Influence of intensity and frequency of ultrasonic waves on capillary interaction and oil recovery from different rock types

Oil saturated cylindrical sandstone cores were placed into imbibition cells where they contacted with an aqueous phase and oil recovery performances were tested with and without ultrasonic radiation keeping all other conditions and parameters constant. Experiments were conducted for different initial water saturation, oil viscosity and wettability. The specifications of acoustic sources such as ultrasonic intensity (45–84 W/sq cm) and frequency (22 and 40 kHz) were also changed. An increase in recovery was observed with ultrasonic energy in all cases. This change was more remarkable for the oil-wet medium. The additional recovery with ultrasonic energy became lower as the oil viscosity increased. We also designed a setup to measure the ultrasonic energy penetration capacity in different media, namely air, water, and slurry (sand + water mixture). A one-meter long water or slurry filled medium was prepared and the ultrasonic intensity and frequency were monitored as a function of distance from the source. The imbibition cells were placed at certain distances from the sources and the oil recovery was recorded. Then, the imbibition recovery was related to the ultrasonic intensity, frequency, and distance from the ultrasonic source.     

High order quadratures for the evaluation of interfacial velocities in axi-symmetric Stokes flows

We propose new high order accurate methods to compute the evolution of axi-symmetric interfacial Stokes flow. The velocity at a point on the interface is given by an integral over the surface. Quadrature rules to evaluate these integrals are developed using asymptotic expansions of the integrands, both locally about the point of evaluation, and about the poles, where the interface crosses the axis of symmetry. The local expansions yield methods that converge to the chosen order pointwise, for fixed evaluation point. The pole expansions yield corrections that remove maximal errors of low order, introduced by singular behaviour of the integrands as the evaluation point approaches the poles. An interesting example of roundoff error amplification due to cancellation is also addressed. The result is a uniformly accurate fifth order method. Second order, pointwise fifth order, and uniform fifth order methods are applied to compute three sample flows, each of which presents a different computational difficulty: an initially bar-belled drop that pinches in finite time, a drop in a strain flow that approaches a steady state, and a continuously extending drop. In each case, the fifth order methods significantly improve the ability to resolve the flow. The examples furthermore give insight into the effect of the corrections needed for uniformity. We determine conditions under which the pointwise method is sufficient to obtain resolved results, and others under which the corrections significantly improve the results.     

The effect of fractional calculus on the formation of quantum-mechanical operators

In this paper, the deformation of the ordinary quantum mechanics is formulated based on the idea of conformable fractional calculus. Some properties of fractional calculus and fractional elementary functions are investigated. The fractional wave equation in 1 + 1 dimension and fractional version of the Lorentz transformation are discussed. Finally, the fractional quantum mechanics is formulated; infinite potential well problem, density of states for the ideal gas, and quantum harmonic oscillator problem are discussed.     

Some remarks on the Hodge conjecture for abelian varieties

We show how the classical Hodge conjecture for the middle cohomology of an abelian variety is equivalent to the general Hodge conjecture for the middle cohomology of a smooth ample divisor in the abelian variety. This is best suited to abelian varieties with actions of imaginary quadratic fields.     

Substituted quinolinones. 31. Some new pyrano[3,2‐c]quinoline‐3‐carboxamides and their antioxidant activity

1‐Ethyl‐4‐hydroxy‐2‐oxo‐1,2‐dihydroquinoline‐3‐carbaldehyde ( 1 ) was annulated using malonic acid and/or its ethyl ester to furnish pyrano[3,2‐c]quinoline‐3‐carboxylic acid 2 and its ester 3 . Interconversions between acid 2 and ester 3 were successfully carried out. The anticipated pyrano[3,2‐c]quinoline‐3‐carboxamides 5–12 were conveniently attained via condensation of ester 3 with the proper amine. Surprisingly, treatment of ester 3 with dimethylformamide (DMF) in acidic media led to the carboxamide 5 . All attempts to convert ester 3 to its corresponding acid hydrazides by interaction with the proper hydrazine derivative led to formation of pyrazolidinediones 15 and 17 . Ester 3 underwent cyclo‐condensation with malononitrile dimer affording pyrido[3′,4′:5,6]pyrano[3,2‐c]quinoline derivative 18 . The new compounds revealed significant antioxidant effect, which suggests that most of them are possible potent antioxidant agents.     

Air‐assisted liquid–liquid extraction coupled with dispersive liquid–liquid microextraction and a drying step for extraction and preconcentration of some phthalate esters from edible oils prior to their determination by GC

In this work, a new, cheap, simple, fast, and low organic solvent consuming procedure is proposed for isolation, enrichment, and gas chromatographic determination of some phthalate esters in edible oils. The method is based on a combination of air‐assisted liquid–liquid extraction and dispersive liquid–liquid microextraction followed by a drying step under N₂ gas. Several experimental parameters affecting both extraction and preconcentration steps were investigated and optimized. Under the optimum conditions for the proposed method, wide linear ranges (0.05–800 μg/L) and low detection limits (0.007–0.023 μg/L) were observed. The ranges of enrichment factors and extraction recoveries were 68–340 and 14–68%, respectively. Eventually, the target analytes were successfully determined in different edible oils using the proposed method.     

One-pot,solvent-free and efficient synthesis of 2,4,6-triarylpyridines catalyzed by nano-titania-supported sulfonic acid as a novel heterogeneous nanocatalyst

Nano titania-supported sulfonic acid (n-TSA) has found to be a highly efficient, eco-friendly and recyclable heterogeneous nanocatalyst for the solvent-free synthesis of 2, 4, 6-triarylpyridines through one-pot three-component reaction of acetophenones, aryl aldehydes and ammonium acetate. This reported method illustrates several advantages such as environmental friendliness reaction conditions, simplicity, short reaction time, easy work up, reusability of catalyst and high yields of the products. One new compound is reported too. Furthermore, the catalyst could be recycled after a simple work-up, and reused at least six times without substantial reduction in its catalytic activity.     

Shape control of nanostructured TiO2 using a Schiff base ligand via sol–gel hydrothermal method

Employing a Schiff base ligand in a hydrothermal sol–gel method for preparation of TiO₂ nanostructures was studied. The as-prepared products were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectrum, electron dispersive X-ray spectroscopy and ultraviolet–visible spectroscopy. It is shown that in the controlled reaction conditions, a Schiff base ligand containing hard atoms is capable of driving the growth mechanism in a way that anisotropic shapes of TiO₂ nanostructures are formed. Considering the structure of the Schiff base ligand, the possible growth mechanism of TiO₂ nanostructures is proposed. The optical studied as well as calculated molecular orbital structure of ligand by density functional theory is done.