Addition Of Ca2 Research Articles

Effect of dietary calcium source, exogenous phytase, and formic acid on inositol phosphate degradation, mineral and amino acid digestibility, and microbiota in growing pigs.

The choice of the calcium (Ca) source in pig diets and the addition of formic acid may affect the gastrointestinal inositol phosphate (InsP) degradation and thereby, phosphorus (P) digestibility in pigs. This study assessed the effects of different Ca sources (Ca carbonate, Ca formate), exogenous phytase, and chemical acidification on InsP degradation, nutrient digestion and retention, blood metabolites, and microbiota composition in growing pigs. In a randomized design, 8 ileal-cannulated barrows (24kg initial BW) were fed 5 diets containing Ca formate or Ca carbonate as the only mineral Ca addition, with or without 1,500 FTU/kg of an exogenous hybrid 6-phytase. A fifth diet was composed of Ca carbonate with phytase but with 8g formic acid/kg diet. No mineral P was added to the diets. Prececal InsP6 disappearance and P digestibility were lower (P ≤ 0.032) in pigs fed diets containing Ca formate. In the presence of exogenous phytase, InsP5 and InsP4 concentrations in the ileal digesta were lower (P ≤ 0.019) with Ca carbonate than Ca formate. The addition of formic acid to Ca carbonate with phytase diet resulted in greater (P = 0.027) prececal InsP6 disappearance (87% vs. 80%), lower (P = 0.001) InsP5 concentration, and greater (P ≤ 0.031) InsP2 and myo-inositol concentrations in the ileal digesta. Prececal P digestibility was greater (P = 0.004) with the addition of formic acid compared to Ca carbonate with phytase alone. Prececal amino acid (AA) digestibility of some AA was greater with Ca formate compared to Ca carbonate but only in diets with phytase (P ≤ 0.048). The addition of formic acid to the diet with Ca carbonate and phytase increased (P ≤ 0.006) the prececal AA digestibility of most indispensable AA. Exogenous phytase affected more microbial genera in the feces when Ca formate was used compared to Ca carbonate. In the ileal digesta, the Ca carbonate diet supplemented with formic acid and phytase led to a similar microbial community as the Ca formate diets. In conclusion, Ca formate reduced prececal InsP6 degradation and P digestibility, but might be of advantage in regard to prececal AA digestibility in pigs compared to Ca carbonate when exogenous phytase is added. The addition of formic acid to Ca carbonate with phytase, however, resulted in greater InsP6 disappearance, P and AA digestibility values, and changed ileal microbiota composition compared to Ca carbonate with phytase alone.

Effect of magnesium and calcium ions on the strength and biofunctionality of GelMA/SAMA composite hydrogels.

Natural polymers and synthetic polymers have been extensively studied as scaffold materials, with the former offering advantages such as biocompatibility, biodegradability, and structural similarity to the natural extracellular matrix (ECM). However, the use of natural polymers in extrusion-based 3D printing has been limited by their poor mechanical properties and challenging rheological properties. In this study, gelatin and sodium alginate were utilized as scaffold materials, with the addition of Ca2+ and Mg2+ components to enhance their physical and chemical properties, and influence early cell behavior. Subsequently, these materials were fabricated into scaffolds using 3D printing. Our results demonstrated that the addition of Ca2+ and Mg2+ could improve the compactness of the 3D network structure, mechanical strength, swelling properties and degradation properties of methacrylated gelatin/methacrylated sodium alginate (GelMA/SAMA) composite hydrogel. In vitro cell tests revealed that the GelMA/SAMA composite hydrogel exhibited negligible cytotoxicity and promoted early cell viability, particularly with the higher concentration of Mg2+ in the material. Notably, the extrusion 3D printing process successfully produced GelMA/SAMA scaffolds. These results collectively indicate that GelMA/SAMA composite scaffolds hold promise as potential biomaterials for tissue engineering applications.

The effects of Nd, La, and Ca addition on the corrosion properties of as-cast and as-rolled ZM21 Mg alloys

In this study, the effects of Nd, La, and Ca elements added to ZM21 alloy was investigated in terms of parameters such as microscopic, mechanical, and corrosion properties. The content of each of the elemental constituents was 0.5% by weight. The microstructural and mechanical behaviours of the investigated alloys were examined by XRD, EDX, SEM, OM, hardness surveys, tensile tests, and corrosion experiments. According to the XRD results, Ca5Zn3, Ca2Mg6Zn3, LaZn2, LaMg3, Mg41Nd5, and Mg12Nd phases emerged on the investigated alloys. The grain sizes of the alloys were refined by element addition and rolling process, thus increasing their mechanical properties. Ca increased the hardness of the ZM21 alloys, but this had a negative effect on the rolled specimens. The tensile value of ZM21 alloy as cast decreased by 39.702%, 48.080%, 45.678% with the addition of (0.5% La+0.5% Nd), (0.5% La+0.5% Ca), (0.5% La+0.5% Nd+0.5% Ca), respectively. The tensile value of ZM21 alloy with (0.5% La+0.5% Nd) addition increased by 58.302% as rolled. Tensile test could not be performed because the rolled alloys with 0.5% Ca addition were fragmented during rolling. Ca contributed positively to the corrosion behaviour of the casting ZM21 alloy, but it worsened it in the rolled alloys. White oxide areas on the surface of the rolled alloys indicated an increased degree of corrosion formation.

Microplastics as potential barriers to ultraviolet light emitting diode inactivation of MS2 bacteriophage: Influence of water-quality parameters

Microplastics have emerged as a concerning contaminant in drinking water sources, potentially interacting with pathogenic microorganisms and affecting the disinfection processes. In this study, MS2 was selected as an alternative for the human enteric virus. The influence of microplastics polyvinylchloride (MPs-PVC) on ultraviolet light emitting diode (UV-LED) inactivation of MS2 was investigated under various water chemistry conditions, such as MPs-PVC concentration, pH, salinity, and humic acid concentration. The results revealed that higher concentrations of MPs-PVC led to the reduced inactivation of MS2 by decreased UV transmittance, hindering the disinfection process. Additionally, the inactivation efficiency of MS2 in the presence of MPs-PVC was influenced by pH, and acidic solution (pH at 4, 5, and 6) exhibited higher efficiency compared to alkaline solution (pH at 8 and 9) and neutral solution (pH at 7). The low Na+ concentrations (0–50 mM) had a noticeable effect on MS2 inaction efficiency in the presence of MPs-PVC, while the addition of Ca2+ posed an insignificant effect due to the preferential interaction with MPs-PVC. Furthermore, the inactivation rate of MS2 initially increased and then decreased with increasing the concentration of humic acid, which was significantly different without MPs-PVC. These findings shed light on the complex interactions between MPs-PVC and MS2 in the UV-LED disinfection process under various water-quality parameters, contributing to drinking water safety and treatment.

Revitalizando fertilidade dos solos globais: Meta-análise sobre benefícios do biochar de cama de frango na saúde do solo

ABSTRACT This study aimed to conduct a meta-analysis (MA) of systematic review data on poultry litter biochar (PLB) to answer the following questions: (i) What are the major studies regarding this worldwide? (ii) Which soil chemical attributes are the most affected? and (iii) Does PLB improve soil quality and crop productivity? MA revealed that the application of PLB significantly changed several key soil attributes, including pH, cation exchange capacity (CEC), and nitrogen, carbon, potassium, calcium, magnesium, and aluminum content. Specifically, MA showed that PLB decreased Al3+ in the soil by 71% while increasing pH, N, C, and CEC by 16, 20, 36, and 82%, respectively. This significant increase in CEC was associated with the addition of Ca2+, Mg2+, and K+ cations by 43, 202, and 636%, respectively. It was verified that PLB serves a dual function: it corrects soil acidity and pH while also enhancing the content of key nutrients, such as C and N. This study broadens the understanding of the potential of reusing poultry litter in biochar production, offering valuable data for developing strategies to improve both soil health and fertility.

Investigation of the effect of different additives on the qualities, <i>in vitro</i> degradation, and rumen fermentation profile of indigo waste silage

<abstract> <p>Natural indigo dye production produces indigo waste as a by-product. Our purpose of this study was to examine the effects of calcium hydroxide (Ca(OH)<sub>2</sub>), cellulase (CE), molasses (MO), and their combinations on the silage quality, <italic>in vitro</italic> degradability, and rumen fermentation parameters of indigo waste silage. A completely randomized design (CRD) was used for the experiment. Indigo waste was chopped and ensiled in a small-scale silo with no additive (control), Ca(OH)<sub>2</sub>, MO, CE, Ca(OH)<sub>2</sub>:MO, Ca(OH)<sub>2</sub>:CE, MO:CE, and MO:CE:Ca(OH)<sub>2</sub>. After 30 days of storage, the silages were tested for quality and chemical composition, as well as an <italic>in vitro</italic> fermentation. The ruminal fluid inoculum was collected from two beef cattle with a body weight (BW) of 200±10 kg, and the inoculum had been pre-heated before being transported to the laboratory. Silage with MO, CE, or their combination increased the amount of lactic acid (<italic>p</italic> < 0.01). The silage pH was lowest in MO:CE (4.5) and was highest in Ca(OH)<sub>2</sub>:CE (10.6) in indigo waste (<italic>p</italic> < 0.01). In comparison to the control (19.5% CP), the CP content of all additives increased by 20.7% to 21.5% (<italic>p</italic> = 0.02). The addition of Ca(OH)<sub>2</sub>:MO and Ca(OH)<sub>2</sub>:CE resulted in a reduction of NDF content by 60.7% and 59.4%, respectively, in comparison to the control group (72.4%) (<italic>p</italic> < 0.01). Silage with additives had no effect on the cumulative gas production or gas kinetics, except that the constant rate of gas production for the insoluble fraction (c) was higher in MO (<italic>p</italic> = 0.03). <italic>In vitro</italic> dry matter degradability (IVDMD) was higher in CE and MO and highest in MO:CE-treated silage (<italic>p</italic> < 0.01). The <italic>in vitro</italic> organic matter degradability (IVOMD) increased in Ca(OH)<sub>2</sub>:MO compared with the control (<italic>p</italic> = 0.03). The additives alone or in their two combinations in silage reduced the ruminal ammonia-nitrogen (NH<sub>3</sub>-N) concentration (28.0 to 31.5 mg/dL) when compared to the control (32.7 mg/dL) (<italic>p</italic> < 0.01). In addition, the highest total volatile fatty acid (VFA) level was found in the silage of the MO (92.9 mmol/L) compared with the control (71.3 mmol/l) (<italic>p</italic> < 0.01). The proportion of propionic acid and butyric acid increased (<italic>p</italic> < 0.01) whereas acetic acid decreased (<italic>p</italic> < 0.01) in the rumen of silage with MO and CE. In summary, the addition of MO and CE has the potential to be used in the silage of indigo waste.</p> </abstract>

The effect of addition of calcium mineral in feed containing fishery wastes on egg production and hatching performance of Mojosari ducks.

Calcium (Ca) is an essential mineral for eggshell formation and muscle contraction, and a lack of it can result in poor egg quality and decreased egg output in laying ducks. This study aims to see how feeding the mineral Ca in a ration containing Shrimp head meal and Bilis fish head affects the laying performance and quality of hatching eggs in Mojosari ducks. A total of 105 female and 15 male Mojosari ducks, aged 78 weeks, were raised for three months and randomly divided into 15 flocks (each flock containing seven females and one male duck). There were three kinds of treatment, namely P0 (control, without mineral), P1 (ratio of Shrimp head meal and Bilis fish head 2:1 + 1% mineral), and P2 ((ratio of Shrimp head meal and Bilis fish head 1:2 + 1% mineral). The findings revealed that adding mineral Ca to feed, including Shrimp head meal and Bilis fish head, had no significant influence (P>0.05) on laying Mojosari duck performance in terms of feed intake, egg production, egg weight, egg quality, ducklings produced, and income over feed cost (IOFC). Furthermore, Ca addition in the ration did not result in substantial increases (P>0.05) in fertility, hatchability, or egg size characteristics. Based on the findings of this study, feeding ducks with shrimp head meal and Bilis fish head can be used as an alternate calcium-free feed formulation.

Electrochemical behavior and discharge performance of dilute Mg-Bi-based alloy as an anode for primary Mg-air battery

In this study, the electrochemical behavior and discharge performance of dilute Mg-0.5Bi-0.5Ca-0.5Ag alloy as an anode for primary Mg-air battery are studied and compared with those of Mg-0.5Bi base alloy. The results show that the addition of trace Ca and Ag to Mg-0.5Bi base alloy is conducive to enhancing the dynamic recrystallization (DRX) extent, reducing the basal texture component and kernel average misorientation value. In addition, re-deposited Ag in the discharge products can improve discharge activity by promoting the dissolution of the Mg matrix and rupturing the discharge product film. For these reasons, the Mg-0.5Bi-0.5Ca-0.5Ag anode presents a high level of synergy between cell voltage and anodic efficiency by means of the enhanced anode dissolution kinetics and effective reactive area. Therefore, dilute MgBi based anode micro-alloyed with Ag and Ca presents a great potential to be developed as novel anode material for Mg-air battery.

Enhancing concrete resilience and sustainability through fly ash-assisted microbial biomineralization for self-healing: From waste to greening construction materials

This study presents a pioneering approach that enables remarkable crack closure up to 0.8 mm through stimulated biomineralization aiming to enhance the self-healing capacity of concrete. The innovative synergy tackles the pressing environmental challenges head-on investigates the intriguing germination process of endospores in a cementitious environment and underscores the function of calcareous fly ash in promoting Microbially Induced Calcium Carbonate Precipitation (MICP) by providing additional Ca2+ ions, that are converted into carbonate phases through bacterial metabolic processes. These phenomena are thoroughly examined using an in-situ model particularly concerning MICP in bio-concrete, and thermodynamic modelling is performed to forecast the influence of fly ash on the quantity of Ca-bearing (carbonation sensitive) phases present in the hydrated phases of fly ash-blended cement system. Incorporating 30 % class C fly ash significantly amplifies the biomineralization activity, with 6.5 % calcium carbonate deposition in bio-concrete leds to significant healing activity. Concurrently, MICP contributes to a significant reduction in pore sizes, thereby enhancing the overall durability of concrete. Beyond structural improvements, this innovative bio-concrete formulation showcases an impressive 39 % reduction in CO2 emissions, aligning with sustainability goals. Additionally, repurposing fly ash, typically consigned to landfills, seamlessly adheres to the tenets of a circular economy, despite incurring a 7 % rise in the initial production cost. That promising advanced methodology can deliver transformative environmental benefits, ushering in a paradigm shift in sustainable construction practices, and finding the synergistic interplay between microbial activity and calcium-dependent fly ash.

Removal of Diclofenac in Wastewater by Activated Sludge in Batch and Moving-bed Biofilm Reactor Experiments

This study aimed to determine the diclofenac removal in wastewater by sludge taken from an operating wastewater treatment facility. Laboratory experiments were conducted in two parts: batch and moving-bed biofilm reactor (MBBR) experiments. Results from batch experiments showed that 0.1–2 mg L-1 of diclofenac could be removed more than 80% within 72 h, and the removal efficiency reduced to less than 60% for higher concentrations. The increase in the removal rate from 0.00058 to 0.16527 mg L-1 h-1 was observed when the initial diclofenac concentration increased from 0.1 to 10 mg L-1, respectively. The average first-order rate constants of 24-h and 72-h degradation were calculated as 4.71 × 10-2 and 1.99 × 10-2 h-1, respectively. The removal of diclofenac by sludge was mainly from biodegradation by microorganisms in sludge, followed by the adsorption onto the sludge biomass. The addition of various metal ions in the studied range did not significantly increase the diclofenac removal; however, the addition of Ca2+, Co2+, Fe3+, Mn2+, and Zn2+ tended to increase both diclofenac removal rate and efficiency. This positive effect was reduced when the metal ion concentrations were increased up to 0.75 ppm. Lastly, results from an initial phase of continuous MBBR showed that sludge addition during the start-up also extended the diclofenac removal efficiency to one week compared with 3 days in the experiment without sludge addition. In conclusion, the findings show the capability of using activated sludge in diclofenac wastewater treatment by the traditional or alternative systems.

Stepwise recovery of critical metals from spent NCM lithium-ion battery via calcium hydroxide assisted pyrolysis and leaching

The stepwise extraction of critical metals from spent LiNixCoyMnzO2 lithium-ion batteries (NCM LIBs) has received particular attention for efficient resource recycling. In present paper, Ca(OH)2 was used as an additive in the pyrolysis process to realize the stepwise recovery of critical metals from spent NCM LIBs. During the Ca(OH)2 assisted pyrolysis, lithium in the NCM was converted into LiOH, Li2O, Li2CO3 and LiF. Under optimal conditions, exceeded 93 % of lithium can be extracted preferentially by water leaching without additional additives and the recovery efficiencies of nickel, cobalt and manganese reached 99 % by subsequent acid leaching. Furthermore, LiOH·H2O was successfully prepared by evaporation and crystallization of lithium leachate. The addition of Ca(OH)2 could achieve the in-situ fixation of harmful pyrolytic gas, the transformation of lithium phase and reduction of cathode materials, which promoted the lithium leaching. This study provides an environmentally-friendly and competitive process for recycling spent NCM LIBs by pyrolysis.

Metal cation-induced conformational changes of soybean protein isolate/soybean soluble polysaccharide and their effects on high-internal-phase emulsion properties.

Metal ions commonly inevitably appear in food products and have adverse effects on high-internal-phase emulsions (HIPEs) foods, but conformational conversion of soybean protein isolate (SPI)/soybean soluble polysaccharide (SSPS) on the interface layer of HIPEs influenced by different metal ions has rarely been reported. Here, the conformational conversion of SPI/SSPS induced by Na+ , K+ , Ca2+ , Mg2+ and Fe3+ ions and its effects on HIPEs were investigated. After adding the ions to SPI and SPI/SSPS dispersions, the particle size and zeta potential results showed different degrees of flocculation; the zeta potential and Fourier transform infrared spectra indicated that SPI and SPI/SSPS changes in structure involve electrostatic interactions and hydrogen bonding. Moreover, Raman spectra showed that the content of β-sheet of SPI/SSPS HIPEs increased with the addition of Ca2+ , Mg2+ and Fe3+ , suggesting that SPI molecules at the interface formed a more orderly structure. The ultraviolet and fluorescence results showed that the hydrophobic environment of tryptophan and tyrosine residues inside protein molecules played a vital role in the emulsifying stability of SPI. These findings suggested that the SPI/SSPS complexes for food applications were not susceptible to ions, thus ensuring complex stability, showing potential for commercial application in the production of emulsions. © 2023 Society of Chemical Industry.

Manufacturing and processing of sheets using a Mg–Al–Ca–Zn–Y alloy for automotive applications

As the transportation industry evolves, so do its needs, creating opportunities for the use of non-standard materials. While electrically powered vehicles (EVs) generally operate at lower temperatures than those with internal combustion engines, operation at elevated temperature is still important for battery cases and motor housings. There, Mg alloy sheets could be used, as they have great potential for lightweighting. Mg–Al–Ca-alloys are particularly suitable, as they form temperature-stable phases, providing advantages compared to classical Mg–Al–Zn alloys.In this work, sheets made of an Mg–Al–Zn–Ca–Y alloy (AZXW3120) were manufactured via hot-rolling. The microstructure and texture in various conditions were analyzed and the mechanical properties were investigated at RT and 150 °C. The Ca additions led to a reduced texture after rolling and allowed for an increase in tensile strength of 15–20 MPa by age hardening. The age-hardenable AZXW3120 sheets showed better formability during cup-drawing (31.4 vs. 27.5 mm) and higher elevated temperature yield strength, of up to 25 MPa, compared to industrially produced AZ31 Mg sheet.

Cementation of degraded residues of spent radioactive organic solvents by fenton oxidation

The safe treatment and disposal of radioactive organic solvents is a priority and a challenge in the field of radioactive waste management. Fenton oxidation is a promising method for transforming it into inorganic components. This work focused on cementation of the residues of spent organic solvent oxidized by Fenton reaction. Sulphoaluminate cement (SAC) was used as the matrix material with the addition of Ca(OH)2 and H3BO3. The influence of Ca(OH)2 and H3BO3 on the fluidity and setting time of cement mortar was studied. The cementation formula was optimized and a suitable cementation formula was obtained. The experimental results indicated that the 28 d compressive strength could reach 18.5 MPa. The results of the freeze-thaw test, immersion test, irradiation test and impact test also meet the requirement. The 42 d leaching rate was 8.0 × 10−4 cm/d for Sr2+, 3.4 × 10−3 cm/d for Cs+, and 3.5 × 10−7 cm/d for Co2+, all of which could meet the national standard requirements.

Investigations of Electrochemical Characteristics of Mg-Al-Ca Alloys

Magnesium alloys possess a high strength-to-density ratio, thereby increasingly being utilized as lightweight structural materials in a range of industrial applications. Nevertheless, to compete with established materials like aluminum alloys, it is essential to understand the corrosion behavior of Mg and its alloys, as their high reactivity hampers industrial application. The addition of Ca to wrought Mg-Al alloys has gained attention for its ability to improve mechanical properties while also enhancing processing behavior. However, the wide range of alloy compositions within the class of Mg-Al-Ca alloys results in a variety of different corrosion properties. Consequently, this study contributes by investigating the corrosion behavior of two Mg-Al-Ca alloys, highlighting the influence of chemical composition and microstructure.

Evaluation of Ca-alloyed and HAp-reinforced magnesium matrix surface composite properties developed by friction stir processing

ABSTRACT The objective of this study is to fabricate AZ31 surface composites (MMSC) through friction stir processing (FSP) by introducing calcium (Ca) as an alloying element and hydroxyapatite (HAp) as reinforcement in different proportions. The analysis reveals that the β-Mg17Al12 phase remains more stable in its as-fabricated state, while the Mg2Ca phase exhibits greater stability during the aging period. The addition of Ca and HAp leads to higher Mg2Ca and Ca3Mg4Al5 formation during aging process. The incorporation of Ca and HAp results in an increased elastic modulus (E) of the as-fabricated MMSC in comparison to AZ31, with no significant degradation observed following the aging process. The hardness of MMSCs increases with the increase in β-Mg17Al12, and Mg2Ca phases. Moreover, the incorporation of Ca and HAp results in enhanced corrosion resistance of the as-fabricated MMSCs in comparison to AZ31.

Effect of Ca addition on near-infrared reflection of SrCuSi4O10

Abstract In this study, SrCuSi4O10 powders were synthesized by a complex polymerization method and the effect of Ca addition on the crystal structure and optical properties in the visible and near-infrared regions was examined. Crystalline SrCuSi4O10 was formed at 1,000 °C in air. From the X-ray diffraction measurements, the (002) and (004) reflections of SrCuSi4O10 shifted to higher angles, and the lattice parameter (a and c) decreased with the addition of Ca, suggesting that Ca was successfully introduced into SrCuSi4O10. However, the lattice constant of SrCuSi4O10 increased with further addition of Ca to 10 mol%. Optical measurements of SrCuSi4O10 identified three optical absorption bands in the visible light region, attributed to the d–d transition of Cu2+: namely 2B1g → 2B2g (540 nm), 2B1g → 2Eg (628 nm), and 2B1g → 2A1g (800 nm). The addition of Ca decreased the intensity of these absorptions. The –b* value, which indicates blueness, was estimated using the L*a*b* color system, and SrCuSi4O10 with 5 mol% Ca showed the highest value among the measured samples. On the other hand, the reflectance of SrCuSi4O10 in the near-infrared region increased significantly with the addition of Ca. These results indicate that Ca addition is effective in improving the blue coloration and near-infrared reflectivity of SrCuSi4O10.

The Effects of the Addition of Ca, Gd, La, and Y on Mechanical Properties and Microstructure of Pure Magnesium

The effects of different elements on the mechanical properties and microstructure of pure Mg were studied by XRD, SEM, and tensile tests. The results show that with the addition of 1wt% Ca, Gd, La, and Y elements alone, different second-phase particles appear in the microstructure of Mg-1X. The addition of Gd and Y elements generates a small amount of Mg5Gd and Mg24Y5 particles, respectively. In contrast, the addition of the Ca element generates a large number of coarse Mg2Ca particles, and the addition of the La element generates a large number of fine and evenly distributed Mg12La particles. After extrusion, the extruded Mg-1X magnesium alloy shows a fine equiaxed recrystallization structure. All four alloys show bimodal texture distribution with deflection along the ED direction, and the texture deflected along the TD direction appears in Mg-1La alloy. The tensile test shows that the yield strength of MG-1La alloy is the highest when it is drawn along the ED direction. The yield strength of Mg-1La alloy is the lowest when it is drawn along TD.

Effect of Mn and Ca on mechanical, corrosion and surface roughness of Mg-5Sn alloy

Magnesium and its alloys have an extensive application prospect in the aerospace, automotive industry, sports equipment, biomedical and energy storage due to their high specific strength and low density compared with iron and Aluminum alloys. However, the strength and the corrosion resistance of Mg alloys is still the major drawback that hampers their application. Alloying is generally used to improve mechanical and corrosion properties. The mg-Sn alloy system was extensively studied and the Mg-5Sn alloy was chosen as the base composition owing to the addition of 5 wt% Sn improves the strength and corrosion resistance of pure Mg. The present work aims to investigate the effect of Mn and Ca addition on mechanical, corrosion and roughness properties of as-cast Mg-5Sn-Mn-Ca alloy. The addition of Mn and Ca elements significantly refined α-Mg grains. Mn-rich phase precipitated alongside intermetallic eutectic Mg2Snphases and CaMgSn eutectics observed on the grain boundaries. The strength, hardness, roughness, and corrosion resistance of Mg-5Sn alloy are observed to be improved by the addition of Mn and Ca.

Mg2+ Ions Stimulate both Helical Protoplast-Callose-Fiber Formation and Protoplast Division in a Mangrove Tree, Sonneratia caseolaris: Analysis of Sub-fibril Structures of PCF by Atomic Force Microscopy

The effects of four salts, NaCl, KCl, MgCl2 and CaCl2, on protoplast division and protoplast-callose-fiber (PCF) formation were examined using suspension cultured cells of a mangrove tree, Sonneratia caseolaris. Basal medium was hormone-free Murashige & Skoog’s medium containing 0.8 M sorbitol and 3% sucrose. Addition of 50-100 mM of Mg2+ ions highly stimulated both cell division and PCF formation, while addition of Ca2+ ions was inhibitory. Addition of Na+ ions at 10-25 mM and K+ ions at 50-100 mM stimulated protoplast division but not PCF formation. Helical PCF rapidly elongated from a specific site of cell division plate after 3 days of culture. The β-1,3-glucan (callose) component of the protoplast-fibers was stained with Aniline Blue fluorescent dye and was re-certified enzymatically using laminarinase. After selecting the PCF using a micromanipulator, we analyzed the fibril- and sub-fibril- structures using laser confocal scanning microscopy (LCSM), and atomic force microscopy (AFM). We discuss the uniqueness of the PCF of S. caseolaris as compared to PCFs of several plants.