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228 articles for “zero”

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Research ArticleOpen accessIn the abstractDetermination of Ibuprofen and Paracetamol in Binary Mixture Using Chemometric-Assisted Spectrophotometric MethodsWafaa S. HassanThree methods are presented for simultaneous determination of ibuprofen and paracetamol without previous separation. The first method depends on first derivative UV spectrophotometry, with zero-crossing measurement. The first derivative amplitudes at 230 and 290 nm were selected for the assay of ibuprofen and paracetamol, respectively. The second method depends on first derivative of the ratio-spectra by measurements of the amplitudes … …American Journal of Applied Sciences, Vol. 5, Issue 8 · 31 Aug 2008 · 8,199 accessesView PDFCite
Research ArticleOpen accessIn the abstractA Novel Approach for Testing Stability of 1-D Recursive Digital Filters Based on Lagrange MultipliersK. R. Santhi, N. Gangatharan, M. PonnavaikkoDigital filters have found their way into many products from every day consumer items such as mobile phones to advanced maritime and military communications and avionics systems. Design of digital filters faces two fundamental problems, their stability and synthesis. Recursive filters have more stability problems than nonrecursive filters. Stability of a filter can be determined by the location of the … …American Journal of Applied Sciences, Vol. 5, Issue 5 · 31 May 2008 · 6,484 accessesView PDFCite
Research ArticleOpen accessIn the abstractChaos Control in Nonlinear Systems Using the Generalized Backstopping MethodA.R. Sahab, M. Haddad ZarifOne of the most important nonlinear systems for checking the abilities of control methods is chaos. In this study chaos in Lorenz system was used for checking abilities of new control method. This new method to control nonlinear systems was called Generalized Backstepping method because of its similarity to Backstepping but its abilities to control more systems than Backstepping. This … …American Journal of Engineering and Applied Sciences, Vol. 1, Issue 4 · 31 Mar 2008 · 7,064 accessesView PDFCite
Research ArticleOpen accessIn the abstractTotal SO2 Emissions from Power Stations and Evaluation of their Impact in Kuwait Using a Gaussian Plume Dispersion ModelA.A. Ramadan, M. Al-Sudairawi, S. Alhajraf, A.R. KhanIn Kuwait, most of the power stations use fuel oil as the prime source of energy. The sulphur content (S%) of the fuel used as well as other factors have a direct impact on the ground level concentration of sulphur dioxide (SO2) released by power stations into the atmosphere. The SO2 ground level concentration has to meet the environmental standards … …American Journal of Environmental Sciences, Vol. 4, Issue 1 · 29 Feb 2008 · 6,850 accessesView PDFCite
Research ArticleOpen accessIn the abstractAutomatic Calibration of Frequency Compensation System in Computer-Controlled Patch-Clamp AmplifierJun Xiong, Gang Hu, Anlian QuComputer-controlled patch-clamp amplifier is a digitally controlled analog device used to record the cellular ion channel currents in electrophysiology research. The inherent bandwidth and performance of the headstage is limited by the stray capacitance and distributed capacitance across the feedback resistors. In order to effectively improve the performance of the headstage, the paper advanced a simplified automatic calibration method of … …Journal of Computer Science, Vol. 3, Issue 10 · 31 Oct 2007 · 6,814 accessesView PDFCite
Research ArticleOpen accessIn the abstractSample Selection Analysis of Wage Equation for Women In Ondo State NigeriaSola Olorunfemi, Olorunsola E. OlowofesoThe study analysis wage equation for women in Ondo State Nigeria, in other to identify the determinant factors of their wages. Data collected from 250 women heads of households through a multi-stage random system technique were analyzed. In order to deal with the zero wage problem associated with those who did not work, various single – equation models were applied. … …Journal of Social Sciences, Vol. 3, Issue 3 · 30 Sep 2007 · 7,557 accessesView PDFCite
Research ArticleOpen accessIn the abstractDetermination of Metoprolol and Felodipine in Binary Mixture Using Chemometric-Assisted Spectrophotometric and High-Performance Liquid Chromatographic-UV MethodsHesham Salem, Ola M. AbdallahFour methods were developed for simultaneous determination of metoprolol and felodipine without previous separation. In the first method both drugs were determined using first derivative UV spectrophotometry, with zero crossing measurement at 222 and 235 nm for metoprolol and felodipine, respectively. The second method depends on first derivative of the ratios spectra by measurements of the amplitudes at 250.1 nm … …American Journal of Applied Sciences, Vol. 4, Issue 9 · 30 Sep 2007 · 8,025 accessesView PDFCite
Research ArticleOpen accessIn the abstractFeedback of the Input Voltage in FDTC Control Using a Three-Level NPC-VSIR. Zaimeddine, E.M. BerkoukA new control structure for sensorless induction machine dedicated to electrical drives using a three-level voltage source inverter VSI-NPC is completely analysed. The amplitude and the rotating velocity of the flux vector could be controlled freely. Both fast torque and optimal switching logic could be achieved; the selection is based on the value of the stator flux and the torque. … …American Journal of Applied Sciences, Vol. 4, Issue 7 · 31 Jul 2007 · 6,687 accessesView PDFCite
Research ArticleOpen accessIn the abstractA Priori Estimation of the Resolvent on Approximation of Born-OppenheimerSabria Bouheroum-Mentri, Amina BenbernouIn this study, we estimate the resolvent of the two bodies Shrodinger operator perturbed by a potential of Coulombian type on Hilbert space when h tends to zero. Using the Feschbach method, we first distorted it and then reduced it to a diagonal matrix. We considered a case where two energy levels cross in the classical forbidden region. Under the … …Journal of Mathematics and Statistics, Vol. 3, Issue 2 · 30 Jun 2007 · 6,725 accessesView PDFCite
Research ArticleOpen accessIn the abstractInduction Motor Flux Estimation using Nonlinear Sliding ObserversHakiki Khalid, Mazari Benyounès, Djaber Sid’AhmedA nonlinear sliding flux was proposed for an induction motor. Its dynamic observation errors converge asymptotically to zero, independently from the inputs. The aim of this work was to study the robustness of this observer with respect to the variation of the rotor resistance known to be a crucial parameter for the control. The dynamic performance of this sliding observer … …Journal of Mathematics and Statistics, Vol. 3, Issue 2 · 30 Jun 2007 · 6,794 accessesView PDFCite