Alexander Badalyan

Bio: Alexander Badalyan is an academic researcher from University of Adelaide. The author has contributed to research in topics: Hydraulic fracturing & Porous medium. The author has an hindex of 24, co-authored 82 publications receiving 1469 citations. Previous affiliations of Alexander Badalyan include Cooperative Research Centre & University of South Australia.

Particle mobilization in porous media: Temperature effects on competing electrostatic and drag forces

Abstract: The fluid flow in natural reservoirs mobilizes fine particles. Subsequent migration and straining of the mobilized particles in rocks greatly reduce reservoir permeability and well productivity. This chain of events typically occurs over the temperature ranges of 20-40 degrees C for aquifers and 120-300 degrees C for geothermal reservoirs. However, the present study might be the first to present a quantitative analysis of temperature effects on the forces exerted on particles and of the resultant fines migration. Based on torque balance between electrostatic and drag forces acting on attached fine particles, we derived a model for the maximum retention concentration and used it to characterize the detachment of multisized particles from rock surfaces. Results showed that electrostatic force is far more affected than water viscosity by temperature variation. An analytical model for flow toward wellbore that is subject to fines migration was derived. The experiment-based predictive modeling of the well impedance for a field case showed high agreement with field historical data (coefficient of determination R-2=0.99). It was found that the geothermal reservoirs are more susceptible to fine particle migration than are conventional oilfields and aquifers.

Size-exclusion colloidal transport in porous media - stochastic modeling and experimental study

Abstract: Suspension, colloidal, and emulsion flow in rocks with particle size-exclusion may have a strong effect on the reservoir and on the well behavior during fines migration and production, drilling-fluid invasion into oil- or gas-bearing formations, or injection of seawater or produced water. The stochastic microscale equations for size-exclusion colloidal transport in porous media (PM) are derived. The proposed model includes the following new features: It accounts for the accessible flux in the expression for capture rate, it accounts for the increase of inlet concentration caused by the injected particles entering only the accessible area, and it accounts for the dilution of effluent accessible flux in the overall flux of the produced suspension.

The Nature Of The Chemical Bond

Abstract: Thank you very much for reading the nature of the chemical bond. As you may know, people have search numerous times for their chosen books like this the nature of the chemical bond, but end up in malicious downloads. Rather than enjoying a good book with a cup of tea in the afternoon, instead they are facing with some harmful virus inside their laptop. the nature of the chemical bond is available in our digital library an online access to it is set as public so you can get it instantly. Our books collection hosts in multiple locations, allowing you to get the most less latency time to download any of our books like this one. Kindly say, the the nature of the chemical bond is universally compatible with any devices to read.

A review of solar energy driven desalination technologies

Abstract: Water plays an important role in all our day to day activities and its consumption is increasing day by day because of increased living standards of mankind. Some regions of the globe are under severe stress due to water scarcity and pollution. The fresh water needs of mankind can be only satisfied if saline water which is available in plenty is converted to potable water by desalination. Desalination industry has shown increased threats of CO2 emissions and severe environmental impacts. Desalination industry can be made sustainable if they are integrated with renewable energy and if proper brine disposal methods are followed. In this review different desalination units integrated with renewable energy with special emphasis given to solar energy is discussed. The problems associated with desalination units and their remedies have been presented. Apart from this some novel methods of desalination process has also been explained. This review will allow the researchers to choose appropriate desalination technology for further development.

A New Visible-Light Photocatalyst: CdS Quantum Dots Embedded Mesoporous TiO2

Abstract: Cadmium sulfide quantum dots (QDs) sensitized mesoporous TiO2 photocatalysts were prepared by preplanting cadmium oxide as crystal seeds into the framework of ordered mesoporous titanium dioxide and then converting CdO to CdS QDs through ion-exchange. The presence of CdS QDs in the TiO2 framework extended its photoresponse to the visible-light region by accelerating the photogenerated electron transfer from the inorganic sensitizer to TiO2. The new photocatalyst showed excellent photocatalytic efficiency for both oxidation of NO gas in air and degradation of organic compounds in aqueous solution under visible light irradiation. The photocatalysts were characterized by XRD, N2 adsorption−desorption, TEM, XPS, UV/vis, and PL spectroscopy. The relationship between the physicochemical properties and the photocatalytic performance of the sample is discussed.

Perovskite-like Metal Formates with Weak Ferromagnetism and as Precursors to Amorphous Materials

Abstract: Three isomorphous compounds M(CHOO)3[NH2(CH3)2] (M = Mn(1·Mn), Co(2·Co), Ni(3·Ni)) have been synthesized in solvothermal conditions. Single-crystal X-ray diffraction shows that they are all crystallized in the trigonal space group R 3c with small differences in the lattice parameters. Bridged by the three-atom single-bridge CHOO-, M ions form a three-dimensional distorted perovskite-like structure with dimethylamine (DMA) cations located in the cages of the network. Based on the magnetic data, these three 3D compounds are weak ferromagnets with the critical temperature Tc = 8.5 K (1·Mn), 14.9 K (2·Co), and 35.6 K (3·Ni), and for 2·Co and 3·Ni, spin reorientation might take place at 13.1 and 14.3 K, respectively. At 1.8 K, hysteresis loops can be observed for all three compounds with the coercivity field ca. 90 Oe (1·Mn), 920 Oe (2·Co), and 320 Oe (3·Ni). The canting angles are estimated to be 0.08°, 0.5°, and 0.6° for 1·Mn, 2·Co, and 3·Ni, respectively. The magnetic coupling between MnII ions in 1·Mn was...