Statistical Calibration of Model Solution of Analytes

Abstract

Abstract:A new method based on spectrophotometric-partial least-squares procedure was proposed for simultaneously determination of thorium and zirconium using SPADNS (4,5-Dihydroxy-3-(p-sulfophenylazo)-2,7-naphthalene disulfonic acid, trisodium salt) as a color reagent. Absorbance measurements were made in the range of λ = 541÷620 nm with 1.0 nm steps in buffered solutions at pH 3.5. The linear ranges were obtained for 0.5÷11.5 and 1.5÷14.5 µg cm -3 for Th 4+ and Zr 4+ ions, respectively. The limits of detection were determined 0.4 and 1.2 µg cm -3 for thorium and zirconium, respectively. The standard deviation (n = 3) and recovery percent of 10 samples in the prediction set were obtained in the amplitude 0.22÷0.38 µg cm -3 and 91.3÷109.2, respectively. The proposed method was used for simultaneously determination of mentioned ions in spiked real water samples and wastewater. The results show that the method is applicable for the analysis of samples with similar matrix.

Modelling of Centralized Two-Phase Locking With Integrated Mechanism of Timestamps by the “Wait – Die” Method

“…We continue the gathering of statistics of simulations of the modeling algorithm in different parameters of the system and the coming streams [3],[10] and a comparative analysis of the results in different solutions for the data replication and the concurrency control.…”

“…The concurrency control algorithms in the database management systems (DBMS) are considered as pessimistic (using a lock mechanism), optimistic (with deadlock avoidance) and their hybrid solutions. According to many authors [1][2][3][4][5], [7] and [10] two-phase locking -2PL methods are more effective when the system is saturated by conflicts.…”