Temperature dependent study of thermophysical properties of binary mixtures of 1,4-butanediol + picolines

The experimental values of densities (r) and speeds of sound (u) of (1,4-butanediol + α-, orβ- picoline) binary mixtures have been used to calculate the internal pressure (πi), free volume (Vf), enthalpy (H), entropy (Ts), excess internal pressure (πiE), excess free volume (VfE), excess enthalpy (HE), excess free energy (GE) and excess entropy (TsE) at temperatures 303.15, 308.15, 313.15 and 318.15K over the entire composition range. The results have been discussed in terms of molecular interactions due to physical, chemical and structural effects between the unlike molecules. It has been observed that the strength of intermolecular interaction between 1,4-butanediol and picoline molecules is in order ɑ-picoline>β-picoline

Photoinduced Electron Spin Resonance Phenomenon in α

The photoinduced phenomenon in α-Cr2O3 nanoscaled spherical particles was investigated in the temperature range of 150 up to 315 K. An X-band electron-spin resonance spectrometry was employed to probe the magnetic behavior in α-Cr2O3 under an IR illumination in the nanosecond regime. The photoinduced effect on both low and high field ESR signals appears above 280 K and is remarkably enhanced just below Néel temperature TN. Such a photoinduced ESR phenomenon disappears in a reproducible way in the paramagnetic insulating state which occurs above TN of crystalline α-Cr2O3. In the antiferromagnetic phase, that is, below TN, the shift of the low field absorption could be attributed to the interaction of the light with specific Cr3+ ions located in strongly distorted sites correlated to strong ligand-field effect

Non-resonant microwave absorption studies of superconducting MgB_2

Non-resonant microwave absorption(NRMA) studies of superconducting MgB_2 at a frequency of 9.43 GHz in the field range -50 Gauss to 5000 Gauss are reported. The NRMA results indicate near absence of intergranular weak links. A linear temperature dependence of the lower critical field H_c1 is observed indicating a non s-wave superconductivity. However, the phase reversal of the NRMA signal which could suggest d-wave symmetry is also not observed.Comment: 8 pages, 2 figure

Rural Education and Employment Skill Improvement Model Using Artificial Intelligence

This groundbreaking initiative introduces an advanced AI-powered model designed to revolutionize education and employment prospects in rural communities. The Rural Education and Employment Skill Improvement Model is an all-encompassing solution that adapts learning paths using sophisticated AI algorithms, ensuring a personalized approach tailored to the unique challenges faced by rural learners. This model collaborates closely with local educators, leveraging technology to augment traditional teaching methods and bridge the digital divide. At its core, a cutting-edge Learning Management System (LMS) powered by AI integrates various features, including interactive video tutorials, real-time assessments, and a dynamic grading system. The system goes beyond conventional evaluations by employing AI to monitor and prevent cheating during exams, ensuring a fair and secure evaluation process. The multifaceted LMS also includes a job portal, facilitating a seamless transition from academia to the professional arena. Live meeting classes create an interactive virtual environment for real-time engagement, complemented by community discussion chat for collaborative learning. Notably, the project introduces a unique article-creation feature, allowing both instructors and students to contribute valuable content to the educational community. The success metrics of this ambitious project include improved educational outcomes, increased employment rates, and an overall enhancement in community well-being. Serving as a scalable and adaptable solution, this AI-driven model offers a transformative blueprint for leveraging technology to empower individuals in rural areas, paving the way for a more prosperous economic future

Critical current densities of high pressure oxygen sputtered thin films of YBa<SUB>2</SUB>Cu<SUB>3</SUB>O<SUB>7-x</SUB> by non-resonant rf absorption method

The critical current densities (Jc) have been measured at 77K in high pressure oxygen sputtered thin films of YBa2Cu3O7-x superconductor using the non-resonant rf absorption technique. High values of Jc (~ 105A/cm2) are observed in these relatively large area (~ 1.2 cm2) films

Analysis of Oil Content in Jatropha by Nuclear Magnetic Resonance Spectrometry

Thirty two diverse Jatropha curcas L. cultivars were analyzed for their oil content by the standard Soxhlet extraction method using hexane as solvent. The results were then compared with those obtained by nuclear magnetic resonance (NMR) spectrometer. The cultivars had a wide range in oil content, which ranged from 4.8 to 38.8% by the Soxhlet method, and from 6.0 to 38.9% by the NMR method. The values of oil content determined by the NMR method were highly significantly correlated (R2 = 0.9929, P<0.0001, n = 32) with those obtained using the Soxhlet method. The NMR method is simple, non-destructive, rapid, and accurate for the routine analysis of oil content in Jatropha

Molecular interaction in binary mixtures of 1,4-butanediol+picolines: Viscometric approach

The viscosity (h) of {1,4-butanediol (i) + α-, or β-, or γ-picoline (j)}binary mixtures have been measured and reported at 303.15, 308.15, 313.15 and 318.15 K over the entire range of composition. Viscosity deviation (∆h) and excess Gibbs energy of activation of viscous flow (∆G*E) based on Eyring’s theory have been evaluated and the results fitted to the Redlich-Kister equation. The ∆h values are observed to be negative over the entire range of composition for (1,4-butanediol+α-picoline), (1,4-butanediol+β-picoline) and (1,4-butanediol+γ-picoline) systems. The experimental viscosity data have been compared with some well-known equations of Frenkel, modified Frenkel approach and predictive ones like McAllister, Grunberg-Nissan, Hind et al., Tamura Kurata and Katti-Chaudhri. The effects of molecular sizes and shapes of the component molecules on the molecular interactions present thereof in the mixtures have been discussed.

Long-term morphological and power spectral studies of VHF amplitude scintillations recorded over Waltair (17.7°N, 83.3°E), India

This research reports on recently recorded 250 MHz amplitude scintillations at Waltair (17.7°N, 83.3°E), a low-latitude station in India, using the signals radiated from a geostationary satellite (FLEETSAT, 73°E) during a six-year period (2008 - 2013), which covers extremely low and higher solar activity years (2008 and 2013). The morphological features in terms of local time, month, and season during different geophysical conditions are presented. The scintillation patches (segregated based on their occurrence durations) have shown an increasing trend with the increasing sunspot activity. The scintillation patches with 30-min duration show increasing trends with increasing sunspot activity, and their occurrence frequencies also show increasing trends with increasing sunspot activity. The scintillation activity during disturbed epochs (Kp index lies between 3+ and 9) is found to be less compared to its quiet day counterparts. The plausible mechanisms for these observational results are discussed. In addition, power spectral characteristics, including Fresnel frequency, upper role of frequency and spectral slope of scintillations are calculated and the salient results are presented