J. Membr. Sci.

Colloidal emulsion aphrons (CEAs) can be considered as the micrometer- sized water-in-oil emulsion cores encapsulated by a "soapy shell" consisting of multi-layer surfactant molecules. The emulsion core sizes of CEA dispersion are roughly in 10-100 mu m, whereas the sizes of inner phase are in 1-5 mu m. CEAs can be used as a microreactor to synthesize fine powder materials. Silver powders with various sizes and shapes were prepared with di-(2-ethylhexyl) phosphoric acid (D2EHPA) as the mobile carrier in membrane phase, ascorbic acid (V,) as reducing agent in inner phase and cyclohexane as the membrane of CEAs. The linear silver particles were formed under low mobile carrier concentration in membrane phase or low ascorbic acid concentration in inner phase, whereas the granular silver particles with comparatively small sizes were obtained under the high mobile carrier concentration or high ascorbic acid concentration, and also silver powder of "nano-porous microsphere" was prepared with CEAs by adjusting the D2EHPA concentration in membrane phase, ascorbic acid concentration in inner phase and the molar ratio of silver ion to ascorbic acid (n(Ag+/vc)). Compared with emulsion liquid membrane (ELM) method, the silver powder prepared with CEAs was usually in granular form with smaller sizes because of the higher transfer rate, but for that prepared with ELMs was only in linear form. Two kinds of silver powder samples with typical shapes, one is the "nano-porous microsphere" prepared with CEAs and the other is the linear silver powder prepared with ELMs, were characterized by thermogravimetry (TG)-differential thermal analysis (DTA), X-ray powder diffraction analysis and field emission scanning electron microscope (FESEM). (c) 2006 Elsevier B.V. All rights reserved.Colloidal emulsion aphrons (CEAs) can be considered as the micrometer- sized water-in-oil emulsion cores encapsulated by a "soapy shell" consisting of multi-layer surfactant molecules. The emulsion core sizes of CEA dispersion are roughly in 10-100 mu m, whereas the sizes of inner phase are in 1-5 mu m. CEAs can be used as a microreactor to synthesize fine powder materials. Silver powders with various sizes and shapes were prepared with di-(2-ethylhexyl) phosphoric acid (D2EHPA) as the mobile carrier in membrane phase, ascorbic acid (V,) as reducing agent in inner phase and cyclohexane as the membrane of CEAs. The linear silver particles were formed under low mobile carrier concentration in membrane phase or low ascorbic acid concentration in inner phase, whereas the granular silver particles with comparatively small sizes were obtained under the high mobile carrier concentration or high ascorbic acid concentration, and also silver powder of "nano-porous microsphere" was prepared with CEAs by adjusting the D2EHPA concentration in membrane phase, ascorbic acid concentration in inner phase and the molar ratio of silver ion to ascorbic acid (n(Ag+/vc)). Compared with emulsion liquid membrane (ELM) method, the silver powder prepared with CEAs was usually in granular form with smaller sizes because of the higher transfer rate, but for that prepared with ELMs was only in linear form

Dendrite growth and micromechanical properties of rapidly solidified ternary Ni-Fe-Ti alloy

The rapid solidification of undercooled liquid Ni45Fe40Ti15 alloy was realized by glass fluxing technique. The microstructure of this alloy consists of primary γ-(Fe, Ni) phase and a small amount of interdendritic pseudobinary eutectic. The primary γ-(Fe, Ni) phase transferred from coarse dendrite to fragmented dendrite and the lamellar eutectic became fractured with the increase of undercooling. The growth velocity of γ-(Fe, Ni) dendrite increased following a power relation with the rise of undercooling. The addition of solute Ti suppressed the rapid growth of γ-(Fe, Ni) dendrite, as compared with the calculation results of Fe-Ni alloy based on LKT model. The microhardness values of the alloy and the primary γ-(Fe, Ni) phase increased by 1.5 times owing to the microstructural refinement caused by the rapid dendrite growth. The difference was enlarged as undercooling increases, resulting from the enhanced hardening effects on the alloy from the increased grain boundaries and the second phase. Keywords: Undercooling, Rapid solidification, Dendrite growth, Microstructure, Microhardnes

Recycled-Oil-Based Polyurethane Modified with Organic Silicone for Controllable Release of Coated Fertilizer

Fertilizer is very important for increasing food yield, but the extensive use of fertilizer will cause environmental pollution. To enhance the effectiveness of fertilizer, we developed the double organic silicone-modified recycled-oil-based polyurethane as a coating material to prepare degradable polymer coating urea for constant fertilizer release. The moisture, heat resistance, and sustained release properties of polyurethane coating materials were investigated by modification with hydroxyl-terminated polydimethyl silicone (HTPMS) and γ-Aminopropyl triethoxy silane (KH550). The content and distribution of the siloxane groups were effectively controlled by adjusting the content ratio of two kinds of organosilicon. Meanwhile, the organic–inorganic hybrid structure was further controlled to form three-dimensional networks with a uniform distribution and a small scale. The moisture and heat resistance of polyurethane were thus improved, resulting in reduced porosity and an excellent sustained release performance. Observably, the best sustained release property of modified polyurethane coated urea was obtained when the ratio of KH550 to HTPMS is 0.3:0.7

Pilot-scale Study on NCMBR Process for Upgrading of Sewage Treatment Plant in Industrial Park

A pilot-scale research was conducted on nanostructured ceramic membrane bio-reactor (NCMBR) for treatment of comprehensive wastewater from industrial park. The quality of the effluent water was sable and good. During stable operation, the COD, NH3-N and TP concentrations of the influent water were 147-475, 42-23.5 and 0.65-0.85 mg/L, respectively, and those of the effluent water were 147-475, 0.08-0.82 and 0.18-0.26 mg/L, respectively, so the average removal rates of COD, NH3-N and TP were 82%, 97% and 72%, respectively, meeting the standard for Class-A emissions of Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant (GB18918-2002). In addition, the process has certain anti-impact capacity and ability to mitigate membrane fouling, meeting the objectives of upgrading and transformation. This study will provide reference for upgrading of existing sewage treatment plants

Localized crystallization in shear bands of a metallic glass

Stress-induced viscous flow is the characteristic of atomic movements during plastic deformation of metallic glasses in the absence of substantial temperature increase, which suggests that stress state plays an important role in mechanically induced crystallization in a metallic glass. However, it is poorly understood. Here, we report on the stress-induced localized crystallization in individual shear bands of Zr60Al15Ni25 metallic glass subjected to cold rolling. We find that crystallization in individual shear bands preferentially occurs in the regions neighboring the amorphous matrix, where the materials are subjected to compressive stresses demonstrated by our finite element simulations. Our results provide direct evidence that the mechanically induced crystallization kinetics is closely related with the stress state. The crystallization kinetics under compressive and tensile stresses are interpreted within the frameworks of potential energy landscape and classical nucleation theory, which reduces the role of stress state in mechanically induced crystallization in a metallic glass

Study on the treatment of postmenopausal osteoporosis with quercetin in Liuwei Dihuang Pill based on network pharmacology

Abstract Background Liuwei Dihuang Pill (LP) was verified to alleviate postmenopausal osteoporosis (PMOP) development. Nevertheless, the major constituent of LP and the related network pharmacology study remain unexplored. Methods Protein–protein interaction was established to identify the downstream target of LP in PMOP, and the related signaling pathway was investigated by bioinformatics analysis. MC3T3-E1 cells were added to ferric ammonium citrate (FAC) to mimic osteoporosis in vitro. The osteoblasts were identified by Alizarin red staining. Western blot was applied to evaluate protein levels. In addition, Cell Counting Kit-8 (CCK8) assay was applied to assess cell viability, and cell apoptosis was assessed by flow cytometry. Results Quercetin was the major constituent of LP. In addition, quercetin significantly reversed FAC-induced inhibition of osteogenic differentiation in MC3T3-E1 cells. In addition, quercetin notably abolished the FAC-induced upregulation of Bax, Caspase-3, FOS, JUN, TGFB1 and PPARD. In contrast, Bcl-2, p-mTOR/mTOR, p-AKT/AKT and p-PI3K/PI3K levels in MC3T3-E1 cells were reduced by FAC, which was restored by quercetin. Meanwhile, FAC notably inhibited the viability of MC3T3-E1 cells via inducing apoptosis, but this impact was abolished by quercetin. Furthermore, quercetin could reverse pcDNA3.1-FOS-mediated growth of FAC-treated osteoblasts by mediating PI3K/AKT/mTOR signaling. Conclusion Quercetin alleviated the progression of PMOP via activation of PI3K/AKT/mTOR signaling. Hence, this study would shed novel insights into discovering new methods against PMOP

Ti₃C₂T_x as a Sensor for SF₆/N₂ Nitrogen-Containing Fault Decomposition Characteristic Products: A Theoretical Study

The SF6/N2 gas mixture is an alternative gas to SF6. SF6/N2 will decompose and generate nitrogenous characteristic gases, such as NO, NO2, N2O, and NF3, when exposed to long-term partial discharge. The adsorption models of Ti3C2Tx (T=O, F, OH) and NO, NO2, N2O, NF3 were constructed, and the most stable adsorption structure was selected in this paper. The electron density and density of states of the adsorption system were further analyzed to study the adsorption behavior, and the sensing performance was evaluated in the end. The results are as follows: four gases could be spontaneously adsorbed on Ti3C2Tx, and strong adsorption occurred when surface terminal groups were OH, forming hydrogen or chemical bonds with significant charge transfer. Results show that Ti3C2(OH)2 had a stronger sensing ability than Ti3C2F2 and Ti3C2O2. The conductivity of the Ti3C2Tx with different terminal groups was improved after the adsorption of NO and NO2, showing Ti3C2Tx had a good sensing ability for NO and NO2. It was difficult for the four gases to desorb from the Ti3C2(OH)2 surface, but the adsorption on the Ti3C2F2, Ti3C2O2 surface had a short recovery time at room temperature