Design of universal,variable frequency range FIR digital differentiators

An efficient design of digital differentiators (DD), with a variable frequency range of operation at low and midband frequencies, has been proposed. Implemented as a Taylor structure, a DD designed for orderN can be made to function as a universal configuration giving optimal transfer functions for all possible ordersN, without changing the coefficients.     

Performance Determination of a Chopper-Controlled Separately Excited DC Motor

Chopper-controlled dc motors have a wide field of application as variable speed drives. The techniques used for chopper control of dc power make use of pulse-width modulation (PWM), pulse-frequency modulation (PFM), and current-limit control. Of these, the pulse-width modulation and current-limit control are more widely used.     

Availability analysis of transit systems

This paper presents two mathematical models of repairable transit systems. State probability equations for both models are developed.     

Isolated bilateral renal aspergillosis: an unusual presentation in an immunocompetent host

A 35 year old apparently immunocompetent farmer developed isolated bilateral renal aspergillosis. He presented with acute renal failure due to granulomatous interstitial nephritis and had bilateral renal abscesses on CT scan. Diagnosis came from renal histology and was confirmed on serology. The patient responded quite satisfactorily to single agent antifungal chemotherapy with IV amphotericin B.     

An algorithm for segmenting juxtaposed objects

This work is an attempt to develop an algorithm for segmentation of juxtaposed objects arising in the recognition of certain scenes. The approach is based on matrix manipulation. The algorithm is implemented in two parts. The first part is to find the significant points of concavity. In the second part, the direction of the paths of segmentation is found and the paths are grown into the pattern until complete segmentation is achieved. The algorithm is illustrated by considering examples from biomedical imagery.     

Bibliography of literature on fault trees

This paper presents a brief introduction and an extensive list of selective references on fault trees.     

Applications for Low Frequency Impedance Analysis Systems

We present methodology and instrumentation used to carry out and log automated multiple electrical impedance measurements using multiplexed control. We also address the issue of measurement error introduced by the instrumentation, and demonstrate how we reduce these effects in our experiments. Finally, we present two potential applications for our automated electrical impedance analysis systems: tissue scanning and mapping via impedance measurements between arrays of electrodes, and materials testing of novel conductive polymer materials.     

Chemical, optical, vibrational and luminescent properties of hydrogenated silicon-rich oxynitride films

X-ray photoelectron spectroscopy, spectroscopic ellipsometry, Fourier transform infrared and room temperature photoluminescence spectroscopy has been used to investigate the chemical, optical, vibrational and luminescent properties of Plasma Enhanced Chemical Vapor Deposited SiO_xN_y/H (0.17≤x≤0.96; 0.07≤y≤0.27), hydrogenated silicon-rich oxynitride (SRON). The linear dependence of the refractive index of the SRON films on the O/Si ratio was established. The photoluminescence from the SRON films were attributed to the embedded amorphous silicon clusters in the films. The dependence of luminescence maximum values on the O/Si and O/N ratios has been explored. We postulate that at O/Si ratio of 0.18 and an O/N ratio of 2.0 (SiO_0.18N_0.09) the film underwent a transformation from silicon-rich oxynitride to a-Si/H film with oxygen and nitrogen impurities.