31 research outputs found
Black Tea: Chemical and Pharmacological Appraisal
Medicinal plants are gaining popularity as folk medicine due to future demand to get rid of synthetic health promoting medicines. Nowadays, black tea is gaining interest as the most frequently consumed therapeutic drink after the water. The importance of black tea is due to existence of flavonoids such as (Thearubigins (TRs) and theaflavins (TFs) and catechins) that are the main therapeutic agents and are more bio-direct and stable compounds compared to those exist in other herbal plants alongside some other promising compounds which enhance is credentials as therapeutic drug. Numerous scientific explorations have elucidated the biological worth of these bioactive moieties against plethora of ailments with special reference to metabolic disorder. The mandate of current chapter is to discuss the black tea chemistry for elucidating its pharmacological worth
New finite difference formulas for numerical differentiation
Conventional numerical differentiation formulas based on interpolating polynomials, operators and lozenge diagrams can be simplified to one of the finite difference approximations based on Taylor series, and closed-form expressions of these finite difference formulas have already been presented. In this paper, we present new finite difference formulas, which are more accurate than the available ones, especially for the oscillating functions having frequency components near the Nyquist frequency. Closed-form expressions of the new formulas are given for arbitrary order. A comparison of the previously available three types of approximations is given with the presented formulas. A computer program written in MATHEMATICA, based on new formulas is given in the appendix for numerical di erentiation of a function at
Taylor series based finite difference approximations of higher-degree derivatives
AbstractA new type of Taylor series based finite difference approximations of higher-degree derivatives of a function are presented in closed forms, with their coefficients given by explicit formulas for arbitrary orders. Characteristics and accuracies of presented approximations and already presented central difference higher-degree approximations are investigated by performing example numerical differentiations. It is shown that the presented approximations are more accurate than the central difference approximations, especially for odd degrees. However, for even degrees, central difference approximations become attractive, as the coefficients of the presented approximations of even degrees do not correspond to equispaced input samples