486 research outputs found
Temperature determination from the lattice gas model
Determination of temperature from experimental data has become important in
searches for critical phenomena in heavy ion collisions. Widely used methods
are ratios of isotopes (which rely on chemical and thermal equilibrium),
population ratios of excited states etc. Using the lattice gas model we propose
a new observable: where is the charge multiplicity and
is the charge of the fragmenting system. We show that the reduced multiplicity
is a good measure of the average temperature of the fragmenting system.Comment: 11 pages, 2 ps file
A high-precision polarimeter
We have built a polarimeter in order to measure the electron beam
polarization in hall C at JLAB. Using a superconducting solenoid to drive the
pure-iron target foil into saturation, and a symmetrical setup to detect the
Moller electrons in coincidence, we achieve an accuracy of <1%. This sets a new
standard for Moller polarimeters.Comment: 17 pages, 9 figures, submitted to N.I.
Liquid-gas phase transition in nuclei in the relativistic Thomas-Fermi theory
The equation of state (EOS) of finite nuclei is constructed in the
relativistic Thomas-Fermi theory using the non-linear
model. The caloric curves are calculated by confining the nuclei in the
freeze-out volume taken to be a sphere of size about 4 to 8 times the normal
nuclear volume. The results obtained from the relativistic theory are not
significantly different from those obtained earlier in a non-relativistic
framework. The nature of the EOS and the peaked structure of the specific heat
obtained from the caloric curves show clear signals of a liquid-gas phase
transition in finite nuclei. The temperature evolution of the Gibbs potential
and the entropy at constant pressure indicate that the characteristics of the
transition are not too different from the first-order one.Comment: RevTex file(19 pages) and 12 psfiles for fugures. Physical Review C
(in Press
Corticotropin-releasing factor receptors in GtoPdb v.2023.1
Corticotropin-releasing factor (CRF, nomenclature as agreed by the NC-IUPHAR subcommittee on Corticotropin-releasing Factor Receptors [34]) receptors are activated by the endogenous peptides corticotrophin-releasing hormone, a 41 amino-acid peptide, urocortin 1, 40 amino-acids, urocortin 2, 38 amino-acids and urocortin 3, 38 amino-acids. CRF1 and CRF2 receptors are activated non-selectively by CRH and UCN. CRF2 receptors are selectively activated by UCN2 and UCN3. Binding to CRF receptors can be conducted using radioligands [125I]Tyr0-CRF or [125I]Tyr0-sauvagine with Kd values of 0.1-0.4 nM. CRF1 and CRF2 receptors are non-selectively antagonized by α-helical CRF, D-Phe-CRF-(12-41) and astressin. CRF1 receptors are selectively antagonized by small molecules NBI27914, R121919, antalarmin, CP 154,526, CP 376,395. CRF2 receptors are selectively antagonized by antisauvagine and astressin 2B
Corticotropin-releasing factor receptors (version 2019.4) in the IUPHAR/BPS Guide to Pharmacology Database
Corticotropin-releasing factor (CRF, nomenclature as agreed by the NC-IUPHAR subcommittee on Corticotropin-releasing Factor Receptors [30]) receptors are activated by the endogenous peptides corticotrophin-releasing hormone, a 41 amino-acid peptide, urocortin 1, 40 amino-acids, urocortin 2, 38 amino-acids and urocortin 3, 38 amino-acids. CRF1 and CRF2 receptors are activated non-selectively by CRH and UCN. CRF2 receptors are selectively activated by UCN2 and UCN3. Binding to CRF receptors can be conducted using radioligands [125I]Tyr0-CRF or [125I]Tyr0-sauvagine with Kd values of 0.1-0.4 nM. CRF1 and CRF2 receptors are non-selectively antagonized by α-helical CRF, D-Phe-CRF-(12-41) and astressin. CRF1 receptors are selectively antagonized by small molecules NBI27914, R121919, antalarmin, CP 154,526, CP 376,395. CRF2 receptors are selectively antagonized by antisauvagine and astressin 2B
An investigation of standard thermodynamic quantities as determined via models of nuclear multifragmentation
Both simple and sophisticated models are frequently used in an attempt to
understand how real nuclei breakup when subjected to large excitation energies,
a process known as nuclear multifragmentation. Many of these models assume
equilibriumthermodynamics and produce results often interpreted as evidence of
a phase transition. This work examines one class of models and employs standard
thermodynamical procedure to explore the possible existence and nature of a
phase transition. The role of various terms, e.g. Coulomb and surface energy,
is discussed.Comment: 19 two-column format pages with 24 figure
Finite size effects and the order of a phase transition in fragmenting nuclear systems
We discuss the implications of finite size effects on the determination of
the order of a phase transition which may occur in infinite systems. We
introduce a specific model to which we apply different tests. They are aimed to
characterise the smoothed transition observed in a finite system. We show that
the microcanonical ensemble may be a useful framework for the determination of
the nature of such transitions.Comment: LateX, 5 pages, 5 figures; Fig. 1 change
Application of Information Theory in Nuclear Liquid Gas Phase Transition
Information entropy and Zipf's law in the field of information theory have
been used for studying the disassembly of nuclei in the framework of the
isospin dependent lattice gas model and molecular dynamical model. We found
that the information entropy in the event space is maximum at the phase
transition point and the mass of the cluster show exactly inversely to its
rank, i.e. Zipf's law appears. Both novel criteria are useful in searching the
nuclear liquid gas phase transition experimentally and theoretically.Comment: 5 pages, 5 figure
Liquid-gas phase transition in hot nuclei studied with INDRA
Thanks to the high detection quality of the INDRA array, signatures related
to the dynamics (spinodal decomposition) and thermodynamics (negative
microcanonical heat capacity) of a liquid-gas phase transition have been
simultaneously studied in multifragmentation events in the Fermi energy domain.
The correlation between both types of signals strongly supports the existence
of a first order phase transition for hot nuclei.Comment: 9 pages, 2 figures, Invited talk to Nucleus-nucleus 2003 Moscow June
200
Randomly Broken Nuclei and Disordered Systems
Similarities between models of fragmenting nuclei and disordered systems in
condensed matter suggest corresponding methods. Several theoretical models of
fragmentation investigated in this fashion show marked differences, indicating
possible new methods for distinguishing models using yield data. Applying
nuclear methods to disordered systems also yields interesting results.Comment: 10 pages, 4 figure
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