Real-time Thermal Error Compensation Module for Intelligent Ultra Precision Turning Machine (iUPTM)

AbstractAccuracy & precision are 1he main requirements for ultra precision machine tools. Many factors affect 1he performance of 1he system 1hat in turns affect 1he product quality. Among all sources of errors, the thermo mechanical deformation errors are the main contributor for 1he overall geometrical errors. This paper mainly aims at establislunent of methodology to compensate thermal deformation errors in real-time for ultra precision machine tools. The real-time thermal error compensation module has been developed and integrated to intelligent Ultra Precision Turning machine. The module includes temperatures as inputs, neural network algorithm for computing the thermal deformations errors, ‘C’ programming for real-time calculations and integration with open architecture CNC controller. The module runs in silent mode which avoids human intervention for correction of thermal deformation errors

Sensitivity of electromagnetic spectra to equation of state and initial energy density in the Pb+Pb collisions at SPS

We study Pb+Pb collisions at 158 A GeV/c using a hydrodynamical approach. We test different equations of state (EoSs) and different initial conditions and show that there are more than one initial state for each EoS which reproduce the observed hadronic spectra. We also find that different equations of state favour different freeze-out temperature. Simultaneously we calculate the thermal dilepton and photon spectra for each EoS and initial state. We compare the dilepton mass spectrum to data measured by the CERES collaboration and find that the differences in spectra obtained using different EoSs and initial states are not resolvable within the current experimental resolution. However, at invariant masses over 2 GeV the difference in the yield due to various initial states is close to an order of magnitude. We also study the rapidity distribution of lepton pairs and find that for masses around 800 MeV the shape of the distribution depends strongly on the EoS.Comment: 20 pages, 17 figures, LaTeX using elsart.sty; introduction rewritten to clarify the aim of the paper, references added; accepted for publication in Nuclear Physics

On the mechanisms governing gas penetration into a tokamak plasma during a massive gas injection

A new 1D radial fluid code, IMAGINE, is used to simulate the penetration of gas into a tokamak plasma during a massive gas injection (MGI). The main result is that the gas is in general strongly braked as it reaches the plasma, due to mechanisms related to charge exchange and (to a smaller extent) recombination. As a result, only a fraction of the gas penetrates into the plasma. Also, a shock wave is created in the gas which propagates away from the plasma, braking and compressing the incoming gas. Simulation results are quantitatively consistent, at least in terms of orders of magnitude, with experimental data for a D 2 MGI into a JET Ohmic plasma. Simulations of MGI into the background plasma surrounding a runaway electron beam show that if the background electron density is too high, the gas may not penetrate, suggesting a possible explanation for the recent results of Reux et al in JET (2015 Nucl. Fusion 55 093013)

Electroosmotic flow behaviour of metal contaminated expansive soil

It is important to study the flow behaviour through soil during electrokinetic extraction of contaminants to understand their removal mechanism. The flow through the expansive soil containing montmorillonite is monitored during laboratory electrokinetic extraction of heavy metal contaminants. The permeability of soil, which increases due to the presence of contaminants, is further enhanced during electrokinetic extraction of contaminants due to osmotic permeability. The variations in flow rates through the soil while the extracting fluid is changed to dilute acetic acid (used to control the increase of pH) and EDTA solution (used to desorb the metal ions from soil) are studied. The trends of removal of contaminants vis-a-vis the changes in the flow through the soil during different phases of electrokinetic extraction are established. Chromium ions are removed by flushing of water through the soil and increased osmotic flow is beneficial. Removal of iron ions is enhanced by induced osmotic flow and desorption of ions by electrokinetic processes. © 2007 Elsevier B.V. All rights reserved

Synthesis and characterization of the layered double hydroxides of Mg with Cr

Layered double hydroxides of Mg with Cr having the general formula Mg1-xCrx(OH)2(CO3)x/2·yH2O(x = 0.15-0.33) crystallize in a hexagonal structure on hydrothermal treatment. These LDHs incorporate oxalate and ferricyanide ions in their interlamellar regions to yield turbostratically disordered phases. Their ability to incorporate organic as well as inorganic anions was presented

Artificial neural networks (ANN) based algorithms for chlorophyll estimation in the Arabian Sea

368-373In-situ bio-optical measurements were collected during six ship campaigns in the north eastern Arabian Sea using SeaWiFS Multi-channel Profiling Radiometer (SPMR). An artificial neural network (ANN) based algorithms were constructed to estimate oceanic chlorophyll concentration using in-situ data. The different ANNs were obtained by systematic variations of architecture of input and hidden layer nodes for the Arabian Sea training data set. The performance of individual ANN-based pigment estimation algorithm was evaluated by applying it to the remote sensing reflectance data contained in validation data set. The performance of the most successful ANN was compared with commonly used empirical pigment algorithms. Compared to e.g. the SeaWiFS algorithms Ocean Chlorophyll-2 (OC2) and Ocean Chlorophyll-4 (OC4), the square of the correlation coefficient r2 is increased from 0.69 for OC4, respectively 0.70 for OC2 to 0.96 for ANN algorithm. The RMS error of the estimated log-transformed pigment concentration dropped from 0.47 for OC2, respectively 0.41 for OC4 to 0.11 for ANN-based pigment algorithm