CORDIC-Based VLSI Architecture for Implementing Kaiser-Bessel Window in Real Time Spectral Analysis

Windowing techniques have been widely used for preprocessing of samples before fast Fourier transform (FFT) in real time spectral analysis to minimize spectral leakage and picket fence effect. Among all popular window functions, Kaiser-Bessel window is an obvious choice for its better spectral characteristics. In this paper, CORDIC (CO-ordinate Rotation DIgital Computer) based VLSI architecture for implementing Kaiser-Bessel window has been proposed for real time applications. The parallel-pipelined technique has been adopted for the present design to ensure high throughput. Various architectural design and implementation issues have been discussed. The physical synthesis for ASIC implementation of proposed architecture using Synopsys design compiler(Design Vision) and commercially available 0. 18 μm CMOS yields the core area of 52 mm ²and worst case dynamic power of 890 mW at an operating frequency and voltage of 400 MHz and 1.8 V respectively.     

Glass-ceramic glazes for future generation floor tiles

Glaze in the CaO–MgO–Al₂O₃–SiO₂ system was heated at 950–1190 °C for 2 h and characterized. X-ray diffraction showed that only trace amount of mullite was formed in the glass-ceramic glaze heated at 950 °C. Both mullite and α-cordierite were formed in the glass-ceramic glaze heated at 1050 °C as primary and secondary phases. Glass-ceramic glazes heated at 1120 °C and 1190 °C contained α-cordierite and mullite as major and minor phases. Rietveld analysis revealed that the amount of α-cordierite increased and mullite decreased with increasing heating temperature. Field emission scanning electron microscopy showed presence of mullite crystals dispersed within residual glassy phase in the glass-ceramic glazes heated at 950 °C and 1050 °C. In the microstructures of glass-ceramic glazes heated at 1120 °C and 1190 °C α-cordierite crystals were mainly appeared. Energy Dispersive X-ray analysis corroborated X-ray diffraction results. Vickers microhardness measurement demonstrated highest hardness (8.38 ± 0.07 GPa) of the glass-ceramic glaze heated at 1190 °C.     

Recursive formulation of the matrix Padé approximation in packed storage

The Extended Euclidean algorithm for matrix Padé approximants is applied to compute matrix Padé approximants when the coefficient matrices of the input matrix polynomial are triangular. The procedure given by Bjarne S. Anderson et al. for packing a triangular matrix in recursive packed storage is applied to pack a sequence of lower triangular matrices of a matrix polynomial in recursive packed storage. This recursive packed storage for a matrix polynomial is applied to compute matrix Padé approximants of the matrix polynomial using the Matrix Padé Extended Euclidean algorithm in packed form. The CPU time and memory comparison, in computing the matrix Padé approximants of a matrix polynomial, between the packed case and the non-packed case are described in detail.     

Self-microemulsifying smaller molecular volume oil (Capmul MCM) using non-ionic surfactants: a delivery system for poorly water-soluble drug

The main purpose of this work is to formulate self-microemulsifying drug delivery system (SMEDDS) using smaller molecular oil with Atorvastatin calcium as a model drug. Solubility of the selected drug was accessed in oils and surfactants. Percent transmittance (%T) test study was performed to identify the efficient self-microemulsifying formulations. Those formulations which showed higher value for %T were evaluated for droplet size, polydispersity index, ζ potential, refractive index and cloud point measurement. Effect of drug loading on droplet size, increasing dilution in different media, thermodynamic stability and in vitro dissolution was performed to observe the performance of the selected formulation. Further cytotoxicity and permeation enhancement studies were carried out on Caco2 cell lines. Of all the oils accessed for drug solubility, Capmul MCM showed higher solubility capacity for Atorvastatin calcium. Capmul MCM was better microemulsified using combination of Tween 20 and Labrasol surfactant. Droplet size was as low as 86.93?nm with polydispersity index and ζ potential at 0.195?±?0.011 and -7.27?±?3.11 mV respectively. The selected undiluted formulation showed refractive index values ranging from 1.40 to 1.47 indicating the isotropicity of the formulation. The selected formulation was robust to dilution in different media and thermodynamically stable. Dissolution profile was enhanced for the selected drug as compared to marketed formulation with t85% and DE values at 10?min and 80.15 respectively. Also cytotoxicity measurement showed minimum effect with good permeation enhancing capacity. Thus our study demonstrates the use of smaller molecular oil (Capmul MCM) for developing self-microemulsifying drug delivery system for better in vitro and in vivo performance.     

Fabrication and evaluation of electrospun collagen/poly(N-isopropyl acrylamide)/chitosan mat as blood-contacting biomaterials for drug delivery

The recent advances in electrospinning have resulted in technologies facilitating easy drug entrapment, obtaining high surface area and thereby higher drug loading and release efficacy, burst control as well as the specific morphology which could be controlled according to the desired requirement. The present study focused on the fabrication of collagen/poly(N-isopropyl acrylamide)/chitosan complex with incorporated 5-fluorouracil, an anticancer drug by the method of electrospinning. The effect of chitosan on the fiber morphology and release kinetics was analyzed by varying its concentration. The release kinetics showed that the increase in chitosan concentration delayed the release of the drug from the fiber network. Nano hydroxyapatite was added to the fiber matrix in order to impart bioactivity, which was confirmed by studies in simulated body fluid. The addition of poly(N-isopropyl acrylamide) increased the blood compatibility of the prepared model. Thus, the model prepared to can find potential application in the field of cancer therapy as a drug-delivery agent in post-surgical treatment of cancer and as blood contacting biomaterial.     

Sintering Behavior of Nanocrystalline Silicon Carbide Using a Plasma Pressure Compaction System: Master Sintering Curve Analysis

Nanostructured ceramics offer significant improvements in properties over corresponding materials with larger grain sizes on the order of tens to hundreds of micrometers. Silicon carbide (SiC) samples with grain sizes on the order of 100 nm can result in improved strength, chemical resistance, thermal stability, and tailored electrical resistivity. In this study, nanocrystalline SiC was processed in a plasma pressure compaction (P²C) system at a temperature of 1973 K (1700 °C) that was much lower than the temperatures reported for other sintering techniques. Microstructure of the resulting samples was studied and the hardness and the fracture toughness were measured. The grain sizes were on the order of 700 nm, the hardness between 22 and 24 GPa, and the toughness between 5 and 6.5 MPa·m^1/2. The master sintering curve (MSC) analysis was used to model the densification behavior of SiC powder sintered by the P²C method. The apparent activation energies for three different pressures of 10, 30, and 50 MPa were obtained to be 1666, 1034, and 1162 kJ/mol, respectively. Although densification occurs via diffusion, the activation energies were higher than those associated with self-diffusion in SiC (between 570 and 920 kJ/mol). A validation study of the MSC was also conducted and the variation in observed density from the density predicted by the MSC was found to range from 1 to 10 pct.     

Satellite and surface-based remote sensing of Saharan dust aerosols

The spatial and temporal characteristics of dust aerosols and their properties are assessed from satellite and ground-based sensors. The spatial distribution of total column aerosol optical depth at 550 nm (AOD) from the Moderate Resolution Imaging SpectroRadiometer (MODIS) coupled with top of atmosphere Clouds and the Earth's Radiant Energy System (CERES) shortwave fluxes are examined from the Terra satellite over the Atlantic Ocean. These data are then compared with AOD from two Aerosol Robotic Network (AERONET) ground-based sun photometer measurement sites for nearly six years (2000-2005). These two sites include Capo Verde (CV) (16°N, 24°W) near the Saharan dust source region and La Paguera (LP) (18°N, 67°W) that is downwind of the dust source regions. The AOD is two to three times higher during spring and summer months over CV when compared to LP and the surrounding regions. For a unit AOD value, the instantaneous TOA shortwave direct radiative effect (DRE) defined as the change in shortwave flux between clear and aerosol skies for CV and LP are − 53 and − 68 Wm^− 2 respectively. DRE for LP is likely more negative due to fall out of larger particles during transport from CV to LP. However, separating the CERES-derived DRE by MODIS aerosol effective radii was difficult. Satellite and ground-based dust aerosol data sets continue to be useful to understand dust processes related to the surface and the atmosphere.     

Proteomic approaches for discovery of new targets for vaccine and therapeutics against visceral leishmaniasis

Visceral leishmaniasis (VL) is the most devastating type caused by Leishmania donovani, Leishmania infantum, and Leishmania chagasi. The therapeutic mainstay is still based on the antiquated pentavalent antimonial against which resistance is now increasing. Unfortunately, due to the digenetic life cycle of parasite, there is significant antigenic diversity. There is an urgent need to develop novel drug/vaccine targets against VL for which the primary goal should be to identify and characterize the structural and functional proteins. Proteomics, being widely employed in the study of Leishmania seems to be a suitable strategy as the availability of annotated sequenced genome of Leishmania major has opened the door for dissection of both protein expression/regulation and function. Advances in clinical proteomic technologies have enable to enhance our mechanistic understanding of virulence/pathogenicity/host-pathogen interactions, drug resistance thereby defining novel therapeutic/vaccine targets. Expression proteomics exploits the differential expression of leishmanial proteins as biomarkers for application towards early diagnosis. Further using immunoproteomics efforts were also focused on evaluating responses to define parasite T-cell epitopes as vaccine/diagnostic targets. This review has highlighted some of the relevant developments in the rapidly emerging field of leishmanial proteomics and focus on its future applications in drug and vaccine discovery against VL.     

Manning’s ‘n’ co-efficient for flexible emergent vegetation in tandem configuration

A comprehensive laboratory study on the hydraulic resistance characteristics due to a group of slender cylindrical members representing flexible plantation has been carried out in a laboratory open channel. The model stem group comprised of individual members arranged in a tandem configuration. The tests with model vegetation were carried out by adopting different sizes for the individual stems and concentrations which were chosen in such a way that they would fall into practical ranges of vegetations in coastal forestry. The results indicate that the flow resistance varies with stem concentration, stem diameter and elastic properties of the individual members and the flow velocity. Based on the flume data, the Manning’s n, for various flow conditions as well as for vegetative parameters was determined. A new empirical equation is proposed for evaluating the Manning’s n friction coefficient for partially submerged flow when, the depth of flow is greater than 0.8 times the un-deflected plant height. It is expected that the Manning’s n thus determined will be useful in modelling shallow flows using shallow water equations.     

Anthropomorphism of computers: Is it mindful or mindless?

In analyzing the human tendency to treat computers as social actors (CASA), researchers tend to rule out the anthropomorphism explanation because anthropomorphism is understood to be “a sincere, conscious belief” that computers are human and/or deserving of human attributions. But, does anthropomorphism have to be necessarily mindful? Could it not also be a mindless tendency, especially given that most of us have somewhat long associations with our computers and have built human-like bonds with them? We examined these questions empirically by investigating whether the user tendency to treat computers as human beings is conscious (mindful) or non-conscious (mindless). We manipulated two variables (presence/absence of human-like agent and the low/high interactivity) on a health website and experimentally investigated whether they serve as anthropomorphic cues to trigger mindful attributions of human-ness to the website or mindless evaluations of the site in human terms. We found evidence for mindless anthropomorphism, with implications for user judgments of credibility of information on the site.