Salinity-Alkane Carbon Number (ACN) Relationship of Some Anionic Nonionic Surfactant Mixtures

Salinity scans were performed for petroleum sulphonate/eugenol ethoxyate mixtures having the same composition (0.75 mole fraction of witco TRS 10-80 petroleum sulphonate + 0.25 mole fraction of any of the prepared eugenol ethoxylates). Widths of the obtained three-phase (3?) microemulsion regions, were determined and the optimum salinity (S*) values of these anionic/nonionic systems, were calculated at different oil phase alkane carbon numbers (ACN). Phase behaviour diagrams, of the investigated systems, were constructed by plotting the width of the 3? region against oil phase ACN. From the obtained phase maps, the areas of the 3? regions, bounded between the upper and lower phase boundaries (UPB & LPB), were located. Also, the areas bounded between the UPB and LPB fitted curves for the whole ACN range (from hexane to hexadecane, 3?6-16) and that for the preferred ACN (from hexane to nonane, 3?6-9), were determined through computational approach. Linear and polynomial equations were developed to describe the S*-ACN relationship of the investigated systems.Results obtained reveal that more pronounced shift, in the 3? region, to higher ACN was observed when nonionic having longer polyoxyethylene chain was employed. Sulphonate/eugenol ethoxylate mixtures gave 3 ?6-9 regions at a relatively higher salinity ranges if compared with that of sulphonate alone. Such mixtures are more beneficial in surfactant flooding for high salinity reservoirs. Keywords : Eugenol ethoxylates, Petroleum sulphonates, Phase behaviour, Phase map, Surfactant flooding formulation systems

Serum Iron Status of Children with Cyanotic Congenital Heart Disease in Lagos, Nigeria

Objectives: Cyanotic congenital heart disease (CCHD) predisposes patients to iron deficiency due to compensatory secondary erythrocytosis. This study aimed to determine the serum iron status and prevalence of iron deficiency among children with cyanotic congenital heart disease attending the Paediatric Cardiology outpatient clinic of Lagos State University Teaching Hospital, Lagos, Nigeria. Methods: This cross-sectional casecontrol study took place between May and October 2015 at the Lagos State University Teaching Hospital. A total of 75 children with cyanotic congenital heart disease and 75 apparently healthy age-, gender- and socioeconomicallymatched controls were analysed to determine serum iron status and the prevalence of iron deficiency as defined by the World Health Organization criteria. Results: The mean age of the children was 47.5 ± 2.9 months (range: 6–144 months old). Iron deficiency was significantly more frequent among CCHD patients compared to control subjects (9.3% versus 0%; P = 0.006). While latent iron deficiency was more prevalent among children in the control group compared to those with CCHD, this difference was not statistically significant (13.3% versus 9.3%; P = 0.303). No cases of iron deficiency anaemia were observed in the studied sample. Conclusion: Neither the children in the control group nor those with CCHD had iron deficiency anaemia. However, iron deficiency was significantly more prevalent among children with CCHD in Lagos. Periodic serum iron status screening is therefore recommended for this population.Keywords: Congenital Heart Defects; Cyanosis; Iron Deficiency Anemia; Children; Case-Control Studies; Nigeria

Characterizing cell adhesion by using micropipette aspiration

International audienceWe have developed a technique to directly quantify cell-substrate adhesion force using micropipette aspiration. The micropipette is positioned perpendicular to the surface of an adherent cell and a constant-rate aspiration pressure is applied. Since the micropipette diameter and the aspiration pressure are our control parameters, we have direct knowledge of the aspiration force, whereas the cell behavior is monitored either in brightfield or interference reflection microscopy. This setup thus allows us to explore a range of geometric parameters, such as projected cell area, adhesion area, or pipette size, as well as dynamical parameters such as the loading rate. We find that cell detachment is a well-defined event occurring at a critical aspiration pressure, and that the detachment force scales with the cell adhesion area (for a given micropipette diameter and loading rate), which defines a critical stress. Taking into account the cell adhesion area, intrinsic parameters of the adhesion bonds, and the loading rate, a minimal model provides an expression for the critical stress that helps rationalize our experimental results

Antiknock Properties and Volatility Criteria of Some Gasoline-Butanol Blends

Antinock properties and volatility criteria were studied for all-hydrocarbon gasoline before and after blending with 8 and 12 volume percent n-and iso-butanol. Composition and specifications of the hydrocarbon- base gasoline and the formulated gasoline- oxygenate blends, were determined through gas chromatographic analysis and the standard test methods. The effects of n-and iso-butanol addition on driveability performance and volatility criteria, were studied. Keywords: oxygenated gasoline, gasoline-butanol blend volatility criteria, antiknock properties.

Any ll-state solutions of the Hulth\'en potential by the asymptotic iteration method

In this article, we present the analytical solution of the radial Schr\"{o}dinger equation for the Hulth\'{e}n potential within the framework of the asymptotic iteration method by using an approximation to the centrifugal potential for any $l$ states. We obtain the energy eigenvalues and the corresponding eigenfunctions for different screening parameters. The wave functions are physical and energy eigenvalues are in good agreement with the results obtained by other methods for different $\delta$ values. In order to demonstrate this, the results of the asymptotic iteration method are compared with the results of the supersymmetry, the numerical integration, the variational and the shifted 1/N expansion methods.Comment: 14 pages and 1 figur

A simple approach for synthesis, characterization and bioactivity of bovine bones to fabricate the polyurethane nanofiber containing hydroxyapatite nanoparticles

In the present study, we had introduced polyurethane (PU) nanofibers that contain hydroxyapatite (HAp) nanoparticles (NPs) as a result of an electrospinning process. A simple method that does not depend on additional foreign chemicals had been employed to synthesize HAp NPs through the calcination of bovine bones. Typically, a colloidal gel consisting of HAp/PU had been electrospun to form nanofibers. In this communication, physiochemical aspects of prepared nanofibers were characterized by FE-SEM, TEM and TEM-EDS, which confirmed that nanofibers were well-oriented and good dispersion of HAp NPs, over the prepared nanofibers. Parameters, affecting the utilization of the prepared nanofibers in various nano-biotechnological fields have been studied; for instance, the bioactivity of the produced nanofiber mats was investigated while incubating in simulated body fluid (SBF). The results from incubation of nanofibers, indicated that incorporation of HAp strongly activates the precipitation of the apatite-like particles, because of the HAp NPs act as seed, that accelerate crystallization of the biological HAp from the utilized SBF

Solution of the Bosonic and Algebraic Hamiltonians by using AIM

We apply the notion of asymptotic iteration method (AIM) to determine eigenvalues of the bosonic Hamiltonians that include a wide class of quantum optical models. We consider solutions of the Hamiltonians, which are even polynomials of the fourth order with the respect to Boson operators. We also demonstrate applicability of the method for obtaining eigenvalues of the simple Lie algebraic structures. Eigenvalues of the multi-boson Hamiltonians have been obtained by transforming in the form of the single boson Hamiltonian in the framework of AIM

Methodology for Jointly Assessing Myocardial Infarct Extent and Regional Contraction in 3-D CMRI

Automated extraction of quantitative parameters from Cardiac Magnetic Resonance Images (CMRI) is crucial for the management of patients with myocardial infarct. This work proposes a post-processing procedure to jointly analyze Cine and Delayed-Enhanced (DE) acquisitions in order to provide an automatic quantification of myocardial contraction and enhancement parameters and a study of their relationship. For that purpose, the following processes are performed: 1) DE/Cine temporal synchronization and 3D scan alignment, 2) 3D DE/Cine rigid registration in a region about the heart, 3) segmentation of the myocardium on Cine MRI and superimposition of the epicardial and endocardial contours on the DE images, 4) quantification of the Myocardial Infarct Extent (MIE), 5) study of the regional contractile function using a new index, the Amplitude to Time Ratio (ATR). The whole procedure was applied to 10 patients with clinically proven myocardial infarction. The comparison between the MIE and the visually assessed regional function scores demonstrated that the MIE is highly related to the severity of the wall motion abnormality. In addition, it was shown that the newly developed regional myocardial contraction parameter (ATR) decreases significantly in delayed enhanced regions. This largely automated approach enables a combined study of regional MIE and left ventricular function

Stokes Parameters as a Minkowskian Four-vector

It is noted that the Jones-matrix formalism for polarization optics is a six-parameter two-by-two representation of the Lorentz group. It is shown that the four independent Stokes parameters form a Minkowskian four-vector, just like the energy-momentum four-vector in special relativity. The optical filters are represented by four-by-four Lorentz-transformation matrices. This four-by-four formalism can deal with partial coherence described by the Stokes parameters. A four-by-four matrix formulation is given for decoherence effects on the Stokes parameters, and a possible experiment is proposed. It is shown also that this Lorentz-group formalism leads to optical filters with a symmetry property corresponding to that of two-dimensional Euclidean transformations.Comment: RevTeX, 22 pages, no figures, submitted to Phys. Rev.