查看更多>>摘要：Background: Long-chain FAMEs, also called biodiesel, are viewed as the alternative to petroleum diesel for renewability and sustainability. Because the fatty acid profiles significantly varied for the sources, the compositions significantly affected the biodiesel properties, such as cloud points. The cloud point of biodiesel indicates the phenomenon of solid-liquid phase change. Previous models for cloud point predictions were limited to known components in the mixtures. Methods: The cloud points of the binary, ternary and multicomponent mixtures of fatty acid methyl esters were measured in this study. A cloud point prediction model was established based on phase equilibrium with the modified Universal functional activity coefficient (UNIFAC) model and excess fusion enthalpy for predicting the nonideal behaviors of the components resulting from the molecular shape and molecule interactions. Significant findings: The developed thermodynamic model accurately predicts the cloud point according to compositions. The model extends the application scope to the low-temperature range. There had eutectic points in the phase diagrams when the mixtures consisted of either saturated FAMEs or unsaturated FAMEs. This study proved that saturated FAMEs regulate the cloud points, but unsaturated FAMEs affect them through group interactions. Moreover, the proposed model can predict unknown FAMEs mixture as it is built on the group contributions. (c) 2022 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.
查看更多>>摘要：Background: To solve the safety problem aroused by Li dendrites and liquid electrolytes for lithium batteries, this work reported a new solid-state electrolyte technology. Method: Helical mesoporous 1,4-phenylene bridged and 1,2-ethylidene bridged polysilsesquioxane nanofibers were firstly prepared via a sol-gel transcription method, using self-assembled chiral gelator as the template and organic bridged-siloxane as the precursor. After immersing them in ion liquid electrolyte till absorption saturation, two self-standing ionogel electrolyte membranes (EB-IE and EE-IE) were obtained. Significant findings: Electrochemical test showed that they exhibited good thermal stability (up to 327C and 293 C, respectively), wide electrochemical window (4.8 V and 5.6 V, respectively) and ideal room temperature ionic conductivity (up to 0.55 and 2.10 mS cm(-1), respectively), which was related to their special organic-inorganic hybrid composition and hierarchical porous nanostructure. When they were applied as electrolyte as well as separator in a LiFePO4/Li cell, they performed excellent cycle stability and superior rate performance, which proved the practicability and feasibility of design and application of nanostructured hybrid polymer as quasi solid state electrolyte scaffold for safe lithium batteries.
查看更多>>摘要：Background: Electrochemical advanced oxidation processes (EAOPs) have received considerable attention due to their ability to transform or mineralize emerging organic contaminants. Methods: Herein, we report that MnO2 covered with polyelectrolyte films has been fabricated using layer-bylayer (LBL) assembly to modify the anode for efficient oxytetracycline (OTC) oxidation in water. Significant Findings: It is found that over 89.19% of OTC was degraded in 20 min in this EAOPs system with MnO2@(PSS/PDDA)2PSS modified anode. Quenching experiments and electron-spin resonance (ESR) spectra have shown that hydroxyl radicals ('OH) and direct electron transfer play the dominant roles in OTC oxidation. Several possible pathways of OTC degradation were proposed on the basis of the by-products detected by liquid chromatography-mass spectrometry (LC-MS). Toxicity Estimation Software Tool (T.E.S.T) based on quantitative structure-activity relationships (QSARs) revealed increased toxicity of several transformation products. Moreover, flow cytometry method was applied to quantify the cytotoxic effects of the reaction solution. It may provide an alternative approach to design metal oxide/polymer composites modified anodes for contaminants degradation. It is notable that toxicological assessment of the transformation products is essential especially for newly developed anode materials. (c) 2022 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.
查看更多>>摘要：Background: The PID algorithm has been widely used in control of chemical processes. A maximum-stability PID controller can provide superior stability robustness towards plant's variations and maximum exponential decay rate for disturbance rejection. However, design of maximum-stability PID controller is a min-max optimization problem and an effective method is still lack in the literature. Methods: Based on the characterization of stabilizing PID controller set, an efficient algorithm is developed to test if a plant is sigma-stabilizable, where sigma is abscissa or stability degree of the Hurwitz stable closed-loop characteristic polynomial. This algorithm is then used along with a bisection strategy to find a sigma-interval [sigma(epsilon)*, sigma epsilon* + epsilon] which contains the maximum stability degree sigma* for a specified epsilon, and the PID controller parameter set for achieving the stability degree sigma(epsilon)*. Significant findings: This paper has presented a systematic and efficient approach to design PID controllers with maximum degree of stability. The principal results include: (i) an improved theorem is presented for identifying stabilizing k(p)-intervals such that unnecessary computations are avoided; (ii) a simple yet effective method has been adopted to provide a non-conservative interval of sigma which facilitates the bisectional branch-and-bound operation; (iii) the design procedure does not involve the actual construction of stabilizing PID controller sets thus renders its efficiency. (C) 2022 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.
查看更多>>摘要：Background: Poly-(dimethylsiloxane) (PDMS) is widely used as a negative triboelectric material for triboelectric nanogenerator (TENG) to harvest mechanical-converted-to- electricity energy. The process of conventional nanomaterial doped PDMS is complicated for a long time of 5~72 h. Methods: Here, a facile economic method using the low-cost graphite micro-powders (GP MP) of 2-13 mu m rather than high-cost nano-graphene is proposed to modify the PDMS composite (PDMS@GP). The modification can enhance Al-PDMS TENG performance and only take about 2~3 h. The PDMS@GP composite is made of casting PDMS (11 g) with GP (0.05~1 g) addition from the reusable laser-ablated PMMA planar master mold. Significant findings: The output performance of Al-PDMS@GP TENG (APGP-TENG) initially increases with GP MP from 0 (pure PDMS) to 0.1 g, then decreases from 0.1 to 1g. The open-circuit voltage (V-OC) and short-circuit current (I-SC) of APGP-TENG at 0.1 g with the maximum output performance are nearly 2.67 and 3.25 times enhancement of the pure PDMS-TENG. Also, the performance of APGP-TENG keeps stable output during 13,000 cycles. It can light up to 102 LEDs connected in series and used for the self-powered digital devices and pressure sensor switch for potential environmental internet of things.
查看更多>>摘要：Background: Smac mimetics functioned against inhibitors of apoptosis proteins (IAP) often fail to achieve sufficient ability in glioblastoma multiforme (GBM) treatment due to the obstruction of the blood-brain barrier (BBB). Methods: BV6-and GDC0152-encapsulated solid lipid nanoparticles (SLNs) with surface transferrin (Tf) and folic acid (FA) (BV6-GDC0152-Tf-FA-SLNs) were developed to downregulate IAP in U87MG cells and human brain cancer stem cells (HBCSCs) for GBM treatment. Significant findings: An increase in stearic acid (SA) level enlarged SLNs with improved entrapment of BV6 and GDC0152. H-1 NMR study revealed hydrogen bonding between SA and the two IAP antagonists, supporting controlled release of BV6 and GDC0152 from SLNs. Increasing sodium dodecyl sulfate concentration reduced the size of SLNs, and raised the particle stability. Conjugated Tf and FA on SLNs favored permeating the BBB as corroborated from decreased transendothelial electrical resistance, and raised BBB permeability of propidium iodide, BV6 and GDC0152. The ability of BV6-GDC0152-Tf-FA-SLNs to target IAP in U87MG cells and HBCSCs was validated from the downregulated XIAP and cIAP-1 expressions and upregulated caspase-3 expression in immunofluorescence staining, flow cytometry and western blot analysis. Hence, Tf-and FA-grafted SLNs can be an effective colloidal delivery system to deliver BV6 and GDC0152 across the BBB, facilitate IAP targeting, and enhanced drug bioavailability of the two Smac mimetics in GBM cells for potential clinical trials.
查看更多>>摘要：Background: Magnetohydrodynamic (MHD) jet in saltwater possesses potential applications to improve marine vehicle propulsion and hydrogen collection. In the present paper, pattern and flow transition of MHD bubbly jets are studied. Bubbles of oxygen and hydrogen, produced by electrolysis in saltwater and displaced by the Lorentz force, form a typical multiphase MHD jet flow. Methods: Taking advantage of the brightness of gaseous bubbles, emergence of bubbly jet can be directly observed. Pattern of the bubbly jet is experimentally confirmed to resemble the saltwater jet, and used for further analysis. Findings: A Lorentz-force based Reynolds number Re-L is proposed to demonstrate the pattern similarity of the MHD jet, and thus applied to categorize the transition of flow regimes from laminar to turbulent. For a jet of lower Re-L, the pattern of the bubbly jet appears as a continuous, wavy and laminar stream. Turbulent breakups start to evolve at farther downstream of the bubbly jet once the Re-L exceeds a critical value. The critical value of Re-L asymptotic to 1500 is verified both by visual observation and relevant quantitative measures of the bubbly jet. (C) 2022 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.
Su, WentaoLi, YujieHong, XiapingLin, Kun-Yi Andrew...
8页
查看更多>>摘要：Background: Catalytic ozonation is a commonly used technique in deep treatment of water. Magnesium oxide is an effective catalyst in ozonation, but how to effectively separate and improve its stability remains big challenge. Method: The magnetic core-shell Fe3O4@SiO2@MgO was prepared by co-precipitation method, and the prepared catalyst could be easily recovered through magnetic separation. Significant findings: Ozonation of N, N-dimethylacetamide (DMAC) was used to test the performance of Fe3O4@SiO2@MgO. The removal fraction of DMAC by Fe3O4@SiO2@MgO catalytic ozonation was 99.96% in 12 min, which was almost 4.3 times that of ozonation alone under the same conditions. In addition, the mineralization rate of DMAC at 12 min was 43.70%, much higher than that of ozone alone (11.90%). The recycling test manifested the excellent stability and recoverability of Fe3O4@SiO2@MgO, indicating the formed composite is a potential practical catalyst. The possible DMAC degradation pathways and reaction mechanism of Fe3O4@SiO2@MgO/O-3 process were proposed. (c) 2022 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.
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Elsevier