CaSO4 Research Articles

Geochemical Characteristics and Genesis of Brine Chemical Composition in Cambrian Carbonate-Dominated Succession in the Northeastern Region of Chongqing, Southwestern China

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.

Evaluation of Germination and Early Seedling Growth of Different Grasses Irrigated with Treated Mine Water

Coal mining is known to have negative impacts on the environment, necessitating land rehabilitation after mining activities. Amongst the problems associated with coal mining is the accumulation of acid mine drainage characterized by large amounts of heavy metals and high acidity. The impact of these environmental problems on the ecosystem around mining areas underscores a need to devise strategies that will ensure sustainable restoration of the ecosystem integrity to ensure environmental protection. Of these, treatment of acid mine drainage using calcium sulfate dihydrate, which is subsequently used for irrigation during phytoremediation, holds great promise for restoration of open-cast mines. However, although grasses are used for rehabilitation of coal mined areas, the impacts of treated mine water on the germination, seedling emergence, and plant growth of grasses are not well known. The aim of the study was to evaluate the germination and early seedling growth responses of different forage grasses to treated mine water. Seven forage grass species were selected, with four species represented by two varieties while others were represented by one variety, totaling 11 forage grasses. For each plant entry, 100 seeds were placed in J.R. Petri’s dishes lined with Whatman No. 2 filter paper and watered with distilled and mine water to assess germination. For the seedling establishment experiment, only five species were studied, in which twenty seeds per species were sown in pots containing mine soil and irrigated using distilled and treated mine water. The final germination percentage (FGP), germination rate index (GRI), corrected germination rate index (CGRI), and T50 were determined for the germination trail and total biomass was assessed for the seedling growth trail. The highest FGP for all grasses was attained under controlled conditions, using distilled water, ranging from 38–94%. All grasses germinated when watered using treated mine water and had a FGP ranging from 20–91%. Relative to distilled water, GRI and CGRI were highest only for L. multiflorum cv AgriBoost when seeds were watered using the treated mine water. All grasses watered with treated mine water produced high biomass for the first two weeks, after which biomass production started to decline. Two grasses, Eragrostis curvula cv Ermelo and Lolium multiflorum cv Archie, showed tolerance to treated mine water irrespective of its high electrical conductivity (557 mS∙m−1). Therefore, these grasses could be used in the rehabilitation of coal-mined areas irrigated with treated mine water.

Methallylsulfonate Polymeric Antiscalants for Application in Thermal Desalination Processes.

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.

From Ions to Crystals: A Comprehensive View of the Non-Classical Nucleation of Calcium Sulfate.

After years ofintensive research andnumerous important observations, our understanding of the early stages of crystallization is still limited due to the complexity of the underlying processes and their elusive character. 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.

Identification of Peptide Binding Motifs for Calcium Sulfate Hemihydrate using Phage Display.

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.

Exploring the role of calcium sulfate in supersulfated cement: A study of rheological, mechanical, and microstructural properties

In order to investigate the impact of different calcium sulfate (CS) sources and forms on the rheology, hydration, and mechanical properties of supersulfated cement (SSC), SSC pastes were produced with anhydrite from gypsum calcined at 650ºC and raw and calcined phosphogypsum (PG) at 150, 350, and 650ºC. Isothermal calorimetry, rheometry using parallel-plate geometry, compressive strength testing, and microstructural analysis through X-ray diffraction (XRD) and thermogravimetric analysis (TGA/DTG) were performed. Results showed that SSC containing gypsum and PG calcined at 650ºC exhibited similar rheological behavior. Pastes containing PG calcined at 150ºC and raw PG respectively, exhibited the highest and lowest shear stress at a given shear rate. The calcination temperature and CS source did not significantly impact SSC compressive strength. Rietveld XRD analysis revealed that pastes with PG calcined at 350ºC and gypsum calcined at 650ºC had the lowest and highest ettringite development, respectively, from 7 to 28 days of curing.

Repairing Dehiscence Defects at Implant Sites using β-Tricalcium Phosphate/Calcium Sulfate versus Xenograft Combined With Membrane: A Randomized Clinical Trial.

Guided bone regeneration (GBR) typically involves bone grafts and a membrane to enhance bone formation. Beta-tricalcium phosphate calcium sulfate (β-TCP/CS) is a novel material with self-hardening and tissue growth inhibition properties and can potentially replace the need for a membrane. This study compares β-TricalciumPhosphate/CalciumSulfate with deproteinized bovine bone mineral and a collagen membrane (DBBM/CM) to repair bone defects at implant sites over six months. Sixteen implant defects were divided into β-TCP/CS (n = 8) and DBBM/CM (n = 8). The results showed no significant differences in vertical and horizontal defect fill in millimeters between β-TCP/CS (2.87±1.25 and 2.37±1.06 mm., respectively) and DBBM/CM (3.5±0.92 and 2.87±1.12 mm. , respectively). Buccal bone thickness (BT) alterations at the implant platform levels (BT0) were similar for both materials. However, β-TCP/CS exhibited greater bone alteration at the 2-mm level (BT2: -1.85 mm vs. -0.47 mm) and 4-mm level (BT4: -1.79 mm vs. 0.12 mm) apical to the implant platform compared to DBBM/CM. When assessing volume alteration, β-TCP/CS showed a significantly greater reduction at the platform to the 2 mm level (-61.98% vs. -23.76%) than DBBM/CM. In conclusion, β-TCP/CS demonstrated promise for treating buccal bone defects around implants but exhibited higher graft reduction. This suggests that while β-TricalciumPhosphate/CalciumSulfate may offer clinical benefits, its potential for greater graft reduction should be considered. Further research and evaluation are warranted to fully understand the long-term implications of using β-TCP/CS in guided bone regeneration procedures.

Mechanical property and microstructure of fly ash-based geopolymer by calcium activators

Geopolymer is a green and environmentally friendly new type of gel material generated from the reaction of activators with silica-alumina raw materials, possessing extensive research and application value. Fly ash can be used as reaction material, enabling the industrial solid waste to be recycled and reused. In this paper, unconfined compressive strength test, X-ray diffraction analysis, Fourier transform infrared light, 29Si nuclear magnetic resonance, scanning electron microscope and energy disperse spectroscopy, and physisorption experiment were carried out to study the effects of the type and dosage on the mechanical property and microstructure of fly ash-based geopolymer activated by calcium hydroxide, calcium sulfate and their compound. The results indicated that calcium hydroxide and calcium sulfate can promote the dissolution of fly ash crystals, providing adequate Ca2+ for the formation of gel products. The products of calcium hydroxide and calcium sulfate activation are hydrated calcium aluminate, hydrated calcium sulfate, and ettringite, respectively. The effect of the compound activator is superior to that of single activators. With the increase of the proportion of calcium hydroxide, the reorganization and polymerization of gel products were accelerated so that the integrity and continuity of the microstructure of geopolymer were improved, and then the strength increased. When the ratio of calcium hydroxide to calcium sulfate was 3:1 and the total dosage was 20 %, the unconfined compressive strength reached the maximum value. According to this study, it was investigated that type and dosage of calcium activators had evident influence on the geopolymerization of fly ash. And the reutilization and resource utilization of fly ash waste can be achieved, which can provide an engineering theoretical basis for using fly ash-based geopolymer to alter the physical and chemical properties of special soils and achieve solidification effect.

Characterizing diffusion-controlled release of small-molecules using quantitative MRI in view of applications to orthopedic infection.

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 4weeks 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 × 10-11m2s-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.

Highly efficient CO2 mineralization: Mechanisms and feasibility of utilizing electrolytic manganese residue as a feedstock and implementing ammonia recycling

Electrolytic manganese residue (EMR) and CO2 emissions from the electrolytic manganese metal (EMM) production process present significant challenges to achieving cleaner production within the industry. Given the high capacity for CO2 sequestration and the stability of the sequestered forms, CO2 mineralization methods utilizing minerals or industrial residues have garnered considerable research interest. The efficacy of such methods is fundamentally dependent on the properties of the materials employed. EMR, due to its calcium sulfate dihydrate (CaSO4·2H2O) content, possesses an intrinsic potential for CO2 solidification. In this study, we propose a novel method for CO2 mineralization utilizing EMR, coupled with NH3·H2O recycling. Experimental results indicated that under conditions of a reaction temperature of 55 °C and a pH of approximately 8, each ton of EMR can sequester 0.16 t of CO2, with equilibrium achieved within 10 min. The mineralization mechanism was elucidated using SEM, TG curves, and XRD analyses, which revealed that Ca2+ ions are initially leached from CaSO4·2H2O in the EMR, subsequently precipitating with CO32− ions to form CaCO3. This CaCO3 layer effectively covers the surface of CaSO4·2H2O, inhibiting further Ca2+ release and stabilizing the reaction equilibrium. Furthermore, the ammonia in the solution is regenerated into NH3·H2O, facilitating its reuse and preventing secondary pollution. The utilization of EMR for CO2 mineralization not only mitigates carbon emissions in the EMM production process but also promotes environmentally sustainable practices in the industry. This study highlights a promising pathway towards achieving carbon neutrality and cleaner production in electrolytic manganese production.

Resorption characteristics of an open architecture biocomposite interference screw after ACL reconstruction.

Absorbable interference screws for anterior cruciate ligament reconstruction (ACLR) can lead to tunnel widening and cyst formation. The Biosure Regenesorb interference screw (Smith & Nephew). has been developed with an optimised calcium phosphate/polymer composition to promote bone formation during resorption. The present study aims to investigate screw resorption, new bone formation, and tunnel geometry following ACLR with Biosure Regenesorb screw tibial fixation. The study is a prospective single-centre case series of 12 patients with ACL lesions and treated with ACLR using hamstring tendon autograft with Biosure Regenesorb interference screw tibial fixation with a two-year follow-up period. The Biosure Regenesorb consists of 65% polylactide-glycolic acid poly. 20% calcium sulphate and 15% tricalcium phosphate. Primary endpoint: Tunnel volume. implant volume and new bone formation in the tibial tunnel is evaluated by quantitative computed tomography (CT) scanning. Secondary endpoints: Arthrometric knee laxity, International Knee Documentation Committee (IKDC) and Knee Osteoarthritis and Injury Outcome Scores (KOOS) and Tegner activity scale. Screw volume decreased to 44% within the two-year follow-up period while tunnel volume remained unchanged. Only a minor amount (<1% of tunnel volume) of new bone formation in the screw remnants was observed. Sagittal knee laxity at one year was 0.9 mm. The IKDC score increased by 15 points and the KOOS sport and KOOS quality of life scores increased by 25 and 26 points. respectively. ACLR using Biosure Regenesorb interference screw does not result in tunnel widening. showing a screw resorption of 44% after two years and minor new bone formation. Knee stability and subjective outcome improvements are as expected after other ACLR methods. IV.

Formulasi Serbuk Wedang Tahu dan Pendugaan Umur Simpan Menggunakan Metode Kadar Air Kritis

Indonesia silken tofu dessert is a traditional dish made from silken tofu and ginger sauce. To enhance its shelf life, this study explored the development of silken tofu dessert into a powdered form. Traditionally, silken tofu is coagulated using calcium sulfate (CaSO₄), but there has been little research on the optimal concentration of CaSO₄ necessary for forming curd in powdered silken tofu comparable to the traditional version. This study aimed to identify the ideal concentration of CaSO₄ as a coagulant to be added to powdered silken tofu and to estimate its shelf life using the critical moisture method. Sensory testing was conducted to select the appropriate concentration of CaSO₄, comparing different levels to a control method. The results revealed significant differences between the powdered silken tofu dessert and the traditional counterpart. Among the three CaSO₄ concentrations tested (3, 5, and 7%), the dessert prepared with 3% CaSO₄ exhibited the closest resemblance to the traditional silken tofu dessert. A single serving of this powdered silken tofu dessert provides 125 kcal of total energy, accounting for 12% of the recommended daily allowance (RDA) for protein, 3% for total fat, and 6% for carbohydrates. When packaged in metallized plastic and stored at a relative humidity of 78% and a temperature of 30 °C, the shelf life of the powdered silken tofu dessert is extended up to 12 months.

Bio-Inspired Fluorescent Calcium Sulfate for the Conservation of Gypsum Plasterwork.

In this work, the potential of bio-inspired strategies for the synthesis of calcium sulfate (CaSO4·nH2O) materials for heritage conservation is explored. For this, a nonclassical multi-step crystallization mechanism to understand the effect of calcein- a fluorescent chelating agent with a high affinity for divalent cations- on the nucleation and growth of calcium sulfate phases is proposed. Moving from the nano- to the macro-scale, this strategy sets the basis for the design and production of fluorescent nano-bassanite (NB-C; CaSO4·0.5H2O), with application as a fully compatible consolidant for the conservation of historic plasterwork. Once applied to gypsum (CaSO4·2H2O) plaster specimens, cementation upon hydration of nano-bassanite results in a significant increase in mechanical strength, while intracrystalline occlusion of calcein in newly-formed gypsum cement improves its weathering resistance. Furthermore, under UV irradiation, the luminescence produced by calcein molecules occluded in gypsum crystals formed upon nano-bassanite hydration allows the easy identification of the newly deposited consolidant within the treated gypsum plaster without altering the substrate's appearance.

Improved in-situ characterization for the scaling-induced wetting in membrane distillation: Unraveling the role of crystalline morphology

Despite being recognized as a promising technique for treating high salinity water, membrane distillation (MD) has been plagued by the scaling of sparingly soluble salts. The growth of crystals can not only create additional resistance to evaporating water at the feed-membrane interface, but also alter the hydrophobic network to bridge the feed and distillate (i.e., result in the phenomenon of wetting). When recognizing the uncertain behaviors of calcium sulfate (CaSO4) scaling in MD, this study was motivated to ascertain whether the crystal-membrane interactions could be dependent on the variation in crystalline morphology. In particular, optical coherence tomography (OCT) was employed to characterize the scaling-induced wetting via a direct-observation-through-the-membrane (DOTM) mode, which mitigated the effects of developing an external scaling layer on resolving the crystal-membrane interactions. The improved in-situ characterization suggests that the crystalline morphology of CaSO4 could be effectively regulated by varying the stoichiometry of crystallizing ions; the richness of calcium in the aqueous environment for crystallization would be in favor of weakening the crystal-membrane interactions. The stoichiometry-dependent growth of CaSO4 crystals can be exploited to develop an effective strategy for preventing the hydrophobic network from being wetted or irreversibly damaged.

Alpha-calcium sulfate hemihydrate incorporated with tri-calcium phosphate and hydroxyapatite bioceramics as potential scaffold for bone regeneration

The development of artificial grafts, including biodegradable materials and non-biodegradable ones, for bone regeneration is a significant advance in the field of biomaterial science. Notably, bioceramics such as calcium sulfate hemihydrate and calcium phosphates have attracted extensive attention from researchers due to their natural bone-like composition. However, some requirements related to mechanical properties, resorption ability, osteoinduction and osteoconduction of each bioceramics have not been effectively controlled to make them ideal materials for bone regeneration applications. In this study, composites of β-tricalcium phosphate, hydroxyapatite, and α-calcium sulfate hemihydrate (β-TCP/HA/α-CSH) were synthesized using wet mixing method in order to create a template that degrades in sync with bone growth, offer sufficient mechanical strength during healing process, and has appropriate setting time for precise surgical application. The β-TCP/HA compositional phase with the ratio of 80/20 (% in weight) would be used for the entire study meanwhile the influence of α-CSH on the behaviour of β-TCP/HA/α-CSH composites would be investigated. The successful preparation of β-TCP/HA/α-CSH composite was evaluated by FTIR, XRD, and SEM. In vitro testing has further demonstrated the commendable biodegradability of β-TCP/HA/α-CSH composites and its ability for cell adhesion and migration, suggesting that β-TCP/HA/α-CSH composites would be a promising biomaterial for bone engineering.

Effects of Agricultural Land Use on Desert Soil Classification in Holy Karbala Governorate

This study was conducted to evaluate physical, chemical, and morphological features to classify soils at the subgroup level. The research area, located west of Karbala, consists of three locations, each comprising pedons in both cultivated and uncultivated lands. GPS coordinates were recorded, and morphological descriptions of pedon horizons were made in accordance with the American Soil Survey Manual. This study investigates the effect of agricultural land use on the classification of desert soils in the Holy Karbala Governorate. The results revealed that the dry climate caused diversity in the morphological features of the soils, mainly in horizon type, thickness, and arrangement. Agricultural usage had an impact on diagnostic horizons, particularly the gypsic horizon, and features such as soil color, structure, organic matter, carbonate minerals, gypsum, and root distribution. However, there was no substantial impact on soil texture development, and soils did not show a consistent pattern of soil separation distribution with depth, indicating weak pedogenic processes. The most common texture classes were loamy sand, sandy loam, and sand, with sand contents ranged from 902.08 to 574.12 g kg. Soil bulk density differed from 1.67 to 1.30 Mg m³, with lower values in farmed areas. Chemical properties were influenced, with soil pH ranging from 8.36 to 7.54, electrical conductivity (EC) from 5.46 to 2.03 dS m, cation exchange capacity (CEC) from 15.25 to 2.05 meq.100g, organic matter from 43.51 to 1.18 g kg, carbonate minerals from 461.18 to 174.06 g kg, and calcium sulfate from 182 to 21 g kg. The soils were classed as Aridisols because they were found in a dry desert with an Aridic moisture regime. The presence of distinctive saline layers such as Calcic and Gypsic was discovered, resulting in the classification of cultivated soils as Typic Haplocalcids and uncultivated lands as Typic Calcigypsids.

Blending phosphogypsum to mitigate radionuclide leaching for sustainable road base applications

Production of phosphoric acid generates a calcium sulfate byproduct known as phosphogypsum (PG). PG is not considered a suitable standalone road base material because of concerns such as strength and presence of radionuclides. This paper investigates the latter, specifically the influence of blending PG with common alkaline road base aggregates – limerock (LR) and recycled concrete aggregate (RCA) – on radionuclide leaching. Radionuclide leaching from several PG sources was assessed for gross alpha, gross beta, uranium, and combined radium (226 + 228). Solution pH affected Ra226 mobility, with minimum concentrations exhibited at a pH in the range of 6 to 8. Mobile Ra226 concentrations in RCA blends decreased compared to original PG; Ra226 mobility initially increased at low LR replacements but decreased with increasing mass of LR (50 %–75 %). The data suggest an additional mechanism beyond pH alone impacted Ra226 mobility from the blends, possibly the binding or substitution of radium by elevated concentrations of Ba, Sr, or Ca. Blending with RCA resulted in radionuclide concentrations below respective drinking water thresholds, mitigating leaching concern from PG-RCA road base blends. PG-LR blends can meet regulatory limits when incorporating appropriate PG sources, providing an avenue for PG-amended road base materials. The blending approach reduced Ra226 mobility from PG-amended base, accommodating more PG use, serving as an alternative scenario to end-of-life stacking.

Phosphonated Polyetheramine-Coated Superparamagnetic Iron Oxide Nanoparticles: Study on the Harsh Scale Inhibition Performance of Calcium Carbonate and Barium Sulfate.

Harsh scale buildup, such as calcium carbonate (calcite) and barium sulfate (barite), poses significant challenges in the oil and gas industry. While various scale inhibitors (SIs) are employed to mitigate this issue, there is a need for greener, more efficient, compatible, and affordable alternatives. Calcium compatibility often complicates the use of SIs, potentially leading to formation damage. Our group has recently synthesized a recyclable nanocomposite scale inhibitor made of superparamagnetic nanoparticles coated with a trisodium citrate linker to phosphonated poly(ether amine) (SPION-TSC-PPEA) and tested it against calcium sulfate (gypsum), a simple form of scale buildup. This study evaluates the recyclable nanocomposite scale inhibitor's efficiency in mitigating calcite and Barite scales through static jar tests and high-pressure dynamic tube-blocking tests at 80 bar and 100 °C. The nanocomposite demonstrated high calcium ion compatibility, excellent inhibition efficiency against calcite, moderate efficiency against Barite, and maintained efficacy over five recycling cycles.

Decoding organic compounds in lava tube sulfates to understand potential biomarkers in the Martian subsurface

Exploring molecular biomarkers in lava tube speleothems offers insights into environmental dynamics, biogeochemical processes, and subsurface life, with implications for astrobiology, particularly in Martian analog environments. Despite extensive biomarker research in marine and terrestrial settings, lava tube studies are limited. This study employed molecular, isotope and mineralogical characterization to analyze sulfate speleothems from six lava tubes of Lanzarote (Canary Islands), considered analog for the Moon and Mars. The combination of mass spectrometry, thermogravimetry, and mineralogical techniques, revealed geological processes, biomarkers and their biological sources. The identified minerals were primarily calcium and sodium sulfates. Sulfur isotope analyses indicated volcanic and oceanic origins, while carbon isotope composition and pyrolysis analyses suggested influences from vegetation and microbial activity. Lipidic profiles highlighted branched and n-alkanes, as well as palmitic and stearic acid methyl esters, suggesting microbial origins. These findings contribute to understanding geological and environmental dynamics in lava tubes and recognizing potential biosignatures on Earth and other planets.

Septic Nonunion Of Radius and Ulna. Treatment with Calcium Sulphate Beads Impregnated With Antibiotic, Plate Fixation and Iliac Crest Autograft

Septic Nonunion Of Radius and Ulna. Treatment with Calcium Sulphate Beads Impregnated With Antibiotic, Plate Fixation and Iliac Crest Autograft