Standard addition involves adding varying amounts of the analyte to sample portions of fixed mass or fixed volume and submitting those portions to the sample preparation procedure. After measuring the final extract solutions, the observed signals are linearly regressed on the spiked amounts. The original unknown amount is estimated by the opposite of the abscissa intercept of the fitted straigh...

A new, simple, inexpensive, and sensitive method for the simultaneous spectrophotometric determination of Cu(II) and Pd(II) by H-point standard addition method and derivative spectrophotometry is described. 4Phenylpiperazinecarbodithioate (PPDTC) in an anionic micellar solution of SLS was used as a reagent at pH 4. The experimental parameters, such as pH, type of surfactant, concentration of re...

In this study, we investigate whether there is a need for the h index and its variants in addition to standard bibliometric measures (SBMs). Results from our recent study (L. Bornmann, R. Mutz, & H.-D. Daniel, 2008) have indicated that there are two types of indices: One type of indices (e.g., h index) describes the most productive core of a scientist’s output and informs about the number of pa...

The measles distribution model is a system of differential equations that included in continuous dynamic system. This research focuses on transforming the form into discrete by discretization using non-standard finite difference and stability analysis which then carried out numerical simulations to prove its graphically. Based analysis, it found assumed have two fixed points, namely disease-fre...

We consider numeration systems where digits are integers and the base is an algebraic number β such that |β| > 1 and β satisfies a polynomial where one coefficient is dominant in a certain sense. For this class of bases β, we can find an alphabet of signed-digits on which addition is realizable by a parallel algorithm in constant time. This algorithm is a kind of generalization of the one of Av...