Permutation-invariant distance between atomic configurations

We present a permutation-invariant distance between atomic configurations, defined through a functional representation of atomic positions. This distance enables to directly compare different atomic environments with an arbitrary number of particles, without going through a space of reduced dimensionality (i.e. fingerprints) as an intermediate step. Moreover, this distance is naturally invariant through permutations of atoms, avoiding the time consuming associated minimization required by other common criteria (like the Root Mean Square Distance). Finally, the invariance through global rotations is accounted for by a minimization procedure in the space of rotations solved by Monte Carlo simulated annealing. A formal framework is also introduced, showing that the distance we propose verifies the property of a metric on the space of atomic configurations. Two examples of applications are proposed. The first one consists in evaluating faithfulness of some fingerprints (or descriptors), i.e. their capacity to represent the structural information of a configuration. The second application concerns structural analysis, where our distance proves to be efficient in discriminating different local structures and even classifying their degree of similarity

Regeneración edáfica y control erosivo en un espacio reforestado: el parque natural de los montes de Málaga

[Resumen] En esta comunicación se pone de manifiesto, a través del análisis de 16 perfiles de suelos, la regeneración edáfica que se ha producido en el Parque Natural de lo Montes de Málaga como consecuencia del abandono de las prácticas de cultivo y de la reforestación. Ambos procesos han permitido reducir considerablemente las tasas de erosión por escorrentía superficial.[AbstractThis communication emphasized that through the analysis of 16 soil profiles, the edafic regeneration wich has taken place in the Parque Natural de los Montes de Málaga as resusult of both the abandoning the cultivation practices and the reforestation. Both processes have allowed to reduce levels of erosion by overland flow

Suelos y morfología en el parque natural de los montes de Málaga

[Resumen] Los suelos observados y analizados en el Parque Natural de los "Montes de Málaga", a escala 1:10.000, presentan estrecha dependencia con la morfología, tanto directamente (laderas, cumbres, rellanos, terrazas, ...) como indirectamente a través de las modificaciones que intoduce en las condiciones bioclimáticas.[Abstract] The observed and analyzed soils in the Natural Park of the "Montes de Málaga" scale 1:10.000. depend closely on the morphology, both directIy (slopes, summits, fluvial terraces, rocky terraces) and indirectly through the modifications introduced in the bioclimatic conditions

The SMA: an effective damper in civil engineering that smoothes oscillations

The properties of SMA (Shape Memory Alloys, that are smart materials) are associated to a first order phase transition named martensitic transformation that occurs between metastable phases: austenite and martensite. At upper temperature or at lower stress the austenite is the metastable phase. The martensite appears at lower temperature or higher stresses. The hysteresis of the transformation permits different levels of applications, i.e., in their use as a damper. Two types of applications can be considered in damping of structures in Civil Engineering. The first one is related to diminishing the damage induced by earthquakes. The second one is a reduction of oscillation amplitude associate to an increase of the lifetime for the stayed cables in bridges.Peer Reviewe

External temperature effects on the hysteresis of NiTi wires in dampers for stay-cables

The use of NiTi wires, one of the Shape Memory Alloy (SMA) materials that permits efficient damping in stayed cables for bridges, requires an appropriate behavior when exposed to the external temperature effects. The Clausius-Clapeyron thermodynamic equation establishes a shift of the hysteretic cycle in the stress-temperature representation of about 6 MPa/K for the used wires of diameter 2.46 mm. Hence, an adequate experimental study is necessary to characterize the temperature effects in working conditions. The conducted analysis is twofold. First, the practical evolution of the hysteresis cycle is investigated. The results suggest that the wire permits a completely satisfactory use for temperatures as low as 253 K (i.e., -20 oC). Second, the focus is placed on the effects of extreme winter actions (i.e., as low as 233 K or -40 oC). A preliminary stress aging process at 373K seems adequate to this requirement. Indeed, after the stress aging, the SMA wire increases their working domain by 300 or 400 MPa and the temperature domain is expanded by 30 – 50 K. Measurements visualizing recoverable dynamical actions in the SMA alloys are also outlined.Peer ReviewedPostprint (published version

Toxicity of several d-endotoxins of Bacillus thuringiensis against Helicoverpa armigera (Lepidoptera: Noctuidae) from Spain

Toxicity and larval growth inhibition of eleven insecticidal proteins of Bacillus thuringiensis were evaluated against neonate larvae of Helicoverpa armigera, a major pest of important crops in Spain and other countries, by a whole-diet contamination method. The most active toxins were Cry1Ac4 and Cry2Aa1, with LC50 values of 3.5 and 6.3 μg/ml, respectively. At the concentrations tested, Cry1Ac4, Cry2Aa1, Cry9Ca, Cry1Fa1, Cry1Ab3, Cry2Ab2, Cry1Da, and Cry1Ja1, produced a significant growth inhibition, whereas Cry1Aa3, Cry1Ca2, and Cry1Ea had no effect

Orbital Optimized Density Functional Theory for Electronic Excited States

Density functional theory (DFT) based modeling of electronic excited states is of importance for investigation of the photophysical/photochemical properties and spectroscopic characterization of large systems. The widely used linear response time-dependent DFT (TDDFT) approach is however not effective at modeling many types of excited states, including (but not limited to) charge-transfer states, doubly excited states and core-level excitations. In this perspective, we discuss state-specific orbital optimized (OO) DFT approaches as an alterative to TDDFT for electronic excited states. We motivate the use of OO-DFT methods and discuss reasons behind their relatively restricted historical usage (vs TDDFT). We subsequently highlight modern developments that address these factors and allow efficient and reliable OO-DFT computations. Several successful applications of OO-DFT for challenging electronic excitations are also presented, indicating their practical efficacy. OO-DFT approaches are thus increasingly becoming a useful route for computing excited states of large chemical systems. We conclude by discussing the limitations and challenges still facing OO-DFT methods, as well as some potential avenues for addressing them

Red or green : Overprinting of the climatic signal in Miocene sediments, South China Sea (IODP Expedition 368, Site U1502)

Funding Information: Support was provided by Chinese 111 (HW), ECORD (SS), Korean IODP (DC), National Science Foundation (ECF), Natural Environment Research Council (SAB) and U.S. Science Support Program, Lamont‐Doherty Earth Observatory (ECF, PP). Marco Maffione, an anonymous reviewer, the Associate Editor and Max Coleman are kindly acknowledged. Publisher Copyright: © 2023 The Authors. Terra Nova published by John Wiley & Sons Ltd.Peer reviewedPublisher PD