Systematic challenges for future gravitational wave measurements of precessing binary black holes

The properties of precessing, coalescing binary black holes are presently inferred through comparison with two approximate models of compact binary coalescence. In this work we show these two models often disagree substantially when binaries have modestly large spins ($a\gtrsim 0.4$) and modest mass ratios ($q\gtrsim 2$). We demonstrate these disagreements using standard figures of merit and the parameters inferred for recent detections of binary black holes. By comparing to numerical relativity, we confirm these disagreements reflect systematic errors. We provide concrete examples to demonstrate that these systematic errors can significantly impact inferences about astrophysically significant binary parameters. For the immediate future, parameter inference for binary black holes should be performed with multiple models (including numerical relativity), and carefully validated by performing inference under controlled circumstances with similar synthetic events.Comment: 12 pages, 9 figure

Evolución geoquímica de la salmuera de la laguna de Alcahazo, Pedro Muñoz (Ciudad Real).

La Mancha, por sus condiciones climáticas y geomorfológicas, es una región natural en la que se forman frecuentes encharcamientos que derivan hacia sistemas tipo "sebkha" en los que se produce precipitación de sales por evaporación. En la laguna se han determinado las siguientes fases minerales: sulfato magnésico (epsomita, hexahidrita, pentahidrita y kieserita), sulfato cálcico (yeso), cloruro sódico (halita) y cloruro magnésico (bischofita). Las aguas de la laguna, en el período de máxima dilución, presentan una composición marcadamente sulfatada, con alto contenido en cloruros, magnesio y sodio. En laboratorio se ha realizado el seguimiento de la evolución de la salmuera en condiciones equivalentes a las naturales, estableciéndose su correlación con la secuencia teórica de precipitación según VALYASHKO. Por último, se hace una valoración más detallada de los contenidos en estroncio, lo que permite establecer la hipótesis, en función de los aportes, de que esta laguna funciona como un sistema cerrado con recargas limitadas a aportes de lluvia en su cuenca de recepción

Global Antifungal Profile Optimization of Chlorophenyl Derivatives against Botrytis cinerea and Colletotrichum gloeosporioides

Twenty-two aromatic derivatives bearing a chlorine atom and a different chain in the para or meta position were prepared and evaluated for their in vitro antifungal activity against the phytopathogenic fungi Botrytis cinerea and Colletotrichum gloeosporioides. The results showed that maximum inhibition of the growth of these fungi was exhibited for enantiomers S and R of 1-(40-chlorophenyl)- 2-phenylethanol (3 and 4). Furthermore, their antifungal activity showed a clear structure-activity relationship (SAR) trend confirming the importance of the benzyl hydroxyl group in the inhibitory mechanism of the compounds studied. Additionally, a multiobjective optimization study of the global antifungal profile of chlorophenyl derivatives was conducted in order to establish a rational strategy for the filtering of new fungicide candidates from combinatorial libraries. The MOOPDESIRE methodology was used for this purpose providing reliable ranking models that can be used later

Impact of gravitational radiation higher order modes on single aligned-spin gravitational wave searches for binary black holes

Current template-based gravitational wave searches for compact binary coalescences (CBC) use waveform models that neglect the higher order modes content of the gravitational radiation emitted, considering only the quadrupolar $(\ell,|m|)=(2,2)$ modes. We study the effect of such a neglection for the case of aligned-spin CBC searches for equal-spin (and non-spinning) binary black holes in the context of two versions of Advanced LIGO: the upcoming 2015 version, known as early Advanced LIGO (eaLIGO) and its Zero-Detuned High Energy Power version, that we will refer to as Advanced LIGO (AdvLIGO). In addition, we study the case of a non-spinning search for initial LIGO (iLIGO). We do this via computing the effectualness of the aligned-spin SEOBNRv1 ROM waveform family, which only considers quadrupolar modes, towards hybrid post-Newtonian/Numerical Relativity waveforms which contain higher order modes. We find that for all LIGO versions, losses of more than $10\%$ of events occur for mass ratio $q\geq6$ and $M \geq 100M_\odot$ due to the neglection of higher modes. Moreover, for iLIGO and eaLIGO, losses notably increase up to $(39,23)\%$ respectively for the highest mass $(220M_\odot)$ and mass ratio ($q=8$) studied. For the case of early AdvLIGO, losses of $10\%$ occur for $M>50M_\odot$ and $q\geq6$. Neglection of higher modes leads to observation-averaged systematic parameter biases towards lower spin, total mass and chirp mass. For completeness, we perform a preliminar, non-exhaustive comparison of systematic biases to statistical errors. We find that, for a given SNR, systematic biases dominate over statistical errors at much lower total mass for eaLIGO than for AdvLIGO

Mapping the Universe Expansion: Enabling percent-level measurements of the Hubble Constant with a single binary neutron-star merger detection

The joint observation of the gravitational-wave and electromagnetic signal from the binary neutron-star merger GW170817 allowed for a new independent measurement of the Hubble constant $H_0$, albeit with an uncertainty of about 15\% at 1$\sigma$. Observations of similar sources with a network of future detectors will allow for more precise measurements of $H_0$. These, however, are currently largely limited by the intrinsic degeneracy between the luminosity distance and the inclination of the source in the gravitational-wave signal. We show that the higher-order modes in gravitational waves can be used to break this degeneracy in astrophysical parameter estimation in both the inspiral and post-merger phases of a neutron star merger. We show that for systems at distances similar to GW170817, this method enables percent-level measurements of $H_0$ with a single detection. This would permit the study of time variations and spatial anisotropies of $H_0$ with unprecedented precision. We investigate how different network configurations affect measurements of $H_0$, and discuss the implications in terms of science drivers for the proposed 2.5- and third-generation gravitational-wave detectors. Finally, we show that the precision of $H_0$ measured with these future observatories will be solely limited by redshift measurements of electromagnetic counterparts

Visualization of facet-dependent pseudo-photocatalytic behavior of TiO2 nanorods for water splitting using In situ liquid cell TEM

We report an investigation of the pseudo-photocatalytic behavior of rutile TiO2 nanorods for water splitting observed with liquid cell transmission electron microscopy (TEM). The electron beam serves as a “light” source to initiate the catalytic reaction and a “water-in-salt” aqueous solution is employed as the electrolyte. The observation reveals that bubbles are generated preferentially residing near the {110} facet of a rutile TiO2 nanorod under a low electron dose rate (9.3–18.6 e-/Å2·s). These bubbles are ascribed to hydrogen gas generated from the pseudo-photocatalytic water splitting. As the electron beam current density increases to 93 e-/Å2 ·s, bubbles are also found at the {001} and {111} facets as well as in the bulk liquid solution, demonstrating the dominant effects of water electrolysis by electron beam under higher dose rates. The facet-dependent pseudo-photocatalytic behavior of rutile TiO2 nanorods is further validated using density functional theory (DFT)calculation. Our work establishes a facile liquid cell TEM setup for the study of pseudo-photocatalytic water splitting and it may also be applied to investigation of other photo-activated phenomena occurring at the solid-liquid interfaces

Confusing Head-On Collisions with Precessing Intermediate-Mass Binary Black Hole Mergers

We report a degeneracy between the gravitational-wave signals from quasi-circular precessing black-hole mergers and those from extremely eccentric mergers, namely head-on collisions. Performing model selection on numerically simulated signals of head-on collisions using models for quasi-circular binaries we find that, for signal-to-noise ratios of 15 and 25, typical of Advanced LIGO observations, head-on mergers with respective total masses of $M\in (125,300)M_\odot$ and $M\in (200,440)M_\odot$ would be identified as precessing quasi-circular intermediate-mass black hole binaries, located at a much larger distance. Ruling out the head-on scenario would require to perform model selection using currently nonexistent waveform models for head-on collisions, together with the application of astrophysically motivated priors on the (rare) occurrence of those events. We show that in situations where standard parameter inference of compact binaries may report component masses inside (outside) the pair-instability supernova gap, the true object may be a head-on merger with masses outside (inside) this gap. We briefly discuss the potential implications of these findings for the recent gravitational-wave detection GW190521, which we analyse in detail in [Phys. Rev. Lett. 126, 081101]

Composición isotópica (13C/12C y 18 O/16 O) de las rocas encajantes de los yacimientos Zn-Pb del Cretácico Inferior de Cantabria (Sector Reocín-La Florida).

En este trabajo se presentan datos de la composición isotópica en carbono y oxígeno de rocas carbonáticas (calizas y dolomías) en el sector Reocín-La Florida (Cantabria). Estos materiales constituyen la roca encajante de importantes mineralizaciones dé Zn-Pb (tipo Mississippi Valley) de edad Cretácica. Las calizas analizadas tienen valores medios del ð13C(PDB) y ð18 O(SMOW) de +3,15 y +27,21, respectivamente. y las dolomías de +2,05 y +25,53, respectivamente. Estos datos sugieren una génesis diferente para ambos tipos de carbonatos, de tal forma que un origen singenético para las mineralizaciones debe ser rechazado. También se analizan otros tipos de carbonatos presentes (calizas de dolomitización y espeleotemas), cuyos datos indican un origen relacionado con aguas meteóricas, dado el empobrecimiento que estos materiales poseen en los isótopos pesados

Estudio inmunohistoquímico del carcinoma epidermoide de labio

Objetivos: Determinar la sobreexpresión de las proteínas cerb- B2, p53, bcl-2, Ki67 y CD44varV6 y establecer su valor pronóstico en el carcinoma epidermoide de labio. Diseño del estudio: Estudio inmunohistoquímico de las proteínas p53, c-erb-B2, bcl-2, ki67 y CD44varV6 en 79 carcinomas epidermoides de labio diagnosticados y tratados a lo largo de un periodo de 20 años. Los datos obtenidos fueron sometidos a análisis estadístico uni y multivariante. Resultados: La inmunotinción fue positiva en el 75% de los casos para la proteína c-erb-B2, en el 70,6% para la proteína p 53, en el 3,8% para la proteína bcl-2 y en el 89,9% para la molécula de adhesión cd44varV6. La expresión proteica de ki67 osciló entre un mínimo de 0% y un máximo de 6,29%. Los factores inmunohistoquímicos analizados no presentaron valor pronóstico en el carcinoma epidermoide de labio, y solamente los pacientes afectados por este tipo de tumores que expresaban la molécula de adhesión CD44varV6 se asociaron de forma significativa con una mayor supervivencia mediante el análisis de Kaplan-Meier. Conclusiones: Las técnicas inmunohistoquímicas analizadas para el estudio anatomopatológico del carcinoma epidermoide de labio no deberían realizarse rutinariamente, dado su mayor coste y su menor utilidad en la práctica clínica diaria.Objectives: To determine the expression of the c-erb-B2, p53, bcl-2, Ki67 and CD44varV6 proteins, and to establish their prognostic value in epidermoid carcinoma of the lip. Study design: Immunohistochemical study of the c-erb-B2, p53, bcl-2, Ki67 and CD44varV6 proteins in 79 epidermoid carcinomas of the lip, diagnosed and treated over a period of 20 years. The data obtained were subjected to uni- and multi-variate statistical analyses. Results: Immunostaining was positive in 75% of cases for c-erb- B2 protein, in 70.6% for p53 protein, in 3.8% for bcl-2 protein and in 89.9% for adhesion molecule CD44varV6. Ki67 protein expression varied between a minimum of 0% and a maximum of 6.29%. Most immunohistochemical factors analyzed presented no prognostic value for epidermoid carcinoma of the lip. Only those patients affected by this type of tumor that expressed the adhesion molecule CD44varV6 were significantly associated with a greater survival calculated by means of Kaplan-Meier analysis. Conclusions: The immunohistochemical techniques analyzed for the anatomicopathological study of epidermoid carcinoma of the lip should not routinely be used due to their high cost and low utility in daily clinical practice

A machine-learning based solution for chatter prediction in heavy-dutymilling machines

The main productivity constraints of milling operations are self-induced vibrations, especially regenerative chatter vibrations. Two key parameters are linked to these vibrations: the depth of cut achievable without vibrations and the chatter frequency. Both parameters are linked to the dynamics of machine component excitation and the milling operation parameters. Their identification in any cutting direction in milling machine operations requires complex analytical models and mechatronic simulations, usually only applied to identify the worst cutting conditions in operating machines. This work proposes the use of machine learning techniques with no need to calculate the two above-mentioned parameters by means of a 3-step strategy. The strategy combines: 1) experimental frequency responses collected at the tool center point; 2) analytical calculations of both parameters; and, 3) different machine learning techniques. The results of these calculations can then be used to predict chatter under different combinations of milling directions and machine positions. This strategy is validated with real experiments on a bridge milling machine performing concordance roughing operations on AISI 1045 steel with a 125 mm diameter mill fitted with nine cutters at 45°, the results of which have confirmed the high variability of both parameters along the working volume. The following regression techniques are tested: artificial neural networks, regression trees and Random Forest. The results show that Random Forest ensembles provided the highest accuracy with a statistical advantage over the other machine learning models; they achieved a final accuracy of 0.95 mm for the critical depth and 7.3 Hz for the chatter frequency (RMSE) in the whole working volume and in all feed directions, applying a 10 × 10 cross validation scheme. These RMSE values are acceptable from the industrial point of view, taking into account that the critical depth of this range varies between 0.68 mm and 19.20 mm and the chatter frequency between 1.14 Hz and 65.25 Hz. Besides, Random Forest ensembles are more easily optimized than artificial neural networks (1 parameter configuration versus 210 MLPs). Additionally, tools that incorporate regression trees are interesting and highly accurate, providing immediately accessible and useful information in visual formats on critical machine performance for the design engineer.Hidrodamp Project (IDI-20110453) of the Centre for Industrial Technological Development (CDTI