Diante da atual situação da aprendizagem no país, nos capítulos que seguem desse trabalho, discutiremos que é possível mudarmos esse quadro através dos métodos de ensino. Abordamos especialmente a divisão, a multiplicação e as frações. Analisamos a evolução dos números desde sua origem até o atual padrão usado assim como as propriedades dos números inteiros, seguido da discussão de números racionais e congruências que permitem que a divisão e a multiplicação sejam operações usáveis e de fácil compreensão. Finalizamos nossas pesquisas com um capítulo voltado a atividades lúdicas que possam ser aproveitadas em projetos e laboratório de matemática. / Before present situation of the learning in the country, near chapter this work, discuss what is possible to chance this picture through teaching methods. Broach especially the division, multiplication, and the fraction. We analyze the evolution of the numbers since its origin until the present model used, like this how analysis the property in the whole numbers, followed, of the discussion of rational numbers and congruences what permit the division and the multiplication are operation usual and of easy understandable. We finished our research, with a chapter think the playful activities what own be take in project and laboratory of mathematics.

Aprender decorre da interpretação que cada pessoa faz do que está a sua volta e lhe emite signos. Este pressuposto norteou a construção deste texto, a partir de uma prática docente desenvolvida em duas turmas de estudantes do sexto ano do Ensino Fundamental, por meio da qual se propôs a elaboração do conceito de fração, levando-se em consideração diferentes contextos e significados para essa forma de representação dos números racionais. Os estudantes, em geral, apresentaram elementos indicadores de uma aprendizagem do conteúdo proposto, não concluída em termos de um acabamento conceitual, visto que a representação fracionária referente ao conceito de número racional é móvel, conforme seu contexto de significação. As constatações e percepções experimentadas nessa prática expressaram-se por meio de um fazer compartilhado entre os alunos, complementado por momentos de reflexão individual, e aqui são relatadas por meio da análise dos registros e produções realizadas. Enquanto professor-pesquisador, acompanhado de Deleuze, percebi-me como alguém, cujo fazer docente em um cotidiano de vivências de afetos e decifração de signos altera-se e me afeta de maneira contínua. / Learning derives from the interpretation that each person makes of what surrounds him or her and emits signs. This assumption guided the construction of this text, based on a teaching experience carried out in two classes of sixth grade elementary school students, through which the elaboration of the concept of fraction was proposed, taking into account the different contexts and meanings of this form of representation of rational numbers. In general, the students presented elements that indicate that they learned the proposed content, although not finished in terms of its conceptual completion, considering that the fractional representation of the concept of rational numbers is mobile, according to the context of its meaning. The findings and perceptions experienced in such a practice were expressed through a shared performance among the students, which was complemented by moments of individual reflection, and are reported here through the analysis of records and productions made. As a teacher-researcher, accompanied by Deleuze, I realized myself as a person continuously changed and affected by teaching in a daily life of affections and decipherment of signs.

Diante da atual situação da aprendizagem no país, nos capítulos que seguem desse trabalho, discutiremos que é possível mudarmos esse quadro através dos métodos de ensino. Abordamos especialmente a divisão, a multiplicação e as frações. Analisamos a evolução dos números desde sua origem até o atual padrão usado assim como as propriedades dos números inteiros, seguido da discussão de números racionais e congruências que permitem que a divisão e a multiplicação sejam operações usáveis e de fácil compreensão. Finalizamos nossas pesquisas com um capítulo voltado a atividades lúdicas que possam ser aproveitadas em projetos e laboratório de matemática. / Before present situation of the learning in the country, near chapter this work, discuss what is possible to chance this picture through teaching methods. Broach especially the division, multiplication, and the fraction. We analyze the evolution of the numbers since its origin until the present model used, like this how analysis the property in the whole numbers, followed, of the discussion of rational numbers and congruences what permit the division and the multiplication are operation usual and of easy understandable. We finished our research, with a chapter think the playful activities what own be take in project and laboratory of mathematics.

Dryland salinity is increasing in the upper catchments of central and northern New South Wales, Australia. Consequently, salts may be exported downstream, which could adversely affect cotton irrigated-farming systems. In order to assess the potential threat of salinity a simple salt balance model based on progressively saline water (i.e., ECiw 0.4, 1.5, 4.0 and 9.0 dS/m) was used to simulate the potential impact of salinisation due to the farming systems. The study was carried out in the lower Namoi valley of northern New South Wales, Australia. A comparison has been made of the various non-linear techniques (indicator kriging, multiple indicator kriging and disjunctive kriging) to determine an optimal simulation method for the risk assessment. The simulation results indicate that potential salinisation due to application of the water currently used for irrigation (ECiw) is minimal and may not pose any problems to sustainability of irrigated agriculture. The same results were obtained by simulation based on irrigation using slightly more saline water (ECiw 1.4 dS/m). However, simulations based on irrigation using water of even lower quality (ECiw of 4 and 9.0 dS/m), shows potential high salinisation, which will require management inputs for sustainable cropping systems, especially legumes and wheat, which are used extensively in rotation with cotton. Disjunctive kriging was the best simulation method, as it produced fewer misclassifications in comparison with multiple-indicator kriging and indicator kriging. This study thus demonstrates that we can predict the salinity risk due to application of irrigation water of lower quality than that of the current water used. In addition, the results suggest here problems of excessive deep drainage and inefficient use of water might be a problem. The second part of this thesis deals with soil information required at the field scale for management practices particularly in areas where deep drainage is large. Unfortunately, traditional methods of soil inventory at the field level involve the design and adoption of sampling regimes and laboratory analysis that are time-consuming and costly. Because of this more often than not only limited data are collected. In areas where soil salinity is prevalent, detailed quantitative information for determining its cause is required to prescribe management solutions. This part deals with the description of a Mobile Electromagnetic Sensing System (MESS) and its application in an irrigated-cotton field suspected of exhibiting soil salinity. The field is within the study area of part one of this thesis-located about 2 km south west of Wee Waa. The EM38 and EM31 (ECa) data provide information, which was used in deciding where soil sample sites could be located in the field. The ECa data measured by the EM38 instrument was highly correlated with the effective cation exchange capacity. This relationship can be explained by soil mineralogy. Using different soil chemical properties (i.e. ESP and Ca/Mg ratio) a detailed transect study was undertaken to measure soil salinity adjoining the water storage. It is concluded that the most appropriate management option to remediation of the problem would be to excavate the soil directly beneath the storage floor where leakage is suspected. It is recommended that the dam not be enlarged from its current size owing to the unfavourable soil mineralogy (i.e. kaolin/illite) located in the area where it is located.

Le cadre général de cette thèse est d'obtenir une meilleure compréhension des écoulements géophysiques comme les glissements de terrains. Dans tous ces évènements, on sait que le couplage entre milieu granulaire et fluide interstitiel joue un rôle important. Lors du démarrage, la présence d'eau influe sur la déformation des sols; ainsi, des sols initialement différents se comportent différemment. Cette thèse présente une expérience et un modèle mettant en évidence les phénomènes physiques lors du déclenchement des avalanches immergées. Notamment, la dynamique de l'avalanche dépend fortement de la fraction volumique de l'empilement initial, le déclenchement étant fortement retardé lors d'une légère compaction initiale.

<p>This thesis is performed at Saab Bofors Dynamics in Karlskoga and investigates a technique for ranging with laser pulses. The investigated technique is called Constant Fraction Detection (CFD). Described briefly, the received laser pulse is split into two equal parts, where one part is delayed half the pulse width and inverted. This signal is added to the original pulse. The resulting curve has the shape of a laying S and the detection of the zero level is used to stop the time measurement. The time measurement will be independent of the incoming signal’s amplitude. The CFD technique has the advantage of collecting accurate data for each send pulse, which results in an ability to collect values of measurement with a high frequency. The theses investigates a measurement frequency of 10 kHz that will give an opportunity to implement a scanning function with the possibility to, for example, reproduce a ground structure from a flying object. </p><p>The theses include both digital and analog electronics, which makes it a complex design task. The detector was constructed using analog circuits, from the signal processing of the incoming reflected pulse to the generation of a voltage level as a representation of the distance. The analog part is controlled by digital signals generated by a FPGA, which also performs calculations to convert the voltage level into a distance displayed on a LCD. </p><p>A large part of the work was dedicated to designing a layout and constructing a surface mounted printed circuit board (PCB) and therefor the report treats the whole development process, from technical requirement to construction and verification of a prototype. </p><p>The conclusion states that the CFD technique is a suitable technique for ranging with demands on fast collection of data. The prototype has sufficient accuracy at constant amplitude and was at the time of presentation shown as a prototype for demonstration. The independence of amplitude on the incoming signal was never accomplished and the reason for this is stated in the report. However, further development should solve the problem.</p>

Knowledge of the two-phase flow state is fundamental for two-phase flow system design and operation. In traditional two-phase flow studies, the flow regime refers to the physical location of the gas and liquid in a conduit. Flow configuration is important for engineering correlations of heat and mass transfer, pressure drop, and wall shear. However, it is somewhat subjective since it is mostly defined by experimental observation, resulting in an approximate and equivocal definition. Thus, there is need for a better, objective flow regime identification. The void fraction is a key parameter in monitoring the operating state of a two-phase system and several tools have been developed in order to measure it. The purpose of this study is to use the void fraction and other parameters of the system to achieve a model for flow pattern identification. Recently, an experimental program using the Foster-Miller two-phase flow test bed and Creare Inc. capacitance void fraction sensors was conducted in the microgravity environment of the NASA KC-135 aircraft. Several data types were taken for each phase, such as flow rate, superficial velocity, density and transient void fraction at 100Hz. Several analytical approaches were pursued, including a statistical approach of the fluctuation of the void fraction, Martinelli analysis, and Drift Flux analysis, in order to reach a model for flow pattern identification in microgravity conditions. Several parameters were found to be good flow pattern identifiers such as the statistical moments variance and skewness, Signal -to- noise ratio (SNR), Half Height Value (HHV) and Linear Area Difference (LAD). Moreover, relevant conclusions were achieved using the Martinelli parameter and the Drift Flux model in microgravity conditions. These results were compared with the basic literature.

Bubbles are often present in the natural ocean. Bubbly liquid will have the significant influence the sound propagation, and creates a significant disturbance to under water target's detection. Therefore, it is an important research subject of bubble influence to the sound wave propagation. This study used the sonar training system which developed by British's iTP corporation, through suitable additional design discuss the attenuation of sound propagating through a bubble screen. At first this study collects and infers the formula by the literature review. Secondly, the experimental design of measuring the attenuation of sound wave. The experiment process by using two parallel iron boards to carry on the measurement of gas-volume fraction. Then correlate with the sound pressure from the measurement of hydrophone. After curve fitting, we can clearly know the each other correlation. Finally taking the result compare with the attenuation coefficient formula. The experimental consists of two parts. The first part is to measure the gas-volume fraction of the bubbly liquid contained in the screen; while the second part is to measure the sound attenuation of the bubble screen. The result display that the bubble screen can attenuate about 8 dB per centimeter as the gas-volume fraction stay at 1 percent. At high gas-volume fraction the coefficient of attenuation has increased, and is different from theoretical value. This is because the bubble's correlation has not been considered. In addition, the low frequency sound wave is close to theoretical value, but the high frequency sound wave has big different to theoretical value. Because the high frequency sound wave's wavelength is too small to satisfy the condition. At experiment I suggest to use more appropriate transducers and precise bubble's tube. Thus the experimental result will be better.

The progressing cavity pump is a type of positive displacement pump that is capable of moving nearly any fluid. This type of pump transports fluids in a series of discrete cavities formed by the helical geometries of its rigid rotor and elastomeric stator. With appropriate materials for the rotor and stator, this pump can move combinations of liquids, suspended solids, and gasses equally well. Because of its versatility, the progressing cavity pump is widely used in the oil industry to transport mixtures of oil, water, and sediment; this investigation was prompted by a desire to extend the use of progressing cavity pumps to wet gas pumping applications. One of the progressing cavity pump's limitations is that the friction between the rotor and stator can generate enough heat to damage the rotor if the pump is not lubricated and cooled by the process fluid. Conventional wisdom dictates that this type of pump will overheat if it pumps only gas, with no liquid in the process fluid. If a progressing cavity pump is used to boost the output from a wet gas well, it could potentially be damaged if the well's output is too dry for an extended period of time. This project seeks to determine how a progressing cavity pump behaves when operating at gas volume fractions between 0.90 and 0.98. A progressing cavity pump manufactured by seepex, model no. BN 130-12, is tested at half and full speed using air-water mixtures with gas volume fractions of 0.90, 0.92, 0.94, 0.96, and 0.98. The pump's inlet and outlet conditions are controlled to produce suction pressures of 15, 30, and 45 psi and outlet pressures 0, 30, 60, 90, 120, and 150 psi higher than the inlet pressure. A series of thermocouples, pressure transducers, and turbine flow meters measures the pump's inlet and outlet conditions, the flow rates of water and air entering the pump, and pressures and temperatures at four positions within the pump's stator. Over all test conditions, the maximum recorded temperature of the pump stator did not exceed the maximum safe rubber temperature specified by the manufacturer. The pump’s flow rate is independent of both the fluid's gas volume fraction and the pressure difference across the pump, but it increases slightly with the pump's suction pressure. The pump's mechanical load, however, is dependent only on the pressure difference across the pump and increases linearly with that parameter. Pressure measurements within the stator demonstrated that the leakage between the pump's cavities increases with the fluids gas volume fraction, indicating that liquid inside the pump improves its sealing capability. However, those same measurements failed to detect any appreciable leakage between the two pressure taps nearest the pump's inlet. This last observation suggests that the pump could be shortened by as much as 25 percent without losing any performance in the range of tested conditions; shortening the pump should increase its efficiency by decreasing its frictional mechanical load.

The oil sands, located in north-eastern Alberta, are one of the largest deposits of oil worldwide. Because the Alberta Environmental Protection and Enhancement Act prohibits the release of oil sands process-affected material into the environment, industry is storing vast quantities of tailings on mine lease sites. The oil sands industry is currently accumulating tailings waste at a rate of >105 m3/day, for which reclamation strategies are being investigated. Naphthenic acids (NAs) have been identified as the most toxic component of oil sands tailings as they are considered acutely toxic to a variety of biota, and are therefore a target contaminant for tailings pond reclamation strategies. Current literature based on Microtox® assays (marine bacteria Vibrio fischeri) suggests that lower molecular weight NAs are more toxic than higher molecular weight NAs. The following thesis involves the utilization of NA fractions and their relative toxicities to determine if NA toxicity is related to NA molecular weight. A previous study generated an oil sands-derived naphthenic acid extract (NAE), which was fractionated by distillation at stepped temperatures, yielding five fractions with increasing median molecular weights (Daltons). In the present study, the same extract and five fractions were utilized. To expand on the earlier characterization which involved a low resolution electrospray ionization mass spectrometry (ESI-MS), the whole extract and five fractions were analysed using electrospray ionization high-resolution mass spectrometry (ESI-HRMS) and synchronous fluorescence spectroscopy (SFS). Mean molecular weights were generated for each fraction, and an increase in molecular weight with increasing fraction number was confirmed. Respective mean Daltons and relative proportions for each fraction are as follows: 237 and 11.9 % (fraction 1), 240 and 32.3% (fraction 2), 257 and 33.4% (fraction 3), 308 and 16.8% (fraction 4), and 355 and 5.6% (fraction 5). When chemical analyses of fractions were compared, it was determined that structures contributing to increased molecular weight included increased cyclic structures (up to 7-ring structures), aromaticity (mono- and diaromatics), nitrogen, sulfur, and oxygen heteroatoms, and dihydroxy/dicarboxy compounds. In addition, characterization data suggested the presence of NAs exhibiting estrogenic structures. Following chemical characterization, NA fractions were subject to embryo/larval bioassays using two fish species: Oryzias latipes (Japanese medaka) and Pimephales promelas (fathead minnow). Endpoints evaluated were mortality, time to hatch, hatch length, and abnormalities. Results suggest that relative NA fraction toxicity is not related to molecular weight, as no trend relating mean Dalton weight to toxicity was observed for any endpoint in both species. Acute toxicity data indicated differences between fractions as high as 2-fold, although results were species-dependent. Fraction 1 displayed the lowest potency (highest LC50) for both Japanese medaka (0.291 mM) and fathead minnow (0.159 mM). Fractions 3 and 2 for Japanese medaka (0.149 and 0.157 mM, respectively), and fractions 5 and 2 for fathead minnow (0.061 and 0.080 mM, respectively) displayed the greatest potencies for mortality (lowest LC50). When fraction LC50s for Japanese medaka were compared to the whole NAE (0.143 mM), the mid molecular weight fractions (fractions 2 and 3) appeared most similar to the whole NA. . In terms of relative toxicity and proportion, constituents in the mid molecular range fractions (2 and 3) likely represent greater risk compared to other fractions, and further chemical and toxicological characterization of constituents within these fractions is warranted particularly for long-chained, monocarboxylic acids, with low aromaticity. Japanese medaka and fathead minnow varied in their sensitivity and their relative response to different fractions. In general, fathead minnow were more sensitive than Japanese medaka based on lower estimates of LC50 and threshold (growth) values in addition to the presence of developmental abnormalities (predominately yolk sac edema) associated with a few of the fractions. Compared to differences in toxicity between fractions for a given species (>2-fold for fathead minnow), there was more variability between species for a given fraction (> 3-fold for fraction 5). Also, the relative toxicity of fractions as indicated in the present study is contrary to the results generated using Vibrio fischeri for the same fractions. Thus, there is a need for multi- endpoint and species toxicity evaluations to assess the efficacy of remediation and reclamation options for reducing toxicity of oil sands tailings.