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AbstractThe current research presents a dynamically coupled mathematical model considering the energy method and employing the classical Ritz-approximation method for a thin-walled anisotropic tapered rotating box beam. The novelty of this work lies in presenting the effect of circumferentially uniform stiffness (CUS) ply layup to investigate the reverberations of not considering bending-shear couplings toward vibration behavior. The current model is formulated by considering transverse shear and cross-sectional warping of order primary and secondary. The repercussions of not including non-classical effects like Coriolis-force, centrifugal-acceleration and warping, inertial-warping is explored. Mode switching arising for change in geometry and centrifugal stiffening is presented for various ply angles and rotational speeds. [ABSTRACT FROM AUTHOR]

To plan great photocatalytic performance, fast photo-generated charge recombination in nanocatalysts should be repressed. Thus, copper sulphide-Zirconium dioxide (CuS-ZrO2) nanocomposites were synthesised via a facile chemical method. The field-emission scanning electron microscopy (FESEM) results indicated that a heterojunctions interface among CuS and ZrO2. XRD analysis showed optimum CuS-ZrO2 photocatalyst with an average diameter of 42.58 nm were found. The UV–vis diffuse reflection spectroscopy (DRS) illustrated that the synthesised CuS-ZrO2 nanocomposites owned the highest absorption intensity in the UV-light range compared with pure ZrO2 nanoparticles. The bandgap (Eg) values of ZrO2 nanoparticles and CuS-ZrO2 nanocomposites were found 3.55 eV, and 2.65 eV, respectively. These characteristic structural and optical property consequence showed that the CuS-ZrO2 nanocomposites with great photocatalysis progress for degradation of tetracycline. Among the different ratio nanocomposites, CuS-ZrO2-2 indicates the highest photocatalytic efficiency (97.15%) in acidic pH and 60 min. Photocatalytic was optimised by response surface methodology with the Box-Behnken model. The study provides a promising photocatalyst to be used for organic pollutant removal in a large scale. [ABSTRACT FROM AUTHOR]

Bis(thiomorpholinyldithicarbamate)Cu(II) complex was prepared and characterized by single crystal X-ray crystallography. The molecular structure revealed a mononuclear copper(II) ion bonded to two thiomorpholinyl dithiocarbamate anion to form a distorted square planar geometry. The compound was thermolyzed at 130°C to prepare CuS nanoparticle confirmed as pure hexagonal covellite crystalline phase by powder X-ray diffraction (pXRD). HRTEM image showed CuS nanoparticle with particle sizes in the range 23.3–48.8 nm. The lattice fringes confirm polycrystalline nanoparticles with an interplanar distance of 0.24 nm that corresponds with the lattice plane (101) of hexagonal CuS. SAED patterns confirmed the crystallinity by showing two separate diffraction rings ascribed to (101) and (102) lattice planes of hexagonal CuS phase. The CuS nanoparticles exhibited excellent photocatalytic activity for methylene blue (MB) and methyl orange (MO) dyes degradation. [ABSTRACT FROM AUTHOR]

The synergism of CuS and tartaric acid (TA) in the reduction of Cr(VI) with an irradiation of simulated solar light was investigated through observing the effects of solution pH, temperature, CuS loading and TA concentration on the removal efficiency of Cr(VI). Approximately 32% and 54% of the initial Cr(VI) (100 µmol/L) were reduced within 180 min by TA and CuS with light, respectively. Under the same condition, however, almost a complete removal of the initial Cr(VI) was achieved within 130 min in the coexistence of CuS and TA. In the case, it is considered that Cr(VI) was rapidly reduced in two main pathways. One is that H2S produced from the dissolution of CuS in weak acidic solution directly reduced Cr(VI) to Cr(III). The other is that Cu(II) released from CuS reacted with TA to form complexes with photochemical activity, producing Cu(I) through ligand-to-metal electron transfer, and then the reduction of Cr(VI) was coupled with a conversion of Cu(I) to Cu(II). Thus, a cycle catalytic system was established for the reduction of Cr(VI). Moreover, it is observed that the reaction could be divided into two stages: the initial chemical reduction of Cr(VI) by H2S and the later photochemical reduction of Cr(VI) by Cu(II)-TA complexes. [ABSTRACT FROM AUTHOR]

The CuS/Ag2S microspheres with reduced graphene oxide (CuS/Ag2S-rGO) composites have been successfully prepared via a hydrothermal method. The characteristic of CuS/Ag2S-rGO microspheres were characterized by the Scanning electron microscopy (SEM), the transmission electron (TEM), the X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and UV-Vis diffuse reflection spectroscopy (DRS). The photocatalytic experiments results shown that the CuS/Ag2S-rGO have high photodegradation rate about 98% for methylene blue (MB) under visible-light irradiation, and still retained 90% original catalytic activity after four cycles. The high visible photocatalytic degradation was attributed to the interfacial charge transfer in the Z-scheme photocatalytic systems of CuS/Ag2S and fast separation of photoelectric. This composition was expected to show considerable potential applications in water purification. [ABSTRACT FROM AUTHOR]

Aim: To investigate the behavioral deficits, cognitive impairment and possible mechanisms induced by chronic unpredictable stress (CUS) in mice of different ages. Methods: The behaviors and cognition were tested using the open field test, tail suspension test and the Morris water maze. The changes in the insulin-like growth factor II (IGF-II) and the extracellular signal-regulated kinase (ERK) and phosphorylation (p-ERK) in the hippocampus (HP) and prefrontal cortex (PFC) were evaluated by immunohistochemistry. Results: The 15-month-old mice revealed a significant decline in spontaneous behavior and the learning–memory function and showed a decrease in IGF-II and p-ERK expression levels in HP and PFC. Four weeks of CUS exposure induced significant anxiety- and depression-like behavior and learning–memory function impairment in 3- to 15-month-old mice, and reduced IGF-II and p-ERK expression levels in HP and PFC, compared with control group mice, respectively. Conclusions: The behavioral deficits and cognitive impairment induced by CUS and aging in mice could be associated with the down-regulated expression of IGF-II and p-ERK in HP and PFC. This role seems to be dependent on the intracellular ERK pathway. [ABSTRACT FROM AUTHOR]

Flower-like CuS microspheres were synthesised at 25 °C for 24 h in a choline chloride/ethylene glycol (1:3)-based deep eutectic solvent (DES) via an elemental-direct-reaction method. The as-synthesised CuS samples were characterised by XRD, SEM, EDS, TEM and UV–Vis diffuse reflectance spectra. Moreover, a detailed mechanism on the formation of a CuS flower-like structure has been elucidated. In addition, CuS microspheres exhibit high photocatalytic activity for the degradation of MB dye under visible light irradiation in the presence of H2O2. On the basis of the experimental results, a mechanism of photocatalysis also has been discussed. [ABSTRACT FROM PUBLISHER]

Micron-sized flower-like copper sulfide (CuS) has been successfully synthesized via an elemental-direct-reaction route in an amide-based ternary eutectic melt at room temperature (25°C). The characterization results from X-ray diffraction pattern, scanning electron microscopy images and energy-dispersive X-ray spectroscopy reveal that the as-synthesized product was pure hexagonal phase flower-like CuS microspheres (about 500 nm in diameter). A possible formation mechanism of CuS flower-like structure has been proposed. Moreover, the as-prepared CuS samples were applied to decompose ammonium perchlorate (AP) and the role of CuS in the process also has been explained. [ABSTRACT FROM PUBLISHER]

For the first time, a flower-like nanostructured CuS material was synthesised through a facile hydrothermal route using copper foil and brenstone as Cu and S sources, respectively. The obtained CuS was characterised by X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy and transmission electron microscopy. The effects of the concentrations of the brenstone, reaction time, reaction temperature and NH4F additive on the morphologies of CuS nanostructures were studied in detail. It was found that morphological adjustment of the samples could be easily realised by optimising the amount of NH4F. However, the thickness of the CuS nanoplates highly depends on the combination of reaction time, reaction temperature and the concentrations of the brenstone and NH4F. [ABSTRACT FROM AUTHOR]

Copper sulphide (CuS) nanomaterials with interesting morphology were synthesised using copper nitrate trihydrate, thiourea and water as a solvent by a simple hydrothermal route. A systematic investigation was carried out to investigate the effect of reaction time (5, 16 and 24 h) at 150°C on the morphology of the materials. Without the use of any template or additives, shape controlled synthesis of CuS nanocrystallites were achieved. The possible mechanism for the formation of the various nanostructures of CuS in this system is discussed. The prepared materials were characterised by X-ray diffraction, field emission scanning electron microscopy (FE-SEM) and DRS-UV–Vis absorption analysis. The UV–Vis spectrum shows that it is the promising material which can absorb in the visible region and hence could be used for photocatalytic applications. In addition, the electrochemical characteristic of the synthesised material was investigated by cyclic voltammetric analysis, which shows that CuS could be used for electrocatalytic applications. [ABSTRACT FROM AUTHOR]