Production of beads like hollow nickel oxide nanoparticles using colloidal -gel electrospinning methodology

In the present study colloidal-gel electrospinning technique is proposed to produce new shape of nickel oxide hollow nanoparticles. In the colloidal-gel process, a colloidal precursor was prepared by dissolving nickel acetate tetra hydrate in ethanol at 352 K. The precursor was mixed with poly(vinyl acetate)/N, N-dimethylformamide (14 wt%). The polymer-precursor mixture was electrospun at relatively low voltage depending on the concentration of nickel acetate in the precursor. The obtained mat was dried under vacuum at 353 K for 24 h, and then sintered at 827 K for 3 h. The XRD and SEM results indicated that the proposed methodology produces pure nickel oxide hollow nanoparticles with beads-like form.     

Transvasal closure of interatrial defects using the Babic double-umbrella occluder system

The purpose of the study was to assess the feasibility and safety of closure of atrial septal defects and patent foramen ovale by means of a new interventional technique. Transvasal closure of ostium secundum atrial septal defect and patent foramen ovale was performed in 18 patients using an occluder system for atrial septal defects. Two patients had undergone unsuccessful direct surgical closure years before. Implantation and follow-up were controlled using radiographic views both with and without contrast injection, transthoracic and multiplane transesophageal echocardiographic imaging, color Doppler sonography, and computed tomography. The defect was closed in 16 patients using 19 procedures. Removal of the devices through the sheath was indicated in 4 patients because of placement failure. Intraprocedural complications were ventricular fibrillation in one patient and fixation of the device in Chiari's network in an additional one. During 7-26 months follow-up occluder damage was seen in two patients and perforation of the left atrium in one patient. Thickening on the occluder surface was observed in two patients. There was no death. The system for closure of atrial septal defect is feasible and safe in patients with defects < or = 27 mm in diameter. Long-term observation of outcome is limited yet.     

Considering the business system’s complexity with a network approach

Business management involves collecting information, goods, and funds as they move from supplier to manufacturer to wholesaler to retailer to consumer. Such business comprises interconnected parts that can be fundamentally complex and dynamic. A disturbance in one subnet of the system may thus have an opposed impact on another subnets, thus disturbing the business. Disruptions can have expensive and extensive results. This research aims to improve an increased Bayesian network method to consider business disruptions. The goal is to develop strategies that can diminish the opposed impacts of the disruptions and improve overall system reliability. Two influence agents are specified: the Bayesian and junction lack influence agents. An industrial model is used to demonstrate the proposed application, making the business more reliable. Moreover, two network learning methodologies are reviewed to update the probabilities in a model. The neural network seems to be a more favorable updating tool.     

Full-Potential Calculation of Structural, Electronic, and Thermodynamic Properties of Fluoroperovskite \text{ CsMF}_{3} (M?=?Be and Mg)

The structural and electronic properties of the cubic fluoroperoveskite $\text{ CsBeF}_{3}$ and $\text{ CsMgF}_{3}$ have been investigated using the full-potential-linearized augmented plane wave method within the density functional theory. The exchange-correlation potential was treated with the local density approximation and the generalized gradient approximation. The calculations of the electronic band structures show that $\text{ CsBeF}_{3 }$ has an indirect bandgap, whereas $\text{ CsMgF}_{3}$ has a direct bandgap. Through the quasi-harmonic Debye model, in which the phononic effects are considered, the effect of pressure $P$ and temperature $T$ on the lattice parameter, bulk modulus, thermal expansion coefficient, Debye temperature, and the heat capacity for $\text{ CsBeF}_{3}$ and $\text{ CsMgF}_{3}$ compounds are investigated for the first time.     

Cationic Mobility Via Cation-Exchange Mechanism on Poly(8-Hydroxyquinoline) Matrix

The insertion of Al(III) cation into a poly(8-Hydroxyquinoline) (PHQ) instead of some metal ions such as Co(II), Ni(II), Zn(II) or Fe(III) ions via cation-exchange mechanism has been studied by several techniques. The presence of Al(III) and the absence of Co(II) cations has been proved by elemental analysis of the polymer chelates product. Molecular mechanics (MM+) calculations showed that the potential energy (PE, kJ mol⁻¹) of the optimum molecular geometric structure (OMG) of the PHQ–Al(III) matrix is about seventy-six (76.185) greater than the PE of the PHQ–Co(II) complex. The TGA thermograms show that the PHQ–Al(III) matrix is thermally unstable than the PHQ–Co(II) complex under the same conditions. These observations indicate that the PHQ–Al(III) is expanded coil-like form. So, the thermal decomposition of PHQ–Al(III) complex is easy than the compacted coil-likes form of PHQ–Co(II) complex. The incorporation of Al(III) ion via cation-exchange properties have been investigated by spectrophotometric technique. The decrease of the absorbance at about ~370 nm of PHQ–Co(II) complex associated with increasing concentration of Al(III) revealed the replacement of that metal ion by Al(III) into PHQ chain. The cation-exchange constant (K _ex) of the divalent ions [Ni(II), Co(II), Cr(II), Zn(II), Mn(II), Mg(II) and Cu(II)] from PHQ–M(II) by the additions of Al(III) according to the following series: Ni(II) > Co(II) > Cr(II) > Cu(II) > Zn(II) > Mn(II) > Mg(II).     

Analytical approximation of nonlinear vibration of string with large amplitudes

Study of nonlinear problems in strings with large amplitude is a very important research area in many fields of physics and engineering. variational approach method (VAM) is in particular selected because the method is appropriate to solve nonlinear vibration of a constanttension string. VAM is an explicit method with high capability for resolving strong nonlinear oscillation system problems. It has been found that VAM is well suited for a range of parameters and the approximate frequencies and periodic solutions show a good agreement with the exact ones. This paper compares the various aspects of VAM in relative to exact approaches and higher-order approximate solutions for the constant-tension string. The comparison indicates that VAM is very fast, effective and convenient. The method does not require any linearization or small perturbation, and it leads to high accuracy of the solutions in a single iteration.     

Recycling of some domestic wastes to produce green corrosion inhibitors and biocides for sulfate reducing bacteria

Egypt suffers from a huge amount of domestic wastes which causes a lot of economic and environmental problems. This work investigated the possibility of recycling of some of these wastes into green corrosion inhibitors and biocides. The studied aqueous extracts of outer brown peels of onion (A), outer peels of garlic (B), orange (C), and mandarin (D) peels reduced markedly the corrosion rate of carbon steel alloy in 1.0 M HCl and behaved as mixed inhibitors. The inhibition efficiency decreased in the following order: C > B > A > D and generally increased with the increase of the extract concentration. The inhibition mechanism and adsorption isotherms were discussed to describe the adsorption characteristics of the extracts on the carbon steel surface. The extracts of orange and mandarin peels expressed biocidal effect on sulfate reducing bacteria (SRB). However, those of onion and garlic peels did not express any biocidal activity against SRB.