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The PVDF/BST thick films were synthesized using a solution casting method. The introduction of BST into the PVDF matrix increased the dielectric constant (ε′) of the thick films. Subsequently, the pristine PVDF films and the PVDF/BST thick films underwent radiation with a 662 keV Cs1+ ion beam. Following radiation, changes were observed in the materials and their dielectric properties were studied. PVDF underwent recrystallization process accompanied by a phase shift from the α to β state. Consequently, the ε′ increased for all the PVDF-BST thick films after exposure to 662 keV Cs1+ ions, while the tangent loss also increased with increased loading of the BST filler. Notably, it is intriguing to observe that the 662 keV Cs1+ ion radiation led to a reduction in the dielectric constant, likely due to a cross-linking effect within the PVDF/BST thick films. [ABSTRACT FROM AUTHOR]

The electrophysical properties of nanostructured MgAl2O4 ceramics sintered at 1300 °C for 5 h, as well as thick films were obtained and investigated. The study of adsorption-desorption cycles was carried out after sintering and aging test. It is shown that ceramic has a sensitivity to humidity in the range of 25–95% with minimal hysteresis of the characteristic in adsorption-desorption cycles, which can be eliminated after the aging test. Thick films based on it are characterized by hysteresis and loss of sensitivity at low values of relative humidity, which is caused by the clogging of small nanopores. [ABSTRACT FROM AUTHOR]

AbstractLiquid nitrogen spray cooling is crucial in cryogenic wind tunnels, while the understanding of its basic phenomenon, liquid nitrogen droplet impact, remains elusive. In this study, a numerical model of a liquid nitrogen droplet impacting on a liquid nitrogen film is established, and the impact mechanisms and influencing factors are analyzed. The dynamic behavior of the liquid nitrogen droplets reveals that as the dimensionless liquid film thickness varies from 0.1 to 0.8, the droplet impact behavior changes from deposition, and crown formation to splash with the Weber number increasing from 0 to 1000. The variation of the dimensionless crown diameter with the dimensionless time solely negatively correlated with liquid film thickness. The maximum dimensionless crown height increases approximately linearly with the Weber number. The splash characteristics indicate that the lower surface tension and viscosity of liquid nitrogen make the droplet easier to exhibit splash as compared with water droplets. As the dimensionless liquid film thickness increases from 0.1 to 0.4, the critical Weber number enabling splash to occur increases from 170 to 375, indicating that a thick liquid film suppresses the splash. [ABSTRACT FROM AUTHOR]

Heavy metals are potent polluters of marine ecosystems. Consumption of contaminated seafood may lead to adverse health effects. In this work, thick film modified graphite sensors are used as working electrodes for the simultaneous determination of copper, lead, cadmium and zinc in mussel tissue from the Sea of Japan. The samples were prepared by HNO3 wet mineralization and analyzed in pH 4 acetate buffer by anodic stripping voltammetry. The analytical signal was studied as a function of accumulation potential, accumulation time, and sweep rate to determine the optimal electrolysis conditions. Standard addition method was used to evaluate the heavy metal concentrations to minimize matrix effects. The developed procedure is rapid, inexpensive, and reproducible, and has high selectivity and low limits of detection for the analytes. The relative standard deviations for the concentrations of Cu, Pb, Cd, and Zn are 13%, 21%, 7.7%, and 15%, respectively. The accuracy was confirmed by comparing the results with those obtained by inductively coupled plasma – optical emission spectrometry (ICP-OES) and inductively coupled plasma – mass spectrometry (ICP-MS). [ABSTRACT FROM AUTHOR]

The rheology of a conventional lithium-12 hydroxystearate bearing grease changes significantly when it is subjected to mechanical shear. Often this shear energy–along with the consequent entropy–is measured and used in engineering and thermodynamic models, leading to grease life models for predicting bearing seizure due to insufficiently thick film or loss of lubricity of the base oil/grease. In this degradation process, the bonds between the individual molecules, consisting mainly of the fairly weak van der Waals bonds and/or hydrogen bonds, are broken during this shearing process. In this article, we show that only a very small portion of the shear energy is needed to break these bonds and that the vast majority is dissipated as heat due to the lubricant viscosity, also known as viscous dissipation. We model the thickener as rod-shaped fibers, wherein the grease viscosity is reduced by a factor of 5 when the length of a fiber is reduced by a factor of 2.5. The energy needed to break the bonds between the molecules to shorten these fibers is 6 to 7 orders of magnitude smaller than the energy applied by shear. Hence, it is very difficult to measure this fiber structure breakage energy from grease shear aging experiments directly. [ABSTRACT FROM AUTHOR]

Clarifying the evolution of in-service asphalt pavement aging is critical to the project-level strategy decision of pavement maintenance. However, the environmental-induced differences in field aging evolution are still unclear. To address this problem, this research aims to first characterise field aging in terms of both chemistry and rheology, and then to investigate the factors controlling the aging gradient of asphalt pavement from both the environment and the mixture itself. Field cores were collected from 14 sections of 10 highways with different in-service times, climatic conditions, and mixture types. Field-aged binder was extracted from wearing course with different depths. Laboratory-aged binder after different cycles of Pressure Aging Vessel (PAV) were also evaluated as a benchmark for field-aged binders. The rheological and chemical properties of both the field-based and lab-based aged binders were measured using dynamic shear rheometer (DSR) and Fourier transform infrared (FTIR) spectrometer, respectively. Moreover, the mortar film thickness index (Tm) of mixture from 4 sections was characterised through image processing techniques. The changing rate of the pavement in 0–2 cm characterised by carbonyl index was closely correlated with environmental factors. Higher solar radiation, lower annual days >30°C, and thicker mortar film thickness lead to a greater aging gradient. [ABSTRACT FROM AUTHOR]

The phase composition, microstructure, and electrical properties of nanostructured thick films based on Cu0.1Ni0.8Co0.2Mn1.9O4 and Cu0.8Ni0.1Co0.2Mn1.9O4 ceramics were studied. Degradation tests were performed at 170 °C to stabilize the functional properties of thick films. The effect of thermal "shock" at the initial stage of isothermal exposure with subsequent stabilization of electrical resistance at this level was revealed. It is shown that high-temperature sensitivity and stabilization of electrical parameters in the studied single-phase thick films can be used for the production of thick-film sensor components for nanoelectronics devices. [ABSTRACT FROM AUTHOR]

The electrical properties and kinetic dependences of thermally induced drift of electrical resistance in eco-friendly single- and multilayer temperature-sensitive thick-film structures based on Cu0.1Ni0.1Co1.6Mn1.2O4 (with p+-type electrical conductivity) and Cu0.1Ni0.8Co0.2Mn1.9O4 (with p-type of electrical conductivity) ceramics for multisensor nanosystems. It has been established that in the p- and p+-type thick films the processes of burning out the residues of the organic bond between grain spinels and simultaneous penetration of metallic silver into the space are activated. Such processes are described by a compressed exponential-power relaxation function. Thick-film p+-p structures are characterized by own aging processes, which manifest themselves in an increase in electrical resistance. Kinetics of their thermally-induced aging is adequately described by an extended exponential-power function. [ABSTRACT FROM AUTHOR]

In order to solve the problem that the optical fiber surface plasmon resonance (SPR) sensor is insufficiently sensitive for biomolecule detection, a novel sensing probe was proposed and designed, where the semiconductor material α-Fe2O3 was introduced for the first time. The α-Fe2O3 with high refractive index enhances the electric field and evanescent field depth at the interface between the α-Fe2O3 film and the ambient medium, resulting a sensitive performance. The characteristics of the sensors with gold film and α-Fe2O3 film at different thicknesses were analyzed and compared by finite element method. The thicker the α-Fe2O3 film, the higher the sensitivity. When the thickness of gold nanofilm is 50 nm and the thickness of α-Fe2O3 nanofilm is 20 nm, the highest figure of merit (FOM) is 50.98 RIU−1, corresponding to a sensitivity of 4800 nm/RIU, which is 2.16 times more sensitive than the traditional SPR sensor. In addition, three α-Fe2O3 film thickness-assisted SPR sensors were successfully prepared with the highest sensitivity of 4173.1 nm/RIU, which is nearly two times higher than without the α-Fe2O3 film. The enhancement after introducing α-Fe2O3 nanofilms and its promising application in the field of biosensing were confirmed through experiments and simulations. [ABSTRACT FROM AUTHOR]

130,000 g/mol molecular weight of polyvinylpyrrolidone (PVP) was purposed to prepare PZT sol desiring the thick film (≥1.0 µm) deposition on Pt(111)/TiO2/SiO2/Si. Centrifugal force and the spilling of sol during spin coating were found to control the cracks and surface coverage of the films. A rotation-dependent typical pattern formation at the central part of the substrate was observed and better coverage was observed on gel drying 60 °C than 125 °C. Though the remnant polarization (2Pr) of 21.4 µC/cm2 was recorded at 100 Hz for 2.1 µm, it is 41.8 µC/cm2 for 1.06 µm thick films. [ABSTRACT FROM AUTHOR]

Area-selective atomic layer deposition (AS-ALD) has been studied as an alternative method for metal oxide ALD film patterning in the microelectronics industry. To perform AS-ALD, area-deactivation or -activation processes should be implemented in advance using selective surface modification through a photography-based lift-off process and printing techniques. This study introduces a novel approach for Al2O3 AS-ALD using inkjet-printed inhibition patterns. ALD-inhibition patterns with two-layer structures of fluorocarbon (FC) thin film and photoresist (PR) were patterned by inkjet printing. Low surface energy FC thin films were used to block the Al2O3 nucleation and growth during the ALD process, and PR was patterned to easily remove ALD-inhibition patterns using a lift-off process. To demonstrate AS-ALD, an Al2O3 thin film approximately 10 nm thick was deposited via an in-house built system with a multiple-slit gas source. The proposed AS-ALD method was evaluated for topological analysis using atomic force microscopy and surface composition analysis using a time of flight secondary ion mass spectrometry after Al2O3 deposition and a lift-off process. Finally, a 6 nm thick Al2O3 film was selectively patterned by the lift-off process using an inkjet-printed 1.28 μm thick FC-covered PR inhibition pattern. [ABSTRACT FROM AUTHOR]

Aging processes in the two types of temperature-sensitive Cu0.1Ni0.8Co0.2Mn1.9O4 ceramics (two-phase and with different amount of NiO phase) as well as thick films base on Cu0.1Ni0.1Co1.6Mn1.2O4 ceramics were investigated. It is shown for Cu0.1Ni0.8Co0.2Mn1.9O4 ceramics prepared at 1170 °C with addition treatment at 850 °C that the post-separation process of the second phase continue under heat at temperatures of 125 and 170 °C. It has been found that higher thermal aging leads to more pronounced changes in electrical resistance. Addition temperature influences contribute to the stabilization of ceramic parameters. The aging test at 170 °C results in a 7.5% reduction in electrical resistance, while at 125 °C this value is only 6%. It is shown that NiO phase additives formed during sintering of Cu0.1Ni0.1Co1.6Mn1.2O4 ceramics and located near the grain boundaries of ceramics inhibit the aging process in these materials. This effect is characteristic of fine-grained ceramics obtained by thermal energy converted during sintering. It is established that the kinetics of aging in Cu0.1Ni0.1Co1.6Mn1.2O4 ceramics is described by the relaxation function of DeBast-Gillard or Williams-Watts, regardless of the composition of the ceramics. The aging kinetics in thick films based on Cu0.1Ni0.1Co1.6Mn1.2O4 ceramics at 170 °C is also adequately described by the compression-exponential relaxation function. [ABSTRACT FROM AUTHOR]

A series of Ba2NdFeNb4O15 thin films with a thickness from 75 nm to 1 μm on Si(001) substrates was fabricated by RF-cathode sputtering. The surface of the films was smooth and uniform. Ba2NdFeNb4O15/Si(001) thin films were polycrystalline with the c-axis texture. A significant increase in the lattice parameter c of the films was found in comparison with the bulk sample. It was found that an external field action could create polarized regions in both thin and thick films, but rapid relaxation of these regions took place. [ABSTRACT FROM AUTHOR]

An applied electrochemical method in the form of a chronocoulometry technique is proposed for measuring Fick's diffusion constant of a thin protective coating layer over the conductive base materials. Using this method, the capacitance is monitored for a capacitor formed using the base material, an electrolyte such as aqueous NaCl, and an insulating coating layer in between. The capacitance increases when the distance between the base material and the electrolyte decreases in the diffusion of the electrolyte through the insulating coating layer. Therefore, the change in the capacitance provides a diffusion rate related to Fick's diffusion constant. Conventional gravimetric methods require a long measurement time to reach saturation, and thin coating layers of minimal weight increment through water diffusion were demonstrated to be inadequate for the methods. However, the new electrochemical method is appropriate for thin coating layers and requires a limited duration after the onset of diffusion. Experimental for 1-mm thick PA6 films provided Fick's diffusion constants of safer side with the new method of 15h by reflecting the heterogeneous properties of the surface, while the conventional gravimetric method in 360h provided smaller or danger-side values. [ABSTRACT FROM AUTHOR]

Wave propagation through a nonmagnetic achiral/chiral (ACC) interface (en route to chiral/achiral (CAC) interfaces and resonant slabs) is investigated in-depth using amplitude Fresnel coefficients (FCs). A p-polarized plane wave at the interface is tracked for rarer-to-denser configuration, followed by incidence at a CAC interface under stand-alone and ACC source interface conditions. Finally, a model involving a low-loss tangent chiral dielectric is examined by investigating the corresponding reflection and transmission behaviour. Detailed understanding of the (anomalous or normal) occurrence of total internal reflection (TIR), inverse total internal reflection (ITIR), evanescence, α e f f – and β e f f – based envelope decay and propagation across the modes in the longitudinal and transverse directions. A few sample simulations involving chiral slab resonators with p-polarization incidence are also presented. In ongoing follow-up work, dual lossy interfaces combined to create chiral resonators and arrays (in the thick or thin film regimes) will be investigated building upon the results presented here. [ABSTRACT FROM AUTHOR]

Lead-free piezoelectrics are considered an alternative to lead-based piezo-material for various device applications such as energy harvesters, actuators, and sensors. Ba0.85Ca0.15Zr0.1Ti0.9O3 (BCZT) and 0.94(Na0.5Bi0.5)TiO3-0.06BaTiO3 (NBT-BT) are the lead-free piezoelectrics that are commonly studied due to their superior properties. In this study, we have fabricated thick films of NBT-BT (∼700 nm), BCZT (∼700 nm), and heterostructures comprising both BCZT/NBT-BT(∼500 nm) on commercial Pt(111)/TiO2/SiO2/Si substrates using Pulsed Laser Deposition method. The phase purity of these films was confirmed by X-ray diffraction analysis. The ferroelectric properties of these films were measured using piezo-response force microscopy. The devices were tested by subjecting them to the vibrations of varying frequencies and loads using a vibration simulator/tester for vibration sensing. The BCZT film generated a significant voltage output (∼2 mV). These thick films possess excellent sensitivity and high voltage output, making them candidates for device applications. [ABSTRACT FROM AUTHOR]

Peculiarities of diffusion processes of Ag after aging test at 170 °C in the nanostructured temperature-sensitive Cu0.1Ni0.1Co1.6Mn1.2O4-based thick films are investigated. Microstructural and electrical properties of studied thick films before and after annealing (aging test) are investigated. It is shown that aging of thick films results in diffusion of Ag from contact area in region of grain boundaries. Analytical description of aging processes in these materials was performed using relaxation functions. It is shown, that studied aging kinetics are adequately described by compression–exponential relaxation function. Obtained Cu0.1Ni0.1Co1.6Mn1.2O4-based thick films with stabile electrical properties can be used as temperature-sensitive elements for micro- and nanoelectronics. [ABSTRACT FROM AUTHOR]

Graphene-based materials have peculiar optical, electrical, mechanical and chemical properties, which make them useful for making thin films and thick sheets suitable for different needs. Matter physics, nuclear physics, microelectronics, biomedicine, engineering, agriculture and cultural heritage just represent some of the sectors in which these materials can be successfully used. The advancements allow us to go from a given graphene-based material to another transforming, for example, the insulator graphene oxide to electrically and thermally conductive reduced graphene oxide. Thanks to the interesting properties possessed by graphene-based materials, it is possible to realize gas sensors, dosimeters for ionizing radiation, light detectors, electronic devices, membranes for gases and desalination, biocompatible surfaces, medical protheses and thin coating films to preserve underlying layers. Different analysis techniques are presented to control the physical modifications of reduced graphene oxide (rGO) due to the different treatments for the pristine one. The paper reports the possibility to realize GO micro-dosimeters for ionizing radiations, sensors for air humidity and other gases, field effect transistors as the detector of visible and UV radiations, GO and rGO membranes realization for different gases, source ion strippers to enhance the charge state of different ions to be accelerated. Some of these aspects and possible applications will be presented and discussed with measurements carried out in our laboratories. [ABSTRACT FROM AUTHOR]

New applications of porous anodic aluminium oxide (alumina) structures for the fabrication of photonic devices, etching masks, and periodic pore templates with prospective magnetic, photoluminescent, anti-reflecting properties recently are of high interest. In this respect, new anodising processes for controllable formation of periodic structures in unconventional solutions at low voltages might be challenging. In this study, the anodic behaviour of aluminium in aqueous formate solutions was studied within a wide range of concentrations, pH, electrolyte temperatures, anodising times, and voltages. It was established that the thickness of porous anodic films depended on the concentration of solution applied (c), pH, bath temperature (T), and voltage (Ua) increasing with increase in c, Ua, and T. The thickest films were formed in the solution containing 0.2 mol L−1 formic acid at a pH of 2.5. These films contained up to 5.8 at% of entrapped carbon. The transition of porous anodising to the 'burning' type occurred at 22–25 V. Under appropriate anodising conditions ordered hexagonal cell arrays can be formed. [ABSTRACT FROM AUTHOR]

We report here a facile method of modulating the lengthscales of self-organized dewetting of polystyrene thin films by varying the extent of silane grafting on the substrate. The self-assembled monolayers (SAM) of octadecyltrichlorosilane (OTS) were grafted on glass substrates by exposing them to different doses of OTS vapors in a controlled, low pressure environment. Measurement of water contact angles on the modified glass surfaces showed that the contact angles could be continuously increased from 40° to 70° by increasing the time of exposure to the OTS vapors from a few minutes to several hours. Polystyrene (PS) thin films were spin coated on the modified glass substrates and water-solvent mixture induced dewetting of the PS thin films was carried out, where the dewetting kinetics depended on the spreadability of water on the surface. We observed a reduction in the length scales of the dewetting, i.e. the wavelength of instability (λ) and droplet size (d), by increasing the extent of OTS exposure. The λ for a 50 nm thick PS film decreased from 12 to 4 µm while the droplet diameter (d) also decreased, from 2.5 to 1.6 µm. [ABSTRACT FROM AUTHOR]

Onion-like fullerenes possess distinctive physical and chemical performance, and thus are believed to have great significance in theoretical study and engineering applications. In this exploratory research, we introduced a novel way, namely electrochemical reduction method performed in aqueous solution at room temperature and very low voltages, for preparing a film composed of onion-like fullerene nanostructures. The method was discovered by accident. During the preparation of thick Cr coating by electrodepositing from Cr (III) electrolyte, a layer of black film was found at the interface between the steel substrate and Cr coating. XPS analysis shows that the main element contained in the film is C. The results from Raman spectrum, HRTEM and SAED reveal that the carbonaceous film is composed of the nanostructures roughly having onion-like fullerene unit. This means with significant advantages has the potential to develop into a practical technique for fabricating carbonaceous films or coatings. [ABSTRACT FROM AUTHOR]

With the development of electrical industry, demand for a ceramic-based capacitor with high energy storage density has been increased gradually. The efficiency considered as a key factor of energy storage density is sensitive to temperature change. In this study, using the aerosol deposition (AD) method, we have fabricated lead-free 6Bi0.5Na0.5TiO3(BNT)-4Sr0.7Bi0.2TiO3(SBT) nano-grain composites to improve the energy storage properties and thermal stability. Through the novel AD method, artificially engineered ferroelectric thick films with nano-grain can be fabricated at room temperature. The thick films of 6BNT-4SBT post-annealed at 550°C had an energy storage density of 10.4 J/cm3, high efficiency of 64.5% at 900 kV/cm, and excellent thermal stabilities (ΔWrec < ~9% and Δη < ~30%) heating to 140°C. These results reveal that 6BNT-4SBT thick films fabricated by the AD method have excellent dielectric properties and thermal stabilities as a lead-free material. [ABSTRACT FROM AUTHOR]

A novel 0.36BiScO3-0.64PbTiO3 (0.36BS-0.64PT) textured ceramic was developed using plate-like BaTiO3 (BT) templates for high temperature piezoelectric device applications. Sintering temperature and amount of BT template played important roles in improving the density, crystal orientation, and ferroelectric and piezoelectric properties of the BT-templated 0.36BS-0.64PT thick films. When sintered at 1000°C, highly dense BS-PT textured films were obtained without formation of a secondary phase. The increased amount of BT template facilitated the degree of texture but deteriorated the relative density of BS-PT thick film. In particular, enhanced ferroelectric and piezoelectric properties were obtained for 1 vol% BT-templated 0.36BS-0.64PT thick film sintered at 1000°C; this film exhibited the very large Pr (44.2 μC/cm2 at 4 kV/mm), d33 (444 pC/N), kp (57.4%), and g33 (36 × 10−3Vm/N) values. In addition, considering the inverse relation between TC and strain, the electrostrain of d33* (622 pm/V at 4 kV/mm) was excellent, showing potential for piezoelectric actuator applications. [ABSTRACT FROM AUTHOR]

ITO thin films must have good electro-optical and mechanical characteristics to use them as integrated touch sensors for flexible OLED displays. We fabricated ITO thin films on a separation-layer-coated glass substrate under various deposition or annealing conditions, and then transferred them to cyclo-olefin polymer films to evaluate their electro-optical and mechanical characteristics. ITO films with a thickness of approximately 136 nm deposited at 250°C showed a sheet resistance of 36 Ω/□, light transmittance of 88%, and 2.4% of elongation at break. The 136 nm thick ITO films deposited at 150 °C and transferred on 50 μm thick COP film survived 500 h of 85 °C, 85% relative humidity under 180-degree bending preservation test, endured at 200,000-time repetitive bending test with a curvature radius of 1.5 mm. These high-performance ITO thin films can be applied to fabricate on-cell touch sensors for foldable OLED displays. [ABSTRACT FROM AUTHOR]

In this paper, thick film antiferroelectric ceramics (1-x)(Pb0.97La0.02)(Zr0.46Sn0.48Ti0.06)O3-xH3BO3 ((1-x)PLZST-xH3BO3, x = 0–0.025) were prepared by solid state sintering and tape-casting method. The effects of boron-doping on the microstructure, dielectric properties and energy storage properties of (1-x)PLZST-xH3BO3 ceramics were investigated. Appropriate boron-doping can improve the stability of antiferroelectric phase, delay phase transition and increase saturation polarization strength. Compared with the undoped PLZST thick films, the maximum polarization intensity increased by 1.9 times and the residual polarization decreased by 37%. When x = 0.020, the maximum recoverable energy storage density is 2.74 J/cm3, and the energy storage efficiency is 88.12%. [ABSTRACT FROM AUTHOR]

Nanocrystalline ZnFe2O4, NiFe2O4 and CoFe2O4 were prepared using rapid microwave assisted combustion technique. Single phase Nanocrystalline structure of ferrites confirmed by X-ray diffraction and Rietveld refinement. Fine powder of Nanocrystalline Zn, Ni and Co ferrites resulted from rapid synthesis route were used for gas sensor fabrication in the form of thick film by screen printing method. Scanning electron microscopy was used to study surface of the sensing element and to study the surface morphology of the sensor. The gas sensing responses of the indigenously built sensor were analyzed by measuring the resistance of sensing element in presence and in absence of LPG. Amongst the studied sensors, NiFe2O4 thick film sensor showed superior response. [ABSTRACT FROM AUTHOR]

Thin films of poly (3-hexylthiophene), abbreviated as P3HT, are widely used systems of semiconducting polymer for applications in organic electronic devices. We studied the microstructure of spin-coated thin films of P3HT using grazing incidence x-ray diffraction (GID) by combining high-resolution vertical scan with 2D intensity maps obtained using area detector. Microstructure of the films was quantitatively analyzed in terms of relative crystalline density, texture and coherence length. The structure of the films was relaxed by annealing at 110°C. The relaxed microstructure shows strong thickness dependence. Thick film (61 nm) was highly crystalline and textured. For thin film (32 nm), relative crystalline density was very weak but the coherence length of crystallites was larger and the orientation of crystallites was even more strongly textured. For thick film, the strong increase of crystalline density takes place through fresh nucleation and reorientation of crystallites already present in the films. For thin films, the substrate interaction induced very strong alignment of lamellar crystallites through degeneration of off-oriented crystallites and increased lamellar crystalline coherence. The drastic change of microstructure within a small thickness range is an important aspect to be considered while preparing thin film devices. [ABSTRACT FROM AUTHOR]

In the present work, we realize a miniaturized piezoresistive accelerometer with high magnitude of prime-axis signal and a very low cross-axis signal. Numerical simulations are performed to investigate the electro-mechanical response of three structures with different flexure positions and an electroplated gold layer. Of the three structural configurations, one structure with the proof mass-edge-aligned-beams and an electroplated gold film has better performance with lesser real estate consumption. Experimental results show that a fabricated sensor depicts around 20% improvement in the prime-axis signal and a maximum reduction of 7.6% in the cross-axis signal compared to other structures. [ABSTRACT FROM AUTHOR]

Introduction: Fluid flow has a prominent influence on the metabolism of surface-attached biofilms. Dental biofilms are covered by a thin saliva film that flows at different rates in different locations under stimulated and unstimulated conditions. Methods:The present study employed pH ratiometry to study the impact of different flow velocities, saliva film thicknesses and saliva concentrations on microscale pH developments in Streptococcus mutans biofilms of different age. Results:While saliva flow at a velocity of 0.8 mm/min (unstimulated flow) had little impact on biofilm pH, stimulated flow (8 mm/min; 80 mm/min) affected vertical pH gradients in the biofilms and raised the average pH in 48-h biofilms, but not in 72-h and 168-h biofilms. The saliva film thickness had a strong impact on biofilm pH under both static and dynamic conditions. pH drops were significantly higher in biofilms exposed to a thin saliva film (≤ 50 µm) than a thick saliva film (> 50 µm). pH drops in the biofilms were also strongly dependent on the saliva concentration and thus the buffer capacity of the salivary medium. For 48-h and 72-h biofilms, but not for 168-h biofilms, pH drops in distinct microenvironments were more pronounced when the local biofilm thickness was high. [ABSTRACT FROM AUTHOR]

This paper studies the interaction of two droplets splashing on a stationary film. A source term is included in the large-density-ratio pseudopotential lattice Boltzmann method to achieve tuneable surface tension. This model offers excellent numerical accuracy and stability for droplet impacts on liquid films. The influence of the Reynolds number, Weber number, film thickness, and horizontal/vertical distance between the droplets on the crown geometry evolution is investigated. The energy loss during the impact process and the velocity discontinuity in the liquid film are the two key factors affecting the stability and evolution process of the crown. A smaller Reynolds number or thicker liquid film enhances the energy loss and decreases the velocity discontinuity, leading to more stable side and central jets. An increase in the horizontal distance between the droplets reduces the velocity discontinuity, causing the central jet height to decrease. An increase in the Weber number does not affect the energy loss or velocity discontinuity, but the lower surface tension leads to a dramatic deformation in both the central and side jets. A vertical distance between the two droplets causes an asymmetrical evolution of the crown geometry, and postpones the breakup time of the central jet. [ABSTRACT FROM AUTHOR]

Films fabricated by aerosol deposition (AD) can be coated through interactions between the particles and substrate. Accelerated particles collide with the substrate, generating impact energy at the contact point. These interactions depend on the hardness of the substrate. This study examined the effects of the hardness of the substrate on the deposition behavior of thick glass films by AD. Substrates with different hardness, Al2O3, glass, and STS304, were used, and the film formation behavior was observed. The coating thickness of the initial layer was inversely proportional to the hardness of the substrate. The STS304 substrate exhibited a phase transition after the coating process that was induced by the strong impact energy. The film formation mechanism depending on the substrate hardness was proposed based on the microstructure of the interface between the film and substrate. [ABSTRACT FROM AUTHOR]

Epitaxial Cr2AlC MAX phase thin films were grown on MgO(111) and Al2O3(0001) by pulsed laser deposition (PLD) at 600°C. X-ray diffraction and morphology studies of Cr2AlC thin films on MgO (111) reveal phase purity, columnar growth, the epitaxial relation Cr2AlC(0001) || MgO(111) and Cr2AlC [11-20] || MgO[10-1] and similar growth behaviour on Al2O3(0001). Resistivity measurements show semiconductor-like behaviour for 10 and 20 nm thick films, and metallic-like behaviour for thicker films, suggesting a percolation thickness slightly above 20 nm. Our results demonstrate the potential of PLD as a novel method for the growth of epitaxial MAX phase thin films. Pulsed Laser Deposition is applied to grow phase pure and epitaxial Cr2AlC MAX phase thin films on MgO(111) and Al2O3(0001). Control of the sample stoichiometry is achieved by elemental targets. [ABSTRACT FROM AUTHOR]

We have developed a process of joining metals and plastics using three-dimensional electrodeposited films of a Ni–Cu alloy. In the present study, the effect of the shape of electrodeposited films, which was changed by using different concentrations of Ni amidosulfate in the Ni–Cu alloy plating solution and by plating at current densities, on the joint strength between stainless steel and polyamide 6 was investigated. The results show that when the concentration ratio of Ni amidosulfate to that of Cu sulfate was 150:15 (g/L) and the plating current density was 10 mA/cm2, a dendritic structure of the electrodeposited film was formed. When the concentration of Ni amidosulfate was 300–450 g/L, dendritic electrodeposited films with thick trunks were formed. When a stainless steel plate with an electrodeposited film and a polyamide 6 plate were joined by heating and compression, voids were formed directly above the dendritic electrodeposited film inside the polyamide 6 plate. A lap joint specimen with the stainless steel plate and polyamide 6 plate joined using the electrodeposited film made of 450 g/L Ni amidosulfate showed an average joint strength of 17 MPa. [ABSTRACT FROM AUTHOR]

The gas-water separator is an important auxiliary component of the hydrogen recirculation subsystem for the proton exchange membrane fuel cell (PEMFC) system. This study investigated three baffle separators with different structures used for a 75 kW PEMFC system by computational fluid dynamics (CFD) simulation and experimental validation. An Euler-Lagrange two-phase simulation model was established to investigate the gas-phase flow characteristics and the droplets trajectory and film distribution in separators. Moreover, an experimental bench was set up to test the overall performance of the separators. The results showed that the CFD model can predict the performance of the gas-water separator accurately. Through the comparison of air and mixed hydrogen, it was found that the density of the gas phase fluid has a great influence on the pressure drop. The local gas flow at the baffle bottom where the film fall directly is at high velocity in separator A, resulting in that the liquid film is broken easily to cause more fine droplets being entrained again into the outflow. Besides, thicker liquid film still formed in the top part of the separators A and B compared with separator C, which is not conducive for high separation performance. Thus, the separator C is preferred to be suggested for PEMFC systems. [ABSTRACT FROM AUTHOR]

In the present article, a brief introduction about multiferroic composites is provided. Recent advancement in the field of multiferroic composites is discussed by classifying these in bulk composites, thick & thin films and other heterostructures. Research findings of some renowned work are summarized, considering new emerging materials, new methods of synthesis and latest characterization techniques. Further recent applications are discussed along with future challenges of the field. [ABSTRACT FROM AUTHOR]

Growing repeat-fruiting strawberries (Fragaria ×ananassa Duchesne ex Rozier) under low tunnels can extend a strawberry harvest season from a few weeks to several months. Yields from multiple dayneutral cultivars have been compared under a single film, and yields from single cultivars have been compared under multiple films, but a study of possible cultivar and film interaction effects in low tunnels has not been reported. From 2014–2018, six cultivars were compared under low tunnels covered with a standard polyethylene film and three other films purported to improve growing conditions. Traits analyzed included total yield, percent rotted yield, berry weight, percent marketable yield, and average market score. 'Monterey' performed above average for all traits and better under TIII TES/IR 0.102 mm thick film (TES film) or Kool Lite Plus 0.152 mm thick polyethylene film (KL film). 'Albion' performed above average for all traits except yield and better under TES film or Clear TIII 0.102 mm thick polyethylene film ("standard clear" or SC film). 'Portola' performed above average for all traits except percent rotted yield, better under SC, KL, and TES films, and had lower percent rotted yield under TES film. Because TES film was helpful to the three better-performing cultivars evaluated, it was considered a good choice for growers to try in on-farm evaluations of available repeat-fruiting cultivars. Generally, yield, berry weight, market score, and percent marketable yield were correlated positively with each other. [ABSTRACT FROM AUTHOR]

Barium Zirconate Titanate–Barium Calcium Titanate (BZT–BCT) is an environmentally friendly piezoelectric-ferroelectric ceramic that is a promising alternative to lead zirconate titanate (PZT), whose toxicity is well known. Producing thin films by sol–gel deposition with properties comparable to their bulk counterparts is quite a difficult task, because of the substrate constraints which typically generate residual stresses during the production process, leading to the onset of cracks. Moreover, typically employed solutions contain toxic and harmful substances or are unstable over time. Recently, we produced a highly stable BZT–BCT precursor solution based on nontoxic and non-carcinogenic solvents. In this work, we optimized the BZT–BCT sol–gel deposition process by varying the spin coating velocity, which influences the thickness of each deposited layer, and the pyrolysis temperature, which impacts on the formation of cracks. Moreover, we explored the possibility to add a third heat treatment step to the deposition process with the aim of releasing the residual stresses, further improving the film properties. As a result, 250 nm thick films were obtained with optimized morphology and limited presence of cracks, thus enhancing the ferroelectric properties (Pr = 33.26 μC cm−2, Ec = 220.6 kV cm−1, ε = 1817). [ABSTRACT FROM AUTHOR]

The use of high applied voltage during the electrochemical discharge machining (ECDM) process forms a thick gas film and generates high discharge energy on film breakdown. This results in polarization and evaporation of electrolyte at the tooltip. Consequently, the ECDM process results in a low depth of penetration (DOP) with a large hole overcut (HOC). The present investigation is an attempt for utilizing high discharge energy during the ECDM process using sonication of tool electrode. The experimental results reveal that sonication regulates the gas bubble departure radius and thereby controls the gas film thickness. Besides, an increase in the electrolyte concentration reduces the gas film thickness and results in the generation of high-intensity and high-frequency electric discharges. Sonication results in improved electrolyte replenishment and sludge removal. A mathematical model is developed to understand the effect of process parameters on the gas bubble departure radius. Also, the present investigation compares ultrasonic-assisted electrochemical discharge machining (UAECDM) and the general ECDM process. Sonication of tool electrode during UAECDM process exhibit improvement in material removal rate (MRR) by 11.13%, DOP by 27.17% and reduction in HOC by 23.10% over the ECDM process. [ABSTRACT FROM AUTHOR]

We analyzed 53 historical textile samples from a collection of caftans and brocades dating between the sixteenth and nineteenth century in the Topkapi Palace Museum (TPM) by scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX). Data were collected on the type, dimensions, elemental composition, and level of corrosion. The technique is presented in this work as an efficient and micro-destructive tool for the characterization of the structure of historical metal threads. SEM-EDX analysis for different energies was performed on a selection of gold and silver threads belonging to the historical textiles. The results were interpreted via laboratory prepared samples of gilt Ag and sulfur reacted Ag at different thicknesses for Au and Ag2S layers respectively. A series of Au–Ag alloys for different Au/Ag ratios were prepared for comparative analysis. The threads were made of metal strips wound around a silk core. Metal wires and flat strips were also used. The use of differential energies allowed for differentiating strips and wires made of homogeneous silver and gold alloys from the ones coated with a thin gold layer. Analysis of EDX data revealed that the Au film thickness was very thin (10–60 nm). Formation of Ag2S layers over the thin Au film as thick as 1.5 µm was taking place. Formation of thinner Ag2S layers over non-gilt Ag suggested different reaction mechanisms for gilt and non-gilt cases. [ABSTRACT FROM AUTHOR]

In this work, we investigated the structural properties of ferroelectric PbZr0.2Ti0.8O3 (PZT) and ferrimagnetic/ferroelectric [CoFe2O4(CFO)/PZT] bilayers grown on (001)SrTiO3 (STO) substrates with 50 nm thick LaNiO3 bottom electrodes via X-ray diffraction by θ-2θ scan, reciprocal space mapping (RSM), rocking curve, and phi-scan modes. Interestingly, structural properties of the PZT layer exhibited remarkable changes after the top-layer CFO deposition. Both the c- and a-domains exist in the PZT layer by the data acquired and the tetragonality of the PZT decreases after the CFO top-layer deposition. [ABSTRACT FROM AUTHOR]

We have made an attempt to fabricate free standing warpage free PZT thick films of 100 µm thickness by tape casting method. The poly crystalline nature and nanoscale polarization switching of free standing thick film were confirmed using X-ray diffraction technique and piezo force microscopy, respectively. The piezoelectric coefficient (d33) of 100 µm free-standing Pb(Zr0.56Ti0.44)O3 [PZT] thick film was calculated using double beam laser interferometer and found to be 400 pm/V. From the results, it indicates that free-standing PZT thick films are suitable candidate for miniaturization of harvesting device by directly bonding them on microsystem components for microelectromechanical systems (MEMS) applications. [ABSTRACT FROM AUTHOR]

The non-IPR fulleride compound CsxC68 was investigated in analogy to previous experiments on CsxC58. While the vibrational properties as well as the electronic structure in the valence band range appear to be pretty similar to CsxC58, a striking difference could be observed by XPS and Photoemission Microscopy analysis: apparently, C68 forms different phases within a thick film including islands in which it is able to store more than 70 Cs atoms per fullerene cage and to keep these amounts even after annealing over 1100 K. This means that CsxC68 constitutes the highest alkali metal doping degree of any Fullerene species known so far. Spatially resolved photoemission analysis also revealed that the Cs-rich fulleride phases constitute a unique chemical state that has never been observed before. [ABSTRACT FROM AUTHOR]

The development and evaluation of a cathode consisting of a gold electrode covered by a polyaniline film, PANI/Au modified electrode, for electrochemical generation of arsine is described. The efficiency of arsine production using the new electrode was ascertained by comparison with corresponding hydride generation atomic absorption spectroscopy determinations of arsenic (As) in aqueous standards. The PANI/Au modified electrodes provide better sensitivity, accuracy and precision than the pure Au cathodes. The PANI/Au cathodes were prepared by controlled electrodeposition cycles of polyaniline films on top of Au electrodes. Cathodes obtained after 10 electrodeposition cycles showed the best performance, while the ones obtained after five voltammetry cycles produced films too thin and those obtained after 20 voltammetry cycles produced films too thick for the purpose of this work. Under optimised conditions, the As limit of detection in aqueous solutions, according to the (3σ) criterion, was 2.48 µg L−1. For accuracy determination, the modified electrode was applied to quantification of As(III) in acidified aqueous solutions of the certified standard reference material, NIST SRM 1643d, and in well-water samples containing possible interfering ions. Application of the Student’s t-test showed no significant difference between the expected and obtained results of the NIST SRM standard analysis at the 95% confidence level. Values for six replicate determinations of As(III) in the well-water samples showed close agreement with values obtained by analyses using hydride generation atomic absorption. Recoveries were in the range of 95-105% at test for acceptable accuracy in the analysis of real samples. [ABSTRACT FROM AUTHOR]

Whereas industrial elastohydrodynamic (EHD) contacts are generally noncircular, most experimental observations are made on sphere-on-plane conjunctions. The circular case is indeed a specific elliptical case, and it was widely investigated. The differential colorimetric interferometry (DCI) technique was often used to perform precise film thickness measurements in circular EHD contacts. From a single picture of the dynamic contact, it enables mapping the film thickness of the full conjunction, and postprocessing can be applied afterwards. Moreover, it is possible to record sequences at relatively high-frequency sampling. However, until now, the method could not be directly applied to noncircular conjunctions. In the present article, a generalized DCI method is proposed and assessed by several static and EHD validation cases for elliptical and torus-on-plane contact geometries. This new method no longer necessitates particular requirements on the contact shape while retaining the advantages of the original DCI method. It allows precise film thickness measurements in realistic industrial EHD contacts and opens the way for new experimental observations. [ABSTRACT FROM AUTHOR]

Chemical vapour deposition (CVD) grown boron-doped nanocrystalline diamond (B-NCD) is an attractive material for the fabrication of high frequency superconducting nanoelectromechanical systems (NEMS) due to its high Young's modulus. The as-grown films have a surface roughness that increases with film thickness due to the columnar growth mechanism. To reduce intrinsic losses in B-NCD NEMS it is crucial to correct for this surface roughness by polishing. In this paper, in contrast to conventional polishing, it is demonstrated that the root-mean-square (RMS) roughness of a 520 nm thick B-NCD film can be reduced by chemical mechanical polishing (CMP) from 44.0 nm to 1.5 nm in 14 hours without damaging the sample or introducing significant changes to the superconducting transition temperature, , thus enabling the use of B-NCD films in the fabrication of high quality superconducting NEMS. [ABSTRACT FROM AUTHOR]

The heating behavior of nanoscopic and microscopic Nickel particle-embedded thermoplastic polyurethane (TPU) adhesive under induction heating is studied. Different particle sizes and content of Nickel were applied to TPU with varying film thicknesses and output power of the induction heater. From the results, heat generation of the TPU films increased with increases in Nickel content, TPU film thickness, and output power. The heat generation of the Nickel particle-embedded TPU films was in the order of 70 nm > 1 µm > 70 µm > 20 µm in terms of particle size, and this result can be explained by increases in the ratio of eddy current heating to hysteresis heating with increases in particle size. [ABSTRACT FROM AUTHOR]

Regular periodic stripe patterns that are found in the menisci of smectic C and Cfreely suspended films were described first by Meyer and Pershan (Solid State Commun.13(1973)) more than 40 years ago, but their physical origin is still under debate. Loudet et al. (Phys. Rev. Lett.106117, 802 (2011)) proposed a layer dilatation model to explain their formation. Our observation of such patterns in films with a direct transition from smectic C to a nematic or isotropic phase is in sharp conflict with that model. Moreover, we demonstrate the disappearance of the patterns at the transition from synclinic to anticlinic smectic C phases. An essentially different explanation of the physical mechanism of the stripe formation must be sought. We propose potential sources of the instability. [ABSTRACT FROM PUBLISHER]

The discovery of piezoelectricity in calcined thin films and sintered ceramics of synthetic hydroxyapatite is of interest to understand the role of electricity in bone growth and to find use of piezoelectric implants in bone growth stimulation or deceleration and in energy harvesting to run spinal or neuro stimulators. Synthetic apatites including hydroxyapatite and a mixture of hydroxyapatite and tricalcium phosphates are extensively used in bone graft substitute and cement-less implant coating. We provide experimental evidence of piezoelectricity in screen-printed thick-films of hydroxyapatite, which may allow many real-time experiments to understand physiological significance of piezoelectricity and potential in vivo exploitation. [ABSTRACT FROM PUBLISHER]

Based on the templates of sheet-like KNN powders synthesized by a hydrothermal method, lead-free textured KNN films with a thickness of 5 μm were prepared by sol-gel methods. The composition, microstructure, crystal structure, ferroelectric properties and grain growth mechanisms of the textured KNN thick films were studied. It was found that the KNN thick films possessed large grain sizes, dense morphology and increased ratio of Na+. After annealed at 650 °C, the perovskite structure was observed in the KNN thick films textured along the <00l> crystallography direction with an orientation factor of 0.393, reflecting a preferential growth characteristics. Furthermore, the residual polarization value of 12.3 µc/cm2was achieved under the same condition. [ABSTRACT FROM PUBLISHER]

The lubrication performance of cycloid drives affects the dynamic characteristics, mechanical efficiency, and contact fatigue behavior. Starved lubrication performance of a cycloid gear drive is studied using a numerical thermo-starved elastohydrodynamic lubrication model. The parameter of the inlet oil film thickness is chosen to represent the starvation degree. Effects of the inlet film thickness on the central film thickness, friction coefficient, frictional power loss, starting position of the effective film thickness, and lubrication efficiency are investigated. The optimum inlet film thickness is defined and is calculated under different rolling–sliding ratios, speeds, and loads. Finally, the optimum inlet film thickness during the meshing process of a cycloid drive is calculated. [ABSTRACT FROM AUTHOR]