Optimal Concentration Research Articles

A complementary eco-friendly approach to heavy metal removal from wastewater/produced water streams through mineralization

With the world's ever-increasing population, portable water needs have significantly increased. This has put enormous pressure on the limited supply of freshwater around the globe and has necessitated the development of water treatment technologies that would convert saline waters into potable water for domestic and industrial uses. As saline water is treated for usage, so is wastewater generated from domestic and industrial processes. More prominently, another wastewater source is produced water consequent to oil production. Wastewater and produced water are similar in that they are both high in pollutants (heavy metals), which in discharge streams need to be kept within a threshold. The fact that heavy and rare earth metals linked to the produced water cannot be completely removed by state-of-the-art technologies is even more concerning. Thus, a complementary technology must be developed for this reason. This study investigates the mineralization of water-polluting heavy metals. The approach adopted involves the exposure of contaminated water to atmospheric or captured CO2 and the use of additives to achieve the removal. To gain a deeper understanding of how these innovative efforts function, the study also looked into the mechanism used to eliminate the heavy metals. The findings show that heavy metals in produced water and industrial effluent can be precipitated and immobilized to remove them. More so, this is made possible by the infusion of heavy metals into the crystal structures of precipitates like aragonite, calcite, and halite. Furthermore, the mechanism of the heavy metal removal involves their dehydration, immobilization and precipitation. Additionally, DFT calculations were utilized to support the experimental results by shedding light on the heavy metal hydration's ground-state structures and how EDTA chelates the heavy metals and enhances the process kinetics. The study's findings show how this strategy complements the most advanced wastewater treatment method in terms of increasing its efficiency and water security and safety. More so, as this is a pioneering effort, the optimum concentration of chelating agent and route (atmospheric or captured CO2) must be determined on a case-to-case basis for field implementation. Furthermore, the limitation of this study is that the efficiency of heavy metal removal may differ based on the starting brine composition, thus, optimization must be conducted beforehand.

In vitro analysis of a novel dimethylaminododecyl methacrylate modification of dental acrylic soft liner material

Soft denture liners have limitations like short lifespan and increased microbial buildup. Despite promise as a non-leaching antimicrobial polymer in dentistry, the impact of dimethylaminododecyl methacrylate (DMADDM) on soft liner performance remains unexplored. This study aimed to evaluate the effect of integrating different concentrations of DMADDM to cold cure acrylic resin soft liner, on its antimicrobial activity, cytotoxicity, and physical properties. The same properties were compared to a conventional commercially available denture soft liner. The study employed a control group (conventional soft liner) and three test groups containing 3.3%, 6.6%, and 10% (total mass fraction) DMADDM, respectively. Antimicrobial activity against Candida albicans and Streptococcus mutans was assessed through colony counts and biofilm biomass. Cytotoxicity was evaluated using an oral epithelial cell line. Additionally, wettability and hardness were measured to assess physical properties. Incorporation of DMADDM significantly reduced Candida albicans and Streptococcus mutans counts, and biofilm biomass, compared to the control. Additionally, DMADDM improved the soft liner's wettability and mitigated long-term hardness increase. In conclusion, DMADDM holds promise in enhancing soft liner performance. However, careful selection of its optimum concentration is crucial to ensure both safety and efficacy for future clinical use.

Programmable Aggregation of Self-Assembled DNA Constructs.

Biomolecular aggregates ensure the optimum concentration and proximity required for biochemical processes to take place. Synthetic aggregating systems are becoming increasingly essential to study/mimic dynamic condensates in nature. Herein the ratiometric DNA aggregation of self-assembled DNA constructs using lanthanide salts is reported. In addition, the aggregation is shown to be reversed by the addition of specific lanthanide-binding ligands. The aggregate formation is confirmed by dynamic light scatteringexperiment, electrophoretic mobility shift assay, and field emission scanning electron microscope. This programmed DNA aggregation and its reversion are applied to evaluating the lanthanide-DNA and lanthanide-ligand binding constants, respectively. To achieve this, Forster resonance energy transfer (FRET)pair dyes at the 3' or 5' end of the DNA strands are strategically placed that generate unique fluorescence patterns upon interaction with the DNA constructs and different triggers such as lanthanides/ligands/monovalent cations, thus enabling the tracking of various states of binding. It also demonstrates a "fast method" to form and stabilize G-quadruplex (GQ) using lanthanides which complements the existing slow formation of GQs with Na+/K+ ions. The formation of GQ by lanthanides is corroborated by FRET, circular dichroism (CD), and enzyme linked immunosorbent assay (ELISA) experiments. These DNA constructs, formed by lanthanides, have shown resistance to cleavage by DNase I, and distinctive binding to Protoporphyrin dyes and Thioflavin T.

Effect of naringenin on post-thaw quality, fertility-associated gene expression and fertilization potential of buffalo (Bubalus bubalis) bull sperm

Our objectives were to explore the effect of naringenin addition in the semen extender on the post-thaw 1) sperm quality, 2) fertility-associated gene expression, and 3) fertilization potential of buffalo bull sperm. In experiment 1, semen samples (n = 32) from four Nili-Ravi buffalo bulls were pooled (n = 8) and diluted with the tris-citric acid (TCF-EY) extender containing different concentrations of naringenin, i.e., placebo (DMSO), 0 (control), 50, 100, 150 and 200 μM naringenin. After dilution, semen samples were packed in 0.5 mL French straws, cryopreserved and analyzed for post-thawed sperm quality and gene expression. Computer-assisted Semen Analysis, Hypo-osmotic Swelling test, Normal Apical Ridge assay, Rhodamine 123, Acridine orange, Propidium iodide staining and Thiobarbituric Acid Reactive Substances assay were performed to assess sperm motility parameters, plasma membrane functionality, acrosome integrity, mitochondrial membrane potential, DNA integrity, viability and lipid peroxidation, respectively. Expression levels of sperm acrosome-associated SPACA3, DNA condensation-related PRM1, anti-apoptotic BCL2, pro-apoptotic BAX, and oxidative stress-associated ROMO1 genes were evaluated through qPCR. Results revealed that total and progressive motility, plasma membrane functionality, acrosome integrity, mitochondrial membrane potential, DNA integrity and viability were higher (P < 0.05) with 50, 100 and 150 μM naringenin compared to 200 μM naringenin, placebo and control groups. Moreover, all naringenin-treated groups improved catalase activity, and reduced lipid peroxidation compared to placebo and control groups (P < 0.05). Relative expression levels of SPACA3 and PRM1 genes were higher (P < 0.05) with 150 μM naringenin compared to all groups except 100 μM (P > 0.05). No difference (P > 0.05) in the expression level of BCL2 gene was observed among all groups. Furthermore, BAX gene was expressed higher (P < 0.05) in the 200 μM naringenin group, whereas no difference (P > 0.05) in expression was noticed among the remaining groups. In addition, ROMO1 gene was expressed lower (P < 0.05) in all naringenin-treated groups compared to the control. In experiment 2, the in vivo fertility of semen doses (n = 400; 200/group) containing optimum concentration of naringenin (150 μM; depicted better in vitro sperm quality in experiment 1) was compared with control during the breeding season. Buffaloes were inseminated 24 h after the onset of natural estrus and palpated transrectal for pregnancy at least 60 days post-insemination. The fertility rate of 150 μM naringenin group was higher (P = 0.0366) compared to the control [57.00 ± 0.03 % (114/200) vs. 46.50 ± 0.04 % (93/200), respectively]. Taken together, it is concluded that naringenin supplementation in semen extender improves post-thaw quality, fertility-associated gene expression and fertilization potential of buffalo bull sperm, more apparently at 150 μM concentration.

Effects of B2O3 Dopants on the Electrical Properties of Ta‐Doped SnO2 Varistors

As a new core component of surge arresters, it is crucial for manganese dioxide varistors to solve the challenges of reducing the leakage current and lowering the residual voltage ratio. In this study, the electrical characteristics of tin dioxide varistors using B2O3 as the acceptor dopant and Ta2O5 as the donor dopant are investigated. Several tin dioxide based varistors doped with different amounts of B2O3 are prepared and characterized by the researchers. X ray diffraction (XRD) is used to analyze the structural features of the samples and to observe the phases involved. It is found that the B2O3 dopant provides oxygen vacancies, reduces the grain size, increases the barrier height, and decreases the residual pressure ratio. The Ta2O5 dopant provides donor defects and free electrons needed to form the barrier. When balancing the concentrations of B2O3 and Ta2O5, the optimum dopant concentrations is found to be 0.1 mol% of B and 0.05 mol% of Ta; these concentrations result in a leakage current of 0.25 μA cm−2, a residual pressure ratio of 1.95, a nonlinear coefficient of 25, and a voltage gradient of 394 V mm−1 for the varistor.

Design optimization of lightweight automotive seatback through additive manufacturing compression overmolding of metal polymer composites

With the growing demand for enhanced automotive fuel efficiency and environmental sustainability, there is a need for lightweighting automotive components through innovative design and manufacturing processes. This study leverages a combination of numerical iterative design optimization and hybrid additive manufacturing–compression molding (AM-CM) technique for metal polymer composites to lightweight an automotive seatback. The AM-CM process enables robust mechanical interlocking between metals and composites, boasting high stiffness and strength with low overall density. Replacing metallic components with such metal polymer composites allows for comparable mechanical performance while significantly reducing the overall weight. First, the automotive seatback design space is reduced to critical load carrying regions using topology optimization and high stress concentration areas are identified using finite element analysis. Next, a lightweight metal polymer subcomponent is designed for a high stress concentration region. The full seatback frame with spatially heterogeneous material-specific design is then iteratively optimized to enable enhanced stiffness with minimal weight. Overall, the automotive seatback frame designed with location-specific metal, polymer, and metal polymer composite materials weighs 20% less than the metal-only design while exhibiting similar stiffness.

Ballistic impact performance of aramid fabrics impregnated with single‐phase shear thickening fluids STFs and SiC additive multi‐phase shear thickening fluids

AbstractThis study presents STF/Fabric composite configurations by impregnating single‐phase shear thickening fluids (S‐STF) and multi‐phase shear thickening fluids (M‐STF) into aramid fabrics. S‐STFs were first prepared at different concentrations by weight (25%, 40%, 55%, and 65%). In addition, M‐STFs were produced by adding silicon carbide (SiC) additive to S‐STFs. As a result of the impregnation of the produced STFs on Aramid fabrics, 30‐layer composite samples were prepared. To determine the ballistic performance of the produced samples, tests were carried out with a single‐stage gas gun system. The shots were performed at an average velocity of 670 m/s. Ballistic tests show that STF‐impregnated fabric samples have better ballistic performance compared to fabric without STF. The STF65/Aramid sample is notable for a 238% increase in energy absorption. In addition, the STF40SiC10/Aramid composite sample produced with M‐STF was found to absorb 18.7% more energy compared to the STF40/Aramid sample. It has been confirmed that keeping the weight ratio of the additive at an optimum level will contribute to ballistic performance. These results contributed to determining the optimum concentration amount for STF/Aramid composites at high speed.Highlights S‐STF and SiC additive M‐STFs were produced. STFs were impregnated into 30‐layer Aramid fabrics. Ballistics tests were performed on S‐STF/Aramid and M‐STF/Aramid composite samples with a single‐stage gas gun system. The effects of S‐STF and M‐STF on ballistic performance were investigated. The addition of STF enhanced ballistic performance by increasing energy absorption.

Optimizing additive Y2O3 concentration for improving corrosion resistance of ceramic coatings formed by plasma electrolytic oxidation on Zr-4 alloy

Abstract The corrosion resistance of ceramic coatings developed by plasma electrolytic oxidation (PEO) can be improved by embedding particles. Optimizing the concentration of particles in the electrolyte is essential to obtain the best coating performance. This work aims to optimize the concentration of Y2O3 embedded in the PEO coatings on Zr-4 alloy to obtain the best corrosion resistance. Nanoparticles Y2O3 was suspended in the PEO electrolyte at a concentration of 2, 3 and 4 g l−1. The particles were successfully embedded in the PEO coating composed of ZrO2–SiO2. The electrochemical test in an aqueous solution and oxidation test at 600 °C revealed a consistent result that the best corrosion resistance was obtained in the coating formed in the 3 g l−1 Y2O3-containing electrolyte. At the corresponding optimum concentration, the coating contained high SiO2 and tetragonal (t) ZrO2 phase, which potentially formed a stable solid solution ZrO2–SiO2. The improved coating stability enhanced the corrosion resistance during both aqueous solution and high temperature exposure.

Clinical, Microbiological Profile, and Treatment Response to Intraventricular Antibiotics in the Management of Postneurosurgical Meningitis: A Single-Center Experience.

Postneurosurgical meningitis (PNM) is a serious medical condition with high mortality and morbidity caused by Gram positive organisms like Staphylococcus aureus and Gram-negative organisms like Acinetobacter baumannii. Optimum concentration of antibiotics in the cerebrospinal fluid (CSF) to treat these infections is difficult to achieve. Intraventricular antibiotic administration bypasses the blood-brain barrier and can achieve high CSF concentration without causing systemic toxicity. Retrospective review of all patient records were done to identify patients who developed postneurosurgical meningitis and received intraventricular antibiotic therapy during the period of July 2017 to December 2022. Demographic and clinical data along with the type of antibiotic, route, dose, and duration of administration were collected. CSF parameters before and after intraventricular antibiotic administration were collected and analyzed. Twenty-six patients with postneurosurgical meningitis received intraventricular antibiotic therapy. Intracranial tumors were the most common underlying pathology followed by aneurysms. In all, 17/26 patients had received vancomycin and 9/26 patients had received colistin. External ventricular drain was used in 17/26 cases and Ommaya reservoir was used in 9/26 cases. Six patients showed growth of organism in CSF before starting intraventricular antibiotics, while one patient remained culture positive despite treatment. Of the 26 patients, 3 died despite treatment. There were significant changes in the CSF parameters after intraventricular antibiotic therapy. Intraventricular administration of antibiotic provides an alternative therapeutic option in the management of patients who are not responding or poorly responding to systemic antibiotics.

Optimization of Medium for Lipid Production from &lt;i&gt;Lipomyces maratuensis&lt;/i&gt; InaCC Y720 Using Statistical Experiment Design

&lt;i&gt;Lipomyces maratuensis&lt;/i&gt; InaCC Y720 is a potential novel oleaginous yeast. Media-based production optimization has never been carried out using this strain. This study aims to define an optimized medium from 12 medium component factors, where the Taguchi method is used for screening significant factors of medium and the response surface methodology (RSM) is used to optimize the concentration of significant factors. According to Taguchi, glucose, yeast extract, and magnesium sulfate (MgSO&lt;sub&gt;4&lt;/sub&gt;) have a significant influence on lipid accumulation, with their concentrations maintained at optimal levels through RSM optimization. Conversely, potassium dihydrogen phosphate, sodium hydrogen phosphate, and calcium chloride inhibit lipid accumulation, and copper(II) sulfate has the least influence, categorizing them as eliminated factors. The RSM-optimized medium increased lipid content by 3.6-fold compared to the initial medium. Glucose and yeast extract showed a positive correlation with lipid accumulation, suggesting potential for further optimization, while the optimum concentration for MgSO&lt;sub&gt;4&lt;/sub&gt; was 0.15 g/L. This study is intended to serve as a reference for increasing lipid accumulation by &lt;i&gt;L&lt;/i&gt;. &lt;i&gt;maratuensis&lt;/i&gt; InaCC Y720.

Synergistic mixture of the Dactyloctenium aegyptium extract and KI as an environment friendly and highly efficient corrosion inhibitor for steel in 0.5 M HCl

To prevent steel from corroding in HCl solution, a cost-effective inhibitor of Dactyloctenium aegyptium and KI is presented. UV–Vis, infrared spectroscopy, and scanning electron microscopy analysis are used to undertake a comprehensive experimental evaluation of the inhibitors and their interactions with the steel. The optimum concentration of the Dactyloctenium aegyptium extract (DAE) with the maximum corrosion protection efficacy is found via electrochemical measurements. The bioactive constituents of the DAE such as Tricin, Vanillic acid, p-hydroxybenzaldehyde, and p-hydroxybenzoic acid conferred a maximum inhibition efficiency of 95.7 % at 800 ppm. The inhibitory activity of its ethanolic extract increased with increasing concentration. Further various adsorption isotherm models including Langmuir, Temkin and Frendluich were used to understand the adsorption of the DAE on the metal surface. The DFT based investigations show that the active constituents of the DAE are highly polarized, soluble in aqueous solution and adsorb on the steel surface efficiently.

Synthetic Clay Application to Reduce the Segregation of Barite-Based Oil-Well Cement.

In the oil and gas industry, cement segregation is a significant concern that can have disastrous consequences, such as the failure of cement. The change of hardened cement's properties is observed, resulting in a decrease in its strength and an increase in its permeability. Therefore, providing some solutions to prevent this is crucial. The objective of this study is to assess the efficacy of synthetic clay in mitigating the problem of segregation in cement having barite. Six concentrations of synthetic clay were used to prepare six heavy-weighted cement samples with a high density of 18 lb/gal using the barite weighting material. The approaches of density distribution and nuclear magnetic resonance (NMR) were employed to characterize the heterogeneity in the hardened cement samples with the aim of identifying the potential of cement segregation. Then, the optimum concentration of the synthetic clay was selected and its effects on the rheological, strength, petrophysical, and elastic properties were evaluated and compared with the properties of the base cement (without synthetic clay). The results showed that 0.4% by weight of cement (BWOC) synthetic clay was the optimum concentration, which yielded the minimum cement segregation as represented by a 61% reduction in the density variation compared to the control specimen. The results obtained from the NMR technique validated the findings of the density distribution method, indicating that the porosity distribution of the synthetic clay cement with a concentration of 0.4% BWOC exhibited uniformity across its top, middle, and bottom sections, with a slight deviation window, while the porosity distribution of the control cement specimen displayed noticeable variation. Moreover, the synthetic clay had better properties than the control cement specimen. For example, the rheological properties were improved as represented by a 22% reduction in plastic viscosity and 42 and 11% increase in the yield point and gel strength, respectively. Compared to the base cement, the compressive and tensile strength were increased by 39 and 43%. The synthetic clay decreased the permeability and porosity by 73 and 24%, respectively. The synthetic clay enhanced the elastic properties as represented by a 1.5% reduction in Young's modulus and a 1.3% increase in Poisson's ratio compared to the base cement sample.

Antibacterial and antibiofilm effect of Zinc Oxide nanoparticles on P. aeruginosa variants isolated from young patients with cystic fibrosis

BackgroundP. aeruginosa, a biofilm-forming bacteria, is the main cause of pulmonary infection in CF patients. We applied ZnO-np as a therapeutic agent for eradicating multi-drug resistance and biofilm-forming P. aeruginosa isolated from young CF patients. MethodsA total of 73 throat and sputum samples taken from young CF patients were inquired. ZnO-np was synthesized and characterized in terms of size, shape, and structure for anti-bacterial activity. The antibiotic susceptibility of isolates before and after the addition of 16 μg/ml of ZnO was evaluated using disc diffusion and microtiter methods, respectively. The gene expression level of QS genes was assessed after treatment with 16 μg/ml ZnO-np. ResultsThe optimum concentration of ZnO-np with a higher inhibitory zone was 16 μg/ml (MIC) and 32 μg/ml (MBC). All isolates were resistant to applied antibiotics, and about 45 % of isolates were strong biofilm-forming bacteria. After treatment with 16 μg/ml ZnO-np, all strains became susceptible to the applied antibiotic except for amikacin, which confers an intermediate pattern. About 63 % and 20 % of isolates were, respectively, non-biofilm and weak biofilm-forming bacteria following the addition of ZnO-np. Relative gene expression of gacA, lasR, and rhlR genes were downregulated significantly (P < 0.001). Although the retS did not have a significant reduction (P = 0.2) ConclusionZnO-np at a concentration of 16 μg/ml could significantly reduce the P. aeruginosa infection by altering the antibiotic susceptibility pattern and inhibiting biofilm formation. Due to their photocatalytic properties and their ability to penetrate the extracellular polysaccharide layer, ZnO nanoparticles can produce ROS, which increases their susceptibility to antibiotics. Nasal delivery of ZnO-np in the form of aerosol can be considered a potential strategy to decrease the mortality rate in CF patients at an early age.

Development and Characterization of Polyethylene Terephthalate-rice Husk (PET-RH) Composites: Thermal Stability, Morphological Analysis, and Burning Rate Evaluation

A polyethylene terephthalate – Rice husk (PET-RH) composite was produced from waste plastic water bottle and rice husk. Burning rate test, scanning electron microscope (SEM), thermogravimetric analysis (TGA) and differential thermal analysis (DTA) were employed to study the produced composite. The burning rate carried out on the composite revealed resistance to burning as result of the introduction of more PET material into the composite at varied proportions, it also revealed that to produce a more durable PET-RH composite, the ratio of PET to RH must be at optimum concentration to achieve a desired application. The SEM analysis revealed a well-structured morphology of the produced composite as there were less areas of fracture or unfilled fiber regions that could cause breakdown or fissure in the matrix of the composite. The TGA analysis of the produced composite revealed thermal stability of the PET-RH composite within the range 0 to 300 ℃ with a 20 % weight residue recorded in the temperature range 500 to 887 °C. The DTA analysis revealed and correlated with the results obtained from the TGA thermogram, whose initial drying was due to a 4 % loss in mass and a narrow endotherm which was visible at the 240 and 545 °C temperature range which corresponded to the pyrolytic stage visible in the TGA thermogram, this clearly suggested that the produced composite can serve in applications dependent on thermal resistant properties. Results so far obtained from this study suggested that the produced PET-RH composites exhibited good performance characteristics that could be likened to properties of conventional materials with the same matrix.

Iron Effects in Advanced Alkaline Electrolyzer

Global warming, characterized by an alarming rise in the Earth’s temperature, is one of the serious impacts of industrialization. Transition towards a sustainable future requires the diversification of our energy sources by replacing fossil fuels with renewable energy such as green H2, to lower global CO2 emissions. Alkaline water electrolysis is one of the widely used affordable water splitting techniques that produces hydrogen gas. Since Fe contamination in this system is an unavoidable factor, it is important to understand the optimum Fe concentration for maximum performance. In this work, we are investigating the change in the total cell performance by spiking Fe2+ (0 to 140 ppm) solution at industrial standard conditions (6 M KOH, 80° C).In this work, we are investigating the change in the total cell performance by spiking Fe2+ (0 to 140 ppm) solution at industrial standard conditions (6 M KOH, 80° C). The KOH was purified prior to the experiment making sure the Fe limits are below the ICP-MS detection limit. To fully understand how Fe activates/deactivates the electrode performance, we chose NixCoy(O)OH coated on Ni mesh anode, commercial AWE cathode and Zirfon-220 as separator and performed testing in both 3-electrode set up and zero-gap electrolyzer set up. Our initial results show that, Fe effect on the total cell performance follows a bell curve where the maximum contribution comes from the activation of the anode. It must be noted that by spiking 40 -50 ppm Fe in the electrolyte the total cell potential is reduced by over 1V which is a huge gain. As we spike over 60 ppm the performance starts to go down. This can be explained by the deposition of FeOx on the anode which is a bad OER catalyst in comparison with NixCoy(O)OH. Our anode has a high active surface area from the nano sheet composition along with high conductivity from CoOx. At 20 ppm Fe in the electrolyte, the anode over potential reduced by 49 mV at 10 mA and by ~110mV at 250mA at 80 °C. Unlike bare Ni electrode as cathode, commercial cathodes are very resistant to Fe fouling only leading to a few millivolts of change. It is important to understand that Fe has maximum effect at low temperature, where the total cell potential was reduced by 200mV by adding 40 ppm Fe solution. As we increase the temperature to 80 °C, reaction kinetics gets improved and the optimum Fe concentration for maximum performance decreases.The activation in the anode performance at high Fe concentration has been verified by studying the surface morphology SEM imaging and by taking the EDX analysis. It has been seen that the anode gives maximum performance when we have sites of NixCoyFeO(OH) deposited on the anode catalyst. As our next step, we will be evaluating the changes in the surface morphology of the cathode along with the amount of Fe being deposited at each spiking. This will provide more information on how we should engineer the cell components to achieve the maximum output. Figure 1

Effect of Silicate Addition on ZnO Formation during Zn Discharging Process

Rechargeable zinc batteries have been attracting extensive attention as promising candidates for next-generation energy storage, owing to their intrinsic safety, mature recycling processes, low material cost and high theoretical energy density.[1] Nevertheless, there are still several issues holding back the development of zinc batteries, such as the capacity loss due to Zn passivation and poor cyclability caused by Zn dendrite formation. [2] In the past few years, efforts have been made to improve the performance of zinc batteries, among which electrolyte modification with additives is the most widely used. [3] For further development of zinc batteries towards practical application, it is also essential to deepen the understanding of chemical state changes in a working Zn electrode. In our previous work, Zn dissolution−passivation behavior with ZnO formation during Zn discharging process has been systematically elucidated via in-situ analysis. [4] Herein this work, through comparative studies with silicate addition in the electrolyte, the correlation between ZnO formation and the discharging performance of Zn anodes is further clarified, shedding new insights into further optimization of zinc batteries.Firstly, various electrolyte additives were evaluated during Zn discharging at a current density of 40 mA/cm2. As a result, potassium silicate addition with an optimum concentration of 100 mM effectively enhanced the discharge capacity of Zn anode. Effects of silicate addition on Zn discharging process were then further investigated. After 500 s of discharging, ZnO layer with a thickness around 7 um is formed on Zn anodes, which is attributed to the dehydration of supersaturated zincate ions. [4] It is observed that as-formed ZnO petals turned from sharp to round with silicate addition. Moreover, a porous ZnO layer was formed with silicate addition, while a compact one was obtained without any additives. Accordingly, it is assumed that silicate may form adsorption or coordination with ZnO particles, leading to morphology and porosity changes in ZnO.Further analyses were carried out to verify whether the chemical state of ZnO changes with silicate addition. The TEM-EDS mapping result and XPS depth profile indicate that Si is uniformly distributed within the ZnO layer. Moreover, the presence of Si-O bond is confirmed, along with both Zn 2p 2/3 and O 1s peak shifts towards higher binding energy side. Accordingly, the coordination between silicate and ZnO via the formation of Si-O-Zn bridge is suggested, which is also supported by the DFT calculation result, as a stable existence of silicate on ZnO can be achieved.On the other hand, it is noticed via XRD and HRTEM characterization that the crystallite size of ZnO became smaller with silicate addition. Moreover, ZnO formed with silicate addition presented lower crystallinity with higher defect contents, as evidenced by Raman spectra. Given the above, it is considered that silicate modulates the electronic structure of ZnO molecules via the Si-O-Zn bonding, thereby suppresses ZnO crystal growth and particle aggregation, which eventually contributes to a loose ZnO structure that can maintain the activity of Zn anodes. With the discussion of ZnO formation herein, we hope this work may open a new avenue for developing high-performance zinc batteries.AcknowledgementsThis study was supported by the Research and Development Initiative for Scientific Innovation of New Generation Batteries (RISING) Projects, RISING3 [JPNP21006], commissioned by the New Energy and Industrial Technology Development Organization (NEDO), Japan.[1] P. Ruan et al., Angew. Chem., 2022, 134, e202200598[2] W. Shang et al., Energy Storage Mater., 2020, 31, 44–57[3] S. Guo et al., Energy Storage Mater., 2021, 34, 545–562[4] T. Wang et al., Energy Environ. Mater., 2023, 0, e12481

Photo-isomerization enabled reversible wavelength switching in fiber random laser for color image encryption.

Random lasers owing the functionality of generating random spectra facilitate the chaotic encrypted systems essential for cryptography in the current information epoch. Nevertheless, single wavelength bands of random lasers provide an unsuitable key for image encryption that causes outline interpretation and a fragile complex dual chaotic encryption demanding secured image encryption. This research presents an inevitable development of a reversible switchable wavelength fiber random laser composed of the mixture of highly polarized intramolecular charge transfer dye molecules and the optimum concentration of titanium dioxide acting as gain and efficient scattering mediums respectively within a polyvinyl alcohol matrix. This mixture with a certain ratio is coated on a fiber employing a dip coated method, followed by a layer of polydimethylsiloxane to facilitate with high coefficient of thermal expansion. Random laser emission is enabled with dynamically switchable wavelengths obeying the excited state intramolecular proton transfer phenomenon under the photo-isomerization. The optimum scatters concentration yields a lower threshold of 32 µJ/cm2 with full width at half maximum of 0.4 nm and dual emission reversible switchable wavelength bands centered around 443 nm and 464 nm attributed to inter charge transfer feature of the dye molecules. Thereby, the dual reversible switchable wavelength bands feed as input for a dual chaotic color image encryption system. Further, in this integrated system, beam divergence of random laser emissions remains less than 20° during both situations of with- and without irradiation. This delicate approach paves the way in laying the foundation about the applicability of fiber random lasers in an information security system.

Optimization and Kinetic Study of Manganese Leaching from Pyrolusite Ore in Hydrochloric Acid Solutions with Oxalic Acid

The leaching behavior of pyrolusite minerals was examined in hydrochloric acid solutions, including oxalic acid, to evaluate the influence of various experimental conditions. The optimum parameters for the leaching process were found in the first stage, and the process's kinetics were assessed in the second. The concentrations of oxalic acid, hydrochloric acid, and temperature were chosen as independent variables in the optimization experiments, with the central composite design used to analyze the experimental data. The optimum concentrations for oxalic acid, hydrochloric acid, and temperature were determined to be 0.75 mol/L, 1.2 mol/L, and 60 °C, respectively. The leaching rate was determined to be 97.4% for 120 min of response time in optimum situations. The kinetic assessment experiments studied the effects of solid/liquid ratio, particle size, stirring speed, and temperature on the manganese leaching rate from pyrolusite. In the studies, the leaching rate was shown to rise with increasing temperature and stirring speed, as well as with decreasing particle size and solid/liquid ratio. The kinetic analysis revealed that the leaching kinetics matched the mixed kinetic model, and a mathematical model for the leaching process was developed. This process's activation energy was determined to be 29.05 kJ/mol.Graphical

A novel single near-infrared luminescence of negative thermal quenching materials for optical temperature measurement

In recent years, upconversion (UC) luminescence has gained attention due to its unique optical properties, and the thermal response spectral characteristics of these materials have been widely utilized in various fields including temperature sensing and biomedical research. However, the photoluminescence (PL) intensity of most rare earth ions doped phosphors decreases with increasing temperature, and the visible fluorescence emission penetration is still limited. In the work, the pure phase of Yb3+ and Er3+ ions co-doped Sc2Mo3O12 was successfully prepared. The Sc2Mo3O12: Yb3+, Er3+ sample showed a single emission of UC near-infrared (NIR) light. The optimum doping concentrations of 0.2 for Yb3+ ions and 0.01 for Er3+ ions were achieved. The possible upconversion luminescence (UCL) mechanism was investigated by analysing the UCL spectra, the down-shift (DS) excitation and emission spectra of Sc2Mo3O12: Yb3+, Er3+ phosphor. The excitation path of NIR emission is mainly through Er3+ from 2H11/2 to 4I9/2 energy level. What's more, the temperature-dependent near-infrared UCL properties of sample is explored in the temperature range from 323 K to 673 K. The enhancement of upconversion luminescence intensity shows a linear relationship with increasing temperature. The study paves a new way for non-contact optical temperature measurement with single near-infrared UCL emission.

The changes in selected properties of flax fibre-reinforced biocomposites affected by plant modifier concentration

The application of the sustainable materials is one of the basic steps towards environmentally friendly and resource-efficient society. The aim of the study was to characterise the effects of the natural plant modifier concentration on properties of the biocomposites. The paper describes the influence of tannic acid (TA) concentration on flax fibre-reinforced biocomposites. The prepared biocomposites contained polylactide in 20 wt% and flax fibres (Linum usitatissimum) in 80 wt%, while the modifier concentrations varied from 1 % to 10 %. The manufacturing methods included extrusion and injection moulding of the biocomposites. The evaluation of the effects of modifier concentration on selected parameters of biocomposites was conducted using mechanical tests - tensile tests, thermomechanical - dynamic mechanical analysis (DMA), and thermal tests - differential scanning calorimetry (DSC) and thermogravimetry (TG). Additionally, biocidal and wettability studies were conducted. The examination results revealed, that 5 % is an optimum concentration of modifier which positively affected both mechanical and biocidal properties. The efficient use of modifiers can help in natural resources conversion and minimization of environmental impacts.