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The purpose of this study is to develop a thermoelectric egg incubator (TEI) integrated with a thermal energy storage (TES) system, using electricity from photovoltaic (PV) cells in order to operate without on-grid electricity. The TEI was constructed with the same dimensions as a commercial egg incubator (CEI), which was made to the required dimensions for hatching 24 eggs per period of 21 days. The TEI was designed with 2 operating modes of heat sources: a thermoelectric (TE) module used for daytime operation and a TES containing phasechange materials (PCM) which supplied heat to the TEI for nighttime operation. The PV panels were designed to be the primary energy source for generating 360 W of electricity, which was supplied to heat sources of TEI according to the energy load for providing fertile chicken eggs (24 eggs/hatching). The incubating temperature and relative humidity (RH) inside the TEI-TES were controlled under optimum environmental conditions for hatching (36-39°C and 60-80% RH) to stimulate embryonic growth. As a result, the TEI-TES achieved and maintained an optimum incubating temperature in the range of 36.7-38.8°C and the correct RH of 66±0.2 % in the warm weather of Thailand over the incubating period of 21 days. The TEI-TES was able to maintain optimum environmental conditions for chicken-egg hatching, and its performance was comparable to that of the CEI. The working mechanisms of the TE module and TES are also discussed. The results show that the TEI-TES with PV panels as the primary energy source is suitable for use in remote areas which have no on-grid electricity supply. [ABSTRACT FROM AUTHOR]

Bismuth oxide (Bi2O3) and Bi2O3–supported Kaolin were synthesized using household microwave–assisted methods (350 W, 5 min), with catalyst characteristics analyzed. XRD patterns confirmed the monoclinic structure of Bi2O3. Incorporating 20%w/w Kaolin increased the specific surface area of Bi2O3 from 6.2879 to 16.1345 m2/g, observed in FESEM images showing a hierarchical flower-like morphology resembling French fries alongside Kaolin plates. XRF analysis identified elements in Kaolin contributing to self–doping in band structure of Bi2O3, reducing its band gap and PL intensity. Kaolin/Bi2O3 composites demonstrated enhanced photocatalytic degradation of tetracycline (TC) under visible light, attributed to Bi2O3-generated radicals and increased surface area. The composite photocatalyst can be recycled up to three times. This research not only enhances the photocatalytic activity of Bi2O3 but also increases the value of a local waste material, Kaolin clay. Such enhancements could potentially extend to other metal oxides and abundant waste materials within the country. [ABSTRACT FROM AUTHOR]

The incorporation of waste materials into cementitious binders serves as a strategy to diminish waste volume and lower carbon emissions. This study presents an in-depth evaluation of calcium carbide residue and coal fly ash as alternative binders. The assessment of raw materials emphasized their chemical composition and potential for pozzolanic reactions. Based on these factors, the optimal ratio of Ca/(SiO2 + Al2O3) in the raw materials was determined to be 1.5. Therefore, this study was designed to vary the raw material composition with a CaO/(SiO2 + Al2O3) ratio ranging from 1.7 to 0.9. Upon investigating the effect of the raw material proportion on the compressive strength of pastes and mortars, the composition yielding the highest compressive strength was selected for its potential application as a stabilizer for loess soil. A mixture of calcium carbide residue and coal fly ash with a Ca/(SiO2 + Al2O3) ratio of 1.5 resulted in the highest compressive strength at long curing periods in both pastes and mortars. Mineralogical and microstructural analyses revealed several products, beyond those formed from the pozzolanic reactions, that occurred and enhanced the compressive strength of samples. The highest performing mixture of carbide residue and coal fly ash was then used to stabilize loess soil at 10–25 wt%. The unconfined compressive strength, along with mass and strength loss due to wetting and drying cycles, was also studied. It was observed that the unconfined compressive strength of the stabilized soils remained consistent after six wet-dry cycles but decreased after twelve cycles due to microcracks. The findings suggest that carefully designed mixtures based on the chemical interactions of calcium carbide residue and coal fly ash can offer a sustainable, efficient approach for soil stabilization, potentially revolutionizing construction practices. [ABSTRACT FROM AUTHOR]

This study developed a grid-connected biogas power generation system for a rural community using a 3-phase 2.2 kW squirrel-cage induction machine as the self-excited induction generator. The generator was driven by a 196 cc single-cylinder spark-ignition engine fueled by biogas. We developed a back-to-back converter that consists of a 3-phase PWM rectifier as the generator-side converter and a single-phase LCL-filtered grid-connected inverter. The generator-side converter transferred the active power to the grid-side converter and supplied the reactive power control back to the generator. The notch filter-based bus voltage control on the generator side mitigated the inter-harmonics in the generator current. The injected grid current complied with the IEEE 1547 standard because of the multi-frequency unbalanced synchronous reference frame control. The proposed system was validated with biogas produced from pig manure at a pig farm in central Thailand, which found a maximum output of 1.2 kW with a thermal system efficiency of 10.7%. The proposed system was scheduled to operate at 1.2 kW for 8 h per day with a levelized cost of 0.07 US$/kWh, 42% cheaper than the retail electricity price, and a payback period of 2.76 years. The proposed system is suitable for a farm with a minimum of 34 pigs. [ABSTRACT FROM AUTHOR]

(1 − x)[(K0.44Na0.52Li0.04)(Nb0.84Ta0.10Sb0.06)O3] − xBi0.8Ba0.2FeO3 [(1 − x)KNLNTS-xBBF] lead-free ceramics, with different x contents, were prepared by the solid-state combustion technique. The effect of Bi0.8Ba0.2FeO3 content on the phase formation, microstructure, and electric and magnetic properties of KNLNTS ceramics were investigated. The KNLNTS ceramic exhibited co-existing orthorhombic and tetragonal phases. When x increased, the samples demonstrated an increased tetragonal phase and unit cell volume. The average grain size, density and relative density deceased when x increased up to 0.06 and then continuously increased. For x = 0, a well-saturated P–E loop was found in which the Pr and Ec values were about 21.27 μC/cm2 and 12.38 kV/cm, respectively. However, x = 0.02–0.2 exhibited a round P–E loop because the leakage current was performed. For higher x, the leakage current of the samples decreased, suggesting that the samples exhibited slim P–E loops. The KNLNTS ceramic exhibited diamagnetic behavior while the x = 0.02–0.4 samples showed ferromagnetic behavior. At room temperature, multiferroic behavior, which exhibited fair ferroelectric and ferromagnetic hysteresis loops, was obtained from the samples with x = 0.3–0.4, which means these ceramics can be applied in multifunctional devices. The maximum magnetoelectric coupling (αE) was obtained from the KNLNTS-xBBF with x = 0.4. [ABSTRACT FROM AUTHOR]

This research investigated the increases of the voltage profile on the Provincial Electricity Authority (PEA)'s low voltage (LV) network due to the solar photovoltaic (PV) penetration. This study proposed the solution to maintain the voltage profile within the PEA's standard limitation by using battery energy storage system (BESS) application. The algorithm using bisection method to figure out the optimal size and location of BESS was examined and simulated in different scenarios such as summer/winter and weekend/weekday behaviors. Furthermore, the allocation of a battery in various locations was also considered. DIgSILENT power factory with DPL script and Python are the tools used to cover diverse scenario cases. The results showed that the best practice of how to implement BESS to solve the voltage rise problem was the BESS installation at the distribution transformer and the BESS installation separately at the end of each feeder near the loads. However, the optimal size of BESS installation at the distribution transformer was almost double that of installation at the end of each feeder. [ABSTRACT FROM AUTHOR]

Metal oxide photocatalyst is a promising wastewater treatment process due to its simplicity, high efficiency, and low cost, as well as being environmentally friendly and non-energy consuming. The perovskite structure material, SrTi1−xNbxO3 (STNO) with x = 0, 0.01, 0.03, and 0.05, was successfully synthesized by the sol-gel auto-combustion method. Samples with a pure phase and cubic perovskite structure were obtained. The Rietveld refinement results showed that the lattice parameter and unit cell density increased as the Nb-doping level increased. The particle size of the STNO decreases with increasing Nb doping content. Photoluminescence was excited at 327 nm, producing violet, green, and blue emissions, while the Nb content asserts an insignificant effect on the bandgap (Eg). The Nyquist plot and Mott-Schottky analysis were used to determine the photoelectrode performance of the STNO samples. The photocatalytic activity of STNO on the decolorization of methylene blue (MB) under UV irradiation increased with increasing Nb content and optimization at x = 0.05, corresponding to the results obtained from photoluminescence, Eg, Nyquist plot, and Mott-Schottky analyses. [ABSTRACT FROM AUTHOR]

The effect of the firing conditions on the phase formation, microstructure, and electrical properties of (K0.5Na0.5)(Nb0.7Ta0.3)O3 (KNNT) ceramics synthesized by the solid-state combustion technique using glycine as fuel has been investigated. All samples were calcined at 600°C to 800°C for 2 h and sintered at 1150°C to 1190°C for 2 h to 5 h. Pure KNNT powders were produced after calcination at 600°C for 2 h. The average particle size increased when the calcination temperature was increased. The KNNT powder calcined at 600°C for 2 h showed rather square morphology with average particle size of ∼ 160 nm. The x-ray diffraction (XRD) analysis results for the ceramics revealed the presence of orthorhombic (O) and tetragonal (T) phases in all samples. When sintering at 1150°C for 4 h, the O:T ratio was 50:50, as verified by the Rietveld refinement technique. The average grain size, density values, and dielectric properties tended to increase when the dwell time was increased from 2 h to 4 h, but then degraded. The KNNT ceramic produced at the optimum firing condition (1150°C for 4 h) showed good crystalline morphology, the highest density (ρ = 5.28 g/cm3), the highest dielectric constant (εC = 5002), and good ferroelectric behavior (Pr = 18.50 μC/cm2 and Ec = 9.04 kV/cm). [ABSTRACT FROM AUTHOR]

Lead-free 0.94Bi0.50Na0.50TiO3–0.06Ba0.85Ca0.15Ti0.90Zr0.10O3–xmol%Bi2FeCrO6 ceramics, with x = 0–0.021 (BNT–BCTZ–xBFCO), were calcined at 650 °C for 2 h and sintered at 1150 °C for 2 h using the solid-state combustion technique. The effect of BFCO content (x) on the phase formation, microstructure, electrical and magnetic properties was studied. The sintered pellets exhibited a pure perovskite phase with the coexistence of rhombohedral (R3c) and tetragonal (P4bm) phases in all the studied compositions. The percentage of R3c increased as x increased from 0 to 0.013, before decreasing, as obtained from the Rietveld refinement analysis (Fullprof). A morphotropic phase boundary of BNT–BCTZ–xBFCO ceramics was observed at x = 0.013, and the ratio between the rhombohedral and tetragonal phases of this composition was 51.0:49.0. The scanning electron microscopy analysis showed polyhedral-shaped grains whose average size increased with increase in the BFCO content (x). The appropriate amount of BFCO doped into BNT–BCTZ ceramics enhanced the electrical, ferroelectric and piezoelectric properties. At optimum doping (x = 0.013), the sample exhibited the highest relative density (98.2%), a high dielectric constant (εR = 1572 and εm = 5137), maximum remanent polarization (Pr = 42.41 µC/cm2), low coercive field (Ec = 33.57 kV/cm), maximum piezoelectric coefficient (d33 = 241 pC/N) and the highest normalized strain ( d 33 ∗ = Smax/Emax = 765 pm/V). These improvements to BNT–BCTZ make the ceramic a potential candidate for use in capacitors, sensors and actuators. The magnetic properties also changed with different BFCO content (x). The sample with x = 0 showed diamagnetic behavior, while the samples with 0.003 ≤ x ≤ 0.021 exhibited a paramagnetic behavior with higher magnetization at higher BFCO content. [ABSTRACT FROM AUTHOR]

The tin-pigmented aluminium oxide film (Sn-AlO) based solar selective absorber was successfully prepared with three different contents of tin by an anodization process. The phase and morphology of the Sn-AlO were measured by X-ray diffractometer and a scanning electron microscope equipped with an energy dispersive X-ray analyser. The reflectance ( R) of the coating was determined by Ultraviolet-visible-near infrared spectrophotometer in the wavelength interval of 300-2500 nm and the Fourier transform infrared spectrophotometer in the wavelength of infrared region (2500-25,000 nm). As a result, aluminium and tin phases were detected at the coating surface. The AlO films were formed and compacted as a barrier on the Al substrate. The compositions of the oxide film composed of tin (Sn), aluminium (Al) and oxygen (O) elements. With increasing Sn content, the solar absorptance ( α) gradually increased, but it has little effect on the thermal emittance ( ε). The thermal conductivity of Sn-AlO samples decreased with increasing Sn content as a result of the increasing thickness of the Sn layer at the interface leading to obstruct the free electrons and phonon contributions. The present result suggests that the increasing Sn content in the Sn-AlO coating can enhance the solar selectivity properties and a good solar absorber material. [ABSTRACT FROM AUTHOR]

This article reports an investigation into ferrite and nanocrystalline materials for the medium-frequency transformer of a dual active bridge DC-DC converter, which plays a key role in the converter's efficiency and power density. E65 MnZn ferrite cores and toroidal and cut nanocrystalline cores are selected for the construction of 20-kHz transformers. Transformer performance is evaluated with a 1.1-kW (42–54 V)/400 V dual active bridge DC-DC converter with single-phase shift and extended phase shift modulations. The experimental results indicate that the toroidal nanocrystalline transformer had the best performance with an efficiency range of 98.5–99.2% and power density of 12 W/cm3, whereas the cut-core nanocrystalline transformer had an efficiency range of 98.4–99.1% with a power density of 9 W/cm3, and the ferrite transformer had an efficiency range of 97.6–98.8% with a power density of 6 W/cm3. A small mismatch in the circuit parameters is found to cause saturation in the nanocrystalline toroidal core, due to its high permeability. The analytical and experimental results suggest that cut nanocrystalline cores are suitable for the dual active bridge DC-DC converter transformers with switching frequencies up to 100 kHz. [ABSTRACT FROM AUTHOR]

This study investigates the influence of Ni-Al coating thickness on the spectral selectivity and thermal performance of a parabolic trough collector (PTC). Three thicknesses of Ni-Al coating for use as solar absorber material were successfully prepared on the outer surface of a stainless steel 316L (SS) tube by flame spray. The phase, morphology, and reflectance (R) of the Ni-Al coatings were characterized using several techniques. The PTC and solar receiver tube were specially designed and constructed for observing the collector thermal performance by following ASHRAE 93-1986. Looking at the results, the actual average thicknesses of the three Ni-Al coatings turn out to be 195, 215, and 299 μm. The morphology and chemical composition of all three thicknesses are similar. The chemical composition in the cross-sectional view exhibits non-uniform distribution. The three thicknesses of the coating are composed of NiO and Al2O3 phases, which also corresponded to the results of SEM-EDX mapping. The differences in a solar absorptance (α) of the three thicknesses of Ni-Al coating are not statistically significant, with an average α value of 0.74-0.75. However, there are differences in thermal efficiency of the PTC depending on the thickness of the Ni-Al coating. Of the three samples, the thickest one (299 µm) demonstrates the highest ability to convert solar radiation into thermal energy. [ABSTRACT FROM AUTHOR]