[en] Relationship between gamma radiation sensitivity and morphological and physiological traits was studied in four rice varieties: Osaka-Asahi and Ginbozu (Japonica) and Jhona 349 and Magnolia (Indica). R D₅₀ values were almost double in Indica varieties than Japonica. The release of endogenous reducing sugar decreased with the increase in radiation dose and corresponded to the degree of morphological damage. It seems that the difference in radiosensitivity among these varieties, particularly between Indica and Japonica types, may be due to differences in sensitivity to gamma radiation in a release process including and/or activation of enzymes

[en] Seal leak test part is a polyurethane material-based product. Based on past data, defect level of this product was 8%, higher than the target of 5%. Quality improvement effort was done using six sigma method that included phases of define, measure, analyse, improve, and control. In the design phase, a Delphi method was used to identify factors that were critical to quality. In the measure phase, stability and process capability was measured. Fault tree analysis (FTA) and failure mode and effect analysis (FMEA) were used in the next phase to analize the root cause and to determine the priority issues. Improve phase was done by compiling, selecting, and designing alternative repair. Some improvement efforts were identified, i.e. (i) making a checklist for maintenance schedules, (ii) making written reminder form, (iii) modifying the SOP more detail, and (iv) performing a major service to the vacuum machine. To ensure the continuity of improvement efforts, some control activities were executed, i.e. (i) controlling, monitoring, documenting, and setting target frequently, (ii) implementing reward and punishment system, (iii) adding cleaning tool, and (iv) building six sigma organizational structure. (paper)

[en] A quantum Brayton engine using a massless Boson trapped in a one-dimensional potential well as a working substance has been constructed to be studied. We used a modified analogical model by the first law of thermodynamics for a quantum system implementation. The system was built with Klein Gordon equation, relativistic quantum mechanics Hamiltonian, without the mass term of the Hamiltonian and it was trapped in a one-dimensional potential well. Then, it underwent the quantum ideal Brayton cycle process. The quantum Brayton process consisted of adiabatic compression, isobaric expansion, adiabatic expansion, and isobaric compression processes. This relativistic quantum mechanics Brayton engine has found that the efficiency formulation was similar to the classical one. This study obtained the conformity results between the quantum relativistic and classical Brayton engines. By this cycle process, we also invented that the ratio of heat capacity under constant pressure and volume of the system was 2. It could indicate that the efficiency of quantum relativistic Brayton engine is higher than the classical one. (paper)

[en] TiO₂ is usually employed as a protective layer for Cu₂O in photoelectrocatalytic CO₂ reduction. However, the role of TiO₂ layer on CO₂ reduction activity and selectivity is still elusive. In this work, a systematic investigation is carried out to probe the impact of the deposition parameters of TiO₂ overlayer, including the temperature and thickness, on CO₂ reduction performance. Compositional and (photo-)electrochemical analysis is performed to explore the property of TiO₂ overlayers. Carrier behavior, including donor density and electron energy, and stability of TiO₂ are demonstrated to be influenced by atomic layer deposition conditions and thus play a role in controlling CO₂ reduction reaction. Specifically, as the thickness of the TiO₂ layer increases from 2 to 50 nm, the electron energy tends to be lowered accompanying the electron transfer mode from tunneling for TiO₂ thin layers to type II for thick TiO₂, leading to a decrease in CO₂ reduction selectivity. With an increase of the TiO₂ deposition temperature, the stability increases with a loss of conductivity. Cu₂O coated with 2 nm TiO₂ at 150 °C is proven to be the optimized candidate in this work for photoelectrochemical reduction of CO₂ to CO, HCOOH and CH₃COOH under an applied bias of −0.4 versus RHE. (paper)

[en] The paper deals with the study of heat and mass transfer in an unsteady viscous incompressible water-based nanofluid (containing Titanium dioxide nanoparticles) between two orthogonally moving porous coaxial disks with suction. A combination of iterative (successive over relaxation) and a direct method is employed for solving the sparse systems of linear algebraic equations arising from the FD discretization of the linearized self similar ODEs. It has been noticed that the rate of mass transfer at the disks decreases with the permeability Reynolds number whether the disks are approaching or receding. The findings of the present investigation may be beneficial for the electronic industry in maintaining the electronic components under effective and safe operational conditions

[en] Crystal structure and surface morphology play vital role in the performance of Solid Oxide Fuel cells (SOFCs) anode. Sufficient electrocatalytic activity and high conductivity are the key requirements for anode to enhance the electrochemical capability. In current work, sintering temperature effects are investigated on the properties of advanced LiNiCuZn-Oxide based electrode for solid oxide fuel cells (SOFCs). The powders were prepared by simple solid-state reaction method was followed by sintering at different temperatures (700 °C–1200 °C). Moreover, various characterization techniques have been employed to investigate the sintering temperatures effects on the crystallite size, morphology, particle size, energy band gap and absorption peaks. The energy gap (Eg) was observed to increase from 2.94 eV to 3.32 eV and dc conductivity decreased from 9.084 Scm⁻¹ to 0.46 Scm⁻¹ by increasing sintering temperature from 700 °C to 1200 °C. Additionally, the best fuel cell performance of 0.90 Wcm⁻² was achieved for LiNiCuZn-Oxide sintered at 700 °C using H₂/air as a fuel and oxidant and it decreased to 0.17 Wcm⁻² for powders sintered at 1200 °C. Based on these results, we can conclude that 700 °C is the best optimum temperature for these chemical compositions, where all parameters of electrode are as per SOFCs requirement. (paper)

[en] Highlights: • A high-performing and stable non-doped CeO₂ was developed for LT-SOFCs. • The CeO₂ prepared by Na₂CO₃ precipitant exhibited higher performance than other two samples prepared by NH₄HCO₃ and KOH. • An ultra-thin Na₂CO₃ coating layer was detected in the high-performing non-doped CeO₂. • The coating layer played a crucial role in enabling good stability and high ionic conduction. -- Abstract: Recent studies have realized fast ionic transport in pure ceria (CeO₂) via surface conduction without using conventional structural doping, indicating a promising strategy to develop electrolytes for low-temperature solid oxide fuel cells (LT-SOFCs). In this work, to further develop the potential of non-doped ceria, a new CeO₂ electrolyte (CeO₂#1) is synthesized through precipitation method by using Na₂CO₃ as precipitant for surface modification, and compared with two other CeO₂ samples (CeO₂#2 and CeO₂#3) prepared by NH₄HCO₃ and KOH precipitants. The CeO₂#1 is found to be composed of ceria and slight amorphous Na₂CO₃, while CeO₂#2 and CeO₂#3 contain simplex ceria. When applied in SOFCs, the CeO₂#1 electrolyte achieves attractive fuel cell performance (706 mW cm⁻² at 550 °C) with good stability, demonstrably superior to those of CeO₂#2 and CeO₂#3 electrolytes. Further impedance spectra analysis manifests the high proton conductivity of CeO₂#1, and suggests that the electrochemical performance superiority of CeO₂#1 should be ascribed to its micro-structural feature. Subsequent TEM characterization confirms the existence of Na₂CO₃ in CeO₂#1 as an ultra-thin coating layer, benefiting from which, the CeO₂ can be protected from being reduced by H₂ and enable high ionic conductivity by virtue of ceria/carbonate interface. This work thus points out a new type of non-doped ceria electrolytes with different working mechanism from previous studies and indicates a feasible approach to develop high-performing and stable electrolytes for LT-SOFCs.

[en] The current study reports advanced, ecofriendly and biosynthesized silver NPs for diverse biomedical and environmental applications using Flammulina velutipes as biosource. In the study, a simple aqueous extract of F. velutipes was utilized to reduce the AgNO₃ into stable elemental silver (Ag⁰) at a nanometric scale. The NPs had average size of 21.4 nm, spherical morphology, and were highly stable and pure. The characterized nanoparticles were exploited for a broad range of biomedical applications including bacteriocidal, fungicidal, leishmanicidal, in vitro antialzheimer’s, antioxidant, anti-diabetic and biocompatibility studies. Our findings showed that F. velutipes mediated AgNPs exhibited high activity against MDR bacterial strains and spore forming fungal strains. All the tested urinary tract infection bacterial isolates, were resistant to non-coated antibiotics but by applying 1% of the synthesized AgNPs, the bactericidal potential of the tested antibiotics enhanced manifolds. The NPs also exhibited dose-dependent cytotoxic potential against Leishmania tropica with significant LC₅₀ of 248 μg ml⁻¹ for promastigote and 251 μg ml⁻¹ for amastigote forms of the parasite. Furthermore, promising antialzheimer and antidiabetic activities were observed as significant inhibition of α-amylase, α-glucosidase, acetylcholinesterase (AChE) and butrylcholineterase (BChE) were noted. Moreover, remarkable biocompatible nature of the particles was found against human red blood cells. The biosynthesized AgNPs as photocatalyst, also resulted in 98.2% degradation of indigo carmine dye within 140 min. Owing to ecofriendly synthesis, biosafe nature and excellent physicochemical properties F. velutipes AgNPs can be exploited as novel candidates for multifaceted biomedical and environmental applications. (paper)

[en] In recent scientific research, an interest has been gained significantly by rare earth metals such as cerium (Ce), samarium (Sm) and gadolinium (Gd) due to their use in fuel cells as electrolyte and catalysts. When used in an electrolyte, these materials lower the fuel cell's operating temperature compared to a conventional electrolyte, for example, yittria-stabilized zirconia (YSZ) which operates at a high temperature (≥800 °C). In this paper, the tri-doped ceria, M_0.2Ce_0.8O_2-δ (M = Sm_0.1, Ca_0.05, Gd_0.05) electrolyte powders was synthesized using the co-precipitation method at 80 °C. These dopants were used for CeO₂ with a total molar ratio of 1 M. Dry-pressed powder technique was used to make fuel cell pellets from the powder and placed them in the furnace to sinter at 700 °C for 60 min. Electrical conductivity of such a pellet in air was 1.2 × 10⁻² S cm⁻¹ at 700 °C measured by the ProboStat-NorECs setup. The crystal structure was determined with the help of X-ray diffraction (XRD), which showed that all the dopants were successfully doped in CeO₂. Raman spectroscopy and UV-VIS spectroscopy were also carried out to analyse the molecular vibrations and absorbance, respectively. The maximum open-circuit voltages (OCVs) for hydrogen and ethanol fuelled at 550 °C were observed to be 0.89 V and 0.71 V with power densities 314 mW cm⁻² and 52.8 mW cm⁻², respectively.

[en] Nowadays, constructing a narrow bandgap nanocomposite photocatalyst that can degrade contamination under visible light is critical but challenging. In this report, poly (acrylic acid) microgel (PAA) based nanocomposites (Ag@CuO/PAA NC) were constructed via free radical solution polymerization by varying the concentration of silver-doped copper oxide nanoparticles (Ag@CuO NPs) from 0 to 12%. As prepared Ag@CuO and Ag@CuO/PAA were characterized by X‐ray diffraction spectroscopy, scanning electron microscopy, transmission electron microscopy, energy dispersive X-ray and X-ray photoelectron spectroscopy. The size of Ag@CuO NPs was found to be 30–50 nm. The photocatalytic activity of CuO is increased by Ag doping and C3 NPs show the best photodegradation of methylene blue (MB). Then, 4% of Ag@CuO nanoparticles were incorporated into PAA microgel, the resultant nanocomposite showed a drastic increase in photodegradation of MB. Ag@CuO/PAA NC completely degraded dye in only 30 min which was degraded up to 65% in 60 min. by Ag@CuO NPs. The successful combination of PAA with Ag@CuO boosts the photocatalytic activity because microgel provides a large surface to adsorb pollutants. Ag@CuO/PAA NC reused successfully for photodegradation of dye due to the recycling ability of microgels. This study gives a good insight into planning a significant visible‐light‐driven photocatalyst for environmental remediation.