Intracameral SF6 injection and anterior segment OCT-based documentation for acute hydrops management in pellucid marginal corneal degeneration

PURPOSE: To report a case of acute hydrops in pellucid marginal corneal degeneration (PMCD) documented with anterior segment optical segment tomography and successfully treated with sulphur hexafluoride (SF6) intracameral injection. METHODS: A 47-year-old female patient presented with spontaneous onset of pain, redness and decreased vision in her left eye. Clinical evaluation revealed bilateral PMCD with evidence of acute hydrops in the left eye. Anterior segment Slit lamp Adapted Optical Coherence Tomography (SL-OCT) examination revealed intrastromal clefts with Descemet's membrane detachment in the left eye. She was managed with descemetopexy with 0.2ml injection of iso-expansile SF6 (18%) intracameral. RESULTS: The patient showed excellent early resolution of the stromal edema with reattachment of the Descemet's membrane. CONCLUSION: Prompt intervention in acute hydrops in PMCD cases helps in achieving early good visual results and prevents potentially serious complications such as perforation. Newer imaging modalities like SL-OCT helps in better visualisation and also in monitoring the response to treatment.     

Lactic acid fermentation of anthocyanin-rich sweet potato (Ipomoea batatas L.) into lacto-juice

Sweet potato (SP) is an important root crop grown all over the world and consumed as a vegetable, boiled, baked or often fermented into food and beverages. The grated SP roots [non- boiled and fully boiled (boiled in water at 100 °C for 15 min) were treated with 0.05% of commercial pectinase enzyme (Pectinex, Novoenzyme) in order to extract the juice. The fresh juice was inoculated with Lactobacillus plantarum MTCC 1407 culture at 28 ± 2 °C for 48 h to produce lacto-juice (LJ). The anova analysis of analytical data revealed that there was significant effect of boiling conditions (fully boiled and non-boiled) on pH [ F (1, 4) = 220.5, P  < 0.001), TA [ F (1, 4) = 78.89, P  < 0.01], starch [ F (1, 4) = 26.63, P  < 0.01), total sugar [ F (1, 4) = 61.36, P  < 0.01) and anthocyanin [ F (1, 4) = 32.86, P  < 0.01) but not on reducing sugar [ F (1, 4) = 2.48, P  = 0.19). Sensory evaluation rated the SP LJ acceptable based on texture, taste, aroma, flavour and after taste. LJ prepared from fully boiled roots with 10% cane sugar was most preferred by a consumer's panelist based on Linear Discriminant Analysis. Principal component analyses (PCA) reduced the seven original analytical variables to three independent components (factors), which accounted for 99.9% of the total variations. Similarly, six original sensory variables were reduced to two independent components, which accounted for 65.7% of the total variations.     

Surface inhibition of double base rocket propellants with photocurable unsaturated esters

Inhibition of a double base propellant surface with a good percentage of nitro bodies in the propellant composition is a rather difficult process. One of the methods of inhibiting the surface is to use unsaturated polyesters with free radical cure having high exotherm as a barrier coating. This system has been improved by using a 1:1 mix of photocurable vinyl ester with pendant —OH groups and unsaturated polyester that underwent room temperature free radical cure. Adhesion of the barrier coat to the propellant surface through its —OH groups was stronger than the propellant strength itself. Additional layers of commercially available unsaturated polyester could be easily grafted on to the barrier coat through chemical cure.     

Processing of Piezocomposites by Fused Deposition Technique

Piezoelectric ceramic/polymer composites were made by a fused deposition (FD) technique, which is a solid-freeform fabrication (or layered manufacturing) technique where three-dimensional (3-D) objects are built layer by layer from a computer-aided design (CAD) file on a computer-controlled fixtureless platform. Indirect and direct FD methods were used to fabricate lead zirconate titanate (PZT)/polymer composites. For the indirect method, a CAD file for the negative image of the final part was created. A polymer mold was made via FD using a thermoplastic filament, and composite formation was completed via a lost mold technique. In the direct FD method, a thermoplastic polymeric filament that was filled with 50–55 vol% of PZT powder was used to form a positive image of the desired structure. Three-dimensional honeycomb ("3-D honeycomb") composites and "ladder" composites with 3-3 connectivity, which were formed via the FD technique, showed excellent electromechanical properties for transducer applications. In addition, the FD technique showed the ability to form composites with controlled phase periodicity, various volume fractions, and a variety of microstructures and macrostructures that are not possible with traditional composite-forming techniques.     

Temperature-Dependent Giant Magnetoimpedance Effect in Amorphous Soft Magnets

Giant magnetoimpedance (GMI)-based devices offer potential as next-generation low-cost, flexible, ultrasensitive sensors. They can be used in applications that include current sensors, field sensors, stress sensors, and others. Challenging applications involve operation at high temperatures, and therefore studies of GMI temperature dependence and performance of soft magnetic materials are needed. We present a high-temperature GMI study on an amorphous soft magnetic microwire from room temperature to 560°C. The GMI ratio was observed to be nearly constant at ～86% at low temperatures and to decrease rapidly at ～290°C, finally reaching a near-zero value at 500°C. The rapid drop in GMI ratio at 290°C is associated with a reduction in the long-range ferromagnetic order as measured by the spontaneous magnetization (M) at the Curie temperature (T _c). We also correlated the impedance with the magnetic properties of the material. From room temperature to 290°C, the impedance was found to be proportional to the square root of the magnetization to magnetic anisotropy ratio. Lastly, M(T) has been fit using a Handrich–Kobe model, which describes the system with a modified Brillouin function and an asymmetrical distribution of exchange interactions. We infer that the structural fluctuations of the amorphous phase result in a relatively small asymmetry in the fluctuation parameters.     

Revolute manipulator workspace optimization using a modified bacteria foraging algorithm: A comparative study

Robotic manipulators with three-revolute (3R) motions to attain desired positional configurations are very common in industrial robots. The capability of these robots depends largely on the workspace of the manipulator in addition to other parameters. In this study, an evolutionary optimization algorithm based on the foraging behaviour of the Escherichia coli bacteria present in the human intestine is utilized to optimize the workspace volume of a 3R manipulator. The new optimization method is modified from the original algorithm for faster convergence. This method is also useful for optimization problems in a highly constrained environment, such as robot workspace optimization. The new approach for workspace optimization of 3R manipulators is tested using three cases. The test results are compared with standard results available using other optimization algorithms, i.e. the differential evolution algorithm, the genetic algorithm and the particle swarm optimization algorithm. The present method is found to be superior to the other methods in terms of computational efficiency.     

Nonlinear analysis of an imperfect radially graded annular plate with a heated edge

The present work deals with a geometrically nonlinear finite element analysis of an imperfect radially graded annular plate with a heated edge. The geometrical imperfection of the graded annular plate is assumed in aspect of its little intrinsic transverse deflection. The analysis is mainly for investigating the effects of intrinsic geometrical imperfection and temperature in the graded annular plate on its nonlinear flexural behaviour under a transverse mechanical load. The temperature is uniformly distributed across the thickness of the plate and it varies along the radial direction only. The temperature-dependent material properties are radially graded according to a simple power-law that is formed by power-law exponent and material properties of constituent materials (ceramic and metal). Based on the Von Karman nonlinear strain–displacement relations for imperfect annular plates, the nonlinear finite element equations of equilibrium are derived employing the principle of minimum potential energy. A single nodal displacement-control solution strategy is described for numerical solutions of nonlinear finite element equations of equilibrium. The numerical illustrations show a significant role of geometrical imperfection of the annular plate for its unstable equilibrium and alteration of structural behaviour under thermo-mechanical load. The analysis reveals the usefulness of radially graded annular plate in order to mitigate the unstable equilibrium of imperfect monolithic annular plate under thermo-mechanical load. It is found that the radial location for maximum value of a stress component insignificantly depends on the magnitudes of power-law exponent and applied temperature. The effects of material properties and applied temperature on the critical mechanical load corresponding to the unstable equilibrium of the imperfect radially graded annular plate are also presented.     

A new training strategy for neural network using shuffled frog-leaping algorithm and application to channel equalization

This paper makes use of shuffled frog-leaping algorithm (SFLA) as a training algorithm to train multi-layer artificial neural network (ANN). Next, The SFLA ANNs are used for channel equalization. We, in this paper, also introduce SFLA for channel equalization that is formulated as an optimization problem. In short, this paper introduces a novel strategy for training of ANN and also proposes two novel approaches for channel equalization problem using shuffled frog-leaping algorithm (SFLA). The proposed strategies are tested both in time-invariant and time varying channels and interestingly yield better performance than contemporary approaches as evidenced by simulation results.     

Fast computation of multidimensional discrete Hartley transform

Efficient algorithms for the fast computation of 2D and 3D discrete Hartley transforms have been proposed. It is shown that the proposed algorithms offer a significant saving in computation over the existing methods for various array sizes.<>