High Concentrations Of Ca Research Articles

The Geochemical Characteristics of Trace Elements in the Magnetite and Fe Isotope Geochemistry of the Makeng Iron Deposit in Southwest Fujian and Their Significance in Ore Genesis

The Makeng iron deposit in southwest Fujian is a significant iron polymetallic deposit containing various types of iron ore, including garnet magnetite, diopside magnetite, and quartz magnetite. The metallogenetic type of the deposit has been a subject of debate, particularly in relation to the genesis of magnetite and the source of iron. In situ microanalysis of trace elements in magnetite from different ores shows relatively low levels of V, Ti, Cu, and Zn, with higher concentrations of Ca and Si, indicating the characteristics of a skarn type deposit. The δ57Fe values of the magnetite range from −0.091‰ to 0.317‰. Combining these data, whole-rock iron isotope analyses, including Juzhou and Dayang granites, diabase, and the Lower Carboniferous Lindi Formation sandstone, suggest that Fe in the magnetite primarily originates from granitic pluton, with potential contributions from diabase and the Lower Carboniferous Lindi Formation sandstone. Combined with field work, these results indicate that Makeng iron deposit is a skarn-type magnetite deposit associated with Yanshanian granitic intrusions. Therefore, the initial ore-forming fluid is postulated to be a high-temperature magmatic hydrothermal fluid with high oxygen fugacity. This fluid infiltrates spaces such as interlayer fracture zones between the Upper Carboniferous Jingshe Formation–Middle Permian Qixia Formation carbonate rocks and the Lower Carboniferous Lindi Formation sandstone, resulting in diverse magnetite ores due to metasomatism. The mineralization process of the Makeng iron deposit is basically the same, as it is composed of typical skarn deposits. Magnetite was mainly formed during calcic skarn formation stage, and this process persisted until the initial phase of the retrograde alteration of skarns. In contrast, sulfide minerals, including molybdenite, sphalerite, and galena, precipitated during the quartz–sulfide stage.

Investigating the mechanism of formation of Ca-rich Ca[sbnd]Yb apatite that forms from the Yb-silicate–CMAS reaction at 1300°C

The formation mechanism and structure of Ca-rich CaYb apatite, which forms from the corrosion of Yb-silicate based coatings with CMAS at 1300°C in air for 48 h was investigated. X-ray photoelectron spectroscopy (XPS) was used to determine the bond type and oxidation states of the apatite. XPS data showed that the Si2p peaks are related to silicates, while the Ca2p and Yb4d are linked to apatite structures. The mechanism of growth for the apatite is proposed using the Wagner-Hauffe oxidation principle and the Kröger-Vink notations. The formation mechanism of the apatite-structure reaction phase is by substitutional diffusion, which is governed by the movement (formation and destruction) of point defects within the Yb2O3 lattice, particularly oxygen vacancies and electron holes. When Ca2+ substitutes Yb3+ in its lattice position, this results in the formation of anionic vacancies, which leads to more Ca2+ diffusion. The diffusion process continues until vacancies can no longer form to achieve electroneutrality, which leads to the newly formed Yb–Ca–Si being saturated with cations. Thus, based on this investigation, it is assumed that a CaYb silicate oxyapatite coatings can suppress the vacancy formation mechanism by containing high Ca and Si content which can thus decrease the ionic diffusion from CMAS melt into the EBC lattice. This can be the premises of a more CMAS-resistant coating family.

Hydrothermal transformation of fly ash to tobermorite or katoite: Impact of Ca and Si concentration in the liquid phase without alkali activation

In the study of hydrothermal conversion of fly ash to calcium silicate hydrates (C–S–H), the concentration of Ca and Si in the liquid phase plays a vital role in determining the hydrothermal transformation results. This paper selected a fly ash as a research object, which can leach a high Si concentration into the solution in the hydrothermal process even in a slight alkaline solution, based on a new finding when studying the alkali dissolution kinetics of different fly ashes. To explore the effects of Ca and Si concentrations in the liquid phase on the hydrothermal transformation of fly ash to tobermorite or katoite, Na2SiO3 (Na2O·xSiO2·yH2O) and CaSO4 were used to change the concentration of Si and Ca in the liquid in the hydrothermal system. Characterization methods such as XRD, SEM, infrared spectroscopy, and solid-state nuclear magnetic resonance indicated that a little more concentration of Si can promote the transformation from fly ash to tobermorite and persuade the conversion of the Si–O tetrahedron in C–S–H from Q2 to Q3 and Q4. However, too high a liquid Si concentration made the hydrothermal product change to colloidal calcium silicate. On the other hand, a high Ca concentration in the liquid was found to lead to the conversion of the hydrothermal product from tobermorite to katoite. According to the above results, the deep transformation from fly ash to tobermorite under the conditions of a low temperature of 160 °C and no extra alkali addition was achieved by the induction of a small quantity of Na2SiO3.

A step towards understanding plastic complexity: Antimony speciation in consumer plastics and synthetic textiles revealed by XAS

We identified the antimony species present in a wide variety of plastic samples by X ray absorption spectroscopy (XAS) at the Sb L3-edge. The samples contained different concentrations of antimony (Sb), ranging from PET bottles in which Sb compounds are used as catalysts, with concentrations around 300 mg/kg, to electrical equipment in which the element is used as a flame retardant, with concentrations of several tens of thousands of mg/kg. Although the shape of the spectra at the L3-edge is quite similar for all Sb reference materials, we were able to identify antimony glycolate or acetate in PET bottles, bound organic Sb in c-PET trays and senarmontite in electrical materials as the main Sb components. In samples with high Ca content (e.g., electrical objects, some c-PET food trays and textiles) the Ca Ka emission line interferes with the Sb La line by introducing a high background which reduces the signal-to-noise ratio in the Sb XAS spectrum, resulting in noisy and distorted spectra. The element-resolved map on a PET bottle sample revealed both Sb and Ca hot spots of around 10-20 microns in size, with no correlation.

A numerical study of CaCO3 deposition on the membrane surface of direct contact membrane distillation

This numerical study investigates the effect of CaCO3 deposition on the performance of direct contact membrane distillation (DCMD). It is the first numerical study to directly evaluate the deposition and film thickness of CaCO3 on the membrane surface. Therefore, a 3D computational fluid dynamics (CFD) model, which combines momentum, heat, species transport reaction, and the Eulerian wall film model, is used to analyze the CaCO3 mass deposition rate and scaling deposition thickness on the membrane surface. HSC Chemical Software is used to evaluate the ion compositions and reaction kinetics, including the activation energy (Ea) and pre-exponential factor (Ar). The CFD model is validated with experimental results. The results reveal that the CaCO3 deposition rate increases significantly at a high temperature, velocity, and salinity of the solution. The CaCO3 mass deposition increased by 15 times and scaling deposition thickness increased from 0.05 nm to 1 nm when the temperature was raised from 318.15 K to 348.15 K, whereas an increase of approximately 25 % in deposition was observed with an increase in velocity from 0.17 to 1.38 m/s at a concentration of calcium (Ca+2) ions, 0.03 % and bicarbonate (HCO3−) ions 0.004 %. The results also indicate that CaCO3 deposition decreases the flux and efficiency of the DCMD by 2 % with a low concentration of Ca+2 ions, 0.03 %, and HCO3− ions, 0.004 %. The findings indicate that the high feed salinity (75.23 g/l) increases CaCO3 mass deposition and scaling deposition thickness on the membrane surface due to the high concentration of Ca+2 ions, 0.07 %, and HCO3− ions, 0.01 %, significantly reducing the permeate flux by 14 %. The study's model development and implementation can be adjusted to offer guidance for studying the MD process in treating high saline water with fouling issues.

Developing a sorptive material of cadmium from pyrolysis of hen manure

A large amount of manure is generated from concentrated animal feeding operations (CAFOs), leading to serious environmental issues and hazardous risks from pathogens, such as methicillin-resistant Staphylococcus aureus. Therefore, developing an effective method for manure disposal is essential. Thus, in this study, we suggest the use of CO2 in pyrolysis of hen manure (HM) as an effective method to convert the carbon in HM into syngas (especially carbon monoxide (CO)). HM was used and tested as the model compound. From the results of thermo-gravimetric analysis, the decarboxylation of CaCO3 in HM in the presence of N2 was realized at temperatures ranging from 638 to 754 °C. The Boudouard reaction was observed at ≥ 664 °C in the presence of CO2. Despite the lack of occurrence of the Boudouard reaction, more CO formation was observed in the presence of CO2 at ≥ 460 °C. This was deemed as a homogeneous reaction induced by CO2. Considering the high Ca content of HM, HM biochar in N2 and CO2 were used as adsorbent for removal of Cadmium (Cd), which is toxic heavy metal. The adsorption capacities of HM_N2 and HM_CO2 were 302.4 and 95.7 mg g−1, respectively. The superior performance of HM_N2 is mainly attributed to the presence of Ca(OH)2, which provides favorable (alkaline) conditions for precipitation and ion exchange. Our results indicate the environmental benefits from using CO2. Specifically, CO2 (representative greenhouse gas) converted into fuel. Given this, pyrolysis of HM in the presence of CO2 was achieved at ≤ 640 °C, and the atmospheric condition should be switched from CO2 to N2 at ≥ 640 °C to ensure the decarboxylation of CaCO3.

Evaluation of the effect of calcium concentration in the wool of sires on se- men quality characteristics

Chemical elements, as structural components of the body, influence physiological processes and functions of the organism, growth, productive and reproductive traits, resistance and others. In this regard, the present study aimed to evaluate the effect of different calcium concentrations in the wool of Holstein sires on the semen quality characteristics. The studies were conducted in conditions of Leningrad and Vologda regions on Holstein sires, 3–5 years old (n = 40). Calcium concentration in wool was determined by atomic emission and mass spectrometry (AES–ICP and MS–ICP). According to the results of this analysis and comparison with previously developed reference intervals, we formed four groups of sires: I – level of Ca concentration less than 25th percentile, II and IV – within 25–75th percentile (physiological norm: 1597–2926 mg/kg) and III – more than 75th percentile. As a result of this distribution, the Ca concentration in the wool of animals of Group II was higher by 75.9 % compared to Group I; in turn, individuals of Group IV exceeded Group III – by 27.9 %. According to the results of semen quality characteristics evaluation, it was found that in the group of sires with Ca level within the previously developed reference intervals, the concentration of spermatozoa was higher by 15.3 % and their activity – by 0.17 points in fresh semen in comparison with the group with its reduced level (below the 25th percentile). High Ca content (above the 75th percentile) in wool contributed to a 9.0 % decrease in the concentration of spermatozoa compared to its average values. Thus, the calcium concentration, assessed by its level in the fur, affects the concentration and activity of sperm. It is necessary to evaluate it to improve the quality characteristics of sperm systematically.

Effects of Ca addition on microstructure, mechanical properties and corrosion behaviors of solution treated Mg-5Ga-xCa alloys

Effects of Ca addition on microstructure, mechanical properties and corrosion behaviors of solution treated Mg-5Ga-xCa (x = 0, 0.2, 0.5, 0.8 wt%) alloys are investigated. The Mg5Ga2 phase is almost dissolved into the matrix after solution treatment, while the residual phases mainly the Mg-Ga-Ca phase increases with the higher Ca content. The solution treated Mg-5Ga-0.2Ca alloy exhibits the highest corrosion resistance (with the average weight loss rate of 0.349 mg·cm−2·d−1 in Hank’s solution for 7 days) and the appropriate mechanical properties, with the ultimate tensile strength of 212 MPa and the elongation to rupture of 16.9%. Its high corrosion resistance can be mainly attributed to the protective effect of the Mg2Ca phase as a corrosion anode with low standard potential, the well-protected corrosion product film and the small grain size, while its good mechanical properties are due to the grain refinement and the solid solution strengthening of more Ga atoms. With a further increase in Ca content (≥0.5 wt%), although the grains are more refined, both the mechanical properties and corrosion resistance of the alloy decrease because of the residual phases in large quantities and low solution of Ga atoms.

Differences in the nutritional quality of improved finger millet genotypes in Ethiopia

Improved crop genotypes are constantly introduced. However, information on their nutritional quality is generally limited. The present study reports the proximate composition and the concentration and relative bioavailability of minerals of improved finger millets of different genotypes. Grains of finger millet genotypes (n = 15) grown in research station during 2019 and 2020 in Ethiopia, and replicated three times in a randomized complete block design, were analysed for proximate composition, mineral concentration (iron, zinc, calcium, selenium), and antinutritional factors (phytate, tannin and oxalate). Moreover, the antinutritional factors to mineral molar ratio method was used to estimate mineral bioavailability. The result shows a significant genotypic variation in protein, fat and fibre level, ranging from 10% to 14.6%, 1.0 to 3.8%, and 1.4 to 4.6%, respectively. Similarly, different finger millets genotypes had significantly different mineral concentrations ranging from 3762 ± 332 to 5893 ± 353 mg kg−1 for Ca, 19.9 ± 1.6 to 26.2 ± 2.7 mg kg−1 for Zn, 36.3 ± 4.6 to 52.9 ± 9.1 mg kg−1 for Fe and 36.6 ± 11 to 60.9 ± 22 µg kg−1 for Se. Phytate (308–360 µg g−1), tannin (0.15–0.51 mg g−1) and oxalate (1.26–4.41 mg g−1) concentrations were also influenced by genotype. Antinutritional factors to minerals molar ratio were also significantly different by genotypes but were below the threshold for low mineral bioavailability. Genotype significantly influenced mineral and antinutritional concentrations of finger millet grains. In addition, all finger millet genotypes possess good mineral bioavailability. Especially, the high Ca concentration in finger millet, compared to in other cereals, could play a vital role to combating Ca deficiency. The result suggests the different finger millet genotypes possess good nutrient content and may contribute to the nutrition security of the local people.

Cadmium (Cd) influences calcium (Ca) levels in the skeleton of a freshwater fish Channa gachua.

Environmental contamination with heavy metals is a threat to the organisms due to their toxicity, persistence and bioaccumulation in food chains. The study was aimed to assess cadmium (Cd) effect on calcium (Ca) level in bones of a freshwater fish Channa gachua. 42 fish individuals were kept into six (6) aquaria; labelled aq.0, 1, 2, 3,4 and 5 in the laboratory for treatment. Aq.0 was control group and aq.1, 2,3,4,5 were experimental with treatment solution of Cd 0, 0.1ppm, 0.5ppm, 1ppm, 2.5ppm and 5ppm respectively for three months. After exposure, bones tissue were examined for Cd accumulation and Ca concentration. Highest accumulation of Cd were recorded in aq.5 mean 46.86 ± 0.46 mgkg-1 .and lowest in the control group with mean 0.61 ± 0.06 mgkg-1. The order of Cd bioaccumulation in bones were aq.5 > aq.4 >aq.3 > aq.2 > aq.1 > aq.0. Highest concentration of Ca were noted in aq.0 (Control group) mean 7888.06 ± 4827.22 mgkg-1 and lowest were 1132.36 ± 203.73 mgkg-1 in aq.5 (at 5.0 ppm). Generally a pattern of decreasing Ca level were observed with each rise of Cd bioaccumulation aq.0 > aq.1 > aq.2 > aq.3 > aq.4 > aq.5. Current study indicated that Cd accumulation have substantial effect on Ca level in bones and hence on skeleton system. Strict rules must be implemented by government to control metals pollution and exploitations of biota.

Chemical assessment and spatial distribution of selected elements in aquatic sediments in the region of Peja (Kosovo)

In Kosovo, the supply of potable water from water sources is represented by about 40%. This study represents the geochemical analyses of sediments, spatial and statistical analyses of major elements in sediments (fraction < 63 µm) of water sources in the Drini i Bardhë River basin. For a better understanding of the geochemical consistency of sediments, inductively coupled plasma-mass spectrometry (ICP-MS) was used and the amounts of P and S were determined by inductively coupled plasma-optical emission spectrometry (ICP-OES). By comparing the concentrations of Ba, Se, and P with the existing criteria, it was found that 26 of 50 sample points exceed recommended norms, which cause low/significant toxic effects and 23 of 50 sample points include anomalies of the analyzed elements. In terms of statistical interpretation, the average concentration of the studied elements decreased in such order: Ca > Al > Mg > K > S > P > Na > Ba > Sr > Li > Rb > B > Ga > Cs > Be > Se. In terms of correlation analyses, elements such as Li, Be, Mg, P, and Ba did not show a significant positive correlation with any element. Cluster analysis of R-modality shows a branch of dendrogram linked with Ca, Al, Mg, S, K, P, Na, Ba, Sr, Cs, B, Ga, Se, Be, Rb, and Li. Spatial distribution maps of major elements show that high concentrations of Li, Ca, and Ba were located mostly in the northern part, high concentrations of B, Na, Mg, Sr, and Cs were located in the north-east part, high concentrations of Be and Al were located in the north and south part and high concentrations of P, S, K and Rb were located mostly in the south-east part of the catchment basin. This high concentration of elements is impacted by the lithology of rocks and by the minor influence of human activity (the case of P).

Quality of Soils in Soybean Producing Areas in Caraga Region

This study aims to determine the soil quality of selected soybean producing farms in the Caraga region using soil quality index (SQI) measurements. Five sites were selected in the municipalities of San Miguel, Surigao del Sur and Trento, Agusan del Sur. Three 10×10 m soil monitoring plots were established within soybean fields in each site. Within each monitoring plot, three composite samples were collected coming from 10 subsamples using a soil probe. SQI was calculated following three general steps, (1) selection of minimum dataset (MDS) via Principal Components Analysis (PCA), (2) Scoring of MDS via linear method, and (3) Calculation of weighted overall SQI. Out of the 16-soil property indicator, a total of five soil properties (exchangeable Ca, % Sand, Electrical conductivity, available P, and Soil respiration) were extracted and used as the MDS for the calculation of SQI in each site. The main indicator properties for determining the quality of the soils in the area were Exchangeable Ca and % Sand contents offering a 68% and 26% weights over other soil properties, respectively. High SQI classification was found on four out of five sites evaluated, these were the two sites in the Municipality of Trento (Cebolin.M (61%) & Cebolin.T (54%)) and two sites in the Municipality of San Miguel (Libag-Gua (68%) & Upper Carromata (93%)). One site in San Miguel revealed a low SQI (Lower Carromata (41%)). These SQI values indicate that in these areas, soils with very high Exchangeable Ca and Sand content could have a low-quality condition, and sites with optimal Exchangeable Ca (400 - 600 ppm) contents and loamy to sandy loam texture could be classified as high quality soils. Proper drainage system could be best done to manage the very high exchangeable Ca content in these soil and thus, could improve its quality.

Comparative evaluation of phytochemical, in vitro antioxidant activities and elemental composition of the fruit, leaves, and stem bark of Tetrapleura tetraptera

Introduction: Nowadays, medicinal plants are widely accepted as a better option than synthetic medications due to their lower cost and little to no side effects. The current study aimed to compare the elemental composition, phytochemical profile, and antioxidant efficacy of n-hexane extracts derived from Tetrapleura tetraptera fruit, stem bark, and leaves. Methods: The fresh fruits, leaves, and stem bark of the plant were collected and dried. The dried samples were pulverized and exhaustively extracted with n-hexane. The extracts were screened for both qualitative and quantitative phytochemical constituents. Antioxidant parameters such as Ferric Reducing Antioxidant Property (FRAP) and 2,2-Diphenyl-1-picryl hydroxyl radical scavenging activity (DPPH) were also carried out. The elemental analysis of the various organs was also evaluated using standard protocols. Results: The presence of alkaloids, flavonoids, tannins, saponins, terpenes, resins, and phenolswas revealed in the phytochemical data. The stem bark of T. tetraptera has higher concentrations of alkaloids and flavonoids than the leaf and fruit, according to a quantitative examination of the phytochemical elements of the plant. The stem bark had the highest Total Phenolic Content at 1000 µg/mL, whereas the leaves had the lowest TPC at 200 µg/mL.At a concentration of 1000 µg/mL, the stem bark exhibited the greatest activity of total flavonoid (TFC) in the plant extracts, followed by the fruits and leaves. At 1000 µg/mL concentration, the FRAP test revealed the maximum activity in the stem bark. Generally speaking, when concentration rises, so do the TPC, TFC, and FRAP activities. Compared to the standard ascorbic acid (2.76 µg/mL), stem bark exhibited the highest level of DPPH antioxidant activity, with an IC 50 of 13.34 µg/mL. The elemental analysis revealed that the stem bark had the highest concentrations of Ca, Mg, and Fe, followed by the fruit and leaves, in that order.Conclusion: This research result has established that the plant, T tetraptera can be standardized and offer an alternative eco-friendly drug for immunity building. The stem barks are underutilized, however, its phytochemical studies and other investigations pointed to its potential in the cosmeceutical industries and medicine. Keywords: Antioxidant activity, ethnomedicine, ferric-reducing assay, medicinal plant

Metallurigical Analysis of Third to Fifth Century Swords with Ring Pommels Excavated in the Asan-Cheonan Region

This study conducts a metallurgical analysis of three swords with ring pommels (Hwandu sword) manufactured during the Proto–Three Kingdoms period and the Baekje period and excavated from the Asan and Cheonan. Specifically, we carried out analyses based on a metallurgical microscope, scanning electron microscopy with energy dispersive spectroscopy. the swords were made of bloomery iron produced through direct smelting and formed by hammering hypoeutectoid steel. It was also confirmed that other heat treatment techniques than shaping were not applied to them. In addition, all of them have a high carbon content and the crystal grains are well refined, so it is believed that the hardness and strength are high. Moreover, the analytic results of nonmetallic inclusions, No.2 swords have glassy slag and the others verified the existence of fayalite and wüstite on the glassy matrix. And a high Ca content overall. The results of comparing the swords with other swords with ring pommels excavated from the corresponding region indicated that heat treatment techniques were not applied to these artifacts despite the existence of such techniques. Thus, we analyze that the study subjects were produced as ceremonial items rather than weapons. Furthermore, the calculation results of ratios, such as CaO/SiO<sub>2</sub> and (Al<sub>2</sub>O<sub>3</sub>/SiO<sub>2</sub>)/(CaO/SiO<sub>2</sub>), indicate that the study subjects were produced based on a similar smelting processing system. Based on the analytic results, this study also suggests a possibility of the addition of slag generation agents or the use of iron ores with a high Ca content.

Geochemical proxies of the gryphon breccia of mud volcanoes in East Azerbaijan: regularities in the distribution of chemical elements and spatial characteristics of sedimentation

The paper is devoted to the study of the patterns of distribution of major oxides and trace elements in the gryphon breccia of 12 active mud volcanoes located in various oil and gas regions (Absheron, Gobustan and Lower Kura) of Azerbaijan. Interpretations of the chemical elements found in gryphon breccia samples have allowed the composition of their source rocks, sedimentation conditions, and sedimentation areas to be determined. Purpose. The main goal of the study is to conduct geochemical studies of gryphon breccias belonging to various oil and gas regions, determine spatial patterns, achieve their explanation, and at the same time determine the conditions for the deposition of mud sediments. Methods. The chemical composition of mud volcanic breccia samples was analyzed using an “S8 TIGER Series 2” spectrometer and an “Agilent 7700 Series ICP-MS” mass spectrometer. Based on the results obtained, in addition to identifying patterns in the areas, modern approaches based on geochemical interpretation were used to explain them. The results on the genesis of breccias are consistent with the results of the published literature on the development of geodynamic and paleobasin conditions in the region. Results. Samples with the lowest Si content are characteristic of the Lower Kura mud volcanoes, where the youngest (Quaternary) deposits are recorded. In samples from these mud volcanoes, relatively high contents of Mg and P are also noticeable. High contents of Ca are characteristic of volcanoes located near the Caspian Sea. These mud volcanoes are also rich in trace elements such as Li, Ga, Rb, Zr, Mo, Cs, Pr, Tl, Pb, Th, U and others, but depleted in Ni, Sr, Ba and etc. Conclusions. Plagioclase-rich source rocks and oxygen-dominated paleobasin environments played a key role in the formation of breccia deposits belonging to the mud volcanoes of Azerbaijan. Geochemical proxies make it possible to link the paleobasin conditions of the formation of the gryphon breccia of the most mud volcanoes of South and Central Gobustan with the continental setting, especially in comparison with some volcanoes of the Lower Kura, as well as Gobustan and Absheron, located on the shores of the Caspian Sea and relatively close to it. The breccias of mud volcanoes located at a relatively large distance from the modern sea boundary and in the steepest northern part of the Lower Kura are associated with marine conditions, as are breccias of mud volcanoes located in the south of this tectonic zone (subjected to intense subsidence) and at a short distance from the Caspian Sea, may be due to geological factors.

Sol-gel derived B2O3-CaO borate bioactive glasses with hemostatic, antibacterial and pro-angiogenic activities.

Sol-gel borate bioactive glasses (BGs) are promising ion-releasing biomaterials for wound healing applications. Here, we report the synthesis of a series of binary B2O3-CaO borate BGs (CaO ranging from 50 to 90 mol%) using a sol-gel-based method. The influence of CaO content in B2O3-CaO borate BG on morphology, structure and ion release behavior was investigated in detail. Reduced dissolution (ion release) and crystallization could be observed in borate BGs when CaO content increased, while the morphology was not significantly altered by increasing CaO content. Our results evidenced that the ion release behavior of borate BGs could be tailored by tuning the B2O3/CaO molar ratio. We also evaluated the in vitro cytotoxicity, hemostatic, antibacterial and angiogenic activities of borate BGs. Cytocompatibility was validated for all borate BGs. However, borate BGs exhibited composition-dependent hemostatic, antibacterial and angiogenic activities. Generally, higher contents of Ca in borate BGs facilitated hemostatic activity, while higher contents of B2O3 were beneficial for pro-angiogenic activity. The synthesized sol-gel-derived borate BGs are promising materials for developing advanced wound healing dressings, given their fast ion release behavior and favorable hemostatic, antibacterial and angiogenic activities.

Extractability indices for screening coal combustion byproduct feedstocks for recovery of rare earth elements

A simple, standardized test is needed to screen coal combustion byproducts to determine their suitability for large-scale extraction and recovery of rare earth elements (REE). An ideal commercial process for acid extraction of the lanthanides will employ short residence times with no external heating of the reactor, and minimum quantities of a commodity acid. In this work, a rapid screening test mimicking these conditions was established by using (1) 2 M hydrochloric acid at (2) 20:1 Liquid: Solid ratio and (3) ambient temperature with (4) a reactor residence time of 15 min. The test was applied to seventeen different fly, bottom, landfilled or ponded ashes. REE recovery is directly correlated with Ca and Mg content, and inversely correlated with particle size. Fly ashes derived from sub-bituminous coals are ideal feedstocks due to their relatively high Ca content (> 10%) and small particle sizes, leading to as high as 73% REE recovery after only a 15-min leaching at room temperature with 2 M HCl. After a brief grinding step to break up agglomerates that may be >1 cm in diameter, REE recovery from ponded ash of up to 71% is achieved.

Evaluation of photobiomodulation therapy (PBMT) on salivary flow and composition in head and neck cancer patients undergoing radiation therapy

Assess the impact of photobiomodulation therapy (PBMT) on xerostomia, salivary flow rate (SFR) and composition in patients undergoing radiotherapy (RT) for head and neck cancer (HNC). Thirty patients undergoing RT (65 Gy) for HNC were enrolled. Saliva and xerostomia evaluations collected pre- and post-PBMT-RT. PBMT involved irradiation of extra and intraoral points, 15-20 sessions, 2-3 times/week. SFR, trace elements, total protein, alkaline phosphatase, xerostomia, and pH were analyzed. The average age was 60.7 years. After treatment, there was not a significant reduction in SFR and there was no difference on xerostomia. Significant reductions in Al, Cd, Fe, Ni, P, and Sb concentrations were observed, along with a significant increase in Mg concentration. Sample data were organized into 3 groups based on a self-organizing map. Low concentrations of Al, As, Co, Cr, Cu, Fe, Mn, Mo, S, Sr, and Zn were the primary discriminatory factors for group A, while group B consisted of post-PBMT-RT samples with high concentrations of Ca, K, Mg, Na, and S. PBMT prevented a significant reduction in SFR and xerostomia induced by radiation therapy. These findings suggest that PBMT prevents salivary gland damage minimizing the decline in salivary flow.

Acid controlled washing of municipal solid waste incineration fly ash: Extraction of calcium inhibiting heavy metals and reaction kinetics

Washing method has attracted much attention in the research of municipal solid waste incineration (MSWI) fly ash treatment and resource utilization. However, the controlled leaching of heavy metals and the extraction of recyclable calcium in the washing process are still blank. Acid controlled washing was conducted with different acids, concentrations, times and temperatures to extract calcium while inhibiting heavy metals. The mechanism was investigated by reaction kinetics calculation and washed fly ash characterization. The high Ca concentration of 37,420 mg/L while the low heavy metal concentrations of around or <1 mg/L were achieved at 25 °C for 60 min under a liquid-solid ratio (L/S) of 3/1 in 1.5 M HCl. The reaction kinetics of acid controlled washing conformed the layer diffusion control. The results of X-ray diffraction (XRD), scanning electron microscope (SEM) and energy dispersive spectrum (EDS) analysis indicated that the rate-limiting step was the diffusion of ions through the product layer. Simultaneously, the washing solution enriched in Ca, Na and K and the washed fly ash, which met the standard requirements (HJ 1134–2020) for leach toxicity, both had the potential for further resource utilization.

Elemental concentrations of seven types of green vegetables grown on small-scale farmlands in rural areas of Japan: Differences according to the type and place of production

We collected seven types of green vegetables produced in 11 areas of Japan and analyzed their elemental concentrations. Halogen analyses were performed with and without prior chemical treatment. The most popular type of spinach exhibited the highest concentrations of Mg, K, and Zn, and the lowest concentrations of alkaline earths (Ca and Sr) and halogens (Cl and Br). Japanese mustard spinach, the second most consumed type of spinach in Japan, exhibited the highest concentrations of P, S, Ca, Fe, and Br and adequate amounts of other essential elements. The other five green vegetables had unique elemental concentrations. In particular, radish had the highest concentrations of Ca, Na, and Cl and the lowest concentrations of Mg, P, Cu, and Zn. Leaves and stalks were separately analyzed. Fe, Cu, Zn, and Mn concentrations tended to be higher in leaves, and K, Na, and Rb concentrations were higher in stalks. Halogen (Cl and Br) concentrations in Japanese mustard spinach produced on farmland near the coast were remarkably high, suggesting an effect of sea salt. However, even in green vegetables produced near the coast, halogen uptake clearly differed by production area. The concentrations of Cl and Br in Japanese mustard spinach produced in two coastal areas were very high and were not removed by washing, but were mostly lost after boiling samples from Taneichi for 3[Formula: see text]min. In contrast, there was no difference in Na concentrations among vegetables produced in coastal and inland areas. The concentrations of essential elements such as Mg, Ca, and Fe were clearly higher in green vegetables from small- versus large-scale production areas, perhaps attributable to differences in the farming methods employed.