92 research outputs found
DOE Hydropower Program Biennial Report for FY 2005-2006
SUMMARY The U.S. Department of Energy (DOE) Hydropower Program is part of the Office of Wind and Hydropower Technologies, Office of Energy Efficiency and Renewable Energy. The Program's mission is to conduct research and development (R&D) that will increase the technical, societal, and environmental benefits of hydropower. The Department's Hydropower Program activities are conducted by its national laboratories: Idaho National Laboratory (INL) [formerly Idaho National Engineering and Environmental Laboratory], Oak Ridge National Laboratory (ORNL), Pacific Northwest National Laboratory (PNNL), and National Renewable Energy Laboratory (NREL), and by a number of industry, university, and federal research facilities. Programmatically, DOE Hydropower Program R&D activities are conducted in two areas: Technology Viability and Technology Application. The Technology Viability area has two components: (1) Advanced Hydropower Technology (Large Turbine Field Testing, Water Use Optimization, and Improved Mitigation Practices) and (2) Supporting Research and Testing (Environmental Performance Testing Methods, Computational and Physical Modeling, Instrumentation and Controls, and Environmental Analysis). The Technology Application area also has two components: (1) Systems Integration and Technology Acceptance (Hydro/Wind Integration, National Hydropower Collaborative, and Integration and Communications) and (2) Supporting Engineering and Analysis (Valuation Methods and Assessments and Characterization of Innovative Technology). This report describes the progress of the R&D conducted in FY 2005-2006 under all four program areas. Major accomplishments include the following: Conducted field testing of a Retrofit Aeration System to increase the dissolved oxygen content of water discharged from the turbines of the Osage Project in Missouri. Contributed to the installation and field testing of an advanced, minimum gap runner turbine at the Wanapum Dam project in Washington. Completed a state-of-the-science review of hydropower optimization methods and published reports on alternative operating strategies and opportunities for spill reduction. Carried out feasibility studies of new environmental performance measurements of the new MGR turbine at Wanapum Dam, including measurement of behavioral responses, biomarkers, bioindex testing, and the use of dyes to assess external injuries. Evaluated the benefits of mitigation measures for instream flow releases and the value of surface flow outlets for downstream fish passage. Refined turbulence flow measurement techniques, the computational modeling of unsteady flows, and models of blade strike of fish. Published numerous technical reports, proceedings papers, and peer-reviewed literature, most of which are available on the DOE Hydropower website. Further developed and tested the sensor fish measuring device at hydropower plants in the Columbia River. Data from the sensor fish are coupled with a computational model to yield a more detailed assessment of hydraulic environments in and around dams. Published reports related to the Virtual Hydropower Prospector and the assessment of water energy resources in the U.S. for low head/low power hydroelectric plants. Convened a workshop to consider the environmental and technical issues associated with new hydrokinetic and wave energy technologies. Laboratory and DOE staff participated in numerous workshops, conferences, coordination meetings, planning meetings, implementation meetings, and reviews to transfer the results of DOE-sponsored research to end-users
Natural disturbance impacts on trade-offs and co-benefits of forest biodiversity and carbon
With accelerating environmental change, understanding forest disturbance impacts on trade-offs between biodiversity and carbon dynamics is of high socio-economic importance. Most studies, however, have assessed immediate or short-term effects of disturbance, while long-term impacts remain poorly understood. Using a tree-ring-based approach, we analysed the effect of 250 years of disturbances on present-day biodiversity indicators and carbon dynamics in primary forests. Disturbance legacies spanning centuries shaped contemporary forest co-benefits and trade-offs, with contrasting, local-scale effects. Disturbances enhanced carbon sequestration, reaching maximum rates within a comparatively narrow post-disturbance window (up to 50 years). Concurrently, disturbance diminished aboveground carbon storage, which gradually returned to peak levels over centuries. Temporal patterns in biodiversity potential were bimodal; the first maximum coincided with the short-term post-disturbance carbon sequestration peak, and the second occurred during periods of maximum carbon storage in complex old-growth forest. Despite fluctuating local-scale trade-offs, forest biodiversity and carbon storage remained stable across the broader study region, and our data support a positive relationship between carbon stocks and biodiversity potential. These findings underscore the interdependencies of forest processes, and highlight the necessity of large-scale conservation programmes to effectively promote both biodiversity and long-term carbon storage, particularly given the accelerating global biodiversity and climate crises
The Maine Tidal Power Initiative: Transdisciplinary sustainability science research for the responsible development of tidal power
The Maine Tidal Power Initiative (MTPI), an interdisciplinary team of engineers, marine scientists, oceanographers, and social scientists, is using a transdisciplinary sustainability science approach to collect biophysical and social data necessary for understanding interactions between human and natural systems in the context of tidal power development in Maine. MTPI offers a unique opportunity to better understand how group structure and process influence outcomes in transdisciplinary sustainability science research. Through extensive participant observation and semi-structured interviews we: (1) describe MTPI’s organizational structure; (2) examine MTPI’s research approach and engagement with stakeholders from different sectors of society (i.e., industry, government, and the local community); and (3) identify challenges and opportunities for involving different disciplinary expertise and diverse stakeholders in transformational sustainability science research. We found that MTPI’s holistic mission, non-hierarchical structure, and iterative stakeholder engagement process led to important benefits and significant challenges. Positive outcomes include knowledge development, a transferable research framework, shared resources, personal reward, and a greater understanding of the local environment and community. Challenges identified include balancing diverse interests and priorities, maintaining engagement, managing stakeholder relationships, and limited resources. Lessons learned from the process of integrative collaborative research in Maine can offer guidance on what should be considered when carrying out similar transdisciplinary sustainability science projects in other research contexts
Enhanced follicular delivery of finasteride to human scalp skin using heat and chemical penetration enhancers
© The Author(s) 2020. This article is an open access publication. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.Purpose The aim of this work was to evaluate whether improved topical delivery of finasteride, focussed to the hair follicles of human scalp skin could be achieved with application of short durations of heat and use of specific chemical penetration enhancers. Methods Franz cell experiments with human scalp skin were performed with a range of chemical penetration enhancers at 32°C and 45°C to simulate normal and heated conditions. Selected chemical penetration enhancers were taken forward for finite dose Franz cell studies which examined the effect of heat produced by a prototype external heating system that supplied either 20 or 30 min of additional heat over both a 24 h and a 1 h time period. Results Short durations of externally applied heat significantly increased finasteride penetration into human scalp skin after 24 h. Analysis of drug distribution in the skin after 1 h and 24 h indicated that both heat and chemical penetration enhancer selection influenced drug delivery to the hair follicles. Conclusion The use of short durations of heat in combination with specific chemical penetration enhancers was able to increase the delivery of finasteride to human scalp skin and provide focussed drug delivery to the hair follicles.Peer reviewe
Hydrokinetic Turbine Effects on Fish Swimming Behaviour
Hydrokinetic turbines, targeting the kinetic energy of fast-flowing currents, are under development with some turbines
already deployed at ocean sites around the world. It remains virtually unknown as to how these technologies affect
fish, and rotor collisions have been postulated as a major concern. In this study the effects of a vertical axis
hydrokinetic rotor with rotational speeds up to 70 rpm were tested on the swimming patterns of naturally occurring
fish in a subtropical tidal channel. Fish movements were recorded with and without the rotor in place. Results showed
that no fish collided with the rotor and only a few specimens passed through rotor blades. Overall, fish reduced their
movements through the area when the rotor was present. This deterrent effect on fish increased with current speed.
Fish that passed the rotor avoided the near-field, about 0.3 m from the rotor for benthic reef fish. Large predatory fish
were particularly cautious of the rotor and never moved closer than 1.7 m in current speeds above 0.6 ms-1. The
effects of the rotor differed among taxa and feeding guilds and it is suggested that fish boldness and body shape
influenced responses. In conclusion, the tested hydrokinetic turbine rotor proved non-hazardous to fish during the
investigated conditions. However, the results indicate that arrays comprising multiple turbines may restrict fish
movements, particularly for large species, with possible effects on habitat connectivity if migration routes are
exploited. Arrays of the investigated turbine type and comparable systems should therefore be designed with gaps of
several metres width to allow large fish to pass through. In combination with further research the insights from this
study can be used for guiding the design of hydrokinetic turbine arrays where needed, so preventing ecological
impacts
Immunosuppressive therapy for pediatric aplastic anemia: a North American Pediatric Aplastic Anemia Consortium study
Quality of response to immunosuppressive therapy and long-term outcomes for pediatric severe aplastic anemia remain incompletely characterized. Contemporary evidence to inform treatment of relapsed or refractory severe aplastic anemia for pediatric patients is also limited. The clinical features and outcomes for 314 children treated from 2002 to 2014 with immunosuppressive therapy for acquired severe aplastic anemia were analyzed retrospectively from 25 institutions in the North American Pediatric Aplastic Anemia Consortium. The majority of subjects (n=264) received horse anti-thymocyte globulin (hATG) plus cyclosporine (CyA) with a median 61 months follow up. Following hATG/CyA, 71.2% (95%CI: 65.3,76.6) achieved an objective response. In contrast to adult studies, the quality of response achieved in pediatric patients was high, with 59.8% (95%CI: 53.7,65.8) complete response and 68.2% (95%CI: 62.2,73.8) achieving at least a very good partial response with a platelet count ≥50×109L. At five years post-hATG/CyA, overall survival was 93% (95%CI: 89,96), but event-free survival without subsequent treatment was only 64% (95%CI: 57,69) without a plateau. Twelve of 171 evaluable patients (7%) acquired clonal abnormalities after diagnosis after a median 25.2 months (range: 4.3-71 months) post treatment. Myelodysplastic syndrome or leukemia developed in 6 of 314 (1.9%). For relapsed/refractory disease, treatment with a hematopoietic stem cell transplant had a superior event-free survival compared to second immunosuppressive therapy treatment in a multivariate analysis (HR=0.19, 95%CI: 0.08,0.47; P=0.0003). This study highlights the need for improved therapies to achieve sustained high-quality remission for children with severe aplastic anemia
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