Green Approach To Corrosion Inhibition Of Aluminium By Senna Auriculata Leaves Extract In 1 N NaOH Solution

Corrosion inhibition of aluminium in 1N NaOH by leaves extract of Senna auriculata (SL) was studied using chemical and electrochemical techniques at 30-60°C. It was found that the leaves of Senna auriculata inhibited the base induced corrosion of aluminium.The inhibition efficiency increases with increase in concentration of SL extract and reached the maximum of 76.2% but decrease with rise in temperature. The adsorption of SL on metal surface obeyed Langmuir adsorption isotherm. Polarization measurements showed that SL extract acted as mixed type inhibitor. The surface morphology of aluminium, in the absence and presence of SL extract in 1N NaOH solution, was studied using scanning electron microscopy. Results obtained from chemical and electrochemical techniques were in good agreement. Thermodynamic parameters such as activation energy and free energy of adsorption were calculated and given in kJ/mol

The effects of combined chemical treatments on the mechanical properties of three grades of sisal

Different grades of sisal fibres (S3, STOW, and SUG) were immersed in five different treatment solutions: sodium hydroxide (NaOH) for 24 h; silane for 24 h; and NaOH followed by silane for 6, 12, and 24 h. The treated fibres were tested for bonding strength using the micro-droplet method. It was established that NaOH and silane treatments improved bonding strength with the unsaturated polyester resin that was used. However, it can be concluded that NaOH followed by silane (each for 6 h) produced the highest bonding strength compared with the other combined treatments. This is most likely because of fibre erosion caused by the chemicals in the other treatments, which causes fibres to lose the ability to bond with the resin. Fibres treated with silane had the highest bonding strength. The tensile mechanical properties, characterised using the single-fibre test method according to the ASTM standard C1557-03 (2008), showed that the NaOH treatment improved ultimate tensile strength, while the silane treatment decreased ultimate tensile strength for all sisal grades. Nevertheless, the ultimate tensile strength was reduced when the duration of the combined treatments was increased. The highest results for the mechanical properties were obtained from the combined treatments of NaOH followed by silane (each for 6 h)

Remote sensing and GIS

Presented at the fifth international conference on irrigation and drainage, Irrigation and drainage for food, energy and the environment on November 3-6, 2009 in Salt Lake City, Utah.Includes bibliographical references.Managing water resources in western US has been a challenge for decision makers. In the last few decades, the rapid growth rates of population along with the alarming rates of global warming have added to the complexity of this issue. In this study, remote sensing techniques have been applied to evaluate the performance of agricultural irrigation, the largest consumptive user of water. The study area, "Palo Verde irrigation District" which is located in Riverside and Imperial counties, California, is an old irrigation district with a fairly heterogeneous cropping pattern. Landsat Thematic Mapper satellite images were used to estimate the actual ET using the SEBAL energy balance model. These estimates were integrated to obtain crop water demand for different periods throughout the growing season. The amount of diverted water was also estimated for the same periods, using flow measurements within the Palo Verde irrigation district. The results were analyzed within the ArcGIS environment in conjunction with water conveyance and field boundary layers to evaluate different performance indicators such as relative water supply, overall consumed ratio, depleted fraction, crop water deficit, and relative evapotranspiration. The results of these indicators can help irrigation managers to get a general idea of how the system performs and to identify possible ways of improving it

The Vibrio cholerae Minor Pilin TcpB Initiates Assembly and Retraction of the Toxin- Coregulated Pilus

Type IV pilus (T4P) systems are complex molecular machines that polymerize major pilin proteins into thin filaments displayed on bacterial surfaces. Pilus functions require rapid extension and depolymerization of the pilus, powered by the assembly and retraction ATPases, respectively. A set of low abundance minor pilins influences pilus dynamics by unknown mechanisms. The Vibrio cholerae toxin-coregulated pilus (TCP) is among the simplest of the T4P systems, having a single minor pilin TcpB and lacking a retraction ATPase. Here we show that TcpB, like its homolog CofB, initiates pilus assembly. TcpB co-localizes with the pili but at extremely low levels, equivalent to one subunit per pilus. We used a micropillars assay to demonstrate that TCP are retractile despite the absence of a retraction ATPase, and that retraction relies on TcpB, as a V. cholerae tcpB Glu5Val mutant is fully piliated but does not induce micropillars movements. This mutant is impaired in TCP-mediated autoagglutination and TcpF secretion, consistent with retraction being required for these functions. We propose that TcpB initiates pilus retraction by incorporating into the growing pilus in a Glu5-dependent manner, which stalls assembly and triggers processive disassembly. These results provide a framework for understanding filament dynamics in more complex T4P systems and the closely related Type II secretion system

Search for the Flavor-Changing Neutral Current Decay D0→μ+μ−D^0 \to \mu^+\mu^- with the HERA-B Detector

We report on a search for the flavor-changing neutral current decay $D^0 \to \mu^+\mu^-$ using $50 \times 10^6$ events recorded with a dimuon trigger in interactions of 920 GeV protons with nuclei by the HERA-B experiment. We find no evidence for such decays and set a 90% confidence level upper limit on the branching fraction $Br(D^0 \to \mu^+\mu^-) <2.0 \times 10^{-6}$.Comment: 17 pages, 4 figures (of which 1 double), paper to be submitted to Physics Letters

Measurement of the J/Psi Production Cross Section in 920 GeV/c Fixed-Target Proton-Nucleus Interactions

The mid-rapidity (dsigma_(pN)/dy at y=0) and total sigma_(pN) production cross sections of J/Psi mesons are measured in proton-nucleus interactions. Data collected by the HERA-B experiment in interactions of 920 GeV/c protons with carbon, titanium and tungsten targets are used for this analysis. The J/Psi mesons are reconstructed by their decay into lepton pairs. The total production cross section obtained is sigma_(pN)(J/Psi) = 663 +- 74 +- 46 nb/nucleon. In addition, our result is compared with previous measurements

Single hadron response measurement and calorimeter jet energy scale uncertainty with the ATLAS detector at the LHC

The uncertainty on the calorimeter energy response to jets of particles is derived for the ATLAS experiment at the Large Hadron Collider (LHC). First, the calorimeter response to single isolated charged hadrons is measured and compared to the Monte Carlo simulation using proton-proton collisions at centre-of-mass energies of sqrt(s) = 900 GeV and 7 TeV collected during 2009 and 2010. Then, using the decay of K_s and Lambda particles, the calorimeter response to specific types of particles (positively and negatively charged pions, protons, and anti-protons) is measured and compared to the Monte Carlo predictions. Finally, the jet energy scale uncertainty is determined by propagating the response uncertainty for single charged and neutral particles to jets. The response uncertainty is 2-5% for central isolated hadrons and 1-3% for the final calorimeter jet energy scale.Comment: 24 pages plus author list (36 pages total), 23 figures, 1 table, submitted to European Physical Journal

Measurement of χ c1 and χ c2 production with s√ = 7 TeV pp collisions at ATLAS

The prompt and non-prompt production cross-sections for the χ c1 and χ c2 charmonium states are measured in pp collisions at s√ = 7 TeV with the ATLAS detector at the LHC using 4.5 fb−1 of integrated luminosity. The χ c states are reconstructed through the radiative decay χ c → J/ψγ (with J/ψ → μ + μ −) where photons are reconstructed from γ → e + e − conversions. The production rate of the χ c2 state relative to the χ c1 state is measured for prompt and non-prompt χ c as a function of J/ψ transverse momentum. The prompt χ c cross-sections are combined with existing measurements of prompt J/ψ production to derive the fraction of prompt J/ψ produced in feed-down from χ c decays. The fractions of χ c1 and χ c2 produced in b-hadron decays are also measured

Measurement of the production of a W boson in association with a charm quark in pp collisions at √s = 7 TeV with the ATLAS detector

The production of a W boson in association with a single charm quark is studied using 4.6 fb−1 of pp collision data at s√ = 7 TeV collected with the ATLAS detector at the Large Hadron Collider. In events in which a W boson decays to an electron or muon, the charm quark is tagged either by its semileptonic decay to a muon or by the presence of a charmed meson. The integrated and differential cross sections as a function of the pseudorapidity of the lepton from the W-boson decay are measured. Results are compared to the predictions of next-to-leading-order QCD calculations obtained from various parton distribution function parameterisations. The ratio of the strange-to-down sea-quark distributions is determined to be 0.96+0.26−0.30 at Q 2 = 1.9 GeV2, which supports the hypothesis of an SU(3)-symmetric composition of the light-quark sea. Additionally, the cross-section ratio σ(W + +c¯¯)/σ(W − + c) is compared to the predictions obtained using parton distribution function parameterisations with different assumptions about the s−s¯¯¯ quark asymmetry

Search for squarks and gluinos with the ATLAS detector in final states with jets and missing transverse momentum using √s=8 TeV proton-proton collision data

A search for squarks and gluinos in final states containing high-p T jets, missing transverse momentum and no electrons or muons is presented. The data were recorded in 2012 by the ATLAS experiment in s√=8 TeV proton-proton collisions at the Large Hadron Collider, with a total integrated luminosity of 20.3 fb−1. Results are interpreted in a variety of simplified and specific supersymmetry-breaking models assuming that R-parity is conserved and that the lightest neutralino is the lightest supersymmetric particle. An exclusion limit at the 95% confidence level on the mass of the gluino is set at 1330 GeV for a simplified model incorporating only a gluino and the lightest neutralino. For a simplified model involving the strong production of first- and second-generation squarks, squark masses below 850 GeV (440 GeV) are excluded for a massless lightest neutralino, assuming mass degenerate (single light-flavour) squarks. In mSUGRA/CMSSM models with tan β = 30, A 0 = −2m 0 and μ > 0, squarks and gluinos of equal mass are excluded for masses below 1700 GeV. Additional limits are set for non-universal Higgs mass models with gaugino mediation and for simplified models involving the pair production of gluinos, each decaying to a top squark and a top quark, with the top squark decaying to a charm quark and a neutralino. These limits extend the region of supersymmetric parameter space excluded by previous searches with the ATLAS detector