Water aerosols affect the climate because they have an impact on the radiation balance and cloud formation. Water is present in all forms in the atmosphere (water, ice and steam), for example as rain and hail. Water aerosols play an important role in many biological and chemical processes in the atmosphere. The most common form of water in the atmosphere is water droplets or vapor which often come from oceans and lakes and these aerosols often contain organic compounds. It is therefore interesting to study if organic compounds, in this case glycerol, will reside on the surface or inside the water droplets. The investigations were performed by using theoretical studies, molecular dynamic simulations in GROMACS, and experimental investigations; X-ray photoelectron spectroscopy with a liquid jet. The experiments were performed at BESSY II, Berlin. The concentrations of glycerol were varied from 75:1; 8:1 to 4:1 (water: glycerol molecules). The results were that the experiments and simulations indicated that when theconcentration of glycerol increased the glycerol concentration at the surface of the waterdroplet increases until a monolayer of glycerol molecules was formed at the surface. When the monolayer was formed (or close to) less and less glycerol molecules were placed at thewater surface and more and more glycerol molecules were placed in the bulk of the waterdroplet. / Vattenaerosoler påverkar klimatet eftersom de har en inverkan på strålningsbalansen och molnbildningen. Vatten finns i alla former i atmosfären (vatten, is och ånga) som bland annat regn och hagel. Vatten aerosolerna spelar en viktig roll i många kemiska och biologiska processer i atmosfären. Den vanligaste formen av vatten i atmosfären är små vattendroppar eller ånga som ofta kommer från hav och sjöar och som ofta innehar organiska föreningar. Då vattenaerosoler påverkar klimatet och organiska föreningar är vanligt förekommande i vattendroppar är det intressant att undersöka om organiska föreningar, i detta fall glycerol, hamnar på ytan eller inuti vattnet. Undersökningarna har gjorts genom att använda teoretiska perspektiv, molekylärdynamiska simuleringar i GROMACS, samt experimentella undersökningar i form av röntgen fotoelektronspektroskopi med en vätskejet. Dessa experiment utfördes i BESSY II, Berlin. Koncentrationerna av glycerol varierades från75:1; 8:1 till 4:1 (vatten: glycerolmolekyler). Resultaten från experimenten och simuleringarna indikerade att när koncentrationen av glycerol ökade så ökade glycerolkoncentrationen på ytan av vattendroppen tills det bildades ett monolager av glycerolmolekyler på vattenytan. När monolagret hade bildats så placerades mindre och mindre glycerolmolekyler på vattenytan och fler och fler glycerolmolekyler placerades inne i vattendroppen.

Till följd av Covid-19-pandemin har sjukvården i Sverige fått bära mycket stor belastning, samtidigt som den globala efterfrågan och användningen av personlig skyddsutrustning (PPE) kraftigt ökat. Under våren 2020 har den globala handeln upplevt störningar, vilket haft inverkan på leveransen av PPE till sjukvården. Studiens mål var att undersöka vad den inhemska industrin behöver för att ställa om en produktion till att leverera kvalitetssäkrade skyddsprodukter till samhällsviktiga funktioner i ett läge av kris. Metoden har gått ut på litteratur- och fallstudie av en medicinteknisk (MD) operationsrock, samt en intervjustudie med ett antal nyckelpersoner kopplade till produktionsomställning (PO) under pandemins utveckling. Studien resulterade i följande verktyg inför en PO för att snabbt leverera kritiska produkter i en tid av kris.- Beredskapspyramid kopplad till samordning av produktionen.- Producenttriangel kopplad till behov och förutsättningar för den inhemska produktionsindustrin.- Textilteknisk analys av produktionsprocessen för engångs operationsrockar. En slutsats från studien var att för en snabb PO, behövs en tydlig behovsbild med klara ansvarsfördelningar. Den inhemska industrin har skilda förutsättningar för omställning till de höga kvalitetskraven vilka följer produktionen av PPE och MD. Genom att analysera produktionsprocessen för efterfrågade produkter i kris förtydligas vilka parter eller processer som behöver samordnas för en inhemsk produktion. Vidare arbete kan vara utformning av strategisk plan, redo att användas när krisen bryter ut. En samordnad, proaktiv och resurseffektiv beredskap anses öka möjligheten till en miljövänlig PO, då producenter kan anpassa sin omställning enligt prioriterade krav. / As a result of the Covid-19 pandemic, the Swedish healthcare system has had to carry a heavy burden, while the global demand and use of personal protective equipment (PPE) has increased. During the spring of 2020, global trade experienced disruptions, which has had an impact on the delivery of PPE to the healthcare system. The study's goal was to investigate what the domestic industry needs to initiate a production changeover to deliver quality-assured products to the socially important functions in a crisis situation. The method is based on a literature- and case study together with an interview study with key personnel linked to production changeovers (PO) during the pandemic. The study resulted in the following tools for a PO to quickly deliver critical products in a time of crisis:- A contingency pyramid regarding coordination of production.- A producer triangle regarding the needs and prerequisites for the domestic production industry.- A textile-technical analysis of the production process for single-use surgical gowns. Conclusions from the study were that in order to coordinate a fast and resource efficient PO, a clear overview of demands with clear responsibilities is needed. The changeover conditions for the domestic industry varies following the high-quality requirements for producing PPE and MD. By analysing the production process for requested products in various crises, the conditions for which parties or processes need to be coordinated for domestic production are clarified. Further studies can be development of a strategic plan ready to implement when the crisis breaks out. A coordinated, proactive and effective contingency is considered enabling an environmentally friendly PO, as producers can adapt their changeover according to prioritized demands.

We monitored distribution and abundance of food resources and determined food habits of nonbreeding bald eagles (<i>Haliaeetus leucocephalus</i>) on the northern Chesapeake Bay, as a preliminary step toward examining food-base effects on bald eagle distribution and abundance. To correctly interpret our food habits results, we first examined biases of 2 commonly-used food habits techniques, pellet analysis and food remains collection, through feeding trials with 2 captive bald eagles. Eagles were fed a variety of food items found on the northern Bay. Egested pellet contents and frequency of remains were compared with actual diet. We also examined efficacy of direct observation by observing eagles in high-use foraging areas. We found pellet analysis accurately indicated the species of birds and mammals eaten, but overrepresented medium-sized mammals and underrepresented large carrion in percent occurrence results. Fish were poorly represented in pellets. Eagles rarely produced pellets after eating fish, suggesting that pellet egestion rate, defined as the number of pellets produced per eagle per night, can serve as an index to relative use of birds and mammals. Food remains collection was highly biased toward birds, medium~sized mammals, and large, bony fish. Direct observation was labor intensive and required close proximity of the observer for unbiased identification of food items. Observation may be the only means of documenting eagles' use of small, soft-bodied fish. We used direct observation, pellet analysis, and pellet formation rates to determine bald eagle food habits from December 1986 through April 1988. We monitored fish abundance by gill netting and waterfowl abundance by aerial surveys over this same period. Fish and waterfowl abundance varied reciprocally; waterfowl numbers peaked in winter and fish numbers peaked in spring and late summer. Bald eagles responded to differences in food abundance with diet shifts. Canada geese (<i>Branta canadensis</i>), mallard (<i>Anas platyrhynchos</i>), and white-tailed deer (<i>Odocoileus virginianus</i>) carrion were primary foods from November through February. Cold-stressed gizzard shad (<i>Dorosoma cepedianum</i>) were captured frequently by eagles below a hydroelectric dam on the Susquehanna River in November and December, and also were taken frequently throughout the study area during a winter when ice cover was extensive. Shad were not commonly available during a milder winter. From April through September, bald eagles fed on a variety of fish species, primarily gizzard shad, channel catfish (<i>Ictalurus punctatus</i>), Atlantic menhaden (<i>Brevoortia tyrannus</i>), white perch (<i>Morone americana</i>), American eel (<i>Anguilla rosfrata</i>), and yellow perch (<i>Perca flavescens</i>). The 4 most commonly consumed fish species also were the most commonly gill netted species. At least 25% of all fish taken were scavenged. Live fish were most abundant at the water's surface in shallow water. Bald eagles' use of live fish reflected this availability; water depth at live fish capture sites was less than at sites where fish of dead or unknown status were taken. Eagles foraged most intensively within 1 hour of sunrise. A second smaller peak in foraging activity was observed in early afternoon. / Master of Science

The freshwater-saltwater transition zone was investigated in an unconfined aquifer on Virginia’s Eastern Shore. The Steelman’s Landing study site consisted of a well transect which began in an 800 meter wide upland agricultural field, and proceeded seaward through a 300 meter wide mesic forest, 300 meter wide saltmarsh, and 550 meters offshore into Magothy Bay. Wells in the surficial, Columbia aquifer were screened over 30 centimeters at depths of 3.05, 9.14, and 15.25 meters below the surface. Most monitoring sites consisted of clusters of multiple wells which were periodically sampled for inorganic nutrients and salinity. In the saltmarsh portion of the study site, salinity of monitoring well samples indicated the presence of two horizontal flow systems. The deeper flow system contained freshwater flowing seaward from upland areas. The shallower system contained saline water recharged by the tides and concentrated by evaporation. Salinity measurements and positive vertical (0.019-0.046 meters/meter) and horizontal (0.001-0.005 m/m) hydraulic gradients of wells located across the marsh suggested movement of freshwater offshore which was confirmed by the direct measurement of submarine groundwater discharge (SGWD) using seepage meters. Upland wells contained high nitrate freshwater (>600μmol / 1 NO₃⁻, <1.0% salinity), while shallow (3.05m) wells located from the marsh-forest interface across the saltmarsh to Magothy Bay contained increasingly saline water and reduced nitrate levels (<1μmol / 1 NO₃⁻, 4-21% salinity). Deeper (9.14m) wells across the study site from the agricultural field seaward 420 meters offshore, contained fresh water (<1.0%). A deep (9.14m) well located 550 meters offshore contained water of nearly equal salinity to ambient water in Magothy Bay (30-32%). This represented a point on the saline side of the transition zone. In order to more completely identify and account for movement of nutrients in groundwater across the study site from upland agricultural fields to Magothy Bay, the second portion of the study consisted of an investigation of nutrient movement through a small tidal creek located adjacent to the Steelman’s Landing study site. Creek water had a higher velocity and shorter residence time in comparison to groundwater. Exercises describing nutrient movement were conducted in February and May, 1993 in Wall’s Landing Creek. A seasonal component of nutrient reduction was investigated as indicated by ambient creek samples, and bulk flux of nutrients across the sediment-water interface using light and dark benthic dome chambers. Nitrate flux measurements for the February and May sampling exercises were approximately 14,500 μmol/sec (17.6kg/day as N) and 5400 μmol/sec (6.5kg/day as N), respectively. The primary mechanism of nitrate reduction on reaching the creek channel was physical dilution by seawater. / Master of Science

The movement of nitrogen from the surface, where it is applied as fertilizer, to groundwater is of importance due to the health concerns associated with nitrate and potential eutrophication of groundwater impacted surface water. The computer model, PRZM (Pesticide Root Zone Model) was used to simulate the transportation of nitrogen through the soil column, past the crop root zone to groundwater. Then MOC (Method of Characterization), a groundwater model, was used to transport the nitrogen that had reached the water table offsite. Results were compared to existing field data in an attempt to verify the validity of the simulation. / Master of Science

Le premier volet de la présente étude vise à évaluer la performance du réacteur biologique à support fluidisé SMBRMD avec garnissage PEENOX MD pour l'épuration des eaux usées de la Municipalité de Mont-Saint-Grégoire (MMSG). Ce système comprend deux réacteurs à biomasse fixe disposés en série, suivis d'un décanteur. Conformément aux critères de suivi de démonstration du MDDEP, cette nouvelle technologie a été analysée sur une période d'un an (de juin 2009 à mai 2010). Le suivi a permis de mieux comprendre les processus impliqués dans le réacteur en fonction des conditions environnementales et de la qualité de l'affluent. Une fois le système stabilisé, il a été démontré que le premier réacteur était très efficace pour l'enlèvement de la matière organique, où des taux d'abattement de 78 ± 21 et 89 ± 18 % ont été observés pour la DCO S et la DBOC5S , respectivement. Aussi, les deux réacteurs SMBR ont permis un enlèvement de l'azote ammoniacal de 99 ± 1 %. La nitrification, présente dans les deux réacteurs, était responsable de l'enlèvement de l'azote ammoniacal à 67 ± 19 %. Globalement, la performance observée à l'usine depuis l'implantation des réacteurs SMBR est supérieure à celle mesurée avec le système précèdemment utilisé, soit les biodisques. De plus, les paramètres à l'effluent sont davantage constants. Le deuxième volet du projet aborde le traitement par coagulation et floculation de l'eau usée échantillonnées à l'usine de la MMSG. L'efficacité déphosphotante de l'alun a d'abord été évaluée en laboratoire, sous des conditions expérimentales contrôlées, et comparée à celle observée à la MMSG. Puis, l'influence des conditions de mélange et de la concentration en MES sur la performance de l'alun a été analysée. Par la suite, le pouvoir déphosphatant de deux solutions de chitosane, un polymère biodégradable et non toxique issu de la chitine, a été examiné. Toutefois, le chitosane ne permettant pas d'abattre les fractions dissoutes de phosphore, l'utilisation simultanée du chitosane et de l'alun a été considéré Ainsi, deux des trois solutions de chitosane utilisées permettent de diminuer les dosages d'alun requis pour l'atteinte des exigences de rejet, réduisant par le fait même la teneur en sulfates et en aluminium dans les biosolides. De plus, pour un dosage donné d'alun, ces solutions de chitosane permettent de réduire la concentration en aluminium du surnageant. Malheureusement, les tests ne permettent pas d'associer le pouvoir déphosphatant du chitosane à son degré de déacétylation ou à son poids moléculaire.

Le mémoire est consacré à l'étude numérique des phénomènes survenant à l'interface solide-fluide. Trois processus ont été étudiés: auto-organisation de films moléculaires sur un substrat solide, adsorption du gaz moléculaires dans un matériau nanoporeux et la cristallisation à l'interface organique/inorganique. L'étude de l'auto-organisation et des transitions de phase dans des multicouches de l'azote moléculaires adsorbées sur graphite est présentée dans le chapitre III. L'analyse est focalisée sur l'hétérogénéité spatiale du système et son influence sur le mécanisme et température de transitions ordre/désordre et la fusion des couches. Elle complète ainsi l'étude numérique du diagramme de phase de l'azote moléculaire, bien connu pour le matériau massif (3D) et les monocouches (2D) adsorbées sur un substrat. Le chapitre IV présente une étude de cinétique du mélange des gaz (méthane et méthyle-mercaptan) confiné dans les nanopores de carbone (pores en forme de fentes, de dimensions latérales finies et largeur nanométrique). L'étude porte sur la capacité de stockage de pores, la dynamique des composantes du mélange des gaz sous confinement et l'évaluation de la quantité de l'odorant nécessaire pour une détection facile en cas de fuite. Chapitre V résume les résultats de l'étude préliminaire ayant pour but la mise en place des simulations de biomineralization à l'interface organique/inorganique. Les structures secondaires de deux biomolécules, human leucine-rich peptide hLRAP et full length amelogenin, rM179 ont été prédéterminées. Les plus probables configurations ont été optimisées dans un environnement aqueux. / The present work is devoted to computer simulations of phenomena occurring at solid-fluid interfaces. Three processes have been studied in details: auto organization of molecular films at a solid substrate, adsorption of molecular gas in confined geometry and crystal formation at organic-inorganic interface. Two classical simulation methods have been used: stochastic Monte Carlo and deterministic Molecular Dynamics.The study of self-organisation and phase transitions in molecular nitrogen multilayers adsorbed on the basal plane of graphite is presented in chapter III. It focusses on the systems' spatial heterogeneity and its influence on temperatures of order-disorder and melting transitions. This study completes the numerical analysis of molecular nitrogen phase diagram, well described and understood for 3d (bulk) and 2D (monolayer film) systems.The analysis of kinetics of fluid confined in nanopores is presented in chapter IV. The working case consists of methane-methyl mercaptan mixtures confined in slit-shaped carbon nanopores. Simulations focused on both: storage capacity of carbon pores of finite size and nanometric width, and dynamics of gas mixture components under confinement. An evaluation of odorant content necessary for easy gas leak detection is presented.Chapter V gathers the results of calculations performed to set up the simulations of biomineralization at the organic-inorganic interface. The secondary structures of two amelogenins (human leucine-rich peptide, hLRAP, and full length amelogenin, rM179) have been predicted. The most probable structures have been further refined and the chain folding optimized in aqueous environment.

O Brasil é uma referência mundial na produção e exportação de citros, entretanto esse cultivo pode sofrer diversos problemas e perdas de produtividade por motivos diversos, como por exemplo, pragas. Para reduzir os riscos e perdas, torna-se interessante o uso de sistemas automatizados de monitoramento, justificando a necessidade de realizar a coleta de dados para determinar diversos fatores. Determinadas plantações, como a de citros, não podem ser monitoradas somente via solo ou somente via imagens aéreas, tornando necessário mesclar ambas as abordagens de acordo com o parâmetro a ser monitorado. Para a realização desse monitoramento devem ser utilizados robôs com habilidades distintas, robôs aéreos e robôs terrestres. Assim, é preciso designar as tarefas que cada robô realizará e também coordenar todos os robôs durante a execução do sistema como um todo, visando otimizar o processo de coleta de dados. Esse problema pode ser analisado e modelado como um problema de alocação de tarefas para robôs (Multi-Robot Task Allocation (MRTA)). Para resolver esse problema propõe-se um framework baseado em técnicas de cobertura de conjuntos e em mecanismo de mercado baseado em leilão. Teste simulados são realizados e demonstram que a presente proposta cumpre o papel na alocação das tarefas aos robôs. Além disso, visando a aplicação da solução proposta é projetado e desenvolvido uma plataforma robótica aérea (quadrirotor) de baixo custo utilizando peças prototipadas. Para o controle de estabilidade dessa plataforma, propõe-se um modelo matemático de acordo com os parâmetros inerciais do quadrirotor. Esse quadrirotor é utilizado em diversas aplicações reais, mostrando que o projeto desenvolvido pode ser reproduzido e destinado a execução de tarefas reais, como por exemplo a coleta de dados na agricultura de precisão. / Brazil is a world reference in the production and export of citrus, although this crop can suffer several problems and losses of productivity for diverse reasons, as for example, pests. In order to reduce risks and losses, it is interesting to use automated monitoring systems, justifying the need to perform data collection to determine several factors. Certain plantations, such as citrus plantations, can not be monitored only via soil or only via aerial images, making it necessary to merge both approaches according to the parameter to be monitored. To perform this monitoring, robots with different abilities, such asunmanned aerial vehicle (UAV) and unmanned ground vehicle (UCV) should be used. Therefore, it is necessary to assign the tasks that each robot will perform and also to coordinate all the robots during the execution of the system as a whole, in order to optimize the process of data collection. The problem can be studied and modeled as a task allocation problem for robots (MRTA). To solve this problem we propose a framework based set covering techniques and auction-based market mechanism. Simulated tests are performed and demonstrate that the present proposal fulfills the role in assigning tasks to robots. In addition, aiming at the application of the proposed solution is designed and developed a low cost aerial robotic platform (quadrirotor) which use prototyped parts. This quadrirotor is used in several real applications, showing that the developed project can be reproduced and destined to perform real tasks, such as data collection in precision agriculture.

In the present work, the plasma repair for damaged ultra-low-k (ULK) materials, newly developed at the Fraunhofer ENAS, is studied with density functional theory (DFT) and molecular dynamic (MD) methods to obtain new insights into this repair mechanism. The ULK materials owe their low dielectric constant (k-value) to the insertion of k-value lowering methyl groups. During the manufacturing process, the ULK materials are damaged and their k-values increase due to the adsorbtion of hydroxyl groups (OH-damage) and hydrogen atoms (H-damage) that replaced themethyl groups. The first investigation point is the creation of repair fragments. For this purpose the silylation molecules bis(dimethylamino)-dimethylsilane (DMADMS) and octamethylcyclotetrasiloxane (OMCTS) are fragmented. Here, only fragmentation reactions that lead to repair fragments that contain one silicon atom and at least one methyl group were considered. It is shown that the repair fragments that contain three methyl groups are preferred, especially in a methyl rich atmosphere. The effectivity of the obtained repair fragments to cure an OH- and H-damage are investigated with two model systems. The first system consists of an assortment of small ULK-fragments, which is used to scan through the wide array of possible repair reactions. The second system is a silicon oxide cluster that investigates whether the presence of a cluster influences the reaction energies. In both model systems, repair fragments that contain three methyl groups or two oxygen atoms are found to be most effective. Finally, the quantum chemical results are compared to experimental findings to get deeper insight into the repair process.

Title: Preference Top-k Search Based on Multidimensional B-Tree Author: RNDr. Matúš Ondreička Department: Department of Software Engineering Faculty of Mathematics and Physics Charles University in Prague Supervisor: Prof. RNDr. Jaroslav Pokorný, CSc. Author's e-mail address: ondreicka@ksi.mff.cuni.cz Supervisor's e-mail address: pokorny@ksi.mff.cuni.cz Abstract: In this thesis, we focus on the top-k search according to user pref- erences by using B+ -trees and the multidimensional B-tree (MDB-tree). We use model of user preferences based on fuzzy functions, which enable us to search according to a non-monotone ranking function. We propose model of sorted list based on the B+ -tree, which enables Fagin's algorithms to search for the top-k objects according to a non-monotone ranking function. We apply this model in the Internet environment with data on different remote servers. Furthermore, we designed novel dynamic tree-based data structures, namely, MDB-tree composed of B+ -trees, MDB-tree with lists, MDB-tree with groups of B+ -trees and multiple-ordered MDB-tree. Concurrently, we have developed novel top-k algorithms, namely, the MD algorithm, the MXT algorithm and their variants which are able search for the top-k objects ac- cording to a non-monotone ranking function. These top-k algorithms are efficient...