On a hybrid fourth moment involving the Riemann zeta-function

We provide explicit ranges for $\sigma$ for which the asymptotic formula \begin{equation*} \int_0^T|\zeta(1/2+it)|^4|\zeta(\sigma+it)|^{2j}dt \;\sim\; T\sum_{k=0}^4a_{k,j}(\sigma)\log^k T \quad(j\in\mathbb N) \end{equation*} holds as $T\rightarrow \infty$, when $1\leq j \leq 6$, where $\zeta(s)$ is the Riemann zeta-function. The obtained ranges improve on an earlier result of the authors [Annales Univ. Sci. Budapest., Sect. Comp. {\bf38}(2012), 233-244]. An application to a divisor problem is also givenComment: 21 page

On some problems involving Hardy's function

Some problems involving the classical Hardy function $$Z(t) := \zeta(1/2+it)\bigl(\chi(1/2+it)\bigr)^{-1/2}, \quad \zeta(s) = \chi(s)\zeta(1-s)$$ are discussed. In particular we discuss the odd moments of $Z(t)$, the distribution of its positive and negative values and the primitive of $Z(t)$. Some analogous problems for the mean square of $|\zeta(1/2+it)|$ are also discussed.Comment: 15 page

On the Rankin-Selberg problem: higher power moments of the Riesz mean error term

Let $\Delta_1(x;\phi)$ be the error term of the first Riesz means of the Rankin-Selberg zeta function. We study the higher power moments of $\Delta_1(x;\phi)$ and derive an asymptotic formula for 3-rd, 4-th and 5-th power moments by using Ivi\'c 's large value arguments.Comment: 18 Page

Racism and Patriarchy in the Meaning of Motherhood

The catalytic abilities of a gold electrode were tested for the quantitative determination of amphetamine (A) and 3,4-methylenedioxy-N-methylamphetamine (MDMA) standards by their oxidation using cyclic voltammetry (CV). The values of the oxidative currents of A and MDMA standards at 0.80 V vs. SCE in 0.05 M NaHCO3 at a scan rate of 50 mV s-1 were linear functions of the concentration in range of 110.9-258.9 μM and 38.7-229.2 μM, respectively. Square wave voltammetry (SWV) revealed a linear increase of current with the concentration of MDMA (range 30.9-91.6 μM), which enabled the quantitative determination of amphetamine derivates. SWV analysis was also successfully performed in spiked urine samples. A and MDMA in the presence of sucrose and as a content in illegally produced tablets were also determined. The voltammetric determinations of A and MDMA derivatives using CV and SWV at gold a electrode are rapid, selective and simple procedures and their accuracy was confirmed with a reference method, high performance liquid chromatography (HPLC). The analysis of spiked urine samples offers an additional possibility for the rapid detection of A and MDMA in human urine.Katalitička svojstva elektrode od zlata su testirana za kvantitativno određivanje amfetamina (A) i 3,4-metilendioksi-N-metilamfetamina (MDMA) standarda. Elektroksidacija A i MDMA je praćena cikličnom voltametrijom (CV). Vrednost oksidativnog pika A i MDMA standarda je linearna funkcija koncentracija u opsegu 110,9-258,9 μM (A) i 38,7-229,2 μM (MDMA). Voltametrija sa pravougaonim impulsima (SWV) je pokazala linearnu zavisnost struja od koncentracija za MDMA standard (u opsegu: 30,9-91,6 μM) kao i u spajkovanim uzorcima humanog urina. Uspešno je analiziran i sadržaj A i MDMA u ilegalno proizvedenim tabletama. Voltametrijsko određivanje A i MDMA derivata uz pomoć CV i SWV na elektrodi od zlata je brza, selektivna i jednostavna procedura. Analiza spajkovanih uzoraka urina nudi dodatnu mogućnost za brzu detekciju A i MDMA u humanom urinu

The electrochemical investigation of inclusion complexes of nifedipine and amlodipine with ß-cyclodextrin and (2-hydroxypropyl)-ß-cyclodextrin

The electrochemical behavior of inclusion complexes of nifedipine (Nif) and amlodipine (Aml), a long-acting calcium channel blockers dihydropyridine (DHP) class, with ß-cyclodextrin (ßCD) and (2-hydroxypropyl)-ß-cyclodextrin (HPßCD), is examined using cyclic and square wave voltammetry in 0.05 M NaHCO3 and phosphate buffer (pH=11) on a gold electrode. The voltammograms show a single irreversible anodic wave with the current controlled by adsorption. It was found that phosphate buffer favorites the electrochemical activity of both complexes of Nif with the linear dependency of the oxidative currents on their concentrations. In phosphate buffer, only HPßCD-Aml complex showed linear dependency of the oxidative currents on the concentration. In 0.05 M NaHCO3 as electrolyte only HPßCD-Nif exhibited apparent activity. The initial potential of the anodic reaction as well as the value of the potential for anodic currents maximum of all the examined complexes in both electrolytes were shifted to the positive direction compared to their standards. In addition, the value of anodic currents decreased

Elektroredukcija cefetameta na elektrodama od žive, platine i zlata

The electroreduction of cefetamet (CEF) using gold and platinum electrodes has been investigated in slightly alkaline medium (pH 8.40) where adsorption, previously observed at mercury electrode, was pronounced. This investigation was performed in order to determine whether the adsorption interferes with the reduction process even at solid electrodes and to compare with a mercury electrode.Redukcija cefetameta na elektrodama od zlata i platine je proučavana u slabo alkalnoj sredini (pH 8,40) gde je u prethodnim ispitivanjima na živinoj elektrodi u toku reakcije uočena adsorpcija antibiotika. Ovaj rad je posvećen ispitivanju uticaja adsorpcije na elektroredukciju cefetameta na čvrstim elektrodama i poređenju sa živom

Elektroredukcija cefetameta na elektrodama od žive, platine i zlata

The electroreduction of cefetamet (CEF) using gold and platinum electrodes has been investigated in slightly alkaline medium (pH 8.40) where adsorption, previously observed at mercury electrode, was pronounced. This investigation was performed in order to determine whether the adsorption interferes with the reduction process even at solid electrodes and to compare with a mercury electrode.Redukcija cefetameta na elektrodama od zlata i platine je proučavana u slabo alkalnoj sredini (pH 8,40) gde je u prethodnim ispitivanjima na živinoj elektrodi u toku reakcije uočena adsorpcija antibiotika. Ovaj rad je posvećen ispitivanju uticaja adsorpcije na elektroredukciju cefetameta na čvrstim elektrodama i poređenju sa živom

Model za predikciju broja prsnuća tračnica

Broken rails can cause train delays, trains cancelations and, unfortunately, they are common causes of accidents. This affects planning of a resources, budget and organization of railway track maintenance. Planning of railway track maintenance cannot be done without an estimation of number of rails that will be replaced due to the broken rail incidents. There are many factors that influence broken rails and the most common are: rail age, annual gross tonnage, degree of curve and temperature in the time of breakage. The fuzzy logic model uses acquired data as input variables to predict the frequency of broken rails for the certain rail types on some Sections.Prsnuća tračnica mogu prouzrokovati kašnjenje vlakova i jedan su od najčešćih uzroka izvanrednih događaja. Zbog toga utiču i na planiranje resursa, budžeta i održavanja željezničkih pruga. Planiranje održavanja pruga ne može se uraditi bez procjene broja tračnica koje će se zamijeniti zbog prsnuća. Postoji mnogo faktora koji utiču na prsnuće tračnica, a najčešći su: strarost tračnica, godišnje bruto tone, radijus krivine i temperatura u vrijeme prsnuća. Model fuzzy logike koristi prikupljene podatke kao ulazne promjenljive da bi proračunao broj prsnuća tračnica za određeni tip tračnice na nekim sekcijama pruga

In Memorium: Bogoljub Stanković (November 1, 1924 –May 16, 2018)

The eminent scientist Bogoljub Stanković, Full member of the Serbian Academy of Sciences and Arts (SASA) and a longtime Editor-in-Chief of the SASA Bulletin of Mathematical Sciences, died on 16 May 2018.Bulletin t. 151 de l'Académie serbe des sciences et des arts, Classe des sciences mathématiques et naturelles, sciences mathematiques no 4