Heating Irradiation Research Articles

Development of Novel Frontsheets With Protective Coatings to Increase the Durability and Reliability of Glass‐Free Lightweight PV Modules

ABSTRACTIn this work, novel PET‐based frontsheet materials with UV‐cured coatings were developed and investigated. UV‐curing urethane acrylates were selected as innovative, fluorine‐free coating systems. Polyurethane coatings exhibit excellent UV resistance, chemical and moisture resistance and, thus, high durability in outdoor applications. A homogeneous application without coating defects such as bubbles, voids or detachments was achieved. Material tests with cross‐cut tests showed no separation from the PET substrate. The water vapor transmission rates and the physical (optical and thermal) and chemical properties of the novel polymeric frontsheets were measured and compared with uncoated reference systems and products already on the market. The aging‐related changes after irradiation and humid heat storage were investigated and described in detail. Based on this comprehensive study, the newly developed frontsheets can be considered a suitable alternative to polymeric frontsheets with fluorine‐containing top layers.

Microstructure, electrical resistivity, and tensile properties of neutron-irradiated Cu–Cr–Nb–Zr

High strength, high conductivity copper alloys that can resist creep at high temperatures are one of the primary candidates for efficient heat exchangers in fusion reactors. Cu–Cr–Nb–Zr (CCNZ) alloys, which were designed to improve the strength and creep life of ITER Cu–Cr–Zr (CCZ) reference alloys, have been found to have comparable electrical conductivity and tensile properties to CCZ alloys. The measured creep rupture times for these improved alloys is about ten times higher than the ITER reference alloys at 90–125 MPa at 500 °C. However, the effects of neutron irradiation on these alloys, and the ensuing material properties, have not been studied; thus, their utility in a fusion reactor environment is not well understood. This study characterizes the room temperature mechanical and electrical properties of a neutron-irradiated CCNZ alloy and compares them to a neutron-irradiated ITER reference heat sink CCZ alloy. Tensile specimens were neutron irradiated in the High Flux Isotope Reactor (HFIR) to 5 dpa between 250 °C and 325 °C. Post-irradiation characterization included electrical resistivity measurements, hardness, and tensile tests. Microstructural evaluation used scanning electron microscopy, energy dispersive x-ray spectroscopy, and atom probe tomography to characterize the irradiation-produced changes in the microstructure and investigate the mechanistic processes leading to post-irradiation properties. Transmutation calculations were validated with composition measurements from atom probe data and used to calculate contributions to the increased electrical resistivity measured after irradiation. Comparisons with CCZ alloys in the same irradiation heat found that the post-irradiated CCNZ and CCZ alloys had comparable electrical resistivity. Although CCNZ alloys suffered more irradiation hardening than CCZ, the overall tensile behavior deviated very little from non-irradiated values in the temperature range studied.

Application Research of Infrared Technology in Safety Detection in Ship Field

Abstract. This paper studies infrared technology and its application in the field of ship detection, mainly studying infrared thermal imaging of failure equipment refueling oil spill and ship safety problems because infrared technology is a high precision contact thermal measurement method through infrared camera infrared objects, the infrared spectrum wavelength range of infrared radiation heat, on the receiver into electronic signals, through electronic attenuation and electronic scanning form the corresponding heat map or temperature field image, to intuitively reflect the temperature distribution and heat focus of the object. In addition, the infrared detection device can be reasonably installed in the ship without affecting the work of other equipment, and it has been found that infrared technology has significantly improved the solution to the safety problems of ships.

Hybrid heating in the fused filament fabrication process

AbstractAltering the heating regime of the polymer during the fused filament fabrication (FFF) process can lead to changes in both the behaviour of the polymer and the characteristics of the printed product. This study proposes replacing the traditional resistive heating system with two hybrid systems that introduce an additional temperature of 120–160 °C: one combining resistive and hot air jet heating, and the other combining resistive and infrared radiation heating. The samples printed using these hybrid systems were analysed using differential scanning calorimetry (DSC) and visually inspected. Commercial ABS and PLA filaments were used in the experimental programme. A model to evaluate the polymer’s melting during the printing process was proposed and experimentally validated. Visual testing revealed that the printed lattice structure had smaller voids, characterised by depositions that were flattened rather than circular in cross-section due to the extended time in a viscous/partially molten state. The elongation viscosity and storage modulus decreased by approximately 10%, with a slightly smaller decrease observed for the infrared radiation heat source. The glass transition temperature remained unchanged, and the molecular mobility was not affected by the additional heat. Similarly, the energy required for crystal formation was unaffected by the supplementary heat. The mechanical behaviour of the printed pieces during compression tests was also influenced by the addition of a second heat source. For both materials, a decrease in deformability was observed as the temperature of the hot air jet increased.

Phytic acid-induced durable fire-proof and hydrophobic complex coating for versatile cotton fabrics

To address the current development requirements for multifunctional cotton fabrics, a phytic acid-induced flame-retardant hydrophobic coating containing nitrogen (N), phosphorus (P), and silicon (Si) was grafted on the surface of cotton fabrics using a facile step-by-step immersion method. The limiting oxygen index value improved to 31.2 %, decreasing to 26.7 % after 50 laundering cycles, while the fabric remained self-extinguishing effect in the vertical flammability test and showed a water contact angle of 126.1°. Cone calorimetry test showed that the modified fabric could not be ignited at the irradiation heat flux of 35 kW/m2. When the irradiation heat flux was raised to 50 kW/m2, there was a significant decline in the peak heat release rate of the modified cotton fabric, which decreased by 43.2 % to a remarkably low value of 114.0 kW/m2, indicating excellent flame-retardant properties. The analysis of the flame-retardant mechanism uncovered that the modified coating exhibited a significant dual flame-retardant mechanism involving both the gaseous phase and the condensed phase. Additionally, the oil-water separation tests revealed that the separation efficiency of the modified cotton fabrics was as high as 97.1 % and remained around 96 % after 10 cycles, which made them reusable for the clean-up of hazardous chemicals.

Synthesis pathways of (HfZrTiCe/La/Y)O2-x nanoparticles via benzyl alcohol route at critical temperature

The controllable synthesis of high-entropy fluorite oxide (HEO) having large ionic radius mismatch remains a challenging due to poor understanding on nucleation. The (HfZrTiLn)-5HEO nanoparticles with 15 % ionic radius mismatch were synthesized via benzyl alcohol route at 220 °C-5 min in presence of PtCl4 and Fe(acac)3, exhibiting novel optical, electrical and magnetic properties. Nucleation pathways of the 5HEO at the critical temperature were elucidated by using a comparison study of conventional heating and microwave irradiation heating. Consistency of XRD patterns and STEM-EDX observation indicate that the resultant Hf-OBn monomers acted as the nucleation center of the 5HEO, determined by diffusion kinetics. The nucleation rate depended on the metal monomers assembly and esterification reaction, which was accelerated by water vapor pressure produced in-situ by 0.5×10−4mol/l PtCl4 catalyst. The Fe-metal organic cages derived from 1.5×10−4mol/l Fe(acac)3 additive served as the structure stabilizer of Zr/Ti monomers, and prevented early hydrothermal reaction route.

Remediation of seawater polluted by oil spills via integrating porous materials with phase-change materials

The cleanup of viscous oil spills, especially in frigid regions, presents significant challenges due to the low fluidity of the oil. While the integration of absorption materials with photo/electric thermal conversion has shown significant promise, its effectiveness can be greatly influenced by environmental factors. To address these challenges, this study introduces an innovative solution: three-dimensional porous materials (3D-PMs) combined with phase change materials (PCMs). By utilizing energy pre-stored in PCMs through sunlight irradiation or electric heating, heat can be efficiently released when 3D-PMs come into contact with crude oil. A novel superhydrophobic melamine sponge (PPCPP@MS), composed of polypyrrole (PPy) and polyethylene glycol (PEG), has been developed for this purpose. The PPy polymerization layer reliably converts light/electricity into heat, while the PEG‑carbon nanotube (CNT) composite coating layer facilitates heat storage and release. This innovative design significantly enhances safety, energy utilization efficiency, and operational effectiveness. Furthermore, COMSOL simulation was employed to the interfacial heat transfer and phase transformation process of PPCPP@MS during crude oil absorption. Demonstrating stable heat release and oil-adsorbing performance in simulated low-temperature marine environments, PPCPP@MS exhibits great potential for addressing oil spills in extreme climates. The innovative design of PPCPP@MS offers crucial insights for managing viscous oil spills, particularly in frigid regions, providing a promising approach in environmental protection and remediation efforts.

Effect of microwave irradiation and conventional heating on high pressure modified white finger millet starch hydrogel properties

High pressure modified (200 MPa and 400 MPa for 10 min) white finger millet starch hydrogels were prepared with three starch concentrations (12 %, 15 % and 18 % (w/v)), by conventional heat treatment (75 °C for 12 min) and microwave treatment (50 s at 900 W, surface temperature 75 °C). The prepared hydrogels were compared to native white finger starch hydrogels for understanding the effect of modification as well as the gel synthesis method. Effect of the storage period on physical stability was evaluated for ten days by evaluating weight loss, water activity, and color. The whiteness index of the prepared hydrogel intensified during the storage period, and water activity was reduced (0.99–0.976). While stored at 4 °C, the hydrogel weight decreased due to moisture migration. The results emphasize that treatment conditions, starch modification, and concentration significantly affected water absorption. The maximum gel strength was identified for conventional heat-induced 400 MPa high-pressure modified hydrogel stored for ten days. 1H NMR relaxation time showed microwave-induced gel synthesis had a shorter relaxation time. The gel microstructure helped to correlate the swelling and gel strength increment in the modified gel sample, as it had a higher wall thickness and a smaller pore size than heat-induced hydrogels. These findings help to conclude high pressure modified white finger millet starch hydrogel synthesised by microwave irradiation can be alternative to conventional heat gelatinisation method.

High-efficient microwave-assisted conversion of fructose to 5-hydroxymethylfurfural over rice straw-derived sulfonated porous carbonaceous catalyst

5-Hydroxymethylfurfural (HMF) has emerged as a pivotal platform chemical derived from biomass, attracting considerable attention for its renewable applications. In this study, sulfonated rice straw biochar (RSBC-SA) catalysts were developed and employed for microwave-assisted catalytic conversion of fructose to HMF. The RSBC-SA catalysts, synthesized by pyrolyzing rice straw biomass at different temperatures and subsequent functionalization with sulfonic acid groups, were characterized using X-ray photoelectron spectroscopy (XPS), elemental analysis, temperature programmed desorption (TPD) and Fourier-transform infrared spectroscopy (FT-IR). A comparative analysis of catalytic performance between microwave irradiation and conventional oil bath heating revealed a substantial enhancement in efficiency with the former. Notably, the 700 ℃ pyrolyzed RSBC-SA catalyst demonstrated the highest HMF yield of 92.6 % within just 5 min of reaction time under a microwavehydrothermal condition, surpassing the conventional oil bath heating method. In addition, moderate to high yields of HMF were achieved from different carbohydrates in our developed microwave reaction system, demonstrating significant catalytic activity. This superior catalytic effect under microwave irradiation can be attributed to the responsive dipole polarization of sulfonic acid groups, selective heating of the RSBC carrier via microwave absorption, and synergistic interactions among these factors. Overall, this study highlights the innovative use of agricultural waste and introduces a new method for creating microwave-responsive catalysts with biochar. This strategy enables efficient fructose conversion to HMF, promotes sustainable biomass transformation, and offers value-added uses for agricultural residues in chemical production.

Recover the tensile strength of hard aluminum alloy through laser assisted cold spray

In the present study, Al6061/Al2O3 composite coating was produced to repair the notched Al7075 substrate by cold spraying (CS) and laser assisted cold spray (LACS) technology. The preparation process and parameter selection of high-performance coating were discussed by combining simulation and experiment. Results showed that the LACS experiment guided by simulation results achieved high-quality bonding of single particle with the substrate. In addition, the tensile strength of samples repaired by LACS recovered to the level of original substrate, and the ductility was significantly higher than that of CS process. This is attributed to the introduction of laser irradiation heating, which improves the plastic deformation ability of particles and produces atomic-level metallurgical bonding between the particles. This study provides a possibility for the repair and remanufacture research of high-quality components, and has great development potential in future research.

Effect of Post-Implantation Heat Treatment Conditions on Photoluminescent Properties of Ion-Synthesized Gallium Oxide Nanocrystals.

A novel and promising way for creating nanomaterials based on gallium oxide is the ion synthesis of Ga2O3 nanocrystals in a SiO2/Si dielectric matrix. The properties of nanocrystals are determined by the conditions of ion synthesis-the parameters of ion irradiation and post-implantation heat treatment. In this work, the light-emitting properties of Ga2O3 nanocrystals were studied depending on the temperature and annealing atmosphere. It was found that annealing at a temperature of 900 °C leads to the appearance of intense luminescence with a maximum at ~480 nm caused by the recombination of donor-acceptor pairs. An increase in luminescence intensity upon annealing in an oxidizing atmosphere is shown. Based on data from photoluminescence excitation spectroscopy and high-resolution transmission electron microscopy, a hypothesis about the possibility of the participation of a quantum-size effect during radiative recombination is proposed. A mechanism for the formation of Ga2O3 nanocrystals during ion synthesis is suggested, which makes it possible to describe the change in the luminescent properties of the synthesized samples with varying conditions of post-implantation heat treatment.

Design and numerical simulation of a 45 kWel multi-source high-flux solar simulator as a heating source of dielectric materials positioned in a microwave characterization cavity

This study reports the design and modelling of a high-flux solar simulator (HFSS) combined to a resonant cavity for microwave dielectric properties characterization of ceramics at very high temperatures. The HFSS comprises seven xenon arc lamps with ellipsoidal reflectors, delivering a maximal electrical power of 6.5 kWel each. Positioned on a virtual sphere of around 1600 mm radius, the lamps provide concentrated irradiation heating on a sample positioned inside the resonant cavity. The propagation of the lamp’s irradiation to the sample and the cavity is simulated using Monte Carlo ray tracing method. An ANSYS Fluent finite volume method for solving the resulting multimode heat transfer and flow indicate a radiative flux reaching 1.84 MW m−2, and a sample temperature of approximately 1470°C with 10 % non-uniformity. These results suggest that the designed heating system and resonant cavity is suitable for conducting microwave dielectric properties characterization of refracting ceramic materials at high temperatures, addressing a gap in studies focusing on temperatures exceeding 1000°C.

Improved Operation of Chloralkaline Reversible Cells with Mixed Metal Oxide Electrodes Made Using Microwaves.

This study focuses on the synthesis of mixed metal oxide anodes (MMOs) with the composition Ti/RuO2Sb2O4Ptx (where x = 0, 5, 10 mol) using hybrid microwave irradiation heating. The synthesized electrodes were characterized using scanning electron microscopy, X-ray energy-dispersive analysis, X-ray diffraction, cyclic voltammetry, and electrochemical impedance spectroscopy. These electrodes were then evaluated in both bulk electrolytic and fuel cell tests within a reversible chloralkaline electrochemical cell. The configurations using the electrodes Ti/(RuO2)0.7-(Sb2O4)0.3 and Ti/(RuO2)66.5-(Sb2O4)28.5-Pt5 presented lower onset potential for oxygen and chlorine evolution reactions and reduced resistance to charge transfer compared to the Ti/(RuO2)63-(Sb2O4)27-Pt10 variant. These electrodes demonstrated notable performance in reversible electrochemical cells, achieving Coulombic efficiencies of up to 60% when operating in the electrolytic mode at current densities of 150 mA cm-2. They also reached maximum power densities of 1.2 mW cm-2 in the fuel cell. In both scenarios, the presence of platinum in the MMO coating positively influenced the process. Furthermore, a significant challenge encountered was crossover through the membranes, primarily associated with gaseous Cl2. This study advances our understanding of reversible electrochemical cells and presents possibilities for further exploration and refinement. It demonstrated that the synergy of innovative electrode synthesis strategies and electrochemical engineering can lead to promising and sustainable technologies for energy conversion.

Far‐infrared drying influence on machine learning algorithms in improving corn drying process with graphene irradiation heating plates

AbstractDrying methods often suffer from appropriate drying process modeling, low heating efficiency, and high‐energy consumption. However, graphene may provide significant improvements during the drying process due to its ability to save energy and convert electro‐thermal energy effectively. In this study, random forest (RF), surface vector machine (SVM), artificial neural network (ANN), and k‐nearest neighbor (kNN) were the four machine‐learning algorithms employed to analyze the drying process of two types of corn (ZD88 and RP909) at varying temperatures of 35, 45, and 55°C in a graphene far‐infrared drying. The study found that the drying process of corn showed a decrease in moisture ratio during the falling rate period from 35 to 55°C. The moisture diffusivity increased from 35 to 55°C with the rise in the temperature, ranging from 2.74 to 4.36 × 10−8 m2/s for ZD88 and 2.05 to 3.07 × 10−8 m2/s for RP909. The ZD88 showed a heat efficiency of 81.62% at 55°C. The results of the machine learning algorithms revealed that 1–6 ANN was the best architecture. Normalized PUK was the best for SVM filters. A k = 3 and s‐fold = 5 were the best values for k‐NN and RF, respectively. Among the computed algorithms, the tested data for normalized Pearson universal kernel SVM filters proved to be the most effective in computing the process of drying corn. Overall, a graphene far‐infrared dryer showed improved heating efficiency and less energy consumption, providing a new concept for developing a drying process through machine learning algorithms strategies.Practical applicationsDrying methods often suffer from appropriate drying process modeling, low heating efficiency, and high‐energy consumption. This study provides significant improvements due to the ability of graphene irradiation heating plates to save energy and convert electro‐thermal energy effectively. The study achieved a heating efficiency of 81.62% at an infrared temperature of 55°C. Machine learning algorithms are intelligent models that minimize the limitations in describing the drying process of agricultural materials. The study found the normalized Pearson universal kernel was the most effective computation SVM filter. Therefore, using a graphene far‐infrared dryer showed a better drying alternative for industrial applications, as it has the potential to improve heating efficiency and consume less energy, providing a new concept for developing drying equipment through machine learning algorithms modeling strategies.

Enhancing Biodiesel Production: A Review of Microchannel Reactor Technologies

The depletion of fossil fuels, along with the environmental damages brought by their usage, calls for the development of a clean, sustainable and renewable source of energy. Biofuel, predominantly liquid biofuel such as biodiesel, is a promising alternative to fossil fuels, due to its compatible direct usage within the context of compression ignition engines. However, the industrial production of biodiesel is far from being energy and time efficient, which contributes to its high production cost. These inefficiencies are attributed to poor heat and mass transfer of the transesterification reaction. The utilisation of microchannel reactors is found to be excellent in escalating heat and mass transfer of the reactants, benefitting from their high surface area-to-volume ratio. The microchannel also intensifies the mixing of reactants via the reactor design, micromixers and the slug flow patterns within the reactor, thus enhancing the contact between reactants. Simulation studies have aided in the identification of mixing regimes within the microchannel reactors, induced by various reactor designs. In addition, microwave irradiation heating is found to enhance biodiesel production by localised superheating delivered directly to the reactants at a molecular level. This enables the reaction to begin much earlier, resulting in rapid biodiesel production. It is postulated that the synergy between microchannel reactors and microwave heating would catapult a pathway towards rapid and energy-efficient biodiesel production by enhancing heat and mass transfer between reactants.

Doping engineering for high-temperature broadband high emissivity and low thermal conductivity of ytterbium chromate-based ceramics

Developing highly reliable infrared radiation materials with broadband high emissivity at high temperatures, low thermal conductivity, and excellent thermal stability is highly desirable for aerospace thermal protection applications. However, it remains a huge challenge to take into account infrared radiation heat dissipation and blocking heat transfer through low thermal conduction simultaneously. In this work, we reported a broadband high emissivity Ca2+-doped YbCrO3 ceramic with emissivity above 0.89 at room temperature across the entire range of wavelength (1–14 μm). This doping strategy leads to the introduction of impurity energy levels into the band gap of YbCrO3, which increases the possibility of light absorption to promote electron transition, improving the emissivity of the near-infrared band (1–3 μm). Simultaneously, un-equivalent doping induces electron exchange between chromate ceramic ions, which complicates the electronic structure (producing lattice distortion and extra multi-mode vibrations) and reduces the band gap width, thus boosting the emissivity in the mid-infrared band (3–14 μm). More importantly, (Yb0.8Ca0.2)CrO3 presents a high emissivity (0.76) at an elevated temperature of 1200 °C, together with low thermal conductivity (2.5 W m−1 K−1 at 1000 °C) due to strong phonon scattering. Moreover, the doping-dominating phase stabilization effect contributes to impressive thermal stability (stable at 1300 °C for 50 h) and a high coefficient of thermal expansion (9.0–9.5 × 10−6 K−1), which makes it suitable for long-term high-temperature thermal protection application. All these merits render the development of thermally stable high-temperature infrared radiation ceramic materials core competitive.

New insights into the role of color extraction from (Aegle Marmelos leaf) using a non-traditional heating source

Purpose Due to herbs and plants’ therapeutic properties and simplicity of availability in nature, humans have used them to treat a variety of maladies and diseases since ancient times. Later, as technology advanced, these plants and herbs gained significant relevance in some industries due to their suitable chemical composition, abundant availability and ease of access. Aegle marmelos is a species of plant that may be found in nature. Yet, little or very little literature was located on the coloration behavior of this plant’s leaves. This study aims to focus on the effect of different parameters on the extraction of colorant from Aegle marmelos leaves. Design/methodology/approach Some factors that affected on the extraction processes were examined and found to have significant impacts on the textile dyeing such as the initial dye concentration, extracted temperature, extracted bath pH and extracted time were all changed to see how they affected color extraction. The authors report a direct comparison between three heating methods, namely, microwave irradiation (MWI), ultrasonic waves (USW) and conventional heating (CH). The two kinetic models have been designed (pseudo-first and pseudo-second orders) in the context of these experiments to investigate the mechanism of the dyeing processes for fabrics under study. Also, the experimental data were analyzed according to the Langmuir and Freundlich isotherms. Findings From the result, it was discovered these characteristics were found to have a substantial effect on extraction efficiency. Temperature 90°C and 80°C when using CH and USW, respectively, while at 90% watt when using MWI, period 120 min when using CH as well as USW waves, while 40 min when using MWI, and pH 4, 5 and 10 for polyamide, wool and cotton, respectively, were the optimal extraction conditions. Also, the authors can say that wool gives a higher absorption than the other fabric. Additionally, MWI provided the best color strength (K/S) value, and homogeneity, at low temperatures reducing the energy and time consumed. The coloring follows the order: MWI > USW > CH. The adsorption isotherm of wool could be well fitted by Freundlich isotherm when applying CH and USW as a heating source, while it is well fitted by the Langmuir equation in the case of MWI. In the study, it was observed that the pseudo-first-order kinetic model fits better the experimental results of CH with a constant rate K1 = −0.000171417 mg/g.min, while the pseudo-second-order kinetic model fits better the experimental results of absorption of both MWI (K2 = 38.14022572 mg/g.min) and USW (K2 = 12.45343554 mg/g.min). Research limitations/implications There is no research limitation for this work. Dye was extracted from Aegle marmelos leaves by applying three different heating sources (MWI, ultrasonic waves [USWW] and CH). Practical implications This work has practical applications for the textile industry. It is concluded that using Aegle marmelose leaves can be a possible alternative to extract dye from natural resource by applying new technology to save energy and time and can make the process greener. Social implications Socially, it has a good impact on the ecosystem and global community because the extracted dye does not contain any carcinogenic materials. Originality/value The work is original and contains value-added products for the textile industry and other confederate fields.

Artificial aging of rice using a sterilization box equipped with infrared heating and ultraviolet‐C radiation

AbstractAging of rice starts from the time of its harvest and continues until it is consumed. It positively impacts the cooking and eating qualities of rice, but natural aging takes years. In this study, artificial aging of rice was carried out at 70°C using simultaneous infrared (IR) radiation heating (3.18 × 104 W/m2) for 1, 3, 5, and 7 h and ultraviolet‐C (UV‐C) irradiation (49.24 J/cm2‐h) in a designed box. IR heating at 70°C combined with UV‐C irradiation for 5 h was the optimized condition for artificial aging. At optimized conditions, the proportionate change of rice was the highest as 0.21, followed by that for naturally aged (0.15) and non‐aged (0.08). The values of elongation ratio and actual elongation after cooking were the highest in artificial aging, followed by those for naturally aged and non‐aged rice. Water uptake (%) value was also the highest for artificial aging (89.62%), followed by that for naturally aged (68.45%) and non‐aged (59.93%) rice. Furthermore, nutritional values, microstructure, and antibacterial studies were carried out at optimized conditions. No significant changes in nutritional values viz., starch, protein, and fat were observed in artificially aged rice in comparison to one‐year‐old naturally aged rice. Electron microscopy analysis showed no changes in the structure of starch granules, which further revealed no adverse effect of IR radiation heating on the microstructure of rice. Results from the spread plate assay showed no growth of bacterial colony indicating the antibacterial effectiveness of artificial aging. Thus, simultaneous artificial aging as well as surface disinfection of rice can be carried out by combining IR radiation heating and UV‐C irradiation. These observations endorsed the effectiveness of the designed box for the artificial aging of rice without compromising the cooking and nutritional qualities. A preliminary sensory test was conducted. Overall, an efficient, inexpensive, and easy‐to‐handle artificial aging combined with surface disinfection was accomplished.

Enhanced solar absorbance and infrared emittance in Co-doped BaTiO3

Broadband absorber materials with high solar absorptivity and infrared emissivity are conducive to high-efficient and cost-effective heating technology in the civil and industrial field. The BaTi1-xCoxO3 ceramics are prepared by sol-gel method, showing mixed tetragonal/hexagonal phases. Co doping slightly reduces the phase transition temperature of BaTiO3. Meanwhile, BaTi1-xCoxO3 ceramics present a composite Mott/charge transform band nature and the Co-3d impurity level and oxygen vacancies level lead to a narrowed bandgap. The enhancement of the absorption induced by free carriers, impurity level and lattice vibration promote the UV-Vis-NIR absorption and mid-infrared radiation of BaTi1-xCoxO3 ceramics. In conclusion, the optimized BaTi0.95Co0.05O3 ceramic achieves a high solar absorptivity (0.88) in 0.25–2.5 µm and a high infrared emissivity (0.83) in 8–14 µm. The radiative performance presents good temperature stability, unaffected by phase structure and lattice thermal expansion, which provides prospective applications in solar energy conversion and infrared radiation heating.

Experimental Investigation of a System of Two Vacuum Solar Receivers for the Continuous Reduction of Ceria Particles

A solar receiver for the continuous reduction of redox particles under vacuum conditions has been developed previously as part of a system to produce hydrogen from solar energy. Here, we report about a joint effort of Sandia and DLR to improve the receivers design and to demonstrate a system of two receivers with different vacuum pressures at DLR’s solar simulator Synlight. We focus on the design and experimental investigation of three components: the novel beam down mirror, the novel secondary concentrator and the improved version of the particle conveying plate in the receiver. Irradiation test results and heat transfer analyses of the beam-down mirror and the secondary concentrator are being presented. The motion of the conveyor plate was improved by a MATLAB model, which predicts the transport speed of the particles on the conveyor.