Surface spreading of intergranular corrosion on stainless steels

The spreading of intergranular corrosion was investigated using micrometer scale simulations and experimental verifications on sensitized stainless steel [UNS S30400]. The degree of sensitization, presence of a pit, and applied potential all affected spreading. The inputs used in the simulation were obtained from Fe-XCr(X = 10, 12, 14, 16 wt.%)-Mo-Ni alloys representing various grain boundary Cr depletion levels. Corroding grain boundaries and pits triggered corrosion of nearby sensitized boundaries due to Ohmic potential drop. Large connected clusters of corroding grain boundaries formed at high fractions of Cr-depleted grain boundaries. The metallurgical, electrochemical and geometric conditions for this behavior could be forecasted.     

Slip effects on boundary layer stagnation-point flow and heat transfer towards a shrinking sheet

In the present study, we analyze the effects of partial slip on steady boundary layer stagnation-point flow of an incompressible fluid and heat transfer towards a shrinking sheet. Similarity transformation technique is adopted to obtain the self-similar ordinary differential equations and then the self-similar equations are solved numerically using shooting method. This investigation explores the conditions of the non-existence, existence, uniqueness and duality of the solutions of self-similar equations numerically. Due to the increase of slip parameter (δ), the range of velocity ratio parameter (c/a) where the similarity solution exists, increases.     

Studies on microstructure of silicon thin films and its effect on solar cells

Intrinsic microcrystalline silicon films have been deposited at high-power–high-pressure regime. Effects of pressure and hydrogen dilution on the microstructures of the films have been investigated. Crystalline size decreases at high pressure although the deposition rate increases up to 10 Å/s. Microstructure depends sensitively on pressure as well as on hydrogen dilution of silane. Single junction solar cells have been fabricated with Si films having different degrees of crystallinity and grain size and the performances have been studied.     

Defected Ground Based Fractal Antenna for S and C Band Applications

Wireless Personal Communications - Defected ground based modified rectangular fractal patch antenna for mobile devices communication in Delay Tolerant Networks, Wireless sensor networks and Mobile...     

Part I: Mixed-Signal Performance of Various High-Voltage Drain-Extended MOS Devices

In this paper, the optimization issues of various drain-extended devices are discussed for input/output applications. The mixed-signal performance, impact of process variations, and gate oxide reliability of these devices are compared. Lightly doped drain MOS (LDDMOS) was found to have a moderate performance advantage as compared to shallow trench isolation (STI) and non-STI drain-extended MOS (DeMOS) devices. Non-STI DeMOS devices have improved circuit performance but suffer from the worst gate oxide reliability. Incorporating an STI region underneath the gate–drain overlap improves the gate oxide reliability, although it degrades the mixed-signal characteristics of the device. The single-halo nature of DeMOS devices has been shown to be effective in suppressing the short-channel effects.      

Low-Loss Slow Light Transmission in Photonic Crystal Waveguides Comprising of Liquid Crystal Infiltration

A low loss photonic crystal(PhC) waveguide having rectangular air holes in Si core is proposed having an average group index of 55 in the bandwidth of 1.2 THz.The possible propagation losses due to inefficient coupling are also investigated for proposed structure.It is found that high transmission is obtained for a broad bandwidth from the output of the finally designed heterogeneous waveguide consisting of a slow liquid crystal infiltrated PhC waveguide surrounded by fast PhC waveguides on both sides.     

RF packaging and passives: design, fabrication, measurement, and validation of package embedded inductors

Design, modeling, and characterization of inductors embedded in a package substrate promising higher quality factor (Q) and lower cost than on-chip inductors is described. In addition to the problem of large conductor losses, on-die inductors with or without magnetic materials consume considerable die area and require the removal of the first-level interconnect bumps beneath them to maintain a reasonably high Q value. Moving inductors to the package eliminates the need for bump array depopulation and, thus, mitigates the potential reliability problems caused by voids in the epoxy underfill between the die and the substrate. Competency developed to design, fabricate, and characterize inductors based on standard organic flip-chip packaging technology is described. Physical design details along with measurement procedures and results are discussed. In addition, modeling techniques for achieving good correlation to measured data are included.     

Constructing dependable Web services

The majority of today's millions of Web sites offer read-only access to relatively small amounts of infrequently changing information. The load on these sites is usually small, and services can often be hosted as background tasks on general-purpose workstations. Concern for the quality of service (QoS) presented to users at these sites is generally not primary. Conversely, a much smaller number of sites are very popular; they support heavy loads and must meet user expectations regarding QoS to maintain their popularity. We discuss issues involved in supporting high-volume, high-reliability Web services. We begin by surveying the diverse technical challenges and constraints posed in this environment, followed by currently used hardware and network based approaches to meeting the scalability requirements and software-implemented techniques to addressing fault tolerance. However, these approaches do not scale well, so we discuss possible alternatives     

Crystallographic evaluation of titanate ceramics as a host structure for immobilization of samarium

In order to simulate the mechanism of rare earth fixation in perovskite, Ca_1?x Sm_2/3x TiO₃ (x = 0.1–0.5) was synthesized via ceramic route at 1050°C. Up to ～4 mol % Sm could be loaded into calcium titanate formulations without significant changes of the three-dimensional framework structure. Their crystal structures were refined by Rietveld analysis of powder X-ray diffraction data. The structure refinement converged to satisfactory values of the Rietveld parameters (R _p and R _wp ) and goodness of fit. The lattice parameters, structure factors, bond lengths, and bond angles were calculated from General Structure Analysis System software (GSAS). The M-O stretching and bending vibrations in the IR region were assigned. The crystal morphology was examined by scanning electron microscopy. Energy-dispersive X-ray (EDX) analysis of the specimens shows that samarium enters into the structural framework of CaTiO₃.     

Soya protein as possible potential nanocarriers for in-vitro oral delivery of insulin in simulated gastric fluids (SGFs)

The present study aimed to prepare soya protein nanoparticles and employ them as nanocarriers for delivery of insulin. The nanoparticles were characterized by Fourier transform infrared spectroscopy, transmission electron microscopy, scanning electron microcopy, zeta potential, and dynamic light scattering measurements. The particle size analysis revealed that the size of the nanoparticles lays in the range of 40–200?nm with surface charge of ?25.3?mV. The insulin-loaded nanoparticles were investigated in simulated gastric and simulated intestinal fluids and effect of percent drug loading chemical composition of nanoparticles, pH, temperature of the release media, and simulated physiologic fluids was studied on the release of insulin.