Spallation model for the titanium-rich supernova remnant cassiopeia A

Titanium-rich subluminous supernovae are rare and challenge current SN nucleosynthesis models. We present a model in which ejecta from a standard supernova is impacted by a second explosion of the neutron star (a quark nova), resulting in spallation reactions that lead to (56)Ni destruction and (44)Ti creation under the right conditions. Basic calculations of the spallation products shows that a delay between the two explosions of ～5 days reproduces the observed abundance of (44)Ti in Cas A and explains its low luminosity as a result of the destruction of (56)Ni. Our results could have important implications for light curves of subluminous as well as superluminous supernovae.     

Ultrafast three-photon counting in a photomultiplier tube

We demonstrate experimentally ultrafast three-photon counting by three-photon absorption in a GaAsP photomultiplier tube at the wavelength range of 1800-1900?nm, and analyze its sensitivity and time response. Pulse energy of ～500?fJ is shown to be detectable for ultrafast 170?fs pulses. The presented three-photon counter may serve as a unique tool for ultrafast quantum state characterization as well as for ultrasensitive third-order temporal measurements.     

Porous electrolyte-supported tubular micro-SOFC design

Due to the poor redox cycling resistance of the second generation of μ-SOFCs, a new generation of SOFC has been recently developed using a porous electrolyte-supported structure to overcome this problem. In this research, the porous structure was successfully fabricated with slip casting using calcined YSZ (ZrO₂ + 8 mol% Y₂O₃) with or without graphite as a pore former. Calcination of YSZ powder at 1300-1500 °C prior to making the slip leads to growth of YSZ crystals and particle size which results in a decrease in surface area and powder sinterability. This was found to be an important criterion in developing the porous structure as, due to the high sinterability of non-calcined YSZ, even the addition of graphite is inadequate to generate sufficient open porosity. A dense YSZ electrolyte layer was immediately coated on the porous structure using YSZ calcined at 1300 °C with a sequential slip casting method. Sample thickness was found to be a function of both graphite content as well as YSZ calcination temperature. Physical properties of the porous YSZ supports and SEM analysis of the support and coated electrolyte are presented.     

Studies of fractal growth patterns in poly (ethylene oxide) and chitosan membranes

Polymer electrolyte membranes containing various weight percent of salt have been prepared in the authors’ laboratory for the study of their potential applications in solid state electrochemical devices; however, the polymer electrolyte membranes were found to become sort of media for fractal growth, months after they were prepared. Fractal growth patterns in polymer membranes of poly (ethylene oxide) and chitosan membranes have been analyzed, and their fractal dimensions were determined. A diffusion-limited aggregate model which is based on the Brownian motion theory is applied to simulate the experimentally obtained fractal patterns. The approach was extended by performing computer simulations with computing resources available. The fractal dimension values of the simulated and the experimentally obtained original fractal patterns were marginally close. This indicates that the simulation work has successfully produced fractal patterns that are in fairly acceptable conformity with the fractal patterns observed in the polymer membranes.     

SO3H-Functionalized Ionic Liquids: Green, Efficient and Reusable Catalysts for the Facile Dehydration of Aldoximes into Nitriles

Easily synthesized aldoximes have been converted to the corresponding nitriles under very mild conditions by a simple reaction using two halogen‐free SO₃H‐functionalized ionic liquids, 3‐methyl‐1‐(4‐sulfonic acid)butylimi‐ dazolium hydrogen sulfate [MIM(CH₂)₄SO₃H][HSO₄] and 1‐(4‐sulfonic acid)butylpyridinium hydrogen sulfate [PY(CH₂)₄SO₃H][HSO₄], as catalyst and reaction medium without any additional organic solvent. The method was equally effective for aromatic aldoximes bearing electron‐donating and electron‐withdrawing substituents. Taking into account environmental and economical consideration, the protocol presented here has the merits of environmentally friendly, simple operation, easy work‐up and very good yields. The catalysts could be recycled and reused for several times without noticeably decreasing in their catalytic activities.     

Synthesis and characterization of new azo containing Schiff base macrocycle

Fully conjugated Schiff base macrocycle has been prepared through a simple and mild condition,a one-pot cyclization procedure of four-component without using a template.The condensation reaction of related bis（hydroxybenzaldehyde） with phenylenediamines to prepare a conjugated[2 + 2]Schiff base macrocycle has been investigated and fluorescent[2 + 2]Schiff base macrocycles with N₂O₂ binding pockets has been prepared and characterized by elemental analysis,¹H NMR,IR,fluorescent,UV-visible and MALDI mass spectroscopies.     

Photo induced silver on nano titanium dioxide as an enhanced antimicrobial agent for wool

In this study an effective nanocomposite antimicrobial agent for wool fabric was introduced. The silver loaded nano TiO(2) as a nanocomposite was prepared through UV irradiation in an ultrasonic bath. The nanocomposite was stabilized on the wool fabric surface by using citric acid as a friendly cross-linking agent. The treated wool fabrics indicated an antimicrobial activity against both Staphylococcus aureus and Escherichia coli bacteria. Increasing the concentration of Ag/TiO(2) nanocomposite led to an improvement in antibacterial activities of the treated fabrics. Also increasing the amount of citric acid improved the adsorption of Ag/TiO(2) on the wool fabric surface leading to enhance antibacterial activity. The EDS spectrum, SEM images, and XRD patterns was studied to confirm the presence of existence of nanocomposite on the fabric surface. The role of both cross-linking agent and nanocomposite concentrations on the results was investigated using response surface methodology (RSM).     

T-Semisimple Modules and T-Semisimple Rings

We define and investigate t-semisimple modules as a generalization of semisimple modules. A module M is called t-semisimple if every submodule N contains a direct summand K of M such that K is t-essential in N. T-semisimple modules are Morita invariant and they form a strict subclass of t-extending modules. Many equivalent conditions for a module M to be t-semisimple are found. Accordingly, M is t-semisiple, if and only if, M = Z ₂(M) ⊕ S(M) (where Z ₂(M) is the Goldie torsion submodule and S(M) is the sum of nonsingular simple submodules). A ring R is called right t-semisimple if R _R is t-semisimple. Various characterizations of right t-semisimple rings are given. For some types of rings, conditions equivalent to being t-semisimple are found, and this property is investigated in terms of chain conditions.     

Linear Representation of Medial-Like Algebras

In this paper we characterize the paramedial, comedial, and coparamedial pairs of quasigroup operations and paramedial, comedial, and coparamedial algebras with the quasigroup operations. Then we characterize paramedial, comedial, and coparamedial algebras with a unit element and an idempotent regular element.     

An Element-Free Galerkin-Based Multi-objective Optimization of Laminated Composite Plates

An element-free Galerkin method is presented to analyze isotropic and laminated composite plates. This method employs the moving least square technique to approximate functions. In the analysis procedure, a collocation method is used to enforce boundary conditions. A consistent multi-objective optimization procedure is also applied. The function introduced here consists of minimizing the weight and cost, as well as of maximizing the load. A genetic algorithm is used for the optimization process.