Sidho Kanho Birsha University

Although fossil pinnate palms have been widely reported globally, their occurrence in the Cretaceous-Paleogene (K-Pg) of India is poorly documented. Here, we extend the record by reporting eight taxa of pinnately compound arecoid palm leaves from the latest Maastrichtian (upper Cretaceous) to the earliest Danian (lower Palaeocene) sediments (approximately 67-64 million years ago) of Deccan Intertrappean beds, and placing them under the fossil-genus Phoenicites A. Brongniart, Read and Hickey. Here, we also describe a fossil pinnate palm leaf specimen resembling modern pinnate leaves of Clinosperma Becc. (tribe Areceae Mart. ex Dumort.) as a new species, namely Phoenicites deccansis Kumar and Khan, sp. nov. The present fossil evidence and earlier reported palms from the same fossil locality collectively indicate the presence of tropical climatic conditions in the area at the time of deposition. The present finding from the Deccan Intertrappean beds strongly suggests the existence of pinnate palms on the Gondwana landmass that is now part of India. In addition, this study highlights the paleobiogeography of pinnate palms in a global perspective.

The need for cost-effective and high-frequency rectifier has prompted researchers to explore organic semiconductors and their suitable heterostructures. Here, we demonstrate an organic donor/acceptor (D/A) heterostructure-based diode rectifier fabricated with thin films of Copper phthalocyanine/7,7,8,8-Tetracyanoquinodimethane (CuPc/TCNQ). The D/A materials were deposited in a hybrid way; with CuPc film being deposited by solution processing, while TCNQ film was thermally evaporated under vacuum conditions. The diode exhibited excellent electrical stability, reproducibility, and achieved a rectification ratio (RR) greater than 103 at 1.2 V. A low threshold voltage ca. 0.4 V and an ideality factor of 2.3 could be achieved from the diode characteristics. Moreover, with the variation in thickness of TCNQ film, the electrical characteristics of the diode changed drastically, offering a good way to enabling fine-tuning of device characteristics, including, turn-on voltage, leakage current, and overall rectification efficiency. An optimum film thickness of TCNQ (320 nm) with fixed CuPc film thickness (330 nm) has been identified for best device performances. The device produced a steady DC response under varying sinusoidal pulses with a frequency response about 1 MHz, making it suitable for radio frequency identification (RFID) applications. Additionally, CuPC/TCNQ heterostructure was integrated on flexible substrate for promising diode characteristics.

Morphotectonic indices are beneficial for the determination of the intensity of tectonic activity (historical or ongoing) by quantifying the landscape geometry and other characteristics. The Subarnarekha River basin is an example of the Precambrian cratonic landscape of eastern India. The basin area contains several marks of historical tectonic imprints along with major waterfalls and slope breaks at the structural as well as lithological boundaries in the longitudinal course of the river. A set of morphotectonic indices, that is, asymmetry factor (Af), basin shape index (Bs), hypsometric integral (HI), stream length-gradient index (SL), and valley floor width to valley height ratio (Vf) have been applied here for the identification of the intensity of historical tectonic imprints within the concerned region as these indices help to quantify the tectonic influences on a drainage basin. After combining all the indices, the basin has been classified into several classes in terms of the historical tectonic imprint intensity. The result shows that near about 35% of the sub-basins (5 out of 14) are classified under high to very high historical tectonic imprint intensity zones. It is also identified that the upper basin area was relatively more tectonically active. The entire region is not facing any kind of ongoing tectonic activity, but there is numerous evidence of historical tectonic activity or imprints throughout the entire basin area. Longitudinal profiles of the streams indicate an abrupt slope change and the role of litho-structural variation within the basin, and the entire basin area is also characterized by historical tectonic imprints and slow deformation rather than ongoing active tectonic activities. These tectonic imprints provide critical evidence for the reconstruction of the past geological history of the region.

Mycoparasitism, a phenomenon in which certain fungi parasitize other fungi, is quite prevalent in nature; however, it remains poorly studied. Nowadays, this type of interaction is commonly used to suppress pathogen populations and to facilitate biological control of plant diseases. Nevertheless, examination of this phenomenon in the fossil record is exceedingly uncommon, which hinders our comprehension of the evolution and diversity of fungi, along with their interactions. Here, we report and describe a new fossil fungal species, Meliolinites mycoparasitica sp. nov. (Meliolaceae), together with another ascomycetous fungus, Neomycoleptodiscus pertusus, (Muyocopronaceae), on a host plant (cuticular fragments of a compressed dicotyledonous leaf resembling modern Quercus spp., Fagaceae) recovered from middle Siwalik sediments (Late Miocene, ca. 12-8 My) of Himachal Pradesh, western Himalaya. This represents the first fossil evidence of tritrophic interactions involving M. mycoparasitica as a mycoparasitic fungus, N. pertusus as a fungal host, and Quercus sp. as a host plant. This finding provides a unique opportunity to explore the mycoparasitic nature of the melioloid fungus within the context of paleomycological research.

PurposeThis study aims to numerically investigate the double-diffusive convection of a Casson ternary hybrid nanofluid (Al2O3-CuO-Ag/fluid) within a concentric annulus featuring an inner polygonal cylinder. The purpose is to quantify the impact of fluid rheology (Casson parameter) and geometry (circular, triangular, square inner cylinder) on heat and mass transfer rates, providing insights for the design and optimization of advanced thermal management systems.Design/methodology/approachThe governing nonlinear partial differential equations are solved using a Galerkin finite element method. The implementation uses a Newton-Raphson iterative scheme to handle the system's nonlinearity. The analysis is conducted for a range of key parameters, and the results are validated against established benchmark studies to ensure numerical accuracy and reliability.FindingsIncreasing the Casson parameter (gamma) from 0.1 to 10 significantly enhances transport rates, boosting the average Nusselt number by 20.1% (circular), 32.4% (triangular) and 30.0% (square). The average Sherwood number sees even greater enhancement, rising by 137.0%, 154.0% and 158.0%, respectively. The circular inner cylinder geometry consistently outperforms the polygonal shapes, achieving superior heat and mass transfer due to its streamlined geometry which minimizes flow obstruction.Originality/valueThis work provides a novel analysis of double-diffusive convection for a Casson ternary hybrid nanofluid in a complex annular geometry with inner polygonal cylinders. The combined investigation of non-Newtonian rheology, multi-component nanoparticles and geometric effects on both thermal and solutal transport represents a significant extension of existing literature, offering new quantitative insights for system optimization.