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
Biomaterial will shrink during the drying process. The characteristics of shrinkage and rehydration of fresh peas were studied. Drying curves, shrinkage and rehydration curves of peas without seed coats and whole peas...Biomaterial will shrink during the drying process. The characteristics of shrinkage and rehydration of fresh peas were studied. Drying curves, shrinkage and rehydration curves of peas without seed coats and whole peas were compared. In addition, different volumetric shrinkage coefficients were obtained and discussed. The results show that seed coats resist moisture movement not only from inside to outside but also from outside to inside during different drying conditions. During a seed’s drying process, the drying curve is similar to the shrinkage curve. The higher the heat flux is, the less drying time is needed, and in the meantime, volume would shrink more and more intensively. Dried media will break easily at high heat flux. When we create a drying regime, both drying speed and the quality of dried media should be considered.展开更多
A numerical simulation for a model of wood drying process is considered. The model is given by a couple of nonlinear differential equations. One is a nonlinear parabolic equation and the other one is a nonlinear ordin...A numerical simulation for a model of wood drying process is considered. The model is given by a couple of nonlinear differential equations. One is a nonlinear parabolic equation and the other one is a nonlinear ordinary equation. A difference scheme is derived by the method of reduction of order. First, a new variable is introduced and the original problem is rewritten into a system of the first-order differential equations. Secondly, a difference scheme is constructed for the later problem. The solvability, stability and convergence of the difference scheme are proved by the energy method. The convergence order of the difference scheme is secondorder both in time and in space. A prior error estimate is put forward. The new variable is put aside to reduce the computational cost. A numerical example testifies the theoretical result.展开更多
A particular porosity method named ＂slot method＂ is implemented in a depth-integrated shallow water flow model （DIVAST） to simulate wetting and drying processes. Discussed is the relationship between the shape fac...A particular porosity method named ＂slot method＂ is implemented in a depth-integrated shallow water flow model （DIVAST） to simulate wetting and drying processes. Discussed is the relationship between the shape factors of the ＂slot＂ and the preset depth used in ＂wetting-drying＂ algorithm. Two typical tests are conducted to examine the performance of the method with the effect of the shape factors of the ＂slot＂ being checked in detail in the first test. Numerical results demonstrate that： 1 ） no additional effort to improve the finite difference scheme is needed to implement ＂slot method＂ in DIVAST, and 2） ＂slot method＂ will simulate wetting and diying processes correctly if the shape factors of the ＂slot＂ being selected properly.展开更多
A type of antibacterial bacterial cellulose(BC) film was prepared for potential uses as wound dressing.In order to obtain a high antibacterial effect,some forms of BC films,including the wet and dried ones were utiliz...A type of antibacterial bacterial cellulose(BC) film was prepared for potential uses as wound dressing.In order to obtain a high antibacterial effect,some forms of BC films,including the wet and dried ones were utilized as the template to in situ synthesize silver nanoparticles(AgNPs).The effects of drying methods including freeze-drying,heat drying and air drying,on the microstructures and physical properties of BC,as well as the silver contents and the antibacterial performances of the BC/AgNPs composites were investigated.It was found that the AgNPs impregnated on the dried BC films were inclined to achieve a faster silver releasing rate than the wet one,which was suitable for acute traumas treatment.展开更多
OBJECTIVE： To study the effects of the drying processing in terms operational parameters on the bio- active constituents of six YuanzhJ （Radix Palygalae） samples across China. METHODS： Six Yuanzhi （Radix Palygala...OBJECTIVE： To study the effects of the drying processing in terms operational parameters on the bio- active constituents of six YuanzhJ （Radix Palygalae） samples across China. METHODS： Six Yuanzhi （Radix Palygalae） samples were investigated using thermogravimetry analysis. The heating courses were set in two ways： the temperature-programmed process from room temperature to 150℃ ,and the constant-temperature course at 50℃, 70℃ and 90℃. RESULTS： The peak temperature of six Yuanzhi （Radix Palygalae） samples ranged from 78℃ to 88℃. The mass loss rate of Yuanzhi （Radix Palygalae） alcohol-soluble extract was significantly increased when heated at 90℃. Four types of bioactive ingredients were detected in volatile oils of Yuanzhi （Radix Palygalae） sample from Shanxi province by Gas Chromatography-mass spectrometry analysis. Fourier Transform Infrared Spectroscopy results showed that the drying temperature exerted a great influence on types and amount of ingredients of Yuanzhi （Radix Palygalae）. The kinetic study showed that the constant-temperature drying process of Yuanzhi Radix Palygalae） samples could be well de- scribed by the Page Model, especially for the drying process at 50~C, in which R2 and SD values were more than 0.98 and less than 0.04, respectively.The drying constant k of three Yuanzhi （Radix Palygalae） samples from Shanxi, Gansu and Shaanxi provinces in China was corresponding to the Arrhenius equation, and their activation energies were 28.07, 2.5.38 and 21.48 kJ/mol, respectively. CONCLUSION： The drying process of Yuanzhi （Radix Palygalae） was very important for bioactive ingredients improvement in Yuanzhi （Radix Palygalae）. Temperature was a thermodynamic property significantly affecting the process.展开更多
[Objectives]To determine the drying process of different functional rhubarbs.[Methods]The contents of tannins,bianthrone,free anthraquinones and combined anthraquinones in medicinal rhubarb were determined by HPLC.The...[Objectives]To determine the drying process of different functional rhubarbs.[Methods]The contents of tannins,bianthrone,free anthraquinones and combined anthraquinones in medicinal rhubarb were determined by HPLC.The results were analyzed by two-way analysis of variance.[Results]Under different drying conditions,the contents of tannins,bianthrone,free anthraquinones and combined anthraquinones in medicinal rhubarb were significantly different.Taking the tannins content as the index,the optimum drying condition of the rhizome is 1 cm thick,dried at 60℃,the root is cut 1 cm thick,and dried at 30℃;the bianthrone content is used as an indicator,the rhizome is optimally dried.The condition is to cut 1 cm thick,dry at 60℃,the root is cut to 5 cm thick,and dried at 40℃;the free anthraquinones content is used as an index,and the optimum drying condition of the rhizome is 3 cm thick and dried at 50℃.The root is cut to a thickness of 3 cm and dried at 30℃.The combine anthraquinones content is used as an indicator.The optimum drying conditions for the rhizome are 5 cm thick,dried at 40℃,and the root is cut to 5 cm thick and dried at 70℃.[Conclusions]Different functional components of rhubarb have different directional processing methods.The drying process can reduce the drying temperature or increase the thickness of the slice,and the directional processing of the diarrhea-type rhubarb can be processed.The drying process can be carried out by increasing the drying temperature or reducing the thickness of the slice directed processing of heat-clearing and purging-fire rhubarb.展开更多
Carbon aerogels were synthesized via ambient pressure drying process using resorcinolformaldehyde as precursor and P123 to strengthen their skeletons. CO2 activation technology was implemented to improve surface areas...Carbon aerogels were synthesized via ambient pressure drying process using resorcinolformaldehyde as precursor and P123 to strengthen their skeletons. CO2 activation technology was implemented to improve surface areas and adjust pore size distribution. The synthesis process was optimized, and the morphology, structure, adsorption properties and electrochemical behavior of different samples were characterized. The CO2-activated samples achieved a high specific capacitance of 129.2 F/g in 6 M KOH electrolytes at the current density of 1 m A/cm^2 within the voltage range of 0-0.8 V. The optimized activation temperature and duration were determined to be 950 ℃ and 4 h, respectively.展开更多
Drying of the banana in the hot water has a negative impact on the quality of the product and drying effect. The purposes of this study are increasing the drying rate, using the relatively low temperature to improve t...Drying of the banana in the hot water has a negative impact on the quality of the product and drying effect. The purposes of this study are increasing the drying rate, using the relatively low temperature to improve the quality (40℃, 50℃ and 60℃) and investigate the use of electromagnetic waves to increase the drying speed. Therefore, experiments are performed using 5 kHz,10 kHz and 15 kHz low frequency electromagnetic waves in the air velocity values of 0.5 m/s, 1 m/s, 1.5 m/s and 2 m/s and 40℃, 50℃, 60℃ centigrade degrees of air blast in a special compartment. Mathematical model of the drying process has been created as using the electrical circuits methods and experimental results. As a result, a simple equation describing the drying process has been obtained. Nonlinear expression of the diffusion coefficient for a different situation in this equation has been identified for the first time. The obtained theoretical results and experimental results have been provided a good agreement. This study is considered to be useful for all studies in the drying area.展开更多
Drying processing of Habanero chili was improved, through solar energy usage. Habanero chili is a notable seasonal product being drying such important for Mexican producers; this process is expensive and wasteful of e...Drying processing of Habanero chili was improved, through solar energy usage. Habanero chili is a notable seasonal product being drying such important for Mexican producers; this process is expensive and wasteful of energy. A feasibility analysis was developed, to determine the market tendency and the optimal drying conditions for redesign Habanero chili drying process, through a hybrid solar-electric energy usage. The new drying process would be held in two stages： （a） an open solar dryer was used; （b） an existing pilot fluidized bed dryer was adapted with a low temperature solar collector for air heating. Habanero chili was dehydrated from 90% to 5% moisture in 10.3 h, with good quality product, available for commercialization. A reduction in the average drying time of 50% was obtained, also, in the energy usage of 77% in the fluidized bed dryer, with an energy saving of 0.52 kg of natural gas per kg of fresh Habanero chili. An innovative sustainable efficient drying process was developed, and will be strategic to expand the market for Habanero chili with low energy cost.展开更多
Although Rana chensinensis Ovum(RCO)is enriched with high nutritional value,its quality varies due to the different drying methods used by farmers.This study aims to explore the impact of natural and mechanical drying...Although Rana chensinensis Ovum(RCO)is enriched with high nutritional value,its quality varies due to the different drying methods used by farmers.This study aims to explore the impact of natural and mechanical drying methods on the nutritional compositions and physicochemical properties of RCO.Five different drying methods were studied,including blast drying(BD),mild breeze light drying(MBLD),natural air drying(NAD),vacuum heat drying(VHD),and vacuum freeze drying(VFD).The quality assessment was based on unsaturated fatty acid(UFA)content,iodine value,estradiol,vitamin E,saponification value,thiobarbituric acid value(TBA),acid value,and antioxidant properties.The results showed that VFD had higher UFA content and lower acid value(139.950±0.397 mg·g^(−1))and TBA value(0.097±0.003)than others.VFD and NAD had higher iodine values(147.166±1.475 and 146.803±1.209,respectively)than others.There were no significant differences in estradiol,vitamin E,peroxide value and the clearance rates of ABTS+free radicals and DPPH·free radicals with different drying methods.The findings will provide valuable insights into the industrialization of RCO.展开更多
Supercapacitors are efficient and versatile energy storage devices,offering remarkable power density,fast charge/discharge rates,and exceptional cycle life.As research continues to push the boundaries of their perform...Supercapacitors are efficient and versatile energy storage devices,offering remarkable power density,fast charge/discharge rates,and exceptional cycle life.As research continues to push the boundaries of their performance,electrode fabrication techniques are critical aspects influencing the overall capabilities of supercapacitors.Herein,we aim to shed light on the advantages offered by dry electrode processing for advanced supercapacitors.Notably,our study explores the performance of these electrodes in three different types of electrolytes:organic,ionic liquids,and quasi-solid states.By examining the impact of dry electrode processing on various electrode and electrolyte systems,we show valuable insights into the versatility and efficacy of this technique.The supercapacitors employing dry electrodes demonstrated significant improvements compared with conventional wet electrodes,with a lifespan extension of+45%in organic,+192%in ionic liquids,and+84%in quasi-solid electrolytes.Moreover,the increased electrode densities achievable through the dry approach directly translate to improved volumetric outputs,enhancing energy storage capacities within compact form factors.Notably,dry electrode-prepared supercapacitors outperformed their wet electrode counterparts,exhibiting a higher energy density of 6.1 Wh cm^(-3)compared with 4.7 Wh cm^(-3)at a high power density of 195Wcm^(-3),marking a substantial 28%energy improvement in the quasi-solid electrolyte.展开更多
The real-time monitoring and prediction system for quality attributes of jujube slices during the drying process was designed to solve the problem of destructive and inconvenient of the traditional quality detection m...The real-time monitoring and prediction system for quality attributes of jujube slices during the drying process was designed to solve the problem of destructive and inconvenient of the traditional quality detection method and realize quality online monitoring.Firstly,machine vision and automatic weighing were employed to monitor the color and moisture content changes of jujube slices in real-time.Secondly,correlation models between color parameter(a^(*)value)and nutritional quality attributes(vitamin C,reducing sugar)were established to predict vitamin C and reducing sugar content of jujube slices during the drying process.Finally,the upper computer monitoring software was integrated and designed based on LABVIEW virtual instrument,and the real-time monitoring system was tested and validated.Results showed that:the changing trends of color(L^(*),a^(*),and b^(*)values)monitored by the system were basically the same as the results detected by color difference meter,and the average errors of L^(*),a^(*),and b^(*)values were 0.93,0.52,and 0.73,respectively.The average relative error of moisture content between the system monitoring and manual static detection was 0.18%.The average error of vitamin C and reducing sugar content between the system prediction and manual detection were 50 mg/100 g in dry basis and 0.71g/100 g in dry basis,respectively.The current work can provide a useful reference for real-time monitoring of quality attributes of fruits and vegetables during the drying process.展开更多
Hemicellulose has a wide range of applications,including that as an emulsifier for the food industry and raw material for the synthesis of bioethanol/biochemicals and biodegradable films.Hemicellulose is usually prese...Hemicellulose has a wide range of applications,including that as an emulsifier for the food industry and raw material for the synthesis of bioethanol/biochemicals and biodegradable films.Hemicellulose is usually present as a spent liquor,such as the prehydrolysis liquor of the prehydrolysis kraft dissolving pulp production process and the alkali extraction liquor of the cold caustic extraction of pulp fibers.Due to its dilute nature,hemicellulose needs to be dried for practical utilization,and this is challenging.In this study,cellulose and hemicellulose in a bleached bamboo kraft pulp were separated using an alkali extraction process.Hemicellulose obtained from the extraction liquor was dried by an ammonium carbonate-assisted drying process.The effects of drying time and drying temperature were determined.Structure of the hemicellulose obtained by the ammonium carbonate-assisted drying process was similar to that of original hemicellulose,as revealed by detailed Fourier transform infrared and X-ray diffraction analyses.The novel drying method was more energy efficient and required a shorter drying time than the conventional freeze drying method,and the excellent solubility in alkaline solutions favored the chemical modification of hemicellulose.The dried hemicellulose can be used as a renewable raw material for the preparation of hydrogels and other substances such as bioethanol/biochemicals and biodegradable films.展开更多
Four different fresh and dried herb species(sage,thyme,mint and lemonbalm)were evaluated to study the effect of drying process on the total phenolics,antioxidant activity,flavonoid contents and color properties.Fresh ...Four different fresh and dried herb species(sage,thyme,mint and lemonbalm)were evaluated to study the effect of drying process on the total phenolics,antioxidant activity,flavonoid contents and color properties.Fresh mint had the highest contents of total phenolics(335.4 mg GAE/100 g),whereas lower levels were respectively found in sage(316.4 mg GAE/100 g)followed by lemonbalm(303.2 mg GAE/100 g)and thyme(299.2 mg GAE/100 g).Dry processing significantly decreased the phytochemical contents of all investigated herbs.Compare to air drying,total phenolics,antioxidant activity and flavonoids content in herbs decreased apparently by oven dried.Fresh mint had the highest antioxidant activity(87.46%)and flavonoids content(298.51 mg CE/100 g),while the fresh sage,thyme and lemonbalm were found to have antioxidant activity values of 86.81%,86.56% and 85.26%,respectively.Results showed that air drying herbs contained more total phenolics,antioxidant activity,and flavonoids than oven drying herbs.展开更多
Sustainable irrigation method is now essential for adaptation and adoption in the areas where water resources are limited. Therefore, a field experiment was conducted to test the performance of alternate wetting and d...Sustainable irrigation method is now essential for adaptation and adoption in the areas where water resources are limited. Therefore, a field experiment was conducted to test the performance of alternate wetting and drying furrow irrigation（AWDFI） on crop growth, yield, water use efficiency（WUE）, fruit quality and profitability analysis of tomato. The experiment was laid out in randomized complete block design with six treatments replicated thrice during the dry seasons of 2013-2014 and 2014-2015. Irrigation water was applied through three ways of furrow： AWDFI, fixed wetting and drying furrow irrigation（FWDFI） and traditional（every） furrow irrigation（TFI）. Each irrigation method was divided into two levels： irrigation up to 100 and 80% field capacity（FC）. Results showed that plant biomass（dry matter） and marketable fruit yield of tomato did not differ significantly between the treatments of AWDFI and TFI, but significant difference was observed in AWDFI and in TFI compared to FWDFI at same irrigation level. AWDFI saved irrigation water by 35 to 38% for the irrigation levels up to 80 and 100% FC, compared to the TFI, respectively. AWDFI improved WUE by around 37 to 40% compared to TFI when irrigated with 100 and 80% FC, respectively. Fruit quality（total soluble solids and pulp） was found greater in AWDFI than in TFI. Net return from AWDFI technique was found nearly similar compared to TFI and more than FWDFI. The benefit cost ratio was viewed higher in AWDFI than in TFI and FWDFI by 2.8, 8.7 and 11, 10.4% when irrigation water was applied up to 100 and 80% FC, respectively. Unit production cost was obtained lower in AWDFI compared to TFI and FWDFI. However, AWDFI is a useful water-saving furrow irrigation technique which may resolve as an alternative choice compared with TFI in the areas where available water and supply methods are limited to irrigation.展开更多
[Objectives]To optimize the water extraction process of Bawei Shangke Huoxue tablets and determine the best drying method of the extract.[Methods]The orthogonal test method was used to select the optimal water extract...[Objectives]To optimize the water extraction process of Bawei Shangke Huoxue tablets and determine the best drying method of the extract.[Methods]The orthogonal test method was used to select the optimal water extraction process,with the content of total flavonoids and the yield of dry extract as the test indicators,and the soaking time,the amount of water added,the extraction time and the extraction times as the main test factors.The water content of spray powder was taken as the evaluation indicator,the inlet air temperature,the density of liquid phase and the outlet air temperature were selected as the factors,and the spray drying process of water-extracted concentrated liquid was optimized by orthogonal test.[Results]The optimal water extraction process was no immersion,water decoction and extraction twice,adding 10 times of water each time,extraction for 1h,in which the amount of water added was the main factor.The liquid density of spray dried extract powder is 1.05-1.08(60℃),the inlet air temperature is 180℃,the outlet air temperature is 80℃is the most suitable,and the liquid density is the main factor.[Conclusions]The extraction and drying technology of Bawei Huangke Huoxue tablet is feasible,scientific and reasonable,and can be used for industrial production.展开更多
Introduction Cationic starches are a series of products of which various sorts with different properties and usages can all be produced via cationic reactions by using different types of etherification agents under di...Introduction Cationic starches are a series of products of which various sorts with different properties and usages can all be produced via cationic reactions by using different types of etherification agents under different conditions. As an additive and strengthening agent,展开更多
A coupling model between the canopy layer(CL) and atmospheric boundary layer (ABL) for the study of dry deposition velocity is developed. The model consists of six parts: chemical species conservation equation includi...A coupling model between the canopy layer(CL) and atmospheric boundary layer (ABL) for the study of dry deposition velocity is developed. The model consists of six parts: chemical species conservation equation including absorptive factor; the species uptake action including detailed vertical variation of absorptive element in CL; momentum exchange in CL which is represented by a first-order closure momentum equation with an additional larger-scale diffusive term; momentum exchange in ABL which is described by a complete set of the ABL turbulent statistic parameters; absorptivity (or solubility or reflection) at the surface including effects of the physical and chemical characters of the species, land type, seasonal and diurnal variations of the meteorological variables; and deposition velocity derived by distributions of the species with height in CL. Variational rules of the concentration and deposition velocity with both height and time are simulated with the model for both corn and forest canopies. Results predicted with the bulk deposition velocity derived in the paper consist well with experimental data.展开更多
Most outburst mines in China adopt the measures of pre drainage by drilling along the seam for gas control in the mining area, that is, drilling along the seam from the air roadway of the mining machine to the mining ...Most outburst mines in China adopt the measures of pre drainage by drilling along the seam for gas control in the mining area, that is, drilling along the seam from the air roadway of the mining machine to the mining area. The drainage effect of drilling along the seam is directly related to the gas control effect of the mining area. For many years, we have carried out the measures according to the provisions of the detailed rules for the prevention and control of coal and gas outburst. The sealing length of the bedding hole is consistently kept at 8m, and the depth of the sealing section is kept at about 10m, and the extraction concentration and pure amount have been maintained at a low level, resulting in relatively large gas emission during mining. We break the Convention and calculate the sealing depth of the hole according to the pre drainage equivalent width of the coal roadway. At the same time, the extended version of high-pressure grouting is used for two plugs and one injection seal, so that the hole sealing depth of the borehole is within the equivalent width of the roadway pre drainage gas, and the length of the hole sealing section is longer. At the same time, combined with the whole process casing running technology of bedding drilling, the contact area between the screen pipe and the coal wall is likely to be increased, and good results have been achieved in preventing the impact of hole collapse and other phenomena on the drainage effect. The concentration of single hole drainage and the net amount of main pipe drainage have been greatly improved, and the gas content and gas pressure of coal have decreased significantly.展开更多
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.
文摘Biomaterial will shrink during the drying process. The characteristics of shrinkage and rehydration of fresh peas were studied. Drying curves, shrinkage and rehydration curves of peas without seed coats and whole peas were compared. In addition, different volumetric shrinkage coefficients were obtained and discussed. The results show that seed coats resist moisture movement not only from inside to outside but also from outside to inside during different drying conditions. During a seed’s drying process, the drying curve is similar to the shrinkage curve. The higher the heat flux is, the less drying time is needed, and in the meantime, volume would shrink more and more intensively. Dried media will break easily at high heat flux. When we create a drying regime, both drying speed and the quality of dried media should be considered.
基金The National Natural Science Foundation of China (No10471023)
文摘A numerical simulation for a model of wood drying process is considered. The model is given by a couple of nonlinear differential equations. One is a nonlinear parabolic equation and the other one is a nonlinear ordinary equation. A difference scheme is derived by the method of reduction of order. First, a new variable is introduced and the original problem is rewritten into a system of the first-order differential equations. Secondly, a difference scheme is constructed for the later problem. The solvability, stability and convergence of the difference scheme are proved by the energy method. The convergence order of the difference scheme is secondorder both in time and in space. A prior error estimate is put forward. The new variable is put aside to reduce the computational cost. A numerical example testifies the theoretical result.
基金the National Natural Science Foundation of China (Grant No.10702050)the Natural Science Foundation of Tianjin (Grant No.07JCYBJC07500)the Support Plan of Science and Technology of Tianjin (Grant No.07ZCGYSH01700)
文摘A particular porosity method named ＂slot method＂ is implemented in a depth-integrated shallow water flow model （DIVAST） to simulate wetting and drying processes. Discussed is the relationship between the shape factors of the ＂slot＂ and the preset depth used in ＂wetting-drying＂ algorithm. Two typical tests are conducted to examine the performance of the method with the effect of the shape factors of the ＂slot＂ being checked in detail in the first test. Numerical results demonstrate that： 1 ） no additional effort to improve the finite difference scheme is needed to implement ＂slot method＂ in DIVAST, and 2） ＂slot method＂ will simulate wetting and diying processes correctly if the shape factors of the ＂slot＂ being selected properly.
基金“111 Project” Biomedical Textile Materials Science and Technology,China(No.B07024)Natural Science Foundation of Shanghai,China(No.15ZR1401000)the Fundamental Research Funds for the Central Universities,China
文摘A type of antibacterial bacterial cellulose(BC) film was prepared for potential uses as wound dressing.In order to obtain a high antibacterial effect,some forms of BC films,including the wet and dried ones were utilized as the template to in situ synthesize silver nanoparticles(AgNPs).The effects of drying methods including freeze-drying,heat drying and air drying,on the microstructures and physical properties of BC,as well as the silver contents and the antibacterial performances of the BC/AgNPs composites were investigated.It was found that the AgNPs impregnated on the dried BC films were inclined to achieve a faster silver releasing rate than the wet one,which was suitable for acute traumas treatment.
基金Supported by the National Science and Technology Support Program of the Ministry of Science and Technology of the People's Republic of China (No.2011BAI07B05)Shanxi Science and Technology Tackling Fund (No.20100311090,20130313015-2)Department of Health of Shanxi province Tackling Fund (No.200834)
文摘OBJECTIVE： To study the effects of the drying processing in terms operational parameters on the bio- active constituents of six YuanzhJ （Radix Palygalae） samples across China. METHODS： Six Yuanzhi （Radix Palygalae） samples were investigated using thermogravimetry analysis. The heating courses were set in two ways： the temperature-programmed process from room temperature to 150℃ ,and the constant-temperature course at 50℃, 70℃ and 90℃. RESULTS： The peak temperature of six Yuanzhi （Radix Palygalae） samples ranged from 78℃ to 88℃. The mass loss rate of Yuanzhi （Radix Palygalae） alcohol-soluble extract was significantly increased when heated at 90℃. Four types of bioactive ingredients were detected in volatile oils of Yuanzhi （Radix Palygalae） sample from Shanxi province by Gas Chromatography-mass spectrometry analysis. Fourier Transform Infrared Spectroscopy results showed that the drying temperature exerted a great influence on types and amount of ingredients of Yuanzhi （Radix Palygalae）. The kinetic study showed that the constant-temperature drying process of Yuanzhi Radix Palygalae） samples could be well de- scribed by the Page Model, especially for the drying process at 50~C, in which R2 and SD values were more than 0.98 and less than 0.04, respectively.The drying constant k of three Yuanzhi （Radix Palygalae） samples from Shanxi, Gansu and Shaanxi provinces in China was corresponding to the Arrhenius equation, and their activation energies were 28.07, 2.5.38 and 21.48 kJ/mol, respectively. CONCLUSION： The drying process of Yuanzhi （Radix Palygalae） was very important for bioactive ingredients improvement in Yuanzhi （Radix Palygalae）. Temperature was a thermodynamic property significantly affecting the process.
基金National Natural Science Foundation of China(31570331,31170307)National Key Research and Development Program of China(2017YFC1700702)Project of Beijing University of Chinese Medicine(2019-JYB-XS-087).
文摘[Objectives]To determine the drying process of different functional rhubarbs.[Methods]The contents of tannins,bianthrone,free anthraquinones and combined anthraquinones in medicinal rhubarb were determined by HPLC.The results were analyzed by two-way analysis of variance.[Results]Under different drying conditions,the contents of tannins,bianthrone,free anthraquinones and combined anthraquinones in medicinal rhubarb were significantly different.Taking the tannins content as the index,the optimum drying condition of the rhizome is 1 cm thick,dried at 60℃,the root is cut 1 cm thick,and dried at 30℃;the bianthrone content is used as an indicator,the rhizome is optimally dried.The condition is to cut 1 cm thick,dry at 60℃,the root is cut to 5 cm thick,and dried at 40℃;the free anthraquinones content is used as an index,and the optimum drying condition of the rhizome is 3 cm thick and dried at 50℃.The root is cut to a thickness of 3 cm and dried at 30℃.The combine anthraquinones content is used as an indicator.The optimum drying conditions for the rhizome are 5 cm thick,dried at 40℃,and the root is cut to 5 cm thick and dried at 70℃.[Conclusions]Different functional components of rhubarb have different directional processing methods.The drying process can reduce the drying temperature or increase the thickness of the slice,and the directional processing of the diarrhea-type rhubarb can be processed.The drying process can be carried out by increasing the drying temperature or reducing the thickness of the slice directed processing of heat-clearing and purging-fire rhubarb.
基金Funded by the National High Technology Research and Development Program(863 Program)(No.2013AA050905),China Academy of Engineering Physics,Mianyang,China
文摘Carbon aerogels were synthesized via ambient pressure drying process using resorcinolformaldehyde as precursor and P123 to strengthen their skeletons. CO2 activation technology was implemented to improve surface areas and adjust pore size distribution. The synthesis process was optimized, and the morphology, structure, adsorption properties and electrochemical behavior of different samples were characterized. The CO2-activated samples achieved a high specific capacitance of 129.2 F/g in 6 M KOH electrolytes at the current density of 1 m A/cm^2 within the voltage range of 0-0.8 V. The optimized activation temperature and duration were determined to be 950 ℃ and 4 h, respectively.
文摘Drying of the banana in the hot water has a negative impact on the quality of the product and drying effect. The purposes of this study are increasing the drying rate, using the relatively low temperature to improve the quality (40℃, 50℃ and 60℃) and investigate the use of electromagnetic waves to increase the drying speed. Therefore, experiments are performed using 5 kHz,10 kHz and 15 kHz low frequency electromagnetic waves in the air velocity values of 0.5 m/s, 1 m/s, 1.5 m/s and 2 m/s and 40℃, 50℃, 60℃ centigrade degrees of air blast in a special compartment. Mathematical model of the drying process has been created as using the electrical circuits methods and experimental results. As a result, a simple equation describing the drying process has been obtained. Nonlinear expression of the diffusion coefficient for a different situation in this equation has been identified for the first time. The obtained theoretical results and experimental results have been provided a good agreement. This study is considered to be useful for all studies in the drying area.
文摘Drying processing of Habanero chili was improved, through solar energy usage. Habanero chili is a notable seasonal product being drying such important for Mexican producers; this process is expensive and wasteful of energy. A feasibility analysis was developed, to determine the market tendency and the optimal drying conditions for redesign Habanero chili drying process, through a hybrid solar-electric energy usage. The new drying process would be held in two stages： （a） an open solar dryer was used; （b） an existing pilot fluidized bed dryer was adapted with a low temperature solar collector for air heating. Habanero chili was dehydrated from 90% to 5% moisture in 10.3 h, with good quality product, available for commercialization. A reduction in the average drying time of 50% was obtained, also, in the energy usage of 77% in the fluidized bed dryer, with an energy saving of 0.52 kg of natural gas per kg of fresh Habanero chili. An innovative sustainable efficient drying process was developed, and will be strategic to expand the market for Habanero chili with low energy cost.
基金funded by the Department of Science and Technology of Jilin Province(20210204015YY)the Department of Education of Jilin Province(JJKH20210025KJ).
文摘Although Rana chensinensis Ovum(RCO)is enriched with high nutritional value,its quality varies due to the different drying methods used by farmers.This study aims to explore the impact of natural and mechanical drying methods on the nutritional compositions and physicochemical properties of RCO.Five different drying methods were studied,including blast drying(BD),mild breeze light drying(MBLD),natural air drying(NAD),vacuum heat drying(VHD),and vacuum freeze drying(VFD).The quality assessment was based on unsaturated fatty acid(UFA)content,iodine value,estradiol,vitamin E,saponification value,thiobarbituric acid value(TBA),acid value,and antioxidant properties.The results showed that VFD had higher UFA content and lower acid value(139.950±0.397 mg·g^(−1))and TBA value(0.097±0.003)than others.VFD and NAD had higher iodine values(147.166±1.475 and 146.803±1.209,respectively)than others.There were no significant differences in estradiol,vitamin E,peroxide value and the clearance rates of ABTS+free radicals and DPPH·free radicals with different drying methods.The findings will provide valuable insights into the industrialization of RCO.
基金funding of the joint Polish-German project SUPILMIX(PR-1173/27)by the German Research Foundation(DFG,Deutsche Forschungsgemeinschaft)+1 种基金funding from the Alexander von Humboldt Foundation.D.L.the German Chemical Industry Fund for the financial support through a Liebig Fellowship.
文摘Supercapacitors are efficient and versatile energy storage devices,offering remarkable power density,fast charge/discharge rates,and exceptional cycle life.As research continues to push the boundaries of their performance,electrode fabrication techniques are critical aspects influencing the overall capabilities of supercapacitors.Herein,we aim to shed light on the advantages offered by dry electrode processing for advanced supercapacitors.Notably,our study explores the performance of these electrodes in three different types of electrolytes:organic,ionic liquids,and quasi-solid states.By examining the impact of dry electrode processing on various electrode and electrolyte systems,we show valuable insights into the versatility and efficacy of this technique.The supercapacitors employing dry electrodes demonstrated significant improvements compared with conventional wet electrodes,with a lifespan extension of+45%in organic,+192%in ionic liquids,and+84%in quasi-solid electrolytes.Moreover,the increased electrode densities achievable through the dry approach directly translate to improved volumetric outputs,enhancing energy storage capacities within compact form factors.Notably,dry electrode-prepared supercapacitors outperformed their wet electrode counterparts,exhibiting a higher energy density of 6.1 Wh cm^(-3)compared with 4.7 Wh cm^(-3)at a high power density of 195Wcm^(-3),marking a substantial 28%energy improvement in the quasi-solid electrolyte.
基金This work was financially supported by the Natural Science Fund of China(Grant No.31960488)the Shihezi University Achievement Transformation and Technology Promotion Project(Grant No.CGZH201808).
文摘The real-time monitoring and prediction system for quality attributes of jujube slices during the drying process was designed to solve the problem of destructive and inconvenient of the traditional quality detection method and realize quality online monitoring.Firstly,machine vision and automatic weighing were employed to monitor the color and moisture content changes of jujube slices in real-time.Secondly,correlation models between color parameter(a^(*)value)and nutritional quality attributes(vitamin C,reducing sugar)were established to predict vitamin C and reducing sugar content of jujube slices during the drying process.Finally,the upper computer monitoring software was integrated and designed based on LABVIEW virtual instrument,and the real-time monitoring system was tested and validated.Results showed that:the changing trends of color(L^(*),a^(*),and b^(*)values)monitored by the system were basically the same as the results detected by color difference meter,and the average errors of L^(*),a^(*),and b^(*)values were 0.93,0.52,and 0.73,respectively.The average relative error of moisture content between the system monitoring and manual static detection was 0.18%.The average error of vitamin C and reducing sugar content between the system prediction and manual detection were 50 mg/100 g in dry basis and 0.71g/100 g in dry basis,respectively.The current work can provide a useful reference for real-time monitoring of quality attributes of fruits and vegetables during the drying process.
基金the National Key Research and Development Program of China(2017YFB0307900,2019YFC1905903)the National Natural Science Foundation of China(31700507)the Major Project on the Integration of Industry-Education-Research of Fujian Provincial Department of Science and Technology(2018H6003).
文摘Hemicellulose has a wide range of applications,including that as an emulsifier for the food industry and raw material for the synthesis of bioethanol/biochemicals and biodegradable films.Hemicellulose is usually present as a spent liquor,such as the prehydrolysis liquor of the prehydrolysis kraft dissolving pulp production process and the alkali extraction liquor of the cold caustic extraction of pulp fibers.Due to its dilute nature,hemicellulose needs to be dried for practical utilization,and this is challenging.In this study,cellulose and hemicellulose in a bleached bamboo kraft pulp were separated using an alkali extraction process.Hemicellulose obtained from the extraction liquor was dried by an ammonium carbonate-assisted drying process.The effects of drying time and drying temperature were determined.Structure of the hemicellulose obtained by the ammonium carbonate-assisted drying process was similar to that of original hemicellulose,as revealed by detailed Fourier transform infrared and X-ray diffraction analyses.The novel drying method was more energy efficient and required a shorter drying time than the conventional freeze drying method,and the excellent solubility in alkaline solutions favored the chemical modification of hemicellulose.The dried hemicellulose can be used as a renewable raw material for the preparation of hydrogels and other substances such as bioethanol/biochemicals and biodegradable films.
基金the Deanship of Scientific Research at King Saud University for its funding of this research through Research Group Project number 193.
文摘Four different fresh and dried herb species(sage,thyme,mint and lemonbalm)were evaluated to study the effect of drying process on the total phenolics,antioxidant activity,flavonoid contents and color properties.Fresh mint had the highest contents of total phenolics(335.4 mg GAE/100 g),whereas lower levels were respectively found in sage(316.4 mg GAE/100 g)followed by lemonbalm(303.2 mg GAE/100 g)and thyme(299.2 mg GAE/100 g).Dry processing significantly decreased the phytochemical contents of all investigated herbs.Compare to air drying,total phenolics,antioxidant activity and flavonoids content in herbs decreased apparently by oven dried.Fresh mint had the highest antioxidant activity(87.46%)and flavonoids content(298.51 mg CE/100 g),while the fresh sage,thyme and lemonbalm were found to have antioxidant activity values of 86.81%,86.56% and 85.26%,respectively.Results showed that air drying herbs contained more total phenolics,antioxidant activity,and flavonoids than oven drying herbs.
基金Bangladesh Agricultural Research Institute (BARI), Ministry of Agriculture, Bangladesh for providing fund and facilities for sustainable irrigation and water management practices
文摘Sustainable irrigation method is now essential for adaptation and adoption in the areas where water resources are limited. Therefore, a field experiment was conducted to test the performance of alternate wetting and drying furrow irrigation（AWDFI） on crop growth, yield, water use efficiency（WUE）, fruit quality and profitability analysis of tomato. The experiment was laid out in randomized complete block design with six treatments replicated thrice during the dry seasons of 2013-2014 and 2014-2015. Irrigation water was applied through three ways of furrow： AWDFI, fixed wetting and drying furrow irrigation（FWDFI） and traditional（every） furrow irrigation（TFI）. Each irrigation method was divided into two levels： irrigation up to 100 and 80% field capacity（FC）. Results showed that plant biomass（dry matter） and marketable fruit yield of tomato did not differ significantly between the treatments of AWDFI and TFI, but significant difference was observed in AWDFI and in TFI compared to FWDFI at same irrigation level. AWDFI saved irrigation water by 35 to 38% for the irrigation levels up to 80 and 100% FC, compared to the TFI, respectively. AWDFI improved WUE by around 37 to 40% compared to TFI when irrigated with 100 and 80% FC, respectively. Fruit quality（total soluble solids and pulp） was found greater in AWDFI than in TFI. Net return from AWDFI technique was found nearly similar compared to TFI and more than FWDFI. The benefit cost ratio was viewed higher in AWDFI than in TFI and FWDFI by 2.8, 8.7 and 11, 10.4% when irrigation water was applied up to 100 and 80% FC, respectively. Unit production cost was obtained lower in AWDFI compared to TFI and FWDFI. However, AWDFI is a useful water-saving furrow irrigation technique which may resolve as an alternative choice compared with TFI in the areas where available water and supply methods are limited to irrigation.
基金Sci-tech Innovation Program of Guangdong Drug Administration(2019YDZ25)。
文摘[Objectives]To optimize the water extraction process of Bawei Shangke Huoxue tablets and determine the best drying method of the extract.[Methods]The orthogonal test method was used to select the optimal water extraction process,with the content of total flavonoids and the yield of dry extract as the test indicators,and the soaking time,the amount of water added,the extraction time and the extraction times as the main test factors.The water content of spray powder was taken as the evaluation indicator,the inlet air temperature,the density of liquid phase and the outlet air temperature were selected as the factors,and the spray drying process of water-extracted concentrated liquid was optimized by orthogonal test.[Results]The optimal water extraction process was no immersion,water decoction and extraction twice,adding 10 times of water each time,extraction for 1h,in which the amount of water added was the main factor.The liquid density of spray dried extract powder is 1.05-1.08(60℃),the inlet air temperature is 180℃,the outlet air temperature is 80℃is the most suitable,and the liquid density is the main factor.[Conclusions]The extraction and drying technology of Bawei Huangke Huoxue tablet is feasible,scientific and reasonable,and can be used for industrial production.
文摘Introduction Cationic starches are a series of products of which various sorts with different properties and usages can all be produced via cationic reactions by using different types of etherification agents under different conditions. As an additive and strengthening agent,
文摘A coupling model between the canopy layer(CL) and atmospheric boundary layer (ABL) for the study of dry deposition velocity is developed. The model consists of six parts: chemical species conservation equation including absorptive factor; the species uptake action including detailed vertical variation of absorptive element in CL; momentum exchange in CL which is represented by a first-order closure momentum equation with an additional larger-scale diffusive term; momentum exchange in ABL which is described by a complete set of the ABL turbulent statistic parameters; absorptivity (or solubility or reflection) at the surface including effects of the physical and chemical characters of the species, land type, seasonal and diurnal variations of the meteorological variables; and deposition velocity derived by distributions of the species with height in CL. Variational rules of the concentration and deposition velocity with both height and time are simulated with the model for both corn and forest canopies. Results predicted with the bulk deposition velocity derived in the paper consist well with experimental data.
文摘Most outburst mines in China adopt the measures of pre drainage by drilling along the seam for gas control in the mining area, that is, drilling along the seam from the air roadway of the mining machine to the mining area. The drainage effect of drilling along the seam is directly related to the gas control effect of the mining area. For many years, we have carried out the measures according to the provisions of the detailed rules for the prevention and control of coal and gas outburst. The sealing length of the bedding hole is consistently kept at 8m, and the depth of the sealing section is kept at about 10m, and the extraction concentration and pure amount have been maintained at a low level, resulting in relatively large gas emission during mining. We break the Convention and calculate the sealing depth of the hole according to the pre drainage equivalent width of the coal roadway. At the same time, the extended version of high-pressure grouting is used for two plugs and one injection seal, so that the hole sealing depth of the borehole is within the equivalent width of the roadway pre drainage gas, and the length of the hole sealing section is longer. At the same time, combined with the whole process casing running technology of bedding drilling, the contact area between the screen pipe and the coal wall is likely to be increased, and good results have been achieved in preventing the impact of hole collapse and other phenomena on the drainage effect. The concentration of single hole drainage and the net amount of main pipe drainage have been greatly improved, and the gas content and gas pressure of coal have decreased significantly.
