2,581 research outputs found
Time-dependent density functional study of the electronic potential energy curves and excitation spectrum of the oxygen molecule
Orbital energies, ionization potentials, molecular constants, potential energy curves, and the excitation spectrum of O(2) are calculated using time-dependent density functional theory (TDDFT) with Tamm-Dancoff approximation (TDA). The calculated negative highest occupied molecular orbital energy (-epsilon(HOMO)) is compared with the energy difference ionization potential for five exchange correlation functionals consisting of the local density approximation (LDAxc), gradient corrected Becke exchange plus Perdew correlation (B(88X)+P(86C)), gradient regulated asymptotic correction (GRAC), statistical average of orbital potentials (SAOP), and van Leeuwen and Baerends asymptotically correct potential (LB94). The potential energy curves calculated using TDDFT with the TDA at internuclear distances from 1.0 to 1.8 A are divided into three groups according to the electron configurations. The 1pi(u) (4)1pi(g) (2) electron configuration gives rise to the X (3)Sigma(g) (-), a (1)Delta(g), and b (1)Sigma(g) (+) states; the 1pi(u) (3)1pi(g) (3) electron configuration gives rise to the c (1)Sigma(u) (-), C (3)Delta(u), and A (3)Sigma(u) (+) states; and the B (3)Sigma(u) (-), A (1)Delta(u), and f (1)Sigma(u) (+) states are determined by the mixing of two or more electron configurations. The excitation spectrum of the oxygen molecule, calculated with the aforementioned exchange correlation functionals, shows that the results are quite sensitive to the choice of functional. The LDAxc and the B(88X)+P(86C) functionals produce similar spectroscopic patterns with a single strongly absorbing band positioned at 19.82 and 19.72 eV, respectively, while the asymptotically corrected exchange correlation functionals of the SAOP and the LB94 varieties yield similar excitation spectra where the computed strongly absorbing band is located at 16.09 and 16.42 eV, respectively. However, all of the exchange correlation functionals yield only one strongly absorbing band (oscillator strength greater than 0.1) in the energy interval of 0-20 eV, which is assigned to a X (3)Sigma(g) (-) to (3)Sigma(u) (-) transition. Furthermore, the oxygen molecule has a rich spectrum in the energy range of 14-20 eV and no spin allowed absorption bands are predicted to be observed in the range of 0-6 eV
Atmosphere, imminence and the Manchester Arena Inquiry: on the affective modalities of becoming situationally aware to urban terrorism
Building situational awareness has become a central logic among contemporary security apparatuses for abating no-warning urban terrorism. Situational awareness, we contend, casts the sensory, perceptual and affective capacities of human bodies to decipher their immediate surroundings and attune to the non-representational and more-than-known of an enfolding situation, as essential to its execution. What modalities of sense-making and attunement, then, does this burgeoning security rationality demand? And what sensibilities, affectivities and subjectivities are (re)produced and legitimated across urban life? In this paper, we unpack these questions by examining the ways affective and atmospheric attunement(s) are infused within orthodox and emergent security approaches for developing and honing situational awareness. We argue that affective atmospheres in particular furnish the theoretical architecture for attending to the spatio-affective-material registers through which imminence becomes palpable. Empirically, by analysing the Public Inquiry following the 2017 Manchester Arena attack, we elucidate where the Inquiry advanced discussions on (the limits of) situational awareness and its sensorial, affective and atmospheric dimensions, thereby extending situational awareness into an atmospheric agenda within urban geopolitics. Finally, we reflect on how the impending UK Protect Duty might reconfigure the legal landscape of situational awareness, city resilience, and the affective economies of (in)attention
Resilience of a eucalypt forest woody understorey to long-term (34â55 years) repeated burning in subtropical Australia
We investigated the effects of annual burning since 1952, triennial burning since 1973, fire exclusion since 1946 and infrequent wildfire (one fire in 61 years) on woody understorey vegetation in a dry sclerophyll eucalypt forest, south-eastern Queensland, Australia. We determined the influence of these treatments, and other site variables (rainfall, understorey density, topsoil CÂ :Â N ratio, tree basal area, distance to watercourse and burn coverage) on plant taxa density, richness and composition. The richness of woody understorey taxa 0â1Â m in height was not affected by burning treatments, but richness of woody plants 1â7.5Â m in height was lower in the annually burnt treatment than in the triennially burnt treatment from 1989 to 2007. Fire frequency and other site variables explained 34% of the variation in taxa composition (three taxon groups and 10 species), of which 33% of the explained variance was explained by fire treatment and 46% was explained by other site variables. Annual burning between 1974 and 1993 was associated with lower understorey densities mainly due to reduced densities of eucalypts 1â7.5Â m in height. Triennial burning during the same period was associated with higher densities of eucalypts 0â7.5Â m in height relative to the annually burnt and unburnt treatments. Most woody taxa persisted in the frequently burnt treatments through resprouting mechanisms (e.g. lignotuberous regeneration), and fire patchiness associated with low-intensity burning was also found to be important. Persistence of plants <1Â m tall demonstrates the resilience of woody taxa to repeated burning in this ecosystem, although they mainly exist in a suppressed growth state under annual burning
Knudsen Effusion Study Of The Vaporization Of CdO(s)
Knudsen effusion studies were conducted on CdO(s) in fusedâSiO2 Knudsen cells from 889 to 1110 K. The orifice size was varied; the largest cell orifice yielded a calculated pressure significantly lower than could be accounted for by experimental error. Averageâslopeâ and averageâfreeâenergyâfunctionâbased values of ÎHc298 were 86.9 ± 1.1 and 88.8 ± 0.5 kcal/mol, respectively. The data from the present work were combined with those of previous investigators using a method discussed by McCreary and Thorn; a ÎHc298 of 88.2 ± 0.2 kcal/mol was obtained. Using this combined value for ÎHc298 and ÎSc298= 51.40 ± 0.1 eu (obtained from the literature), the equilibrium constant for the reaction CdO(s)= Cd(g)+ 1/2 O2(g) at 900 to 1380 K was calculated to be log K = 10.6â18,800(I/T). Copyright © 1974, Wiley Blackwell. All rights reserve
The impact of facial abnormalities and their spatial position on perception of cuteness and attractiveness of infant faces
This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Research has demonstrated that how âcuteâ an infant is perceived to be has consequences for caregiving. Infants with facial abnormalities receive lower ratings of cuteness, but relatively little is known about how different abnormalities and their location affect these aesthetic judgements. The objective of the current study was to compare the impact of different abnormalities on the perception of infant faces, while controlling for infant identity. In two experiments, adult participants gave ratings of cuteness and attractiveness in response to face images that had been edited to introduce common facial abnormalities. Stimulus faces displayed either a haemangioma (a small, benign birth mark), strabismus (an abnormal alignment of the eyes) or a cleft lip (an abnormal opening in the upper lip). In Experiment 1, haemangioma had less of a detrimental effect on ratings than the more severe abnormalities. In Experiment 2, we manipulated the position of a haemangioma on the face. We found small but robust effects of this position, with abnormalities in the top and on the left of the face receiving lower cuteness ratings. This is consistent with previous research showing that people attend more to the top of the face (particularly the eyes) and to the left hemifield
Sperm dumping as a defense against meiotic drive
Sperm from Drosophila simulans that carry a sex-ratio distorter is preferentially lost from females' sperm-storage organs. This suggests that sperm dumping is a major factor affecting sperm competition in this species, and may have evolved in response to sex-ratio distorters
Optimization of the Penalty Parameter for the Dual-Wind Discontinuous Galerkin Methods on a Prototypical Second Order Pde.
A discontinuous Galerkin (DG) finite-element interior calculus is used as a common framework to describe various DG approximation methods for second- order elliptic problems. The dual-wind discontinuous Galerkin method (DWDG) has been shown to be stable and consistent for a wide range of penalty parameter values, including zero, for second order elliptic problems under certain mesh conditions. In this presentation, we will present the results of numerical experiments on various second order elliptic problems with varying penalty parameters that show the choice of zero for the penalty parameter is an optimal choice for application
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