18 research outputs found
Influence of Heat Input, Working Fluid and Evacuation Level on the Performance of Pulsating Heat Pipe
An experimental study on pulsating heat pipe (PHP) is presented in this work. A closed loop PHP with a single U
turn is fabricated and tested. The transient and steady state experiments are conducted and operating temperatures are
measured. The experiments are carried out for different working fluids, heat input and for different evacuation levels.
The derived parameters include thermal resistance and heat transfer coefficient of PHP. The results of these
experiments show an intermittent motion of the working fluid at lower heat input. The temperature difference
between evaporator and condenser at steady state is found lower for acetone compared to water, ethanol and
methanol. Lower value of thermal resistance and higher value of heat transfer coefficient are observed in case of
acetone compared to water, ethanol and methanol. Lower values of temperature difference between evaporator and
condenser and thermal resistance and higher value of heat transfer coefficient are observed at atmospheric conditions
of operation of PHP compared to evacuation conditions. The Power Spectral Density Analysis is also carried out on
the results of these experiments using FFT technique to analyse the pulsating motion of the fluid in a PHP. In the
Power Spectral Density analysis, the frequency distribution of temperature variation in PHP was observed over a
wider range, signifying the periodic motion in the fluid flow of the liquid slug and vapour plug. This characteristic
frequency corresponded to the characteristic time for a couple of adjacent vapour plug and liquid slug passing
through a specific local wall surface in a PHP
Formation of dense partonic matter in relativistic nucleus-nucleus collisions at RHIC: Experimental evaluation by the PHENIX collaboration
Extensive experimental data from high-energy nucleus-nucleus collisions were
recorded using the PHENIX detector at the Relativistic Heavy Ion Collider
(RHIC). The comprehensive set of measurements from the first three years of
RHIC operation includes charged particle multiplicities, transverse energy,
yield ratios and spectra of identified hadrons in a wide range of transverse
momenta (p_T), elliptic flow, two-particle correlations, non-statistical
fluctuations, and suppression of particle production at high p_T. The results
are examined with an emphasis on implications for the formation of a new state
of dense matter. We find that the state of matter created at RHIC cannot be
described in terms of ordinary color neutral hadrons.Comment: 510 authors, 127 pages text, 56 figures, 1 tables, LaTeX. Submitted
to Nuclear Physics A as a regular article; v3 has minor changes in response
to referee comments. Plain text data tables for the points plotted in figures
for this and previous PHENIX publications are (or will be) publicly available
at http://www.phenix.bnl.gov/papers.htm
The present and future of QCD
This White Paper presents an overview of the current status and future perspective of QCD research, based on the community inputs and scientific conclusions from the 2022 Hot and Cold QCD Town Meeting. We present the progress made in the last decade toward a deep understanding of both the fundamental structure of the sub-atomic matter of nucleon and nucleus in cold QCD, and the hot QCD matter in heavy ion collisions. We identify key questions of QCD research and plausible paths to obtaining answers to those questions in the near future, hence defining priorities of our research over the coming decades