Āryabhata and axial rotation of Earth

Āryabhata (born 476 CE) is regarded as a pioneer of mathematical astronomy in ancient India. In this three-part article, I shall discuss one important contribution of Āryabhata in astronomy involving the least technical background —the principle of axial rotation (Part 1) and computations on the sidereal day (Part 2). Portions of 4 verses, pertaining to Earth’s rotation, from his famous treatise Āryabhatīya will be quoted. In Part 3, I shall give a brief historical account on the concept of axial rotation of Earth.     

Mathematics in ancient India

In this series of articles, we intend to have a glimpse of some of the landmarks in ancient Indian mathematics with special emphasis on number theory. This issue features a brief overview of some of the high peaks of mathematics in ancient India. In the next part we shall describe Aryabhata’s general solution in integers of the equationax -by =c. In subsequent instalments we shall discuss in some detail two of the major contributions by Indians in number theory. The climax of the Indian achievements in algebra and number theory was their development of the ingeniouschakravala method for solving, in integers, the equation x² -Dy² = 1, erroneously known as the Pell equation. We shall later describe the partial solution of Brahmagupta and then the complete solution due to Jayadeva and Bhaskaracharya.     

Stimulating Intrinsic Motivation in Millennial Students: A New Generation,a New Approach

There has been a fundamental change in health care pedagogy to address the demands and challenges posed by the present generation of millennial students. There is also a growing recognition of the role of intrinsic motivation as a catalyst in a positive learning experience. The term intrinsic motivation refers to energizing behavior that comes from within an individual and develops due to an inherent interest in the activity at hand. However, stimulating intrinsic motivation in the present generation of millennial health care students is a daunting task, considering their diverse and disparate nature. In addition, the inherent generational differences between educators and students, and an increasing emphasis on technological tools have resulted in a dichotomy in the educational environment leading to the development of a greater incidence of burnouts among students. Hence, numerous innovative techniques have been introduced in health care education to enhance the levels of intrinsic motivation in these students. Unfortunately, most of these approaches have only been moderately successful due to their limited ability to address the unique educational expectations of millennial students. The cumulative evidence suggests that specific approaches to stimulate intrinsic motivation should aim at nurturing the learning efforts of students, bridging the generational barriers between educators and students, and ameliorating the stress associated with health care education. Hence, the specific aim of this narrative review is to suggest empirically proven curricular strategies and institutional reforms to enhance intrinsic motivation in health care students belonging to the Millennial Generation.     

Electrical rectification

Owing to the saturation of the efficiency of silicon devices in electronics industry, molecular electronics has gained tremendous impetus in recent times. Theoretical predictions and experimental realizations of such systems have given birth to a new generation of miniaturized electronic devices. Organic molecules with delocalized π-electrons show a promising future in this aspect. The long-standing history and interesting properties of two isomeric organic molecules, naphthalene and azulene, motivate us to explore their electrical conductance property and possible electronic device applications that exploit the unique characteristics associated with their structural aspects. Single molecule of azulene shows higher conductivity than naphthalene. The charge transfer from the seven-membered ring to the five-membered ring in azulene gives the system aromatic stability, making it dipolar. As a consequence, the conductance becomes asymmetric for forward and reverse bias, opening an efficient application of azulene as molecular rectifier in electronic device fabrication.     

Combined AC electroosmosis and dielectrophoresis for controlled rotation of microparticles

Electrorotation is widely used for characterization of biological cells and materials using a rotating electric field. Generally, multiphase AC electric fields and quadrupolar electrode configuration are needed to create a rotating electric field for electrorotation. In this study, we demonstrate a simple method to rotate dielectrophoretically trapped microparticles using a stationary AC electric field. Coplanar interdigitated electrodes are used to create a linearly polarized nonuniform AC electric field. This nonuniform electric field is employed for dielectrophoretic trapping of microparticles as well as for generating electroosmotic flow in the vicinity of the electrodes resulting in rotation of microparticles in a microfluidic device. The rotation of barium titanate microparticles is observed in 2-propanol and methanol solvent at a frequency below 1 kHz. A particle rotation rate as high as 240 revolutions per minute is observed. It is demonstrated that precise manipulation (both rotation rate and equilibrium position) of the particles is possible by controlling the frequency of the applied electric field. At low frequency range, the equilibrium positions of the microparticles are observed between the electrode edge and electrode center. This method of particle manipulation is different from electrorotation as it uses induced AC electroosmosis instead of electric torque as in the case of electrorotation. Moreover, it has been shown that a microparticle can be rotated along its own axis without any translational motion.     

Negotiating Structural Absences: Voices of Indigenous Subalterns of Eastern India

Historically, indigenous people have been struggling with the issues of material and communicative absences and their voices systematically erased from discursive spaces. Critical-cultural frameworks such as the culture-centered approach (CCA) argue that reflexive engagements with subaltern communities by listening to their narratives are instrumental in interrogating structural absences. By mindfully attending to the emerging contextual narratives, this CCA study examines how indigenous villagers of eastern-India negotiate and exert agency with situated structural absences in their day-to-day existence. This research seeks to explore as well as extend our understanding of structural marginalization and its negotiations in the realm of subaltern agency.