Search results for "Asma"

Nitric oxide contributes to cadmium toxicity in Arabidopsis by promoting cadmium accumulation in roots and by up-regulating genes related to iron upt…

2009

Abstract Nitric oxide (NO) functions as a cell-signaling molecule in plants. In particular, a role for NO in the regulation of iron homeostasis and in the plant response to toxic metals has been proposed. Here, we investigated the synthesis and the role of NO in plants exposed to cadmium (Cd2+), a nonessential and toxic metal. We demonstrate that Cd2+ induces NO synthesis in roots and leaves of Arabidopsis (Arabidopsis thaliana) seedlings. This production, which is sensitive to NO synthase inhibitors, does not involve nitrate reductase and AtNOA1 but requires IRT1, encoding a major plasma membrane transporter for iron but also Cd2+. By analyzing the incidence of NO scavenging or inhibition …

Identification and biological traits of a planthopper from the genus Pentastiridius (Hemiptera: Cixiidae) adapted to an annual cropping rotation

2009

International audience; Cixiid planthoppers have been shown to vector phloem-limited prokaryotes associated with plant diseases world-wide. In eastern France, an emerging disease of sugar beet called syndrome basses richesses has been associated with phloem-restricted bacteria transmitted by a cixiid planthopper within the genus Pentastiridius. Early investigation suggested the species being Pentastiridius beieri. On the basis of a morphological and phylogenetic study we report the identification of the planthopper as Pentastiridius leporinus. Furthermore we report some biological traits of the species, which shows a surprising ecological adaptation to an annual cropping rotation sugar beet…

Phytoplasmosis of bioenergy cultures

2018

The current state of biofuel distribution in EU, USA and Ukraine and its perspectives, new alternative sources of renewable energy, advantages and disadvantages of their use have been analyzed in this review. The concept growing of energy cultures in Ukraine has been described. Prospects for the use of bioenergy cultures of the 2nd generation have been considered. Particular attention has been paid to advantages and peculiarities of growing cultures with high potential of productivity - willow and poplar. The role of phytoplasmas in plant pathology has been considered; the pathways of distribution of plant phytoplasmosis, their localization in plant-host cells, typical symptoms of plants af…

Two-Dimensional Numerical Modelling of a Moored Floating Body under Sloping Seabed Conditions

2020

A coupled floating body-mooring line model is developed by combining a boundary element model for a two-dimensional floating body and a catenary mooring line model. The boundary element model is formulated in the time domain by a continuous Rankine source, and a reflection potential is introduced to account for the wave reflection due to sloping seabed. This newly developed model is validated by comparisons against available data. Then, dynamic response analyses are performed for the moored body in various seabed conditions. Compared with a flat seabed, a sloping seabed causes unsymmetrical mooring line configuration and generates noticeable effects in the motion responses of the floating b…

II) Wood pellets for home heating can be considered environmentally friendly fuels? Heavy metals determination by inductively coupled plasma-optical …

2016

Abstract The aim of the present study was to determine the concentrations of twelve potentially hazardous elements in wood pellet ashes obtained by the combustion of 13 pellet brands for sale in Italy, the impact of adding the ashes to soils and health risk of operator due to dust exposure. Samples were analysed by Inductively Coupled Plasma Optical Emission Spectrometry. The concentrations of heavy metals in ashes from stoves ranged from 0.41 to 7.2 mg kg − 1 for As, from 1.3 to 12 mg kg − 1 for Sb, from 1.8 to 12 mg kg − 1 for Zn, from 0.23 to 0.8 mg kg − 1 for Pb, from 0.18 to 2.8 mg kg − 1 for Ni, from 0.09 to 1.0 mg kg − 1 for Cd, from 0.46 to 3.4 mg kg − 1 for Cr, from 0.94 to 2.7 mg …

Transition to turbulence in serpentine pipes

2017

Abstract The geometry considered in the present work (serpentine pipe) is a sequence of U-bends of alternate curvature. It is characterized by pipe diameter, d = 2a and bend diameter, D = 2c. The repeated curvature inversion forces the secondary flow pattern, typical of all flows in curved ducts, to switch between two mirror-like configurations. This causes (i) pressure drop and heat or mass transfer characteristics much different from those occurring either in a straight pipe or in a constant-curvature pipe, and (ii) an early loss of stability of the base steady-state flow. In the present work, four values of the curvature δ = a/c (0.2, 0.3, 0.4 and 0.5) were considered. For each value of …

To incinerate or not? - Effects of incineration on the concentrations of heavy metals and leaching efficiency of post-precipitated sewage sludge (RAV…

2020

The major element and heavy metal concentrations of post-precipitated sewage sludge (PPS) and its ash residue (PPA) were determined using microwave digestion followed by inductively coupled plasma optical emission spectrometry (ICP-OES) and mass spectrometry (ICP-MS). To the best of our knowledge, this has not been previously done. In both PPS and PPA the heavy metal concentrations were clearly below the average concentrations than those encountered in sewage sludge in Europe. The leaching efficiency of the metal (Al/ Fe) used as a precipitation agent from post-precipitated sludge and its ash residue with phosphoric acid was also investigated with previously optimized leaching conditions. T…

Comments on “Overflow characteristics of streamlined weirs based on model experimentation” by Bagheri S. and Kabiri-Samani A

2021

Abstract In this paper the stage-discharge equation of a streamlined weir is theoretically deduced applying the Π-Theorem of dimensional analysis and the self-similarity theory. The coefficients of the new stage-discharge relationship are estimated using the experimental results by Bagheri and Kabiri-Samani.

Closure to “Extraction of the Flow Rate Equation under Free and Submerged Flow Conditions in Pivot Weirs with Different Side Contractions” by N. Shei…

2018

Partial Stabilization of Input-Output Contact Systems on a Legendre Submanifold

2017

This technical note addresses the structure preserving stabilization by output feedback of conservative input-output contact systems, a class of input-output Hamiltonian systems defined on contact manifolds. In the first instance, achievable contact forms in closed-loop and the associated Legendre submanifolds are analysed. In the second instance the stability properties of a hyperbolic equilibrium point of a strict contact vector field are analysed and it is shown that the stable and unstable manifolds are Legendre submanifolds. In the third instance the consequences for the design of stable structure preserving output feedback are derived: in closed-loop one may achieve stability only rel…