Optimal Design of Stormwater Basins with Bio-Sorption Activated Media (BAM) in Karst Environments – Phase II: Field Testing of BMPs

Two new designs of stormwater Best Management Practices (BMPs) using Biosorption Activated Media (BAM) were developed, implemented, and tested: (1) blanket filters, located within a stormwater management facility, and (2) vertical infiltration reactors. The blanket filter, comprised of a 1-ft top-soil layer and 3-ft BAM layer, removed 60%-66% of TN, NOx, and NH3 from roadway runoff. Mean removals of total nitrogen (TN), nitrate-nitrite (NOx), and ammonia (NH3) within a 3-ft top-soil layer (containing no BAM) range from 78%-92%, exceeding mean removals observed in the blanket filter. Within a blanket filter, a 3-ft BAM layer removes considerably more nitrogen, and particularly NOx, as compared to 1.5-ft layer of BAM. Similarly, a 3-ft soil layer above the BAM layer may remove considerably more nitrogen as compared to a 1-ft soil layer. It is estimated that through a 20- to 30-year design life, the cost of each pound of TN removed by blanket filters (a 3-ft layer of BAM placed in the vadose zone with 1-ft soil coverage) is $611-$715, while each pound of NOx removed will cost $1,360-$1,590. Of six media configurations tested within vertical reactors, nitrogen removal was best achieved by a 4-ft layer of BAM; a mean 49% TN and over 53% NOx was removed from incoming stormwater. It is estimated that through a 20- to 30-year design life, the cost of each pound of TN removed by vertical reactors placed in the vadose zone is $453-$498. It is estimated that each pound of NOx removed will cost $701-$732

The Hydraulic Size Of A Dam: A Metric Indicating Potential Hydrologic Impact For Storage And Diversion

Easily-calculated metrics describing potential impacts of dams are often used as preliminary investigations, or in analyses describing hydrologic impact over large scales and involving many dams. However, common dam impact metrics overwhelmingly reflect effects of medium to large reservoirs. Indicators applied to describe a dam’s capacity to alter downstream river flows typically consider reservoir storage as a sole mechanism of hydrologic impact. Herein, metrics of hydraulic size are proposed to encompass potential impacts related to both storage and diversion of water. Hydrologic effect due to storage and diversion computed across a sample of diversion and non-diversion dams exemplifies that hydrologic alteration related to diversion may be significant, even where storage-based indicators suggest that potential for hydrologic impact is low. As compared to metrics based on storage alone, the proposed metrics offer a more flexible and inclusive description of hydrologic impact and one which is more universally applicable to dams of variable design and purpose

Modification of an impulse-factoring orbital transfer technique to account for orbit determination and maneuver execution errors

A method has previously been developed to satisfy terminal rendezvous and intermediate timing constraints for planetary missions involving orbital operations. The method uses impulse factoring in which a two-impulse transfer is divided into three or four impulses which add one or two intermediate orbits. The periods of the intermediate orbits and the number of revolutions in each orbit are varied to satisfy timing constraints. Techniques are developed to retarget the orbital transfer in the presence of orbit-determination and maneuver-execution errors. Sample results indicate that the nominal transfer can be retargeted with little change in either the magnitude (Delta V) or location of the individual impulses. Additonally, the total Delta V required for the retargeted transfer is little different from that required for the nominal transfer. A digital computer program developed to implement the techniques is described

Cumulative biophysical impact of small and large hydropower development in Nu River, China

Support for low-carbon energy and opposition to new large dams encourages global development of small hydropower facilities. This support is manifested in national and international energy and development policies designed to incentivize growth in the small hydropower sector while curtailing large dam construction. However, the preference of small to large dams assumes, without justification, that small hydropower dams entail fewer and less severe environmental and social externalities than large hydropower dams. With the objective to evaluate the validity of this assumption, we investigate cumulative biophysical effects of small (< 50 MW) and large hydropower dams in China's Nu River basin, and compare effects normalized per megawatt of power produced. Results reveal that biophysical impacts of small hydropower may exceed those of large hydropower, particularly with regard to habitat and hydrologic change. These results indicate that more comprehensive standards for impact assessment and governance of small hydropower projects may be necessary to encourage low-impact energy development.Keywords: small hydropower, impact assessment, water resources, China, renewable energy, developmen

Developing a Shoreline Restoration Suitability Model for North Indian River and Mosquito Lagoon, Phase II

This project successfully created a living shoreline restoration prioritization model and a mangrove hydrodynamic habitat suitability model for 180 miles of estuarine shorelines in Mosquito Lagoon and northern Indian River. Shoreline model data are available for direct download as a spatial dataset (https://stars.library.ucf.edu/shorelines/), or for online viewing in a GIS storymap: (https://ucfonline.maps.arcgis.com/apps/MapSeries/index.html?appid=45caa29e80e6441c8bf6f75c542860af). New empirical wave data were created through hydrodynamic modeling. Frequency analysis was applied to characterize wave climate in study area shorelines. Wind-wave measurements observed in the field validated that actual wave heights above 2 cm were well represented by the model. Modelled hydrodynamic data were combined with shoreline data (collected in the field during the project Phase I) to develop fundamental knowledge regarding hydrodynamic habitat suitability of IRL shoreline species. Through this analysis, strong relationships between mangrove presence and wind wave hydrodynamics were illuminated, such that the probability of mangrove persistence was predicted at the project site scale based on wave climate. Additionally, the influential role of site intertidal slope and its interaction with site hydrodynamics was confirmed. This is a transformative source of information from the perspective of Planning, Design and Engineering (PD&E) of shoreline stabilization projects and regional-scale restoration planning. Mangroves were found on shorelines with overall lower incoming wave height distributions as compared to shorelines without mangrove vegetation. Mangrove presence became less likely as wave height increased, suggesting that there is a critical wave magnitude-frequency combination above which it is increasingly unlikely that mangrove vegetation will persist. Where wave heights exceeded 5 cm 20% of time, there was over an 80% chance of mangrove persistence. Where wave heights were 8 cm 20% of time, chance of mangrove persistence dropped to 50%. Where wave heights were over 15 cm 20% of time, there was less than 10% chance of mangrove persistence. While wave climate was found to explain the greatest variance within a generalized linear model of mangrove distribution, the influence of shoreline slope was also found to be significant. Low shoreline intertidal slopes were found to increase the threshold wave climate mangroves can survive. For example, the 80th percentile wave height associated with 50% probability of mangrove survival was 8 cm when slope was 0.2, increased to 9 cm when slope was lower than 0.2, and decreased to 4 cm when slope was greater. The presence of oysters or seagrasses at the shoreline were also correlated with wave height; however, conditions within the project area were insufficient to create robust hydrodynamic habitat thresholds for these important coastal ecosystem engineers. There are therefore future research opportunities to apply frameworks developed herein to broader study areas, which will potentially lead to discovery of flow-ecology relationships for a more diverse suite of coastal ecosystem engineers. All study shorelines were classified within a prioritization model according to need and urgency of stabilization. Shoreline sites classified in Urgent need (18% of study shoreline) should be triaged for immediate stabilization. Shoreline sites classified as Priority (10% of study shoreline) will eventually move to the Urgent category without intervention. Shorelines classified as Vulnerable (6% of study shorelines) are sites for pre-emptive restoration. Sites within the Wetland category (38% of study shorelines) do not need to be restored at this time and can serve as reference sites for living shoreline stabilization. Shorelines with hard armoring (28% of study shorelines) may represent opportunities to increase long-term shoreline resilience or restore shoreline ecotone functionality. Analysis of Hardened shorelines in context of local wave climate and slope indicate that many hardened shorelines in the project study area may not actually require armoring. Living shoreline containing mangrove forest could be expected to stabilize many currently hardened shorelines. All study shorelines were classified according to likelihood of mangrove persistence based on hydrodynamic habitat suitability. Within the study area, 68% of the shoreline was characterized by 50% or greater probability of mangrove persistence. At the site scale, likelihood of mangrove persistence can also be increased by design of an equilibrium shoreline slope, adding elasticity to stabilization site designs in areas that are on the borderline of mangrove hydrodynamic habitat suitability. Severe erosion was three times more likely to be observed on shorelines without mangrove vegetation, where over 60% of sites had escarpment heights greater than 30 cm. Similarly, shorelines with mangrove were more than two times as likely to be characterized by no to low levels of erosion. Managers and practitioners within and outside of the direct project area can benefit from this work. First, the actual hydrodynamic habitat thresholds for mangrove discovered in this study can be transferred to other locations within and outside of the Indian River Lagoon system. Locations throughout Florida that fit within the mangrove temperature, salinity and hydrology habitat zones may apply the hydrodynamic habitat knowledge developed herein to site-scale project planning. Second, the synergy between regional-scale project prioritization data and site-scale habitat suitability design tools demonstrated in this project can be a framework for future restoration planning efforts. Provision of information both at a broad geographic scale for use in regional planning, and making the information sufficiently detailed such that it can be applied at the site scale can help managers and practitioners understand when and where restoration is needed, and also the appropriateness of nature-based or green-grey hybrid designs on a site-by-site basis. Widespread investment in this type of information, and dedicated strategies to adopt such information in project PD&E may increase restoration success and impact on a regional scale

Large-Scale Variation in Wave Attenuation of Oyster Reef Living Shorelines and the Influence of Inundation Duration

One of the paramount goals of oyster reef living shorelines is to achieve sustained and adaptive coastal protection, which requires meeting ecological (i.e., develop a self-sustaining oyster population) and engineering (i.e., provide coastal defense) targets. In a large-scale comparison along the Atlantic and Gulf coasts of the United States, the efficacy of various designs of oyster reef living shorelines at providing wave attenuation was evaluated accounting for the ecological limitations of oysters with regards to inundation duration. A critical threshold for intertidal oyster reef establishment is 50% inundation duration. Living shorelines that spent less than half of the time (\u3c 50%) inundated were not considered suitable habitat for oysters, however, were effective at wave attenuation (68% reduction in wave height). Reefs that experienced \u3e 50% inundation were considered suitable habitat for oysters, but wave attenuation was similar to controls (no reef; ~5% reduction in wave height). Many of the oyster reef living shoreline approaches therefore failed to optimize the ecological and engineering goals. In both inundation regimes, wave transmission decreased with an increasing freeboard (difference between reef crest elevation and water level), supporting its importance in the wave attenuation capacity of oyster reef living shorelines. However, given that the reef crest elevation (and thus freeboard) should be determined by the inundation duration requirements of oysters, research needs to be re-focused on understanding the implications of other reef parameters (e.g. width) for optimising wave attenuation. A broader understanding of the reef characteristics and seascape contexts that result in effective coastal defense by oyster reefs is needed to inform appropriate design and implementation of oyster-based living shorelines globally

Real-time observation of dissipative soliton formation in nonlinear polarization rotation mode-locked fibre lasers

Formation of coherent structures and patterns from unstable uniform state or noise is a fundamental physical phenomenon that occurs in various areas of science ranging from biology to astrophysics. Understanding of the underlying mechanisms of such processes can both improve our general interdisciplinary knowledge about complex nonlinear systems and lead to new practical engineering techniques. Modern optics with its high precision measurements offers excellent test-beds for studying complex nonlinear dynamics, though capturing transient rapid formation of optical solitons is technically challenging. Here we unveil the build-up of dissipative soliton in mode-locked fibre lasers using dispersive Fourier transform to measure spectral dynamics and employing autocorrelation analysis to investigate temporal evolution. Numerical simulations corroborate experimental observations, and indicate an underlying universality in the pulse formation. Statistical analysis identifies correlations and dependencies during the build-up phase. Our study may open up possibilities for real-time observation of various nonlinear structures in photonic systems

Effectiveness of individualized physiotherapy on pain and functioning compared to a standard exercise protocol in patients presenting with clinical signs of subacromial impingement syndrome. A randomized controlled trial

<p>Abstract</p> <p>Background</p> <p>Shoulder impingement syndrome is a common musculoskeletal complaint leading to significant reduction of health and disability. Physiotherapy is often the first choice of treatment although its effectiveness is still under debate. Systematic reviews in this field highlight the need for more high quality trials to investigate the effectiveness of physiotherapy interventions in patients with subacromial impingement syndrome.</p> <p>Methods/Design</p> <p>This randomized controlled trial will investigate the effectiveness of individualized physiotherapy in patients presenting with clinical signs and symptoms of subacromial impingement, involving 90 participants aged 18-75. Participants are recruited from outpatient physiotherapy clinics, general practitioners, and orthopaedic surgeons in Germany. Eligible participants will be randomly allocated to either individualized physiotherapy or to a standard exercise protocol using central randomization.</p> <p>The control group will perform the standard exercise protocol aiming to restore muscular deficits in strength, mobility, and coordination of the rotator cuff and the shoulder girdle muscles to unload the subacromial space during active movements. Participants of the intervention group will perform the standard exercise protocol as a home program, and will additionally be treated with individualized physiotherapy based on clinical examination results, and guided by a decision tree. After the intervention phase both groups will continue their home program for another 7 weeks.</p> <p>Outcome will be measured at 5 weeks and at 3 and 12 months after inclusion using the shoulder pain and disability index and patients' global impression of change, the generic patient-specific scale, the average weekly pain score, and patient satisfaction with treatment. Additionally, the fear avoidance beliefs questionnaire, the pain catastrophizing scale, and patients' expectancies of treatment effect are assessed. Participants' adherence to the protocol, use of additional treatments for the shoulder, direct and indirect costs, and sick leave due to shoulder complaints will be recorded in a shoulder log-book.</p> <p>Discussion</p> <p>To our knowledge this is the first trial comparing individualized physiotherapy based on a defined decision making process to a standardized exercise protocol. Using high-quality methodologies, this trial will add evidence to the limited body of knowledge about the effect of physiotherapy in patients with SIS.</p> <p>Trial registration</p> <p>Current Controlled Trials ISRCTN86900354</p