In this work, human serum albumin (HSA) was used to prepare core-shell taxanes-loaded nanoparticle (NP) by self-assembly method. Various experimental technologies were used to character two different taxanes-loaded HSA NPs and analyse the structure of them. The obtained NPs had a spherical morphology and core-shell structure. The data revealed that one paclitaxel (PTX)-loaded HSA NP (∼40 nm) consisted of six HSA molecules and 34 PTX molecules, and one docetaxel (DOC)-loaded HSA NP (∼30 nm) consisted of five HSA molecules and 40 DOC molecules. The infrared, three-dimensional fluorescence and ultraviolet absorption spectra showed that intermolecular hydrogen bond occurred between taxanes and polypeptide chain of HSA and resulted in change of its secondary structure. The fluorescence spectra experiment results suggested that PTX and DOC interacted with tryptophan (Trp)-214, which lie on site I of HSA, and the type of interactions were hydrogen bond and hydrophobic interaction, respectively. It suggested that the binding mode of taxanes with Trp-214 is the primary factor that determined the size and loading capacity of taxanes-loaded HSA NPs. This work indicates that such HSA NP is very promising in the field of nanoscale drug delivery systems research.

The piezoelectric poly(vinylidene fluoride-hexafluoropropylene) ((P(VDF-HFP)) has been incorporated with zinc oxide (ZnO) of different forms, i.e. nanoparticles (NPs), nanorods (NRs), and microrods (MRs). The polymer has been activated the piezoelectric phase with the poling filed of 70 MV/m at 90°C for 10 min. ZnO of various particle types is grown into piezoelectric wurtzite. The addition of ZnO has slightly changed the degree of crystallinity of the polymers and clearly increased the elasticity to the best value in the case of inserted MRs. The electroactive phase of the polymer-based film has been enhanced at 2 wt% of ZnO for both NPs and NRs cases. The dielectric constant of the films increased with ZnO concentration. Finally, a cantilever beam structure with the patch of P(VDF-HFP) reinforced with ZnO of 2 wt% NRs shows the best performance as a microsource of the energy of about 1 µW. Development of micropower energy harvesting in P(VDF-HFP) with ZnO NRs has been substantially and highly promising to power small-scale electronics.‏

The conical copper wires (CCWs) were subjected to alkali assistant oxidation or electrochemical deposition to form superhydrophilic wettability of ∼4° with needle-like or leaf-like morphology, respectively. The superhydrophobic CCWs with water contact angles of ∼156° were further constructed by modification with 1-dodecanethiol. The CCWs were used to study the effect of fog flow velocity and surface morphology on fog collection. With the fog flow velocity increased, the dominant factor for fog collection changed from fog capture to droplet motion. The surfaces with needle-like morphology displayed better fog capture ability while the surfaces with leaf-like morphology were more prone to driving droplet motion.

Alpha alumina nanocrystals that are highly dispersible and have a high specific surface area play an important role in the field of catalytic supports and others. As the phase-transformation temperature of α-Al₂O₃ is 1000°C, it is extremely difficult to fabricate monodisperse nanoparticles. Here, the study reports a new method, referred as the salt microemulsion method, for the fabrication of monodisperse α-Al₂O₃ nanoparticles, and the particle size could be tuned between 3 and 8 nm. The particles precipitated by demulsifying the microemulsion were analysed by transmission electron microscopy. The precipitated particles are found to be inclusions, with the Al₂O₃ precursor nanoparticles are dispersed and isolated by the K₂SO₄ nanoparticles. As the melting point of K₂SO₄ is 1065°C, the Al₂O₃ precursor nanoparticles are separated by the solid K₂SO₄ over the entire high-temperature phase-transition process. As a result, agglomeration and sintering of the α-Al₂O₃ nanoparticles are prevented, leading to monodisperse α-Al₂O₃ nanoparticles.

Design, fabrication, and measurement of a metal-contact radiofrequency (RF) microelectromechanical systems switch with a power divider/combiner structure for high power applications are presented in this work. The multi-contact switch with parallel cantilever beams is implemented in a Y-junction power divider/combiner, which suppresses the uneven current distribution through each contact and results in higher power handling capability at high frequency. The measurement results indicate the excellent RF performance of the switch fabricated on the Borofloat glass substrate with insertion loss and isolation of 0.22 dB and 29 dB@10 GHz, respectively. A lumped-element model is developed and it fits well with the measured S-parameters with the contact resistance of 0.6 Ω and up-state capacitance of 1 fF for each contact. The switch can handle power up to 2 W@10 GHz under prolonged hold-down conditions for 2 h. The reliability measurement shows that the packaged switch can operate for over 1 million cycles at 200 mA under cold-switching conditions.

A prominent field of study in biosensor development is the study of electric properties which provide valuable insight into the fluids contents. In this research, a non-enzymatic glucose sensor is fabricated, characterised, and employed. The developed device determines the effects of electrode surface area on sensing efficacy, the effects of glucose concentration on impedimetric response, and a real-time measurement of glucose concentration. Deviations throughout the entire glucose range are detected as an inverse of the impedance in the cell due to the inverse relationship of glucose concentration and charge transfer resistance. The continuous monitoring of glucose is demonstrated by a rapid device response over two iterations of glucose concentration in ascending order: 50 µM, 400 µM, and 3.2 mM. At a sustained frequency of 10 kHz, the result shows a stable impedimetric response of 1038, 752, and 688 kΩ, respectively. The validity of the device as a continuous glucose monitoring method is carried out by repeating the cycle and observing the response.

An aqueous tetramethylammonium hydroxide (TMAH) solution is widely used for silicon wet anisotropic etching to perform bulk micromachining for the fabrication of microstructures on a silicon wafer. To reduce the etching time to increase the productivity, etchant must provide high etch rate. In the present work, the etching characteristics of Si{110} in low concentration TMAH (5 wt%) with the addition of various concentrations (5–20%) of reducing agent hydroxylamine (NH₂OH) have been studied to increase the etch rate of Si{110} to reduce the etch time for the fabrication of microstructures. Moreover, it is aimed to enhance the undercutting at convex corner for the fast release of the structure. The etch rate of Si{110} and the undercutting at convex corners with the addition of NH₂OH increases by more than three times that in pure TMAH. In addition to the etch rate and undercutting, the effect of NH₂OH on etched surface morphology is investigated systematically. The present study is focused to enhance the application of wet etching in silicon micromachining for the fabrication of various kinds of microstructures for applications in microelectromechanical systems.

Polyethylenimine (PEI) is a cationic polymer with high transfection efficiency as non-viral gene delivery agent that exhibits promising features for gene therapy applications due to its cationic charge and thus favourable DNA-condensing abilities; however, its high cytotoxicity restricts its application. The cellular toxicity of PEI molecules depends on their structure, molecular weight and surface charge density. To improve the properties of branched 25 kDa PEI as a non-viral gene delivery agent, this polymer was conjugated to polyethylene glycol (PEG) molecules at three different molar ratios of 10, 20 and 30. The degree of PEG grafting was determined by 2, 4, 6-trinitrobenzene sulphonic acid assay. The effects of various PEGylation degrees on cellular toxicity and transfection ability of PEI polymer were assessed on BT-474 and MCF-10A cell lines. Compared to unmodified PEI, PEG-grafted PEI copolymers demonstrated reduced cytotoxicity, particularly at higher PEG grafting ratios. Among different PEG-grafted PEIs, the PEG–PEI copolymer which grafted to PEG at a molar ratio of 10:1 had the highest transfection efficiency in both cell lines. The findings of this Letter showed that these PEG-grafted PEI copolymers have desirable gene transfection efficiency and favourable biocompatibility for gene delivery.

In this work, performance degradation of 65 nm N-channel metal-oxide-semiconductor field effect transistors (NMOSFETs) with enclosed gate and two-edged gate layouts under hot carrier stress and constant voltage stress is investigated. Compared with the cold carrier, the hot carrier effect (HCE) causes more serious degradation in threshold voltage and transconductance. It is shown that cold carrier contribution is reversible, while HCE damage is permanent, it cannot be reversed by application of the annealing bias. Meanwhile, an enclosed gate NMOSFET is proved to have higher resistance to HCE than two-edged gate NMOSFET fabricated in the same 65 nm complementary metal-oxide-semiconductor (CMOS) technology according to the results of experiments. That is, the enclosed gate NMOSFET not only provides total-dose radiation tolerance but also improves the hot carrier reliability of advanced CMOS circuits. The contributions of the two types of carriers to the degradation of transistor performance are analysed. The physical mechanism of HCE reliability of different geometry MOSFETs is studied.

Four types of nano-structured SnO₂ thin films were synthesised via a facile one-step hydrothermal method on Ti substrate. All the films were prepared by using SnCl₄ and NaOH as the precursors with urea, mercaptoacetic acid or sodium citrate as the adjusting reagent. The prepared films were characterised by scanning electron microscope, X-ray diffractometer, X-ray photoelectron spectroscopy (XPS) and their properties in ethanol gas sensing were examined. It was found that addition of organic reagents resulted in the formation of different nano-scaled morphologies, i.e. nanowires, nanonets, transparent nanosheets and nanograsses. The characterisation of XPS indicated that SnO₂ was successfully deposited. The gas sensing experiments revealed that morphologies of the nano-SnO₂ films had a great effect on their gas sensing properties. The possible reasons involved were presented.

In this work, an electronic computer chip generates a 50–150 W heat over a surface, requiring dissipation of about . The authors design a copper heat sink () that is mounted over the chip with two active methods for enhancing heat removal from the chip. To enhance the cooling effects, a laminar developing heat and fluid flow is introduced into the assumed seven miniature channels in a rectangular shape (), which takes away heat partly. Ethylene glycol as a base fluid and ethylene glycol + Al₂O₃ as a nanofluid with a volume fraction of nanoparticles 0.5, 1 and 1.5% flow with laminar regimes. To remove heat from the other parts of the sink, an external airflow is used with a free stream velocity of 2 m/s over it. This airflow is a laminar two-dimensional boundary layer over the sink in the direction of its length. By numerical simulation, these two methods of cooling are investigated for enhancing heat removal from the sink. The results show cooling efficiency increased by about 8.5% in comparison with the cooling system with free convection where there is an internal cooling.

To improve light absorption, in this study, the narrow band gap highly-ordered free-standing hydrogenated amorphous germanium nanoparticles (a-Ge:H NPs) were introduced into the CH₃NH₃PbI_3−x Cl _x films. Here, the NPs were fabricated by means of the radio frequency plasma enhanced chemical vapour deposition system. The effects of hydrogen dilution ratio (RH) on the microstructure and bonding configuration of a-Ge:H NPs were investigated by Raman, transmission electron microscopy and Fourier transform infrared spectroscopy measurements. As RH increases, an improvement in the structure order of a-Ge:H NPs was observed. Compared with the pure CH₃NH₃PbI_3−x Cl _x films, the light absorption of the hybrid a-Ge:H NPs/CH₃NH₃PbI_3−x Cl _x active layers was improved, and the surface coverage of the hybrid active layers nearly reached 100%. This new finding provided a novel way to solve the universal unfavourable surface coverage problem that existed in the ultrasonic spray-coating process. Meanwhile, compared with the device that is based on pure CH₃NH₃PbI_3−x Cl _x films, due to the enhanced light absorption in the visible range, a ∼14.6% enhancement in the power conversion efficiency was achieved based on the hybrid a-Ge:H NPs/CH₃NH₃PbI_3−x Cl _x active layers.

In this work, the bismuth telluride (Bi₂Te₃) nanostructure for thermoelectric applications was successfully synthesised by a new cost-effective chemical solution process. Firstly, the metal solutions of bismuth (III) nitrate pentahydrate and tellurium dioxide were mixed together at room temperature with adjusting the hydrodynamic atmosphere and introduced the sodium hydroxide. After that, different characterisation parameters, such as X-ray diffraction, atomic force microscopy (AFM), scanning electron microscopy (SEM), energy dispersive X-ray, and transverse electron microscopy (TEM) were obtained. Then, the average crystalline size of the Bi₂Te₃ nanostructure was found 23 nm. According to these obtained results, the materials consist of every specimen in nano range dimension in AFM studies. The elemental of Bi and Te were arranged with their quite stoichiometric atomic ratio observed by SEM. Ultimately, the TEM micrographs showed that the powders exhibited an aggregate phenomenon, and the primary crystalline size was about low dimension.

High-ordered three-dimensional multilayered Bi₄O₅Br₂ nanoshells have been fabricated successfully via a green ultrasound-assisted anion exchange reaction followed by a calcination treatment approach. The products are characterised by X-ray diffraction, field-emission scanning electron microscopy, transmission electron microscopy, high-resolution transmission electron microscopy, UV–vis diffuse reflectance spectrum and N₂ adsorption/desorption isotherms. The results reveal that ternary Bi₄O₅Br₂ nanoshells possess a pure monoclinic phase with the average thickness of ca. 12 nm, and the walls are of 10–12 layers constructed by nanograins with 10 nm in size. The specific surface is measured to be 36.18 m² g^-1 and the band gap energy E _g value is calculated to be 2.52 eV. The possible formation process for Bi₄O₅Br₂ nanoshells is simply proposed. According to the photocatalytic degradation for resorcinol under visible light irradiation, the as-prepared Bi₄O₅Br₂ nanoshells exhibit excellent photocatalytic performance, which is not only far beyond the degradation rate of BiOBr precursor nanosheets but also superior to that of other reported Bi₄O₅Br₂ architectures, suggesting a practical application for the treatment of organic pollutants.

Magnetite nanoparticles (MNPs) were synthesised and grafted with polymer containing brilliant cresyl blue for the exchange of losartan potassium. The resulted polymeric nanoparticles were characterised with Fourier transform infrared spectroscopy, elemental analysis, thermogravimetric analysis and transmission electron microscopy. The effects of the exchange parameters such as sample pH, temperature and contact time on sorption of losartan potassium were investigated. The sorption capacity of the functionalised sorbent was 19.4 mg g⁻¹. The equilibrium adsorption data of losartan potassium on modified nanoparticles were analysed by Langmuir, Freundlich, Temkin, Dubinin–Radushkevich and Redlich–Peterson equations. Nearly, 74% of losartan potassium was released in simulated gastric fluid of pH 1.2 in 15 h and 50% in simulated intestinal fluid pH 7.4 in 30 h. These results have shown the utility of losartan potassium loaded–modified MNPs for enteric drug delivery.

The provisions and applications of renewable energy have great supply–demand gap problem, and thermal energy storage (TES) is a very promising solution to fully utilise the renewable energy and covers off-peak periods. The application of solid–liquid phase change material (PCM) is an effective way of TES based on the techniques of encapsulation and emulsion, but the capsules are easily broken and the emulsions are easily phase separated as they were phase changed for many times, so some other techniques should be developed. The microemulsion PCM slurry was prepared by the combination uses of emulsifiers (i.e. sorbitan monooleate 80 and polyoxyethylene sorbitan monooleate 80), coemulsifier (i.e. butanol), distilled water, purified paraffin and inorganic salts (i.e. potassium chloride). The average particle size in the slurry was about 50 nm, and the slurry was homogeneous after centrifugal acceleration of 1800g (i.e. ‘g’ is the gravity acceleration) for 5 min and phase change cycles for 1000 times. The latent heat of the slurry was 72.25 J g⁻¹ and the paraffin content in the microemulsion was 43.8 wt %. The slurry can overcome the shortcomings of some other techniques and be expected to be widely applied in the TES.

Commercially available quartz tuning forks (QTFs) can be transformed into self-sensing and actuating force sensors by micro-assembling a sharp tip on the apex of a tine. Mass of the tip is critical in determining the quality (Q)-factor of the sensor, therefore, fabrication of the lightweight nanotips is a precondition for high Q-factor QTF sensors. The work reports fabrication of very lightweight tungsten nanotips with a two-step electrochemical etching technique which can be used to develop high Q-factor QTF force sensor. First, a tungsten wire with protective coating at one end (1–2 mm) is etched with a trapezoidal waveform to form a lengthy (∼2–5 mm) and slender (diameter ∼10–40 μm) micro-needle. In the second step, sharp tip apex is fabricated with a direct current etching. High Q-factor (6600–8000) QTF force sensors have been developed with the fabricated nanotips. Atomic force microscope scanning of nano-grating and a triblock copolymer surface validates the scanning performance of the developed sensors.

Age-related macular degeneration (AMD) is one of the prevailing causes of blindness in the aged over 50 years. There are several conventional treatments for AMD including laser therapy, surgery, and intravitreal injection of anti-vascular endothelial growth factor directly into the eye. Intravitreal injection may result in various side effects such as increasing the eye pressure, eye infections, blurring vision; furthermore, it can negatively affect other body organs. In addition, large number of injections would be required to regenerate the lost vision. To overcome some of these obstacles, the work proposes a new drug delivery technique by using Avastin–Fe₃O₄ nanocomposites synthesised through co-precipitation method with approximate size of 20 nm. The saturation magnetisation (M _s) of the synthesised iron oxide nanoparticles (NPs) was about 55.6648 emu/g which is completely suitable for movement of the (Avastin–Fe₃O₄) NPs. Besides, the results of the flow cytometry tests showed that 90.5% of NPs were Avastin loaded. The proposed new method can be replaced with conventional treatments as the long-term sustained release of Avastin instead of several injections as well as declining the systemic side effects due to the high concentration of Avastin in the posterior segment of the eye.

The improvement of thermoelectric figure of merit of silicon nanowire (SiNW) can be achieved by lowering its thermal conductivity. In this work, non-equilibrium molecular dynamics method was used to demonstrate that the thermal conductivity of bulk silicon crystal is drastically reduced when it is crafted as SiNW and that it can be reduced remarkably by including vacancy defects. It has been found that ‘centre vacancy defect’ contributes much more in reducing the thermal conductance than ‘surface vacancy defect’. The lowest thermal conductivity that occurs is about 52.1% of that of pristine SiNW, when 2% vacancy defect is introduced in the nanowire. The vibrational density of states analysis was performed to understand the nature of this reduction and it has been found that the various boundary scatterings of phonon significantly reduce the thermal conductivity. Also, larger mass difference due to voids induces smaller thermal conductivity values. These results indicate that the inclusion of vacancy defects can enhance the thermoelectric performance of SiNWs.

A silicon on insulator (SOI)-like bulk silicon (SLBS) MOSFET has been recently reported. An ‘n/p-/n+’ structure was contained in SLBS P Metal Oxide Semiconductor (PMOS) device, with ‘p-’ is made of 4H-SiC. This p-layer is fully depleted. In this work, negative bias temperature instability (NBTI) of SLBS pMOSFET is studied and compared with that in bulk and Fully Depleted (FD) SOI PMOSFET. The effects of stress temperature and body bias on NBTI of SLBS device are also be studied in this work. The work demonstrates an advantage of SLBS over bulk and FD SOI devices.

In the current communication, an effort has been made to utilise Gram + ve bacterium Staphylococcus aureus, as a potential, renewable source for the green biosynthesis of selenium nanoparticles. The time-dependent bacterial biosynthesis of selenium nanoparticles was studied at different selenite concentrations. The green synthesised nanoparticles were probed with ultraviolet–visible spectra, inductively coupled plasma optical emission spectrometry, transmission electron microscope, X-ray diffraction, zeta potential and Fourier transform infrared spectroscopy characterisation tools. The strain produced red coloured, protein capped, amorphous, nearly monodispersed spherical nanoparticles of 3.6 nm size. This is the first report, in which the smallest selenium nanoparticles with the narrow size distribution of 2.8–4.7 nm were biosynthesised by the bacteria. Thus, paving a way for the commercial production of size-controlled smaller, selenium nanoparticles.

The effect of the plating voltage on the surface roughness, morphology, chemical composition and wettability of the Ni coatings was investigated by means of Laser scanning confocal microscopy, scanning electronic microscope, X-ray diffraction, energy-dispersive spectroscopy, and water contact angle measurements. The results indicate that the evolution of surface morphology on Ni coatings prepared by brush-plating depends strongly on the variation of plating voltage. The microstructure characterization shows that the typical hierarchical cauliflower-like structures was formed uniformly on the as-prepared Ni coatings. The combination of the porous morphology and hierarchical cauliflower-like structures plays a crucial role in improving the hydrophobic property. In absence of surface chemical modification, the Ni coatings exhibit an excellent hydrophobicity and have a high contact angle of 141 degree. Based on the Cassie-Baxier models, the relationship of two dimensionless geometrical parameters and the wetting property of the Ni coatings were investigated. It was demonstrated that to obtain the stable Cassie hydrophobic state, the aspect ratio and the water contact angle on the basal surface should be as large as possible and the spacing factor should be limited within a specific range for given aspect ratio and water contact angle on the basal surface.

In this work, the electrical characteristics and impact of physical and structural parameters on the performance of a novel heterojunction GaAs_0.1Sb_0.9-InAs semi-junctionless tunnel field effect transistor (SJTFET) is demonstrated. Unlike the conventional p-i-n tunnel field effect transistor, the n-channel SJTFET is a p⁺-p⁺-n structure having similar doping profile for the source and channel regions. First, all the structural and physical parameters are set to their initial values, and then, one parameter is varied to investigate its variation effect on the performance of SJTFET. Standard deviation and mean value of subthreshold swing, off-state and on-state current manifests that the performance of SJTFET is more sensitive to the gate workfunction, source–channel doping density and gate oxide thickness, respectively, in comparison with other structural parameters. The two-dimensional variation matrix of off-state current, on-state current and threshold voltage is calculated as a function of gate workfunction and source–channel p⁺ doping density for determining an optimum value for the source–channel doping concentration and gate workfunction. Due to the n-p⁺ drain–channel junction, the tunnel barrier in the off-state mode can be increased into the drain region, providing low off-state current in the ultra-scaled device and makes this device become less sensitive to short channel effects.

Piezoelectric actuators (PEAs) are widely applied in various nanopositioning equipment. However, the strong hysteresis nonlinearity compromises the positioning accuracy. In this work, a novel modified Bouc-Wen (MBW) model with a polynomial function of the differential of the input is established for modelling the hysteresis nonlinearity of the PEA-actuated nanopositioning stages. The particle swarm optimisation algorithm is adopted to identify the parameters of the MBW model with a set of input–output experimental data. The obtained model with the corresponding identification parameters matches well the experimental data with 0.31% relative error. A feedforward compensator based on the obtained model is also applied to compensate the hysteresis nonlinearity. Experiments are conducted to validate the effectiveness of this approach, and the results show the great improvement of positioning accuracy of the stage.

In this work, 3-aminophenylboronic acid was used as the starting materials to construct boron and nitrogen co-doped carbon dots with tunable dual-emission intensity at 420 and 540 nm with different excitation at 360 and 500 nm, respectively. The dual-emission carbon dots sensor is employed for rapid and sensitive fluorescence-enhancing detection of Pb²⁺. Compared with previous reported methods, their method showed better linear ranges or detection limits. Under the optimal conditions, the limit of detection of 0.9 nM for Pb²⁺ was reached with a wide range of 9 nM to 438 μM. The authors believe that the established method has more opportunities for application for other environmental targets.

In this work, a composite of graphene oxide (GO) supported by granulated manganese dioxide (MnO₂) has been synthesised via a facile one-step hydrothermal process and then used as adsorbent to remove heavy metal ions from aqueous solution. The morphology and surface functional groups of GO–MnO₂ composite were characterised by Fourier transform infrared spectroscopy, Raman spectra, X-ray photoelectron spectroscopy, scanning electron microscopy and thermogravimetric analysis. The results indicated that MnO₂ particles were successfully inserted into graphene sheets, and the agglomeration of GO was prevented. The effects of contact time and initial concentrations of heavy metal ions on the adsorption capacity of GO–MnO₂ composite were studied. The adsorption data fitted well with the pseudo-second-order kinetic model and the Langmuir isotherm model. The maximum adsorption capacity for Pb²⁺ obtained from Langmuir isotherm model was about 490 mg/g. Based on the results from the removal of four heavy metal ions from smelting wastewater and the reusability experiments, it could be deduced that GO–MnO₂ composite is a potential adsorbent for environmental clean-up.

The absorption spectrum and quantum efficiency (QE) of cadmium sulphide/zinc oxide quantum dot (QD) photodetectors are studied at different QD sizes and junction depths. It is shown that doping the QD layer gives high QE. The structures studied cover the range 200–270 nm, which is important in photodetector applications. High QE was obtained at QDs with a small height, while wide QE bath was obtained at QD with enough (but not so much) radius.

Copper (Cu)-doped cadmium sulphide (CdS) quantum dots (QDs) sensitised zinc oxide photoelectrodes have been fabricated for a solar cell (SC). For the synthesis of QDs, simple chemical methods have been adapted and the QDs were prepared on poly-vinyl alcohol capping agent. The influences of doping on structural properties of QDs have been studied using X-ray diffraction analysis and transmission electron microscopy images. Ultraviolet–visible absorption spectroscopy reveals an enhanced optical absorption in doped QDs. The photovoltaic performance of the Cu-doped CdS QDs was studied by measuring the current density–voltage (J–V) characteristics of the fabricated SC. An enhanced photo-conversion efficiency was observed in doped CdS QDs compared with the undoped QDs sensitised SC.

In this work, the authors have reported the reliability issues of dual material control gate tunnel field effect transistor (DMCG-TFET) and proposed heterogeneous gate dielectric dual metal control gate tunnel field effect transistors (HD DMCG-TFETs) in terms of interface trap charges (ITCs). The positive and negative types of localised charges at the semiconductor/insulator interface cause degradation in the device performance (DC/RF). In this regard, the proposed structure which includes combination of low-K and high-K dielectric improves the immunity towards the ITCs at the interface of semiconductor/insulator with better performance. In this concern, the study has analysed the impact of ITCs on DC and analogue/RF performances of the DMCG-TFET and HD DMCG-TFET in terms of various parameters like electric field, energy band diagram, carrier concentration, transfer characteristics, transconductance (), cutoff frequency () and gain bandwidth product. Further to this, impact on device linearity parameters is also analysed through higher order of transconductance coefficients (), VIP2, VIP3 and IIP3.

To investigate the viscosity of hybrid nanofluids containing two kinds of nanoparticles, a series of experiments are conducted on TiO₂–Ag/engine oil, Al₂O₃–Ag/engine oil (a mixture of the volume ratio of 50:50) nanofluids under different shear rates and volume fractions. The results show that the viscosity decreases with increasing shear rate, which suggests TiO₂–Ag/engine oil and Al₂O₃–Ag/engine oil hybrid nanofluids are both shear thinning fluids, whilst the viscosity of all samples enhances with the increase of volume fraction. Moreover, an interesting result is observed that the hybrid nanofluids have a lower viscosity than single particle nanofluids. Also, through the validating experiment based on Al₂O₃–Al₂O₃/engine oil with different diameters, it shows that different materials with unlike morphologies mixture are more likely to reduce the viscosity than dissimilar nanoparticles mixture of just one material.

The purpose of the present research was to address the corrosion protection of silane-based coatings which were positioned on the 304 stainless steel substrate in a 0.1 M H₂SO₄ solution. To this aim, tetraethoxysilane, 3-(aminopropyl) triethoxysilane and silicon carbide (SiC) nanoparticles were coated onto the 304 stainless steel substrate using the sol–gel deposition method. Accordingly, the corrosion behaviour of the bare metal and the coated substrates was assessed through conducting potentiodynamic polarisation tests and electrochemical impedance spectroscopy. Furthermore, for the evaluation of surface properties, scanning electron microscope, a field emission scanning electron microscope, X-ray diffraction and attenuated total reflectance-Fourier transform infrared spectrometer were employed. The result obtained by corrosion studies revealed that the silane coating containing SiC nanoparticles exhibited superior corrosion resistance than the bare 304 stainless steel. A homogenous and highly adherent protective nanostructure coating was produced on the stainless steel substrates by the silane coating including nanoparticles.

High-quality amorphous NiO/C/carbon nanotubes (CNTs) composite with an irregular porous structure have been successfully synthesised by a one-step combustion process at 350°C for 2 h with a heating rate of 3°C/min in air. To fully understand the potential of NiO/C/CNTs, the phase composition, morphology and electrochemical properties of materials were investigated. Benefiting from the in situ formed carbon, the addition of the CNTs and the advantages of the porous structure, the materials have shown superior electrochemical properties for supercapacitors. The specific capacitance of the composite reaches up to 1618 F/g at a current density of 1 A/g. Furthermore, the NiO/C/CNTs||activate carbon asymmetric supercapacitor device demonstrates both a high energy density (25.9 Wh kg⁻¹) and power density (5570 W kg⁻¹), and delivers a better cycling stability (about 94%) after 7000 cycles, which is a potential material for further development of fabricating a supercapacitor electrode.

Concrete appears to be the strongest backbone for the building industry as construction material. The chief constituent of concrete is the cement which has a major negative environmental issue causing huge carbon dioxide contribution during the cement production. The cement can be partly replaced by various wastes and by-products like fly ash, ground granulated blast-furnace slag, micro-silica etc. This study is about the utilisation of micro- and nano-silica in self-compacting concrete (SCC). The replacement level of cement by silica purely depends on its silica content and its structural composition. This is identified solely by the material characterisation techniques in terms of the physical and chemical composition of that particular substitute material. The flowability property as suggested by the European Federation of National Associations Representing for Concrete guidelines was tested on slump flow, J-ring, V-funnel, Orimet and L-Box. The strength parameters are studied for SCC with micro-silica of 5, 10, 15% and nano-silica of 1, 2 and 3%. The important study on the microstructural aspect of scanning electron microscope and energy dispersive X-ray analysis was conducted on concrete at 28 days. Hence, using the by-products like micro-silica, the environment can be saved to some extent against the disposal.

An amino-functionalised magnetic mesoporous silica was prepared through one-step copolymerisation method. Morphology, characteristic-group composition, microscopic morphology and specific surface area of the magnetic mesoporous silicas were analysed by scanning electron microscope, Fourier transform infrared spectroscopy, transmission electron microscope and nitrogen adsorption–desorption. The prepared magnetic silica MS-1 had the characteristics of micron-sized particle size, exceptional long-range ordered pore structure, and as high as 114.6 m²/g in specific surface area. The adsorption kinetics of tetracycline (TC) and Cu(II) onto magnetic mesoporous silicas in sole and binary system were also investigated. MS-1 could adsorb both of TC and Cu(II) with adsorption capacities of 35.14 and 23.65 mg/g, respectively, which were enhanced in binary systems about 26.5 and 19.7%, respectively. The solution pH significantly affected the adsorption because of the pH-responsive speciation of TC, TC–Cu(II) complex and the amine groups on adsorbent. This work proposed a potential effective method for the synergistic adsorption of antibiotics and heavy metals from aquatic environment.

Gold doped reduced graphene oxide (rGO) films prepared via hummer method have been utilised as counter electrode of dye-sensitised solar cell. The samples were subjected to various annealing times at 120°C. The effect of annealing time on the dark current and photovoltaic performance has been investigated. The power conversion efficiency varies with annealing time. The highest efficiency of 0.155% was achieved by the device utilising gold doped rGO annealed for 45 min. This is due to the device employing this sample possesses the smallest leak current.