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HDPE-chitosan composites (HC) prepared using maleic anhydride as compatibilizer and palm oil as plasticizer have been subjected to dielectric characterization and thermal studies. At a lower frequency HC films were seen to exhibit an increasing dielectric constant due to interfacial polarization of the chitosan. This increase in dielectric loss with increasing concentration of chitosan indicated the presence of relaxing dipoles in the system. The addition of palm oil to the optimised HC5 system showed improved segmental mobility due to the interaction of polar amine group in chitosan with HDPE. The thermal stability and activation energy of the composites were computed using Coats- Redfern model.

Marine invertebrates are a major source of bioactive natural products, many of which are produced by associated microbes. These compounds protect the invertebrate host against predators, competitors, or pathogens by affecting the cellular processes of the host’s adversary, but knowledge about the interaction of the host itself with these symbiont-produced natural products is limited. For example, larvae of the marine bryozoan, Bugula neritina, are defended from predation by the bryostatins, polyketides synthesized by its uncultured endosymbiont, “Candidatus Endobugula sertula.” Bryostatins are potent modulators of the eukaryotic signaling protein, protein kinase C (PKC) that is involved in many cellular processes. In this study, we investigated how host reproduction responds to the absence of the symbiont and symbiont-produced bryostatins in colonies after antibiotic curing and in colonies with naturally reduced symbiont titers. The fecundity of the symbiont-reduced B. neritina colonies was significantly decreased, suggesting that host reproduction is dependent on the symbiont, and/or the bryostatins they produce. To assess the role of PKC in this response, Western blot analysis of protein extracts from symbiotic and symbiont-reduced B. neritina colonies revealed a difference in bryostatin-activated conventional PKCs, but none for bryostatin-independent PKCs. Similar results were observed for PKCs in symbiotic and naturally occurring symbiont-reduced colonies, as well as in the model invertebrate, Caenorhabditis elegans, exposed to bryostatin, suggesting that the bryostatins potentially modulate PKC activity in symbiotic B. neritina and bryostatin-exposed C. elegans. Analysis of the B. neritina transcriptome led to the identification of five PKC isozymes. Since PKCs have been reported to be involved in regulation of reproductive processes and oocyte maturation in various organisms, the findings of this study suggest that the symbiont-produced bryostatins are an important cue for reproduction in the host B. neritina via PKC activation.

40 alternate a-Si/SiN x multilayer are incorporated as an absorber layer in a p–i–n solar cell. The device is fabricated using hot-wire chemical vapor deposition (HWCVD) technique. The structure of the multilayer film is examined by high resolution transmission electron microscopy (HR-TEM) which shows distinct formation of alternate a-Si and SiN x layers. The a-Si and SiN x layers have thickness of ~3.5 and 4 nm, respectively. The photoluminescence (PL) of multilayer film shows bandgap energy of ~2.52 eV, is larger than that of the c-Si and a-Si. Dark and illuminated current–voltage (I–V) characterization of the ML films shows that these ML are photosensitive. In the present work, it is seen that the p–i–n structure with i-layer as ML quantum well (QW) structures show photovoltaic effect with relatively high open-circuit voltage (V OC). The increment of bandgap energy in PL and high V OC of the device is attributed to the quantum confinement effect (QCE).

Effect of chlorine doping on the opto-electronic properties of β-In 2 S 3 thin film, deposited by spray pyrolysis technique is studied for the first time. Chlorine was incorporated in the spray solution, using HCl. Pristine sample prepared using In(NO 3 ) 3 and thiourea as the precursors showed very low photosensitivity. But upon adding optimum quantity of chlorine, the photosensitivity increased by 3 orders. X-ray analysis revealed that crystallinity was also increasing up to this optimum level of Cl concentration. It was also observed that samples with high photosensitivity were having higher band gap. The present study proved that doping with chlorine was beneficial as this could result in forming crystalline and photosensitive films of indium sulfide.