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.

PurposeThe purpose of this study is to explore how geometry, magnetic field and nanofluid composition affect the thermal performance and irreversibility of an electroconductive hybrid nanofluid inside a wavy inverted T-shaped chamber with a cold T-shaped fin.Design/methodology/approachThe governing momentum and energy transport equations are solved using the finite-difference method under appropriate initial and boundary conditions. Key dimensionless parameters, including the Rayleigh number, Hartmann number, baffle length and nanoparticle volume fraction, are systematically varied. Two different base fluids, water and kerosene, are considered to examine their comparative effects.FindingsThe findings reveal that the presence of wavy cavity walls and the T-shaped baffle substantially modifies circulation patterns, enhancing convective transport. The kerosene-based hybrid nanofluid demonstrates superior thermal efficiency compared with the water-based counterpart. The study further highlights the interplay between magnetic field strength, nanoparticle concentration and geometric modification in governing heat transfer, entropy generation and ecological performance.Originality/valueThe originality of this research lies in uncovering how geometry, magnetic field and hybrid nanofluids work together to enhance heat transfer in complex enclosures. These findings provide practical guidance for the design of next-generation cooling and thermal management systems that achieve greater efficiency while minimizing irreversibility.