Analysis of Power Supply Noise in the Presence of Process Variations

Characterizing the impact of variability on circuit performance measurements (delay, power, and signal integrity) is necessary to avoid chip failure. The authors present a comprehensive methodology for analyzing the impact of device and metal variations on the power supply noise, and hence the signal integrity, of on-chip power grids.     

United Kingdom EM gun programme

The authors review the progress in the RARDE (Royal Armament Research and Development Establishment) electromagnetic gun (REMGUN) program. They cover research on both railgun and LIA (linear induction accelerator) technology, including work on modeling, projectile/barrel interactions armatures, switching, and instrumentation. They also describe the major research facilities. Progress is reported in the identification and development of single-shot switches, integrated switch/barrel concepts, armatures and pulse power supplies as well as the integration of railgun components. LIA research has concentrated on launcher design and projectile/barrel interactions, highlighting the problems of pulse power systems for this form of electromagnetic launcher     

Profile dependence and measurement of absolute Raman scattering cross-section in optical fibres

A simple measurement method for the absolute Raman scattering cross-section of an optical fibre is presented. This method does not require a high power pump laser and it measures the fibre directly. It is also shown that the calculation of the cross-section depends on the fibre structure, such as its refractive index profile and the differential attenuation between the pump wavelength and Raman wavelength.<>     

Preparation and characterization of doped WO3 photocatalyst powders

WO₃ semiconductor particles, useful in solar energy conversion processes, were doped with transition metal ions, Ti(III), V(IV), Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II), Zn(II) and Ru(III) by a high-temperature sintering technique. The method of preparation of these photocatalysts is described in detail. The structural changes effected during sintering were investigated by X-ray powder diffraction (XRD) and scanning electron microscopy (SEM). The XRD analysis indicated that the monoclinic crystal structure of WO₃ was not altered during sintering. SEM studies showed that the sizes of the particles ranged from 1 to 10 μm and the crystallinity was increased due to doping. The dopants were found to be mostly distributed on the surface of WO₃ particles.     

Mass transfer across wind-sheared interfaces

A predictive analogy of turbulent mass transfer across wavy, sheared air-water interface, in deep water bodies is proposed. The theory is based on the formulation of a theoretical eddy diffusivity profile in the surface region, and it applies to the non-breaking wave regime. The predictions for a water-side friction velocity range of 0.5–6 cm/s are in excellent agreement with laboratory data from wind-wave facilities with an average error of 15.4%.     

Improved Complexometric Determination of Calcium in Cheese

Accuracy and repeatability of complexometric methods for measuring calcium in cheese are limited by titration endpoints that are difficult to recognize. Much of this difficulty results from turbidity during titration. An alternative procedure is described in which 2 to 3 g of cheese are ashed, dissolved in dilute acid, and added calcium chloride is back titrated with ethylenediaminetetraacetic acid using hydroxy naphthol blue as indicator. Samples remain free of turbidity, and the titration endpoint is recognized easily.Recovery of calcium from solutions containing magnesium and phosphate was 100.9 ± .3%, indicating that a portion of sample magnesium (about 12%) also was measured. Error caused by magnesium recovery represented less than 1% of true calcium content.Analyses of 10 Cheddar cheese samples by the proposed method and by atomic emission differed by an average of .010% calcium. Mean values of the 10 samples did not differ significantly (P>.05) between methods. Duplicate analyses of 67 Cheddar cheese samples differed by an average of .008 ± .006% calcium. Similar repeatability was achieved by several inexperienced analysts. The method is applied readily to other dairy products.     

Lipoamide dehydrogenase, citrate synthase and beta-hydroxyacyl-CoA-dehydrogenase in skeletal muscle. 12. The influence of electric stimulation of beef carcasses on activity and subcellular distribution

The effect of electrical stimulation (ES) of beef carcasses at 450 V on the total extractable activity and subcellular distribution of the mitochondrial enzymes lipoamide dehydrogenase, citrate synthase and beta-hydroxyacyl-CoA-dehydrogenase in skeletal muscle (activities in the supernatant of a phosphate buffer extract and in muscle press juice) was studied. There was no influence of ES on the total activity and the subcellular distribution of these enzymes in the muscle tissue stored at +2 degrees C for 7 days nor did ES influence the extent of the release of the three enzymes from the mitochondria into the sarcoplasm by freezing (-20 degrees C) and thawing. From these results it can be concluded that ES does not result in an appreciable disintegration of the inner membrane of muscle mitochondria.     

On-body propagation velocity estimation using ultra-wideband frequency-domain spatial correlation analyses

On-body communications around the human torso are considered, using ultra-wideband transmissions. The velocity of the diffracted wave propagating around the body is extracted from frequency- domain spatial correlation analyses.     

A VLSI CMOS delay oriented waveform converter for polyphasefrequency synthesizer

In this paper, we present a waveform converter implemented on a 0.25-μm CMOS technology using a dedicated design methodology (Delay Oriented Design). The circuit converts a square wave signal in both in-phase and quadrature-phase sinusoidal differential outputs. It also multiplies the frequency by seven. The output frequency range of this converter extends from 1.05 GHz up to 2.17 GHz. This converter is dedicated for the design of a third-generation mobile phone synthesizer using a double-loop architecture. For an output frequency of 2 GHz, the measured phase noise at 10-kHz offset from the carrier is -97 dBc/Hz. The circuit consumes 50 mW from a 2.5-V supply     

PKI: it's not dead, just resting

Like other flexible objects, the public key infrastructure sacrifices some utility in trying to be all things to all people. Mainly, PKI's generic, all-purpose identity certificates fall short of what the marketplace demands, forcing vendors to develop more economically efficient, useful, and imaginative business models. Thus, we must adapt the PKI design to the real world rather than trying to constrain the real world to match the PKI. A variety of alternative approaches, ranging from simple workarounds to designing the application to sidestep PKI's shortcomings entirely, can help solve the problems inherent in the standard X.509 model.

Despite an original design that failed to address the marketplace's needs, the use of innovative public key infrastructure models can make the technology meet today's requirements.