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BACKGROUND For the determination of P2O5 in complete silicate analysis of uranium-producing ore by alkali fusion-phosphovanoclonolybeate spectrophotometry with wavelength of 420nm, iron (Fe) was detected simultaneously, because Fe as the co-existing element complexed with ammonium vanadium molybdate and showed the same yellow with phosphovanoclonolybeate. Iron produced positive interference on the results of P2O5. OBJECTIVES To correct the interference of Fe on the determination of P2O5. METHODS Taking Fe2O3 as the assessment amount of Fe in complete silicate analysis, when detection wavelength was changed from 400nm to 480nm, the effects of different amounts of Fe2O3 (0.00 to 0.70mg/mL) on the absorption value of P2O5 with content of 0.20g/mL, 2.00g/mL and 8.00g/mL were investigated, respectively. RESULTS (1) It was found that when the detection wavelength of P2O5 was changed from 420nm to 450nm, the positive interference produced by Fe2O3 on the analysis results of P2O5 was corrected. Moreover, the contents of Fe2O3 and P2O5 in the sample was within the calibration range at the correction wavelength of 450nm when taking national standard materials GBW04117-GBW04122 of uranium-producing ore as verification samples. (2) When P2O5 in national standard material of uranium-producing rocks, basalts and argillaceous limestone was analyzed at 450nm, the results were within the error range. The method precision (RSD) was between 1.1% and 15.7%, which met requirements of analyzing P2O5 in other samples with a similar matrix such as silicate and uranium ores. CONCLUSIONS The corrected method is simple and easy to operate. It provides a supplementary method for accurate spectrophotometric determination of P2O5 during complete silicate analysis in uranium-producing ore.

The sintering and dielectric properties of (1 − x)Li2Mg0.95Co0.05SiO4 + xTiO2 ceramics created by the solid state reaction method were investigated. X-ray diffraction and energy-dispersive X-ray spectroscopy were used to obtain phase composition of the ceramics, and scanning electron microscopy was used to observe their microstructure. A network analyzer was used to measure dielectric properties, while mechanical, simultaneous-thermal, and dynamic mechanical analyzers were used to obtain mechanical and chemical properties. Li2Mg0.95Co0.05SiO4 (LMCS) and TiO2 co-exist in the composite system. TiO2 addition resulted in decreasing grain size and crystallite size, increasing starting temperature of shrinkage, increasing activation energy, and increasing elasticity and stiffness. A 4%/volume addition of TiO2 and sintering at 1075 °C changed the LMCS τf to 1.57 ppm/°C and resulted in dielectric properties of εr = 6.33 and Q × f = 17,000 GHz (16 GHz) with a relative density equals to 96.13%.

Molecular dynamics is a method of studying microstructure and properties by calculating and simulating the movement and interaction of molecules. The molecular dynamics simulation method has become an important method for studying the structural and dynamic characteristics of slag systems and can make up for the shortcomings of existing detection methods and experiments. Firstly, this paper analyzes the development process and application fields of molecular dynamics, summarizes the general simulation steps and software algorithms of molecular dynamics simulation methods, and discusses the advantages and disadvantages of the algorithms and the common functions of the software. Secondly, the research status and application progress of molecular dynamics simulation methods in the study of phosphate, silicate, aluminate and aluminosilicate are introduced. On this basis, a method of combining molecular dynamics simulation with laboratory experiments is proposed, which will help obtain more accurate simulation results. This review provides theoretical guidance and a technical framework for the effective analysis of the microstructure of different slag systems via molecular dynamics, so as to finally meet the needs of iron and steel enterprises in producing high-quality steel grades.

Silicate ions were incorporated into a pre-treatment to mitigate corrosion in reinforcing steel bars. The efficiency of these pre-treatments was compared by testing steel samples in concrete pore simulating solutions contaminated with chloride ions. The study involved cyclic voltammetry, anodic polarisation curves and weight-loss tests following a 60-day immersion period. Surface analysis included micro-Raman spectroscopy and X-ray photoelectron spectroscopy (XPS). The electrical properties of the film were analyzed by impedance spectroscopy and Mott–Schottky plots. Polarisation curves show higher pitting potentials and lower corrosion current densities when pre-treating with silicate ions. Localised attack appears after 60 days of immersion in solutions containing chloride ions, but weight loss is reduced by 75% for coupons pre-treated in silicate solutions. XPS and Raman spectra indicate that the presence of silicate ions affects the composition of the passive film and the corrosion products. The results show that pre-treatments in silicate solutions are effective to minimise steel corrosion in aggressive environments. [ABSTRACT FROM AUTHOR]

The Carbonate rock weathering Carbon Sink (CCS) and Silicate rock weathering Carbon Sink (SCS) play a significant role in the carbon cycle and global climate change. However, the spatial‐temporal patterns and trends of the CCS and SCS from 1950 to 2099 have not been systematically quantified. Thus, Supported by long‐term hydrometeorological data under the RCP8.5, we use the accepted Suchet and Hartmann models to determine the following. First, we found except for the difference in their weathering rates, the SCS covers 37.2 million km2 more area than the CCS. The CCS Flux (CCSF) and SCS Flux (SCSF) are 5.36 and 1.22 t/km2/yr, respectively. Similarly, the Full CCS (FCCS, 0.3 Pg/yr) is more than the Full SCS (FSCS, 0.08 Pg/yr). Furthermore, the CCS (7.01 kg/km2) and SCS (3.95 kg/km2) are in a state of overall increase. In addition, the mid‐to‐high latitudes of the northern hemisphere are aggravated by warming (0.03°C) and humidity (0.65 mm), while the decrease in runoff in the mid‐latitudes of the southern hemisphere reduces karstification. Specifically, by 2099, the CCSF in the mid‐latitudes of the southern hemisphere will decrease by 5.72%. Instead, the CCSF in the northern hemisphere and lower latitudes of the southern hemisphere will exhibit a gentle upward slope. Particularly, the peak regions of the global FCCS (65.63 Tg/yr) and FSCS (33.01 Tg/yr) are the tropical zone. In conclusion, this study contributes a high‐resolution and long‐time series CS datasets for the CCS and SCS. We provide data and a theory for solving terrestrial carbon sink loss. Plain Language Summary: The carbon cycle and global‐climate change cannot ignore the Carbonate and Silicate rocks weathering Carbon Sink (CCS and SCS). However, the spatial‐temporal patterns and trends of CCS and SCS from 1950 to 2099 have not been quantified. We use the accepted Suchet and Hartmann models to determine the following. First, we found except for the difference in their weathering rates, the SCS covers 37.2 million km2 more area than the CCS. The CCS Flux (CCSF) and SCS Flux (SCSF) are 5.36 and 1.22 t/km2/yr, respectively. Similarly, the Full CCS (FCCS, 0.3 Pg/yr) is more than the Full SCS (FSCS, 0.08 Pg/yr). Furthermore, the CCS (7.01 kg/km2) and SCS (3.95 kg/km2) are in a state of overall increase. In addition, the mid‐to‐high latitudes of the northern hemisphere are aggravated by warming (0.03°C) and humidity (0.65 mm), while the decrease in runoff in the mid‐latitudes of the southern hemisphere reduces karstification. Specifically, by 2099, the CCSF in the mid‐latitudes of the southern hemisphere will decrease by 5.72%. Instead, the CCSF in the northern hemisphere and lower latitudes of the southern hemisphere will exhibit a gentle upward slope. In conclusion, this study contributes a high‐resolution data set for solving carbon sink loss. Key Points: High‐resolution data set for global carbonate and spatial diversification carbon sinks was establishedCarbon cycle can't ignore CCS (5.36 t/km2/yr) and SCS (1.22 t/km2/yr). Especially CCS (7.01 kg/km2) and SCS (3.95 kg/km2) increased significantlyThe peak regions of the global FCCS (65.63 Tg/yr) and FSCS (33.01 Tg/yr) are the tropical zone [ABSTRACT FROM AUTHOR]

Copyright of Steel Pipe is the property of Steel Pipe Magazine and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Climatic and non-climatic factors affect the chemical weathering of silicate rocks, which in turn affects the CO2 concentration in the atmosphere on a long-term scale. However, the coupling effects of these factors prevent us from clearly understanding of the global weathering carbon sink of silicate rocks. Here, using the improved first-order model with correlated factors and non-parametric methods, we produced spatiotemporal data sets (0.25° × 0.25°) of the global silicate weathering carbon-sink flux (SCSFa) under different scenarios (SSPs) in present (1950-2014) and future (2015-2100) periods based on the Global River Chemistry Database and CMIP6 data sets. Then, we analyzed and identified the key regions in space where climatic and non-climatic factors affect the SCSFa. We found that the total SCSFa was 155.80 ± 90 Tg C yr-1 in present period, which was expected to increase by 18.90 ± 11 Tg C yr-1 (12.13%) by the end of this century. Although the SCSFa in more than half of the world was showing an upward trend, about 43% of the regions were still showing a clear downward trend, especially under the SSP2-4.5 scenario. Among the main factors related to this, the relative contribution rate of runoff to the global SCSFa was close to 1/3 (32.11%), and the main control regions of runoff and precipitation factors in space accounted for about 49% of the area. There was a significant negative partial correlation between leaf area index and silicate weathering carbon sink flux due to the difference between the vegetation types. We have emphasized quantitative analysis the sensitivity of SCSFa to critical factors on a spatial grid scale, which is valuable for understanding the role of silicate chemical weathering in the global carbon cycle. [ABSTRACT FROM AUTHOR]

The biomineralization of CO2, in the form of carbonate minerals, is considered as one of the efficient solutions of atmospheric CO2 removal, allowing stable and sustainable storage of this greenhouse gas. Cyanobacteria are among the most powerful microorganisms capable of precipitating carbonate minerals, both in the present and in the past. In the modern environments, high Si concentration during geoengineering biomineralization could occur due to dissolution of Mg‐bearing primary silicates such as olivine. However, most of experimental studies aimed to understand the formation of these carbonates were performed in Si‐poor solutions. Thus, experimental characterizations of the nature, rate, and stoichiometry of precipitated minerals in Si‐rich solutions in the presence of bacteria are lacking. The present study attempted to reproduce, in controlled laboratory experiments, the processes of biomineralization in a carbonate‐ and Mg‐bearing medium having high Si concentrations (2–4 mM, which is below the saturation with respect to amorphous silica). These experiments have been carried out in the presence of three contrasting cyanobacteria: Synechococcus sp., Chroococcidiopsis sp. and Aphanothece clathrata in order to characterize the rate of formation, stoichiometry and mineralogical nature of precipitates. The results demonstrated significant role of cyanobacteria in the precipitation of carbonate and silicate minerals by increasing the pH of the medium during photosynthesis. Magnesium precipitation rates measured between 50 and 150 h of reaction time ranged from 0.05 to 0.5 mmol h−1 gdry1 and decreased (Synechococcus sp. and Chroococcidiopsis sp.) or increased (A. clathrata) with an increase in the Si:Mg ratio in solution. The abiotic instantaneous rates of Mg and Si removal from alkaline solutions were similar to those in the presence of cyanobacteria at the same pH value suggesting that photosynthetically induced pH rise was the main factor of mineral formation. The transmission electron microscopy (TEM) and spectroscopic observations and associated analyses identified an amorphous magnesium silicate together with hydrous Mg carbonates (hydromagnesite). The formation of carbonate solid phase at high Mg: Si ratios indicated the potential for the removal of inorganic carbon at pH > 10. The difference in the degree of C removal between different species was primarily linked to different degree of pH rise during photosynthesis. Taken together, the results obtained in this study allowed an efficient reproduction of combined magnesium hydroxo‐carbonates and hydrous silicates precipitation under cyanobacterial activity, suitable for geoengineering of biologically controlled CO2 sequestration in Si‐Mg‐carbonate‐bearing solutions. [ABSTRACT FROM AUTHOR]

Natural water certified reference materials (CRMs) are mostly available in a liquid form, and they are produced starting from suitable environmental samples. Many precautions are usually needed to avoid biological or physical degradation, including filtration, acidification, and sterilization. In this study, the drawbacks associated with liquid-based seawater CRMs were tackled by developing a salt-based seawater proxy for nutrients that could be reconstituted in water solution just before use. Phosphate, silicate, and nitrate were chosen as target analytes. Sea salt mimicking the composition of seawater was spiked with an aqueous solution of the analytes and homogenized using a high-energy planetary ball mill (uhom < 1.2%). The salt powder CRM SALT-1 (https://doi.org/10.4224/crm.2022.salt-1) demonstrated good short- and long-term stability for nutrients. When the SALT-1 was reconstituted in water at the 4.0% w/w level, the resulting solution had similar properties with respect to typical seawater in terms of major constituents (± 20%), trace metals, density (1.023 g/mL), pH (8.8–9.0), and optical properties relevant to the photometric characterization. Phosphate and silicate were quantified by photometry (molybdenum blue method, batch mode), whereas nitrate was quantified by isotope dilution GC−MS (uchar < 1.2%). In the SALT-1 reconstituted seawater solution at the 4.0% w/w salt level, the nutrient amount concentration was w(phosphate, PO43−) = 1.615 ± 0.030 μmol/L, w(silicate as SiO2) = 8.89 ± 0.31 μmol/L, and w(nitrate, NO3−) = 18.98 ± 0.45 μmol/L at the 95% confidence (k = 2). Overall, the SALT-1 CRM exhibits similar nutrient profile and general analytical characteristics as the MOOS-3 CRM. However, the SALT-1 has much reduced preparation, storage, and distribution cost, likely much better long-term stability, and it could enable the production of lower cost and more accessible seawater reference materials. [ABSTRACT FROM AUTHOR]

The thermochemical degradation of hafnium silicate (HfSiO 4) was investigated with a molten calcium-magnesium-aluminosilicate (CMAS) glass relevant to gas turbine engine applications. Sintered HfSiO 4 coupons were fabricated, within which wells were drilled and filled with CMAS glass powder at a loading of ∼35 mg/cm2. Samples were heat treated at 1200°C, 1300°C, 1400°C, and 1500°C for 1 h, 10 h, and 50 h. At 1200°C and 1300°C, slow formation of a Ca 2 HfSi 4 O 12 cyclosilicate phase was observed at the HfSiO 4 -CMAS interface. At 1300°C and higher, rapid infiltration of CMAS into the material along the grain boundaries was observed. Initial conjecture into CMAS degradation mechanisms of HfSiO 4 are presented herein. [ABSTRACT FROM AUTHOR]

Knowledge of the crystallization stability of bioactive glasses (BGs) is a key factor in developing porous scaffolds for hard tissue engineering. Thus, the crystallization behavior of three mesoporous bioactive glasses (MBGs) in the 70SiO2-(26-x)CaO-4P2O5-xCeO2 system (x stands for 0, 1 and 5 mol. %, namely MBG(0/1/5)Ce), prepared using the sol–gel method coupled with the evaporation-induced self-assembly method (EISA), was studied. A thermal analysis of the multiple-component crystallization exotherms from the DSC scans was performed using the Kissinger method. The main crystalline phases of Ca5(PO4)2.823(CO3)0.22O, CaSiO3 and CeO2 were confirmed to be generated by the devitrification of the MBG with 5% CeO2, MBG5Ce. Increasing the ceria content triggered a reduction in the first crystallization temperature while ceria segregation took place. The amount of segregated ceria of the annealed MBG5Ce decreased as the annealing temperature increased. The optimum processing temperature range to avoid the crystallization of the MBG(0/1/5)Ce powders was established. [ABSTRACT FROM AUTHOR]

The Bi/Sn-doped aluminosilicate glass samples were prepared using a melting–quenching method and their near-infrared (NIR) emission properties were studied. An ultra-broadband NIR emission ranging from 950 nm to 1600 nm was observed in all samples under 480 nm excitation, which covered the whole fiber low-loss window. The NIR emission spectrum showed that the maximum emission peak was about 1206 nm and the full width at half maximum (FWHM) was about 220 nm. Furthermore, the NIR emission intensity strongly depends on the composition of the glass, which can be optimized by modulating the glass composition. The Bi0 and Bi+ ions were the NIR luminescence source of the glass samples in this paper. The Bi/Sn-doped aluminosilicate glass has the potential to become a new type of core fiber material and to be applied to optical fiber amplifiers (OFAs), based on its excellent performance in ultra-broadband NIR emission. [ABSTRACT FROM AUTHOR]

Copyright of Coatings & Protection / Tuceng yu Fanghu is the property of Coating & Protection Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Clean Coal Technology is the property of Clean Coal Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The solid state reaction method was used to synthesise the Li2MnSiO4 ceramic. The first principle calculation, X-ray diffraction, scanning electron microscopy, network analysis, and differentia-thermal analysis were taken to analyse its sintering and dielectric properties. The TE-mode Cylindrical Cavity method based on a cavity resonator was conducted to obtain the dielectric property at different frequencies. Two phases were formed, namely, Li2SiO3 and LiMn2O4, and the increasing sintering temperature increases the amount of LiMn2O4 and decreases that of Li2SiO3. The peak dielectric properties were obtained at 1000 °C; εr = 7.99 at 9.2 GHz, 7.86 at 10.6 GHz and 7.8 at 14.2 GHz; and tanδ = 0.00375 at 9.2 GHz, 0.00387 at 10.6 GHz and 0.004 at 14.2 GHz. The bulk density is 3.44 g/cm3, and the relative density is 96.1%.

Many aquaculture environments suffer from significant silicon deficiencies and severe heavy metal contamination, posing substantial risks to both production and safety in aquaculture. This study aimed to assess the release of silicate from rice husk ash (RHA) and its impact on phytoplankton abundance and community composition, which are key factors affecting shellfish growth and survival. Additionally, the capacity of RHA to adsorb mercury (Hg2+) was examined using different modification methods. The results demonstrated that the concentration of dissolved silicate in seawater increased with higher RHA doses, reaching a maximum of 189.77 ± 45.61 μmol L−1 in the high RHA treatment (HR) with 1.0 g L−1 of RHA. Notably, the HR treatment group exhibited a significant increase in chlorophyll-a concentration for nano-phytoplankton (2–20 μm), with an up to eightfold rise in abundance compared to the control group. Moreover, the HR treatment resulted in a maximum diatom abundance of 4217 ± 741.98 cells L−1, benefiting diatom species such as Coscinodiscus sp., Nitzschia sp., and Cyclotella sp. These findings underscore the potential of RHA as a catalyst for diatom growth, which in turn supports the growth of shellfish. Furthermore, no concentrations of mercury (Hg), lead (Pb), cadmium (Cd), arsenic (As), copper (Cu), zinc (Zn), and chromium (Cr) were detected in any of the silicate enrichment treatments, confirming the safety of the RHA. The treatment of RHA with NaOH achieved an impressive removal efficiency of Hg2+, reaching up to 97.41 ± 0.33 %. This study highlights the promising application of agricultural waste RHA as a catalyst for diatom growth and an adsorbent for heavy metals in water systems relevant to aquaculture practices. • Dissolved silicate concentration in seawater increased with increasing rice husk ash (RHA). • Diatoms abundance were significantly increased in the RHA-treated group. • Diatom species that benefitted from RHA were Coscinodiscus sp., Nitzschia sp. and Cyclotella sp. • The removal efficiency of Hg2+ was up to 97.41 ± 0.33 % in the treatment of RHA with NaOH. [ABSTRACT FROM AUTHOR]

Abstract The Carbonate rock weathering Carbon Sink (CCS) and Silicate rock weathering Carbon Sink (SCS) play a significant role in the carbon cycle and global climate change. However, the spatial‐temporal patterns and trends of the CCS and SCS from 1950 to 2099 have not been systematically quantified. Thus, Supported by long‐term hydrometeorological data under the RCP8.5, we use the accepted Suchet and Hartmann models to determine the following. First, we found except for the difference in their weathering rates, the SCS covers 37.2 million km2 more area than the CCS. The CCS Flux (CCSF) and SCS Flux (SCSF) are 5.36 and 1.22 t/km2/yr, respectively. Similarly, the Full CCS (FCCS, 0.3 Pg/yr) is more than the Full SCS (FSCS, 0.08 Pg/yr). Furthermore, the CCS (7.01 kg/km2) and SCS (3.95 kg/km2) are in a state of overall increase. In addition, the mid‐to‐high latitudes of the northern hemisphere are aggravated by warming (0.03°C) and humidity (0.65 mm), while the decrease in runoff in the mid‐latitudes of the southern hemisphere reduces karstification. Specifically, by 2099, the CCSF in the mid‐latitudes of the southern hemisphere will decrease by 5.72%. Instead, the CCSF in the northern hemisphere and lower latitudes of the southern hemisphere will exhibit a gentle upward slope. Particularly, the peak regions of the global FCCS (65.63 Tg/yr) and FSCS (33.01 Tg/yr) are the tropical zone. In conclusion, this study contributes a high‐resolution and long‐time series CS datasets for the CCS and SCS. We provide data and a theory for solving terrestrial carbon sink loss.

The feasibility of soft mechanochemical synthesis was studied here for hydroxyapatite with various types of substitution. It was shown that this method allows obtaining hydroxyapatites substituted with copper or iron cations and hydroxyapatites cosubstituted with zinc cations and silicate groups. Thermal stability of the synthesized samples was evaluated. It was found that to preserve phase homogeneity of the material, the temperature during the preparation of ceramic products and coatings should not exceed 600–800 °C. An exception is the hydroxyapatite where a hydroxyl group is expected to be replaced by a copper cation during the synthesis at a degree of substitution x = 0.5. For this sample, the temperature of the the heat treatment can be increased to 1100–1200 °C because copper cations return to the hydroxyapatite crystal lattice at these temperatures, and the material becomes single-phase.

The τ-phase Ba1.3Ca0.7-x-ySiO4:xDy3+/yTb3+ phosphors co-doped with Dy3+ (x = 0.03) and Tb3+ (y = 0.01–0.05) trivalent rare-earth ions were prepared by the gel-combustion method. The structure–property relation of the samples was examined by X-ray diffraction, scanning electron microscopy and spectrophotometer. Here, the effect of Tb3+'s concentration on the spectroscopic properties of Ba1.3Ca0.7-x-ySiO4:xDy3+/yTb3+ phosphors was explored by using the photoluminescence excitation, emission and decay curves. Importantly, the photonic energy transfer from (Dy3+:4F9/2 + Tb3+:7F6) to (Dy3+:6H15/2 + Tb3+:5D4) was observed, in which the Dy3+ ions act as a light-emitting donor whereas the Tb3+ ions as a light-absorbing acceptor, resulting in an enhanced emission from the co-doped Ba1.3Ca0.7-x-ySiO4:xDy3+/yTb3+ (x = 0.03 and y = 0.01–0.05) phosphors. Finally, the chromaticity coordinates were determined from the measured emission spectra, locating at the green and white light regions. This observation indicates that the characteristic emission colour could be tuned from white to green by varying Tb3+ concentrations under ultraviolet light.

Soil pollution is a major environmental problem and also makes food production impossible, since 95% of food produced worldwide originates in the soil. There are numerous practices that when improperly made can cause soil contamination, in agriculture the inadequate use of fertilizers and agrochemicals can cause soil contamination by toxic elements. Silicon is already present in the soil in a natural way, but in recent years research is being developed using silicon-based residues to increase plants resistance to pests and diseases, such as soil corrective and for increased productivity, the results are satisfactory. Many published studies show the benefits of silicon in reducing plants stress, but there is still little information about silicon as a remediator of toxic elements in the soil, so the objective of this work was to search for already published works on this theme. Studies were found using different silicon sources and the application occurred in soils contaminated mainly with Zn, Cd, Cu and Pb.

Antioxidant SiO 2 coating exhibits low cost and great compatibility with existing uses, but is strongly limited by its poor fluidity and high oxygen permeability from 973 K to 1273 K. Therefore, the hierarchical-design Glass/MoSi 2 -B 2 O 3 @SiO 2 -SiC coating was fabricated on C/C composite by a simple embedding method, and followed by a hot dip process. This composite yielded excellent combination of long-term antioxidant abilities and thermal shock resistances. As oxidized at 973 K for 1500 h, its mass loss was 0.35 %, and only 0.66 % at 1073 K for 2600 h. After thermal shocks 270 times, the weight loss was only 0.56 %. Interestingly, the Glass/MoSi 2 coating acted as a self-healing encapsulation shelter against oxygen, whilst the B 2 O 3 @SiO 2 layer yielded stable healing effect. The B 2 O 3 @SiO 2 microcapsule facilitated the activation of B 2 O 3 , SiO 2 phases, and borosilicate glass sequentially as temperature rose, leveraging their unique advantages in defect healing. Through the synergistic effects of interface encapsulation and defect self-healing, the oxygen kept osmotic diffusion. This study underscores the significance of hierarchical designs in coatings, facilitating structure optimizations and enhancing antioxidant capabilities at multiple levels. [Display omitted] • The Glass/MoSi 2 -B 2 O 3 @SiO 2 -SiC coating was prepared on the C/C substrate by a simple embedding method, followed by a hot dip process. • The composite stood at 0.35 % mass loss as oxidized at 973 K for 1500 h, and 0.66 % mass loss at 1073 K for 2600 h. After thermal shock for 270 times, the mass loss was 0.56 %. • Benefiting from synergistic effects of interface encapsulations and defect self-healing, the oxygen behaved osmotic diffusion in coatings. [ABSTRACT FROM AUTHOR]

The silicate (Si) molybdenum blue method was modified by combining oxalate and ascorbic acid into a single reagent and was used for determining Si in sea water samples. The first step of this automated assay protocol was designed to perform either a calibration by a single Si standard prepared in deionized (DI) water, or to dilute samples in the range of 0–160 μM Si to fit into 0–20 μM Si calibration range using a 20 cm flow cell. By designing the assay protocol to function in batch mode, the influence of salinity on calibration was eliminated, thus making the method suitable for analysis of samples collected in the open ocean, coastal areas, or rivers. Reproducibility and accuracy of this method were evaluated by analysis of certified sea water reference materials. Phosphate (P) does not interfere significantly if the Si:P ratio is 4:1 or larger. The limit of detection was 514 nM Si, r.s.d. 2.1 %, sampling frequency 40 s/h, reagent consumption 700 μL/sample, and using deionized water as the carrier solution. [Display omitted] • Flow programming that simulates manual batch-type assay protocol. • Autodilution of a standard solution for automated calibration. • Autodilution technique brings samples within a single calibration range. [ABSTRACT FROM AUTHOR]

Heavy metal stress poses a significant threat to both crop production and human health. The application of biochar and selenium (Se) to remediate soil Cd pollution and alleviate plant Cd toxicity has been extensively investigated. However, under Cd, Pb, Cu, and Zn stress, the synergistic mechanisms of key components in lignin–based modified biochar (BC) and foliar selenium fertilizer promoting plant growth and development still need further investigation. The results indicated that, compared to the control, the simultaneous application of BC and foliar selenium fertilizer significantly increased the soil dissolved organic carbon, available silicon, and exchangeable magnesium, while reducing the bioavailability of Cd, Pb, Cu, and Zn by 27.35 %, 42.50 %, 14.50 %, and 11.79 %, respectively. The synergistic interaction between silicon silicate minerals in BC and selenium plays a crucial role in enhancing chlorophyll content, improving photosynthesis, and boosting both enzymatic antioxidant systems (CAT and SOD) and non–enzymatic antioxidant systems (GSH). Interestingly, the combined application of BC and Se shows a more pronounced effect, reducing the absorption of Cd, Zn, Pb, and Cu by pakchoi by 56.04 %, 53.21 %, 32.54 %, and 18.22 %, respectively. This study provides an effective and practical approach to alleviate the composite toxicity of plants to multiple metals such as Cd, Pb, Cu, and Zn. The synergistic effects of BC and Se in reducing heavy metal uptake by pakchoi have significant implications for sustainable agriculture and environmental remediation. [Display omitted] • Modified biochar (MBC) and selenium (Se) reduced the bioavailability of heavy metal. • MBC and Se increase photosynthetic properties in pakchoi under heavy metal stress. • MBC and Se improve antioxidant capacity of pakchoi under heavy metal stress. • MBC and Se impede the enrichmen and transport of Cd, Pb, Cu, and Zn in the pakchoi. • Silicate minerals play a key role in the synergistic effect of MBC and Se. [ABSTRACT FROM AUTHOR]

[Display omitted] The Bushveld Complex is the largest known layered intrusion in the world and has been extensively studied. However, there remains an absence of systematic investigations of cobalt (Co) and nickel (Ni) distribution at various scales. Elements Co and Ni behave varying degrees of compatibility within chromite, silicates, and sulfides, making them effective proxies for elucidating chemical competition and interaction among these minerals. This study aims to characterize Co and Ni distribution in olivine, pyroxenes, chromite, and whole rocks from different seams of the Bushveld Complex and to reveal their controlling factors. Our results indicate large variations of whole-rock Co and Ni concentrations, with a decreasing sequence of dunites (Co: 156–222 ppm; Ni: 2208–2750 ppm) > harzburgites (Co: 87.8–174 ppm; Ni: 152–2050 ppm) > pyroxenites (Co: 58.7–143 ppm; Ni: 387–1947 ppm) > norites (Co: 16.0–113 ppm; Ni: 153–646 ppm) > anorthosites (Co: 3.20–16.3 ppm; Ni: 19.7–97.2 ppm). In general, olivine has higher Ni contents (717–4496 ppm) and lower Co (105–239 ppm) than chromite (Ni: 524–1948 ppm; Co: 236–563 ppm). Pyroxenes have apparently low Co (orthopyroxene: 39.7–184 ppm; clinopyroxene: 17.2–114 ppm) and Ni contents (orthopyroxene: 224–1195 ppm; clinopyroxene: 177–831 ppm). Chromite in chromitites has lower Co content than that in other rocks. The whole-rock and mineral Co and Ni variations in the stratigraphic profile are closely related with lithology, mineral assemblages and element partition coefficients in minerals. The Co contents in the chromite and pyroxenes vary alternately with the chromitites and rock seams, with lower Co contents in ore samples than that in silicate rocks. Whole rocks and mineral separates in the Merensky Reef exhibit the highest Ni contents (whole-rock: up to 4000 ppm; orthopyroxene: 1035–1195 ppm; clinopyroxene: 730–831 ppm; chromite: 1760–1948 ppm), which are likely attributed to sulfide segregation and diffusion between sulfides and other minerals. In addition, the sulfide segregation may also be a main factor resulting in Co-Ni decoupling in pyroxenes from the Main Zone of the Bushveld Complex. [ABSTRACT FROM AUTHOR]

• Contrasting mixed scaling patterns and mechanisms were found in NF and VMD. • Drag force, pressure, temperature are the key factors for different scaling patterns. • Surface crystallization and pore-blocking were the main scaling mechanisms in NF. • Si dominating NF scaling by MSH formation, bulk crystallization was crucial in VMD. • Organic matter showed anti-scaling effects by delaying bulk crystallization. Oriented towards the pressing needs for hypersaline wastewater desalination and zero liquid discharge (ZLD), the contrasting mixed scaling of thermal-driven vacuum membrane distillation (VMD) and pressure-driven nanofiltration (NF) were investigated in this work. Bulk crystallization was the main mechanism in VMD due to the high salinity and temperature, but the time-independent resistance by the adsorption of silicate and organic matter dominated the initial scaling process. Surface crystallization and the consequent pore-blocking were the main scaling mechanisms in NF, with the high permeate drag force, hydraulic pressure, and cross-flow rate resulting in the dense scaling layer mainly composed of magnesium-silica hydrate (MSH). Silicate enhanced NF scaling with a 75% higher initial flux decline rate attributed to the MSH formation and compression, but delayed bulk crystallization in VMD. Organic matter presented an anti-scaling effect by delaying bulk crystallization in both VMD and NF, but specifically promoted CaCO 3 scaling in NF. Furthermore, the incipient scaling was intensified as silicate and organic matter coexisted. The scaling mechanism shifted from surface to bulk crystallization due to the membrane concentration in both VMD and NF. This work fills the research gaps on mixed scaling mechanisms in different membrane processes, which offers insights for scaling mitigation and thereby supports the application of ZLD. [Display omitted] [ABSTRACT FROM AUTHOR]

The mechanism behind radiophotoluminescence (RPL) emission in Ag-doped alkali-phosphate glass remains unclear. To contribute to resolving this issue, the authors measured and analyzed the temporal change of electron spin/paramagnetic resonance (ESR) spectrum of a recently developed, weather-resistant RPL glass, named "SAPANS," after irradiation with X-rays. As a result, a continuous gradual increase in Ag2+-derived signals was observed even at four weeks post-irradiation, which corresponded well with the time build-up pattern of the RPL of SAPANS. In contrast, the signals derived from phosphorous-oxygen-hole centers (POHC) rapidly decreased over a few days. The peaks of Ag0 and Ag 2 + were not successfully separated from the ESR spectra because of the possible overlap of unidentified peaks, which implies a complex mechanism of RPL-center formation in Ag-doped alkali-phosphate glass that requires further investigation. • Temporal changes in the post-irradiation ESR spectrum of a recently developed RPL glass (SAPANS) were analyzed. • The Ag2+ signal gradually increased even at four weeks, which was similar to the time build-up pattern of RPL. • The signals from the phosphorus-oxygen-hole centers (POHC) sharply decreased over three days. [ABSTRACT FROM AUTHOR]

Biostimulants such as silicate (SiO32−) compounds and antagonistic bacteria can alter soil microbial communities and enhance plant resistance to the pathogens and Fusarium oxysporum f. sp. cubense (FOC), the causal agent of Fusarium wilt disease in bananas. A study was conducted to investigate the biostimulating effects of SiO32− compounds and antagonistic bacteria on plant growth and resistance of the banana to Fusarium wilt disease. Two separate experiments with a similar experimental setup were conducted at the University of Putra Malaysia (UPM), Selangor. Both experiments were arranged in a split-plot randomized complete block design (RCBD) with four replicates. SiO32− compounds were prepared at a constant concentration of 1%. Potassium silicate (K2SiO3) was applied on soil uninoculated with FOC, and sodium silicate (Na2SiO3) was applied to FOC-contaminated soil before integrating with antagonistic bacteria; without Bacillus spp. ((0B)—control), Bacillus subtilis (BS), and Bacillus thuringiensis (BT). Four levels of application volume of SiO32− compounds [0, 20, 40, 60 mL) were used. Results showed that the integration of SiO32− compounds with BS (108 CFU mL−1) enhanced the physiological growth performance of bananas. Soil application of 28.86 mL of K2SiO3 with BS enhanced the height of the pseudo-stem by 27.91 cm. Application of Na2SiO3 and BS significantly reduced the Fusarium wilt incidence in bananas by 56.25%. However, it was recommended that infected roots of bananas should be treated with 17.36 mL of Na2SiO3 with BS to stimulate better growth performance.

Chloride is an essential nutrient for plants, but high concentrations can be harmful. Silicon ameliorates both abiotic and biotic stresses in plants, but it is unknown if it can prevent cellular increase of chloride. Therefore, we investigated the influx of Cl− ions in two wheat cultivars different in salt sensitivity, by epifluorescence microscopy and a highly Cl−-sensitive dye, MQAE, N-[ethoxycarbonylmethyl]-6-methoxy-quinolinium bromide, in absence and presence of potassium silicate, K2SiO3. The Cl−-influx was higher in the salt-sensitive cv. Vinjett, than in the salt-tolerant cv. S-24, and silicate pre-treatment of protoplasts inhibited the Cl−-influx in both cultivars, but more in the sensitive cv. Vinjett. To investigate if the Cl−-transporters TaCLC1 and TaNPF2.4/2.5 are affected by silicate, expression analyses by RT-qPCR were undertaken of TaCLC1 and TaNPF 2.4/2.5 transcripts in the absence and presence of 100 mM NaCl, with and without the presence of K2SiO3. The results show that both transporter genes were expressed in roots and shoots of wheat seedlings, but their expressions were differently affected by silicate. The TaNPF2.4/2.5 expression in leaves was markedly depressed by silicate. These findings demonstrate that less chloride accumulates in the cytosol of leaf mesophyll by Si treatment and increases salt tolerance. [ABSTRACT FROM AUTHOR]

KLaSiO4:Tb3+ phosphors were synthesized using the sol–gel method. The structure and luminescence properties of the materials were characterized using X‐ray diffraction, Fourier transform infrared (FTIR) spectroscopy, thermogravimetry–differential thermal analysis, fluorescence spectra and calculated Commission Internationale de l'éclairage coordinates. The results showed that the material had a hexagonal structure, and that doping of Tb3+ did not change the crystal structure of KLaSiO4. FTIR spectroscopy confirmed the existence of stretching vibrations of Si–O, bending vibrations of Si–O–Si, and asymmetric tensile vibrations of Si–O in KLaSiO4. The excitation spectrum of the sample consisted of 4f7→5d1 broadband absorption and the characteristic excitation peak of Tb3+, the excitation peak at 232 nm belongs to the spin allowed 7FJ→7DJ transition of Tb3+, the excitation peak at 268 nm belongs to the spin forbidden 7FJ→9DJ transition of Tb3+, and the absorption band of 7FJ→7DJ transition is split. Under excitation at 232 nm, the emission peak of the sample was composed of the 5D4→7FJ (J = 6, 5, 4, 3) energy level transition of Tb3+. The highest emission peak is located at 543 nm, which belongs to the 5D4→7F5 transition and emits green light. Concentration quenching occurred when the Tb3+ doping concentration was greater than 1% mol, the quenching mechanism was an electric dipole–electric dipole action. When the ratio of citric acid to total metal ions was 1:1 and the annealing temperature was 800°C, the surface defects of the phosphors were greatly reduced, the quenching effect was reduced, and the luminous intensity reached the maximum. [ABSTRACT FROM AUTHOR]

In this study, the groundwater (GW) in the high-fluorine area of the Southwestern Shandong Plain was divided according to the characteristics of high Na% (> 75%), and its water chemistry characteristics and causes were discussed separately, and the hydrochemical process of the formation of high-fluorine GW was determined. Finally, the GW quality of the study area was evaluated. The results proved that silicate hydrolysis can significantly promote the release of F− in fluorine-containing minerals; high %Na can be used as one of the early-warning conditions for judging high-fluoride areas. To this end, 132 GW samples were collected from 66 wells during the dry and wet seasons. The study area was found to have weakly alkaline GW (pH 7.1–8.9) and could be divided into high %Na areas (HNA) and non-HNA. GW exhibited different hydrochemical characteristics between HNA and non-HNA. In non-HNA, total hardness (TH) exceeded 200 mg/L, and total dissolved solids (TDS) ranged from 514.1 to 5246.1 mg/L; in HNA, TH was less than 200 mg/L, TDS ranged from 552.8 to 1298.3 mg/L, and Na+ increased with TDS, whereas Ca2+ and Mg2+ contents were low. The main water type in HNA was HCO3-Na and in non-HNA was SO4·Cl-Ca·Mg and SO4·Cl-Na. The study area is experiencing serious fluoride pollution. GW in HNA is mostly controlled by carbonate and silicate hydrolysis and evaporation, whereas GW in non-HNA is controlled by dolomite dissolution and cation exchange in the main. Moreover, GW in HNA has significantly been altered by albite hydrolysis, which produces Na+ and HCO3− and triggers various reactions promoting the release of F− from fluorine-containing minerals (FCM). Regarding the water quality for irrigation, GW in HNA was found to be less suitable than that in non-HNA. Nevertheless, in terms of the water quality index (WQI), GW is moderate for drinking and poor for irrigation. Therefore, extensive attention should be paid to the exploitation and management of high-sodium GW in the plain area. [ABSTRACT FROM AUTHOR]

The Chukchi Sea is the inflow shelf between the Arctic and the Pacific. A comprehensive research on algal dynamics, physical–biological interactions, and impacts on nutrient drawdown was conducted in summer 2010. The study found a phytoplankton bloom with chlorophyll a (Chla) > 10 mg m−3 at ice edge in July. There were 36 shared algal species in both sea ice and open water, and those species dominated numerically both environments highlighting the seeding role of ice algae for the phytoplankton bloom. The succession pattern of diatom genera at three phases from sea-ice to open-water bloom and post-bloom conditions was revealed, and the phytoplankton abundance was positively correlated with the concentration of > 20 µm fractionated Chla. An anticyclonic eddy was detected in July and significantly reduced nutrient inventories in the impacted area relative to historical values. Phytoplankton composition was an important factor for both variable drawdown ratios of silicate to dissolved inorganic nitrogen (1.31–3.37) and dissolved inorganic nitrogen to dissolved inorganic phosphorus (7.62–12.32); however, both ratios also changed between July and August. The results indicated highly dynamic biogeochemical processes during the summer. In addition, the lower bound of silicate drawdown was comparable to the amount imported through the Bering Strait, indicating the Chukchi Sea is a significant silicate sink. [ABSTRACT FROM AUTHOR]

Mineral reactions in soils demonstrably take place on a human timescale. The weathering of silicate 'rock-forming' minerals releases nutrients that are essential for plant growth, including silica. This process consumes CO2, which is ultimately derived from the atmosphere, through enhanced rock weathering. From a human perspective, the weathering process has two beneficial functions - crop nutrition and climate mitigation - through the removal of atmospheric CO2. By considering these as a coupled process, the release of silica during weathering can be matched to what is taken from the soil by a crop (e.g. wheat). A simple analysis shows that the amount of silica that accumulates in wheat during a 4 month growing period is readily released by the weathering of pyroxene and plagioclase, minerals that commonly occur in basaltic igneous rocks. In contrast, the dissolution rate for quartz is so low that it cannot supply the silica taken up by the crop and is inert. Similarly, dissolution of clay minerals releases sufficient silica for plant uptake. Rapid weathering of silicate minerals within soils is evident from images of surfaces of grains exposed in soils for periods of 10-100 years. The evidence for silicate rock weathering as part of the soil system that sustains humanity is provided by the vegetation that we see around us. [ABSTRACT FROM AUTHOR]

Yttrium mono- and di-silicates are excellent candidate materials for Environmental Barrier Coatings (EBC), to protect Ceramic-Matrix Composites (CMC). A large distribution of microstructures can be generated by varying the duration of sintering, the particle size distribution of the precursor and/or the deposition method. In the present work, investigations of the corrosion resistance of yttrium silicate coatings with various microstructures in the high temperature range, under different oxidizing environments are reported. An original experimental methodology has allowed quantifying the influence of the microstructure (especially grain size and grain boundary surface area) on properties such as ionic conductivity, resistance to oxygen diffusion, volatilization rate and surface recession, and showing that they directly affect their protection efficiency against oxidation. Based on these results, guidelines for the design of an optimized yttrium silicate EBC featuring microstructural and compositional variations are proposed. [ABSTRACT FROM AUTHOR]

Poly(methyl methacrylate) (PMMA)-based resins have been conventionally used in dental prostheses owing to their good biocompatibility. However, PMMA-based resins have relatively poor mechanical properties. In the present study, a novel nanoporous silica filler was developed and introduced into PMMA-based resins to improve their mechanical properties. The filler was prepared by sintering a green body composed of silica and an organic binder, followed by grinding to a fine powder and subsequent silanization. The filler was added to photocurable PMMA-based resin, which was prepared from MMA, PMMA, ethylene glycol dimethacrylate, and a photo-initiator. The filler was characterized by scanning electron microscopy (SEM), X-ray diffraction analysis, nitrogen sorption porosimetry, and Fourier transform infrared (FT-IR) spectroscopy. The PMMA-based resins were characterized by SEM and FT-IR, and the mechanical properties (Vickers hardness, flexural modulus, and flexural strength) and physicochemical properties (water sorption and solubility) were evaluated. The results suggested that the filler consisted of microparticles with nanopores. The filler at 23 wt % was well dispersed in the PMMA-based resin matrix. The mechanical and physicochemical properties of the PMMA-based resin improved significantly with the addition of the developed filler. Therefore, such filler-loaded PMMA-based resins are potential candidates for improving the strength and durability of polymer-based crown and denture base. [ABSTRACT FROM AUTHOR]

Establishing management programs to preserve the benthic communities along the NW Pacific and the Arctic Ocean (AO) requires a deep understanding of the composition of communities and their responses to environmental stressors. In this study, we thus examine patterns of benthic community composition and patterns of species richness along the NW Pacific and Arctic Seas and investigate the most important environmental drivers of those patterns. Overall we found a trend of decreasing species richness toward higher latitudes and deeper waters, peaking in coastal waters of the eastern Philippines. The most dominant taxa along the entire study area were Arthropoda, Mollusca, Cnidaria, Echinodermata, and Annelida. We found that depth, not temperature, was the main driver of community composition along the NW Pacific and neighboring Arctic Seas. Depth has been previously suggested as a factor driving species distribution in benthic fauna. Following depth, the most influential environmental drivers of community composition along the NW Pacific and the Arctic Ocean were silicate, light, and currents. For example, silicate in Hexactinellida, Holothuroidea, and Ophiuroidea; and light in Cephalopoda and Gymnolaemata had the highest correlations with community composition. In this study, based on a combination of new samples and open-access data, we show that different benthic communities might respond differently to future climatic changes based on their taxon-specific biological, physiological, and ecological characteristics. International conservation efforts and habitat preservation should take an adaptive approach and apply measures that take the differences among benthic communities in responding to future climate change into account. This facilitates implementing appropriate conservation management strategies and sustainable utilization of the NW Pacific and Arctic marine ecosystems.

[Display omitted] • Novel mathematical model combining kinetics and surface complexation reactions is developed. • Flowing water alters Si binding mechanisms onto α-FeOOH. • Si monomeric species occupy no more than ~ 22% of the reactive OH groups on goethite. • Surface oligomerization/polymerization is a rate-limited process in column. • Stepwise polymerization of silicate is crucial to adequately predicting the reactive transport of quinolones. Although silicates are the most common anions in aquatic systems, little is known on the roles they play on the transport of emerging contaminants, such as antibiotics. Using dynamic column experiments, we revealed the controls of Si loadings on goethite (α-FeOOH) coated sands on the transport of a widely used quinolone antibiotic, here focusing on Nalidixic Acid (NA). We find that dynamic flow-through conditions (Darcy velocities of 2.98 cm/h and 14.92 cm/h) sustain monomeric Si species with loadings of up to ~ 0.8 Si/nm2 but that oligomeric species can form at the goethite surfaces under static (batch, no-flow conditions). While these monomeric species occupy no more than ~ 22% of the reactive OH groups on goethite, they can effectively suppress NA binding, and therefore enhance NA mobility in dynamic conditions. NA can also bind on goethite when it is simultaneously injected with high concentrations of Si (2000 µM), yet it becomes progressively replaced by Si over time. Combining kinetics and surface complexation modeling, we present a new transport model to account for the stepwise polymerization of Si on goethite and NA transport. Our findings show that dissolved Si, common to natural surface waters, can play a determining role on the surface speciation and transport of antibiotics in the environment. [ABSTRACT FROM AUTHOR]

The influence of surface treatment with compound silicates and silicate/silane composite system on durability of concrete with different strength was studied. SEM and FTIR were used to explore the mechanism of surface treatment. The enhancement effects were compared by anti-chloride ion, carbonization resistance and freeze-thaw resistance tests. The results show that the enhancement effects of silicate/ silane composite treatment are better than that of compound silicates alone, and the improvements effect is more obvious with decrease of concrete grade. Compared with untreated concrete,the 6 h electricity flux of C50 concrete has decreased by 10. 0%, C40 concrete by 14. 4%, and C30 concrete by 29. 4%. Mean-while,the carbonization depth has also decreased from 12. 1% of C50 to 23. 8% of C40 and 33. 0% of C30. At the same time,using silicate/silane composite for concrete surface treatment can effectively improve the number of freeze-thaw cycle,reduce the mass loss rate,and endow the concrete with better durability. [ABSTRACT FROM AUTHOR]

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The present work elucidates a systematic exploration of structural, morphological, and photoluminescence (PL) features of sol–gel derived Dy3+ doped sodium calcium silicate (Na2CaSiO4: NCS) phosphor. The X-ray diffraction (XRD) data indicate single-phase cubic crystal formation of NCS: Dy3+ phosphors as all the present diffraction peaks are in accordance with the standard Na2CaSiO4 data (JCPDS card No. 24-1069). The scanning electron microscopy (SEM) image of the as-synthesized NCS sample reveals irregular crystalline structures coalesced together to form micro-sized particles. The PL studies of NUV excited Dy3+ doped NCS phosphors disclose intense emission peaks at 484 and 575 nm. Dy3+ ion concentration is optimized to achieve the maximum light intensity in NCS phosphors. The concentration quenching is the consequence of energy transfer mechanism beyond 1.0 mol% (optimized) of the Dy3+ ion concentration, which was also examined in detail. The reckoned CIE coordinates (0.337, 0.346) for the optimized Dy3+:NCS phosphor located nearby standard white point coordinates, indicating the pure white light emission. Moreover, temperature-dependent luminescence studies express admirable thermal stability of as-made Dy3+:NCS phosphor as the emission intensity even at 423 K persists up to 77.26% of intensity at room temperature. Aforesaid results support the effective utilization of Dy3+ doped NCS phosphor in white LEDs. Highlights: Single-phase Dy3+ doped Na2CaSiO4 (NCS) phosphors synthesized via sol-gel method. CIE coordinates (0.337, 0.346) for Dy3+:NCS phosphor near to standard white point. As-synthesized Dy3+:NCS phosphor exhibits appreciable thermal stability. White light emission upon NUV excitation suggests its potential role in w-LEDs. [ABSTRACT FROM AUTHOR]

This work aims to examine the effect of two different abrasives: zirconium silicate and mullite with three different particle sizes (5, 44 and 149 µm) on the frictional characteristics of brake pads. Six brake pads were developed using these two abrasives with three different sizes. The effect of the abrasives towards fade, recovery and wear was investigated by carrying out a tribological test in a Chase tester following SAE J661 standards. Results indicated that brake pads with coarser particles generated good fade resistance and acceptable recovery rate. This effect was explained based on the formation of a stable friction film observed through the field emission scanning electron microscopy and testing the microhardness at the surface of the samples after dry sliding. However coarser particles exhibited poor wear resistance. In comparison, smaller abrasive particles exhibited poor friction stability with excellent wear resistance. Detailed examination of the wear surfaces was conducted to identify the possible wear mechanism. [ABSTRACT FROM AUTHOR]

Replacing the chromate and phosphate conversion coatings (CCs) with nontoxic ones has played a key role in CC research in recent years. Although considerable efforts have been devoted to discovering and modifying the toxic CC alternatives, much of the research has been restricted to a few numbers of green CCs. The present study has aimed to review the recent attempts that have been made in this area of research to address the toxicity issue of CCs, with a focus on the steel substrate. It includes investigations on different CCs: cerium (CeCC), neodymium (NdCC), lanthanum (LaCC), zirconium (ZrCC), titanium (TiCC), trivalent chromium (TCC), molybdate (MoCC), silicate (SiCC), and silane (SilCC). Surface studies, electrochemical measurements, CCs' comparison, and film formation mechanisms were summarized. Imparting adhesion to the steel/organic coating interface or the delamination of the organic coating was discussed. Moreover, the influence of several steel substrates (coated and uncoated) and solution parameters (pH, temperature, concentration, stirring, and immersion time) on the CCs properties were outlined. Various methods (such as additives, heat treatment, and subsequent film treatment) that have been employed to improve the green CCs properties and make them comparable to their harmful counterparts were explored. [ABSTRACT FROM AUTHOR]

Diatomaceous earth represents a very important industrial mineral with very diverse use and a material with high commercial value. The diverse use and value are incumbent to its nature. The chemical nature of the frustules, the high purity, the morphology, physical characteristics such as very high porosity, chemical inertness and other properties make this industrial mineral very useful as filtration media, abrasive material, additive in the cement industry, starting material for bricks and ceramics, insulation material, etc. This review paper focuses on the most significant uses of the diatomaceous earth. [ABSTRACT FROM AUTHOR]