CRITICAL EXPONENTS and SCALING PROPERTIES FOR THE CHAOTIC DYNAMICS of A PARTICLE IN A TIME-DEPENDENT POTENTIAL BARRIER

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Silver nanoparticles synthesized by thermal reduction of a silver(I)-aspartame complex in inert atmosphere

Synthesis of silver nanoparticles by thermal treatment of a silver-aspartarne complex under inert atmosphere is described. Spherical metallic silver naroparticles with average diameter of 5 +/-2 nm were obtained by thermal treatment of the complex [Ag(C14H17N2O5)] 1/2H(2)O at 185 degrees C. Thermogravimetric and infrared analysis of the product show the occurrence of an ester bond cleavage of the aspartame ligand followed by rearrangement and release of a molecule of formaldehyde (H2CO), which is transformed in two strong reducing molecules, H-2 and CO. For silver reduction, the presence of the formaldehyde molecules seems to be the key process for the metallic nanoparticles fort-nation. The maintenance of the ligand crystalline structure, with the exception of the ester group loss, was noted as essential for nanoparticles formation and size control. The ligand crystalline structure was completely lost at 200 degrees C and particle growth and coalescence were observed above 250 degrees C. (C) 2005 Elsevier B.V. All rights reserved.

A new method to control particle size and particle size distribution of SnO2 nanoparticles for gas sensor applications

The controlled growth of SnO2 nanoparticles for gas sensor applications is reported by these authors. Nb2O5 additive is used to control nucleation and growth of the SnO2 (see Figure), which is synthesized by the polymeric precursor method. Preliminary gas sensing measurements are performed and it is demonstrated that the response time of the Nb2O5-doped SnO2 is faster than that of the undoped material.

Optimisation of a fermentation process for butanol production by particle swarm optimisation (PSO)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Growth of silver nano-particle embedded in tellurite glass: Interaction between localized surface plasmon resonance and Er3+ ions

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Charged particle transverse momentum spectra in pp collisions at √s = 0:9 and 7 TeV

The charged particle transverse momentum (pT) spectra are presented for pp collisions at √s = 0:9 and 7TeV. The data samples were collected with the CMS detector at the LHC and correspond to integrated luminosities of 231 μb-1 and 2.96 pb-1, respectively. Calorimeter-based high-transverse-energy triggers are employed to enhance the statistical reach of the high-pT measurements. The results are compared with leading and next-toleading order QCD and with an empirical scaling of measurements at different collision energies using the scaling variable xT - 2pT=ps over the pT range up to 136 GeV/c. Using a combination of xT scaling and direct interpolation at fixed pT, a reference transverse momentum spectrum at √s = 2:76TeV is constructed, which can be used for studying high-pT particle suppression in the dense QCD medium produced in heavy-ion collisions at that centre-of-mass energy. Copyright CERN.

Multiplicity and transverse momentum dependence of two- and four-particle correlations in pPb and PbPb collisions

Measurements of two- and four-particle angular correlations for charged particles emitted in pPb collisions are presented over a wide range in pseudorapidity and full azimuth. The data, corresponding to an integrated luminosity of approximately 31nb-1, were collected during the 2013 LHC pPb run at a nucleon-nucleon center-of-mass energy of 5.02 TeV by the CMS experiment. The results are compared to 2.76 TeV semi-peripheral PbPb collision data, collected during the 2011 PbPb run, covering a similar range of particle multiplicities. The observed correlations are characterized by the near-side (|δφ|≈0) associated pair yields and the azimuthal anisotropy Fourier harmonics (vn). The second-order (v2) and third-order (v3) anisotropy harmonics are extracted using the two-particle azimuthal correlation technique. A four-particle correlation method is also applied to obtain the value of v2 and further explore the multi-particle nature of the correlations. Both associated pair yields and anisotropy harmonics are studied as a function of particle multiplicity and transverse momentum. The associated pair yields, the four-particle v2, and the v3 become apparent at about the same multiplicity. A remarkable similarity in the v3 signal as a function of multiplicity is observed between the pPb and PbPb systems. Predictions based on the color glass condensate and hydrodynamic models are compared to the experimental results. © 2013 CERN.

Measurement of neutral strange particle production in the underlying event in proton-proton collisions at √s=7 TeV

Measurements are presented of the production of primary KS0 and Λ particles in proton-proton collisions at √s=7 TeV in the region transverse to the leading charged-particle jet in each event. The average multiplicity and average scalar transverse momentum sum of KS0 and Λ particles measured at pseudorapidities |η|<2 rise with increasing charged-particle jet pT in the range 1-10 GeV/c and saturate in the region 10-50 GeV/c. The rise and saturation of the strange-particle yields and transverse momentum sums in the underlying event are similar to those observed for inclusive charged particles, which confirms the impact-parameter picture of multiple parton interactions. The results are compared to recent tunes of the pythia Monte Carlo event generator. The pythia simulations underestimate the data by 15%-30% for KS0 mesons and by about 50% for Λ baryons, a deficit similar to that observed for the inclusive strange-particle production in non-single-diffractive proton-proton collisions. The constant strange- to charged-particle activity ratios with respect to the leading jet pT and similar trends for mesons and baryons indicate that the multiparton-interaction dynamics is decoupled from parton hadronization, which occurs at a later stage. © 2013 CERN, for the CMS Collaboration Published by the American Physical Society under the terms of the Creative Commons Attribution 3.0 License. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.

Jet and underlying event properties as a function of charged-particle multiplicity in proton-proton collisions at root s=7 TeV

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Moderating effect of ammonia on particle growth and stability of quasi-monodisperse silver nanoparticles synthesized by the Turkevich method

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Long-range two-particle correlations of strange hadrons with charged particles in pPb and PbPb collisions at LHC energies

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Dynamics of a charged particle in a dissipative Fermi-Ulam model

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Particle Competition and Cooperation in Networks for Semi-Supervised Learning

Semi-supervised learning is one of the important topics in machine learning, concerning with pattern classification where only a small subset of data is labeled. In this paper, a new network-based (or graph-based) semi-supervised classification model is proposed. It employs a combined random-greedy walk of particles, with competition and cooperation mechanisms, to propagate class labels to the whole network. Due to the competition mechanism, the proposed model has a local label spreading fashion, i.e., each particle only visits a portion of nodes potentially belonging to it, while it is not allowed to visit those nodes definitely occupied by particles of other classes. In this way, a "divide-and-conquer" effect is naturally embedded in the model. As a result, the proposed model can achieve a good classification rate while exhibiting low computational complexity order in comparison to other network-based semi-supervised algorithms. Computer simulations carried out for synthetic and real-world data sets provide a numeric quantification of the performance of the method.