Physico-Chemical Properties of NaV3O8 Prepared by Solid-State Reaction

Sodium–vanadium oxide NaV3O8 is synthesized via solid-state method and optimum synthesis conditions are chosen based on the data of DSC and TG analysis. The material synthesized is characterized by X-ray phase analysis, Raman spectroscopy and scanning electron microscopy. The ratio V4+/V5+ in the sample obtained is determined by X-ray photoelectron spectroscopy. Conductivity of the material synthesized was measured by impedance spectroscopy, pulse potentiometry and DC method over the range RT–570 °C. It is shown that NaV3O8 has rather high conductivity essentially electron in type (6.3 × 10−2 at room temperature). AC and DC conductivity measurements are performed and cycling of symmetricNaV3O8|Na3.85Zr1.85Nb0.15Si3O12|NaV3O8 cell in galvanostatic conditions. Thermal stability is studied across 25–570 °C temperature range. The results obtained are compared with the properties of NaV3O8 produced via aqueous solution.

Stochastic Optimization of TiO2-Graphene Nanocomposite by Using Neuro-Regression Approach for Maximum Photocatalytic Degradation Rate

TiO2 is one of the most common materials for photocatalytic applications due to its stability, affordability, and photoactive efficiency. However, it has some drawbacks, such as limited solar radiation response and quick recombination of excitons. Using graphene could be one of the methods to enhance the photocatalytic properties of TiO2. This study intends to optimize the photocatalytic performance of TiO2/Graphene (TiO2/G) nanocomposite by using neuro-regression analysis. In the analysis, the effect of some hydrothermal synthesis parameters, namely, amount of graphene oxide, ethanol/water ratio, and hydrothermal reaction time on the photocatalytic activity of TiO2/G nanocomposite, have been investigated. The parameters were determined from a literature study focused on overcoming the drawbacks of TiO2 by combining it with graphene oxide. Nelder-Mead, Simulated Annealing, Differential Evolution, and Random Search algorithms are used to obtain the optimum synthesis parameters for maximum photocatalytic activity in the optimization process. The results are indicated that all algorithms give the realizable value for design variables and photodegradation rate.

Preparation And Sintering Calcium Aluminate Nanopowder By Using Sol Gel Method

The optimal synthesis temperatures and methods of using the alumina-containing waste in the process of obtaining calcium aluminate are determined. It has been established that the optimum synthesis temperature is 1100°C and corresponds to the maximum full formation of calcium aluminate with the smallest dispersion of particles, the size of 100-700 nm.

Synthesis and Characterization of Silver Nanoparticles Using Prodigiosin Pigment and Evaluation of Their Antibacterial and Anti-Inflammatory Activities

This study focused on the biological synthesis of silver nanoparticles (AgNPs), using prodigiosin pigment produced by Serratia marcescens. The effect of parameters such as pH, temperature, time, with various concentrations of silver nitrate (AgNO3) and prodigiosin on the synthesis of AgNPs were also studied. Optimized results of the biosynthesis process revealed an increase in the intensity of Surface Plasmon Resonance (SPR) bands of nanoparticles with shifting at the wavelength of 400 nm. In addition, optimum synthesis of AgNPs was achieved at pH 12, temperature 55℃, and reaction time 24 h, with concentrations of prodigiosin, as a reducing agent, of 12.5 µg/ml and silver ion concentration of 1 mM. Measurement of the size of silver nanoparticles by SEM diffraction revealed a value of 30 nm. Finally, the minimum inhibitory concentration of AgNPs against pathogenic bacteria was 32 µg/ml for Staphylococcus aureus and Pseudomonas aeruginosa. The results of anti-inflammatory effects of Ag NPs obviously demonstrated that the infections of test animals treated with AgNPs were completely healed after 4 days of treatment, while the animals treated with fucidin (as control) did not exhibit any healing.

Modified IWO algorithm for topological optimum synthesis of the displacement amplifying compliant mechanism

The conventional mechanisms transmitted force and displacement through rigid members (high stiffness) and traditional joints (with high softness), where recently, researchers have come up with new systems called compliant mechanisms that transfer power and mobility through the deformation of their flexible members. One of the most frequently used approaches for designing compliant mechanisms is topology optimization. Extracting the optimal design of a displacement amplifying compliant mechanism using the modified Invasive Weed Optimization (MIWO) method is the current study's main novelty. The studied mechanism is a compliant micro-mechanism that can be used as a micrometric displacement amplifier. The goal of this synthesis is to maximize the output-to-input displacement ratio. In this research, a new random step is added to the Invasive Weed Optimization (IWO) method; the new seeds can be spread farther from their parents, which can be improved the algorithm's abilities. The results show that the use of the modified IWO algorithm for this problem has led to a significant improvement over the results from similar articles.

Hydrothermal Synthesis of Ag/Bi2O2CO3 Nanoflakes Photocatalysts with Bismuth Nitrate and Silver Oxalate as Precursors for Organic Pollutants Degradation

Bi2O2CO3 is a UV-light-driven photocatalyst. Bi2O2CO3 nanoflakes modified with plasmonic Ag nanoparticles (Ag/Bi2O2CO3) were obtained by a hydrothermal method. In the synthetic process, Ag2C2O4 worked as the Ag source and C source for the simultaneous formation of Ag particles and CO[Formula: see text]. The optimum synthesis condition was found at [Formula: see text]C for 16[Formula: see text]h under alkaline condition. The binary heterostructure was then used for degrading 2, 4-Dichlorophenol (2, 4-DCP) and Rhodamine B in visible light, with an efficiency of nearly 80% for 2, 4-DCP and 100% for Rhodamine B after 4[Formula: see text]h and 2[Formula: see text]h reaction, respectively. The binary heterostructure exhibited improved photocatalytic activity compared to that of individual Ag and Bi2O2CO3 due to Surface Plasmon Resonance (SPR) effect of Ag. Meanwhile, after five recycling experiments, Ag/Bi2O2CO3 showed higher photocatalytic activity and lower performance degradation in comparison with the one prepared by photo-reduction of Ag[Formula: see text] on Bi2O2CO3 nanoflakes. This indicated the advantage of one-pot synthetic method. This work is expected to provide an efficient photocatalyst for organic pollutants degradation.

A Guide to Water Free Lithium Bis(oxalate) Borate (LiBOB)

The use of LiBOB is limited due to slight instability issues under ambient conditions that might require extra purification steps and might result in poorer performances in real systems. Here, we address some of these issues and report the high purity water free LiBOB synthesized with fewer processing steps employing lithium carbonate, oxalic acid, and boric acid as low-cost starting materials, and via ceramic processing methods under protective atmosphere. The physical and chemical characterizations of both anhydrous and monohydrate phases are performed with X-ray powder diffraction (XRPD), Fourier-transform infra-red spectroscopy (FTIR), Raman spectroscopy and scanning electron microscopy (SEM) analyses to determine the degree of the purity and the formation of impurities like LiBOB.H₂O, HBO₂and Li₂C₂O₄ as a result of the aging investigations performed. Differential thermal analysis (DTA) is applied to determine the optimum synthesis conditions for anhydrous LiBOB and to analyze the water loss and the decomposition of LiBOB.H₂O. Aging experiments with the water free LiBOB are carried out to evaluate the effect of humidity in the phase changes and resulting impurities under various conditions. The detrimental effect of even slightest humidity conditions is shown, and protective measures during and after the synthesis of LiBOB are discussed.

A Guide to Water Free Lithium Bis(oxalate) Borate (LiBOB)

The use of LiBOB is limited due to slight instability issues under ambient conditions that might require extra purification steps and might result in poorer performances in real systems. Here, we address some of these issues and report the high purity water free LiBOB synthesized with fewer processing steps employing lithium carbonate, oxalic acid, and boric acid as low-cost starting materials, and via ceramic processing methods under protective atmosphere. The physical and chemical characterizations of both anhydrous and monohydrate phases are performed with X-ray powder diffraction (XRPD), Fourier-transform infra-red spectroscopy (FTIR), Raman spectroscopy and scanning electron microscopy (SEM) analyses to determine the degree of the purity and the formation of impurities like LiBOB.H₂O, HBO₂and Li₂C₂O₄ as a result of the aging investigations performed. Differential thermal analysis (DTA) is applied to determine the optimum synthesis conditions for anhydrous LiBOB and to analyze the water loss and the decomposition of LiBOB.H₂O. Aging experiments with the water free LiBOB are carried out to evaluate the effect of humidity in the phase changes and resulting impurities under various conditions. The detrimental effect of even slightest humidity conditions is shown, and protective measures during and after the synthesis of LiBOB are discussed.