Dissertationen zum Thema „Environmental discharge“

Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2004.
Includes bibliographical references (leaves 30-31).
Electrical Discharge Machining (EDM) is a non-traditional process that uses no mechanical forces to machine metals. It is extremely useful in machining hard materials. With the advantages EDM has to offer and its presence as a common and useable technique, along with the other machining processes available to the industrial world, there is an added strain on the environment. The scope of this thesis includes analyzing the various inputs into EDM and the resulting outputs into the environment. A simplified model is used to analyze the process. The main categories of flow scrutinized in the model are material flow and energy flow. The most hazardous effect to the environment is found in the resin interaction of the wire EDM process where depending on the type of material machined, there is a potential presence of hazardous materials. There are efforts to recycle all salvageable materials such as wire and metal wastes, but currently no accountability system exists as manufacturers are responsible for their actions.
by Margaret H. Cho.
S.B.

The problem of defining sediment supply conditions is of fundamental importance in the prediction of bedload discharge in alluvial channels, because most bedload equations were developed based on the general assumption that the rates at which sediment becomes available for transport equal the sediment-transport capacity of the flow. The classification of availability of sediment on the accuracy and applicability of seven bedload equations in alluvial channels is described and discussed in this dissertation. Historical hydraulic and sedimentological data from 22 alluvial channels of the United States are used to define the sediment-transport regimes and to compare predicted and measured bedload discharges. Exponential relations between sediment supply end energy are used to show if at a reach scale a channel has supply-limited or non-supply limited regime based on the statistical variations of bedload-transport rates with stream power. The root-mean-square error and the inequality coefficients are use to assess the bedload equation's ability to reproduce the trend of the measured values, whereas the discrepancy ratio is used to evaluate the equation's ability to reproduce individual measured data. Relations between the median particle-size ratio, which quantifies the coarseness or fineness of the channel bed, and the discrepancy ratio are used to illustrate process controlling the accuracy of bedload equations. Information presented here shows that an understanding of channel's sediment regime in the process of bedload prediction improves the applicability of bedload equations in alluvial channels.

The purpose of this paper is to provide assistance in developing a program to control the release of dental mercury amalgam in Missoula, Montana. To do this, three research components were carried out. The first consisted of a survey to determine whether Missoula dentists are following the American Dental Associations (ADA) recommended Best Management Practices (BMPs) for mercury amalgam waste. The second component involved interviewing local dentists in an effort to include their voice in the process, as well as to determine what may motivate them to comply with a dental mercury control program. The final component of research involved developing and analyzing three case studies of municipalities that have designed and implemented a successful BMP program that can be used to help guide the development of a program in Missoula.

Organic and inorganic contaminants accumulate on snow grain surfaces. In an urban environment, snowpacks can retain a high load of anthropogenic contaminants that, upon melting, can deliver concentrated contaminant pulses into the aquatic environment. In climates with an extended period of snowfall accumulation, such as in Anchorage, Alaska, contaminant amplification within meltwater may affect aquatic ecosystem health. A spatiotemporal study of benzotriazoles on snow, meltwater and soils was performed in association with three urban snow disposal facilities. Benzotriazole elution from engineered snow disposal sites behaved similarly to inorganic salt and dissolved organic carbon (DOC) during the initial melt period, with maximum concentrations between 2.23-7.39 μg/L; similar elution behavior was observed in creeks. Assays of disposal site soils revealed the presence of tolytriazole. Furthermore, using fluorescence spectroscopy and Parallel Factor Analysis (PARAFAC) analysis, a modeled component representative of benzotriazoles was identified, containing peaks at Ex/Em 200/306 and Ex/Em 270/387-402. It was determined that this component as well as another modeled component may be utilized as an indicator of anthropogenic input rather than a unique indicator for benzotriazole compounds. Confirmation of suspected consumer antifreeze and windshield wiping fluids containing benzotriazoles exhibited maximum tolytriazole concentrations of 644 mg/L and 138 μg/L respectively.

Much work has been published regarding discharge coefficients for various weir structures. What has not been published to the same extent are the effects of model scale associated with the weirs being studied. If laboratory weirs are too small, scale effects can affect the magnitude of the discharge coefficient. These errors may be significant if the weir serves as a control structure for an emergency spillway. It is imperative that discharge be accurately predicted to enable safe design and operation. Numerical and physical means were employed to analyze the effects of scale associated with Froude Modeling of weirs with sharp and flat crests. An inverse formulation for the ideal flow of water over a weir was developed. The formulation appeared to be sound; however, the numerical method failed because the boundary condition on the free surface had multiple roots, which were almost equal in magnitude and sign. Laboratory data were collected and analyzed to determine the existence of scale effects and the flow conditions under which they were manifested. Results indicate that scale effects are present even with relatively large model sizes (12 inches high with a crest thickness of 24 inches). The scale effects appear to be associated with the size of the weir-wall and the viscosity. Although the viscosity was not altered, the results show a characteristic Reynolds Number for a given crest thickness-to-height ratio where scale effects cease to exist for increasing total head. Several graphs defining the conditions where scale effects exist for a given weir size were developed. Use of the graphs allows one to determine the minimum total head (piezometric plus velocity head) that one may operate a given size of weir or size a weir given the minimum total head to be tested to avoid scale effects. A design curve for discharge coefficients was developed to be used for determining the capacity of prototype weirs. The curve can be used to determine the discharge coefficient for new or existing hydraulic control structures.

The discharge of groundwater into surface water bodies is a hidden, but significant pathway for the input of water and matter into lakes, rivers, estuaries and the coastal sea. Since groundwater is most often characterized by higher levels of nutrients or heavy metals, its discharge has often a crucial effect on the surface water body´s chemistry and the ecosystem health as well as on the related ecosystem service supply. For instance, groundwater-derived nutrient inputs are essential to fuel primary productivity, but if critical thresholds are exceeded groundwater-derived nutrient inputs can cause eutrophication, which may trigger harmful algal blooms or the creation of oxygen minimum zones – a serious threat to aquatic life. This thesis focuses on quantifying submarine and lacustrine groundwater discharge by applying environmental tracer based methods with emphasis on radionuclide (radon and radium isotopes) and stable water isotope (δ18O, δ2H) techniques. These tracers are suitable for determining groundwater discharge as they show distinct concentration and isotope ratio gradients between groundwater and the receiving surface water. Four studies are presented in this thesis: (1) The quantification of the response delay of the mobile radon detector RAD7 applied for radon-in-water mapping. The response delay of the mobile radon-in-air detector RAD7 is determined for two detection set-ups (radon extraction via RADaqua and via a membrane module) as well as for a range of water flow rates. For the membrane module the response delay is less pronounced compared to the RADaqua. For instance, at a water flow rate of 1 l min-1 the peaks of the instruments recordings lag behind the radon-in-water concentrations by ~10 min for the membrane module and by ~18 min for the RADaqua. Further, it was demonstrated that faster water flow rates decrease the response delay. An algorithm is presented that allows the inverse calculation of radon-in-water concentrations from RAD7 records for the described detection set-ups and water flow rates. Thus, it allows a more precise localization of radon-in-water anomalies and, consequently a more precise localization of groundwater discharge areas. (2) Determination of submarine groundwater discharge into a large coastal bay (False Bay, South Africa) SGD consists generally of two components: (a) fresh terrestrial SGD (FSGD) driven by the inland hydraulic gradient and (b) seawater re-circulation (RSGD) through the coastal aquifer driven by seaward effects such as tidal pumping. A bay-wide radon mapping resulted in identification of a SGD site, where subsequently detailed investigations were conducted. At this SGD site a salt and a radon mass balance were applied consecutively for determining FSGD and total SGD, respectively. RSGD was inferred from the difference between FSGD and total SGD. For the radon mass balance, new approaches for calculating the radon degassing and mixing loss were proposed. The tracer mass balance revealed median FSGD of 2,300 m³ d-1 or 0.9 m³ d-1 per m coastline and median RSGD of 6,600 m³ d-1 or 2.7 m³ d-1 per m coastline. The FSGD rate was validated using (a) a hydrological model for calculating the groundwater recharge rate and (b) a groundwater flow model for delineating the subsurficial FSGD capture zone. This validation supported the tracer based findings. The relevance of this study is foremost the presentation of new methodological approaches regarding the radon mass balance as well as the validation of FSGD under consideration of hydrological and hydrogeological information. (3) Differentiation of fresh and re-circulated submarine groundwater discharge in an estuary (Knysna Estuary, South Africa) Knysna Estuary is a more complex system than False Bay since besides seawater, FSGD and RSGD also river water mixes within the estuary. Both FSGD and RSGD were differentiated by applying a mixing analysis of the estuary water. For this purpose, an end-member mixing analysis (EMMA) was conducted that simultaneously utilizes radon and salinity time series of estuary water to determine fractions of the end-members seawater, river water, FSGD and RSGD. End-member mixing ratio uncertainty was quantified by stochastic modelling (Monte Carlo simulation) under consideration of end-member characterization uncertainty. Results revealed highest FSGD and RSGD fractions in the estuary during peak low tide. Median fractions of FSGD and RSGD were 0.2 % and 0.8 % of the estuary water near the mouth over a 24 h time-series. In combi-nation with a radon mass balance median FSGD of 46,000 m³ d-1 and median RSGD of 150,000 m³ d-1 were determined. By comparison to other sources, this implies that the SGD is a significant source of dissolved inorganic nitrogen (DIN) fluxes into the estuary. This study demonstrates the ability of EMMA to determine end-member fractions in a four end-member system under consideration of end-member uncertainty. Further, the importance of SGD for the water and DIN budget of Knysna Estuary was shown. (4) Quantification of groundwater discharge and water residence time into a groundwa-ter-fed lake (Lake Ammelshainer See, Germany). The presented approach utilizes the stable isotopes of water (δ18O, δ2H) and radon for determining long-term average and short-term trends in groundwater discharge rates. The calculations were based on measurements of isotope inventories of lake and groundwater in combination with climatic and isotopic monitoring data (in precipita-tion). The results from steady-state annual isotope mass balances for both δ18O and δ2H are consistent and reveal an overall long-term average groundwater discharge that ranges from 2,800 to 3,350 m³ d-1. These findings were supported by the good agree-ment of the simulated annual cycles of δ18O and δ2H lake inventories utilizing the de-termined groundwater discharge rates with the observed lake isotope inventories. However, groundwater discharge rates derived from radon mass balances were signifi-cantly lower, which might indicate a distinct seasonal variability of the groundwater discharge rate. This application shows the benefits and limitations of combining δ18O/δ2H and radon isotope mass balances for the quantification of groundwater con-nectivity of lakes based on a relatively small amount of field data accompanied by good quality and comprehensive long-term meteorological and isotopic data (precipitation). This thesis presents important methodological achievements with respect to radon and stable water isotope mass balances, uncertainty quantification, geochemical differentia-tion between FSGD and RSGD and validation of FSGD. Further, first SGD estimates are reported for False Bay and Knysna Estuary in South Africa
Der Austritt von Grundwasser in Oberflächengewässer stellt einen unsichtbaren Ein-tragspfad von Wasser und Stoffen in Seen, Flüsse, Ästuare und das küstennahe Meer dar. Die Konzentrationen vieler Stoffe wie beispielsweise von Nährstoffen und Schwermetallen ist im Grundwasser im Allgemeinen signifikant höher als in Oberflächengewässern. Daher können selbst volumetrisch verhältnismäßig kleine Grundwasseraustritte entscheidenden Einfluss auf Wasserchemie und den Gesundheitszustand des aquatischen Ökosystems haben, womit Auswirkungen auf die Bereitstellung von Ökosystemleistungen verbunden sein können. Beispielsweise sind grundwasserbürtige Nährstoffeinträge eine entscheidende Steuergröße für die Primärproduktivität. Überschreiten diese grundwasserbürtigen Nährstoffeinträge jedoch einen Schwellenwert, kann es zur Eutrophierung des Oberflächengewässers kommen. Dies wiederum kann toxische Algenblüten oder die Entstehung von Sauerstoffminimumzonen zur Folge haben und das aquatische Leben bedrohen. Diese Dissertation beschäftigt sich mit Methoden zur Quantifizierung von Grundwas-sereinträgen in den küstennahen Ozean, Ästuare und in Seen. Dabei stützt sich diese Arbeit primär auf Umwelttracer, vor allem auf Radionuklide (Radon- und Radium-Isotope) sowie die stabilen Isotope des Wassers (δ18O, δ2H). Diese Umwelttracer sind für die untersuchten Systeme in besonderer Weise geeignet, da zwischen Grundwasser und Oberflächenwasser ein ausgeprägter Gradient hinsichtlich Konzentration bzw. Isotopensignatur besteht. Vier Einzelstudien stellen den Kern dieser Arbeit dar: (1) Die Quantifizierung der Antwortverzögerung des mobilen Radon-Detektors RAD7, an-gewendet für die Radon-in-Wasser-Kartierung. Die Antwortverzögerung des mobilen Radon-in-Luft-Detektors RAD7 wurde für zwei Messanordnungen (Radonextraktion via RADaqua und via Membranmodul) sowie für einen Bereich von Wasserdurchflussraten bestimmt. Für die Radonextraktion via RADaqua ist die Antwortverzögerung stärker ausgeprägt als für das Membranmodul. Bei einer Wasserdurchflussrate von 1 l min-1 treten die Peaks der aufgezeichneten Werte ~10 min nach den Radon-in-Wasser Peaks auf, während die Verzögerung bei Radonextraktion via RADaqua ~18 min beträgt. Weiterhin wurde eine Reduktion der Antwortverzögerung mit zunehmenden Wasserdurchflussraten beobachtet. Der vorgestellte Algorithmus ermöglicht in Kombination mit den berechneten Radontransfer-Koeffizienten die inverse Modellierung der Radon-in-Wasser-Konzentrationen, basierend auf den RAD7-Messwerten. Dies ermöglicht beispielsweise eine genauere Lokalisierung von räumlichen Radon-in-Wasser Anomalien und folglich eine präzisere Bestimmung von Grundwasseraustrittsstellen. (2) Quantifizierung untermeerischer Grundwasseraustritte in eine große Meeresbucht (False Bay, Südafrika) Untermeerische Grundwasseraustritte (“Submarine Groundwater Discharge” – SGD) bestehen aus zwei Komponenten: (a) Süßwasser-SGD (“Fresh SGD” – FSGD) angetrieben durch den meerwärtsgerichteten hydraulischen Gradienten, und (b) re-zirkuliertem SGD („re-circulated SGD“ – RSGD), verursacht durch Prozesse wie gezeitengesteuerte Infiltration von Meerwasser in den Aquifer. Eine Radon-Kartierung entlang der gesamten Küstenlinie der Bucht führte zur Lokalisierung von SGD, woraufhin dort vertiefende Untersuchungen durchgeführt wurden. In diesem Bilanzgebiet wurden eine Salz- und eine Radon-Massenbilanz durchgeführt, um FSGD bzw. Gesamt-SGD zu bestimmen. RSGD wurde aus der Differenz von FSGD und SGD abgleitet. Für die Radon-Massenbilanz wurden neue Ansätze für die Berechnung der Radon-Entgasung in die Atmosphäre und des Radon-Mischungsverlustes mit küstenfernerem Wasser präsentiert. Die Tracer-Massenbilanzen ergaben einen FSGD-Median von 2.300 m³ d-1 bzw. 0,9 m³ d-1 pro Meter Küstenlinie und einen RSGD-Median von 6.600 m³ d-1 bzw. 2,7 m³ d-1 pro Meter Küstenlinie. Die FSGD-Rate wurde mit Hilfe eines hydrologischen Modells zur Abschätzung der Grundwasserneubildungsrate und eines Grundwasserströmungsmodells zur Abgrenzung des unterirdischen Einzugsgebiets des Bilanzraums bestimmt. Diese unabhängige Methode bestätigte die Tracer-basierten Ergebnisse. Die Bedeutung dieser Studie besteht zuvorderst in der Vorstellung neuer methodischer Ansätze bei der Radon-Massenbilanzierung sowie in der Validierung von FSGD unter Berücksichtigung hydrologischer und hydrogeologischer Daten. (3) Unterscheidung von FSGD und RSGD in einem Ästuar (Knysna Ästuar, Südafrika). Das Knysna-Ästuar ist hinsichtlich der Bestimmung von SGD im Vergleich zur False Bay ein komplexeres System, da sich neben Meerwasser, FSGD und RSGD auch Flusswasser in signifikanten Mengen im Ästuar mischt. FSGD- und RSGD-Anteile wurden anhand der chemischen Zusammensetzung des Ästuarwassers unterschieden. Für diesen Zweck wurde eine End-Member-Mischungsanalyse (EMMA) auf Grundlage von Radon- und Salinitätszeitreihen des Ästuarwassers durchgeführt. Durch ein Optimierungsverfahren wurde die Mischung der End-member Meerwasser, Flusswasser, FSGD und RSGD für jeden Zeitschritt mit dem Ziel der bestmöglichen Übereinstimmung mit den gemessenen Radon- und Salinitätszeitreihen bestimmt. Die Unsicherheit in der Bestimmung der End-member-Anteile wurde durch stochastische Modellierung (Monte-Carlo-Simulation) quantifiziert. Die höchsten Anteile von FSGD und RSGD traten bei Niedrigwasser auf. Die mittleren Anteile von FSGD und RSGD betrugen in der Nähe der Ästuarmündung 0,2 % und 0,8 % während einer 24-stündigen Zeitreihenmessung. Diese Informationen führten in Kombination mit einer Radon-Massenbilanz zur Bestimmung eines mittleren FSGD von 46.000 m³ d-1 sowie eines mittleren RSGD von 150.000 m³ d-1. Diese Ergebnisse implizieren unter Einbeziehung weiterer Daten, dass SGD ein bedeutender Pfad für den Eintrag von gelöstem anorganischem Stickstoff (DIN) in das Knysna-Ästuar darstellt. Diese Studie zeigt das Potenzial einer EMMA für die Bestimmung der Anteile von vier End-membern unter Nutzung von zwei gemessenen Variablen und unter Berücksichtigung der End-member-Unsicherheit. Außerdem wurde die Bedeutung von SGD für das Wasser- und DIN-Budget des Knysna-Ästuars aufgezeigt. (4) Quantifizierung von Grundwasseraustrittsrate und Wasserverweilzeit eines grundwas-sergespeisten Sees (Ammelshainer See, Deutschland). Der vorgestellte Ansatz nutzt die stabilen Isotope des Wassers (δ18O, δ2H) und von Ra-don für die Bestimmung des mittleren langfristigen sowie der aktuellen Grundwas-seraustrittsrate. Die Berechnungen beruhen auf Abschätzungen des Isotopeninventars anhand von Feldmessungen, der Isotopensignatur des Grundwassers sowie ergänzen-den Klima- und Isotopen-Daten (Niederschlag). Die Ergebnisse einer stationären Isoto-pen-Massenbilanz für δ18O und δ2H sind übereinstimmend und ergaben einen langfristigen mittleren Grundwasseraustritt von 2.800 bis 3.350 m³ d-1. Dieses Ergebnis wurde für die Modellierung des jährlichen Zyklus des Isotopeninventars im See benutzt, welches mit den gemessenen Isotopenwerten konsistent ist. Die auf Grundlage einer Radon-Massenbilanz abgeleiteten aktuellen Grundwasserzutrittsraten lagen im Gegensatz dazu deutlich niedriger, was jedoch nicht notwendigerweise einen Widerspruch darstellen muss, sondern vielmehr ein Hinweis auf eine möglicherweise ausgeprägte saisonale Variabilität des Grundwasseraustritts darstellen kann. Diese Studie zeigt Möglichkeiten und Grenzen der Anwendung von einer Kombination aus δ18O/δ2H- und Radon-Massenbilanzen für die Bestimmung der Grundwasseranbindung von Seen mit einem vergleichsweise geringen Messaufwand unter Nutzung qualitativ hochwertiger und umfangreicher Klima-und Isotopen-Daten (Niederschlag). Diese Dissertation präsentiert wichtige methodische Fortschritte hinsichtlich der An-wendung von Radon- und stabilen Isotopen-Massenbilanzen, der Quantifizierung von Unsicherheit, der Unterscheidung von FSGD und RSGD anhand geochemischer Daten und der Validierung von FSGD. Außerdem wurden erstmals SGD-Raten für Standorte in Südafrika (False Bay und Knysna-Ästuar) vorgestellt

The concerns of global warming are guiding most industries and commercial properties towards addressing their energy usage. In large buildings where air conditioning is required, there is often a need for “chillers” to control the temperature of the building. This process is not environmentally friendly and expensive in terms of energy used and maintenance issues. The alternative is to cool buildings using natural resources such as induced wind drafts and water extraction from rivers and canal. The latter has not been used with optimum effectiveness because the prediction procedures are not sufficiently developed to satisfy environmental legislation. The mathematical approaches are unrealistic and extremely conservative in their analysis and this causes many valid proposals to be rejected. This research is aimed at addressing that situation. It will provide a valid interactive 3-dimensional analysis procedure that will better evaluate the potential of using any British Waterways canal or similar water source for cooling purposes. After water has been used for cooling it is returned to the canal in a heated state as a thermal plume. It is the boundaries of the plume that must be predicted with reasonable accuracy so that environmental legislation is not infringed and livestock is not jeopardised. It is equally important to ensure the analysis is not over sensitive so as to result in rejection of valid proposals. Earlier work studied heat distribution but did not consider the thermal discharge into still and shallow water, as in a British Waterways canal. The studies below investigate several canal sites to evaluate a variety of situations where the discharge plume differs. Criteria including discharge direction, volume of water, temperature differences, speed of discharge and depth of discharge pipe all play a part in the formation of the plume. As such it is possible to develop an understanding of how the thermal plume merges into the still water and how the heat is diffused into the general body of water. In conjunction with site measurements a laboratory experimental scale model tank was built to replicate the real canal site. This allowed data to be varied and measured more readily. Two different types of discharge have been the subject of this research - the first being when the discharge pipe is located at the surface of the receiving water, the second being when it is submerged deeply below the surface. In all cases the temperature and velocity are measured at various points and at a variety of depths to provide a three dimensional plot across the mixing zone. In addition to the mathematical analysis, thermal imaging was used to predict the heat diffusion profiles on the surface of the receiving water in both the canal site and the model tank. CFD software is also used to evaluate the distribution of temperature and velocity within the mixing zone. The mathematical analysis produced an equation to predict the heat diffusion profile in surface discharge. And a number of equations were produced to model the plume path line in submerged discharge- relating to temperature and velocity dilution along and across the path lines. The relative effects of the bed and free surface proximity appeared significantly in the equations. A 3-dimensional model of the size of the plume is presented to demonstrate the results. The procedure followed in this study will enable the Environment Agency personnel to assess the waste heat utilization with greater thoroughness and within a shorter period.

Local, national and regional water supplies needed for energy production, meet the irrigation demands, industrial and domestic usage have come under sever degradation hence decreased the piezo metric water table level in the groundwater resources which finally results in negative environmental impacts. Silver Creek basin (area 154.8 mile2 equals to approximately 400.930 km ²) locates in southern part of Illinois State, is connected to highland lake (which has a huge impact in the area and specifically Highland City) with east fork tributary. In this research watershed modeled in a hydrological model called SWAT (Soil and Water Assessment Tool) which is an extension of ArcGIS software, then watershed area is divided into 75 sub watersheds. Different parameters and variables are considered for sensitivity analysis in order to figuring out the most sensitive parameters and their ranges for flow rate calibration within different hydrological response units (HRUs). The flow rate quantified at sub basin level with daily time intervals. The model inputs are precipitations and meteorological data such as Solar Radiation, Wind speed and direction, Temperature and Relative Humidity, then model was calibrated with two sets of real data for Troy and Freeburg Stations in the middle and pouring point of watershed respectively. The main object was to test the performance of SWAT and the feasibility of using this model as a simulator of flow rate at a watershed scale. Model calibration and uncertainty analysis performed with SUFI-2 (sequential Uncertainty Fitting) which is interfaced with SWAT applying iSWAT generic program.

Wider bike facilities intuitively accommodate a greater number of cyclists in the same amount of time, but specific queue discharge characteristics associated with varying widths and/or types of bike facilities have not been thoroughly documented.

The focus of this research analyzed queues of cyclists at four signalized intersections in Portland, OR with varying widths on the approach and downstream intersection legs. A total of 2,820 cyclists within 630 groups of queued cyclists were observed at five different intersection layouts in Portland, Oregon. The layouts consisted of: a standard bike lane six feet wide connecting bicyclists to a standard bike lane six feet wide, a standard bike lane five feet wide connecting bicyclists to two standard bike lanes each five feet wide, a buffered bike lane 12 feet wide connecting bicyclists to a standard bike lane 6.5 feet wide, a bike box 21 feet wide connecting bicyclists to a buffered bike lane 10 feet wide, and a bike box 15 feet wide connecting bicyclists to two standard bike lanes each five feet wide.

For each configuration, the following aspects were analyzed: average headway per cyclist within each queue, the time required for queues to enter the intersection, the time required for queues to clear the intersection, the number of cyclists within queues, the width of the bicycle facilities, the approach grade, and the utilization of a bike box at the intersection approach if it was present.

The first major focus of the analysis reviewed the average headway values associated with each observed queue of cyclists. The queue size with the lowest mean of the average headway was for groups of seven cyclists with an average headway of approximately 0.8 seconds per cyclist. For queues larger than seven in size, the mean of the average headway remained relatively stable until queues of 12 in size and started to slightly increase toward approximately 1.0 seconds for queues larger than 12 cyclists. In addition, it appears that utilization of a bike box has a potential relationship with a reduced average headway as compared to queues that do not utilize a bike box. The associated reduction in the mean of the average headway was approximately 0.2 to 0.3 seconds per cyclist for queues of three or more in size.

The second major focus of the analysis reviewed the queue discharge rate associated with each observed queue of cyclists. The results appear to potentially indicate that wider bike facilities approaching an intersection, wider receiving bike facilities, or utilization of a bike box generally discharge queues of bicyclists into the intersection over a shorter amount of time as compared to facilities that are narrower or underutilized. The installation of a bike box at one of the study intersections increased the approach width from five to 15 feet and resulted in consistently lower average discharge times for all queue sizes, a reduction of greater than one second for queues of two cyclists to as much as about four seconds for queues of nine cyclists.

The third major focus of the analysis reviewed the intersection clearance time associated with each observed queue of cyclists. The results appear to potentially indicate that wider bike facilities approaching an intersection, wider receiving bike facilities, or utilization of a bike box generally clear queues of bicyclists through the intersection over a shorter amount of time as compared to facilities that are narrower or underutilized.

Vortex drop shafts are used to transport water or wastewater from over-stressed existing sewer systems to underground tunnels. During the plunge a large amount of air is entrained into the water and released downstream of the drop shaft into the tunnel. This air is unwanted and becomes costly to treat and move back to the surface. Determining the amount of air that will be entrained is a difficult task. A common method is to build a scale model and measure the air discharge and scale it back to prototype. This study investigated a possible relationship between the geometry of the drop structure, the water discharge and the amount of air entrained. The results have shown that air entrainment is still not entirely understood, however we are close to a solution. Using a relationship of the air core diameter, drop shaft length and terminal velocity of the water, a likely exponential relationship has been developed.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 2005.
Includes bibliographical references.
The fresh and saline groundwater flowing from coastal aquifers into the ocean comprise submarine groundwater discharge (SGD). This outflow is an important pathway for the transport of nutrients and contaminants, and has been shown to adversely affect coastal ecosystems in many areas of the world. The focus of this work is the characterization of SGD and the mechanisms that drive it, with a specific emphasis on seasonal forcing. Field measurements during five summers in Waquoit Bay, Massachusetts reveal the pattern and composition of submarine groundwater discharge. Flow is highly variable over small spatial and temporal scales, and the salinity and radium content of the discharge demonstrates heterogeneity in groundwater origin. Maximum discharge occurred in two alongshore bands: brackish outflow nearshore and saline discharge offshore. Most of the total flow was saline, yet net seawater inflow over a tidal cycle was negligible. Circulation mechanisms such as tides, waves, and hydrodynamic dispersion cause significant saline groundwater discharge, and are potentially important for chemical loading to estuaries. However, these mechanisms can explain only 12-30% of the observed saline outflow in Waquoit Bay. A seasonal forcing mechanism is proposed to explain the source of the remaining observed saline outflow. During periods of high inland recharge, the water table rises, forcing seaward movement of the freshwater-saltwater interface and outflow of saline groundwater; the opposite is true during times of low recharge. A series of idealized simulated systems demonstrates this process for a range of realistic aquifer parameters, and a time lag between maximum recharge and simulated peak discharge may explain the observed net discharge during times of low recharge.
(cont.) Winter hydraulic gradient measurements in Waquoit Bay reveal inflow in the zone of peak summer saline discharge, confirming seasonal variation in SGD. Investigation of the subsurface salinity profile and local hydrogeology forms the basis for a hypothesized groundwater flow pattern that explains the observed discharge. A numerical model of the system supports the profile and exhibits temporally-lagged inflow and outflow of saltwater at the sea floor in response to seasonal recharge that may explain the net saline outflow observed in Waquoit Bay during the summer.
by Holly Anne Michael.
Ph.D.

Development in urban catchments often result in rivers being converted into large stormwater canals where stormwater is removed as quickly as possible to prevent flooding. A combination of elevated peak flows, increased nutrients and contaminants and reduced biotic richness are typical features of these urban waterways. This study explored the dynamics of an urban river in Cape Town by using high-resolution monitoring sensors and loggers to analyse and model real-time discharge and water quality data during and after 14 rainfall events. Discharge and water quality data were collected from the Liesbeek River at three sites during the rainfall events. As expected, the upper most sampling site had the lowest discharge and pollution load, compared to sites in the middle and lowest reaches of the river. An analysis showed significant correlations between the discharge and electrical conductivity at all three sampling sites. Rainfall was the primary factor in altering discharge and electrical conductivity. Predictive modelling using selected rainfall designs indicated that average discharge and total volume increases with increasing rainfall. Linear regression analysis for electrical conductivity indicated a strong relationship whereby an increase in discharge resulted in a decrease in electrical conductivity. This study revealed the discharge and water quality of stormwater in the Liesbeek River during rainfall events showed the improved water quality conditions in the river during the rainfall events particularly after the peak discharge. Furthermore, the implications of this study revealed that the Liesbeek River can become a water source for recharging groundwater and aquifers.

Results are presented from sets of field and laboratory experiments conducted to measure and quantify the Hydraulic Residence Time Distribution in treatment ponds containing vegetation. The field measurements were taken in the Lyby field pond (Sweden) with complementary experiments on a distorted, laboratory scale model pond designed and built in the University of Warwick’s engineering laboratory. Rhodamine WT Dye tracer experiments were used in both the Lyby field pond and the distorted physical scale model to investigate vegetation and discharge affects on HRTD characteristics and the technique of PIV (Particle Image Velocimetry) was used in the distorted physical scale model to investigate how surface flow profiles were affected by different vegetation and discharge configurations. The results show that the distorted physical scale pond did not reflect the HRTD characteristics of the field site, with the actual residence time, (tm), for the distorted physical scale pond ranging from 85 % to 125% of its nominal residence time. For the distorted scale model, pond vegetation and discharge did not affect the relative HRTD centroid, em, or the actual residence time, tm. This finding is attributed to the unique pond geography and associated aspect ratios However, flow rates did have a significant effect on the HRTD e0 (time of first dye arrival at the outlet) and ep (time of peak dye concentration). Changes in vegetation were found to have little effect on e0 and ep. For the laboratory pond, vegetation had a significant control on the surface flow field whereas, flow rates did not – the latter suggests that surface flow fields are not representative of the internal flow field in different layers of the pond. The experiments demonstrate that the specific shape of the distorted physical scale pond in this study enables optimal actual resident times to be achieved over a wide range of vegetation and flow rate configurations. If full scale field ponds based upon this design give the same stable centroid results, then this would be a substantial breakthrough in pond design, which would aid the design and management of pond treatment and allow more robust optimisation of treatment efficiency.

In the Spring of 2012, hydraulic data was collected to calibrate three types of discharge models: stage-discharge, single-regression and multi-regression index velocity models. Unsteady flow conditions were observed at the site (â H/â t = 0.75 cm/min), but the data did not indicate hysteresis nor variable backwater effects on the stage-discharge relation. Furthermore, when corrected with a datum offset (α) value of -0.455, the stage-discharge relation r2 was equal to 0.98. While the multiple regression index velocity models also showed high correlation (r2 = 0.98) values, high noise levels of the parameter index velocity (Vi) complicated their use for the determination of discharge. Because of its reliability, low variance and accessibility to students, the stage-discharge model [Q = 5.459(H-0.455)^2.487] was selected as the model to determine discharge in real-time for LEWAS. Caution should be used, however, when applying the equation to stages above 1.0m. The selected discharge model was applied to ADCP stage (H) data collected during three runoff events in July 2012. Other LEWAS models showed similar discharge values (coefficient of variation = 0.14) while the on-site weir also produced similar discharge values. Precipitation estimates for July 19 and 24 rain events over the Webb Branch watershed were derived from IDW interpolated rain data and rainfall-runoff analyses from this data yielded an average ratio of 0.23, low for the urbanized watershed. However, since the three LEWAS models were very similar, and the on-site weir showed a lower value to LEWAS, it was concluded that any error in the ratio would be attributed to the precipitation estimate, and not the discharge models developed in this study.
Master of Science

Ratings curves are conventional means to continuously provide estimates of discharges in rivers. Among the most-often adopted assumptions in building these curves are the steady and uniform flow conditions for the open-channel flow that in turn provide a one-to-one relationships between the variables involved in discharge estimation. The steady flow assumption is not applicable during propagation of storm-generated waves hence the question on the validity of the steady rating curves during unsteady flow is of both scientific and practical interest. Scarce experimental evidence and analytical inferences substantiate that during unsteady flows the relationship between some of the variables is not unique leading to looped rating curves (also labeled hysteresis). Neglecting the unsteadiness of the flow when this is large can significantly affect the accuracy of the flow estimation. Currently, the literature does not offer criteria for a comprehensive evaluation of the methods for estimation of the departure of the looped rating curves from the steady ones nor for identifying the most appropriate means to dynamically capturing hysteresis for different possible river flow conditions. Therefore, the overarching goal of this study was to explore the uncertainty of the conventional approaches for constructing stage-discharge rating curves (hQRCs) and to evaluate methodologies for accurate and continuous discharge monitoring in unsteady open channel flows using analytical inference, index velocity rating curves (VQRCs), and continuous slope area method (CSA) with considerations on discharge measurement uncertainty. The study will demonstrate conceptual and experimental evidences to illustrate some of the unsteady flow impacts on rating curves and suggest the development of a uniform end-to-end methodology to enhance the accuracy of the current protocols for continuous stream flow estimation for both steady and unsteady river conditions. Moreover, hysteresis diagnostic method will be presented to provide the way to conveniently evaluate when and where the hysteresis becomes significant as a function of the site and storm event characteristics. The measurement techniques and analysis methodologies proposed herein will allow to dynamically tracking both the flood wave propagation and the associated uncertainty in the conventional RCs.

A screening level ecological risk assessment (SERA) was completed to evaluate the potential risks of pesticides found in water in the lower Canal 111 (C-111) Basin and adjacent tidal zones in South Florida. This risk assessment was conducted under general U.S. EPA guidelines and focuses on effects of water exposure to the herbicides atrazine and metolachlor and to the insecticides chlorpyrifos, endosulfan, and malathion. Results found that the highest potential risk was associated with the acute effects of endosulfan to freshwater arthropods at sites near water control structure S-178 and Canal 111e, a branch of C-111. The highest potential risk of acute effects of endosulfan for saltwater organisms was in Joe Bay, which receives discharges from C-111. Results from evaluations of risk of chronic effects from pesticide exposure show that the highest potential risk is associated with endosulfan in freshwater.

Co-operation between states is a necessity to be able to handle environmental issues in the Baltic Sea area, since these are transboundary problems. Two organisations that deal with environmental issues in this region are HELCOM and Baltic 21. The aim has been to study how the problem of pollution from diffuse land-based sources, especially agriculture, has been dealt with through these organisations, to look upon the roles of and the relationship between HELCOM and Baltic 21 and to study the possibilities and the difficulties in the practical co-operation. The study holds a Swedish perspective, as Swedish representatives with connections to the HELCOM and Baltic 21 processes have been interviewed. The analysis shows that the EU is becoming increasingly important as an actor in the Baltic Sea co-operation, which makes the future roles of HELCOM and Baltic 21 uncertain. Concerning the difficulties of the work, aspects mentioned were cultural differences, group problems and lack of resources. To improve the work some proposals made by the interviewees were to use the experiences from different projects and to increase the resources.

This project empirically determined the controls of groundwater discharge potential and surface water chemistry in southern Taylor Slough, Everglades National Park, Florida. Potential for groundwater discharge was calculated as the difference in equivalent freshwater stage between groundwater and surface water on a daily basis for two sites (upland and coastal) along southern Taylor Slough. Upstream water stages were shown to vary most similarly to the timing of groundwater discharge potential in coastal Taylor Slough. Surface water major ion chemistry did not apparently change as a result of groundwater discharge potential. Surface water major ion chemistry at the coastal site was controlled by surface water flow direction, while at the more inland site surface water major ion chemistry was controlled by upstream water levels and evapotranspiration. Surface water phosphorus concentrations at the coastal site were controlled by groundwater discharge and flows of local surface water.

Living in counties where manufacturers release environmental toxins, such as those tracked by the Environmental Protection Agency's (EPA) toxic release inventory (TRI), may elevate infants' health risks. Because infant mortality (IM) is a strong indicator of a population's health status, it is an important topic in public health research. The purpose of this research was to examine the potential relationships between IM, community size, and factors related to mothers' SES in counties where more than 25,000 pounds of annual toxic air releases occur. The dependent variable was IM per 1,000 live births in a given community for each of the 3 years included in this analysis (1987, 1995, and 2004). The independent variables included county size and factors related to mother's SES (education, age, ethnicity, and marital status). The theoretical framework consisted of Mosley and Chen's framework for exploring child survival. Archival, publicly available data were pulled from (a) the EPAs TRI data, and (b) linked birth and infant death files from the National Center for Health Statistics. The researcher followed a quantitative, retrospective cross-sectional design and conducted 3 linear regression models to test the research questions. Results indicated that an increase in community size was significantly associated with an increase in IM. Regarding the relationships between IM and the 4 different maternal characteristics (education, age, ethnicity, and marital status) included in the analysis, findings were mixed for the 3 years examined. Despite these unexpected findings, the overall results from this investigation, when considered alongside findings from previous research on IM, indicate that policy changes and interventions are needed to reduce socioeconomic disparities in IM, and to save the lives of more infants.

The major climatic problem has been worsening extremely rapidly over the last decades and if no measures are taken soon, we will experience severe consequences over the years to come. It is therefore imperative to take instant actions to slow down the climatic changes that are also causing crucial health problems in different parts of the planet. The basis of this thesis is that both Energy Performance Certification (EPC), and Green Building (GB) aim to reduce carbon dioxide emission within the building sector which accounts for more than 40% of the total energy use both locally and globally. This thesis discusses and compares the environmental impacts made by Green Building and Energy Performance Certification in order to evaluate how different or similar they are in terms of energy performance efficiency of buildings.

 

In order to accumulate as much facts and resources possible, research was done to find reliable internet sources and relevant books which took approximately two weeks. The rest of the ten weeks that were assigned for this project were spent writing this thesis while taking practical part in an Energy Performance Certification process and evaluation. There are three questions that this thesis is aimed to answer, which are:

-               How is Energy Performance Certification beneficial for our community welfare?

-               Why should owners/occupiers choose to transform their houses/buildings to Green Building certified constructions?

-               Is there a way of combining Energy Performance Certification with Green Building?

 

There are many benefits that our Swedish and European Community can gain from applying Energy Performance Certification of building according to the Directive, including reducing carbon dioxide emission and introducing alternative and renewable sources of energy. As to whether GB is better than EPC or vice versa, there is ultimately a very fine line that divides the two. When comparing new constructions of EPC with new constructions of GB the only benefits that can be gained from GB are firstly that the buildings are guaranteed to be completely environmental friendly, and secondly that the owner/occupier may choose between four different levels of certifications. Other than that, they both have many similar beneficial factors which make it difficult to a state if one of them is better than the other.

 

Lastly, it is very possible to combine the two into one complete standard, but only for new constructions. The energy performance of old existing buildings is much more difficult to improve due to e.g. the high costs involved or the cultural value of the constructions. Nevertheless, this may very well change in the further future when the rapidly improving technology within the building sector will hopefully contribute to finding cost- and energy-efficient solutions for existing buildings that will consequently contribute to GB and EPC being able to combine their regulations and make one single standard that can be applied in all the Member States, or if possible in the entire European Union Community.

De allvarliga klimatproblemen har förvärrats i oerhört snabb takt under de senaste decennierna och om inget görs snart, kommer vi att få uppleva allvariga konsekvenser under de kommande åren. Det är därför absolut nödvändigt att agera snabbt för att bromsa ner klimatförändringarna som också orsakat allvarliga hälsoproblem i många delar av jorden. Utgångspunkten för detta examensarbete är att både Energideklarationen och Green Building strävar efter att minska koldioxidutsläpp inom byggsektorn, som ansvarar för mer än 40 % av den totala energiförbrukningen i Sverige och utomlands. Detta arbete diskuterar och jämför Green Buildings och Energideklarationens påverkan på miljön för att sedan kunna evaluera hur pass lika eller olika de är när det gäller energiprestandaeffektiviteten av byggnader.

 

För att kunna samla så mycket information som möjligt gjordes en undersökning för att hitta pålitliga Internetkällor och relevanta böcker. Undersökningen tog ungefär två veckor. Resten av de tio veckorna som var tilldelade för detta examensarbete användes för att skriva denna rapport samt praktiskt delta i en Energideklarationsprocess samt värdering. Det finns tre frågor som detta examensarbete syftar på att besvara, som är:

-               Hur viktig är Energideklaration för vårt samhälles välbefinnande?

-               Varför ska fastighetsägare välja att bygga/omvandla sina hus till Green Building?

-               Finns det något sätt att kombinera Energideklaration med Green Building?

 

Det finns många fördelar för det svenska samt europeiska samhället med att tillämpa Energideklaration enligt Direktivet. Fördelarna inkluderar minskning av koldioxidutsläppen samt introducering av alternativa förnybara energikällor i byggnader. Dock är det i slutändan små faktorer som skiljer Green Building och Energideklaration åt och det är därför svårt att säga om den ena är bättre än den andra. Vid jämförelse av nya EPC konstruktioner med nya GB konstruktioner är den enda fördelen med GB först och främst att byggnaden är garanterad att vara helt miljövänlig samt att ägaren har möjligheten att välja mellan fyra olika certifieringsnivåer. Förutom detta, har båda två många likheter som gör det svårt att bedöma om den ena av dem är effektivare än den andra.

 

Det är dessutom mycket möjligt att kombinera dessa två till en enda komplett standard, dock endast för nya konstruktioner. Gamla befintliga byggnaders energiprestanda är mycket svårare att förbättra på grund av t.ex. för höga kostnader eller det kulturella värdet av byggnaderna. Å andra sidan kan detta mycket väl ändras i framtiden då den snabbt utvecklade teknologin inom byggsektorn förhoppningsvis kan bidra till att hitta kostnads- och energieffektiva lösningar för befintliga byggnader som kan i sin tur leda till att GB och EPC kombineras till en enda standard som kan tillämpas i alla Medlemsstater, eller även i hela Europa om möjligt.

Thesis (M.S.)--University of North Carolina at Chapel Hill, 2008.
Title from electronic title page (viewed Dec. 11, 2008). "... in partial fulfillment of the requirements for the degree of Master of Science in Environmental Science in the Department of Environmental Sciences and Engineering, School of Public Health." Discipline: Environmental Sciences and Engineering; Department/School: Public Health.

This study aims to determine the recharge, discharge and the mixing mechanisms of a complex aquifer system located above the Kazan trona ore field using the environmental isotopes of deuterium, oxygen-18, carbon-13 and carbon-14, chlorofluorocarbons (CFC- 11, CFC-12 and CFC-113) and the noble gas isotopes (He, Ne, Ar, Kr and Xe). The groundwater system consists of three different aquifers: shallow, middle and deep. The Akpinar formation lying between deep and middle systems acts as an aquitard. Oxygen-18 and deuterium data showed an isotopic contrast between the shallow and deeper aquifer systems and even between the unconfined and confined parts of the middle and deep aquifers. The Noble gas temperatures indicated the average yearly air temperatures in shallow aquifer system whereas the recharge temperatures came out to be lower than todays in deep groundwater system. This finding is also supported by the dissolved inorganic carbon&rsquo
s radiocarbon activities being close to the detection limits in the same system. These activities together with the stable isotope data revealed there might be evidence of recharge to the middle and deep aquifer systems under colder climate conditions during the late Pleistocene. CFC concentrations indicated modern recharge to the shallow aquifer system, whereas the concentrations were close to the detection limits therefore CFC&rsquo
s were unable to date the middle and deep aquifer systems however proved the existence of modern recharge to this system. Mantle-He escape to shallow aquifer system is believed to be along a deep buried fault system located in downgradient areas.

Regression analyses and delta-lognormal models were used to investigate whether river discharge and environmental variables significantly affected relative abundance of brown shrimp, Farfantepenaeus aztecus, in the northern Gulf of Mexico. Significant negative relationships were found between mean river flow during winter and spring months and catch rates (CPUE) off Texas, Louisiana and Mississippi/Alabama. However, during the same months significant positive relationships between CPUE and the variation in mean river discharge were found for each state. In Texas and Louisiana, delta-lognormal models revealed depth zone was the most significant variable (P≤0.001) in describing distribution, while time of day (P≤0.001) was most significant in describing CPUE and also distribution and CPUE in Mississippi/Alabama. These results suggest that brown shrimp relative abundance is effected by river discharge, while gulf-wide environmental variables exert no influence, except dissolved oxygen concentrations affecting distribution off Louisiana.

Background: Diabetes mellitus (DM) affects more than 29.1 million Americans. Standardized clinical practice guidelines recommended by regulatory healthcare agencies are the standard of care for diabetic patients and must be adhered to by healthcare professionals providing care. Purpose: The purpose of this quality improvement project was to identify Centers for Medicare and Medicaid Services’, Joint Commission on Accreditation of Healthcare Organization’s, and other professional healthcare organizations’ guidelines for nurses’ knowledge of evidence-based discharge practices; determine level of nurses’ knowledge on evidence-based discharge practice process; develop a quality improvement plan, including development of an evidence-based guideline for diabetic discharge instructions; present guideline to stakeholders; implement the guideline in fall of 2017; and evaluate nursing compliance with the guideline at a for-profit adult care hospital in South Florida. Theoretical Framework: The chronic care model was utilized as the framework. This model has been used for improving practice and preventing many chronic illnesses. Methods: Two quantitative nonparametric descriptive designs were used, the Wilcoxon signed- rank test and a paired t test. An online demographic survey and pre- and posttest surveys were administered to determine nurses’ knowledge of diabetes discharge guideline practices. The Appraisal of Guidelines for Research and Evaluation II (AGREE II) evaluation tool evaluated the guideline, and data were analyzed with Wilcoxon and paired t tests. Results: A statistically significant difference was found in the pre-posttest survey responses for question 5 (p=0.046 Wilcoxon; p=0.041t test), and question 13 (p= 0.022 Wilcoxon; p=0.018 t test), indicating improvement. With the AGREE II tool, the multidisciplinary team evaluated the guideline at 100%, and 76% of Advanced Practice Registered Nurses (APRNs) and Registered Nurses (RNs) demonstrated compliance with guideline use. Conclusion: A standardized diabetic discharge guideline incorporated into the hospital’s discharge process provided APRNs and RNs with tools for educating and providing diabetic patients for increase in quality of life after discharge. The guideline was recommended by the administrative team for continued use throughout the hospital. Implementation of an evidence-based standardized diabetic discharge guideline to promote nurses’ adherence results in effective nursing practices and an informed patient population.

Glaciers are known to be prone to climate change. The Xinjiang Uyghur Autonomous Region, China, has approximately 20,000 glaciers, which accounts for half number of glaciers in China. One of important function of glacier is that it provides meltwater, therefore, the glacier response to a warming temperature in this area is becoming critical to be investigated in relation to water sustainable development. The Ürümqi Glacier No.1 (UG1), as one of the most important glaciers, has a dominant role of providing meltwater for the capital city, Ürümqi. In this thesis, the Distributed Enhanced Temperature Index Model (DETIM) was employed, and calibrated to perform UG1’s historical discharge pattern. Then the calibrated discharge model was grafted to future climate projection of four Representative Concentration Pathways (RCPs) from fifth Assessment Report (AR5) of the Intergovernmental Panel on Climate Change (IPCC), in order to investigate UG1’s water supply potential in the future. Moreover, UG1’s water supply role was discussed under a dynamic interaction between water supply and human society in the end. The result showed that the computation meltwater volume is between 121 million m³ to 131 million m³ in 35 years, from 2016 to 2050.

In today’s health care environment of quick discharges and shortened hospital stays discharge planning has become increasingly important in acute care occupational therapy practice. Discharge planning is a complex process and an important aspect of patient care as poor discharge planning has been associated with poor patient outcomes and increased risk of adverse events and readmission. This study addressed the following research questions: (a) How do acute care occupational therapists describe their role in the discharge planning process? (b) What guides acute care occupational therapists discharge decisions and recommendations? (c) How do acute care occupational therapists define optimal discharge planning? and (d) What actions can acute care occupational therapists take to optimize the effectiveness of their discharge planning skills within the current health care system? Using an action research methodology, two groups of five occupational therapists met online to discuss acute care occupational therapy discharge planning practices, and actions that could be taken to strengthen their practice. Action plans generated, implemented, and evaluated focused on improving communication with discharge planners, language used in documentation, and incorporating the use of standardized assessments to assist with discharge planning. Schell’s ecological model of professional reasoning as the theoretical model underlying this study was used to examine factors that influence occupational therapy discharge decision making. Data were collected from audio chat transcripts, survey responses, and researcher notes, and analyzed using Stringer’s action research sequential data analysis and interpretation methodology. Five themes emerged including (a) the role of occupational therapy, (b) the complexity of discharge planning, (c) pragmatics of practice, (d) why don’t they pay attention, and (e) the importance of stakeholder communication. Participants felt that discharge planners were not reading occupational therapy documentation, occupational therapy consults were late so that occupational therapy discharge recommendations were just a formality, and physical therapy discharge recommendations had more weight than occupational therapy recommendations. Participants felt that if patients were discharged without benefit of occupational therapy recommendations they could be at increased risk for an adverse event and compromised safety. Good communication among stakeholders was seen as essential for optimal discharge planning.

A Soil and Water Assessment Tool (SWAT) model was developed for the Iowa-Cedar River Basin (ICRB), a 32,660 km2 watershed dominated by agricultural land cover (∼70%) to simulate hydrology and water quality for the prediction of stream discharge, nitrate loads, and nitrate concentration under climate and land use change scenarios. Iowa exports as much as 20% of the nitrogen entering the Gulf of Mexico at the mouth of the Mississippi, contributing to Gulf hypoxia as well as local threats to water quality in the ICRB. The model utilized a combined autocalibration and sensitivity procedure incorporating Sequential Uncertainty Fitting (SUFI) and generalized additive models. This procedure resulted in Nash-Sutcliffe Efficiency (NSE) goodness-of-fit statistics that met literature guidelines for monthly mean stream discharge (NSE≥0.60) and daily nitrate load (NSE≥0.50). Artificial neural networks coupled with SWAT stream discharges aided in the simulation of daily mean nitrate concentrations that met the literature guideline (NSE≥0.50). The North American Regional Climate Change Assessment Program (NARCCAP) provided an ensemble of 11 climate change scenarios. NARCCAP is a multi-institutional effort to simulate climate change at the mesoscale by downscaling global circulation models (GCM) with regional climate models (RCM). The resulting GCM-RCM produced synthetic precipitation and temperature time-series that drove the SWAT simulations and scenarios. The land use scenarios were a collaboration with the U.S. Army Corps of Engineers, using a rule-based GIS method to generate scenarios that (1) maximized agricultural productivity, (2) improved water quality and reduced flooding, and (3) enhanced local biodiversity. The SWAT simulations and ensemble climate change scenarios resulted in a warmer and wetter climate with greater and more extreme discharge in all seasons except summer where the models indicate a somewhat higher probability of extreme low flows (p-value<0.05). The land use scenarios for SWAT showed that nitrate load and discharge positively and linearly scale with percent of agricultural land area (p-value<0.05).

Ocean Thermal Energy Conversion (OTEC) is a renewable energy technology that has to overcome several key challenges before achieving its ultimate goal of producing baseload power on a commercial scale. The economic challenge of deploying an OTEC plant remains the biggest barrier to implementation. Although small OTEC demonstration plants and recent advances in subsystem technologies have proven OTEC’s technical merits, the process still lacks the crucial operational data required to justify investments in large commercial OTEC plants on the order of 50-100 megawatts of net electrical power (MWe-net). A pre-commercial pilot plant on the order of 5-10 MWe-net is required for an OTEC market to evolve. In addition to the economic challenge,OTEC plants have potential for adverse environmental impacts from redistribution of nutrients and residual chemicals in the discharge plume. Although long-term operational records are not available for commercial sizeOTEC plants, synergistic operational data can be leveraged from the desalination industry to improve the potential for OTEC commercialization. Large capacity desalination plants primarily use membranes or thermal evaporator tubes to transform enormous amounts of seawater into freshwater. Thermal desalination plants in particular possess many of the same technical, economic, and environmental traits as a commercial scale OTEC plant. Substantial long-term economic data and environmental impact results are now widely available since commercial desalination began in the 1950s. Analysis of this data indicates that the evolution of the desalination industry could be akin to the potential future advancement of OTEC. Furthermore, certain scenarios exist where a combined OTEC-desalination plant provides a new opportunity for commercial plants. This paper seeks to utilize operational data from the desalination industry as a progressive approach towards OTEC commercialization.

In the northeastern Gulf of Mexico, relating changes in zooplankton communities to environmental factors is crucial to understanding the marine ecosystem and impacts of perturbations such as oil spills on marine ecosystems. Zooplankton samples were collected each year between 2005–2014 in spring and summer in the vicinity of the oil spill (Deepwater Horizon) that occurred in spring 2010. Zooplankton assemblages and environmental conditions significantly differed seasonally, driven by strong variations in zooplankton at continental shelf stations, and by environmental factors including Mississippi River discharge, wind direction, temperature, and chlorophyll concentrations. Total zooplankton abundances were greatest at shelf stations, intermediate at slope stations, and lowest at offshore stations. Seasonal separation was driven by greater abundances of crab zoea, cladocerans, ostracods, and the copepod, Eucalanus spp. during summer. Copepods, Centropages spp., were significant indicators of summer conditions both before and after the oil spill. Sub-regional comparisons in percent composition and abundances of six major non-copepod and seven copepod taxa revealed that most taxa either remained the same or significantly increased in abundance following the spill. A significant decrease in post oil spill taxa was observed only during spring for total copepods, Eucalanaus spp., and for salps at continental slope stations, however varying processing techniques used for zooplankton before and after the spill were employed and should be considered. . Based on our sampling periods, these results indicate that the 2010 oil spill did not significantly impact zooplankton communities in the northeastern Gulf of Mexico.

The purpose of this study is to analyze how estimates of an important geomorphic parameter, effective discharge, are impacted by the choice of bed material load equations and flow duration curves (FDCs). The Yang (1979), Brownlie (1981), and Pagosa equations developed by Rosgen (2006) were compared for predicting bed material load. To calculate the bed material load using the Pagosa equations, the bedload and suspended load are calculated separately and the results are added together. To compare the effectiveness of the equations, measured bed material load data from the USGS Open-File Report 89-67 were used. Following the calculations, the equation results were compared to the measured data. It was determined that the Pagosa equations performed the best overall, followed by Brownlie and then Yang. The superior performance of the Pagosa equations is likely due to the equations being calibrated. USGS regression equations for FDCs were compared to a method developed by Dr. David Rosgen in which a dimensionless FDC (DFDC) is developed. Weminuche Creek in southwestern Colorado was used as the study site. Rosgen's DFDC method requires the selection of a streamgage for a stream that exhibits the same hydro-physiographic characteristics as the site of interest. An FDC is developed for the gaged site and made dimensionless by dividing the discharges by the bankfull discharge of the gaged site. The DFDC is then made dimensional by multiplying by the bankfull discharge of the site of interest and the resulting dimensional FDC is taken as the FDC of the ungaged site. The USGS regression equations underpredicted the discharges while Rosgen's DFDC method overpredicted them. Rosgen's DFDC method produced more accurate results than the USGS regression equations for Weminuche Creek. To calculate the effective discharge, the FDC was used to develop a flow frequency curve which was then multiplied by the sediment rating curve. Effective discharge calculations were performed for Weminuche Creek using several combinations of bed material load prediction equations and FDCs. The USGS regression equations, Rosgen's DFDC method, and streamgage data were all used in conjunction with the Yang and Pagosa equations. The Brownlie equation predicted zero bed material load for Weminuche Creek, and was thus not used to calculate the effective discharge. When the USGS regression equations were used with the Yang and Pagosa equations, the calculated effective discharge was approximately 4.5 cms for both bed material load prediction equations. When Rosgen's DFDC method and streamgage data were used with the Yang and Pagosa equations, the effective discharge was approximately 13.5 cms. From these results, it was determined that the bed material load prediction equations had little impact on the effective discharge for Weminuche Creek while the FDCs did influence the results.

Tiriamojo darbo objektas: Minijos upės baseinas. Tiriamojo darbo tikslas: atlikti Minijos upės baseino hidrologinių duomenų analizę, apskaičiuoti pagrindines hidrologines charakteristikas bei įvertinti nuotėkio kaitos tendencijas. Tiriamojo darbo uždaviniai: 1. surinkti Minijos upės baseino hidrologinius stebėjimų duomenis; 2. aptarti hidrologiniams skaičiavimams naudojamas programines įrangas; 3. išanalizuoti Minijos upės baseino surinktus hidrologinius duomenis ir įvertinti jų patikimumą; 4. atlikti surinktų hidrologinių duomenų analizę, panaudojant įvairią programinę įrangą. Tiriamojo darbo metodika: Minijos upės ties Kartena hidrologiniai stebėjimų duomenys išrinkti iš hidrologijos metraščių nuo 1954 iki 2010 metų. Literatūros apžvalgos skyrius rašomas referatyviai, analizuojant kitų mokslininkų atliktus tyrimus bei naudojamus metodus. Išsamiai išanalizuojama naudojama programinė įranga, apskaičiuojamos hidrologinės charakteristikos, sutvarkomi gauti rezultatai, daromos išvados. Tiriamojo darbo rezultatai: 1. Naudojant programinę įrangą „HYFRAN“ nustatyta, kad maksimalius vandens debitus geriausiai aprašo Weibull ekstreminių reikšmių skirstinys, o minimalius – Gumbel skirstinys. 2. Naudojant keturis bazinio nuotėkio indekso nustatymo metodus, nustatyta, kad tinkamiausias tam yra Anglijos hidrologijos instituto sukurtas metodas, kuris naudojamas programinėje įrangoje „HYDROTOOLS“. Nustatytas už 1954-2010 metų laikotarpį bazinio nuotėkio indeksas Minijos upei lygus 0,49... [toliau žr. visą tekstą]
Object of the research: the Minija river watershed. Aim of the research: to perform a hydrological data analysis of the Minija river watershed, to calculate the basic hydrological characteristics and evaluate the runoff trends. Objectives of the research: 1. To collect the hydrological monitoring data of the river watershed; 2. To discuss the software used for hydrological calculations; 3. To analyze the collected hydrological data of the Minija river watershed and assess their reliability; 4. To analyze the collected hydrological data by using different software. Methods of the research: the hydrological monitoring data of the Minija river (near Kartena) watershed were taken from annual Hydrological Data Books for the period of 1954-2010. The chapter on the reference sources is written by citing them and analyzing the survey carried out by other scientists and the research methods used. The used software is thoroughly analyzed, the hydrological characteristics are calculated, the results are arranged, and conclusions are drawn. Results of the research: 1. By using the software “HYFRAN” it was founded that the maximum water flow rate is best described by Weibull distribution of extreme values whereas the minimum water flow rate is best described by Gumbel distribution. 2. Using the four basic methods of determining flow index showed that the best method is developed by England’s Hydrological Institute and is used in the “HYDROTOOLS” software. It was estimated that the... [to full text]

Beaver Creek is an impaired streams that is not supporting its designated use for recreation due to Escherichia coli (E.coli), and sediment. To address this problem, this thesis was divided into two studies. The first study explored changes in Land Use Land Cover (LULC), and its impact on surface water quality. Changes in E.coli load between 1997-2001 and 2014-2018 were analyzed. Also, Landsat data of 2001, and 2018 were examined in Terrset 18.31. Mann-Whitney test only showed a significant reduction in E.coli for one site. Negative correlation was established between E.coli load, and Developed LULC, Forest LULC, and Cultivated LULC. The second study modelled discharge for Beaver Creek watershed using HEC-HMS. This study simulated discharge in an upstream sub-watershed of Beaver Creek, and the full Beaver Creek with a Nash-Sutcliffe of 0.007, and R2 0.20. Sub-basins with high discharge were identified for further examination for possible high sediment load.

The need to accommodate larger reservoir discharge events has prompted the improvement or replacement of existing spillways. One possible spillway modification is the use of an in-reservoir arced labyrinth weir in place of a linear weir. Arced labyrinth weirs can increase crest length (more cycles) and have improved hydraulic efficiency in non-channelized approach flow applications, compared to traditional labyrinth weir applications. In this study, arced labyrinth weir flow characteristics were observed for eleven different laboratory-scale model geometries at the Utah Water Research Laboratory. Rating (Cd vs. HT/P) data and observations were recorded for each configuration, and discharge efficiency was determined. Cycle efficiency, which is representative of the discharge per cycle, was also reported.

Temperatures strongly affect physical, chemical, and biological processes in rivers and streams. The processes that influence river temperatures are known across most geographic regions, but the relative importance varies significantly. Little is known about what controls water temperature Arctic rivers, limiting our ability to understand the impacts of climate change. This dissertation addresses this knowledge gap by incorporating field measurements with river temperature modeling to estimate the relative importance of key factors that affect Arctic river temperatures. Results indicate that shortwave radiation (e.g., sunlight) and net longwave radiation are significant throughout an Arctic watershed in all flow conditions. In areas where the river is smaller, however, exchange of water with the riverbed and inputs of water from the landscape become significant under low-flow and high-flow conditions, respectively. Additional field observations and modeling were used to quantify the water and heat exchanges between the river and the riverbed. These heat exchanges were found to cool the river and reduce the daily range of temperatures. To better estimate the flow of water from the landscape to the river, a new method for estimating river flow was developed using high-resolution aerial imagery. This method allows us to estimate river flow without depending on field measurements, and presents a potential solution to barriers in performing river temperature modeling in other parts of the Arctic.