Thèses sur le sujet « Weir »

This thesis is devoted to the study and designs of two important proportional weirs having the discharge-head characteristics of Q α H 2/3 In the first design a geometrically simple weir in the form of a rectangular weir over a inverted V-notch (Chimney weir) is presented. This weir gives for all flows above a threshold depth a discharge proportional to H 2/3 within a maximum percentage error of ±1.5, (measured above a reference plane) within certain limits of head. Second design is concerned with the self-basing weir in which a portion of the weir above the crest acts as a base. This design is achieved by using the complementary weir profile of a Quadratic weir above the parabolic base which has the significant property of fast convergence. This weir gives discharge for all flows above the threshold depth, proportional to (head)2/3 measured above a reference plane, with increasing accuracy as head increases. Experiments with these two weirs confirm the theory by giving a constant average Coefficient of Discharge (Cd) of 0.62. The importance of these weirs as a sensitive discharge measuring device in field and laboratory is highlighted.

This thesis is devoted to the study and designs of two important proportional weirs having the discharge-head characteristics of Q α H 2/3 In the first design a geometrically simple weir in the form of a rectangular weir over a inverted V-notch (Chimney weir) is presented. This weir gives for all flows above a threshold depth a discharge proportional to H 2/3 within a maximum percentage error of ±1.5, (measured above a reference plane) within certain limits of head. Second design is concerned with the self-basing weir in which a portion of the weir above the crest acts as a base. This design is achieved by using the complementary weir profile of a Quadratic weir above the parabolic base which has the significant property of fast convergence. This weir gives discharge for all flows above the threshold depth, proportional to (head)2/3 measured above a reference plane, with increasing accuracy as head increases. Experiments with these two weirs confirm the theory by giving a constant average Coefficient of Discharge (Cd) of 0.62. The importance of these weirs as a sensitive discharge measuring device in field and laboratory is highlighted.

<p>A hydraulically undersized control structure could result in water overtopping a dam or channel banks. To increase hydraulic capacity and reduce flooding risk, nonlinear spillways are frequently replacing linear weirs. This study investigates four subjects to further knowledge for two types of nonlinear weir, the piano key and labyrinth. Weir submergence is a condition when the downstream water level of a weir exceeds the weir crest elevation, and can influence the head-discharge relationship of the structure. The effects of submergence on laboratory-scale piano key weir head-discharge relationships were evaluated experimentally and compared to published submergence data for linear and labyrinth weirs. For relatively low levels of submergence, the piano key weir requires less upstream head relative to the labyrinth weir (<6%). This increase in efficiency was reversed at higher levels. Staged labyrinth weirs feature multiple weir segments with different crest elevations, which confine base flows and/or satisfy downstream discharge requirements. Head-discharge relationships for various laboratory-scale staged labyrinth weir configurations were established. The accuracy of a head-discharge predictive technique based upon superposition and traditional labyrinth weir empirical data was evaluated, and found to be generally within ?5%. The influence of linear, labyrinth, and staged labyrinth weir head-discharge characteristics on the outflow hydrograph behavior was evaluated by numerically routing various flood discharges through a fictitious reservoir; peak outflow, maximum water surface elevation, and required detention volume data are presented for each weir alternative. A staged labyrinth weir can be an effective alternative for decreasing the peak outflow hydrograph for frequent events, while increasing discharge for higher return period storm events. Approach flow perpendicular to the labyrinth weir centerline axis may not be possible in all situations. The head-discharge characteristics of a laboratory-scale labyrinth weir were evaluated with three different approach flow angles (0?, 15?, and 45?). For approach flow angles up to 15?, no measurable loss in discharge efficiency occurred. The discharge efficiency reduced as much as 11% for the 45? approach angle case. While all data presented are specific to the weir configurations and geometries tested, these data can be beneficial to the general understanding of nonlinear weirs.

Thesis (MEng)--Stellenbosch University, 2015.<br>ENGLISH ABSTRACT: General objective of the study This thesis aims to evaluate the hydraulics of an inflatable weir in its fully inflated position to the almost fully deflated position using different diameter circular weirs with varying discharges, by considering the change in the weir radius and the dynamic pressures on the weir. In the evaluation, three cylindrical weirs were installed in a 2m wide flume and tested over various discharges. Methodology The three weirs, one with a 300mm diameter, another with a 250mm diameter, and the last one with a 100mm diameter, were used to determine the effects of over flow water on the weir as seen in the different stages of the normal operation of an inflatable weir. Simulation involved measurement of the upstream and downstream water levels with the weir height involved at stable over flow conditions. Measurement of pressure variations was done on the weir faces with different water inflow rates to the test flume with three pressure sensors installed on each weir at 0°, 11.25° and 22.5° from the crest to the downstream. Additionally a single 0.15m radius weir was tested for pressures 67.5°, 78.75° and 90° from weir crest. Water level variation on the downstream of the weir was created by means of a variable tail gate to observe its effects. Results of the investigation The effects of upstream arches, stage, radius of curvature, discharge, pressure, energy losses over the weir and the downstream hydraulic jump were investigated in the inflation and deflation of the inflatable weir. The findings were as follows: ►Based on literature by Chanson and Montes (1998), Shabanlou et al. (2013), Schmockeret al. (2011) and Bahzad et al. (2010), upstream arches have insignificant influence onthe performance of the inflatable weir. There is rather reduced afflux due to the shape ofthe upstream of the weir from the Bernoulli’s equation. This shape of the upstream of theweir also contributes to the transport of sediments Gebhardt et al. (2012). ►Investigation of the discharge coefficient and factors influencing showed that: oAs the weir radius is reduced during the deflation, the unit discharge over each weirincreased with increase in head above the crest. oDischarge coefficient of the inflatable weir increases with the increase in head aboveweir crest, and the discharge coefficient is inversely proportional to the radius ofcurvature of the weir. ►Investigation of pressures on the downstream face of the weir models showed that: oThe negative (suction) pressure acting on the downstream face of the weir becomesincreasingly negative with increase in H/R values. oPoint of separation of nappe was seen with pulsations of pressure of the recordpressure. Generally, energy dissipation over the weir decreases with the decrease in the weir radius and the jump is more stable with the smallest circular weir and can be more accurately determined in the case of a small weir. Conclusions and Recommendations The inflatable weir has a high discharge at its fully inflated position. Its hydraulic performance is largely influenced by inflow head and is inversely proportional to the radius of curvature. Nappe pulsation as seen in the nappe vibrations can cause the vibration of weir. Future research on inflatable weirs should aim to monitor the negative pressure on measuring pressures further down the face of the weir because larger negative pressures are expected to develop after 90˚ as with this study.

A hydraulically undersized control structure could result in water overtopping a dam or channel banks. To increase hydraulic capacity and reduce flooding risk, nonlinear spillways are frequently replacing linear weirs. This study investigates four subjects to further knowledge for two types of nonlinear weir, the piano key and labyrinth. Weir submergence is a condition when the downstream water level of a weir exceeds the weir crest elevation, and can influence the head-discharge relationship of the structure. The effects of submergence on laboratory-scale piano key weir head-discharge relationships were evaluated experimentally and compared to published submergence data for linear and labyrinth weirs. For relatively low levels of submergence, the piano key weir requires less upstream head relative to the labyrinth weir (<6%). This increase in efficiency was reversed at higher levels. Staged labyrinth weirs feature multiple weir segments with different crest elevations, which confine base flows and/or satisfy downstream discharge requirements. Head-discharge relationships for various laboratory-scale staged labyrinth weir configurations were established. The accuracy of a head-discharge predictive technique based upon superposition and traditional labyrinth weir empirical data was evaluated, and found to be generally within ±5%. The influence of linear, labyrinth, and staged labyrinth weir head-discharge characteristics on the outflow hydrograph behavior was evaluated by numerically routing various flood discharges through a fictitious reservoir; peak outflow, maximum water surface elevation, and required detention volume data are presented for each weir alternative. A staged labyrinth weir can be an effective alternative for decreasing the peak outflow hydrograph for frequent events, while increasing discharge for higher return period storm events. Approach flow perpendicular to the labyrinth weir centerline axis may not be possible in all situations. The head-discharge characteristics of a laboratory-scale labyrinth weir were evaluated with three different approach flow angles (0°, 15°, and 45°). For approach flow angles up to 15°, no measurable loss in discharge efficiency occurred. The discharge efficiency reduced as much as 11% for the 45° approach angle case. While all data presented are specific to the weir configurations and geometries tested, these data can be beneficial to the general understanding of nonlinear weirs.

A piano key (PK) weir is a type of nonlinear (labyrinth-type) weir developed specifically for free-surface flow control structures with relatively small spillway footprints. Currently, no generally accepted standard PK weir design procedure is available. This is due, in part, to the large number of geometric parameters and a limited understanding of their effects on discharge efficiency (discharge efficiency is quantified by the discharge coefficient of the standard weir equation). However, Hydrocoop, a non-profit French dam spillways association, has recommended a PK weir design and a head-discharge relationship specific to that geometry. To develop a better understanding of the effects of PK weir geometry on discharge efficiency, 13 laboratory-scale, 4-cycle PK and rectangular labyrinth weir configurations were tested. As a result, the influence of the following PK weir geometries and/or modifications on discharge efficiency were partially isolated: the inlet-to-outlet key width ratio, upstream, and downstream apex overhangs; sloped floors; raising the crest elevation via a parapet wall; fillets underneath the upstream overhangs; and the crest type. The physical model test matrix also included a PK weir configuration consistent with the Hydrocoop-recommended design. From the experimental results, the appropriateness of the Hydrocoop-recommended head-discharge relationship was evaluated, along with the discharge coefficient behavior associated with the standard weir equation. Finally, trapezoidal labyrinth weirs were compared to PK weirs to make a relative comparison of nonlinear weir discharge efficiency; comparisons were made considering crest length and structure footprint.

If humanity is to make the best of this planet then it is crucial that we develop the capacity to implement the most effective environmental management practices. Essential is a holistic approach to management, as is advocated by integrated catchment management (ICM), which proposes that catchment management issues will be best dealt with when interventions are planned together at the catchment scale and all stakeholder interests are given consideration during decision making. The issue of weir modification is a good example of a problem that would benefit from these principles. Many stakeholder interests are affected by weir modification, and if effective and fair weir modification decisions are to be made, all must be used to evaluate alternative weir modification options. So that decision makers can make the most of the synergies and avoid the conflicts that can occur between interventions, they need to know how multiple weir modifications interact. To do this decision makers must be able to manage and utilise a large amount of information and use it to help them make effective decisions. The objective of the research presented in this thesis is to develop an approach to the management of weirs in the Don Catchment that is holistic both a spatial sense and in terms of the assessment of alternative management options. An evaluatory framework for weir modifications is formulated by adapting published typologies of river ecosystem services (ESs). The prediction of how catchment interventions affect sociocultural ESs is recognized as a particularly challenging to the application of this framework because their qualitative and subjective nature makes them hard to predict. Bayesian Networks (BNs) are identified as a potential solution as they use probabilities to describe the relationships between variables. A BN was built to predict how weir modification affected weir danger and weir fun for canoeists by utilising the knowledge of canoeing groups. It is concluded that despite a number of caveats, BNs offer a potentially important method for allowing sociocultural ESs to be predicted in decision making processes. The consideration ofthe complex interdependencies multiple weir modifications can have is recognised as another of the challenges facing weir management decision making. A spatially explicit modelling approach is developed that can account for the interactive effect multiple weir modifications have on river connectivity for several river species in the Don Catchment. Expert judgement and hydrological modelling are used to discriminate between different levels of habitat quality for European eel (Anguilla anguilla) and Atlantic salmon (Safrna safar). Several strategies to increase connectivity in the Don Catchment were explored. It was found that each had its own set of winners and losers, indicating trade-offs between species need to be considered when planning connectivity enhancements. The modelling approach shows the interdependent effects of weir modifications are vet: important in determining habitat accessibility, particularly the cumulative effect of multiple fish passes.

Thesis (MScEng)--Stellenbosch University, 2014.<br>ENGLISH ABSTRACT: The use of computational fluid dynamics (CFD) as a design tool is becoming increasingly popular in the water resources field. This thesis aims to extend the knowledge of CFD and determine the usefulness of current CFD programs as a modelling tool. This thesis also seeks to determine the accuracy of CFD modelling when compared to physical modelling, the more established form of model testing. It is important that research is conducted on the validation of CFD because with an increase in computer power, processing speed and continual development in the programs used to generate the models, CFD could become an essential tool for the hydraulic engineer. A current key difficulty faced by CFD programs is the mapping of the free surface level of a body of fluid in a two-phase (water and air) flow condition. This is further complicated by the existence of three-dimensional flow over a labyrinth weir and a fluctuating nappe, which at times requires a free surface level to be mapped both above and below the nappe. This thesis begins by detailing the design methods and actual design of a typical labyrinth weir. It then describes the construction of a 1:20 scale physical model, testing procedures, goals, and the results of the physical model tests. Following the physical model study, the thesis discusses the development of a three-dimensional CFD model, designed in a way that matched the physical model. Simulation results obtained from the CFD model are then compared to those from the physical model study and the accuracy and suitability of CFD modelling as a design tool are evaluated. This evaluation considers the surcharge upstream of the weir and transient pressures on the weir. The thesis concludes with recommendations for further research in this field. The results achieved show that the CFD model was able to accurately map the movement of particles within the domain, to fully develop a flow profile, and to accurately predict the water surface level. The pressure readings obtained during CFD modelling were in the same order as those obtained during physical modelling. However, the CFD modelling pressure readings did not often accurately correspond with the physical modelling data, with the average error being 92%. These results indicate that there is still further development required in CFD before it can be relied upon as a design tool independent of other experimental methods. The difficulty and the length of time taken to generate the results also indicate that, at this stage and in this particular scenario, the engineer would be better served through the use of a physical model.<br>AFRIKAANSE OPSOMMING: Die gebruik van gerekenariseerde vloeidinamika (CFD) as ’n ontwerpinstrument het toenemend gewild begin raak op die gebied van waterhulpbronne. Die doel van hierdie verslag is om kennis van CFD uit te brei en die nut van huidige CFD-programme as ’n modelleringsinstrument te bepaal. Daar word voorts ook gepoog om die akkuraatheid van CFD-modellering te bepaal in vergelyking met fisiese modellering – die meer gevestigde vorm van modeltoetsing. Dit is noodsaaklik dat navorsing gedoen word oor die bekragtiging van CFD, want met ’n toename in rekenaarkrag, verwerkingsnelheid en deurlopende ontwikkeling in die programme wat gebruik word om die modelle te genereer, sal CFD ’n noodsaaklike instrument vir die hidroulika-ingenieur word. ’n Belangrike probleem wat CFD-programme tans inhou, is die kartering van die vry oppervlak van ’n liggaam vloeistof in ’n tweefasse vloeitoestand (water en lug). Dit word verder bemoeilik deur die bestaan van driedimensionele vloei oor ’n labirint-stuwal en ’n skommelende “nappe”, wat by tye vereis dat ’n vry oppervlak sowel bo as onder die “nappe” gekarteer met word. Die verslag begin met ’n uiteensetting van die ontwerpmetodes en fisiese ontwerp van ’n tipiese labirintstuwal. Die bou van ’n 1:20-skaal- fisiese model, toetsprosedures, doelwitte en die resultate van die toetse op die fisiese model word dan beskryf. Ná die studie van die fisiese model, word die ontwikkeling van ’n driedimensionele CFD-model bespreek, wat ontwerp is om by die fisiese model te pas. Die simulasie-resultate van die CFD-model word dan vergelyk met dié van die studie van die fisiese model en die akkuraatheid en geskiktheid van CFD-modellering as ’n ontwerpinstrument word geëvalueer. In hierdie evaluering word die opdamming stroomop van die stuwal en druk op die stuwal ondersoek. Die verslag word afgesluit met aanbevelings vir verdere navorsing op hierdie gebied. Die resultate toon dat die CFD-model die beweging van partikels in die domein akkuraat kon karteer ten einde ’n volledige vloeiprofiel te ontwikkel en die watervlak akkuraat te voorspel. Die drukke wat tydens CFD-modellering verkry is, stem egter nie ooreen met die lesings wat tydens fisiese modellering verkry is nie. Die gemiddelde fout is 92%. Hierdie resultate toon dat verdere ontwikkeling in CFD nodig is voordat daarop staat gemaak kan word as ’n ontwerpinstrument wat onafhanklik van ander eksperimentele metodes gebruik kan word. Die moeilikheidsgraad en die lang tydsduur betrokke by die generering van resultate is ook ’n aanduiding dat die gebruik van ’n fisiese model die ingenieur op hierdie stadium en in hierdie spesifieke scenario beter tot diens sal wees.

Experimental physical model studies of hydraulic structures are often conducted to replicate flow behavior that may occur at the prototype scale. Geometric similitude is most often maintained between the prototype and model when studying reservoir and open channel hydraulic structures to account for the dominant gravity and inertia forces while other fluid forces (e.g., viscosity,surface tension) are assumed negligible. However, as model size and/or upstream head decreases, other fluid forces can exceed the negligible level and influence model flow behavior. This phenomenon is referred to as size-scale effects and is one potential origin of error in predicting the prototype behavior through testing geometrically similar models. To extend the existing research of size-scale effects on nonlinear weirs half-and quarter-round trapezoidal labyrinth weirs and piano key weirs were fabricated at length ratios of 1, 2, 3, 6, and 12. The largest weir model for each weir type (i.e., a weir height of 36 in for labyrinth weir models and a weir height of 33 in for piano key weir models) served as the corresponding prototype.Weir models were hydraulically tested to assess differences among head-discharge relationships and flow behavior. Limiting criteria were recommended to avoid size-scale effects depending on the weir type and model size. The results of this study will help hydraulic modelers determine what limiting criteria should be met to avoid size-scale effects.

Linear weirs are a common hydraulic structure that have been used for centuries with many different applications. One characteristic of weirs that is particularly useful is the head-discharge relationship where the discharge over the weir is directly related to the upstream water depth above the crest. In general, the head-discharge relationship for a weir is determined experimentally in laboratories using geometrically similar models. Due to space, time, money, and discharge capacity limitations at water laboratories, creating full scale models is not always a feasible option when determining head-discharge relationships for large prototype weirs. It is typically more cost effective to create a scale model than to build a full scale model or conduct tests on the prototype. Because of this fact, physical modeling has been one the most important tools in determining head-discharge relationships for weirs. However, as the physical size of the model decreases, size scale effects associated with surface tension and viscosity forces can significantly affect the results from the physical model and cause the results to differ from what would actually occur at the prototype scale. Therefore, it is important to understand what affects surface tension and viscosity forces have on the head-discharge relationship for different size weirs and when those effects are no longer negligible. The purpose of this research was to evaluate size scale effects for linear weirs. Weirs models of three different crest shapes (flat-top, quarter-round, and half-round) were constructed and tested at four different geometrically similar sizes [weir heights (P) = 24-, 12-, 6-, and 3-in]. This was done in order to evaluate how size scale effects affect the head-discharge relationship as model size decreases for different crest shapes. Discharge coefficients were calculated for relative upstream head values ranging from 0.01 ≤ Ht/P ≤ 2.0 for vented and non-vented conditions. Nappe aeration behavior was documented and compared to determine where differences in the nappe trajectory occurred as a result of scale effects. Comparisons were made with data from others researchers to determine if the recommendations for minimum head limits were similar to the results from this study. This study examined the errors in the discharge coefficient associated with size scale effects and suggested limits to avoidance depending on model scale and crest shape.

This thesis describes a short study to examine the behaviour of submerged flow over a thin plate weir with differing upstream and downstream bed levels i.e. an unequal bed weir as opposed to an equal bed weir where the upstream and downstream beds are at the same level. As submerged weir flow is a function of downstream conditions, it was thought that a lower downstream bed would make submerged flow over the weir easier, This is turn suggested that; The shape of the upstream head (Hu) vs downstream head (Hd) graph would change, being initially more steep in the unequal bed case. The Froude Number of the approaching flow would be lower for the unequal bed weir than for an equal bed weir at the same submergence. Using one of the existing submerged flow formula would lead to an erroneous calculated value. A series of measurements was done on two model weirs of different sizes subject to successive levels of submergence. Analysis of the readings of upstream and downstream heads indicated that the difference in bed levels was significant and the three effects above were noted. The work also suggested a new form of equation to calculate flow over a submerged weir. This was looked at briefly.

Thesis (S.M.)--Massachusetts Institute of Technology, Computation for Design and Optimization Program, 2008.<br>Includes bibliographical references (p. 127-130).<br>BioMEM microfluidic weirs enable biologists to study biological processes at the cell level. A novel substrate-affixed microfluidic array of weirs allows active sorting of cells via control electrodes. The ability of the weirs to retain cells hydrodynamically is vital to the functionality of the substrate-affixed array of weirs. The objective of this thesis is to give insight using numeric tools to the microfluidic weir designer on how to improve the ability of the microfluidic weir to retain cells. Simulations of the interactions between the cell and the weir were performed using a computer simulation of Stokes flow. The computational approach uses a pre-corrected Fast Fourier Transform Boundary Element Method to evaluate the drag forces acting on the cell and a rigid body physics library to handle rigid body collision dynamics between the cell and the weir. This model was used to address two research questions which are the two main discussions of the thesis. The first discussion studies in detail the mechanisms behind the 'Around The Side' (ATS) and 'Over The Top' (OTT) modes of escape that were observed experimentally. A model example was studied for each mode. The forces and torques experienced by the cell when it escaped through either mode are explained in detail. Each mode was segmented into time periods and the mechanisms behind these modes of escape were discussed to give insight to the microfluidic weir designer. The second discussion focuses on design space exploration and optimization of the ability of the microfluidic weir to retain the cell. In order to make design optimization computationally tractable a surrogate is derived; that is, a model that provides an accurate approximation to the input/output map of the simulation but that is much cheaper computationally to evaluate.<br>(cont.) The surrogate was built using the Support Vector Machine (SVM) algorithm and was then used for the design space exploration and optimization. The weir geometry and flow rate were used as design variables to maximize the ability of the microfluidic weir to retain cells in the design optimization problem. Results from the design space exploration and optimization showed that a minimal depth of the mouth of the weir is required for the weir to be able to retain any beads. However, the ability of the weir to retain beads is more sensitive to the width of the mouth than the depth.<br>by Boon Hooi Ooi.<br>S.M.

Dams and weirs are widely implicated in large-scale declines in both the range and abundance of aquatic fauna. Although many factors are involved, such declines are commonly attributed to the prevention or reduction of migration, reductions in available habitat, alteration of natural flow regimes and changes to physicochemical characteristics. In Australia, studies into the ecological effects of these impacts are limited, and have concentrated mainly on species of recreational and commercial importance. Subsequently, the adverse effects of dams and weirs, and suitable methods of mitigation, remain largely unknown for many other taxa. Therefore, the major aim of this thesis is to investigate the ecological effects of dam and weir construction on previously unstudied migratory assemblages of fish and macroinvertebrates in the Murray-Darling Basin. It is anticipated that the results of these studies will feed back into improved management strategies that help arrest the previously observed declines of aquatic fauna. Initially, fish communities were sampled, by boat electrofishing, from both reference sites and downstream of Balranald and Redbank weirs on the lower reaches of the Murrumbidgee River, Australia. Sampling was stratified over large spatial and temporal scales to gain a comprehensive understanding of species most affected by the presence of these two barriers. In general, the weirs obstructed fish migrations during summer and autumn and many species of small-bodied fish such as Australian smelt, western carp gudgeon, fly-specked hardyhead and crimson-spotted rainbowfish accumulated downstream of Balranald Weir. In addition, downstream accumulations of juveniles of larger-bodied species such as bony herring, common carp and goldfish were also detected. Although many previous studies had either documented or hypothesised that upstream migrating fish accumulate downstream of migration barriers, none attempted to quantify the size of such populations. Therefore, a simple but efficient method to estimate the size of migratory populations was assessed at the Balranald Weir site. The application of two commonly used estimation techniques yielded relatively reliable results for seven species that accumulated downstream of the weir. Population size estimates were greatest for most species during summer and autumn, where accumulations as high as 800 fish per day were detected. The largest calculated population size estimates, in addition to the greatest temporal variation, of any individual species was observed in bony herring. Given the simplicity of the technique and the relative accuracy of population estimates, it was concluded that these methods could easily be applied to other weirs where the size of migratory populations is of particular interest. A study investigating the effects of Yanco Weir on the diets of three migratory percichthyid species, Murray cod, trout cod and golden perch was also conducted. Observed spatial variation in a number of trophic processes strongly implicated Yanco Weir as a major contributor to increased competition among percichthyid species on the Murrumbidgee River. The greater relative abundance of percichthyids from downstream samples, combined with increases in dietary overlap and a greater percentage of empty stomachs, also suggested percichthyids may be significantly affecting the relative abundance of potential prey items such as freshwater prawns and Australian smelt. These significant changes in dietary composition were likely related to migratory behaviour, as these species accumulated downstream of the weir, and could be readily expected at other sites where passage is obstructed. It was suggested that the construction of suitable fish passage facilities would effectively reduce the probability of migratory fish accumulating and, subsequently, potential effects of dams and weirs on trophic processes. Since it was established that dams and weirs of the Murrumbidgee River were significantly affecting migratory fish communities, an innovative but relatively inexpensive fishway design, the Deelder fish lock (after Deelder, 1958), was constructed and assessed for wider application throughout the Murray-Darling Basin. The Deelder lock was effective at mitigating the effects of Balranald Weir by providing passage for a wide range of size classes and species of fish; but importantly, the structure enabled the passage of most species previously observed to accumulate downstream of the structure. Most significant was the ability of the fish lock to pass substantial numbers of small-bodied fish, which were previously not considered migratory, suggesting that these species should be considered when developing options to mitigate the effects of other dams and weirs throughout the Murray-Darling Basin. A significant finding of this study was the realisation that substantially more species and size classes of Australian native fish are migratory than previously thought. Subsequently, it is recommended that, when designing facilities to mitigate the effects of a dam or weir, the structure of the entire migratory community is considered when developing operating parameters. Various options for mitigating the effects of dams and weirs are discussed, but it was concluded that the construction of effective fishways would be the most appropriate means of restoring migration pathways to Australian native fish. A strategic approach for assessing and adaptively mitigating the effects of dams and weirs is presented and discussed.

In recent years there has increased interest in low head ‘on weir’ hydro across the UK. This directly corresponds to carbon reduction targets, renewable energy targets and financial incentives directed at renewable energy generating schemes. Despite increased interests, current understandings of the aquatic implications of low head ‘on weir’ hydro are unclear and not one in field investigation has been carried out at an existing scheme. Yet with important environmental legislation preventing the deterioration of ecological river quality, mainly the Water Framework Directive (WFD), there is an urgent need to improve current understandings. Fundamentally low head ‘on weir’ hydropower is a human activity that could potentially alter the aquatic environment, change natural biotic communities and cause failure to comply with WFD targets. On the other hand, as low head ‘on weir’ schemes are fitted on existing weirs which have already potentially altered the aquatic environment, there is the chance that adding a hydro scheme to a weir could in fact improve the aquatic environment and provide benefits for ecology whilst also providing meaningful amounts of electricity (EA, 2010). The overarching aim of this project was to advance the understanding of how low head ‘on weir’ hydropower can influence physical and chemical habitat condition and the phytobenthic biofilm. In order to achieve the aim, this thesis also investigated how weirs themselves change physical and chemical riverine conditions and the phytobenthic biofilm. To investigate the influence of an existing low head weir on the phytobenthic biofilm comparisons were made between the tail riffle below an existing obsolete weir and riffles upstream and downstream of the weir over time. This design was also replicated for a low head ‘on weir’ hydro scheme. Large scale and small scale spatial surveys were also conducted to explore finer scale spatial patterns below the scheme. There was evidence across this study to suggest that low head ‘on weir’ hydropower is having minimal effects of phytobenthic biomass and community composition. Moreover changes in biomass and community composition were more obvious over time than spatially across sampling locations. There was also evidence to suggest that low head ‘on weir’ hydro schemes can mask the effects of weirs by reducing the proportion of flow over the weir.

Thesis (Ph.D.)--University of Melbourne, Cinema Stduies Program,School of Fine Arts,Classical Studies and Archaeology, 2004.<br>Typescript (photocopy). Includes bibliographical references (leaves 292-336).

<p>The construction of the consecutive weirs and excavation along the Nakdong River in Korea changed many channel characteristics such as longitudinal slope, cross-sectional area, water stage which led to changes in erosion and sediment transport patterns. It is now necessary to assess the sedimentation problem upstream of the weirs and seek a way to mitigate the problem. </p><p> The study site of Sangju Weir has been selected for this study because it is a representative site for these types of problems and because sufficiency and availability of data. The purpose of this research is to: (1) estimate incoming sediment yield, define the trap efficiency and estimate the reservoir sedimentation rates of weirs and low-head dams using the Flow-Duration and Sediment Rating Curve (FD/SRC) method, along with the Series Expansion of the Modified Einstein Point Procedure (SEMEPP) to determine the long-term sediment yield for Sangju Weir from suspended load concentration measurement; (2) find the B/C ratio and break-even point between hydropower production revenues and sediment excavation costs using a Benefit and Cost Analysis (BCA); (3) suggest new operation rules for Sangju Weir and propose a systematic analysis procedure to find a better operation rules for mitigating sedimentation problems using the Multi- Criterion Decision Analysis (MCDA) method. </p><p> First, in this study, the Integrated Reservoir Sedimentation Estimation Procedure (IRSEP) was proposed to estimate the reservoir sedimentation at weirs and low-head dams. IRSEP integrates all conventional methods related to reservoir sedimentation: (1) Flow-Duration (FD), (2) Sediment-Rating Curve (SRC), (3) Series Expansion of the Modified Einstein Point Procedure (SEMEPP), and (4) Trap efficiency (TE), in order to estimate reservoir sedimentation rate. Steps (3) and (4) constitute the new elements of this type of analysis. Through stream flow runoff modeling and channel geometry analysis, the trap efficiencies in accordance with certain stages were defined. The trap efficiency of Sangju Weir was calculated for each sediment size fraction as a function of the variables, sediment load at daily discharges and particle size distribution of the sediment transported by the Nakdong River. The trap efficiency is also dependent on channel geometry, inflow discharge and reservoir stage determined by the operation rules at Sangju Weir. Then, the amount of reservoir sedimentation was calculated by multiplying the annual sediment load with trap efficiencies, which vary with discharge and water stage. As a result, the reservoir filling rates were examined. Second, the B/C ratio and break-even point between hydropower production revenues and sediment excavation costs were estimated using a Benefit and Cost Analysis (BCA) method based on daily-modeling. It is essential to determine the effects of the reservoir operation rules using the Multi-Criterion Decision Analysis (MCDA) technique in order to seek improvement in the operation rules to mitigate sedimentation costs, simultaneously considering the other decision makers&rsquo; interests. Finally, new operational rules for Sangju Weir and a systematic analysis procedure were proposed. </p><p> The conclusions of this research are summarized as follows: (1) the total incoming sediment load and the average trap efficiency (TE) at the lowest (EL37.2m) and highest (EL47.0m) stages were estimated as 425,000 tons/year, 50.1 % and 78.1%, respectively; and the maximum annual amount of reservoir sedimentation at Sangju Weir was estimated as 332,000 tons/year (207,000 m³/year) which corresponds to 0.76 %/year of the total reservoir storage of Sangju Weir. On the contrary, the minimum reservoir sedimentation rate was 0.49 %/year, which was come when the water stage was the lowest (EL37.2m). (2) Since the operation rules of Sangju Weir affects significantly the trap efficiency, a Benefit and Cost Analysis (BCA) based on daily-modeling was performed in order to find the break-even point between hydropower production revenues and sediment excavation costs. For daily sediment transport modeling, historical and predicted reservoir stream flow data (2015&ndash;2034) were generated by Tank model using seventy-six daily precipitation data. The B/C ratio obtained 20 years of daily simulation was calculated as 2.28. Also, the discharge and stage thresholds, balancing both hydropower production revenues and sediment excavation costs, are found as 600 m3/s and EL43.6m, respectively. (3) based on the daily Multi-Criterion Decision Analysis (MCDA) modeling, the most favorable Sangju Weir operation rules to mitigate reservoir sedimentation were found in Alternative 5 after including seasonal management of stage control according to the magnitude of the upstream inflow. [table omitted]</p><p> The systematic analysis procedure, the combination of the Integrated Reservoir Sedimentation Estimation Procedure (IRSEP) and the Multi-Criterion Decision Analysis (MCDA) method, are deemed useful to find optimum operation rules of weirs and low-head dams, which can mediate the disputes among various decision makers who have different interests related to reservoir operation. The proposed methodology could be applied to the other weirs of the Four River Restoration Project, and elsewhere. (Abstract shortened by ProQuest.)</p>

A atualidade à marcada por uma forte exploraÃÃo aos recursos naturais sendo que o resultado da sobre-exploraÃÃo à refletido imediatamente na paisagem. Os ambientes aquÃticos sÃo um dos sistemas que rapidamente respondem as modificaÃÃes instauradas sobre o seu meio, dessa forma, as bacias hidrogrÃficas apresentam-se como Ãreas excelentes para estudos de diagnÃstico, pois podem indicar transformaÃÃes ocorridas em escala espacial e temporal como foi realizado por Gorayeb (2008) e Lima (2012). Foi nesse sentido que se desenvolveu um estudo na bacia de drenagem do aÃude Forquilha, localizada no setor noroeste do estado do CearÃ, regiÃo semiÃrida do estado entre as coordenadas 40Â06â51ââ de longitude oeste e 3Â45â39ââ de latitude sul. A bacia de drenagem do aÃude Forquilha abrange uma Ãrea de 191,83 Km2 e està inserida dentro do municÃpio Forquilha, no distrito de mesmo nome, distante 220 km de Fortaleza. AlÃm do aÃude Forquilha existem na Ãrea outros reservatÃrios de pequeno porte como o aÃude Pocinhos e o Juazeiro. O trabalho teve como objetivo a efetivaÃÃo de uma anÃlise geoecolÃgica, baseada no estudo das paisagens, visando à obtenÃÃo de um diagnÃstico do estado dos recursos naturais. Metodologicamente, utilizou-se da Geoecologia das Paisagens que visa à investigaÃÃo do meio natural atravÃs de um enfoque sistÃmico, desta forma, fundamentando-se principalmente nos trabalhos de Rodriguez; Silva; Cavalcanti (2004); Rodriguez, Silva (2002) e Rodriguez, Silva, Leal (2011). Para isso, realizou-se um levantamento bibliogrÃfico e cartogrÃfico; elaboraram-se mapas temÃticos da bacia na escala de 1:80000 atravÃs das tÃcnicas de geoprocessamento com apoio de produtos cartogrÃficos como a Folha SA.24-X-D-IV Sobral na escala de 1:100.000 (1972) alÃm de imagens de satÃlite Landsat 5 e 8 (2009/2014) que tambÃm serviram como suporte as prÃticas de campo. Com a efetivaÃÃo da anÃlise paisagÃstica, obteve-se a caracterizaÃÃo e a classificaÃÃo da paisagem identificando cinco unidades na bacia onde se apontou suas potencialidades e limitaÃÃes. Com o diagnÃstico, pode-se afirmar que a paisagem da bacia do aÃude Forquilha encontra-se descaracterizada de seus aspectos naturais com processos acelerados de degradaÃÃo, pois identificaram-se diversos impactos negativos na Ãrea como o desmatamento, a degradaÃÃo dos solos e a poluiÃÃo do aÃude Forquilha que apresentou eutrofizaÃÃo na maior parte do ano de acordo com as anÃlises realizadas. Por fim, constatou-se que o uso e ocupaÃÃo do solo na Ãrea vÃm sendo realizado de forma irregular o que indica a necessidade de se propor aÃÃes educativas junto à populaÃÃo e aos ÃrgÃos administrativos responsÃveis pela gestÃo da bacia a fim de viabilizar o uso sustentÃvel dos recursos naturais.<br>Nowadays has been marked by a strong exploration for natural resources and the result of overexploitation is reflected immediately in the landscape. The aquatic environments are one of the systems that respond quickly to changes brought about it thus the hidrografic basins are presented as excellent areas for studies of diagnostic as they may indicate transformations in spatial and temporal scale as done by Gorayeb (2008) and Lima (2012). It was developed in this sense a study on the river drainage basin the Forquilha dam, located northwest of Cearà semiarid region of the state in the coordinates 40Â06'51 '' west longitude and 3Â45'39 '' south latitude. The river drainage basin Forquilha dam covers an area of 191, 83 km2 and is inserted into the Forquilha municipality in the district of the same name, 220km far from Fortaleza. In addition to the Forquilha dam exist in the area other small reservoirs as the Pocinhos dam and Juazeiro dam. The study aimed to the realization of a geoecological analysis, based on the study of landscapes, in order to obtain a diagnosis of the state of natural resources. Methodologically, it was used the Geoecology of Landscapes that aims to research the natural environment through a systemic approach in this way, basing it primarily on studies of Rodriguez; Silva; Cavalcanti (2004); Rodriguez; Silva (2002) and Rodriguez; Silva; Leal (2011). For this, there was a literature and mapping research; it was prepared thematic maps of the basin in the scale of 1: 80,000 by using geoprocessing techniques with the support of cartographic products as SA.24-XD-IV Sobral leaf on a scale of 1: 100,000 (1984) as well as Landsat 5 satellite images and 8 (2009/2014) which also served to support the practical field. With the conclusion of landscape analysis, obtained the characterization and the landscape classification identifying five units in the basin where they pointed their potentialities and limitations. With the diagnosis, it can be said that the landscape of Forquilha dam basin is uncharacteristic of their natural aspects with accelerated processes of degradation for many negative impacts such as deforestation in the area has been identified, soil degradation and pollution on the Forquilha Weir and eutrophication presented most of the year according to the analyzes. Finally, it was found that the use and occupation of land in the area have been held irregularly indicating the need to propose educational activities among the population and the administrative agencies responsible for basin management in order to enable the sustainable use of natural resources.

This study is an experimental research to formulate the discharge over sharp-crested rectangular weirs. Firstly, a series of measurements on different weir heights were conducted to find the minimum weir height for which channel bed friction has no effect on discharge capacity. After determining the appropriate weir height, weir width was reduced to collect data on discharge-water head over weir relationship for a variety of different weir openings. Then, the data was analyzed through regression analysis along with utilization of global optimization technique to reach the desired formulation for the discharge. By taking advantage of a newly-introduced &ldquo<br>weir velocity&rdquo<br>concept, a simple function was eventually detected for the discharge where no discharge coefficient was involved. The behavior of the weir velocity function obtained in the present study illustrates the transition between the fully contracted and partially contracted weirs. In addition, the proposed weir velocity formulation is simple and robust to calculate the discharge for full range of weir widths.

The weir was built by Joaquim Tavora DNOCS between the years 1932 and 1933 with the main objective to meet irrigation and fish farming. Its construction allowed the installation of residents in the region, thus resulting in the district Wizard, which appeared as a good location to stay, even during periods of drought, common in the region, passing also being used to supply the perpetuation sorcerer e creek leisure .Multiple uses of this reservoir can produce many problems, especially when water availability is limited by quantity or quality, which can generate conflicts. No case the weir Joaquim Tavora, it is observed that, in the years of âwater abundance " issues related to water availability are not discussed , the conflict over access and use of water is forgotten , returning , however, during periods of low fluid intake , coupled with increased demand and lack of more public policy research efficient. That investigated the conflict that was established by the use of the public water reservoir Joaquim Tavora, leading to Terms of Adjustment of Conduct - TAC, established by the State Prosecutor of the District of Jaguaribe, with signatures of irrigators on October 3, 2012, which was to determine if requiring irrigators responsabilizassem for cleaning the stretch of its stream his property, with a minimum margin of two feet wide. The term also includes the adequacy of existing along the creek and other irregularities which may impair the flow of water in the creek bed Wizard buses. The survey aimed to: identify key users involved in the conflict; locate and map the points of resistance whether or not the TAC; relate the multiple uses of water from the reservoir and identify ways of attracting water used by users, both surrounding the reservoir and in the downstream region. To arrive at the results achieved, we adopted a methodology of direct and indirect investigations, with questionnaires aimed at rural populations surrounding the weir; visits to obtain quantitative and qualitative data, and questionnaires to users of the water reservoir.<br>O aÃude Joaquim TÃvora foi construÃdo pelo DNOCS entre os anos 1932 e 1933, com o objetivo principal de atender a irrigaÃÃo e a piscicultura. A sua construÃÃo possibilitou a instalaÃÃo de moradores na regiÃo, surgindo assim o distrito de Feiticeiro, que se apresentava como uma localidade propÃcia à permanÃncia, inclusive nos perÃodos de estiagem, comuns na regiÃo, passando, tambÃm, a ser utilizado para abastecimento, perenizaÃÃo do Riacho Feiticeiroe lazer. Os mÃltiplos usos desse aÃude podem produzir vÃrios problemas, especialmente quando a disponibilidade de Ãgua à limitada por sua quantidade ou por sua qualidade, o que pode gerar conflitos. No caso do aÃude Joaquim TÃvora, observa-se que, nos anos de âfartura hÃdricaâ, as questÃes relacionadas à disponibilidade de Ãgua nÃo sÃo discutidas, o conflito pelo acesso e uso da Ãgua fica esquecido, retornando, contudo, nos perÃodos de baixo aporte hÃdrico, aliado ao aumento da demanda e a falta de mais polÃticas pÃblicas eficientes. Essa pesquisa investigou o conflito que foi estabelecido pelo uso dÂÃgua do aÃude pÃblico Joaquim TÃvora, levando ao Termo de Ajustamento de Conduta â TAC, estabelicido pela Promotoria PÃblica Estadual da Comarca de Jaguaribe, com assinaturas dos irrigantes no dia 03 de outubro de 2012, que teve como determinaÃÃo exigir que os irrigantes se responsabilizassem pela limpeza do trecho do riacho respectivo a sua propriedade, respeitando uma margem mÃnima de dois metros de largura. O termo tambÃm prevà a adequaÃÃo dos barramentos existentes ao longo do riacho e outras irregularidades que venham a comprometer o fluxo de Ãgua no leito do riacho feiticeiro. A pesquisa teve ainda como objetivos: identificar os principais usuÃrios envolvidos no conflito; localizar e mapear os pontos de resistÃncia ao cumprimento ou nÃo do TAC; relacionar os usos mÃltiplos da Ãgua do reservatÃrio e identificar os meios de captaÃÃo de Ãgua utilizada pelos usuÃrios, tanto no entorno do aÃude quanto na regiÃo a jusante. Para chegar aos resultados alcanÃados, foi adotada uma metodologia de investigaÃÃes diretas e indiretas, com aplicaÃÃo de questionÃrios dirigidos Ãs populaÃÃes rurais localizadas no entorno do aÃude; visitas, para obter dados quantitativos e qualitativos; e aplicaÃÃo de questionÃrios aos usuÃrios da Ãgua do aÃude.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior<br>Soybean target spot has become important recently, once the disease has generated economic losses to soybean producer, mainly in the Midwest. Therefore, this study aimed to evaluate alternatives managements on soybean target spot. Experiments were conducted in Canarana and Primavera do Leste, Mato Grosso State, in order to evaluate the effect of sowing date, cultivar and fungicide application programs on the severity of target spot. The application programs, that differed in the number of applications and timing of the first spraying, were tested on three soybean cultivars (TMG 7188 RR, TMG 132 RR, M-8766 RR) sown in two seasons (CHAPTER I). The efficiency of fungicides applied at different stages of the crop cycle (vegetative + reproductive, and just at reproductive stage) on cultivar TMG 7188 RR was also tested (Chapter II). Interaction betwen location and treatments was observed for severity of target spot and asiatic rust, as happened to yield. The severity of target spot was higher in the earlier sowing season, unlike soybean asiatic rust. Cultivars were differently susceptible to target spot, showing that choosing cultivar may be a disease management option. Fungicide application at vegetative stage only increased the control of target spot for TMG 132 RR sown in first sowing season in Primavera do Leste. The use of fungicides containing the molecule Fluxapyroxad were more efficient in target spot controlling, regardless of the number of sprays. The correct choice of fungicide, sowing season and less susceptible cultivars are factors to be considered in the management of the target spot in soybean.<br>A mancha alvo da soja vem ganhando importância nos últimos anos, visto que a doença tem gerado perdas econômicas ao sojicultor, principalmente na região Centro-Oeste do Brasil. Deste modo o presente estudo teve como objetivo avaliar alternativas de manejo da mancha alvo em soja. Experimentos foram conduzidos em Primavera do Leste e Canarana, Mato Grosso, com o intuito de avaliar o efeito da época de semeadura, de cultivares e programas de aplicação foliar de fungicidas sobre a severidade da mancha alvo em soja. Os programas de aplicação, que diferiram quanto ao número de aplicações e época da primeira pulverização, foram testados sobre três cultivares de soja (TMG 7188 RR, TMG 132 RR, M-8766 RR) semeadas em duas épocas (CAPÍTULO I). Também foi testada a eficiência de fungicidas aplicados em diferentes estágios da cultura (vegetativo + reprodutivo; e somente reprodutivo) na cultivar TMG 7188 RR (CAPÍTULO II). Os locais de condução dos experimentos apresentaram interação com os tratamentos para a área abaixo da curva de progresso de mancha alvo e de ferrugem asiática da soja, assim como se deu para a produtividade. A severidade de mancha alvo foi maior nas épocas de semeadura mais precoces, diferentemente do que ocorreu para ferrugem asiática da soja. As cultivares testadas apresentaram diferentes graus de suscetibilidade à mancha alvo, mostrando que a escolha da cultivar é uma opção no manejo da doença. A aplicação de fungicida no estádio vegetativo só apresentou benefício no controle de mancha alvo frente ao programa de aplicação contemplando aplicações apenas no período reprodutivo para o cultivar TMG 132 RR semeado na primeira época no município de Primavera do Leste. A utilização de fungicidas que continham a molécula Fluxapiroxade mostraram-se mais eficientes no controle da mancha alvo, independente do número de pulverizações. A escolha correta do fungicida, bem como a época de semeadura e a utilização de cultivares menos suscetíveis são fatores a serem levados em consideração no manejo da mancha alvo em soja.

Comprehensive rehabilitation projects of dam spillways are made in Sweden, due to stricter dam safety guidelines for their discharge capacity. The Piano Key Weir (PKW) is an innovative design which has proven effective through several renovation projects made in many countries including France. In this study we investigate the flow patterns around a prototype PKW, located in Escouloubre dam in southern France, with numerical simulations through three different flow cases in Ansys Fluent. A computational domain containing the PKW is created in the CAD software Ansys SpaceClaim for the simulations. Three polyhexcore meshes are further generated using Ansys Fluent Meshing. The three flow cases are then simulated with a Reynolds-averaged Navier-Stokes (RANS) model, coupled with realizable k-epsilon and volume of fluid models. Through an assessment of the discretization error between three meshes, a relative error of one percent is obtained for the discharge rate. The numerical results are qualitatively compared with results from previously conducted physical experiments on this PKW. The RANS model does not capture the water surface undulations (due to turbulence) around the PKW. The effects from under modelled surface undulations are alleviated by inserting an air vent to the PKW, which results in a flow behaviour in good agreement with the physical experiments. Through this alteration, water discharge rates are computed with a maximum discrepancy of five percent compared with the corresponding experimental values. A large eddy simulation should be conducted in the future, to bring further light on air exchange and water interaction phenomena present in the PKW flow pattern.

Salvador Dali, is known primarily as a Surrealist painter, dandy and provocateur. His theoretical works are far less known. Dali’s theories, interspersed throughout his eleven books and numerous essays and interviews range across the fields of art, architecture, psychology and science. In this thesis I examine these ideas, in particular Dali’s paranoiac critical method, for their potential application in contemporary issues regarding representation and architecture.

This thesis describes the current state of the river Oslava in Oslavany design and reconstruction of the existing fixed weir in the affected location. As a best alternative reconstruction of the existing fixed weir reconstruction was chosen the hard threshold floating weir inflatable weirs. The next part of the thesis describes the proposed solution, and the last part of the thesis deals with the assessment of the proposed solutions.

The construction of a partial exclusion amenity barrage across the lower estuary of the River Tawe, South Wales, was completed in 1992. The structure includes a pool and weir fish pass consisting of 16 pools interlinked by deep notches in alternately downstream and cross facing traverses. Modifications to the fish pass weirs were carried out at the end of June 2000 in order to address the problem of excessive turbulence within the pools. The primary aim of this thesis was to examine the effectiveness of the modified fish pas under a range of environmental conditions. Underwater video was selected as the most suitable method for monitoring fish use of the pass and a system was designed and installed below the fish pass exit notch. The effects of time of day, tidal state, river flow volume and water quality on fish use of the modified pass were examined. Diel and tidal rhythms appeared to have the greatest impact on fish movements. The majority of fish exited the pass during daylight, supporting the hypothesis that fish utilise visual cues to negotiate obstacles. The timing of movement during tides which completely inundated the fish pass suggested that fish were using the rising tide to aid ascent, however a greater number of fish used the pass during non-inundating tides when this was main route past the barrage. Fish use of the pass appeared to be stimulated between river flows of 3.00 – 6.99 m³ s^-1 and 10 – 10.99 m³ s^-1, and there was evidence that salmonids use of the fish pass increased in response to changes in flow. Dissolved oxygen concentrations remained above levels which would affect the swimming ability of fish, although oxygen supersaturation may potentially cause periodic problems.

Rock weirs are small dam-like structures composed of large loose rock commonly found in ecological engineering design. By appearing more natural than concrete structures, rock weirs are preferred for use as hydraulic control structures in river engineering, stormwater management, and constructed wetlands. Rock weirs increase hydraulic head upstream, and facilitate fish passage, channel stabilization, floodplain reconnection, and in-stream habitat creation. When used in constructed wetlands, rock weirs play a valuable role in developing appropriate wetland hydrology. Although rock weirs are commonly used, a deficit of knowledge exists relating to the stage-discharge relationship of these structures. Therefore, the goal of this research was to determine a weir equation and corresponding discharge coefficients that improve predictions of flow through rock weirs. A flume study was conducted to develop a rock weir equation and discharge coefficients. Scaled model rock weirs were tested in a 1 m x 8 m x 0.4 m recirculating flume. Rock weirs varied by length (0.152 m, 0.305 m, and 0.457 m), depth (0.152 m and 0.305 m), and minimum rock diameter (12.7 mm, 19.1 mm, 25.4 mm). Three channel slopes were used (0%, 0.5%, 1%), and the flume discharge was varied for five water stages for each rock weir. Buckingham Pi analysis was used to develop seven dimensionless parameters. Regression analyses were then used to develop a model for discharge and the discharge coefficient. Results showed that weir length and depth play a significant role in predicting the discharge coefficient of rock weirs.<br>Master of Science<br>Rock weirs are small dam-like structures composed of large loose rock; by appearing more natural, they are preferred for use in river engineering, stormwater management, and constructed wetlands. Rock weirs increase upstream water depth, improving fish passage, channel stabilization, floodplain reconnection, and in-stream habitat creation. When used in design of constructed wetlands, rock weirs are used to establish the necessary water depths for a given type of wetland. Although rock weirs are commonly used in engineering design, there are no equations to predict water velocity or flow rate across these structures. Therefore, the goal of this research was to determine a weir equation that improves predictions of flow through rock weirs. A flume study was conducted to develop a rock weir equation. Miniature rock weirs were tested in a 1 m x 8 m x 0.4 m recirculating laboratory channel. Rock weirs varied by length (0.152 m, 0.305 m, and 0.457 m), depth (0.152 m and 0.305 m), and minimum rock diameter (12.7 mm, 19.1 mm, 25.4 mm). Three channel slopes were used (0%, 0.5%, 1%), and the water flow rate was varied for five water depths for each rock weir. Statistical analyses were conducted to determine an equation that predicts water flow through rock weirs for use in engineering design. Results showed that weir length and depth played a significant role in predicting water flow through rock weirs.

Sharp crested rectangular weirs used for discharge measurement purposes in open channel hydraulics are investigated experimentally. A series of experiments were conducted by measuring discharge and head over the weir for different weir heights for full width weir. It is seen that after a certain weir height, head and discharge relation does not change. Hence a constant weir height is determined. For that height<br>discharge and head over the weir are measured for variable weir width, starting from the full width weir to slit weir. Description of the discharge coefficient valid for the full range of weir widths and an empirical expression involving dimensionless flow variables is aimed. Experimental data obtained for this purpose and the results of the regression analysis performed are represented.

Abstract Fishways are hydraulic structures designed to dissipate the energy of flowing water in order to decrease water velocities and increase water depths. The history of fishways is long, the first written remarks date back to the 17th century. Fishway hydraulics, however, have been intensively studied only starting since the 1980's. Fishways have been classified into three main categories according to their hydraulic characteristics: pool-and-weir, vertical slot, and Denil fishways. Fishways are hydraulically complex structures, and thus designing tools for different fishway types have been developed. In this report, a new designing procedure has been established, and equations for each main fishway type have been suggested. In addition, flow conditions below different fishway types have been examined, and velocity distributions at weirs with V-shaped crests in both pool-and-weir fishways and at a single weir have been compared in different discharges and drops. Fishway flows have been compared with flows over single weirs.

Thesis (MSc)--Stellenbosch University, 2015.<br>ENGLISH ABSTRACT: Rivers are one of the earth's major readily available sources of fresh water. Abstractions from rivers are however not without problems. Firstly, river ow is variable and to deliver a constant yield is difficult. Secondly, rivers transport sediment which will be included in the diverted ow. Sediment control at diversion works have been studied for many years and this study attempts to gain further knowledge on certain sediment control features of diversion works. Sediment control at diversion works and abstraction works is crucial to prolong the life of the mechanical components like pumps and turbines. A Commonly used diversion works design is one with a low weir and a graveltrap. The weir dams water for abstraction, which is of importance in South Africa with its variable rainfall and river ow. The study focused on the following design features of diversion works: (1) the intake angle, which is the angle at which the structure is pushed into the river, (2) the intake opening height above a datum, (3) the river ow range where sediment is sufficiently scoured from the graveltrap and (4) the efficiency and river ow range of sediment ushing through a sluice gate at the graveltrap. A Physical model study was conducted in the laboratory of the University of Stellenbosch, which consisted of designing the diversion works that were to be tested. The designs were based on guidelines from previous studies, case studies and hydraulic principles. The above mentioned features (1-4) were studied at three structures with prototype weir sizes of 2.5 m, 3.5 m and 4.5 m. The river was modelled as a straight rectangular channel with a loose bed surface, which was simulated with crushed peach pips. Sediment was also fed into the system with a conveyor belt feed system. Pumps were used to abstract water and sediment through the intake opening, during the diverted sediment tests. Flow was diverted at a specific ow rate for each structure. The diverted sediment was caught and weighed. Each structure was designed to divert sediment through one of three intake opening heights, to determine whether a higher intake opening sufficiently reduces the amount of diverted sediment. The self-scour efficiency at the graveltrap was determined with a sediment level survey in the graveltrap. From the survey a clearance ow was determined, which is the minimum river ow that clears the intake opening of sediment along its complete length. It was also determined what intake angle induces secondary ow which results in the lowest clearance ow. The sediment ushing through the sluice gate was evaluated by recording the time it takes a full graveltrap to be ushed clean at various river ow rates. The maximum river ow at which the graveltrap still ushes efficiently was determined for each structure. It was found that between the 300, 450 and 600 intake angle that were tested, the 60 0 angle yields the lowest diverted sediment ratio (DSR) over the range of structures as well as river ows tested. The tests yielded a river ow at each structure where the DSR is at minimum. During the self-scour tests of the graveltrap, it was determined that a 450 intake angle promotes better self-scour at the graveltrap. To promote both features, a 450 intake angle is suggested, as it reduces diverted sediment and has a lower risk of issues due to too large ow constriction. The intake opening height was evaluated with analysis of diverted load and concentration. The conclusions on the intake opening vary between structure sizes. In the case of the smallest structure, with a 2.5 m weir height, the improvement observed for intake openings higher than the first (lowest) were variable. In the case of the 3.5 m weir structure, the results showed three consecutive intake openings could be feasible. In the case of the 4.5 m weir structure, less improvement was observed between the highest two intakes. Flood frequency should determine whether an intake opening with top-of-inlet of 1.6 m or 3.3 m above the minimum operating level should be designed. It was observed during the sediment ushing tests that submergence of either the graveltrap wall and/or the downstream water level affects the ushing efficiency. y3/y2, which is the downstream ow depth over the contracted ow depth under the sluice gate of the graveltrap, was evaluated as an indicator of efficient ushing. The study found that a good guideline would be to ush during river ows where y3/y2 < 1, while also ensuring the ow over the graveltrap wall entrains the sediment in the graveltrap. A figure which plots the downstream ow depth over sluice gate opening size was developed to serve as an operational guideline to efficient sediment ushing. The figure shows zones of efficient and non-efficient ushing. Further, the observed sediment ushing and self-scour ranges at each structure are also represented graphically. The fact that there was designed for a specific river scenario and also the lack of varied model sediment size, limits the applicability of the findings and conclusions.<br>AFRIKAANSE OPSOMMING: Riviere is van die aarde se hoof, maklik beskikbare bronne van vars water. Onttrekking uit riviere is wel nie sonder probleme nie. Eerstens is rivier vloei wisselvallig en om 'n konstante lewering te handhaaf is moeilik. Tweedens, vervoer riviere sediment wat ingesluit sal wees in die uitgekeerde vloei. Sediment beheer by uitkeerwerke word al vir baie jare bestudeer en hierdie studie poog om verdere kennis te verkry oor sekere sediment beheer funksies van uitkeerwerke. Sediment beheer by uitkeerwerke en onttrekkingswerke is noodsaaklik om die lewensduur van meganiese komponente soos pompe en turbines te verleng. 'n Algemeen toegepaste uitkeerwerke ontwerp is een met n lae keerwal en gruisvangkanaal. Die keerwal dam water op, wat nodig kan wees om die lewering te handhaaf, veral met Suid-Afrika se wisselvallige reënval en rivier vloei. Die studie het gefokus op die volgende ontwerp funksies van uitkeerwerke: (1) die inlaathoek, wat die hoek is waarteen die struktuur in die rivier ingedruk is, (2) die inlaatopening hoogte bo 'n datum, (3) die rivier vloei reeks waar sediment voldoende uitgeskuur word uit die gruisvangkanaal uit en (4) die effektiwiteit en rivier vloei reeks van 'n sediment spoel aksie deur 'n sluishek in die gruisvangkanaal. 'n Fisiese model studie was onderneem in die laboratorium van die Universiteit van Stellenbosch, wat bestaan het uit die ontwerp van die uitkeerwerke wat getoets sou word. Die ontwerp is gebasseer op riglyne van vorige studies, gevallestudies en hirouliese beginsels. Die bogenoemde funksies (1-4) was bestudeer by drie strukture met prototipe keerwal hoogtes van 2.5 m, 3.5 m en 4.5 m. Die rivier was gemodelleer as 'n reguit, reghoekige kanaal met 'n los bed oppervlakte, wat gesimuleer is met fyngemaakte perske pitte. Sediment was ook in die sisteem ingevoer met 'n vervoerband voer sisteem. Pompe was gebruik om water en sediment te onttrek deur die inlaatopening tydens die uitgekeerde sediment toetse. Vloei was uitgekeer teen 'n spesifieke vloeitempo vir elke struktuur. Die uitgekeerde sediment was gevang en geweeg. Elke struktuur was ontwerp om sediment uit te keer deur een van drie inlaatopening hoogtes, om te bepaal of 'n hoër inlaatopening hoogte die hoeveelheid uitgekeerde sediment voldoende verminder. Die self-uitskuur effektiwiteit van die gruisvangkanaal was bepaal deur 'n sediment vlak opmeting in die gruisvangkanaal. Vanaf die opmeting was 'n skoonmaak vloei bepaal, wat die minimum rivier vloei is wat die inlaatopening skoon maak van sediment oor die totale lengte. Dit was ook bepaal watter inlaathoek veroorsaak sekondêre vloei wat die laagste skoonmaak vloei oplewer. Die sediment spoel aksie deur die sluishek was geëvalueer deur die tyd wat dit neem om 'n vol gruisvangkanaal skoon te spoel, teen verskeie rivier vloeitempos te bepaal. 'n Maksimum rivier vloei waarteen die guisvangkanaal steeds effektiewelik skoon spoel was bepaal vir elke struktuur. Dit was bevind dat tussen die 300, 450 en 600 inlaathoeke wat getoets is, lewer die 600 hoek die laagste uitgekeerde sediment verhouding (USV) oor die reeks van strukture, asook rivier vloeitempos wat getoets is. Die toetse het 'n rivier vloei opgelewer by elke struktuur, waar USV 'n minimum was. Gedurende die self-uitskuur toetse was dit bepaal dat 'n 450 inlaathoek beter uitskuur in die gruisvangkanaal bevorder. Om beide funksies te bevorder word 'n 450 inlaathoek voorgestel, omdat dit ook uitgekeerde sediment verminder en 'n laer risiko van probleme as gevolg van te groot vloei vernouing het. Die inlaatopening hoogte was geëvalueer met analise van die uitgekeerde sediment lading en konsentrasie. Die gevolgtrekkings oor die inlaatopening hoogte varieer tussen struktuur groottes. In die geval van die kleinste struktuur, met 'n 2.5 m keerwal hoogte, was die verbetering wat waargeneem was by inlaatopeninge hoër as die eerste (laagste) inlaat, wisselvallig. In die geval van 'n 3.5 m keerwal struktuur het die resultate getoon dat drie opeenvolgende inlaatopeninge kan uitvoerbaar wees. In die geval van 'n 4.5 m keerwal struktuur was minder verbetering waargeneem tussen die hoogste twee inlate. Vloed frekwensie moet bepaal of 'n inlaatopening hoogte met 'n bokant-van-inlaat vlak van 1.6 m of 3.3 m bo minimun bedryfvlak moet ontwerp word. Dit was waargeneem dat gedurende die sediment spoel toetse dat versuiping van die gruisvangkanaal muur en/of die stroomaf watervlak die spoel effektiwiteit beïnvloed. y3/y2, wat die stroomaf vloeidiepte oor die vernoude vloeidiepte onder die sluishek van die gruisvangkanaal is, was geëvalueer as 'n indikator van effektiewe spoel aksie. Die studie het bevind dat 'n goeie riglyn sal wees om te spoel tydens rivier vloeie waar y3/y2 < 1 is, terwyl dit ook verseker moet word dat vloei oor die gruisvang kanaal sediment meevoer in die gruisvangkanaal. 'n Figuur wat die stroomaf vloeidiepte teenoor die sluisopening grootte plot was ontwikkel om te dien as 'n bedryfsriglyn tot effektiewe spoel aksie. Die figuur toon zones van effektiewe en nie-effektiewe spoel aksie aan. Verder is die waargeneemde sediment spoel aksie en self-uitskuur reekse van elke struktuur ook grafies voorgestel. Die feit dat daar ontwerp is vir 'n spesifieke rivier scenario asook die gebrek aan variëerende model sediment grootte, beperk die toepasbaarheid van die bevindings en gevolgtrekkings.

As part of the water resources policy of the state of CearÃ, in Northeast Brazil, COGERH, as an operational instrument, has among its tasks the distribution of bulk water for various uses. Among the water systems that COGERH operates are the pumping stations, which are responsible for supplying water for cities, industries, irrigation, etc. It is vital that these structures operate satisfactorily and efficiently. Among the many devices that make up the pumping stations are the semisubmersible floating metal chambers that are located on the water surface of the reservoirs, providing support to the pumps and motors such that they can be set and operated reliably and efficiently. However, these structures are made from steel and therefore are subject to severe corrosion processes, making it necessary for the painting of the submerged areas to ensure the necessary protection to avoid oxidation of them. As painting alone is not a process that ensures 100% efficiency in terms of coating and has a relatively short lifespan, complementary processes are necessary to ensure safe protection against corrosion. Among these processes is the Cathodic Protection, which ensures that, while a difference in electrochemical potential is being generated between the structure to be protected and a sacrificial anode, the structure will not undergo corrosion processes. For this study, it has been designed and installed an Impressed Current Cathodic Protection System with a potential ON of protection of -2.67 Volts (DC) for the Pumping Station known as "EB GaviÃoâ chosen due to its strategic importance within the state infrastructure of water resources, responsible for supplying water for major cities and industries. Keywords :<br>Dentro da polÃtica dos recursos hÃdricos do estado do CearÃ, no Nordeste do Brasil, a COGERH, como instrumento operacional, tem entre suas atribuiÃÃes a distribuiÃÃo de Ãgua bruta para usos diversos. Dentre os sistemas que a COGERH operacionaliza estÃo as estaÃÃes de bombeamento, as quais sÃo responsÃveis por abastecer cidades, indÃstrias, irrigantes, etc. à fundamental que tais estruturas operem de forma satisfatÃria e eficiente. Dentre os muitos equipamentos que compÃem as estaÃÃes de bombeamento estÃo Ãs cÃmaras metÃlicas flutuantes emisubmersÃveis que se localizam na superfÃcie de Ãgua dos reservatÃrios, dando sustentaÃÃo para que as bombas e motores possam ser fixados e operados de forma confiÃvel e eficiente. No entanto estas estruturas, por serem de aÃo, estÃo sujeitas a processos de corrosÃo severos, fazendo-se necessÃrio que a pintura das Ãreas submersas assegurem a proteÃÃo necessÃria para que nÃo haja oxidaÃÃo das mesmas. Como a pintura nÃo à um processo que garante uma eficiÃncia de 100% e termos de revestimento e tem uma vida Ãtil relativamente curta, fazem-se necessÃrios processos complementares para uma segura proteÃÃo anti-corrosÃo. Dentre esses processos està a ProteÃÃo CatÃdica que assegura que enquanto estiver sendo gerada uma âdiferenÃa de potencial eletroquÃmicoâ entre a estrutura a ser protegida e um anodo de sacrifÃcio a estrutura nÃo sofrerà severos processos de corrosÃo. Neste estudo foi dimensionado e instalado um Sistema de ProteÃÃo CatÃdica por Corrente Impressa assegurando um potencial ON de proteÃÃo de -2,67 Vcc para a estaÃÃo de bombeamento denominada âEB GaviÃoâ pela importÃncia estratÃgica que ocupa dentro da infraestrutura estadual de recursos hÃdricos, fazendo parte de sistema responsÃvel pelo abastecimento de importantes cidades e indÃstrias.

A soleira lateral desempenha um papel importante nos reservatórios de detenção/ retenção (off-line), atuando na captação das vazões afluentes e evitando possíveis enchentes, problema em destaque nos períodos chuvosos das principais capitais brasileiras. Um melhor entendimento do seu comportamento hidráulico possibilitará o desenvolvimento de estruturas laterais mais eficientes. O presente trabalho tem como objetivo criar um modelo da soleira lateral através da tecnologia CFD (Dinâmica dos Fluidos Computacional) e validá-lo através de experimentos em modelo reduzido do Laboratório de Hidráulica da Escola Politécnica da USP. A partir disso, explorar as características hidráulicas do modelo de CFD, como o comportamento dos níveis dágua e a distribuição de velocidades. No estudo da validação estudaram-se três tipos de refinamento de malhas e três modelos de turbulência (k-, k- (RNG) e SST k-). O modelo computacional validado é composto pela malha 3, com um refinamento cerca de 342000 elementos (hexaédricos predominante), e o modelo de turbulência k- (RNG), que apresentaram a maior precisão dos resultados. A análise da distribuição de velocidades possibilitou visualizar uma região de mínima velocidade abaixo da soleira lateral, e também quantificar uma região de baixas velocidades no início da soleira, onde é pequena a eficiência das vazões escoadas. Através do comportamento da superfície dágua foi possível visualizar a região de influência do dispositivo lateral no canal principal. A comparação do coeficiente de descarga do modelo de CFD com trabalhos de outros pesquisadores, um nacional e outro internacional, mostrou a representatividade do modelo criado para condições diferentes. A ferramenta CFD é promissora para o estudo de estruturas hidráulicas, contribuindo para o seu desenvolvimento e aperfeiçoamento.<br>The side weir plays an important role in the detention / retention tanks (off-line), operating in the uptake of water inflow and preventing possible flooding, which is a highlighted problem on rainy periods of the main Brazilian capitals. A better understanding of the hydraulic behavior allows the development of more efficient lateral structures. This work aims at creating a model of the side weir through CFD technology (Computational Fluid Dynamics) and validating it through experiments on a reduced model of the Laboratório de Hidráulica da Escola Politécnica da USP. Thereafter, explore the hydraulic characteristics of the CFD model, like the behavior of water levels and the velocity distribution. In the validation study, three types of mesh refinement and three turbulence models were studied (k-, k- (RNG) and SST k-). The computational model is validated by the composite mesh 3 with a refinement about 342,000 elements (hexahedral predominant), and the turbulence model k- (RNG), which had the highest precision of results. Analysis of the velocities distribution allowed us to visualize a region of minimum velocity below the side weir, and also to quantify a region of low velocities at the beginning of the weir, where the efficiency of overflows is small. Through water surface behavior it was possible to visualize the influence region of the side device in the main channel. A comparison of discharge coefficient of the CFD model between other works (one national and the other one international) showed the representativeness of the model created for different conditions. The CFD is a promising tool for the study of hydraulic structures, contributing to its development and improvement.

Thèse Ecole polytechnique fédérale de Lausanne EPFL, no 3872 (2007), Faculté de l'environnement naturel, architectural et construit ENAC, Programme doctoral Environnement, Institut des infrastructures, des ressources et de l'environnement ICARE (Laboratoire de constructions hydrauliques LCH). Dir.: Anton Schleiss.

Atualmente, o setor produtivo vem impulsionando o interesse da comunidade científica no estudo das técnicas de transmissão/reflexão (T/R) para a caracterização de propriedades eletromagnéticas de amostras sólidas de materiais em amplas faixas de frequências. Tais propriedades são aplicáveis, por exemplo, no desenvolvimento de projetos de circuitos de micro-ondas, estudos biológicos e de materiais absorvedores de radiação eletromagnética. Neste contexto, este trabalho tem por objetivo o estudo do algoritmo de Nicolson-Ross-Weir (NRW), que associa os parâmetros de espalhamento, medidos com o auxílio de Analisadores de Redes Vetoriais (VNA), com os valores de permissividade e permeabilidade relativas complexas para amostras toroidais inseridas dentro de linhas coaxiais de ar. A metodologia de estudo consiste na implementação de uma rotina NRW computacional, desenvolvida em ambiente VEE 8.0, e validada por meio de comparação de seus resultados com aqueles obtidos de programas comerciais. O programa Agilent Co. foi empregado na extração de permissividade e permeabilidade complexas relativas para uma amostra experimental de Ferrita Mn-Mg, estudada de 50MHz a 500MHz. Modelos eletromagnéticos de simulação para uma linha coaxial de ar preenchida com amostras de Teflon, Madeira e Ferrita Virtual, estudados até 5GHz, são desenvolvidos com a ferramenta CST Microwave Studio 2008 (MWS) para auxílio no processo de validação das rotinas de correções de erros provenientes da existência de lacunas de ar longitudinais e transversais, situadas entre as extremidades das amostras e dos portas-amostra. As simulações permitem ainda o estudo de instabilidade do método NRW em faixas de frequências próximas àquelas onde o comprimento da amostra torna-se múltiplo de meio comprimento de onda do sinal eletromagnético que se propaga através dela. A conclusão do trabalho discute as divergências encontradas entre os resultados alcançados por meio da rotina implementada e os das ferramentas comerciais (Agilent Co, e MWS 2008), e também apresenta sugestões para trabalhos futuros.

Os vertedores são estruturas hidráulicas de suma importância no controle de escoamento e também para medição de vazões. Estas estruturas são amplamente utilizadas em aproveitamento múltiplos principalmente como controle de vazão. Neste trabalho é apresentado um histórico dos estudos elaborados para vertedores, demonstrando as principais características entre cada estudo.Também são apresentados os resultados obtidos através dos cálculos de linha d\'água é pressão utilizando as equações para superfícies de fundo curvo para um perfil segundo o equacionamento de Creager e o perfil Cossenoidal proposto por este trabalho. O escoamento realizado em um perfil Cossenoidal apresenta um comportamento muito semelhante ao escoamento realizado em um perfil do tipo Creager. Com a utilização do perfil Cossenoidal foi possível realizar a coincidência de raio de curvatura no trecho da crista onde o raio de curvatura do perfil Cossenoidal ajustado a um perfil do tipo Creager, apresentou o mesmo valor para o raio de curvatura para uma elipse proposta por Maynord modificado por este trabalho. Os resultados de linha d\'água e pressão foram bons e satisfatórios muito semelhantes aos valores já apresentados pelas soleiras convencionais (Creager e Maynord).<br>The spillways are hydraulic structures very important in the control flow and for measuring flow rates. These structures are widely used mainly for multiple use flow control. This work presents a history of the studies prepared for spillways, showing the main features of each study. It is intended to study a cosinusoidal profile through a mathematical model seeking to obtain satisfactory answers to the water lines and pressure for the studied profile. Showing the results obtained through the water level and pressure calculations, using the equations for curve surface for a Creager\'s profile and Cossenoidal\'s profile suggest in this work. The flow realized in a Cossenoidal\'s profile show a behavior similar at the flow realized in a Creager\'s profile. The utilization of the Cossenoidal\'s profile was possible to realize the coincidence of the curvature radius in the crest between Cossenoidal\'s profile and Maynord Modified ellipse, and this profile was adjusted with a Creager\'s profile and Maynord\'s ellipse. The results of water level and pressure showed goods and satisfactory, very similar with the values showed in other studies for a conventional weirs (Creager and Maynord).

Judith Weir (b. 1954) composed King Harald’s Saga: Grand Opera in Three Acts for Unaccompanied Solo Soprano Singing Eight Rôles (1979) for radio broadcast. She wrote the libretto for the opera based on Snorri Sturluson’s book, King Harald’s Saga. This opera illustrates Weir’s remarkable compositional style, including her treatment of the libretto in narrative style and her representation of multiple characters by one singer. Despite Weir’s fame as an opera composer, King Harald’s Saga is rarely performed owing to three major musical and performing challenges. These challenges are performer’s ability to delineate eight separate characters (dramatic challenges), to sing wide leaps and long melismas (vocal challenges), and to perform a cappella with wide leaps and complex rhythms (musical challenges). This dissertation presents a performance guide for the soprano addressing these three challenges and suggesting possible solutions. Such a guide will assist the soprano in preparing and performing this grand opera, which thus far has not received the due attention and appreciation of either performers or audiences.

This diploma thesis dealt with the influence of relative weir height of rectangular broad-crested weir on discharge coefficient. Based on the level measurement in front of weir for different heights of the weir P and discharges were determined values of discharge coefficient according h/P. These values were compared with the results of measurements and relationships, which are mentioned in the professional literature. In conclusion were derived new relationships that can be used to calculate the discharge coefficient relative to the overflow head.

Este trabalho propõe uma soleira assimétrica elíptica-circular com apenas dois pontos de descontinuidade, com parâmetros geométrico associados à vazão específica de projeto, com possibilidade de padronização e cujas características hidráulicas (linha d´água, pressões, coeficiente de vazão) podem ser determinadas teoricamente. Um sistema de equações diferenciais parciais permite o desenvolvimento de um modelo computacional para determinação dos valores teóricos dessas características. A validação dos valores teóricos das características hidráulicas da soleira por um modelo computacional foi realizada com a confrontação desses mesmos valores obtidos em um modelo físico, permitindo a comparação de pressões, linha d´água, coeficiente de vazão e profundidade crítica.<br>In this work is proposed an asymmetrical (elliptical-circular) weir with two points of discontinuity only, with geometrical parameters associated to the specific design discharge, allowing the standardization, and whose hydraulic characteristics (water profile, pressures and discharge coefficient) may be theoretically determinate. Their hydraulic characteristics, developed by a system of partial differential equations, system allowing the development of a computational model to determine the theoretical values of the weir hydraulic characteristics. The validation of these theoretical values of the weir hydraulic characteristics, obtained by a computational model, was made by the comparison between the values of water profile, pressures, discharge coefficient and critical depth obtained by the theoretical model and the values obtained by the physical model.

CoordenaÃÃo de AperfeiÃoamento de NÃvel Superior<br>Natural and synthetic estrogens are naturally excreted by humans and some vertebrates. These emerging contaminants classified as endocrine disruptors (EDs) present, even in small quantities, in water and sediment are able to affect the endocrine system and the stages of growth and reproduction of aquatic organisms and humans. In this context, this study aimed to perform a physical-chemical and microbiological characterization of reservoir water from Santo AnastÃcio, located in CearÃ, Brazil, and the develop and validate an analytical method using High-performance liquid chromatography with detector diode array (HPLC-DAD) for the determination of caffeine (CAF) and estrone hormones, 17&#946;-estradiol, estriol (natural) and 17&#945;-ethinylestradiol (synthetic) for water and sediment phase of reservoir water studied. The physicochemical parameters evaluated were phosphorus, chlorophyll A, pheophytin, nitrogen, chloride, sulfide, hardness, calcium, magnesium, pH, alkalinity, turbidity and total and dissolved solids. Microbiological characterization evaluated the presence of total and fecal coliforms. For the determination of EDs by HPLC-DAD was used to extract solid phase techniques (SPE) for water sample and QuEChERS for the sediment sample. The results of physicochemical analyzes indicated above the allowed values by CONAMA 357/05 for class 2, only to phosphorus and sulfide. Microbiological characterization indicated the presence of coliforms far above the values stipulated by CONAMA. In determining the DEs concentrations from 0.54 to 0.93 &#956;g L-1 were detected caffeine in water, and 0.76 to 4.94 mg kg-1 17&#946; estradiol and estriol in the sediment. Therefore, the water reservoir is unsuitable for direct consumption and recreation within the law. The validated analytical method was efficient for the determination of analytes can be used for routine analysis since there is no legislation to caffeine and EDs.<br>EstrÃgenos naturais e sintÃticos sÃo naturalmente excretados por seres humanos e alguns vertebrados. Estes contaminantes emergentes classificados como desreguladores endÃcrinos (DEs) presentes, mesmo em pequenas quantidades, na Ãgua e no sedimento sÃo capazes de afetar o sistema endÃcrino e as fases de crescimento e reproduÃÃo de organismos aquÃticos e humanos. Nesse contexto, este trabalho teve como objetivos efetuar uma caracterizaÃÃo fÃsico-quÃmica e microbiolÃgica da Ãgua do aÃude Santo AnastÃcio, localizado no CearÃ, Brazil, alÃm de desenvolver e validar um mÃtodo analÃtico empregando a cromatografia lÃquida de alta eficiÃncia com detector de arranjos de diodos (HPLC-DAD) para determinaÃÃo da cafeÃna e dos hormÃnios estrona, 17&#946;-estradiol, estriol (naturais) e 17&#945;-etinilestradiol (sintÃtico) na Ãgua e no sedimento do aÃude mencionado. Os parÃmetros fÃsico-quÃmicos avaliados foram fÃsforo, clorofila A, feofitina, nitrogÃnio, cloreto, sulfeto, dureza, cÃlcio, magnÃsio, pH, alcalinidade, turbidez e sÃlidos totais e dissolvidos. A caracterizaÃÃo microbiolÃgica avaliou a presenÃa de coliformes totais e termotolerantes. Para a determinaÃÃo dos DEs por HPLC-DAD utilizou-se as tÃcnicas de extraÃÃo em fase sÃlida (SPE) para a amostra de Ãgua e QuEChERS para a amostra de sedimento. Os resultados das anÃlises fÃsico-quÃmicas indicaram valores acima do permitido pelo CONAMA 357/05, para classe 2, apenas para fÃsforo e sulfeto. A caracterizaÃÃo microbiolÃgica indicou a presenÃa de coliformes muito acima dos valores estipulados pelo CONAMA. Na determinaÃÃo dos DEs foram detectados as concentraÃÃes de 0,54 a 0,93 &#956;g L-1 de cafeÃna na Ãgua, e, 0,76 a 4,94 mg kg-1 do 17&#946; estradiol e estriol no sedimento. Diante disso, a Ãgua do aÃude encontra-se inadequada para consumo direto e recreaÃÃo dentro da legislaÃÃo vigente. O mÃtodo analÃtico validado mostrou-se eficiente para determinaÃÃo dos analitos podendo ser utilizado para anÃlises de rotina uma vez que nÃo existe legislaÃÃo para a cafeÃna e os DEs.