Classical properties of algebras using a new graph association

We study the relation between algebraic structures and Graph Theory. We have defined five different weighted digraphs associated to a finite dimensional algebra over a field in order to tackle important properties of the associated algebras, mainly the nilpotency and solvability in the case of Leibniz algebras

Una reconsideración del modelo Balassa-Samuelson en la zona euro

En este trabajo analizamos, en un conjunto de países de la eurozona, si se han verificado dos de las premisas en las que se basa el modelo Balassa-Samuelson: la equiparación de los salarios en el sector comerciable y no comerciable, y el cumplimiento de la PPA en el sector expuesto al comercio internacional. En términos generales, nuestros resultados indican que ninguna de las dos hipótesis se ha cumplido en el periodo analizado (1973-2003). Por ello, ampliamos el marco de estudio del modelo y contrastamos si dentro de cada país ha existido una relación de cointegración entre los precios, las productividades y los salarios relativos. Analizamos, además, la existencia de una relación de largo plazo entre los tipos de cambio reales, los tipos de cambio reales en el sector comerciable, y la diferencia de productividades y de salarios relativos con respecto a Alemania. Mientras que los salarios resultan escasamente significativos en ambas relaciones, la evolución de los precios en el sector comerciable recibe un amplio respaldo empírico como variable explicativa de los tipos de cambio reales.tipos de cambio reales, productividad, no comerciables, cointegración

Application of Anodic Stripping Voltammetry to assess sorption performance of an industrial waste entrapped in alginate beads to remove As(V)

AbstractA solid waste material containing Fe(III) and other metal (hydr)oxides produced in a metal surface treatment industry has been investigated for As(V) removal. In order to facilitate sorbent application, 2% of raw material has been entrapped in calcium alginate gel matrix (2% O-CA).An accurate characterization of the sorption on gel beads was undertaken, considering thermodynamic and kinetic aspects. All experiments were carried out at pH 8, since the maximum As(V) sorption was reached between pH 6 and 9. About isotherms, the best fit was obtained considering the Langmuir model and a capacity of 1.9mg/g was achieved. The kinetic profiles evidenced that a quantitative sorption was obtained within 10h. The 2% O-CA beads were also tested for continuous As(V) removal in a fixed bed column. Experiments were performed at constant flow rate, and varying the inlet As(V) concentration. With a view to design an automatic system for As(V) analysis in the outlet flow, the suitability of applying Anodic Stripping Voltammetry was evaluated: the method resulted appropriated to follow the As(V) content in the outlet solutions of columns with metal inlet concentration <1 mg/L.These results suggested that 2% O-CA beads could be a promising sorbent candidate for As(V) removal

Effects of varying the intensity of the primary tones on the amplitudes of Distortion Product Otoacoustic Emissions (OAEdp) in patients with normal hearing

Indexación: Web of Science; ScieloIntroducción: Las emisiones otoacústicas (EOA) son sonidos generados por las células ciliadas externas (CCE). Se ha visto que la generación y registro de las EOA evocadas depende de factores técnicos de evaluación como el nivel de intensidad de los tonos primarios, relación frecuencial entre los tonos, etc. Objetivos: Estudiar el efecto de la variación de la intensidad de los tonos primarios en la amplitud de la respuesta de las EOA producto de distorsión (pd) en individuos con audición normal. Material y método: Se evaluaron 35 individuos a los cuales se les midieron EOApd utilizando diferentes intensidades de tonos primarios: Intensidad baja (I1=50dBSPL e I2=50dBSPL), intensidad media (I1=55dBSPL e I2=65dBSPL) e intensidad alta (I1=70dBSPL e I2=70dBSPL). Resultados: Se observó que para tonos primarios a bajas intensidades (I1=50dBSPL e I2=50dBSPL) existe una disminución tanto en amplitud y presencia de las EOApd, mientras que para tonos primarios a intensidades mayores (I1=55dBSPL e I2=65dBSPL - I1=70dBSPL e I2=70dBSPL) se evidenció un aumento en amplitud y presencia de EOApd en los sujetos estudiados. Conclusión: Se evidencian diferencias estadísticamente significativas en la amplitud de las EOApd al variar la intensidad de los tonos primarios. Por lo cual se puede establecer que las intensidades medias-altas son las más adecuadas para la evaluación de EOApd en sujetos con audición normal.Introduction: Otoacoustic emissions (OAE) are sounds produced by outer hair cells. The generation and recording of evoked OAE depends on technical factors such as level of intensity of primary tones, frequency relationship between the tones, etc. Aim: To study the effect of varying the intensity of primary tones in the amplitude of the response of Distortion Product OAE (DP) in individuals with normal hearing. Material and method: 35 individuals were measured using different intensities OAEdp primary tones: Low Intensity (I1= I2 =50dBSPL 50dBSPL e), Medium Intensity (11= I2 =65dBSPL 55dBSPL e) and High Intensity (I1 =70dBSPL and I2 =70dBSPL). Results: Using Low primary tones (I1 =I2 =50dBSPL 50dBSPL) there is a decrease in amplitude and presence of DPOAE, while for primary tones at higher intensities (I1 and I2 = = 55dBSPL 65dBSPL -11 =70dBSPL and I2 =70dBSPL) an increase in amplitude and presence of OAEdp in subjects with normal hearing was observed . Conclusion: There are statistically significant differences in OAEdp amplitude by varying the intensity of the primary tones. Therefore medium-high intensities are best suited for the evaluation of OAEdp in subjects with normal hearing.http://ref.scielo.org/36dbs

Reflexões sobre a integração pan-amazônica: o papel da Organização do Tratado de Cooperação Amazônica (OTCA) na regulação da água

Este artigo discute a história institucional dos marcos regulatórios para o acesso e uso da água no Brasil, assim como a influência dessa regulação na elaboração de uma gestão integrada dos recursos hídricos na Pan-Amazônia. Os processos que envolvem a regulação da água no Brasil e a confecção do Tratado de Cooperação Amazônica (TCA) são pontos sobre os quais são construídas as reflexões sobre o papel desses formatos institucionais numa gestão integrada e específica da água no contexto amazônico.

Harmonic generation by atomic and nanoparticle precursors in a ZnS laser ablation plasma

Harmonic generation of a driving laser propagating across a laser ablation plasma serves for the diagnosis of multicomponent plumes. Here we study the contribution of atomic and nanoparticle precursors to the generation of coherent ultraviolet and vacuum ultraviolet light as low-order harmonics of the fundamental emission (1064 nm) of a Q-switched Nd:YAG laser in a nanosecond infrared ZnS laser ablation plasma. Odd harmonics from the 3rd up to the 9th order (118.2 nm) have been observed with distinct temporal and spatial characteristics which were determined by varying the delay between the ablation and driving nanosecond pulses and by spatially scanning the plasma with the focused driving beam propagating parallel to the target. At short distances from the target surface (≤1 mm), the harmonic intensity displays two temporal components peaked at around 250 ns and 10 μs. While the early component dies off quickly with increasing harmonic order and vanishes for the 9th order, the late component is notably intense for the 7th harmonic and is still clearly visible for the 9th. Spectral analysis of spontaneous plume emissions help to assign the origin of the two components. While the early plasma component is mainly constituted by neutral Zn atoms, the late component is mostly due to nanoparticles, which upon interaction with the driving laser are subject to breakup and ionization. With the aid of calculations of the phase matching integrals within the perturbative model of optical harmonic generation, these results illustrate how atom and nanoparticle populations, with differing temporal and spatial distributions within the ablation plasma, contribute to the nonlinear medium.Funding has been provided by Ministerio de Economía y Competitividad (MINECO) of Spain under Project CTQ2013-43086-P. I.L-Q., A.B-C. and M.O. thank respectively MINECO, for a FPI fellowship (BES-2011-044738), CSIC, for a JAE-TEC 2010 contract and CSIC for a contract. Fruitful discussions with Dr. Mikel Sanz and Prof. A. Gonzalez-Arroyo are acknowledged.Peer reviewe