Squeezing generation and revivals in a cavity-ion system in contact with a reservoir

We consider a system consisting of a single two-level ion in a harmonic trap, which is localized inside a non-ideal optical cavity at zero temperature and subjected to the action of two external lasers. We are able to obtain an analytical solution for the total density operator of the system and show that squeezing in the motion of the ion and in the cavity field is generated. We also show that complete revivals of the states of the motion of the ion and of the cavity field occur periodically.Comment: 9 pages, 3 figure

Efeito da deficiência hídrica e do fotoperíodo no rendimento de grãos da soja semeada na região de Dourados, MS.

bitstream/item/24702/1/COT200489.pdfDocumento on-line

Impact of iron amendment on soil bacterial abundance and diversity

info:eu-repo/semantics/publishedVersio

Análise da Influência do Diafragma Externo na Ligação Entre Viga de Seção i e Pilar Tubular de Seção Circular

O uso do diafragma externo na ligação entre viga de seção I e pilar tubular de seção circular tem por objetivo o aumento na eficácia da transferência dos esforços entre estes elementos. O estudo dos diafragmas teve início na década de 1970, no Japão, onde foram feitas análises teóricas e experimentais da sua aplicação. No Brasil, as pesquisas iniciaram em 2005, quando Carvalho (2005) realizou as primeiras análises numéricas com e sem o uso de diafragma externo na ligação. A norma brasileira ABNT NBR 16239:2013 não trata do dimensionamento deste tipo de ligação, que é contemplado somente por Kurobane (2004) do Comité International pour Le Développement et lEtude de La Construction Tubulaire (CIDECT). O objetivo deste estudo foi analisar o comportamento do diafragma externo em ligações entre viga de seção I e pilar tubular de seção circular. Análises numéricas foram realizadas variando a geometria do diafragma externo e verificando sua eficácia quando submetido a cargas nas vigas e no pilar. O diafragma se mostrou um mecanismo eficaz para aumento da rigidez inicial e da resistência da ligação proporcionando ganhos de resistência que variam de 30 a 173%, dependendo da geometria. Quando o pilar é submetido a carga axial, verifica-se que o modelo sem diafragma, apresenta redução gradual de até 17% no momento último, enquanto que o modelo com a menor dimensão de diafragma, apresenta redução de somente 3,2% em sua resistência

Implantação de desenvolvimento da produção integrada de mandioca em cinco regiões produtoras do Brasil.

Publicado também na: RAT: Revista Raízes e Amidos Tropicais, v. 3, 2007. (SEP 040)

Modified electrodes for electrochemical reduction of carbon dioxide

The efforts to constrain greenhouse gas emissions and concerns over security of fossil fuels have led to increased attention for renewable energy for the past decade. Renewable energy is one of the key solutions to the actual energy challenges. Omnidea in collaboration with Research Institutes is developing a technology based upon a regenerative energy storage cycle that could be a contribution to a low-carbon energy future. In this cycle the recharge system, which is composed of an electrochemical cell, converts CO2 into fuel (hydrocarbons and hydrogen) using an external source of power (e.g. solar power). The discharge system produces electric energy when hydrocarbons and oxygen from the recharge system are directly supplied to a Solid Oxide Fuel Cell (SOFC). Currently state of the art systems for direct electrochemical reduction of CO2 exhibit low current densities and or low Faradaic efficiencies. Thus considerable research activity is still needed to develop electrodes with a performance suitable for an industrial application. This paper describes the progress to date and the work carried out with the aim of achieving this goal. It addresses particularly the modification of electrodes for electrochemical conversion of CO2 and reports voltammetric studies as a tool for screening and optimizing electrodes for CO2 conversio

Comparative linkage mapping of Oryza glumaepatulaand Oryza sativa interspecific crosses based on microsatellite and expressed sequence tag markers.

Molecular linkage maps representing the rice genome have been an important tool for breeding programs because they allow the elucidation of polygenic traits and are an efficient tool for monitoring wild introgressions in interspecific crosses. Common markers among rice genetic maps are important in defining the homology of chromosomes and the synteny between genomic target regions. We used 148 markers (expressed sequence tags, microsatellites and single nucleotide polymorphisms) to construct a molecular linkage map based on co-dominant markers for an interspecific backcross population using a wild rice ( Oryza glumaepatula) from Brazil and performed a comparative analysis with other interspecific maps. The comparative analysis revealed a Spearman correlation index of 0.86 for marker order conservation to a previous map constructed for an interspecific cross using the same wild parent. Approximately 90% of markers common to other interspecific maps kept the same order. These results indicate that it will be possible to generate a unique genetic map using the wild donor and that it may be a helpful tool for breeding programs because plants derived from different interspecific populations can be rapidly scanned using markers associated with useful wild traits

Experimental and modeling studies of a micro direct methanol fuel cell

The Direct Methanol Fuel Cell (DMFC) has attracted much attention due to its potential applications as a power source for transportation and portable electronic devices. Based on the advantages of the scaling laws, miniaturization promises higher efficiency and performance of power generating devices and the MicroDMFC is therefore an emergent technology. In this work, a set of experiences with a MicroDMFC of 2.25 cm2 active area are performed in order to investigate the effect of important operating parameters. Maximum power density achieved was 32.6 mW/cm2 using 4M mehanol concentration at room temperature. Polarization curves are compared with mathematical model simulations in order to achieve a better understanding of how parameters affect performance. The one-dimensional model used in this work takes in account coupled heat and mass transfer, along with the electrochemical reactions occurring in a direct methanol fuel cell and was already developed and validated for DMFC in previous work [1-3]. The model is also used to predict some important parameters to analyze fuel cell performance, such as water transport coefficient and methanol crossover. This easy to implement simplified model is suitable for use in real-time MicroDMFC simulations

Photon pair-state preparation with tailored spectral properties by spontaneous four-wave mixing in photonic-crystal fiber

We study theoretically the generation of photon pairs by spontaneous four-wave mixing (SFWM) in photonic crystal optical fiber. We show that it is possible to engineer two-photon states with specific spectral correlation (``entanglement'') properties suitable for quantum information processing applications. We focus on the case exhibiting no spectral correlations in the two-photon component of the state, which we call factorability, and which allows heralding of single-photon pure-state wave packets without the need for spectral post filtering. We show that spontaneous four wave mixing exhibits a remarkable flexibility, permitting a wider class of two-photon states, including ultra-broadband, highly-anticorrelated states.Comment: 17 pages, 7 figures, submitte