The study presented in this thesis was motivated by the large uncertainty on the concentration of atmospheric electrical discharges to the global nitrogen budget. This uncertainty is partly due to the fact that information concerning the NOx production efficiency of electrical discharges having current signatures similar to those of lightning flashes is not available in the literature. Another reason for this uncertainty is the fact that energy is used as a figure of merit in evaluating NOx production from lightning flashes even though insufficient knowledge is available concerning the energy dissipation in lightning flashes. The third reason for this uncertainty is the lack of knowledge concerning the contribution of discharge processes other than return strokes to the NOx production in the atmosphere. Lightning is not the only process in the atmosphere that causes ionisation and dissociation of atmospheric air. Cosmic rays continuously bombard the Earth with high energetic particles and radiation causing ionization and dissociation of air leading to the production of NOx in the atmosphere. The work carried out in this thesis is an attempt to improve the current knowledge on the way in which these processes contribute to the global NOx production. Experiments have been conducted in this thesis to estimate the NOx production efficiency of streamer discharges, laser-induced plasma, laboratory sparks having current signatures similar to those of lightning flashes, alpha particle impact in air and finally with the lightning flash itself. The results obtained from laboratory electrical discharges show the following: (a) The NOx production efficiency, in terms of energy, of positive streamer discharges is more or less similar to those of hot discharges. (b) The NOx production efficiency of an electrical discharge depends not only on the energy but also on the peak and the shape of the current waveform. (c) The current signature is a better figure of merit in evaluating the NOx yield of electrical discharges. As a part of this thesis work a direct measurement of NOx generated by lightning flashes was conducted and the results show that slow discharge processes such as continuing currents could be the main source of NOx in lightning flashes. Concerning NOx production by other ionisation processes such as alpha particle impacts in the atmosphere, the data gathered in this thesis show that each ionising event in air leads to the creation of one NOx molecule. In terms of energy the NOx production efficiency of alpha particles is similar to that of electrical discharges. The theoretical studies conducted within this thesis indicate that M-components contribute more than the return strokes to the NOx production. The calculations also show that the contribution to the global NOx budget by return stroke is not as high as that assumed in the current literature.

Soil water content (SWC) measurements are crucial worldwide for hydrological predictions, agricultural activities, and monitoring the progress of reclamation on disturbed land from industrial activities. In colder climates, snow water equivalent (SWE) measurements are equally important, and directly contribute to improved spring water supply forecasting. Both these variables, SWC and SWE, are commonly measured with either point-scale (e.g. soil cores for SWC and snow tubes for SWE) or large-scale (remote sensing) methods. The cosmic-ray soil moisture probe (CRP) was recently developed to fill this gap between small- and large-scale measurements. The CRP provides an average SWC reading in a landscape-scale measurement footprint (300 m radius) by taking advantage of the relationship between aboveground neutrons and soil water. Although the CRP has proved accurate in relatively homogenous sites, it has not been validated at highly heterogeneous sites. Since snow is simply frozen water, the CRP also has the potential for monitoring SWE at the landscape-scale. However, no calibration has been developed for measuring SWE with the CRP. This thesis aimed to further validate the use of a CRP for measuring SWC at a highly heterogeneous site, and calibrate a CRP for monitoring landscape-scale SWE at an agriculture field. The heterogeneous site used to validate the CRP for SWC measurement was an oil sand reclamation site made up of multiple test plots of varying soil layer treatments. Despite the clear differences in soil texture at the site, the CRP-monitored SWC compared accurately to sampled soil water content and a network of soil moisture probes. With the use of modeling, it was also possible to downscale the CRP measurement to the plot scale. For calibrating the CRP for monitoring SWE, an empirical calibration function was developed based on the relationship between the CRP-measured neutrons and SWE from snow surveys with snow tubes. Using the calibration equation, CRP-estimated SWE closely matched SWE measured from snow surveys. Differences were attributed to mid winter and spring melting of the snowpack along with varying soil water content in the top of the soil profile. This research demonstrates the usefulness of the CRP for monitoring SWC at unique sites and its ability to monitor SWE at the landscape-scale.

The research presented in this thesis investigates several aspects of the evolutionary processes of T Tauri stars and their accompanying circumstellar disks. The versatile Monte Carlo radiation transfer technique, with several modifications and extensions, is used throughout to study the structure and constitution of both the circumstellar disk at large and the changeable and dynamic inner disk regions. The photopolarimetric variability of AA Tau in the Taurus star forming region is modelled in a fully 3D manner. I find that a magnetospherically induced warp in the accretion disk at roughly the stellar co-rotation radius occults the star and reproduces both the observed period and duration and the required brightness and polarisation variations. The model SEDs allow estimates of the disk mass, radial extent and large- scale density structure. Using a modified SPH code we find the interaction of a 5.2kG stellar magnetic field inclined at 30° to the rotation axis with the disk, is capable of generating a warp of the size and shape needed to reproduce the observed variations. Modified Monte Carlo models capable of incorporating any number of dust particle grain sizes distributed throughout the disk in vertical and radial distributions, in a fully 3D manner are presented. This versatile tool allows the investigation of evolutionary processes such as dust settling and grain growth predicted to occur in T Tauri sources as they age. A Mie Scattering code was also adapted and incorporated into the models allowing us to determine optical properties for dust grains and distributions of any size. I present model SEDs fitting the latest publicly available IR data for a number of T Tauri sources and reproduce the observational effects of dust grain growth and settling with a high degree of success. The fits are by no means unique and the structural parameters required to produce them are quite uncertain but it is possible to determine useful information on the larger scale structure and bulk constituents of these disks. A fully 3D non-LTE radiative transfer code using CO line emissions as a tracer of the disk dynamics and able to simulate any disk structure or geometry, either analytical or imported from a hydrodynamic simulation, is presented. Signatures attributed to the disk dynamics and spiral density structure derived from hydrodynamic simulations of massive disks are investigated and resolved. Line profiles and contour maps of the velocity of the emitting material are generated and compared with observations.

Sammanfattning: SAAB Communication i Linköping sysslar med konsultverksamhet mot ett flertal nationella och internationella företag inom både den civila och militära sektorn. Fokus ligger på flyget med uppdrag inom telesystem, radiosystem, signaturanpassning, EMC, atmosfärisk påverkan mm. I det sistnämnda ingår även kosmisk strålnings inverkan på elektronik. Den fortsatta miniatyriseringen av elektronik, speciellt minneselektronik leder till ökad känslighet mot den kosmiska partikelstrålningen som ständigt regnar ner på jorden, därför är det extra noga att minnen testas innan de sätts i bruk vid flygburna system. Syftet med detta examensarbete är att konstruera en provplattform som registrerar fel som uppkommer i ett DDR2 SDRAM minne vid påverkan av den ovannämnda strålningen. Detta examensarbete är en vidareutveckling av en provplattform baserad på en FPGA – lösning. Eftersom denna provplattform saknade stöd för den snabbare minnestypen DDR2 SDRAM, blev syftet med detta examensarbete att ta fram en ny plattform som stödjer denna typ av minne. Den nya provplattformen är en PowerPC baserad lösning från Freescale Semiconductor®. Provplattformen kommer att anslutas till en PC som kör ett program som analyserar antalet detekterade minnesfel, typ av fel samt hur många neutroner minnet har blivit utsatt för under testet. Mjukvaruutvecklingen implementeras i programmeringsspråken assembler samt C. Innan testet av minnet påbörjas, fylls minnet med ett förbestämt bitmönster, om förändringar av bitmönstret sker vid bestrålning av minnet kommer dessa ändringar att registreras tillsammans med den minnesadress där felet inträffade. Abstract: SAAB Communication in Linköping offers consulting toward several national and international companies, both within the civilian and the military market. Focus is in the field of avionics and deals with telecommunication system, radio system, signature adaption, EMC, atmospheric impact etc. The later also includes the influence of cosmic radiation in electronics. The oncoming miniaturisation of electronics, especially within the memory fields causes an increased susceptibility of cosmic radiation that constantly hits our planet, therefore it is of great importance that memories is to be tested before used in airborne systems. The purpose of this thesis is to construct a test platform in order to register faults that occur in a DDR2 SDRAM memory under influence of the mentioned radiation. This thesis is further development of a test platform previously based on a FPGA – solution. Since this test platform had not to support for the more rapidly type of memory as DDR2 SDRAM, the purpose of this thesis became to develop a new platform with support for this type of memory. This new test platform is based on PowerPC from Freescale Semiconductor® The test platform will be connected to a PC running a program that counts the number of detected memory faults, recognises a type of error and records the number of neutrons that the memory has been exposed to during the test. The software is implemented in the programming languages assembler and C. The tested memory will be loaded with a predetermined bit pattern before the test begins, if a change in the bit pattern is detected during exposure of radiation, these faulty bit patterns will be registered together with the memory address where the error has occurred. / Andreas Skoglund Gustav adolfsg. 4 58220 Linköping 0739-230620 ti00ask@student.bth.se, andreas.skoglund@gmail.com, andreas.skoglund@saabgroup.com

It is shown in three examples that future cosmological data may allow us to constrain fundamental physics in interesting ways. The first example illustrates that correlations in the polarization of the cosmic microwave background may allow us to put the strongest limit yet on the mass of a particle, the graviton, at a level of m . 10−30 eV. In the second example, it is shown that observations of the correlations of temperature anisotropies and polarization of the cosmic microwave background may reveal hints for the realization of a class of string theoretic inflationary models that go by the name of axion monodromy inflation, or, rule them out. If the evidence for inflation strengthens substantially, just the requirement that inflation occurred may be used to constrain models of fundamental physics. The third example shows that a class of string compactifications that are commonly used in the context of string phenomenology cannot support inflation and might thus be ruled out by cosmology. For completeness, a review of the physics underlying the cosmic microwave background radiation is included and some analytical results for the signatures of primordial gravitational waves in the cosmic microwave background are given. / text

<p>Nothing has been that consistent as the change is for the knowledge revolution to nourish and cultivate. Different forms of changes are occurring in organizations with the aim to improve the output performances. Health organizations have been more attached to the changes and the consequences that are brought with such changes. Such consequences are primarily connected with concepts of unlearning and learning. Any form of the change if initiated in organization asks for new routines learning, tasks conductions and the organizational cultural revolution. These new routines have been occurring at individual and organizational levels. The unlearning at any level in the organizational culture can be performed through investigating a primary connection between the organizational and individual routines. At the individual level unlearning brings a number of psychological, cognitive, social and moral hurdles. These hurdles at individual level basically help the organizational unlearning to occur. All of the routines occurring at individual level encompass the necessary information that goes from lower levels to upward, strengthening and holding the organizational memory firm.</p><p>This research was about to find how the health organizations unlearn the older practices and learn the new practices in IT change. This research had two streams i) finding whether there had been any connection between the organizational and individual unlearning in the cases of IT change, ii) For unlearning what kind of hurdles had been there at the individual level. Kalmar hospital pediatric department had been chosen for the empirical investigations. The research streams were about how and what parts which helped the researcher to go for the qualitative data gathering techniques.</p><p>The Results showed there had been a very thin connectivity between the organizational and individual unlearning. The results revealed and unfolded that many of the new learning are occurring simultaneously with discarding the older ways of practices. The impression of absorbing the change with respect to the unlearning had been varied from person to person. There had been a numbers of individual hurdles observed at individual level of unlearning. Apart from them, many individual routines (performative tasks) had the primary connectivity with the organizational routines (Ostensive routines) and shaping and reshaping of the organizational memory.</p><p>It is important to understand the unlearning notions with the type of change. In this research each of the interviewee had shared his thoughts of how the things could have been done differently by revealing the consequences with new learning. Literature suggests that for a profound and successful implementation of change more formal and informal trainings, clear strategy for shuffling the older individuals in the camp, more social and cognitive meetings and fast and quick actions in the cases of technical difficulties are to be taken.</p><p><strong> </strong></p><p><strong> </strong></p><p><strong> </strong></p><h1> </h1><h1> </h1><h1> </h1><p> </p><p> </p><p> </p><p> </p><p> </p><p> </p><p> </p><p> </p><p> </p><p> </p><p> </p><p> </p><p> </p><p> </p><p> </p> / Thesis

<p>Nothing has been that consistent as the change is for the knowledge revolution to nourish and cultivate. Different forms of changes are occurring in organizations with the aim to improve the output performances. Health organizations have been more attached to the changes and the consequences that are brought with such changes. Such consequences are primarily connected with concepts of unlearning and learning. Any form of the change if initiated in organization asks for new routines learning, tasks conductions and the organizational cultural revolution. These new routines have been occurring at individual and organizational levels. The unlearning at any level in the organizational culture can be performed through investigating a primary connection between the organizational and individual routines. At the individual level unlearning brings a number of psychological, cognitive, social and moral hurdles. These hurdles at individual level basically help the organizational unlearning to occur. All of the routines occurring at individual level encompass the necessary information that goes from lower levels to upward, strengthening and holding the organizational memory firm.</p><p>This research was about to find how the health organizations unlearn the older practices and learn the new practices in IT change. This research had two streams i) finding whether there had been any connection between the organizational and individual unlearning in the cases of IT change, ii) For unlearning what kind of hurdles had been there at the individual level. Kalmar hospital pediatric department had been chosen for the empirical investigations. The research streams were about how and what parts which helped the researcher to go for the qualitative data gathering techniques.</p><p>The Results showed there had been a very thin connectivity between the organizational and individual unlearning. The results revealed and unfolded that many of the new learning are occurring simultaneously with discarding the older ways of practices. The impression of absorbing the change with respect to the unlearning had been varied from person to person. There had been a numbers of individual hurdles observed at individual level of unlearning. Apart from them, many individual routines (performative tasks) had the primary connectivity with the organizational routines (Ostensive routines) and shaping and reshaping of the organizational memory.</p><p>It is important to understand the unlearning notions with the type of change. In this research each of the interviewee had shared his thoughts of how the things could have been done differently by revealing the consequences with new learning. Literature suggests that for a profound and successful implementation of change more formal and informal trainings, clear strategy for shuffling the older individuals in the camp, more social and cognitive meetings and fast and quick actions in the cases of technical difficulties are to be taken.</p><p><strong> </strong></p><p><strong> </strong></p><p><strong> </strong></p><p><strong> </strong></p><h1></h1><h1></h1><h1></h1><p> </p><p> </p><p> </p><p> </p><p> </p><p> </p><p> </p><p> </p><p> </p><p> </p><p> </p> / Thesis

No description available.

No description available.

The CMS Tracker is an all silicon detector and it is the biggest of its kind to be built. The system consists of over 15,000 individual detector modules giving rise to readout through almost 107 channels. The data generated by the Tracker system is close to 650 MB at 40 MHz. This has created a challenge for the CMS collaborators in terms of data storage for analysis. To store only the interesting physics data the readout rate has to be reduced to 100 Hz where the data has to be ltered through a monitoring system for quality checks. The Tracker being the closest part of the detector to the interaction point of the CMS creates yet another challenge that needs the data quality monitoring system. As it operates in a very hostile environment the silicon detectors used to detect the particles will be degraded. It is very important to monitor the changes in the sensor behaviour with time so that to calibrate the sensors to compensate for the erroneous readings. This thesis discusses the development of a monitoring system that will enable the checking of data generated by the tracker to address the issues discussed above. The system has two parts, one dealing with the data used to monitor the Tracker and a second one that deals with statistical methods used to check the quality of the data.