246,938 research outputs found

    Fano-ADC(2,2) method for electronic decay rates

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    Fano-ADC is a family of ab initio methods for prediction of electronic decay widths in excited, singly- and doubly-ionized systems. It has been particularly successful in elucidating the geometry dependence of the inter-atomic decay widths in clusters and facilitated prediction of new electronic decay phenomena. However, the available Fano-ADC schemes are limited to the second order treatment of the initial state and fist-order treatment of the final states of the decay. This confines the applicability of the Fano-ADC approach to first-order decay processes, e.g. normal but not double Auger decay, and compromises the numerical accuracy of the schemes through the unbalanced treatment of electronic correlation. Here we introduce the ADC(2,2) approximation for singly ionized states which describes both initial and final states of the decay up to second order. We use the new scheme to construct the Fano-ADC(2,2) approximation for the decay widths and show that it provides superior accuracy for the decay widths of a series of processes. Moreover, the Fano-ADC(2,2) method provides access to second-order decay processed, such as double Auger decay, which are qualitatively beyond reach of the previously available Fano-ADC implementations.Comment: 41 pages, 4 figure

    Private-Law Models for Official Immunity

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    A method for correcting matching errors in an ADC is presented. The method uses the unknown input data from the application and does not require any test signal. Two algorithms for implementing the method are compared. One algorithm is general and works on any type of ADC. The other algorithm utilizes the subranged architecture of a specific ADC and is very simple to implement in hardware. The signal quality is similar for both algorithms

    A 0.45pJ/conv-step 1.2Gs/s 6b full-Nyquist non-calibrated flash ADC in 45nm CMOS and its scaling behavior

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    A 6-bit 1.2 Gs/s non-calibrated flash ADC in a standard 45nm CMOS process, that achieves 0.45pJ/conv-step at full Nyquist bandwidth, is presented. Power efficient operation is achieved by a full optimization of amplifier blocks, and by innovations in the comparator and encoding stage. The performance of a non-calibrated flash ADC is directly related to device properties;\ud a scaling analysis of our ADC in and across CMOS technologies gives insight into the excellent usability of 45nm technology for AD converter design

    A 76nW, 4kS/s 10-bit SAR ADC with offset cancellation for biomedical applications

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    This paper presents a 10-bit fully-differential rail-to-rail successive approximation (SAR) ADC designed for biomedical applications. The ADC, fabricated in a 180nm HV CMOS technology, features low switching energy consumption and employs a time-domain comparator which includes an offset cancellation mechanism. The power dissipated by the ADC is 76.2nW at 4kS/s and achieves 9.5 ENOB.Ministerio de Economía y Competitividad TEC2012-33634Office of Naval Research (USA) N0001414135

    A 10-bit Charge-Redistribution ADC Consuming 1.9 μW at 1 MS/s

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    This paper presents a 10 bit successive approximation ADC in 65 nm CMOS that benefits from technology scaling. It meets extremely low power requirements by using a charge-redistribution DAC that uses step-wise charging, a dynamic two-stage comparator and a delay-line-based controller. The ADC requires no external reference current and uses only one external supply voltage of 1.0 V to 1.3 V. Its supply current is proportional to the sample rate (only dynamic power consumption). The ADC uses a chip area of approximately 115--225 μm2. At a sample rate of 1 MS/s and a supply voltage of 1.0 V, the 10 bit ADC consumes 1.9 μW and achieves an energy efficiency of 4.4 fJ/conversion-step

    The inner mass distribution of late-type spiral galaxies from SAURON stellar kinematic maps

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    We infer the central mass distributions within 0.4-1.2 disc scale lengths of 18 late-type spiral galaxies using two different dynamical modelling approaches - the Asymmetric Drift Correction (ADC) and axisymmetric Jeans Anisotropic Multi-gaussian expansion (JAM) model. ADC adopts a thin disc assumption, whereas JAM does a full line-of-sight velocity integration. We use stellar kinematics maps obtained with the integral-field spectrograph SAURON to derive the corresponding circular velocity curves from the two models. To find their best-fit values, we apply Markov Chain Monte Carlo (MCMC) method. ADC and JAM modelling approaches are consistent within 5% uncertainty when the ordered motions are significant comparable to the random motions, i.e, vϕ/σR\overline{v_{\phi}}/\sigma_R is locally greater than 1.5. Below this value, the ratio vc,JAM/vc,ADCv_\mathrm{c,JAM}/v_\mathrm{c,ADC} gradually increases with decreasing vϕ/σR\overline{v_{\phi}}/\sigma_R, reaching vc,JAM2×vc,ADCv_\mathrm{c,JAM}\approx 2 \times v_\mathrm{c,ADC}. Such conditions indicate that the stellar masses of the galaxies in our sample are not confined to their disk planes and likely have a non-negligible contribution from their bulges and thick disks.Comment: 44 pages, 60 figures, MNRAS accepted. The ADC-MCMC and JAM-MCMC python codes are available at: https://github.com/Kalinova/Dyn_models. The Multi-Gaussian Expansion (MGE) results are also available in the Appendi
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