774 research outputs found
Dynamic Modeling and Environmental Analysis of Hydrokinetic Energy Extraction
The world is facing an imminent energy supply crisis. Our well-being is linked to the energy supply, and energy is in high demand in both the developed and the developing world. In order to sustain our energy supply, it is necessary to advance renewable technologies. Despite this urgency, however, it is paramount to consider the larger environmental effects associated with using renewable resources.Hydropower, in the past, has been seen as a viable resource to examine, given that its basics of mechanical to electrical energy conversion seem to have little effect on the environment. Discrete analysis of dams and in-stream diversion set-ups has shown otherwise, though. Modifications to river flows and changes in temperature (from increased and decreased flows) cause adverse effects to fish and other marine life because of changes in their adaptive habitat.Recent research has focused on kinetic energy extraction in river flows, which may prove to be more sustainable, as this type of extraction does not involve a large reservoir or large flow modification. The field of hydrokinetic energy extraction is immature; little is known about the devices' performance in the river environment, and their risk of impingement, fouling, and suspension of sediments. Governing principles of hydrokinetic energy extraction are presented, along with a two-dimensional computational fluid dynamics (CFD) model of the system. Power extraction methods are compared, and verification and validation of the CFD model through mesh sensitivity and experimental data are presented. A 0.0506 average mesh skew and 0.2m/s velocity convergence was obtained within the mesh sensitivity analysis. In comparing particle image velocimetry (PIV) data with the CFD model, a 0.0155m offset and 20\% error were present. However, including a volume of fluid (VOF) model within the CFD model produced a 5\% error improvement and gave a 0.0124m offset. These are improvements over the current state of the art, where visual comparisons are common. Three-dimensional CFD models of a submerged water wheel, Savonius turbine, squirrel cage Darrieus turbine, and Gorlov Darrieus turbine are also presented; however, they are non-VOF CFD models.Using the results of the CFD models, preliminary predictions could be made of the environmental impact of hydrokinetic turbines with respect to fish swimming patterns. Additionally, a life cycle assessment (LCA) was conducted for hydrokinetic energy extraction (HEE), which gives insight into the total system environmental impact. HEE has been seen as a potentially ``benign' form of renewable hydropower. This work provides a benchmark for initial measurement of HEE environmental impacts, since negative outcomes have been present with previously-assumed benign renewable hydropower. A Gorlov system was used to represent a HEE system. LCA was utilized to compare the environmental impacts of HEE with small hydropotential (HPP) power, coal, natural gas and nuclear power. Environmental Protection Agency (EPA) criteria air emissions were quantified and compared over the life cycle of the systems. Life cycle air emissions were used in combination with the TRACI impact assessment tool to compare the systems. The Gorlov system was found to have the lowest life cycle impact with a system lifetime comparison, and compared closely with small HPP.Finally, various issues connected to the implementation of hydrokinetic power generation were discussed. Policy development and sediment movement were investigated in more detail. Additionally, two applications of this technology were explored: in-situ river health monitoring and remote energy generation
Sweat rate and sodium loss during work in the heat
Significant and poorly documented electrolyte losses result from prolonged sweating. This study aimed to quantify likely sodium losses during work in heat. Male subjects exercised in an environmental chamber on two consecutive days in both winter and summer. Sweat collecting devices were attached to the upper arms and legs. Sweat rates were higher and sodium concentrations were lower in the summer (acclimatised) than the winter (unacclimatised) trials. Sweat sodium concentration was reduced on the second day in summer but not winter. Regional differences were found in both seasons. The difference between days in summer probably reflects short-term acclimation. The difference between seasons reflects acclimatisation. The data predict average sodium (Na) losses over a work shift of 4.8-6 g, equivalent to 10-15 g salt (NaCl). Losses are potentially greater in unacclimatised individuals. Fluid and electrolyte losses resulting from prolonged sweating must be replaced to prevent imbalance in body fluids, however guidelines for this replacement are often conflicting. This study provides important information for occupational health practitioners by quantifying the likely sodium losses over a work shift and providing recommendations for replacement
Dance/Movement Therapy and Competitive Dance: An In Depth Self Evaluation
I used artistic inquiry self-study methodology to extend my knowledge, awareness, and understanding of how dance/movement therapy (DMT) and counseling concepts can positively alter and enhance my personal dance aesthetic, style, and pedagogy. Reflection is a personal process that can deepen the sense of self and can lead to significant discoveries or insights, while self-assessment is a process that involves establishing strengths, improvements, and insights based on predetermined performance criteria. Using artistic inquiry gave me the opportunity to study, analyze, and document where and how the DMT process and concepts have developed within my natural teaching approach. Engaging in this study presented me with a clearer understanding of the specific DMT concepts that enhanced my natural approach to working with competitive dance students. The research detailed how the combination of these concepts have improved my pedagogic style and are utilized in a field of work not as yet broadly addressed by dance/movement therapists
The enduring influence of institutions on universal health coverage: an empirical investigation of 62 former colonies
In this paper, we argue that particular institutional arrangements partly explain the large and persistent differences in health systems and health outcomes observed in former colonies. Drawing on data from the World Health Organization for 62 countries, covering the period 2000â2014, we explore whether economic (risk of expropriation) and health (complete cause of death registries) institutions explain mortality rates and access to healthcare. To identify this relationship, we use settler mortality and the distance of the capital from the nearest major port â factors associated with institutional arrangements â to explain cross-national variation in health outcomes and the universality of health systems. We find that inclusive institutions arrangements â that protect and acknowledge the rights of citizens â are associated with better health outcomes (e.g. lower infant mortality and lower maternal mortality) as well as with better health systems (e.g. more skilled birth attendance and greater immunization). Inclusive institutions not only foster economic growth but improve health and well-being too
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Vocabulary and Main Idea Reading Intervention Using Text Choice to Improve Content Knowledge and Reading Comprehension of Adolescents With Autism Spectrum Disorder.
This simultaneous replication single-case design study investigated a vocabulary and main idea intervention with an aspect of text choice provided to students with autism spectrum disorder (ASD). Five middle school students with ASD participated in two instructional groups taught by school-based personnel. Results were initially mixed. These results were followed by upward and stable trends, indicating a functional relationship between the independent and dependent variables. Social validity measures indicated that students appreciated the opportunity to make choices on text selection
Inventory of Non-Energy Sources of Greenhouse Gas Emissions in Hawaii Phase I
International concern for global climate change has stimulated a wide range of data gathering and analysis efforts worldwide. The recognition that certain atmospheric gases, many of which are anthropogenic in origin, have the capacity to absorb infrared radiation-and thus trap heat in the atmosphere--has focused research efforts on these so-called "greenhouse" gases. In order for a country to assess its contribution to such global warming, it must first develop an emissions inventory of greenhouse gas sources and sinks. In the United States, the U.S. Environmental Protection Agency (EPA) has recently published such an inventory (U.S. EPA, 1994) and has been funding the efforts of each state to develop their own inventories of sources of greenhouse gas emissions (U.S. EPA, 1995, hereafter titled the State Phase I Workbook). It is this latter document which serves as the basis for the present report by providing the bulk of its overall methodology.Clean Air Branch, Department of Health, State of Hawai
Party On: The Labor Market Returns to Social Networks in Adolescence
We investigate the returns to adolescent friendships on earnings in
adulthood. Using data from the National Longitudinal Study of Adolescent to
Adult Health, we document that individuals make investments to accumulate
friends in addition to educational investments. Because both education and
friendships are jointly determined in adolescence, OLS estimates of their
returns are biased. To estimate the causal returns to friendships, we implement
a novel procedure that assumes the returns to schooling range from 5 to 15% (as
the literature has documented), and instrument for friendships using homophily
(similarity) measures among peers to obtain bounds on the returns to
friendships. We find that having one more friend in adolescence increases
earnings between 7 and 14%, which is substantially larger than the OLS
estimates: measurement error and omitted variables lead to significant downward
bias
Determination of the Secondary Structure of an RNA fragment in Solution: Selective 2`- Hydroxyl Acylation Analyzed by Primer Extension Assay (SHAPE)
This protocol describes the methodology for the determination of the secondary structure of an RNA fragment in solution using Selective 2ÂŽ-Hydroxyl Acylation analyzed by Primer Extension, abbreviation SHAPE. It consists in the very fast chemical modification of flexible and therefore possibly single-stranded nucleotides in a sequence-independent manner using benzoyl cyanide (BzCN), forming 2ÂŽ-O-adducts. The modifications in the RNA are then analyzed by primer extension. Reverse transcriptase is blocked by the 2ÂŽ-O-adducts formed. The advantage of the method is, first, that not each RNA molecule studied but the primer used in the extension reaction is labelled and, second, that the resulting cDNA analyzed in sequencing gels is much more stable than the modified RN
Systems biology and synthetic biology: A new epoch for toxicology research
Copyright © 2015 Mark T. Mc Auley et al. This is an open access article distributed under the Creative Commons Attribution License 3.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.Systems biology and synthetic biology are emerging disciplines which are becoming increasingly utilised in several areas of bioscience. Toxicology is beginning to benefit from systems biology and we suggest in the future that is will also benefit from synthetic biology. Thus, a new era is on the horizon. This review illustrates how a suite of innovative techniques and tools can be applied to understanding complex health and toxicology issues. We review limitations confronted by the traditional computational approaches to toxicology and epidemiology research, using polycyclic aromatic hydrocarbons (PAHs) and their effects on adverse birth outcomes as an illustrative example. We introduce how systems toxicology (and their subdisciplines, genomic, proteomic, and metabolomic toxicology) will help to overcome such limitations. In particular, we discuss the advantages and disadvantages of mathematical frameworks that computationally represent biological systems. Finally, we discuss the nascent discipline of synthetic biology and highlight relevant toxicological centred applications of this technique, including improvements in personalised medicine. We conclude this review by presenting a number of opportunities and challenges that could shape the future of these rapidly evolving disciplines.Veronica M. Miller would like to acknowledge funding from Alexander and Bo McInnis and the Autism Research Institute for her toxicological studies and support
Association Between Hispanic Parentsâ Attitudes and Knowledge Regarding Obesity and Their Childrenâs Body Mass Index
According to the Centers for Disease Control and Prevention, more than 13.7 million children experience obesity nationally and Hispanic children display the highest occurrences of obesity for all racial/ethnic groups (Hales et al., 2020). Because parents have a significant influence on their childrenâs overall health, we were interested in examining whether parentsâ attitudes and knowledge about obesity impacted their childâs body mass index (BMI) for their age. We surveyed 210 adult Hispanic parents whose children were receiving general healthcare services at a pediatric medical clinic located near the U.S.-Mexico border. A multiple regression analysis was conducted to evaluate the estimation between the independent variables (knowledge about obesity, socioeconomic status, education, physical activity, dietary habits, medical history, age, and gender) and the dependent variable (attitudes toward obesity). Specifically, the study examined the relationship between Hispanic childrenâs BMI-for-age and their parentsâ attitudes toward obesity, and the relationship between Hispanic childrenâs BMI-for-age and their parentsâ knowledge regarding obesity-related risks. The results indicated the level of physical activity, dietary habits, and level of knowledge were predictive of Hispanic parentsâ attitudes toward obesity. Implications of the study and recommendations for researchers, educators, and counselors to minimize the obesity epidemic are provided
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