Yang-Mills observables: from KMOC to eikonal through EFT

We obtain a conservative Hamiltonian describing the interactions of two charged bodies in Yang-Mills through $$ \mathcal{O}\left({\alpha}^2\right) $$ O α 2 and to all orders in velocity. Our calculation extends a recently-introduced framework based on scattering amplitudes and effective field theory (EFT) to consider color-charged objects. These results are checked against the direct integration of the observables in the Kosower-Maybee-O’Connell (KMOC) formalism. At the order we consider we find that the linear and color impulses in a scattering event can be concisely described in terms of the eikonal phase, thus extending the domain of applicability of a formula originally proposed in the context of spinning particles.

Architectural Characteristics of Different Configurations Based on New Geometric Determinations for the Conoid

The aim of this article is to orient the evolution of new architectural forms offering up-to--date scientific support. Unlike the volume, the expression for the lateral area of a regular conoid has not yet been obtained by means of direct integration or a differential geometry procedure. In this type of ruled surface, the fundamental expressions I and II, for other curved figures have proved not solvable thus far. As this form is frequently used in architectural engineering, the inability to determine its surface area represents a serious hindrance to solving several problems that arise in radiative transfer, lighting and construction, to cite just a few. To address such drawback, we conceived a new approach that, in principle, consists in dividing the surface into infinitesimal elliptic strips of which the area can be obtained in an approximate fashion. The length of the ellipse is expressed with certain accuracy by means of Ramanujan’s second formula. By integrating the so-found perimeter of the differential strips for the whole span of the conoid, an unexpected solution emerges through a newly found number that we call psi (ψ). In this complex process, projected shapes have been derived from an original closed form composed of two conoids and called Antisphera for its significant parallels with the sphere. The authors try to demonstrate that the properties of the new surfaces have relevant implications for technology, especially in building science and sustainability, under domains such as structures, radiation and acoustics. Fragments of the conoid have occasionally appeared in modern and contemporary architecture but this article discusses how its use had been discontinued, mainly due to the uncertainties that its construction posed. The new knowledge provided by the authors, including their own proposals, may help to revitalize and expand such interesting configurations in the search for a revolution of forms.

Model of normal cracks level formation and opening in stretched reinforced concrete elements

The article highlights the most important studies results of the mechanism of normalcracks formation and opening in stretched reinforced concrete elements during their deformation. Acritical analysis of the existing methods and ways for calculating normal cracks level formation andopening, in which the reinforcement to concrete adhesion is taken into account directly or indirectly,is carried out. The main advantages and disadvantages of each of these methods are indicated. It hasbeen experimentally confirmed that the crack formation process is generally leveled. The mainfeatures and patterns of cracking in stretched reinforced concrete elements and structures arerevealed. The main characteristics of the prototypes are given, according to the test results of whichit was established that in practical calculations of the reinforced concrete elements crack resistance,it is usually possible to restrict oneself to two levels of normal cracking. For the indicated crackinglevels, the corresponding load level, step and crack opening width are established. The expediencyof using in practical calculations the nonlinear function of the reinforcement with concrete averageadhesion stresses is also substantiated. Based on the studies results carried out, the existing methodsfor calculating the normal cracks formation and opening in reinforced concrete elements andstructures were evaluated from the standpoint of local disadvantage of the reinforcement to concreteadhesion.General and simplified methods for calculating normal cracks level formation and opening inreinforced concrete elements have been developed. In them, the direct integration of the expressionfor the concrete and reinforcement mutual displacements is proposed to be replaced not by thenumerical integration of the indicated expression, but by the successive accumulation of the indicateddisplacements. Corresponding statistical comparisons of the calculations results by these methodswith experimental data are carried out. The effectiveness of the developed methods for calculatingnormal cracks level formation and opening by comparing them with existing methods is estimated.

An Efficient and Robust Nonlinear Dynamic Analysis Method for Framed Structures Using the Rigid Body Rule

In this paper, by implanting the rigid body rule (RBR)-based strategy for static nonlinear problems into the implicit direct integration procedure, an efficient and robustness nonlinear dynamic analysis method for the response of framed structures with large deflections and rotations is proposed. The implicit integration method proposed by Newmark is improved by inserting an intermediate time into the time step and by adding the 3-point backward difference in the second substep so as to preserve the momentum conservation and to maintain the stability of the direct integration method. To solve the equivalent incremental equations of motion, the RBR is built in to deal with the rigid rotations and the resulting additional nodal forces of element. During the increment-iterative procedure, the use of RBR-qualified geometric stiffness in the predictor reduces the numbers of iterations, while the elastic stiffness alone in the corrector to update the element nodal forces makes the computation efficiency and convergence with no virtual forces caused by the ill geometric stiffness. The proposed algorithm is advanced in the applications of several framed structures with highly nonlinear behavior in the dynamic response by its simplicity, efficient and robustness.

Optimization of Focused Ion Beam Patterning Parameters for Direct Integration of Plasmonic Nanostructures on Silicon Photodiodes

The possibility of integrating plasmonic nanostructures directly on an active device, such as a silicon photodetector, is a challenging task of interest in many applications. Among the available nanofabrication techniques to realize plasmonic nanostructures, Focused Ion Beam (FIB) is surely the most promising, even if it is characterized by certain limitations, such as ion implantation in the substrate. In this work, we demonstrate the direct integration of plasmonic nanostructures directly on an active Si-photodetector by patterning a silver film with FIB. To avoid ion implantation and to therefore guarantee unaltered device behavior, both the patterning parameters and the geometry of the nanostructures were implemented by Montecarlo and Finite-Difference Time-Domain simulations.