CMOS Sigma-Delta Converters Rosa, Jos? M. de la; R?o, Roc?o del
2013, 2013-05-06T00:00:00, 2013-03-13, 2013-02-25
eBook
A comprehensive overview of Sigma-Delta Analog-to-Digital Converters (ADCs) and a practical guide to their design in nano-scale CMOS for optimal performance.This book presents a systematic and ...comprehensive compilation of sigma-delta converter operating principles, the new advances in architectures and circuits, design methodologies and practical considerations minus; going from system-level specifications to silicon integration, packaging and measurements, with emphasis on nanometer CMOS implementation. The book emphasizes practical design issues – from high-level behavioural modelling in MATLAB/SIMULINK, to circuit-level implementation in Cadence Design FrameWork II. As well as being a comprehensive reference to the theory, the book is also unique in that it gives special importance on practical issues, giving a detailed description of the different steps that constitute the whole design flow of sigma-delta ADCs. The book begins with an introductory survey of sigma-delta modulators, their fundamentals architectures and synthesis methods covered in Chapter 1. In Chapter 2, the effect of main circuit error mechanisms is analysed, providing the necessary understanding of the main practical issues affecting the performance of sigma-delta modulators. The knowledge derived from the first two chapters is presented in the book as an essential part of the systematic top-down/bottom-up synthesis methodology of sigma-delta modulators described in Chapter 3, where a time-domain behavioural simulator named SIMSIDES is described and applied to the high-level design and verification of sigma-delta ADCs. Chapter 4 moves farther down from system-level to the circuit and physical level, providing a number of design recommendations and practical recipes to complete the design flow of sigma-delta modulators. To conclude the book, Chapter 5 gives an overview of the state-of-the-art sigma-delta ADCs, which are exhaustively analysed in order to extract practical design guidelines and to identify the incoming trends, design challenges as well as practical solutions proposed by cutting-edge designs.Offers a complete survey of sigma-delta modulator architectures from fundamentals to state-of-the art topologies, considering both switched-capacitor and continuous-time circuit implementationsGives a systematic analysis and practical design guide of sigma-delta modulators, from a top-down/bottom-up perspective, including mathematical models and analytical procedures, behavioural modeling in MATLAB/SIMULINK, macromodeling, and circuit-level implementation in Cadence Design FrameWork II, chip prototyping, and experimental characterization.Systematic compilation of cutting-edge sigma-delta modulatorsComplete description of SIMSIDES, a time-domain behavioural simulator implemented in MATLAB/SIMULINKPlenty of examples, case studies, and simulation test benches, covering the different stages of the design flow of sigma-delta modulatorsA number of electronic resources, including SIMSIDES, the statistical data used in the state-of-the-art survey, as well as many design examples and test benches are hosted on a companion websiteEssential reading for Researchers and electronics engineering practitioners interested in the design of high-performance data converters integrated in nanometer CMOS technologies; mixed-signal designers.
► Three different functional phenol-enriched virgin olive oils were prepared. ► Phenolic metabolites pharmacokinetics was assessed in a randomised, cross-over study. ► A linear trend was observed for ...hydroxytyrosol sulfate, the main metabolite in plasma. ► A dose-dependent response of phenol metabolites in human plasma was observed.
Three different functional phenol-enriched virgin olive oils (FVOO) were prepared with a phenolic content of 250 (L-FVOO), 500 (M-FVOO), and 750mg (H-FVOO) total phenols/kg. In a randomised, cross-over study with 12 healthy volunteers, the pharmacokinetics of phenolic biological metabolites was assessed. An increasing linear trend was observed for hydroxytyrosol sulfate, the main phenolic metabolite quantified in plasma, with Cmax values of 1.35, 3.32, and 4.09μmol/l, and AUC mean values of 263.7, 581.4, and 724.4μmol/min for L-FVOO, M-FVOO, and H-FVOO, respectively. From our data an acute intake of phenol-enriched olive oils promotes a dose-dependent response of phenol conjugate metabolites in human plasma. Also, we point out for the first time hydroxytyrosol acetate sulfate as a main biological metabolite of hydroxytyrosol from olive oil ingestion.
To describe the safety and effectiveness of a self-expanding and fully retrievable stent (Solitaire AB; ev3 Inc, Plymouth, MN) in revascularization of patients with acute ischemic stroke.
...Prospective, single-center study of 20 patients with an acute ischemic stroke attributable to a large artery occlusion of the anterior circulation within the first 8 hours from symptoms onset (median National Institutes of Health Stroke Scale, 19 interquartile range, 15-23). The occlusion site was middle cerebral artery in 12 patients, proximal internal carotid artery/middle cerebral artery tandem occlusion in 3 patients, and terminus internal carotid artery in 5 patients. Thrombectomy was used as rescue therapy in 2 patients who were refractory to intra-arterial plasminogen activator, and in 3 patients in whom successful recanalization with the MERCI retriever was not achieved.
Successful revascularization defined as thrombosis in cerebral ischemia grade 2b or 3 was achieved in 18 of 20 (90%) treated vessels, and 16 patients showed immediate restoration of flow after stent deployment. The mean number of passes for maximal recanalization was 1.4, and the median (quartiles) time from groin puncture to recanalization was 50 (38-71) minutes. No case required adjuvant therapy after deployment of the embolectomy device. No significant procedural events occurred. Symptomatic intracranial hemorrhage was found in 2 (10%) patients, 4 (20%) patients died during the 90-day follow-up period, and 45% of patients showed good functional outcome at 3 months (modified Rankin Scale score <or=2).
These results suggest that the Solitaire AB device can rapidly, safely, and effectively retrieve clots from the middle cerebral artery and terminus internal carotid artery within 8 hours from symptoms onset.
Abstract
As we speak, corollary discharge mechanisms suppress the auditory conscious perception of the self‐generated voice in healthy subjects. This suppression has been associated with the ...attenuation of the auditory N1 component. To analyse this corollary discharge phenomenon (agency and ownership), we registered the event‐related potentials of 42 healthy subjects. The N1 and P2 components were elicited by spoken vowels (
talk
condition; agency), by played‐back vowels recorded with their own voice (
listen‐self
condition; ownership) and by played‐back vowels recorded with an external voice (
listen‐other
condition). The N1 amplitude elicited by the
talk
condition was smaller compared with the
listen‐self
and
listen‐other
conditions. There were no amplitude differences in N1 between
listen‐self
and
listen‐other
conditions. The P2 component did not show differences between conditions. Additionally, a peak latency analysis of N1 and P2 components between the three conditions showed no differences. These findings corroborate previous results showing that the corollary discharge mechanisms dampen sensory responses to self‐generated speech (agency experience) and provide new neurophysiological evidence about the similarities in the processing of played‐back vowels with our own voice (ownership experience) and with an external voice.
This paper presents a tutorial overview of \Sigma\Delta modulators, their operating principles and architectures, circuit errors and models, design methods, and practical issues. A review of the ...state of the art on nanometer CMOS implementations is described, giving a survey of cutting-edge \Sigma\Delta architectures, with emphasis on their application to the next generation of wireless telecom systems.
The European Directive 98/83/CE legislates the presence of pesticides in drinking water, but apart from a few compounds, nothing is said about which pesticides should be monitored. Nevertheless, ...water companies need to go beyond the accomplishment of the legislation and find out pesticide contamination in all sources of water in order to manage the hazard assessment, and to guarantee safe drinking water to all the population.
The aim of this work was to develop an analytical multi-residue method for circa 100 compounds. The method analyses previously monitored compounds in Barcelona city and its metropolitan area, as well as many emerging pesticides and some transformation products.
An on-line sample extraction (0.75 mL) coupled to fast UHPLC-MS/MS method was developed. Good linearity (r2 > 0.995, with less residuals than 15%), accuracies and precisions under 25%, and acceptable expanded uncertainties were obtained for most of the monitored compounds, according to ISO/IEC 17025, obtaining limits of quantification between 5 and 25 ng/L for all compounds.
A monitoring campaign on natural and treated waters in the Barcelona metropolitan area was carried out during 2016–2017. Results showed that pesticide contamination at the low stretch of Llobregat River and in its aquifer is severe. The maximum concentrations were in the range of few μg/L for carbendazim, DEET, diuron and propiconazole, and in the range 0.1–0.5 μg/L for bentazone, imidacloprid, isoproturon, simazine, metazachlor, methomyl, terbutryn and tebuconazole. However, the efficiency of advanced treatments in the DWTPs involved in drinking water production in the Barcelona metropolitan area allows the complete removal of pesticides and a safe water production for consumers.
The method shows a good analytical performance for most compounds with a fast sample preparation and analysis. In addition, it has updated the knowledge about the occurrence of pesticides in the Barcelona city area.
Display omitted
•Monitoring data from Llobregat River and tap water of Barcelona during two years.•Identification of non-previously reported pesticides in natural waters•Occurrence of pesticide in drinking water and risk assessment reavaluation•High pollution in water resources but efficiently removed in the treatment plants•Validation of a novel on-line extraction method according EN ISO/IEC 17025.
A Control-Bounded Quadrature Leapfrog ADC Malmberg, Hampus; Feyling, Fredrik; Rosa, Jose M. de la
IEEE transactions on circuits and systems. I, Regular papers,
06/2024, Letnik:
71, Številka:
6
Journal Article
Recenzirano
Odprti dostop
In this paper, the design flexibility of the control-bounded analog-to-digital converter principle is demonstrated. A band-pass analog-to-digital converter is considered as an application and case ...study. We show how a low-pass control-bounded analog-to-digital converter can be translated into a band-pass version where the guaranteed stability, converter bandwidth, and signal-to-noise ratio are preserved while the center frequency for conversion can be positioned freely. The proposed converter is validated with behavioral simulations on several filter orders, center frequencies, and oversampling ratios. Additionally, we consider an op-amp circuit realization where the effects of first-order op-amp non-idealities are shown. Finally, robustness against component variations is demonstrated by Monte Carlo simulations.
The low prevalence of rare diseases poses a significant challenge in advancing their understanding. This study aims to delineate the clinical and genetic characteristics of patients with rare eye ...diseases (RED) enrolled in the Spanish Rare Diseases Patient Registry. A total of 864 patients from the registry database were included. Diseases were categorized into inherited retinal dystrophies (n=688); anterior segment diseases (n=48); congenital malformations (n=27); and syndromic diseases with ocular involvement including muscular (n=46), neurological (n=34), or metabolic (n=13); inflammatory diseases (n=4); and tumors (n=4). Data on visual acuity (VA) and/or visual field (VF), symptoms and signs, concurrent diseases in syndromic cases, age of onset and at diagnosis, affected genes, disability rating, inability to work and dependency grade recognition were collected. A mean diagnostic delay of 7 years from symptom onset was observed. Commonly reported symptoms included photophobia, night blindness, and progressive vision loss (greater than or equal to57% of patients). Cataract was the most prevalent secondary disease (46%), with pseudophakia being the most common ocular surgery (26%). Hearing loss and cardiovascular diseases were the most prevalent concurrent systemic diseases (greater than or equal to13%). Certificates of disability, incapacity for work, and dependency were held by 87%, 42%, and 19% of patients, respectively. Among the 719 patients with available VA data, 193 (27%) were blind, and 188 (26%) had moderate to severe visual impairment. Over half of the patients (54%) exhibited VF defects, and 216 (25%) had concentric contraction less than or equal to5degrees or abolished VF. Most had genetic diseases with autosomal recessive (55%), autosomal dominant (30%), X-linked (9%), and mitochondrial (6%) patterns. One patient had mutations in both recessive USH2A and dominant RHO genes simultaneously. Of the 656 patients (75.7%) who underwent genetic testing, only 461 (70.3%) received a positive result (pathogenic or likely pathogenic mutations explaining the phenotype). We found 62 new gene variants related to RED not previously reported in databases of genetic variants related to specific phenotypes. This study delineates the clinical and genotypic profiles of RED in Spain. Genetic diseases, particularly retinal disorders, predominate, but a significant proportion of affected patients remain genetically undiagnosed, hindering potential gene therapy endeavors. Despite notable improvements in reducing diagnosis delays, it is still remarkable. RED frequently lead to disability and blindness among young populations.
The interest of using biochar, the solid byproduct from organic waste pyrolysis, as soil conditioner is significantly increasing. Nevertheless, persistent organic pollutants, such as polycyclic ...aromatic hydrocarbons (PAHs), are formed during pyrolysis due to the incomplete combustion of organic matter. Consequently, these pollutants may enter the environment when biochar is incorporated into soil and cause adverse ecological effects. In this study, we examined the content of the 16 United States Environmental Protection Agency (USEPA) PAHs in biochars produced from rice husk, wood, wheat and sewage sludge residues using three different pyrolytic reactors and temperatures (400, 500 and 600 °C). The total concentration of PAHs (∑PAH) ranged from 799 to 6364 μg kg−1, being naphthalene, phenanthrene and anthracene the most abundant PAHs in all the biochars. The maximum amount of PAHs was observed for the rice husk biochar produced in the batch reactor at 400 °C, which decreased with increasing temperature. The ∑PAH value of the wood biochar produced via traditional kilns doubled compared with the wood biochar produced using the other pyrolytic reactors (5330 μg kg−1 in Kiln; 2737 μg kg−1 in batch and 1942 μg kg−1 in the rotary reactor). Looking for a more reliable risk assessment of the potential exposure of PAHs in biochar, the total toxic equivalent concentrations (TTEC) of the 14 produced biochars were calculated. When comparing the same feedstock and temperature, TTEC values indicated that the rotary reactor produced the safest biochars. In contrast, the biochars produced using the batch reactor at 400 and 500 °C have the greatest hazard potential. Our results provide valuable information on the potential risk of biochar application for human and animal health, as well as for the environment due to PAHs contamination.
Display omitted
•Risk assessment of biochar due to PAHs contamination•Pyrolysis conditions and reactors are evaluated in terms of the total toxic equivalent concentrations (TTEC) in biochars.•Greatest PAHs levels in the biochar produced in the batch reactor at 400 °C•Rotary reactor produced the most secure biochars regardless of the feedstock or temperature.•TTEC is proposed for evaluating the potential hazard of biochars instead of total PAHs.
Pyrogenic organic matter (PyOM) is assumed to be biochemically recalcitrant, but recent studies indicated a quick decrease of PyOM in post-fire soils. Regardless erosion and abiotic degradation, ...microbial decomposition has been the explanation for this response, but no direct proof has been provided up to now. In the present study, we were able to demonstrate for the first time that the soil-borne fungus Fusarium oxysporum is not only colonizing the pore system of pyrochar (PyC) but is also involved in the degradation of its aromatic network. We showed that PyC not only stimulates microbial degradation of soil organic matter (SOM), but is also attacked and decomposed by microorganisms. Our observations are based on the chemical and morphological alterations of a sewage-sludge derived PyC produced at 600 °C after its amendment to a Calcic Cambisol by solid-state
C nuclear magnetic resonance spectroscopy, analytical pyrolysis, elemental analysis, field emission scanning electron microscopy and DNA-based analysis of the isolated fungi. We showed that biofilms detected in the PyC play an essential role in the degradation process. These results are indispensable for a reliable assessment of the carbon sequestration potential of PyC in soils but also for improving global C cycling models.
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