930 research outputs found
Development of a Data-Based Method for Performance Monitoring of Heat Exchangers
A multivariate analysis method is developed for processing measurements, and for detecting and isolating faults and monitoring performance degradation in heat exchanger control loops. A heat exchanger inside a typical temperature to flow cascade loop is considered. This system includes a constant speed pump with flow control valves, pressure and temperature measurement. A proportional-integral-differential (PID) controller is used to maintain a temperature set point for the exit flow on one side of the exchanger. A thermal-fluid model for the components in the system is developed. A Fault Detection and Isolation (FDI) rule-base is formulated from results of simulations performed using these models. Measurements from an installed laboratory heat exchanger control loop are also used. Faults simulated and induced on the physical heat exchanger loop include tube fouling, sensor drift, fluid leakage, unresponsive valves, plugged process lines, and controller errors. The rule base allows the identification of faults in a heat exchanger control loop given suitable process measurements
Fission of a multiphase membrane tube
A common mechanism for intracellular transport is the use of controlled
deformations of the membrane to create spherical or tubular buds. While the
basic physical properties of homogeneous membranes are relatively well-known,
the effects of inhomogeneities within membranes are very much an active field
of study. Membrane domains enriched in certain lipids in particular are
attracting much attention, and in this Letter we investigate the effect of such
domains on the shape and fate of membrane tubes. Recent experiments have
demonstrated that forced lipid phase separation can trigger tube fission, and
we demonstrate how this can be understood purely from the difference in elastic
constants between the domains. Moreover, the proposed model predicts timescales
for fission that agree well with experimental findings
Grand canonical ensemble in generalized thermostatistics
We study the grand-canonical ensemble with a fluctuating number of degrees of
freedom in the context of generalized thermostatistics. Several choices of
grand-canonical entropy functional are considered. The ideal gas is taken as an
example.Comment: 14 pages, no figure
Development of cost-effective SNP assays for chickpea genome analysis and breeding
A total of 1499 ESTs generated from 26 different Cicer species, available in the public domain at the time of analysis, were used for in silico identification of SNPs using the bioinformatic tools developed at the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT) (http://hpc.icrisat.org/PBSWeb). Cluster analysis provided a total of 118 clusters, of which 11 clusters contained sequences from more than one Cicer species. Further, these clusters were assembled into 19 contigs and 184 putative SNPs were identified in 15 contigs. However, only 73 SNPs involved restriction enzyme sites for development of the CAPS assays as identified through the SNP2CAPs program. Primer pairs were designed for only 8 contigs (CL3a, CL3c, CL3d, CL3e, CL4a, CL10, CL20 and CL99) which had SNPs, resulting in putative recognition sites to commonly used restriction enzymes. Results of the demonstrates the utility of Cicer EST resources and the availability of bioinformatics analysis pipelines for the large-scale identification of SNPs on the HPC (High Performance Computer) at ICRISAT and the development of costeffective CAPS assay for SNP genotyping. It is anticipated that the availability of large number of ESTs from more than one genotype of cultivated chickpea (C. arietinum) in the near future will make it possible to develop larger number of SNPs in cultivated chickpea germplasm for genome analysis and breeding application
Comment on "On the importance of the free energy for elasticity under pressure"
Marcus et al. (Marcus P, Ma H and Qiu S L 2002 J. Phys.: Condens. Matter 14
L525) claim that thermodynamic properties of materials under pressure must be
computed using the Gibbs free energy , rather than the internal energy .
Marcus et al. state that ``The minima of , but not of , give the
equilibrium structure; the second derivatives of , but not of , with
respect to strains at the equilibrium structure give the equilibrium elastic
constants.'' Both statements are incorrect.Comment: Commen
Trans-cinnamaldehyde nanoemulsion wash inactivates Salmonella Enteritidis on shelled eggs without affecting egg color
Salmonella Enteritidis is a major foodborne pathogen that causes enteric illnesses in humans, primarily through the consumption of contaminated poultry meat and eggs. Despite implementation of traditional disinfection approaches to reduce S. Enteritidis contamination, egg-borne outbreaks continue to occur, raising public health concerns and adversely affecting the popularity and profitability for the poultry industry. Generally Recognized as Safe (GRAS) status phytochemicals such as Trans-cinnamaldehyde (TC) have previously shown to exhibit anti-Salmonella efficacy, however, the low solubility of TC is a major hurdle in its adoption as an egg wash treatment. Therefore, the present study investigated the efficacy of Trans-cinnamaldehyde nanoemulsions (TCNE) prepared with emulsifiers Tween 80 (Tw.80) or Gum Arabic and lecithin (GAL) as dip treatments, at 34°C, for reducing S. Enteritidis on shelled eggs in presence or absence of 5% chicken litter. In addition, the efficacy of TCNE dip treatments in reducing trans-shell migration of S. Enteritidis across shell barrier was investigated. The effect of wash treatments on shell color were evaluated on d 0, 1, 7, and 14 of refrigerated storage. TCNE-Tw.80 or GAL treatments (0.06, 0.12, 0.24, 0.48%) were effective in inactivating S. Enteritidis by at least 2 to 2.5 log cfu/egg as early as 1 min of washing time (P \u3c 0.05). In presence of organic matter, nanoemulsions (0.48%) reduced S. Enteritidis counts by ∼ 2 to 2.5 log cfu/egg as early as 1 min, (P \u3c 0.05). Nanoemulsion wash also inhibited trans-shell migration of S. Enteritidis, as compared to control (P \u3c 0.05). The nanoemulsion wash treatments did not affect shell color (P \u3e 0.05). Results suggest that TCNE could potentially be used as an antimicrobial wash to reduce S. Enteritidis on shelled eggs, although further studies investigating the effect of TCNE wash treatments on organoleptic properties of eggs are necessary
Remnants of Greenstone sequence from the Archaean rocks of Rajasthan
An interesting association of granitoid-amphibolite-metasediments occurs around Jagat, southeast of Udaipur in Rajasthan. Lying a little south of the area from where 3.3-billion-year-old gneisses have been reported, these rocks compare well with the known greenstone associations of Archaean age. The mafic and granitoid rocks show chemical affinity with the modern volcanic arc rocks
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A new nonlinear ''reconstructive'' control approach applied to the axial xenon oscillation problem in PWRs
The concept of dynamic equilibrium of control in conjunction with a proportional corrector constitutes the structure of the new control technique. The controller utilizes direct measurements and model- based state estimations in the feedback loop. The method includes recovering unanticipated parametric variations or partially unknown dynamics. An application of this approach to the axial xenon oscillation problem of PWRs was considered. A two-point xenon oscillation model was used in designing the controller and testing it through simulations. 6 refs., 8 figs
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