Miracle-dz/UniFAR-FTUs huggingface dataset:
Electrospinning: a facile technique for fabricating polymeric nanofibers doped with carbon nanotubes and metallic nanoparticles for sensor applications

The increased interest in electrospinning (ES) and its recent applications for fabrication of sensors and biosensors is driven by the development of materials science and nanotechnology. Compared with other fabrication processes, ES is versatile and superior for producing and constructing ordered and complex nanofibrous materials. The introduction of carbon nanotubes (CNTs) and metallic nanoparticles (MNPs) into the electrospun polymeric nanofibers (NFs) extends their potential applications as electrical and electrochemical sensors and biosensors. In this review, we summarize the recent progress using the ES technique to fabricate different polymeric NFs doped with CNTs and various MNPs, as well as their applications for detecting alcohols, H2S, H2, glucose, H2O2, and urea. The fabrication, intrinsic fundamentals, and optimization design of the sensors were introduced and discussed in detail. In addition, the improvements and challenges of ES techniques were mentioned. It is expected that this review will promote development in the ES field and guide studies to create nanofibrous hybrid materials as novel sensors and biosensors.
Efficiency enhancement of solid‐state dye sensitized solar cell by in situ deposition of CuI

Solid‐state dye‐sensitized solar cells based on nanocrystalline TiO2 thin film with the structures TiO2/dye/CuI/Pt and TiO2/dye/In situ CuI/CuI/Pt were developed in order to compare the use of In situ deposited CuI (In situ CuI). Porosity of the screen‐printed nanoporous TiO2 thin film was enhanced by the addition of polystyrene balls. Evidence of decrease in interfacial resistance was observed by electrochemical impedance measurement for the device with In situ deposited CuI as compared to that without In situ deposited CuI as hole conductor. This was attributed to good interfacial contacts and better charge transfer between CuI and dye‐sensitized TiO2 nanoparticles, which resulted in the enhancement of power conversion efficiency from 0.058 to 1.01%. Copyright © 2008 John Wiley & Sons, Ltd.
Modelling of time-dependent dielectric barrier breakdown mechanisms in MgO-based magnetic tunnel junctions

An investigation of barrier endurance till electrical breakdown in MgO-based magnetic tunnel junctions (MTJs) is presented. Samples were tested under pulsed electrical stress. By studying the effect of delay between successive pulses, an optimum endurance of MTJs is observed for an intermediate value of delay between pulses corresponding to an optimum trade-off between the average density of charge trapped in the barrier and the amplitude of its time-modulation at each voltage pulse. A charge trapping–detrapping model was developed which shows good coherence with experimental results. The influence of the delay between pulses on the trapped charge density in the tunnel barrier and on its time-modulation is discussed. The average density of trapped charges and its time-modulation are, respectively, responsible for a static and dynamic stress within the tunnel barrier, both leading to breakdown. The probability of breakdown of the MTJ for different applied pulse conditions has been evaluated. The expected endurance of the MTJs was deduced depending on the characteristics of the electrical stress in terms of delay, and unipolarity versus bipolarity. The study emphasizes the role of electron trapping/detrapping mechanisms on the tunnel barrier reliability. It also shows that extremely long endurance could be obtained in MTJs by reducing the density of electron trapping sites in the tunnel barrier.
Investigation on preparation and protein release of biodegradable polymer microspheres as drug‐delivery system

Among the different approaches to achieve protein delivery, the use of polymers, especially biodegraded, holds great promise. This work aimed to study the preparation and protein release of a novel drug-delivery system based on human serum albumin (HSA) encapsulated into biodegradable polymer microspheres. The microspheres containing HSA were elaborated by the solvent-extraction method based on the formation of multiple w/o/w emulsion. The encapsulation efficiency (E.E.) of HSA was determined by the CBB method. Alginate/alginate and calcium chloride was added into an internal aqueous phase to investigate the protein loading efficiency, protein stability, and in vitro release profiles. Microspheres were characterized in terms of their morphology, size distribution, loading efficiency, and in vitro protein release. SDS–PAGE results showed that HSA kept its structural integrity during the encapsulation and release procedure. In vitro studies indicated that the microspheres with alginate added in the internal aqueous phase had a smaller extent of burst release. In conclusion, the work presents a new approach for macromolecular drugs (such as protein drugs, vaccines, and peptide drugs) delivery. © 2002 John Wiley & Sons, Inc. J Appl Polym Sci 84: 778–784, 2002; DOI 10.1002/app.10327
Topological polymer chemistry: a cyclic approach toward novel polymer properties and functions

Recent progress observed in Topological Polymer Chemistry is outlined with particular emphasis on single-cyclic (ring) and multi-cyclic polymers having programmed chemical structures, now becoming obtainable with guaranteed purity by newly developed synthetic protocols. By making use of these topological polymers, unprecedented opportunities have now been realized to provide new insights on fundamental polymer properties either in solution or bulk, in static or dynamic states, or in self-assemblies. Moreover, unusual properties and functions for polymer materials have now been revealed based on their cyclic topologies, i.e., topology effects, unattainable either by linear or branched counterparts.
The study on properties of CdS photocatalyst with different ratios of zinc-blende and wurtzite structure

The mixtures of zinc blende and wurtzite CdS nanoparticles were prepared via a solvothermal method by controlling the precursor ratio (Cd/S molar ratio). The as-prepared samples were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM) and ultraviolet-visible (UV-vis) spectroscopy. These results demonstrate that not only the morphology but also the phase composition of CdS nanostructures was sensitively altered by the precursor ratio (Cd/S molar ratio). Photocatalysis test results show that the photocatalytic activity was mainly dependent on the ratio between zinc blende and wurtzite phases in CdS samples. The product prepared with 1:2 Cd/S molar ratio exhibited higher photocatalytic activities in comparison with products prepared with other Cd/S molar ratios, which can be attributed to the improved charge separation at the zinc blende/wurtzite junction interface.
Brownian motion of a hydrosol particle in a colloidal force field

Total-internal-reflection microscopy (TIRM) was used to monitor Brownian fluctuations in separation between a 10 µm polystyrene sphere and a glass plate when the two bodies are separated by a fraction of a micrometre of aqueous solution. Preliminary results clearly show evidence of double-layer repulsion which is weakened by increasing the ionic strength. Potential-energy profiles were obtained with a resolution of 2.5 nm. Although this falls short of the atomic resolution obtained with the crossed-mica cylinder technique for measuring colloidal forces, TIRM allows one of the interacting bodies to have colloidal dimensions. Besides measurement of colloidal and hydrodynamic forces, other applications include the study of hindered diffusion of the particle near a flat boundary and reversible adsorption of a single particle onto a plane surface.
Production and consumption of ethylene in temperate volcanic forest surface soils

To date our knowledge is limited with regard to the cycling of ethylene (C2H4) in temperate forest soils containing volcanic ash, and the effect of forest‐to‐orchard conversion on its cycling. We studied ethylene accumulation in such forest soils by oxic and anoxic incubations, along with the stimulatory effect of glucose addition on soil C2H4 accumulation. We also studied the effect of antibiotics and autoclaving on C2H4 production and consumption by volcanic forest soils, and the cycling of C2H4 and CH4 in surface soils after conversion of a Japanese cedar forest to an orchard. Ethylene production and consumption by forest surface soils results from a microbial process, and soil streptomycin‐sensitive bacteria make a minor contribution. Soil C2H4 accumulation was much larger during anoxic than during oxic incubation, which indicates that anoxic conditions can induce C2H4 accumulation in forest soils. Glucose addition as a carbon source can sharply increase C2H4 accumulation rates in the anoxic and oxic forest soils during the first week of incubation. However, there was no difference in total C2H4 accumulation in the amended and non‐treated soils after 35 days of anoxic incubation. Ethylene production of the 0–5 cm and 5–10 cm soils beneath forest and orchard showed the greatest rate after 2 weeks of anoxic incubation when soil CH4 production started to increase sharply, and later it was strongly suppressed. The forest‐to‐orchard conversion showed little influence on the CH4 production of surface soils during short‐term anoxic incubation, but significantly reduced soil C2H4 production. The conversion also significantly decreased the consumption of soil CH4 and C2H4, the former more than the latter. Soil properties such as total C, water‐soluble organic C and pH contribute to the consumption and production of C2H4 in the 0–5 cm and 5–10 cm soils, and there are the parallels between CH4 and C2H4 consumption in soils, which suggests the presence of similar microorganisms. Long‐term anoxic conditions of in situ surface upland soils are normally not prevalent, so it can be reasonably concluded that there is a larger C2H4 accumulation rather than CH4 accumulation in surface soils beneath forest and orchard after heavy rainfall, especially beneath forest.
Dispersions and fibers of carbon nanotubes

We study the phase behavior of single walled carbon nanotubes in aqueous solutions of surfactant molecules or amphiphilic polymers. Homogeneous dispersions can be obtained by using sodium dodecyl sulfate (SDS) in a well-defined concentration range. In contrast, polyvinyl alcohol (PVA) is not efficient at stabilizing the tubes. Carbon nanotubes stick with each other when PVA is added to homogeneous dispersions initially stabilized by SDS. This behavior is the basis of a simple method that we developed to assemble single walled carbon nanotubes into indefinitely long ribbons and fibers. The processing consists of dispersing the nanotubes in SDS solutions, re-condensing the nanotubes in the flow of a PVA solution to form a nanotube mesh, and then collating this mesh to a nanotube fiber. Flow induced alignment may lead to a preferential orientation of the nanotubes in the mesh that has the form of a ribbon. Unlike classical carbon fibers, the nanotube fibers can be strongly bent without breaking. Their obtained elastic modulus is 10 times higher than the modulus of high-quality bucky paper.
Combustion Behaviors and Flame Structure of Methane/Coal Dust Hybrid in a Vertical Rectangle Chamber

Methane/coal dust hybrid flame propagating in a vertical rectangle chamber was examined experimentally. In these experiments, the coal dusts were dispersed into the chamber by premixed methane/air mixture flow to form a methane/coal dust/air hybrid and the hybrid was ignited by an electrode spark. A high-speed video camera was used to record the images of the propagating flame, and a photodiode was used to study the emitting light characteristics of the flame. Micro-thermocouples and ion current probes were used to obtain temperature profiles and reaction behaviors of the combustion zone, respectively. Based on experimental results, combustion behaviors and flame structure of methane/coal dust hybrid propagating flame were analyzed. After the methane/coal dust hybrid is ignited by the electrode spark, the flame begins to propagate in the chamber. The flame front propagates downwards in the initial 20 ms, and then propagates upwards. The flame emits strong yellow light and the luminous zone length increases during propagation. The measured temperature starts to increase at a position about 2.15 cm ahead of the reaction zone, then to a maximum value near the end of the reaction zone and then subsequently decreases. The chemical reaction begins while the temperature is about 200°C, and the reaction intensity increases quickly with the temperature increasing. The reaction intensity increases to the maximum value while the temperature is about 500°C and then decreases gradually. According to the measured temperature and ion current curves, the preheated zone of the methane/coal dust hybrid is about 2.15 cm in width.
Analysis of the influence of vertical disparities arising in Toed-in stereoscopic cameras

A basic task in the construction and use of a stereoscopic camera and display system is the alignment of the left and right images appropriately-a task generally referred to as camera convergence. Convergence of the real or virtual stereoscopic cameras can shift the range of portrayed depth to improve visual comfort, can adjust the disparity of targets to bring them nearer to the screen and reduce accommodation-vergence conflict, or can bring objects of interest into the binocular field of view. Although camera convergence is acknowledged as a useful function, there has been considerable debate over the transformation required. It is well known that rotational camera convergence or "toe-in" distorts the images in the two cameras producing patterns of horizontal and vertical disparities that can cause problems with fusion of the stereoscopic imagery. Behaviorally, similar retinal vertical disparity patterns are known to correlate with viewing distance and strongly affect perception of stereoscopic shape and depth. There has been little analysis of the implications of recent findings on vertical disparity processing for the design of stereoscopic camera and display systems. I ask how such distortions caused by camera convergence affect the ability to fuse and perceive stereoscopic images.
Oriented Growth of Metal and Semiconductor Nanostructures within Aligned Mesoporous Channels

In the present work, we show how different types of inclusion chemistry can be used to generate oriented, high-aspect-ratio metal and semiconductor nanowires in insulating silica host structures prepared within anodic alumina membranes (AAMs). The structural features of the Pluronic123-templated silica filaments in the AAMs with their intriguing columnar and circular arrangement of mesopores allow for the inclusion of a variety of aligned 1D nanostructures ranging from metallic (Pt, Au, and Pd) and semiconductor (Ge) to carbon nanotubes and filaments. The synthetic techniques include wet chemical impregnation and reduction in precalcined mesopores, impregnation of surfactant-containing mesopore systems, and mass transport via supercritical fluid deposition in surfactant-containing mesopores. Important issues such as the crystallinity and continuity of the encapsulated wires as a function of material and deposition technique have been discussed.
Activated carbons prepared from Thymelaea hirsuta wood: Sustainable adsorbents for polyvinyl alcohol

In this study, activated carbon as novel adsorbent was prepared from low cost and locally available source such as Thymelaea hirsuta wood. Characterization of the adsorbent was carried out and BET surface area of the adsorbent was found to be 1496 m2/g. Subsequently, the Thymelaea hirsuta wood activated carbon (TWAC) was applied for the removal of polyvinyl alcohol from aqueous solutions. It was found that adsorption efficiency significantly depend to the level of initial solution pH and polymer concentration, metal addition, temperature, and adsorption time. Among the various conventional isotherm models, Langmuir is more suitable for analyzing the explanation data. The process of removal of polyvinyl alcohol was better governed by second order kinetics with a rate constant of 0.0079 g mg−1 min at initial concentration 20 mg/L. The calculated thermodynamic parameters indicate the entropy‐driven and endothermic nature of polymer adsorption process. For desorption study, more than 86.2% of polyvinyl alcohol could be desorbed from the adsorbent. © 2015 American Institute of Chemical Engineers Environ Prog, 35: 70–79, 2016
Removal Characteristics of Cd(II), Cu(II), Pb(II), and Zn(II) by Natural Mongolian Zeolite through Batch and Column Experiments

The removal characteristics of Cd(II), Cu(II), Pb(II), and Zn(II) from model aqueous solutions by 5 natural Mongolian zeolites were investigated. The adsorption of metals on zeolites reached a plateau value within 6 h. The adsorption kinetic data were fitted with adsorption kinetic models. The equilibrium adsorption capacity of the zeolites was measured and fitted using Langmuir and Freundlich isotherm models. The order of adsorption capacity of zeolite was Pb(II) > Zn(II) > Cu(II) > Cd(II). The maximum adsorption capacity of natural zeolite depends on its cation exchange capacity and pH. The leaching properties of metals were simulated using four leaching solutions. The results show that natural zeolite can be used as an adsorbent for metal ions from aqueous solutions or as a stabilizer for metal-contaminated soils.
Fabrication and stabilization of nanoscale emulsions by formation of a thin polymer membrane at the oil–water interface

This study introduces a robust approach for the fabrication of extremely stable oil-in-water nanoemulsions in which the interface is stabilized by assembly of amphiphilic poly(ethylene oxide)-block-poly(e-caprolactone) (PEO-b-PCL) copolymers. Phase inversion emulsification, induced by variation of the water volume fraction, facilitated effective assembly of the block copolymers at the oil–water interface. Subsequent application of simple probe-type sonication reduced the droplet size of the precursor emulsions to approximately 200 nm. The prepared nanoemulsions were surprisingly stable against drop coalescence and aggregation, as confirmed by analysis of changes in the droplet size after repeated freeze–thaw cycling and by monitoring the creaming kinetics under conditions of high ionic strength and density mismatch. The results highlight that good structural assembly of the PEO-b-PCL block copolymers at the oil–water interface generated a mechanically flexible but tough polymer film, thereby remarkably improving the emulsion stability.
A CFD assessment of film coating process viscosity models

Computer fluid dynamic simulations of the metering nip flow were used to assess the process viscosity of the coating colours. The numerical solution was based on a Calerkin/finite element technique that included the deformation of the roll cover to better represent the flow elastohydrodynamics. The Navier-Stokes prediction was compared with experimental measurements of torque and pressure in the metering nip. From the comparisons, the process viscosity determined in a region of shear-dominated flow is the one, among the three models analyzed, that can better describe the hydrodynamics of the metering nip flow. To improve further the fluid flow numerical description, this process viscosity was combined with an adapted transient Cross model. This new semianalytical rheological model decreased the differences between the numerical and experimental results. The findings also suggested that the model requires further enhancements, topic that will be addressed in future work. On a utilise la simulation par ordinateur des ecoulements dans une pince de dosage pour determiner la viscosite de procede des sauces de couchage. La solution numerique basee sur la methode des elements finis de Calerkine tient compte de la deformation de l'enveloppe du rouleau afin de mieux representer le comportement elastohydrody-namique de l'ecoulement. La prediction a ete comparee a des mesures experimentales du couple et de la pression dans la pince de dosage. On a pu montrer que la viscosite de procede determinee dans la region de l'ecoulement dominee par le cisaillement est celle qui, des trois modeles analyses, peut le mieux decrire l'hydrodynamique de l'ecoulement dans la pince de dosage. Afin d'ameliorer encore la description numerique de l'ecoulement du fluide, cette viscosite de procede est combinee a un modele de Cross adapte au cas instationnaire. Ce nouveau modele rheologique semi-analytique permet de reduire l'ecart entre les resultats numeriques et experimentaux. Les resultats suggerent egalement que le modele necessite d'autres ameliorations, un theme qui sera etudie dans des travaux ulterieurs.
SERIES "CONTRIBUTIONS FROM THE EUROPEAN RESPIRATORY MONOGRAPH" Edited by M. Decramer and A. Rossi Number 12 in this Series

Physiology and pathophysiology of pleural fluid turnover. L. Zocchi. #ERS Journals Ltd 2002. ABSTRACT: Tight control of the volume and composition of the pleural liquid is necessary to ensure an efficient mechanical coupling between lung and chest wall. Liquid enters the pleural space through the parietal pleura down a net filtering pressure gradient. Liquid removal is provided by an absorptive pressure gradient through the visceral pleura, by lymphatic drainage through the stomas of the parietal pleura, and by cellular mechanisms. Indeed, contrary to what was believed in the past, pleural mesothelial cells are metabolically active, and possess the cellular features for active transport of solutes, including vesicular transport of protein. Furthermore, the mesothelium was shown, on the basis of recent experimental evidence, both in vivo and in vitro, to be a less permeable barrier than previously believed, being provided with permeability characteristics similar to those of the microvascular endothelium. Direct assessment of the relative contribution of the different mechanisms of pleural fluid removal is difficult, due to the difficulty in measuring the relevant parameters in the appropriate areas, and to the fragility of the mesothelium. The role of the visceral pleura in pleural fluid removal under physiological conditions is supported by a number of findings and considerations. Further evidence indicates that direct lymphatic drainage through the stomas of the parietal pleura is crucial in removing particles and cells, and important in removing protein from the pleural space, but should not be the main effector of fluid removal. Its importance, however, increases markedly in the presence of increased intrapleural liquid loads. Removal of protein and liquid by transcytosis, although likely on the basis of morphological findings and suggested by recent indirect experimental evidence, still needs to be directly proven to occur in the pleura. When pleural liquid volume increases, an imbalance occurs in the forces involved in turnover, which favours fluid removal. In case of a primary abnormality of one ore more of the mechanisms of pleural liquid turnover, a pleural effusion ensues. The factors responsible for pleural effusion may be subdivided into three main categories: those changing transpleural pressure balance, those impairing lymphatic drainage, and those producing increases in mesothelial and capillary endothelial permeability. Except in the first case, pleural fluid protein concentration increases above normal: this feature underlies the classification of pleural effusions into transudative and exudative. Eur Respir J 2002; 20: 1545-1558.