965 resultados para sediment retention in reservoirs
Resumo:
This paper focusses on attracting and retaining young people into technical disciplines. It introduces a new model of technical education from age 14 that the UK Government initiated in 2008. A concept of University led Technical Colleges (UTCs) for 14-19 year olds. These state supported schools, sponsored by a University, have technical curricula, technologically enabled learning environments and strong engagement with employers. As new schools they have been able to recruit outstanding staff that are conversant with the use of technology to enhance learning and all students have their own iPads. The Aston University Engineering Academy opened in September 2012 and a recent survey of staff, students and parents has provided both qualitative and quantitative data on the benefits to motivation and learning of these embedded iPads. The devices have also had advantages for the management of data on student achievement from a leadership, teaching staff and parental view point.
Resumo:
Since the mid-1990s, the United States has experienced a shortage of scientists and engineers, declining numbers of students choosing these fields as majors, and low student success and retention rates in these disciplines. Learning theorists, educational researchers, and practitioners believe that learning environments can be created so that an improvement in the numbers of students who complete courses successfully could be attained (Astin, 1993; Magolda & Terenzini, n.d.; O'Banion, 1997). Learning communities do this by providing high expectations, academic and social support, feedback during the entire educational process, and involvement with faculty, other students, and the institution (Ketcheson & Levine, 1999). ^ A program evaluation of an existing learning community of science, mathematics, and engineering majors was conducted to determine the extent to which the program met its goals and was effective from faculty and student perspectives. The program provided laptop computers, peer tutors, supplemental instruction with and without computer software, small class size, opportunities for contact with specialists in selected career fields, a resource library, and Peer-Led Team Learning. During the two years the project has existed, success, retention, and next-course continuation rates were higher than in traditional courses. Faculty and student interviews indicated there were many affective accomplishments as well. ^ Success and retention rates for one learning community class ( n = 27) and one traditional class (n = 61) in chemistry were collected and compared using Pearson chi square procedures ( p = .05). No statistically significant difference was found between the two groups. Data from an open-ended student survey about how specific elements of their course experiences contributed to success and persistence were analyzed by coding the responses and comparing the learning community and traditional classes. Substantial differences were found in their perceptions about the lecture, the lab, other supports used for the course, contact with other students, helping them reach their potential, and their recommendation about the course to others. Because of the limitation of small sample size, these differences are reported in descriptive terms. ^
Resumo:
This study focuses on quantifying explicitly the sediment budget of deeply incised ravines in the lower Le Sueur River watershed, in southern Minnesota. High-rate-gully-erosion equations along with the Universal Soil Loss Equation (USLE) were implemented in a numerical modeling approach that is based on a time-integration of the sediment balance equations. The model estimates the rates of ravine width and depth change and the amount of sediment periodically flushing from the ravines. Components of the sediment budget of the ravines were simulated with the model and results suggest that the ravine walls are the major sediment source in the ravines. A sensitivity analysis revealed that the erodibility coefficients of the gully bed and wall, the local slope angle and the Manning’s coefficient are the key parameters controlling the rate of sediment production. Recommendations to guide further monitoring efforts in the watershed and increased detail modeling approaches are highlighted as a result of this modeling effort.
Resumo:
Increased treatment retention among substance abusing individuals has been associated with reduced drug use, fewer arrests, and decreased unemployment, as well as a reduction in health risk behaviors. This longitudinal study examined the predictors of client retention for alternative to prison substance abuse treatment programs through assessing the roles of motivational factors and the client-worker relationship. The sample was comprised of 141 male felony offenders who were legally mandated to community based long-term residential drug treatment programs. ^ The primary measures used in the study were the consecutive days a participant remained in treatment, Stages of Change Readiness Model and Treatment Eagerness Scale (SOCRATES), the Working Alliance Inventory (WAI), and The Readiness Ruler. Hierarchical multiple regression analysis was conducted for four hypotheses (a) participants who are more motivated to change at the time of entry will remain in treatment longer, (b) participants who have a strong therapeutic alliance will remain in treatment a greater number of consecutive days than participants who have weaker therapeutic alliance, (c) motivation to change, as measured at treatment entry, will be positively related to therapeutic alliance, (d) during the course of treatment variation in motivation to change will be predicted by the therapeutic alliance. ^ Results support the following conclusions: Among clients in alternative-to prison programs the number of days in treatment is positively related to their motivation to change. The therapeutic alliance is not a predictor of the number of days in treatment. Motivation to change, particularly recognition of a drug problem, is positively related to the therapeutic alliance. Changes in motivation to change in response to treatment are positively related to the therapeutic alliance among clients in an alternative to prison substance abuse treatment programs. These results carry forward prior research and have implications for social work practice, research, and social welfare policy. ^
Resumo:
Increased treatment retention among substance abusing individuals has been associated with reduced drug use, fewer arrests, and decreased unemployment, as well as a reduction in health risk behaviors. This longitudinal study examined the predictors of client retention for alternative to prison substance abuse treatment programs through assessing the roles of motivational factors and the client-worker relationship. The sample was comprised of 141 male felony offenders who were legally mandated to community based long-term residential drug treatment programs. The primary measures used in the study were the consecutive days a participant remained in treatment, Stages of Change Readiness Model and Treatment Eagerness Scale (SOCRATES), the Working Alliance Inventory (WAI), and The Readiness Ruler. Hierarchical multiple regression analysis was conducted for four hypotheses (a) participants who are more motivated to change at the time of entry will remain in treatment longer, (b) participants who have a strong therapeutic alliance will remain in treatment a greater number of consecutive days than participants who have weaker therapeutic alliance, (c) motivation to change, as measured at treatment entry, will be positively related to therapeutic alliance, (d) during the course of treatment variation in motivation to change will be predicted by the therapeutic alliance. Results support the following conclusions: Among clients in alternative-to prison programs the number of days in treatment is positively related to their motivation to change. The therapeutic alliance is not a predictor of the number of days in treatment. Motivation to change, particularly recognition of a drug problem, is positively related to the therapeutic alliance. Changes in motivation to change in response to treatment are positively related to the therapeutic alliance among clients in an alternative to prison substance abuse treatment programs. These results carry forward prior research and have implications for social work practice, research, and social welfare policy.
Resumo:
This study focuses on quantifying explicitly the sediment budget of deeply incised ravines in the lower Le Sueur River watershed, in southern Minnesota. High-rate-gully-erosion equations along with the Universal Soil Loss Equation (USLE) were implemented in a numerical modeling approach that is based on a time-integration of the sediment balance equations. The model estimates the rates of ravine width and depth change and the amount of sediment periodically flushing from the ravines. Components of the sediment budget of the ravines were simulated with the model and results suggest that the ravine walls are the major sediment source in the ravines. A sensitivity analysis revealed that the erodibility coefficients of the gully bed and wall, the local slope angle and the Manning’s coefficient are the key parameters controlling the rate of sediment production. Recommendations to guide further monitoring efforts in the watershed and increased detail modeling approaches are highlighted as a result of this modeling effort.
Resumo:
This material is based upon work supported by the National Science Foundation through the Florida Coastal Everglades Long-Term Ecological Research program under Cooperative Agreements #DBI-0620409 and #DEB-9910514. This image is made available for non-commercial or educational use only.
Resumo:
This material is based upon work supported by the National Science Foundation through the Florida Coastal Everglades Long-Term Ecological Research program under Cooperative Agreements #DBI-0620409 and #DEB-9910514. This image is made available for non-commercial or educational use only.
Resumo:
During the last glacial termination, the upper North Pacific Ocean underwent dramatic and rapid changes in oxygenation that lead to the transient intensification of oxygen minimum zones (OMZs), recorded by the widespread occurrence of laminated sediments on circum-Pacific continental margins. We present a new laminated sediment record from the mid-depth (1100 m) northern Bering Sea margin that provides insight into these deglacial OMZ maxima with exceptional, decadal-scale detail. Combined ultrahigh-resolution micro-X-ray-fluorescence (micro-XRF) data and sediment facies analysis of laminae reveal an alternation between predominantly terrigenous and diatom-dominated opal sedimentation. The diatomaceous laminae are interpreted to represent spring/summer productivity events related to the retreating sea ice margin.We identified five laminated sections in the deglacial part of our site. Lamina counts were carried out on these sections and correlated with the Bølling-Allerød and Preboreal phases in the North Greenland Ice Core (NGRIP) oxygen isotope record, indicating an annual deposition of individual lamina couplets (varves). The observed rapid decadal intensifications of anoxia, in particular within the Bølling-Allerød, are tightly coupled to short-term warm events through increases in regional export production. This dependence of laminae formation on warmer temperatures is underlined by a correlation with published Bering Sea sea surface temperature records and d18O data of planktic foraminifera from the Gulf of Alaska. The rapidity of the observed changes strongly implies a close atmospheric teleconnection between North Pacific and North Atlantic regions.We suggest that concomitant increases in export production and subsequent remineralization of organic matter in the Bering Sea, in combination with oxygen-poor waters entering the Being Sea, drove down oxygen concentrations to values below 0.1ml/l and caused laminae preservation. Calculated benthic-planktic ventilation ages show no significant variations throughout the last deglaciation, indicating that changes in formation rates or differing sources of North Pacific mid-depth waters are not prime candidates for strengthening the OMZ at our site. The age models established by our correlation procedure allow for the determination of calendar age control points for the Bølling-Allerød and the Preboreal that are independent of the initial radiocarbon-based chronology. Resulting surface reservoir ages range within 730-990 yr during the Bølling-Allerød, 800-1100 yr in the Younger Dryas, and 765-775 yr for the Preboreal.