No / The main attributes that have been used to conserve the energy in wireless sensor networks (WSNs) are clustering, synchronization and low-duty-cycle operation. Clustering is an energy efficient mechanism that divides sensor nodes into many clusters. Clustering is a standard approach for achieving energy efficient and hence extending the network lifetime. Synchronize the schedules of these clusters is one of the primary challenges in WSNs. Several factors cause the synchronization errors. Among them, clock drift that is accommodated at each hop over the time. Synchronization by means of scheduling allows the nodes to cooperate and transmit data in a scheduled manner under the duty cycle mechanism. Duty cycle is the approach to efficiently utilize the limited energy supplies for the sensors. This concept is used to reduce idle listening. Duty cycle, nodes clustering and schedules synchronization are the main attributes we have considered for designing a new medium access control (MAC) protocol. The proposed OLS-MAC protocol designed with the target of making the schedules of the clusters to be overlapped with introducing a small shift time between the adjacent clusters schedules to compensate the clock drift. The OLS-MAC algorithm is simulated in NS-2 and compared to some S-MAC derived protocols. We verified that our proposed algorithm outperform these protocols in number of performance matrix.

This report studies the effect the opening up of routineroad maintenance in Sweden, traditionally carried out by theSwedish National Road Administration (SNRA). The main aim is tostudy the effect contracting out has had on work quality,transaction costs and the learning organization year 2001. Theresearch is built upon three hypotheses: Hypotheses 1: The SNRAcannot determine if the quality of the work is as contracted.Hypotheses 2: Transaction costs are less than 5% of theproduction costs. Hypotheses 3: The lack of cooperation ofSNRA's regional offices with each other and with the headoffice makes it difficult for SNRA to function as a learningorganization. The main research methods used were interviews, aquestionnaire, and participation in various meetings, such assite meetings and quality audits. Great emphasis has been puton the detailed questionnaire, which was sent to clientrepresentatives. The report includes a description of thebackground, definition and use of three theoretical concepts;quality, transaction costs and learning organization. Theresults show that client representatives at the regional levelcan determine that the SNRA receives the contracted quality,but at the central level it is not possible to determinequality fulfillment due to lack of complete and comparabledata. The study also concludes that it is not possible tocompletely separate transaction costs from the other productioncosts, mainly because man-hours spent per task is not accountedfor at the regional level. The questionnaire results show thatthe largest single transaction costs are those associated withreviewing the contracted work. This study shows that the clientrepresentatives think that the SNRA receives the contractedquality. The client representatives believe that the reviewprocess plays an important role in assuring the quality of theentrepreneurs' work. This study also shows that the client'swork is carried out differently in the different SNRA regionsstudied. This lack of administrative control by a centralauthority has lead to the main offices in the regions becoming"head offices" for the offices at the local level. The freedomallowed each regional office affords its employees theopportunity to develop new methods and organizationalstructures. At the same time substantial differences betweenthe regions and the lack of cooperation between the regionaloffices and the regional offices with the head office makes itdifficult for the SNRA to function as a learningorganization.

The whole universe is filled with plasma. There are different kinds of plasmas filling large volumes, separated by distinct boundaries. Many important energy conversion, particle acceleration and plasma transport processes occur at these boundaries, and therefore it is important to study the plasma processes there. It will for example help us to better understand the interaction and energy exchange between the Sun and the Earth. The lower hybrid drift waves (LHDW) are strong plasma waves that are often excited within boundaries, but their role in different plasma processes are still unclear. Many studies of the LHDW have been done, both in space and in laboratory. However, the LHDW are electron scale waves, and due to their small wavelength it has been difficult to study them in detail experimentally. For the first time we are able to make very detailed studies of the LHDW using observations by the Cluster spacecraft in the plasma surrounding Earth. By making cross spacecraft correlations of the electric field and examining existence conditions, we were able to determine the velocity of propagation and wavelength of the waves and thereby identify them as LHDW. We also calculate the electrostatic potential and find that it corresponds to about a third of the electron temperature. This indicate that they might be able to affect the electrons and thus take part in the processes within the boundary layer. By deriving a linear relation between the electrostatic potential, and the wave magnetic field, we compare them both and find that they correspond very well. We can use this to estimate the electrostatic potential in cases when cross spacecraft correlation is not possible.

<p>This report studies the effect the opening up of routineroad maintenance in Sweden, traditionally carried out by theSwedish National Road Administration (SNRA). The main aim is tostudy the effect contracting out has had on work quality,transaction costs and the learning organization year 2001. Theresearch is built upon three hypotheses: Hypotheses 1: The SNRAcannot determine if the quality of the work is as contracted.Hypotheses 2: Transaction costs are less than 5% of theproduction costs. Hypotheses 3: The lack of cooperation ofSNRA's regional offices with each other and with the headoffice makes it difficult for SNRA to function as a learningorganization. The main research methods used were interviews, aquestionnaire, and participation in various meetings, such assite meetings and quality audits. Great emphasis has been puton the detailed questionnaire, which was sent to clientrepresentatives. The report includes a description of thebackground, definition and use of three theoretical concepts;quality, transaction costs and learning organization. Theresults show that client representatives at the regional levelcan determine that the SNRA receives the contracted quality,but at the central level it is not possible to determinequality fulfillment due to lack of complete and comparabledata. The study also concludes that it is not possible tocompletely separate transaction costs from the other productioncosts, mainly because man-hours spent per task is not accountedfor at the regional level. The questionnaire results show thatthe largest single transaction costs are those associated withreviewing the contracted work. This study shows that the clientrepresentatives think that the SNRA receives the contractedquality. The client representatives believe that the reviewprocess plays an important role in assuring the quality of theentrepreneurs' work. This study also shows that the client'swork is carried out differently in the different SNRA regionsstudied. This lack of administrative control by a centralauthority has lead to the main offices in the regions becoming"head offices" for the offices at the local level. The freedomallowed each regional office affords its employees theopportunity to develop new methods and organizationalstructures. At the same time substantial differences betweenthe regions and the lack of cooperation between the regionaloffices and the regional offices with the head office makes itdifficult for the SNRA to function as a learningorganization.</p>

Parasiter kan påverka sina värdar på många olika sätt. Flodpärlmusslans (Margaritifera margaritifera L.) glochidielarver lever inkapslade som parasiter på gälarna hos öring (Salmo trutta L.) i flera månader innan de blir frilevande. Genom experiment i ett strömakvarium har denna studie undersökt hypoteserna att öring med inkapslade gälparasiter tar färre byten, och simmar kortare avstånd när de födosöker än öring utan gälparasiter.   Resultaten visade att infekterad öring tog signifikant färre byten/minut än oinfekterad öring både i början och i slutet av en födosöksperiod under vilken individerna konfronterades med tvåhundra poteniella byten. Vilket visar att infekterad öring har en lägre furageringshastighet är oinfekterad öring. Däremot påvisades ingen skillnad mellan öring med och utan parasiter med avseende på antal byten tagna i förhållande till avstånd från bytet.    Den lägre furageringshastigheten som påvisades hos de infekterade öringarna tyder på att infektion av flodpärlmusslans larver kan ha negativa effekter på fiskarnas tillväxt, och därmed överlevnad. Detta kan bero på faktorer som minskad aktivitet, ökad ventilation och förändringar i beteende hos de infekterade fiskarna, som är en effekt av parasitinfektionen. / Parasites can impact their hosts in many different ways. The larval glochida of freshwater pearl mussels (Margaritifera Margaritifera L.) infect the gills of brown trout (Salmo trutta L.), where they spend several months before becoming free-living. Using stream aquarium experiments, this study investigated the hypotheses that infected trout would capture fewer prey, and would swim less distance to capture prey, than would uninfected trout.   The results showed that infected brown trout caught significantly fewer prey/minute both at the beginning and at the end of a foraging period during which individuals were fed two hundred potential prey. This suggests that infected brown trout have a lower foraging rate than uninfected brown trout. However, no significant difference between infected and uninfected fish was found in terms of the number of prey taken in relation to distance to the prey.   The lower foraging rate for infected brown trout suggests that infection of the freshwater pearl mussel’s glochidia may have negative effects on their growth rate, and consequently survival. This may be due to factors such as reduced activity, increased ventilation and changes in behavior, which are effects from the parasite infection.

We establish in this paper the existence of weak solutions of infinite-dimensional shift invariant stochastic differential equations driven by a Brownian term. The drift function is very general, in the sense that it is supposed to be neither small or continuous, nor Markov. On the initial law we only assume that it admits a finite specific entropy. Our result strongly improves the previous ones obtained for free dynamics with a small perturbative drift. The originality of our method leads in the use of the specific entropy as a tightness tool and on a description of such stochastic differential equation as solution of a variational problem on the path space.

Detrital magnetite, although averaging less than I% of till volume, is a common constituent in glacial tills of eastern Indiana and western Ohio. Because of its abundance and ease of sampling, detrital magnetite was chosen to determine its potential as a tool to 1) determine provenance of the glacial tills and 2) to chemically fingerprint glacial sedimentary deposits for use in stratigraphic analysis. Two sampling programs were performed. First, glacial till samples were collected from a vertical section in western Ohio at the location of Doty's High Bank. Second, glacial tills were collected from a lateral distribution of five moraines in northeast and east central Indiana.Petrographic analysis of 946 detrital magnetite grains from eastern Indiana and western Ohio has shown that 81% of the magnetite grains are homogeneous, 15% have magnetite-ilmenite intergrowths, and 4% have exsolved phases of ulvospinel/pleonaste.Eighteen percent of all detrital magnetite grains have some level of hematite alteration. Chemical analyses were performed on 403 homogeneous detrital magnetite grains. These grains were analyzed for Fe, Ti, Mg, Mn, Cr, V, Al, and Si. The means and standard deviations of these eight elements, in weight percent oxide, are FeO (89.8087.696), TiO2 (1.58 ± 4.99), MgO ( 0.052 ± 0.200), MnO ( 0.172 ± 0.284), Cr2O3 (0.1942.256), V2O3 ( 0.241 ± 0.245), Al2O3 (0.455 ± 1.234), and SiO2 ( 0.035 ± 0.047).A Canadian source north of Lake Huron and south of James Bay is suggested based on previous studies of flow directions of the Laurentide Ice Sheet and bedrock geology in southern Canada. The bedrock in this area is primarily felsic plutonic and mafic volcanic. The petrographic and geochemical results of this study indicate this area as the source area for the detrital magnetite in eastern Indiana and western Ohio tills. Chemical fingerprints based on cluster analysis and bivariate plots were found within the vertical exposure of Doty's High Bank and the lateral moraines of eastern Indiana. Samples from the Muncie esker (unknown age) were found to correlate with the southernmost set of eastern Indiana moraines based on the chemical fingerprint analysis. / Department of Geology

The following report is the results of a master thesis project performed on the behalf of Boliden Tara Mines. The work includes a numerical modelling study with the main purpose to evaluate the room- and pillar stability for the mining method "drift-and-slash" mining currently used in the Tara Mine when mining in thin, low-rise lenses. Also, the potential of applying the "drift-and-fill" mining method was studied during the project. The numerical modelling work was performed both two-dimensionally and three-dimensionally, using the Itasca software FLAC and FLAC3D.  The study resulted in recommendations regarding the room- and pillar dimensions, mining sequence, rock support, mining method and further studies. It was concluded that the currently used room- and pillar dimensions could be altered to increase the extraction ratio and that the mining sequence and rock support should be determined depending on the room- and pillar dimensions. Also, that it could be possible to change from the drift-and-slash method to the drift-and-fill method from a stability perspective. Lastly, it was recommended to further study the rock strength and to monitor the pillar behaviour.

Ce travail de thèse s’intéresse aux phénomènes de surface ayant lieu lorsque l’on combine un procédé en phase homogène – contrôlé par la chimie d’un plasma non-thermique – et un procédé en phase hétérogène – contrôlé par la chimie ayant lieu à la surface d’un matériau nanostructuré Ag/TiO₂/SiO₂ – lors de la dégradation de l’acétaldéhyde, CH₃CHO.Il a été montré que le procédé diphasique permet de convertir 100 % de l’acétaldéhyde à traiter avec une SIE de 168 J.L-1 (soit une puissance de 280 mW). Dans ces conditions, CH₃CHO est converti en COx à plus de 60 %. Une telle efficacité n’est pas atteinte avec les procédés en phase homogène et en phase hétérogène seuls. Les processus se déroulant au sein du procédé diphasique mènent donc à une dégradation de CH₃CHO autrement meilleure que l’ensemble des cinétiques mises en oeuvre lors de l’utilisation des deux procédés seuls.Afin de comprendre quels processus physico-chimiques permettent d’obtenir un tel effet de synergie, l’étude de l’interaction acétaldéhyde/surface a été initiée, par spectroscopie infrarouge à réflexion diffuse (DRIFTS), et constitue le coeur de ce travail de thèse. Une attention particulière a été portée à l’étude des modes d’adsorption de l’acétaldéhyde sur Ag/TiO₂/SiO₂ en absence de plasma. Puis, l’effet de l’apport d’une source thermique et d’une espèce à fort pouvoir oxydant (l’ozone) sur l’acétaldéhyde présent en phase adsorbé a été évalué. / This thesis investigates the surface phenomena which occur when combining a homogeneous phase process – governed by the chemistry of a non-thermal plasma – and a heterogeneous phase process – controlled by the chemistry taking place on the surface of a nanostructured Ag/TiO₂/SiO₂ material – during acetaldehyde (CH₃CHO) removal.It has been shown that acetaldehyde can be removed up to 100 % with a 168 J.L-1 SIE consumption, by using the diphasic process. In these conditions, CH₃CHO is converted into 60 % of COx. Such efficiency is not achieved when using the homogeneous and heterogeneous phase processes alone. Thus, the physico-chemical phenomena occurring in the diphasic process allow a higher CH₃CHO removal compared to the whole kinetics involved in the homogeneous and heterogeneous phase processes alone. So as to understand which physico-chemical processes are involved in this synergistic effect, the study of the acetaldehyde/surface interaction has been started, by Diffuse-Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS), in this thesis. The acetaldehyde adsorption modes on the Ag/TiO₂/SiO₂ surface, without plasma, have been pointed out. Moreover, the effect of bringing a thermal energy source or an oxidizing species (like ozone) on adsorbed acetaldehyde has been evaluated.

Skandaler inom revisionsprofessionen har lett till en ökad kritik mot revisorer, eftersom deras förmåga att upplysa om problem med fortsatt drift ifrågasattes. I revisionsberättelsen ska revisorn uttala sig om det föreligger tvivel till fortsatt drift, vilket är ett stort ansvar eftersom det handlar om en bedömning av framtida händelser. Forskning visar att bedömningar av fortsatt drift mellan byråer skiljer sig åt beroende på olika faktorer som kan påverka revisorns bedömning. Detta leder till en nyfikenhet för vilka faktorer som kan påverka revisorns bedömning av fortsatt drift. Syftet med studien är att identifiera revisorer i olika revisionsbyråers tillvägagångssätt vid bedömning av fortsatt drift för att skapa en ökad förståelse för vilka faktorer som kan påverka en revisors bedömning av fortsatt drift. Studiens ansats är abduktiv där teorin utgår ifrån revisorns bedömning av fortsatt drift, men som vidare innehåller teorier som kan förklara och hjälpa till att tolka hur revisorn fattar sitt beslut om fortsatt drift. För att få ytterligare förståelse har semi-strukturerade intervjuer utförs med auktoriserade revisorer på olika revisionsbyråer. Empirin från intervjupersonerna resulterar i nya iakttagelser i form av de berättelser revisorerna ger om sin kunskap och erfarenhet av fortsatt drift. Slutsatsen av denna studie är att de olika faktorer som påverkar revisorns bedömning av fortsatt drift är byråstorlek, klientportfölj, kunskap, erfarenhet, specialistpersonal, beslutsstöd, användning av beslutsstöd, samt lagar och standarder.