Electrocoagulation process applied to wastewater containing dyes from textile industry

In the present work, electrocoagulation was applied for the colour removal of solutions containing Direct red 81. Experiments were performed for synthetic solutions in batch mode.     

Salinity effect on the compaction behaviour,matric suction,stiffness and microstructure of a silty soil

To better understand the salinity effect on the compaction behaviour of soil,standard Proctor compaction test was conducted on soil samples with different salinities.Matric suction and small-strain shear modulus,G_(max),were determined and pore size distribution was also investigated on samples statically compacted at different water contents.Results showed that with the decrease of soil salinity from initial value of 2.1‰(g of salt/kg of dry soil) to zero,the maximum dry density increased and the optimum water content decreased,whereas there was no significant change with the increase of soil salinity from2.1 ‰ to 6.76‰.Interestingly,it was observed that G_(max) also decreased when the soil salinity decreased from initial value of 2.1‰ to zero and kept almost constant when the soil salinity increased from 2.1‰ to6.76‰, for dry samples with similar matric suction and also for samples compacted at optimum state and on wet side whose matric suctions were slightly different due to the difference in remoulded water content.Furthermore,the effect of salinity on compaction behaviour and G_(max) decreased for samples compacted from dry side to wet side.The pore size distribution exhibited bi-modal characteristics with two populations of micro-and macro-pores not only for samples compacted on dry side and at optimum state,but also for those compacted on wet side.Further examination showed that the modal size of micro-pores shifted to lower values and that of macro-pores shifted to higher values for saline soil compared to the soil without salt.     

Numerical damage prediction in dowel connections of wooden structures

The behaviour of timber connections is very complex because of the interaction between brittle and ductile failure modes that develop within the contact areas between the timber and the dowel. Simulating this behaviour numerically requires the use of multidimensional failure criteria as well as the use of coupled constitutive equations accounting for both non-linear isotropic hardening and isotropic ductile damage. Such a formulation is proposed in the present work and implemented within a Vumat user-defined subroutine in Abaqus/Explicit. The model is used to simulate the behaviour of a double shear timber steel connection. Good agreement was found between the FE results and experimental ones, which showed the good capability of the model to predict the onset of ductile damage and growth. It was found that failure results from ductile defects initiation, growth and propagation inside narrow shear bands wherein the plastic strain is highly localised.     

Correlation between high pressure effect and alloying in GaAs and Ga1-xAlx As

The empirical pseudopotential method coupled with the virtual crystal approximation has been used to compute the electronic band gaps and pseudocharge densities for the compound semiconductor GaAs and the alloy Ga_1−xAl_xAs. The variation of the compositional fraction of AlAs in GaAs has been correlated to the high pressure effect on GaAs.     

Design of coplanar waveguide elliptic low pass filters

This article proposes three design topologies of coplanar waveguide elliptic low pass filters. The design procedure is simple and explained in detail for the first topology. Numerical results are provided using the commercially available simulation softwares IE3D and HFSS to show the validity of the design with very good agreement. The proposed filters yield less than 0.1 dB attenuation in the passband (0–2 GHz), with a controllable slope of the transition between passband and stopband. The width of the rejection band is increased by simple filter cascading resulting in a passband to stopband ratio of up to 1:6. © 2009 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2009.     

Modelling of a hybrid photovoltaic thermal collector based on CdTe

A few years ago, silicon photovoltaic panels had yields of 10 to 18%, which made them interesting because is not profitable enough (too expensive to energy conversion yield too low).But recently, thin film technology appears to increase the efficiency and reduce the cost. For application in hybrid collectors, various types of solar photovoltaic hybrid collectors (PVT) based on new materials for solar cells have been developed as the binary semiconductor, ternary and quaternary materials and organic. CdTe is a the most appropriate binary materials for use in photovoltaic structures in thin layers, this material can produce a high yield of about 15% and is also known by a direct band structure gap of a value of 1.45 eV and a very high absorption coefficient (>105 cm^–1 in the visible). In this work we present the modeling of a hybrid photovoltaic thermal collector based on the thin films solar cells of CdTe, and then we made the determination of the temperature levels of the various layers through the development of the energy balance sheet involves heat exchange between the different components of the collector and to study its electrical and thermal performance, and finally compare their efficiency with it of the PVT collector based on monocrystalline silicon.     

European collaborative study of LH assay: 3. relationship of immunological reactivity, biological activity and charge of human luteinizing hormone

This report describes the results of the third part of the collaborative study organized by a working group sponsored by the Community Bureau of Reference of the European Community Commission. The aim of the present work was to establish the link between immunoreactivity and biological activity of human LH, thus allowing to determine the antigenic domains of the molecule involved in the induction of the biological effect. The relationship between immunoreactivity and electric charge of hLH was also studied. This work allowed to further apprehend hLH isomorphism and its role in discrepancies observed among hLH assays and clinical status. It also made the feasibility of measuring biologically active isoforms by an immunological method to be assessed. The effect of 36 mAb with known epitopic specificity, was evaluated on both hLH binding to rat membrane receptor and hLH induced production of testosterone by porcine Leydig cells. All the epitopes located on the beta subunit were found to be strongly involved in the biological activity whereas 4/9 and 10/18 epitopes present on the alpha subunit or specific for the holomolecule respectively appeared weakly involved. Assaying biological hLH using immunological method would require that mAb specific for all the epitopes involved in the receptor activation be tested, and thus appears presently unsuitable for routine clinical evaluation. In the previous work some LH immunoassays were found to underestimate LH concentrations (J. Endocrinol. Invest 1994, 17: 397-406 and 407-416). The mAb used in liquid phase in these kits were found in the present work to be directed against the domains of LH weakly involved in the activation of the receptor and would suggest that bioactive LH would be misevaluated by these kits. The immunoreactivity of hLH isoforms separated by isoelectric focusing (IEF) in liquid phase was also determined. IEF allowed to separate three groups of hLH isoforms but none of them exhibited a specific discriminating pattern of immunoreactivity when they were tested against a panel of mAb. It suggests that, in our experimental conditions, the electric charge and the immunoreactivity of hLH were not closely linked.     

Interleukin 1alpha stimulates lactate dehydrogenase A expression and lactate production in cultured porcine sertoli cells

By using cultured porcine Sertoli cells as a model, the action of interleukin 1alpha (IL-1alpha) on lactate production and the site of this action were studied. IL-1alpha stimulated Sertoli cell lactate production in a time- and dose-dependent manner (with a half-maximal effect [ED50] of 6 pM). Two major sites involved in IL-1alpha action were identified. First, IL-1alpha was shown to increase the uptake of glucose substrate in a time- and dose-dependent manner. The maximal effect, with an ED50 of 10 pM, was observed after 24 h of treatment. Second, IL-1alpha increased the activity of the lactate dehydrogenase (LDH) A4 isoform, which is involved in the conversion of pyruvate into lactate. This increase in LDH A4 activity was detected at 12 h and was maximal, with an ED50 of 9 pM, after 24-h treatment with IL-1alpha. The increase was related to an increase in LDH A4 expression, since IL-1alpha stimulated LDH A mRNA (size: 1.5 kilobases, evidenced through Northern blotting analysis) in a dose- and time-dependent manner. Assuming that IL-1alpha might be produced in the seminiferous tubules by both Sertoli and germ cells, which utilize lactate for their energy metabolism, we suggest that these results together show 1) that the cytokine may represent a signal in the metabolic cooperation existing between Sertoli cells and germ cells, and 2) that a redistribution of LDH isoforms in favor of LDH A4 under IL-1alpha control is a key mechanism(s) in such cooperation used by germ cells to enhance lactate production in Sertoli cells.     

The variation of valence and conduction band edges charge densities with lattice constant in GaP and InP

Valence and conduction band edge charge densities for direct band gap InP and indirect band gap semiconductors GaP are calculated for different values of the lattice constant. These variations affect the bonding properties of these semiconductors and the effect of interstitial impurities.     

InxGa1−xN refractive index calculations

The growth of In_xGa_1−xN Wurtzite structure is a well established fact. It permits to design optoelectronic devices such as laser diodes or LEDs, from the near ultraviolet to the infrared light spectrum. This sweeps indeed, the whole of the visible spectrum and, hence, appears to be very useful to the recent development of liquid crystal display screens, or designing photodiodes and perhaps solar cells (after studying their energetical efficiencies). Nevertheless, refractive indices of In_xGa_1−xN structure have not been studied.The refractive index of such structures is increasing from the GaN refractive index to the InN one, with therefore, a bowing of the curve due to the lattice mismatch between these two constituting binary alloys.The index is, in a certain range of the “n(x)” characteristic, less than the GaN one. This seems to be particularly interesting in the integrated optics domain or optical waveguides realization, because the growth of GaN is easier than the growth of In_xGa_1−xN.