86,133 research outputs found
Engaging the Digitally Engaged Student: Comparing Technology-Mediated Communication Use and Effects on Student Learning
The role of communication technologies in the learning process is both a dynamic and complex issue. Yet, we know surprisingly little about how the use of specific communication technologies may influence classroom performance, key learning outcomes, and other measures of course satisfaction. The research reported here attempts to add to our knowledge about the role of communication in the technology enhanced classroom (TEC) education and in technology-enhanced online (TEO) education through a direct comparison of two courses. Our findings indicate additional support for “The No Significant Difference Phenomenon.” Furthermore, we found that prior experiences lead students to gravitate towards their preferred learning environments, and that basic website elements are required in any learning environment to enhance student outcomes. Finally, we found that when used appropriately, the benefits of communication technology use in education outweigh many of the drawbacks
Solar tracking system
A solar tracker for a solar collector is described in detail. The collector is angularly oriented by a motor wherein the outputs of two side-by-side photodetectors are discriminated as to three ranges: a first corresponding to a low light or darkness condition; a second corresponding to light intensity lying in an intermediate range; and a third corresponding to light above an intermediate range, direct sunlight. The first output drives the motor to a selected maximum easterly angular position; the second enables the motor to be driven westerly at the Earth rotational rate; and the third output, the separate outputs of the two photodetectors, differentially controls the direction of rotation of the motor to effect actual tracking of the Sun
Classical Functional Bethe Ansatz for : separation of variables for the magnetic chain
The Functional Bethe Ansatz (FBA) proposed by Sklyanin is a method which
gives separation variables for systems for which an -matrix is known.
Previously the FBA was only known for and (and associated)
-matrices. In this paper I advance Sklyanin's program by giving the FBA for
certain systems with -matrices. This is achieved by constructing
rational functions \A(u) and \B(u) of the matrix elements of , so
that, in the generic case, the zeros of \B(u) are the separation
coordinates and the P_i=\A(x_i) provide their conjugate momenta. The method
is illustrated with the magnetic chain and the Gaudin model, and its wider
applicability is discussed.Comment: 14pp LaTex,DAMTP 94-1
Solar site test module
A solar site test module using the Rockwell AIM 65microcomputer is described. The module is designed to work at any site where an IBM site data acquisition system (SDAS) is installed and is intended primarily as a troubleshooting tool. It collects sensor information (temperatures, flow rates, etc.) and displays or prints it immediately in calibrated engineering units. It will read one sensor on demand, periodically read up to 10sensors or periodically read all sensors. Performance calculations can also be included with sensor data. Unattended operation is possible to, e.g., monitor a group of sensors once per hour. Work is underway to add a data acquisition system to the test module so that it can be used at sites which have no SDAS
Electrical self-aligning connector
A self-aligning electrical connector device includes a receptacle component having a conically contoured interior and a plug component having a correspondingly contoured conical body receivable in the receptacle component. The plug component has a number of spaced conductive ring elements with a mating face and the receptacle component includes corresponding spaced conductive ring elements providing mating interface with the mating face of the ring elements of the plug component when connected to it. Each ring element of the receptacle component has several segmented portions which defect downwardly when the plug component is inserted. A biasing force is asserted against the face of the ring elements of the plug component providing positive electrical contact and connection between the ring elements of the components
Fluorescence Analysis for Multi-Site Aluminum Binding to Natural Organic Matter
Natural organic matter (NOM) samples isolated from different water sources in Norway were compared using their fluorescence properties. Fluorescence surfaces were observed at pH 4.36 and deconvoluted using SIMPLISMA (Windig and Guilment 1991). There were a total of seven different fluorophores observed for these samples and each sampling site had between four and six ofthe fluorescent components. These components were observed to bind Al during titrations at the same pH. Multiresponse titration curves were fit using the method of Smith and Kramer (1998) and most of the binding strengths are similar to values for Suwannee River fulvic acid (1ogK’ between 4.8 and 5.5), but there are strong sites (IogK’ = 7) and weak sites (1ogK’ between 3 and 4) also observed. Results depended on the isolation method used; reverse osmosis and low pressure evaporation yielded different values but with no consistent trends
Getting on the E List: E-Mail Use in a Community of Service Provider
This case examines how a community of organizations providing service to people experiencing homelessness made use of an electronic mail list. Current economic conditions have encouraged organizations in various sectors—including nonprofits—that might normally compete for scarce resources to collaborate with one another to increase their chances of survival. One set of tools likely to be of value in such relationships includes various online discussion technologies. An examination of this community’s email list use over a three-year period suggests a somewhat complex picture regarding technology use. More specifically, some issues both constrain and enable use. Additionally, seemingly basic and minimal uses of the list provided not only the greatest functionality for the users, but also led to several unanticipated consequences for those involved
Linear effects of perturbed recombination
Perturbations in the ionization fraction after recombination affect the
Compton cooling of density perturbations. Once the gas temperature starts to
decouple from the CMB temperature, ionization fraction perturbations can have a
significant influence on the subsequent gas temperature perturbation evolution.
This directly affects the 21cm spin temperature of the gas, and also modifies
the small-scale baryon perturbation evolution via the difference in baryon
pressure. The effect on the gas temperature perturbations can be significant on
all scales, and galactic-scale baryon perturbations are modified at the percent
level at redshifts z >~ 100 where numerical simulations are typically started.Comment: 5 pages; for more details of effect on 21cm see astro-ph/0702600;
code available at http://camb.info/sources
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