Optical Pumping of TeH+: Implications for the Search for Varying mp/me

Molecular overtone transitions provide optical frequency transitions sensitive to variation in the proton-to-electron mass ratio ($\mu\equiv m_p/m_e$). However, robust molecular state preparation presents a challenge critical for achieving high precision. Here, we characterize infrared and optical-frequency broadband laser cooling schemes for TeH$^+$, a species with multiple electronic transitions amenable to sustained laser control. Using rate equations to simulate laser cooling population dynamics, we estimate the fractional sensitivity to $\mu$ attainable using TeH$^+$. We find that laser cooling of TeH$^+$ can lead to significant improvements on current $\mu$ variation limits

Geomorphological responses due to storm wave events at praia da barra, garopaba – Santa Catarina state, southern Brazil

his work presents a beach morphodynamics analysis for Praia da Barra, located in the municipality of Garopaba, Santa Catarina State, Brazil. Praia da Barra has sectors with a natural beach/dune system and sectors where the foredune is completely anthropized. In 2017, during autumn and winter, eight storm wave events reached the study area, resulting in a coastline retreat and infrastructure damages at the site and along the southern Brazilian coastal zone. This work applied two methodologies to study the impacts of storm waves at the study area, 1) Four photogrammetric surveys using UAV high-resolution Orthophoto and DEMs for monitoring geomorphological changes at the site, before and after storm wave events in 2017; and 2) wave simulation using the SMC-Brazil platform to assess wave and current patterns from three main wave directions scenarios. The authors integrated the results from both methodologies to understand the behavior of Praia da Barra's beach/dune system when attacked by storm wave events. The authors identified erosive hot spots at Praia da Barra that are concentrated at the central sector of the beach, which presents more anthropization. While the northern and southern sectors present a vegetated and well-developed foredune system, they also presented a higher resilience against the storm events that hit Praia da Barra during the autumn and winter seasons of 2017

Oxidation of single-walled carbon nanotubes under controlled chemical conditions

Single-walled carbon nanotubes are oxidized in the presence of H2SO4/HNO3 mixtures containing distinct concentrations of the nitronium ion, [NO2+]. The spectroscopic analyses of the final samples suggest a higher structural disorder in the oxidized systems with increasing [NO2+]. This is due to a considerable oxygen amount on the tube surface, reaching up to 30%, depending on the reaction time and [NO2+]. Interestingly, if long reaction time is considered, the oxygen amount on the tube surface is maximum for low [NO2+] and reduces slightly for larger [NO2+]. On the other hand, the oxidation process occurs gradually at 4 h, allowing a fine control of the oxidation process. Therefore, if fine tuning of the oxidation degree is desirable, the reaction must be conducted during short time (4 h) using increasing [NO2+] as those obtained from 2:1, 2.5:1 and 3:1 H2SO4/HNO3 acid mixtures to produce increasing content of functionalization.

Low frequency radiation and possible harmful influence on biological systems.

Neste trabalho apresenta-se um estudo te?rico que mostra a influ?ncia de radia??es de baixa frequ?ncia, principalmente as provenientes de dispositivos celulares ou Smartphones, e os poss?veis danos associados a doen?as que esse tipo de radia??o pode causar. Indica-se o aumento da produ??o de esp?cies reativas de oxig?nio que a radia??o n?o ionizante pode gerar a sistemas biol?gicos. Esse tipo de radia??o pode ocasionar varia??o na bioatividade, podendo ser considerada um agente externo potencialmente nocivo ?s pessoas.In this paper we present a theoretical study that shows the influence of low frequency radiation, mainly from mobile devices or Smartphones, and the possible damages associated with diseases caused by these kind of radiation. We indicate that the rise of reactive oxygen species, caused by non-ionizing radiation, can generate biological influence on the bioactivity. We argue that this type of radiation can, occasionally, be harmful and thus a potentially danger external agent

Normal Stress Distribution of Rough Surfaces in Contact

We study numerically the stress distribution on the interface between two thick elastic media bounded by interfaces that include spatially correlated asperities. The interface roughness is described using the self-affine topography that is observed over a very wide range of scales from fractures to faults. We analyse the correlation properties of the normal stress distribution when the rough surfaces have been brought into full contact. The self affinity of the rough surfaces is described by a Hurst exponent H. We find that the normal stress field is also self affine, but with a Hurst exponent H-1. Fluctations of the normal stress are shown to be important, especially at local scales with anti-persistent correlations.Comment: 11 pages LaTeX, 4 Postscript figures, submitted to Geophysical Research Letter

Raman study of doped-ZnO thin films grown by rf sputtering

A Raman spectroscopy study of doped versus undoped ZnO layers is presented. The layers were grown by RF magnetron sputtering and the doping with Al, Sb and Mn was achieved by ion implantation with subsequent annealing. First-order Raman response measured under λ=488 nm excitation is discussed. It is shown that doping with any of the impurities used in this work produces a strong enhancement of the longitudinal optical (LO) phonon band, which is attributed to the intra-band Fröhlich mechanism. In addition, doping with Mn results in an extra mode located at 530 cm-1, tentatively attributed to a local vibrational mode of Mn substituting Zn in the lattice sites.FCT through project PTDC/FIS/72843/200

Efficiency of Phytoseiulus longipes Evans as a control agent of Tetranychus evansi Baker & Pritchard (Acari: Phytoseiidae: Tetranychidae) on screenhouse tomatoes

The spider mite Tetranychus evansi Baker & Pritchard can cause severe damage to tomato crops. The predatory mite Phytoseiulus longipes Evans was recently reported in association with T. evansi in Uruguaiana, Rio Grande do Sul State, Brazil. The objective of the present study was to evaluate the effects of P. longipes on the population of T. evansi on tomatoes under screenhouse condition. The study consisted on four experiments, in each of which 80 potted plantlets were distributed in two plots of 40 plantlets each. Two weeks later, each plantlet of both plots was infested with eight adult females of T. evansi; one week after, four adult females of P. longipes were released onto each plant of one plot. The population levels of T. evansi and the damage caused by these mites were significantly lower (P < 0.05; linear mixed-effect model) in the plots where P. longipes had been released. The results indicate the potential of this predator as a candidate for classical biological control of T. evansi by inoculative releases on tomato plants.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Federal Ministry for Economic Cooperation and Developmen

Resonant raman scattering in ZnO : Mn and ZnO: Mn : Al thin films grown by RF sputtering

Raman spectroscopy results obtained under visible (non-resonant) and UV (resonant) excitation for nanocrystalline ZnO, ZnO:Mn and ZnO:Mn:Al thin films grown by radio frequency magnetron sputtering are presented and compared. The origin of the multiple longitudinal optical (LO) phonon Raman peaks, strongly enhanced under resonance conditions, and the effects of the dopants on them are discussed in the framework of the ‘cascade’ model. It is suggested that the observed suppression of the higher-order LO phonon lines for ZnO:Mn:Al is caused by the dissociation of excitons in the heavily n-type doped material. On the basis of the cascade model interpretation of the higher-order Raman peaks in the resonant spectra, the LO phonon frequencies for wavevectors away from the gamma point are evaluated and compared topreviously published phonon dispersion curves.Financial support from the FCT through project PTDC/FIS/72843/2006 is acknowledged

Reconhecimento de Padrão em Imagens, Análise de Componentes Principais e Lógica Fuzzy: Um estudo com foco na Esclerose Sistêmica

This work aims to merge Pattern Recognition in Images , Principal Component Analysis and Fuzzy Logic through a case study involving a disease called Systemic Sclerosis