A Unified Approach to Submicron DC MOS Transistor Modeling for Low-Voltage ICs

A unified single-equation approach for the MOS transistordrain current modeling for energy-efficient submicron MOS circuitsis presented. Instead of three sets of separate equations forthe triode, saturation, and weak inversion regions, only a continuousexpression which is valid to describe the behavior of drain currentand the derivatives in all operation regions can be realizedby using a combination of hyperbola, sigmoid, and interpolationmethods. The model expression can predict accurate results forthe current, output conductance, and transconductance with continuousand smooth characteristics. The simulation results agree wellwith experimental data.     

Corticofugal regulation of auditory sensitivity in the bat inferior colliculus

Risk factors for severe acute asthma involve the patient, the environment and the society in general. In addition, there are strong interrelationships between these factors. Personal characteristics linked to acute severe asthma include age (teenagers), denial leading to poor compliance, depression with atypical symptoms in children, and some medical features of asthma associated with increased severity. Environmental factors include airborne allergens, infections, irritants such as air pollutants and passive smoking. Life events have not been extensively studied but are likely to play a predominant role. The social setting, particularly the health care system, acts as an interface between the patient and the environment. Most all asthma deaths are avoidable and related to dysfunctions in the health care system.     

Ultrasonic thin-walled tube wave structure for sensing devices

Theoretical and experimental investigations of thin-walled tube acoustic wave devices for gravimetric sensing applications are presented. Integrated sensor configurations have been demonstrated by employing a sol-gel processed thin piezoelectric lead zirconate titanate (PZT) film. This was coated coaxially on stainless steel tubes and interdigital transducers (IDT) fabricated as the transmitter and receiver on the curved tube surfaces. We have observed tube waves along both the axial and circumferential directions between 1 and 6.6 MHz. We have also analyzed the mass sensitivities of different modes propagating along the tubes and shown that high mass sensitivity can be achieved by keeping the tube wall thin     

Mathematical Relationship Between Surface Emission and Diffusion Coefficients

This naver analvzes the surface emission coefficient corresponding to anv diffusion coefficient expressed as an exponential function of the concentration diffusing substance in capillary porous solids. Theoretical equations for surface emission coefficient for both sorption and desorption are presented. Procedures to derive the diffusion coefficient and to verify the corresponding surface emission coefficient are made using experimental sorption data of aspen (Populur sp.) wood. It is of interest to note that the theoretical models for diffusion and surface emission coefficients can be established and/or evaluated using the same set of experimental dara.     

Analysis of weakly guiding cladded acoustic fibers of hexagonal crystal symmetry

An approximate analysis of the weakly guiding cladded acoustic fiber consisting of a core and infinite thick cladding both with hexagonal crystal symmetry is presented. The crystalline Z axis is parallel to the fiber axis. Weak guidance conditions require that the stiffness constants of the core are slightly less than those of the cladding, and the density of the core and cladding are almost the same. Approximate dispersion and cutoff equations are derived for all pure guided modes. Dispersion curves of several lower-order guided torsional, radial-axial and flexural modes are evaluated using both exact and approximate formulas and they are in good agreement. A simple approximate dispersion equation for leaky (longitudinal-type) modes is also obtained.     

Promotion of the NO + O2 Reaction by Ba–Y, FAU Zeolite at 25 °C

A remarkably high inferred initial rate of NO oxidation by O₂ has been observed over Ba–Y, FAU zeolite at 25 °C in simple flow-reactor experiments. The rate of reaction at steady state was found to be lower, but still an order of magnitude greater than over alumina-supported Pt, also at 25 °C.