Role of electronic correlations in photoionization of NO2 in the vicinity of the 2A1/2B2 conical intersection

We present the first ab initio multi-channel photoionization calculations for NO2 in the vicinity of the 2A1/2B2 conical intersection, for a range of nuclear geometries, using our newly developed set of tools based on the ab initio multichannel R-matrix method. Electronic correlation is included in both the neutral and the scattering states of the molecule via configuration interaction. Configuration mixing is especially important around conical intersections and avoided crossings, both pertinent for NO2, and manifests itself via significant variations in photoelectron angular distributions. The method allows for a balanced and accurate description of the photoionization/photorecombination for a number of different ionic channels in a wide range of photoelectron energies up to 100 eV. Proper account of electron correlations is crucial for interpreting time-resolved signals in photoelectron spectroscopy and high harmonic generation (HHG) from polyatomic molecules

Preparation of Knill-Laflamme-Milburn states using tunable controlled phase gate

A specific class of partially entangled states known as Knill-Laflamme-Milburn states (or KLM states) has been proved to be useful in relation to quantum information processing [Knill et al., Nature 409, 46 (2001)]. Although the usage of such states is widely investigated, considerably less effort has been invested into experimentally accessible preparation schemes. This paper discusses the possibility to employ a tunable controlled phase gate to generate an arbitrary Knill-Laflamme-Milburn state. In the first part, the idea of using the controlled phase gate is explained on the case of two-qubit KLM states. Optimization of the proposed scheme is then discussed for the framework of linear optics. Subsequent generalization of the scheme to arbitrary n-qubit KLM state is derived in the second part of this paper.Comment: 5 pages, 4 figures, accepted in Journal of Physics

Magnetospheric transmission function approach to disentangle primary from secondary cosmic ray fluxes in the penumbra region

[1] The AMS-01 observations (in June 1998, on board the space shuttle orbiter Discovery) have shown the presence of primary (PCR) and secondary (SCR) cosmic rays (most of them protons) at a low Earth orbit (about 400 km altitude). The SCRs are mostly created in interactions with the atmosphere by fast PCRs and can be trapped or become reentrant albedo particles. Some of them seem to be sufficiently energetic to populate the "penumbra region" above the local geomagnetic cutoff rigidity. A backtracking procedure of simulated protons entering the AMS-01 spectrometer has provided the fraction of allowed (and hence forbidden) trajectories of PCRs. Consequently, it has allowed the determination of the so-called transmission function (TF) which is able to describe the properties of the PCR transport from the Earth's magnetopause (i.e., the primary spectrum at 1 AU) to the atmosphere and finally the fluxes of the PCRs in the ten geomagnetic regions for AMS-01 observations. In the penumbra regions, the observed spectra of the AMS-01 geomagnetic regions have been found to be larger than those predicted for the PCRs in the penumbra region by means of the TF, i.e., some SCRs (mainly reentrant albedo protons) are also found to populate the rigidity regions above the local geomagnetic cutoff rigidity. The fraction of the secondary to overall particle flux in the penumbra region increases gradually as the geomagnetic latitude increases

Heat bounds and the blowtorch theorem

We study driven systems with possible population inversion and we give optimal bounds on the relative occupations in terms of released heat. A precise meaning to Landauer's blowtorch theorem (1975) is obtained stating that nonequilibrium occupations are essentially modified by kinetic effects. Towards very low temperatures we apply a Freidlin-Wentzel type analysis for continuous time Markov jump processes. It leads to a definition of dominant states in terms of both heat and escape rates.Comment: 11 pages; v2: minor changes, 1 reference adde

Investigation on the mechanisms govergning the robustness of self-compacting concrete at paste level

In spite of the many advantages, the use of self-compacting concrete (SCC) is currently widely limited to application in precast factories and situations in which external vibration would cause large difficulties. One of the main limitations is the higher sensitivity to small variations in mix proportions, material characteristics and procedures, also referred to as the lower robustness of SCC compared to vibrated concrete. This paper investigates the mechanisms governing the robustness at paste level. Phenomenological aspects are examined for a series of paste mixtures varying in water film thickness and superplasticizer-to-powder ratio. The impact of small variations in the water content on the early-age structural buildup and the robustness of the paste rheology is investigated using rotational and oscillating rheometry

Acute and Chronic Toxicity of Cobalt to Freshwater Organisms: Using a Species Sensitivity Distribution Approach to Establish International Water Quality Standards

Water quality standards for cobalt (Co) have not been developed for the European Union or United States. The objective of the present study was to produce freshwater Co toxicity data that could be used by both the European Union and the United States to develop appropriate regulatory standards (i.e., environmental quality standards or predicted-no-effect concentrations in Europe and ambient water quality criteria or state water quality standards in the United States). Eleven species, including algae, an aquatic plant, and several invertebrate and fish species, were used in the performance of acute and chronic Co toxicity tests. Acute median lethal or median effective concentration (LC50 or EC50) values ranged from 90.1 mu g Co/L for duckweed (Lemna minor) to 157 000 mu g Co/L for midges (Chironomus tentans). Chronic 10% effect concentration (EC10) values ranged from 4.9 mu g Co/L for duckweed to 2170 mu g Co/L for rainbow trout (Oncorhynchus mykiss). Chronic 20% effect concentration (EC20) values ranged from 11.1 mu g Co/L for water flea (Ceriodaphnia dubia) to 2495 mu g Co/L for O. mykiss. Results indicated that invertebrate and algae/plant species are more sensitive to chronic Co exposures than fish. Acute-to-chronic ratios (derived as acute LC50s divided by chronic EC20s) were lowest for juvenile O. mykiss (0.6) and highest for the snail Lymnaea stagnalis (2670). Following the European-based approach and using EC10 values, species sensitivity distributions (SSDs) were developed and a median hazardous concentration for 5% of the organisms of 1.80 mu g Co/L was derived. Chronic EC20 values were used, also in an SSD approach, to derive a US Environmental Protection Agency-style final chronic value of 7.13 mu g Co/L

Development of CliniPup, a Serious Game Aimed at Reducing Perioperative Anxiety and Pain in Children: Mixed Methods Study

Background: Increasing numbers of children undergo ambulatory surgery each year and a significant proportion experiences substantial preoperative anxiety and postoperative pain. The management of perioperative anxiety and pain remains challenging in children and is inadequate, which negatively impacts physical, psychosocial, and economic outcomes. Existing non-pharmacological interventions are costly, time consuming, vary in availability, and lack benefits. Therefore, there is a need for an evidence-based, accessible, non-pharmacological intervention as an adjunct to existing pharmacological alternatives to reduce perioperative anxiety and pain in children undergoing ambulatory surgery. Technology-enabled interventions have been proposed as a method to address the unmet need in this setting. In particular, serious games for health (SGHs) hold unique potential to change health beliefs and behaviors in children. Objective: The objective of this research was to describe the rationale, scientific evidence, design aspects, and features of CliniPup, an SGH aimed at reducing perioperative anxiety and pain in children undergoing ambulatory surgery. Methods: The SERES framework for SGH development was used to create the SGH, CliniPup. In particular, a mixed-methods approach was applied that consisted of a structured literature review supplemented with ethnographic research, such as expert interviews and a time-motion exercise. The resulting scientific evidence base was leveraged to ensure that the resulting SGH was relevant, realistic, and theory-driven. A participatory design approach was applied wherein clinical experts qualitatively reviewed several versions of the SGH and an iterative creative process was used to integrate the applicable feedback. Results: CliniPup, an SGH, was developed to incorporate (1) scientific evidence base from a structured literature review, (2) realistic content collected during ethnographic research such as expert interviews, (3) explicit pedagogical objectives from scientific literature, and (4) game mechanics and user interface design that address key aspects of the evidence. Conclusions: This report details the systematic development of CliniPup, an SGH aimed at reducing perioperative anxiety and pain in children undergoing ambulatory surgery. Clinical experts validated CliniPup’s underlying scientific evidence base and design foundations, suggesting that it was well designed for preliminary evaluation in the target population. An evaluation plan is proposed and briefly described

f(R) actions, cosmic acceleration and local tests of gravity

We study spherically symmetric solutions in f(R) theories and its compatibility with local tests of gravity. We start by clarifying the range of validity of the weak field expansion and show that for many models proposed to address the Dark Energy problem this expansion breaks down in realistic situations. This invalidates the conclusions of several papers that make inappropriate use of this expansion. For the stable models that modify gravity only at small curvatures we find that when the asymptotic background curvature is large we approximately recover the solutions of Einstein gravity through the so-called Chameleon mechanism, as a result of the non-linear dynamics of the extra scalar degree of freedom contained in the metric. In these models one would observe a transition from Einstein to scalar-tensor gravity as the Universe expands and the background curvature diminishes. Assuming an adiabatic evolution we estimate the redshift at which this transition would take place for a source with given mass and radius. We also show that models of dynamical Dark Energy claimed to be compatible with tests of gravity because the mass of the scalar is large in vacuum (e.g. those that also include R^2 corrections in the action), are not viable.Comment: 26 page

Evidence for Localized Moment Picture in Mn-based Heusler Compounds

X-ray absorption spectroscopy (XAS) and X-ray magnetic circular dichroism (XMCD) were used to probe the oxidation state and element specific magnetic moments of Mn in Heusler compounds with different crystallographic structure. The results were compared with theoretical calculations, and it was found that in full Heusler alloys, Mn is metallic (oxidation state near 0) on both sublattices. The magnetic moment is large and localized when octahedrally coordinated by the main group element, consistent with previous theoretical work, and reduced when the main group coordination is tetrahedral. By contrast, in the half Heusler compounds the magnetic moment of the Mn atoms is large and the oxidation state is +1 or +2. The magnetic and electronic properties of Mn in full and half Heusler compounds are strongly dependent on the structure and sublattice, a fact that can be exploited to design new materials.Comment: 15 pages, 4 figure

Dirac Constraint Quantization of a Dilatonic Model of Gravitational Collapse

We present an anomaly-free Dirac constraint quantization of the string-inspired dilatonic gravity (the CGHS model) in an open 2-dimensional spacetime. We show that the quantum theory has the same degrees of freedom as the classical theory; namely, all the modes of the scalar field on an auxiliary flat background, supplemented by a single additional variable corresponding to the primordial component of the black hole mass. The functional Heisenberg equations of motion for these dynamical variables and their canonical conjugates are linear, and they have exactly the same form as the corresponding classical equations. A canonical transformation brings us back to the physical geometry and induces its quantization.Comment: 37 pages, LATEX, no figures, submitted to Physical Review