A two-dimensional relaxation scheme for the hybrid modelling of two-phase flows

International audienceRecently, a new relaxation scheme for hybrid modelling of two-phase flows has been proposed. This one allows to obtain stable unsteady approximations for a system of partial differential equations containing non-smooth data. This paper is concerned with a two-dimensional extension of the present method, in which two alternative relaxation schemes are compared. A partial analysis of continuous stability is given

Design and Synthesis of Substituted N,3,3-Triphenylpropanamide and 1-Benzhydryl-N-phenylazetidine-3-carboxamide Analogs and their Biological Evaluation

As D1R agonism has significant implications in the treatment of cognitive deficits, we sought to develop novel D1R PAMs, through the derigidification of BMS D1R PAM hit compound. While we were able to synthesize derigidified analogs of the BMS hit compound, derigidification did not produce active D1R ligands

A relaxation scheme for hybrid modelling of gas-particle flows

International audienceThis paper aims at proposing a relaxation scheme that allows to obtain stable approximations for a system of partial differential equations which governs the evolution of the void fraction and the mean velocity in the particle phase of two-phase flows. This system involves the divergence of a particle kinetic tensor, which is provided by a Lagrangian code and whose components are not smooth. The simulation algorithm is based on the combined use of upwinding and relaxation techniques. The main properties of the method are given, together with the Finite Volume Godunov scheme and this approach is compared to an analogous one that was developed earlier. Some measured rates of convergence in L 1-norm are provided, for a particular choice of the kinetic tensor. To complete the picture, we present some numerical results obtained when non-smooth external data are provided to the system

Radiative recombination in BiI₃(Mn) and BiI₃(Cr) layered single crystals

The photoluminescence spectra of BiI₃(Mn) and BiI₃(Cr) single crystals were studied. The new bands at λ = 1.1 and λ = 1.83 μm were registered at the temperature 4.2 K. It was shown that the first and second bands arise due to Mn²⁺ and Cr³⁺ ions, accordingly. The experimental results were explained using the configuration model. The energies between minima of configuration curves of excited and basic states for both centres were estimated

Розробка мінерального в'яжучого матеріалу з підвищеним вмістом червоного шламу

The object of present research is the technology of production of mineral binding materials of low-temperature (Tmax=1100 ºC) roasting of the romancement type with maximal possible use of waste from alumina production – red mud as a technogenic raw material. We employed as research methods a combination of computer calculations using the new software, modern physical-chemical methods of analysis and standardized testing of the properties of raw materials and binding materials.Based on computer calculations, applying the developed software «RomanCem», we performed analysis of dependence of the concentration of red mud in 3-component blends on the number of hydraulic module of the binder NM=1.1–1.7. We determined compositions of blends containing red mud of 27.0–27.5 % by weight (versus 3–5 % by weight in the technology of Portland cement) for the production of a hydraulic mineral binder at a maximum temperature of roasting 1100 ºC (versus 1400–1450 ºC for Portland cement) with improved indicators of strength at 18–22 MPa (versus 5–10 MPa for romancement). Effectiveness of our technique is defined by a comprehensive solution to the issues of ecology (due to reducing the volumes of waste accumulation), resource saving (through a replacement with waste of part of the raw materials of natural origin), and technology of binders (due to obtaining a product of the romancement type with improved indicators of properties). We demonstrated the features of phase composition and properties of the binders based on the systems of carbonate component with polymineral clay, quartz powder and red mud.Рассмотрена возможность увеличения объемов утилизации отходов производства глинозема – красного шлама путем применения как техногенного сырья для изготовления вяжущего материала низкотемпературного обжига типа романцемента. Показаны особенности фазового состава и свойств вяжущего на основе систем карбонатного компонента с полиминеральной глиной, пылекварцем и красным шламом.Розглянуто можливість збільшення обсягів утилізації відходів виробництва глинозему – червоного шламу шляхом використання як техногенної сировини для виготовлення в’яжучого матеріалу низько температурного випалу типу романцементу. Показано особливості фазового складу та властивостей в’яжучого на основі систем карбонатного компоненту з полімінеральною глиною, пилокварцом і червоним шламом

Influence of Si doping on InAs/GaAs quantum dot solar cells with AlAs cap layers

A novel all-optical forward-viewing photoacoustic probe using a flexible coherent fibre-optic bundle and a Fabry- Perot (FP) ultrasound sensor has been developed. The fibre bundle, along with the FP sensor at its distal end, synthesizes a high density 2D array of wideband ultrasound detectors. Photoacoustic waves arriving at the sensor are spatially mapped by optically scanning the proximal end face of the bundle in 2D with a CW wavelength-tunable interrogation laser. 3D images are formed from the detected signals using a time-reversal image reconstruction algorithm. The system has been characterized in terms of its PSF, noise-equivalent pressure and field of view. Finally, the high resolution 3D imaging capability has been demonstrated using arbitrary shaped phantoms and duck embryo

Si-Doped InAs/GaAs Quantum-Dot Solar Cell With AlAs Cap Layers

One of the requirements for strong subbandgap photon absorption in the quantum-dot intermediate-band solar cell (QD-IBSC) is the partial filling of the intermediate band. Studies have shown that the partial filling of the intermediate band can be achieved by introducing Si doping to the QDs. However, the existence of too many Si dopants leads to the formation of point defects and, hence, a reduction of photocurrent. In this study, the effect of Si doping on InAs/GaAs QD solar cells with AlAs cap layers is studied. The AlAs cap layers prevent the formation of the wetting layer during QD growth and reduce the Si doping density needed to achieve QD state filling. Furthermore, the passivation of defect states in the QD with moderate Si doping is demonstrated, which leads to an enhancement of the carrier lifetime in the QDs and, hence, the open-circuit voltage

Aharonov-Bohm interference in quantum ring exciton: effects of built-in electric fields

We report a comprehensive discussion of quantum interference effects due to the finite structure of excitons in quantum rings and their first experimental corroboration observed in the optical recombinations. Anomalous features that appear in the experiments are analyzed according to theoretical models that describe the modulation of the interference pattern by temperature and built-in electric fields.Comment: 6 pages, 7 figure