through evaporation from liquid to gaseous phase are solved simultaneously.In this model,the variable is block locations,the object function is changing water saturation inside the porous medium and the constraint is the constant mass of porous material.It shows that there is an optimal configuration for the purpose of water removal from the specimen.The results are compared with experimental and analyticalmethods Benchmark.Then for the purpose of configuration optimization,multi-agent reinforcement learning(MARL)is used while multiple porous blocks are considered as agents that transfer their moisture content with the environment in a real-world scenario.MARL has been tested and validated with previous conventional effective optimization simulations and its superiority proved.Our study examines and proposes an effective method for validating and testing multiagent reinforcement learning models and methods using a multiagent simulation.
基金This work is supported by the Fundamental Research Program of Shanxi Province in China(202403021211083)the Central Government Guided Local Science and Technology Development Project of China(No.YDZJSX20231A007)the Natural Science Young Foundation of Shanxi Province in China(201901D211178)to which the authors are very grateful.
文摘Drying shrinkage is an important factor affecting the durability of alkali-activated materials.The drying shrinkage of alkali-activated carbon steel slag and the effect of silica fume substitution were studied.The drying shrinkage test lasted for 300 d.The compressive strength,flexural strength,Vickers hardness,mass recovery and drying shrinkage recovery of the samples after drying shrinkage were tested.The hydration products and microstructure were characterized by X-ray diffraction,mercury intrusion porosimetry,thermogravimetry–differential thermogravimetry,and scanning electron microscopy–energy dispersive spectroscopy.The results show that although the chemical expansion compensates for the drying shrinkage in 42 d,the drying shrinkage increases continuously within 300 d.Silica fume affects drying shrinkage by refining pore size and increasing matrix microhardness.Solid surface tension and capillary pressure are the driving forces for drying shrinkage in the early and middle to late stages,respectively.The evolution of drying shrinkage is also influenced by chemical expansion,matrix microhardness and macropore collapse.
