Search results for "ion source"
showing 10 items of 337 documents
Pragmatic languages with universal grammars
2012
Abstract This paper constructs the equilibrium for a specific code that can be seen as a “universal grammar” in a class of common interest Sender–Receiver games where players communicate through a noisy channel. We propose a Senderʼs signaling strategy which does not depend on either the game payoffs or the initial probability distribution. The Receiverʼs strategy partitions the set of possible sequences into subsets, with a single action assignment to each of them. The Senderʼs signaling strategy is a Nash equilibrium, i.e. when the Receiver responds best to the Senderʼs strategy, the Sender has no incentive to deviate. An example shows that a tie-breaking decoding is crucial for the block…
Prelaunch assessment of worldview-3 information content
2014
The upcoming WorldView-3 satellite is designed to collect unique data by combining very-high spatial resolution (VHR) with observation bands in the short wave infrared (SWIR) in addition to the visible and near-infrared (VNIR) multispectral and panchromatic bands currently available on the VHR WorldView-2 system. These SWIR bands were specifically selected in order to target unique reflectance and absorption features presented by various surface materials and should, therefore, significantly improve the platforms information content for many image mining applications. This presentation explores the information content available to the WorldView-3 platform in two ways. First, second-order st…
An asynchronous covert channel using spam
2012
AbstractCurrent Internet e-mail facilities are built onto the foundation of standard rules and protocols, which usually allow a considerable amount of “freedom” to their designers. Each of these standards has been defined based on a number of vendor specific implementations, in order to provide common inter-working procedures for cross-vendor communication. Thus, a lot of optional and redundant information is being exchanged during e-mail sessions, which is available to implement versatile covert channel mechanisms.This work exploits this possibility by presenting a simple but effective steganographic scheme that can be used to deploy robust secret communication through spam e-mails. This s…
THE EXPRESSION OF EVIDENTIALITY IN SPOKEN AND WRITTEN TEXTS: EMPIRICAL APPROACHES TO ROMANCE LANGUAGES
2020
Evidentiality is a grammatical category that encodes information source as its primary meaning. The information can be: acquired through direct perception, reported by others (hearsay) or inferred by the speaker upon considering the information that is available. Languages with an evidential grammatical category have morphemes with a primary evidential value (Aikhenvald 2004). Nevertheless, Romance languages, like many other languages, have a tense- modal system and lack an evidential grammatical category, instead of which several lexical units or certain constructions convey information source. This special issue is devoted to some of those items, such as modal adverbs, evidential meanings…
Gas cell studies of thorium using filament dispensers at IGISOL
2020
Abstract Filament-based dispensers of thorium have been investigated at the IGISOL facility, Jyvaskyla, for potential use as a thorium ion source for future collinear laser spectroscopy experiments. Several different filaments were manufactured in the Institute of Atomic and Subatomic Physics of TU Wien, with 232Th and 229Th prepared on tantalum substrates either by drying thorium nitrate solution or via molecular plating, while adding a layer of zirconium for oxide reduction. The filaments were characterized in a helium-filled gas cell by performing selective and efficient in-gas-cell resonance laser ionization and by analyzing the resulting ion beams by mass spectrometry. Additionally, th…
Direct Peel Monitoring of Xenobiotics in Fruit by Direct Analysis in Real Time Coupled to a Linear Quadrupole Ion Trap–Orbitrap Mass Spectrometer
2013
Study of xenobiotics present in fruit peel by exposing it (without any pretreatment) to direct analysis in real time coupled to a high-resolution orbitrap mass spectrometer (DART-HRMS) is reported for the first time. Variables such as DART gas heater temperature and pressure, source-to-MS distance, and sample velocity are investigated. The analysis of one sample by DART-MS lasts ca. 1 min, and the benefits of both high-resolution and tandem mass spectrometry to elucidate nontarget or unknown compounds are combined. Identification of postharvest fungicides, antioxidants, and sugars in fruit peel is performed in the positive ion mode. A possible elemental formula is suggested for marker compo…
Critical assessment of ionization patterns and applications of ambient desorption/ionization mass spectrometry using FAPA-MS
2016
Ambient desorption/ionization mass spectrometry (MS) has gained growing interest during the last decade due to its high analytical performance and yet simplicity. Here, one of the recently developed ambient desorption/ionization MS sources, the flowing atmospheric-pressure afterglow (FAPA) source, was investigated in detail regarding background ions and typical ionization patterns in the positive as well as the negative ion mode for a variety of compound classes, comprising alkanes, alcohols, aldehydes, ketones, carboxylic acids, organic peroxides and alkaloids. A broad range of signals for adducts and losses was found, besides the usually emphasized detection of quasimolecular ions, i.e. […
A new interface to couple thin-layer chromatography with laser desorption/atmospheric pressure chemical ionization mass spectrometry for plate scanni…
2005
An interface to allow on-line qualitative and quantitative full-plate detection and analysis of compounds separated by thin-layer chromatography (TLC) is presented. A continuous wave diode laser is employed as a desorption source. Atmospheric pressure chemical ionization mass spectrometry ionizes and subsequently identifies the desorbed sample molecules. Besides direct laser desorption on untreated TLC plates, graphite particles were used as a matrix to couple in the laser power and improve the efficiency of desorption.
Measurement of nanoparticle mass distributions by laser desorption/ionization time-of-flight mass spectrometry.
2011
In this paper, access to the mass distribution analysis of nanoparticles is described based on laser desorption/ionization and time of flight mass spectrometry. Two examples are given, demonstrating the accurate mass distribution analysis of nanoparticles fabricated both ex situ and in situ during the laser-assisted desorption process. The potentials and the limitations of the method are discussed, with special emphasis on carbonaceous clusters and molecules.
Information sources used for vacation tourists in tourist destinations
2012
En esta investigación se analiza el uso de las fuentes de información y su incidencia en distintas etapas del proceso de decisión, incidiendo en la búsqueda de información realizada por los turistas en destino. Los resultados muestran que tanto el número y tipo de fuentes de información utilizadas, así como la intensidad de la búsqueda y las decisiones tomadas en destino, es muy diferente del que realizan los turistas antes de llegar a su destino vacacional. Basados en los resultados, como parte de las conclusiones, se exponen ciertas directrices de interés para la gestión empresarial, en relación a la utilización de fuentes de información en los destinos turísticos. This research examines …