Lithium-Ion Battery and Beyond: Oxygen Vacancy Creation in Tungsten Trioxide and Surface Modification of Lithium Metal

The graphite-based anode material has a low theoretical specific capacity of 371 mAh g-1. The transitional metal oxides (TMOs) are considered a better choice owing to their relatively higher specific capacity. Among TMOs, tungsten trioxide (WO3) is considered promising due to a higher specific capacity of 693 mAh g-1, low cost, mechanically stable, and eco-friendly. It has been a challenge to utilize the TMOs as anode materials as they suffer from poor electronic conductivity and large electrode volume expansion during discharge/charge cycles. In our first project, we demonstrate a unique self-recovery of capacity in reduced WO3 by the incorporation of urea followed by annealing at 500 °C under the N2 environment. The reduced WO3 exhibited a unique cycling phenomenon, where the capacity was significantly self-recovered after an initial sharp decrease. This can be attributed to the activation of oxygen vacancy sites or defects, making the WO3 electrode more electrochemically active with cycling. In our second and third projects, we modify the surface of lithium metal to utilize them as anode because LIBs are approaching their theoretical energy density limit. Lithium metal anodes are expected to drive practical applications that require high energy-density storage. However, the direct use of metallic lithium causes safety concerns, low rate capabilities, and poor cycling performances due to unstable solid electrolyte interphase (SEI) and undesired lithium dendrite growth. To address these issues, in our second project, radio frequency (R-F) sputtered graphite-SiO2 ultrathin bilayer on a Li metal chips was demonstrated, for the first time, as an effective solid-electrolyte interface (SEI) layer. In the third project, we developed a facile, costeffective, and one-step approach to generate an artificial lithium metal/electrolyte interphase by treating lithium anode with an electrolyte containing tin fluoride. The development of artificial SEI on top of lithium metal anode led to a dendrite free uniform Li deposition to achieve a stable voltage profile and outstanding long hours plating/stripping compared to the bare Li. The generated SEI not only ensures fast lithiumion diffusion and suppression of lithium dendrite growth but also brings a synergistic effect of storing lithium via a reversible silicon-lithium or tin-lithium alloy formation and lithium plating

Inhomogeneous Cooling of the Rough Granular Gas in Two Dimensions

We study the inhomogeneous clustered regime of a freely cooling granular gas of rough particles in two dimensions using large-scale event driven simulations and scaling arguments. During collisions, rough particles dissipate energy in both the normal and tangential directions of collision. In the inhomogeneous regime, translational kinetic energy and the rotational energy decay with time $t$ as power-laws $t^{-\theta_T}$ and $t^{-\theta_R}$. We numerically determine $\theta_T \approx 1$ and $\theta_R \approx 1.6$, independent of the coefficients of restitution. The inhomogeneous regime of the granular gas has been argued to be describable by the ballistic aggregation problem, where particles coalesce on contact. Using scaling arguments, we predict $\theta_T=1$ and $\theta_R=1$ for ballistic aggregation, $\theta_R$ being different from that obtained for the rough granular gas. Simulations of ballistic aggregation with rotational degrees of freedom are consistent with these exponents.Comment: 6 pages, 5 figure

Shock propagation in locally driven granular systems

We study shock propagation in a system of initially stationary hard-spheres that is driven by a continuous injection of particles at the origin. The disturbance created by the injection of energy spreads radially outwards through collision between particles. Using scaling arguments, we determine the exponent characterizing the power law growth of this disturbance in all dimensions. The scaling functions describing the various physical quantities are determined using large scale event driven simulations in two and three dimensions for both the elastic and the inelastic system. The results are shown to describe well the data from two different experiments on granular systems that are similarly driven.Comment: 8 pages, 9 figure

CONCEPT OF SHUSHKAKSHIPAKA (DRY EYE SYNDROME) IN AYURVEDA WITH MODERN COUNTERPART: A REVIEW

Eyes are the windows to the soul. Ayurvedic classical texts have mentioned about eye and its diseases since Vedic and Samhita kala, thus showing the importance of eye and ways to protect it. That is why eye care has been one of the priorities since the ages. In Ayurveda clinical features related to Dry eye are generally seen in Suskaksipaka. Over use of Video Display Terminals (V.D.T) like Computer, Mobiles, and Television & faulty lifestyle are some of the causes. Among these disorders, many are related to Indriya (Sensory Organ) especially Caksurindriya (Eye). In metro city, more than 50% cases from ophthalmic OPD are of Dry Eye Syndrome. Dry Eye Syndrome is a common ophthalmic condition, in its real sense is a problem for eye care practitioners due to its variegated etiologies, multi factorial physiopathology, lack of gold standard for diagnostic procedure. No curative treatment modalities are available and the palliative measures are inadequate too. It presents a great challenge to physicians. That’s why its prevalence is very high. It is 5% to 35% worldwide, while in India it is 29.25%. Dry Eye Syndrome also known as Kerato-Conjunctivitis Sicca (KCS) is considered a disease of the modern era. Dry eye syndrome, one of the most frequently encountered ocular morbidities, a growing public health problem and one of the most common conditions seen by the eye care practitioners. Tear secretion provides continuous moisture and lubrication on the ocular surface and provides oxygen to the corneal- epithelium. When the normal tear production is compromised, it leads to dry eyes

Child Internet Protection System

Nowadays internets is becoming an amazing resource and provide hours of fun for kids. Clearly there are many benefits that result from Internet usage, but there is a side to the internet that can be worrying for any parent. Internet is explored, in particular: child sexual exploitation; children\u27s exposure to sexually explicit or offensive material, so there is need of a system which prevents child abuse from internet. Currently many systems are developed to prevent Internetrelated child abuse. In this paper, we have developed a web page classification model, which will protect children from harmful and offensive material available on internet. Our approach uses entropy term weighting scheme, Principal Component Analysis for feature reduction and Back propagation neural network as classifier. Our experiment result shows that our approach performed well as comparison to other approaches

Does Promoter Ownership Affect Dividend Policy? An Agency Problem Perspective

In this paper, we show a nonlinear relation between promoter ownership and dividends in the Indian context, that is, promoters pay more dividends at lower level of their ownership while they pay lesser dividends when their ownership increases beyond a threshold. In particular, we find that the adverse impact of promoter ownership on dividends is greater only at higher level of ownership, where promoters become entrenched with their effective control, and outsiders face the greatest risk of expropriation. We contend that agency and information asymmetry problems are the factors driving our results. We establish this by showing that the nonlinear relation between promoter ownership and dividend payment is more pronounced for standalone firms than group affiliated firms, for firms with more free cash flows and for firms with smaller board and less number of independent directors in the board. Our results are robust to endogeneity concerns and testing the dividend payment decision (to pay or not to pay) using the binary choice logit model