A calibration technique for a hot-wire-probe vector anemometer

Calibration tests using hot wires were conducted using a newly developed test rig that greatly reduced the data acquisition time. A comparison of measured and computed velocity vector magnitude and direction indicates the necessity of complete probe calibration to determine flow interference and/or operating limitation regions. Calibration results indicate that flow rates with 3 percent accuracy and flow angles with 5 deg accuracy are attainable

Correspondence - J. G. Vann and P. L. Elliott

Correspondence from J. G. Vann to Phillip Loven Elliott, president of Gardner-Webb College, declining the invitation to the dedication of the Gardner Memorial Student due to other occurring eventshttps://digitalcommons.gardner-webb.edu/gardner-webb-buildings-and-grounds-o-max-gardner-building/1007/thumbnail.jp

Under-represented Students\u27 Engagement in Secondary Science Learning: a Non-equivalent Control Group Design

Problem. A significant segment of the U.S. population, under-represented students, is under-engaged or disengaged in secondary science education. International and national assessments and various research studies illuminate the problem and/or the disparity between students’ aspirations in science and the means they have to achieve them. To improve engagement and address inequities among these students, more contemporary and/or inclusive pedagogy is recommended. More specifically, multicultural science education has been suggested as a potential strategy for increased equity so that all learners have access to and are readily engaged in quality science education. While multicultural science education emphasizes the integration of students’ backgrounds and experiences with science learning , multimedia has been suggested as a way to integrate the fundamentals of multicultural education into learning for increased engagement. In addition, individual characteristics such as race, sex, academic track and grades were considered. Therefore, this study examined the impact of multicultural science education, multimedia, and individual characteristics on under-represented students’ engagement in secondary science. Method. The Under-represented Students Engagement in Science Survey (USESS), an adaptation of the High School Survey of Student Engagement, was used with 76 highschool participants. The USESS was used to collect pretest and posttest data concerning their types and levels of student engagement. Levels of engagement were measured with Strongly Agree ranked as 5, down to Strongly Disagree ranked at 1. Participants provided this feedback prior to and after having interacted with either the multicultural or the nonmulticultural version of the multimedia science curriculum. Descriptive statistics for the study’s participants and the survey items, as well as Cronbach’s alpha coefficient for internal consistency reliability with respect to the survey subscales, were conducted. The reliability results prompted exploratory factory analyses, which resulted in two of the three subscale factors, cognitive and behavioral, being retained. One-within one-between subjects ANOVAs, independent samples t-test, and multiple linear regressions were also used to examine the impact of a multicultural science education, multimedia, and individual characteristics on students’ engagement in science learning. Results. There were main effects found within subjects on posttest scores for the cognitive and behavioral subscales of student engagement. Both groups, using their respective versions of the multimedia science curriculum, reported increased engagement in science learning. There was also a statistical difference found for the experimental group at posttest on the measure of “online science was more interesting than school science.” All five items unique to the posttest related to the multimedia variable were found to be significant predictors of cognitive and/or behavioral engagement. Conclusions. Engagement in science learning increased for both groups of participants; this finding is aligned with other significant research findings that more embracive and relevant pedagogies can potentially benefit all students. The significant difference found for the experimental group in relation to the multimedia usage was moderate and also may have reflected positive responses to other questions about the use of technology in science learning. As all five measures of multimedia usage were found to be significant predictors of student engagement in science learning, the indications were that: (a) technical difficulties did not impede engagement; (b) participants were better able to understand and visualize the physics concepts as they were presented in a variety of ways; (c) participants’ abilities to use computers supported engagement; (d) participants in both groups found the online science curriculum more interesting compared to school science learning; and (e) the ability to immediately see the results of their work increased engagement in science learning

The importance of mammillary body efferents for recency memory: towards a better understanding of diencephalic amnesia

Despite being historically one of the first brain regions linked to memory loss, there remains controversy over the core features of diencephalic amnesia as well as the critical site for amnesia to occur. The mammillary bodies and thalamus appear to be the primary locus of pathology in the cases of diencephalic amnesia, but the picture is complicated by the lack of patients with circumscribed damage. Impaired temporal memory is a consistent neuropsychological finding in Korsakoff syndrome patients, but again, it is unclear whether this deficit is attributable to pathology within the diencephalon or concomitant frontal lobe dysfunction. To address these issues, we used an animal model of diencephalic amnesia and examined the effect of mammillothalamic tract lesions on tests of recency memory. The mammillothalamic tract lesions severely disrupted recency judgements involving multiple items but left intact both recency and familiarity judgements for single items. Subsequently, we used disconnection procedures to assess whether this deficit reflects the indirect involvement of the prefrontal cortex. Crossed-lesion rats, with unilateral lesions of the mammillothalamic tract and medial prefrontal cortex in contralateral hemispheres, were unimpaired on the same recency tests. These results provide the first evidence for the selective importance of mammillary body efferents for recency memory. Moreover, this contribution to recency memory is independent of the prefrontal cortex. More broadly, these findings identify how specific diencephalic structures are vital for key elements of event memory

Fiber-Optic Gratings for Lidar Measurements of Water Vapor

Narrow-band filters in the form of phase-shifted Fabry-Perot Bragg gratings incorporated into optical fibers are being developed for differential-absorption lidar (DIAL) instruments used to measure concentrations of atmospheric water vapor. The basic idea is to measure the relative amounts of pulsed laser light scattered from the atmosphere at two nearly equal wavelengths, one of which coincides with an absorption spectral peak of water molecules and the other corresponding to no water vapor absorption. As part of the DIAL measurement process, the scattered light is made to pass through a filter on the way to a photodetector. Omitting other details of DIAL for the sake of brevity, what is required of the filter is to provide a stop band that: Surrounds the water-vapor spectral absorption peaks at a wavelength of 946 nm, Has a spectral width of at least a couple of nanometers, Contains a pass band preferably no wider than necessary to accommodate the 946.0003-nm-wavelength water vapor absorption peak [which has 8.47 pm full width at half maximum (FWHM)], and Contains another pass band at the slightly shorter wavelength of 945.9 nm, where there is scattering of light from aerosol particles but no absorption by water molecules. Whereas filters used heretofore in DIAL have had bandwidths of =300 pm, recent progress in the art of fiber-optic Bragg-grating filters has made it feasible to reduce bandwidths to less than or equal to 20 pm and thereby to reduce background noise. Another benefit of substituting fiber-optic Bragg-grating filters for those now in use would be significant reductions in the weights of DIAL instruments. Yet another advantage of fiber-optic Bragg-grating filters is that their transmission spectra can be shifted to longer wavelengths by heating or stretching: hence, it is envisioned that future DIAL instruments would contain devices for fine adjustment of transmission wavelengths through stretching or heating of fiber-optic Bragg-grating filters nominally designed and fabricated to have transmission wavelengths that, in the absence of stretching, would be slightly too short

Kinetic simulations of X-B and O-X-B mode conversion

We have performed fully-kinetic simulations of X-B and O-X-B mode conversion in one and two dimensional setups using the PIC code EPOCH. We have recovered the linear dispersion relation for electron Bernstein waves by employing relatively low amplitude incoming waves. The setups presented here can be used to study non-linear regimes of X-B and O-X-B mode conversion.Comment: 4 pages, 3 figure

Using Goodwill Impairment To Effect Earnings Management During SFAS No. 142s Year Of Adoption And Later

Prior research (Bens and Heltzer, 2004) shows that the market penalizes firms less for reporting goodwill write-downs below-the-line than it does for presenting them above-the-line.  Only in 2002, the year SFAS No. 142 became effective, did goodwill impairments enjoy below-the-line treatment.  The current research provides evidence that firms “cherry picked” this year to recognize large impairment losses, thus removing much of the burden from future years when these losses otherwise would have been reported above-the-line.  The study also indicates that, even though the number of firms taking goodwill write-offs declined subsequent to 2002, those entities that did so seemed to be taking these discretionary hits because earnings were already depressed in the current year.  As such, the big bath earnings management observed in the year of adoption in previous studies (Jordan and Clark, 2004 and 2005) appears to continue even though these impairment losses no longer receive favorable below-the-line treatment