Isoparametric finite difference energy method for plate bending problems

This paper incorporates the concept of isoparametry in finite difference energy method making it more powerful and versatile to tackle complex plate bending problems with curved boundaries. This approach overcomes the drawbacks of the finite difference energy method and its application to practical problems is now feasible. In order to estimate the accuracy and reliability of the present formulation several isotropic plates with a variety of planform are solved and the results are compared with the existing analytical and numerical solutions.     

Inference for dependence competing risks with partially observed failure causes from bivariate Gompertz distribution under generalized progressive hybrid censoring

Competing risks model is considered with dependence causes of failure in this paper. When the latent failure times are distributed by a bivariate Gompertz model, statistical inference for the unknown model parameters is studied from classical and Bayesian approaches, respectively. Under a generalized progressive hybrid censoring, maximum likelihood estimators of the unknown parameters together with the associated existence and uniqueness are established, and the approximate confidence intervals are also obtained based on asymptotic likelihood theory via the observed Fisher information matrix. Moreover, Bayes estimates and the highest posterior density credible intervals of the unknown parameters are also provided based on a flexible Gamma–Dirichlet prior, and Monte Carlo sampling method is also derived to compute associated estimates. Finally, simulation studies and a real-life example are given for illustration purposes.     

Electrically Controlled Localized Charge Trapping at Amorphous Fluoropolymer–Electrolyte Interfaces

Charge trapping is a long‐standing problem in electrowetting on dielectric, causing reliability reduction and restricting its practical applications. Although this phenomenon is investigated macroscopically, the microscopic investigations are still lacking. In this work, the trapped charges are proven to be localized at the three‐phase contact line (TPCL) region by using three detecting methods—local contact angle measurements, electrowetting (EW) probe, and Kelvin probe force microscopy. Moreover, it is demonstrated that this EW‐assisted charge injection (EWCI) process can be utilized as a simple and low‐cost method to deposit charges on fluoropolymer surfaces. Charge densities near the TPCL up to 0.46 mC m^?2 and line widths of the deposited charge ranging from 20 to 300 µm are achieved by the proposed EWCI method. Particularly, negative charge densities do not degrade even after a “harsh” testing with a water droplet on top of the sample surfaces for 12 h, as well as after being treated by water vapor for 3 h. These findings provide an approach for applications which desire stable and controllable surface charges.     

Plasmonic Nanoassemblies: Tentacles Beat Satellites for Boosting Broadband NIR Plasmon Coupling Providing a Novel Candidate for SERS and Photothermal Therapy

Optical theranostic applications demand near‐infrared (NIR) localized surface plasmon resonance (LSPR) and maximized electric field at nanosurfaces and nanojunctions, aiding diagnosis via Raman or optoacoustic imaging, and photothermal‐based therapies. To this end, multiple permutations and combinations of plasmonic nanostructures and molecular “glues” or linkers are employed to obtain nanoassemblies, such as nanobranches and core–satellite morphologies. An advanced nanoassembly morphology comprising multiple linear tentacles anchored onto a spherical core is reported here. Importantly, this core‐multi‐tentacle‐nanoassembly (CMT) benefits from numerous plasmonic interactions between multiple 5 nm gold nanoparticles (NPs) forming each tentacle as well as tentacle to core (15 nm) coupling. This results in an intense LSPR across the “biological optical window” of 650?1100 nm. It is shown that the combined interactions are responsible for the broadband LSPR and the intense electric field, otherwise not achievable with core–satellite morphologies. Further the sub 80 nm CMTs boosted NIR‐surface‐enhanced Raman scattering (SERS), with detection of SERS labels at 47 × 10^‐9 m , as well as lower toxicity to noncancerous cell lines (human fibroblast Wi38) than observed for cancerous cell lines (human breast cancer MCF7), presents itself as an attractive candidate for use as biomedical theranostics agents.     

An LMI based criterion for the global asymptotic stability of 2-D discrete state-delayed systems with saturation nonlinearities

This paper deals with the problem of global asymptotic stability of a class of two-dimensional (2-D) discrete systems described by the Fornasini–Marchesini second local state-space (FMSLSS) model in presence of saturation nonlinearities and state delays in each of the two independent directions of information propagation. A linear matrix inequality (LMI) based criterion for the global asymptotic stability of such systems is presented. It is shown that several previously reported stability criteria for 2-D discrete FMSLSS model with saturation nonlinearities are recovered from the presented approach as special cases.     

Traffic modeling in a reconfigurable broadband nomadic computing environment

Reconfiguring a network to counter variations in traffic is expected to greatly enhance optimal usage of network resources. But an important input to this method is the traffic fluctuations themselves. We have developed two models for this purpose to describe the time-dependent variations in traffic at a base station in a nomadic computing, wireless environment. The first model is rather simple and does not take into account details of human behavior. It takes into account the probabilities of choosing different applications. The model is also analyzed and experimented with to identify the important input parameters. The second model, a refined version of the first model, takes into account details of relevant human behavior (in the context of a wireless nomadic computing environment). Finally, we have compared the two models on the basis of their complexity and validity in different situations.     

Eigen deformation of 3D models

Recent advances in mesh deformations have been dominated by two techniques: one uses an intermediate structure like a cage which transfers the user intended moves to the mesh, the other lets the user to impart the moves to the mesh directly. The former one lets the user deform the model in real-time and also preserve the shape with sophisticated techniques like Green Coordinates. The direct techniques on the other hand free the user from the burden of creating an appropriate cage though they take more computing time to solve larger non-linear optimizations. It would be ideal to develop a cage-free technique that provides real-time deformation while respecting the local geometry. Using a simple eigen-framework, we devise such a technique. Our framework creates an implicit skeleton automatically. The user only specifies the motion in a simple and intuitive manner, and our algorithm computes a deformation whose quality is similar to that of the cage-based scheme with Green Coordinates.     

Meshing interfaces of multi-label data with Delaunay refinement

In medical imaging, the generation of surface representations of anatomical objects obtained by labeling images from various modalities, is a critical component for visualization, simulation, and analysis. The interfaces between labeled regions can meet at arbitrary angles and with complex topologies, causing most automatic meshing algorithms to fail. We apply a recent Delaunay refinement algorithm to generate high quality triangular meshes that approximate the interface surfaces. This algorithm has proven guarantees for meshing piecewise-smooth shapes and its implementation overhead is low. Consequently, the approach is applicable to labeled datasets generated from binary segmentations as well as from probabilistic segmentation algorithms. We show the effectiveness of this technique on data from a variety of medical fields and discuss its ability to control the quality and size of the output meshes. The same algorithm can be used to generate tetrahedral meshes of the segmentation space.     

Novel lipase isolated from a Pseudomonas strain and its application in the synthesis of S(+)‐2‐O‐benzylglycerol‐1‐acetate

Isolation of a novel microbial lipase (EC 3.1.1.3) having specific catalytic activity for the synthesis of optically pure 2‐O‐benzylglycerol‐1‐acetate, the building block for the preparation of many β‐blockers, phospholipase A2 inhibitors and other biologically active compounds was the aim of this investigation. A Pseudomonas (strain G6), recently isolated from soil, produced an extracellular lipase. SDS–PAGE analysis showed that the lipase protein was a hexamer. The molecular weight of the sub‐units of the lipase protein were 10, 19, 29, 30, 47 and 53. The catalytic activity of the lipase was exploited for the synthesis of 2‐O‐benzylglycerol‐1‐acetate from 2‐O‐benzylglycerol through transesterification using vinyl acetate as acylating agent. High selectivity of the lipase towards the monoacetate product was demonstrated. A 97% enantiomeric excess (ee) of S(+)‐2‐O‐benzylglycerol‐1‐acetate was obtained when the reaction was carried out at room temperature with shaking. The lipase was highly active in anhydrous organic microenvironments and in non‐polar organic solvents with log P values above 2.5. © 2002 Society of Chemical Industry     

Microstructure Evolution of Pulsed Laser-Deposited (Ba, Sr)TiO3 Films on MgO for Microwave Applications

To develop low-loss tunable microwave circuits, based on the field dependence of dielectric permittivity, phase pure (Ba_0.5, Sr_0.5)TiO₃ doped with 1% W (BST) thin films 0.3-μm thick were deposited on single crystal MgO wafers by pulsed laser deposition. The BST films were characterized by X-ray θ–2θ scans and pole figure analysis, field emission scanning electron microscopy (FESEM), and cross-sectional transmission electron microscopy (TEM), coupled with selected-area electron diffraction (SAED). Although, the X-ray θ–2θ scan indicated an epitaxial nature of BST with an out-of-plane orientation of (100), the pole figure analysis confirmed the presence (4–6%) of (111)-oriented grains in a matrix of (100) textured grains. The columnar grains exhibited an in-plane (i.e., along the plane perpendicular to the growth direction) grain size that was thickness-dependent. The cross-sectional TEM, coupled with SAED in the thickness direction, corroborated the pole figure analysis. Additionally, from X-ray analysis, it was observed that the textured films were under in-plane tension. The deposited film was characterized at microwave frequencies (1–20 GHz) using interdigitated electrodes deposited on top of the film. The film was characterized by a relatively low dielectric Q of 5–7. A 17% change in the capacitance was observed when applying a 40 V bias. From the observed microstructure, a preliminary understanding of its evolution and its relationship with the microwave dielectric properties is discussed, and some ideas to obtain truly epitaxial BST films are presented.