University of Calcutta

Using the Wien2k code, comprehensive first-principles calculations on the half-Heusler (HH) compounds MgSrPb and MgSrSi provide valuable insights into their structural, electronic, and optical properties. The most stable structural phase of MgSrPb and MgSrSi was identified through volume optimization using the Birch–Murnaghan equation of state. The study reveals that MgSrPb and MgSrSi are nonmagnetic semiconductors with a modest band gap of approximately 0.6 eV. Significantly, the optical conductivity and absorption peaks occur in the visible spectrum, making these materials promising candidates for optical and electronic applications due to their stable nonmagnetic semiconductor characteristics. The mechanical stability of these compounds, confirmed by their elastic constants, further underscores their suitability for practical applications. Additionally, the analysis of electronic band structures provides crucial information about their potential performance in various optoelectronic devices.

Nuclei in the rare-earth region are known to be strongly deformed and show rotational bands up to high spins. Ground state and high spin states of Yb and Er isotopes $(N\ge 100)$ have been studied using the Hartree–Fock–Bogoliubov approach as well as the projected shell model. A large number of quasiparticle bands are observed in these nuclei and the present study explores the possible origins of some of them. Projected shell model with variable pairing can provide a good description of the ground-state bands up to very high spins.

A BSTRACT Introduction Like general health, oral health also depends upon their occupational environment and occupational health policies. Workplace exposure to environmental tobacco smoke and its harmful effect is well known. The consumption of tobacco, arecanut, and alcohol is the leading preventable cause for development of oral potentially malignant disorders. Aim To determine prevalence of habit-induced oral lesions in different occupations in different geographical places of West Bengal and compare among them. Method A total of 841 people aged 15 years and above were selected from different parts of West Bengal. Face-to-face interview was conducted using a structured questionnaire, and oral cavity examination was done in daylight. Data were summarized, and statistical analysis was done. Statistical Analysis Used Chi-square test and univariate logistic regression done. Results The people in armed forces had cancer-causing habits most, and managers had cancer-causing habits least. People in armed forces had cancer-causing habits most, and people with Group-1 occupation/managers had cancer-causing habits least.

Agriculture is a significant contributor to the country’s economic development. We used multiple Landsat images from 1990 to 2021 in the Murshidabad-Jiaganj Block to assess changes in the agricultural system and their underlying causes. The Rabi season saw a 10.99% growth in agrarian regions from 1990 to 2000 and an 8.86% increase in 2010, yet it declined by 28.12% in 2021. During the summer, the cultivated lands diminished by 26.63%, 19.43%, and 19.64%, while in the Kharif season, they declined by 21.78%, 15.68%, and 11.99% from 1990 in the years 2000, 2010, and 2021, respectively. The agricultural area had 36.82%, 34.16%, and 19.01% increases between 1990 and 2021, respectively. Regarding direction, farmland acreage decreased in all zones except the SSE, which had a 0.95% increase. Mono-, double-, and triple-cropping systems have decreased in area, while multi-cropping systems have experienced increases of 43.51%, 4.50%, and 18.49% in 1990–2021, respectively. The multi-cropping system has a good correlation with all agroclimatic factors. The reduction of irrigated lands post-2009 significantly affected the agriculture system. The fall in agricultural employment in recent decades is attributable to migration seeking higher-paying occupations. The advancement of accurate remote sensing–based modeling is crucial for mitigating food security risks, particularly those posed by climate change, and informing policy decisions.

This article investigates the impact of the semiconformal curvature tensor's symmetry on the base and fiber manifolds of a warped product manifold. It establishes that the fiber manifold of a warped product manifold has a constant sectional curvature, whereas the base manifold is semiconformally symmetric. Furthermore, the article derives the specific forms of the semiconformal curvature tensor for both the base and fiber manifolds. Also, it is demonstrated that a semiconformally symmetric (flat) GRW space-time is a perfect fluid space-time and exhibits an irrotational velocity vector field.

To realize the aim of easy and accurate detection of ammonia and picric acid (PA) in both aqueous and vapor phases based on function‐oriented investigation principles, in the present study, we include a luminescent performance with recognition performance, taking into account the application conditions. Zn(II) ions with luminescence qualities and an amine‐substituted imidazole moiety with selective recognition properties towards picric acid and ammonia are coupled to generate a novel 1D luminous Zn(II) coordination polymer, Zn‐CP [{Zn(II)( 2‐ABZ)2(2‐BDC)}].MeOH]∞, where 2‐ABZ and 2‐BDC stand for terephthalic acid and protonated 2 aminobenzimidazole, respectively. Tests for luminescence recognition demonstrate that Zn‐CP has potent selectivity, and strong sensitivity to ammonia and PA in both media. In both detection processes, the limit of detection (LOD) values are determined to be 40 nm. Spectroscopic and DFT studies reveal that the detection of Trinitrophenol (TNP) primarily involves a synergistic mechanism of Photoinduced Electron Transfer (PET), Fluorescence Resonance Energy Transfer (FRET), and Charge Transfer (CT). In contrast, the detection of ammonia (NH3) vapor is predominantly driven by hydrogen bonding (H‐bonding) formation. The constructed 1D luminous Zn‐CP is a new material that guides the development of novel luminous sensors in the future.

This article examines the scattering of surface gravity waves by two types of structures: a bottom-mounted inverted Π-shaped structure or a floating Π-shaped structure, in the presence of an infinite trench. The physical phenomenon is formulated as a boundary value problem governed by the modified Helmholtz equation, which is transformed into a system of Fredholm-type integral equations through the eigenfunction expansion technique. To enhance numerical accuracy and convergence, basis functions (such as Chebyshev and ultraspherical Gegenbauer polynomials) multiplied by appropriate weights are incorporated into a multi-term Galerkin approximation. Thus, the model effectively captures the singular behavior of the horizontal fluid velocity near the sharp lower edges of the Π-shaped structure and the corners of the trench. Validation of the model is achieved by comparing its results with existing solutions from the literature on water wave problems in specific limiting scenarios. Numerical results for reflection and transmission coefficients, mean drift forces, and free surface elevation are presented graphically. These results provide a comprehensive understanding of the influence of various non-dimensional wave and structural parameters on these hydrodynamic characteristics. Notably, the floating Π-shaped structure achieves a more significant reduction in free surface elevation in the transmitted region compared to the bottom-mounted inverted Π-shaped structure.

The current investigation explores tri-hybrid mediated blood flow through a ciliary annular model, designed to emulate an endoscopic environment. The human circulatory system, driven by the metachronal ciliary waves, is examined in this study to understand how ternary nanoparticles influence wave-like flow dynamics in the presence of interfacial nanolayers. We also analyze the effect of an induced magnetic field on Ag–Cu–𝐴⁢𝑙2⁢𝑂3 blood flow within the annulus, focusing on thermal radiation, heat sources, buoyancy forces and ciliary motion. The Casson fluid model characterizes the non-Newtonian viscous properties of the biofluid. To describe the steady fluid flow mathematically, we use coupled partial differential equations and apply the homotopy perturbation method to derive rapidly convergent series solutions for the non-linear flow equations. The obtained hemodynamic consequences are graphically represented with the variations of emerging parameters. These are significantly influenced by the rheological factors of the nanofluid flow, improving flow velocity with changes in shear viscosity, while a decrease in flow is observed for intensified Lorentz forces. Ciliary motion accelerates the expansion of the induced magnetic field on nanolayers, while a higher Magnetic Reynolds number decreases the current density distribution. Increased radiative heat generation lowers the temperature, indicating that thermal radiation enhances heat transfer and improves cooling efficiency. In contrast, an increased ciliary length along the wall raises the temperature due to wave-like motion, which strengthens the thermal boundary layer in the fluid flow. Additionally, a higher nanoparticle concentration increases wall shear stress due to frictional forces, while enhanced magnetic forces decrease the shear stress along the ciliary wall. Furthermore, a higher Strommer’s number may regulate the formation of blood boluses in the wavy flow. The key findings play an important role in the development of analytical benchmarks to validate computational methods, ensuring accuracy in clinical research tools and supporting reliable medical applications.

Horticulture diseases in the post-harvest are worrying as they are leading to aggravated losses. Different chemical methods for controlling these diseases have already been tried, and many are still in use. However, in their residual forms, these chemicals are entering the food chain causing all sorts of medical concerns to higher beings. Therefore, some non-chemical but effective methods are needed. Several microorganisms, unlike disease-causing pathogens, are also present in association with plants and have some capabilities and action mechanisms for combating the harmful species. If studied, identified, and utilized effectively against problematic pathogens, they would help eliminating post-harvest diseases and, in turn, reduce post-harvest losses. Therefore, the present chapter is based on the above concept to discuss interesting microbial agents and their antagonistic properties against post-harvest horticultural pathogens. The review also highlights some recent developments in research, market-based biocontrol products, and future requirements in the sector.

Mycorrhizae, the symbiotic associations between fungi and plant roots, are fundamental to plant biology, ecology, and agricultural practice. This chapter delves into the mutually beneficial relationships between plants and fungi, emphasizing their critical role in nutrient uptake, disease resistance, and environmental sustainability. Through the lens of sustainable agriculture, it critically assesses the potential for leveraging mycorrhizal fungi in reducing dependency on chemical pesticides, thereby mitigating environmental impact and enhancing food safety. Beyond nutrient acquisition, mycorrhizae are pivotal in bolstering plant resilience against abiotic and biotic stresses. This symbiosis is crucial for plant health and productivity, soil health, and ecosystem dynamics, influencing nutrient cycling and carbon storage. The practical applications of mycorrhizal associations in agriculture are vast, offering sustainable solutions to some of the most pressing challenges in food production, including disease management in vegetable crops. Through a combination of historical insights, current research findings, and case studies, this chapter illustrates how mycorrhizae contribute to disease resistance and the potential for these associations in sustainable agricultural practices. Looking forward, the chapter explores innovative strategies to harness mycorrhizal benefits fully, including genetic approaches and precision agriculture, underscoring the importance of interdisciplinary research and collaboration in advancing our understanding and application of mycorrhizal symbioses, for a resilient and sustainable agriculture.

Polyvinyl alcohol (PVA), sodium polyacrylate, and polyacrylonitrile are very effective for stabilizing and controlling the size of nanoparticles. Thus, PVA was grafted to the copolymer of acrylonitrile (AN) and acrylic acid/sodium acrylate (AA/NaAA) using N,N′‐methylenebisacrylamide comonomer–crosslinker (MBA). Silver nanoparticles (AgNPs) were synthesized in situ in the polymerization mixtures by reduction of AgNO3 with ascorbic acid. These nanocomposites were characterized and used for the removal and photocatalytic degradation of p‐nitrophenol (PNP) from water. Based on the Box–Behnken design of the response surface methodology, the nanocomposite prepared with the AN:NaAA/AA molar ratio/MBA wt.%/PVA wt.% of 5:1/0.5/2 and impregnated with AgNPs of 18–30 nm average size (noted as PVACP5Ag) showed the optimized results. PVACP5Ag showed the equilibrium batch adsorption (qe, mg/g) of 240.93 from 50 mg/L PNP in water and a qe of 36.2 in fixed bed adsorption at a feed inlet concentration (mgL⁻¹)/inflow rate (mLmin⁻¹)/bed height (mm) of 50/30/30. The same composite showed a degradation of 96% after 7 min of exposure to sunlight in the presence of NaBH4 with a first‐order rate constant of 0.3 min⁻¹ and 90.3% degradation after 110 min of exposure with a first‐order rate constant of 0.01 min⁻¹ without any reducing agent.

In this study, we analyzed 41 mitogenomes including eight newly sequenced to explore genetic diversity within Asian pan-golins. Our findings reveal a cryptic phylogenetic species that diverged from the Chinese pangolin (Manis pentadactyla) approximately 3.4 million years ago. This newly identified species, which we propose to name the Indo-Burmese pangolin (Manis indoburmanica), exhibits a significant genetic distance from the Chinese pangolin, with a divergence of 0.038 and a barcode gap of 3.8%. The distribution of this species aligns with major geo-climatic events, which have likely shaped its current geographic spread. The discovery emphasizes the necessity of further research to precisely describe its morphological features and define its distribution boundaries, enhancing our understanding of pangolin biodiversity and aiding in conservation efforts.

The main objective of the present article is to study almost Bach solitons on coKähler manifolds with certain types of potential vector fields. It is shown that the almost Bach solitons reduce to the Bach solitons when the potential vector field is the torse-forming vector field. In this regard, we also prove that the solitons are steady. In the three-dimensional case, considering the potential vector field as concircular, the vector field becomes parallel. Almost gradient Bach solitons are also considered in the present article. Finally, we provide some examples of three-dimensional coKähler manifolds.

In this study, the authors have presented a 2-D analytical model for a silicon-based source underlap SiGe p-type pocket layer dopingless TFET biosensor for label free detection of neutral biomolecules. The theoretical model demonstrates strong alignment with the simulated data acquired from Silvaco TCAD. The utilization of a charge plasma-based approach has facilitated the eradication of random dopant fluctuations and the reduction of the thermal budget, which are inherent shortcomings of conventional TFET. A nanogap cavity was incorporated under the source electrode to enable immobilization of the neutral biomolecules. The inclusion of the SiGe pocket layer at the source-channel interface enhanced the tunneling probability, resulting in a significant increase in the device's sensitivity. The highest drain current sensitivity obtained for the proposed device is $\sim 4.213\times {10}^{11}$. This model shows substantial potential for developing high-speed switching biosensor devices in the future generation.