102,595 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)
Capabilities of the ADDA code for nanophotonics
No full textInternational audienceThe open-source code ADDA (https://github.com/adda-team/adda) is based on the discrete dipole approximation (DDA) – a numerically exact method derived from the frequency-domain volume-integral formulation of the Maxwell equations [1]. It can simulate interaction of electromagnetic fields (scattering and absorption) with finite 3D objects of arbitrary shape and composition. Besides standard sequential execution on a CPU or a GPU, ADDA can run on a multiprocessor distributed-memory system, parallelizing a single DDA calculation. This together with almost linear scaling of computational complexity with the number of dipoles (discretization voxels) allows huge system sizes and/or fine discretization levels. The code is written in C99, is highly portable, and includes a graphical user interface.ADDA provides full control over the scattering geometry (particle morphology and orientation, incident beam) and allows one to calculate a wide variety of integral and angle-resolved quantities. In addition to far-field scattering by various beams (including built-in Gaussian and Bessel ones), this includes near fields as well as excitation by a point dipole or a fast electron. Moreover, ADDA can rigorously and efficiently simulate the scattering by particles near a plane homogeneous substrate or placed in a homogeneous absorbing host medium. It also incorporates many DDA improvements aimed at increasing both the accuracy and computational speed.At the conference we will describe the main features of ADDA, including the ones still in development, with special emphasis on nanoparticles. They include a wide range of built-in Bessel 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 emits the Cherenkov radiation, or for particles on top of a semi-infinite substrate (under certain approximations). These capabilities also generalize the concept of the Purcell effect, which ADDA can rigorously compute in free space or near a substrate. Placing a point source inside a nanoparticle allows one to calculate near-field radiative heat transfer or Casimir forces between two objects. Recent numerical improvements include block- or shifted iterative methods to accelerate computations for multiple incident beams (e.g., particle orientations) or refractive indices.References:[1] M.A. Yurkin and A.G. Hoekstra, “The discrete-dipole-approximation code ADDA: Capabilities and known limitations,” J. Quant. Spectrosc. Radiat. Transfer 112, 2234–2247 (2011).[2] S.A. Glukhova and M.A. Yurkin, “Vector Bessel beams: General classification and scattering simulations,” Phys. Rev. A 106, 033508 (2022).[3] A.A. Kichigin and M.A. Yurkin, “Simulating electron energy-loss spectroscopy and cathodoluminescence for particles in arbitrary host medium using the discrete dipole approximation,” J. Phys. Chem. C 127, 4154–4167 (2023)
The discrete-dipole-approximation code ADDA: capabilities and known limitations
No full textThe open-source code ADDA is described, which implements the discrete dipole approximation (DDA), a method to simulate light scattering by finite 3D objects of arbitrary shape and composition. Besides standard sequential execution, ADDA can run on a multiprocessor distributed-memory system, parallelizing a single DDA calculation. Hence the size parameter of the scatterer is in principle limited only by total available memory and computational speed. ADDA is written in C99 and is highly portable. It provides full control over the scattering geometry (particle morphology and orientation, and incident beam) and allows one to calculate a wide variety of integral and angle-resolved scattering quantities (cross sections, the Mueller matrix, etc.). Moreover, ADDA incorporates a range of state-of-the-art DDA improvements, aimed at increasing the accuracy and computational speed of the method. We discuss both physical and computational aspects of the DDA simulations and provide a practical introduction into performing such simulations with the ADDA code. We also present several simulation results, in particular, for a sphere with size parameter 320 (100-wavelength diameter) and refractive index 1.05
G. G. Meerssemann, E. Adda et Jean Deshusses. L'Orazionale dell' Arcidiacono Pacifico e il Carpsum del Cantore Stefano. Studi e testi sulla liturgia del Duomo di Verona dal IX all' XI sec (Spicilegium Friburgense, 21)
No full textHuglo Michel. G. G. Meerssemann, E. Adda et Jean Deshusses. L'Orazionale dell' Arcidiacono Pacifico e il Carpsum del Cantore Stefano. Studi e testi sulla liturgia del Duomo di Verona dal IX all' XI sec (Spicilegium Friburgense, 21). In: Scriptorium, Tome 31 n°1, 1977. pp. 131-132
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
Is ultrasound-guided laser thermal ablation for parathyroid adenomas safe and effective? Reply
No full textConsensus report of the joint workshop of the Italian Society of Diabetology, Italian Society of Periodontology and Implantology, Italian Association of Clinical Diabetologists (SID-SIdP-AMD)
No full textPeriodontitis has been defined as the Sixth complication of Diabetes Mellitus. Since both diabetes mellitus and periodontitis have a high prevalence in the general population, the Italian Society of Diabetology, the Italian Society of Periodontology and Implantology and the Italian Association of Clinical Diabetologists revised the present scientific literature in the present consensus report. A bi-directional interaction was demonstrated: Patients affected by type 1 and type 2 diabetes have a higher prevalence of periodontitis than the general population, due to several metabolic factors (e.g. chronic hyperglycemia, autoimmunity, dietary and life-style factors); similarly, periodontitis predisposes to type 2 diabetes mellitus mainly via the increase of systemic cytokines release. Conversely, improvement of metabolic control of diabetic patients delay the progression of periodontitis as well as periodontitis treatment reduces glycosylated hemoglobin levels in blood. Due to the bi-directional causal interaction between periodontitis and diabetes mellitus, a strict collaboration among dentists and diabetologists is required and strongly recommended. The inter-societies consensus proposes specific flow-diagrams to improve the treatment of patients and management of the general population regarding the issue of periodontitis and diabetes
Bibliographie Hilarion G. Petzold 1958 – 2009 mit Anhang als Einführung
No full textDieses Archiv enthält die Gesamtbibliographie der Werke des Autors nebst einiger Texte „Über H. G. Petzold“ im Schlussteil der Bibliographie sowie einen Anhang mit einer Einführung in die Architektur des Werkes in seinem wissenslogischen Aufbau als Ausarbeitung seines „Tree of Science Modells“ (2007).This archive contains the complete bibliography of the author and some texts about H. G. Petzold, moreover an epilogue with an introduction to the architecture of the works in its epistemological structure and composition and as an elaborations of Petzold’s „Tree of Science Modell (2007).https://www.fpi-publikation.de/polyloge/01-2009-petzold-h-g-gesamtbibliographie-h-g-petzold-1958-2009-updating-november2009/peerReviewedpublishedVersio
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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