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High-purity Li7La3Zr1.5Sn0.5O12 samples that formed with garnet-type crystal structure were prepared using biopolymer sol-gel method. X-ray diffraction shows that Li7La3Zr1.5Sn0.5O12 formed a tetragonal phase with a space group of I41/acd) at 1000°C. Then, the crystal symmetry transformed to a cubic phase with a space group of Ia-3m at 1100°C. Impedance spectroscopy analysis was used to determine the electrical properties of Li7La3Zr1.5Sn0.5O12. Equivalent circuit analysis was performed to distinguish microscopic contribution in the samples. The impedance data were accurately fitted to the impedance data measured from 120°C to 210°C with the equivalent circuit analysis contributed by bulk and grain boundary effects. The Arrhenius plots show a change of slope with different activation energies for low- and high-temperature regions, which is contributed to by order-disorder transitions that affect the mobility of Li+ ions. The heterogeneity of the sample was observed from Z′ and M″ spectroscopic plots. The SEM micrographs reveal that a large grain size was obtained in the Li7La3Zr1.5Sn0.5O12 samples.

Drying is one of the popular preservation methods in food products. This work was done to investigate the influence of the drying temperatures and methods on the drying characteristics of ‘ikanbakar’ paste. The ‘ikanbakar’ paste was dried by using oven drying and vacuum drying methods at temperatures of 50°C, 60°C and 70°C. The drying rate was estimated from the moisture content and drying time data. The drying curve showed the falling rate period as the drying rate decreased with increasing time. For colour analysis of the paste, the L* values from the oven drying method were lower than those from the vacuum drying method, ranging from 7.4210 to 7.2752. This showed that the colour of paste from oven drying was darker than vacuum drying. The mathematical models used to describe the drying curve of ‘ikanbakar’ paste were Lewis, Page, Two-term, and Midilliet. al. model. The performance of these models was evaluated by comparing their root mean square error (RSME) and chi-square (X²) values, and it was found that the most suitable model was the Two-term model. There were insignificant differences between the effective moisture diffusivity (Deff) values for the ‘ikanbakar’ paste in both drying methods.

Achieving high-quality perovskite films with uniform morphology and homogeneous crystallinity is challenging owing to the coffee ring effect (CRE) in the spray-coating technologies. In this study, an evaporation/spray-coating two-step deposition method is used to fabricate Cs0.19FA0.81PbI2.5Br0.5 light harvesters for perovskite solar cells (PSCs). Considering the solid-liquid reaction, we establish a reaction-dependent regulating strategy that inhibits CRE successfully and prepare a high-quality perovskite layer, wherein the solvent for the FAI/Br solution during the spraying process is changed from isopropanol to n-butyl alcohol (NBA). The retarded-drying-enhanced spreading of the NBA solution inhibits contact line pinning to suppress the capillary flows and increases the reaction between metal halides (CsI/PbI2) and organic salts (FAI/Br), which result in a reduction in the accumulation of solutes in the periphery effectively inhibiting CRE. Consequently, we obtain a high performance Cs0.19FA0.81PbI2.5Br0.5 PSC with a power conversion efficiency (PCE) of 19.17%. An enlarged perovskite film (10 × 10 cm2) containing 40 sub-cells is prepared. The average PCE of these devices is 18.33 ± 0.56%, proving the reliability of the “coffee ring” regulating strategy. This study provides an effective approach for CRE controlment in spraying technology to achieve high repeatability devices with good performance.

In proton therapy, a highly conformal proton dose can be delivered to the tumor by means of the steep distal dose penumbra at the end of the beam range. The proton beam range, however, is highly sensitive to range uncertainty, which makes accurately locating the proton range in the patient difficult. In-vivo range verification is a method to manage range uncertainty, one of the promising techniques being prompt gamma imaging (PGI). In earlier studies, we proposed gamma electron vertex imaging (GEVI), and constructed a proof-of-principle system. The system successfully demonstrated the GEVI imaging principle for therapeutic proton pencil beams without scanning, but showed some limitations under clinical conditions, particularly for pencil beam scanning proton therapy. In the present study, we upgraded the GEVI system in several aspects and tested the performance improvements such as for range-shift verification in the context of line scanning proton treatment. Specifically, the system showed better performance in obtaining accurate prompt gamma (PG) distributions in the clinical environment. Furthermore, high shift-detection sensitivity and accuracy were shown under various range-shift conditions using line scanning proton beams.

Anisotropic porous boron carbide (B4C) structures were successfully produced, for the first time, using the magnetic field-assisted freeze casting method. The effect of the magnetic field on the structure and mechanical strength of the formed porous B4C was compared for two different magnetic field directions that were either aligned with ice growth (vertical), or perpendicular to the ice growth direction (horizontal). It was shown that applying even a weak horizontal magnetic field of 0.1–0.3 T noticeably affected the alignment of mineral bridges between lamellar walls. Both the porosity and the channel widths decreased with increasing horizontal magnetic field strength. In the case of a vertical magnetic field, a larger strength of 0.4 T was required for highly aligned lamellar walls and larger channel widths. Compression strength tests indicated that the application of magnetic fields led to more homogeneously aligned channels, which resulted in increased compression strength in the longitudinal (parallel to the ice growth) direction. Applying a vertical magnetic field of 0.4 T with a cooling rate of 2 °C/min during the freezing step of the magnetic field-assisted freeze-casting method was found to result in the best conditions for producing highly anisotropic structures with large channel widths and fewer mineral bridges, which led to an increase in the mechanical strength.

Biocomposites have received a great deal of attention in academic research and industry because they are environmentally friendly and produce less carbon footprint, especially with the use of natural fibers. Nevertheless, compatibility issues require complexity to overcome the field of composite materials. Biocomposites based from poly(lactic acid) (PLA), natural rubber (NR) and kenaf were prepared by melt blending in an internal mixer. PLA/NR composition was fixed at 90/10 (wt/wt), while kenaf loading varied from 0 to 20 phr. The aim of this work was to study the effect of epoxidized natural rubber (ENR) and poly(methyl methacrylate) (PMMA) addition as co-compatibilizers in the biocomposites. Rheological behavior during mixing showed higher processing torque and stabilization torque after compatibilization. The mechanical properties deteriorated with increasing kenaf loading in biocomposites. Incorporation of rigid kenaf particles within matrix resulted in poor stress transfer and restricted chain movement. Addition of compatibilizer increased the tensile strength, elongation-at-break, tensile modulus and impact strength. Upon compatibilization, the interfacial interaction between kenaf and matrix is improved, enabling more efficient stress transfer, thus higher mechanical properties. Water absorption of biocomposites was studied by immersion in distilled water for 30 days. At high kenaf loading, water absorption percentage increased due to hydrophilic nature of kenaf. After compatibilization, water absorption decreased due to better interfacial adhesion. Morphological study of tensile fractured and impact fractured surface of biocomposites was investigated using scanning electron microscopy. Less fiber pull-out, more work of fracture and less interfacial gap between fiber and matrix were observed for compatibilized biocomposites, indicating enhanced interfacial adhesion. Addition of ENR and PMMA in PLA/NR/KF biocomposites was able to pare down the compatibility issues, contributing to improvement of overall properties.

The piezoelectric performance of (Ba0.85Ca0.15)(SnxZr0.1-xTi0.9)O3 (BCSZT) ceramics with x = 0, 0.025, 0.05, 0.075, and 0.10 for energy harvesting applications can be optimized by varying the sintering temperature. These BCSZT ceramics were prepared at three different sintering temperatures (1250 °C, 1350 °C and 1450 °C). The relative density for all samples increased as the sintering temperature increased, thereby enhancing the dielectric properties of the BCSZT ceramics. The emax values of the BCSZT ceramics were improved up to 50% when the sintering temperature was increased from 1250 °C to 1450 °C. The Tc shifted towards a lower temperature (95 °C down to 59 °C) as the Sn content increased. However, the effect of sintering temperature on Tc was barely observed because the variation in grain size between all BCSZT ceramics was very small. Therefore, it was suggested that the sintering temperature had a small impact on Tc because of the diffusibility of the samples. The ΔT value for the BCSZT ceramics was the highest when the samples were sintered at 1250 °C, which meant that the diffuse phase transition was more obvious at lower sintering temperatures. The sample with x = 0.025 showed the most promise as a piezoelectric material for energy harvesting applications.

Magnetic agglomeration of magnetic particles under the influence of magnetic field plays a vital role in enhancing the separation of fine magnetic mineral particles. In this study, the major forces acting on weakly magnetic particles and the ratio between forces in high-gradient magnetic separators (HGMS) are investigated. A 3D high-gradient magnetic field based on HGMS was simulated, and the major forces (magnetic force Fm, magnetic agglomeration force Fmm, and gravity G) acting on weakly magnetic particles were calculated in the form of Fm/Fmm, Fm/G by finite element method (FEM). The results show that the value of Fm/Fmm became lower as the increase of magnetic field intensity and the relative permeability of particles, higher as the increase of the magnetic field gradient, the particle size and the distance between particles. However, there was no correlation between the value of Fm/Fmm and the density of the magnetic particles. Furthermore, the value of Fm/G was inversely proportional to the density of the particles and directly proportional to the relative permeability of particles, the magnetic field intensity and magnetic field gradient. Meanwhile, Fm was at least 190 times greater than Fmm in any case and Fm was far bigger than G in most cases, indicating that the magnetic agglomeration is not significant in HGMS and gravity has little effect on high-gradient magnetic separation, and HGMS are destined to be a kind of high-efficiency magnetic separation equipment.

Here, we report an inexpensive and highly catalytic carbon/AgNWs counter electrode for flexible dye-sensitized solar cells (DSSCs). In order to reduce the process time, an organic surfactant is added to disperse the carbon composites. Then, a uniform catalytic layer can deposit on the silver nanowire (AgNW) transparent conductive electrode. Ultimately, a low temperature UV irradiation post-treatment is proposed to clean the surface of the catalytic layer. Through the electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV) curve and Tafel curve, it can be established that this carbon/AgNWs counter electrode exhibits high catalytic activity than that of Pt/ tin-doped indium oxide (ITO) electrode. In addition, the current density–voltage characteristic curves also prove that the as-assembled DSSC has a superior photoelectrical conversion efficiency.

BACKGROUND While it is well recognized that different biomaterials induce thrombosis at low shear rates, the effect of high shear rates may be quite different. We hypothesize that the amount of thrombus formation on a given material can be greatly influenced by the local shear rate. METHODS We tested this hypothesis with two different whole blood perfusion loop assays to quantify biomaterial thrombogenicity as a function of shear stress. One assay uses obstructive posts (pins) of material positioned centrally in a tube perfused at high shear rate of >5000/s for 24 h. A second assay uses a parallel plate chamber to perfuse low (

Additive manufacturing (AM) has created a new era of digital manufacturing, where engineering practices, computer-aided design platforms, and part sourcing pipelines are dramatically changing. AM techniques are capable of producing plastic, metal, and ceramic components for both prototyping and end-use purposes. In this review, the fabrication of dense, structural advanced ceramic components using the seven families of additive manufacturing is discussed through a historical perspective. Initial studies on additive manufacturing of ceramic materials were reported just a few years after those of metal and plastic materials. However, industrial application of ceramic additive manufacturing is more than a decade behind metallic and plastic materials. Many of the challenges of ceramic AM can be traced back to the intrinsic difficulties of processing structural ceramic materials, including high processing temperatures, defect-sensitive mechanical properties, and poor machining characteristics. To mature the field of ceramic AM, future research and development should focus on expanding material selection, improving printing and post-processing control, realizing single-step processing, and unique capabilities such as multi-material and hybrid processing.

Neuromorphic computing has garnered significant attention because it can overcome the limitations of the current von-Neumann computing system. Analog synaptic devices are essential for realizing hardware-based artificial neuromorphic devices; however, only a few systematic studies in terms of both synaptic materials and device structures have been conducted so far, and thus, further research is required in this direction. In this study, we demonstrate the synaptic characteristics of a ferroelectric material-based thin-film transistor (FeTFT) that uses partial switching of ferroelectric polarization to implement analog conductance modulation. For a ferroelectric material, an aluminum-doped hafnium oxide (Al-doped HfO2) thin film was prepared by atomic layer deposition. As an analog synaptic device, our FeTFT successfully emulated short-term plasticity and long-term plasticity characteristics, such as paired-pulse facilitation and spike timing-dependent plasticity. In addition, we obtained potentiation/depression weight updates with high linearity, an on/off ratio, and low cycle-to-cycle variation by adjusting the amplitude and number of input pulses. In the simulation trained with optimized potentiation/depression conditions, we achieved a pattern recognition accuracy of approximately 90% for the Modified National Institute of Standard and Technology (MNIST) handwritten data set. Our results indicated that ferroelectric transistors can be used as an alternative artificial synapse.

With global advancement towards green technology, bamboo fiber has been treated as an extensive resource for eco-friendly living and competitive materials for industrial uses, due to their favorable characteristics such as durability, recyclability and promising mechanical properties. In this study natural fabric reinforced composites were prepared by bamboo fibers (BF) weave in a 1–1 (warp, weft) method by hand layup technique. There are three composition of composite prepared by varying the weight percentage of each nano-material with 0.5%, 0.75% and 1.0%. The various mechanical and thermal properties of prepared composites were compared by addition of two types of nanofillers: Graphene Oxide (GO) and functionalized Graphene (FG). The findings revealed that the incorporation of functionalized Graphene (FG) composites can be an effective approach in-term of mechanical properties as compared to pure and GO composite. From the experimental values it was clear that at 0.75 wt% of FG the Bamboo fabric reinforced composite shown better tensile strength, impact strength, hardness and heat deflection of 30%, 19%, 16% and 15% respectively. It was also observed that after optimal wt. % of nanofillers the mechanical properties are degraded by addition of nano-materials.

Gas tungsten arc welding have been carried out using two multicomponent fluxes. Fluxes used in welding were made out of various compositions of metal oxides with different weight percentages. Flux assisted gas tungsten arc welding were performed on dissimilar metals like stainless steel 316L and Alloy 800. Large improvement in depth of penetration was observed with applied multicomponent flux. Nevertheless, metal oxides like ZnO and MoO3 could provide even better weld properties compared to some other multicomponent fluxes. Depth of penetration along with weld shape were analyzed for two multicomponent fluxes. Microstructure, grain growth, and intermixing of metals were analyzed at different locations of welds. Hardness alteration at weld locations and neighborhood were investigated. Effect of multicomponent flux at welded regions on corrosive behavior were analyzed using electrochemical corrosion tests. Multicomponent flux comprised of oxides like ZnO and MoO3 with other metal oxides appeared as better flux in terms of metallurgical accomplishments.

The high throwing power (TP) value is one of the most important parameters for the Cu electroplating of through-holes in flexible printed circuit (FPC). It was found that an ultra-high TP value could be obtained using a specific suppressor, i.e., iodonitrotetrazolium chloride (INT) in the electrolyte. The ultra-high TP value was attributed to fast-consumption of this suppressor instead of traditional convection-dependence adsorption mechanism. A consumption model was built and simulated to clarify the formation of the ∆θ, i.e., the difference of suppressor fractional coverage between the entrance and center of through-holes sidewalls. It revealed that the TP, proportional to the ∆θ, was determined by the consumption rate of a suppressor. This simulation results were well consistent with the results of electroplating using INT with different concentration. The electrochemical analysis verified the characteristics of fast consumption of INT due to the reduction reaction. The difference of residual INT between the entrance and center of the plated through-holes confirmed the occurrence of ∆θ. These results supported the opinion that the ultra-high TP value was obtained by fast-consumption mechanism of INT suppressor.

This article presents a power-efficient hybrid energy-harvesting system that scavenges energy from solar, vibration, and radio frequency (RF) energy sources and converts into regulated output dc voltage courtesy buck–boost dc–dc converter. The proposed architecture incorporates tetra-paths for maintaining high power conversion efficiency (PCE) over extended input power range (−10 to 30 dBm). A time-domain maximum power point tracking technique is proposed for solar energy harvester. A high-efficiency full wave rectifier is designed for triboelectric rectifier. A 5.8-GHz RF-dc converter with adaptive matching is proposed to increase dynamic range of the input power. The chip is implemented in 0.18-µm bipolar-CMOS-DMOS process. The die area of the chip is 2.8 mm × 5.0 mm, including the pads. The solar and triboelectric energy harvesters achieve a measured peak efficiencies of 75.4% and 92.3%, respectively. The high-power 5.8-GHz RF-dc converter achieves measured PCE of 76% at 30 dBm input power. The low-power dual-band RF-dc converter operating at 900 MHz and 2.4 GHz obtains measured peak efficiencies of 73% and 71.9% at 0 dBm input, respectively. The buck–boost dc–dc converter employed in the proposed hybrid energy harvesting system achieves a measured peak PCE of 94.5%.

Novel materials and structures with abundant active sites have been in continuous demand for electrochemical catalytic applications. In this study, we synthesized platinum telluride (Pt3Te4) nanocrystals on two-dimensional metallic molybdenum ditelluride (MoTe2) using a dynamic hydrogen bubble template method in the hydrogen evolution reaction (HER). The local crystal structure and chemical state of the Pt3Te4 nanocrystals were investigated using X-ray nano-diffraction and X-ray nano-absorption spectroscopy. In our electrochemical deposition method, the morphology, and HER performance of the Pt3Te4 nanocrystals could be manipulated through the hydrogen bubble generation rate. Thus, the nanorod-shaped Pt3Te4 nanocrystals, fabricated by a high rate of hydrogen bubble generation, exhibited outstanding HER performance, which is in contrast with the HER performance of hemisphere-shaped Pt3Te4. Our study provides a facile and systematic way of synthesizing high-performance electrochemical catalysts using the hydrogen bubble-assisted growth method.

The crystal structure, cryogenic magnetic properties, and magnetocaloric performance of double perovskite Eu2NiMnO6 (ENMO), Gd2NiMnO6 (GNMO), and Tb2NiMnO6 (TNMO) ceramic powder samples synthesized by solid-state method have been investigated. X-ray diffraction structural investigation reveal that all compounds crystallize in the monoclinic structure with a P21/n space group. A ferromagnetic to paramagnetic (FM-PM) second-order phase transition occurred in ENMO, GNMO, and TNMO at 143, 130, and 112 K, respectively. Maximum magnetic entropy changes and relative cooling power with a 5 T applied magnetic field are determined to be 3.2, 3.8, 3.5 J/kgK and 150, 182, 176 J/kg for the investigated samples, respectively. The change in structural, magnetic, and magnetocaloric effect attributed to the superexchange mechanism of Ni2+–O–Mn3+ and Ni2+–O–Mn4+. The various atomic sizes of Eu, Gd, and Tb affect the ratio of Mn4+/Mn3+, which is responsible for the considerable change in properties of double perovskite.

An ultrathin tactile sensor with directional sensitivity and capable of mapping at a high spatial resolution is proposed and demonstrated. Each sensor node consists of two gallium nitride (GaN) nanopillar light-emitting diodes. Shear stress applied on the nanopillars causes the electrons and holes to separate in the radial direction and reduces the light intensity emitted from the nanopillars. A sensor array comprising 64 sensor nodes was designed and fabricated. Two-dimensional directional sensitivity was experimentally confirmed with a dynamic range of 1-30 mN and an accuracy of ±1.3 mN. Tracking and mapping of an external force moving across the sensor array were also demonstrated. Finally, the proposed tactile sensor's sensitivity was tested with a fingertip gently moving across the sensor array. The sensor successfully registered the finger movement's direction and fingerprint pattern.

Next-generation devices and systems require the development and integration of advanced materials, the realization of which inevitably requires two separate processes: property engineering and patterning. Here, we report a one-step, ink-lithography technique to pattern and engineer the properties of thin films of colloidal nanocrystals that exploits their chemically addressable surface. Colloidal nanocrystals are deposited by solution-based methods to form thin films and a local chemical treatment is applied using an ink-printing technique to simultaneously modify (i) the chemical nature of the nanocrystal surface to allow thin-film patterning and (ii) the physical electronic, optical, thermal, and mechanical properties of the nanocrystal thin films. The ink-lithography technique is applied to the library of colloidal nanocrystals to engineer thin films of metals, semiconductors, and insulators on both rigid and flexible substrates and demonstrate their application in high-resolution image replications, anticounterfeit devices, multicolor filters, thin-film transistors and circuits, photoconductors, and wearable multisensors.

Chemo-resistance has pushed cancer treatment to the boundary of failure. This challenge has encouraged scientists to look for nanotechnological solutions. In this study, we have taken this goal one step further without depending on chemotherapy. Specifically, hybrid metal, polymer, and lipid nanoparticles that formed an IR780-a photosensitizer and Zinc copper oxide incorporated nanoparticle (ZCNP) nanoparticles were utilized in a combined photothermal and photodynamic therapy. Through the mediation of triphenylphosphonium (TPP) as a mitochondria-targeting moiety, TPP-conjugated polymer-lipid hybrid nanoparticles containing ZCNP/IR-780 significantly enhanced cellular uptake by cancer cells and selectively targeted the mitochondria, which improved the induction of apoptosis. In tumor-bearing mice, the nanoparticles were detected predominantly in tumors rather than in the other principle organs, which did not show notable signs of toxicity. Both in vitro and in vivo results demonstrated a great improvement in photothermal and photodynamic efficacy in combination when compared to either one individually, and a significant inhibition of tumor growth was observed with the combined therapies. In summary, this study describes an effective mitochondria-targeting nanocarrier for the treatment of cancer using combined photothermal and photodynamic therapies.

Engineering can be used to create uniquely oriented 2D materials, especially graphene, and can play a crucial role in the development of multifunctional films for applications in supercapacitors and thermal management, imparting excellent electrical and thermal properties to the films. However, the preparation of a uniquely structured graphene film with high-quality often requires a complex multi-step technique. Herein, we propose a facile and efficient one-step laser irradiation process for the synthesis of multifunctional laser-induced graphene electrodes consisting of L-shaped reduced graphene oxide nanosheets with vertical alignment (VrGO). Notably, the instantaneous high thermal energy of the laser irradiation can heal the defects of graphene oxide (GO) nanosheets, thus, enhancing the electrical conductivity and crystallinity while inducing the vertical alignment. Additionally, the vertical alignment of high-quality GO nanosheets leads to more isotropic thermal transport, thus, enhancing the out-of-plane thermal conductivity to 6.202 W m−1K−1. GO nanosheets also exhibited superior performances as supercapacitor electrodes, demonstrating an outstanding areal capacitance of 36.8 mF cm−2 at 1.2 mA cm−2, and excellent stability up to 10,000 cycles of charging/discharging. This simple laser technique opens up new possibilities for engineering the structural and physical properties of graphene for applications in various fields that require functional thin films.

Lithium-ion batteries (LIBs) are widely used in applications ranging from electric vehicles to wearable devices. Before the invention of secondary LIBs, the primary lithium-thionyl chloride (Li-SOCl2) battery was developed in the 1970s using SOCl2 as the catholyte, lithium metal as the anode and amorphous carbon as the cathode1–7. This battery discharges by lithium oxidation and catholyte reduction to sulfur, sulfur dioxide and lithium chloride, is well known for its high energy density and is widely used in real-world applications; however, it has not been made rechargeable since its invention8–13. Here we show that with a highly microporous carbon positive electrode, a starting electrolyte composed of aluminium chloride in SOCl2 with fluoride-based additives, and either sodium or lithium as the negative electrode, we can produce a rechargeable Na/Cl2 or Li/Cl2 battery operating via redox between mainly Cl2/Cl− in the micropores of carbon and Na/Na+ or Li/Li+ redox on the sodium or lithium metal. The reversible Cl2/NaCl or Cl2/LiCl redox in the microporous carbon affords rechargeability at the positive electrode side and the thin alkali-fluoride-doped alkali-chloride solid electrolyte interface stabilizes the negative electrode, both are critical to secondary alkali-metal/Cl2 batteries. Rechargeable Na/Cl2 and Li/Cl2 batteries are produced with a microporous carbon positive electrode, aluminium chloride in thionyl chloride as the electrolyte, and either sodium or lithium as the negative electrode.

PbS colloidal quantum dots (QDs) are promising infrared detecting materials because of their widely tunable bandgap spanning the visible to the mid-infrared region, low exciton binding energy, and high electron and hole mobility. PbS QD photodiodes (PDs) exhibit high specific detectivity and high energy convergence efficiency. However, the performance of PbS QDPDs has been limited by the poor degree of ligand passivation on PbS QDs, resulting in oxidation and aggregation of the QDs. Herein, we review the surface morphology of PbS QDs and advanced methods for surface passivation of large PbS QDs. The various methods highlighted in this article provide scientific insight for promoting the commercialization of PbS QDPDs in the near future.

Several NiO/TiO2 composites fabricated by the impregnation method were employed as photocatalysts for the photoreduction of gaseous CO2 in this study. The characterizations of fabricated photocatalysts were observed by XRD, FE-SEM, EDS, N2 adsorption-desorption, and UV–vis spectroscopy. The distribution of Ni, Ti, and O atoms on the surface of these photocatalysts was demonstrated to be uniform, and the BET surface areas were varied slightly with the increase of NiO loading. Meanwhile, the absorption edge of fabricated photocatalysts was found to shift towards the visible region and the bandgap energy was decreased. The photocatalytic reaction was conducted in a continuous-flow reactor under UV irradiation. Methane was identified to be the main product and produced in the order: 10 wt% NiO/TiO2 > TiO2 > 20 wt% NiO/TiO2. The maximum methane yield reached at 4.69 mmol/gcatalyst over 10 wt% NiO/TiO2 and was twice higher than that of P-25. The formation of p-n junction significantly improved the photocatalytic activity of P-25. Furthermore, the proposed schematic diagram for photocatalytic CO2 reduction in the gaseous phase under NiO-TiO2 / UV process was introduced.

The discovery of the dopant effects on BaTiO3 has attracted great interest after a compound of 50(BaTi0.8Zr0.2O3)–50(Ba0.7Ca0.3TiO3) system exhibited extraordinarily high piezoelectric properties (d33 > 600 pC/N). Recently, modifications made on the BaTiO3-based piezoelectric materials, particularly at the A-site, have gained the most attention due to the existence of the morphotropic phase boundary (MPB) region. In this paper, we reviewed several dopants that have been extensively used to enhance the piezoelectric and dielectric properties of a BaTiO3 such as Sn and Zr. A ternary triangle of BaTiO3–BaSnO3–BaZrO3 is used to evaluate the correlations between the changes in the Sn- and/or Zr-doped BaTiO3 piezoelectric ceramic properties. The structural changes that have been affected by the dopant contents were also comprehensively reviewed. There is clear evidence that the dopants significantly affect the intrinsic properties of the BaTiO3-based ceramic materials. The dielectric constant er value increases from 1900 to ~ 6000 at room temperature, while the piezoelectric constant d33 value is also increased from 191 pC/N to ~ 600 pC/N. All the compositions described in this review were prepared by using a conventional solid-state route.

Polylactic acid (PLA) biocomposites were prepared by melt blending in an internal mixer with various types of rubber. The rubber was 90/10 wt% and was mixed before the addition of kenaf fiber (0 to 20 phr). Natural rubber (NR), nitrile butadiene rubber (NBR), and styrene butadiene rubber (SBR) were used. The effects of different types of rubber and kenaf loading were investigated based on processing torque, water absorption, mechanical properties, and fractured surface morphology. A similar trend in processing torque was observed throughout the composition of biocomposites. The stabilization torque was highest for the biocomposite with NR, followed by SBR and NBR. Water absorption increased as the kenaf loading increased. The polarity of NBR and SBR contributed to higher water absorption in the biocomposites compared to the NR. The strain-induced crystallization phenomenon and higher green strength of NR contributed to the highest tensile strength, elongation at break, and impact strength of the biocomposite compared to the NBR and SBR toughened PLA/kenaf biocomposite. More plastic deformation and less fiber pullout were observed in the fractured surface morphology. However, by increasing the kenaf loading, the mechanical properties decreased for all biocomposites, which was due to poor interfacial adhesion and agglomeration.

In this work, thermal and rheological properties of self-fabricated polylactic acid (PLA) filaments without and with 10-wt% polyethylene glycol (PLA/0PEG and PLA/10PEG, respectively) were investigated, and the properties were compared with a commercial PLA filament used for fused deposition modeling (FDM). The result showed that the melt flow index for self-fabricated filaments was comparable with commercial filaments at approximately 10 g/10 min at 190°C, suggesting suitability to be used as filament for FDM with well-wetted layers. Variation in thermal properties was found in PLA/10PEG with 20°C higher cold crystallization temperature ( T cc) after FDM in which disruption of the molecular arrangement reduced the ability for chain alignment and folding. The result also revealed that addition of PEG decreased the storage modulus ( G′), loss modulus ( G″), and complex viscosity ( η*), resulting in slow crystallization behavior, and however, the properties did not induce degradation of the filaments and printing products.

The objective of this study was to develop protein bioplastics from fish waste using different types of plasticizers; polyethylene glycol, triethylene glycol and glycerol. Fish protein powders (head, skin, scales, viscera) were prepared from sardine byproduct (SBP), mackerel fillet powder (MFP) and mackerel byproduct powder (MBP). Protein content was characterized using proximate analysis and amino acids was determine using amino acid analysis. SBP was transform into bioplastics by using extrusion and compression moulding. The properties were characterized using thermo gravimetric analysis (TGA) and mechanical testing. Protein content in byproduct (SBP and MBP) were reasonable at approximately 40-60%. TGA result showed two stages of thermal decomposition starting at 230 °C. Below 230 °C, it was believed that protein denaturation occurred, involve structural or conformational changes from native structure without alteration of amino acid sequence. Further heating after 230 °C showed massive weight loss that lead to degradation. Mechanical properties was majorly influenced by plasticizers which improved the elongation at break properties. Glycerol was found to be the most effective plasticizer among those studied here, possibly because of its characteristics such as low molecular weight, high solubility in water, and large protein miscibility. The results obtained in this study showed that plasticizer types and concentration significantly improve film properties and enhances their suitability for single used of agriculture applications.

Device miniaturization and complex work load due to rapid growth in technologies have imposed great challenges in aspects of thermal management to prevent overheating. Nanofluids are emerging as thermal solutions due to their enhanced thermal properties. Recently, graphene oxide (GO) nanofluids (NFs) has been studied and found to have high thermal conductivity. However, their potential in microchannel heat exchangers (MCHEs) remains unknown. This study aims to investigate the thermal performance of GO-NFs in MCHEs. GO nanoparticles were synthesized and confirmed using X-ray diffraction, whereas GO-NFs (0.02-0.1 wt.) were prepared and analyzed in terms of viscosity and thermal conductivity. The results showed that the minor addition of GO nanoparticles did not significantly affect the viscosity of GO-NFs, whereas the thermal conductivity was remarkably enhanced. This indicates that GO-NFs are very promising since they are able to improve the thermal performance of MCHEs with negligible impact on the pressure drop at low nanoparticle loading. The thermal performance of GO-NFs in MCHEs was investigated at different inlet flow rates (0.5-2 mL/min) and set temperatures (50-90°C). At a given set temperature, GO-NFs showed excellent thermal performance compared to water due to their higher thermal conductivity. Furthermore, GO-NFs showed better thermal performance at higher set temperatures due to their higher thermal conductivity at higher temperatures. This temperature-dependent thermal conductivity of GO-NFs is essential especially in applications involving higher temperatures. Furthermore, no clogging of GO nanoparticles in microchannels was observed at minor GO loadings (0.02-0.1 wt.). These results indicate that GO-NFs are very effective in heat transfer applications compared to water. © 2020 by Begell House, Inc.

Purpose The purpose of this study is to investigate the performance of the fabricated liquid–liquid hydrocyclone (LLHC) with dimensions similar to those of one of the Malaysian oilfields with the presence of an anionic surfactant, S672. The effect of salinity and initial oil concentration were also investigated following the actual range concentration. Design/methodology/approach The current control system’s pressure drop ratio (PDR) does not necessarily lead to an efficient LLHC. Therefore, rather than using the PDR, the efficiency of the LLHC was analyzed by comparing the concentration of oil in the effluents with the concentration of oil at the feed of the LLHC. An LLHC test rig was developed at Centre of Enhanced Oil Recovery, Universiti Teknologi PETRONAS. Emulsions were prepared by mixing the brines, S672 and oil by using Ultra Turrax ultrasonic mixer. The emulsion was pumped into the LLHC at different feed flowrate and split ratio. The brines concentration, initial oil concentration and S672 concentration were also varied in this study. Samples were taken at the underflow of the LLHC and the oil in water concentration analysis was done for the samples using TD-500D equipment. Findings It was found that the efficiency of oil removal decreased with an increase in S672 concentration but increased with the increase in salinity and initial oil concentration. Originality/value The optimum feed flowrate for the LLHC of 45 mm diameter and length of 1,125 mm with the presence of S672 surfactant was found to be 40 L/min with a split ratio of 14%. This study can be used as a guidance for future optimization of the LLHC in the presence of the surfactant.

Ba0.85Ca0.15Zr0.10Ti0.90O3 ceramics prepared in air (BCZTair) and nitrogen (BCZTN2) exhibit significant changes on the unit cell parameters and volume. BCZTair ceramic has higher dielectric constant, er = 4805, than BCZTN2 ceramic, er = 4771. BCZTN2 that was sintered in N2 gas was expected to contain oxygen vacancies which might create a high-resistivity blocking layer at the grain boundaries which give similar behaviour as ferroelectric polarization disappearance hence reduce the dielectric constant. BCZTair deviated from the Curie–Weiss law with ΔT = 17 which is higher than BCZTN2 with ΔT = 14 represents a characteristic of relaxor ferroelectric behaviour with diffused characteristic. The value of γ for both samples represents normal ferroelectrics even the γ for BCZTN2 was slightly higher with γ = 1.6334 than BCZTair with γ = 1.6146.

In this study, moth-eye-inspired structures (MISs), which improve optical performance of surfaces, were developed to enhance light efficiency in various optical fields. As the polymer-based soft lithography process can easily optimize MIS materials and nanostructures, 12 MIS/inverse MIS (IMIS) surfaces of 300, 500, and 1000 nm composed of polyurethaneacrylate (PUA) and polydimethylsiloxane (PDMS) polymers were fabricated, and a thin octafluorocyclobutane (C4F8) layer was deposited on the surfaces to reduce their surface energies. The results showed that the 300-nm PDMS-MIS showed excellent optical properties with 94.44 % transmittance and 3.28 % reflectance. Additionally, two theoretical phenomena, the diffraction effect and double-slit diffraction, were experimentally demonstrated using three single-wavelength lasers. Subsequently, contact-angle measurements demonstrated all MIS/IMIS surfaces to possess hydrophobic and superhydrophobic properties, which can protect devices from outdoor liquids. Finally, we confirmed the applicability of MIS by attaching it to a cell phone display and an ITO glass, which is used as a substrate in various optical instruments.

Powder metallurgy (P/M) has been widely used in automobile, home appliances, and electronic devices, but its uses are very limited due to the low relative density of 85 to 95 pct. The Fe–Ni–B–C alloy system can mitigate the aforementioned issues by the liquid phase sintering, which results in a nearly full densification. However, the boron-containing alloys produced the brittle eutectic phases [Fe3(C, B) and Fe2B] along the grain boundaries, which are detrimental to the mechanical properties. The main objective of this study is to improve the ductility of boron-containing alloys through the microstructure modification. For this, the volume fraction of solidified phase was optimized by controlling the composition, and the coarsening of solidified α-Fe particles into the pearlite matrix was induced by a post annealing, which reduces the continuous network of eutectic phases and increased the grain continuity. In addition, the effect of microstructure modification on the mechanical properties of Fe–B–C and Fe–Ni–B–C alloys was comparatively investigated. As a result of microstructure modification, the post-annealed Fe–1Ni–0.4B–0.8C alloy exhibited a high elongation to failure of 5.2 pct.