The electrostatic behaviour of the different configurations of n-type heterojunction double-gate tunnel field-effect transistor (HDGTFET) has been analysed. The analysis is based on the basics of the circuit elements such as drain current, transconductance, parasitic capacitances, cut-off frequency and gain bandwidth product. From the investigation carried out, it can be inferred that dual metal hetero-dielectric double-gate HDGTFET with gate underlap achieves both low standby power OFF state current and high performance at low supply voltage. The performance of the device having different configurations has been analysed for drain region having a uniform and Gaussian doping profile.

Copper nanowires (NWs) were constructed on a dendritic copper powder precursor by a facile thermal oxidation–reduction method. First, copper oxide NWs were grown from high purity dendritic copper powder by thermal oxidation at 500°C. Next, these oxide NWs were reduced to copper NWs under a hydrogen flow at two different temperatures of 220 and 500°C. Oxide NW diameters distribution was in the range of 50–105 nm with length ranging from 1 to 5 µm while copper NWs were shorter and wider. A time-dependent study of oxide NWs growth was carried out. The morphology, composition and crystal structure of the resulting products were characterised by X-ray diffraction and scanning electron microscope. The results indicated that the final product of oxidation process was dispersed cupric oxide (CuO) NW whose density and length increased with time. Furthermore, it was observed that as the reduction temperature increased, the copper NW melted and adhered to the powder surface.

A functionalised hydroxyapatite (HAP) nanoparticles based drug delivery system (DDS) [anti-angiogenesis (ANG)/amine functionalised HAP (NHAP) nanoparticles] composed of HAP nanoparticles and therapeutic ANG plasmid was successfully developed for gene therapy of breast cancer. ANG/NHAP nanoparticles displayed nano-sized diameter of around 50 nm and effective plasmid condensation ability. Cellular assays on MCF-7 cells further confirmed high transfection and ANG efficacy as well as low cytotoxicity of ANG/NHAP nanoparticles, which suggested that ANG/NHAP nanoparticles might be a safe and effective DDS for potential breast cancer gene therapy.

Homogeneous and compact antiferroelectric (AFE) (Pb, La)(Zr, Ti)O₃ thick films in large area with different thicknesses were successfully fabricated by the sol–gel processing on Pt(111)/Ti/SiO₂/Si(100) substrates. The characteristics of switching current of samples with different thicknesses under thermo-electric coupled field were investigated in detail. The experimental result shows that the peak of switching current density increased with the increase of temperature in three samples. Moreover, it is found that the thickness of the films has a big effect on the current density. Therefore, the peak of switching current density increased with increasing in the thickness at the same temperatures. The maximum switching current density of film with the thickness of 2254 nm is 4.35 × 10⁻⁵A/cm². These results are quite important and necessary for design and preparation of the AFE materials applied on high sensitivity and intelligent micro-sensors and micro-actuators.

Superamphiphobic (both superhydrophobic and superoleophobic) surfaces on Al substrates are fabricated by the high speed wire electrical discharge machining (HS-WEDM) and chemical etching technology. The surface morphology, chemical composition and wettability of the sample surfaces are investigated using scanning electron microscopy, energy dispersive X-ray diffraction system and optical contact angle (CA) measurements. The results show that, after the HS-WEDM and chemical etching, the micrometer-scale craters and nanometer-scale acicular structures are present on the sample surfaces. The obtained sample surfaces show superamphiphobicity after fluorination. The CAs of water, ethylene glycol and peanut oil are 155.9°, 153.1° and 151.7°, respectively. The sliding angles of water, ethylene glycol and peanut oil are 2°, 3.5° and 5°, respectively. The micro/nanometer-scale rough structures and the low surface energy are essential to fabricate superamphiphobic surfaces. Compared with the other methods, the main advantages of the HS-WEDM and chemical etching technology are simple, safe, highly effective and low cost. In addition, superamphiphobic Al surfaces have potential applications in fields such as self-cleaning, oil capture, oil transportation and anti-smudge.

The lithium-ion battery cathode materials spinel LiMn₂O₄, LiAl_0.1Mn_1.9O₄ and Li_0.94Na_0.06Al_0.1Mn_1.9O₄ materials are synthesised by sol–gel method. The structure, morphology and electrochemical performances of the aluminium and sodium co-doped materials are studied by X-ray diffraction measurement, scanning electron microscopy, and Electron diffraction spectroscopy, respectively. The results reveal that appropriate amount doping of aluminium and sodium does not change the spinel structure of LiMn₂O₄. Those materials have a good crystallinity and the sizes are approximately 150 nm. The initial discharge capacity of Li_0.94Na_0.06Al_0.1Mn_1.9O₄ is 113.8 mAh/g at 0.5 C. Compared with the rate capability of LiMn₂O₄, the discharge capacity of 107.5 mAh/g at 5 C for Li_0.94Na_0.06Al_0.1Mn_1.9O₄ has 46.8% improvement. Obviously, aluminium and sodium co-doping is a very effective way to improve LiMn₂O₄ rate capability.

Mesoporous nanocrystalline magnesium aluminate (MgAl₂O₄) particles with different surface area (70–230 m² g⁻¹) were synthesised via the homogeneous co-precipitation method using different surfactants (cationic, anionic and non-ionic). The obtained powders were used as the support to prepare 10.5 nickel (Ni)/MgAl₂O₄ catalysts, and the resulting samples were tested in the steam pre-reforming of natural gas. The obtained samples were characterised by Fourier transform infrared spectroscopy, Brunauer-Emmett-Teller (BET), X-ray diffraction, thermogravimetric/differential thermal analysis, transmission electron microscopy and temperature programmed desorption (TPD) techniques. Experimental results showed that the shape, surface area and porosity of MgAl₂O₄ particles were strongly dependent on the type of surfactants used. In addition, the Ni catalyst supported on the MgAl₂O₄ with the highest surface area exhibited the smallest size of Ni particles (14.1 nm). This catalyst has over 97% of ethane and propane conversions in steam pre-reforming of natural gas under atmospheric pressure, 550°C, low steam to carbon molar ratio (S/C = 1.5) and high gas hourly space velocity (GHSV = 100,000 ml g⁻¹ _catalysth⁻¹).

A terahertz (THz) modulator based on graphene is proposed and analysed by use of equivalent transmission line of a homogeneous medium and the local anisotropic model of the graphene conductivity. The result calculated by the equivalent circuit is consistent with that obtained by Fresnel transfer matrices. For the modulator proposed here, when the frequency of carrier wave is 0.6 THz, the theoretical analysis indicates that the modulation bandwidth is 55.5 kHz and the modulation depth is 81.3% for voltage change from 0 to 50 V.

A comparative study of cylindrical gate-all-around (Cyl-GAA) tunnel field effect transistor (TFET) based on underlaps with varying spacer width is presented. Extensively, simulation results show that asymmetrical underlap (AU) GAA-TFET with low spacer width enhances the fringing field within the spacer. The proposed device structure has high I _ON (6.9 × 10⁻⁴ A/µm), low I _OFF (2.5 × 10⁻¹⁷ A/µm), and an enhanced I _ON/I _OFF (10¹³). This is due to the high series resistance at drain channel junction caused by AU. Furthermore, the proposed structure exhibits a steeper subthreshold swing (30 mV/dec) when compared with symmetrical underlap (SU) Cyl-GAA-TFET.

In the present investigation outer membrane protein (OMP) from Vibrio cholerae were encapsulated successfully with poly-lactic acid (PLA) and poly-lactic glycolic acid (PLGA) microparticles by the double emulsion preparation technique. The prepared OMP-PLA and OMP-PLGA microparticles were characterised by scanning electron microscopy for observing their morphology and dynamic light scattering for their size, charge and poly dispersity index. The microparticles were further characterised by Fourier transmission infrared spectroscopy for observing the interaction of OMP antigens within the PLA and PLGA polymer matrix. The primary motive of the study was to observe the stability of the prepared microparticles when they are subjected to various pH ranges of 1.2, 6.8 and 7.2 with simulated body fluids for 30 days of incubation at body temperature. Both OMP-PLA and OMP-PLGA microparticles showed greater stability with pH 1.2 and 7.2 in the size and charge parameter scale with very marginal change in size and surface zeta potential. In the desired pH 6.8, the microparticles were degraded gradually up to the nanometre scale without affecting their surface zeta potential values. Thus, this present method can be a simple and cost-effective approach for observing the stability measurement of pharmaceutical drugs.

Carbon nanofibres (CNFs) and carbon spheres (CSs) are successfully synthesised using coal particles (<44 micron) in solid phase. Coal and ferrocene as catalyst were fed to the reactor in the solid form. The reaction is carried out in a tubular reactor. The as-synthesised samples have been characterised through Raman spectroscopy, X-ray diffraction, scanning and transmission electron microscopy. The results show CNFs formed in 25–40 nm and mono dispersed CSs in 200–300 nm are amorphous. A feasible mechanism of CNFs and CSs formation from coal described here with the help of coal structure.

Size-controlled silver nanoparticles (Ag NPs) with a size of 2–15 nm have been synthesised from silver (Ag) mirror reaction in toluene , which refers to reduction of Ag precursor (Ag–dodecylamine complexes solution) by acetaldehyde (CH₃CHO) in the presence of oleic acid (OLA). In this synthesis, the size of Ag NPs was finely tuned by just varying the Ag precursor concentrations (c _Ag). The addition of OLA can play an important role in stabilising the emerging Ag nuclei. With the OLA/Ag molar ratio at 3:1, the adsorption layer of enough OLA on the surface of the emerging Ag nuclei prevented the direct contact between Ag⁺ ions and Ag nuclei, and Ag nuclei grew up to their final size by the aggregation mechanism.

Flower-like ZnO nanostructures were successfully produced on a polyethylene naphthalate (PEN) substrate through a chemical bath deposition method. Field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), photoluminescence (PL), and ultraviolet-visible were utilised to investigate the structural and optical properties of grown flower-like ZnO nanostructures. FESEM image indicates that fabricated ZnO nanostructures formed from the ZnO nanoflowers with different shape and the petals of the ZnO nanoflower grow symmetrically and radially from the centre. XRD pattern of the ZnO nanoflowers indicate that the ZnO nanorods of the nanoflowers were preferentially grown along the c-axis. The PL results of the ZnO nanoflowers exhibited a strong violet and indigo emission peaks are centred approximately at 413 and 425 nm, respectively.

A dual material control gate tunnel field effect transistor (TFET) for asymmetric doping at source and drain regions is proposed. The gate consists of three segment different workfunctions ϕ ₁, ϕ ₂, and ϕ ₃, which are named as tunnelling gate (M ₁), control gate (M ₂), and auxiliary gate (M ₃), respectively. Forward to this, three possible combinations of ϕ ₁, ϕ ₂ and ϕ ₃ to maintain the dual workfunctionality of the device (ϕ ₂ = ϕ ₃ > ϕ ₁, ϕ ₁ = ϕ ₂ > ϕ ₃, ϕ ₁ = ϕ ₃ < ϕ ₂) were considered. Further, the comparison of these possible combinations are performed with conventional TFET (ϕ ₁ = ϕ ₂ = ϕ ₃). Among these ϕ ₁ = ϕ ₃ < ϕ ₂, generates most optimum results in terms of suppression of ambipolar behaviour, and enhancement in ON state current (I _ON) of the device. The proposed device shows significant improvement in terms of I _ON (1.66 × 10⁻⁵ A/μm for SiO ₂), I _ON/I _OFF (7.22 × 10¹¹), and sub-threshold swing (∼19 mV/decade) as compared with conventional and the dual material TFET devices. Further, the analysis of analogue/RF performance is performed for the devices showing optimum performance in terms of suppression of ambipolar behaviour.

To understand the role of mullite powder synthesis method on the microstructural aspects and mechanical properties of the consolidated samples, this powder was prepared with two methods including sol–gel technique and direct reaction of alumina and kaolin (A–K mullite). The microstructural studies showed that the particle size of mullite powders synthesised with sol–gel method is lower than the mullite prepared from direct reaction. The spark plasma sintering (SPS) method was used for the consolidation of the samples. The scanning electron microscopy/energy-dispersive X-ray analysis showed that the samples prepared from sol–gel powder after the SPS process contain lower porosity and better compositional homogeneity compared with A–K mullite sample consolidated in a similar condition. The bending and hardness (H) tests results confirmed the better performance of sol–gel samples which is attributed to its lower porosity and better microstructural homogeneity.