Search results for "fluid"
showing 10 items of 5513 documents
Some past and present challenges of econophysics
2016
We discuss the cultural background that was shared by some of the first econophysicists when they started to work on economic and financial problems with methods and tools of statistical physics. In particular we discuss about the role of stylized facts and statistical physical laws in economics and statistical physics respectively. As an example of the problems and potentials associated with the interaction of different communities of scholars dealing with problems observed in economic and financial systems we briefly discuss the development and the perspectives of the use of tools and concepts of networks in econophysics, economics and finance.
Influence of total solids concentration on membrane permeability in a submerged hollow-fibre anaerobic membrane bioreactor.
2012
The main aim of this work was to study the influence of the mixed liquor total solids (MLTS) concentration on membrane permeability (K 20) in a submerged anaerobic membrane bioreactor (SAnMBR) pilot plant, which is equipped with industrial hollow-fibre membranes and treats urban wastewater. This pilot plant was operated at 33°C and 70 days of SRT. Two different transmembrane fluxes (13.3 and 10 LMH) were tested with a gas sparging intensity of 0.23 Nm 3 m -2 h -1 (measured as Specific Gas Demand referred to membrane area). A linear dependence of K 20 on MLTS concentration was observed within a range of MLTS concentration from 13 to 32 g L -1 and J 20 of 10 LMH. K 20 was maintained at sustai…
Impact of Plasmopara viticola on starch metabolism and stomachal functions in grapevine leaves
2011
The grapevine downy mildew affects leaves and young berries and can affect the harvest quality and quantity. The causal agent is the obligate biotroph oomycete Plasmopara viticola that induces severe physiological alterations in infected leaves. One is the abnormal accumulation of starch in oil spots, the characteristic symptoms of the disease. Another is a deregulation of stomatal movements. Stomata, natural openings on the leaf surface allowing gas exchanges between the plant and the atmosphere, stay abnormally open during the night and do no longer close upon water stress or ABA treatment in infected leaves. This thesis is divided into two chapters that aim to i) explain the origin and m…
Effects of sewage sludge addition to Norway spruce seedlings on nitrogen availability and soil fauna in clear-cut areas
2012
Anaerobically digested and composted sewage sludge (CSS) has been suggested to be a slow-release fertilizer in forestry and an alternative to quick-release inorganic fertilizers. The effects of CSS with or without added carbohydrate on inorganic nitrogen availability and on soil animals were tested in two Norway spruce plantations. Half of the seedlings were individually fertilized with CSS, and the rest were left as controls. Solid sucrose was added to half of the fertilized and untreated seedlings. Soil samples were taken in the autumn in the first and the second year after the treatments. CSS increased soil NH4-N (2100%), the proportion of soil NO3-N, and the N concentration of spruce ne…
Disordered hyperuniformity in superconducting vortex lattices
2020
Particles occupying sites of a random lattice present density fluctuations at all length scales. It has been proposed that increasing interparticle interactions reduces long range density fluctuations, deviating from random behaviour. This leads to power laws in the structure factor and the number variance that can be used to characterize deviations from randomness which eventually lead to disordered hyperuniformity. It is not yet fully clear how to link density fluctuations with interactions in a disordered hyperuniform system. Interactions between superconducting vortices are very sensitive to vortex pinning, to the crystal structure of the superconductor and to the value of the magnetic …
Complex conductivity in high-Tc single crystal superconductors
1994
The electromagnetic surface impedance of single crystal high-T c superconductors has been examined within the framework of the two-fluid model and the hypothesis that the em field modulates the partial concentrations of both normal and condensate fluids. A comparison with experimental data is reported
Patterning of Suitable Structures for the Investigation of the Josephson Effect in YBa2Cu3O7/PrBa2Cu3O7 Superlattices
1996
The aim of our work is to investigate the Josephson effect in YBa 2 Cu 3 O 7-δ /PrBa 2 Cu 3 O 7-δ superlattices. In the case of current flow along c axis direction the superlattice forms an array of artificial Josephson junctions where the YBa 2 Cu 3 O 7-δ layers are the superconducting electrodes which are separated but Josephson coupled by the PrBa 2 Cu 3 O 7-δ sheets. In this paper we report on the preparation, characterisation and patterning of the superlattices into suitable structures via standard photolithograpy and lift-off technique.
Josephson effect in superfluid atomic Fermi-gases
2002
We consider an analog of the internal Josephson effect in superfluid atomic Fermi-gases. Four different hyperfine states of the atoms are assumed to be trapped and to form two superfluids via the BCS-type pairing. Weshow that Josephson oscillations can be realized by coupling the superfluids with two laser fields. Choosing the laser detunings in a suitable way leads to an asymmetric below-gap tunneling effect for which there exists no analogue in the context of solid-state superconductivity.
Transport anisotropy and of thin films
2005
Abstract The resistivity R ( T ) of superconducting UNi 2 Al 3 thin films shows a pronounced dependence on the current direction. Specifically, the superconducting transition temperature T c is directional dependent as well as the influence of the magnetic ordering on the transport properties. Also the upper critical field B c 2 ( Θ , T ) is moderately influenced by the probe current direction. These anisotropies are discussed in the framework of multiband superconductivity. The initial slope of the upper critical field B c 2 ′ ( T ) provides evidence for a spin singlet state.
Strong vacuum squeezing from bichromatically driven Kerrlike cavities: from optomechanics to superconducting circuits
2015
AbstractSqueezed light, displaying less fluctuation than vacuum in some observable, is key in the flourishing field of quantum technologies. Optical or microwave cavities containing a Kerr nonlinearity are known to potentially yield large levels of squeezing, which have been recently observed in optomechanics and nonlinear superconducting circuit platforms. Such Kerr-cavity squeezing however suffers from two fundamental drawbacks. First, optimal squeezing requires working close to turning points of a bistable cycle, which are highly unstable against noise thus rendering optimal squeezing inaccessible. Second, the light field has a macroscopic coherent component corresponding to the pump, ma…