Tripartite entanglement generation using cavity-QED and its dynamics in dissipative environments

We investigate the generation of tripartite field states inside the high-Q cavities using the cavity QED. The main goal is to successfully generate the entanglement in tripartite systems by passing two-level atoms through three identical high-Q cavities. Our scheme gives the successful generation of entangled tripartite W and GHZ states for pre-determined interaction times of atoms with the cavity fields. The dynamics of initial entangled states is studied as the system evolves in the dissipative environments.     

Non-covalent functionalization of pristine few-layer graphene using triphenylene derivatives for conductive poly (vinyl alcohol) composites

In this paper, we demonstrate a facile technique to disperse pristine few-layer graphene (FLG) in water utilizing a triphenylene based stabilizer (C10) that non-covalently functionalizes the surface without micelle formation. The yield of FLG in the final dispersion (0.2 mg FLG/mg C10) is much higher than comparable surfactants and polymers stabilizers. This dispersion is reversible in response to pH changes unlike conventional stabilizers. The C10-stabilized FLG dispersion is also stable against heat and lyophilization. This non-covalent functionalization does not disrupt the pristine structure of the graphene sheets; instead, these coatings allow for stable, aggregation-resistant FLG dispersion, as characterized through TEM. To demonstrate the utility of such dispersions, we prepared pristine FLG-loaded poly (vinyl alcohol) (PVA) composites by a simple solution casting process. This is the first example of PVA composites based on pristine graphene. These composites have enhanced electrical properties at relatively low filler fraction (0.26 vol% FLG). Moreover, these composites exhibit improved mechanical properties established by tensile and hardness tests results; these data suggest anisotropic reinforcement caused by graphene alignment.     

Surface tension of Nanofluid-type fuels containing suspended nanomaterials

ABSTRACT: The surface tension of ethanol and n-decane based nanofluid fuels containing suspended aluminum (Al), aluminum oxide (Al2O3), and boron (B) nanoparticles as well as dispersible multi-wall carbon nanotubes (MWCNTs) were measured using the pendant drop method by solving the Young-Laplace equation. The effects of nanoparticle concentration, size and the presence of a dispersing agent (surfactant) on surface tension were determined. The results show that surface tension increases both with particle concentration (above a critical concentration) and particle size for all cases. This is because the Van der Waals force between particles at the liquid/gas interface increases surface free energy and thus increases surface tension. At low particle concentrations, however, addition of particles has little influence on surface tension because of the large distance between particles. An exception is when a surfactant was used or when (MWCNTs) was involved. For such cases, the surface tension decreases compared to the pure base fluid. The hypothesis is the polymer groups attached to (MWCNTs) and the surfactant layer between a particle and the surround fluid increases the electrostatic force between particles and thus reduce surface energy and surface tension.     

Effect of Martensite Morphology on Tensile Deformation of Dual-Phase Steel

Three morphologies of martensite in dual-phase microstructure of 0.2% C steel were obtained by different heat treatment cycles. These morphologies consisting of grain boundary growth, scattered laths, and bulk form of martensite have their distinct patterns of distribution in the matrix (ferrite). In tensile testing martensite particles with these distributions behaved differently. A reasonable work hardening was gained initially during plastic deformation of the specimens. The control on ductility was found to depend on the alignment of martensite particles along the tensile axes. The increased surface area contact of martensite particles with ferrite, in grain boundary growth and scattered lath morphologies, facilitated stress transfer from ductile to hard phase. The ductility in the later part of deformation was dependent on the density of microvoids in the necked region. The microvoids are formed mostly by de-cohesion of martensite particles at the interface. The fracture of martensite particles is less prominent in the process of microvoid formation which predicts high strength of martensite.     

Development of novel chitin/nanosilver composite scaffolds for wound dressing applications

Antibiotic resistance of microorganisms is one of the major problems faced in the field of wound care and management resulting in complications like infection and delayed wound healing. Currently a lot of research is focused on developing newer antimicrobials to treat wounds infected with antibiotic resistant microorganisms. Silver has been used as an antimicrobial agent for a long time in the form of metallic silver and silver sulfadiazine ointments. Recently silver nanoparticles have come up as a potent antimicrobial agent and are finding diverse medical applications ranging from silver based dressings to silver coated medical devices. Chitin is a natural biopolymer with properties like biocompatibility and biodegradability. It is widely used as a scaffold for tissue engineering applications. In this work, we developed and characterized novel chitin/nanosilver composite scaffolds for wound healing applications. The antibacterial, blood clotting and cytotoxicity of the prepared composite scaffolds were also studied. These chitin/nanosilver composite scaffolds were found to be bactericidal against S. aureus and E. coli and good blood clotting ability. These results suggested that these chitin/nanosilver composite scaffolds could be used for wound healing applications.     

Comparison of thermomechanical stresses produced in work rolls during hot and cold rolling of Cartridge Brass 1101

Thermomechanical stresses play an important role in defining the life of the work roll used in hot rolling process. In this research temperature dependent mechanical properties of cartridge brass are determined experimentally using high temperature compression tests at different temperatures and strain rates. Real life measurements are made from a brass rolling mill as input data for the simulation boundary conditions. Hot rolls are made of AISI H11 hot work tool steel. Temperature dependent mechanical properties of AISI H11 steel are used. Thermal and mechanical stresses produced in the work rolls during hot rolling process are predicted using a thermoplastic finite element approach in the ABAQUS Standard software. Hot rolling is compared with cold rolling to determine the effects produced on the work rolls. A criterion is introduced to compare the severity of stresses produced on the rolling surfaces in case of hot rolling and cold rolling based on the yield stress of the roller material for different temperatures. A method for separating thermal and mechanical stresses in the simulation is also described.     

Near infrared nonlinearity in silver telluride-core/carbon-sheath and tellurium-core/carbon-sheath nanostructures synthesized by reduction carbonization approach

A reduction-carbonization approach for the formation of one-dimensional (1D) silver telluride nanocables and tellurium nanorods with a sheath of amorphous carbon are proposed. Here the carbon shell is obtained with the assistance of glucose which behaves as carbonizing agent; silver nitrate and sodium tellurite are utilized as precursors and ethylene glycol acts as reducing agent. The results demonstrate the Ag₂Te/C and Te/C nanostructures with average diameters of 150 and 100 nm, respectively. The crystal structures, morphology, and composition are studied using X-ray diffraction, scanning electron microscopy, high-resolution transmission electron microscopy, and Energy-dispersive X-ray spectroscopy characterizations. The formation mechanism of amorphous carbon sheath and finally core–shell nanostructures is elaborated on the basis of the experimental results. In addition, nonlinear absorption and refraction coefficients along with 3rd order nonlinear optical properties are investigated by open/closed-aperture Z-scan measurements using femtosecond pulse laser at 800 nm in a systematic way. This study provides a guide to the nonlinear properties, which may hold promise as advanced materials for various applications.     

Effect of microvoid formation on the tensile properties of dual-phase steel

A steel containing 0.32 wt.% C, 0.88 wt.% Mn, 0.99 wt.% Si, 0.9 wt.% Ni, and 0.9 wt.% Cr was intercritically annealed at different temperatures from 775 to 870 °C and quenched in oil to produce dual-phase steel microstructure. Tensile testing of these samples gave a series of strengths and ductilities. The tensile strength increased with the increased annealing temperatures and the martensite percentage increased with a reduction in ductility. Microvoids were formed near the fracture surfaces. The morphology of the microvoids changed with the martensite percentage from decohesion of the martensite particles to the intergranular and transgranular cracks, which defined the ultimate fracture mode of the specimens. The change in the morphology of microvoids may be due to a high percentage of carbon in the steel, which produced stresses in the matrix (ferrite) during phase transformation.     

Behavioral and Neuronal Effects of Inhaled Bromine Gas: Oxidative Brain Stem Damage

The risk of accidental bromine (Br₂) exposure to the public has increased due to its enhanced industrial use. Inhaled Br₂ damages the lungs and the heart; however, adverse effects on the brain are unknown. In this study, we examined the neurological effects of inhaled Br₂ in Sprague Dawley rats. Rats were exposed to Br₂ (600 ppm for 45 min) and transferred to room air and cage behavior, and levels of glial fibrillary acidic protein (GFAP) in plasma were examined at various time intervals. Bromine exposure resulted in abnormal cage behavior such as head hitting, biting and aggression, hypervigilance, and hyperactivity. An increase in plasma GFAP and brain 4-hydroxynonenal (4-HNE) content also was observed in the exposed animals. Acute and delayed sympathetic nervous system activation was also evaluated by assessing the expression of catecholamine biosynthesizing enzymes, tryptophan hydroxylase (TrpH1 and TrpH2), and tyrosine hydroxylase (TyrH), along with an assessment of catecholamines and their metabolites. TyrH was found to be increased in a time-dependent manner. TrpH1 and TrpH2 were significantly decreased upon Br₂ exposure in the brainstem. The neurotransmitter content evaluation indicated an increase in 5-HT and dopamine at early timepoints after exposure; however, other metabolites were not significantly altered. Taken together, our results predict brain damage and autonomic dysfunction upon Br₂ exposure.     

Bulk and interfacial effects in Co-Cr2O3 nanocomposites

The exchange bias field has been measured in a set of Co-Cr2O3 nanocomposites in order to distinguish between the bulk and interfacial contributions to H(ex). The studies were carried out on a set of samples prepared by the sol gel technique in which the Co concentration was varied between 30 and 80 wt%. The particle sizes in all samples were carefully controlled so as to enable a comparison of their magnetic properties. Using thermal activation measurements we are able to distinguish between contributions to H(ex) arising from the thermal stability of the antiferromagnetic particles (bulk behaviour) and that due to changing interface density with increasing Co concentration. We have interpreted our results in terms of the independent particle volume model.