Transfer Properties Research Articles

Transient flow and heat transfer characteristics of single-phase nanofluid past a stretching sheet under the influence of thermal radiation and heat source

This work aims to investigate the unsteady hydromagnetic free convective flow of a viscous, electrically incompressible fluid influenced by an inclined magnetic field, radiation, and heat source. Specifically, it explores the behavior of water-based nanofluids under these conditions. The Newton-Raphson shooting technique combines the 4th-order Runge-Kutta approach to obtain dimensionless and accurate solutions to the governing equations. The study assesses flow characteristics and heat transfer properties over various parameter values. The outcomes are visualized through graphical representations of velocity, temperature, skin friction coefficient, and the local Nusselt number. The present study examines the impact of copper (Cu), silver (Ag), alumina (Al2O3), and titanium dioxide (TiO2) nanoparticles in water as the base fluid on the percentage increase in skin friction and Nusselt number under various physical conditions. Suction increases skin friction by 10–15 % and the Nusselt number by a similar margin, whereas injection can reduce these metrics. Radiation enhances heat transfer, resulting in a 5–10 % increase in skin friction and a 10–15 % rise in the Nusselt number, with nanoparticles like Ag showing the most substantial effects due to their superior thermal properties.

Determination of the Electronic Structure, Charge-transfer, and Optical Properties of Neutral, Anionic, and Cationic Perfluoropentacene

Perfluoropentacene ( is an n-type organic semiconductor made by fluorination of p-type semiconductor Pentacene and can find applications in molecular thin film devices. In this work, a theoretical study of Perfluoropentacene was carried out based on density functional theory (DFT) and time dependent (TD-DFT) as implemented in Gaussian 09 package using B3LYP/6-311++G (d, p) and B3LYP/6-31+G(d) basis sets. The electronic, charge transfer, Linear and nonlinear optical properties of the molecule were calculated and reported for the neutral, anionic, and cationic forms of the molecule. The results show that the cationic state of the molecule has the strongest bond length at R(28,32) using the basis sets B3LYP/6-311++G (d,p) and the weakest bond length was found at R(4,6) in the ionic state with 6-31+G (d) basis set. The energy gap obtained for the neutral molecule using 6-31+G (d) and 6-311++G (d,p) basis sets are 2.00eV, 1.99eV respectively. The results show a strong agreement with a previously related work that reported the energy gap as 2.02eV thus indicating high stability of the molecule. Perfluoropentacene has the highest value of chemical hardness of 1.3929eV in its anionic state (Beta MO), so is considered to be harder and more stable than the neutral and cationic. The findings also revealed that with toluene as solvent, the strongest absorption was found at wavelength of 738.38, highest oscillator strength of 0.0599 and the lowest excitation energy of 1.6791eV. The calculated results of polarizability, first and second hyperpolarizability confirm that this molecule is a good non-linear optical material. On the whole, the molecule could be a good material for optoelectronic applications.

AIE paper shred for the detection of evolved amine vapor from putrefaction processes of fish

Seafood plays a major role in the human diet. During transportation, without proper storage and supply chain, its quality deteriorates easily. The post-harvesting processes such as the storage of food play a crucial role in human health. So it is highly imperative to have a technique for identifying food spoilage earlier to ensure the food safety and security of the consumers. Herein we have developed a highly selective and sensitive fluorescent ‘Turn-on’ probe 2-amino-5-nitrobenzo [d] thiazol-2-yl) imino)methylphenol ANT based on aggregation induced emission (AIE). ANT molecule possesses both restricted intramolecular rotation (RIR) and excited state intramolecular proton transfer (ESIPT) properties leading to fluorescent enhancement rather than aggregation caused quenching (ACQ). The probe shows high selectivity and sensitivity towards the NH3 vapor. This probe with the AIE property is employed for the real-time detection of NH3 in both aqueous and gaseous phases. ANT molecule is deposited on the paper shred by a physical method is utilized to monitor NH3 vapor from red snapper fish as a real-time sample during its degradation processes. After two days there is a ratiometric color change in the paper shred from yellow to orange for the fish stored at room temperature indicating its rotten and unpalatability nature. Paper shred is reused by immersing it into the tetrahydrofuran (THF), in which it retains its initial color due to deprotonation of NH3, keto to enol tautomerism discloses the reusability of the fluorescent probe. Studies carried out using UV–visible and fluorescence spectroscopy infer that the ANT probe has high affinity towards NH3 vapor.

Exploration of sensing behavior B3O3 quantum dot toward methyl halides; a quantum chemical approach

In this study, B3O3 quantum dot has been used for sensing of various methyl halides for the first time. The suitable cavity of B3O3 makes it more suitable for the sensing of variety of analytes. The three, very simple and most important methyl halides (CH3F, CH3Cl and CH3Br) are selected to adsorb on B3O3 surface. Density functional theory (DFT) method with appropriate basis set was implemented. Among the considered complexes, methyl bromide complex CH3Br@B3O3) showed higher interaction energy of −16.90 kcal mol−1. The noncovalent interaction (NCI) analysis identified the existence of van der Waals interactions among all analytes and adsorbent. The density of state (DOS) and natural bond orbital (NBO) charges analyses identified the charge transfer and conductive properties of B3O3 nanosheet after interaction with alkyl halides. Frontier molecular orbital study revealed the electronic attributes of considered complexes. It is revealed that B3O3 quantum dot can be a very good choice for sensing of methyl halides and could be helpful for monitoring and reducing the environmental pollution.

Photocatalytic degradation of iohexol by photo-driven double Z heterojunction photocatalyst under strong internal electric field in synergy with peroxymonosulfate (PMS)

This paper describes the preparation of a double Z heterojunction photocatalyst, g-C3N4/Bi2O2CO3/MnWO4 (CBCM), with a potent internal electric field using the hydrothermal method. The degradation efficiency can be further improved by combining photocatalytic technology with activated persulfate (PMS) technology. The synthesis of CBCM-7 was validated through XRD and TEM analyses, while XPS provided evidence of electron transfer and the establishment of heterojunctions within its structure. Additionally, PL, PC, and EIS measurements underscored CBCM-7′s proficient rate of photogenerated charge separation and robust charge transfer properties. The experimental results showed that the photocatalytic degradation of the iodinated contrast agent was substantially enhanced by this catalyst coupled with PMS. The degradation rate of Iohexol was up to more than 90 % within 40 min. After the completion of the recycling experiment, the degradation efficiency of this system remained above 80 %. Mechanistic analyses, including EPR tests, indicate that the main active groups generated by the degradation of this dual Z-scheme heterostructured photocatalyst coupled with activated PMS were superoxide radicals and hydroxyl radicals.

Structural, optical and heat transfer characteristics of rotating [MgO+ ZrO2/PEG-H2O]h Hybrid nanofluid flow over an expanding surfaces with activation energy

SignificanceHybrid nanofluids have garnered significant interest due to their potential for enhanced thermal and optical properties compared to their individual counterparts. AimThe aim of this research is to examine the structural, optical, and heat transfer properties of a hybrid nanofluid [MgO+ZrO2/PEG-H2O]h within a rotating system. This research integrated variable viscosity, MHD, convection, and activation energy terms into the momentum, energy, and concentration equations. A comprehensive experimental analysis, including Fourier-transform infrared and ultraviolet visible spectroscopy, elucidates the structural arrangement, optical behavior, and thermal transport properties of the nanofluids. MethodologyThe partial differential equations that govern the system are converted into nonlinear ordinary differential equations through similarity transformations. Then, these ODEs are numerically solved by employing the Runge-Kutta-Fehlberg method in combination with a shooting procedure. FindingsThe research findings demonstrate that the rotational factor impacts skin friction differently by 2 % on x and y axes, while skin friction surges by 3.63 % in [MgO+ZrO2/PEG-H2O]h hybrid nanofluid with higher magnetic field intensity. The heat transmission rates of the [MgO+ZrO2/PEG-H2O]h hybrid nanofluid are significantly higher by 4.58 % compared to the [ZrO2/PEG-H2O]n nanofluid. The mass transfer rate of [ZrO2/PEG-H2O]n declines by 3.57 % with the rise of the activation energy factor. Utilizing spin coating, thin films of nanostructures [ZrO2/PEG-H2O]n, [MgO/PEG-H2O]n and [MgO+ZrO2/PEG-H2O]h are fabricated, resulting in films with a consistent thickness of ∼200 nm at a temperature of 25 °C. A reduction in the difference in energy bandgap values from 4.5 eV for [ZrO2/PEG-H2O]s to 5.3 eV for [MgO/PEG-H2O]n and 4.8 eV for [MgO+ZrO2/PEG-H2O]h is observed. This indicates that the [MgO+ZrO2/PEG-H2O]h hybrid nanofluid yields an appropriate bandgap compared to individual nanofluids because hybrid nanofluids can lead to synergistic mechanisms that elevate their electronic attributes.

Spray technique inspired fabrication of metal-organic framework/aerogel composite for catalytic CO2 cycloaddition

Growing metal–organic framework (MOF) on the appropriate porous matrix can effectively circumvent its poor processability and recyclability owing to its powder state by providing more exposed area and enhanced stability. A feasible and efficient spray technique was applied to prepare five kinds of MOF/aerogel composites by spraying the MOF precursor droplet sequentially onto the aerogel, including carboxylate-based MOF/aerogel composites and azolate-based MOF/aerogel composites. The sprayed precursor droplets render MOF growth concentrated on the aerogel walls with resulting continuous and homogeneous MOF film, and avoid the waste of precursor solution, which is scalable with industrial potential. MOF/aerogel composites integrates the porous nature of aerogels with excellent mass transfer property and MOF film grown on aerogel walls with more active sites, which exhibit excellent catalytic activity and stability in CO2 cycloaddition.

Construction of a BiOCl/Bi2O2CO3 S-Scheme Heterojunction Photocatalyst via Sharing [Bi2O2]2+ Slabs with Enhanced Photocatalytic H2O2 Production Performance.

The construction of a close contact interface is key to enhancing the photocatalytic activity in heterojunctions. In the work, the BiOCl/Bi2O2CO3 of sharing [Bi2O2]2+ slabs S-scheme heterojunction was prepared by a HCl in situ etching method. The optimal composite photocatalyst could accomplish sizable productivity of H2O2 to 2562.95 μmol g-1 h-1 under simulated solar irradiation, higher than that of primitive Bi2O2CO3 and BiOCl. Moreover, the synthesized catalysts showed good stability. The band structures of BiOCl and Bi2O2CO3 were determined, confirming the formation of BiOCl/Bi2O2CO3 S-scheme heterojunction The BiOCl/Bi2O2CO3, which obviously improved the separation efficiency of photoinduced carriers and effectively enhanced the redox ability of the photocatalyst. In addition, density functional theory (DFT) calculations were utilized to analyze the electron transfer properties and the constitution of the built-in electric field at the interface of BiOCl and Bi2O2CO3. The photocatalytic reaction process was further researched by electron paramagnetic resonance (EPR), indicating the active species in the photocatalytic production of hydrogen peroxide. Eventually, a feasible S-scheme electron transfer mechanism on the BiOCl/Bi2O2CO3 heterojunction during the photocatalytic H2O2 production process was proposed and discussed. This work provides a reliable strategy for the fine design of the S-scheme heterojunction.

Effective heat transfer associated with CO2 and CH4 adsorption on HKUST-1 metal-organic framework deposited in situ on heat exchanger

The aim of this study was to analyze the heat transfer properties a copper heat exchanger with the in situ synthesized HKUST-1 metal-organic framework (MOF). For this purpose, a dedicated reactor was constructed to enable the direct measurements of heat of adsorption of CO2 and CH4, that accompanies the dynamic course of these processes. In parallel, CO2 and CH4 adsorption isotherms were determined at various temperatures and the heat of adsorption was calculated by an indirect method. Temperature changes on the heat exchanger as a result of cyclic adsorption/desorption processes of CO2 and CH4 on the HKUST-1 layer were registered, and the results of adsorption heat by direct and indirect methods were compared. Comparing the results of indirect and direct measurements of temperature changes accompanying CO2 adsorption, a difference of 19 % was obtained. In the case of CH4 adsorption, the results obtained by the two methods differed by 22 %. Based on the experimental results, it was proven that HKUST-1 synthesized in situ on a copper heat exchanger has improved heat transfer properties. The proposed concept of MOF layer on heat exchanger allows for efficient thermal stimulation of sorption processes and simultaneous MOF regeneration while minimizing the thermal energy supplied to the system.

Numerical treatment of MHD micropolar nanofluid flow with activation energy, thermal radiation, and Hall current past a porous stretching sheet

ABSTRACT This communication investigates the heat and mass transfer properties of MHD micropolar nanofluid fluid flow behaviour with activation energy, thermal radiation, and Hall current past a linear stretching sheet. The governing non-linear partial differential equations of the flow are transformed into non-linear ordinary differential equations using similarity transformation variables and solved using Runge Kutta 4th order in conjunction with the shooting methodology. The shooting approach in MAPLE is then employed to solve the associated system of ordinary differential equations. The impact of pertinent parameters is revealed and discussed on velocity, temperature, and concentration. Increasing micropolar parameters increases tangential velocity profiles while decreasing the transfer velocity profiles. The comparison table for local skin friction coefficient, Nusselt number, and Sherwood number are represented with the effects of pertinent non-dimensional variables. The model has undergone thorough validation using existing data and has shown outstanding performance. It is revealed in the study that an increase in the micropolar term increases the tangential velocity for an enhanced engineering working fluid. Also, a rise in the Hall current term boosts the heat transfer to strengthen thermal science fluids performance.

Chlorine-Substituent Regulation in Dopant-Free Small-Molecule Hole-Transport Materials Improves the Efficiency and Stability of Inverted Perovskite Solar Cells

Although doped hole-transport materials (HTMs) offer an efficiency benefit for perovskite solar cells (PSCs), they inevitably diminish the stability. Here, we describe the use of various chlorinated small molecules, specifically fluorenone-triphenylamine (FO-TPA)-x-Cl [x = para, meta, and ortho (p, m, and o)], with different chlorine-substituent positions, as dopant-free HTMs for PSCs. These chlorinated molecules feature a symmetrical donor–acceptor–donor structure and ideal intramolecular charge transfer properties, allowing for self-doping and the establishment of built-in potentials for improving charge extraction. Highly efficient hole-transfer interfaces are constructed between perovskites and these HTMs by strategically modifying the chlorine substitution. Thus, the chlorinated HTM-derived inverted PSCs exhibited superior efficiencies and air stabilities. Importantly, the dopant-free HTM FO-TPA-o-Cl not only attains a power conversion efficiency of 20.82% but also demonstrates exceptional stability, retaining 93.8% of its initial efficiency even after a 30-day aging test conducted under ambient air conditions in PSCs without encapsulation. These findings underscore the critical role of chlorine-substituent regulation in HTMs in ensuring the formation and maintenance of efficient and stable PSCs.

Surface modification prepared porous copper oxide/(Cu-S)n metal-organic framework/reduced graphene oxide hierarchical structure for highly selective electrochemical quercetin detection.

Electrochemical alkalization of (Cu-S)n metal-organic framework (MOF) and graphene oxide ((Cu-S)n MOF/GO) composite yields a new CuO/(Cu-S)n MOF/RGO (reduced GO) composite with porous morphology on screen printed carbon electrode (SPCE) which facilitated the electron transfer properties in electrochemical quercetin (QUE) detection. A selective QUE detection ability has been demonstrated by the constructed electrochemical sensor (CuO/(Cu-S)n MOF/RGO/SPCE), which also has a broad dynamic range of 0.5 to 115µM in pH 3 by differential pulse voltammetry. The detection limit is 0.083µM (S/N = 3). In this study, it was observed that the real samples contained 0.34mgmL-1 and 27.7µgg-1 QUE in wine and onion, respectively.

Analysis of cooling effects and measurement errors in water-cooled thermocouples for total temperature measurement in aviation engine combustion chambers

Accurate measurement of the total temperature in the main combustion chamber of an aviation engine is crucial for assessing engine performance. However, a significant challenge exists in balancing the heat transfer errors caused by the necessary cooling of the measuring device with measurement precision. The research employs a combination of numerical simulations and experimental methods to investigate this issue. The numerical simulations utilized the Reynolds-averaged Navier Stokes (RANS) coupled with a conjugate heat transfer approach to study the primary flow characteristics and heat transfer properties within the combustion chamber and the probe body. The experiments were conducted in a heat-calibration wind tunnel, validating the results of the numerical simulations. The results show that by implementing water cooling, the probe's body temperature can be reduced from 1200 °C in high-temperature conditions to 400 °C, with localized temperature imbalances still present in the edge areas of the probe. Tracing the cooling water path reveals that the vertical bends in the internal channels lead to an increase in localized pressure loss of the cooling water. The study quantitatively analyzes measurement errors caused by three heat transfer modes: radiation, convection, and conduction. In low-load conditions of the combustion chamber, heat conduction plays a dominant role, with measurement errors due to conduction reaching up to 70 % of the total measurement error. Radiation further increases the temperature measurement errors of the thermocouple's junctions near the chamber wall. As the combustion chamber temperature increases, entering high-load conditions, the cooling effect of water becomes limited, reducing conduction errors and increasing radiation errors. In these conditions, radiation errors constitute 60–70 % of the total measurement error. It suggests the importance of considering temperature corrections when using water-cooled temperature measurement devices. The research reveals several crucial insights regarding the performance and limitations of water-cooled thermocouples.

Boron Neutron Capture Therapy-Derived Extracellular Vesicles via DNA Accumulation Boost Antitumor Dendritic Cell Vaccine Efficacy.

Radiated tumor cell-derived extracellular vesicles (RT-EVs) encapsulate abundant DNA fragments from irradiated tumor cells, in addition to acting as integrators of multiple tumor antigens. Accumulating evidence indicates these DNA fragments from damaged cells are involved in downstream immune responses, but most of them are degraded in cells before incorporation into derived RT-EVs, thus the low abundance of DNA fragments limits immune responses of RT-EVs. Here, this study found that different radiations affected fates of DNA fragments in RT-EVs. Boron neutron capture therapy (BNCT) induced DNA accumulation in RT-EVs (BEVs) by causing more DNA breaks and DNA oxidation resisting nuclease degradation. This is attributed to the high-linear energy transfer (LET) properties of alpha particles from the neutron capture reaction of 10B. When being internalized by dendritic cells (DCs), BEVs activated the DNA sensing pathway, resulting in functional enhancements including antigen presentation, migration capacity, and cytokine secretion. After vaccination of the BEVs-educated DCs (BEV@BMDCs), the effector T cells significantly expanded and infiltrated into tumors, suggesting robust anti-tumor immune activation. BEV@BMDCs not only effectively inhibited the primary tumor growth and metastasis formation but also elicited long-term immune memory. In conclusion, a successful DC vaccine is provided as a promising candidate for tumor vaccine.

Enhanced heat transfer rate on the flow of hybrid nanofluid through a rotating vertical cone: a statistical analysis

The recent study needs the optimal conditions for maximizing heat transfer rate with minimizing energy consumption. This is a basic objective of several industries in their production processes along with in improving the efficiency in electronic gadgets. Therefore, hybrid nanofluid plays an important role in enhancing heat transport phenomena. The current study investigates the improved heat transfer properties of a water-based hybrid nanofluid containing Al2O3 and Cu nanoparticles flowing through a rotating vertical cone embedded in a porous medium. The convective flow is enhanced by a magnetic field and thermal radiation, contributing to the complexity of the flow dynamics. However, the dimensional physical quantities are transformed to non-dimensional parameters by the implementation of suitable similarity rules. Furthermore, the transformed equations are numerically solved using a fourth-order Runge-Kutta shooting method. Henceforth, to get the optimal heat transfer rate, a robust statistical technique called response surface methodology (RSM) and for the validation a hypothetical test is organized by using analysis of variance. The parametric behavior is conducted via graphs and the physical description is presented briefly. Further, the major outcomes of the study are: both the particle concentrations attenuate the axial velocity whereas the fluid temperature enhances significantly. Increasing radiative heat augments the heat transport phenomena and the observation reveals that the case of hybrid nanofluids overrides the case of nanofluids.

Plasma Engineering of Co4N/CoN Heterostructure for Boosting Supercapacitor Performance.

Supercapacitor electrode materials play a decisive role in charge storage and significantly affect the cost and capacitive performance of the final device. Engineering of the heterostructure of metal-organic framework (MOF)-derived transition metal nitrides (TMNs) can be conducive to excellent electrochemical performance owing to the synergistic effect, optimized charge transport/mass transfer properties, and high electrical conductivity. In this study, a Co4N/CoN heterostructure was incorporated into a nitrogen-doped support by radio-frequency (RF) plasma after simple pyrolysis of Co-based formate frameworks (Co-MFFs), with the framework structure well retained. Plasma engineering can effectively increase the ratio of Co4N in the Co4N/CoN heterostructure, accelerating the electron transfer rate and resulting in a rough surface due to the reduction effect of high-energy electrons and the etching effect of ions. Benefiting from the plasma modification, the obtained electrode material Co4N/CoN@C-P exhibits a high specific capacitance of 346.2 F·g-1 at a current density of 1 A·g-1, approximately 1.7 times that of CoN/Co4N@C prepared by pyrolysis. The specific capacitance of Co4N/CoN@C-P reaches 335.6 F·g-1 at 10 A·g-1, approximately 96.9% of that at 1 A·g-1, indicating remarkable rate capability. Additionally, the capacitance retention remains at 100% even after 1000 cycles, suggesting excellent cycling stability. The rational design and plasma engineering of the TMN heterostructures at the nanoscale are responsible for the excellent electrochemical performance of this novel composite material.

Analysis of unsteady flow of [formula omitted] based nanoparticle of different shapes in the presence of joule heating over stretching surface

This work investigates the unsteady flow behavior of variously shaped Cunanoparticles based EG-nanofluid in the presence of Joule heating across a stretched surface. The study's objective is to comprehend and explore how the geometry of nanoparticles affects the thermal behavior and velocity field of a nanofluid flow. The matter is significant because it has an impact on industrial processes, thermal management systems, and cooling technologies. Moreover, the influence of joule heating on convective heat transfer is examined. In order to account for unsteadiness and shape-dependent nanoparticle features, numerical solutions are derived for the major equations of corresponding thermal phenomenon of nanofluid flow. The acquired results shed important light on how the form of nanoparticles and Joule heating affect the properties of heat transfer across the stretching sheet. Meanwhile, friction coefficient and local Nusselt number are calculated numerically and tabulated for discussion. Cu nanoparticles in various forms and other relevant parameters are investigated for their effects on flow, joule heating properties, and heat transmission. Significant evidence shows that using spherical nanoparticles instead of cylindrical or platelet-shaped ones results in a 15 % boost in heat transmission rates. Moreover, Joule heating has significant effect over thermal boundary layer and can generally boost heat transfer by up to 20 %. It is argued that the thermal efficiency of nanofluid systems can be greatly increased by optimizing the form of nanoparticles and taking Joule heating into account. This work is novel due to it fully examines the combined impact of Joule heating and nanoparticle morphology on unstable nanofluid flow, offering new perspectives beyond previous studies that mostly focused on steady-state conditions or disregarded the shape aspect. Through a deeper comprehension of nanofluid behavior in dynamic environments, our work opens the door to more efficient thermal management system design.

Photogenerated carrier-accelerated 3D mesh-NH2 functionalized Zr-metal organic framework/MgAl-type hydrotalcite composites attacking diclofenac

Developing efficient photocatalysts for high-concentration pharmaceutically active compounds (PhACs) removal in aquatic environments holds immense promise. Metal-organic frameworks (MOF) and layered double hydroxides (LDH), with their metal ions and electron transfer properties, emerge as promising candidates for advanced degradation. The three-dimensional UiO-66-NH2/MgAl-LDH3 (UNL3) composites used in this work exhibited excellent thermal stability and reduced crystallinity. Under optimized conditions, the UNL3/DCF system achieved nearly 100 % DCF degradation in 1 min. Notably, this outstanding photocatalytic activity persisted, maintaining a 90 % DCF removal rate across a pH range of 2–12, even after five cycles. The total organic carbon concentration rapidly halved within 3 min of the initial reaction. Leveraging UNL3′s benign chemical stability (with ion leaching below 0.4 mg/L) and excellent optical properties, photogenerated charges enhanced charge separation and transport, generating ample reactive species (h+) under visible light. This study introduces a novel strategy for designing robust, stable, and environmentally friendly UiO-66-NH2-based photocatalysts for chlorinated PhAC pollutants removal.

Periodic hydration of paddy rice in mass transfer, physical and thermodynamic properties

Hydration is an essential stage in the rice parboiling process, and it can be a time-consuming. We evaluated the effects of periodic operation in paddy rice hydration to reduce the processing time. Periodic hydration with temperature modulation (10 °C amplitude and 12 min periods) was compared with isothermal hydration (conventional) at mean temperatures of 25, 35, 45, 55, and 65 °C. The process comparison was based on mass transfer, process time reduction, change in grain microstructure and thermodynamic properties. The periodic process increased water absorption, with a 41.47 % average reduction in process time. The Diffusion model satisfactorily predicted the moisture uptake experimental data (R2 > 0.97). The significant increase (p < 0.05) in the 27.38 % average in the model parameter indicated that the periodic operation favored the mass transfer phenomenon. Micrographs of hydrated grains revealed that the hydrations at 55 e 65 °C favored starch gelatinization, being able to reduce a subsequent step in the process (steaming). The temperature modulation did not alter the grain microstructure when both processes were compared at the same temperature. However, it interfered with the thermodynamic properties of the system. Periodic operation revealed mean values higher to ΔH# and mean values lower to ΔS# and ΔG#.

Influence of mono‐ and bi‐vacancy doped alkaline‐earth metals on the optoelectronic properties of monolayer defective state MoTe2: A first‐principles study

AbstractThe effects of single‐vacancy and double‐vacancy doping with alkaline‐earth metals on the stability, electronic structure, charge transfer, and optical properties of molybdenum ditelluride in the monolayer defective state (MoTe2) have been investigated using first‐principles methods. It is found that the structure of the molybdenum ditelluride system is more stable after double Te vacancies, with direct band‐gap to indirect band‐gap transitions occurring in single Te vacancies and Mo vacancies, and semiconductor to quasi‐metal transitions occurring in double Mo vacancies. The binding energy in the defect state system of molybdenum ditelluride after vacancy defects is always negative, and the structure remains stable. In this paper, the most stable double Te vacancy state was selected for substitutional doping with alkaline‐earth metals, and the Be atoms were doped with the largest amount of morphology, and Ca atoms were doped with the most pronounced decrease in band gap value. The direct band‐gap semiconductor is maintained after doping with Be atoms. Doping with Mg, Sr and Ba changes the band‐gap from direct to indirect. The double Te defect state MoTe2 doped with Ca atoms has a tendency to transition to a quasi‐metal. Regarding photoelectric properties, the system is blue‐shifted on both the absorption and reflection peaks.