Many articles have been reported in the literature on the relationship between exposure to nano nickel oxide (NiO) and pulmonary toxicity, but no coherent results have been achieved. This research is aimed at investigating the combined toxicity effects of pulmonary induced by nano NiO using meta-analysis. Data of cell and rat models were retrieved according to included and excluded criteria from 1994 to 2016. Twenty one articles were chosen in the meta-analysis. The standardised mean difference between the exposure and control groups was calculated from the different endpoints in cell and rat models, respectively. The meta-estimate was calculated using the computational equations when the effect size is measured in different scales. The results found that nano NiO induced the increasing of lactate dehydrogenase and decreasing of cell viability. We found an abnormal change in bronchoalveolar lavage fluid including the raised number of total cells, neutrophils, alveolar macrophage, and chemokines, as well as the transient increasing of pro-inflammation cytokines. In addition, most of the above-mentioned indicators can be changed after exposure to nano NiO from 1 week to 3 months and recovering at 6 months. Nano NiO could induce pulmonary toxicity, hinting potential adverse effect on the human respiratory system.

The gypsum building material was enriched with photocatalytic properties for indoor air purification. The photocatalytic additive to gypsum was TiO₂ modified with carbon from various sources. The photocatalytic activity of gypsum plates was performed towards NO _x removal. Carbon doping into TiO₂ improved not only total degradation of NO _x on corresponding gypsum plates but also NO₂ selectivity was changed, limiting the production of toxic NO₂. The exhibition of photocatalysts on the visible and ultraviolet irradiation has been also carried out to examine their durability. First, the stability of modifying element – carbon in TiO₂ structure was analysed, indicating on the gradual reduction of carbon content with irradiation time, especially when the carbon source was cyclic hydrocarbon. Second, the photocatalytic activity of the gypsum plates was performed at each stage of the ageing process. Based on this insight, the correlation between carbon content in modified photocatalysts loaded to gypsum plates and photocatalytic activity of them was described in detail.

The determination of fracture properties of hydrogels is of great importance while the hydrogel is used as medical scaffold or soft robotic. The simulations of the mechanical properties were used to reduce the experiment cost and improve efficiency. Here, the work presents a novel method to simulate the fracture behaviour of hydrogels based on discrete element method. Different with continuous methods, the hydrogel was characterised by number of particles. The viscoelastic model and bonding model within the particle model were applied to simulate the microscopic structure of hydrogels. By changing the critical parameters in the model, hydrogels with different mechanical properties were also simulated. Puncture compression test and uniaxial tensile test based on the model were performed. The fracture morphology, stress and strain during the tests were simulated. The results show that the model provides a novel and effective tool to simulate the fracture process of hydrogels.

The study used arc discharge method (ADM) to produce silver nano-colloid in deionised water (DW), and compared the difference between pre-adding and post-adding of polyvinyl alcohol (PVA). First, they added 50 ppm of PVA into 200 mL silver nano-colloid, named Ag-PVA. Second, they added 50 ppm of PVA into 200 mL DW as the dielectrics and produced silver nano-colloid through it, named PVA-Ag. Then they compared the differences between two samples with several instruments. They examined wavelength and absorbance by using UV–visible spectrophotometer (UV–vis), used Zetasizer to measure particle size and zeta potential, adopted scanning electron microscope (SEM) and transmission electron microscope (TEM) to observe shape, size, and distribution of the silver nanoparticles in the colloid. The results indicated that colloid PVA-Ag had higher zeta potential and better suspension.

Graphitic carbon nitride(C₃N₄)/carbon nanotubes (CNTs) composite photocatalyst was synthesised by a facile and simple method. The resulting graphitic C₃N₄/CNTs composite was characterised by X-ray powder diffraction, scanning electron microscopy and ultraviolet–visible diffuse reflectance spectroscopy techniques. The results showed that the CNTs modified by polyvinylpyrrolidone could provide a large amount of space and support for the surface area of graphitic C₃N₄ so that the redox reaction was faster. Therefore, the photocatalytic properties of graphitic C₃N₄/CNTs composite could be greatly improved. Meanwhile, compared to the pure graphitic C₃N_4, the surface-modified graphitic C₃N₄/CNTs composite showed stronger photocatalytic activity in degradation of rhodamine B under visible-light irradiation, especially the graphitic C₃N₄/CNTs (0.03 wt.%). In addition, the results also showed that the photocatalytic properties of the optimised nanocomposites were not decreased obviously.

This work studies field distribution and nanosensing based on a metallic rectangle nanoparticles arrays structure. The structure consists of a metallic rectangle nanoparticles layer, a dielectric layer and a metallic layer. A finite-difference time-domain approach is adopted to investigate the optical properties. Simulation results show that the localised surface plasmon resonance of the metallic rectangle nanoparticles give rise to absorption peaks in the spectra. Also, the absorption spectrum can be controlled by varying the geometrical parameters of the structure. It is also found that the reflection spectra dependence on the surrounding refractive index. The proposed structure can be used as an excellent plasmonic nanosensor. The simulation results show that the proposed plasmonic structure can serve as an optical absorber in the range of 700–1800 nm, which will have potential application in optical switching, optical modulator and nanosensors.

TiC nanoparticles/Ag composite films were successfully prepared on an indium tin oxide (ITO) substrate through co-electrodeposition, using the Ag plating solutions with minor addition of TiC nanoparticles, followed by heat treatment in vacuum. The X-ray diffractometer, scanning electron microscope and UV–Vis spectrophotometer were used to characterise phase composition, morphologies and optical properties of as-fabricated films, respectively. Experimental results show that only TiC and Ag phases are identified for the TiC nanoparticles/Ag composite films and TiC nanoparticles are incorporated tightly and uniformly on the surface of the composite films, without obvious clustering. The results of optical property test reveal that the TiC nanoparticles/Ag composite films have similar optical properties as thick silver films perforated with nanohole arrays, which will pave the way towards numerous potential applications of Ag nanohole arrays.

Recently, the study of power consumption and heat dissipation has attracted considerable research interest due to the development of various electric products. In this research, the authors replaced the solid conducting wire with a microfluidic channel and an electrolyte to conduct electricity and dissipate heat in a light-emitting diode (LED). The optical power and temperature of the LED using three electrolytes including salt (NaCl), sodium bicarbonate, and citric acid were measured. The measured optical power was the highest when NaCl was used as the electrolyte. The temperatures of the LED and at the bottom of the microfluidic channel were much lower when a liquid conductor was used as compared to when a solid conducting wire was used. The optical power of the LED obtained using a solid conducting wire was higher than that obtained using a liquid conductor. The temperature decreased and optical power increased with increasing flow rate. They hypothesised that a liquid conductor with a lower electric resistance would improve the optical power of the LED.

The liquid is usually driven by capillary force to flow forward in a channel network of a point-of-care testing device. However, it is not enough to drive the liquid flow forward that only relies on the surface tension of the chip material itself. While the liquid drops into the chip, the unstable liquid front shape may produce bubbles or the liquid flowing will even stop which will resist the signal detection. Here, a novel method, hydrophilic coating, is demonstrated. This method used an automatic device to dip the chips from the self-prepared TiO₂ sol forming the gel film on the surface of chips’ channel. Results have shown that the coating film will enhance the liquid flow performance and improve the detection precision and accuracy.

Zinc oxide nanorods (ZnONRs) were grown directly on the generally used sensing electrodes of alumina ceramic tubes by a hydrothermal method. Multi-walled carbon nanotubes (MWCNTs) were assembled on the surface of the ZnONRs using ultrasonic dispersing. The ethanol gas sensing properties of the prepared ZnONRs sensor, MWCNTs sensor, and ZnONRs/MWCNTs nanocomposite gas sensor were investigated. The ZnONRs/MWCNTs nanocomposite sensor demonstrated a higher response, faster response-recovery, and better selectivity to ethanol than the ZnONRs and MWCNTs sensors. At an optimal working temperature of 370°C, the response to 100 ppm ethanol is 26.1 for the ZnONRs/MWCNTs nanocomposite sensor, which is much higher than those of the ZnONRs sensor (10.4) and MWCNTs sensor (5.1). A short response time of 2 s and a recovery time of 16 s are achieved for the ZnONRs/MWCNTs sensor. Moreover, the long-term stability and repeatability of the ZnONRs/MWCNTs sensor were also discussed. The improved ethanol sensing properties of the ZnONRs/MWCNTs sensor can be attributed to the synergistic effects of ZnONRs and MWCNTs, including the large specific surface area and high electron transport capability.

Cu-modified Co₃O₄ nanosheets were designed and fabricated via a facile two-step process by a simple microwave-assisted reaction to synthesise Co₃O₄ sheets, followed by chemically reducing copper ion on Co₃O₄ sheets. The structures and morphologies of the obtained sheet-like Cu-modified Co₃O₄ nanomaterials were characterised by X-ray diffractometer, scanning electron microscopy, and transmission electron microscopy. As the anode materials for the lithium-ion battery applications, the Cu-modified Co₃O₄ nanosheet electrode delivered an initial discharge capacity of 1208 mAh g⁻¹ and its initial coulombic efficiency was 82.24%, much higher than 74.8% for Co₃O₄ sheets. More importantly, a reversible capacity of ca. 600 mAh g^–1 could be reached at a higher current density of 890 mA g⁻¹. The enhanced electrochemical performance may be attributed the incorporated Cu as well as the porous structure and the sheet-like morphology of the Co₃O₄ active materials.

Phonon Boltzmann transport equation and consequently the Equation of Phonon Radiative Transfer govern the conductive heat transfer in semiconductors at the nanoscale. Here a semiconducting nanoparticle composite, consisting of cubic Si nanoparticles in a Ge substrate is considered. A detailed three-dimensional heat transfer analysis is done, the temperature distributions are generated, the Effective Thermal Conductivity (ETC) of the nanocomposite is obtained, and the effect of the Si nanoparticle size and the constituents’ atomic percentage on the ETC is explored. As the most comprehensive study, the effect of the interface density on the ETC is investigated and the results are compared with those obtained using the Monte Carlo simulation. The results show that at a fixed atomic percentage, as the dimensions are decreased, the ETC reduces and the temperature jumps become larger. At a fixed Si nanoparticle size, as the Ge atomic percentage increases, the ETC also increases, and the ETC reduces as the interface density increases. Reducing the ETC is a way to improve the thermoelectric energy conversion.

To prevent parthenogenesis effect under embryo formation from sperms and oocyte, this study demonstrates that parthenogenesis of the oocyte of an ICR mouse can be induced with an AC electric field and without sperm insemination. The mouse oocytes were trapped with a positive dielectrophoretic force at the electrodes on an ITO-glass chip. The rates of parthenogenesis were tested under conditions of varied intensity of electric field from 33.35 kV/m to 266.8 kV/m and trapping durations 1, 3, 5 and 10 min. The results indicated that there is no significant statistical difference with varied trapping time (p > 0.1); with AC p-DEP electric activation, there is a significant statistical difference for 133.6 kV/m and 266.8 kV/m of electric field (p = 0.0013 and 0.0001 vs. control group respectively). The rate of parthenogenesis of the control group, oocytes with no electric activation, was 10.17±0.17% (n = 205). The rates of parthenogenesis were 51.65±7.8% (n = 27) at electric field 133.6 kV/m and 79.9±4.85% (n = 35) at 266.8 kV/m. The viability of these oocytes treated with an electric field exceeded 80%; this method of electric activation is hence safe for a mouse oocyte.

In this work, Ti₂AlC powders of high purity were prepared successfully by a facile microwave sintering technique which can reduce the sintering temperature from 1300 to 850°C obviously. This was probably because of the fact that the microwave field can decrease the activation energy of the particle surface, and improve ionic conductivity and the grain surface migration of charged vacancies. In addition, the purity of Ti₂AlC powders can be controlled by adjusting the molar ratio of Ti/Al/C/TiC as a precursor. It was interestingly found that Ti₂AlC powders with the highest purity of 96.6% were obtained at the molar ratio of Ti/Al/C/TiC = 1.5:1.0:0.5:0.45. This was probably attributed to the addition of TiC which favoured the formation of Ti₂AlC. However, excess TiC would influence the reaction path in the Ti–Al–C system and thus reduce the purity of Ti₂AlC. Therefore, this work can provide a facile method to synthesise other MAX powders.

A simple method is used to improve metal/n-germanium (Ge) contact characteristics by inserting plasma-enhanced atomic layer deposition (PEALD) deposited titanium dioxide (TiO₂)/GeO _x . Cross-sectional transmission electron microscope results confirm the thickness of the 30 PEALD cycles TiO₂/GeO _x is 1.62/1.38 nm. By inserting 1.62/1.38 nm TiO₂/GeO _x between aluminium (Al) and n-Ge, current densities increased by about 1800 times at −0.1 V compared with contacts without insertion layer (IL). With IL, ρ _c of 9.52 × 10⁻³ Ω cm² for Al/IL/n-Ge with an n-Ge concentration of 6 × 10¹⁶ cm⁻³ was achieved. ρ _c reduced by a factor 83 compared with no TiO₂ IL, and it also shows 4.72 times reduction compared with ρ _c extracted from samples inserting thermal ALD-deposited TiO₂. X-ray photoelectron spectroscopy (XPS) results shows that the valence state for GeO _x was 3.682, thus Ge surface may be passivated. It was also determined by XPS that TiO₂ was oxygen-vacancies rich, which may dope TiO₂ and may contribute to lower tunnelling resistance. All of the characteristics will be beneficial for low contact resistivity.

This work reported the fabrication of bovine serum albumin stabilised gold nanoclusters (BSA-Au NCs)–graphene oxide nanocomplex (BSA-Au NCs-GO) as a ‘turn-on’ fluorescent probe for the detection of Cd²⁺. The prepared BSA-Au NCs showed an intense red fluorescence, and the fluorescence of BSA-Au NCs was reduced significantly by graphene oxide due to its excellent quenching properties. However, in the presence of 65 µmol l⁻¹ Cd²⁺, the fluorescence intensity recovered to 82.5% of the intensity of BSA-Au NCs, and the fluorescence intensity increased 1.3-fold relative to the BSA-Au NCs-GO nanocomplex. This proposed probe expands the application of BSA-Au NCs, which can be used as a reversible fluorescence nanoswitch for inexpensive, label free and simple detection of Cd²⁺ in the aqueous samples.

The effect of the TiO₂ surface property on the conductivity of TiO₂/antimony-doped tin oxide (ATO) has been revealed by the substrate modification with SiO₂ and ZrO₂. Their morphology, structural, and electric characteristics were investigated through field emission scanning electron microscopy, transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and electrochemical impedance spectra. The surface character of the raw and modified TiO₂ particles in water was investigated. The results indicated that the negatively charged substrate (−29.7 mV) was formed through the incorporation of SiO₂ coating, which facilitated the uniform deposition of positively charged ATO precursors further significantly improved the conductivity of TiO₂/ATO composite. Conversely, the conductivity of TiO₂/ZrO₂–ATO composite decreased due to the increase of electrostatic repulsion from the positively charged surface (+55.3 mV) of the substrate. The results confirmed the feasibility of the method proposed in this work.

In this work, a new type of diaphragms called ‘piston coupled diaphragm’ is introduced to use as mechanical structure of sensors and micro-electrostatic actuators. Using the static theory based on Kirchhoff–Love theory of plates, expression of deflection is derived. It is assumed that the connection bar area is rigid and simulation results show accuracy of deflection expression. In order to use piston coupled diaphragm as mechanical structure of sensors, electrical and mechanical sensitivity, dynamic range and linear behaviour of the diaphragm are studied. The results show that by choosing a proper dimension of piston coupled diaphragm, because of increased centre rigidity the mechanical sensitivity will decrease but because of realisation of piston-like movement in mechanical structure electrical sensitivity improved by factor of about three in compression to conventional simple diaphragm with the same dimensions and also minimum detectable pressure is improved and linear behaviour of diaphragm degrades. An expression to describe linear behaviour of diaphragm up to 0.54% error from linear response is derived.

Herein, the work reports a novel approach to silver nanoparticles (AgNPs) with high fluorescence emission and smooth sphere morphology are prepared by a facile template synthesis strategy using polyvinyl pyrrolidone k-30 as a novel protective agent. It shows excellent fluorescence property and special morphology, and thus has great potential for the applications in biological imaging. It is also precise and highly reproducible in determining Cd²⁺ in real samples such as natural mineral water, tap water, milk and sewage with recoveries ranging from 90 to 111%, indicating the wide practical application to samples suspected of Cd²⁺ exposure.

A three-dimensional NiCo₂O₄@Co₃O₄ hybrid array on Ni foam electrode for supercapacitors was synthesised via a facile two-step hydrothermal method, in which the NiCo₂O₄ was self-assembled on the Co₃O₄ nanowire grown on Ni foam. Moreover, the electrochemical properties of the binder-free electrodes were studied by cyclic voltammograms, galvanostatic charge/discharge tests and electrochemical impedance spectroscopy. Electrochemical characterisations indicated that the unique nano-architecture exhibited excellent electrochemical properties of a high capacitance (1075 F/g), good rate (102.4%), cycling stability (92.6%), which were superior to the pristine Co₃O₄ nanowire. The results clearly confirmed that growing NiCo₂O₄ on Co₃O₄ nanowire could substantially improve the capacitive performance of Co₃O₄ materials.

Biosynthesis of silver nanoparticles (AgNPs) by flavonoids extracts from petals of Lilium casa blanca was reported. Reaction conditions such as pH, concentration of flavonoids or silver nitrite, reaction temperature and reaction time were optimised to control the formation of the AgNPs. Synthesised AgNPs were characterised by UV–Vis spectroscopy, transmission electron microscopy (TEM), dynamic light scattering (DLS), zeta potential measurement and Fourier transform infrared (FT-IR) spectroscopy. Stability, antibacterial and catalytic activities of the synthesised AgNPs were also discussed. The optimum synthetic conditions were 10 mL 20 mM AgNO₃ added to 1 mL flavonoids extracts, adjusting pH to 10, and reacted at 70°C for 1 h. The formation of AgNPs was confirmed by UV–Vis spectroscopic analysis, which showed maximum absorption peak at 404 nm. TEM analysis revealed spherical particles with size about 12.7 nm. FT-IR spectra revealed flavonoids were present on the surface of the AgNPs. AgNPs showed highest antibacterial activity against Escherichia coli and Salmonella, and the lesser antibacterial activity of AgNPs was found against Bacillus subtilis and Staphylococcus aureus. The biosynthesised AgNPs showed good catalytic activity as well by hydroboration of p-nitrophenol. Catalytic reduction followed pseudo-first-order kinetic.

The new nano–micro hybrid scaffolds were fabricated through electrospinning the poly 3-hydroxibutyrate-chitosan-multi-walled carbon nanotube (MWNT) nanofibres on the silky knitted microfibers, orderly and randomly. The scaffolds were prepared by varying the concentration of MWNT. The samples were compared as to their alignment and MWNT concentration. The morphological and physical properties were assessed through scanning electron microscopy, Fourier transform infra-red (FT-IR) spectroscopy and water contact angle test. Mechanical properties were determined through tensile strength test run on optimal samples chosen according to the results obtained from above-mentioned tests. The morphological view of the scaffolds showed that an increase in the amount of MWNT up to 1 wt% led to a better fibres diameter distribution and alignment in comparison with other samples. The porosity percentage of all scaffolds were >80% which is appropriate for tissue engineering applications. The FT-IR spectra indicated that the nanofibrous coat on knitted silk did not have any effect on crystallinity structures of silk fibroin. There existed a direct relation between hydrophilicity of scaffolds and MWNT concentration according to water contact angle. The presence of nanofibrous coat on knitted silk had no effect on tensile strength increment in comparison with pure knitted silk. The poly 3-hydroxybutyrate-Chitosan-1 wt% MWNT/Silk scaffolds could be an appropriate biomimetic for extracellular matrix of long-term healing tissues in order to their tissue engineering applications.

The size of particles is a principal parameter to design drug delivery vehicles. In this work, albumin nanoparticles were fabricated from microscaled poly[lactic-co-(glycolic acid)] (PLGA) templates using layer-by-layer (LbL) assembly, which are different from traditional LbL-based hollow capsules. The albumin nanoparticles exhibit a spherical shape and solid inner structure. The formation mechanism of these albumin nanoparticles was proposed based on PLGA templates, mechanical property of albumin and external sonication.

In this work, the investigation of high-K gate-stack-based junctionless (JL) double-gate (DG) metal-oxide-semiconductor field-effect transistor (MOSFET) is carried out to study the high-K gate dielectric effect on six-transistor (6T)-static random-access memory (SRAM) built with JLDG-MOSFET. It is observed that the utilisation of the high-K gate dielectric in JLDG-MOSFETs improves the static noise margin (SNM) that is the stability of the cell as well as access time (AT) which reflects the delay performance of the SRAM cell. Furthermore, scaling down of L_g degrades the stability. Moreover, it is also described that the enhancement in hold SNM (ΔHSNM = HSNM_(K=40)−HSNM_(K=3.9)), read SNM (ΔRSNM = RSNM_(K=40)−RSNM_(K=3.9)), and write SNM (ΔWSNM = WSNM_(K=40)−WSNM_(K=3.9)) is restricted at lower L_g without much enhancement in the improvement of read AT and write AT. Therefore, it is appropriate to consider higher channel length (∼30 nm) while designing high-K gate-stacked-based JLDG-MOSFETs for the 6T-SRAM cell.

Graphene nanowalls (GNWs) were deposited on the surface of the copper foil, nickel foam and glass using the plasma-enhanced chemical vapour deposition (13.56 MHz) method. The etching effect of hydrogen on the morphology of the GNWs was investigated by varying the CH₄/H₂ ratio during the graphene growth. Supercapacitor electrodes made of GNWs on nickel foam were tested with cyclic voltammetry and galvanostatic charge/discharge methods, showing premium electrical double-layer performance and cyclic stability.

This work demonstrates the fabrication of a composite nanomaterial consisting of spherical silica nanoparticles decorated onto the graphene sheets which has been prepared by the sonication-assisted method. Graphene/silica nanocomposites were fabricated by the hydrolysis of tetraethyl orthosilicate in the presence of graphene oxide which has been obtained by modified Hummer's method. The obtained nanostructures were characterised by the X-ray diffraction (XRD), Raman spectroscopy, Brunauer–Emmett–Teller (BET), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The XRD analysis depicts the coexistence of silica and graphene in the composite material. The morphology of synthesised silica–graphene nanocomposites was characterised by SEM and TEM. All images have been observed in the presence of SiO₂ nanoparticles of similar sizes which were grafted on the surface of graphene effectively. More significantly, the BET analysis revealed that the silica decorated graphene nanocomposites exhibit enhanced surface area than bare silica and graphene.

Novel composite phase change materials (PCMs) based on three-dimensional reduced graphene oxide (3D-rGO) were fabricated. Both borax (Na₂B₄O₇·10H₂O) and 3D-rGO were used to reduce the supercooling degree of sodium sulphate decahydrate. The T-history method was used in studying the effect of Na₂B₄O₇·10H₂O and 3D-rGO on supercooling of PCM. It was found that both borax and 3D-rGO can reduce the supercooling degree of the composite PCMs, and the positive synergy effect between 3D-rGO and Na₂B₄O₇·10H₂O is significant. These results provide valuable guidance for improving the phase transition properties of hydrated salts.

The purpose of this work was to model and optimise the preparation of silica aerogel using low-cost material and modified sol–gel process. A central composite design was employed to optimise the synthesis factors. Among all factors discussed in literatures, silica concentration, gelation time and hydrophobic agent amount were the most efficacious ones. All experiments were performed at the same conditions, but the elected factors were varied in five levels. The response (density of silica aerogel) was fitted by quadratic regression model to find the optimal condition. Computation results showed that the minimum density of silica aerogel was achieved at silica concentration of 4.12 g/l, acid amount of 14.46 ml and trimethylchlorosilane (TMCS) consumption of 10.39 ml. The best density of silica aerogel was 0.078915 g/cm³ and the specific surface area determined by Brunauer–Emmett–Teller (BET) analysis was 780 m²/g.

Vibration-based nonlinear energy harvester has acknowledged great effort to harvest power out of low-frequency wideband applications. The nonlinear analytical model of a cutout two degree of freedom piezo-magneto-elastic energy harvester is developed to obtain electrical responses of wide bandwidth in between first two successive lower-vibration modes. Specifically, the nonlinear static tip displacements, mechanical potential energy, modified nonlinear stiffness and tuned resonant frequencies are analytically obtained as a function of initial distance between two magnets which include spring and damping effects of each joint of cantilever beams. The numerical models of magnetic force interactions and harvester models are developed using finite element methods to validate the solutions of analytical models along with available experimental data from the literature. Finally, the optimised inner beam length is found to avoid the anti-resonant frequency in between the bandwidth region.

Fibre reinforced polymer composites are a popular alternative to traditional metal alloys. However, their internally occurring damage modes call for strategies to monitor these structures. Nowadays, carbon nanotube buckypaper is usually used as a sensor to monitor the strain and/or damage of composites subjected to tensile and cyclic fatigue loadings. In this work, this result is achieved by measuring the electrical resistance response of the buckypaper sensor which is co-cured with the composites. The test results show that the buckypaper sensor has a very high strain sensitivity in static tensile test and the strain sensing factor can reach about 64.77; moreover, in the fatigue test, although the temperature decreases the resistance of buckypaper sensor, the rate of resistance change still changes linearly with loading and unloading. These studies indicate that buckypaper sensor has a very good stability and synchronisation for strain monitoring and it can meet the needs for health monitoring of composite structures.

Malachite green (C₂₃H₂₅ClN₂) is an illegal fungicide of aquatic products due to its potential carcinogenic, teratogenic, and mutagenic effects. It is typically challenging to detect C₂₃H₂₅ClN₂ in fish with conventional techniques. The study reported a simple and rapid method for detecting C₂₃H₂₅ClN₂ on fish surface with surface-enhanced Raman scattering (SERS). Using the seed growth method with trometamol as the modifier, 110 nm in-diameter gold nanoparticles on thin glass as SERS substrate were prepared, which exhibited high SERS activity, reproducibility, stability, and flexibility in SERS measurement. The fish samples required no pretreatment and the entire measurement took <5 min. Quantitative analyses were also conducted. Excellent linear relationships (R ² = 0.9397–0.9977) were obtained between the concentrations and the peak intensities of C₂₃H₂₅ClN₂ at some characteristic peaks with a wide concentrations range (0.5–10 μM). The detection limit can reach 0.5 μM. This method provided an easy and fast way to detect C₂₃H₂₅ClN₂ on fish surface for food safety.

The work analyses the significance of fringing capacitance in modelling effectively the amplitude of the ultrasonic waves generated by silicon nitride membrane-based micromachined ultrasonic transducer (MUT). The amplitude of the ultrasonic waves is proportional to the displacement of the biased membrane under the influence of a sinusoidal signal. Fringing capacitance is significant as for operating the transducer in the medical imaging regime of frequency range 1–10 MHz, the dimension of the electrodes of the MUT capacitor becomes comparable with the separation between them. The device is modelled first without the fringing effect and then Palmer, Landau's and Younes Ataiiyan's approaches are considered for evaluating the fringing capacitance. The device is finite element method analysed by PZFLEX 3D simulator. The membrane displacement is evaluated with variation in device structural parameters of membrane radius and thickness, electrode separation and bias voltage for an extensive range of values. Fractional percentage error of the above analytical approaches is evaluated with respect to the PZFLEX which are regarded as closest to reality. Substantial decrease in the error is observed on modelling the device with the effect of the fringing capacitance.

In situ vapour grown carbon fibres (VGCFs) were fabricated on carbon felt by chemical vapour infiltration. In this work, the different conditions of the preparation process were determined to obtain VGCFs in large quantities, namely pressure in the reactor and concentration of the aqueous catalyst precursor solution. Observations regarding the growth process of the VGCFs reveal that the catalyst particles with a round shape and diameters of 1 μm or above are most likely to produce VGCFs. The final results indicate that the diameters of VGCFs range from 80 to 150 nm and that their lengths range from 5 to 30 μm. Furthermore, the lengthening and thickening processes of VGCFs were proved to occur simultaneously in the experiment.

Novel flake-belt integrative silver (Ag) nanocrystals have been constructed for the first time by a facile one-step reduction reaction. In the process, as a modulator, a trace amount of ethylenediaminetetraacetic acid disodium salt played an important role. According to the basic characterisation, a selective deposition and an epitaxial growth mechanism of the reduced Ag were used to explain the formation of the flake-belt integrative structure. The high integration of a flake and belt in one particle is completely different from the stacked assembly of nanobelts and flakes. Interestingly, uniform Ag nanobelts were obtained by simply modulating experiments. This work provided a methodology to fabricate metal hierarchical nanoparticles and a new thinking on the growth of Ag nanocrystals.

Pattern density is an important factor in UV nanoimprint stamp design. Various pattern densities may affect the thickness of the residual layer and its uniformity. This work investigated the effect of pattern density as well as other stamp parameters, including stamp material, stamp thickness and cavity height, on residual layer thickness (RLT), contact pressure, and imprint quality. Two kinds of stamps were designed for simulation, one with detached uniform lines and the other with adjacent non-uniform lines. Results show that areas near the edges of the imprint field in all stamps are the first to achieve high contact pressure. The study observed that long imprint time enables a reduction of RLT after a stable period, particularly obvious with high density. For a long-term imprint of patterns with various densities, flowing behaviour of the residual resist was revealed. These conclusions are beneficial for making guidelines for stamp design in UV nanoimprint lithography.