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Nano-Tin oxide was synthesized using hydrothermal method at 150 °C for 6 h and then thin films were deposited by electrophoretic method at an optimized voltage of 100 V for 5 min on electropolished aluminum substrate. Spherical particles of about 30–50 nm diameters are observed with partial agglomeration when observed under electron microscope, which are tetragonal rutile structure. XPS results showed peaks related to Sn 4 d , Sn 3 d , O 1 s & C 1 s with spin–orbit splitting of 8.4 eV for Sn 3 d . Feasibility studies of enzyme less urea sensing characteristics of nano-tin oxide thin films are exhibited herein. The deposited films have been used for enzyme less urea sensing from 1 to 20 mM concentration in buffer solution. The sensors were characterized electrochemically to obtain cyclic voltammogram as a function of urea concentration and scan rate. The sensitivity is estimated as 18.9 μA/mM below 5 mM and 2.31 μA/mM above 5 mM with a limit of detection of 0.6 mM. [ABSTRACT FROM AUTHOR]

Abstract: In the present work, a dynamic thermo-mechanical analysis technique has been used to investigate the effect of pre-heat treatments on the visco-elastic properties of Ultra-High Molecular Weight Polyethylene (UHMWPE) as a function of frequency and temperature. These properties include storage modulus (E′) and loss modulus (E″). The UHMWPE specimens were pre-heated at 50, 80 and 100°C for periods of 2 and 4h, respectively. The effect of these pre-heat treatments on the quasi-static mechanical properties (Young''s modulus, yield strength, fracture strength, ductility and micro-hardness) has also been investigated. Finally, the degree of crystallinity of the UHMWPE has been measured as a function of pre-heat treatment time and temperature. The results show a strong dependence of most of these properties on the degree of crystallinity which is a function of pre-heat treatment temperature and duration. [Copyright &y& Elsevier]

Natural fibre–reinforced epoxy composites have been increasingly utilised in construction and building applications. These materials introduce cost-effective alternatives to conventional materials and their utilisation often has related to financial advantages that are immediate and can be expected over the structure service life. In this work, the results of thermal, dynamic-mechanical, and thermal-mechanical properties of date palm fibre (DPF)/bamboo fibre (BF) hybrid composite were compared to bamboo fibre-reinforced epoxy to demonstrate the importance of hybridization. The thermal stability was improved when DPF/BF fillers were added in epoxy resin comparatively to BF reinforced epoxy. The glass transition temperature (T g) was increased by incorporating the date palm fibre/bamboo hybrid composite in epoxy compared to the BF reinforced epoxy. The thermal expansion was enhanced by modifying the hybrid composites in epoxy in contrast to the single fibre composites, without hybridisation. Hence, the hybridisation technique of date palm fibre with bamboo has improved the thermal and thermal-mechanical properties suitable for several applications including non-structural applications. [ABSTRACT FROM AUTHOR]

In this research NaOH treated date palm fibres were used as reinforcement in phenolic based composites. The composites were prepared by hot press technique and evaluated tensile flexural, structural, thermo gravimetric dynamic mechanical properties. Overall properties of modification/treatment of fibers' surface enhanced, that have been studied as compared to untreated samples. The treated samples of 50% DPF composites showed highest Tensile properties among all composites but flexural properties declined compared to the untreated composites but this decline is very less. Fibre treatment showed declined properties of three point bending of DPF composites. Scanning Electron Microscopy studied the behavior of fibre and matrix bonding before and after treatment. Treated 50% DPF showed better fibre distribution, 60% DPF showed void content however 40%DPF showed poor fibre/matrix interfacial bonding. Thermogravimetric analysis studied the behavior of Treated DPF/Phenolic composites at high temperature, and found thermal stability enhanced because good interfacial bonding. Dynamic mechanical analysis showed that stability at stress of material with temperature and also studied the energy dissipation and internal friction. Treated 50%DPF showed better properties due to the ratio of mixing of fibre/matrix and better interfacial bonding. DPF composite have potential to use for exterior applications and false wall and roof. [ABSTRACT FROM AUTHOR]

In recent work, we demonstrated the successful fabrication of core-shell nanofiber composites with enhanced tensile, surface wetting and cytocompatibility properties via coaxial electrospinning using PLA and PVA. It has been shown that core/shell-structured PLA/PVA nanofiber mat has the hydrophilic benefits of PVA and the attractive biological properties of PLA. In this paper, we present detailed mechanical evaluation of the electrospun coaxial nanofiber mats under static, dynamic and creep loading. The core/shell-PLA/PVA nanofibers showed nearly 233% and 150% increase in tensile strength and ductility, respectively, compared to pristine PLA. Dynamic loading tests were employed to study the viscoelasticity of the coaxial core-shell composite nanofibers at various temperatures and frequencies. The results of the storage and loss moduli of the coaxial nanofibers suggested strong physical interaction between the PLA and PVA layers, that contribute to the observed good mechanical behaviour. The better creep resistance of the coaxial PLA/PVA nanofibers under axial loading compared to the pristine materials provides further evidence for the physical interaction between the two constituent materials. A simple linear viscoelastic model is used to quantify the evolution of creep strain in pristine and coaxial materials. This research may help to understand the physical relation between the observed viscoelastic behaviour and the internal structure of coaxial core/shell nanofibers of PLA and PVA. [ABSTRACT FROM AUTHOR]

Graphene oxide (GO)-incorporated TiO 2 nanofibers was successfully synthesized via a simple and effective technique, electrospinning and applied as a working electrode for dye sensitized solar cells (DSSCs). The effects of graphene oxide on the structural and photoelectric conversion performance of the DSSCs were inspected by various analytical techniques. The results suggest that presence of graphene oxide increases the amount of dye absorption which leads to high migration of photoinduced electrons to the conduction band of the collection electrode and inhibition of electron recombination. Furthermore, the presence of graphene oxide improves the electron transport from the films to the fluorine doped tin oxide (FTO) substrates. Accordingly, remarkably enhanced power conversion efficiency of 4.52% was observed in case of utilizing 0.5 wt% graphene oxide-incorporated TiO 2 nanofibers as working electrode based DSSC which is higher than that of the conversion efficiency in case of pristine TiO 2 nanofibers (i.e. 1.54%). The high amount of graphene oxide content results in decrease the power conversion efficiency. Therefore, it can be claimed that graphene oxide-incorporated TiO 2 nanofibers as working electrode is a promising candidate for improving the performance of the DSSCs. [ABSTRACT FROM AUTHOR]

• TIA and DCIA positively affect the probability of runoff yield. • DCIA contributes far more than TIA to generating far-above-average runoff depth. • The contributions of TIA and DCIA to far-above-average peak flow are comparable. • The impacts of TIA and DCIA are subject to climate variability. • TIA and DCIA control is effective within a specific range of rainfall depth. Total impervious area (TIA) is one of the most common measures for predicting runoff yield in hydrologic studies and regulating urbanization in land use policy. Directly connected impervious area (DCIA), a subset of TIA, represents the hydraulic connection between development and underground sewer systems. Which indicator to use in runoff prediction has been subject to debate. The effectiveness of TIA and DCIA in the face of climate variability also remains unclear. The present study empirically assessed the impacts of TIA and DCIA on urban runoff in three metropolitan statistical areas (MSAs) in the U.S. state of Texas. The total monthly runoff depths of 92 watersheds and peak flows of 43 watersheds were computed using streamflow monitored by the U.S. Geological Survey from 2010 to 2017. A series of ordinal logit regression models were developed to determine which imperviousness indicator better predicted probable runoff yield. Additionally, an average marginal effect analysis was performed to investigate how TIA and DCIA responded to changing precipitation depths. The results demonstrate that DCIA outperformed TIA in runoff depth prediction, whereas TIA predicted peak flow better than DCIA. However, for far-above-average runoff, the contribution of DCIA to runoff depth was far greater than that of TIA, but no difference was found for peak flow. The effectiveness of TIA and DCIA also varied by total and 24-hour peak depths of monthly precipitation. After reaching their maximum capacity, both TIA and DCIA became less effective in predicting runoff and did not correlate with rainfall depth in extremely wet months. Meanwhile, the control of TIA and DCIA for runoff volume reduction was most effective for monthly rainfall of a 5% to 10% probability of exceedance in all MSAs, whereas that of peak flow reduction was most effective if the 24-hour peak storm in a month had a 2% to 5% probability of exceedance. The findings of this study demonstrate the hydrologic significance of regulating DCIA over TIA for high-risk runoff under certain rainfall depths and return periods. The study expands the current knowledge of urban hydrology for effective stormwater management and mitigation of future flooding risk. [ABSTRACT FROM AUTHOR]