Al Content Research Articles

Nanomechanical and Microstructural Characterization of Biocompatible Ti3Au Thin Films Grown on Glass and Ti6Al4V Substrates.

Ti-Au intermetallic-based material systems are being extensively studied as next-generation thin film coatings to extend the lifetime of implant devices. These coatings are being developed for application to the articulating surfaces of total joint implants and, therefore, must have excellent biocompatibility combined with superior mechanical hardness and wear resistance. However, these key characteristics of Ti-Au coatings are heavily dependent upon factors such as the surface properties and temperature of the underlying substrate during thin film deposition. In this work, Ti3Au thin films were deposited by magnetron sputtering on both glass and Ti6Al4V substrates at an ambient and elevated substrate temperature of 275 °C. These films were studied for their mechanical properties by the nanoindentation technique in both variable load and fixed load mode using a Berkovich tip. XRD patterns and cross-sectional SEM images detail the microstructure, while AFM images present the surface morphologies of these Ti3Au thin films. The biocompatibility potential of the films is assessed by cytotoxicity tests in L929 mouse fibroblast cells using Alamar blue assay, while leached ion concentrations in the film extracts are quantified using ICPOEMS. The standard deviation for hardness of films deposited on glass substrates is ∼4 times lower than that on Ti6Al4V substrates and is correlated with a corresponding increase in surface roughness from 2 nm for glass to 40 nm for Ti6Al4V substrates. Elevating substrate temperature leads to an increase in film hardness from 5.1 to 8.9 GPa and is related to the development of a superhard β phase of the Ti3Au intermetallic. The standard deviation of this peak mechanical hardness value is reduced by ∼3 times when measured in fixed load mode compared to the variable load mode due to the effect of nanoindentation tip penetration depth. All tested Ti-Au thin films also exhibit excellent biocompatibility against L929 fibroblast cells, as viability levels are above 95% and leached Ti, Al, V, and Au ion concentrations are below 0.1 ppm. Overall, this work demonstrates a novel Ti3Au thin film system with a unique combination of high hardness and excellent biocompatibility with potential to be developed into a new wear-resistant coating to extend the lifetime of articulating total joint implants.

Aluminum dynamics in nitrogen‐saturated Andisols in Tokyo

AbstractThe debate over whether forests around the Tokyo metropolitan area are nitrogen (N) saturation persists, as atmospheric N deposition in throughfall has decreased. This decrease is evidenced by a notable decline in samples collected in the 1990s (especially 1991–1992 and 1995). This decline can be attributed to a reduction in nitrogen oxide (NOx) emissions from automobiles. The acidity derived from N deposition can increase aluminum (Al) mobility. We conducted a monitoring study from September 2010 to December 2021 to elucidate the effects of decreased N deposition on Al concentrations and flux in a forested Andisol. Throughfall and soil‐percolated water samples were collected under stands of Japanese cedar and Japanese cypress in Hachioji, Tokyo (Field Museum Tamakyuryo). Major inorganic ions were determined by ion chromatography. Total Al concentrations were determined using atomic absorption spectrometry after concentration under acidic conditions. Aluminum and nitrate () concentrations were significantly correlated in the both Japanese cedar and Japanese cypress stands. In the case of the Japanese cedar stand, Al concentrations tended to decrease over time from November 2010 to May 2015. Based on stepwise multiple regression analysis, acid load associated with N transformation ([H+]load) was chosen as the sole factor affecting Al mobilization in the Japanese cedar stand. Decreased N deposition affects Al dynamics via a decrease in [H+]load.

New insights on clusters stacking mechanism within medium range in Fe-Al amorphous alloys

Molecular dynamics simulation has been employed to investigate the stacking mechanism of short-range-order structures in Fe-Al amorphous alloys. We explore the effect of Al content (0–50 %) on the nearest-neighbour correlation index and stacking degree between their main clusters. The results show that the correlation index changes little over the Al content range, and the stacking degree decreases with the Al content increasing on the whole. Through the spatial correlation analysis, it is found that the clusters with similar structural symmetry are more likely to connect. Moreover, we find that the stacking degree depends on the number of clusters and their correlation index, i.e., the stacking degree is found to increase as the number or correlation index of clusters increases, but the cluster number shows a greater influence on the stacking degree compared to their correlation index. We believe that these are the inherent stacking features in medium range in Fe-Al amorphous alloys, which can also be extended to other amorphous alloys. This work provides a deeper insight into the spatial relationship of short-range-order structures and the stacking of clusters from short to medium range.

Efficient preparation of metallic titanium from lower valence titanium chloride slurry by electrochemical reduction in molten salts

Short extraction of metallic titanium by the electrochemical reduction process in molten salt has attracted increasing interest due to its many advantages. The electrolysis of high-purity titanium to produce lower valence titanium chlorides has so far been industrialized as balancing agents but large-scale production is still challenging due to the high cost of raw materials and easy deterioration. Herein, metallic titanium was extracted from lower valence titanium chlorides (LTCs) slurries by electrochemical reduction in molten salts. The results of LTC slurries at 260 ºC for 48 h revealed the formation of red-violet α- and γ- TiCl3 with an Al content below 0.09 wt%, which gradually reduced to form metallic titanium in molten salt electrolytes. Porous metallic Ti powders were obtained from TiCl3 by electrochemical reduction in KCl-LiCl-MgCl2 molten salt at 400 °C. The reaction at the anode area was accompanied by TiCl4 gas overflow, and continuous electrolysis of metallic titanium was achieved by supplementing the consumed TiCl3. Overall, the proposed electrolysis process looks promising for large-scale applications due to its simple electrolysis equipment, relatively stable electrolyte components, and good product quality, thereby worth further future investigation.

[Pollution Characteristics, Source, and Health Risk Assessment of Metal Elements in PM2.5 Between Winter and Spring in Zhengzhou].

A total of 18 metal elements in ambient PM2.5 in Zhengzhou were continuously determined using an online heavy metal observation instrument in January and April, 2021, and the changes in element concentrations were analyzed. Metal elements were traced via enrichment factors, positive matrix factorization (PMF), and a characteristic radar chart. The US EPA health risk assessment model was used to assess the health risks of heavy metals, and the backward trajectory method and the concentration-weighted trajectory (CWT) method were used to evaluate the potential source regions of health risks. The results showed that the element concentrations were higher in spring, and the sum of Fe, Ca, Si, and Al concentrations accounted for 89.8% and 87.5% of the total element concentrations in winter and spring, respectively. Cd was enriched significantly, which was related to human activities. The concentrations of Pb, Se, Zn, Ni, Sb, and K in winter and Cr, Ni, Fe, Mn, V, Ba, Ca, K, Si, and Al in spring increased with the increasing pollution level. The results of PMF and the characteristic radar chart showed that the main sources of metal elements in winter and spring were industry, crust, motor vehicles, and mixed combustion, with industry and mixed combustion pollution occurring more often in winter and crust pollution occurring more often in spring. Significant non-carcinogenic risks existed in both winter and spring with more severe health risks in winter, and Mn caused significant non-carcinogenic risks. The health risks in winter were mainly influenced by Zhengzhou and surrounding cities and long-distance transport in the northwest, and the health risks in spring were mainly influenced by Zhengzhou and surrounding cities.

The effect of Al on the corrosion resistance of binary Mg-Al solid solutions: Combining in-situ electrochemistry with combinatorial thin films

The effect of varying Al concentrations on the electrochemical corrosion resistance of binary Mg-Al solid solutions thin films under alkaline immersion conditions was investigated via a combination of in-situ flow-cell, scanning vibrating electrode technique and microscopy analysis. These spatially resolving characterization techniques are employed along the Al concentration gradient of the combinatorically grown thin films enabling efficient screening of the Al concentration dependent electrochemical corrosion behaviour. The analysis revealed an increasing corrosion resistance with increasing Al concentration, as a consequence of Al induced hydroxide reinforcement. Specifically, the addition of >4 wt.% Al decreases the corrosion current density in the range of 70–90 % compared to pure Mg.

Altered spinels act as a mirror of multi-episodic fluid metasomatism in the forearc mantle: An example from the Minhe ophiolite in Qilian Orogen, NW China

Forearc mantle peridotites commonly undergo complex melt/fluid metasomatism, which inevitably has a considerable influence on their geochemical compositions at the whole-rock scale. Serpentinites predominantly comprise the Minhe ophiolite, which is a fragment of the Proto-Tethys Ocean that outcrops in the Qilian Orogen in NW China. These serpentinites contain zoned spinels that vary compositionally from the centers to the margins, with a spinel core overgrown by ferritchromite layer and magnetite at the outermost rim. The mineral chemistry of the spinel cores (i.e., Cr#, Mg#, Cr2O3, and Al2O3) suggests that the protolith of the serpentinites was an oceanic mantle remnant in a forearc setting. Moreover, the ferritchromite exhibited increases in Fe, Mn, Sc, and Ni contents and decreases in Mg, Cr, Al, V, Zn, and Ga contents. Considering the linear correlation among elements (e.g., Co, Ni, and Zn) and the absence of mineral inclusions, the ferritchromite likely formed through ionic substitutions induced by slab fluids. The magnetite was enriched in Cr, Ni, V, Zn, Co, and Cu, but did not have a magmatic origin owing to low V concentrations. All evidence indicates that the peridotites underwent at least two episodes of fluidic metasomatism in the subduction zone. During early slab subduction, aqueous fluids released from the dehydration of the subducted slab directly serpentinized the forearc mantle peridotites, thereby altering the olivine and orthopyroxene to lizardite/chrysotile. During this process, certain mobile elements (e.g., Fe, Ni, and Mn) in the fluids and/or olivine serpentinization were incorporated into existing spinels, favoring ferritchromite growth. The second fluidic episode was dependent on prograde metamorphism at greater depths in the subduction channel, which not only produced antigorite via the recrystallization of lizardite and chrysotile, but also drove the fluids towards a more oxidizing state, thereby facilitating the growth of Cr-magnetites. Subsolidus re-equilibration controlled by fluid infiltration further promoted the inter-diffusion of elements (e.g., Cr, V, Co, Ni, Cu, and Zn) in the zoned spinels.

Stress-related physiological responses and ultrastructural changes in Hypoxis hemerocallidea leaves exposed to cadmium and aluminium

AbstractHypoxis hemerocallidea is a medicinal plant containing hypoxoside (a pharmacologically active phytosterol diglucoside). This study evaluated the elemental composition in leaves of H. hemerocallidea treated with cadmium (Cd) and aluminium (Al) using scanning electron microscopy (SEM) combined with energy-dispersive X-ray spectroscopy (EDX). The impact of Cd and Al on photosynthetic pigments and performance, antioxidant activities and ultrastructure were also assessed. Corms of H. hemerocallidea were micropropagated, rooted and then exposed to varying concentrations of Cd, Al, and Cd + Al for six weeks. The SEM/EDX analysis indicated a two-fold increase in carbon content across all treated plants compared to the control. No/little Cd was detected in the leaves compared to a progressive increase in Al concentration with increasing Al treatment levels. This indicted that Al is more readily translocated to the shoots compared to Cd. Plants treated with Cd exhibited a significant decrease in total chlorophyll content accompanied by reduced photosynthetic performance and lower relative electron transport rates. Cd and Al exposure led to higher carotenoid, superoxide dismutase and malondialdehyde levels, indicating oxidative stress. Cd-treated plants displayed increased amylase activity and decreased carbohydrates content. Ultrastructural alterations occurred with exposure to Cd and Al, including abnormal swelling or disintegration of chloroplasts and thylakoid degeneration. An increase in starch grains and a decrease in plastoglobuli were also noted. In conclusion, this investigation provides evidence that both Cd and higher concentrations of Al exert detrimental effects on the ultrastructure, metabolism and photosynthetic performance of H. hemerocallidea, contributing to reduced growth and biological activity when stressed.

Probing Bond Length and Compositional Disorder in β‐(AlxGa1−x)2O3 Alloys Using Extended X‐Ray Absorption Fine Structure Spectroscopy

Local structure of β‐(AlxGa1−x)2O3 alloys with Al contents is determined from extended X‐ray absorption fine structure spectroscopy (EXAFS). A model to fit the EXAFS data for monoclinic β‐(AlxGa1−x)2O3 is suggested to independently determine local structure parameters. An increase in compositional disorder corresponding to the near neighbors (NNs) for lower Al contents establishes that the Al atom does occupy tetrahedron sites in addition octahedron sites even for smaller Al contents. NNs and next‐nearest neighbor (NNN) bond lengths corresponding to tetrahedron and octahedron coordinated gallium (Ga) atoms with surrounding oxygen (O) atoms as well as tetrahedron–tetrahedron/octahedron–octahedron coordinated GaGa atoms on average decrease with Al content up to x = 33.3% and then they saturates with further increase in Al content. However, tetrahedron–octahedron coordinated GaGa atoms move far apart with Al content up to x = 33.3% and then it saturates. The physical picture indicates the creation of tetrahedra and octahedra sublattices locally for β‐(AlxGa1−x)2O3, and their sizes decrease, but they move far apart up to a certain Al content. Thereafter, both saturate. Thus, EXAFS provide a clear insight into the evolution of local structure of β‐(AlxGa1−x)2O3 with Al content, which is useful for better understanding of their physical properties.

Impact of air quality on the health of present-day workers in an Asbestos roof manufacturing industry, Sri Lanka.

The study's objective was to determine the air quality in an asbestos-related industry and its impact on current workers' respiratory health. Seventy-seven air and 65 dust samples were collected at 5-day intervals in an asbestos roofing sheets production factory in Sri Lanka having two production facilities. Sampling was performed in ten sites: Defective sheets-storage, Production-plant, Pulverizer, Cement-silo, and Loading-area. A detailed questionnaire and medical screening were conducted on 264 workers, including Lung Function Tests (LFT) and chest X-rays. Asbestos fibres were observed in deposited dust samples collected from seven sites. Free chrysotile fibres were absent in the breathing air samples. Scanning Electron Microscopy confirmed the presence of asbestos fibres, and the Energy Dispersive X-ray analysis revealed Mg, O, and Si in depositions. The average concentrations of trace metals were Cd-2.74, Pb-17.18, Ni-46.68, Cr-81.01, As-7.12, Co-6.77, and Cu-43.04mg/kg. The average Zn, Al, Mg, and Fe concentrations were within 0.2-163g/kg. The highest concentrations of PM2.52.5 and PM1010, 258 and 387µg/m3, respectively, were observed in the Pulverizer site. Forty-four workers had respiratory symptoms, 64 presented LFT abnormalities, 5 indicated chest irregularities, 35.98% were smokers, and 37.5% of workers with abnormal LFT results were smokers. The correlation coefficients between LFT results and work duration with respiratory symptoms and work duration and chest X-ray results were 0.022 and 0.011, respectively. In conclusion, most pulmonary disorders observed cannot directly correlate to Asbestos exposure due to negligible fibres in breathing air, but fibres in the depositions and dust can influence the pulmonary health of the employees.

Avoiding microstructural instabilities in high tungsten containing superalloys by adjusting Al content

The effects of Al contents on the microstructures and mechanical properties of superalloy with high tungsten content were studied. During solidification, Al was found to be enriched in the residual liquid, which led to the transformation of eutectic morphology from reticular to bulk-like. When the Al content was increased to 8 wt%, β-NiAl phase formed in the inter-dendritic region, Thermo-Calc calculations confirms such transformation. The absolute value of the lattice misfit between the γ/γ' phases and the elastic strain energy increases, then the size of the γ' phase increases when the Al concentration rises from 7 wt% to 8 wt%. When the Al content was increased to 7 wt%, the tungsten-rich α-W phase is precipitated and the volume fraction is 1.20%. The volume fraction of the α-W phase increases to 7.84% when the Al content comes 8 wt%, which is consistent with the Thermo-Calc calculation results. After the room temperature tensile and stress rupture life test at 975 °C / 235 MPa, it revealed that the precipitation of hard and brittle α-W and β-NiAl phases with high Al content led to cracks sprouting at multiple locations and then interconnected, resulting in degraded performance. The high γ' phase density of 6 wt% Al makes it difficult to bypass the dislocation, and there is no brittle phase, the crack initiation site is decreased. The stress rupture life can reach 49.21 h of the alloy.

Determination of hydrogen compatibility for Cu-Al-Ni-Fe-Mn cast alloys prepared by varying Al and Ni contents

Hydrogen compatibility of Cu-Al-Ni-Fe-Mn cast alloys was investigated via slow strain rate tensile tests in high-pressure hydrogen gas. Four types of alloys were prepared by varying the Al and/or Ni contents. Larger Al and Ni contents resulted in more elongated microstructures with smaller grains and more precipitates, respectively. The tensile strength of the alloys increased with larger Al and/or Ni contents, whereas the ductility decreased only by adding a larger amount of Al. The maximum tensile strength was produced by adding larger amounts of both Al and Ni, which was fairly higher than those of stable austenitic stainless steels. Despite the difference in the microstructures and tensile strengths of the alloys, the hydrogen contents and hydrogen diffusivities showed no substantial difference. Additionally, their reduction in area measured after the tensile tests was not degraded by the high-pressure hydrogen gas, revealing an excellent resistance to hydrogen embrittlement.

Selective separation of rare earths and aluminum from low-concentration rare earth solution via centrifugal extraction

The separation of rare earths (REs) and aluminum (Al) has always been a practical challenge in the rare earth industry. In this paper, the effects of contact time, the concentrations of Al3+ and RE3+ on the extraction and separation of REs and Al during the solvent extraction of low-concentration rare earth sulfate solution using P507 were investigated. Significant differences in the extraction kinetics between REs and Al can be observed at the same contact time. For instance, when the contact time is 10 s, the extraction efficiency of Y reaches up to 97.5 %, whereas that of Al is only 9.1 %. Under the conditions of initial pH of the rare earth solution 4.0, Al3+ concentration 0–20.0 mmol/L, and RE3+ concentration 1.5–12.0 mmol/L, both the separation factors of Gd/Al (βGd/Al) and Y/Al (βY/Al) are higher than 100 at the contact time of 10–300 s, indicating that M−HREs can be easily separated from Al through solvent extraction using P507. The separation factors of La/Al (βLa/Al) and Nd/Al (βNd/Al) are 10.8–12.3 and 40.5–58.7, respectively, at the contact time of 15–30 s, which are much lower than those of M−HRE (such as Gd and Y), but are much higher than those at the contact time of 300 s (βLa/Al = 2.8, βNd/Al = 31.5). It means that the separation of LRE and Al serves as the key for the separation of REs and Al in the low-concentration rare earth solution, and controlling the contact time in the range of 15–30 s is conducive to the separation of LREs from the Al. The increase in the Al3+ concentration in the rare earth solution has no significant impact on the separation of REs and Al at the contact time of 10–60 s, but the increase in the RE3+ concentration induces the separation of REs and Al. In conclusion, REs in the low-concentration rare earth solution can be selectively separated from the Al via centrifugal extraction technology.

Assessment of three different approaches for integrating phosphorus recovery from sewage sludge and derived products in existing wastewater treatment plants

Three different technological solutions, namely acidogenic fermentation and chemical extraction (alkaline or acidic), followed by precipitation with 1 % Ca(OH)2, were investigated in the view of integrating phosphorus recovery into existing wastewater treatment plants. Experiments were conducted at the lab-scale using (i) sludge taken from biologically and chemically promoted phosphorus removal activated sludge processes and (ii) ashes obtained from sludge muffle incineration. Results highlighted the benefits of enhanced biological phosphorus removal (EBPR) systems rather than chemically promoted phosphorus removal in not only phosphorus extraction (up to 40 % with EBPR) and recovery directly from secondary sludge (P precipitation between 66 and 92 %), but after sludge incineration as well (P extraction up to 96 % and precipitation above 96 %). Acidogenic fermentation ensured the highest phosphorus release from EBPR sludge (equal to a concentration in solution of 122 mg/L P-PO43−), while the derived ashes had a lower level of metal contamination (particularly Fe and Al content < 2 %). The phosphorus-rich product obtained by means of the recovery process showed relevant metal contamination (Cu, Zn, and Ni) under some operating conditions, suggesting the need for further treatments.

Revealing microstructural degradation mechanism induced by interdiffusion between Amdry365 coating and IN792 superalloy

Metallic coatings are widely employed to improve the oxidation resistance of superalloys. However, the interdiffusion between the metallic coatings and the superalloys leads to microstructural degradation in both. Some of the underlying degradation mechanisms are still elusive, e.g., the γ′ (Ni3Al) phase depletion in superalloys, where a large amount of γ′ precipitates are dissolved in the γ matrix even though the incoming Al from coatings indeed increases the Al content. Here, we investigated the interdiffusion behavior between the Amdry365 coating and the IN792 superalloy at 1100 °C, using multiple microscopic techniques and thermodynamics calculations. Our results showed an excellent agreement between experiments and thermodynamics simulations, indicating the dominant role of Al on the initial diffusion-induced phase transitions. We proposed the Al-Cr interference effect to account for the pile-up behavior of Cr and the reduced Al content near the coating/superalloy interface. The local phase equilibrium calculations revealed that the γ′ depletion in the superalloy is primarily attributed to the loss of γ′-forming elements, such as Ta and Ti. Our findings opened up an avenue for studies on the superalloy/coating interdiffusion, contributing to reducing this damaging impact

The effect of FeGa (0/–) level presence on material properties in dilute AlxGa1−xN layers

AlxGa1−xN epilayers are used as the basis of ultraviolet LEDs and detectors. The trap states produced by defects and impurities can play a key role in the device performance. In this work, conventional deep-level transient spectroscopy, photoluminescence (PL), and secondary ion mass spectrometry have been used to characterize a deep-level trap termed as E3 in dilute AlxGa1−xN (x &amp;lt; 0.063) epilayers grown by metal-organic vapor phase epitaxy (MOVPE) on highly conductive ammono-GaN substrates. The AlxGa1−xN epilayers were doped with silicon to about 3 × 1016 cm−3. The electrical and the optical measurements were conducted on Ni/Au Schottky barrier diodes and virgin samples, respectively. First, we observed a general trend that the E3 (FeGa) electron trap concentration significantly changes along the wafers in AlxGa1−xN layers that is fully consistent with previously reported results for GaN materials grown by the MOVPE technique. Second, we report that the activation energies for electron emission for the E1 and E3 traps in dilute AlxGa1−xN exhibit linear variations with Al content. Moreover, low-temperature PL results show a proportional relation between the intensity of the line with its maximum at 1.299 eV and concentration of residual Fe impurity. Finally, we discuss how the presence of defects resulting from Fe contamination may result in degradation of AlxGa1−xN-based devices.

Effect of interdiffusion layer of functionally graded Al–Cu composites fabricated by spark plasma sintering on mechanical and thermal properties

The effect of the microstructure of multi-layer Al–Cu functionally graded materials (FGMs) fabricated through spark plasma sintering (SPS) on the mechanical and thermal properties was systemically investigated. Uniformly mixed Al–25, 50, 75 Cu (vol%) powder samples were prepared by mechanical ball milling and used for fabricating two types of FGMs: FGM 1 with three layers (Cu/Al–50Cu/Al) and FGM 2 with five layers (Cu/Al–75Cu/Al–50Cu/Al–25Cu/Al). These FGMs were then sintered at 400 °C under a compressive pressure of 250 MPa for 5 min. The microstructures of the sintered FGMs exhibited gradual variations in the Al and Cu contents. An interdiffusion layer composed of Cu9Al4 and CuAl2 at the layer/layer interfaces was observed, the thickness of which was analyzed by energy-dispersive spectroscopy line mapping. The Vickers hardness of FGM 1 and FGM 2 were higher than that calculated by rule of mixture due to the formation of Al-Cu IC such as Cu9Al4 and CuAl2. The drastic enhancement in a Al-75Cu layer was obtained by dominant formation of Cu9Al4. On the other hand, the thermal conductivity of the prepared FGMs was lower than that of Al due to the formation of Al–Cu ICs, enhanced heat dissipation compared with the Al–Cu composite materials. The mechanical and thermal properties of Al-Cu FGMs can be controlled by designing the layer composition or the number of layers.

Distribution and human health risk assessment of trace elements in the bivalve Polymesoda erosa from mangroves on Hainan Island, China

Distributions and potential health risks of 14 trace elements in Polymesoda erosa from four mangrove wetlands on Hainan Island, China, were investigated. Concentrations (µg⋅g-1 d.w.) in P. erosa soft tissue decreased from Fe (935) > Al (642) > Zn (254) > Mn (44.1) > Sr (36.2) > Ni (13.5) > Cu (8.16) > As (4.54) > Se (3.06) > Cr (1.46) > Sn (0.63) > Pb (0.58) > Cd (0.44) > Hg (0.11), and tissue concentrations differed significantly among wetlands. Al, Fe, Cd, and Se contents were highest in P. erosa muscle from the estuary (S1-B); whereas, Cu, Zn, and Sn contents were highest in P. erosa muscle near the port. The average daily trace element dose for children and adults was acceptable and non-carcinogenic risks were not evident. For children and adults, carcinogenic risks posed by trace elements at the median percentile were 11.6- and 7.84-times higher than the acceptable level (10-4), respectively. The maximum allowable consumption rate and monthly meals highlighted the necessity to reduce trace elements exposure in most sampled regions, with the lowest values at the estuary site. The findings suggest a high risk of consuming P. erosa from inner bay of Dongzhai Harbor.

Towards wake-up free ferroelectrics and scaling: Al-doped HZO and its crystallographic texture

Ferroelectric (FE) hafnium zirconium oxide (HZO) is an excellent candidate for data storage applications. However, it has some reliability limitations such as imprint and retention. Herein, we explore Al doping of HZO to overcome these limitations. FE behavior is tuned by the aluminum (Al) concentrations in the films and by annealing temperature. A correlation is done between electrical behavior, crystallographic texture, and FE phases determined by grazing-incidence X-ray diffraction (GIXRD) measurements. Reduced coercive field (2Ec) values and wake-up free HZO-based ferroelectrics are explored. We show the tunability of remanent polarization (2Pr) and 2Ec with respect to Al-doping concentration and anneal temperature, hence crystallographic texture.

Scalable polycondensation approach for efficient Al/S@g-C3N4 hydrogen production catalyst

This article investigates the development of an efficient Al/S@g-C3N4 catalyst for hydrogen production through sodium borohydride (NaBH4) methanolysis. The catalyst was prepared using a facile and scalable polycondensation technique. The prepared catalyst was characterized extensively by XRD, FTIR, SEM, and surface area analyses. XRD and FTIR analysis showed a reduction in the interlayer distance between the S@g-C3N4 sheets with increasing Al content. The SEM images showed a rough and uneven surface of the nanosheets. The obtained values of Eg are 2.6, 2.4 and 2.5 eV for the samples doped with 0.0, 1.0 and 2.0 wt% of Al. Increased surface area (up to 92 m2/g) and slightly smaller mesopores (1.56 nm) observed with increasing Al doping up to 2.0 wt%. Significant enhancement in hydrogen generation rate with a maximum of 10,112 mL/g.min was achieved for 2.0 wt% Al. Low activation energy of 27.08 kJ/mol for the 2.0 wt% Al-doped catalyst. The catalyst demonstrates good stability after undergoing multiple NaBH4 methanolysis cycles.