Delta modulation with slope-overload prediction

An improved delta-modulation system is described which uses a delay line to obtain information about the `future? behaviour of the input signal. Conditions of potential slope overload are detected before the signal is encoded and the encoding pattern altered accordingly. Computer simulation results show that signal/noise ratios can be 3 dB better than for simple delta modulation.     

Delay analysis of series-connected MOSFET circuits

In order to derive analytical delay expressions for CMOS gates in the submicrometer region, a realistic MOS model which incorporates an nth power law MOS model is developed. Closed-form delay formulas are obtained for CMOS inverters and series-connected MOSFET structures (SCMSs) that include short-channel effects. It is shown that the ratio of the delay of NAND/NOR to the delay of the inverter becomes smaller in the submicrometer region, because the V_DS and V_GS of each MOSFET in the SCMS are smaller than those of an inverter MOSFET. The smaller voltages in turn mitigate and relax the severe carrier velocity saturation in miniaturized MOSFETs. The results of the analysis for submicrometer VLSI designs show that if the maximum number of series-connected MOSFETs is considered to be five in 2-μm designs, then the number can be increased to six or seven in the submicrometer circuit design. In typical cases in VLSI designs, the delay ratio for N-SCMS is much less than N². The delay dependence on input terminal position for SCMS structures is also described     

Coherent FMCW reflectometry using a temperature tuned Nd:YAG ringlaser

A long-coherence-length, diode-pumped, monolithic Nd:YAG laser operating at 1.32 μm is used to perform coherent FMCW (frequency-modulated continuous wave) reflectometry measurements. Compared with semiconductor-based lasers, the low phase noise of the Nd:YAG source offers greatly increased distance range combined with increased sensitivity to optical reflections. Measurement of Rayleigh backscatter from 50 km of fiber is demonstrated with over 60 dB of two-way optical dynamic range. Two-point spatial resolution is demonstrated to be better than 10 cm. This source and coherent measurement technique may have potential for both short and long-haul reflectometry applications     

Absolute method of measuring the acceleration due to gravity using Doppler radar

It is shown that by using a Doppler radar system the acceleration due to gravity can be measured in terms of the frequency of a microwave oscillator, the velocity of light and the number of Doppler cycles received in a known time. The block diagram of a simple radio-electronic system for making this measurement is described, and some preliminary results are given.     

Localization of intraorbital foreign bodies: an improved photoradiographic method

Corynebacterium parvum, strain 10390, whole organisms were shown to bind to the surface of glass-adherent mouse peritoneal exudate cells in vitro. An HCl extract and a lipid extract of the organism were both capable of inhibiting this binding. The attachment of organisms was not affected by trypsin treatment of the cells, indicating that the plasma membrane receptor is not cell-bound antibody in nature. The binding was inhibited by various sugars, most of which are major components of the cell wall of C. parvum. Removal of divalent cations prevented binding. At room temperature some binding occurred in the presence of magnesium ions alone, whereas both calcium and magnesium ions were required at 4 degrees C. The possibility is discussed that the attachment of C. parvum to the plasma membrane of macrophages may lead directly to their activation.