Emission characteristics and dynamics of species in a TEA-CO2 laser-produced CaO plasma

IBER2015, Aveiro, Portugal, 6th to 9th September of 2015; http://iber2015.web.ua.pt/Laser-produced plasmas (LPPs) are nowadays a topic of great interest in fundamental and applied areas of Physics such as the manufacture of thin films by pulsed laser deposition, spectrochemical analysis through laser-induced breakdown spectroscopy (LIBS) [1-3], production of nanoparticles, etc. Laser-target interaction involves complex processes and the analysis of LPPs can be very difficult considering its transient nature as well as large variations in plasma properties with space and time. In this work, we investigated the optical emission and imaging features of plasmas produced by a high-power laser [transversely excited atmospheric (TEA) CO2 and Nd: YAG] pulses on calcium oxide, CaO (Fig. 1). The analyzed plasma emission shows electronically excited neutral Ca and O atoms, ionized Ca+, Ca2+, O+, O2+ and O3+ species and molecular bands of CaOH (A2Π-X2Σ+, B2Σ+-X2Σ+ and D2Σ+- A2Π) (Fig. 2). We focus our attention on the dynamics of the CaO LPP species expanding into vacuum. In conventional one dimensional optical emission spectroscopy (OES) studies (Fig. 3), various plasma-plume segments were selected along the plume expansion axis and averaged over line-of-sight. The temporal evolution of spectral atomic and ionic line intensities at a constant distance from the target has been used to build optical timeof-flight profiles (TOF) (Fig. 4a). The velocity distributions that are derived from these TOF distributions are shown in Fig. 4b. Fig. 5 gives the time evolution of electron density and its first derivative with respect to time by setting the gate width of the intensifier at 0.1 μs. This setup was easily transformed to a two-dimensional (2D) OES setup by inserting a Dove prism between the focusing and collimating lenses (Fig. 1). Time and space-resolved 2D OES plasma profiles (Figs. 6 and 7) were recorded as a function of emitted wavelength and distance from the target. Fast side-on views of the plume expansion were made by recording overall visible emission from the plasma (Fig. 8). Emission intensities of axial area at 0.1 Pa as a function of the delay are given in Fig. 9a. The dynamic of the plume front was compared with the shock wave expansion model (Fig. 9b).Peer Reviewe

Time- and space-resolved spectroscopic characterization of laser-induced swine muscle tissue plasma

10 págs.; 12 figs.; 1 tab.The spatial-temporal evolution of muscle tissue sample plasma induced by a high-power transversely excited atmospheric (TEA) CO2 pulsed laser at vacuum conditions (0.1–0.01 Pa) has been investigated using high-resolution optical emission spectroscopy (OES) and imaging methods. The induced plasma shows mainly electronically excited neutral Na, K, C, Mg, H, Ca, N and O atoms, ionized C+, C2 +, C3 +, Mg+, Mg2 +, N+, N2 +, Ca+, O+ and O2 + species and molecular band systems of CN(B2Σ+–X2Σ+), C2(d3Πg–a3Πu), CH(B2Σ−–X2Π; A2Δ–X2Π), NH(A3Π–X3Σ−), OH(A2Σ+–X2 Σ+), and CaOH(B2Σ+–X2Σ+; A2Π–X2Σ+). Time-resolved two-dimensional emission spectroscopy is used to study the expanded distribution of different species ejected during ablation. Spatial and temporal variations of different atoms and ionic excited species are reported. Plasma parameters such as electron density and temperature were measured from the spatio-temporal analysis of different species. Average velocities of some plasma species were estimated. © 2015 Elsevier B.V. All rights reserved.We gratefully acknowledge the support received in part by the DGICYT (Spain) Project MICINN: CTQ2013-43086-P for this research. The authors wish to thank the Geomaterials2 Program (S2013/MIT 2914) supported by the Comunidad de Madrid and EU structural and cohesion funds (FSE and FEDER).Peer reviewe

Quantum Measurements and the kappa--Poincare Group

The possible description of the vacuum of quantum gravity through the so called kappa--Poincare group is analyzed considering some of the consequences of this symmetry in the path integral formulation of nonrelativistic quantum theory. This study is carried out with two cases, firstly, a free particle, and finally, the situation of a particle immersed in a homogeneous gravitational field. It will be shown that the kappa--Poincare group implies the loss of some of the basic properties associated to Feynman's path integral. For instance, loss of the group characteristic related to the time dependence of the evolution operator, or the breakdown of the composition law for amplitudes of events occurring successively in time. Additionally some similarities between the present idea and the so called restricted path integral formalism will be underlined. These analogies advocate the claim that if the kappa--Poincare group contains some of the physical information of the quantum gravity vacuum, then this vacuum could entail decoherence. This last result will also allow us to consider the possibility of analyzing the continuous measurement problem of quantum theory from a group--theoretical point of view, but now taking into account the kappa--Poincare symmetries.Comment: Accepted in General Relativity and Gravitation. Dedicated to Alberto Garcia on the occasion of his 60th. birthda

Feedback methods for inverse simulation of dynamic models for engineering systems applications

Inverse simulation is a form of inverse modelling in which computer simulation methods are used to find the time histories of input variables that, for a given model, match a set of required output responses. Conventional inverse simulation methods for dynamic models are computationally intensive and can present difficulties for high-speed applications. This paper includes a review of established methods of inverse simulation,giving some emphasis to iterative techniques that were first developed for aeronautical applications. It goes on to discuss the application of a different approach which is based on feedback principles. This feedback method is suitable for a wide range of linear and nonlinear dynamic models and involves two distinct stages. The first stage involves design of a feedback loop around the given simulation model and, in the second stage, that closed-loop system is used for inversion of the model. Issues of robustness within closed-loop systems used in inverse simulation are not significant as there are no plant uncertainties or external disturbances. Thus the process is simpler than that required for the development of a control system of equivalent complexity. Engineering applications of this feedback approach to inverse simulation are described through case studies that put particular emphasis on nonlinear and multi-input multi-output models

Automated generation of program translation and verification tools using annotated grammars

Automatically generating program translators from source and target language specifications is a non-trivial problem. In this paper we focus on the problem of automating the process of building translators between operations languages, a family of DSLs used to program satellite operations procedures. We exploit their similarities to semi-automatically build transformation tools between these DSLs. The input to our method is a collection of annotated context-free grammars. To simplify the overall translation process even more, we also propose an intermediate representation common to all operations languages. Finally, we discuss how to enrich our annotated grammars model with more advanced semantic annotations to provide a verification system for the translation process. We validate our approach by semi-automatically deriving translators between some real world operations languages, using the prototype tool which we implemented for that purpose

Theoretical study of the absorption spectra of the sodium dimer

Absorption of radiation from the sodium dimer molecular states correlating to Na(3s)-Na(3s) is investigated theoretically. Vibrational bound and continuum transitions from the singlet X Sigma-g+ state to the first excited singlet A Sigma-u+ and singlet B Pi-u states and from the triplet a Sigma-u+ state to the first excited triplet b Sigma-g+ and triplet c Pi-g states are studied quantum-mechanically. Theoretical and experimental data are used to characterize the molecular properties taking advantage of knowledge recently obtained from ab initio calculations, spectroscopy, and ultra-cold atom collision studies. The quantum-mechanical calculations are carried out for temperatures in the range from 500 to 3000 K and are compared with previous calculations and measurements where available.Comment: 19 pages, 8 figures, revtex, eps

Caracterización morfológica, cultural y molecular de aislados de Macrophomina phaseolina de España y Argentina

Macrophomina phaseolina es un hongo de suelo necrotrófico, agente causal de la podredumbre carbonosa de raíz y corona que afecta a más de 500 especies de plantas. El objetivo del presente trabajo fue caracterizar morfológica, cultural y molecularmente 32 aislados de M. phaseolina procedentes de España y Argentina, obtenidos de diferentes hospedantes: fresa, girasol, soja, judía, arándano y cáñamo. La caracterización se realizó a partir de los cultivos puros y se determinó la resistencia a clorato y el crecimiento a distintas temperaturas y pH. Para la caracterización molecular se extrajo ADN, se amplificaron 4 regiones del mismo y se realizó un árbol filogenético. En la caracterización según resistencia a clorato, no se vio un patrón de asociación con respecto al país o cultivo de procedencia de los aislados. Los 3 aislados más sensibles al mismo provenían de fresa, arándano y girasol. La temperatura media óptima de crecimiento estuvo entre 30 y 35ºC. El único aislado que presentó una temperatura óptima de crecimiento menor fue el procedente de judía. El rango de pH medio óptimo de crecimiento de los aislados estuvo entre 5 y 6. Hubo 3 aislados que presentaron pH óptimo de 4 y uno de 8. En cuanto a la caracterización molecular, se encontró muy poca variabilidad genética entre los aislados, sin observarse agrupación por país o cultivo de procedencia en el árbol filogenético. Todos fueron identificados como Macrophomina phaseolina salvo el aislado de judía, que se agrupó junto con los aislados de Macropomina pseudophaseolina. La gran variabilidad obtenida en los parámetros analizados dificulta la clasificación de este hongo en subespecies.EEA FamailláFil: Viejobueno, Josefina. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Famaillá; ArgentinaFil: Medina, J.J. Instituto de Investigación y Formación Agraria y Pesquera. Centro IFAPA Huelva; EspañaFil: Aguado, A. Instituto de Investigación y Formación Agraria y Pesquera; EspañaFil: Camacho, María. Instituto de Investigación y Formación Agraria y Pesquera; EspañaFil: Camacho-Sánchez, M. Centro de Investigação em Biodiversidade e Recursos Genéticos; PortugalFil: Salazar, Sergio Miguel. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Famaillá; ArgentinaFil: Salazar, Sergio Miguel. Universidad Nacional de Tucumán. Facultad de Agronomía y Zootecnia; ArgentinaFil: Santos, Berta de los. Instituto de Investigación y Formación Agraria y Pesquera; Españ

Verrucous carcinoma of the oral mucosa: an epidemiological and follow-up study of patients treated with surgery in 5 last years

Introduction: Oral Verrucous Carcinoma (OVC) is described apart of the Squamous Cell Carcinoma (SCC) due to its specific properties. The objective of our study is to show our series of cases of OVC and to compare with the SCC in terms of clinical manifestations, epidemiology, histopathology, treatment and follow-up. Material and Methods: This is a retrospective study of all the OVC treated in our department between January- 2007 and December-2011. The analyzed variables were sex, age, localization in the oral cavity, histopathology, number of biopsies needed to diagnose OVC, TNM classification, treatment and recurrences during follow-up. Results: Our sample was composed by n=14 patients, 57% female, with a mean age of 69.14 years. The most com - mon localization was buccal mucosa (n=5). Seven patients were diagnosed of OVC with the first biopsy. TNM classification was: pT1: 7 patients, pT2: 3 patients, pT3: 3 patients, pT4: 1 patient. No cervical metastases were observed either in cervical neck dissection or during the follow-up of the patients. The treatment was surgery with clinical resection margins up to 1 cm in all cases, followed by radiotherapy in selected cases. Only n=1 patient (7.69%) presented a recurrence after 34 months of follow-up. The overall survival rate was 92.85%. Conclusions: In our population, OVC represents the 6.16% of all oral cavity and oropharynx cancer, and is more frequent in female patients above 70 years old. It uses to rise over a previous lesion, and usually affects the buccal mucosa. In patients with high suspicious lesions, more than one biopsy may be needed to diagnose OVC. No pa - tient showed cervical dissemination. In our experience, treatment based on local resection, without cervical neck dissection, could be a good option for these patients

Scaling Tests of the Cross Section for Deeply Virtual Compton Scattering

We present the first measurements of the \vec{e}p->epg cross section in the deeply virtual Compton scattering (DVCS) regime and the valence quark region. The Q^2 dependence (from 1.5 to 2.3 GeV^2) of the helicity-dependent cross section indicates the twist-2 dominance of DVCS, proving that generalized parton distributions (GPDs) are accessible to experiment at moderate Q^2. The helicity-independent cross section is also measured at Q^2=2.3 GeV^2. We present the first model-independent measurement of linear combinations of GPDs and GPD integrals up to the twist-3 approximation.Comment: 5 pages, 4 figures, 2 tables. Text shortened for publication. References added. One figure remove

Exclusive Neutral Pion Electroproduction in the Deeply Virtual Regime

We present measurements of the ep->ep pi^0 cross section extracted at two values of four-momentum transfer Q^2=1.9 GeV^2 and Q^2=2.3 GeV^2 at Jefferson Lab Hall A. The kinematic range allows to study the evolution of the extracted hadronic tensor as a function of Q^2 and W. Results will be confronted with Regge inspired calculations and GPD predictions. An intepretation of our data within the framework of semi-inclusive deep inelastic scattering has also been attempted