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1
Sapp, Brian Keith. "Observations of Laboratory Rip Currents." Thesis, Georgia Institute of Technology, 2006. http://hdl.handle.net/1853/10453.
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Laboratory experiments of rip current systems are performed in a wave basin with a bar and rip channel geometry at the Ocean Engineering Laboratory at the University of Delaware. The experiments include both in situ water level and velocity measurements and optical visualization of the flow field under a variety of normal-incident wave conditions. Digital video is used to record surface drifters moving through a rip current system. A method is presented that tracks these digitally-recorded drifters into long Lagrangian sequences. The laboratory measurements capture both an Eulerian and Lagrangian description of the rip current system.
Time-averaged rip current properties are calculated and analyzed using both in situ and video measurements. From the video, Lagrangian velocities are computed with forward differencing of the low-pass filtered drifter tracks. Wave properties are also estimated using the orbital drifter motions and linear (Airy) wave theory. The effects of various wave conditions on the time-averaged rip current systems are investigated to show that wave height is a critical parameter. Measurements of circulation cells are obtained by spatially averaging the drifter track velocity measurements into a polar grid ranging from 0.25 m to 3.25 m from the center of the cell. Circulation cell features, such as the center of circulation and cell width, are calculated to characterize their response to various wave conditions.
Spectral analyses are used to characterize the rip current pulsations in the experimental measurements. Three frequencies are found to be energetic in several of the experiments in the low frequency band: the wave group frequency, a lower frequency, and the interaction of the wave group and lower frequencies. Some experiments have significant energy at each of the three peaks, where others have only one or none. The lower frequency motions have also been found in the video measurements and attributed to rip meandering. Possible causes for the low-frequency pulsations, including wave basin seiching, circulation cell instabilities, and wave-current interaction, are discussed.
This thesis adds to previous rip current studies by providing a spatially-large and time-varying perspective of rip current systems as a whole.
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Gutierrez, Enrique. "Effects of longshore currents on rip currents." [Gainesville, Fla.] : University of Florida, 2004. http://purl.fcla.edu/fcla/etd/UFE0004905.
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Morrison, Jonathan David. "Lagrangian observations of rip currents." Thesis, Monterey, Calif. : Naval Postgraduate School, 2007. http://bosun.nps.edu/uhtbin/hyperion-image.exe/07Sep%5FMorrison.pdf.
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Thesis (M.S. in Physical Oceanography)--Naval Postgraduate School, September 2007.Thesis Advisor(s): MacMahan, Jamie H. "September 2007." Description based on title screen as viewed on October 25, 2007. Includes bibliographical references (p. 39-41). Also available in print.
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Maryan, Corey C. "Detecting Rip Currents from Images." ScholarWorks@UNO, 2018. https://scholarworks.uno.edu/td/2473.
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Rip current images are useful for assisting in climate studies but time consuming to manually annotate by hand over thousands of images. Object detection is a possible solution for automatic annotation because of its success and popularity in identifying regions of interest in images, such as human faces. Similarly to faces, rip currents have distinct features that set them apart from other areas of an image, such as more generic patterns of the surf zone. There are many distinct methods of object detection applied in face detection research. In this thesis, the best fit for a rip current object detector is found by comparing these methods. In addition, the methods are improved with Haar features exclusively created for rip current images. The compared methods include max distance from the average, support vector machines, convolutional neural networks, the Viola-Jones object detector, and a meta-learner. The presented results are compared for accuracy, false positive rate, and detection rate. Viola-Jones has the top base-line performance by achieving a detection rate of 0.88 and identifying only 15 false positives in the test image set of 53 rip currents. The described meta-learner integrates the presented Haar features, which are developed in accordance with the original Viola-Jones algorithm. Ada-Boost, a feature ranking algorithm, shows that the newly presented Haar features extract more meaningful data from rip current images than some of the current features. The meta-classifier improves upon the stand-alone Viola-Jones when applying these features by reducing its false positives by 47% while retaining a similar computational cost and detection rate.
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Brown, Jeffrey W. "Lagrangian field observations of rip currents." Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file, 133 p, 2008. http://proquest.umi.com/pqdweb?did=1633772921&sid=6&Fmt=2&clientId=8331&RQT=309&VName=PQD.
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Woods, John E. "Rip current/cuspate shoreline interactions in Southern Monterey Bay." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2005. http://library.nps.navy.mil/uhtbin/hyperion/05Sep%5FWoods.pdf.
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Thesis (M.S. in Meteorology and Physical Oceanography)--Naval Postgraduate School, September 2005.Thesis Advisor(s):Edward Thornton, Timothy Stanton. Includes bibliographical references (p.41-42). Also available online.
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Holt, Robert D. "Rip current spacing in relation to wave energetics and directional spreading." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2003. http://library.nps.navy.mil/uhtbin/hyperion-image/03Jun%5FHolt.pdf.
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Thesis (M.S. in Physical Oceanography)--Naval Postgraduate School, June 2003.Thesis advisor(s): Edward B. Thornton, Timothy Stanton. Includes bibliographical references (p. 59-62). Also available online.
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Thorpe, Antony. "Sediment transport and bedform dynamics in rip currents." Thesis, University of Plymouth, 2016. http://hdl.handle.net/10026.1/6558.
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Simultaneous in-situ measurements of waves, currents, water depth, suspended sediment concentrations and bed profiles were made in a rip channel on Perranporth Beach, Cornwall, UK. Perranporth is a high energy beach (annual offshore Hs = 1.6 m) which is macro-tidal (mean spring range = 6.3 m) and the grain size is medium sand (D50 = 0.28 – 0.34 mm). It can be classified as a low tide bar – rip beach and exhibits a relatively flat inter-tidal zone with pronounced rhythmic low tide bar - rip morphology. Data were collected over two field campaigns, totalling 14 tidal cycles and including 27 occurrences of rip currents, in a range of offshore wave heights (Hs = 0.5 – 3 m). The in-situ measurements were supplemented with morphological beach surveys. Sediment samples were taken for grain size analysis. The rip current was found to be tidally modulated. The strongest rip flow (0.7 m/s) occurred at mid to low tide, when waves were breaking on the adjacent bar. Rip flow persisted when the bar had dried out at the lowest tidal elevations. The rip was observed to pulse at a very low frequency (VLF) with a period of 15 - 20 minutes, which was shown to be influenced by wave breaking on the adjacent bar. The rip was completely in-active at high tide. Bedforms were ubiquitous in the rip channel and occurred at all stages of the tide. Visual observations found bedforms to be orientated shore parallel. When the rip was active, mean bedform length and height was 1.45 m and 0.06 m respectively. The size and position of the bedforms in the nearshore suggested that they were best classified as megaripples. When the rip was not active, the mean bedform length and height was 1.09 m and 0.06 m respectively. In rip conditions, with typical mean offshore flow rates of > 0.3 m/s, the bedforms migrated in an offshore direction at a mean rate of 0.16 cm/min and a maximum rate of 4.6 cm/min. The associated mean bedform sediment transport rate was 0.0020 kg/m/s, with a maximum rate of 0.054 kg/m/s. In the rip, migration rates were correlated with offshore directed mean flow strength. In non-rip conditions, bedform migration was onshore directed with a mean rate of 0.09 cm/min and a maximum rate of = 2.2 cm/min. The associated mean bedform transport rate was 0.0015 kg/m/s, with a maximum rate of = 0.041 kg/m/s. The onshore bedform transport was correlated with incident wave skewness, and was weakly correlated with orbital velocity. Over a tidal cycle, the offshore directed bedform transport was only marginally larger in rip currents than when it was when onshore directed in non-rip conditions. Sediment suspension in the rip current was shown to be dependent on the presence of waves. Suspended sediment transport was dominated by the mean flux. The mean flux contributed > 70% of total suspended transport on 19 out of the 27 observed rip current occurrences. The net contribution of the oscillatory flux was small compared to the mean flux. Within the oscillatory component, a frequency domain partitioning routine showed that the VLF motion was an important mechanism for driving offshore directed sediment transport. This was balanced by onshore directed sediment transport at incident wave frequency of a similar magnitude. Depth integration showed that the mean total suspended sediment transport was in the range of 0.03 kg/m/s to 0.08 kg/m/s. At high tide, when the rip was inactive suspended sediment transport rates were minimal compared to when the rip was active. Bedform transport was (on average) 6% of the total suspended sediment transport in a rip current. The new results presented here show that rip currents make an important contribution to offshore directed sediment transport. The magnitudes of transport indicate that future improvements to morphology change models should include rip driven offshore sediment transport.
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Minetree, Courtney M. "Rip channel migration in the nearshore." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2006. http://library.nps.navy.mil/uhtbin/hyperion/06Sep%5FMinetree.pdf.
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Thesis (M.S. in Physical Oceanography)--Naval Postgraduate School, September 2006.Thesis Advisor(s): Edward Thornton. "September 2006." Includes bibliographical references (p. 39-40). Also available in print.
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He, Liang. "Video-based particle image velocimetry of laboratory rip currents." Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file, 120 p, 2007. http://proquest.umi.com/pqdlink?did=1253510551&Fmt=7&clientId=79356&RQT=309&VName=PQD.
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Chabaud, Valentin. "The potential of extracting wave energy from rip currents." Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for energi- og prosessteknikk, 2011. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-12993.
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Existing wave energy converters are only based on a few ways to produce electricity from ocean waves. All of them suffer from low cost-efficiency so the proposal of new technologies is still up to date. This is a preliminary study to an innovative concept, based on wave-induced currents. As waves propagate into shallow water and break over a barrier, they dissipate their energy. The latter can be partly transformed in a hydraulic potential through the wave set-up behind the barrier and the cross-shore mass transport from waves. Electricity can then be produced by the mean of a water turbine.This study estimates qualitatively this energy potential. The 2D set-up is analyzed by the model of Calabrese et al. (2008) and is adapted to 3D for a regulated net cross-shore discharge. The 3D model of Bellotti (2004) is also used. Experiments have been carried out on a simplified lab-scale model to check qualitatively the applicability of the models, determine experimentally their calibration parameters and find the optimal combination flow rate/pressure head which gives the highest hydraulic potential. Two different barrier profiles are tested: a breakwater-like barrier with a steep seaward slope and a sandbar-like barrier with a mild slope. Despite a significant uncertainty, experimental and analytical results correlate well.The conclusions on the future of this technology are not thorough. Experimental conditions applied to full scale show a quite low efficiency compared to the main competitors, but much more perspectives of optimization are conceivable. Some of them have been studied from an analytical point of view.
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Keefer, Thomas B. "Dune erosion, mega-cusps and rip currents modeling of field data." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2006. http://library.nps.navy.mil/uhtbin/hyperion/06Sep%5FKeefer.pdf.
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Thesis (M.S. in Physical Oceanography and Meteorology)--Naval Postgraduate School, September 2006.Thesis Advisor(s): Edward B. Thornton. "September 2006." Includes bibliographical references (p. 37-38). Also available in print.
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Woodward, Eleanor Molly. "Rip currents in the UK : incident analysis, public awareness, and education." Thesis, University of Plymouth, 2015. http://hdl.handle.net/10026.1/3529.
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Rip currents present a severe hazard to water users worldwide, resulting in over 100 drownings and thousands of lifeguard rescues annually. This thesis examines the demographics of who is effected by rip currents in the UK, what activity they are undertaking, when and where incidents occur, how much the public know, what people have experienced, and how best to educate them. Analysis of 7909 rip current lifeguard rescues (16777 people) across the UK between 2006-2013 highlighted the most at risk group, and subsequent target audience for education, to be male teenagers aged between 13-17 years old (n=2906, 17%). Geographically, the highest incidents occurred on the beaches in the Southwest of England (n=6911, 87%). Incidents mostly occurred outside of lifeguard flagged areas (n=4302, 54%) and mainly involved those using bodyboards (n=5290, 52%). Through the analysis of 407 public beach-based rip current and beach safety questionnaires, it was established that beach users have a poor understanding of rip currents (n=263, 65%) but a good perception of the beach safety flags (n=389, 96%). People with greater knowledge were typically educated by a lifeguard, enter the sea more frequently or have been caught in rip currents themselves. The experiences of 553 people caught in rip currents were analysed using an online questionnaire. The gender split was 69% male (n= 382) to 31% female (n= 171), indicating that males are caught in rip currents more than females. Swimming directly to shore against the rip followed an initial panic (n=108, 34%) for most people caught in a rip. Swimming parallel to the beach was the most remembered, advised, utilised, and promoted safety message. Respondents advocated the use of lifeguards to disseminate rip current safety messages. A new and unique rip current education programme was developed from the synthesis of these results. A lifeguard delivered a pilot programme to 185 teenagers in three schools and two community groups in the Southwest of England. This interactive pilot consisted of exercises using videos, photographs, news reports, and a swimming machine. Levels of rip current knowledge were evaluated before and after, and at regular intervals, to assess knowledge retention. The short-term effects after 3 months were positive, showing statistically significant (p < 0.0005) improvements in mean knowledge levels. This thesis provides a new contribution to the expanding field of social and behavioural rip current research. The development of a unique rip current education programme presents an alternative method for increasing public awareness, and supports the worldwide prevention of rip current incidents and fatalities.
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Weir, Brad. "The transfer of momentum from waves to currents due to wave breaking." Diss., The University of Arizona, 2010. http://hdl.handle.net/10150/195128.
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The research presented in this dissertation focuses on understanding the dynamics of waves and currents in the presence of wave breaking. The simplest approach, direct numerical simulation of the ocean dynamics, is computationally prohibitive--waves typically have periods of tens of seconds, while currents vary on times from hours to days. This work uses a multi-scale asymptotic theory for the waves and currents (Craik and Leibovich, 1976; McWilliams et al., 2004}, similar to Reynolds-averaged Navier-Stokes, in order to avoid resolving the wave field. The theory decomposes the total flow into the mean flow (current) and fluctuations (waves), then takes a moving time average of the total flow equations to determine the wave forcing on the current. The main challenge is extending this theory to include a physical model for dissipative wave effects, notably breaking, in terms of the wave age, wind speed, and bottom topography. Wave breaking is difficult to observe, model, and predict, because it is an unsteady, non-linear process that takes place over disparate scales in both space and time. In the open ocean, white-capping often covers less than 2% of the surface, yet still plays an important role in the flux of mass, momentum, heat, and chemicals between the atmosphere and ocean. The first part of this dissertation proposes a stochastic model for white-capping events, and examines the stability of the ensemble average of these events. Near the shore, the decreasing ocean depth causes waves to overturn and break. Over time, this drives currents that erode sediment from beaches and deposit it around coastal structures. These currents are often so strong that their effect on the wave field, and thus their own forcing, is significant. A detailed analysis of this phenomena makes up the second part of this dissertation.
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Johnson, David. "The spatial and temporal variability of nearshore currents." University of Western Australia. Centre for Water Research, 2004. http://theses.library.uwa.edu.au/adt-WU2004.0067.
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The nearshore current field, defined here as the residual horizontal flow after averaging over the incident wave period, exhibits variability at a range of time and space scales. Some of the variable currents are low frequency gravity wave motions. However, variable, rotational (in the sense of possessing vertical vorticity) flow can also exist as part of the overall nearshore current field. A field and numerical modelling investigation of these variable rotational currents has been carried out. Drifters, which were developed for surfzone use, enabled measurement of the nearshore current structure; the design and testing of these new instruments is described. Two sets of field measurements, using the new drifters and Eulerian instruments were carried out for conditions with swell perpendicular to a plane beach and in strong longshore currents. In the perpendicular swell conditions, an interesting and well-defined feature of the measured trajectories was the development of transient rip currents. Discrete vortices were also observed. In the longshore current case, trajectories with the longshore current displacement removed had complex meandering paths. Lagrangian data were used to make estimates of length scales and dispersion, both of which provide strong evidence that the current field cannot be due to low frequency gravity waves alone. Under the assumption of equipartition of kinetic and potential energy for low frequency gravity waves, Eulerian measurements of velocities and pressure show significant energy due to non-divergent, rotational flow in both the perpendicular swell and longshore current case. A numerical model that can simulate horizontal flow with a directionally spread, random wave field incident on a plane beach was implemented. The model developed transient rip currents that are qualitatively very similar to those seen in the drifter trajectories from the field. The number and intensity of rip currents in the model depended on the beach slope and incident wave spectra. The energy content and cross-shore flux (and hence transport of material) of the rotational current flow component in the simulated flow fields is comparable to that due to low frequency gravity waves. The modelling also provided some evidence that there may be universal characteristics of the rotational currents. The field results and modelling show that variable rotational currents are ubiquitous in the field even when longshore currents and hence shear waves are not present. The term “infragravity turbulence” is suggested to describe the general class of nearshore hydrodynamics not directly associated with shear waves, which is largely disorganised, but contains well defined features such as transient rips currents and large scale horizontal vortices. The results have important implications in the understanding of the transport of material, including sediment, biological material, pollution, and sometimes bathers, in the nearshore zone.
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Leatherman, Stephen B. "Rip Current Generation, Flow Characteristics and Implications for Beach Safety in South Florida." FIU Digital Commons, 2018. https://digitalcommons.fiu.edu/etd/3884.
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Rip currents are the most dangerous hazard at surf beaches. Rip currents in South Florida have previously not been studied. Beach profiles for three Florida beaches (Miami Beach, Lido Beach, Sarasota, and Pensacola Beach) and one Georgia beach (South Cumberland Island) were chosen for surveying because of their variable sand bar heights. Rip current hazard at each beach was assessed by lifeguard rip rescue and drowning statistics. A relationship was found between sand bar height, beach slope and rip current hazard.
Rip current measurements in South Florida, which involved utilizing GPS drifters, laser rangefinder and drone-imaged fluorescent tracer dye, showed that the speed ranged from 0.1-0.5 m/s, which is fairly slow compared to such measurements undertaken in California and Australia. The effect of rip currents on swimmers was analyzed based on the drag force acting on swimmers and the power they generate to overcome the currents when swimming against them. The drag force and power increase quadratically and cubically, respectively, with the increase of rip current and swimming speeds. Hence, even rip currents of low velocity can be dangerous and swimming against the current should be avoided if possible.
Strong rips in California have been shown to exhibit a circulatory pattern, which could bring a floater back to the safety of a shallow sand bar. Field measurements of rip currents in South Florida clearly defined the flow characteristics of a nearly straight-line current, sometimes deflected to the east-southeast. Therefore, the traditional approach of swimming left or right, parallel to the shore is the best escape strategy, but not against the longshore current if present. A logistic regression analysis was conducted to predict the occurrence of rip currents based on beach conditions. The logistic model showed that wave height, wave period and wind speed were statistically significant factors in rip generation. Rips were found to be most commonly generated by relatively small, non-threatening waves (e.g., 0.6 to 0.9m in height). These physical factors, along with social and safety considerations, pose a significant problem for coastal management.
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Strauss, Darrell Richard. "Morphological Modelling of Intermediate Beach State Transitions." Thesis, Griffith University, 2010. http://hdl.handle.net/10072/367253.
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Temporal and spatial changes in nearshore bathymetry result from sediment transport interactions with the hydrodynamic processes and provide a highly variable and rapidly changing environment. Rip currents are one example of a morphody- namic system presenting a significant hazard to swimmers unfamiliar with their behaviour. Rip currents pose a particular threat as they can develop suddenly and quickly transport water offshore.
The widely accepted beach state model of Wright & Short (1984) uses param- eters which are functions of breaking wave height, wave period and sediment (Dean 1973, Gourlay 1968, Guza & Inman 1975) to classify the beach environment into distinct morphological states. These states range from reflective through inter- mediate to dissipative.
Breaking wave type is influenced by the bathymetry as the wave approaches breaking point within the surf-zone and can be classified by the the Iribarren num- ber or surf-similarity parameter (Battjes 1974). Intermediate beach states can be more difficult to assess with these parameters and may even consist of a combination of outer dissipative and inner locally reflective zones.Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
Griffith School of Environment
Science, Environment, Engineering and Technology
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Fallon, Kathleen Michelle. "Rip Current Formation and Beach Safety Implications for Several U.S. Atlantic Coast Beach Areas." FIU Digital Commons, 2017. http://digitalcommons.fiu.edu/etd/3382.
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This dissertation combines seemingly different studies, which work together to describe the physical characteristics of rip current development and associated social implications at several locations. These fast-moving, concentrated flows of water travel offshore and can be found on any beach with sufficient wave action. Any event of increased wave steepness will erode a large quantity of sediment from the beach. The material deposited offshore eventually makes its way back; during this process, ocean water becomes trapped behind a shore-attached bar resulting in a ridge-and-runnel. These formations are seen at East Hampton, where rip-like currents form as concentrated water drains from the runnel through a breach in the ridge. Camera images from 2010-2016 captured ridge-and-runnel formations and the ensuing currents. These newly described rips behave similarly to bar-gaps; however, they are not directly related to wave action. Coastal scientists consider rip currents to be the number one hazard at most beaches. In Palm Beach County, two traditional rip types were studied: bar-gap and structurally-controlled. Lifeguard incident reports from 2011-2016 were used to correlate wind speeds and wave heights to rip related rescues at three beaches. This research was undertaken in an effort to determine under what conditions most beachgoers become caught in this hazard. Rip currents were seen to be the most dangerous to bathers on days with moderate wind and wave activity. The same beach states that lead to the strongest rips also tend to keep beachgoers from entering the ocean. A social survey at Miami Beach, from 2011 to 2012, quantified beachgoer’s rip knowledge and their recognition of hazards. A significant portion of the respondents showed insufficient knowledge, which indicated they are at-risk of being caught or drowning in a rip current. Frequent exposure to the beach, maturation, and residency were identified as the main contributors to one’s literacy whereas education was the only variable that influenced a beachgoer’s visual recognition of hazard. The information gathered by these surveys can aid in creating better rip current awareness campaigns targeted to demographics that were determined as the most at-risk. An understanding of the physical and social science of rip currents can mitigate the impact of these beach hazards.
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Murray, Thomas Peter. "Surf Zone Circulation and Transient Rip Currents on a Microtidal and Wave Dominated Open Coast Beach, Gold Coast, Australia." Thesis, Griffith University, 2016. http://hdl.handle.net/10072/367054.
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Surf zone circulation patterns are recognised in the literature as having an important influence on cross- and alongshore exchange of water, sediment, and floatsam in the surf zone. Any study of surf zone circulation patterns therefore has implications for sediment transport, biological processes and beach safety, with the majority of studies focusing upon rip current circulation and rates of cross-shore exchange of drifters due to rip currents.
The aim of recent research has been to describe surf zone circulation patterns and retention of floatsam in the surf zone, with a major focus on informing rip current escape strategies and hazard mitigation. Previous studies have focused upon single bar embayed beaches in a microtidal environment or open coast beaches in a mesotidal or macrotidal environment, exposed to a generally shore-normal wave climate and displaying relatively stable bar morphology. This thesis explored surf zone circulation patterns and transient rip currents on the open beaches of the northern Gold Coast, Australia. These beaches are characterised as being microtidal and wave dominated, double bar, open coast beaches with no bounding headland morphology. The beaches are exposed to a highly variable wave climate, which is often bimodal and bidirectional and the dominant angle of wave approach is oblique to the shoreline. The double bar beach state combinations are complex and highly dynamic and sandbar and rip features are often skewed in response to the oblique angle of wave approach and prevailing longshore current.Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
Griffith School of Engineering
Science, Environment, Engineering and Technology
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Bruneau, Nicolas. "Modélisation morphodynamique des plages sableuses." Thesis, Bordeaux 1, 2009. http://www.theses.fr/2009BOR13765/document.
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Le long des littoraux sableux tels que la côte Aquitaine, les vagues et principalement les courants moyens induits par celles-ci jouent un rôle majeur dans l’évolution morphologique des plages. Que ce soit d’un point de vue socio-économique (aménagement des plages, protection de l’environnement) ou sécuritaire (noyade), comprendre la dynamique de tels environnements est devenu un réel enjeu scienti?que ces dernières années. Le développement d’une plateforme de modélisation morphodynamique opérationnelle a été menée au cours de cette thèse. Ce modèle est basé sur le couplage du modèle spectral de houle SWAN (Delft University of Technology) avec le modèle MARS 2DH (Ifremer), initialement conçu pour calculer les courants induits par la marée et les vents. Après avoir ajouté les phénomènes liés à la houle, un modèle sédimentaire a été développé pour estimer les évolutions morphodynamiques. La campagne de mesures Biscarrosse-PréECORS menée en juin 2007 sur la plage de Biscarrosse a permis de valider le modèle pour une large gamme d’état de mer. Le modèle a montré son e?cacité et sa robustesse pour décrire les courants et des circulations induites par les vagues au dessus de fortes hétérogénéités bathymétriques. Nous avons mis en évidence la forte modulation tidale des courants sagittaux qui sont intenses même pour de faibles conditions de vagues. La plateforme de modélisation morphodynamique a permis d’analyser la formation et le développement de morphologies tridimensionnelles rythmiques pour des systèmes simple et double barre. Pour les environnements à double barre comme la côte Aquitaine, l’intense couplage morphologique entre la barre externe et la barre interne a été étudié en réponse aux conditions de forçages. Nous avons mis en évidence l’in?uence de la marée sur la croissance des barres et révélé la corrélation existant entre croissance des barres et dissipation d’énergie des vagues sur les barres. Cette thèse a abouti au développement d’un modèle complet permettant d’appréhender la dynamique des environnements littoraux sableuxAlong many sandy environments as the Aquitanian Coast, waves and wave-induced currents play a key role on the beach morphodynamics. Within a socio-economic (human interventions, natural environment protection) and touristic (human safety) framework, understand the complex dynamics of these systems is a real scienti?c challenge these last decades. The development of an operational morphodynamical modeling platform was performed during this PhD thesis. The modeling strategy consists in coupling the spectral wave model SWAN (Delft Univer- sity of Technology) with the non-linear shallow water model MARS 2DH (Ifremer). The MARS model was initially designed to compute tide- and wind-induced currents. Thus, the wave processes and a sed- imentary unit were implemented inside MARS to compute morphological evolutions of wave-dominated sandy beached. The Biscarrosse-PréECORS ?eld experiment carried out in June 2007 at Biscarrosse Beach was used to validate our modeling platform for a large range of o?shore wave conditions. Results have proved the e?ciency and the robustness of our model to calculate wave-induced currents and circulations over alongshore non-uniformities. The strong tidal modulation of currents and the intense rip currents for low-energy conditions were highlighted. The morphodynamical modeling platform was also used to analyze the generation and the development of rhythmic three-dimensional morphologies for one- and double-barred systems. For double-barred en- vironments, the intense morphological coupling between the inner and outer bar was studied in the response of wave and tide forcing. We have highlighted the in?uence of the tide on the bar growth and showed the correlation between the growth and the wave dissipation over the bar. This thesis has succeeded in the development of a complete model for understanding the dynamics of sandy coastal environments
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Engle, Jason A. "Formulation of a rip current forecasting technique through statistical analysis of rip current-related rescues." [Gainesville, Fla.] : University of Florida, 2003. http://purl.fcla.edu/fcla/etd/UFE0000680.
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Schrader, Matthew. "Evaluation of the modified ECFL LURCS rip current forecasting scale and conditions of selected rip current events in florida." [Gainesville, Fla.] : University of Florida, 2004. http://purl.fcla.edu/fcla/etd/UFE0004854.
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Thomas, David A. "Laboratory rip current circulation using video-tracked lagrangian drifters." [Gainesville, Fla.] : University of Florida, 2003. http://purl.fcla.edu/fcla/etd/UFE0001217.
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Pitman, Sebastian John. "Wave dissipation patterns as an indicator of rip current hazard." Thesis, University of Southampton, 2017. https://eprints.soton.ac.uk/415493/.
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Rip currents (rips) are hazardous offshore-directed flows in the surfzone of beaches worldwide. Rips are a major hazard for recreational beach use and are the dominant cause of beach rescues and drownings. It is therefore important to understand what conditions make a rip most hazardous, in order for beach safety practitioners to mitigate the risk. The aim of this thesis was to determine how patterns of wave breaking influence rip channel hazard on beaches. In order to quantify wave breaking, video imagery from three hydrodynamically diverse case studies was used, and validated at two sites against Lagrangian GPS drifter data. This thesis firrst developed pre-processing techniques for video imagery which then subsequently improved the reliability of rip channel detection. Hitherto, the noise inherent in such signals has made automated detection of rip currents problematic. Wave breaking patterns could then be identified with the novel application of synoptic typing methods to the imagery, resulting in a classification scheme for rip currents based on wave breaking. Two dominant types were identified: (1) open channels, whereby the rip channel has free connectivity to the region beyond the surfzone; and (2) closed channels, where wave breaking across the seaward extent of the channel effectively closes this connectivity to the offshore region. Investigation of Lagrangian data for each of the prevailing states shows that under open conditions, drifters were highly likely to be transported beyond the edge of the surfzone by the rip current, with exit rates reaching 100 % at times. Under closed conditions, drifters were more likely to be retained in the surfzone, with typical exit rates between 0 and 35 %. A rip current that exits the surfzone is more hazardous to bathers, and therefore, this thesis subsequently investigated the prevalence of open and closed rip channels in records of rip rescue events. Over two sites for which data were available, upwards of two thirds of major rip rescues occurred when the channel could be classified by this new method as open. Furthermore, the majority of surfer and bodyboarder rescues occurred under open conditions. Despite their over-representation in the rip rescue record, the overall prevalence of open channels over a year is only around 40 %. Normalising the number of rescues in open rips by their occurrence shows open rips to be twice as hazardous as closed channels. This new approach provides a quick and inexpensive means to assess high risk surf conditions at rip beaches worldwide, with the deployment of only a small (often mobile) imaging system.
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O'Neill, Andrea C. "Characterization of episodic rip current pulsations in the inner shelf during RCEX 2007." Thesis, Monterey, Calif. : Naval Postgraduate School, 2009. http://edocs.nps.edu/npspubs/scholarly/theses/2009/March/09Mar%5FFO%5FNeill.pdf.
Full textAbstract:
Thesis (M.S. in Meteorology and Physical Oceanography)--Naval Postgraduate School, March 2009.Thesis Advisor(s): MacMahan, Jamie. "March 2009." Description based on title screen as viewed on April 23, 2009. Author(s) subject terms: Rip currents, rip current structure, episodic rip current pulsations, inner shelf, RCEX 2007, surf zone volume exchange, Sand City, nearshore circulation Includes bibliographical references (p. 45-48). Also available in print.
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Paxton, Charles Hugh. "Atmospheric and Ocean Conditions and Social Aspects Associated with Rip Current Drownings in the United States." Scholar Commons, 2014. https://scholarcommons.usf.edu/etd/5096.
Full textAbstract:
The purpose of this research is to provide a better understanding of the physical and social aspects of rip currents in ocean areas that will lead to better forecasts, better governmental policies in beach areas, and ultimately to save lives. A rip current is a nearshore circulation in which breaking waves run up onto the beach then retreat rapidly in deeper channels back toward the sea. Rip currents pose a significant threat to beachgoers and can pull even the strongest swimmers out to sea. The primary factors associated with rip current formation on unarmored beaches are variations in the local beach bathymetry, wind-generated longshore waves of varying height, and lower tidal stages. The rationale for this study is highlighted when rip current deaths are put in context with deaths from other weather related deaths. The average number of rip current deaths per year in the United States is 46 and in the year 2010 rip currents were responsible for 64 deaths which was higher than the deaths associated with lightning, tornadoes, hurricanes and the cold winter during the year. The methodology followed for this study includes a review of demographics from over 500 rip current drowning reports along the Atlantic Ocean, Pacific Ocean and Gulf of Mexico coasts of the United States from 1994-2012. This research indicates that tourists are often victims, and rescuers can become the victims. For each state or sub-state area where rip current drownings are prevalent, an analysis of social aspects, beach areas, and associated ocean and weather patterns was conducted using averaged wind and pressure fields over wave generation areas, buoy data, and tide data. It is important to understand the evolution of these drowning events and seek solutions to mitigate the problem.
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Jooste, Kritzman Phillip. "A load management system for fixed appliances in a safe DC RDP house." Thesis, Cape Peninsula University of Technology, 2017. http://hdl.handle.net/20.500.11838/2634.
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Thesis (MTech (Electrical Engineering))--Cape Peninsula University of Technology, 2017.This dissertation represents the design and development of a load management system for fixed appliances in a safe direct current (DC) Reconstruction and Development Programme (RDP) house. A combination of valley filling, load shifting and peak clipping load management techniques were employed to assist in reducing the peaks observed in the RDP house load profile during peak hours. A DC RDP house laboratory model was developed. The study is based on the assumption that the normally 220 V alternative current (AC) grid is replaced by a 350 V DC grid. The assumption is thus that 350 V DC is available at the distribution box in the RDP house laboratory model. All theoretical work was based on a 350 V DC system, but due to the lack of a laboratory 350 V DC supply, all physical tests were conducted by making use of a 300 V DC supply which was available. Consequently all calculations were thus based on 300 V DC as well. The geyser was the main fixed appliance focused on since it contributes to a significant portion of the power used. An AC geyser was successfully modified in order to be used in the DC network. Safety of the system was considered in order to interrupt the power in case of overcurrent or to isolate the power. Electronic switches were also developed and implemented to ensure that the DC power could be safely switched on and off and that the low power DC was isolated from the high power DC. LabVIEW allowed all other appliances in the DC RDP house to be virtually represented so that a holistic view of the power use of the house could be represented. This also allowed the system to be successfully simulated before any physical work was conducted. The load management system was successfully implemented by making use of power line communication. This proved to be a cost effective means to apply the load management algorithm. The algorithm consisted mainly of power on / off instructions that were executed during peak and off-peak times. It follows the normal use of timers used in the AC system to help reduce demand. It was found that the load management system successfully reduced the demand during peak hours without compromising the basic needs of the user. The power line communication modem proved to be very reliable in implementing the load management algorithm.
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SANTOS, RAFAEL FERNANDES DOS. "CURRENT SITUATION AND DEVELOPMENT PROSPECTS OF PLANNING AREA 3 OF RIO DE JANEIRO CITY." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2012. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=21836@1.
Full textAbstract:
A dispersão da mancha urbana das cidades provoca alto custo para toda a
população, com a necessidade de investimentos em saneamento, transportes e
equipamentos urbanos, além do problema da poluição e desmatamento causados
por essa expansão. Em casos como o da cidade do Rio de janeiro, a mancha
urbana ocupa praticamente todo o território municipal e se desenvolve em áreas
ainda desprovidas de infraestrutura que suporte novos empreendimentos,
enquanto outras, melhor estruturadas, ficam estigmatizadas por conceitos urbanos
pejorativos e desprestigiadas pela sociedade - os seus chamados subúrbios, hoje
conhecidos como Área de Planejamento 3. Formam-se, com isso, vazios urbanos
em áreas próximas ao centro, que poderiam ser melhor aproveitados para termos
um território mais compacto e poupador de recursos públicos. O atual Plano
Diretor da cidade estabeleceu como zonas de incentivo áreas antes
desprestigiadas, em quase toda a Zona Norte e parte da Zona Oeste, sendo um
ponto de partida para reversão do atual quadro de crescimento desordenado e
segregatório da cidade.Rio de Janeiro has had a fragmented model of expansion, where many new regions occupied not have transportation and sanitation infrastructure, and old areas, structured, tend to be disparaged and stigmatized as places of low social value. The effects on the city is catastrophic, affecting the routine of all the population and hindering the control of the territory by the government. While there were new areas to grow, the city took advantage of that. Many neighborhoods were born, evolved and died, while new spaces were created and encouraged. Came to Barra da Tijuca, the greatest example of how Rio de Janeiro has expanded to meet the desires of a particular group in search of a safe and elitist environment. Condos upper middle class were built and attracted people from all over the city and, in parallel, its sewage was dumped in the lagoons of the neighborhood. While a new Rio grew, much of the city was deteriorating, especially downtown and North Zone. In the central region, the idea of transferring downtown to Barra da Tijuca gained strength, with large companies moving into this new neighborhood. Modern buildings, wide open spaces and parking were the main differences between the two regions. In the residential aspect, concern for downtown was virtually nil. In the North Zone, with the increase of slums and violence, traditional neighborhoods were no longer the focus of the middle class carioca, with stagnating real estate investments over time and making the region passed by a process of forgetting his relevance within the context of the city, having his image associated with violence and crime. In areas called suburbian, the situation was even worse. The old industries have moved to other cities due to the daily violence of those neighborhoods, highlighting Benfica, Bonsucesso, Ramos and Penha, suffering a massive stagnation over the past decades. Associated with urban problems, prejudice was responsable for the not occupation of a large space in the city, well structured and located. But none of this was seen as a problem, but as a solution, because in Rio there were still many areas to grow and receive new residents, not being interesting recover and encourage the occupation of what had actually structure to receive new ventures. The thought of rejection of old areas and interest in new lasted nearly three decades and, as a consequence of this neglect, we have seen emerge an ancient and undervalued city and another one new and prosperous, resulting in a decentralized Rio and full of empty urban, increasingly dependent of transport, sanitation and opening new routes, generating costs for the entire population. Analyzing the urban area in Rio, in North Zone, we can see how there is a waste of urbanized areas, where there is a structured urban space, with transportation and sanitation system established, but underutilized and virtually without good projects being introduced. In certain parts of West Zone, investments are numerous, without a previous and efficient infrastructure that can receive all these investments. This is a contradiction. Currently known as Planning Area 3 (AP 3), a huge and discredited region in North Zone is in a strategic location, but is stigmatized by the media and society with pejorative concepts of class, who treats it like a suburb, but the application of that name ends up being contradictory, because, in Rio de Janeiro, this concept is associated with an etymology and not with a urban fact. There are in AP 3 urbanized neighborhoods and near downtown, but they are viewed negatively, often caused by so-called opinion leaders. AP 3 is the gateway of the city, with a strategic location to anywhere else in the city, state, country and abroad (the international airport is located there). It is the most populated area in the city and needs to be well treated, as a new investment option, regardless of titles assigned to it. With its proper use, we would have a less process of expansion toward the West Zone, giving to the Rio a efficient urban
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GOMES, PATRICIA CAROLINE GUEDES. "SOLID WASTE MANAGEMENT AT PUC-RIO GAVEA CAMPUS: DESIGN, IMPLEMENTATION AND OPERATIONAL CURRENT STATUS." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2012. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=35026@1.
Full textAbstract:
O Plano de Gestão de Resíduos Sólidos do Campus Gávea da PUC-Rio visa, inicialmente, elaborar um diagnóstico da situação gerencial, funcional e física dos resíduos sólidos na Universidade. Com isso, determinam-se dados que auxiliam na elaboração do plano de gerenciamento de resíduos, no qual estão
expostas ações para melhoria ambiental, social e financeira da Instituição de Ensino Superior. Com a elaboração das definições dos aspectos físicos e operacionais do Plano de Gestão de Resíduos Sólidos direcionado ao Campus Gávea da PUC-Rio, será planejada a implementação do Projeto de Coleta Seletiva
em duas edificações da Universidade. Considerando que um Plano de Gestão de Resíduos Sólidos passa pelas etapas de diagnóstico, implementação, verificação e revisão da gestão, ao final da implantação do Projeto, visando à melhoria contínua, será apresentado um diagnóstico relativo às características de funcionamento e operação do projeto implantado, gerando, assim, sugestões para aprimoramento do Plano de Gestão.TThe Solid Waste Management Plan at PUC-Rio, on the Gávea Campus, draws up a diagnosis of the managerial, functional and physical situation of solid waste at the University. The objective is to determine the data which will help in the preparation of the Waste Management Plan, in which actions are laid out for environmental, social and financial improvements of the institution. Once the definitions of physical and operational aspects of the Solid Waste Management Plan are laid out on the Gávea Campus, at PUC-Rio, the implementation of Selective Waste Collection Project will start in two places. Considering that a Solid Waste Management Plan goes through the stages of diagnosis, implementation, verification and revision of the management process at the end of the project, aiming at the continuous improvement, a relative diagnosis of the functional and operational characteristics of the project will be presented, generating, thus, suggestions for improvements of the Management Plan. After the diagnosis, it was possible to get a more comprehensive view of the origin, composition and system of the Solid Waste Management produced on the Gávea Campus at PUC-Rio. The management of the solid waste is done by the administrative department of the Campus, at PUC-Rio, having its operational part done by a third-party. That is, the collection, sweeping and storage of the waste proceeding from the educational, administrative and operational areas are the responsibility of the Sodexho Company, which in 2008 had 209 employees, and in the year of 2010, 220 employees, distributed in three shifts (mornings, afternoons and evenings).
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Senol, Murat Verfasser], Doncker Rik W. [Akademischer Betreuer] [De, and Torbjörn [Akademischer Betreuer] Thiringer. "Drivetrain integrated Dc-Dc converters utilizing zero sequence currents / Murat Senol ; Rik Wivina Anna de Doncker, Torbjörn Thiringer." Aachen : Universitätsbibliothek der RWTH Aachen, 2017. http://d-nb.info/1186141077/34.
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Senol, Murat [Verfasser], Doncker Rik W. [Akademischer Betreuer] De, and Torbjörn [Akademischer Betreuer] Thiringer. "Drivetrain integrated Dc-Dc converters utilizing zero sequence currents / Murat Senol ; Rik Wivina Anna de Doncker, Torbjörn Thiringer." Aachen : Universitätsbibliothek der RWTH Aachen, 2017. http://d-nb.info/1186141077/34.
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Dahlin, Jon-Erik. "Numerical studies of current profile control in the reversed-field pinch." Doctoral thesis, Stockholm : Alfvén Laboratory, Royal Institute of Technology, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-4167.
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Layman, Timothy Paul. "Productivity in the South African Public Section: Analysis of current issues and future prospects." University of the Western Cape, 1999. http://hdl.handle.net/11394/7882.
Full textAbstract:
Masters in Public Administration - MPAThis study examined the issues and concerns for improving productivity in the public sector in South Africa, aligned in particular with the processes of its fundamental transformation, and the aims and objectives of the Reconstruction and Development Programme (RDP). More than that, it provided the view, the approach, the strategies and techniques to bring about productivity improvement. Productivity is not presented as a panacea to solve all problems. It is presented mainly as an attitude about the importance of productivity that must be acquired followed by suggestions for how to bring about its development. To provide both a comprehensive and at the same time a focused approach to improving productivity in the public sector. A second objective was to describe new skills and proven strategies that could be used for productivity improvement. The study discusses various approaches to improving productivity in the public sector that can be implemented in a number of practical ways. A third and primary objective was to recommend a model that would effectively improve productivity in the public sector. This model deals with the quantification of productivity gains through the restructuring of budgets and thereby achieving significant savings that could be transferred to priority RDP programmes. This study used both qualitative and quantitative methods. The study reviewed both domestic and international published work and current research within universities, policy bodies, government departments and elsewhere, including a reconsideration of previous work. The following conclusions were reached and recommendations made: Substantial efficiency and productivity gains are envisaged through the introduction of various models for improving productivity which include a structured productivity improvement programme, the use of performance enhancing methods, performance measurements and performance related pay. Furthermore, savings, resources and capacity can be released by the RDP programmes through: Restructuring and reprioritizing the budget programmes by making small cuts in what were apartheid-serving programmes and reallocating the human, material and financial resources thus released for high priority RDP programmes/projects. International experiences show that a direct link between falls in public investment, physical infrastructure and decline in productivity exists. The effectiveness of the public sector to a large extent conditions economic development. The move towards a leaner and more cost effective public service in South Africa should be based, not on privatisation, but on the creation of effective partnerships between government, labour, business and civil society, and the building of high levels of community involvement in the local delivery of services.
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Sampaio, Paula Florence. "Nascer em hospital amigo da criança no Rio de Janeiro: um fator de proteção ao aleitamento materno?" Universidade do Estado do Rio de Janeiro, 2010. http://www.bdtd.uerj.br/tde_busca/arquivo.php?codArquivo=1516.
Full textAbstract:
Apesar de existirem evidências suficientes sobre benefícios do aleitamento materno (AM), apenas 35% das crianças são amamentadas exclusivamente até o quarto mês de vida. Visando estender esta prática, OMS/UNICEF lançaram a Iniciativa Hospital Amigo da
Criança (IHAC), que estabelece sistema de credenciamento para maternidades de acordo com
grau de incentivo ao AM. Esta dissertação pretende investigar a efetividade da IHAC na duração de dois tipos de aleitamento materno: exclusivo (AME) e predominante (AMP) entre crianças usuárias de Unidades Básicas de Saúde (UBS) do Rio de Janeiro. Trata-se de estudo transversal, sendo a população de estudo constituída de 811 mães de crianças menores de 5 meses de idade, selecionadas aleatoriamente em cinco UBS na cidade do Rio de Janeiro. A
variável de exposição foi categorizada em local de nascimento ocorridos em HAC, naqueles
em vias de receber titulação (EVHAC) e naqueles sem titulação. Os desfechos considerados foram duração do AME e do AMP, que inclui também crianças em AME (AMEP). Na análise dos dados, optou-se pelo modelo log-log complementar, que permitiu recompor experiência longitudinal da coorte através do recordatório alimentar de 7 dias e da informação da idade das mesmas, caracterizando abordagem tipo current status data. Mesmo após controle por
variáveis sociodemográficas, relativas ao estilo de vida e aos aspectos psicossociais maternos, à utilização dos serviços de saúde, idade e saúde da criança, houve maior duração do AME e AMEP em crianças nascidas em HAC e EVHAC. As taxas de AME e de AMEP são mais de
duas vezes maiores entre recém-nascidos que nasceram em HAC e EVHAC. Tal efeito diminui ao longo da idade da criança, mantendo-se evidente até quatro (EVHAC) e dois (HAC) meses de vida quando se considera AME e até dois (EVHAC) e cinco (HAC) meses quando se considera AMEP. Os resultados confirmam a efetividade da IHAC nesta clientela,especialmente na manutenção de AME e AMEP nos primeiros meses de vida. Estes também sugerem necessidade de fortalecimento da IHAC e maior integração entre maternidades e UBS, visando garantir aleitamento exclusivo até seis meses de vidaAlthough there are sufficient evidences about breastfeeding (BF) benefits, only 35% of infants worldwide are exclusively breastfed during the first four months of life. As an effort to extend BF duration, WHO/UNICEF launched the Baby-Friendly Hospital Initiative (BFHI), which establishes hospitals accreditation as Baby-Friendly Hospitals (BFH) when it meets the Ten Steps for Successful Breastfeeding. This dissertation aims to investigate the effectiveness of the BFHI on exclusive breastfeeding (EBF) and exclusive plus predominant breastfeeding (EPBF) duration. This is a cross-sectional study with collected information throughout interviews of 811 mothers of children under 5 months old, randomly selected at five health centers in Rio de Janeiro. Exposure variable was classified according to hospitals compliance with the Ten Steps. There were three possible status: accredited hospitals (BFH), working in becoming BFH or certified hospitals (CBFH) and hospitals without BFHI accreditation or certification. Outcomes were EBF and EPBF duration. Data was analyzed by complementary log-log transformation models, which allowed capture cohort longitudinal experience through 7-day feeding recordatory and infants age (current status data). Even after adjusting analysis for sociodemographic, life style and psychological maternal factors, health services use and babies age and state of health, there was longer duration of EBF and EPBF of infants born in BFH and CBFH. EBF and EPBF rates were twice higher in newborns born in BFH and CBFH. This protective effect on EBF and EPBF decreases along childs age and its noticed until four (CBFH) and two (BFH) months of age when EBF is considered and until two (CBFH) and five (EBF) months for EPBF. The finding indicates the effectiveness of BFHI in maintaining EBF and EPBF through the first months of life in this population. In order to extend BF duration until six months of life, as recommended by WHO, it would be necessary not only to strengthen the BFHI but also to develop and encourage more actions in favor of breastfeeding, focusing on primary health care facilities
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Cecílio, Renato Oliveira. "\"Estrutura tridimensional das correntes geradas pelo vento na Plataforma Continental da região sul do Brasil\"." Universidade de São Paulo, 2006. http://www.teses.usp.br/teses/disponiveis/21/21132/tde-05042007-163945/.
Full textAbstract:
Um modelo numérico tridimensional foi adaptado para o estudo da circulação gerada pelo vento sobre a plataforma continental da Região Sul do Brasil durante o verão e o outono. O modelo oceânico de Princeton (POM) é usado em um domínio limitado com grade curvilínea de alta-resolução, além de linha de costa e batimetria realísticas. As forçantes são variáveis no tempo e incluem tensão de cisalhamento do vento, descarga fluvial, campos termohalinos e nível médio do mar. Os objetivos são simular a resposta da plataforma a estas forçantes, comparar os resultados do modelo com observações oceanográficas afim de estabelecer a confiança do modelo, e subseqüentemente analisar os campos resultantes para ajudar na compreensão do comportamento da circulação observada. As variáveis do modelo mostram boa concordância geral com as correspondentes observações. É encontrado um claro padrão sazonal da circulação gerada pelo vento sobre a plataforma, com fluxos de superfície para sul e para o largo durante o verão, resultando em ressurgência de águas frias de fundo, e para norte e para a costa durante o outono, resultando em subsidência de águas menos densas. Tal circulação aumenta a estabilidade vertical no verão, devido ao aquecimento de superfície e ressurgência de águas frias, e aumenta a mistura vertical e a homogeneidade vertical no outono, devido à subsidência de águas menos densas, a qual causa forte aceleração da pluma fluvial existente na plataforma interna. Os resultados também demonstram que os cabos e promontórios da Região Sul do Brasil desempenham papel fundamental na variabilidade ao longo da costa do fluxo de ressurgência, incluindo o estabelecimento de jatos costeiros baroclínicos, os quais tendem a se separar da costa ao sul de cabos, mostrando uma circulação tridimensional de ressurgência, com complexa dependência espaço-temporal. Durante o outono, o empilhamento de subsidência, somado à presença da pluma fluvial, estabelece uma corrente costeira barotrópica, chamada aqui de \'\'Corrente Costeira de Rio Grande\'\', causando a intrusão de águas frias a partir do sul para a plataforma continental brasileira. A avaliação dos campos de velocidade mostra que o transporte de Ekman pleno se desenvolve na região ao largo das frentes de ressurgência ou subsidência, deixando em direção à costa uma zona dominada por fricção, com estratificação e velocidades perpendiculares fracas. Esta região é denominada aqui de \'\'plataforma interna\'\' e se estende da costa até a isóbata de 30m no verão e até a isóbata de 45m no outono, com esta variação resultando de variações na profundidade da camada de Ekman.A three-dimensional numerical model has been adapted for the study of the wind-driven flow on the continental shelf off southern Brazil during the summer and autumn seasons. The Princeton Ocean Model (POM) is used in a limited area domain with a high-resolution (eddy resolving) curvilinear grid, with realistic coastline and bottom topography. The forcings include time-varying wind stress, termohaline fields, fluvial discharges and mean sea level. The objectives of the study are to simulate the response of the shelf circulation to these forcings, to compare model results with oceanographic observations, to stablish the model confidence, and to subsequently analyse the model fields a contribution to understand the behavior of the observed flow. The model variables show overall good agreement with corresponding observations. It is found a clear seasonal pattern of wind-driven circulation over the shelf, with surface offshore and southward net flow during summertime, which results in bottom cold water upwelling, and onshore and northward net flow during autumntime, which results in less dense water downwelling. This circulation enhances vertical stability in summer, due to solar surface heating and cold water bottom upwelling, and enhances vertical mixing and unstratified conditions in autumn due to downwelling of less dense water, which causes strong downwind acceleration of river plume innershelf waters. The results also demonstrate that coastal capes and promontories play a dominant role in causing alongshore variability of the upwelling flow over southern Brazil, including the setup of alongshore coastal baroclinic jets, which tend to separate from the coast south of capes, showing a three-dimensional upwelling circulation, with complex time and space dependence. During autumntime, the downwelling wind setup, in addition to the river plume waters, set up a barotropic coastal current, named here \'\'Rio Grande Coastal Current\'\', causing the intrusion of southern colder water over the Brazilian shelf. The evaluation of velocity fields shows that full Ekman transport develops in the region offshore of the upwelling or downwelling fronts, leaving onshore a region dominated by friction with relatively weak stratification and cross-shore currents. This region is named here \'\'innershelf\'\' and extends seaward from the coast until the 30m isobath in summer and the 45m isobath in autumn, showing this seasonal variation due to Ekman layer depth variations.
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Bitencourt, Diego Mello. "Descrição pontual de maré, perfil de correntes e suas inter-relações em um ponto do estuário do Rio Mearim, São Luis, Maranhão." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2016. http://hdl.handle.net/10183/142122.
Full textAbstract:
Este estudo visa à descrição pontual do comportamento hidrodinâmico do estuário do Rio Mearim, analisando os padrões de corrente de maré, do registro de marés e das possíveis relações entre eles. Durante novembro e dezembro de 2012 um ADCP foi fundeado no canal do estuário, onde coletou dados por 31 dias. Os dados foram qualificados e processados para futura análise e inter-relações. Foi observado que a coluna de água estuarina no ponto de medição move-se como uma coluna de água homogênea com fluxo bidirecional no eixo NE-SW. As medições ocorreram no período de baixo índice de pluviosidade. O espectro de energia de velocidade de correntes indicou contribuições parciais dos harmônicos M2, M4, M6 e M8 no padrão de correntes encontrados. Defasagens no tempo entre os picos de máxima velocidade de corrente durante enchente e vazante mostraram a dominância do processo de maré vazante sobre a enchente no estuário. A análise integrada apresentada permitiu uma melhor compreensão no entendimento do comportamento das correntes forçadas pela maré, as chamadas correntes de maré, no estuário do Rio Mearim.This study aim to describe the punctual hydrodynamic behavior of Mearim River estuary, analyzing the pattern of the tidal current, the tidal data and possible relationship between them. During 2012 november and december an ADCP was deployed in the estuary channel, where it collected data for 31 days. The data were qualified and processed for further analysis and inter-comparisons. It was observed the estuarine water column in the point of deployment moved as a homogeneous water column with bidirectional flux in axis NE-SW. The deployment was made in a period of low pluviosity index. The energy spectrum of current velocity indicated partial contribution of harmonics M2, M4, M6 e M8 in the current pattern found. Delays between the maximum velocity during flood and ebb conditions, showed the dominance of the edd process over the flood in the estuary. An analysis integrated presented on this paper allowed a better understanding of the behavior of the current forced by tides, called the tidal current in the Mearim River estuary.
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Lagoas, Fabiana da Cunha. "Correntes geomagneticamente induzidas: detecção e influência no sistema elétrico de potência." Universidade Federal do Pampa, 2017. http://dspace.unipampa.edu.br:8080/jspui/handle/riu/2029.
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Correntes geomagneticamente induzidas (GICs) são correntes espelhadas na superfície terrestre, que ocorrem em função do movimento de partículas ionizadas no campo magnético terrestre. Tais partículas eletricamente carregadas são provenientes da massa coronal expelida em erupções solares, as quais viajam a uma velocidade de, aproximadamente, 450 km/s. Ao entrarem em contato com a magnetosfera, proporcionam distorções no campo magnético, as quais são medidas por meio de três índices geomagneticos: Kp e Ap, que representam o grau de perturbação do campo magnético, e Dst, o qual informa a intensidade da tempestade solar por hora. Quando as GICs penetram no sistema elétrico de potencia (SEP) através dos aterramentos dos equipamentos, problemas podem ocorrer, tais como o aquecimento de componentes da rede, além de desligamentos de linhas de transmissão, decorrentes da atuação indevida de dispositivos de proteção. Destaca-se que, atualmente, as concessionarias brasileiras de energia são severamente multadas pelos órgãos reguladores quando ha a ocorrência de um desligamento não programado que não seja causado por uma falta permanente. Al˜ em disso, ressalta-se que os dispositivos de proteção são desprovidos de funções capazes de detectar as GICs, as quais comprometem também a vida útil de alguns equipamentos. Nesse contexto, um estudo aprofundando deste fenômeno geomagnético e apresentado neste trabalho. Para tal, um histórico de desarmes da Linha de Transmissão (LT) de 138 kV ALE SE – SMA1, localizada entre as cidades de Alegrete e Santa Maria, no estado do Rio Grande do Sul, foi analisado em função dos dados dos índices geomagnéticos para o período de 2010 a 2015. Além disso uma analise do ciclo solar, evidenciou a possibilidade de ocorrência de GICs nesta LT, o que pode justificar muitos dos desligamentos indeterminados. Dessa forma, o presente trabalho apresenta uma técnica para detecção de GICs, a qual pode ser aplicada em reles digitais ou em ferramentas computacionais para determinação das causas de desligamentos indevidos sem justificativa aparente. Tal método consiste em um filtro morfológico para detecção dessas correntes, o qual foi implementado em Matlab e testado a partir do processamento de sinais de corrente, gerados computacionalmente pela simulação de um sistema teste no software EMTP-ATP. Os valores de GICs utilizados para testar o seu desempenho foram obtidos a partir do software OPENDSS, o qual calcula o fluxo de corrente geomagneticamente induzida a partir de dados técnicos da LT, como o comprimento da linha e as respectivas latitudes e longitudes de seus terminais. Os resultados obtidos através das simulações em OPENDSS mostraram a ocorrência de GICs na linha estudada. Por fim, o processamento dos sinais conseguidos através da simulação do sistema, por parte da metodologia para detecção de GICs, comprovaram a excelência da técnica proposta.
Geomagnetically induced currents (GICs) are mirrored currents on the Earth’s surface, which occur as a function of the movement of ionized particles in the Earth’s magnetic field. Such electrically charged particles are derived from the coronal mass expelled in solar flares, which travel at a speed of approximately 450 km / s. When they come into contact with the magnetosphere, they provide distortions in the magnetic field, which are measured by means of three geomagnetic indices: Kp and Ap, which represent the degree of perturbation of the magnetic field, and Dst, which informs the intensity of the solar storm per hour. When GICs penetrate the electrical power system (SEP) through the grounding of the equipment, problems can occur, such as the heating of network components, as well as disconnections of transmission lines, due to the improper performance of protection devices. It should be noted that, currently, Brazilian energy concessionaires are severely fined by regulatory agencies when there is an unplanned shutdown that is not caused by a permanent shortage. In addition, it is emphasized that the protection devices are devoid of functions capable of detecting the GICs, which also compromise the useful life of some equipment. In this context, an in-depth study of this geomagnetic phenomenon is presented in this paper. To do so, a history of disarranges of the 138 kV ALE SE - SMA1 transmission line, located between the cities of Alegrete and Santa Maria, in the state of Rio Grande do Sul, was analyzed according to geomagnetic index data for The period from 2010 to 2015. And together with a study of sunspots, the possibility of occurrence of GICs in this LT was evidenced, which may justify many of the indeterminate disconnections. Thus, the present work presents a technique to detect GICs, which can be applied in digital relays or in computational tools to determine the causes of undue disconnections without apparent justification. This method consists of a morphological filter for the detection of these currents, which was implemented in Matlab R and tested from the current signal processing generated by the simulation of a test system in the EMTP-ATP R software. The values of GICs used to test their performance were obtained from OPENDSS R software, which calculates geomagnetically induced current flow from technical data of the LT, such as the length of the line and the respective latitudes and longitudes of its terminals. The results obtained through the simulations in OPENDSS showed the occurrence of GICs in the studied line. The results obtained from the processing of the signals obtained through the simulation of the system proved the excellence of the proposed technique.
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Pereira, Marçal Duarte. "Caracterização sazonal da hidrodinâmica e do transporte de material particulado em suspensão em um estuário dominado por maré : Estuário de Caravelas (BA)." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2009. http://hdl.handle.net/10183/21083.
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O objetivo do presente estudo é caracterizar a hidrodinâmica e o transporte de material particulado em suspensão (MPS) no estuário de Caravelas sob diferentes condições de maré e vazão fluvial. Foram realizadas quatro campanhas hidrográficas durante ciclos completos de maré, sendo em condições de maré de sizígia e quadratura, e durante os períodos seco e chuvoso. Dados de nível de água, velocidade e direção de correntes, salinidade, temperatura e turbidez foram obtidos em uma estação fixa próxima da desembocadura do estuário. A partir destes dados foram obtidos os transportes residuais de MPS e calculado os mecanismos de transporte. As maiores concentrações médias de material particulado em suspensão ocorreram em condições de sizígia. Em condições de maré de quadratura o transporte resultante de MPS foi com sentido estuário acima, porém de pequena intensidade. Em condições de sizígia o estuário é caracterizado por correntes mais intensas e assimétricas, com dominância de vazante. Durante a condição de sizígia o estuário pode atuar como importador ou exportador de MPS. O estuário do rio Caravelas foi classificado como bem misturado e fracamente estratificado. A hidrografia e o balanço sedimentar são principalmente modulados pela altura da maré e o aporte de água doce é irrelevante.The objective of the present study is to characterize the hydrodynamics and the suspended particulate matter (SPM) in the Caravelas Estuary under different tidal and river regimes. Four hydrographic campaigns were carried out comprising a complete semi-diurnal tidal cycle, comprising neap and spring tidal phases, and during dry and wet seasons. Water level, current speed and direction, salinity, temperature and turbidity were recorded in an anchored station near to the estuarine mouth. The residual SPM flux and the mechanisms of transport were calculated. The higher SPM concentrations were recorded during the spring tidal phase. During neap tides, the net SPM flux 1 was up-estuary, although with low scale. During spring tides the tidal currents are strongly ebb dominant, and the net flux can be either up- or down-estuary. The estuary was classified as well mixed or weakly stratified. The hydrography and the sediment balance are firstly modulated by the tidal range, and the fresh water inflow is negligible.
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Titiz, Furkan Kaan [Verfasser], Doncker Rik W. [Akademischer Betreuer] De, and Sibylle [Akademischer Betreuer] Dieckerhoff. "A three-phase low-voltage grid-connected current source inverter / Furkan Kaan Titiz ; Rik W. de Doncker, Sibylle Dieckerhoff." Aachen : Universitätsbibliothek der RWTH Aachen, 2019. http://d-nb.info/1216040907/34.
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Titiz, Furkan Kaan Verfasser], Doncker Rik W. [Akademischer Betreuer] [De, and Sibylle [Akademischer Betreuer] Dieckerhoff. "A three-phase low-voltage grid-connected current source inverter / Furkan Kaan Titiz ; Rik W. de Doncker, Sibylle Dieckerhoff." Aachen : Universitätsbibliothek der RWTH Aachen, 2019. http://d-nb.info/1216040907/34.
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Stieneker, Marco [Verfasser], Doncker Rik W. [Akademischer Betreuer] De, and Antonello [Akademischer Betreuer] Monti. "Analysis of medium-voltage direct-current collector grids in offshore wind parks / Marco Stieneker ; Rik W. de Doncker, Antonello Monti." Aachen : Universitätsbibliothek der RWTH Aachen, 2017. http://d-nb.info/1171447760/34.
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Theel, Thomas M. "The relation between currency value and stock returns evidence from Germany /." View electronic thesis, 2008. http://dl.uncw.edu/etd/2008-3/rp/theelt/thomastheel.pdf.
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Montaño, Edgard Manuel Hito. "A formulação da política de segurança alimentar no Peru 2001-2006: um estudo de caso no departamento de Puno." Programa de pós-graduação em Saúde Coletiva, 2009. http://www.repositorio.ufba.br/ri/handle/ri/10382.
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En el Perú una cuarta parte de niños menores de 5 años se encuentran en desnutrición crónica y la evolución de este indicador desde 1996 prácticamente se ha mantenido igual. En el departamento de Puno el problema aún es mayor por sus condicionantes socio-económicas y políticas. Después del ajuste estructural provocado por los cambios del sistema económico, la mitad de la población peruana, pasó al estado de pobreza y una cuarta parte a la extrema pobreza; siendo afectado el acceso a los alimentos por parte de las familias peruanas, es aquí donde la política alimentaria formó parte del programa. En el periodo del gobierno de Alberto Fujimori y Alejandro Toledo se incrementó el financiamiento en programas alimentarios, trabajándose aún innovaciones en la gestión de estos programas. Producto de esta realidad social, el Perú se encuentra en la inseguridad alimentaria. Pese a las iniciativas y esfuerzos realizados por el estado peruano por disminuir la inseguridad alimentaria se observa aún instituciones públicas y privadas en la yuxtaposición de implementación de políticas alimentarias. El objetivo de la investigación fue describir y analizar el proceso de formulación de las políticas de seguridad alimentaría en el departamento de Puno – Perú durante el periodo 2001 al 2006. Utilizamos el enfoque teórico - metodológico del ciclo de la política enfatizando sobre el modelo de las ―múltiples corrientes‖. Este estudio de caso utilizó la revisión documental y las entrevistas en profundidad aplicadas a los ―informantes clave‖. Estas informaciones fueron procesadas, descritas y analizados para caracterizar el contexto nacional y regional; obtener las racionalidades de los actores en el proceso de formulación de la política de seguridad alimentaria; así como identificar a los emprendedores políticos que facilitó la reconstrucción del momento de predecisión, decisión y la apertura de la ―ventana política o de oportunidad‖ que condujo a la formulación de la Estrategia Nacional de Seguridad Alimentaria 2004-2015 y la Estrategia Regional de Seguridad Alimentaria – Puno 2006-2015. Constatamos que estas políticas aún tienen dificultad para implementarse, existiendo vacío de responsabilidades y articulación con los planes sectoriales, a pesar de haber obtenido apoyo general de la comunidad política para su formulación. Observándose que el gobierno de Alejandro Toledo (2001-2006) promovió el dialogo y la negociación con la sociedad civil, todavía insuficiente para el enfrentamiento de la inseguridad alimentaria.
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Dias, Francisco José da Silva. "Circulação e massas de água na plataforma continental leste do Ceará: modelagem numérica e observações." Universidade de São Paulo, 2011. http://www.teses.usp.br/teses/disponiveis/21/21132/tde-19042012-153907/.
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A Plataforma Continental do Estado do Ceará (PCCE) foi dividida em: Plataforma Continental Externa (PCE), Plataforma Continental Média (PCM) e Plataforma Continental Interna (PCI). Os critérios físicos adotados levaram em consideração intrusões mais ou menos intensas de água tropical (AT) transportada pela Corrente Norte do Brasil (CNB) em direção à costa; a intensificação dos gradientes de salinidade superficial; e a mistura entre diferentes massas de água. Durante a estação de chuva, observamos que na região da PCE a massa de Água Tropical (AT) ficou aprisionada em níveis verticais maiores que 60 m, enquanto que na PCI observamos a formação de uma pluma estuarina que ocupou os dois primeiros metros da coluna de água e provocou o rebaixamento do topo da massa de água costeira (AC), chegando a 6 km da linha de costa. A variação espaço-temporal das correntes na frequência submaregráfica mostram que a tensão de cisalhamento do vento (TCV) foi o principal agente na transferência de momentum para as águas da PCCE, gerando uma corrente de deriva polarizada para NW, paralela à direção das isóbatas, em resposta ao empilhamento de água na costa. Este comportamento, associado a espessura da camada de Ekman muito maior que a profundidade local, mostra que a dinâmica do primeiro modo de oscilação (barotópico) é dominante, gerando correntes na direção do vento forçante, como resposta à sua ação. O modo barotópico também foi dominante nas correntes de maré, com as componentes semi-diurnas (M2 e S2) caracterizando-se como as mais energéticas. A orientação normal das elipses de maré associada ao sentido horário de rotação, foram responsáveis pelas maiores velocidades de corrente na frequência maregráfica. Os resultados obtidos com o modelo numérico mostram a res\\-posta barotrópica das águas da PC a um vento estacionário com correntes para NW. Os maiores valores das corrente e elevação do nível do mar ocorreram na região mais próxima à costa. As correntes de maré e a orientação das elipses de maré obtidas com a modelagem corroboram o o comportamento dos dados observacionais. Para o estuário do Rio Jaguaribe (CE), o período de grandes descargas fluviais resultou em fluxos unidirecionais transportando volumes de 97 x 106 m3, advectando os processos de mistura para a região da PCI. Entretanto, na estação seca, a minimização dos fluxos fluviais resultou na maior atuação da maré na região, controlando a posição espacial da zona de máxima turbidez. Nesta época do ano o estuário foi classificado de acordo com parâmetros de estratificação e circulação como do tipo 2a, parcialmente misturado.The Continental Shelf of Ceará State was divided in: External (ECS), Middle (MCS) and Inner (ICS) Continental Shelf. The physical criteria of classification considered intrusions of Tropical Water (TW) transported onshore by the North Brazil Current (NBC); intensification of surface saline gradient; and mixing of different water masses. During the rainy season, the TW was retained the ECS at levels higher than 60 m, while an estuarine plume formation was observed in the PCI, occupying the two first meters of the water column, sinking top of the coastal water mass (CW) to 6 km off coast. The space-time variation of the currents in the subtidal frequency shows that wind stress was the main agent in the momentum transfer to continental shelf waters, generating a current to NW, parallel to the direction of the isobaths, in response to the stacking of water on the coast. This behavior associated to the thickness of the Ekman layer much larger than local depth, shows the dominance of the barotropic dynamic, generating currents in the wind direction, as response to its action. The barotropic mode was also dominant in the tidal currents, with semi-diurnals components (M2 e S2) characterized as the most energetic. The normal orientation of tidal ellipses, associated to clockwise rotation, were responsible for the highest current velocities in tidal frequency in MCS. Numerical model results show a barotropic response of waters to a stationary wind, with currents to NW, and highest values of currents and sea level ocurring closer the coast. Tidal currents and tidal ellipses orientation obtained by numerical model support the observations. In relation to Jaguaribe River estuary, the period of great river input led to unidirectional flows, which transport volumes of 97 x 106 m3, advecting the mixing process to the ICS region. However, during the dry season, river input decrease resulted in a larger tide influence in the region, controlling the spatial position of the mixing zone. For this time, the estuary was classified according to the parameters of estratification and circulation as a 2a type, partially mix
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Assmann, Suelem Martini. "Na beira do rio tem uma plantação: estudando o novo código florestal na bacia do Ribeirão Paraíso, Jataí – GO." Universidade Federal de Goiás, 2016. http://repositorio.bc.ufg.br/tede/handle/tede/6761.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES
The Forest Code is a measure created in order to establish balance between nature exploitation and conservation. Since the first Brazilian Forest Codes (BFCs), the efficiency of the regulation has been discussed, for it established measures that preserved the minimum of each biome. Among the three BFCs which were created, the New Forest Code (NFC), Law no 12651, of May 25, 2012, is the one which least fulfills its role. The NFC has proved to be a result of needs of capital in a distorted perspective of the sustainability school of thought, which is dealt in this thesis. Regarding such a line of thought, one may understand the reasons for the controversial code amendments and which techniques determine them. In this thesis, we analyzed the NFC consequences in the Cerrado landscape by the means of a case study in the Paraíso creek sub-basin, in Jataí-GO, where several alterations were observed. Our results showed that the total area quantity, which was said to be protected by the forest code, decreased by 38% after the NFC. Areas of this study which suffered most from the code changes were: firstly, the wetlands PPAs (permanent preservation areas), which were decreased by 100%; secondly, the headwaters PPAs, which were decreased by 91%; and, thirdly, lake PPAs, which were decrease by 70% on their permanent area. It was also found, by means of other studies on Cerrado and on other biomes, that such landscape alterations can be noted in the entire ecosystem, causing complications to plants, insects, birds, reptiles, amphibians, fishes and mammals. Such alterations are caused mainly due to habitat changes, shortening a vast diversity of species into some merely generalist species. Besides that, the effects on quality and quantity of water in rivers and rainfall in the region, on physical, chemical and biological quality of the soil and on atmospheric temperature were also found. By using landscape projection maps, before and after the NFC, we were able to understand with this study that the code alterations are much greater to practice than the law alterations which were made.
O Código Florestal é a medida criada para estabelecer um equilíbrio entre a exploração e a preservação da natureza. Desde os primeiros Códigos Florestais Brasileiros (CFBs), já se discutia a eficiência da norma, pois estipulavam medidas que preservavam o mínimo de cada bioma. Entre os três CFBs criados, o Novo Código Florestal (NCF), lei nº 12.651 de 25 de maio de 2012, é o que menos cumpre seu papel. O NCF demonstra ser reflexo dos anseios do capital em uma ótica um tanto deturpada da corrente sustentabilista tratada neste trabalho. Perante este modelo de pensamento, percebe-se o porquê das polêmicas alterações deste código e quais práticas as definem. Neste trabalho, analisaram-se as consequências do NCF na paisagem do Cerrado por meio de um estudo de caso na sub-bacia do Ribeirão Paraíso, no município de Jataí-GO, onde se puderam constatar diversas alterações. Nos resultados, observou-se que a quantidade total de área, antes dita protegida pelo código florestal, diminuiu em 38% no NCF. As áreas deste estudo que mais sofreram com as alterações do código foram: em primeiro lugar, as APPs de alagados, que sofreram uma diminuição de 100%; em segundo lugar, as APPs de nascentes, sofrendo uma diminuição de 91%; e, em terceiro lugar, a APP de lago, sofrendo uma diminuição de 70% da área permanente. Observaram-se, por meio de outros estudos do Cerrado e em outros biomas, que essas alterações na paisagem refletem em todo o ecossistema, apresentando complicações para espécies de plantas, insetos, aves, répteis, anfíbios, peixes e mamíferos. Alterações estas dadas, principalmente, pela mudança de habitats, resumindo uma vasta diversidade de espécies em apenas algumas generalistas, além dos efeitos na qualidade e na quantidade da água de rios e da pluviosidade da região, na qualidade física, química e biológica dos solos. Através de mapas de projeção da paisagem de antes e depois do NCF, pôde-se compreender que as alterações do código são muito maiores na prática do que foi na lei.
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Lima, B?rbara Carvalho Marques Toledo. "Proposta pedag?gica para a educa??o infantil: educa??o escolar ou compensat?ria?" Pontif?cia Universidade Cat?lica de Campinas, 2013. http://tede.bibliotecadigital.puc-campinas.edu.br:8080/jspui/handle/tede/716.
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Previous issue date: 2013-02-26This research dissertation discusses the concepts of child, school and professor of early childhood education outlined in a pedagogical proposal of an institution that serves children 0-6 years of age in the city of Campinas. Through historical materialist and dialectical epistemology we propose the analysis of such pedagogical institution, in order to identify their design school, child and teacher of early childhood education, using interviews with teachers and pedagogic advisor and analysis of the documents of the institution. This is on the assumption that early childhood education, currently, needs to overcome the arguments that set a space in which education must accompany child development, intervening as little as possible and also those who value the capability and skills training for the student to meet market requirements. Based on the assumptions of cultural-historical theories of human development and critical historic l education, it was possible to understand the contradictions which underlie the education of children today, I propose, therefore, contribute to the defense of the early childhood education must be conceived as school education, to be valued as practices that enforce the teaching and learning through transmission of systematized knowledge.
A presente pesquisa de disserta??o de mestrado objetiva discutir as concep??es de crian?a, escola e professor de educa??o infantil delineadas em uma proposta pedag?gica de uma institui??o que atende crian?as de zero a seis anos incompletos no munic?pio de Campinas. Atrav?s da epistemologia materialista hist?rico-dial?tica realizamos a an?lise da proposta pedag?gica de tal institui??o com vistas a identificar sua concep??o de escola, crian?a e professor de educa??o infantil, utilizando a entrevista com professoras e orientadora pedag?gica e an?lise dos documentos da institui??o. Parte-se do pressuposto de que a educa??o infantil, atualmente, necessita superar os argumentos que a colocam como espa?o na qual a educa??o deve acompanhar o desenvolvimento infantil, intervindo o m?nimo poss?vel e tamb?m aqueles que valorizam a potencialidade e forma??o de compet?ncias no aluno para atender ?s exig?ncias do mercado. Com base nos pressupostos das teorias hist?rico-cultural do desenvolvimento humano e hist?rico-cr?tica da educa??o, foi poss?vel compreender as contradi??es por quais perpassam a educa??o da inf?ncia na atualidade, propomos, com isso, contribuir com a defesa de que a educa??o infantil deve ser concebida como educa??o escolar, para que sejam valorizadas as pr?ticas que efetivem o ensino e a aprendizagem atrav?s da transmiss?o do conhecimento sistematizado.
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Walker, Dennis Eugene Jr. "The role of defects on Schottky and Ohmic contact characteristics for GaN and AlGaN/GaN high-electron mobility transistors." The Ohio State University, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=osu1141766860.
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Jatobá, Pedro Henrique Gomes. "Desenvolvimento de ambientes virtuais de aprendizagem e gestão colaborativa: casos de cultura solidária na economia criativa." Escola de Administração da Universidade Federal da Bahia, 2014. http://repositorio.ufba.br/ri/handle/ri/21715.
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A economia da cultura tem se tornado, nas últimas décadas, um importante vetor produtivo e de inclusão social na economia brasileira. Dentre as políticas públicas que estimulam a organização produtiva na cultura, destacam-se o Programa Cultura Viva e as ações de fomento da Secretaria de Economia Criativa, ambos ligados ao Ministério da Cultura. Mesmo beneficiados com incentivos públicos, os empreendimentos comunitários têm dificuldades em acessar o mercado cultural do seu território, formar público e dominar as tecnologias da informação necessárias a sua sustentabilidade. O desenvolvimento de ambientes virtuais de aprendizagem e gestão colaborativa, adaptado à realidade desses grupos, pode ser bem sucedido quando os futuros usuários dos empreendimentos comunitários são capacitados para utilizar a nova solução em paralelo ao seu desenvolvimento. A pesquisa participante junto a Produtora Colabor@tiva.PE na Universidade Federal de Pernambuco e a pesquisa-ação realizada Universidade LIVRE de Teatro Vila Velha na Bahia, analisam como essas produtoras culturais colaborativas conseguiram se beneficiar de novos suportes digitais em seus processos de gestão interna e formação continuada. A colaboração desses usuários na comunidade de desenvolvimento da plataforma CORAIS possibilitou aprimorar as ferramentas de groupware existentes e desenvolver novas funcionalidades como a gestão transparente de uma moeda social digital.
The culture economy has become in the last decades one of the most important productive and social inclusion vectors on Brazilian economy. Among the public finance actions made by the government the main actions that support productive organization on the cultural groups are the Points of Culture network and the creative economy secretary, both related do the Minister of Culture of Brazil. Even the institutions that received public investments are showing difficulties in access in the local market create and maintain consumers have access and learn how to use information technology that is necessary to achieve economical sustainability. The development of collaborative management and learning virtual environments customized to these realities are only possible when these groups learn how to use free software tools in their internal activities. The study of the Produtora Colabor@tiva.PE in Recife at the Federal University of Pernambuco and the Universidade LIVRE de Teatro Vila Velha in Salvador, Bahia, part of this research execute an analysis about how this collaborative cultural producers got better results by adopting virtual environments. The participation of these groups in the CORAIS platform development community made possible that the existing groupware tools and develop new solutions as the public management of a local digital currency.
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Fernández, Laura Raffone. "DESENVOLVIMENTO SUSTENTÁVEL NA ZONA SUL DO RIO GRANDE DO SUL: DEMANDAS PARA AS POLÍTICAS EDUCACIONAIS." Universidade Catolica de Pelotas, 2010. http://tede.ucpel.edu.br:8080/jspui/handle/tede/109.
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Previous issue date: 2010-02-19ABSTRACT. Over the centuries, the concept of sustainable development was defined mainly through studies conducted by the Commission of Bründtlandt in 1986. The goal of the season was to reconcile economic development with environment. On this track, there was also concern as to measure the development, not only by the increase of income, but also the quality of life of people. To that end, in 1990, was presented the first version of the Human Development Index (HDI). Currently, society, with the incorporation of environmental concern, with demands for education, needs indicators that reflect the quality of life of this, but if we can keep it in the future. In that sense this work showed some indicators, the search field and projects. In the analysis of data, showed that the Human Development is unable alone to reflect the issues involving human development and the environment. In order to incorporate an environmental dimension, guided into the current of eco-development thought, created by the Local Educational Development Index (IDEL), the new indicator shows the opposite response to questions involving sustainable development, where education and quality of life of man must be aligned to the preservation of nature
Ao longo dos séculos, o conceito de Desenvolvimento Sustentável foi definido principalmente através dos estudos realizados pela Comissão de Bründtlandt em 1986. O objetivo da época era conciliar desenvolvimento econômico com meio ambiente. Nessa trajetória, houve também a preocupação na forma de medir o desenvolvimento, não apenas pelo aumento de renda, mas também pela qualidade de vida das pessoas. Com esse intuito, em 1990, foi apresentada a primeira versão do Índice de Desenvolvimento Humano (IDH). Atualmente, a sociedade, com a incorporação da preocupação ambiental, com demandas para a educação, necessita de indicadores que reflitam a qualidade de vida do presente, mas também se é possível mantê-la no futuro. Nesse sentido, o presente trabalho apresentou alguns conceitos, pesquisa de campo e projetos realizados. Na análise das técnicas utilizadas, demonstrou-se que o Desenvolvimento Humano não é capaz sozinho de refletir as questões que envolvem o desenvolvimento humano e o meio ambiente. Com o intuito de incorporar uma dimensão ambiental, norteada dentro da Corrente de Pensamento Ecodesenvolvimentista, frente a possível existência de políticas públicas educacionais no estado do Rio Grande do Sul, esta nova análise demonstra a resposta frente às questões que envolvam o Desenvolvimento Sustentável, onde a educação e a qualidade de vida do homem precisam estar alinhadas à preservação da natureza
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Nagai, Renata Hanae. "Mid- to Late Holocene paleoceanographic changes in the Southeastern-Southeastern Brazilian shelf." Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/21/21136/tde-11022015-122231/.
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Mid- and Late Holocene paleoceanographic changes over the S/SE Brazilian continental shelf have been accessed through a multi-proxy approach. Sedimetological, geochemical and microfaunal proxies were investigated in three high resolution marine sedimentary cores collected along the S/SE Brazilian shelf and discussed under a regional and global oceanographic and climatic perspective. The depositional processes of the S/SE Brazilian margin were submitted to two different hydrodynamic controls during Mid- and Late Holocene: (i) the northward penetration of the La Plata River Plume, bringing La Plata River derived sediments, and (ii) the high energetic Brazil Current onshore/offshore movements transporting SE Brazilian derived sediments for the northernmost part of the Santos Basin (25°S) during the Mid-Holocene. In the Late Holocene, especially after 3000 yr cal. BP, La Plata River derived sediments reached up to 25°S, highlighting a stronger influence of the La Plata River over the S/SE Brazilian shelf as a result of increase in precipitation over the La Plata River drainage basin. As the La Plata River colder and less saline waters influence over the S/SE Brazilian shelf increased, the oligotrophic waters of the shelf were fertilized, promoting enhancement of surface waters primary productivity and seafloor exportation. In the vicinity of 25°S, surface waters primary productivity was also enhanced by increase in colder and less saline South Atlantic Central Waters (SACW) shelf penetration. An overall a background trend of lower water temperature and salinities corroborates to a stronger influence of the La Plata River Plume waters during the Late Holocene as a result of higher precipitation over SE South America. This trend followed the summer insolation at 30°S, in accordance to other proxy records and numerical models. In the northernmost part of study area, superimposed to the general background trend, two major temperature and salinity negative incursions with abrupt contacts centered at 5500 yr cal. BP and after 2800 yr cal. BP highlight multi-centennial scale changes, possibly related to SACW shelf penetrations due to persistent NE winds. These changes occurred simultaneously to rapid climatic events at regional and global spatial scale. AMOC slowdown events, mediated by amplifying mechanisms, are the proposed triggering mechanism for the changes observed in the SE Brazilian shelf records. The amplifying mechanisms may have changed throughout time and as atmospheric teleconnections are not yet fully understood we hypothesize that different modes of climatic variability, such as ENSO and the South Atlantic dipole, may have acted as mediators during Mid- and Late Holocene.Neste estudo uma visão multi-proxy foi aplicada na compreensão das mudanças nas condições oceanográficas em que a plataforma continental S/SE Brasileira foi submetida ao longo do Holoceno Médio e Tardio. Para isso proxies sedimentológicos, geoquímicos e microfaunísticos foram estudados em três testemunhos marinhos de alta resolução coletados ao longo da plataforma S/SE do Brasil e discutidos sob uma perspectiva oceanográfica e climática regional e global. No Holoceno Médio e Tardio, os processos deposicionais da plataforma S/SE Brasileira foram influenciados por dois processos hidrodinâmicos distintos: (i) a presença da Pluma do Rio La Plata, trazendo sedimentos oriundos da Bacia de drenagem do Rio La Plata, e (ii) os movimentos onshore/offshore da Corrente do Brasil, no Holoceno Médio, trazendo sedimentos oriundos da margem SE Brasileira para porção norte da Bacia de Santos (25°S). A zona de influência do Rio La Plata estendeu-se a latitudes mais ao norte atingindo 25°S, no Holoceno Tardio, especialmente nos últimos 3000 anos, como resultado do aumento nos regimes de precipitação sobre a Bacia de drenagem desse rio. As águas superficiais da plataforma S/SE Brasileira foram fertilizadas pelas águas mais frias e menos salinas da Pluma do Rio La Plata, disponibilizando mais matéria orgânica para o sistema bentônico. Nas proximidades de 25°S, a penetração na plataforma da Água Central do Atlântico Sul (ACAS) também promoveu aumento na produtividade primária das águas superficiais. Ao longo do Holoceno Médio e Tardio, uma tendência geral de diminuição da temperatura e salinidade das águas superficiais corrobora com uma maior influência da Pluma do Rio La Plata sobre a plataforma S/SE Brasileira como consequência de um aumento na precipitação no SE da América do Sul. Essa tendência segue a tendência da insolação de verão em 30°S, e concorda com outros registros proxy e modelos numéricos. Na porção norte da área de estudo, sobreposta à tendência geral, duas grandes incursões negativas temperatura e salinidade, com contatos abruptos, centradas em 5500 anos cal. BP e depois de 2800 anos cal. BP sugerem a ocorrência de mudanças de escala multi-centenárias, possivelmente relacionadas a penetração da ACAS na plataforma em decorrência de ventos de NE persistentes. Estas mudanças ocorreram simultaneamente a eventos rápidos climáticos em escala regional e global. Eventos de desaceleração da AMOC, mediada por mecanismos de amplificação, são propostos como o mecanismo responsável por desencadear estas mudanças (triggering mechanism). Os mecanismos amplificadores podem ter mudado ao longo do tempo e dado o não total entendimento das teleconexões atmosféricas do sistema climático, colocamos como hipótese que, no Holoceno Médio e Tardio, diferentes modos de variabilidade climática tais como, ENSO e dipolo do Atlântico Sul, podem ter atuado.