Synergistic effect of graphene with graphene oxide,nanoclay, and nanosilica in enhancing the mechanical and barrier properties of bromobutyl rubber/epoxidized natural rubber composites

The present work aims to investigate the effect of hybrid nanofillers in bromobutyl rubber/epoxidized natural rubber (ENR 50) composites for developing highly air-impermeable nanocomposites. The nanocomposites with hybrid nanofillers were prepared by a simple melt mixing method, and the morphology of the developed nanocomposites was studied using X-Ray diffraction, transmission electron microscopy, and atomic force microscopy. Improvement in the mechanical, barrier and dynamic properties can be observed for hybrid nanocomposites compared to the composites filled with individual graphene nanoplatelets (GNPs). The strong interfacial attraction between GNP monolayers enhance its aggregation in nanocomposites. While, in the current study the results are showing that the addition of graphene oxide, nanoclay, and nanosilica enhances the dispersion of GNP in the composites. The homogeneous dispersion of GNP nanofillers will develop a tortuous pathway in the composites, which are responsible for their air barrier properties. Bound rubber content and dynamic strain measurements (Payne effect) show a maximum value for binary nanocomposites.     

Synthesis,characterization and application of novel polyacrylamide‐grafted barley

Polyacrylamide‐grafted barley (BAR‐g‐PAM) was synthesized by ceric ion‐based conventional method. The grafting of polyacrylamide chains on the polysaccharide backbone was confirmed through various physicochemical techniques such as intrinsic viscosity measurement, ¹³C‐NMR spectra, FTIR spectroscopy, elemental analysis, scanning electron microscopy morphology, thermogravimetric analysis study, number‐average molecular weight, and aqueous solubility. Furthermore, flocculation efficacy of the graft copolymers was studied in coal fine suspension through “jar test” procedure, toward its possible application as a novel flocculant for treatment of coal washery effluent. BAR‐g‐PAM is reported as a novel flocculant that can be used for bulk treatment of coal washery effluents. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 41046.     

An Evaluation of Drapeability of Jute Fabric

From the very inception of the Indian Jute Industry, jute fiber has proved its superiority over other fibers particularly in the area of packaging for food grains, in terms of its functionality and reusability due to its considerable tensile strength, low extensibility, and good dimensional stability, which is obviously the natural choice for packaging. One of the growing alternatives in today’s context is the emergence of technical textiles made out of natural fibers which includes geotextile products for geotechnical applications, agrotextile products as well as other such relevant areas. Jute geotextile can certainly be considered as a potential aspirant replacing majority of today’s popular synthetic products which are posing severe threats to our environment thereby adversely affecting the eco-congruity. During the application of jute fabrics of different types at the sites and even in designing garments in the Apparel Sector, it has been observed that the ability of the fabric to assume a graceful appearance of the contour is very crucial conveying the significance of drapeability of the jute fabric. An attempt has been made in this paper to study the effect of relevant property parameters and their comparative analysis on the drapeability of jute fabric as well as synthetic woven and nonwoven fabrics with respect to their end-use requirements.     

Micro‐shear deformation of pure copper

In this paper a new micro‐shear experiment is introduced using a double shear specimen machined by a focused ion beam technique. The micro‐shear specimen is structured from pure copper promoting (111) [101] slip. Comparing scanning electron microscopy images before and after deformation provides evidence for localized shear. Load‐displacement data identify a load plateau and characterize the localized shear process (critical shear‐stress for activation of (111) [101] slip: 170 MPa).     

Effect of Zn source concentration on structural,optical and electrical properties of zinc sulphide–polyaniline (ZnS–PANI) nanocomposite thin films

Zinc sulphide–polyaniline (ZnS–PANI) nanocomposites are prepared by preparing ZnS nanoparticles in the same reaction bath for synthesis of PANI. Three different composites have been prepared by varying the concentration of zinc source. The films obtained from the colloidal dispersion are characterized by Scanning electron microscopy, energy dispersive analysis of X-rays, transmission electron microscopy, X-ray diffraction studies, Fourier transform infrared spectroscopy, UV–visible optical absorption, photoluminescence and current–voltage studies. Broadening of X-ray diffraction peaks suggest change in crystallite size and this is in agreement with the results from transmission electron microscopy. Fourier transform infrared spectra indicate crosslinking in the composite film. UV–visible absorption spectra of the film exhibit enhancement of doping level which is assigned to the existence of greater number of charges on the polymer backbone. Optical properties of the films are studied by measuring photoluminescence spectra. This shows decrease in intensity and blue shift with the increase in zinc source concentration. The blue shift indicates strong quantum confinement. Current–voltage characteristics exhibit excellent light response indicating tunneling type of conduction.     

Generalized optical gain analysis in nonparabolic semiconductor laser

A simple generalized theory is developed for optical gain of nonparabolic semiconductor lasers based on the three‐band model of Kane, by taking into account the wave‐vector () dependence of the optical matrix element. The gain in laser of nonparabolic semiconductors is demonstrated, by taking InAs, InSb, Hg_1−xCd_xTe and In_1−xGa_xAs_yP_1−y lattice matched to InP as examples, and it has been found that the peak of the gain spectra for a given carrier density is higher in the three‐band model of Kane than those with parabolic energy band approximations in all the cases. The difference between the peak of gain spectra for three‐band model and the parabolic band model is greater for laser of narrow band gap materials in comparisons with that of laser of wide band gap materials, thereby reveals the necessity for inclusion of the nonparabolicity in modeling lasers of small band gap materials. The well‐known results for wide band gap materials having parabolic energy bands has also been obtained from our generalized formulation under certain limiting condition. Copyright © 2013 John Wiley & Sons, Ltd.     

Impacts of community-based fish culture in seasonal floodplains on income,food security and employment in Bangladesh

This paper examines the impact of community based fish culture in seasonal floodplains on fish production, consumption, income, and food security of the participating households in Bangladesh. An analysis was performed using a randomly selected 46 % of the households from the three project and control floodplains; data were collected using longitudinal surveys on a seasonally, quarterly and monthly basis for the years 2007, 2008 and 2009. Fish production, income and food security of the participating households was improved due to the adoption of an equitable and inclusive multi-stakeholder approach introduced by the project. Average fish production increased from 124 kg/ha/yr. to 464 kg/ha/yr. The introduced community-based fish culture approach generated 3.74 times more fish income for households in the project sites in comparison to the control sites. Per capita monthly fish consumption increased from 1.26 kg to 2.31 kg in the project sites, which was 32 % higher than the control sites. Project implementation reduced the vulnerability of local beneficiaries, particularly of the landless and poor fishermen, by creating additional fishing opportunity for up to 6 months of the year. Promotion of the community based fish culture in seasonal floodplains may thus be useful in bringing about positive changes in the overall floodplain productivity and livelihood gains for the poor people of Bangladesh.     

Stability analysis on dual solutions of MHD Casson fluid flow with thermal and chemical reaction over a permeable elongating sheet

The endeavor of this study is to explore the nature of dual solutions (steady and unsteady) for the Casson fluid flow with the simultaneous consequences of both thermal and mass transmissions. The flow passes above an absorbent elongating sheet in the existence of a constant magnetic field. The supported leading equations are remodeled into a set of solvable forms with the assist of suitable similarity variables and hence deciphered utilizing the “MATLAB routine bvp4c scheme.” Due to the sudden changes in the surface with time, the temperature and flow behavior over the sheet also change, and hence dual-type flow solutions exist. Stability scrutiny is implemented to examine the less (more) stable and visually achievable solutions. From this study, we have achieved many interesting facts, among them, we can use magnetic and Casson fluid parameters to control the motion of the fluid and to enlarge of thermal transmission of the fluid. This flow model has many important applications in different physical fields, such as engineering sciences, medical sciences, and different industrial processes. One of the most important results, which has been achieved from this investigation, is that the Prandtl number enriches the heat transfer rate of the fluid at the surface during the time-independent case under the suction environment. Also, the chemical reaction parameter helps to enhance the mass accumulation rate of the fluid in both cases.     

Novelty on reduction of raw and pre-oxidised titaniferous magnetite ore with boiler grade coal

Pre-oxidation of fines of magnetite containing materials is usually carried out to get better yield of metals. Titaniferous magnetite ore (TMO) is one kind of low-grade iron ore (around 45–50% of total Fe) with a significant amount of TiO₂ (23.23%) and V₂O₅ (0.403%). TMO fines have been pre-oxidised at 973?K (700°C) for 9?h under air atmosphere. The effect of reduction of raw TMO fines as well as the pre-oxidised TMO fines using boiler grade coal in the form of cylindrical briquettes has been studied in the temperature range of 1273?K (1000°C) to 1473?K (1200°C) for periods of 10, 20, 30, 40 and 60?min to estimate the relative yield of iron. The influence of temperature and time on reduction experiments has also been investigated with XRD, FESEM analyses along with chemical analysis of the reduced samples. The most novel result is that the yield of Fe by direct reduction of raw TMO (92.42%) is even marginally better than that of reduction of pre-oxidised TMO (90.89%) at 1473?K (1200°C) for 60?min. Thus the single-step reduction of raw TMO is techno-economically more viable than the pre-oxidation followed by reduction technique.