Electrochemical and surface analytical characterization study of the inhibition effect of boiled red onion extract on tin corrosion in 0.2 M Maleic acid medium.

The inhibition efficiency of boiled red onion skin extracts (BROE) against tin corrosion in 0.2 M Maleic acid has been studied using electrochemical and surface analytical methods. The electrochemical polarization curves displayed the active/passive transition of the anodic behavior of the tin electrode. The electrochemical impedance measurements demonstrated the effect of increasing BORE concentration on the inhibition efficiency (η %) (to a ηmax = 94% at 300 mg/L of BORE). The inhibition mechanism is attributed to the formation of adsorbed protective layers, on the metal surface, that fit the Langmuir adsorption isotherm model. Increasing the temperature hindered the η values

Algebraic Geometry Realization of Quantum Hall Soliton

Using Iqbal-Netzike-Vafa dictionary giving the correspondence between the H$_{2}$ homology of del Pezzo surfaces and p-branes, we develop a new way to approach system of brane bounds in M-theory on $\mathbb{S}^{1}$. We first review the structure of ten dimensional quantum Hall soliton (QHS) from the view of M-theory on $\mathbb{S}^{1}$. Then, we show how the D0 dissolution in D2-brane is realized in M-theory language and derive the p-brane constraint eqs used to define appropriately QHS. Finally, we build an algebraic geometry realization of the QHS in type IIA superstring and show how to get its type IIB dual. Others aspects are also discussed. Keywords: Branes Physics, Algebraic Geometry, Homology of Curves in Del Pezzo surfaces, Quantum Hall Solitons.Comment: 19 pages, 12 figure

Mixing Within Patterned Vortex Core

The video shows the flow dynamics within inner and outer regions of a vortex core. The observed phenomena mimic a transport process occurring within the Antarctic vortex. The video shows two distinct regions: a strongly mixed core and broad ring of weakly mixed region extending out the vortex core boundaries. The two regions are separated by a thin layer that isolates the weakly and strongly mixed regions; this thin layer behaves as barrier to the mixing of the two regions. The video shows that the barriers deplete when a swirl of the vortex core increases and the vortex core espouses a triangular pattern.Comment: 62nd Annual Meeting of the APS Division of Fluid Dynamics, Fluid Dynamics Vide

THE ACTIVITY CONCENTRATIONS AND HAZARD INDICES IN SEDIMENT SAMPLES FROM THE AFRICAN COASTS

In this work we have been interested in a compilation of data covering the period from 2000 to present of radionuclide activity concentrations in estuary or marine sediments of the African continent. So, we included three radionuclides as the most representative of natural radioactivity (226Ra, 232Th and 40K) in sediment samples taken from 20 coastal areas, by considering the Atlantic Ocean (Nigeria, Ghana, Morocco and Canary Islands), the Mediterranean Sea (Spain and Egypt) and the Red Sea (Egypt). Therefore, we have relied on scientific publications as well as on our own results.Moreover, to characterize the potential radiation dose to humans resulting from exposure to sediment natural radioactivity, eight radiological hazard indices were estimated: Total Absorbed Dose Rate in air (D), Annual Effective Dose Equivalent (AEDE), Annual Gonadal Dose Equivalent (AGDE), Radium Equivalent Activity (Raeq), External Hazard Index (Hex), Internal Hazard Index (Hin), Gamma Index (Ig) and Excess Lifetime Cancer Risk (ELCR).The highest activity concentrations were found in sediment samples in Atlantic Ocean, especially in one site in Nigeria with a great exceed of the World Wide Average concentrations of 226Ra, 232Thand 40K, which are 35, 30 and 400 Bq Kg-1 respectively.Also, the calculation of the eight radiological hazard indices indicated significant radiological risks always in the same site in Nigeria in Atlantic Ocean

Rare event sampling with stochastic growth algorithms

We discuss uniform sampling algorithms that are based on stochastic growth methods, using sampling of extreme configurations of polymers in simple lattice models as a motivation. We shall show how a series of clever enhancements to a fifty-odd year old algorithm, the Rosenbluth method, led to a cutting-edge algorithm capable of uniform sampling of equilibrium statistical mechanical systems of polymers in situations where competing algorithms failed to perform well. Examples range from collapsed homo-polymers near sticky surfaces to models of protein folding.Comment: First International Conference on Numerical Physic

Classification of N=2 supersymmetric CFT_{4}s: Indefinite Series

Using geometric engineering method of 4D $\mathcal{N}=2$ quiver gauge theories and results on the classification of Kac-Moody (KM) algebras, we show on explicit examples that there exist three sectors of $\mathcal{N}=2$ infrared CFT$_{4}$s. Since the geometric engineering of these CFT$_{4}$s involve type II strings on K3 fibered CY3 singularities, we conjecture the existence of three kinds of singular complex surfaces containing, in addition to the two standard classes, a third indefinite set. To illustrate this hypothesis, we give explicit examples of K3 surfaces with H$_{3}^{4}$ and E$_{10}$ hyperbolic singularities. We also derive a hierarchy of indefinite complex algebraic geometries based on affine $A_{r}$ and T$$ algebras going beyond the hyperbolic subset. Such hierarchical surfaces have a remarkable signature that is manifested by the presence of poles.Comment: 12 pages, 2 figure

Uncommon Cause of Acute Pelvic Pain: Isolated Torsion of Hydrosalpinx

Isolated torsion of hydrosalpinx is a rare cause of acute pelvic pain. Pre-operative diagnosis is very difficult because of non specific clinical presentation. Definitive diagnosis is always made at surgicalexploration performed for suspected adnexal torsion and salpingectomy is performed in the majority of cases. A 34-year-old woman was admitted for acute pelvic pain with nausea and vomiting. Vaginal examination revealed a right adnexal tender mass and ultrasound revealed a well circumscribed right adnexal cystic mass. Surgical exploration has revealed torsion of a right hydrosalpinx and right salpingectomy was performed. Differential diagnosis between adnexal and tubal torsion is very difficult, however both should be managed by rapid surgical exploration which an allow precocious diagnosis and conservative treatment(Afr J Reprod Health 2009; 13[4]:147-150)

Study of the mechanical behavior of leaded copper by scratch test and nanoindentation

Copper-lead was investigated by scratch tests under two set of experiments conditions: at progressive loads (0 – 200 N) and at two different constant loads (20 – 30 N). These tests were made to assess the adhesion properties to determine the critical normal load of copper- lead journal bearings material. The morphologies of material after scratches are synthesized by optical microscope. Nanoindentation studies of copper-lead provide the possibility of examining a variety of mechanical events due to porosity and pre-existing defects in material. The resulting data are analyzed in terms of load–displacement curves and various comparative parameters, such as hardness and Young’s modulus

Black hole mass and angular momentum in topologically massive gravity

We extend the Abbott-Deser-Tekin approach to the computation of the Killing charge for a solution of topologically massive gravity (TMG) linearized around an arbitrary background. This is then applied to evaluate the mass and angular momentum of black hole solutions of TMG with non-constant curvature asymptotics. The resulting values, together with the appropriate black hole entropy, fit nicely into the first law of black hole thermodynamics.Comment: 20 pages, references added, version to appear in Classical and Quantum Gravit