pinecone/core-2020-05-10-deduplication huggingface dataset:
Global vs local energy dissipation: the energy cycle of the turbulent
  von K\'arm\'an flow

In this paper, we investigate the relations between global and local energy
transfers in a turbulent von K\'arm\'an flow. The goal is to understand how and
where energy is dissipated in such a flow and to reconstruct the energy cycle
in an experimental device where local as well as global quantities can be
measured. We use PIV measurements and we model the Reynolds stress tensor to
take subgrid scales into account. This procedure involves a free parameter that
is calibrated using angular momentum balance. We then estimate the local and
global mean injected and dissipated power for several types of impellers, for
various Reynolds numbers and for various flow topologies. These PIV estimates
are then compared with direct injected power estimates provided by torque
measurements at the impellers. The agreement between PIV estimates and direct
measurements depends on the flow topology. In symmetric situations, we are able
to capture up to 90% of the actual global energy dissipation rate. However, our
results become increasingly inaccurate as the shear layer responsible for most
of the dissipation approaches one of the impellers, and cannot be resolved by
our PIV set-up. Finally, we show that a very good agreement between PIV
estimates and direct measurements is obtained using a new method based on the
work of Duchon and Robert which generalizes the K\'arm\'an-Howarth equation to
nonisotropic, nonhomogeneous flows. This method provides parameter-free
estimates of the energy dissipation rate as long as the smallest resolved scale
lies in the inertial range. These results are used to evidence a well-defined
stationary energy cycle within the flow in which most of the energy is injected
at the top and bottom impellers, and dissipated within the shear layer. The
influence of the mean flow geometry and the Reynolds number on this energy
cycle is studied for a wide range of parameters
Developing pervasive multiagent systems with nature-inspired co-ordination

Pervasive computing systems can be modelled effectively as populations of interacting autonomous components. The key challenge to realizing such models is in getting separately-specified and -developed sub-systems to discover and interoperate with each other in an open and extensible way, supported by appropriate middleware services. In this paper, we argue that nature-inspired coordination models offer a promising way of addressing this challenge. We first frame the various dimensions along which nature-inspired coordination models can be defined, and survey the most relevant proposals in the area. We describe the nature-inspired coordination model developed within the SAPERE project as a synthesis of existing approaches, and show how it can effectively support the multifold requirements of modern and emerging pervasive services. We conclude by identifying what we think are the open research challenges in this area, and identify some research directions that we believe are promising.PostprintPeer reviewe
Nuclear modification factor for charged pions and protons at forward rapidity in central Au plus Au collisions at 200 GeV

We present spectra of charged pions and protons in 0–10% central Au + Au collisions at View the MathML sourcesNN=200 GeV at mid-rapidity (y=0y=0) and forward pseudorapidity (η=2.2η=2.2) measured with the BRAHMS experiment at RHIC. The spectra are compared to spectra from p+pp+p collisions at the same energy scaled by the number of binary collisions. The resulting nuclear modification factors for central Au + Au collisions at both y=0y=0 and η=2.2η=2.2 exhibit suppression for charged pions but not for (anti-) protons at intermediate pTpT. The View the MathML sourcep¯/π− ratios have been measured up to pT∼3 GeV/cpT∼3 GeV/c at the two rapidities and the results indicate that a significant fraction of the charged hadrons produced at intermediate pTpT range are (anti-) protons at both mid-rapidity and η=2.2η=2.2
Measurement of the total cross section from elastic scattering in pp collisions at √s=7TeV with the ATLAS detector

A measurement of the total pp cross section at the LHC at √s = 7 TeV is presented. In a special run with high-β* beam optics, an integrated luminosity of 80 μb−1 was accumulated in order to measure the differential elastic cross section as a function of the Mandelstam momentum transfer variable t . The measurement is performed with the ALFA sub-detector of ATLAS. Using a fit to the differential elastic cross section in the |t | range from 0.01 GeV2 to 0.1 GeV2 to extrapolate to |t | →0, the total cross section, σtot(pp→X), is measured via the optical theorem to be: \ud
σtot(pp→X) = 95.35± 0.38 (stat.)± 1.25 (exp.)± 0.37 (extr.) mb, \ud
where the first error is statistical, the second accounts for all experimental systematic uncertainties and the last is related to uncertainties in the extrapolation to |t | → 0. In addition, the slope of the elastic cross section at small |t | is determined to be B = 19.73 ±0.14 (stat.) ±0.26 (syst.) GeV−2
Threshold resummation at N3LL accuracy and soft-virtual cross sections at N3LO

We consider QCD radiative corrections to the production of colorless high-mass systems in hadron collisions. We show that the recent computation of the soft-virtual corrections to Higgs boson production at N3LO [1] together with the universality structure of soft-gluon emission can be exploited to extract the general expression of the hard-virtual coefficient that contributes to threshold resummation at N3LL accuracy. The hard-virtual coefficient is directly related to the process-dependent virtual amplitude through a universal (process-independent) factorization formula that we explicitly evaluate up to three-loop order. As an application, we present the explicit expression of the soft-virtual N3LO corrections for the production of an arbitrary colorless system. In the case of the Drell-Yan process, we confirm the recent result of Ref. [2]
Measurement of polarization amplitudes and CP asymmetries in $B^0 \to \phi K^*(892)^0$

An angular analysis of the decay $B^0 \to \phi K^*(892)^0$ is reported based on a $pp$ collision data sample, corresponding to an integrated luminosity of 1.0 fb$^{-1}$, collected at a centre-of-mass energy of $\sqrt{s} = 7$ TeV with the LHCb detector. The P-wave amplitudes and phases are measured with a greater precision than by previous experiments, and confirm about equal amounts of longitudinal and transverse polarization. The S-wave $K^+ \pi^-$ and $K^+K^-$ contributions are taken into account and found to be significant. A comparison of the $B^0 \to \phi K^*(892)^0$ and $\bar{B}^0 \to \phi \bar{K}^*(892)^0$ results shows no evidence for direct CP violation in the rate asymmetry, in the triple-product asymmetries or in the polarization amplitudes and phases
Empirical investigation on the dependence of TCP downstream throughput on SNR in an IEEE80 2.11b WLAN system

The dependence of TCP downstream throughput (TCPdownT) on signal to noise ratio (SNR) in an IEEE802.11b WLAN system was investigated in various environments and varieties of QoS trafﬁc. TCPdownT was measured for various SNR observed. An Infrastructure based IEEE802.11b WLAN system having networked computers on which measurement software were installed, was set up consecutively in various environments (open corridor, small ofﬁces with block walls and plaster boards and free space). Empirical models describing TCPdownT against SNR for different signal ranges (all ranges of signals, strong signals only, grey signals only and weak signals only) were statistically generated and validated. As the SNR values changed from high (strong signals) through low (grey signals) to very low (weak signals), our results show a strong dependence of TCPdownT on the received SNR. Our models showed lower RMS errors when compared with other similar models. We observed RMS errors of 0.6734791 Mbps, 0.472209 Mbps, 0.9111563 Mbps and 0.5764460 Mbps for general (all SNR) model, strong signals model, grey signals model and Weak signals model respectively. Our models will provide researchers and WLAN systems users with a tool to estimate the TCP downstream throughput in a real network in various environments by monitoring the received SNR
Higgs inflation from new Kähler potential

We introduce a new class of models of Higgs inflation using the superconformal approach to supergravity by modifying the Kähler geometry. Using the above-mentioned mechanism, we construct a phenomenological functional form of a new Kähler potential followed by construction of various types of models which are characterized by a superconformal symmetry breaking parameter χ . Depending on the numerical values of χ we classify the proposed models into three categories. Models with minimal coupling are identified by <math altimg="si1.gif" xmlns="http://www.w3.org/1998/Math/MathML"><mi>χ</mi><mo>=</mo><mo>±</mo><mfrac><mn>2</mn><mn>3</mn></mfrac></math> branch which are made up of shift symmetry preserving flat directions. We also propose various other models by introducing a non-minimal coupling of the inflaton field to gravity described by <math altimg="si2.gif" xmlns="http://www.w3.org/1998/Math/MathML"><mi>χ</mi><mo>≠</mo><mfrac><mn>2</mn><mn>3</mn></mfrac></math> branch. We employ all these proposed models to study the inflationary paradigm by estimating the major cosmological observables and confront them with recent observational data from WMAP9 along with other complementary data sets, as well as independently with PLANCK. We also mention an allowed range of non-minimal couplings and the Yukawa type of couplings appearing in the proposed models used for cosmological parameter estimation
Next-to-leading order QCD corrections to di-photon production in association with up to three jets at the Large Hadron Collider

We present the computation of next-to-leading order (NLO) QCD corrections to di-photon production in association with two or three hard jets in pp collisions at a centre-of-mass energy of 8 TeV. The inclusion of NLO corrections is shown to substantially reduce the theoretical uncertainties estimated from scale variations on total cross section predictions. We study a range of differential distributions relevant for phenomenological studies of photon pair production in association with jets at the LHC. Using an efficient computational set-up we performed a detailed study of uncertainties due to parton distribution functions. The computation of the virtual corrections is performed using new features of the C++ library NJ et
Matching 3d N =2 vortices and monopole operators

In earlier work with N. Seiberg, we explored connections between monopole operators, the Coulomb branch modulus, and vortices for 3d N $$ \mathcal{N} $$ =2 supersymmetric, U(1) k Chern-Simons matter theories. We here extend the monopole / vortex matching analysis, to theories with general matter electric charges. We verify, for general matter content, that the spin and other quantum numbers of the chiral monopole operators match those of corresponding BPS vortex states, at the top and bottom of the tower associated with quantizing the vortices’ Fermion zero modes. There are associated subtleties from non-normalizable Fermi zero modes, which contribute non-trivially to the BPS vortex spectrum and monopole operator matching; a proposed interpretation is further discussed here
β+ /EC decay rates of deformed neutron-deficient nuclei in the deformed QRPA with realistic interactions

The weak-decay ( β+ and EC) rates of neutron-deficient Kr, Sr, Zr, and Mo isotopes are investigated within the deformed quasiparticle random-phase approximation with realistic nucleon–nucleon interactions. The particle–particle and particle–hole channels of residual interactions are handled in large single-particle model spaces, based on the Brückner G -matrix with charge-dependent Bonn nucleon–nucleon forces. Contributions from allowed Gamow–Teller and Fermi transitions as well as first-forbidden transitions are calculated. The calculated half-lives show good agreement with the experimental data over a wide range of magnitude, from 10−2 to 107 s . Moreover, predictions of β -decay half-lives are made for some extremely proton-rich isotopes, which could be useful for future experiments
On effective Kähler potential in N=2 , d=3 SQED

We compute the two-loop effective Kähler potential in three-dimensional N=2 supersymmetric electrodynamics with Chern–Simons kinetic term for the gauge superfield. The effective action is constructed on the base of background field method with one parametric family of gauges. In such an approach, the quadratic part of quantum action mixes the gauge and matter quantum superfields yielding the complications in the computations of the loop supergraphs. To avoid this obstacle and preserve dependence on the gauge parameter we make a non-local change of quantum matter superfields after which the propagator is diagonalized, however the new vertices have appeared. We fix the suitable background and develop the efficient procedure of calculating the two-loop supergraphs with the new vertices. We compute the divergent and finite parts of the superfield effective action, find the two-loop effective Kähler potential and show that it does not depend on the gauge parameter
Universal features of Lifshitz Green’s functions from holography

We examine the behavior of the retarded Green’s function in theories with Lifshitz scaling symmetry, both through dual gravitational models and a direct field theory approach. In contrast with the case of a relativistic CFT, where the Green’s function is fixed (up to normalization) by symmetry, the generic Lifshitz Green’s function can a priori depend on an arbitrary function G ω ^ $$ \mathcal{G}\left(\widehat{\omega}\right) $$ , where ω ^ = ω / k → z $$ \widehat{\omega}=\omega /{\left|\overrightarrow{k}\right|}^z $$ is the scale-invariant ratio of frequency to wavenumber, with dynamical exponent z . Nevertheless, we demonstrate that the imaginary part of the retarded Green’s function (i.e. the spectral function) of scalar operators is exponentially suppressed in a window of frequencies near zero. This behavior is universal in all Lifshitz theories without additional constraining symmetries. On the gravity side, this result is robust against higher derivative corrections, while on the field theory side we present two z = 2 examples where the exponential suppression arises from summing the perturbative expansion to infinite order
Development of an integrated methodology for the sustainableenvironmental and socio-economic management of river ecosystems

The development of theWater Framework Directive aimed to establish an integrated framework of water management at European level. This framework revolves around inland surface waters, transitional waters, coastal waters and groundwaters. In the process of achieving the environment and ecological objectives set fromthe Directive, the role of economics is put in the core of thewatermanagement. An important feature of the Directive is the recovery of total economic cost of water services by all users. The total cost of water services can be disaggregated into environmental, financial and resource costs. Another important aspect of the directive is the identification of major drivers and pressures in each River Basin District.We describe a methodology that is aiming to achieve sustainable and environmental and socioeconomic management of freshwater ecosystem services. The EcosystemServices Approach is in the core of the suggested methodology for the implementation of a more sustainable and efficientwater management. This approach consists of the following three steps: (i) socio-economic characterization of the River Basin area, (ii) assessment of the current recovery of water use cost, and (iii) identification and suggestion of appropriate programs of measures for sustainablewatermanagement over space and time. Thismethodology is consistent with a) the economic principles adopted explicitly by theWater Framework Directive (WFD), b) the three-step WFD implementation approach adopted in the WATECO document, c) the Ecosystem Services Approach to valuing freshwater goods and services to humans. Furthermore, we analyze how the effects ofmultiple stressors and socio-economic development can be quantified in the context of freshwater resources management.We also attempt to estimate the value of four ecosystemservices using the benefit transfer approach for the Anglian River Basin, which showed the significance of such services
Local oxidation of silicon surfaces by dynamic force microscopy: Nanofabrication and water bridge formation

3 pages, 4 figures.Local oxidation of silicon surfaces by atomic force microscopy is a very promising lithographic approach at nanometer scale. Here, we study the reproducibility, voltage dependence, and kinetics when the oxidation is performed by dynamic force microscopy modes. It is demonstrated that during the oxidation, tip and sample are separated by a gap of a few nanometers. The existence of a gap increases considerably the effective tip lifetime for performing lithography. A threshold voltage between the tip and the sample must be applied in order to begin the oxidation. The existence of a threshold voltage is attributed to the formation of a water bridge between tip and sample. It is also found that the oxidation kinetics is independent of the force microscopy mode used (contact or noncontact).This work was supported financially\ud
by the Commission of the European Communities,\ud
ESPRIT Project 22955 (LASMEDS).Peer reviewe
Volcanomagnetic Evidence of the Magmatic Intrusion on 13th May 2008

During the onset of 2008 volcanic crisis at Mt Etna, the near-real time magnetic data provided a continuous updating of the volcano activity state on the northern flank. On the morning of 13th May 2008, significant local magnetic field changes marked the resumption of the eruptive activity characterized by the opening of a fracture field on the northern flank, and an eruptive fissure in the Valle del Bove. In agreement with the northward propagation of seismic events, magnetic signals at 5 stations in the summit area revealed a nearly NNW-SSE oriented magmatic intrusion, which started at about 9:00 GMT, propagated northward for about 2 km, and stopped at 14:00 GMT before reaching the North-East Rift. Magnetic variations, with amplitude ranging between 1.8 nT and -6.5 nT, are consistent with those calculated from piezomagnetic models, where stress-induced changes in rock magnetization are produced by the magmatic intrusion
Cooling and manipulation of a levitated nanoparticle with an optical fiber trap

Accurate delivery of small targets in high vacuum is a pivotal task in many branches of science and technology. Beyond the different strategies developed for atoms, proteins, macroscopic clusters, and pellets, the manipulation of neutral particles over macroscopic distances still poses a formidable challenge. Here, we report an approach based on a mobile optical trap operated under feedback control that enables cooling and long range 3D manipulation of a silica nanoparticle in high vacuum. We apply this technique to load a single nanoparticle into a high-finesse optical cavity through a load-lock vacuum system. We foresee our scheme to benefit the field of optomechanics with levitating nano-objects as well as ultrasensitive detection and monitoring.Peer ReviewedPostprint (published version
Climatic changes and social transformations in the Near East and North Africa during the 'long 4th millennium BC: A comparative study of environmental and archaeological evidence

This paper explores the possible links between rapid climate change (RCC) and social change in the Near East and surrounding regions (Anatolia, central Syria, southern Israel, Mesopotamia, Cyprus and eastern and central Sahara) during the ‘long’ 4th millennium (∼4500–3000) BC. Twenty terrestrial and 20 marine climate proxies are used to identify long-term trends in humidity involving transitions from humid to arid conditions and vice versa. The frequency distribution of episodes of relative aridity across these records is calculated for the period 6300–2000 BC, so that the results may be interpreted in the context of the established arid episodes associated with RCC around 6200 and 2200 BC (the 8.2 and 4.2 kyr events). We identify two distinct episodes of heightened aridity in the early-mid 4th, and late 4th millennium BC. These episodes cluster strongly at 3600–3700 and 3100–3300 BC. There is also evidence of localised aridity spikes in the 5th and 6th millennia BC. These results are used as context for the interpretation of regional and local archaeological records with a particular focus on case studies from western Syria, the middle Euphrates, southern Israel and Cyprus. Interpretation of the records involves the construction of plausible narratives of human–-climate interaction informed by concepts of adaptation and resilience from the literature on contemporary (i.e. 21st century) climate change and adaptation. The results are presented alongside well-documented examples of climatically-influenced societal change in the central and eastern Sahara, where detailed geomorphological studies of ancient environments have been undertaken in tandem with archaeological research. While the narratives for the Near East and Eastern Mediterranean remain somewhat speculative, the use of resilience and adaptation frameworks allows for a more nuanced treatment of human–-climate interactions and recognises the diversity and context-specificity of human responses to climatic and environmental change. Our results demonstrate that there is a need for more local environmental data to be collected ‘at source’ during archaeological excavations
Heritage, health and place:The legacies of local community-based heritage conservation on social wellbeing

Geographies of health challenge researchers to attend to the positive effects of occupying, creating and using all kinds of spaces, including 'green space' and more recently 'blue space'. Attention to the spaces of community-based heritage conservation has largely gone unexplored within the health geography literature. This paper examines the personal motivations and impacts associated with people's growing interest in local heritage groups. It draws on questionnaires and interviews from a recent study with such groups and a conceptual mapping of their routes and flows. The findings reveal a rich array of positive benefits on the participants' social wellbeing with/in the community. These include personal enrichment, social learning, satisfaction from sharing the heritage products with others, and less anxiety about the present. These positive effects were tempered by needing to face and overcome challenging effects associated with running the projects thus opening up an extension to health-enabling spaces debates