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In this study, Kodo millet grains were roasted in the microwave at 360, 720, and 900 W for 3 and 5 min and pan‐roasted at 195°C for 5 min. The Kodo millet flours (KMFs) were characterized on the basis of physical, functional, pasting, rheological, antioxidant, morphological, and structural properties. After roasting, the bulk density (BD) of all treated samples decreased, while the tap density, Hausner's ratio, and compressibility index (CI) increased with roasting. Higher microwave power (720 and 900 W) and duration time (5 min) resulted in lower L∗ values and higher a∗ and b∗ values. The roasting in pan and microwave significantly improved the water absorption capacity (WAC) of flour. However, the destruction of hydrophobic functional groups resulted in a significant reduction in the oil absorption capacity (OAC). The pasting and rheological curves confirmed that low power can improve the pasting properties, producing thick pastes. However, the pan and microwave roasting (MWR) at 900 W for 5 min degraded starch and resulted in a flat pasting curve. Scanning electron microscope (SEM) micrographs also confirmed this, showing pore space formation, initiated at a power of 720 W and becoming more noticeable until 900 W, when the structure is destroyed. The X‐ray diffraction (XRD) patterns of all samples suggested a type A crystalline structure, and the degree of crystallinity increased with microwave power, except for the 900 W for 5 min and the pan‐roasted KMF. The antioxidant activity (AOA) of all roasted samples was higher than that of the control sample, except for 900 W for 5 min. Total flavonoid content (TFC) decreased in all KMF compared to the control, except 360 W for 3 min. Furthermore, all microwave‐roasted KMF showed significantly higher total phenolic content (TPC) than control and pan‐roasted KMF. These findings provide valuable information on optimizing the roasting process to improve the nutritional and functional properties of KMF. [ABSTRACT FROM AUTHOR]

Wellbore scaling is a complex and one of the common problems encountered during the depletion of an oilfield. Many studies have been conducted on general scale mechanisms, scale predictions, and removal measurements. However, the detailed study of the scaling characteristics and mechanisms in Huanjiang oilfield is limited. The objective of this work is to investigate the scaling mechanisms and characteristics to provide guidance for scale inhibitor selection, synthesis, and testing in the Huanjiang oilfield. Ion chromatography (IC) was used to test the composition of 100 water samples, and energy dispersive spectroscopy (EDS), scanning electron microscope (SEM), and X-ray diffraction (XRD) were utilized to analyze the composition of 120 wellbore scale samples that were collected from the Huanjiang oilfield. The results show that the water types of formation and groundwater are CaCl2 and Na2SO4, respectively. The oil wells produced from Chang 4 + 5 , Chang 6, and Chang 8 reservoir layers in the development of Yanchang group are mainly calcium-based scale (CaCO3 and CaSO4), supplemented by wax deposition scale, corrosion scale, and NaCl and KCl crystal scale. In contrast, the oil wells in Yan'an group (Yan 6, Yan 7, Yan 8, Yan 9, and Yan 10 reservoir layers) are mainly wax deposition scale and corrosion scale. [ABSTRACT FROM AUTHOR]

Warm mix agent is the key factor to restrict the performance of warm mix asphalt. In this paper, methods of X-ray diffraction, thermal stability test, and laser particle size analysis were used to test and analyze the internal structure, composition, and properties of three kinds of warm mix agents. In order to study the performance impact of the warm mix agent on SBS-modified asphalt, the warm mix agents of Advera®, LTA synthetic zeolite, and 13X synthetic zeolite were added to SBS-modified asphalt in different contents. The three kinds of warm mix asphalt were tested by the experiments of softening point, penetration, and ductility to analyze their physical properties. The testing results showed that the softening point of three kinds of warm mix SBS-modified asphalt is greater than the softening point of SBS-modified asphalt without adding warm agents, which indicate the warm mix additives can improve the high-temperature stability of SBS-modified asphalt. The three kinds of the warm mix agent make SBS-modified asphalt hard, and the consistency and the ability of resisting deformation increase. The low temperature performance of SBS-modified asphalt decreased in different degrees with mixing different zeolite warm mix agents. [ABSTRACT FROM AUTHOR]

As one of the key factors that limit the development of vanadium redox flow battery (VRFB), the positive redox couple of VO2+/VO2+ plays an important role on the overall performance of VRFB. To improve the kinetics of a positive reaction, a new designed nitrogen-doped reduced graphene oxide-modified graphite felt (N-rGO/GF) electrode was prepared by coupling the methods of freeze-drying and pyrolysis. The characteristics of the prepared electrode were measured by scanning electron microscope (SEM), Brunauer–Emmett–Teller (BET) analysis, Raman spectroscopy (Raman), X-ray diffraction (XRD), cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and charge-discharge tests. By coupling the methods of freeze-drying and pyrolysis, the N-rGO can be evenly dispersed on the surface of GF electrode, resulting in an excellent catalytic activity. The results demonstrate that the proposed N-rGO/GF electrode with pyrolysis temperature of 900°C shows excellent electrochemical performance and significantly improves the catalytic activity and electrochemical reversibility for the positive VO2+/VO2+ reaction, indicating that the proposed composite electrode has potential applications in the improvement of VRFB performance. [ABSTRACT FROM AUTHOR]

The microstructures evolution of precipitations for an ultra-low iron Alloy 625 subjected to long term aging treatment at 750°C was investigated using scanning electron microscope (SEM) and X-ray diffraction (XRD). The intergranular corrosion behaviors of Alloy 625 were evaluated by using ASTM G28A. The result shows that the precipitated phase γ′′-Ni3Nb was mainly precipitated at the grain boundaries and twin boundaries. The number and volume fraction of γ′′ increased with the prolonging of aging time. The transformation of γ′′ to δ-Ni3Nb occurred after aging periods of 200 h. The corrosion resistance of Alloy 625 was significantly reduced during aging treatment. The decrease in intergranular corrosion resistance of Alloy 625 was attributed to the dissolution of precipitated phase and chromium depleted zone. The mass loss rate of Alloy 625 after aging treatment is related to the volume of precipitated phase and can be simulated by Johnson-Mehl-Avrami equation. [ABSTRACT FROM AUTHOR]

Microcrystalline cellulose (MCC) fiber‐reinforced polyamide 6.10 (PA) composites were prepared in the presence of an impact modifier (IM), exxelor VA1803 (VA), by melt compounding process. Fiber loading was considered from 20 to 30 wt.%, whereas IM was varied from 2.0 to 5.0 wt.%. Composites were characterized by tensile test, impact test, dynamic thermal mechanical analysis (DTMA), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and X‐ray diffraction (XRD). Composites' fractured surfaces were examined by scanning electron microscope (SEM). In addition, fiber size distribution was also analyzed. Result analyses showed that the fiber incorporation changed the tensile strength (TS) slightly, but the tensile modulus (TM) significantly. The TM was found to be improved by 45% at the amount of fiber loading of 30 wt.%. Moreover, the thermomechanical properties revealed that the storage modulus (SM) and loss modulus (LM) were increased due to the incorporation of MCC, which was improved further by the uses of 5.0 wt.% of VA. The MCC possess high crystallinity index and high crystallite size along with enhanced mechanical and thermal properties. Therefore, the extraordinary benefit of using MCC in PA was evaluated in terms of thermomechanical, structural, and thermal properties in the presence of the impact modifier. [ABSTRACT FROM AUTHOR]

The electrochemical properties of various iron oxide scales on steel exposed in saturated calcium hydroxide solutions were investigated. The iron oxide scales were manufactured by different heat treatments and grinding processes and characterized using X-ray diffraction and scanning electron microscope. The electrochemical properties of the scales were assessed by measuring the corrosion potential and using electrochemical impedance spectroscopy and potentiodynamic polarization curves. It was found that wustite and magnetite are less noble compared to hematite but are more effective as cathodic surfaces. The results show that the electrochemical properties of the mill scale can be an important contributing factor in the corrosion of steel in concrete. [ABSTRACT FROM AUTHOR]

We proposed a type of low-alkali liquid state setting accelerator, named HLSA; it was environmentally friendly product. To investigate the temperature adaptation and cement flexibilities of HLSA, the setting time and strength development properties of cement with HLSA were discussed in this paper. The effects of HLSA on hydration process, hydration products, and microstructure were studied by means of X-ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscope (SEM), and mercury intrusion porosimetry (MIP). The results show that four typical 42.5-grade ordinary Portland cement types with 6-8% HLSA could satisfy the first-grade requirements according to JC477-2005 even at a lower temperature (e.g., 10°C). Further, the percentage ratio of 28 d compressive strength of cement with 6-8% HLSA was over 90%; the XRD diffraction peak of AFt integrated area of cement with 7% HLSA was 3818 at 5 min of hydration; SEM observation revealed that AFt crystals were filled in the pore of cement at 28 d of hydration; the temperature adaptation and cement flexibilities of HLSA were excellent; the cement with HLSA coagulating in a short time attributed to promoting the formation of abundant AFt and the hydration of C3S. [ABSTRACT FROM AUTHOR]

Hollow ZnSnO3 nanospheres were synthesized by a hydrothermal method using ZnO nanospheres as the hard template and raw material simultaneously. The combined characterizations of X-ray diffraction (XRD), scanning electron microscope (SEM) and high-resolution transmission electron microscopy (HRTEM) confirmed the successful preparation of hollow ZnSnO3 nanospheres. The gas-sensing results indicated that the sensor made from hollow ZnSnO3 nanospheres exhibited high sensitivity, good selectivity, and stability to ethanol at a low operating temperature of 200°C. The sensitivity was about 32 and the response and recovery time were about 4 s and 30 s for 100 ppm ethanol, respectively. The enhancement in gas-sensing properties was attributed to the hollow nanostructures and high specific surface areas of ZnSnO3. [ABSTRACT FROM AUTHOR]

The relations among the uniaxial compressive strength of cemented paste backfill (CPB) with solid phase mass fraction, cement sand ratio, and curing age were studied. The UCS of CPB samples increased exponentially with the increase of solid phase mass fraction and curing age but increased linearly with the increase of cement sand ratio. The results of X-ray diffraction (XRD) and scanning electron microscope (SEM) showed that the strength was determined by the amount of ettringite and C-S-H gelling. With the increase of ettringite and C-S-H gelling, the strength became larger. The triaxial compression test was conducted by selecting four kinds of CPB samples. The results showed that, with the increase of confining pressure, peak and residual strength became larger, but the elastic modulus decreased. When the ratio of confining pressure and uniaxial strength is about 1 : 2, the CPB samples show significant ductility characteristics and the ratio of residual strength and peak strength increased obviously. [ABSTRACT FROM AUTHOR]

Series of WO3/TiO2 nanocomposites were obtained by hydrothermal method followed by calcination in the temperature range from 400°C to 900°C. The characteristics of photocatalysts by X-ray diffractometry (XRD), scanning electron microscope (SEM), and diffuse reflectance spectroscopy (DRS) showed that increasing the calcination temperature from 400 to 900°C resulted in change of photocatalytic activity under UV-Vis light. Moreover, the amount of WO3 crystalline phase and amorphous phase in WO3/TiO2 aggregates, as revealed by XRD analysis, was dependent on the calcination temperature. The WO3/TiO2 samples with 8 mol% load of WO3 in respect to TiO2 calcinated at 500 and 800°C possess the highest photocatalytic activity in reaction of phenol degradation, which is about 1.2 and 1.5 times that with calcination at 400°C. The increase in calcination temperature above 400°C resulted in increase of WO3 crystallinity and reduction of the amount of amorphous phase in the nanocomposite structure. Moreover, the annealing of nanocomposites above 700°C decreases the value of optical band gap energies of obtained WO3/TiO2 nanomaterials. [ABSTRACT FROM AUTHOR]

The present research work involves the study of AA 7075-TiB2-Gr in situ composite through stir casting route. This in situ method involves formation of reinforcements within the matrix by the chemical reaction of two or more compounds which also produces some changes in the matrix material within the vicinity. Titanium Diboride (TiB2) and graphite were the reinforcement in a matrix of AA 7075 alloy. The composite was prepared with the formation of the reinforcement inside the molten matrix by adding salts of Potassium Tetrafluoroborate (KBF4) and Potassium Hexafluorotitanate (K2TiF6). The samples were taken under casted condition and the properties of the composite were tested by conducting characterization using X-ray diffraction (XRD), hardness test, flexural strength by using three-point bend test, scanning electron microscope (SEM), optical microstructure, grain size analysis, and surface roughness. It was found that good/excellent mechanical properties were obtained in AA 7075-TiB2-Gr reinforced in situ hybrid composite compared to alloy due to particulate strengthening of ceramic particles of TiB2 in the matrix. Further, Al 7075-3% TiB2-1% Gr hybrid in situ composite exhibited improved machinability over the alloy and composites due to self-lubricating property given by the Gr particles in the materials. [ABSTRACT FROM AUTHOR]

As a new two-dimensional material, MXene (nano-Ti3C2) has been widely applied in many fields, especially for reinforced composite materials. In this paper, mechanical testing, X-ray diffraction (XRD), hydration heat, scanning electron microscope (SEM), and EDS analysis were used to analyze the impact of MXene on cement hydration properties. The obtained results revealed that (a) MXene could greatly improve the early compressive strength of cement paste with 0.04 wt% concentration, (b) the phase type of early-age hydration products has not been changed after the addition of MXene, (c) hydration exothermic rate within 72 h has small difference at different amount of MXene, and (d) morphologies of hydration products were varied with the dosage of MXene, a lot of tufted ettringites appeared in 3 d hydration products when the content of MXene was 0.04 wt%, which will have a positive effect on improving the early mechanical properties of cement paste. MXene has inhibited the Portland cement hydration process; the main role of MXene in the cement hydration process is to promote the messy ettringite becoming regular distribution at a node and form network connection structure in the crystals growth process, making the mechanics performance of cement paste significantly improved. [ABSTRACT FROM AUTHOR]