Eficiência agronômica da mistura de uréia com zeolita natural aplicada na cultura da roseira (Rosa spp.), Nova Friburgo, RJ.

Com objetivo de avaliar a eficiência agronômica da mistura de uréia com zeolita natural (arenito zeolítico), realizou-se experimento em área de produção comercial de flores de corte em Nova Friburgo, RJ, Brasil. Foram realizadas duas adubações de cobertura na cultura da roseira com duas doses de uréia (60 e 120 kg N. ha-1 ) misturadas ou não com arenito zeolítico, na proporção de 20% p/p. As colheitas foram avaliadas quantitativamente, através do total de hastes (HT), massa fresca (MFT) e massa seca (MST) produzidas, e qualitativamente, através da divisão em hastes curtas (HC), médias (HM) e longas (HL). Determinou-se também a extração total de N pelas hastes comerciais colhidas (EXTNH) e a eficiência agronômica dos fertilizantes (EAF). A eficiência agronômica dos fertilizantes (EAF) sobre as produções de HT, MFT, MST e EXTNH é elevada pelo efeito do arenito zeolítico, e a maior influência sobre HT provém do aumento nas produções de HL, elevando a qualidade das hastes produzidas. A mistura de arenito zeolítico com uréia mantém maior quantidade de N-uréia no sistema solo-planta, liberando o nutriente lentamente para a solução do solo, em sincronia com as demandas nutricionais das plantas, resultando no aumento da eficiência agronômica dos fertilizantes avaliados. O arenito zeolítico (CETEM) apresenta características favoráveis para uso em desenvolvimento de fertilizantes nitrogenados de liberação lenta, principalmente com objetivo de aumentar a eficiência agronômica dos fertilizantes

The VIP Experiment

The Pauli Exclusion Principle (PEP) is a basic principle of Quantum Mechanics, and its validity has never been seriously challenged. However, given its importance, it is very important to check it as thoroughly as possible. Here we describe the VIP (Violation of PEP) experiment, an improved version of the Ramberg and Snow experiment (Ramberg and Snow, Phys. Lett. B238 (1990) 438); VIP shall be performed at the Gran Sasso underground laboratories, and aims to test the Pauli Exclusion Principle for electrons with unprecedented accuracy, down to $\frac{\beta^2}{2} \sim 10^{-30}$Comment: 7 pages, 5 figures, PDF only, presented by Edoardo Milotti to the conference "Quantum Theory: reconsideration of foundations-3", Vaxjo (Sweden), June, 6-11 200

Perdas por volatilização de N-NH3 proveniente da mistura de uréia com zeolita natural aplicada no inverno na cultura da roseira.

Com objetivo de avaliar a mistura de zeolita natural (arenito zeolítico) com uréia quanto às perdas de NH3 por volatilização, realizou-se experimento em área de produção comercial de flores de corte em Nova Friburgo, RJ. No verão de 2007 foi realizada adubação de cobertura na cultura da roseira (Rosa spp.) com duas doses de uréia (60 e 120 kg N. ha-1) misturadas ou não com arenito zeolítico, na proporção de 20% p/p. As perdas de NH3 por volatilização foram avaliadas por período de seis dias consecutivos após aplicação dos fertilizantes. Utilizou-se câmara semi-aberta livre estática, confeccionada com frasco plástico transparente de 2 litros (PET). A mistura é eficiente na redução das perdas de NH3 por volatilização, sendo a mesma, em média 24%. O arenito zeolítico (CETEM) apresenta características favoráveis para uso em desenvolvimento de ?fertilizantes zeolíticos? de liberação lenta, principalmente com objetivo de proporcionar redução nas perdas de NH3 por volatilização

The Star Formation Rate in disk galaxies: thresholds and dependence on gas amount

We reassess the applicability of the Toomre criterion in galactic disks and we study the local star formation law in 16 disk galaxies for which abundance gradients are published. The data we use consists of stellar light profiles, atomic and molecular gas (deduced from CO with a metallicity-dependent conversion factor), star formation rates (from H-alpha emissivities), metallicities, dispersion velocities and rotation curves. We show that the Toomre criterion applies successfully to the case of the Milky Way disk, but it has limited success with the data of our sample; depending on whether the stellar component is included or not in the stability analysis, we find average values for the threshold ratio of the gas surface density to the critical surface density in the range 0.5 to 0.7. We also test various star formation laws proposed in the literature, i.e. either the simple Schmidt law or modifications of it, that take into account dynamical factors. We find only small differences among them as far as the overall fit to our data is concerned; in particular, we find that all three SF laws (with parameters derived from the fits to our data) match particularly well observations in the Milky Way disk. In all cases we find that the exponent n of our best fit SFR has slightly higher values than in other recent works and we suggest several reasons that may cause that discrepancy.Comment: 18 pages, 12 figures, accepted in MNRA

Reconstruction of the gravitational wave signal h(t)h(t) during the Virgo science runs and independent validation with a photon calibrator

The Virgo detector is a kilometer-scale interferometer for gravitational wave detection located near Pisa (Italy). About 13 months of data were accumulated during four science runs (VSR1, VSR2, VSR3 and VSR4) between May 2007 and September 2011, with increasing sensitivity. In this paper, the method used to reconstruct, in the range 10 Hz-10 kHz, the gravitational wave strain time series $h(t)$ from the detector signals is described. The standard consistency checks of the reconstruction are discussed and used to estimate the systematic uncertainties of the $h(t)$ signal as a function of frequency. Finally, an independent setup, the photon calibrator, is described and used to validate the reconstructed $h(t)$ signal and the associated uncertainties. The uncertainties of the $h(t)$ time series are estimated to be 8% in amplitude. The uncertainty of the phase of $h(t)$ is 50 mrad at 10 Hz with a frequency dependence following a delay of 8 $\mu$s at high frequency. A bias lower than $4\,\mathrm{\mu s}$ and depending on the sky direction of the GW is also present.Comment: 35 pages, 16 figures. Accepted by CQ

Rotation Curves of Spiral Galaxies

Rotation curves of spiral galaxies are the major tool for determining the distribution of mass in spiral galaxies. They provide fundamental information for understanding the dynamics, evolution and formation of spiral galaxies. We describe various methods to derive rotation curves, and review the results obtained. We discuss the basic characteristics of observed rotation curves in relation to various galaxy properties, such as Hubble type, structure, activity, and environment.Comment: 40 pages, 6 gif figures; Ann. Rev. Astron. Astrophys. Vol. 39, p.137, 200

Implementation and testing of the first prompt search for gravitational wave transients with electromagnetic counterparts

Aims. A transient astrophysical event observed in both gravitational wave (GW) and electromagnetic (EM) channels would yield rich scientific rewards. A first program initiating EM follow-ups to possible transient GW events has been developed and exercised by the LIGO and Virgo community in association with several partners. In this paper, we describe and evaluate the methods used to promptly identify and localize GW event candidates and to request images of targeted sky locations. Methods. During two observing periods (Dec 17 2009 to Jan 8 2010 and Sep 2 to Oct 20 2010), a low-latency analysis pipeline was used to identify GW event candidates and to reconstruct maps of possible sky locations. A catalog of nearby galaxies and Milky Way globular clusters was used to select the most promising sky positions to be imaged, and this directional information was delivered to EM observatories with time lags of about thirty minutes. A Monte Carlo simulation has been used to evaluate the low-latency GW pipeline's ability to reconstruct source positions correctly. Results. For signals near the detection threshold, our low-latency algorithms often localized simulated GW burst signals to tens of square degrees, while neutron star/neutron star inspirals and neutron star/black hole inspirals were localized to a few hundred square degrees. Localization precision improves for moderately stronger signals. The correct sky location of signals well above threshold and originating from nearby galaxies may be observed with ~50% or better probability with a few pointings of wide-field telescopes.Comment: 17 pages. This version (v2) includes two tables and 1 section not included in v1. Accepted for publication in Astronomy & Astrophysic

Search for gravitational waves associated with the InterPlanetary Network short gamma ray bursts

We outline the scientific motivation behind a search for gravitational waves associated with short gamma ray bursts detected by the InterPlanetary Network (IPN) during LIGO's fifth science run and Virgo's first science run. The IPN localisation of short gamma ray bursts is limited to extended error boxes of different shapes and sizes and a search on these error boxes poses a series of challenges for data analysis. We will discuss these challenges and outline the methods to optimise the search over these error boxes.Comment: Methods paper; Proceedings for Eduardo Amaldi 9 Conference on Gravitational Waves, July 2011, Cardiff, U

Calibration and sensitivity of the Virgo detector during its second science run

The Virgo detector is a kilometer-length interferometer for gravitational wave detection located near Pisa (Italy). During its second science run (VSR2) in 2009, six months of data were accumulated with a sensitivity close to its design. In this paper, the methods used to determine the parameters for sensitivity estimation and gravitational wave reconstruction are described. The main quantities to be calibrated are the frequency response of the mirror actuation and the sensing of the output power. Focus is also put on their absolute timing. The monitoring of the calibration data as well as the parameter estimation with independent techniques are discussed to provide an estimation of the calibration uncertainties. Finally, the estimation of the Virgo sensitivity in the frequency-domain is described and typical sensitivities measured during VSR2 are shown.Comment: 30 pages, 23 figures, 1 table. Published in Classical and Quantum Gravity (CQG), Corrigendum include