IV–VI group compounds are excellent candidates for optoelectronics. Here, a solvothermal controlled synthesis of SnS₂ nanosheets with different thickness is reported. The bandgap of nanosheets with thickness of 15 nm was estimated as 2.0 eV which is quite suitable for visible light harvesting. The nanosheets show about 180 times photoinduced current compare with the 35 nm nanosheets and fast response time of 4.9 ms, indicating that the SnS₂ nanosheets are potential materials for high-performance photodetectors.

Formation of anodic samarium oxide thin film by anodisation of 15 nm thin sputtered samarium metal on silicon substrate was systematically investigated. Sputtered Sm on Si substrate was followed by anodisation in 0.01 M NaOH (pH 11) at various applied voltages (10, 15, 20, and 25 V). All anodisation processes were performed for 10 min at room temperature in the bath with constant stirring. The crystallinity of Sm₂O₃ film was evaluated by X-ray diffraction analysis. The crystallite size of Sm₂O₃ was calculated by Scherrer equation. The cross-section of 20 V sample was examined by high-resolution transmission electron microscope. The sample anodised at 20 V demonstrated the highest electrical breakdown field of 9.50 MV/cm at 10⁻⁴ A/cm². This is attributed to the lowest effective oxide charge, slow trap charge density, average interface trap density, and total interface trap density.

In this work, the antibacterial potential of different plant's leaves, i.e. Psidium guajava (guava), Raphanus sativus (radish), Solanum pseudocapsicum (winter cherry), Mentha royaleana (mint) and Calotropis procera (rubber tree) was evaluated against the multidrug-resistant (MDR) bacteria. Methicillin-resistant Staphylococcus aureus (MRSA), Vibrio cholerae O1 El Tor (VC O1 ET), V. cholerae Non-O1/Non-O139 (VC N-O1/N-O139), enteroaggregative Escherichia coli (EAEC) and enteropathogenic Escherichia coli (EPEC) were included among the MDR bacterial strains. The significantly high (P < 0.001) antibacterial activities were observed against the MDR bacteria in case of the methanol extract of the P. guajava (GUV) leaves. The characterisation studies of GUV extract were done by thin layer chromatography, wide angle X-diffraction and Fourier transform infrared techniques. The GUV extract was encapsulated in poly-3-hydroxybutyrate-co-3-hydroxyvalerate (PHBV) nanoparticles using the nanoprecipitation method. Blank PHBV nanoparticles demonstrated no antibacterial activity against the selected MDR strains. The GUV extract loaded PHBV nanoparticles produced significantly large (P < 0.001) zones of inhibition, i.e. MRSA (24 mm), EPEC (23 mm), EAEC (23 mm), VC O1 ET (21 mm) and VC N-O1/N-O139 (20 mm) against the MDR bacterial strains as compared with the GUV extract alone. The results have demonstrated a great potential of PHBV nanoparticles to become an efficient carrier for delivery of the potent bioactive molecules.

The charge plasma-based tunnel field-effect transistor (TFET) has been seen as the potential candidate to replace the conventional TFET as it offers fabrication simplicity and its proficiency to be used for ultra-low-power applications. A charge plasma TFET (CPTFET) with hetero materials for enhancement of device performance is presented. For this, a narrow bandgap material (InAs) is used instead of silicon in source region for reducing the lateral tunnelling distance at the source/channel interface. The reduced tunnelling width at the source/channel junction enables higher band-to-band tunnelling generation rate, thus the device offers higher ON-state current. In this context, a comparative study of CPTFET and hetero junction charge plasma TFET (H-CPTFET) has been performed in terms of transfer characteristic (I _ds–V _gs), transconductance (g _m ), gate-to-drain capacitance (C _gd), cut-off frequency (f _T) and gain-bandwidth product. In addition to this, the effect of variation in channel length (L _g) and drain to source voltage (V _ds) on the DC and analogue/radio frequency performance of H-CPTFET is also analysed.

A series of CuO/SiO₂ catalysts containing different modifiers were prepared via co-precipitation and used for glycerol hydrogenolysis. CuO–CeO₂/SiO₂ gave the best glycerol conversion rate (100%) and highest selectivity for 1,2-propanediol (up to 95%). Reactions were carried out under the following conditions: temperature, 220°C; H₂ pressure, 0.5 MPa; glycerol concentration, 100 wt.%; and H₂/glycerol molar ratio, 35:1. The catalysts were characterised by X-ray diffraction, NH₃ temperature-programmed desorption, N₂ adsorption, and scanning electron microscopy. The CuO–CeO₂/SiO₂ catalyst had smaller particle sizes, better dispersion, and greater specific surface area than the CuO/SiO₂, CuO–phosphotungstic acid (PTA)/SiO₂, and CuO–CeO₂–PTA/SiO₂ catalysts.

In this work, a comparative analysis of vertical light-emitting diodes (VLEDs) examining the device properties is performed with different surface treatment schemes. The VLEDs on graphite substrate are fabricated by the laser lift-off and the wafer bonding processes. The significance of KrF laser irradiation to form protrusions on the surfaces of undoped gallium nitride (u-GaN) and n-GaN is analysed in detail. The light output power of the fabricated VLEDs is significantly increased through the formation of micro-sized protrusions by the laser irradiation. For VLED irradiated with an energy density of 600 mJ/cm² on n-GaN surface with a thin u-GaN layer, the light output power is improved by 24.8% at 350 mA without degradation of electrical properties compared with that of the conventional VLED.

The bit error rate (BER) performance of a cooperative relaying transmission scheme for wireless nanosensor networks in the terahertz (THz) band is investigated. Nanosensor networks comprising several graphene-based devices deployed at the nanoscale are considered. Both amplify-and-forward (AF) and decode-and-forward (DF) relaying modes are studied. A line-of-sight (LOS) channel model in the THz band is considered which takes into account both spreading loss and molecular absorption loss. Given the high path loss and level of noise from significant random fluctuations through the THz channel, relay-assisted schemes offer advantages in terms of significant performance improvements. To quantify the likely benefits, the predicted BER of the proposed scheme is derived. A simulation of the proposed relay schemes based on the THz LOS channel model utilising a Monte Carlo method is conducted. The results obtained show that a performance improvement of 2.2 dB for AF and of 5 dB for DF is achievable at a target BER of 10⁻⁵.

Parameters for sample introduction, dried reagents dissolution and mixing with sample for bienzyme system NAD(H):FMN-oxidoreductase and luciferase immobilised in microfluidic chip were successfully determined. Numerical simulations of reaction chamber geometry, flavin mononucleotide (FMN) escape from starch gel and mixing options were conducted to achieve higher sensitivity of bioluminescent reaction. Results of numerical simulations were verified experimentally. The active mixer for dried reagents was made from an electro-mechanical speaker's membrane which was connected to the input of the chip. Such a mixer provided better efficiency than a passive mixing, and it is simple enough for use in point-of-care devices with any systems based on immobilised enzymes in chips.

In this work, grass-like, needle-like and chrysanthemum-like ZnSe nanostructures have been prepared by hydrothermal method at 200°C for 24 h successfully. With different amounts of diethanolamine, various morphologies of ZnSe formed. The structures, morphologies and crystal orientation of as-synthesised ZnSe nanostructures were characterised by X-ray diffractometer (XRD) and scanning electron microscope. The experiment result of XRD indicated that the structures of all as-synthesised ZnSe nanomaterials were cubic crystal. The field emission (FE) properties of as-synthesised samples were tested and the results revealed that the FE properties were influenced by the morphologies significantly. The FE measurement showed that the chrysanthemum-like ZnSe nanostructures had the best FE properties with a high field enhancement factor of 4328 and a low turn-on electric field of 3.4 V μm⁻¹ among all the as-synthesised ZnSe nanostructures. The reaction mechanism of various morphologies ZnSe was also explained as follow.

Chitosan microspheres were prepared by ion induction and chemical cross-linking using water as the medium. Natural rubber/chitosan microsphere blends were then prepared by blending the chitosan microsphere suspension with natural rubber latex. An infrared spectrometer, particle size analyser, scanning electron microscope, surface contact angle analyser, thermogravimetric analyser, and differential scanning calorimeter were employed for structure and property characterisation. The results showed that the average particle diameter and the polydispersity index of chitosan microspheres were 323.8 nm and 0.283, respectively. The thermal stability and mechanical properties of natural rubber/chitosan blends were enhanced by introducing chitosan microspheres into natural rubber latex. The water contact angle was significantly decreased, from 94.64° to 55.47°, indicating improved hydrophilic properties for the natural rubber/chitosan film. The natural rubber/chitosan blends showed excellent antibacterial properties when the chitosan microsphere content was >4.00% w/w.

Cadmium selenide (CdSe) thin films were prepared on indium tin oxide substrate by an alternating cold–hot method, in which cadmium nitrate solution was used as a cold deposition solution, while sodium selenite and potassium borohydride mixed solution was used as a hot deposition solution. The influences of the preparation conditions such as the concentration of Cd(NO₃)₂, the number of deposition cycle and the cycle time, on the photoelectric performance of the sample under simulated sunlight were explored. The results show that the CdSe thin film prepared under the reaction conditions of 0.06 mol/l Cd(NO₃)₂ at the tenth deposition cycle (30 s per cycle) reaches the highest photovoltage of 0.285 V. Under the simulated solar illumination, the open-circuit voltage and short-circuit currents are 0.419 V and 5.57 mA/cm², respectively. X-ray diffraction indicates that the strongest diffraction peak at 42.215° of the (111) crystal plane is corresponding to 15.15 nm CdSe nanocrystals. Scanning electron microscopy observation shows that the thickness of the CdSe film is about 200 nm and the size of the spherical and uniformly dispersed nanocrystals is around 50 nm.

All spin logic (ASL) device is one of the promising post-CMOS candidates. Owing to unique features such as non-volatility, simple configuration, ultra-low-switching energy, and good scalability, ASL devices can be exploited in logic applications. Based on the characteristics of non-volatility and bistable states of ASL device, an RS flip-flop is proposed which is composed of seven ASL devices and employs a complementary clock signal scheme. Using the coupled spin-transport/magneto-dynamics model, validity of its logic operation is demonstrated. As a fundamental building block of sequential logic circuits, the proposed RS flip-flop will be an useful component for designing large-scale ASL sequential logic circuits.

Poly(cyclotriphosphazene-co-4,4′-sulphonyldiphenol) nanotubes (PZS) were synthesised via an in situ template method under mild conditions and applied on epoxy resin (EP) as a novel flame retardant. The PZS nanotubes were characterised by SEM, TEM, EDS and element mapping and the flammability was investigated by microscale combustion calorimeter and limited oxygen index (LOI) tests. The results showed a significant improvement of the carbonisation ability and flame retardancy of The PZS/EP nanocomposites. Under merely 3% of addition of PZS nanotubes, the LOI value was increased to 30.1 from 26.6, the peak of heat release rate was reduced to 335 W/g, about 40% lower than that of neat EP. The great improvement of flame retardancy can be ascribed to the formation of graphene-like structure during combustion of PZS/EP nanocomposites.

Here, the synthesis conditions involved in the obtention of magnesium hydroxide [Mg(OH)₂] nanoparticles by hydrothermal route are studied. The aim is to control the characteristics of the products only by setting the correct reaction conditions. In addition, they have simplified the method by using simpler equipment in the synthesis and eliminating any further purification processes to obtain pure Mg(OH)₂ particles in a scalable, safe, and economic process. They present the role of the treatment temperature by means of differential scanning calorimetry, water/magnesium oxide ratio, ageing time, and temperature increase rate and the characteristics of the resulting Mg(OH)₂ particles. Characterisation of the products was carried out by X-ray diffraction, dynamic light scattering, scanning electron microscopy, and transmission electron microscopy.

Four kinds of nanosilica-supported metallic and metatitanic acid nanocatalysts were synthesised as potential phase transfer catalysts for enhancing heavy oil recovery via a liquid-reduction method. The catalysts were carried by water and transferred into oil phase, and the catalytic performance of catalysts for the aquathermolysis reaction and viscosity reduction of the extra-heavy oil recovered at Shengli Oilfield (Dongying, China) was investigated. At a mass fraction of 1%, an aquathermolysis reaction temperature of 150°C and an aquathermolysis time of 36 h, the as-synthesised silica/zero valence iron and nickel (denoted as SiO₂/Fe/Ni) catalyst was able to reduce the apparent viscosity of the two kinds of heavy oils by 79.3 and 77.6%, showing promising application in the industrial production of heavy crude oil.

Polyurethane (PU) nanofibres are widely used in tissue engineering of elastic tissues such as tendon and ligament, vascular and arterial grafts etc. Alignment of the PU nanofibres is also a desirable property of some tissues to mimic the morphology of the extracellular matrix. Elasthane™ 55D nanofibres were produced using a common electrospinning method and a rotating drum to collect the aligned fibres. Four flow rates and five collector speeds were investigated for their effects on nanofibres alignment and diameter. Field emission scanning electron microscopy (FESEM) images of nanofibrous webs were captured, and the diameter and alignment of the nanofibres were measured. Finally, stem cells from human exfoliated deciduous tooth (SHED) were seeded on the surface of the PU nanofibres to investigate the cell–scaffold interaction. Statistical results showed that the flow rate had a significant effect on the fibres diameter. Enhancing the flow rate led to increasing the diameter of the PU nanofibres. The results showed that the fibres alignment index was promoted by increasing the rotating speed of the collector. In addition, the morphological observation of SEM images indicated that cells grew in the alignment direction of the nanofibres. The results of this study can be applicable to produce and control the aligned PU nanofibres for specific applications such as vascular grafts, esophagus prosthesis, arterial grafts and tissue engineering of tendon and ligament.

Stability of silver-containing nanocomposites, synthesised from medicinally promising humic substances, has been studied. The nanocomposites obtained possess aggregative stability and conserve their properties for a long time. All compounds have been investigated by physical and chemical methods including electron paramagnetic resonance, plasmon absorption spectroscopy and X-ray diffraction analysis. It is shown that unlike the composites synthesised from humic substances of deeper decomposition, in natural macromolecular matrixes of nanocomposites formed from mud and shale humic substances both 6–14 nm nanoparticles and silver clusters Ag _n are generated and stabilised.