Institutional Repository of Institute of Process Engineering, CAS (IPE-IR）
Not a member yet
40778 research outputs found
Sort by
A Magneto-Heated Silk Fibroin Scaffold for Anti-Biofouling Solar Steam Generation
No full textMacroscopic 3D porous materials are ideal solar evaporators for water purification. However, the limited sunlight intensity and penetrating depth during solar-driven evaporation cannot prevent the biofouling formation by photothermal effect, thus leading to the deterioration of evaporation rate. Herein, a magnetic heating strategy is reported for anti-biofouling solar steam generation based on a magnetic silk fibroin (SF) scaffold with bi-heating property. Under one sun, the solar-heated top surface of magnetic SF scaffolds accelerates water evaporation at 2.03 kg m(-2) h(-1), while the unheated inner channels suffer from the formation of biofilm. When exposed to alternating magnetic field (AMF), the magnetic SF scaffold can be integrally heated, leading to an efficient inner temperature to prevent biofouling in channels for water transportation. Accordingly, magneto-heated scaffolds show steady water evaporation rates after exposure to S. aureus and E. coli, which maintained 93.6-94.6% of original performance. In contrast, the evaporation rates of the scaffolds without AMF treatment are reduced to 1.31 (S. aureus) and 1.32 (E. coli) kg m(-2) h(-1), decreased by 35.5% and 35.0%, respectively. In addition, the magneto-heated scaffold inhibits biofouling formation in natural lake water, maintaining 99.5% original performance
Gas-solid fluidization modification of calcium carbonate for high-performance poly (butylene adipate-co-terephthalate) (PBAT) composites
No full textModifying biodegradable poly (butylene adipate-co-terephthalate) (PBAT) plastic with inorganic fillers is critical for improving its overall performance, lowering the costs, and expanding its application scope. The chemical modification method for the inorganic filler determines the application performance of PBAT composites. In this work, gas-solid fluidization method was developed as a simple, efficient, and scalable strategy for chemically modifying CaCO3 filler. The modified CaCO3 filler was mixed with PBAT and melt extruded to prepare biodegradable PBAT/CaCO3 composites. The characterization results show that gas-solid fluidization method combines the traditional wet modification method's excellent modification effect with the scalability of the traditional dry modification method. The effects of modification methods and amount of CaCO3 filling on the crystallinity, mechanical, and rheological properties of PBAT/CaCO3 composites were compared. The results demonstrated that PBAT/CaCO3 composites containing 30% gas-solid fluidization modified CaCO3 could still maintain excellent overall performance. As a result, this work provides a simple, efficient, and scalable method for chemically modifying inorganic fillers and preparing biodegradable composites
Time-resolved particle-scale dynamics of a particle-laden jet
No full textParticle-laden jet flow is important to both jet-related industry applications and transmission of the virus through violent expiratory events, such as coughing and sneezing. To help understand its dynamics from the particle level, we develop a time-resolved, three-dimensional (3D), particle tracking velocimetry method, coupled with particle image velocimetry measurement of gas flow, and perform experiments on a dilute particle-laden gas jet. The spatial distributions of velocity and fluctuating velocity of the gas and particles are obtained. It is found that the presence of particles significantly changes the gas turbulence and stretch the gas flow field to the downstream. The probability density function of axial particle velocity shows non-Gaussian distribution and deviates much from those of the spanwise velocities, indicating strong non-equilibrium and anisotropic states. A new drag model is derived based on the reconstructed particle trajectories and gas flow field near the ejector exit with particle Reynolds numbers between 30 and 300. It is found in better agreement with the experimental data than the standard single-particle drag model. A simple model relating the particle volume fraction with particle displacement is developed based on the self-similarity theory of jet, showing good agreement with the experimental measurement
Achieving efficient pretreatment of corn straw at elevated temperatures via constraining cellulose degradation
No full textGreatly reducing the cellulose crystallinity and lignin content of lignocellulose can substantially improve the enzymatic hydrolysis efficiency, dramatically reducing the enzyme dosage; however, it is difficult to be simultaneously achieved. A solution was put forward - biomass pretreatment was carried out with the binary system consisted of 1-n-butyl-3-methylimidazole chloride (BMIMCl) and arginine (Arg) at temperatures higher than the glass transition temperature of lignin (Tg-lignin). The cellulose crystallinity decreased because of hydrogen bonding with BMIMCl. Delignification was promoted via raising the temperature higher than the Tg-lignin, while cellulose degradation was constrained by Arg. The delignification rate reached 90.36 %. The yield of cellulose remained at a level of 88.89 %, while the Crystallinity Index (CI) of cellulose decreased from 36.13 % (raw corn straw) to 13.50 % (regenerated material, RM). It was found that the average molecular weight (Mw) of lignin decreased from 1632 g/mol to 584 g/mol after pretreatment, indicating the lignin was depolymerized; the 2DHSQC result showed the beta-O-4 ' bond of lignin was broken. Because the cellulose crystallinity and the lignin content of the regenerated material were reduced greatly at the same time, the RM was easily hydrolyzed by cellulase. The enzymatic hydrolysis glucose yield of the RM was 3.75 times that of raw corn straw when the enzyme dosage was only 0.41 FPU/g sample, reaching 99.5 %. The IL was successfully recycled four times, and the recovery rate was higher than 93 % each time. RM obtained in four cycles maintained high lignin removal rate and enzymatic hydrolysis glucose yield. The degradation products of hemicellulose and lignin were the main impurities in the recovered IL. This work may provide a new solution for green and efficient biomass pretreatment
NAMPT encapsulated by extracellular vesicles from young adipose-derived mesenchymal stem cells treated tendinopathy in a "One-Stone-Two-Birds" manner
No full textBackground Tendinopathy is the leading sports-related injury and will cause severe weakness and tenderness. Effective therapy for tendinopathy remains limited, and extracellular vesicles (EVs) derived from adipose tissue-derived mesenchymal stem cells (ADMSCs) have demonstrated great potential in tendinopathy treatment; however, the influence of aging status on EV treatment has not been previously described. Results In this study, it was found that ADMSCs derived from old mice (ADMSC(old)) demonstrated remarkable cellular senescence and impaired NAD+ metabolism compared with ADMSCs derived from young mice (ADMSC(young)). Lower NAMPT contents were detected in both ADMSCold and its secreted EVs (ADMSC(old)-EVs). Advanced animal experiments demonstrated that ADMSC(young)-EVs, but not ADMSC(old)-EVs, alleviated the pathological structural, functional and biomechanical properties in tendinopathy mice. Mechanistic analyses demonstrated that ADMSC(young)-EVs improved cell viability and relieved cellular senescence of tenocytes through the NAMPT/SIRT1/PPAR gamma/PGC-1 alpha path-way. ADMSC(young)-EVs, but not ADMSC(old)-EVs, promoted phagocytosis and M2 polarization in macrophages through the NAMPT/SIRT1/Nf-kappa b p65/NLRP3 pathway. The macrophage/tenocyte crosstalk in tendinopathy was influenced by ADMSC(young)-EV treatment and thus it demonstrated "One-Stone-Two-Birds " effects in tendinopathy treatment.Conclusions This study demonstrates an effective novel therapy for tendinopathy and uncovers the influence of donor age on curative effects by clarifying the detailed biological mechanism
Performance prediction of disc and doughnut extraction columns using bayes optimization algorithm-based machine learning models
No full textPulsed disk and doughnut column (PDDC) is widely applied in liquid-liquid solvent extraction. Due to a nonlinear and complex mechanism in PDDC, existing single empirical models often fail to predict the performance of different PDDCs. In this work, machine learning (ML) models such as random forest (RF), support vector machine (SVM), and artificial neural network (ANN) are developed to predict the PDDC's performance including dispersed-phase holdup (xd), drop size (d32), axial diffusion coefficient (Ec) and the height of mass transfer unit (Hoc). ML models were trained based on a comprehensive dataset and the results showed that the prediction performances of the ML models are better than the empirical correlations. The best average absolute relative error (AARE) and correlation coefficient (R2) of d32, xd, Ec and Hoc were 3.97% and 0.99, 10.16% and 0.955, 12.71% and 0.973, 13.44% and 0.982, respectively. RF and SVM exhibited the highest predictive accuracy. Furthermore, the feature importance was determined, which indicated the most significant features for d32, xd, Ec and Hoc were pulse intensity, the velocity of dispersed phase, the velocity of continuous phase and the properties of continuous phase, respectively. This study provided a new perspective to model and design PDDC
Prospective on the recovery of waste iron phosphate: Structure regulation by calcination and dissolution kinetics in acid solution
No full textThe regeneration of waste iron phosphate has not been achieved. In this study, a calcination-assisted structure regulation-solution purification process was proposed to recover waste iron phosphate based on the dissolution performance of various iron phosphate. It has been demonstrated that iron phosphate dihydrate can transform from monoclinic to hexagonal and trigonal structures at 573 K and 773 K, respectively. The removal of crystal water changes the stable structure coordinated by octahedron to the metastable structure coordinated by tetrahedral. The structure conversion leads to a change in acid dissolution performance. The dissolutions of iron phosphate dihydrate and anhydrous iron phosphates are all controlled by chemical reactions but with various apparent activation energy, 70.84 kJ/mol for iron phosphate dihydrate, 56.15 kJ/mol for tridymite FePO4, and 44.36 kJ/mol for alpha-quartz FePO4. The dissolution efficiency was increased from 0.23% (iron phosphate dihy-drate) to 64% (tridymite FePO4) and 86% (alpha-quartz FePO4) at 293 K, and from 4% (iron phosphate dihydrate) to 89% (tridymite FePO4) and 88% (alpha-quartz FePO4) at 353 K, in 2 h. Guided by this dissolution behavior, the waste iron phosphate was calcined at 473 K, dissolved in 1 mol/L sulfuric acid, and hydrothermally treated at 393 K. Iron phosphate dihydrate that met the battery standard was regenerated. The research has provided an effective strategy to recover the waste iron phosphate