A new negative temperature coefficient of resistor (NTCR) thermistors based on nitrile butadiene rubber/magnetite (NBR/Fe 3 O 4 ) nanocomposites were successfully fabricated by conventional roll milling technique. X-ray diffraction and transmission (TEM) analysis showed that the product is mainly magnetite nanoparticles with diameter of 10-13 nm. The microstructure of (NBR/Fe 3 O 4 ) nanocomposites were examined by scanning electron microscopy (SEM) and FTIR spectroscopy. The dispersion of magnetite nanoparticles in the NBR rubber matrix and interfacial bonding between them were rather good. The thermal stability of nanocomposites was also obviously improved with the inclusion of the magnetite nanoparticles. The thermal conductivity, thermal diffusivity and specific heat of nanocomposites were investigated. The electrical conductivity of the NBR/Fe 3 O 4 increases with the rise in temperature exhibiting a typical negative temperature coefficient of resistance (NTCR) behavior like a semiconductor. The nature of the temperature variation of electrical conductivity and values of activation and hopping energy, suggest that the transport conduction process is controlled by hopping mechanism. Values of characteristics parameters of the thermistors like thermistor constant, thermistor sensitivity and thermistor stability is quite good for practical application as NTCR devices at high temperature.

We herein, report growth of zinc oxide nanorods by a simple reaction of zinc powder and de-ionized water at very low temperature of ~ 110 o C without using any organics. The formation of nanorods by the reaction of metals with water is suggested to occur due to the decomposition of water. The decomposed water produces controlled supply of OH -which further reacts with metal to form ZnO and releases hydrogen. The synthesized ZnO products were characterized in terms of their structural and optical properties. It was observed that the grown nanorods possess good optical property. Compared with other methods, the present method is simple, soft, inexpensive and environmentally benign which will make it suitable for large-scale production for devices and other applications. Keywords: Soft synthesis, Nanorods, Structural and optical properties 1. Introduction Zinc oxide (ZnO) is rapidly gaining credibility as a material with excellent possibilities for electronic and photonic devices. Owing to the semiconducting and piezoelectric dual properties, novel applications are introduced which have profound effect in many areas such as self-powdered nanodevices and nanosystems. The demonstration of room temperature ultraviolet lasers, field effect transistors and field emission arrays based on zinc oxide nanorods have stimulated great interest in developing functional nanodevices (C.

The effect of carbon nanotubes (CNTs) on the stability of the mechanical and electrical properties of recycled waste rubber was experimentally investigated. The stress-strain curves of the composites were studied. The results show that the toughness, the area under the stressstrain curve, of the recycled rubber increased monotonically as a result of the addition of CNTs. The modulus of the nanocomposites increased by 28 times when only 5 wt % CNTs was added to the recycled rubber matrix. The effects of the cyclic fatigue and hysteresis for the composites were also examined. The strain energy density, dissipation energy, and linear damage accumulation versus the number of cycles are discussed for all of the samples. The analysis of the results showed that the strain energy density increased by 15 times at a CNT concentration of 5 wt %. The electrical properties were measured for all of the samples. The results indicate that the addition of CNTs to the recycled rubber improved its electrical conductivity by more than two orders.

Captopril (KPL) (1-(3-mercapto-z-1)-methyl-1-oxopropyl)-l-proline (S,S) is a potential drug for the treatment of high blood pressure that can result from over production of angiotension II. Captopril inhibits the enzyme, which catalyzes the conversion of inactive angiotension II (schem-1) . The mechanism of the action has not been proved, but probably accurs through interaction with the enzyme a zinc containing metalloprptien, at its active site 1 . Captopril is an antihypertensive drug currenlly being administered in tablet from. ORIENTAL JOURNAL OF CHEMISTRY ABSTRACTIn this work captopril an antihypertensive (KPL) drug, was investigated using thermal analysis (TA) measurements (TG-DTA) in comparison with electron impact (EI) mass spectral (MS) fragmentation at 70 eV. Semi-empirical molecular (MO) calculations, using PM3 method in the neutral and positively charged forms of the drug. These include molecular geometry, bond order, charge distribution, heats of formation and ionization energy. The behavior of the drug under drug TA decomposition, reveal a moderate stability up to 160C o before a completely decomposition in the range 160-240 C o . The initial decomposition is due to COOH + CH 3 loss, followed by SH loss. On the other hand, the molecular ion can easily fragmented by CO 2 loss followed by SH loss. This is the best-selected pathway comparable with decomposition using TA. MO-Calculation is used to declare these observations.

We report an organics free and safe route for the preparation of titanium dioxide (TiO₂) nanoparticles having tetrapad shape. The approach is based on a very simple reaction of titanium powder and de-ionized water at very low temperatures of ~140^oC without using any organics or surfactants. By the morphological investigations using FESEM and HRTEM, it was observed that the grown products are having tetrapad shape with the diameters in the range of 10-50nm. The EDS and XRD pattern confirmed the composition and crystallinity of the grown nanoparticles and revealed that the grown products are pure TiO₂ with the tetragonal anatase phase. Since only water, which is regarded as a benign solvent is used during the preparation of nanoparticles, we believe that the product so produced is biocompatible and bio-safe and can be readily used for food and medicine. Besides other advantages, the present method is economical, fast, low temperature, free of pollution and environmentally benign which will make it suitable for large scale production.