Aluminum Content Research Articles

Electrochemical characterization and discharge performance of AZ31, AZ61 and AZ91 alloys as anodes for seawater battery

The abundance, environmental friendliness and high energy density of magnesium makes it an attractive option for eco-friendly battery development. This research article explores the performance of commercial magnesium alloys AZ31, AZ61 AZ91 in seawater battery applications, with a focus on corrosion resistance, discharge efficiency and long-term stability. The study highlights the role of aluminium concentration in these alloys, with a specific emphasis on how variations in concentration impact the performance metrics such as corrosion susceptibility, hydrogen evolution and anode utilization. Increasing the aluminium concentration to around 6 wt % in AZ61 not only boosts discharge activation but also enables the formation of protective magnesium aluminide (Mg17Al12), which acts as a barrier, preventing the self-peeling of corrosion products and enhancing stability during prolonged discharge. AZ61 emerges as the optimal alloy, balancing corrosion resistance, discharge efficiency, high anode utilization factor and long-term stability in highly corrosive seawater conditions. The results of electrochemical and discharge performance testing are supported by electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis. The work offers a framework for future research that can boost the development on design of seawater battery with corrosion-resistant materials, high discharge efficiency and minimal adverse environmental impact.

Shading Reduces Root Aluminum Content and Restructures Epiphytic Microbial Communities on the Subtropical Plateau of Southwest China

Shading Reduces Root Aluminum Content and Restructures Epiphytic Microbial Communities on the Subtropical Plateau of Southwest China

Rubber Crumb Infill in Synthetic Turf and Health Outcomes: A Review of the Literature on Polycyclic Aromatic Hydrocarbons and Metalloids

Synthetic turf has become a popular alternative to natural grass due to low upkeep costs; however, its health impacts have not been clearly elucidated. This review examines and consolidates the existing literature on rubber crumb in infill in synthetic turf and its associated adverse health outcomes, along with recommendations for future research. A database search was conducted in PubMed, Web of Science, Scopus, Embase, and Google Scholar of studies on exposures to rubber crumb in infills in synthetic turf. The search focused on epidemiological and toxicological laboratory studies (including exposure simulation and animal studies), as well as government reports. Non-English studies and those addressing injuries (musculoskeletal and burn injuries) were not considered. Eighteen laboratory studies examined concentrations of PAHs found in synthetic turf rubber infill. The total level of PAHs detected in samples varied between 0.4 mg/kg and 3196 mg/kg. The PAH levels were influenced by the age of the synthetic turf, with the older synthetic surface fields containing lower concentrations (compared to newly laid turfs). Synthetic turfs composed of industrial rubber crumb infill also had a lower PAH composition relative to end-of-life tyre-derived infill. In the six studies that investigated the metal content and composition of rubber crumb infill, Aluminium (5382 mg/kg), Zinc (5165 mg/kg), and Iron (489.6 mg/kg) had the highest median concentrations. There were minor differences in heavy metal concentrations found in newly installed synthetic turf compared to older turfs and synthetic sporting fields exposed to direct sunlight (versus indoor fields). There were two epidemiological studies on synthetic turf rubber crumb infill (one ecological and one cross-sectional study), which found no significant associations between synthetic turf exposure and the incidence of leukemia, non-Hodgkin lymphoma, and Hodgkin lymphoma. Similarly, one metabolomic study of urine samples from athletes taken pre- and post-match on synthetic turf, and two studies simulating dermal, ingestion, and inhalation exposure concluded that there was no elevated health risk associated with playing on synthetic turf pitches. Currently, there is very limited evidence of an association between synthetic turf use and adverse health outcomes. Considering the ubiquitous use of synthetic grass globally and the scarcity of epidemiological studies, there is a vital need for further research based on longitudinal study designs and more robust exposure assessments, to help improve our understanding of any potential health risks associated with synthetic turf infill exposures.

New High-Throughput Method for Aluminum Content Determination in Vaccine Formulations

Objective: This manuscript describes an innovative, non-destructive, high-throughput method for the quantification of aluminum hydroxide in aluminum-adjuvanted vaccines, eliminating the need of reagents and providing real-time results. The method is based on a spectrophotometric principle, and several model proteins were studied and tested with the aim to simulate the behavior of aluminum-adjuvanted antigens. Methods: As a proof of concept, the MenB vaccine was used, and the titration of aluminum hydroxide (AH) with ethylenediaminetetraacetic acid (EDTA) was used as an orthogonal reference, as it is one of the current release methods for the content determination of aluminum-hydroxide-adjuvanted vaccine drug products (DPs). The factors influencing the spectrophotometric analysis, such as different plate 96/well containers, variation in the sedimentation of the suspension due to component addition errors during formulation, and batch-to-batch variation were studied to assess the method’s robustness. Five concentration levels (ranging from 2.0 to 4.0 mg/mL AH) with two different batches of aluminum hydroxide were each measured with independent preparations performed by three different operators, for a total of four sessions/operator and 20 formulations/session. An in-depth statistical study was carried out with generated data to assess the precision (in terms of intermediate precision and repeatability), accuracy, linearity, and specificity of the method. Results: The novel spectrophotometric method and the official release one (potentiometric) yielded comparable results, demonstrating the potential of this new method as a release test for AH-adjuvanted products. A simple calibration curve enabled the measurement of samples in a 96-well plate in just a few minutes. Conclusions: We developed a novel method for Aluminum concentration determination in Aluminum-containing pharmaceutical products, like alum-adjuvanted vaccines. This method is fast, completely automatable, and as precise and accurate as already-in-place release methods.

The effects of occupational aluminum exposure on blood pressure and blood glucose in workers - A longitudinal study in northern China.

Trace element and metal exposure is closely related to the occurrence of chronic diseases, particularly affecting blood pressure and blood glucose. Current studies suggest that heavy metal exposure is a risk factor for hypertension and diabetes. Aluminum can enter the human body through daily life and occupational exposure from food, environment, drugs, and other sources, affecting the cardiovascular, endocrine, and other systems. Therefore, it is significant to observe the effect of aluminum on blood pressure and blood glucose in workers with high concentration. In this study, electrolytic workers naturally exposed to high concentrations of aluminum were selected. The aim of the 5-year cohort study was to investigate the effects of continuous occupational aluminum exposure on blood pressure and blood glucose in workers and to assess the risk of potential cardiovascular and metabolic diseases due to heavy metal exposure. In 2014, 183 participants from an electrolysis workshop at an aluminum plant in Shanxi were enrolled. Inductively coupled plasma mass spectrometry (ICP-MS) was performed to determine the plasma aluminum (P-Al) concentration of the workers and measured their blood pressure and glucose levels. At the 2019 follow-up, all parameters were measured again in the same workers. The relationship of the P-Al concentration with blood pressure and glucose levels was assessed using generalized linear regression, and risks of developing hypertension and hyperglycemia (diabetes or pre-diabetes) due to Al exposure were assessed using binary logistic regression. Dose-response relationships between average annual rates of change in P-Al and average annual rates of change in blood pressure and blood glucose were analyzed using RCS. The relative risk (RR) and attributable risk (AR) were also calculated. Generalized linear regression showed that the average annual rate of change in P-Al concentration was positively correlated with the annual rates of change in SBP, DBP, and blood glucose levels, with each e-fold increase in P-Al concentration increasing the annual rates of change in SBP and DBP by 3.55 % (P < 0.01) and 3.43 % (P = 0.03), respectively. Binary logistic regression showed that as the average annual rate of change in P-Al concentration (categorical variable) increased, the risk of developing hypertension increased (Ptrend < 0.05). The RCS results showed that the relationship between the average annual rate of change in P-Al and the average annual rate of change in SBP was a showed a dose-response relationship (P for overall association<0.05). RR and AR increased with increasing P-Al concentration in both hypertensive and diabetic patients. Persistent occupational aluminum exposure is associated with elevated blood pressure levels in workers and increases the risk of developing hypertensive disorders.

Mouse pulmonary response following solid surface composite dust inhalation

Purpose: Pulmonary exposure to emissions from manipulating solid surface composite (SSC) materials has been associated with adverse health effects in humans and laboratory animals. Previous in vitro and in vivo investigations of SSC toxicity have been limited by particle delivery methods that do not fully recapitulate the workplace environment. This study sought to determine the acute SSC-induced pulmonary responses via whole-body inhalation exposure. Materials and Methods: A chamber for dust particle generation and an exposure system for characterization and animal exposures was constructed. The system successfully generated SSC at a concentration of 19.9 ± 1.5 mg/m3. The aerosol count median aerodynamic diameter was 820 nm. First, C57BL/6 mice were exposed to SSC particles for 4 h (n = 6) or filtered air control followed by euthanasia either immediately or 24 h post-exposure. Lungs were analyzed for aluminum (Al) content using inductively coupled plasma atomic emission spectroscopy (ICP-AES) which measured a lung deposition of 19.13 ± 5.03 µg/g elemental Al, or approximately 64 µg/g SSC dust. Second, a group of mice (n = 9) was exposed to SSC particles at 20 mg/m3 for 4 days, 4 h/day to assess the acute and sub-chronic pulmonary effects of SSC inhalation. Animals were euthanized at 1- and 56-days post-exposure. Results: Total estimated pulmonary deposition for these animals was 49.2 µg SSC dust/animal. No histopathologic changes were observed at any post-exposure time point; however, BALF total protein was increased at 1-day post-exposure. Conclusions: We conclude that exposure to dust from cutting SSC at this dose and post-exposure durations induces mild, transient inflammation.

Boron Behaviors in Upland Humid Tropical Soils: A Case of Plant-Available Implication for Cassava

ABSTRACT Understanding the role of soil boron (B) through its reaction, mobility, and availability could provide effective B nutritional management for a cassava crop (Manihot esculenta crantz). This study investigated a soil B status suitable method for making B fertilizer recommendation through determining the B sorption index and the chemical fractionation of soil B and available B in soils, using single extractants in 11 benchmark soils intensively cultivated for cassava in northeast, Thailand. All soils studied were considered low B-sorbed soils that were equally well described using either Langmuir or Freundlich models, with respective adsorption capacities of 2.00–17.22 mg kg−1 and 0.91–4.31 L mg−1. The B desorption index exhibited hysteresis desorption behavior for all soils. Boron adsorption by the soils significantly showed a positive correlation (>0.75, p ≤ .01) with organic carbon, silt, amorphous aluminum, and silicon contents. Of the total B, the native B pool in the soils was mostly in the residual fraction, contributing 70–80%, while the readily soluble fraction contributed only 0.07–0.59%. Among the soil extractants tested, only hot CaCl2 and NH4OAc adequately assessed soil B availability for cassava, while they were less extractability to extract B from total B. Chemical fractions of B could all be used for available B assessment for cassava with a residual B fraction being superior, although this was unlikely to contribute significantly to plant-available B in the short term, but it was a potential B reserve that could maintain adequate B status in the long term throughout the cassava growing period.

Mineralogical Characterization of Mortars in Ancient Portuguese Tile and Embrechado Restorations: The Cases of Maceió (AL) and Salvador (BA)

ABSTRACT Portuguese tiles and embrechados rare colonial historical and artistic heritage capable of safeguarding the luso-bazilian cultural link over time. The inappropriate use of mortars to resettle these elements gives rise to diverse pathological manifestations. Therefore, this article aims to characterize mineralogical mortars used in ancient Brazilian restorations to ascertain their composition and the presence of cementitious material or other contamination. To this end, the microstructure of mortar samples from the Cloister of the Church and Convent of São Francisco (BA) and samples from the Bom Jesus of Martírios Church (AL) were mapped. In this way, the XRD, XRF and SEM/EDS methods were applied. The mortars originating from the construction period of the works (18th and 19th century), mostly made of lime, had a porous microstructure, presence of medium silicon content, absence of chlorine, high calcium oxide content and little contamination. Those from subsequent restorations, mostly cementitious, presented dense microstructure, medium aluminum oxide content, high silicon dioxide content, low to medium calcium oxide content and contamination. It is suggested, therefore, that there be continuous documentary recording of interventions throughout the useful life of the building, to evaluate the performance of practices and thus obtain data with a view to improving processes and readjusting materials. In this sense, preparing detailed reports on the condition of the work before, during and after rehabilitation becomes essential.

Ultrafast Water Purification by Template-Free Nanoconfined Catalysts Derived from Municipal Sludge.

Nanoconfinement at the interface of heterogeneous Fenton-like catalysts offers promising avenues for advancing oxidation processes in water purification. Herein, we introduce a template-free strategy for synthesizing nanoconfined catalysts from municipal sludge (S-NCCs),specifically engineered to optimize reactive oxygen species (ROS) generation and utilization for rapid pollutant degradation. Using selective hydrofluoric acid corrosion, we create an architecture that confines atomically dispersed Fe centers within a micro-mesoporous carbon matrix in situ. This method maximizes the utilization of silicon and aluminum content from sludge, prevents metal agglomeration, andprecisely regulates the chemical environment of Fe active sites.As a result,the S-NCCs promote a transition from nonradical to hybrid radical/nonradical reaction mechanisms, significantly enhancing ROS efficiency, stability, and pollutant degradation rates. These catalysts demonstrate exceptional pollutant removal performance, achieving a 261-fold increase in degradation efficiency for compounds such as phenol and sulfamethoxazole compared to unconfined analogs, outperforming most state-of-the-art Fenton-like systems. Our findings highlight the transformative potential of nanoconfined catalysis in environmental applications, providing an effective and scalable solution for sustainable water purification.

Mononuclear Aluminum-Fluoride Ions, AlFx(+/-)-Study of Plausible Frameworks of Complexes with Biomolecules and Their In Vitro Toxicity.

The importance of fluorine and aluminum in all aspects of daily life has led to an enormous increase in human exposure to these elements in their various forms. It is therefore important to understand the routes of exposure and to investigate and understand the potential toxicity. Of particular concern are aluminum-fluoride complexes (AlFx), which are able to mimic the natural isostructural phosphate group and influence the activity of numerous essential phosphoryl transferases. Our review of salts of ionic AlFx species, which plausibly form the framework of complexes with biomolecules, revealed that the octahedral configuration of aluminum in the active site of the enzyme is preferred over the trigonal-bipyramidal structure. The effects of varying concentrations of fluoride, aluminum and AlFx-from micromolar to millimolar levels-on the viability and apoptosis rate of THP-1 monocytes were investigated using phosphate buffer solution as a culture media to simulate physiological conditions. Our results suggest that aluminum can reduce the direct toxicity of fluoride through the formation of AlFx. In view of the results found, further in vitro studies are required to clarify the toxicity mechanisms of these species.

Boron fertilization in a boreal Norway spruce forest: long-lasting effects on growth and nutrition

Abstract Background and aims Boron (B) deficiency is widespread in boreal forests, but it can be prevented by fertilization. As B deficiency reduces root growth, it may affect the uptake of other nutrients. We assessed the persistence of the effects of a one-time B application on growth and nutrition of Norway spruce (Picea abies). Methods A single-tree B-fertilization experiment was established in a highly productive stand in eastern Finland in 2000 and followed until 2018. The applied B dose was 2 kg ha−1. Results After 19 growing seasons, height growth was higher in B-fertilized trees and the effect was not waning. Diameter growth was not affected. The mean needle-B concentration without B fertilizer was 1.7 mg kg−1 and with B-fertilizer, 4.8 mg kg−1. Boron-fertilized trees had higher foliar aluminium (Al), carbon (C), copper (Cu) and sulfur (S) concentrations, and lower soluble silicon (Si). Conclusions The positive B effect on growth persisted after 19 years. Boron concentrations remained higher in fertilized trees, although lower than at the early stages of the experiment. Boron fertilization maintained Cu and S levels above deficiency limits. The small but consistent change in C indicates a change in needle compounds. Increased Al may result from reduced Si accumulation, as Al co-deposition with Si alleviates Al toxicity. Further studies are required to optimize B-fertilization practices and to elucidate the mechanisms behind the effects on height growth and the levels of other elements. A combination of soluble and sparingly soluble fertilizers could further increase the duration of the effect.

Purification of arsenic-contaminated drinking water by Fe-Al-CO3 layered double hydroxide derived from secondary aluminum dross: adsorption and stabilization studies

This study aims to utilize secondary aluminum dross waste to synthesize Fe-Al layered double hydroxide (Fe-Al LDH) for efficient adsorption of arsenic from drinking water. The synthesis process was based on a multi-step hydrometallurgical approach, in which the aluminum content in the waste was first converted to sodium aluminate. This was followed by the transformation into Fe-Al LDH through a series of processes, including gelation, sol formation, simultaneous precipitation, and aging. A suitable crystal structure of the LDH adsorbent was successfully synthesized at a Fe: Al molar ratio of 3, a pH of 7, and an aging time of 12 h. The characterization tests revealed that the synthesized Fe-Al-LDH had an interlayer space of 7.5 Å, a specific surface area of ​​145 m2/g, and a pore volume of 0.57 cm3/g. The resulting Fe-Al-LDH was then used to adsorb arsenic from aqueous solutions. The results showed that the amount of arsenic adsorbed by the LDH was 0.144 mg/g at room temperature, the adsorbent dose of 0.5 g/L, pH = 7 and the initial arsenic concentration of 80 µg/L. The Fe-Al LDH reduced the amount of arsenic in the water below the standard value after a period of 40 min. In addition, the results showed that the Fe-Al LDH can stabilize arsenic species in its structure and thus prevent their re-release into the environment.

A Novel (AlCrNbTaTi)N Multilayer Hard High-Entropy Alloy Nitride Coating with Variable Aluminum Content Deposited by Cathodic Arc Ion Plating

Traditional binary coatings like TiN and CrN display limited thermal stability and wear resistance under extreme conditions. High-entropy alloy nitride (HEAN) coatings offer a promising solution due to their customizable composition and unique properties, including high hardness, corrosion resistance, and thermal stability. This study focused on (AlCrNbTaTi)N HEAN coatings to address a critical need for materials capable of enduring extreme mechanical and tribological demands by examining the impact of aluminum content on their structural and mechanical properties, providing insights for optimizing coatings in harsh conditions through a self-assembled nanolayer structure with enhanced resilience and performance. The coatings were deposited via a cathodic arc by employing an AlCrNbTaTi alloy target composed of aluminum (20, 50, 60, 70%) and equal molar ratios of Cr, Nb, Ta, and Ti. The coatings were characterized through grazing incidence X-ray diffraction, SEM, HR-TEM, a nano-indentation test, and a friction and wear test. The results indicated that with increasing Al content, the structure of (AlCrNbTaTi)N coatings shifted from FCC to an amorphous state, leading to a reduction in the hardness and elastic modulus, accompanied by an increase in the wear rate and friction coefficient. The (AlCrNbTaTi)N coating, with an equal atomic ratio of metallic elements, showed potential as a hard tool coating. It demonstrated outstanding mechanical and tribological properties, with a 34.5 GPa hardness, 369 GPa modulus, 0.35 friction coefficient, and 8.2 × 10−19 m2·N−1 wear rate. The findings highlight the potential of (AlCrNbTaTi)N coatings to extend tool life and improve operational efficiency, helping advance materials engineering for industrial applications.

Monitoring and Prevention Strategies for Iron and Aluminum Pollutants in Acid Mine Drainage (AMD): Evidence from Xiaomixi Stream in Qinling Mountains

Acid mine drainage (AMD) generated during the exploitation and utilization of mineral resources poses a severe environmental problem globally within the mining industry. The Xiaomixi Stream in Ziyang County, Shaanxi Province, is a primary tributary of the Han River, which is surrounded by historically concentrated mining areas for stone coal and vanadium ores. Rainwater erosion of abandoned mine tunnels and waste rock piles has led to the leaching of acidic substances and heavy metals, which then enter the Haoping River and its tributaries through surface runoff. This results in acidic water, posing a significant threat to the water quality of the South-to-North Water Diversion Middle Route within the Han River basin. According to this study’s investigation, Xiaomixi’s acidic water exhibits yellow and white precipitates upstream and downstream of the river, respectively. These precipitates stem from the oxidation of iron-bearing minerals and aluminum-bearing minerals. The precipitation process is controlled by factors such as the pH and temperature, exhibiting seasonal variations. Taking the Xiaomixi Stream in Ziyang County, Shaanxi Province, as the study area, this paper conducts field investigations, systematic sampling of water bodies and river sediments, testing for iron and aluminum pollutants in water, and micro-area observations using field emission scanning electron microscopy (FESEM) on sediments, along with analyzing the iron and aluminum content. The deposition is analyzed using handheld X-ray fluorescence (XRF) analyzers, X-ray diffraction (XRD), and visible–near-infrared spectroscopy data, and a geochemical model is established using PHREEQC software. This paper summarizes the migration and transformation mechanisms of iron and aluminum pollutants in acidic water and proposes appropriate prevention and control measures.

Benchtop Machining of Self-Standing Alumina Doughs for Low-Number Fabrication and Prototyping.

Cold isostatic pressing, gel casting, and protein coagulation are the most common techniques to produce green bodies prior to computer numerical control (CNC)-based machining for the near-net-scale shaping of ceramics. These methods typically involve various additives and entail several steps to create a green body that is capable of withstanding machining forces. Here, utilizing a single additive, we first introduced a facile benchtop method to generate self-standing, malleable doughs of alumina in under 2 min. We then optimized the parameters of CNC machining to obtain surfaces with minimum surface roughness and produced custom-sized crucibles as a showcase for low-number production. To consolidate a dough from highly loaded suspensions of alumina, we employed a poly(ethylene glycol)-grafted random copolymer of acrylic acid and N-[3-(dimethylamino)propyl]methacrylamide at 0.75 wt % with respect to the weight of alumina powder. We surveyed machining parameters with spindle speeds ranging from 5000 to 30000 rpm and cutting speeds from 1000 to 1800 mm/min using 1 and 2 mm tool sizes. The highest surface quality, characterized by the minimal surface roughness as evaluated by profilometry, was achieved at a spindle speed of 20000 rpm and a cutting speed of 1200 mm/min with a 1 mm tool and at a spindle speed of 15000 rpm and a cutting speed of 1800 mm/min with a 2 mm tool. Upon sintering, the hardness of the machined samples was measured to be 15.16 ± 1.15 GPa. Additionally, we demonstrated the recycling of alumina (up to 30 wt % of alumina content) sourced from intentionally broken parts in the green state. The recycling scheme contributes to the lowering of the use of resources and emphasizes the possibility of a greener future for ceramic production on a broader scale. Overall, this cost-effective and easy-to-implement methodology starts at the materials formulation level and parametrization of the machining paves the way for immediate industrial adaptation.

Mechanisms of Rhizosphere Microorganisms in Regulating Plant Root System Architecture in Acidic Soils

Red soil occupies an important position in China's agriculturally cultivated land resources. However, its low pH value, high aluminum concentration, and inefficient phosphorus utilization limit the productivity of acidic red soil farmland. Plant roots exhibit remarkable plasticity, capable of absorbing water and nutrients and modulating root system architecture in response to biotic and abiotic stresses, either autonomously or through rhizosphere microorganisms. This study primarily investigates the regulatory effects of rhizosphere microorganisms, including plant growth-promoting rhizobacteria, such as arbuscular mycorrhizal fungi and rhizobia, and synthetic microbial consortia, on plant root system architecture. These regulatory mechanisms encompass the production of hormones, the release of volatile organic compounds, nitrogen fixation, phosphorus solubilization, and the improvement of rhizospheric soil structure. Such mechanisms can influence root biomass, branching, lateral roots, and root hair growth. Furthermore, we summarize new visualization methods for plant root system architecture and rhizosphere microorganisms, providing technical support for studying the regulation of root system architecture by rhizosphere microbes. Under acidic soil conditions, rhizosphere microorganisms serve as a crucial regulatory strategy. By adjusting plant root system architecture, they can enhance the productivity of acidic soils, representing a potential solution for ameliorating the constraints of acidic soils.

Experimental study on compression mechanical properties of functionally graded shape memory alloys

Functionally graded shape memory alloy (FG-SMA) hold considerable promise for diverse applications in aerospace and micro electro mechanical system (MEMS) fields, owing to their elevated ceramic hardness and distinctive phase transition characteristics. To investigate the mechanical properties and phase transition behaviors of FG-SMA, an FG-SMA specimen was fabricated for the first time using the spark plasma sintering and ball-mill mixing method. Subsequently, microstructure, phase transformation, hardness, compression fracture and shape memory effect testing experiments were carried out. The results revealed a microstructure of the FG-SMA without noticeable pores in the alumina content range of 0.1% to 0.6%. Alumina particles were effectively integrated into the NiTi matrix, enhancing the FG-SMA’s compressive strength. Varied alumina gradients in the FG-SMA cross-section led to distinct phase transitions. The addition of alumina increased the hardness of the NiTi matrix, resulting in higher fracture stress and strain in the FG-SMA. The elastic recovery strain of FG-SMA augmented with increasing alumina content, although the recoverable strain associated with the shape memory effect gradually decreased. This study provides valuable insights for the preparation, optimization, and practical applications of FG-SMAs. At the same time, the research in this article can lay an experimental foundation for the application of FG-SMA in the field of aerospace and MEMS.

IMPORTÂNCIA DOS ENSAIOS FÍSICO-QUÍMICOS NO CONTROLE DE QUALIDADE DE VACINAS

IMPORTANCE OF PHYSICAL-CHEMICAL TESTS IN VACCINE QUALITY CONTROL. The National Immunization Program (NIP), established in 1973, is recognized nationally and internationally as one of the largest vaccination programs in the world, integrated into the Unified Health System (SUS). Over the years, the NIP has faced challenges in vaccine quality control, leading to significant evolution, especially since 1983 when the National Institute of Quality Control in Health (INCQS) centralized this control. INCQS conducts biological, microbiological, and physicochemical assays, such as pH, appearance, aluminum content, and thiomersal, the latter present in multidose vaccines as a preservative. Retrospective analysis of physicochemical assays reveals variations in analysis quantities, often correlated with specific vaccination campaigns. The introduction of new vaccines in the NIP, such as the pentavalent and inactivated polio vaccines, impacted quality control. Regarding the pH and appearance of vaccines, assays demonstrate improvements over time, including the adoption of more sensitive and specific techniques. The implementation of visual inspection aspect analysis as a preventive measure after occurrences of unsatisfactory lots underscores the commitment to vaccine safety. Public laboratories, like INCQS, play a crucial role in this process, ensuring the safety of immunobiological for the entire Brazilian population. The current challenge lies in the need to keep up with technological advancements to maintain vaccine quality.

Effects of trimester-specific urinary aluminum concentrations on ultrasound measures of fetal growth and size at birth: A longitudinal cohort study in Chinese women.

Aluminum (Al) has been proposed as a potential factor influencing fetal growth. However, the existing study findings are inconsistent and there is a lack of population-based epidemiological studies. Our study aimed to evaluate the trimester-specific correlations of Al exposure with fetal development characteristics. Between 2013 and 2016, 3599 women from Wuhan, China were enrolled in the prospective cohort study. The concentrations of Al were quantified in urine samples obtained from pregnant women during the 1st, 2nd and 3rd trimesters by inductively coupled plasma mass spectrometry. The study used linear regressions with generalized estimating equation to determine the connections between specific gravity-adjusted urinary Al concentrations in each trimester and fetal growth parameters and birth size indicators. Trimester-specific Al exposure throughout pregnancy was found to have a negative impact on fetal growth and birth parameters. Besides, statistically significant interactions were detected between biparietal diameter (BPD) (Pinteraction = 0.007), head circumference (Pinteraction = 0.026) at 16 weeks' gestation in the first trimester, BPD (Pinteraction = 0.015) at 24 weeks' gestation in the second trimester, BPD (Pinteraction = 0.014) at 31 weeks' gestation in the second trimester and BPD (Pinteraction = 0.035) at 37 weeks' gestation in the third trimester and fetal sex, and the strength of the association between the level of Al exposure and BPD was significantly stronger in female fetuses than in male fetuses. Furthermore, we observed three distinct trajectories of trimester-specific Al concentrations during pregnancy. Compared to participants with low-stable group of Al concentrations trajectory, high-stable group was associated with more decrease level of fetal growth parameters and birth size indicators. Our study results reveal that Al might have harmful effects on fetal growth and birth size indicators, especially in female fetuses. Further study is required to examine our findings in other populations.

THERMODYNAMIC AND EXPERIMENTAL STUDIES ON THE INFLUENCE OF HIGH-ASH COAL IN THE PRODUCTION OF HIGH-CARBON FERROCHROME

This paper presents the results of scientific research that served as the foundation for developing a technology for producing high-carbon ferrochrome using a new reducing agent in the charge-high-ash coal from the "Saryadyr" deposit. To analyze the carbothermic reduction of chromium, a method of complete thermodynamic modeling (CTM) of metallurgical processes was employed, implemented using the HSC Chemistry 10.0 software package over a temperature range of 600-2800 K. The thermodynamic analysis demonstrated that the production of carbon ferrochrome using high-ash coal does not lead to sharp technological deviations: the process proceeds stably, ensuring complete reduction of chromium and iron. An analysis of the silica and alumina content in the coal ash indicated that it can replace quartzite in the charge mixture. Based on the thermodynamic data, experimental studies of the high-carbon ferrochrome production process using Saryadyr high-ash coal were conducted in a high-temperature Tammann laboratory furnace. The Tammann resistance furnace is a research facility designed to model metallurgical processes at high temperatures. During the laboratory tests, experimental samples of high-carbon ferrochrome corresponding to grade FeCr800 were obtained.