Photoinduced phase transitions

Employing actinic light to alter/stabilise a particular thermodynamic phase via the photo-isomerisation of the constituent molecules is an interesting tool to investigate soft matter from a new dimension. This article focuses on our recent results on several aspects of these non-equilibrium phase transitions, which are isothermal in nature. We specifically discuss (i) the influence of different parameters, such as confinement, applied electric field, pressure etc., on the dynamics associated with both the photochemical transition driving the equilibrium nematic to the non-equilibrium isotropic phase and the thermal back relaxation recovering the nematic phase, (ii) unique light-driven disorder–order transition in a reentrant system, (iii) dynamic self-assembly of the smectic A phase, which is stabilised only in the presence of actinic light, (iv) novel temperature-intensity phase diagrams and an example of primary and secondary photo-ferroelectric effects in an antiferroelectric smectic C system. These results highlight the fact that the actinic light can be used as a new tool to study phase transitions and the associated critical phenomena that could also bring about effects that are not seen in equilibrium situations.     

Parametric inference for multiple repairable systems under dependent competing risks

The focus of this article is on the analysis of repairable systems that are subject to multiple sources of recurrence. The event of interest at the system level is assumed to be caused by the earliest occurrence of a source, thereby conforming to a series system competing risks framework. Parametric inference is carried out under the power law process model that has found significant attention in industrial applications. Dependence among the cause‐specific recurrent processes is induced via a shared frailty structure. The theoretical inference results are implemented to a warranty database for a fleet of automobiles, for which the warranty repair is triggered by the failure of one of many components. Extensive finite‐sample simulation is carried out to supplement the asymptotic findings. Copyright © 2014 John Wiley & Sons, Ltd.     

Thermal radiation impact on magneto-hydrodynamic heat transfer micropolar fluid flow over a vertical moving porous plate: A finite difference approach

For this research, an examination on the magnetohydrodynamic flow of a micropolar fluid across a moving vertical porous plate for the presence of thermal radiation is achieved. It is necessary to translate the partial differential equations regulating the flow, heat, & mass transfer into dimensionless form employing proper non-dimensional variables, which are then cracked numerically by utilizing the Finite difference approach. Graphs are used to represent numerical values of various flow profiles; however, tables are used to represent the simulated values of rate coefficients. The velocity rises when the value of Grashof number, dimensionless viscosity ratio is raised, and the opposite effect is seen when the value of magnetic parameter, micro-gyration factor is raised. The result in skin friction coefficient improves when the values of magnetic parameter, micro-gyration factor, Prandtl number, and radiation are raised higher.     

Synthesis and thermal evaluation of novel mono- and bis-adamantylated resorcinol-based phthalonitrile resins with enhanced solubility

Journal of Thermal Analysis and Calorimetry - Phthalonitrile (PN) resins are high-temperature-resistant thermosetting polymers which find applications in military as well as aerospace owing to...     

Correlating off-stoichiometric doping and nanoscale electronic inhomogeneity in the high-Tc superconductor Bi2Sr2CaCu2O8+delta

A microscopic theory is presented for the observed electronic disorder in superconducting Bi2Sr2CaCu2O8+delta. The essential phenomenology is shown to be consistent with the existence of two types of interstitial oxygen dopants: those serving primarily as charge reservoirs and those close to the apical plane contributing both carriers and electrostatic potential to the CuO2 plane. The nonlinear screening of the latter produces nanoscale variations in the doped hole concentration, leading to electronic inhomogeneity. Based on an unrestricted Gutzwiller approximation of the extended t-J model, we provide a consistent explanation of the correlation between the observed dopant location and the pairing gap and its spatial evolutions. We show that the oxygen dopants are the primary cause of both the pairing gap disorder and the quasiparticle interference pattern.     

Dispersion measurements using time-of-flight remote detection MRI

Remote detection nuclear magnetic resonance and magnetic resonance imaging can be used to study fluid flow and dispersion in a porous medium from a purely Eulerian point of view (i.e., in a laboratory frame of reference). Information about fluid displacement is obtained on a macroscopic scale in a long-time regime, while local velocity distributions are averaged out. It is shown how these experiments can be described using the common flow propagator formalism and how experimental data can be analyzed to obtain effective porosity, flow velocity inside the porous medium, fluid dispersion and flow tracing of fluid.     

Total Stereospecific Synthesis of (3E,7Z)-Tetradecadienyl Acetate,the Major Sex Pheromone Component of the Potato Pest Symmetrischema tangolias

Chemistry of Natural Compounds - (3E,7Z)-Tetradecadienyl acetate, the major sex pheromone component of the potato pest Symmetrischema tangolias (Gyen), was stereoselectively synthesized from the...     

Microalgae separation by inertia-enhanced pinched flow fractionation

To improve the accuracy and efficiency of ships’ ballast water detection, the separation of microalgae according to size is significant. In this article, a method to separate microalgae based on inertia-enhanced pinched flow fractionation (iPFF) was reported. The method utilized the inertial lift force induced by flow to separate microalgae according to size continuously. The experimental results show that, as the Reynolds number increases, the separation effect becomes better at first, but then stays unchanged. The best separation effect can be obtained when the Reynolds number is 12.3. In addition, with the increase of the flow rate ratio between sheath fluid and microalgae mixture, the separation effect becomes better and the best separation effect can be obtained when the flow rate ratio reaches 10. In this case, the recovery rate of Tetraselmis sp. is about 90%, and the purity is about 86%; the recovery rate of Chlorella sp. is as high as 99%, and the purity is about 99%. After that, the separation effect keeps getting better but very slowly. In general, this study provides a simple method for the separation of microalgae with different sizes, and lays a foundation for the accurate detection of microalgae in the ballast water.