Use of threshold electrolyte concentration analysis to determine salinity and sodicity limit of irrigation water

This research studied threshold electrolyte concentration (TEC) of irrigation water and its effect on the infiltration rate of two contrasting soils from Pernambuco state, Brazil. The experiment was conducted in the Soil Chemistry and Salinity Laboratory of Federal Rural University of Pernambuco. Each soil was packed in five Buchner funnels, where one funnel from each soil was submitted to treatment with solution of electrical conductivity (EC) of 0.5, 1.0, 2.0, 4.0 or 8.0 dS m-1. For each funnel containing soil, an increasing ratio of NaCl to CaCl2 was applied in a treatment solution to achieve 10 increasing values of sodium adsorption ratio (SAR) from 0 to 100. These solutions were applied through a Mariotte bottle, with a constant hydraulic head of ~2 cm (pressure potential). After a liter of solution had drained, in the flux was collected for a known time interval, until steady state was reached. Darcy's equation was used to calculate saturated hydraulic conductivity (Ksat) and a mathematical model used to calculate the TEC as a 20% reduction in Ksat. By increasing SAR similar behavior was noted between the two soils, whereby Ksat decreased, although the relative decrease in Ksat was greater for SAR of 100 in the soil with higher clay content

Transverse Momentum Spectra of Pions in Particle and Nuclear Collisions and Some Ratio-Behaviours: Towards A Combinational Approach

The nature of transverse momentum dependence of the inclusive cross-sections for secondary pions produced in high energy hadronic($PP$), hadronuclear($PA$) and nuclear($AA$) collisions has here been exhaustively investigated for a varied range of interactions in a unified way with the help of a master formula. This formula evolved from a new combination of the basic Hagedorn's model for particle(pion) production in PP scattering at ISR range of energies, a phenomenological approach proposed by Peitzmann for converting the results of $NN(PP)$ reactions to those for either $PA$ or $AA$ collisions, and a specific form of parametrization for mass number-dependence of the nuclear cross sections. This grand combination of models(GCM) is then applied to analyse the assorted extensive data on various high energy collisions. The nature of qualitative agreement between measurements and calculations on both the inclusive cross-sections for production of pions, and some ratios of them as well, is quite satisfactory. The modest successes that we achieve here in dealing with the massive data-sets are somewhat encouraging in view of the diversity of the reactions and the very wide range of interaction energies.Comment: 19 pages, 19 figure

NEMO: A Project for a km3^3 Underwater Detector for Astrophysical Neutrinos in the Mediterranean Sea

The status of the project is described: the activity on long term characterization of water optical and oceanographic parameters at the Capo Passero site candidate for the Mediterranean km$^3$ neutrino telescope; the feasibility study; the physics performances and underwater technology for the km$^3$; the activity on NEMO Phase 1, a technological demonstrator that has been deployed at 2000 m depth 25 km offshore Catania; the realization of an underwater infrastructure at 3500 m depth at the candidate site (NEMO Phase 2).Comment: Proceeding of ISCRA 2006, Erice 20-27 June 200

Measurement of the atmospheric muon depth intensity relation with the NEMO Phase-2 tower

The results of the analysis of the data collected with the NEMO Phase-2 tower, deployed at 3500 m depth about 80 km off-shore Capo Passero (Italy), are presented. Cherenkov photons detected with the photomultipliers tubes were used to reconstruct the tracks of atmospheric muons. Their zenith-angle distribution was measured and the results compared with Monte Carlo simulations. An evaluation of the systematic effects due to uncertainties on environmental and detector parameters is also included. The associated depth intensity relation was evaluated and compared with previous measurements and theoretical predictions. With the present analysis, the muon depth intensity relation has been measured up to 13 km of water equivalent.Comment: submitted to Astroparticle Physic

New MACRO results on atmospheric neutrino oscillations

The final results of the MACRO experiment on atmospheric neutrino oscillations are presented and discussed. The data concern different event topologies with average neutrino energies of ~3 and ~50 GeV. Multiple Coulomb Scattering of the high energy muons in absorbers was used to estimate the neutrino energy of each event. The angular distributions, the L/E_nu distribution, the particle ratios and the absolute fluxes all favour nu_mu --> nu_tau oscillations with maximal mixing and Delta m^2 =0.0023 eV^2. A discussion is made on the Monte Carlos used for the atmospheric neutrino flux. Some results on neutrino astrophysics are also briefly discussed.Comment: Invited Paper at the NANP03 Int. Conf., Dubna, 200

Centrality and sNNDependenceofthe\sqrt{s_{NN}} Dependence of the dE_{T}/d\etaand and dN_{ch}/d\eta$ in Heavy Ion Collisions at Mid-Rapidity

The PHENIX experiment at RHIC has measured transverse energy and charged particle multiplicity at mid-rapidity in Au + Au collisions at $\sqrt{s_{NN}}$ = 19.6, 130, 62.4 and 200 GeV as a function of centrality. The presented results are compared to measurements from other RHIC experiments, and experiments at lower energies. The $\sqrt{s_{NN}}$ dependence of $dE_{T}/d\eta$ and $dN_{ch}/d\eta$ per pair of participants is consistent with logarithmic scaling for the most central events. The centrality dependence of $dE_{T}/d\eta$ and $dN_{ch}/d\eta$ is similar at all measured incident energies. At RHIC energies the ratio of transverse energy per charged particle was found independent of centrality and growing slowly with $\sqrt{s_{NN}}$. A survey of comparisons between the data and available theoretical models is also presented.Comment: Proccedings of the Workshop: Focus on Multiplcity at Bari, Italy, June 17-19,2004. To be submitted to the Jornal of Physics, "Conference series". Includes: 20 Pages, 15 figures, 3 Tables, 80 Referencie

The ANTARES Optical Beacon System

ANTARES is a neutrino telescope being deployed in the Mediterranean Sea. It consists of a three dimensional array of photomultiplier tubes that can detect the Cherenkov light induced by charged particles produced in the interactions of neutrinos with the surrounding medium. High angular resolution can be achieved, in particular when a muon is produced, provided that the Cherenkov photons are detected with sufficient timing precision. Considerations of the intrinsic time uncertainties stemming from the transit time spread in the photomultiplier tubes and the mechanism of transmission of light in sea water lead to the conclusion that a relative time accuracy of the order of 0.5 ns is desirable. Accordingly, different time calibration systems have been developed for the ANTARES telescope. In this article, a system based on Optical Beacons, a set of external and well-controlled pulsed light sources located throughout the detector, is described. This calibration system takes into account the optical properties of sea water, which is used as the detection volume of the ANTARES telescope. The design, tests, construction and first results of the two types of beacons, LED and laser-based, are presented.Comment: 21 pages, 18 figures, submitted to Nucl. Instr. and Meth. Phys. Res.

Wavelength-shifting fibers for calorimetric measurements in a long base line neutrino oscillation experiment

Abstract The NOE Collaboration has proposed a calorimeter to measure the energy of the final states of ν interaction events. The properties of long scintillator bars with wavelength-shifting fiber readout have been studied to develop a calorimeter design option. Various prototypes have been exposed to a cosmic rays stand. The total measured light yield in the middle of a 6 m -long fiber is about 15 photoelectrons. With this photon collection performance, it has been simulated that the calorimeter can achieve 17%/ E and 50%/ E resolutions for electrons and pions, respectively

Status of NEMO

The activities towards the realization of a km3 Cherenkov neutrino detector carried out by the NEMO Collaboration are described. Long-term exploration of a 3500 m deep-sea site close to the Sicilian coast has shown that it is optimal for the installation of the detector. The realization of a Phase-1 project, which is under way, will validate the proposed technologies for the realization of the km3 detector on a Test Site at 2000 m depth. The realization of a new infrastructure on the candidate site (Phase-2 project) will provide the possibility to test detector components at 3500 m depth