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A study of the time-dependent modulation of cosmic rays in the inner heliosphere / E. MagidimishaMagidimisha, Edwin January 2010 (has links)
A two-dimensional (2-D) time-dependent cosmic ray modulation model is used to calculate the
modulation of cosmic-ray protons and electrons for 11-and 22-year modulation cycles using a
compound approach to describe solar cycle related changes in the transport parameters. The
compound approach was developed by Ferreira and Potgieter (2004) and incorporates the concept
of propagation diffusion barriers, global changes in the magnetic field, time-dependent
gradient, curvature and current-sheet drifts, and other basic modulation mechanisms. By comparing
model results with 2.5 GV Ulysses observations, for both protons and electrons, it is
shown that the compound approach results in computed intensities on a global scale compatible
to observations. The model also computes the expected latitudinal dependence, as
measured by the Ulysses spacecraft, for both protons and electrons. This is especially highlighted
when computed intensities are compared to observations for the different fast latitude
scan (FLS) periods. For cosmic ray protons a significant latitude dependence was observed for
the first FLS period which corresponded to solar minimum conditions. For the second, which
corresponded to solar maximum, no latitude dependence was observed as was the case for the
third FLS period, which again corresponded to moderate to minimum solar activity. For the
electrons the opposite occurred with only an observable latitude dependence in intensities for
the third FLS period. It is shown that the model results in compatible intensities when compared
to observations for these periods. Due to the success of the compound approach, it is
also possible to compute charge-sign dependent modulation for 2.5 GV protons and electrons.
The electron to proton ratio is presented at Earth and along the Ulysses trajectory. Lastly, it is
also shown how the modulation amplitude between solar minimum and maximum depends
on rigidity. This is investigated by computing cosmic ray intensities for both protons and electrons,
not only at 2:5 GV, but also up to 7:5 GV. A refinement for the compound approach
at higher rigidities is proposed. / Thesis (M.Sc. (Space Physics))--North-West University, Potchefstroom Campus, 2011.
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A study of the time-dependent modulation of cosmic rays in the inner heliosphere / E. MagidimishaMagidimisha, Edwin January 2010 (has links)
A two-dimensional (2-D) time-dependent cosmic ray modulation model is used to calculate the
modulation of cosmic-ray protons and electrons for 11-and 22-year modulation cycles using a
compound approach to describe solar cycle related changes in the transport parameters. The
compound approach was developed by Ferreira and Potgieter (2004) and incorporates the concept
of propagation diffusion barriers, global changes in the magnetic field, time-dependent
gradient, curvature and current-sheet drifts, and other basic modulation mechanisms. By comparing
model results with 2.5 GV Ulysses observations, for both protons and electrons, it is
shown that the compound approach results in computed intensities on a global scale compatible
to observations. The model also computes the expected latitudinal dependence, as
measured by the Ulysses spacecraft, for both protons and electrons. This is especially highlighted
when computed intensities are compared to observations for the different fast latitude
scan (FLS) periods. For cosmic ray protons a significant latitude dependence was observed for
the first FLS period which corresponded to solar minimum conditions. For the second, which
corresponded to solar maximum, no latitude dependence was observed as was the case for the
third FLS period, which again corresponded to moderate to minimum solar activity. For the
electrons the opposite occurred with only an observable latitude dependence in intensities for
the third FLS period. It is shown that the model results in compatible intensities when compared
to observations for these periods. Due to the success of the compound approach, it is
also possible to compute charge-sign dependent modulation for 2.5 GV protons and electrons.
The electron to proton ratio is presented at Earth and along the Ulysses trajectory. Lastly, it is
also shown how the modulation amplitude between solar minimum and maximum depends
on rigidity. This is investigated by computing cosmic ray intensities for both protons and electrons,
not only at 2:5 GV, but also up to 7:5 GV. A refinement for the compound approach
at higher rigidities is proposed. / Thesis (M.Sc. (Space Physics))--North-West University, Potchefstroom Campus, 2011.
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Construction and performance of the ATLAS SCT barrels and cosmic testsDemirköz, Bilge Melahat January 2007 (has links)
ATLAS is a multi-purpose detector for the LHC and will detect proton-proton collisions with center of mass energy of 14 TeV. Part of the central inner detector, the Semi-Conductor Tracker (SCT) barrels, were assembled and tested at Oxford University and later integrated at CERN with the TRT (Transition Radiation Tracker) barrel. The barrel SCT is composed of 4 layers of silicon strip modules with two sensor layers with 80 micro m channel width. The design of the modules and the barrels has been optimized for low radiation length while maintaining mechanical stability, bringing services to the detector, and ensuring a cold and dry environment. The high granularity, high detector efficiency and low noise occupancy (< 5*10^-4) of the SCT will enable ATLAS to have an efficient pattern recognition capability. Due to the binary nature of the SCT read-out, a stable read-out system and the calibration system is of critical importance. SctRodDaq is the online software framework for the calibration and also the physics running of the SCT and has been developed and tested during construction and commissioning of the detector with cosmics. It reliably measures the SCT performance parameters for each of the 6.3*10^6 channels in the SCT, identifies defects and problematic modules and writes them to an offline database for access from Athena, the ATLAS offline software framework. This dataflow chain has been exercised during the cosmics run at CERN, where a 5*10^5 cosmics sample for the combined SCT and TRT detectors was collected with a scintillator based trigger. It is now being commissioned in the ATLAS pit.
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Webbapplikation för att hämta/visavårdinformation från olika vårdsystemPatel, Satyamkumar, Nguyen, Johan January 2015 (has links)
Ett vårdsystem inom IT är ett mycket stort och komplext system som innehållermoduler med olika funktioner som behandlar vårddata för t.ex. journalföring,läkemedelshantering, remisser, ekonomisystem, planeringsstöd för olikaverksamhetsgrenar. Journalsystemet är en av de viktigaste komponenterna förlandstinget inom vårdsystemet, och information i patientjournalen ger ettgrundläggande underlag för bra vård. Det finns sex olika större journalsystem iSverige och Sveriges landsting har idag möjligheten att fritt välja vilketjournalsystem de vill använda för att bedriva sin dagliga verksamhet.Cambio Healthcare Systems är ett e-hälsoföretag som levererar bland annatvårdsystemet Cambio COSMIC. Eftersom olika vårdsystem är helt oberoende avvarandra uppstår problem när vårdinformation ska hanteras mellan olikavårdsystem. För att hämta vårdinformation för patienter från andra vårdsystemanvänds en extern nationell tjänst, NPÖ (Nationell patientöversikt). NPÖ samlarinformation från olika vårdsystem hos landsting, kommuner och privatavårdgivare. På uppdrag av Cambio utvecklades prototypen OmegaX som skaeliminera uthoppen till den externa NPÖ klienten och ska även integreras ivårdsystemet COSMIC. Syftet med prototypen är att visa att vårdinformationfrån andra vårdsystem kan användas direkt in i COSMIC. Prototypen är enwebbapplikation som är utvecklad i HTML5 tillsammans med flera andrawebbtjänster och ramverk som AngularJS, JavaFX, Java, Apache Tomcat ochMaven.Rapporten beskriver de olika utvecklingsverktyg och komponenter som haranvänts för att ta fram prototypen OmegaX. Rapporten innehåller även enbeskrivning av designen och hur de olika modulerna i applikationen fungerar.Dessutom utreds säkerhetsfrågor kring applikationen.En väl fungerade prototyp har tagits fram som körs i applikationen COSMIC.Prototypen befinner sig i sitt tidiga utvecklingsstadium då flera moduler körs ien simulerad miljö. Det krävs fortfarande en del utredning och vidareutvecklingsamt testning innan prototypen kan sättas i produktion.
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Topological defects in low-energy string gravityDando, Owen Robert January 1999 (has links)
Cosmologists are interested in topological defects as a possible source for the primordial density perturbations which seeded structure formation through gravitational instability. In this thesis, the gravitational properties of various topological defects are studied in the context of low-energy string theory, a likely modification of Einstein gravity at the high energy scales prevalent in the early universe. We consider in turn global monopole, local monopole, global cosmic string and global texture defects, allowing for an arbitrary coupling of defects to the string theory dilaton. For global defects we find the following behaviour. If the dilaton is massless, this modification to general relativity generically destroys the global good behaviour of the monopole and cosmic string, making their spacetimes singular. For the texture non-singular spacetimes exist, but only for certain values of the matter-dilaton coupling, dependent on the gravitational strength of the defect; in addition, this non-singular behaviour exists only in a certain frame. In the case of a massive dilaton, the metric behaviour of these defects is similar to that found in Einstein gravity, though we find they generically induce a long-range dilaton cloud. For the local monopole, which we study only in the presence of a massless dilaton, a rich variety of behaviour is found. For particular parameter values the local monopole spacetime approximates that of an extremal dilaton black hole.
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Cosmic ray muons in the deep oceanO'Connor, Daniel Joseph January 1990 (has links)
Typescript. / Thesis (Ph. D.)--University of Hawaii at Manoa, 1990. / Includes bibliographical references (leaves 172-177) / Microfiche. / xiii, 177 leaves, bound ill. 29 cm
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Gravitational waves from a string cusp in Einstein-aether theoryLalancette, Marc 05 1900 (has links)
The motivation of this thesis is to look for a signature of Lorentz violation, hopefully observable, in the gravitational waves emitted by cosmic strings. Aspects of cosmic strings are reviewed, in particular how focused bursts of gravitational radiation are emitted when a cusp forms on the string. The same phenomenon is then studied in an effective field theory with Lorentz violation called Einstein-aether theory. This is a simple theory with a dynamic preferred frame, but it retains rotational and diffeomorphism invariance. The linearized version of the theory produces five wave modes. We study the usual transverse traceless modes which now have a wave speed that can be lower or greater than the speed of light. This altered speed produces distinctive features in the waves. They depend on two free parameters: roughly the wave speed and the acceleration of the string cusp. The profile of the wave is analyzed in detail for different values of the parameters and explained by close comparison with the string motion.
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The development of cosmic ray showers (1015-1017 e V) /Thornton, Gregory J. January 1984 (has links) (PDF)
Thesis (Ph. D.)--University of Adelaide, Dept. of Physics, 1984. / Includes bibliographical references (leaves 117-124).
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Cherenkov studies of extensive air shower development /Liebing, D. F. January 1983 (has links) (PDF)
Thesis (Ph. D.)--Dept. of physics, University of Adelaide, 1983. / Includes bibliographical references.
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Evolution of cosmic strings /Vanchurin, Vitaly. January 2005 (has links)
Thesis (Ph.D.)--Tufts University, 2005. / Adviser: Alexander Vilenkin. Submitted to the Dept. of Physics and Astronomy. Includes bibliographical references (leaf 99). Access restricted to members of the Tufts University community. Also available via the World Wide Web;
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