Antifungal,antiaflatoxin and antioxidant potential of chemically characterized Boswellia carterii Birdw essential oil and its in vivo practical applicability in preservation of Piper nigrum L. fruits

The study explores the chemical profile, antimicrobial and antioxidant activity of Boswellia carterii essential oil (EO). The EO significantly inhibited growth and aflatoxin production by the food borne toxigenic strain of Aspergillus flavus at 1.75 μl/ml and 1.25 μl/ml respectively. It exhibited broad fungitoxic spectrum against 12 food borne moulds and also showed strong antioxidant activity, IC₅₀ value and % inhibition of linoleic acid peroxidation being 0.64 μl/ml and 51.68% respectively. The antifungal action of EO was observed in terms of reduction in ergosterol content of plasma membrane of A. flavus. As fumigant in food system in storage containers, the EO provided 65.38% protection against fungal deterioration of Piper nigrum. GC–MS results revealed 31 components of EO. The chemically characterized B. carterii EO may thus be recommended as plant based preservative in view of its antifungal, antiaflatoxigenic, antioxidant activity and efficacy in food system.     

Policy-based Awareness Management (PAM): Case study of a wireless communication system at a hospital

The present paper evaluates the use of software agents to identify relevance of information, called awareness. This evaluation is based on existing policies and scenarios in the context of wireless communication of a hospital in Norway. The study is to address the lack of literature for experimental studies on a method to employ software agents for awareness identification. Research in computer supported cooperative work indicates the significant contributions of software agents to assist individuals. There are bodies of work that show awareness provides the means for software agents in which effective cooperation can take place. In addition, the role of the methods to identify awareness is emphasized in the literature of both computer supported cooperative work and software agents. This paper explains a step-wise process, called Policy-based Awareness Management, which allows agents to use policies as a source to identify awareness and thus change their behaviors accordingly. The contribution of this method is based on the concepts proposed by the logic of general awareness. The present study applies Directory Enabled Networks-next generation as the policy structure for the method. The paper evaluates the process via its application to identify the relevance of information in wireless communication scenarios in a hospital. The present study conducts observations, interviews and discussions on the wireless communication system of the hospital to identify the different scenarios happening in the system. The paper presents a set of simulations on these scenarios and concludes that the method is effective and cost-efficient.     

Synthesis and kinetics of ascorbic acid initiated graft copolymerized delignified cellulosic fiber

Graft copolymerization of delignified Grewia optiva fiber with methyl methacrylate (MMA) as vinyl monomer was attempted using ascorbic acid/H₂O₂ as redox initiator. Different reaction conditions affecting the grafting percentage (P_g) were optimized to get the maximum P_g (32.56%) of MMA onto delignified Grewia optiva fibers. Grafted and ungrafted fibers were subsequently subjected to evaluation of physico‐chemical properties such as swelling behavior and acid and alkali resistance. The rate expression for the grafting reaction (R_g = k [ASC]^0.12 [H₂O₂]^0.53 [MMA]^0.05) was evaluated and a suitable mechanism for grafting was suggested. The overall activation energy of the copolymerization reaction was found as 11.97 kJ mol^?1 at temperature range 25–65°C. Further, morphological and structural analysis of raw, delignified, and grafted Grewia optiva‐g‐poly(MMA) were studied by using Fourier‐transform Infrared spectroscopy, scanning electron microscopy, X‐ray diffraction, and thermogravimetric analysis.The tensile properties of grafted and ungrafted fiber samples were also reported. POLYM. ENG. SCI., 55:474–484, 2015. © 2014 Society of Plastics Engineers     

Shear rheological properties of acrylic copolymers and terpolymers suitable for potentially melt processable carbon fiber precursors

In an effort to generate melt processable polyacrylonitrile (PAN) precursor fibers suitable for conversion to carbon fibers, an acrylonitrile/methyl acrylate (AN/MA) copolymer and two acrylonitrile/methyl acrylate/acryloyl benzophenone (AN/MA/ABP) terpolymers were synthesized at molar ratios of 85/15 and 85/14/1, respectively. The termonomer (ABP) was incorporated to accelerate crosslinking via UV irradiation, which serves to prevent relaxation of orientation and flow as the temperature of the fiber is raised during thermooxidative stabilization. Two molecular weights of the terpolymer and one molecular weight of the copolymer were studied to determine the effect of the termonomer, and the effect of molecular weight (MW), on the steady shear viscosity (η) and magnitude of the complex viscosity (η*). A higher rate of increase of η as a function of time was observed for the high MW terpolymer relative to that of the copolymer over the temperature range used. Using a temperature sweep and monitoring levels of η*, a minimum was observed at lower temperatures for both terpolymers. These results suggest that copolymerization with ABP significantly increased the thermally induced kinetics of crosslinking. Comparison of the η and η* data for the low and high MW terpolymers suggested that molecular weight also significantly reduced the melt stability (increased the kinetics of crosslinking). A chemorhelogical correlation was then used to quantify the effects of the termonomer and of molecular weight on the kinetics of crosslinking of the AN terpolymers. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 2856–2865, 2004     

Compaction and Sintering Behavior of Niobium Powder for Making Consumable Electrodes

Niobium consumable electrodes of 10?mm dia?×?50?mm length were prepared by cold isostaic pressing with compaction pressure of 125?C250?MPa. The compacts were sintered under vacuum at different temperatures in the range of 1000?C1800?oC. The CIPed and sintered electrodes were characterized with respect to chemical analysis, density, microstructure and bend strength. The results showed that there is a marginal improvement in density at a sintering temperature in the range of 1000?C1400?oC, while a significant improvement in density was observed at sintering temperature in the range of 1600?C1800?oC. The bend strength of sintered electrode was found to increase with increasing sintering temperature and that attains a highest value at a sintering temperature in the range of 1600?C1800?oC. Sintering at a temperature higher than 1400?oC leads to decrease in oxygen content of the electrodes. The oxygen content was decreased from 2000 to 500?ppm when electrode was sintered at 1800?oC.     

Tensile and Fracture Properties of Aluminium Alloy AA2219-T87 Friction Stir Weld Joints for Aerospace Applications

Metallurgical and Materials Transactions A - The purpose of the present work is to study the mechanical behaviour of AA2219-T87 friction stir weld (FSW) joints at different temperatures (Room...     

1,2,3-Triazolium-based poly(acrylate ionic liquid)s

Nitroxide-mediated radical polymerization of a tailor-made acrylate carrying a 1,2,3-triazole group with an undecanoyl spacer affords a well-defined (M_n = 7860 g mol⁻¹ and D = 1.39) neutral polyacrylate precursor. A series of 1,2,3-triazolium-based poly(ionic liquid)s (TPILs) is then obtained by straightforward quaternization of the 1,2,3-triazole groups with methyl iodide and subsequent anion metathesis reactions. Among the prepared materials, TPIL with bis(trifluoromethane)sulfonimide anion exhibits low glass transition temperature (T_g = −40 °C), high thermal stability (T_d10 = 325 °C) and anhydrous ionic conductivity of 4 × 10⁻⁶ S cm⁻¹ at 30 °C, as measured by differential scanning calorimetry, thermogravimetric analysis and broadband dielectric spectroscopy, respectively.     

Green composites based on high‐density polyethylene and Saccharum spontaneum: Effect of filler content on morphology,thermal, and mechanical properties

Here we report the preparation and characterization of a green composite based on high‐density polyethylene and Kaans grass (Saccharum spontaneum). The composites were prepared by conventional melt‐mixing method, using maximum loading of Kaans grass in powder form (KG‐filler) to achieve acceptable range of required properties. Maleic anhydride grafted polyethylene was used as compatibilizer to achieve effective interaction for improved surface adhesion which was confirmed by FT‐IR spectroscopy. Morphological studies revealed good interaction between the base polymer matrices and the KG‐fillers that improved the mechanical and thermal properties of the composites up to certain (10 phr) KG‐filler loading. Study on water absorption property revealed moderate increase in weight at higher KG‐filler loadings. Thermogravimetric analysis (TGA) and melt flow index (MFI) studies indicated retention of thermal stability and flow property of the HDPE/KG‐filler composite at lower filler loadings. POLYM. COMPOS., 36:2157–2166, 2015. © 2014 Society of Plastics Engineers     

Spin-wave excitations in amorphous ferromagnets

Mössbauer measurements have been performed on a number of metallic glasses. The temperature dependence of average hyperfine or internal magnetic fieldH _eff(T) arises from long wavelength spin wave excitations in these glasses. Values ofB _3/2 andC _5/2 are in general much higher than those observed for crystalline ferromagnets indicating higher density of states for spin waves in amorphous ferromagnets.