782 research outputs found
Curious Spawn in the Hotbed of Thought in Theogony
Senior Project submitted to The Division of Languages and Literature of Bard College
Universality of Highly Damped Quasinormal Modes for Single Horizon Black Holes
It has been suggested that the highly damped quasinormal modes of black holes
provide information about the microscopic quantum gravitational states
underlying black hole entropy. This interpretation requires the form of the
highly damped quasinormal mode frequency to be universally of the form:
, where is an integer, and is the
black hole temperature. We summarize the results of an analysis of the highly
damped quasinormal modes for a large class of single horizon, asymptotically
flat black holes.Comment: 9 pages, 1 figure, submitted to the proceedings of Theory CANADA 1,
which will be published in a special edition of the Canadian Journal of
Physic
Fast, inexpensive, and reliable HPLC method to determine monomer fractions in poly(3-hydroxybutyrate-co-3-hydroxyvalerate)
The determination of the monomer fractions in polyhydroxyalkanoates is of great importance for research on microbial-produced plastic material. The development of new process designs, the validation of mathematical models, and intelligent control strategies for production depend enormously on the correctness of the analyzed monomer fractions. Most of the available detection methods focus on the determination of the monomer fractions of the homopolymer poly(3-hydroxybutyrate). Only a few can analyze the monomer content in copolymers such as poly(3-hydroxybutyrate-co-3-hydroxyvalerate), which usually require expensive measuring devices, a high preparation time or the use of environmentally harmful halogenated solvents such as chloroform or dichloromethane. This work presents a fast, simple, and inexpensive method for the analysis of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) with high-performance liquid chromatography. Samples from a bioreactor experiment for the production of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) with Cupriavidus necator H16 were examined regarding their monomer content using the new method and gas chromatography analysis, one of the most frequently used methods in literature. The results from our new method were validated using gas chromatography measurements and show excellent agreement. Key points ∙ The presented HPLC method is an inexpensive, fast and environmentally friendly alternative to existing methods for quantification of monomeric composition of PHBV. ∙ Validation with state of the art GC measurement exhibits excellent agreement over a broad range of PHBV monomer fractions
Quark Matter in Neutron Star Mergers
Binary neutron star mergers are expected to be one of the most promising
source of gravitational waves (GW) for the network of laser interferometric and
bar detectors becoming operational in the next few years. The merger wave
signal is expected to be sensitive to the interior structure of the neutron
star (NS). The structure of high density phases of matter is under current
experimental investigation in heavy-ion collisions. We investigate the
dependence of the merger process and its GW signal on the presence of quarks in
these phases by performing numerical simulations, where the smoothed particle
hydrodynamics (SPH) method and the conformally flat approximation for the
3-geometry in general relativistic gravity are implemented.Comment: 4 Pages, 4 Figures, Proc. Nuclei in the Cosmos 7, 200
The Mystery of the Asymptotic Quasinormal Modes of Gauss-Bonnet Black Holes
We analyze the quasinormal modes of -dimensional Schwarzschild black holes
with the Gauss-Bonnet correction in the large damping limit and show that
standard analytic techniques cannot be applied in a straightforward manner to
the case of infinite damping. However, by using a combination of analytic and
numeric techniques we are able to calculate the quasinormal mode frequencies in
a range where the damping is large but finite. We show that for this damping
region the famous appears in the real part of the quasinormal mode
frequency. In our calculations, the Gauss-Bonnet coupling, , is taken
to be much smaller than the parameter , which is related to the black hole
mass.Comment: 12 pages and 5 figure
The Highly Damped Quasinormal Modes of Extremal Reissner-Nordstr\"om and Reissner-Nordstr\"om-de Sitter Black Holes
We analyze in detail the highly damped quasinormal modes of -dimensional
extremal Reissner-Nordstrm and
Reissner-Nordstrm-de Sitter black holes. We only consider the
extremal case where the event horizon and the Cauchy inner horizon coincide. We
show that, even though the topology of the Stokes/anti-Stokes lines in the
extremal case is different than the non-extremal case, the highly damped
quasinormal mode frequencies of extremal black holes match exactly with the
extremal limit of the non-extremal black hole quasinormal mode frequencies.Comment: 17 pages, 5 figure
Enhancement of Resonant Thermonuclear Reaction Rates in Extremely Dense Stellar Plasmas
The enhancement factor of the resonant thermonuclear reaction rates is
calculated for the extremely dense stellar plasmas in the liquid phase. In
order to calculate the enhancement factor we use the screening potential which
is deduced from the numerical experiment of the classical one-component plasma.
It is found that the enhancement is tremendous for white dwarf densities if the
^{12}C + ^{12}C fusion cross sections show resonant behavior in the
astrophysical energy range. We summarize our numerical results by accurate
analytic fitting formulae.Comment: 13 pages, 3 figures, accepted for publication in ApJ, replaced with
revised versio
Sustained, multifaceted improvements in mental well-being following psychedelic experiences in a prospective opportunity sample
In the last 15 years, psychedelic substances, such as LSD and psilocybin, have regained legitimacy in clinical research. In the general population as well as across various psychiatric populations, mental well-being has been found to significantly improve after a psychedelic experience. Mental well-being has large socioeconomic relevance, but it is a complex, multifaceted construct. In this naturalistic observational study, a comprehensive approach was taken to assessing well-being before and after a taking a psychedelic compound to induce a “psychedelic experience.” Fourteen measures of well-being related constructs were included in order to examine the breadth and specificity of change in well-being. This change was then analysed to examine clusters of measures changing together. Survey data was collected from volunteers that intended to take a psychedelic. Four key time points were analysed: 1 week before and 2 weeks, 4 weeks, and 2 years after the experience (N = 654, N = 315, N = 212, and N = 64, respectively). Change on the included measures was found to cluster into three factors which we labelled: 1) “Being well”, 2) “Staying well,” and 3) “Spirituality.” Repeated Measures Multivariate Analysis of Variance revealed all but the spirituality factor to be improved in the weeks following the psychedelic experience. Additional Mixed model analyses revealed selective increases in Being Well and Staying Well (but not Spirituality) that remained statistically significant up to 2 years post-experience, albeit with high attrition rates. Post-hoc examination suggested that attrition was not due to differential acute experiences or mental-health changes in those who dropped out vs. those who did not. These findings suggest that psychedelics can have a broad, robust and sustained positive impact on mental well-being in those that have a prior intention to use a psychedelic compound. Public policy implications are discussed
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