Green synthesis of lanthanum oxide nanoparticles using Moringa oleifera leaves extract and its biological activities

Phytosynthesis is a reliable way to produce metal nanoparticles without affecting the environment. Plant extracts act as reducing agent and favors nanoparticle synthesis. Recently, potential drugs were developed in nanotechnology platforms by the green synthesis approach. In this study, the leaves extract of ‘Moringa Oleifera’ (M. oleifera) used as a reducing agent for the synthesis of Lanthanum oxide nanoparticles (La₂O₃ NPs). The X-ray diffraction (XRD) confirmed the formation of body-centered cubic structure of La₂O₃ NPs. The optical behavior of La₂O₃ NPs was analyzed by UV–Vis spectrum. The bandgap energy of the La₂O₃ NPs was found to be 4.31 eV using Tauc’s plot. The morphology and purity of La₂O₃ NPs was analyzed by using Field Emission Scanning Electron Microscope (FESEM) and Energy Dispersive X-ray (EDX) spectrum. High Resolution Transmission Electron Microscope (HR-TEM) analysis reveals the morphology, lattice spacing, and selected area electron diffraction (SAED) pattern of the La₂O₃ NPs. The XPS analysis of the La₂O₃ NPs reveals the binding energy of La (3d_5/2 and 3d_3/2) and O 1s at 835.5, 852.3, and 536 eV respectively. The total antioxidant activity (TOA) of La₂O₃ NPs was found to be 75.32% at 500 µg/mL with the standard drug of vitamin C. The anti-inflammatory activity of the La₂O₃NPs was found to be 94.15% at 500 µg/mL using the bovine serum albumin denaturation (BSA) technique. The inhibitory activity of La₂O₃ NPs against α-amylase was found to be 79.99% at 500 µg/mL. In summary, the pure, highly stable and good biocompatible, greener approach based M. oleifera assisted La₂O₃ was synthesized for radical scavenging, α-amylase and BSA denaturation inhibition activities which can play a key role in the future biomedical and nano-biotechnological applications.     

Semantic-enabled CARE Resource Broker (SeCRB) for managing grid and cloud environment

Grid computing is mainly helpful for executing high-performance computing applications. However, conventional grid resources sometimes fail to offer a dynamic application execution environment and this increases the rate at which the job requests of users are rejected. Integrating emerging virtualization technologies in grid and cloud computing facilitates the provision of dynamic virtual resources in the required execution environment. Resource brokers play a significant role in managing grid and cloud resources as well as identifying potential resources that satisfy users’ application requests. This research paper proposes a semantic-enabled CARE Resource Broker (SeCRB) that provides a common framework to describe grid and cloud resources, and to discover them in an intelligent manner by considering software, hardware and quality of service (QoS) requirements. The proposed semantic resource discovery mechanism classifies the resources into three categories viz., exact, high-similarity subsume and high-similarity plug-in regions. To achieve the necessary user QoS requirements, we have included a service level agreement (SLA) negotiation mechanism that pairs users’ QoS requirements with matching resources to guarantee the execution of applications, and to achieve the desired QoS of users. Finally, we have implemented the QoS-based resource scheduling mechanism that selects the resources from the SLA negotiation accepted list in an optimal manner. The proposed work is simulated and evaluated by submitting real-world bio-informatics and image processing application for various test cases. The result of the experiment shows that for jobs submitted to the resource broker, job rejection rate is reduced while job success and scheduling rates are increased, thus making the resource management system more efficient.     

A sensitive electrochemical detection of hydroquinone using newly synthesized α-Fe<Subscript>2</Subscript>O<Subscript>3</Subscript>-graphene oxide nanocomposite as an electrode material

This article presents the effect of hematite phase iron oxide (α-Fe₂O₃) on the electrocatalytic activity of graphene oxide (GO) for electrochemical detection of hydroquinone in aqueous solution. The different weight percentage (wt%) (1, 2 and 3%) of α-Fe₂O₃ added GO nanocomposites were synthesized by wet-impregnation method. The cyclic voltammetry studies using 2% α-Fe₂O₃-GO modified glassy carbon electrodes was found to exhibit an excellent electrocatalytic activity than α-Fe₂O₃ and GO electrodes that may be due to the synergistic effect of α-Fe₂O₃nanoparicles and GO sheet. In addition, the modified electrode exhibited a good reproducibility as well as long-term stability. Hence, the 2% α-Fe₂O₃-GO can be a promising catalytic material for electrochemical sensor applications.     

Hybrid Cloud Resource Provisioning (HCRP) Algorithm for Optimal Resource Allocation Using MKFCM and Bat Algorithm

Wireless Personal Communications - The basic purpose of resource allocation is to make the most efficient allocation of available resources. It contains resources and the number of tasks. The...     

Electrochemical behavior of nanocrystalline Ni–P alloys containing tin and tungsten

Autocatalytic ternary Ni-Sn-P, Ni-W-P and quaternary Ni-W-Sn-P films were prepared using an alkaline bath. Plain Ni-P films were also prepared for comparison. Corrosion resistance of the films was evaluated in 3.5% sodium chloride solution in non-deaerated condition by potentiodynamic polarization and electrochemical impedance spectroscopy methods. Deposits were also immersed in 3.5% sodium chloride solution for 7 days. All the coatings attained stable equilibrium potential within 30 minutes in NaCl medium. Lower corrosion current density values were obtained for ternary Ni-Sn-P coatings compared to the plain Ni-P coatings. Ternary Ni-W-P and quaternary Ni-W-Sn-P alloys did not show improved corrosion resistance compared to the ternary Ni-Sn-P coatings. Similar behavior of these coatings was further confirmed by the electrochemical impedance studies. After the potentiodynamic polarization test deposits were examined by scanning electron microscope. It was found that more corrosion occurred for the quaternary deposit compared to other deposits. Energy dispersive analysis of X-ray results indicated that more amount of Fe present on NiWP and NiWSnP coated samples. Similar behavior was confirmed from the optical images of the surfaces obtained for the deposits after the immersion test. The article is published in the original.     

Enhancing energy storage efficiency of lithiated carbon nitride (C7N6) monolayers under co-adsorption of H2 and CH4

There is a great interest in the design of innovative concepts and strategies of nitrogen rich carboneous materials for exploring their hydrogen (H₂) storage properties. Methane (CH₄) storage can be an alternative to H₂ because the combustion energy of the former is around three times higher than the latter. However, strong inter-molecular repulsion between the CH₄ molecules is a major bottleneck to achieve a high gravimetric density. In this study, we use first principles density functional calculations to investigate the coadoption of H₂ and CH₄ on Li decorated carbon nitride (Li–C₇N₆) monolayer. The repulsion between CH₄ molecules has been avoided by keeping them in asymmetric configuration whereas the repulsion between CH₄–H₂ is in moderation due to the exploitation of open Li doped sites on C₇N₆ surface. Though Li–C₇N₆ has a lower H₂ or CH₄ storage capacity due to weak van der Waals interactions, the capacity could be doubled with a novel strategy of co-mixing of H₂ with CH₄ which results into a significantly high gravimetric density of 8.1 wt%. This clearly shows that the CH₄–H₂ co-mixing strategies have the potential to further propel the prospects of C₇N₆ monolayers for reversible clean energy storage applications.     

海马齿对土壤的植物修复（1）：制革废水污染的土壤中Na^＋和Cl^-的去除

盐生植物海马齿（S．Portulacastrum）具有良好的耐盐能力，能够吸收氯化钠。本文研究了将海马齿作为生物累积体，用于吸收制革废水中存在的NaCl^-的可行性。将海马齿栽培在土壤中，用含不同浓度NaCl^-的制革废水进行灌溉，记录其生长参数，如根和枝的长度，并测定海马齿的叶和枝中累积的Na^＋和CF离子含量。结果表明，Na^＋和CF的累积量随着栽培密度和制革废水中盐浓度的增大而增加。但是，盐浓度的增加会导致海马齿生长减缓。在高栽培密度条件下，用含15000ppmNaCl的制革废水灌溉海马齿，Na^＋和Cl^-的吸收率可以分别达到34％和22％。与根和茎相比，海马齿叶子中Na^＋和Cl^-累积量最大。本文的研究结果说明．海马齿用于氯化钠的生物累积是可行的。     

Synthesis and properties of electrodeposited Ni/ceria nanocomposite coatings

Composite plating is a method of co-depositing fine particles of metallic or non-metallic compounds or polymers in the plated layer to improve material properties such as lubrication, wear resistance and corrosion resistance. In the present study, Ni was chosen as the matrix material and ceria nanoparticles were chosen as the distributed phase. Nanocrystalline ceria powder was synthesized by the solution combustion process and characterized by powder X-ray diffractometry (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The nanosize ceria particles were co-deposited with nickel from a nickel sulfamate bath using conventional electrodeposition method. The electrodeposition was carried out at current densities of 0.23, 0.77, 1.55, 3.1 and 5.4 A/dm². The microhardness of the Ni matrix was enhanced by the incorporation of ceria particles. Potentiodynamic polarization, electrochemical impedance spectroscopy and SEM were used to characterize the corrosion behaviour of Ni and Ni/CeO₂ coatings. These studies showed improved corrosion resistance for Ni/CeO₂ when compared to Ni. The microhardness, corrosion resistance and wear resistance of Ni and Ni/CeO₂ were compared.     

Role of conducting carbon in electrodes for electric double layer capacitors

Six electrodes with a varying amount (5, 10, and 15 wt.%) of conducting carbon nanotubes (CNT) and carbon nanofibers (CNF) were fabricated and their performance evaluated against a control sample that was devoid of any conducting material. The goal of this work was to determine the correlation between electrode conductivity and capacitance in 1 M tetraethyl ammonium tetrafluoroborate (TEABF₄) in propylene carbonate (PC) electrolyte. CNT electrodes exhibit the lowest electrical resistance, while CNF electrodes had the highest capacitance. The specific capacitance (120-140 F/g) increased monotonically up to 2.5 V. An inverse correlation between electrical resistance and capacitance was observed for various concentrations. The electrodes were characterized using CV, EIS, SEM, and BET analysis.