197,098 research outputs found
Recent developments of the ADDA code
No full textInternational audienceThe open-source code ADDA (https://github.com/adda-team/adda) is based on the discrete dipoleapproximation (DDA) – a numerically exact method derived from the frequency-domain volume-integralformulation of Maxwell’s equations [1]. It can simulate the interaction of electromagnetic fields(scattering and absorption) with finite 3D objects of arbitrary shape and composition. Besides standardsequential execution on a single CPU or GPU, ADDA can run on a multiprocessor distributed-memorysystem, parallelizing a single DDA calculation. This, combined with the almost linear scaling ofcomputational complexity with the number of dipoles (discretization voxels), allows large system sizesand/or fine discretization levels.ADDA is written in C99 and is highly portable. It provides full control over the scattering geometry(particle morphology and orientation, incident beam) and allows users to calculate a wide variety ofintegral and angle-resolved quantities. In addition to far-field scattering by various beams (includingbuilt-in Gaussian and Bessel beams), this includes near fields as well as excitation by a point dipole or afast electron. Moreover, ADDA can rigorously and efficiently simulate the scattering by particles near aplane homogeneous substrate or embedded in a homogeneous absorbing host medium. It alsoincorporates many DDA improvements aimed at increasing both accuracy and computational speed.In this talk we will focus on the recently implemented ADDA features, either incorporated into themain codebase or available in separate development branches. These include a wide range of built-inBessel beams [2] and simulations of electron energy-loss spectroscopy (EELS) and cathodoluminescence[3]. The latter two can be computed in an arbitrary passive host medium, even when the electron emitsthe Cherenkov radiation, or for particles on top of a semi-infinite substrate (under certainapproximations). These capabilities also generalize the concept of the Purcell factor (i.e., theenhancement of a point-dipole emitter), which ADDA can rigorously compute in free space or near asubstrate [4].Next, we will discuss the analytical approximations of Green’s-tensor integrals for the correspondingDDA formulation, known as IGT, as well as various enhancements to the iterative solvers. Theseenhancements include block- or shifted iterative methods to accelerate computations for multipleincident beams (e.g., particle orientations) or refractive indices, as well as the use of specialized initialguesses for large particles [5]. Finally, many of these features are accessible through a graphical userinterface and we are actively working on integrating ADDA with Spack – a package manager thatfacilitates installation on a wide range of systems, including supercomputing environments.[1] M. A. Yurkin and A. G. Hoekstra, J. Quant. Spectrosc. Radiat. Transfer 112, 2234 (2011).[2] S. A. Glukhova and M. A. Yurkin, Phys. Rev. A 106, 033508 (2022).[3] A. A. Kichigin and M. A. Yurkin, J. Phys. Chem. C 127, 4154 (2023).[4] A. E. Moskalensky and M. A. Yurkin, Phys. Rev. A 99, 053824 (2019).[5] K. G. Inzhevatkin and M. A. Yurkin, J. Quant. Spectrosc. Radiat. Transfer 277, 107965 (2022)
Adda. Tra percezione e conoscenza.
No full textIl considerevole asse pedonale che con mobilità dolce si percorre da Brivio a Trezzo, lungo l’alzaia
a Nord del fiume Adda, è stato in fase sperimentale concepito quale studio di come questa
straordinaria greenway lombarda possa essere impiegata per svolgere “esercizi ginnici” di
percezione e traduzione grafica del paesaggio circostante ed ospitante. Il disegno manuale,
materialmente traducibile in spontanei appunti di viaggio o più stereotipate tavole tecniche e
sinottiche diventa lo strumento con cui “l’atleta” della percezione, può esercitarsi nell’insolita
“palestra” che lo circonda: il territorio, l’ambiente, il fiume
The transition to digital television
No full textThis paper studies the role of economic policy for the transition from analogue to digital television, with particular attention to the switch off of the analogue terrestrial signal. The analogue signal cannot be credibly switched off until almost all viewers have migrated to digital, due to the policy objective of universal access to television. But before switch off, only part of the population can be reached with the digital signal. In addition, those who are reached need to spend more to upgrade their reception equipment than after switch off, because the capacity to increase the power of the digital signal will be made available only then. After reviewing the competitive structure and the role of government intervention in television markets, we present the early experience of a number of industrialized countries in the transition to digital television. We then formulate a microeconometric model of digital television adoption by individual viewers. The model is calibrated to UK data and simulated to predict the impact of government policies on the take-up of digital television. Policy makers can affect the speed of take up of digital television by: (1) controlling the quality of the signals and the content of public service broadcasters; (2) intervening in the market for digital equipment with subsidies; and (3) publicizing the conditions and date of switch off of the analogue signal. We find that if the analogue terrestrial signal is switched off only when certain aggregate adoption targets are reached, strategic delays may arise and expectations may affect the success of the switch off policy
Adda M. Hite, (1885-1971), purchased by Warren Rayman on July 12, 1971.
No full textDocuments regarding the double headstone for Adda M. Hite, (1885-1971), buried with Grover C. Hite (1884-1938), purchased by Warren Rayman. The marker was placed at Toledo Memorial Park Cemetery, Lot 447, Section 17 in Toledo, Ohio. The stone is duplicate of Grover C. Hite, (1884-1938) and made of duplicate blown in panel lettering. Rubbings and Obituary are included
Improved diastolic function in type 2 diabetes after a six month liraglutide treatment
No full textAbstractAimsTo investigate whether liraglutide improves diastolic function in type 2 diabetes.MethodsThirty-seven patients with type 2 diabetes who began liraglutide therapy between June 2013 and May 2014 were enrolled in this observational, prospective study. 26 patients received liraglutide therapy for at least 6months. The remaining 11 patients withdrew from liraglutide therapy during the first month, were started on other hypoglycaemic therapies and formed the control group. Anthropometric, metabolic and echocardiographic parameters including pulsed wave tissue Doppler imaging were evaluated at baseline and at 6months.ResultsIn the liraglutide group the early diastolic mitral annulus velocity on the lateral (e-lat) and medial (e-med) sides of the mitral annulus increased from 9.2±3.4 to 11.6±4.7cm/s (p<0.001) and from 6.9±1.7 to 8.4±2.6cm/s (p<0.003), respectively. The ratio of early-to-late velocities on the lateral and medial sides of the mitral annulus increased from 0.7±0.3 to 0.9±0.4 (p<0.001) and from 0.5±0.1 to 0.6±0.1 (p<0.02), respectively. The ratio of early diastolic mitral inflow velocity to early diastolic myocardial relaxation velocity decreased from 10.7±4.3 to 8.5±2.5 (p<0.005). No improvements in diastolic function was detected in the control group. Glucose control improved similarly in both groups: HA1bc −1.5% (−17mmol/mol) vs −1.3% (−14mmol/mol), p=0.67.ConclusionsIn patients with type 2 diabetes, 6months liraglutide treatment was associated with a significant improvement in diastolic function
1845–2016 gridded dataset of monthly precipitation over the upper Adda river basin: a comparison with runoff series
No full textA new high-resolution gridded dataset of 1845–2016 monthly precipitation series for the upper Adda river basin was computed starting from a network of high-quality and homogenised station records covering Adda basin and neighbouring areas and spanning more than two centuries. The long-term signal was reconstructed by a procedure based on the anomaly method and consisting in the superimposition of two fields which were computed independently: 1961–1990 monthly climatologies and gridded anomalies. Model accuracy was
evaluated by means of station series reconstruction in leave-one-out approach and monthly relative mean absolute errors were found to range between 14% in summer and 24% in winter. Except for the period before the 1870s when station coverage is rather low, reconstruction errors are quite stable. The 1845–2016 monthly areal precipitation series integrated over Adda basin was finally computed. The robustness of this series was evaluated and it was investigated for long-term trend. While no significant trend emerged for precipitation, the analysis performed on 1845–2016 annual runoff values recorded at Lake Como outlet highlighted a negative trend. Runoff decrease is supposed to be mostly due to an increasing role of evapotranspiration linked to temperature increase, which is only partially compensated by the increase in glacier melting rate. In order to test the applicability of the gridded database for the reconstruction of extreme past events, the episode with the highest precipitation in Adda basin series (November 2002) was considered and the corresponding gridded fields of monthly anomalies and precipitation values were evaluated both with actual station density and with station densities corresponding to 1922 and 1882. Even considering 1882 station density, the main spatial patterns are well depicted proving the suitability of anomaly method to deal also with sparse station networks
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