ZnO Nanoparticles as Ethanol Gas Sensors and the Effective Parameters on Their Performance

<正>ZnO nanoparticles are synthesized and applied as ethanol gas sensors.In some cases,the sensitivity and response time of these particles are shown to be higher than that has been reported in the literature.It has been investigated that the most possible reason for this higher gas sensing performance can be attributed to the quantity of the activity coefficient of its initial components.However,other effects such as pH and thermal decomposition are of importance as well.Specific ion interaction(SIT) model is applied to derive the mean activity coefficient values of the additives used in synthesis of ZnO nanoparticles.     

Monitoring therapeutic processes using risk-adjusted multivariate Tukey's CUSUM control chart

Using control charts for monitoring therapeutic processes has become popular lately. As the application of traditional control charts in the therapeutic processes may be misleading due to the inherent differences between patients, a multifactor correlated risk measure is considered in monitoring of these processes. Therefore, using risk-adjusted control charts for monitoring the therapeutic processes is of interest to practitioners. Furthermore, in health care monitoring, statistical models should account for abnormal distributions and outlier data to minimize misinterpretations of monitoring schemes. This study proposes a risk-adjusted multivariate Tukey's cumulative sum (RA-MTCUSUM) control chart. The proposed method is a combination of the accelerated failure time (AFT) regression model, the Tukey's control chart (TCC) featuring robustness against abnormality, and the multivariate cumulative sum (MCUSUM) control chart for monitoring multivariable process. Simulation experiments are performed to evaluate the performance of the proposed control chart using the average run length (ARL) measure. Results show that the RA-MTCUSUM control chart has better performance in comparison with traditional ones for monitoring various distributions (normal and non-normal). Based on the simulation results, outlier data do not disturb the proposed control chart's performance. Moreover, applying the RA-MTCUSUM control chart to a real-world dataset related to sepsis patients of a hospital located in Tehran, Iran indicates that the control chart has more reasonable performance than the traditional control charts in the real applications due to its robustness.     

Amylopectin Multiple Aldehyde Crosslinked Hydrogel as an Injectable and Self‐Healing Cell Carrier for Bone Tissue Engineering

Despite excellent processing and biological properties of gelatin for use as a cell carrier, none of the gelatin‐based hydrogel cell carriers reported to date offer all characteristics including quick formation, injectability, self‐healing, and durability, which are simultaneously required for an ideal system. Here, a gelatin‐based hydrogel with dynamic Schiff base linkages, so‐called “dynamic hydrogel,” as an injectable cell carrier consisting of gelatin and amylopectin multiple aldehyde (AMPA), with all the required characteristics is reported. Biocompatibility and osteoinductivity of the hydrogel are verified through the culture of human bone marrow‐derived mesenchymal stem cells (hBMSCs). As live/dead results show, hBMSCs are alive and highly viable ≈85–90% within the hydrogel after 5 days. According to bromodeoxyuridine cell proliferation assay, a significant increase in the number of the cells seeded in the hydrogel confirms its clinical significance for cell therapy. Most importantly, histological visualization using Mason's Trichrome staining indicates secretion of extracellular matrix around the cells loaded in the hydrogel and also expression level evaluation of the crucial osteogenic markers, confirms that the hydrogel can provide osteoinductive support for osteocyte differentiation of hBMSCs after 14 days. Therefore, this hydrogel provides more progress on the path toward bone tissue engineering and further treatment of bone diseases.     

Numerical solution of doubly singular nonlinear systems using neural networks-based integrated intelligent computing

Neural Computing and Applications - In this paper, a bio-inspired computational intelligence technique is presented for solving nonlinear doubly singular system using artificial neural networks...     

Simultaneous improvement of photocatalytic and superhydrophilicity properties of nano TiO2 thin films

Anatase TiO₂ nano thin films were prepared on glass substrates by sol–gel dip coating method using Tween-80 as a surfactant, TiCl₄ as the Ti precursor, and ethanol as a solvent. Atomic force microscopy, X-ray diffraction, and UV–Vis. photospectrometery experiments were performed to analyze the surface, structural and optical characteristics of the films. The effects of chemical aging time on the morphology, photocatalytic and superhydrophilicity behaviors of the films were studied. We show there is an optimum aging time at 2 h which photocatalytic and superhydrophilicity properties are at their maximum values simultaneously. This is useful in the self-cleaning industry.     

PHENOLIC WASTEWATER TREATMENT BY SUPPORTED LIQUID MEMBRANE USING DIFFERENT COOKING OILS AS LIQUID MEMBRANE

Transport of phenol through a flat sheet supported liquid membrane (SLM) containing cooking oil as liquid membrane (LM) was investigated. Factors affecting permeation of phenol such as membrane phase, support material, feed phase pH, stripping phase concentration, stirring speed, and initial concentration of phenol were studied. It was found that these parameters strongly influence phenol removal efficiency; PTFE membrane as support material, grape seed oil as liquid membrane, feed pH of 2.0, initial phenol concentration of 100 mg/L, stirring speed of 350 rpm, and 0.2 M sodium hydroxide as effective stripping agent were found as the best conditions for greater phenol transport. Under these conditions, permeability was found to be 7.46 × 10^?6 m/s. After 10.5 h, phenol was completely removed from the feed phase to strip phase. According to stability experiments, it was observed that the SLM is stable after 22 h. Thus, the use of cheap, nontoxic, and naturally oil as a novel and green membrane for recovery of phenol from wastewater was demonstrated.     

Free vibration analysis of variable thickness thin plates by two-dimensional differential transform method

This paper aims at extending the application of two-dimensional differential transform method (2D-DTM) to study the free vibration of thin plates with arbitrarily varying thickness. First, the differential equation of motion governing thin plates with varying thickness is derived using Hamilton’s principle. Afterward, the 2D-DTM, a numerical method which is capable of reducing the size of computational work and can be applied to various types of differential equations, has been applied to derive the natural frequencies of variable thickness thin plates with different boundary conditions. Several numerical examples have been carried out to demonstrate the applicability and accuracy of the present method in free vibration analysis of both uniform plates and plates with variable thickness.     

Study of Total Detection Efficiency (η) of Charge Exchange Analyzer (CXA) in TVD Tokamak

Diagnostic devices detection efficiency consist of many parameters. Contribution of each part in main detection efficiency need to study all aspect of devices and experimentally researches. In this paper experimental results and theoretical study merged to figure out the total detection efficiency of CXA. Most important primary parameters has been recognized (stripping foil thickness, incident energy, etc.) and effect of these parameters in related part studied. For CXA of TVD tokamak total detection efficiency presented and shown for 3 keV this parameter equal to .09 and stripping efficiency is equal 1.1 approximately. Choosing appropriate system for stripping of neutral beam is the most important factor in CXA diagnostic devices specially for high energy beams.     

Cyclic voltammetry and scanning electrochemical microscopy studies of methylene blue immobilized on the self-assembled monolayer of n-dodecanethiol

Electron transfer (ET) kinetics through n-dodecanethiol (C₁₂SH) self-assembled monolayer on gold electrode was studied using cyclic voltammetry (CV), scanning electrochemical microscopy (SECM) and electrochemical impedance spectroscopy (EIS). An SECM model for compensating pinhole contribution, was used to measure the ET kinetics of solution-phase probes of ferrocyanide/ferricyanide (Fe(CN)₆^4−/3−) and ferrocenemethanol/ferrociniummethanol (FMC^0/+) through the C₁₂SH monolayer yielding standard tunneling rate constant () of (4 ± 1) × 10⁻¹¹ and (3 ± 1) × 10⁻¹⁰ cm s⁻¹ for Fe(CN)₆^4−/3− and FMC^0/+ respectively. Decay tunneling constants (β) of 0.97 and 0.96 Å⁻¹ for saturated alkane thiol chains were obtained using Fe(CN)₆⁴⁻ and FMC respectively. Also, it was found that methylene blue (MB) molecules are effectively immobilized on the C₁₂SH monolayer and can mediate the ET between the solution-phase probes and underlying gold substrate. SECM-mediated model was used to simultaneously measure the bimolecular ET between the solution-phase probes and the monolayer-immobilized MB molecules, as well as tunneling ET between the monolayer-immobilized MB molecules and the underlying gold electrode, allowing the measurement of k_BI = (5 ± 1) × 10⁶ and (4 ± 2) × 10⁷ cm³ mol⁻¹ s⁻¹ for the bimolecular ET and and (7 ± 3) × 10⁻² s⁻¹ for the standard tunneling rate constant of ET using Fe(CN)₆^4−/3− and FMC^0/+ probes respectively.