We are developing a Time-of-Flight Positron Emission Tomography detector using flat panel micro-channel plate photomultiplier tubes (MCP PMT). The high-speed waveform sampling data acquisition is adopted to exploit the fast time response of MCP PMT efficiently by using transmission-line readout scheme. To demonstrate the feasibility of the proposed detector, prototype detector modules were buil...

The role of substrate modulus on critical loads to initiate and propagate radial cracks to failure in curved brittle glass shells on compliant polymeric substrates is investigated. Flat glass disks are used to drive the crack system. This configuration is representative of dental crown structures on dentin support in occlusal contact. Specimens are fabricated by truncating glass tubes and filli...

The flow structure of a DNS of a flat-plate turbulent boundary layer (Wu & Moin 2010) is studied by combining the topological techniques developed by Chong et al. (1990) and Ooi et al. (1999) with the multiscale non-local geometric analysis of Bermejo-Moreno & Pullin (2008), extending the latter to include physical parameters in the analysis and relating them to the geometry of the educed struc...

Pressure sensors are required in all walks of life, irrespective of civilian, defense, aerospace, biomedical, automobile, Oceanography or domestic applications. Naturally, rapid progress has been made in micromachined pressure sensors and the microsystems using these sensors. Starting with metal strain gauges and moving forward with silicon based pressure sensors with flat diaphragms, the searc...

There is a growing pool of evidence showing the biological importance of membrane nanotubes (with diameter of a few tens of nanometers and length upto tens of microns) in various intraand intercellular transport processes. These ubiquitous structures are often formed from flat membranes by highly localized forces generated by either the pulling of motor proteins or the pushing of polymerizing c...

Low-frequency fluctuations with a 1/f frequency spectrum were first noticed by Johnson [1] in thermionic-emission currents in vacuum tubes, and exist in a very wide range on phenomena. A feature common to most of these phenomena is that they involve a quasirandom sequence of pulses on the microscopic scale. The spectrum of energies associated with a short pulse of characteristic width Δt is rou...

Autocatalytic reaction fronts generate density gradients that may lead to convection. Fronts propagating in vertical tubes can be flat, axisymmetric, or nonaxisymmetric, depending on the diameter of the tube. In this paper, we study the transitions to convection as well as the stability of different types of fronts. We analyze the stability of the convective reaction fronts using three differen...

One of the most challenging scientific industrial problems in recent years is automatic defect detection and characterization. Automatic defect detection can replace human operators who locate and identify defects. Detection of defects in the steam generating tubes through periodic inservice inspection is one of the most significant issues of the fast breeder reactors. Among various pipeline in...