One-minute microwave-assisted chemical bath deposition of nanostructured ZnO rod-arrays

Microwave-assisted chemical bath deposition (MACBD) is an emerging route for rapid synthesis of films and nanostructured particles. In this paper we report MACBD of ZnO rod-array films on bare glass substrates from an aqueous bath of tetra ammonium zinc complex. The deposition time is reduced to about 1 min as compared to around 60 min for conventional CBD. X-ray diffraction study shows that as-deposited films are uniaxially out-of-plane textured along the c-axis. Scanning Electron Microscopy reveals that the films consist of elongated elliptical tapered rods of diameters 250 to 350 nm. Atomic Force Microscopy shows that the films consist of about 350 nm grains. The RMS roughness is about 60 nm. The energy band gap is 3.27 eV as estimated from optical data. The films are n-type with electrical conductivity of 1 × 10^− 4 S/cm.     

A three-dimensional eigenfunction expansion approach for singular stress field near an adhesively-bonded scarf joint interface in a rigidly-encased plate

A three-dimensional eigenfunction expansion approach for determination of the singular stress field in the vicinity of an adhesively-bonded scarf joint interface in a plate, with its top and bottom surfaces being encased, fully or partially, between infinitely rigid blocks is presented. The plate is subjected to extension/bending (mode I) and in-plane shear/twisting (mode II) far-field loading. Both the adhesive layer and plate materials are assumed to be isotropic and elastic. The boundary conditions that are prescribed on the end-faces (free, fixed and lubricated) of the plate as well as those, prescribed at the bottom or top surface of the scarf-bonded plate on either side of the interface between the plate and adhesive layer materials (fixed-fixed, free-fixed and fixed-free), are exactly satisfied. Numerical results include the dependence of the lowest eigenvalue (or most severe stress singularity) on the wedge aperture angle of the plate material. Variation of the same with respect to the shear moduli ratio of the constituent plate and adhesive layer materials is also an important part of the present investigation. Hitherto unobserved interesting and physically meaningful conclusions in regards to the fixed edge singularity and delamination type flaw sensitivity of an adhesively bonded plate surface are also presented. Finally, hitherto unavailable results, pertaining to the through-width variations of stress intensity factors corresponding to symmetric and skew-symmetric sinusoidal loads that also satisfy the boundary conditions on the end-faces of the adhesively bonded plate, in the vicinity of the scarf joint interface, under investigation, bridge a longstanding gap in the bonded joint stress singularity/fracture mechanics literature.     

Nano Molecular‐Platform: A Protocol to Write Energy Transmission Program Inside a Molecule for Bio‐Inspired Supramolecular Engineering

In a coded self‐assembly, a simple code is written in the molecule, which self‐assembles the molecules into a fractal like structure, which acts as a seed for the next step. As the molecule turns into a complex seed, the code transforms into another form and several seeds self‐assemble into another structure, which acts as a seed for the next step. Until now, this technology was considered as a prerogative of nature. Here, a dendritic network is used to write a basic code by synthetically attaching 32 molecular rotors and doping two controller molecules in its cavity. The code live, which is an energy transmission path in the molecule, is imaged. When the energy transmission path or code is triggered, a series of products generate one after another spontaneously. Two examples are: i) dendritic seed (5–6 nm)→paired nanowire (≈12 nm)→nanowire (≈200 nm)→microwire (500 nm)→wire like rod (1–2 μm)→jelly→rectangular sheet (5 μm). ii) dendritic seed→nano‐sphere (20 nm)→micro‐sphere (500 nm)→large balls(1 μm)→oval shape rod (5–10 μm)→Y, L or T shaped rod assembly. The energy level interactions are tracked using spectroscopy how exactly a directed energy transfer code generates multi‐step synthesis from nano to the visible scale.     

Synthesis of satellite footprint patterns from rectangular planar array antenna by using swarm‐based optimization algorithms

A pattern synthesis method based on Firefly Algorithm (FA) and Artificial Bee Colony (ABC) optimization has been presented to generate satellite footprint patterns from a rectangular planar array of isotropic antennas by modifying the amplitude, phase, and the state of the array elements. Three cases comprising three different footprints of rectangular, square, and circular boundary are generated from the same array by using two different swarm‐based optimization algorithms FA and ABC. Both the algorithms, following the proposed procedures are able to generate the three different footprint patterns while maintaining a satisfactory lower peak side lobe level and ripple. A comparative analysis has been carried out between FA, ABC, and Genetic Algorithm (GA) for the presented problem in terms of fitness value for the three different cases. The superiority of FA and ABC over GA has been established in terms of finding better solutions for all the three cases of the proposed problem. Copyright © 2013 John Wiley & Sons, Ltd.     

Detecting anomalous packets in network transfers: investigations using PCA,autoencoder and isolation forest in TCP

Machine Learning - Large-scale scientific workflows rely heavily on high-performance file transfers. These transfers require strict quality parameters such as guaranteed bandwidth, no packet loss...     

A finite-difference time-domain method for the design and analysisof guided-wave optical structures

A CAD tool employing the finite-difference time-domain (FDTD) algorithm is developed for the design and analysis of optical waveguide structures. The basic formulation of the algorithm is given, and practical conditions for its application are briefly outlined. The accuracy of the numerical scheme is investigated through a study of a canonical parallel-slabs coupling structure. Both the coupling length and the field distribution are in good agreement with results in the literature. The use of the method is illustrated by an analysis of a directional coupler     

Finite element analysis of cavitating facet interaction in a fully lamellar titanium aluminide alloy under creep conditions

Creep constrained grain boundary cavitation in a fully lamellar (FL) form of a titanium aluminide intermetallic alloy has been studied using finite element (FE) techniques. Two different forms of FL models were considered. Cavitation was modeled in the presence of grain boundary sliding (GBS) for the case of straight former γ grain boundaries. Models of cavitation without GBS were also performed for a FL microstructure with serrated forme γ grain boundaries. The effect of cavitating facet interaction on rupture life has been studied. A comparison between the FL forms and a dual-phase equizxed microstructure having the same phase ratio (α₂/γ) was also made to examine the relative susceptibility of these microstructures to high-temperature damage. It has been observed that the overall effect of interaction between cavitating facets increases the rupture time significantly when these facets are on adjacent grains. However, in the presence of GBS, cavitation on the facet with narrower separation effectively reduces the cavity growth rate on the facet with wider separation. ANIRBAN CHAKRABORTY, formerly Graduate Student Researcher with the Chemical & Biochemical Engineering and Materials Science (CBEMS) Department, University of California, Irvine. This article is based on a presentation made in the symposium “Fundamentals of Gamma Titanium Aluminides”, presented at the TMS Annual Meeting, February 10–12, 1997, Orlando, Florida, under the auspices of the ASM/MSD Flow & Fracture and Phase Transformations Committees.     

Evaluation of Petroleum Impurities in Motor Spirit and Diesel Oils Using Artificial Neural Network

Studies have been conducted for the ternary mixture of motor spirit, diesel, and kerosene oil samples using artificial neural network (ANN). American standard for testing materials (ASTM) distillation data of samples were used for the evaluation of respective components. Results of such evaluation of the samples were found to comply well with experimental values.