Modulation of SST, SSS over northern Bay of Bengal on ISO time scale

High resolution observations of atmospheric and oceanic variables are carried out at northern Bay of Bengal from 22nd July to 6th August 2009 on-board ORV Sagar kanya under the Continental Tropical Convergence Zone research/observational programme. Freshening of surface layer by more than 4 psu within 24 hours is observed, which is followed by warming in the surface layer temperature. The heat and salt budget analysis primarily indicates dominant role of advection processes on the evolution of temperature and salinity. The amount of rainfall received at observation site could not explain the observed freshening, thus an extensive analysis using wavelet coherence is done to find out the source of advected fresh water to the observed location. It is found that surface salinity in the northern Bay of Bengal (at 15 N) varies coherently with the rainfall over Ganga-Brahmaputra catchment area on intraseasonal time scale and with lag of about 60 days. Based on above observations, this study hypothesize that the intraseasonal rainfall variation modulates the amount of river discharge, which in turn modulates the salinity over northern Bay of Bengal on intraseasonal time scale. Since surface warming always follows the surface freshening, the time delay between the rainfall over catchment area and freshening at northern Bay of Bengal may explain the post monsoon warming. Importance of atmosphere-ocean coupling in driving the dynamics of the northern bay of Bengal has been clearly brought out in this study

Improved Performance of Solution-Processed n‑Type Organic Field-Effect Transistors by Regulating the Intermolecular Interactions and Crystalline Domains on Macroscopic Scale

The development of four new n-channel naphthalene diimide (NDI) and perylene diimide (PDI) copolymers (NDI-Ph, NDI-BT, PDI-Ph, and PDI-BT) and their solution processed thin film transistor (TFT) devices are reported. Remarkable enhancements in the electron transport behavior for all the four copolymers were achieved on improving the intermolecular interactions in their thin film structures. These solution processable n-type copolymers having NDI and PDI backbone were synthesized in high yields (83–86%) by palladium catalyzed Suzuki coupling reactions, and their excellent solubility in several organic solvents allowed their deposition in organic thin film transistor (OTFT) devices from solution directly. Since these copolymers possess crystalline domains, annealing their films induced crystalline phases in the thin film structures with a very high degree of enhancement in crystallinity that was more prominent for PDI copolymers as compared to NDI derivatives. This resulted in significant enhancement in the intermolecular interactions in the thin film state on the macro scale, facilitating improved and higher charge carrier transport in annealed devices as compared to the as-spun devices that have lesser crystalline phases. The transport measurements performed for these four copolymers helped us to understand the difference in transport mechanism between D–A and A–A moiety and confirmed that tuning the thin film structures and the electronic properties by modifying the copolymer backbone structures as well as annealing them at appropriate temperature has profound implications on the level of improvement in electron transport behavior. The enhancement in μ_e values for all four copolymers is very large for any reported n-type copolymers. It is observed that the extended conjugation in the four copolymer structures, the efficient intermolecular interactions in the thin film state, and the formation of crystalline domains in the copolymers after annealing are, in principle, responsible for the enhanced device performance. These copolymers demonstrated electron mobility enhancement of several orders and are reported to be as high as 0.8 cm² V^–1 s^–1 and 0.2 cm² V^–1 s^–1 with <i>I</i>_on/<i>I</i>_off ratios 10⁵ for NDI-Ph and NDI-BT, while those of PDI-Ph and PDI-BT are 0.04 cm² V^–1 s^–1 and 0.032 cm² V^–1 s^–1, respectively, with <i>I</i>_on/<i>I</i>_off ratios of 10³–10⁴

Current Research Trends and Prospects for Yield and Quality Improvement in Sesame, an Important Oilseed Crop

Climate change is shifting agricultural production, which could impact the economic and cultural contexts of the oilseed industry, including sesame. Environmental threats (biotic and abiotic stresses) affect sesame production and thus yield (especially oil content). However, few studies have investigated the genetic enhancement, quality improvement, or the underlying mechanisms of stress tolerance in sesame. This study reveals the challenges faced by farmers/researchers growing sesame crops and the potential genetic and genomic resources for addressing the threats, including: (1) developing sesame varieties that tolerate phyllody, root rot disease, and waterlogging; (2) investigating beneficial agro-morphological traits, such as determinate growth, prostrate habit, and delayed response to seed shattering; (3) using wild relatives of sesame for wide hybridization; and (4) advancing existing strategies to maintain sesame production under changing climatic conditions. Future research programs need to add technologies and develop the best research strategies for economic and sustainable development