2,901 research outputs found
Libre culture: meditations on free culture
Libre Culture is the essential expression of the free culture/copyleft movement. This anthology, brought together here for the first time, represents the early groundwork of Libre Society thought. Referring to the development of creativity and ideas, capital works to hoard and privatize the knowledge and meaning of what is created. Expression becomes monopolized, secured within an artificial market-scarcity enclave and finally presented as a novelty on the culture industry in order to benefit cloistered profit motives. In the way that physical resources such as forests or public services are free, Libre Culture argues for the freeing up of human ideas and expression from copyright bulwarks in all forms
Merger of compact stars in the two-families scenario
We analyse the phenomenological implications of the two-families scenario on
the merger of compact stars. That scenario is based on the coexistence of both
hadronic stars and strange quark stars. After discussing the classification of
the possible mergers, we turn to detailed numerical simulations of the merger
of two hadronic stars, i.e., "first family" stars in which delta resonances and
hyperons are present, and we show results for the threshold mass of such
binaries, for the mass dynamically ejected and the mass of the disk surrounding
the post-merger object. We compare these results with those obtained within the
one-family scenario and we conclude that relevant signatures of the
two-families scenario can be suggested, in particular: the possibility of a
rapid collapse to a black hole for masses even smaller than the ones associated
to GW170817; during the first milliseconds, oscillations of the postmerger
remnant at frequencies higher than the ones obtained in the one-family
scenario; a large value of the mass dynamically ejected and a small mass of the
disk, for binaries of low total mass. Finally, based on a population synthesis
analysis, we present estimates of the number of mergers for: two hadronic
stars; hadronic star - strange quark star; two strange quark stars. We show
that for unequal mass systems and intermediate values of the total mass, the
merger of a hadronic star and a strange quark star is very likely (GW170817 has
a possible interpretation into this category of mergers). On the other hand,
mergers of two strange quark stars are strongly suppressed.Comment: 18 pages, 16 figure
Innovative solutions for enhanced illicit drugs profiling using comprehensive two-dimensional gas chromatography and mass spectrometry technologies
This project aimed to determine whether comprehensive two-dimensional gas chromatography is suitable for routine use in a forensic laboratory for profiling illicit substances.
Abstract
Analytical gas chromatographic methods usually rely upon a single dimension (ie single column) high-resolution capillary GC column to provide separation of target analyses. When a matrix is especially complex, the ability of the column to provide adequate resolution is severely compromised. Often, mass spectrometry may provide the ability to uniquely measure the target compounds, but if the matrix generates similar ions to the target compounds, this can lead to confounded analysis. Mass spectrometry offers many potential solutions to the lack of resolution of GC; however, this usually involves selected ion monitoring or similar approaches. This removes the important opportunity to use a full-scan spectrum to match with a database library. In the present project, high-resolution GC analysis using the multidimensional separation method of comprehensive two-dimensional gas chromatography (GCxGC) was used to provide sufficient resolution to allow full-scan acquisition with library confirmation of illicit drug identity. It was shown that the WADA criteria for a selection of test steroid compounds could be suitably met under this new high-resolution environment. In addition, analysis of samples of ecstasy were profiled and all synthetic residues involved in the synthesis of ecstasy could be fully resolved and located in the 2D separation space with excellent library matches, even though the underlying matrix was very complicated and would have strongly interfered in a 1D separation analysis. This will allow facile profiling of the reaction procedure for ecstasy synthesis
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EFFECTS OF BIOMASS BURNING ON SUMMERTIME NONMETHANE HYDROCARBON CONCENTRATIONS IN THE CANADIAN WETLANDS
Modeled and Measured Dynamics of a Composite Beam with Periodically Varying Foam Core
The dynamics of a sandwich beam with carbon fiber composite facesheets and foam core with periodic variations in material properties are studied. The purpose of the study is to compare finite element predictions with experimental measurements on fabricated beam specimens. For the study, three beams were fabricated: one with a compliant foam core, a second with a stiffer core, and a third with the two cores alternating down the length of the beam to create a periodic variation in properties. This periodic variation produces a bandgap in the frequency domain where vibrational energy does not readily propagate down the length of the beam. Mode shapes and natural frequencies are compared, as well as frequency responses from point force input to velocity response at the opposite end of the beam
Search for Heavy Stable Charged Particles at CMS Using Tracker dE/dx Measurement
This dissertation starts with an overview of the physics of heavy stable charged particles, which arise in various models beyond the standard model like supersymmetry and universal extra dimensions. Then it describes the current experimental status on searching for these particles. The main content of this dissertation is discussing the physics potential of the compact muon solenoid (CMS) detector at the large hadron collider (LHC) in detecting such high-mass particles, primarily using dE/dx information from the silicon strip tracker system of CMS, based on Monte-Carlo simulation data. Cosmic data from the Tracker Integration Facility is also used to better understand the performance of tracker dE/dx measurements
An assessment of hydrocarbon species in the methanol-to-hydrocarbon reaction over a ZSM-5 catalyst.
A ZSM-5 catalyst is examined in relation to the methanol-to-hydrocarbon (MTH) reaction as a function of reaction temperature and time-on-stream. The reaction profile is characterised using in-line mass spectrometry. Furthermore, the material contained within a catch-pot downstream from the reactor is analysed using gas chromatography-mass spectrometry. For a fixed methanol feed, reaction conditions are selected to define various stages of the reaction coordinate: (i) initial methanol adsorption at a sub-optimum reaction temperature (1 h at 200 °C); (ii) initial stages of reaction at an optimised reaction temperature (1 h at 350 °C); (iii) steady-state operation at an optimised reaction temperature (3 days at 350 °C); and (iv) accelerated ageing (3 days at 400 °C). Post-reaction, the catalyst samples are analysed ex situ by a combination of temperature-programmed oxidation (TPO) and spectroscopically by electron paramagnetic resonance (EPR), diffuse-reflectance infrared and inelastic neutron scattering (INS) spectroscopies. The TPO measurements provide an indication of the degree of 'coking' experienced by each sample. The EPR measurements detect aromatic radical cations. The IR and INS measurements reveal the presence of retained hydrocarbonaceous species, the nature of which are discussed in terms of the well-developed 'hydrocarbon pool' mechanism. This combination of experimental evidence, uniquely applied to this reaction system, establishes the importance of retained hydrocarbonaceous species in effecting the product distribution of this economically relevant reaction system
Perform a gyro test of general relativity in a satellite and develop associated control technology
The progress accomplished in the Stanford Gyro Relativity program during the period November 1974 to October 1975 was described. Gyro developments were continued in the main laboratory dewar, concentrating on the operation of a three axis gyro readout and on improvements to the methods of canceling trapped fields in the rotor; these efforts culminated in the first successful observation of the London moment in the spinning gyro rotor in March 1975. Following a review meeting at that time, a new goal was formulated for the next 12 to 18 months, namely to operate a gyroscope in the new ultra-low field facility with readout resolution approaching 1 arc-second. The following other tasks were also completed: (1) sputtering work, (2) magnetometry, (3) construction and installation of the North Star simulator, (4) analysis of torques on the gyro, especially in inclined orbits, (5) equivalence principle accelerometer, and (6) analysis of a twin-satellite test of relativity
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