Interaction of oxygen (O+7) ion beam on polyaniline thin films

High-energy ion beam irradiation of the polymers is a good technique to modify the properties such as electrical conductivity, structural behaviour and mechanial properties. Polyaniline thin films doped with hydrochloric acid (HCl) were prepared by oxidation of ammonium persulphate. The effect of Swift Heavy Ions irradiation on the electrical and structural properties of polyaniline has been measured in this study. Polyaniline films were irradiated by oxygen ions (energy 80 MeV, charge state O+7) with fluence varying from 1 × 1010 to 3 × 1012 ions/cm2. The studies on electrical and structural properties of the irradiated polymers were investigated by measuring V-I using four probe set-up and X-ray diffraction (XRD) using Bruker AXS, X-ray powder diffractometer. V-I measurements shows an increase in the conductivity of the film, XRD pattern of the polymer shows that the crystallinity improved after the irradiation with Swift Heavy Ions (SHI), which could be attributed to cross linking mechanism.Subhash Chandra1*, S Annapoorni2, R G Sonkawade3, P K Kulriya3 Fouran Singh3, D K Avasthi3, J M S Rana1 and R C Ramola1 1Department of Physics, H N B Garhwal University, Badshahi Thaul Campus, Tehri Garhwal-249 199, Uttarakhand, India 2Department of Physics and Astrophysics, University of Delhi, Delhi-110 007, India 3Inter University Accelerator Center, Aruna Asaf Ali Marg, New Delhi-110 067, India E-mail : [email protected] of Physics, H N B Garhwal University, Badshahi Thaul Campus, Tehri Garhwal-249 199, Uttarakhand, India Department of Physics and Astrophysics, University of Delhi, Delhi-110 007, India Inter University Accelerator Center, Aruna Asaf Ali Marg, New Delhi-110 067, Indi

Numerical test of the Edwards conjecture shows that all packings are equally probable at jamming

In the late 1980s, Sam Edwards proposed a possible statistical-mechanical framework to describe the properties of disordered granular materials1. A key assumption underlying the theory was that all jammed packings are equally likely. In the intervening years it has never been possible to test this bold hypothesis directly. Here we present simulations that provide direct evidence that at the unjamming point, all packings of soft repulsive particles are equally likely, even though generically, jammed packings are not. Typically, jammed granular systems are observed precisely at the unjamming point since grains are not very compressible. Our results therefore support Edwards’ original conjecture. We also present evidence that at unjamming the configurational entropy of the system is maximal.S.M. acknowledges financial support by the Gates Cambridge Scholarship. K.J.S. acknowledges support by the Swiss National Science Foundation under Grant No. P2EZP2-152188 and No. P300P2-161078. D.F. acknowledges support by EPSRC Programme Grant EP/I001352/1 and EPSRC grant EP/I000844/1. K.R. and B.C. acknowledge the support of NSF-DMR 1409093 and the W. M. Keck Foundation

Coated Controlled-Release Fertilizers: Potential Solution for Sustainable Agriculture

The use of fertilizer in the agricultural field is essential for plant growth but an excess amount of pure chemical contents in fertilizers becomes harmful to every living being. To reduce this chemical exposure, the use of materials coated with Controlled Release Fertilizers (CRFs) are being used. The coating of materials outside the fertilizer does not allow the chemicals to spread completely within one application of fertilizer but its spread can be extended as will be done in 2-3 applications of fertilizer. The features of the undercoating material are thus vital to attain this delayed or slow release of the nutrients present in the fertilizer. The longevity of CRFs depends upon the width of the material coating surrounding the fertilizer, temperature, and moisture. The review focuses on the consequences of conventional fertilizers, the need to control the release of fertilizers and types of coatings used, and their application in sustainable agriculture

Numerical test of the Edwards conjecture shows that all packings are equally probable at jamming

In the late 1980s, Sam Edwards proposed a possible statistical-mechanical framework to describe the properties of disordered granular materials1. A key assumption underlying the theory was that all jammed packings are equally likely. In the intervening years it has never been possible to test this bold hypothesis directly. Here we present simulations that provide direct evidence that at the unjamming point, all packings of soft repulsive particles are equally likely, even though generically, jammed packings are not. Typically, jammed granular systems are observed precisely at the unjamming point since grains are not very compressible. Our results therefore support Edwards’ original conjecture. We also present evidence that at unjamming the configurational entropy of the system is maximal.S.M. acknowledges financial support by the Gates Cambridge Scholarship. K.J.S. acknowledges support by the Swiss National Science Foundation under Grant No. P2EZP2-152188 and No. P300P2-161078. D.F. acknowledges support by EPSRC Programme Grant EP/I001352/1 and EPSRC grant EP/I000844/1. K.R. and B.C. acknowledge the support of NSF-DMR 1409093 and the W. M. Keck Foundation