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The lignocellulosic biomass jute fiber (JF) was chemically modified with polyphenolic tannin in aqueous medium by epoxy activation under mild conditions and applied as a potential adsorbent for the removal of Congo Red, a model azo dye, from aqueous solution. The virgin and tannin-modified JF samples were characterized by solid-state nuclear magnetic resonance spectroscopy, Fourier transform infrared spectroscopy, and scanning electron microscopy. Within the studied range of dye concentrations, the adsorption equilibrium was found to follow the Langmuir isotherm model well, with R 2 > 0.99. The rate of adsorption of the dye onto treated JF was very high, and equilibrium was attained within 15−30 min of contact. The efficiency of modified JF for the spontaneous and exothermic adsorption of azo dye is attributed to the copious availability of hydroxyl and other polar functional groups on the fiber surface. The present adsorption studies of azo dye from aqueous solution revealed the potential of modified JF to be utilized as an alternative, inexpensive, and environmentally benign adsorbent for water purification.

The present investigation deals with the effect of jute as a natural fiber reinforcement on the setting and hydration behavior of cement. The addition of jute fiber in cement matrix increases the setting time and standard water consistency value. The hydration characteristics of fiber reinforced cement were investigated using a variety of analytical techniques including thermal, infrared spectroscopy, X-ray diffraction, and free lime estimation by titration. Through these analyses it was demonstrated that the hydration kinetics of cement is retarded with the increase in jute contents in cement matrix. A model has been proposed to explain the retarded hydration kinetics of jute fiber reinforced cement composites. The prolonged setting of these fiber reinforced cement composites would be beneficial for applications where the premixed cement aggregates are required to be transported from a distant place to the construction site.

We report a comprehensive study on the structure and magnetic properties of ultrafine Ni nanoparticles prepared by the borohydride reduction method. A spontaneous surface oxide layer of NiO encapsulates the Ni particles, as these have been prepared under ambient atmosphere. From the x-ray diffraction ͑XRD͒ pattern, the "as-prepared" sample has been identified as Ni in a tetragonal crystal structure, stabilized by the incorporation of oxygen atoms in the Ni lattice. On annealing this sample in air at different temperatures, the XRD patterns showed an interesting feature: unexpected fcc Ni peaks appeared together with the usual NiO peaks. Anomalous behavior is also observed in the M-H curves, with the as-prepared sample showing a linear response with field and low values of magnetization and the annealed samples showing ferromagnetism with large coercivity ͑290 Oe͒ and high magnetization values. These surprising and seemingly contradictory observations have been coherently explained on the basis of a proposed phenomenological model. Furthermore, we attribute the observed low magnetization values of the as-prepared sample to an antiferromagnetic superexchange interaction between some of the Ni atoms, mediated by the dissolved oxygen atoms in the Ni lattice.

Puberty is a combination of physical, physiological and psychological changes with detectable alterations in physical growth, which is a determining factor for assessment of physical fitness. Several studies have documented the functionality of physical activity for pubertal growth. But the present review has aimed to investigate whether normal pubertal growth, along with its endocrinological variations affect the level of physical fitness and what are the major fitness variables mostly regulated by the hormonal changes during puberty. Different sex hormones in boys and girls have been found to play the key role for regulation of various fitness determinants like body composition, muscle strength, bone development, erythropoiesis, cardiac function, substrate utilization etc. The major fitness components-strength, aerobic and anaerobic fitness, all have been found to be largely associated and influenced by the growth related endocrinological alterations during puberty.