01897nas a2200205   4500008004100000245006600041210006600107260010600173300001400279490000700293520119700300653001101497653001801508653001601526653001801542653000801560653001501568100002301583856008501606       2008                        eng d00aExperimental analysis of the lift force on bubbles in a swarm0 aExperimental analysis of the lift force on bubbles in a swarm  aTHE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLANDbPERGAMON-ELSEVIER SCIENCE LTDcOCT  a1710-17230 v633 a<p>The lift force acting on bubbles in a swarm has been estimated by analyzing the instantaneous velocity-time data obtained using LDA in a cylindrical bubble column. Phase distinction was achieved through the multiresolution analysis of the velocity-time data. Several important issues related to the transverse motion of bubbles subjected to a shear field have been discussed quantitatively. The actually measured bubble sizes, the respective slip velocity values in transverse and axial directions and the local shear rates (gamma) enabled the verification of known formulations for the lift coefficient (C-L) for bubbles. At many locations in the column the radial flux of the gas phase by turbulent dispersion and the radial slip were estimated. The radially inward movement of bubbles from low to high axial velocity (from column wall to center, i.e., C-L &lt; 0) was observed at most of the measurement locations. The local lift coefficient was estimated using the transverse drag force and the values support the results from the material balance approach. The estimated C-L values showed a wide variation over the column cross-section. (c) 2007 Elsevier Ltd. All rights reserved.</p>10aBubble10aBubble column10abubble size10ahydrodynamics10aLDA10alift force1 aKulkarni, Amol, A.  uhttp://library.ncl.res.in/content/experimental-analysis-lift-force-bubbles-swarm01901nas a2200253   4500008004100000022001400041245013400055210006900189260010600258300001400364490000700378520091400385653001801299653001601317653000801333653004501341653003601386100002201422700001801444700002101462700002601483700002101509856011701530       2008                        eng d  a0301-932200aSVR-based prediction of point gas hold-up for bubble column reactor through recurrence quantification analysis of LDA time-series0 aSVRbased prediction of point gas holdup for bubble column reacto  aTHE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLANDbPERGAMON-ELSEVIER SCIENCE LTDcDEC  a1099-11070 v343 a<p>Recurrence quantification analysis (RQA) has emerged as a useful tool for detecting singularities in nonstationary time-series data. In this paper, we use RQA to analyze the velocity-time data acquired using laser doppler anemometry (LDA) signals in a bubble column reactor for Single point and Multipoint point spargers. The recurring dynamical states within the velocity-time-series occurring due to the bubble and the liquid passage at the point of measurement, are quantified by RQA features (namely % Recurrence, % Determinism, % Laminarity and Entropy), which in turn are regressed using support vector regression (SVR) to predict the point gas hold-up values. It has been shown that SVR-based model for the bubble column reactor can be potentially useful for online prediction and monitoring of the point gas hold-up for different sparging conditions. (C) 2008 Elsevier Ltd. All rights reserved.</p>10aBubble column10aGas hold-up10aLDA10aRecurrence quantification analysis (RQA)10aSupport vector regression (SVR)1 aGandhi, Ankit, B.1 aJoshi, J., B.1 aKulkarni, A., A.1 aJayaraman, Valadi, K.1 aKulkarni, B., D.  uhttp://library.ncl.res.in/content/svr-based-prediction-point-gas-hold-bubble-column-reactor-through-recurrence-0