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BACKGROUND: Infection rates in revision total hip arthroplasty are lower when antibiotic loaded cemented stems are utilized. Inspired by this technique, a point-of-care coating of antibiotic-loaded calcium sulfate (CaSO4) was applied to cementless revision stems in aseptic revision and 2nd stage reimplantation total hip arthroplasty. METHODS: One hundred eleven consecutive femoral stems were coated. Just prior to insertion, 10 cc of CaSO4 was mixed with 1 g vancomycin and 240 mg tobramycin with the paste applied to the stem. The results were compared to a matched cohort (N = 104) performed across the previous 5 years. The surgical methods were comparable, but for the stem coating. The study group was followed for a minimum of 3 years. RESULTS: In the study cohort of 111 patients, there were 69 aseptic revisions with one periprosthetic joint infection (PJI) (1.4%) and 42 second-stage reimplantations with 2 PJIs (4.8%). In the control cohort of 104 patients, there were 74 aseptic revisions with one PJI (1.4%) and 30 second-stage reimplantations with 7 PJIs (23.3%). There was no significant reduction in PJI rate in the aseptic revision subgroup (1.4% study vs 1.4% control group), P = 1.000. Antibiotic stem coating reduced PJI rate in the 2nd stage reimplantation subgroup (23.3% control vs 4.8% study group), P = .028. In both groups, there were no cases of aseptic stem loosening. CONCLUSIONS: Point-of-care antibiotic coating of cementless revision femoral stems reduces PJI infection rate in 2nd stage reimplantations only. We theorize that microbes persist in the endosteal cortices after resection and may contribute to infection recurrence.

Phosphogypsum is a waste by-product of phosphate fertilizer production. It contains calcium sulfate (CaSO4.xH2O), which can be decomposed to produce calcium oxide (CaO) and sulfur dioxide (SO2). Steam calcination is a process that uses steam to decompose CaSO4. This study represents the first comprehensive investigation of steam calcination applied to phosphogypsum, comparing its performance to pure CaSO4 at various temperatures (1050–1200 °C) and steam molar ratios (0, 4%, and 30%). The results showed that steam calcination can significantly lower the calcination temperature of both CaSO4 and phosphogypsum. The presence of steam can significantly accelerate the decomposition reaction of pure CaSO4 and phosphogypsum when compared to decomposition in nitrogen or air. It was found that the decomposition reaction in steam follows the contracting cylinder reaction model in the case of CaSO4 and the first-order reaction model for the phosphogypsum. Additionally, the activation energy for the steam calcination of CaSO4 and phosphogypsum were found to be 421.2 kJ/mol and 418.6 kJ/mol, respectively, which are lower than the activation energy for the calcination in oxyfuel combustion products (O2, CO2, SO2, and H2O gases) 531.4 kJ/mol demonstrating its potential for enhanced energy efficiency. As a result, steam calcination emerges as a promising sustainable solution for valorizing phosphogypsum while reducing energy consumption and greenhouse gas emissions. [ABSTRACT FROM AUTHOR]

Ionic interactions affect the mineral composition of plants, which can cause nutritional disorders with reflections on yield, post-harvest quality, and food safety. Thus, this study evaluated the interaction between nitrogen (N) and sulfur (S) and its effects on onion production and post-harvest quality. The study was conducted in a completely randomized design, with a 3 × 5 factorial scheme and four replications. The treatments consisted of a combination of three S rates (0, 20, and 40 mg dm−3) and five N rates (0, 40, 60, 80, and 100 mg dm−3), applied in the form of calcium sulfate (CaSO4·2H2O) and urea, respectively. It was observed that the interaction between N and S negatively affected onion production, reducing the gain of both fresh and dry mass of the bulb. The N/S ratio ranged from 16.5 to 26.2 and was not influenced by the interaction between N and S. Onion pungency was classified as intermediate. The higher pungency value was obtained with the application of 100 mg dm−3 of N, and 40 mg dm−3 of S. The application of N when combined with 20 mg dm−3 of S contributed to increasing titratable acidity and soluble solids content of onion cv. Diamantina. [ABSTRACT FROM AUTHOR]

Plants are able to produce various types of crystals through metabolic processes, serving functions ranging from herbivore deterrence to photosynthetic efficiency. However, the structural analysis of these crystals has remained challenging due to their small and often imperfect nature, which renders traditional X-ray diffraction techniques unsuitable. This study explores the use of Microcrystal Electron Diffraction (microED) as a novel method for the structural analysis of plant-derived microcrystals, focusing on Armeria maritima (Milld.), a halophytic plant known for its biomineralisation capabilities. In this study, A. maritima plants were cultivated under controlled laboratory conditions with exposure to cadmium and thallium to induce the formation of crystalline deposits on their leaf surfaces. These deposits were analysed using microED, revealing the presence of sodium chloride (halite), sodium sulphate (thénardite), and calcium sulphate dihydrate (gypsum). Our findings highlight the potential of microED as a versatile tool in plant science, capable of providing detailed structural insights into biomineralisation processes, even from minimal and imperfect crystalline samples. The application of microED in this context not only advances the present understanding of A. maritima's adaptation to saline environments but also opens new avenues for exploring the structural chemistry of biomineralisation in other plant species. Our study advocates for the broader adoption of microED in botanical research, especially when dealing with challenging crystallographic problems. [ABSTRACT FROM AUTHOR]

The hydration of high-alkali red mud-based ferroaluminate cement (RCFA) clinker with calcium sulfate needs to be regulated. This study explored the effects of the calcium sulfate type and dosage on the hydration and properties of high-alkali RCFA clinker. The research results show that when 4% gypsum was added, the 3 d compressive strength of cement was 39.1 MPa, and the 28 d compressive strength was 63.2 MPa. The 28 d strength increased by 61.6% compared with the 3 d strength. The properties of cement paste can be adversely affected by excessive anhydrite content. The exothermic hydration of clinker was accelerated by calcium sulfate at the beginning, but the rate declined as the process progressed. Sufficient sulfur supply can enhance the hydration of ye'elimite, thereby increasing the AFt content in the hydration product. The mass loss of the hydration product is mainly caused by the dehydration of ettringite, monosulfoaluminate, and AH3. In addition, the Na element in the RCFA hydration product is mainly present in monosulfoaluminate and unhydrated cement particles. [ABSTRACT FROM AUTHOR]

Background: Bone grafts are extensively used for repairing bone defects and voids in orthopedics and dentistry. Moldable bone grafts offer a promising solution for treating irregular bone defects, which are often difficult to fill with traditional rigid grafts. However, practical applications have been limited by insufficient mechanical strength and rapid degradation. Methods: This study developed a ceramic composite bone graft composed of calcium sulfate (CS), β-tricalcium phosphate (β-TCP) with/without graphene oxide (GO) nano-particles. The biomechanical properties, degradation rate, and in-vitro cellular responses were investigated. In addition, the graft was implanted in-vivo in a critical-sized calvarial defect model. Results: The results showed that the compressive strength significantly improved by 135% and the degradation rate slowed by 25.5% in comparison to the control model. The addition of GO nanoparticles also improved cell compatibility and promoted osteogenic differentiation in the in-vitro cell culture study and was found to be effective at promoting bone repair in the in-vivo animal model. Conclusions: The mixed ceramic composites presented in this study can be considered as a promising alternative for bone graft applications. [ABSTRACT FROM AUTHOR]

This article presents the results of deformation characteristics and crack stress thresholds of cement stone under different acid treatment times. A series of true triaxial tests were conducted on cement stones under four sulfuric acid treatment times (0, 7, 14, and 28 days). The microstructures of cement stone under different acid treatment times were examined. In the range of 0 to 14 days, the damaging effect of sulfuric acid dominated, and the structural integrity was damaged by sulfuric acid. In the range of 14 to 28 days, the strengthening effect of calcium sulfate precipitate dominated, and the structural integrity was enhanced by calcium sulfate precipitate. The cement stone exhibited anisotropic deformation characteristics under true triaxial stress states. With an increase in acid treatment time, the deformation modulus of cement stone first decreased and then slightly increased. The crack stress thresholds first increased and then decreased with an increasing intermediate principal stress coefficient. With an increase in acid treatment time, the crack stress thresholds first decreased and then slightly increased. Substantially, the ratio of crack stress thresholds was analyzed. The proportion of the unstable crack growth stage and crack growth stage increased with minimum principal stress. Additionally, the proportion of the unstable crack growth stage and thecrack growth stage first increased and then decreased with increasing acid treatment time. However, the proportion of the stable crack growth stage had the opposite variation law to that of the unstable crack growth stage and crack growth stage. [ABSTRACT FROM AUTHOR]

The early stages of mineralization continue to be in the focus of intensive research due to their inherent importance for natural and engineered environments. While numerous observations have been reported for single steps in the pathways of various crystallizing phases in previous studies, the complexity of the underlying processes and their elusive character have left central questions unanswered in most cases. In the present work, we provide a detailed view on the nucleation of calcium sulfate mineralization—an abundant mineral with broad use in construction industry—in aqueous systems at ambient conditions. As experimental basis, a co‐titration procedure with potentiometric, turbidimetric and conductometric detection was developed, allowing solution speciation and the formation of crystallization precursors to be monitored quantitatively as the level of nominal (super)saturation gradually increases. The nature and spatiotemporal evolution of these precursors was further elucidated by time‐resolved small‐angle X‐ray scattering (SAXS) and analytical ultracentrifugation (AUC) experiments, complemented by cryogenic transmission electron microscopy (cryo‐TEM) as a direct imaging technique. The results reveal how ions associate into nanometric primary species, which subsequently aggregate and develop anisotropic order by intrinsic structural reorganization. Our observations challenge the common understanding of fundamental notions such as the nucleation barrier or the meaning of supersaturation, with broad implications for mineralization phenomena in general and the formation of calcium sulfate in geochemical settings and industrial applications in particular. [ABSTRACT FROM AUTHOR]

Selective control over crystallization in complex multicomponent systems such as hydrating cements is a key issue in modern material science. In this context, rational selection‐based approaches appear highly promising in the quest for new additive chemistries. Here we have used phage display to identify peptide structures showing high affinity to adsorb on the surfaces of calcium sulfate hemihydrate (also referred to as bassanite), an important hydraulic binder employed in large scales by the construction industry. The results suggest a triplet of amino acids consisting of aspartic acid, serine and leucine, to maintain strong interactions with the surfaces of hemihydrate particles. This notion is confirmed by actual hydration experiments, in which the identified peptide motif provides strictly selective effects during the transformation of bassanite into more stable gypsum. Our work thus contributes to a better understanding of hydraulic binders and their required improvement for a sustainable future. [ABSTRACT FROM AUTHOR]

The medical management of osteoarticular infections in patients with diabetes continues to be a considerable clinical dilemma because of inadequate blood supply and weakened immune systems. The objective of this study is to assess the effectiveness of dissolvable synthetic pure calcium sulfate beads with antibiotics in the treatment of osteoarticular infections in individuals diagnosed with diabetes mellitus. A retrospective analysis was conducted on 27 patients with diabetes (19 with type II diabetes and 8 with type I diabetes) who were diagnosed with osteoarticular infections and received treatment with locally delivered antibiotic-loaded calcium sulfate beads. The patients were monitored for a duration ranging from 6 months to 2 years, during which the clearance of infection, bone remodeling, and rates of recurrence were evaluated. The evaluation also included an assessment of glycemic control and its influence on infection treatment. The findings revealed a notable decrease in the recurrence of infections, as patients who were given combinations of two antibiotics showed better results in comparison to those who were exclusively treated with one antibiotic. A 92% eradication rate was achieved within the trial group, and patients who had dual-antibiotic treatment did not have any return of illness. Postoperative bone remodeling was shown to take place between 8 and 16 weeks, with faster recovery in individuals who maintained ideal glycemic control (HbA1c < 7%). Only one instance of soft tissue necrosis was documented, indicating minimal consequences. The results validate the use of dissolvable synthetic calcium sulfate as a secure and efficient local antibiotic administration method for controlling osteoarticular infections in patients with diabetes, providing improved infection management and facilitating bone regeneration. [ABSTRACT FROM AUTHOR]

Background: medical teams continue to face challenges with infections following hip replacement surgery, whether they occur shortly after the procedure or months or years later. Certain medical conditions like diabetes, rheumatoid arthritis, and obesity are risk factors that make patients more susceptible to infections. Traditional intervention methods such as DAIR, one-step, or two-step procedures are being enhanced and refined to ensure quicker and more effective treatment. Some cases present particularly difficult challenges, featuring persistent fistulas and unpredictable responses to treatment. Methods: in our article, we share two unique cases, detailing their histories, progressions, and treatment decisions. We explore the use of antibiotic-impregnated calcium biocomposite as a local adjuvant therapy and the application of negative pressure therapy to expedite healing. The system of NWPT has seen widespread uptake and is now implemented routinely for open wounds, such as open fractures, fasciotomies, ulcers, and infected wounds. Results: our findings demonstrate that surgical debridement and calcium sulfate bead insertion successfully treat bone and joint infections without causing any side effects or complications. As a particularity, in the first case, we encountered the exteriorization of Stimulan pearls after surgery, without other complications related to the biocomposite. Conclusions: we have found that NPWT is a beneficial tool in managing complex wounds in both acute and chronic stages, after the infection is cured, reducing the need for frequent dressing changes, shortening hospital stays, and enhancing patient comfort. [ABSTRACT FROM AUTHOR]

Nine copolymers of acrylic acid and sodium methallyl sulfonate were tested as scale inhibitors in thermal desalination. The nine antiscalants covered molar masses between 2000 and 9500 g.mol–1 and concentrations of sulfonated monomer ranging between 10 and 30 mole percent. A pressure measurement and control (P-MAC) unit and a high-temperature pressurized vessel were used to measure the effectiveness of the scale inhibitors in seawater, concentrated seawater, and model solutions at 125 °C. The effectiveness of the novel copolymers was comparable to commercial antiscalant at times up to 15 min and improved at longer times. Molar mass was a more important determinant of effectiveness than degree of sulfonation, with the greatest mitigation of calcium sulfate precipitation observed for antiscalants of molar mass 2000 to 2500 g.mol–1 regardless of sulfonate content. Antiscalants of molar mass 4500 to 5000 g.mol–1 showed a higher threshold effect than antiscalants of molar mass 7000 to 9500 g.mol–1, with a 30% sulfonated polymer of molar mass 4500 g.mol–1 performing appreciably better than other polymers of a similar molar mass. [ABSTRACT FROM AUTHOR]

The Fe2O3CaOTiO2BaSO4 system is established through miniature sintering experiments to reveal the mechanism of BaSO4 and vanadium‐titanium magnetite (VTM) with the help of X‐ray diffraction, scanning electron microscope and energy dispersive spectroscopy, and thermogravimetry. The results show that in the absence of BaSO4, the phase of the sinter consists of CaFe2O4, TiO2, Fe2O3, CaTiO3, and CaFe2O5. When the content of BaSO4 is 1% and 2%, CaTiO3 decreases and the number of needle‐like CF increases. Some Ba2+ solidly dissolve into CF and CaTiO3 to form trace BaFe12O19 and BaTi2O5. When the content of BaSO4 increases to 4%, the CaSO4 phase appears, the formation of C2F is accelerated, and the content of CF and CaTiO3 continues to decline. The needle‐like calcium ferrate gradually transforms into columnar and lamellar. As the BaSO4 content continues to increase to 6% and 8%, although the trend of each phase is similar to that at 4%, it is almost entirely composed of columnar calcium ferrite, barium ferrite, and incomplete tetragonal and rhombic Fe2O3. The results of the study provide a theoretical basis for the utilization of VTM and barium‐containing iron ores in practical production. [ABSTRACT FROM AUTHOR]

Summary: Tofu, a traditional soy‐based food, is widely consumed globally and serves as a significant source of plant protein. The quality of tofu can vary greatly depending on the coagulation process and the type of coagulants used. This study investigated the impact of a compound coagulant, consisting of transglutaminase (TGase) and calcium sulfate (CaSO4), on tofu quality, specifically focusing on pH, yield, water holding capacity (WHC), cooking loss, protein content, and in vitro digestibility. Soymilk was pre‐crosslinked with TGase for different durations (0, 1, 2, and 3 h) before the addition of CaSO4. Results indicated that TGase pre‐treatment significantly improved tofu yield and WHC, with optimal outcomes at 3 and 2 h, respectively. Cooking loss decreased with TGase treatment but increased at the 3‐h mark, suggesting over‐crosslinking. Electrophoresis revealed substantial protein crosslinking with TGase treatment, while in vitro digestion showed enhanced protein digestibility and higher peptide content in TGase‐treated samples. These findings underscore the potential of TGase treatment to enhance tofu's structural integrity and digestibility, offering valuable insights for optimising plant‐based protein processing to improve nutritional quality. [ABSTRACT FROM AUTHOR]

Fouling mitigation provides many challenges in process equipment, especially in heat exchangers. In this work, the fouling behaviors of two polymers are compared to 1.4301 stainless steel (SS) in calcium sulfate solutions. An experimental setup that allows to classify the materials quickly and under varying process conditions is used to determine the fouling behavior. Results are compared to a screening apparatus which can test up to three materials simultaneously. Finally, the cleaning behavior of all three materials is investigated. Results show that polyether ether ketone (PEEK) is superior to SS in mitigating fouling and is easier to clean; however, polyether ether ketone with 30 % talcum (TKT) is not. This is attributed to the surface roughness of the materials. [ABSTRACT FROM AUTHOR]

Fouling is a challenge in many processes, especially in heat exchangers and evaporators. Even though many treatments have been developed to mitigate fouling on metallic surfaces, no standardized method exists to compare equipment based on its antifouling performance. In this work, a screening apparatus is presented, which allows to compare samples of treated metallic surfaces based on thermal fouling resistance. A parameter screening and a ranking of three differently treated metallic surfaces using two model substances, namely, whey protein concentrate (WPC) and calcium sulfate, are demonstrated. [ABSTRACT FROM AUTHOR]

• Thermo-transformation of gypsum into anhydrous Godanti Bhasma (GB) induced massive cytoplasmic vacuolization without causing cell cytotoxicity. • The parent gypsum particle does not induce cellular uptake and cytoplasmic vacuolation in cells. • All the sequential cellular events of phagocytosis were clearly observed microscopically. • GB particles can be used as a smart biocompatible particle for phagocytosis assay development in animal cells. Phagocytosis is an essential physiological mechanism; its impairment is associated with many diseases. A highly smart particle is required for understanding detailed sequential cellular events in phagocytosis. Recently, we identified an Indian traditional medicine named Godanti Bhasma (GB), a bioactive calcium sulfate particle prepared by thermo-transformation of gypsum. Thermal processing of the gypsum transforms its native physicochemical properties by removing water molecules into the anhydrous GB, which was confirmed by Raman and FT-IR spectroscopy. GB particle showed a 0.5–5 µm size range and a neutral surface charge. Exposure of mammalian cells to GB particles showed a rapid cellular uptake through phagocytosis and induced massive cytoplasmic vacuolation in cells. Interestingly, no cellular uptake and cytoplasmic vacuolation were observed with the parent gypsum particle. The presence of the GB particles in intra-vacuolar space was confirmed using FESEM coupled with EDX. Flow cytometry analysis and live tracking of GB-treated cells showed particle internalization, vacuole formation, particle dissolution, and later vacuolar turnover. Quantification of GB-induced vacuolation was done using neutral red uptake assay in cells. Treatment of lysosomal inhibitors (BFA1 or CQ) with GB could not induce vacuolation, suggesting the requirement of an acidic environment for the vacuolation. In the mimicking experiment, GB particle dissolution in acidic cell-free solution suggested that degradation of GB occurs by acidic pH inside the cell vacuole. Vacuole formation generally accompanies with cell death, whereas GB-induced massive vacuolation does not cause cell death. Moreover, the cell divides and proliferates with the vacuolar process, intra-vacuolar cargo degradation, and eventually vacuolar turnover. Taken together, the sequential cellular events in this study suggest that GB can be used as a smart particle for phagocytosis assay development in animal cells. [ABSTRACT FROM AUTHOR]

Deeply situated brine is abundant in rare metal minerals, possessing significant economic worth. To the authors' knowledge, brine present within the Cambrian carbonate-dominated succession in the northeastern region of Chongqing, Southwestern China, has not been previously reported. In this investigation, brine samples were collected from an abandoned brine well, designated as Tianyi Well, for the purpose of analyzing the hydrochemical characteristics and geochemical evolution of the brine. Halide concentrations, associated ions, and their ionic ratios within the sampled brine were analyzed. The brine originating from the deep Cambrian aquifer was characterized by high salinity levels, with an average TDS value of 242 ± 11 g/L, and was dominated by a Na-Cl facies. The studied brine underwent a moderate degree of seawater evaporation, occurring between the saturation levels of gypsum and halite, accompanied by some halite dissolution. Compared to modern seawater evaporation, the depletion of Mg2+, HCO3−, and SO42− concentrations, along with the enrichment of Ca2+, Li+, K+, and Sr2+, is likely primarily attributed to water–rock interactions. These interactions include dolomitization, combination of halite dissolution, upwelling of lithium- and potassium-bearing groundwater, calcium sulfate precipitation, biological sulfate reduction (BSR), and the common ion effect within the brine system. This research offers valuable insights into the genesis of the brine within the Cambrian carbonate succession and provides theoretical backing for the development of brine resources in the future. [ABSTRACT FROM AUTHOR]

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Tofu is obtained by heating soymilk, to which a coagulant, such as calcium sulfate or magnesium chloride, is added to make it curdle. This study aimed to parameterize the effects of the following three alternative organic coagulant types: apple, rice, and white vinegars, used in different proportions. Six treatments were established with three concentrations (1%, 3%, and 5%), evaluating the coagulation time and curd yield. The treatments with the lowest coagulation time were analyzed for texture by TPA, color through the CIEL*a*b scale, protein content, and moisture. The results showed that the rice vinegar + 3% white vinegar (T6C3) treatment showed the lowest coagulation time (0.78 min). The 5% apple vinegar (T1C5) treatment provided the highest curd yield, averaging 23.73%. This treatment's protein and moisture contents were 3.93% protein and 69.73% moisture, confirming that better texture characteristics are recorded in tofu at lower pH values. The TPA results showed that using apple and rice vinegars as coagulants provided a challenging, less cohesive, more adhesive, and less elastic tofu. White vinegar provided a soft, more cohesive, less adhesive, and more elastic tofu. In the color analysis, it was observed that tofu coagulated with apple vinegar showed a tendency toward a yellow color, and tofu coagulated with rice and white vinegars showed a tendency toward a white color. These findings parameterize the effects of using each type of vinegar as a coagulant. These organic coagulants provide faster coagulation times and desirable texture characteristics, thus offering a practical alternative to traditional coagulants in tofu manufacturing. [ABSTRACT FROM AUTHOR]

Septic arthritis (SA) represents an orthopedics urgency and mainly affects the knee joint. Due to its devastating effects on cartilage, immediate management is crucial. SA is characterized by an annual incidence of 2 to 10 cases per 100,000 individuals, with mortality rates fluctuating between 0.5% and 15%, with a substantially higher mortality rate observed in older people (15%) in contrast to younger cohorts (4%). The etiology of septic arthritis is multifactorial: a spectrum of Gram-positive and Gram-negative bacteria can contribute to the development of this condition, especially Staphylococcus aureus. The treatment involves urgent (arthroscopic or arthrotomic) debridement associated with adequate antibiotic therapy. Intra-articular antibiotic carriers can also be used to increase their local concentration and effectiveness. The case of a 67-year-old woman affected by knee SA from methicillin-susceptible S. aureus is presented. She was treated with an arthroscopic debridement enhanced by intra-articular antibiotic-loaded calcium sulphate beads, together with antibiotic therapy. At 2-year follow up, the infection had been eradicated and the patient fully recovered. This is the first description, to our knowledge, in the English literature, of the use of antibiotic-loaded calcium sulphate beads as an adjuvant in the surgical treatment of SA of a native knee joint. [ABSTRACT FROM AUTHOR]

In response to rising CO2 emissions in the cement industry and the growing demand for durable offshore engineering materials, calcium sulphoaluminate (CSA) cement concrete, known for its lower carbon footprint and enhanced corrosion resistance compared to Ordinary Portland Cement (OPC), is increasingly important. However, the chloride transport behavior of CSA concrete in both laboratory and marine environments remains underexplored and controversial. Accordingly, the chloride ion transport behaviors and mechanisms of CSA concrete in laboratory-accelerated drying-wetting cyclic environments using NaCl solution and seawater, as well as in marine tidal environments, were characterized using the rapid chloride test (RCT), X-ray diffraction (XRD), mercury infiltration porosimetry (MIP), and thermogravimetric analysis (TGA). The results reveal that CSA concrete accumulates more chloride ions in NaCl solution than in seawater, with concentrations 2–3.5 times higher at the same water–cement ratio. Microscopic analysis indicates that calcium and sulfate ions present in seawater facilitate the regeneration of ettringite, thereby increasing the density of the surface pore structure. The hydration and repair mechanisms of CSA concrete under laboratory conditions closely resemble those in marine tidal conditions when exposed to seawater. Additionally, this study found that lower chloride ion concentrations and pH levels inhibit the formation of Friedel's salt. Therefore, laboratory experiments with seawater can effectively simulate CSA concrete's chloride transport properties in marine tidal environments, whereas NaCl solution does not accurately reflect actual marine conditions. [ABSTRACT FROM AUTHOR]

Understanding ionic interactions is essential to promote adequate crop nutrition. This study aimed to evaluate the interaction between nitrogen (N) and sulfur (S) and their effects on strawberries' production and postharvest quality. The experiment was conducted under greenhouse conditions adopting a completely randomized design in a 3 × 5 factorial scheme with four replicates. The treatments consisted of the combination of three rates of S (0, 30, and 60 mg dm−3) in the form of calcium sulfate (CaSO4·2 H2O) and five rates of N (0, 30, 60, 90, and 120 mg dm−3) in the form of urea (pro analysis grade) enriched to 10 atom% 15N. The fruits were harvested weekly when showing ¾ maturation. At the end of the harvest, evaluations of the mineral composition of the plants' shoots, determination of N utilization, and physicochemical analyses of the fruit pulp were performed. The results showed that the interaction between N and S affected the fertilizer use efficiency (FUE), strawberry production, and the physicochemical attributes of the fruit pulp. Applying 120 mg dm−3 N and 30 mg dm−3 S improved both strawberry production and postharvest quality. Therefore, balancing N and S levels can improve both the yield and quality of strawberries. [ABSTRACT FROM AUTHOR]

One of the challenges and limitations of bone tissue engineering includes fast degradation rates, reduced bioactivity, donor site morbidity, and unresolved risks of pathogen transmission. In the field of bone tissue engineering, gradient materials are promising for treating bone defects because they can create graded structures and compositions similar to natural bone. By controlling the amount of components in the structure, the degradation rate, bioactivity, and osteogenic capacity can be manipulated. In the current study, a gradient, multilayer, porous nanocomposite of calcium sulfate/glass (Gn CS/BG) with a gelatin coating (Gn CS/BG-Gel) was prepared using rotational casting technique. The SEM results showed an average pore size of approximately 400 μm within the Gn CS/BG-Gel nanocomposite. An elastic modulus (E) of around 240 MPa and an ultimate tensile strength (σ) of approximately 5.5 MPa were achieved for Gn CS/BG-Gel nanocomposite. The degradation analysis in a dynamic tris-buffer environment revealed a degradation rate of 68 % over a 63-day period, with a decrease in degradation rate as the bioactive glass (BG) content increased in each layer, indicating the influence of BG on the degradation process. The bioactivity results in a dynamic simulated body fluid suggested that increased BG content in each layer promoted hydroxyapatite formation, indicating improved bioactive behavior. The evaluation of ion release with ICP-OES, MTT and Acridine Orange assays using human bone marrow-derived mesenchymal stem cells (hBMSCs) confirmed the non-toxic nature of Gn CS/BG-Gel. Assessments of alkaline phosphatase (ALP) activity, calcium content, Alizarin Red staining and cell attachment behavior substantiated the osteogenic potential of Gn CS/BG-Gel. Collectively, the three-dimensional structure along with the Gn CS/BG-Gel composition contributed to the enhanced cellular responses. These findings hold significant promise for the development of biomaterials with potential applications in bone tissue engineering, and they contribute valuable insights to the field. [Display omitted] [ABSTRACT FROM AUTHOR]

Natural gas has become an important replacement resource for conventional oil and gas resources. However, the generation of trithiane blockages during gas well development can affect the development efficiency and wellbore safety of the gas well. Unfortunately, the current research on the formation mechanism of blockages in wellbore and their removal processes is not yet complete, and cannot provide theoretical support for the removal of blockages in deep-water gas wells. In this study, based on the validation of the adaptability of the experimental system and methods, the composition of wellbore blockages during gas well development was analyzed. Then, the mechanism of dispersion chelation dissolution synergistic unblocking was explored, and the influence of factors such as wellbore temperature was studied. Research has found that blockages in the wellbore are mainly composed of calcium carbonate (accounting for up to 61.3%), and contain a certain amount of highly corrosive iron sulfide and calcium sulfate. Moreover, the dissolution rate of trithiane wellbore blockages by the unblocking system will significantly increase with the increase of temperature. However, when the wellbore temperature exceeds 140°C, the promotion effect of the increase in wellbore temperature on the accelerated dissolution rate of blockages is significantly weakened. At the same time, the dissolution rate of wellbore blockages will increase with the increase of chelating agent concentration within the low chelating agent concentration range. However, when the concentration of chelating agent is higher than 5.0 wt%, the dissolution rate of wellbore blockage will slowly decrease with the increase of chelating agent concentration. Finally, on-site application found that the wellhead pressure and gas production both returned to the level before the wellbore blockage after the removal of the trithiane blockage in the wellbore, and there were no repeated wellbore blockages in the following year. [ABSTRACT FROM AUTHOR]

Upscaling of the laboratory oxygen carriers while keeping comparable performance as laboratory powders remains a challenge in the field of chemical looping combustion (CLC). In this work, two perovskite compositions of CaMn0.375Ti0.5Fe0.125O3 (termed CMTF8341) and CaMn0.5Ti0.375Fe0.125O3 (CMTF8431) have been fabricated by means of spray granulation. The fabricated granules were evaluated by redox cycles under CLC conditions and showed comparable performance with laboratory-prepared powders, i.e. high oxygen transfer capacity and fast redox kinetics. Under chemical looping oxygen uncoupling (CLOU) conditions, it has been found that steam leads to a slower kinetics and lower oxygen transfer capacity for these two compositions. When it comes to sulphur effect on the oxygen carriers, redox cycles with deep reduction showed no influence with H2S since the CaSO4 formed in air decompose but it affected the materials under mild CLOU due to calcium sulphate formed under such condition. Nonetheless, redox performance can be recovered by deep reduction with an enhanced oxygen capacity. These two oxygen carriers showed no degradation as compared to other tested minerals in the field of CLC. Microstructure analyses from SEM showed high degree of structure integrity after redox cycles at temperatures up to 1050 °C for the CMTF8341. Good mechanical strength was evidenced from cold attrition test, and the lifetime of the two granules was also predicted based on a standard reference. [ABSTRACT FROM AUTHOR]

We present a comparison of common electron microscopy sample preparation methods for studying crystallisation processes from solution using both scanning and transmission electron microscopy (SEM and TEM). We focus on two widely studied inorganic systems: calcium sulphate, gypsum (CaSO4·2H2O) and calcium carbonate (CaCO3). We find significant differences in crystallisation kinetics and polymorph selection between the different sample preparation methods, which indicate that drying and chemical quenching can induce severe artefacts that are capable of masking the true native state of the crystallising solution. Overall, these results highlight the importance of cryogenic (cryo)‐quenching crystallising solutions and the use of full cryo‐TEM as the most reliable method for studying the early stages of crystallisation. [ABSTRACT FROM AUTHOR]

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

Sulfate-bearing soils is widely distributed around the world, and this type of soil is prone to rock and soil disasters such as dissolution, corrosion of foundations, and swell when exposed to water. Cement is a frequently used stabilizer to treat sulfate-bearing soils. However, sulfate-bearing soils usually include various types of sulfates, such as, calcium sulfate (CaSO4), sodium sulfate (Na2SO4), potassium sulfate (K2SO4), and magnesium sulfate (MgSO4). So far, the effect of sulfate type on the strength and swelling properties of sulfate-bearing soil stabilized with cement has not been clarified. Therefore, in this study, the strength and swelling properties of four sulfate-bearing soils treated with cement were studied using unconfined compressive strength tests, and swelling tests. X-ray diffraction (XRD), scanning electron microscopy, and inductively coupled plasma spectroscopy were employed to study mineralogical, micro-structural properties, and concentrations of calcium ion of stabilized soils, to explore stabilization mechanisms. The results showed that the formation of magnesium silicate hydrate and highest concentration of free Ca2+ in the stabilized Mg-sulfate-soil caused its lowest strength. The reduction in free Ca2+ concentration was greater in the stabilized Na-sulfate-soil and K-sulfate-soil compared to stabilized Mg-sulfate-soil and Ca-sulfate-soil, contributing to the formation of more calcium silicate hydrate and ettringite. Therefore, the stabilized Na-sulfate-soil and K-sulfate-soil had greater swelling and strength compared to other soils. As the cement content increases, there are abundant in the sulfated cement stabilized soil observed in XRD and SEM photos. Overall, sulfates with monovalent cations increased the strength of cement-stabilized soils more than those with divalent cations, while sulfates with divalent cations improved the resistance to swelling of cement-stabilized soils. Before treating sulfate-bearing soils with cement, it is necessary to first determine the cations type in the soil. If the soil contains Mg2+, seek cement alternatives. If the other three cations are present, choose an appropriate cement content for stabilization. This study provides some references for the stabilization of sulfate-bearing soils with cement. [ABSTRACT FROM AUTHOR]

We have developed a convenient route to transform biomass power plant ashes (BPPA) into porous sponge-like fertilizer composites. The absence of water prevents the chemical reaction and carbon dioxide formation when concentrated sulfuric acid is mixed with BPPA and CaCO3. Adding water, however, initiates the protonation reaction of carbonate ion content and starts CO2 evolution. The key element of the method was that the BPPA and, optionally, CaCO3 and/or CaSO4·0.5H2O were mixed with concentrated sulfuric acid to make a paste-like consistency. No gas evolution occurred at this stage; however, with the subsequent and controlled addition of water, CO2 gas evolved and was released through the channels developed in the pastry-like material due to the internal gas pressure, but without foaming. Using a screw-containing tube reactor, the water can be introduced under pressure. Due to the pressure, the pores in the pastry-like material became smaller, and consequently, the mechanical strength of the granulated and solidified mixture became higher than that of the reaction products prepared under atmospheric pressure. The main reaction products were syngenite (K2Ca(SO4)2·H2O) and polyhalite (K2Ca2Mg(SO4)4·2H2O). These compounds are valuable fertilizer components in themselves, but the material's porous nature helps absorb solutions of microelement fertilizers. Surprisingly, concentrated ammonium nitrate solutions transform the syngenite content of the porous fertilizer into ammonium calcium sulfate ((NH4)2Ca(SO4)2·2H2O, koktaite). Koktaite is slightly soluble in water, thus the amount of ammonium ion released on the dissolution of koktaite depends on the amount of available water. Accordingly, ammonium ion release for plants can be increased with rain or irrigation, and koktaite is undissolved and does not decompose in drought situations. The pores (holes) of this sponge-like fertilizer product can be filled with different solutions containing other fertilizer components (phosphates, zinc, etc.) to adjust the composition of the requested fertilizer compositions for particular soils and plant production. The method allows the preparation of ammonium nitrate composite fertilizers containing metallic microelements, and various solid sponge-like composite materials with adjusted amounts of slowly releasing fertilizer components like syngenite and koktaite. [ABSTRACT FROM AUTHOR]

Tomatoes are one of the most important vegetables in every home, especially in South Asian countries, used as a vegetable, ketchup, and condiment in many kitchen recipes. It is a good source of calcium, potassium, folate, vitamin A, vitamin K, and lycopene, which are beneficial for the human body and protect it against different diseases. Nutrient management is a key factor for the best quality production of tomato fruit. The present study was conducted to compare the efficiency of different calcium salts (calcium sulphate, calcium carbonate, calcium nitrate, and calcium chloride) in improving the growth, yield, and other quality-related parameters of tomatoes. A single field experiment was conducted and laid out according to the Randomized Complete Block Design (RCBD) with a single factor in the field and a Complete Randomized Design (CRD)) for postharvest fruit storage. The results obtained from this experiment suggest that plants treated with 2% calcium chloride solution exhibited the greatest plant height (85.27 cm), number of leaves (221), yield per plant (2.3 kg), ascorbate peroxidase (290.75 m mol s−1 kg−1), superoxide dismutase (7.13 m mol s−1 kg−1), catalase (18.74 m mol s−1 kg−1), total phenolics (2.44 mg g−1), and β carotene (0.48 µg g−1). During postharvest storage, the maximum shelf life (18 days), minimum disease incidence (4.78%), weight loss (6.61%), and ethylene production (119.6 µL C2H4 kg−1h−1) rate were also observed in calcium-treated fruits. [ABSTRACT FROM AUTHOR]

Leaching of calcium phosphate with sulfuric acid was carried out to study phosphogypsum (PG) crystal growth and size distributions in presence and absence of phosphogypsum seed crystals (PGSC) and sorbitol surfactant (SS) additives. PG crystallization simulates industrial Dihydrate process for phosphoric acid production. PG crystals grow in a medium containing 26±1% P2O5 phosphoric acid and 2±0.5 % free sulfuric acid. Better filterability of phosphoric acid can be achieved with large crystals. The formed PG crystals are larger with addition of either 100 ppm Sorbitol surfactant, 5%, 10% or 15% PGSC compared to the baseline (without additives). With addition of surfactant or increasing the % of PGSC from 5% to 15%, both the mean diameter and d90 of crystalized PG are increased due to enhancing the crystallization growth rates. [ABSTRACT FROM AUTHOR]

Calcium molybdate (CaMoO4) is of significant interest due to its unique properties and numerous industrial applications, such as catalysis, electrochemistry, and optoelectronics. In this study, we developed an economical and environmentally friendly method to synthesize calcium molybdate from Moroccan phosphogypsum (PG) industrial waste and sodium molybdate, all at room temperature. Comprehensive analysis through X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Raman vibrational spectroscopy, and scanning electron microscopy (SEM) revealed the high purity of the synthesized calcium molybdate, with particle sizes of only 12 nm. Additionally, optical characteristics were studied using ultraviolet-visible spectroscopy (UV-vis), which showed an optical band gap of Egap = 3.96 eV for CaMoO4. These results confirm the successful synthesis of calcium molybdate nanoparticles from Moroccan phosphogypsum, demonstrating an effective pathway to valorize this industrial waste into a valuable material. This approach contributes to environmental sustainability by reducing dependence on rare chemicals while offering innovative solutions for the industry's sustainable development. [ABSTRACT FROM AUTHOR]

Abstract Background Bone grafts are extensively used for repairing bone defects and voids in orthopedics and dentistry. Moldable bone grafts offer a promising solution for treating irregular bone defects, which are often difficult to fill with traditional rigid grafts. However, practical applications have been limited by insufficient mechanical strength and rapid degradation. Methods This study developed a ceramic composite bone graft composed of calcium sulfate (CS), β-tricalcium phosphate (β-TCP) with/without graphene oxide (GO) nano-particles. The biomechanical properties, degradation rate, and in-vitro cellular responses were investigated. In addition, the graft was implanted in-vivo in a critical-sized calvarial defect model. Results The results showed that the compressive strength significantly improved by 135% and the degradation rate slowed by 25.5% in comparison to the control model. The addition of GO nanoparticles also improved cell compatibility and promoted osteogenic differentiation in the in-vitro cell culture study and was found to be effective at promoting bone repair in the in-vivo animal model. Conclusions The mixed ceramic composites presented in this study can be considered as a promising alternative for bone graft applications.

Calcium sulfate is an established carrier for localized drug delivery, but a means to non‐invasively measure drug release, which would improve our understanding of localized delivery, remains an unmet need. We aim to quantitatively estimate the diffusion‐controlled release of small molecules loaded into a calcium sulfate carrier through a gadobutrol‐based contrast agent, which acts as a surrogate small molecule. A central cylindrical core made of calcium sulfate, either alone or within a metal scaffold, is loaded with contrast agents that release into agar. Multi‐echo scans are acquired at multiple time points over 4 weeks and processed into R2* and quantitative susceptibility mapping (QSM) maps. Mean R2* values are fit to a known drug delivery model, which are then compared with the decrease in core QSM. Fitting R2* measurements of calcium sulfate core while constraining constants to a drug release model results in an R2‐value of 0.991, yielding a diffusion constant of 4.59 × 10−11 m2 s−1. Incorporating the carrier within a metal scaffold results in a slower release. QSM shows the resulting loss of susceptibility in the non‐metal core but is unreliable around metal. R2* characterizes the released gadobutrol, and QSM detects the resulting decrease in core susceptibility. The addition of a porous metal scaffold slows the release of gadobutrol, as expected. [ABSTRACT FROM AUTHOR]

Objective To investigate the physicochemical and biological properties of a new calcium sulfate-based root canal sealer for deciduous teeth containing calcium sulfate hemihydrate, barium sulfate, chlorhexidine acetate, and polyethylene glycol 400 (PEG 400). Methods This study was reviewed and approved by the Ethics Committee. The calcium sulfate hemihydrate and barium sulfate powders with different mass percentages were mixed with liquid PEG 400 at a powder-to-liquid ratio of 3∶1, and chlorhexidine acetate was added to a concentration of 0.2 mg/mL according to the volume of PEG 400. The above materials were mechanically ground at 250 r/min for 24 h to obtain a calcium sulfate-based root canal sealer for deciduous teeth. The sealer was classified into different groups according to mass percentages of components. The mass percentages of components were optimized by performing time, fluidity, and radiopacity experiments, and then the pH, mass loss in vitro, and microscopic morphology of the optimal sealer were evaluated. The antimicrobial properties of the sealer were evaluated by a bacterial-material cocultivation method. The cytocompatibility of the sealer was evaluated by a CCK-8 assay and cytomorphological staining, and its biocompatibility was evaluated by a subcutaneous tissue embedding assay. Results After optimization, mass percentage of calcium sulfate hemihydrate was 80 wt%, and the mass percentage of barium sulfate was 20 wt%. The flowability and radiopacity of the sealer were in accordance with international standards. The pH stabilized between 6-7. On the 7th and 14th days, the pH in the water group was significantly greater than that in the PBS group (PP>0.05). In vitro degradation experiments, the mass loss of the sealer was approximately 15.17% during the preimmersion period, and rate of mass loss decreased after 3 weeks, reaching only approximately 8.33%. X-ray diffraction (XRD) and scanning electron microscopy (SEM) revealed that the main component of the sealer after hydration was calcium sulfate dehydrate. In bacterial growth assays and cytological tests, the sealer showed significant inhibition of the growth of E. faecalis (PPP>0.05). Both the sealer group and the control group (Vitapex and zinc oxide eugenol) caused mild inflammatory reactions in tissue sections. Conclusion In this study, a new type of root canal sealer for deciduous teeth was designed based on calcium sulfate, which has good physicochemical properties and strong antibacterial properties and meets biocompatibility requirements. This study provides an idea for the development of a new type of root canal sealer for deciduous teeth.

In the present study, the polyvinylidene fluoride (PVDF) modified hollow fiber (HF) membranes have been synthesized by dry‐jet wet phase inversion technique for desalination via direct contact membrane distillation (DCMD). UiO‐66 metal‐Organic framework (MOF) and surface‐modified UiO‐66 with h‐BN nanomaterial have been incorporated with PVDF‐HF membrane. The various analytical methods like FE‐SEM, FTIR, PXRD, TGA, tensile strength, were used to characterize prepared MOF and HF membranes. It was observed from DCMD results that the h‐BN@UiO‐66/PVDF (M3) HF membrane gives higher flux than UiO‐66/PVDF (M2) and pure PVDF (M1) membrane. In the present investigation, response surface methodology (RSM) by box‐behnken design (BBD) was used to optimize the DCMD system and evaluate the behavior of operating parameters such as feed temperature, feed concentration, and feed flow rate. The optimum operating values of feed temperature, feed flow rate, and feed concentration were found as 65 °C, 1 LPM, and 1.5 wt.%, respectively. Under optimum conditions, the M3 HF membrane gives the highest flux of 26.78 L/m2 ⋅ h compared to M2 and M1 membranes. During DCMD, salt rejection is almost greater than 99.8 % for all prepared membranes. Other salts like potassium chloride (KCl), Magnisium Sulphate (MgSO4), and calcium sulphate (CaSO4) are also used to check salt rejection of all membranes at optimum operating conditions. Moreover, the M3 membrane exhibits stable permeate flux and high salt rejection (>99.9 %) at optimized process parameters over 80 h running. Overall, the present study provides the positive effects of h‐BN nanoparticles and UiO‐66 MOF on HF membrane to improve performance in DCMD. [ABSTRACT FROM AUTHOR]

The purpose of this in vitro study was to develop calcium sulfate (CS)-based disks infused with an antimicrobial drug, which can be used as a post-surgical treatment modality for osteomyelitis. CS powder was embedded with 10% antibiotic, amoxicillin (AMX) or moxifloxacin (MFX), to form composite disks 11 mm in diameter that were tested for their degradation and antibiotic release profiles. For the disk degradation study portion, the single drug-loaded disks were placed in individual meshes, subsequently submerged in phosphate-buffered saline (PBS), and incubated at 37 °C. The disks were weighed once every seven days and analyzed via Fourier-transform infrared spectroscopy, X-ray diffraction, energy dispersive X-ray spectroscopy, and scanning electron microscopy. During the antibiotic release analysis, composite disks were placed in PBS solution, which was changed every 3 days, and analyzed for antibiotic activity and efficacy. The antibacterial effects of these sustained-release composites were tested by agar diffusion assay using Streptococcus mutans (S. mutans) UA 159 as an indicator strain. The degradation data showed significant increases in the degradation of all disks with the addition of antibiotics. Following PBS incubation, there were significant increases in the amount of phosphate and decreases in the amount of sulfate. The agar diffusion assay demonstrated that the released concentrations of the respective antibiotics from the disks were significantly higher than the minimum inhibitory concentration exhibited against S. mutans over a 2–3-week period. In conclusion, CS-antibiotic composite disks can potentially serve as a resorbable, osteoconductive, and antibacterial therapy in the treatment of bone defects and osteomyelitis. [ABSTRACT FROM AUTHOR]

Introduction: The use of implantable antibiotic beads has become a frequent treatment modality for the management of surgical site infections in human and veterinary medicine. The objective of this study is to describe the elution kinetics of five antibiotics from a commercially available calcium sulfate antibiotic delivery kit. A secondary goal was to compare elution concentrations with minimal inhibitory concentrations (MIC) for commonly encountered bacteria from the University of Florida's veterinary microbiology laboratory database. Methods: Calcium sulfate powder was combined with amikacin, cefazolin, gentamicin, ampicillin/sulbactam, and meropenem. Triplicates of three antibiotic-loaded beads were immersed in 5 mL of phosphate-buffered saline (PBS) and kept at 37°C under constant agitation. Antibiotic-conditioned PBS was sampled at 14 time points from 1-h to 30 days and analyzed by liquid chromatography to determine the antibiotic concentration. Results: All beads eluted concentrations of antibiotics for the 30-day sampling period, except for ampicillin/sulbactam, with the most antibiotics being eluted within the first week. The concentration of antibiotics within the eluent within the first 3-9 days (3- and 5-mm beads, respectively) was greater than the MIC of common isolates. The 5 mm bead samples were superior in maintaining higher concentrations for a longer period, compared to the 3-mm beads. Discussion: CSH beads eluted antibiotics over the 30-day course of the study. Most of the antibiotic elution occurred within the first week and was maintained above the MIC of commonly encountered isolates. This information may be useful for clinical decision making for treatment of local infections encountered in practice. [ABSTRACT FROM AUTHOR]

In the study, polydopamine and oleylamine cooperated to modify the surface of anhydrous calcium sulfate prepared from phosphogypsum, and HDPE matrix composites with different filler content were prepared by filling HDPE before and after modification. The results show that when the filler content is 5 wt%, the elongation at break of mCSA/HDPE composite is 31.7% and 89% higher than that of HDPE and CSA/HDPE. Respectively, when the filler content is as high as 25 wt%, the flexural strength is still 16.8% higher than that of HDPE. After modification, the compatibility and dispersibility of anhydrous calcium sulfate in HDPE were improved, and the crystal structure of anhydrous calcium sulfate was not significantly changed, thus the mechanical properties and thermal stability of mCSA/HDPE composites were improved. Overall, after modification, not only the mechanical properties of the composites are improved, but also the content of inorganic powder as filler added to HDPE is increased, which can be regarded as a method for effective utilization of phosphogypsum. Highlights: Calcium sulfate was modified by polydopamine and oleylamineThe mechanical and thermal properties of the modified calcium sulfate/HDPE composites are good.The resource utilization of phosphogypsum was carried out [ABSTRACT FROM AUTHOR]

The coexistence of different foulant compositions in the feed water of reverse osmosis (RO) systems causes serious complications in the fouling process of the membranes. Hence, in this technical research, the phenomenon of combined inorganic (gypsum)-colloidal (silica particles) fouling (inorganic-colloidal fouling) of brackish water RO (BWRO) process was studied in the lab-scale experiments. Moreover, the effect of the presence of air micro–nano bubbles (AMNBs) in the feed water; as a new practical method for control of membrane fouling, was investigated on this phenomenon. For this purpose, a suspension with the potential of inorganic scaling [calcium sulfate, Saturation index (SI)=0.96 ] and colloidal fouling (colloidal silica, 50 mg/L) was used to form the inorganic and colloidal foulings (simultaneously) on the membrane surface during the inorganic-colloidal fouling process. All experiments were performed twice, once in the absence and once in the presence of AMNBs. Finally, the results of this research were compared with the results of the inorganic and colloidal fouling studies. Based on the results, the inorganic-colloidal fouling formed a dense and compact fouling layer on the membrane surface, which severely reduced the permeate flux (76.3%) and salt rejection (4%). The amount of decrease of these two parameters in inorganic-colloidal fouling was much higher than each of individual inorganic and colloidal foulings. In the presence of AMNBs, both types of inorganic and colloidal foulings greatly reduced and the major portion of inorganic-colloidal fouling was related to the colloidal fouling. Thus, a significant decline was observed in adverse effects of inorganic-colloidal fouling on the membrane performance and the permeate flux and salt rejection decreased by 18.5% and about 1%, respectively. The results of this study could introduce the micro–nano bubbles (MNBs) technology as an effective method to inhibit the inorganic-colloidal fouling in RO systems. Practical Applications: Today, reverse osmosis processes are known as efficient technologies for supplying drinking water from brackish and sea water resources due to their high ability to remove various compounds. The separated compounds from the water accumulate near the membrane surface and consequently deposit on it and/or inside its pores. This phenomenon is called membrane fouling and has adverse effects on the performance of reverse osmosis processes. Water resources usually have different types of pollutants that simultaneous presence of them can intensify the membrane fouling process. Gypsum scaling and colloidal silica fouling are two major common types of reverse osmosis membrane fouling. Therefore, in this research, the effects of the inorganic-colloidal fouling were studied on the performance of a commercial brackish water reverse osmosis membrane, in presence and absence of air micro–nano bubbles. The results showed that the combined fouling formed a complex fouling layer on the membrane surface in absence of air micro–nano bubbles. In real-scale reverse osmosis process, this layer can severely reduce the membrane permeate flux and salt rejection which result to increase in the operational and maintenance costs. Alternatively, the presence of air micro–nano bubbles in the reverse osmosis feed flow could limit both inorganic and colloidal foulings and their synergetic effects on each other. [ABSTRACT FROM AUTHOR]

To reduce environmental pollution and conserve natural resources, calcined oyster shell ash (COSA), class F fly ash (FFA) and flue gas desulfurisation gypsum (FGDG) were used in an attempt to improve the engineering properties of alkali-activated ternary cementitious paste. The COSA – obtained by calcining crushed oyster shells at 800°C for 3 h and then grinding to pass through a no. 100 sieve – was used to substitute FFA at rates of 2.5, 5.0 and 7.5 mass%. The alkali solution used was 10M sodium hydroxide and sodium silicate with a modulus of 2.5. The hardened paste with 7.5% COSA, 1% FGDG and ratio of weight of added water to dry binder of 0.09 at 56 days had the highest compressive strength of 62 MPa. Microstructural analyses (scanning electron microscopy and energy-dispersive X-ray spectroscopy) showed that the resulting calcium aluminosilicate hydrate gel was found to have a compact microstructure, which improved the compressive strength of specimens. In summary, COSA successfully replaced natural limestone as a calcium oxide activator to manufacture an alkali-activated ternary cementitious paste containing FFA and FGDG. [ABSTRACT FROM AUTHOR]

Aims: We aimed to identify the optimal combination of selenium (from Na2SeO4) and secondary elements required for obtaining the best nutritive characteristics and quality of 'Qingcui' plums. Methods: Five treatments (Na2SeO4 with MgSO4 and CaSO4) and a control treatment without Se, Mg, Ca, or S were applied to 2-year-old 'Qingcui' plum trees in a greenhouse. Plum leaves and fruit were analyzed for color, nutrient, and quality characteristics during the growing and deciduous seasons as well as the following year. Results: Leaf color parameters, pigment content, and specific weight significantly improved by CaSO4 addition during the growing and deciduous seasons. Ca and Mg contents during the growth, defoliation, and young leaf stages of the following year exhibited consistent trends under the different treatments, whereas Se and S contents differed according to the season and treatment. Thus, Mg and S showed high mobility and reutilization rates, whereas Ca and S showed poor mobility and reutilization rates. Leaf and fruit nutrient contents decreased in the order of Ca > Mg > S and S > Ca > Mg, respectively. The combination of 77 mg Na2SeO4, 10 g MgSO4, and 19 g CaSO4 yielded optimal fruit quality in terms of fruit weight, hardness, and soluble solids and fruit Se content. A large amount of Ca was present in the cell wall, whereas S and Mg were mainly observed as soluble components. Conclusions: Our study revealed the best combination of Se and secondary elements leading to optimal leaf nutrition and fruit Se content and quality in 'Qingcui' plums. [ABSTRACT FROM AUTHOR]

This paper considers the propagation of ash during the paroxysmal eruption of Sheveluch Volcano which occurred April 10–13, 2023, and its impact on the water resources of the affected area. We characterize ash thicknesses at various population centers and describe the grain-size composition of the ash. We show that the propagation of ash plumes is primarily driven by the eruption dynamics, but atmospheric circulation actually controls the spatial distribution of deposit thickness. The water-soluble salts contained in the ash and the dynamics of their washing out under natural conditions have been determined. The water-soluble part of fresh ash is dominated by calcium and magnesium sulfates, sodium chloride, with minor amounts of chlorides and fluorides of aluminum, potassium, and ammonium. The first substances to be washed out from ashes are well-soluble chlorides, to be followed by sulfates. As time goes on, the total concentration of soluble salts is decreasing, and their qualitative composition changes: hydrogen carbonates of calcium, magnesium, and sodium begin to dominate. Several months after the eruption, the impact of the ashfall on water resources of the settlements, including open springs at the ground surface, was leveled out. [ABSTRACT FROM AUTHOR]

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

Background: Given the increasing rate of infections following hip arthroplasty, one of the current options is the application of a biocomposite at the site of the infection. One of the products used is Stimulan, a completely resorbable calcium sulfate, designed to treat acute and chronic infections. This biocomposite has a controlled purity, is easy to mix with liquid, powder, and antibiotics, and can be applied directly to the site of infection, or it can be injected. Methods: We analyzed data from 76 patients, who were admitted to the County Clinical Hospital of Emergency "St. Apostol Andrei" in Galati during January 2017–September 2023, with a diagnosis of infection associated with hip arthroplasty. Results: In 69.73% of cases (52 patients), we decided to keep the implant in place. In this subgroup, Stimulan was applied in 26 cases (57.78%). Of these, 100% were cured—compared to the subgroup in which Stimulan was not applied, where this percentage was lower. All patients underwent chemical and mechanical toileting, and for 24 patients (20.27%), it was necessary to ablate the implant with or without the application of Stimulan, then reimplantation of the prosthesis. Conclusions: The patients with Stimulan had a longer average length of hospitalization, almost half of them required intervention in two periods, and a quarter required the implantation of spacers. However, the cure rate was higher, only in three people could we not control the infection, and there was no death. This study confirms the effectiveness of the treatment when using a biocomposite in addition to the classical treatment for both acute and chronic cases. [ABSTRACT FROM AUTHOR]