Structural and optical properties of Zn0.9 Mn0.1 O/ZnO core-shell nanowires designed by pulsed laser deposition

Partilhar documento na coleção da comunidade Laboratório Associado I3NCore-shell ZnO/ZnMnO nanowires on a-Al2O3 and GaN (buffer layer)/Si (111) substrates were fabricated by pulsed laser deposition using a Au catalyst. Two ZnO targets with a Mn content of 10% were sintered at 1150 and 550 °C in order to achieve the domination in them of paramagnetic MnO2 and ferromagnetic Mn2O3 phases, respectively. Cluster mechanism of laser ablation as a source of possible incorporation of secondary phases to the wire shell is discussed. Raman spectroscopy under excitation by an Ar+ laser revealed a broad peak related to the Mn-induced disorder and a redshift in the A1-LO phonon. Resonant Raman measurements revealed an increase in the multiphonon scattering caused by disorder in ZnO upon doping by Mn. Besides the UV emission, a vibronic green emission band assisted by a ∼ 71 meV LO phonon is also observed in the photoluminescence spectra. Core-shell structures with smooth shells show a high exciton to green band intensity ratio ( ∼ 10) even at room temperature. © 2009 American Institute of PhysicsSANDiE Network of Excellence of the EUFCT-PTDC/FIS/72843/200

Spontaneous emission between an unusual pair of plates

We compute the modification in the spontaneous emission rate for a two-level atom when it is located between two parallel plates of different nature: a perfectly conducting plate $(\epsilon\to \infty)$ and an infinitely permeable one $(\mu\to \infty)$. We also discuss the case of two infinitely permeable plates. We compare our results with those found in the literature for the case of two perfectly conducting plates.Comment: latex file 4 pages, 4 figure

The compound Poisson limit ruling periodic extreme behaviour of non-uniformly hyperbolic dynamics

We prove that the distributional limit of the normalised number of returns to small neighbourhoods of periodic points of non-uniformly hyperbolic dynamical systems is compound Poisson. The returns to small balls around a fixed point in the phase space correspond to the occurrence of rare events, or exceedances of high thresholds, so that there is a connection between the laws of Return Times Statistics and Extreme Value Laws. The fact that the fixed point in the phase space is a repelling periodic point implies that there is a tendency for the exceedances to appear in clusters whose average sizes is given by the Extremal Index, which depends on the expansion of the system at the periodic point. We recall that for generic points, the exceedances, in the limit, are singular and occur at Poisson times. However, around periodic points, the picture is different: the respective point processes of exceedances converge to a compound Poisson process, so instead of single exceedances, we have entire clusters of exceedances occurring at Poisson times with a geometric distribution ruling its multiplicity. The systems to which our results apply include: general piecewise expanding maps of the interval (Rychlik maps), maps with indifferent fixed points (Manneville-Pomeau maps) and Benedicks-Carleson quadratic maps.Comment: To appear in Communications in Mathematical Physic

Properties of Interfaces in the two and three dimensional Ising Model

To investigate order-order interfaces, we perform multimagnetical Monte Carlo simulations of the $2D$ and $3D$ Ising model. Following Binder we extract the interfacial free energy from the infinite volume limit of the magnetic probability density. Stringent tests of the numerical methods are performed by reproducing with high precision exact $2D$ results. In the physically more interesting $3D$ case we estimate the amplitude $F^s_0$ of the critical interfacial tension $F^s = F^s_0 t^\mu$ to be $F^s_0 = 1.52 \pm 0.05$. This result is in good agreement with a previous MC calculation by Mon, as well as with experimental results for related amplitude ratios. In addition, we study in some details the shape of the magnetic probability density for temperatures below the Curie point.Comment: 25 pages; sorry no figures include

Star and Planet Formation with ALMA: an Overview

Submillimeter observations with ALMA will be the essential next step in our understanding of how stars and planets form. Key projects range from detailed imaging of the collapse of pre-stellar cores and measuring the accretion rate of matter onto deeply embedded protostars, to unravelling the chemistry and dynamics of high-mass star-forming clusters and high-spatial resolution studies of protoplanetary disks down to the 1 AU scale.Comment: Invited review, 8 pages, 5 figures; to appear in the proceedings of "Science with ALMA: a New Era for Astrophysics". Astrophysics & Space Science, in pres

On the independence of hydrogen production from methanogenic suppressor in olive mill wastewater

Anaerobic degradation of olive mill wastewater (OMW) at concentrations ranging from 2 to 100 g/L of chemical oxygen demand (COD) was assessed in batch assays. Methane was the main final product obtained for the lower concentrations tested. For 25 g COD/L, H2 was temporarily produced, albeit H2 depletion occurred, likely due to homoacetogenesis, since acetate was formed concomitantly. Hydrogen was produced and accumulated permanently in the assays containing 50 g COD/L of OMW. Methanogenesis and homoacetogenesis were naturally inhibited, suggesting that hydrogen recovery from OMW can be performed without the addition of methanogenic suppressors such as 2-bromoethanosulfonate. This fact opens new perspectives for the utilization of high OMW concentrations in a two-stage valorisation process combining biohydrogen and biomethane production.The authors thank the FCT Strategic Project PEst-OE/EQB/LA0023/2013, the FCT Project RECI/BBB-EBI/0179/2012, the Project "BioEnv - Biotechnology and Bioengineering for a sustainable world", REF. NORTE-07-0124-FEDER-000048, co-funded by the Programa Operacional Regional do Norte (ON.2 - O Novo Norte), QREN, FEDER. Also through the project PTDC/ENR/69755/2006 and grants given to Marta Goncalves SFRH/BD/40746/2007, Jose Carlos Costa SFRH/BDP/48962/2008 and Angela A Abreu SFRH/BPD/82000/2011

Plantio direto, adubação verde e suplementação com esterco de aves na produção orgânica de berinjela.

Sob manejo orgânico, foram avaliados, em Seropédica, RJ, os sistemas de plantio direto da berinjela(Solanum melongena) nas palhadas de Crotalaria juncea (crotalária), Pennisetum glaucum (milheto, cv. BRS 1501)e vegetação espontânea (pousio), em comparação com o plantio convencional (aração e gradagem ou enxada rotativa). Simultaneamente, foram avaliados três tipos de cultivo: berinjela em monocultura, em consórcio com crotalária e em consórcio com caupi (Vigna unguiculata, cv. Mauá). Não houve diferença entre os sistemas de plantio direto e convencional quanto à produção comercial da berinjela. A palhada da crotalária foi mais eficiente que a do milheto e do pousio para cobertura morta do solo e conseqüentemente o controle de plantas espontâneas foi maior. O cultivo simultâneo com as leguminosas não acarretou redução da produtividade da berinjela.Em um segundo estudo, foram comparados plantio direto (palhadas de crotalária e da vegetação espontânea) e plantio convencional, combinados com doses crescentes de cama de aviário (0, 100, 200 e 400 kg ha-1 de N)aplicada em cobertura. Em termos de aporte de biomassa, a crotalária foi novamente superior à vegetação espontânea.A berinjela respondeu à adubação orgânica, com produtividade máxima de 50,6 t ha-1 , correspondendo à maior dose empregada, contra 36,9 t ha-1 referentes ao controle

Survival Of Aids Patients In The Southeast And South Of Brazil: Analysis Of The 1998-1999 Cohort [sobrevida De Pacientes Com Aids Das Regiões Sudeste E Sul Do Brasil: Análise Da Coorte De 1998-1999]

The aim of this study was to evaluate survival time for AIDS patients 13 years and older in the South and Southeast regions of Brazil, according to socio-demographic, clinical, and epidemiological characteristics. The sample was selected from all cases diagnosed in 1998 and 1999 and notified to the Epidemiological Surveillance System of the National STD/AIDS Program. Use of a questionnaire allowed analyzing 2,091 patient charts. Based on the Kaplan-Meier method, estimated survival was at least 108 months after diagnosis in 59.5% of patients in the Southeast and 59.3% in the South. Cox regression models showed, in both regions, an increase in survival in patients on antiretroviral therapy, those classified as AIDS cases according to the CD4 T-cell criterion, females, and those with more schooling. Other factors associated with longer survival in the Southeast were: white skin color, no history of tuberculosis since the AIDS diagnosis, negative hepatitis B serology, and access to a multidisciplinary health team. In the South, age below 40 years was associated with longer survival.27SUPPL. 1S79S92Fonseca, M.G.P., Bastos, F.I., Twenty-five years of the AIDS epidemic in Brazil: Principal epidemiological findings, 1980-2005 (2007) Cad Saúde Pública, (23 SUPPL 3), pp. S333-S344Boletim Epidemiológico AIDST 2008, 1. , Ministério da Saúde, Ano(2004) Critérios De Definição De Casos De AIDS Em Adultos E Crianças, , Ministério da Saúde, Brasília: Ministério da SaúdeDourado, I., Veras, M.A.S.M., Barreira, D., Brito, A.M., Tendências da epidemia de AIDS no Brasil após a terapia antirretroviral (2006) Rev Saúde Pública, (SUPPL 40), pp. 9-17Casseb, J., Fonseca, L.A., Veiga, A.P., Almeida, A., Bueno, A., Ferez, A.C., AIDS incidence and mortality in a hospital based cohort of HIV-1 seropositive patients receiving highly active antiretroviral therapy in São Paulo, Brazil (2003) AIDS Patient Care STDS, 17, pp. 447-452Crum, N.F., Riffemburg, R.H., Wegner, S., Agan, B.K., Tasker, S.A., Spooner, K.M., Comparison of causes of death and mortality rates among HIV infected persons: Analysis of the pre, early, and late HAART (highly active antiretroviral therapy) eras (2006) J Acquir Immune Defic Syndr, 41, pp. 194-200Santos, N.J.S., Tayra, A., Silva, S.R., Buchala, C.M., Laurenti, R., A AIDS no estado de São Paulo: As mudanças no perfil da epidemia e perspectivas da vigilância epidemiológica (2002) Rev Bras Epidemiol, 5, pp. 286-310Messeri, P., Lee, G., Abramson, D.M., Aidala, A., Chiasson, M.A., Jessop, D.J., Antiretroviral therapy and declining AIDS mortality in New York City (2003) Med Care, 41, pp. 512-521Vellozi, C., Brooks, J.T., Bush, T.J., Conley, L.J., Henry, K., Carperter, C.C.J., The study to understand the natural history of HIV and AIDS in the era of effective therapy (SUN Study) (2009) Am J Epidemiol, 169, pp. 642-652Quinn, T.C., HIV epidemiology and the effects of antiviral therapy on long term consequences (2008) AIDS, (22 SUPPL 3), pp. S7-S12Targets and Commitments Made By the Member-States At the United Nation General Assembly Special Session On HIV/AIDS, , http//www.unaids.org/en/dataanalysis/monitoringcountryprogress/2010progr essreportssubmittedbycountries/brazil_2010_country_progress_report_en.pd f, Brazilian Ministry of Health, accessed on Jul/2010Chequer, P., Hearst, N., Hudes, E.S., Castilho, E., Rutherford, G., Loures, L., Determinants of survival in adult Brazilian AIDS patients, 1982-1989.The Brazilian State AIDS Program Co-ordinators (1992) AIDS, 6, pp. 483-487Marins, J.R., Jamal, L.E., Chen, S.Y., Barros, M.B., Hudes, E.S., Barbosa, A.A., Dramatic improvement in survival among adult Brazilian AIDS patients (2003) AIDS, 17, pp. 1675-1682Collet, D., (2003) Modeling Survival Data In Medical Research, , 2nd Ed. Boca Raton: Chapman & HallEpidemiology of HIV/AIDS, United States, 1981-2005 (2006) MMWR Morb Mortal Wkly Rep, 55, pp. 589-592. , Centers for Disease Control and PreventionWong, K.H., Chan, K.C., Lee, S.S., Delayed progression to death and to AIDS in a Hong Kong cohort of patients with advanced HIV type 1 disease during the era of highly active antiretroviral therapy (2004) Clin Infect Dis, 39, pp. 853-860Gadelha, A.J., Accacio, N., Costa, R.L.B., Galhardo, M.C., Cotrim, M.R., Souza, R.V., Morbidity and survival in advanced AIDS in Rio de Janeiro, Brazil (2002) Rev Inst Med Trop São Paulo, 44, pp. 179-186Hacker, M.A., Petersen, M.L., Enriquez, M., Bastos, F.I., Highly active antiretroviral therapy in Brazil: The challenge of universal access in a context of social inequality (2004) Rev Panam Salud Pública, 16, pp. 78-83Krishnan, S., Dunbar, M.S., Minnis, A.M., Medlin, C.A., Gerdts, C.E., Padian, N.S., Poverty, gender inequalities and women's risk of Human Immunodeficiency Virus/AIDS (2008) Ann N Y Acad Sci, 1136, pp. 101-110Antunes, J.L.F., Waldman, E.A., Borrel, C., Is it possible to reduce AIDS death without reinforcing socioeconomic inequalities in health? (2005) Int J Epidemiol, 34, pp. 586-592Castilho, E.A., Szwarcwald, C.L., Brito, A.M., Fatores associados à interrupção de tratamento anti-retroviral em adultos com AIDS, Rio Grande do Norte, Brasil, 1999-2002 (2006) Rev Assoc Med Bras (1992), 52, pp. 86-92Neme, M.I.B., Carvalho, H.B., Souza, M.F.M., ARV therapy adherence in Brazil (2004) AIDS, (18 SUPPL 3), pp. 515-520Pérez-Hoyos, S., Amo, J., Muga, R., Romero, J., Olalla, P.G., Guerrero, R., Effectiveness of highly active antiretroviral therapy in Spanish cohorts of HIV seroconverters: Differences by transmission category (2003) AIDS, 17, pp. 353-359Porta, D., Forastiere, F., Fusco, D., Perucci, C.A., Lazio AIDS Surveillance Collaborative Group. Socioeconomic status and survival of persons with AIDS before and after introduction of Highly Active Antiretroviral Therapy (2000) Epidemiology, 11, pp. 496-501. , Rapiti EPrograma Nacional DST E AIDS, , http://www.aids.gov.br/cgi/deftohtm.exe?tabnet/aids.def, Ministério da Saúde, accessed on 26/Aug/2009Giovanetti, M.C., Santos, N.J.S., Westin, C.P., Darré, D., Gianna, M.C., A implantação do quesito cor/raça nos serviços de DST/AIDS no Estado de São Paulo (2007) Saúde Soc, 16, pp. 163-170Fry, P.H., Monteiro, S., Maio, M.C., Bastos, F.I., Santos, R.V., AIDS tem cor ou raça? Interpretação de dados e formulação de políticas de saúde no Brasil (2007) Cad Saúde Pública, 23, pp. 497-523Batista, L.E., (2002) Mulheres E Homens Negros: Saúde, Doença E Morte [Doctoral Dissertation], , Araraquara: Fa-culdade de Ciências e Letras, Universidade Estadual PaulistaFonseca, M.G.P., Lucena, F.F.A., Souza, A., Bastos, F.I., AIDS mortality, "race or color", and social inequality in a context of universal access to highly active antiretroviral therapy (HAART) in Brazil, 1999- 2004 (2007) Cad Saúde Pública, (23 SUPPL 3), pp. S445-S455Marins, J.R.P., (2004) Estudo De Sobrevida Dos Pacientes De AIDS Segundo Escolaridade, Co-infecção Hepatite C E Tuberculose. Coorte Brasileira 1995-1996 [Doctoral Dissertation], , Campinas: Faculdade de Ciências Médicas, Universidade Estadual de CampinasFerreira, M.S., Borges, A.S., Avanços no tratamento da hepatite pelo vírus B (2007) Rev Soc Bras Med Trop, 40, pp. 451-462Mussini, C., Manzardo, C., Johnson, M., Monforte, A., Uberti-Foppa, C., Antinori, A., Patients presenting with AIDS in the HAART era: A collaborative cohort analysis (2008) AIDS, 22, pp. 2461-2469Nemes, M.I.B., Alencar, T.M.D., (2008) Equipe Qualiaids. Avaliação Da Assistência Ambulatorial Aos Adultos Vivendo Com HIV/AIDS, , Qualiaids. Relatório 2007/2008. Brasília: Ministério da SaúdeMelchior, R., Nemes, M.I.B., Basso, C.R.B., Castanheira, E.R.L., Alves, M.T.S.B., Buchalla, C.M., Avaliação da estrutura organizacional assistência ambulatorial em HIV/AIDS no Brasil (2006) Rev Saúde Pública, 40, pp. 143-15

Complementarity of the CERN Large Hadron Collider and the e+e−e^+e^- International Linear Collider

The next-generation high-energy facilities, the CERN Large Hadron Collider (LHC) and the prospective $e^+e^-$ International Linear Collider (ILC), are expected to unravel new structures of matter and forces from the electroweak scale to the TeV scale. In this report we review the complementary role of LHC and ILC in drawing a comprehensive and high-precision picture of the mechanism breaking the electroweak symmetries and generating mass, and the unification of forces in the frame of supersymmetry.Comment: 14 pages, 17 figures, to be published in "Supersymmetry on the Eve of the LHC", a special volume of European Physical Journal C, Particles and Fields (EPJC) in memory of Julius Wes

The Milky Way Bulge: Observed properties and a comparison to external galaxies

The Milky Way bulge offers a unique opportunity to investigate in detail the role that different processes such as dynamical instabilities, hierarchical merging, and dissipational collapse may have played in the history of the Galaxy formation and evolution based on its resolved stellar population properties. Large observation programmes and surveys of the bulge are providing for the first time a look into the global view of the Milky Way bulge that can be compared with the bulges of other galaxies, and be used as a template for detailed comparison with models. The Milky Way has been shown to have a box/peanut (B/P) bulge and recent evidence seems to suggest the presence of an additional spheroidal component. In this review we summarise the global chemical abundances, kinematics and structural properties that allow us to disentangle these multiple components and provide constraints to understand their origin. The investigation of both detailed and global properties of the bulge now provide us with the opportunity to characterise the bulge as observed in models, and to place the mixed component bulge scenario in the general context of external galaxies. When writing this review, we considered the perspectives of researchers working with the Milky Way and researchers working with external galaxies. It is an attempt to approach both communities for a fruitful exchange of ideas.Comment: Review article to appear in "Galactic Bulges", Editors: Laurikainen E., Peletier R., Gadotti D., Springer Publishing. 36 pages, 10 figure