Empirical Investigation Of The Stakeholders’ Understanding Of Information Contained In Score Reports For Large-Scale Testing

Recent legislation (e.g. NCLB) has highlighted the need to administer more large-scale assessments to more grade levels and on more occasions. The results from these assessments are presented in score reports in various formats to many audiences, including teachers, students, school administrators, and parents. Because these assessments will be used as one of several evaluations of student achievement, the score reports should be designed and developed considering the needs of the recipients to ensure understanding. The purpose of this study was to demonstrate why this study is important and relevant, summarize some of the pertinent literature that pertains to the reporting of students’ assessment results, and complete a project that examined the impact of various features of score reports on the effectiveness of communicating the results to various audiences. Three separate studies contributed to the overall research by progressively providing information on the use and interpretation of information from score reports by different stakeholders. Study 1 focused on one-on-one interviews with a set of stakeholders to obtain more in-depth information about how persons are able to process the information they receive and are able to answer questions that they have before receiving the reports. It was also used as a pilot study for the other two studies. Study 2 used focus groups to offer feedback on several different types of data display used to convey test results. Focus groups consisting of stakeholders were shown a series of graphs that had been modified to either comply or not comply with several guidelines for data display that had been proposed by several researchers. Study 3 used a survey where sets of graphs were compared, one with original and the other with improved displays, and answers to questions based on the displays was given. A summative score based on dichotomously scored items was used to perform a t-test between the control and experimental group. While no significant difference was found, additional insight was gained into how various stakeholder groups used the information in reports and what they valued. Future studies will take into account the growing use of electronic distribution of assessment results

A pH-based pedotransfer function for scaling saturated hydraulic conductivity reduction: improved estimation of hydraulic dynamics in HYDRUS

Hydraulic conductivity is a key soil property governing agricultural production and is thus an important parameter in hydrologic modeling. The pH scaling factor for saturated hydraulic conductivity (Ks) reduction in the HYDRUS model was reviewed and evaluated for its ability to simulate Ks reduction. A limitation of the model is the generalization of Ks reduction at various levels of electrolyte concentration for different soil types, i.e., it is not soil specific. In this study, a new generalized linear regression model was developed to estimate Ks reduction for a larger set of Australian soils compared with three American soils. A nonlinear pedotransfer function was also produced, using the Levenberg–Marquardt optimization algorithm, by considering the pH and electrolyte concentration of the applied solution as well as the soil clay content. This approach improved the estimation of the pH scaling factor relating to Ks reduction for individual soils. The functions were based on Ks reduction in nine contrasting Australian soils using two sets of treatment solutions with Na adsorption ratios of 20 and 40; total electrolyte concentrations of 8, 15, 25, 50, 100, 250, and 500 mmolc L−1; and pH values of 6, 7, 8, and 9. A comparison of the experimental data and model outputs indicates that the models performed objectively well and successfully described the Ks reduction due to the pH. Further, a nonlinear function provided greater accuracy than the generalized function for the individual soils of Australia and California. This indicates that the nonlinear model provides an improved estimation of the pH scaling factor for Ks reduction in specific soils in the HYDRUS model and should therefore be considered in future HYDRUS developments and applications

An environmental and economic comparison of cooling system designs for steam-electric power plants

Originally presented as a thesis (M.S.), M.I.T., Dept. of Civil Engineering, 1978, by Kenneth F. Najjar.The selection of waste heat rejection systems for steam-electric power plants involves a trade-off among environmental, energy and water conservation, and economic factors. This study compares four general types of cooling systems on the basis of these factors. The cooling systems chosen for study are: once-through systems including surface canals and submerged multiport diffusers; shallow closed cycle cooling ponds; mechanical and natural draft evaporative cooling towers; and mechanical draft dry towers. The cooling system comparison involves, first, an optimization of each cooling system and then a comparison among optimal systems. Comparison is made for an 800 MWe fossil unit and a 1200 MWe nuclear unit located at a hypothetical midwestern river site. A set of models has been developed to optimize the components of each cooling system based on the local meteorological and hydrological conditions at the site in accordance with a fixed demand, scalable plant concept. This concept allows one to compare the costs of producing the same net power from each plant/cooling system. Base case economic parameters were used to evaluate the optimum system for each of the four general cooling systems followed by a sensitivity study for each parameter. Comparison of energy and water consumption follows from the results of the performance model, while comparison of environmental impacts is mostly qualitative. Some quantitative modelling was performed for the environmental effects of thermal discharges from once-through systems, fogging from wet cooling towers and water consumption from the ponds, wet towers and once-through. The results of the optimization models of each of the systems are compared on the basis of: performance - discrete distributions of environmental conditions and transient simulation; economics - using base case scenarios and sensitivity values to arrive at costs expressed in terms of production costs, annualized costs and present value costs; energy and water consumption; and environmental effects. The once-through systems were found to be the least expensive of the four systems, the most energy efficient, but potentially the most environmentally damaging. On the other extreme, dry cooling towers are the most environmentally sound while being the most expensive and least energy efficient. Finally, the results of the economic optimization are compared with results from previous comparative studies

Design of plasma shutters for improved heavy ion acceleration by ultra-intense laser pulses

In this work, we investigate the application of the plasma shutters for heavy ion acceleration driven by a high-intensity laser pulse. We use particle-in-cell (PIC) and hydrodynamic simulations. The laser pulse, transmitted through the opaque shutter, gains a steep-rising front and its peak intensity is locally increased at the cost of losing part of its energy. These effects have a direct influence on subsequent ion acceleration from the ultrathin target behind the shutter. In our 3D simulations of silicon nitride plasma shutter and a silver target, the maximal energy of high-Z ions increases significantly when the shutter is included for both linearly and circularly polarized laser pulses. Moreover, application of the plasma shutter for linearly polarized pulse results in focusing of ions towards the laser axis in the plane perpendicular to the laser polarization. The generated high energy ion beam has significantly lower divergence compared to the broad ion cloud, generated without the shutter. The effects of prepulses are also investigated assuming a double plasma shutter. The first shutter can withstand the assumed sub-ns prepulse (treatment of ns and ps prepulses by other techniques is assumed) and the pulse shaping occursvia interaction with the second shutter. On the basis of our theoretical findings, we formulated an approach towards designing a double plasma shutter for high-intensity and high-power laser pulses and built a prototype.Comment: 30 pages 13 figure

Ocean thermal energy conversion plants : experimental and analytical study of mixing and recirculation

Also issued as Massachusetts Institute of Technology. Ralph M. Parsons Laboratory for Water Resources and Hydrodynamics. Report no.231. Prepared by the Energy Laboratory in association with Ralph M. Parsons Laboratory for Water Resources and Hydrodynamics.Ocean thermal energy conversion (OTEC) is a method of generating power using the vertical temperature gradient of the tropical ocean as an energy source. Experimental and analytical studies have been carried out to determine the characteristics of the temperature and velocity fields induced in the surrounding ocean by the operation of an OTEC plant. The condition of recirculation, i.e. the reentering of mixed discharge water back into the plant intake, was of particular interest because of its adverse effect on plant efficiency. The studies were directed at the mixed discharge concept, in which the evaporator and condenser water flows are exhausted jointly at the approximate level of the ambient ocean thermocline. The OTEC plant was of the symmetric spar-buoy type with radial or separate discharge configurations. A distinctly stratified ocean with uniform, ambient current velocity was assumed. The following conclusions are obtained: The recirculation potential of an OTEC plant in a stagnant ocean is determined by the interaction of the jet discharge zone and a double sink return flow (one sink being the evaporator intake, the other the jet entrainment). This process occurs in the near-field of an OTEC plant up to a distance of about three times the ocean mixed layer depth. The stratified internal flow beyond this zone has little effect on recirculation, as have small ocean current velocities (up to 0.10 m/s prototype). Conditions which are conducive to recirculation are characterized by high discharge velocities and large plant flow rates. A design formula is proposed which determines whether recirculation would occur or not as a function of plant design and ocean conditions. On the basis of these results, it can be concluded that a 100 MW OTEC plant with the mixed discharge mode can operate at a typical candidate ocean site without incurring any discharge recirculation.Prepared under the support of Division of Solar Energy, U.S. Energy Research and Development Administration, Contract no. EY-76-S-02-2909.M001

Internet of things

Manual of Digital Earth / Editors: Huadong Guo, Michael F. Goodchild, Alessandro Annoni .- Springer, 2020 .- ISBN: 978-981-32-9915-3Digital Earth was born with the aim of replicating the real world within the digital world. Many efforts have been made to observe and sense the Earth, both from space (remote sensing) and by using in situ sensors. Focusing on the latter, advances in Digital Earth have established vital bridges to exploit these sensors and their networks by taking location as a key element. The current era of connectivity envisions that everything is connected to everything. The concept of the Internet of Things(IoT)emergedasaholisticproposaltoenableanecosystemofvaried,heterogeneous networked objects and devices to speak to and interact with each other. To make the IoT ecosystem a reality, it is necessary to understand the electronic components, communication protocols, real-time analysis techniques, and the location of the objects and devices. The IoT ecosystem and the Digital Earth (DE) jointly form interrelated infrastructures for addressing today’s pressing issues and complex challenges. In this chapter, we explore the synergies and frictions in establishing an efficient and permanent collaboration between the two infrastructures, in order to adequately address multidisciplinary and increasingly complex real-world problems. Although there are still some pending issues, the identified synergies generate optimism for a true collaboration between the Internet of Things and the Digital Earth

Emerging approaches for data-driven innovation in Europe: Sandbox experiments on the governance of data and technology

Europe’s digital transformation of the economy and society is one of the priorities of the current Commission and is framed by the European strategy for data. This strategy aims at creating a single market for data through the establishment of a common European data space, based in turn on domain-specific data spaces in strategic sectors such as environment, agriculture, industry, health and transportation. Acknowledging the key role that emerging technologies and innovative approaches for data sharing and use can play to make European data spaces a reality, this document presents a set of experiments that explore emerging technologies and tools for data-driven innovation, and also deepen in the socio-technical factors and forces that occur in data-driven innovation. Experimental results shed some light in terms of lessons learned and practical recommendations towards the establishment of European data spaces