Effects of sulfonation process on thermal behavior and microstructure of sulfonated polysulfone membranes as a material for Proton Exchange Membrane (PEM)

This paper reports the effect of sulfonation processon thermal behavior and microstrucutre of sulfonated polysulfone membrane. Various degree of sulfonation reactin has been conducted and the sulfonated membranes were characterized by thermal gravimetric analysis (TGA), differential scanning calorimetry (DSC), x-ray diffraction (XRD) and scanning electron microscopy (SEM). Modifications of the origin polysulfone polymer resulted in an increment value of glass transition temperature (Tg) due to the introduction of sulfonic acid group to the polymer backbone. However, due to some hindrance such as trace amount of organic solvent left during solvent evaporation and high hydrophilicity of the produced sulfonated membranes resulted in decreasing values of Tg. The polymer membrane showed lower degradation temperature as a function of degree of sulfonation. From XRD analysis, it was found that the membrane shows slight crystalline behavior after the sulfonation reaction. Detail discussions and observation of the alteration in microstructure of the sulfonated membrane were supported by SEM micrograph

Auxiliary-field quantum Monte Carlo calculations of molecular systems with a Gaussian basis

We extend the recently introduced phaseless auxiliary-field quantum Monte Carlo (QMC) approach to any single-particle basis, and apply it to molecular systems with Gaussian basis sets. QMC methods in general scale favorably with system size, as a low power. A QMC approach with auxiliary fields in principle allows an exact solution of the Schrodinger equation in the chosen basis. However, the well-known sign/phase problem causes the statistical noise to increase exponentially. The phaseless method controls this problem by constraining the paths in the auxiliary-field path integrals with an approximate phase condition that depends on a trial wave function. In the present calculations, the trial wave function is a single Slater determinant from a Hartree-Fock calculation. The calculated all-electron total energies show typical systematic errors of no more than a few milli-Hartrees compared to exact results. At equilibrium geometries in the molecules we studied, this accuracy is roughly comparable to that of coupled-cluster with single and double excitations and with non-iterative triples, CCSD(T). For stretched bonds in H$_2$O, our method exhibits better overall accuracy and a more uniform behavior than CCSD(T).Comment: 11 pages, 5 figures. submitted to JC

EFFECTIVENESS OF E-BOOK IN IMPROVING OMANI KINDERGARTEN KIDS COMPREHENSION AND MOTIVATION TOWARDS STORIES READING

Nowadays technology became an affective and worthy tool for learning and acquisition of knowledge. Although e-books have many facilities and tools which motivate children to read and develop their reading skills, most of the early childhood institutions in Oman are not using e-books for teaching children. Therefore, this study aims to investigate the difference between using e-books and printed books to motivate kindergarteners to read and enhancing their understanding of the text. This study compares between experimental group which use e-books and control group which use printed books. Findings show that there are no significant differences between the two groups with regard to motivation. However, children who read from paper books got better scores in the comprehension test. The study concludes with some future recommendations.  Article visualizations

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

The Inclusion of Warping in Free Vibration of Structures

Thin walled cellular structures are widely used in many civil, mechanical and aerospace engineering applications. These applications have increased with the economic necessity of providing high strength with low weight and cost. Structural analysis of thin walled girder is usually performed by the beam theory. In the present study, the effect of cross-sectional warping on the dynamic behavior of box girder deck is investigated using discrete element approach in idealizing the structure and incorporating the warping as a seventh degree of freedom in a space frame element. Shear deformation due to uniform torsion in addition to transverse shear deformation are taken into account in the problem formulation. The analysis is performed using the computer programs DNG6 and DNG7.It can be seen that the transverse shear contributes considerably to lowering the natural frequencies of the flexural vibration modes, and the inclusion of warping considerably increased the natural frequencies of the torsional-dominant vibration modes

Some larval morphological characteristics of Camelostrongylus mentulatus and Nematodirus spathiger

Monitoring of gastrointestinal nematode parasites in ruminants (domestic and wild) is often based on fecal examination techniques, looking for excreted eggs and larval forms using morphological keys. These, are more available in domestic ruminants, in which helminths are widely studied, than in wild ruminants.  This study tried to provide certain morphological elements that will help to recognize the L3 larvae of Camelostrongylus mentulatus and Nematodirus spathiger that could parasite either domestic or wild ruminants. For that, we resorted first to the culture of L3 larvae from fecal samples taken from African antelopes, and second by the microscopic characterization of each isolated larval morphological pattern previously identified by sequencing of its internal transcribed spacer (ITS-2) regions of the ribosomal DNA. The results of different microscopic captured images showed that Camelostrongylus mentulatus larva is 16 intestinal cells that measuring approximately 820 µm length, ‎≈ 25 µm wide, and ‎≈ 47 µm for its sheath tail extension and by this be closer to Teladorsagia circumcincta characteristics.  For Nematodirus spathiger, it possesses 8 gut cells and measuring about 1020 µm long, ‎≈ 25 µm wide, and‎ ≈ 143 µm for its sheath tail extension with specific tail appendages. Have done this, we were able to get some clarifications on the morphology of the studied larvae, and we believe thus that this study will contribute to the establishment of morphological identification keys especially for parasitic nematodes of wild ruminants