Ezzat G. Bakhoum

Capacitive Pressure Sensor With Very Large Dynamic Range

A new capacitive pressure sensor with very large dynamic range is introduced. The sensor is based on a new technique for substantially changing the surface area of the electrodes, rather than the inter-electrode spacing as commonly done at the present. The prototype device has demonstrated a change in capacitance of approximately 2500 pF over a pressure range of 10 kPa.

Dynamical Aspects of Macroscopic and Quantum Transitions due to Coherence Function and Time Series Events

This study presents the application of dynamical equations able to generate alternating deformations with increasing amplitude and delayed pulses in a certain material medium. It is considered that an external force acts at certain time interval (similar to a time series) upon the material medium in the same area. Using a specific differential equation (considering nonzero initial values and using a function similar to the coherence function between the external force and the deformations inside the material), it results that modulated amplitude oscillations appear inside the material. If the order of the differential dynamical equation is higher, supplementary aspects as different delayed pulses and multiscale behaviour can be noticed. These features are similar to non-Markov aspects of quantum transitions, and for this reason the mathematical model is suitable for describing both quantum phenomena and macroscopic aspects generated by sequence of pulses. An example of a quantum system, namely, the Hydrogen atom, is discussed.

Specific Mathematical Aspects of Dynamics Generated by Coherence Functions

This study presents specific aspects of dynamics generated by the coherence function (acting in an integral manner). It is considered that an oscillating system starting to work from initial nonzero conditions is commanded by the coherence function between the output of the system and an alternating function of a certain frequency. For different initial conditions, the evolution of the system is analyzed. The equivalence between integrodifferential equations and integral equations implying the same number of state variables is investigated; it is shown that integro-differential equations of second order are far more restrictive regarding the initial conditions for the state variables. Then, the analysis is extended to equations of evolution where the coherence function is acting under the form of a multiple integral. It is shown that for the coherence function represented under the form of an 𝑛th integral, some specific aspects as multiscale behaviour suitable for modelling transitions in complex systems (e.g., quantum physics) could be noticed when 𝑛 equals 4, 5, or 6.

Mathematical Transform of Traveling-Wave Equations and Phase Aspects of Quantum Interaction

The traveling wave equation is an essential tool in the study of vibrations and oscillating systems. This paper introduces an important extension to the Fourier/Laplace transform that is needed for the analysis of signals that are represented by traveling wave equations. Another objective of the paper is to present a mathematical technique for the simulation of the behavior of large systems of optical oscillators.

High-Sensitivity Inductive Pressure Sensor

A new type of pressure sensors with extremely high sensitivity is introduced. Unlike piezoresistive, capacitive, and linear-variable-differential-transformer-based pressure sensors, the new sensor is based on a technique for substantially changing the inductance of a coil. The prototype device has demonstrated a change in inductance of approximately 34.5 mH over a pressure range of 10 kPa. The sensor offers a number of desirable features, including linearity, low temperature, and pressure hysteresis, in addition to small size.

Controller Synthesis of Tracking and Synchronization for Multiaxis Motion System

Accurate motion control for multiaxis motion systems is an important issue for manufacturing industry. In this brief, an adaptive robust control scheme is implemented to synthesize the compensator for tracking and synchronization with the consideration of cross-coupling dynamics among different axes. By using the adaptive strategies, the asymptotic convergence of both tracking and synchronization errors are achieved. The robust control scheme also guarantees the transient performance, tracking errors, and synchronization errors. Experimental results of a three-axis motion system that include system uncertainties and nonlinearity are also illustrated to verify the effectiveness of the proposed approach for different scenarios. The results indicate excellent transient performance as well as both tracking and synchronization accuracies.

New mega-farad ultracapacitors

This paper reports the successful creation of a new ultracapacitor structure that offers a capacitance density on the order of 100 to 200 Farads per cubic centimeter; versus the current state of the art capacitance density of 1 F/cm3. The principle behind the new ultracapacitor structure is the insertion of a few nanometers-thick layer of barium strontium titanate as an interface between an activated carbon electrode and a suitable electrolyte, such as acetonitrile or propylene carbonate. The new ultracapacitors are highly needed in hybrid vehicle applications, because any significant increase in the energy storage capability of the ultracapacitors leads to substantial improvement in the fuel efficiency of hybrid vehicles.

Novel Capacitive Pressure Sensor

A new microelectromechanical-systems capacitive pressure sensor with extremely high sensitivity (2.24 ¿F/kPa) is introduced. The sensor essentially consists of a small drop of mercury and a flat aluminum electrode that are separated by a 1 ¿m-thick layer of Barium Strontium Titanate (a high dielectric-constant ceramic). The assembly constitutes a parallel-plate capacitor where the surface area of the electrodes is variable to a high degree. The mercury drop is pressured by a small corrugated metal diaphragm. As the electrode area of the parallel-plate capacitor varies, a total change in capacitance of more than 6 ¿F is obtained.

Relativistic Short Range Phenomena and Space-Time Aspects of Pulse Measurements

Particle physics is increasingly being linked to engineering applications via electron microscopy, nuclear instrumentation, and numerous other applications. It is well known that relativistic particle equations notoriously fail over very short space-time intervals. This paper introduces new versions of Diracs equation and of the Klein-Gordon equation that are suitable for short-range phenomena. Another objective of the paper is to demonstrate that pulse measurement methods that are based on the wave nature of matter do not necessarily correlate with physical definitions that are based on the corpuscular nature of particles.

Ultrahigh-Sensitivity Pressure and Vibration Sensor

A novel new ultrahigh-sensitivity pressure and vibration sensor is introduced. The sensor is based on the concept of using a variable ultracapacitor rather than a variable capacitor as a transduction mechanism. The variable ultracapacitor assembly consists of two electrodes on which carbon nano-tubes of a length of 20 μm are grown. One electrode is fixed and is fully immersed in the electrolyte, while the other electrode is movable and is positioned outside of the electrolyte. In response to pressure or vibration, an extremely small displacement of 20 μm (less than the width of a human hair) submerges the movable electrode into the electrolyte and results in a substantially large variation in capacitance (from zero to 54 μF in the present prototype).