Moneam Y.K.A.,El Minufiya University |
Sakr H.A.A.,El Minufiya University |
Ali H.E.,National Center for Radiation Research And Technology |
Khalil S.A.,National Center for Radiation Research And Technology |
El-Naggar A.W.M.,National Center for Radiation Research And Technology
International Journal of ChemTech Research | Year: 2014
Unlike conventional methods of polymerization and crosslinking based on chemical initiators, in this work gamma irradiation has been used for the preparation of protective composite for papers against the attack of microbes. In this regard, blends based on plasticized starch (PLST) as major constituent and poly(vinyl alcohol) (PVA) were prepared in the form of thin films by casting solutions. The gamma irradiated blends were characterized by IR spectroscopy, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), mechanical testing, swelling and scanning electron microscopy (SEM). The results of TGA indicated that PLST/PVA blends are thermally more stable than pure PLST. DSC scans do not show the glass transition temperature (Tg) of PVA or PLST, but instead a new single glass transition, indicating the occurrence of compatibility. The mechanical properties of PLST/PVA blends showed that the tensile strength and elongation at break was found to increase by increasing the ratio of PVA. At any ratio of PLST/PVA, the tensile strength and elongation at break was found to increase with increasing irradiation dose. As an application in the field of paper surface modification, solutions of gamma irradiated PLST/PVA blends in the presence of zinc oxide, as an antimicrobial agent, were applied to paper by surface coating. The results showed this technique might provide suitable materials for the protection of papers against microbial attack.
Selim A.,El Minufiya University |
Zayed M.,El Minufiya University
Acta Botanica Hungarica | Year: 2013
Labour and greenhouse experiments were conducted to study the effect of magnetic field treated water on germination, growth and physiological and biochemical changes in tomato (Lycopersicon esculentum L.), wheat (Triticum aestivum L.) and pea (Pisum sativum L.). The results indicated that magnetic field treated water increased seed germination percentage, seed germination value and seedling vigour index. Magnetic field treated water increased also plant height, leaf area per plant, specific leaf area (SLA), leaf relative water content (LRWC), whereas the leaf water deficit (LWD) values were decreased. Biochemical analysis of the plant leaves irrigated by magnetic field treated water clarified changes in the photosynthetic pigments, UV-absorbing substances (UVAS), activities of peroxidase (POX) and polyphenol oxidase (PPO) enzymes, carbohydrates, phenolics and mineral ion contents. The latter changes are associated with the modifications in the membrane integrity of the plant leaves and the concentrations of some endogenous hormones in the plant shoots.