ULTRA-SHARP nonoscillatory convection schemes for high-speed steady multidimensional flow

For convection-dominated flows, classical second-order methods are notoriously oscillatory and often unstable. For this reason, many computational fluid dynamicists have adopted various forms of (inherently stable) first-order upwinding over the past few decades. Although it is now well known that first-order convection schemes suffer from serious inaccuracies attributable to artificial viscosity or numerical diffusion under high convection conditions, these methods continue to enjoy widespread popularity for numerical heat transfer calculations, apparently due to a perceived lack of viable high accuracy alternatives. But alternatives are available. For example, nonoscillatory methods used in gasdynamics, including currently popular TVD schemes, can be easily adapted to multidimensional incompressible flow and convective transport. This, in itself, would be a major advance for numerical convective heat transfer, for example. But, as is shown, second-order TVD schemes form only a small, overly restrictive, subclass of a much more universal, and extremely simple, nonoscillatory flux-limiting strategy which can be applied to convection schemes of arbitrarily high order accuracy, while requiring only a simple tridiagonal ADI line-solver, as used in the majority of general purpose iterative codes for incompressible flow and numerical heat transfer. The new universal limiter and associated solution procedures form the so-called ULTRA-SHARP alternative for high resolution nonoscillatory multidimensional steady state high speed convective modelling

Emulsion-Liquid-Membrane Extraction of Alkali Metals by Nano-baskets

Nano-assisted inclusion separation of alkali metals from basic solutions was reported by inclusionfacilitated emulsion liquid membrane process. The novelty of this study is application of nano-baskets of calixcrown in the selective and efficient separation of alkali metals as both the carrier and the surfactant. For this aim, four derivatives of diacid calix[4]-1,3-crowns-4,5 were synthesized, and their inclusionextraction parameters were optimized including the calixcrown scaffold (4, 4 wt%) as the carrier/ demulsifier, the commercial kerosene as diluent in membrane, sulphonic acid (0.2 M) and ammonium carbonate (0.4 M) as the strip and the feed phases, the phase and the treat ratios of 0.8 and 0.3, mixing speed (300 rpm), and initial solute concentration (100 mg/L). The results reveled that under the optimized operating condition, the degree of inclusion-extraction of alkali metals was as high as 98-99%. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3513

Voltammetric Behavior of Nano-basket Complexes

Eight nano-baskets of cone calix[4]arene-crown-3, -crown-4, -crown-5, -crown-6 were synthesized and their binding abilities towards alkali and alkaline earth metals as well as some lanthanides were studied using differential pulse voltammetry. The novelty of this study was investigation of those nano-basket complexes by voltammetric behaviors of two acidic moieties in each scaffold during complexation of crown ether ring. Their voltammetric behaviors were closely related to the complex formation by entrapment of cation into crown ether cavity and ion-dipole interaction between cation and acidic moieties in nanobaskets. The results revealed the selective changes in voltammetric behavior of synthesized scaffolds toward the cations. By increasing the binding ability of macrocycle and cation, the anodic oxidation peak of carboxylic acids was decreased. It was shown that the voltammetric traces of low energy complexes did not affected by encapsulated cations in the coordination space of crown ether and they showed no voltammetric behavior. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3546

Voltammetric Behavior of Nano-basket Complexes

Eight nano-baskets of cone calix[4]arene-crown-3, -crown-4, -crown-5, -crown-6 were synthesized and their binding abilities towards alkali and alkaline earth metals as well as some lanthanides were studied using differential pulse voltammetry. The novelty of this study was investigation of those nano-basket complexes by voltammetric behaviors of two acidic moieties in each scaffold during complexation of crown ether ring. Their voltammetric behaviors were closely related to the complex formation by entrapment of cation into crown ether cavity and ion-dipole interaction between cation and acidic moieties in nanobaskets. The results revealed the selective changes in voltammetric behavior of synthesized scaffolds toward the cations. By increasing the binding ability of macrocycle and cation, the anodic oxidation peak of carboxylic acids was decreased. It was shown that the voltammetric traces of low energy complexes did not affected by encapsulated cations in the coordination space of crown ether and they showed no voltammetric behavior. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3546

Liquid-Liquid Microextraction of Tetrahedral Oxoanions by Nano-baskets

This paper introduces a nano-based microextraction and examines its ability in preconcentration of dinegative tetrahedral oxoanions in the produced water. Nano-baskets of diacid p-tert-butylcalix[4]arene in the cone conformation were synthesized and used. The related parameters including ligand concentration, volume of water disperser, salt effect, and extraction time were optimized. The linear range, detection limit (S/N 3) and precision (RSD, n 6) were determined to be in the range of 1.0–280, 2.0–42.0 μgL−1 and 2.6– 11.0 %, respectively. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3519

Inclusion Chromatography of Albuterol in Livestock by Nano-baskets

Albuterol, which increases the muscle mass and decreases the adipose tissue, is misused as nutrient repartitioning agent in livestock. Hence, a new sensitive method for determination of albuterol in livestock is presented. Four nano-baskets of calix[4]crown were synthesized and used to prepare nano-based bendedphases of HPLC–UV. The new synthesized bonded-phases were characterized and optimized, the bonding interactions of solute:stationary phases were examined and the main interactions were reported. The albuterol level of six samples of livestock meat including pork, pork casing, beef, beef casing, mutton, and mutton casing were analyzed and the results revealed that for the best bonded-phases, the LOD and LOQ were 0.06 and 0.20 μg/mL, respectively. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3495

Metabolic Fingerprinting of Rat Serum by Nano-baskets and ELM – NMR

A novel approach for metabolite extraction and fingerprinting was introduced base upon the emulsion liquid membrane-nuclear magnetic resonance (ELM – NMR) technique. The objective of this method is optimizing the fingerprints, minimizing the metabolic variation from analysis, increasing the likelihood differences, and obtaining the maximum extraction yield. Low molecular weight metabolites in rat serum were recovered by ELMs using four nano-baskets of calix [4]-1,3-crowns as emulsifier and carrier. The yields of ELMs were optimized by the method of once at a time. According to the NMR data, the maximum metabolic variation was achieved using scaffold 4 (4 wt %), n-decane membrane, stirring rate of 300 rpm, treat and phase ratios of 0.3 and 0.8, respectively. According to the NMR data, the results revealed that calixcrowns 1-3 tend to extract non-specific macromolecules and the repeatability of fingerprints for 4- mediated ELM was more than three others. The yield of extractions was obtained to be higher for n-decane and lower for carbon tetrachloride. Using different membrane types, the fingerprints by chlorinated liquid membranes were more repeatable than toluene or n-decane. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3496

Liquid-Liquid Microextraction of Vanadyl Porphyrins by Nano-baskets

The novelties of this approach are introducing the self-settled dispersive liquid-liquid microextraction technique to remove the centrifuging step, conducting the dispersive liquid phase microextraction in complex organic systems, applicability of water as disperser phase, and nano-extraction of charged porphyrins by nano-baskets of calixcrown, which act as the settling agents as well as the inclusion ligands. Four proton di-ionizable diacid conformers of 25,26-bis(carboxymethoxy)calix[4]arene-27,28-crown-3; -crown-4; - crown-5; and -crown-6 in the cone conformation were synthesized and used. The related parameters including ligand concentration, volume of water disperser, salt effect, and extraction time were optimized. The linear range, detection limit (S/N 3) and precision (RSD, n 6) were determined to be 0.2–50, 0.07 μgL−1 and 5.3%, respectively. The established method was applied to determine the target compound in five samples of live crude oil, were sampled from an Iranian offshore field. Owing to the overall differences (such as organic media, inclusion extraction, water-soluble ligands, etc), the comparison of the proposed method with the traditional liquid-liquid microextraction was inapplicable. These results revealed that the new approach is competitive analytical tool and an alternative of the traditional methods in the crude oil and related systems. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3519

Weyl holographic superconductor in the Lifshitz black hole background

We investigate analytically the properties of the Weyl holographic superconductor in the Lifshitz black hole background. We find that the critical temperature of the Weyl superconductor decreases with increasing Lifshitz dynamical exponent, $z$, indicating that condensation becomes difficult. In addition, it is found that the critical temperature and condensation operator could be affected by applying the Weyl coupling, $\gamma$. Moreover, we compute the critical magnetic field and investigate its dependence on the parameters $\gamma$ and $z$. Finally, we show numerically that the Weyl coupling parameter $\gamma$ and the Lifshitz dynamical exponent $z$ together control the size and strength of the conductivity peak and the ratio of gap frequency over critical temperature $\omega_{g}/T_{c}$.Comment: 25 pages, 22 figure