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A facile one-step combustion route is used for the synthesis of a magnetically separable GO–CuFe2O4–ZnO (GCZ) ternary nanocomposite photocatalyst with varying ZnO contents. Transmission electron microscope (TEM) observations show the exfoliation of graphene oxide sheets and decoration with well-dispersed ZnO and CuFe2O4 nanoparticles. The photocatalytic activity of the ternary nanocomposite was tested under solar light irradiation for the photodegradation of several dyes such as rhodamine-B (RhB), methylene blue (MB), methyl orange (MO), and neutral phenol. The evaluation results demonstrate that the ternary GCZ photocatalyst exhibits the best performance compared to GO–CuFe2O4 (GC), GO–ZnO (GZ), CuFe2O4, ZnO, and CuFe2O4–ZnO (CZ) photocatalysts towards the photocatalytic degradation of the dyes. Photoelectrochemical measurements were carried out to provide deep insights into the enhanced photocatalytic activity in the novel ternary nanocomposite. The improved photocatalytic activity of the ternary nanocomposite can be ascribed to the superior light assimilation, proficient charge transfer process, synergistic effects, high surface area, and superior durability of the composite. Furthermore, a possible reaction mechanism has been proposed. Our results have demonstrated that by precisely introducing GO with appropriate metal oxides, a highly efficient photocatalyst can be designed that would assimilate a wider range of visible light. Furthermore, CuFe2O4 nanoparticles themselves have excellent magnetic properties, which are largely maintained in the GCZ composite, and can be simply separated from the suspension system by applying a magnetic field. [ABSTRACT FROM AUTHOR]

Background: In pregnancy drug treatment presents a special concern due potential teratogenic effects and physiologic alterations in mother. This retrospective study was performed to evaluate the drug prescribing pattern in pregnancy among pregnant women in a secondary care hospital in India.Materials and Methods: This cross-sectional retrospective study was done for 3 months using pre-formatted forms and patient's records.Results: A total of 326 drugs, including 46 different types of drugs, were prescribed to 606 gravid women. Eight different types of medications were started before being seen at the antenatal clinic. Most of these drugs fall under US FDA pregnancy categories B and C and few under categories A, X and N.Conclusion: This study reflects a good, safe and rational medication practice during pregnancy in various common disorders in a secondary care hospital and can be cited as an example to similar primary and secondary care hospitals. [ABSTRACT FROM AUTHOR]

We report the synthesis of 2-supported monometallic , and bimetallic nanoparticle catalysts prepared using sol-gel method via a rational nanoparticle encapsulation route. The samples were thoroughly characterized by ultraviolet-visible spectroscopy, Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), field emission scanning electron microscope (FESEM) transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS) with image mapping and Brunauer-Emmett-Teller (BET) surface area analyzer. The supported bimetallic catalyst had the anatase structure, surface area of 50 m2/g and 2.6 ± 0.6 nm particle size. The efficiency of the catalysts was evaluated on photodegradation of methylene blue (MB) dye under visible light. The photocatalytic activity of MB was significantly enhanced in the presence of bimetallic nanoparticles (NPs) as compared to individual metal nanoparticles. Reusability study of the photocatalyst showed that the catalyst can be reused upto 5 runs with minimal loss in activity. Kinetic study revealed that the degradation reaction follows a pseudo first-order pathway. A novel nanoparticle encapsulation method was employed for the synthesis of monometallic Ag, Sn, and bimetallic AgSn-doped titania. The formation of AgSn was confirmed by STEM-EDS mapping. It was found that the doping of AgSn nanoparticle on titania matrix enhances its photocatalytic activity compared to the bare titania, degussa (P25) and monometallic counterparts for the degradation of methylene blue dye under visible light. The photocatalyst was reused up to five cycles with minimal loss of activity. [ABSTRACT FROM AUTHOR]

The increasing complexities of wellbore geometry imply an increasing well cost. It has become more important than ever to achieve an increased rate of penetration (ROP) and, thus, reduced cost per foot. To achieve maximum ROP, an optimization of drilling parameters is required as the well is drilled. While there are different optimization techniques, there is no acceptable universal mathematical model that achieves maximum ROP accurately. Usually, conventional mathematical optimization techniques fail to accurately predict optimal parameters owing to the complex nature of downhole conditions. To account for these uncertainties, evolutionary-based algorithms can be used instead of mathematical optimizations. To arrive at the optimum drilling parameters efficiently and quickly, the metaheuristic evolutionary algorithm, called the "shuffled frog leaping algorithm, (SFLA) is used in this paper. It is a type of rising swarm-intelligence optimizer that can optimize additional objectives, such as minimizing hydromechanical specific energy. In this paper, realtime gamma ray data are used to compute values of rock strength and bit-tooth wear. Variables used are weight on bit (WOB), bit rotation (N), and flow rate (Q). Each variable represents a frog. The value of each frog is derived based on the ROP models used individually or simultaneously through iteration. This optimizer lets each frog (WOB, N, and Q) jump to the best value (ROP) automatically, thus arriving at the near optimal solution. The method is also efficient in computing optimum drilling parameters for different formations in real time. The paper presents field examples to predict and estimate the parameters and compares them to the actual real-time data. [ABSTRACT FROM AUTHOR]

The crystal phase dependency of stannate based sample was well-understood here. The electrocatalytic activity and stability of ZnSnO 3 and Zn 2 SnO 4 have been investigated for the production of O 2 gas from water. The well-defined perovskite phase of ZnSnO 3 and Ruddlesden-Popper phase of Zn 2 SnO 4 nanoparticles was synthesized via the hydrothermal route. Changing the tin precursor results in the phase transformation of the perovskite phase of ZnSnO 3 into the Ruddlesden-Popper phase of Zn 2 SnO 4 which was characterized by XRD analysis, as well as by high-resolution transmission electron microscopy. It was found that the transformation of phase from perovskite to the Ruddlesden-Popper phase affects the overpotential value for zinc stannate which changes electrochemical catalytic activity resulting from the active site distribution, oxygen vacancy concentration, and electrical conductivity changes a lot. The perovskite phase of ZnSnO 3 exhibits better catalytic activity for oxygen evolution reaction (OER) with an onset potential of 430 mV than the Ruddlesden-Popper phase in an alkaline medium. Furthermore, their performance can be enhanced by changing two factor such as i) replacing A site with different transition metal (Mn, Fe, Co) cations and ii) annealing under a hydrogen atmosphere. We established a relationship for the activity of the catalyst for oxygen evolution reaction by changing zinc with other transition metal cations. This relationship exhibits trends in reactivity (Zn < Mn < Fe < Co), which is governed by the strength of the metal oxygen bond, electronegativity of metal, and the number of 'd' electrons in antibonding orbitals. [Display omitted] [ABSTRACT FROM AUTHOR]

Acidic group functionalized graphene oxide (GO) as a filler to the state-of-art Nafion electrolytes are regarded as potential materials towards next-generation fuel cell application. However, the tedious synthesis process for GO functionalization, and aggravated chemical durability at high temperatures demands the scientific community to design suitable Nafion-based functionalized GO electrolytes with superior proton conductivity and power density at actual fuel cell conditions i.e., 80 °C and 100% relative humidity (RH). Herein, a potential single-step-phosphorylated graphene oxide (sPGO) modified Nafion (sPGO/NF) is introduced to simultaneously multifold the proton conductivity, chemical durability, and power density of Nafion. Under actual fuel cell conditions, the sPGO/NF exhibits maximum proton conductivity (0.306 Scm−1) which is 1.7-fold and 1.6-fold higher than that of rNF and GO/NF, respectively. Moreover, sPGO/NF achieves the maximum power density of 0.652 Wcm−2 (80 °C, 100% RH), much higher than the rNF (0.51 Wcm−2) and GO/NF (0.53 Wcm−2) at same condition. [Display omitted] • For the first time, single-step-phosphorylated GO (sPGO) was prepared. • sPGO incorporation to Nafion (sPGO/NF) uplifted the membrane chemical durability. • Enhanced physicochemical, thermomechanical, and electrochemical properties observed. • Comparatively improved proton conductivity at actual fuel cell conditions. • Demonstration of superior power density than many functionalized GO-nafion PEMs. [ABSTRACT FROM AUTHOR]

Graphene oxide as suitable support material was employed for the synthesis of GO-MnO 2 nanocatalyst via a greener solution combustion route. Rod-like MnO 2 was found to be uniformly adhered to both sides of graphene oxide (GO) sheets. The nanocatalyst was thoroughly characterized using different instrumental methods such as X-ray diffraction (XRD), N 2 adsorption-desorption, Scanning electron microscopy (SEM), Transmission electron microscopy (TEM) with EDS mapping, UV–visible spectroscopy and Thermogravitometric (TG) analysis. From the experimental results, GO-MnO 2 was found to be a potential catalyst for chalcones preparation via Claisen-Schmidt condensation. The catalytic activity of GO-MnO 2 nanocatalyst was found to be superior as compared to pure MnO 2 and GO. The reaction conditions were varied thoroughly by changing several reaction parameters like the solvent polarity, temperature, and catalyst wt%. High yield of chalcones was obtained in a short period of time at 110 °C under solventless conditions. The catalyst was easy to separate and was reused multiple times with minor change in activity. On comparing the activity with other reported catalyst in literatures it was revealed that GO-MnO 2 nanocatalyst has significantly high activity in lesser period of time. Highly efficient GO-MnO 2 nanocomposite with rod like morphology has been synthesized via solution combustion route and its catalytic efficiency was systematically investigated for chalcones synthesis. Image 1 • MnO 2 nanorods on graphene oxide (GO) as catalysts with high surface-area were synthesized by thermal decomposition. • The designed GO-MnO 2 catalyst exhibits excellent catalytic activity for chalcones synthesis. • The synergistic effect of abundant Lewis acidic (Mn4+) and basic (O2-) sites are responsible for higher catalytic activity. • The catalyst showed recyclability up to six times without significant loss of activity. [ABSTRACT FROM AUTHOR]

Urea infiltration is the most extensively and ubiquitous method for depositing the multi-cation oxide catalyst layer on the electrode backbone in the SOFC area. The stoichiometry and composition are the two vital parameters for deposited multi-cation oxide nanocatalyst layer on which the catalytic activity and selectivity depend. However, the understanding behind the mechanism of multi-cation oxide nanocatalyst by urea infiltration is still missing, which restricts the reproducibility of this infiltration approach. The infiltration technique of Sm 0.5 Sr 0.5 CoO 3-δ (SSC) nanoparticle by urea method is highly irreproducible due to the intermediate phase's formation. This may result from the varying cation stoichiometry being formed along with the final product, and it is assumed to arise mainly due to the difference in precipitation tendency of cations present in the urea precursor solution. We investigate the influence of variation in the urea concentration effect on the stoichiometry of SSC nanoparticles. The difference in several parameters, such as electronegativity, ionic potential, cationic charge, and hydroxylation tendency, brings a competitive reaction within the three cations inside the urea infiltrated precursor solution. Thus, a different instrumental analysis was used to interpret the internal composition and heterostructure of the SSC nanoparticles. By applying, transmission electron microscopy with X-ray powder diffraction, the crystal structure of synthesized SSC nanoparticle was confirmed with the appropriate stoichiometry, and a comprehensive understanding of the mechanism was done for further improving the present urea syntheses protocol with proper reproducibility. The infiltration of Sm 0.5 Sr 0. 5 CoO 3-δ nanoparticle by urea method is irreproducible due to the intermediate phase formation caused by the difference in precipitation tendency of cations (Sm3+, Co2+, and Sr2+) within the urea precursor solution. Image 1 • Urea infiltration towards compositional reliability of nanocatalyst in SOFC was probed. • Correlation between urea concentration and nanocatalyst infiltration was studied. • Fluid mechanical & chemical approaches should be tuned for proper stoichiometry. • Careful consideration toward solubility product to be given for designing compositional reliable nanocatalyst. • Urea infiltration is challenging route to obtain single phase multication nanocatalyst. [ABSTRACT FROM AUTHOR]

• Novel, cost-effective, and high-performance surface decorated spinel-oxide electrode for a mixed-potential ammonia sensor. • The DRT analysis was employed for the first time to investigate the multistep relaxation processes during sensor operation. • The mixed-potential was solely governed by the interfacial redox reactions at the TPB rather than mass-transport processes. • The sensor displayed excellent sensitivity, selectivity, and exceptional stability over five months. The mixed-potential gas sensors appeared as the most promising sensing technology for the in-situ quantification of exhaust pollutants due to their simple configuration, low-cost, and thermochemical stability. Presently, high sensitivity and selectivity supplemented by long-term stability is the bottleneck challenge for these sensors to commercialize. Herein, highly sensitive and ammonia (NH 3) selective mixed-potential gas sensors were developed using surface decorated CuFe 2 O 4 (CFO)–MO X (M = Sn, Ni, Zn) composite sensing electrodes (SE). The CFO–NiO SE enriched of the surface oxygen vacancies produced a maximum response of −62 mV to 80 ppm NH 3 , supported by excellent sensitivity at 650 ℃. The comprehensive analysis of the response behavior and current-voltage (I–V) characteristics verified the sensing mechanism to be based upon the mixed-potential model conforming to the reaction-rate limited Butler–Volmer NH 3 oxidation kinetics. Finally, the distribution of relaxation times (DRT) analysis of impedance spectra confirmed that the overall polarization resistance was invariable of the mass-transport processes and solely governed by the extent of interfacial redox reactions proceeding at the triple-phase boundaries (TPB). Moreover, the high sensitivity, selectivity, and exceptional stability over five months substantiate the suitability of the presented sensor as a potential candidate for in-situ ammonia quantifications in industrial and automotive applications. [ABSTRACT FROM AUTHOR]

• Highly sensitive and NH 3 selective mixed-potential type sensor using CuFe 2 O 4 spinel-oxide electrode was firstly developed. • CuFe 2 O 4 and SnO 2 @CuFe 2 O 4 was successfully synthesized by modified Pechini route. • Sensitivity was critically dependent over the extent of Triple-phase boundary (TPB) lengths and operating conditions. • SnO 2 @CuFe 2 O 4 electrode displayed a synergistic enhancement in response compared to bare-CuFe 2 O 4 and SnO 2 for NH 3 detection. • The sensor displayed high sensitivity, NH 3 selectivity and excellent long-term stability. A mixed-potential type NH 3 sensor equipped with CuFe 2 O 4 and SnO 2 @CuFe 2 O 4 sensing electrode is presented. The CuFe 2 O 4 spinel-oxide and SnO 2 @CuFe 2 O 4 composites were synthesized by a modified-Pechini route. The electrode materials were characterized for the physical properties by powder X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Scanning electron microscopy (SEM) and Energy dispersive spectroscopy (EDS) analysis. It was found that the sensing characteristics were critically dependent on the extent of Triple-phase boundary (TPB) lengths and operating conditions of the sensor. Furthermore, the sensing performance of CuFe 2 O 4 spinel-oxide was enhanced by compositing with SnO 2 nanocrystals resulting in a synergistically enhanced response (ΔV) of −40 mV towards 80 ppm NH 3 , almost double and quadruple of the response of bare CuFe 2 O 4 and SnO 2 electrodes at 650 ℃, respectively. The sensor also displayed excellent stability towards oxygen and humidity variations, along with low cross-sensitivities towards interfering gases; e.g. NO, CO, CH 4, and NO 2. The complex impedance spectra (EIS) and dc polarization (I–V) measurements were performed for an insightful analysis of the sensing mechanism conforming to the mixed-potential model. [ABSTRACT FROM AUTHOR]