Search results for "dynamic range"
showing 10 items of 60 documents
Low complexity digital background calibration algorithm for the correction of timing mismatch in time-interleaved ADCs
2019
Abstract A low-complexity post-processing algorithm to estimate and compensate for timing skew error in a four-channel time-interleaved analog to digital converter (TIADC) is presented in this paper, together with its hardware implementation. The Lagrange interpolator is used as the reconstruction filter which alleviates online interpolator redesign by using a simplified representation of coefficients. Simulation results show that the proposed algorithm can suppress error tones for input signal frequency from 0 to 0.4 f s . The proposed structure has, at least, 41% reduction in the number of required multipliers. Implementation of the algorithm, for a four-channel 10-bit TIADC, show that, f…
2017
Significant progress in nonlinear and ultrafast optics has recently opened new and exciting opportunities for terahertz (THz) science and technology, which require the development of reliable THz sources, detectors, and supporting devices. In this work, we demonstrate the first solid-state technique for the coherent detection of ultra-broadband THz pulses (0.1–10 THz), relying on the electric-field-induced second-harmonic generation in a thin layer of ultraviolet fused silica. The proposed CMOS-compatible devices, which can be realized with standard microfabrication techniques, allow us to perform ultra-broadband detection with a high dynamic range by employing probe laser powers and bias v…
Flame atomic absorption analysis of gold in jewelry samples
1990
A new procedure is proposed for the determination of gold by flame atomic absorption in jewelry samples. The method is based on the acid digestion of 10 mg of sample in a microwave oven and on the on-line dilution, using a three-way valve. The dynamic range of the technique is extended to 100 mg/l gold solutions and using a weighted bracketing method for the treatment of the results, accuracy errors lower than 2% can be found in the analysis of real samples as compared with those obtained by fire assay. The method is very fast and implies only little damage to the jewelry samples.
The effect of MPEG audio compression on multidimensional set of voice parameters
2002
The MPEG-1 Layer 3 compression schema of audio signal, or commonly known as mp3, has caused a great impact in recent years as it has reached high compression rates while also conserving a high sound quality. Previous listening tests have shown that music and speech samples compressed at high bitrates are virtually indistinguishable from the original samples, but very little is known about how compression acoustically affects the voice signal. In Experiment 1 the spectral composition of original and compressed speech signals were analyzed by means of the Long-Term Average Spectrum using the Computerized Speech Laboratory (Kay Elemetrics Corp. (Pine Brook, NJ, USA)). In Experiment 2 a set of …
Comparison of UV and charged aerosol detection approach in pharmaceutical analysis of statins
2009
Abstract CAD (charged aerosol detector) has recently become a new alternative detection system in HPLC. This detection approach was applied in a new HPLC method for the determination of three of the major statins used in clinical treatment—simvastatin, lovastatin and atorvastatin. The method was optimized and the influence of individual parameters on CAD response and sensitivity was carefully studied. Chromatography was performed on a Zorbax Eclipse XDB C18 (4.6 mm × 75 mm, 3.5 μm), using acetonitrile and formic acid 0.1% as mobile phase. The detection was performed using both CAD (20 pA range) and DAD (diode array detector—238 nm) simultaneously connected in series. In terms of linearity, …
SphinX soft X-ray spectrophotometer: Science objectives, design and performance
2011
The goals and construction details of a new design Polish-led X-ray spectrophotometer are described. The instrument is aimed to observe emission from entire solar corona and is placed as a separate block within the Russian TESIS X- and EUV complex aboard the CORONAS-PHOTON solar orbiting observatory. SphinX uses silicon PIN diode detectors for high time resolution measurements of the solar spectra in the range 0.8–15 keV. Its spectral resolution allows for discerning more than hundred separate energy bands in this range. The instrument dynamic range extends two orders of magnitude below and above these representative for GOES. The relative and absolute accuracy of spectral measurements is e…
Determination of particle number and brightness using a laser scanning confocal microscope operating in the analog mode
2008
We describe a method to obtain the brightness and number of molecules at each pixel of an image stack obtained with a laser scanning microscope. The method is based on intensity fluctuations due to the diffusion of molecules in a pixel. For a detector operating in the analog mode, the variance must be proportional to the intensity. Once this constant has been calibrated, we use the ratio between the variance and the intensity to derive the particle brightness. Then, from the ratio of the intensity to the brightness we obtain the average number of particles in the pixel. We show that the method works with molecules in solution and that the results are comparable to those obtained with fluctu…
Portable low-cost open-source wireless spectrophotometer for fast and reliable measurements
2020
This article is based upon COST Action CA16215 and supported by the ERDF , European-Union Project No.1.1.1.2/16/I/001.
On-line solvent recycling: a tool for the development of clean analytical chemistry in flow injection Fourier transform infrared spectrometry. Determ…
1998
Abstract A flow injection strategy has been developed for the direct determination of ketoprofen in pharmaceuticals by Fourier transform infrared spectrometry also incorporating a distillation unit which allows the carbon tetrachloride employed to dissolve samples and standards and used as a carrier to be recovered on-line. The system developed permits a drastic reduction of reagent consumption and easy and fast sampling and cleaning of the measurement cell. For the quantification of ketoprofen in pharmaceuticals the carbonyl bands at 1712 and 1666 cm −1 were employed and the developed method provided a 3 σ limit of detection of 0.04 mg ml −1 , a dynamic range up to 10 mg ml −1 and typical …
Optimisation of direct digital frequency synthesisers based on CORDIC
2001
Methods to simplify digital frequency synthesizers based on the co-ordinate rotation digital computer (CORDIC) algorithm are presented. Application of these methods leads to performance enhancement, compared with the topologies previously proposed in the literature. For a given output precision, hardware resources are reduced and spur-free dynamic range is increased.