Effect on thermal,mechanical, and biodegradable properties of plasma-treated fish scale powder/linear low-density polyethylene polymer composite films

In the present work, we report the effect of low-temperature plasma treatment on thermal, mechanical, and biodegradable properties of polymer composite blown films prepared from carp fish scale powder (CFSP) and linear low-density polyethylene (LLDPE). The CFSP was melt compounded with LLDPE using a filament extruder to prepare 1, 2, and 3 wt.% of CFSP in LLDPE polymer composite filaments. These filaments were further pelletized and extruded into blown films. The blown films extruded with 1, 2, and 3 wt.% of CFSP in LLDPE were tested for thermal and mechanical properties. It was observed that the tensile strength decreased with the increased loading content of CFSP, and 1% CFSP/LLDPE exhibited the highest tensile strength. To study the effect of low-temperature plasma treatment, 1% CFSP/LLDP polymer composite with high tensile strength was plasma treated with O₂ and SF₆ gas before blow film extrusion. The 1% CFSP/LLDPE/SF₆-extruded blown films showed increased thermal decomposition, crystallinity, tensile strength, and modulus. This may be due to the effect of crosslinking by the plasma treatment. The maximum thermal decomposition rate, crystallinity %, tensile strength, and modulus obtained for 1% CFSP/LLDPE/SF₆ film were 500.02°C, 35.79, 6.32 MPa, and 0.023 GPa, respectively. Furthermore, the biodegradability study on CFSP/LLDPE films buried in natural soil for 90 days was analyzed using x-ray fluorescence. The study showed an increase in phosphorus and calcium mass percent in the soil. This is due to the decomposition of the hydroxyapatite present in the CFSP/LLDPE biocomposite.     

Investigation of various factors for the extraction of peppermint (Mentha piperita L.) leaves

Ingredients from peppermint leaves are widely used in the food industry as food additives and natural flavours. The traditional way to produce mint extracts is via steam distillation or solvent extraction, both long and energy consuming processes. This paper investigated various extraction methods, namely room temperature extraction, reflux temperature extraction, ultrasonic assisted room temperature extraction and microwave-assisted extraction. Extraction of peppermint leaves was studied for extraction times of 5, 10, 30 and 60 min, varying the sample-to-solvent ratio, along with the study of extraction yields for three mint compounds, menthone, menthol and menthofuran. The use of microwave-assisted solvent extraction allows the reduction of process time, the reduction of solvent use, while increasing extraction yields.     

Preparation of ceria nanoparticles embedded in PMMA using sonochemical technique

Homogeneous distribution of semicrystalline ceria in polymethylmethacrylate has been reported. The ceria has been prepared by sonochemical method, in situ. The as-prepared composite was characterized by XRD, TEM, DSC and TGA methods. An average size of the ceria is found to be  5 nm by XRD and TEM measurements. The photonic band gap has been measured as 3.55 eV, which is in well agreement with the ceria crystals, indicating absence of a quantum size effect.     

Fabrication and electrocatalysis of self-assembly directed gold nanoparticles anchored carbon nanotubes modified electrode

A self-assembly directed approach was adopted to modify glassy carbon electrode (GC) with gold nanoparticles incorporation and the electrocatalytic performance of self-assembly modified electrode, GC/SA-Au-ME was critically evaluated for the oxidation of ascorbic acid (AA). The modification involves the dispersion of multi-wall carbon nanotube (MWNT) and an inclusion complex, beta-cyclodextrin-4-aminothiophenol on the surface of GC electrode in the presence of cetyltrimethylammonium bromide (CTAB). Gold nanoparticles were deposited into the self-assembled sites to fabricate the modified electrode, GC/SA-Au-ME. Another electrode (GC-Au-ME) was fabricated under similar conditions in the absence of CTAB. The electrocatalytic activity of the modified electrodes (GC/SA-Au-ME and GC-Au-ME) towards the oxidation of AA was critically compared. Cyclic voltammetry, chronoamperometry, and double potential chronoamperometry were used to evaluate the characteristics of the modified electrodes. The self-assembled electrode (GC/SA-Au-ME) shows excellent electrocatalytic activity over the other electrode, GC-Au-ME. Augmented current response, faster electron transfer kinetics (with a rate constant for electron transfer process as 3.25 x 10(4) cm3 mol(-1) s(-1)), linear range of response for the analyte (1-50 mM with an extended detection limit to 1 microM), better sensitivity, and selectivity were witnessed for the self-assembly directed modified electrode.     

Microwave assisted combustion synthesis of coupled ZnO–ZrO2 nanoparticles and their role in the photocatalytic degradation of 2,4-dichlorophenol

Zinc oxide (ZnO), zirconium oxide (ZrO₂) and their coupled oxides in the molar ratio 1:1, 2:1 and 1:2 (labeled as ZnZr, Zn₂Zr, and ZnZr₂ respectively) were successfully prepared by a microwave assisted urea–nitrate combustion synthesis. The structure and morphology of the pure ZnO, ZrO₂ and coupled ZnZr, Zn₂Zr, and ZnZr₂ were characterized by powder X-ray diffraction (XRD), diffuse reflectance spectroscopy (DRS), photoluminescence spectroscopy (PL), high resolution scanning electron microscopy (HRSEM), energy dispersive X-ray spectrometry (EDX) and Brunauer–Emmett–Teller (BET) methods. The results of the photocatalytic degradation of 2,4-dichlorophenol (2,4-DCP) in aqueous solution indicated that the coupled metal oxide, Zn₂Zr is more effective towards the degradation of 2,4-DCP when compared to ZnO, ZrO₂, ZnZr and ZnZr₂.     

Design of a robust PID-PSS for an uncertain power system with simplified stability conditions

In a deregulated power system uncertainty exists and lack of sufficient damping can lead to Low Frequency Oscillations (LFO). The problem can be addressed using robust Power System Stabilizers (PSS). In this paper, an optimal procedure to design a robust PID-PSS using interval arithmetic for the Single Machine Infinite Bus (SMIB) power system is proposed. The interval modelling captures the wide variations of operating conditions in bounds of system coefficients. In the proposed design procedure, simple and new closed loop stability conditions for an SMIB interval system are developed and are used to design an optimum PID-PSS for improving the performance of an SMIB system. The optimum PID-PSS is attained by tuning the parameters using the FMINCON tool provided in MATLAB. The robustness of the proposed PID-PSS design is validated and compared to other notable methods in the literature when the system is subjected to different uncertainties. The simulation results and performance error values show the effectiveness of the proposed robust PID-PSS controller.     

Adapting Drying Technologies for Agri-Food Market Development in India

The adoption of new drying technologies is greatly favored by measures taken to adapt the technology to meet local needs. Drying technologies can offer opportunities for new product development, value-added features for enhanced nutrition and shelf stability for food supply management. Existing drying technologies must be modified/adapted to meet the many different properties of traditional Indian commodities and offer potential benefits for entrepreneurial developments. Much of the production and postharvest handling of products in India are done by low-income farmers in rural settings; hence, technological improvements must be based on low-cost available materials and renewable sources of energy. This article presents some of the drying developments accomplished in southern India.     

Probing the local strain-mediated magnetoelectric coupling in multiferroic nanocomposites by magnetic field-assisted piezoresponse force microscopy

The magnetoelectric effect that occurs in multiferroic materials is fully described by the magnetoelectric coupling coefficient induced either electrically or magnetically. This is rather well understood in bulk multiferroics, but it is not known whether the magnetoelectric coupling properties are retained at nanometre length scales in nanostructured multiferroics. The main challenges are related to measurement difficulties of the coupling at nanoscale, as well as the fabrication of suitable nano-multiferroic samples. Addressing these issues is an important prerequisite for the implementation of multiferroics in future nanoscale devices and sensors. In this paper we report on the local measurement of the magnetoelectric coefficient in bilayered ceramic nanocomposites from the variation in the longitudinal piezoelectric coefficient of the electrostrictive layer in the presence of a magnetic field. The experimental data were analyzed using a theoretical relationship linking the piezoelectric coefficient to the magneto-electric coupling coefficient. Our results confirm the presence of a measurable magnetoelectric coupling in bilayered nanocomposites constructed by a perovskite as the electrostrictive phase and two different ferrites (cubic spinel and hexagonal) as the magnetic phases. The reported experimental values as well as our theoretical approach are both in good agreement with previously published data for bulk and nanostructure magnetoelectric multiferroics.     

Mechanical,thermal, and electrical conducting properties of CNTs/bio‐degradable polymer thin films

The objective of this study is to increase mechanical, thermal, and electrical properties of plasticizer free thermoplastic bio polymer, BIOPLAST GS 2189 (BP), a blend of poly lactic acid (PLA) and potato starch. This polymer is highly suitable for sheet molding, film processing; blown film extrusion and injection molding and fully biodegradable. Structural, mechanical, thermal, and electrical properties of these films were manipulated by reinforcement of multiwalled carbon nanotubes (CNTs) in BP. Thin films of various (1–5 wt %) percentages of CNTs/BP were prepared by using a high‐speed spin coating technique. These as‐prepared films are ～60–100 µm in thickness. The thickness measurements of these films were carried out using micrometry and optical microscopy. The maximum tensile strength (200%) and modulus (150%) was observed for 4 wt % loading of CNTs in BP as compared with the neat BP thin film. The X‐ray diffraction results show that the addition of CNTs in BP increases the crystallinity of BP. Electrical conductivity of this film also increased by 48% as compared with the neat BP polymer films. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013