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Waterlogging is a major constraint of mungbean production in the tropical and subtropical regions of the world and can cause a significant yield loss. The study evaluated 100 mungbean genotypes for tolerance to waterlogging employing rigorous field screening procedures. Three-week-old seedlings of 100 mungbean genotypes were subjected to waterlogging for 3 days maintaining a waterlogging depth of 2.5 cm. Waterlogging tolerance was evaluated during the periods of recovery and final harvest considering relative performance (values of waterlogging relative to non-waterlogging controls) of 18 plant traits. All the genotypes showed a wide range of variation in relative values. Some genotypes subjected to waterlogging produced plenty of adventitious roots that contributed to foliage development and chlorophyll increment, which resulted in better shoot growth, and eventually yield of mungbean increased. Nine plant traits highly associated in waterlogged conditions were used in cluster analysis. The genotypes within cluster 6 and cluster 7 performed better regarding almost all plant traits whereas cluster 4 performed very poorly. Discriminant function analysis showed that function 1 and function 2 explained 54.5% and 32.2%, respectively and altogether 86.7% variation in the genotypes. The harvest index and straw dry matter mostly explained the total variance in function 1. Dry matter of root, shoot and straw explained the maximum variance in function 2. Root dry matter played the most dominant role in explaining the maximum variance in the genotypes. The genotypes IPSA-10 and VC 6379 (23-11) showed a better degree of tolerance to waterlogging concerning yield and associated morpho-physiological traits.

The elastic modulus ([E.sub.1]) of crystalline regions in the direction parallel to the chain axis in a new semiaromatic polyamide 9-T (PA9-T) containing a long aliphatic chain unit was measured by X-ray diffraction and the derived [E.sub.1], value was discussed in terms of its molecular conformation and mechanical properties. For low and high molecular weight PA9-Ts, the [E.sub.1] value of 40 GPa was obtained. The low [E.sub.1] value for PA9-T is due to the presence of aromatic groups with long crankshaft arms, which result in a greater moment of force during deformation compared with those polymers with planner zigzag molecular conformation like polyethylene and nylon 6 α-form. Another factor for the low [pounds sterling] is due to the contraction of its molecular chains that is likely originated from the existence of a torsional conformation. The presence of contraction causes some internal rotation in the polymer chain during extensional deformation, which results in low Eh POLYM. ENG. SCI., 52:331-337, 2012. © 2011 Society of Plastics Engineers, INTRODUCTION Polyamide 9-T (PA9-T) is a new semiaromatic polyamide recently industrialized as a high-performance engineering plastic in the name of Genestar (TM) by Kuraray Co. (1). In PA9-T, a long, [...]

High strength polyvinyl alcohol (PVA) fibers with a conventional degree of polymerization of 1500 were prepared by doping iodine with PVA spinning solution. The iodine-doped PVA (I-PVA) aqueous solution was extruded into cold methanol that provides dark purple PVA-iodine complex gel fibers. Only a small amount of iodine was required to enhance drawability and molecular orientation by reducing the interaction between PVA chains. An increase of ca. 10% in the maximum draw ratio of the doped fibers compared with that of undoped PVA translated into values for the tensile strength, 2.2 Giga-Pascal (GPa), and initial modulus (47 GPa) that were more than 30% higher than those of the neat PVA fiber. Easier chain slippage of molecules in the amorphous segments of the I-PVA fiber during drawing leads to increased orientation in these segments, which is believed to be the source of the improvements in mechanical properties. POLYM. ENG. SCI., 51:647-653, 2011. [C] 2010 Society of Plastics Engineers, INTRODUCTION Polyvinyl alcohol (PVA) is a water-soluble and environmentally friendly synthetic polymer with a broad range of industrial and technical applications, especially in fiber-reinforced concrete (FRC). PVA reinforces the strength, [...]

Carbon fibers were fabricated from electrospun poly(vinyl alcohol) (PVA) nanofibers. Electrospun PVA nanofibers were treated with iodine vapor for different periods, subsequently carbonized at different temperatures, and the structural changes of the PVA nanofibers were analyzed. The nanofibers iodinated at 80 °C for 24 h led to a good carbon yield of 21% when carbonized at 1200 °C. The influence of metal nanoparticle on the fabrication of carbon fiber and its properties was also investigated by the addition of a metal salt, nickel(II) acetate tetrahydrate [(CH3COO)2 Ni·4H2O], to the PVA spinning solution. Noticeably, after incorporation of nickel (Ni) nanoparticle continuous electrospinning was realized at lower polymer concentration than that of neat PVA. Moreover, smaller fiber diameter and a higher carbon yield (~34%) were obtained after carbonization. Transmission electron microscopy observation of the carbon fibers revealed that the addition of Ni-nanoparticles accelerated the formation of a graphitic structure at a lower carbonization temperature of 1200 °C. [ABSTRACT FROM PUBLISHER]