Multiphase Flow in Vertical and Inclined Annuli

The present study was undertaken to experimentally determine the in situ volume fraction of the gas phase when air is bubbled through a stagnant liquid column. The data gathered were used to examine the model proposed by Hasan (1986) for estimating gas void fraction during two-phase flow in vertical and inclined pipes. This model, based on a drift flux approach, relates the in situ velocity of the gas phase to the bubble rise velocity and the mixture velocity. An experimental set-up consisting of a plexiglass column of 5 inch inside diameter and eighteen feet in height was used to gather data. The column was deviated at 0, 8, 16, 24, and 32 degrees from the vertical. Pipes of 1.87, 2.24, and 3.409 inches were used to create annuli of different dimensions. Data were gathered for the rise velocities of small and Taylor bubbles as well as for void fraction for gas (air) flowing through a stagnant liquid (water) column. These raw data were then converted to superficial gas velocity (Vgg) and void fraction (Eg). Flow patterns during m u l t i p h a s e flow are loosely grouped into bubbly, slug, churn, and annular types. Due to the relatively low air flow rates available from existing air lines, only bubbly and slug flow patterns were observed. The void fraction during bubbly and slug flow was given by Eg = Vsg / (CVsg + Vt). The p a r a m e t e r C was f o u n d to be u n a f f e c t e d by p i p e inclination and annuli dimensions. The value of this parameter remained constant at 2.0 for bubbly flow and at 1.2 for slug flow. The rise velocity of small bubbles, V t , was found to be unaffected by either pipe inclination or annuli dimensions. The overall average bubble rise velocity of 0.84 ft/sec. was in very good agreement with the value calculated by using the Harmathy (1960) correlation. Taylor bubble rise velocity data, however, indicated strong influence of both pipe inclination and annulus dimensions. The data gathered were found to agree well with the following Taylor bubble rise velocity correlation proposed by Hasan (1986) VtT = [0.35 + 0.1(Dt/Dc)sin^2(alpha)][gDc(d1-dg)/d1]^2[sqrt(sin(alpha))(1 + cos(alpha))^2]. The above expression successfully accounts for both the pipe inclination and the annulus diameters. The predictions of the proposed model for flow pattern transition and void fraction were compared with data from several other sources. Good agreement between the data and the predictions of the model were noted

A Deep Pyramid Deformable Part Model for Face Detection

We present a face detection algorithm based on Deformable Part Models and deep pyramidal features. The proposed method called DP2MFD is able to detect faces of various sizes and poses in unconstrained conditions. It reduces the gap in training and testing of DPM on deep features by adding a normalization layer to the deep convolutional neural network (CNN). Extensive experiments on four publicly available unconstrained face detection datasets show that our method is able to capture the meaningful structure of faces and performs significantly better than many competitive face detection algorithms

A Transverse Lattice QCD Model for Mesons

QCD is analysed with two light-front continuum dimensions and two transverse lattice dimensions. In the limit of large number of colours and strong transverse gauge coupling, the contributions of light-front and transverse directions factorise in the dynamics, and the theory can be analytically solved in a closed form. An integral equation is obtained, describing the properties of mesons, which generalises the 't Hooft equation by including spin degrees of freedom. The meson spectrum, light-front wavefunctions and form factors can be obtained by solving this equation numerically. These results would be a good starting point to model QCD observables which only weakly depend on transverse directions, e.g. deep inelastic scattering structure functions.Comment: Lattice 2003 (theory), 3 page

RISCBOT: A WWW-Enabled Mobile Surveillance and Identification Robot

The final publication is available at www.springerlink.comThis article describes Riscbot, a modular 802.11b - enabled mobile autonomous robot built at the RISC lab of the University of Bridgeport. Riscbot localizes itself and successfully fulfills www - enabled online user requests and navigates to various rooms, employing a visual recognition algorithm. This article describes the mechanical design, hardware and software algorithms of the robot, and the web - based interface for communicating with the robot.http://link.springer.com/article/10.1007%2Fs10846-005-9014-