2,195 research outputs found
Oxidation and passivation of the uranium nitride (001) surface
No full textThe oxidation of uranium mononitride is a potential issue when considering this material as a nuclear fuel. This work investigates the rate and mechanism of this reaction at room temperature, giving insight into fuel surface oxidation during manufacture and storage. Chemical and structural investigation of the ideal surface of an epitaxial (001) UN thin film, shows that a UO2+xNy layer forms on the surface, highlighting the need for better understanding of the U-N-O system. Below this, a U2N3 interlayer is detected. The topotactic formation of these layers is predicted to play a critical role in the passivation measured during long-duration structural investigation
Developing Children's Cognitive Functions and Increasing Learning Effectiveness: An Intervention Using the Bright Start Cognitive Curriculum for Young Children
No full textTo prepare the young generation for the challenges of a competitive and rapidly changing world, the education systems of Singapore and in many countries in East Asia are focusing on developing children's thinking and learning skills.
This research study examines the effects of a cognitive programme, the Bright Start Cognitive Curriculum for young children, on kindergarten children's cognitive functions and their learning effectiveness. The study adopted an experimental, pretest posttest design with an experimental group of 43 children and a control group of 37 children. The Bright Start Cognitive Curriculum was systematically implemented over a period of six months with the children from the experimental group. The children from the control group had their regular integrated thematic curriculum.
The study used a combination of methods to collect data, involving measurements of children's pre and post tests performances on cognitive tasks, analyses of video recordings of teaching observations and teachers‟ feedback of children‟s performances in class.
The findings of the research study suggest that children from the experimental group showed greater improvement in all the cognitive tasks from pre to post testing than the children in the control group. The children‟s response to mediation scores in the experimental group were positively correlated with their post test scores. The experimental teachers scored higher in all three essential components of Mediated Learning Experience (MLE) than the control teachers; with marked difference between the two groups in the criteria of transcendence. However, the control teachers scored better in affective involvement, which is not one of the essential qualifying components of MLE
Letter from J. E. Gavin to Louis C. Cramton regarding Sale of Bright Angel Trail
No full textLetter from J. E. Gavin to Louis C. Cramton regarding the Bright Angel Trail controversy, including newspaper clipping
Epitaxial UN and α-U2N3 thin films
No full textSingle crystal epitaxial thin films of UN and α-U2N3 have been grown for the first time by reactive DC magnetron sputtering. These films provide ideal samples for fundamental research into the potential accident tolerant fuel, UN, and U2N3, its intermediate oxidation product. Films were characterised using x-ray diffraction (XRD) and x-ray photoelectron spectroscopy (XPS), with XRD analysis showing both thin films to be [001] oriented and composed of a single domain. The specular lattice parameters of the UN and U2N3 films were found to be 4.895 Å and 10.72 Å respectively, with the UN film having a miscut of 2.6°. XPS showed significant differences in the N-1 s peak between the two films, with area analysis showing both films to be stoichiometric
Henri Temianka Correspondence; (bright)
No full textThis collection contains material pertaining to the life, career, and activities of Henri Temianka, violin virtuoso, conductor, music teacher, and author. Materials include correspondence, concert programs and flyers, music scores, photographs, and books.https://digitalcommons.chapman.edu/temianka_correspondence/1461/thumbnail.jp
Circadian Phase-Shifting Effects of Bright Light, Exercise, and Bright Light + Exercise
No full textabstract: Limited research has compared the circadian phase-shifting effects of bright light and exercise and additive effects of these stimuli. The aim of this study was to compare the phase-delaying effects of late night bright light, late night exercise, and late evening bright light followed by early morning exercise. In a within-subjects, counterbalanced design, 6 young adults completed each of three 2.5-day protocols. Participants followed a 3-h ultra-short sleep-wake cycle, involving wakefulness in dim light for 2h, followed by attempted sleep in darkness for 1 h, repeated throughout each protocol. On night 2 of each protocol, participants received either (1) bright light alone (5,000 lux) from 2210–2340 h, (2) treadmill exercise alone from 2210–2340 h, or (3) bright light (2210–2340 h) followed by exercise from 0410–0540 h. Urine was collected every 90 min. Shifts in the 6-sulphatoxymelatonin (aMT6s) cosine acrophase from baseline to post-treatment were compared between treatments. Analyses revealed a significant additive phase-delaying effect of bright light + exercise (80.8 ± 11.6 [SD] min) compared with exercise alone (47.3 ± 21.6 min), and a similar phase delay following bright light alone (56.6 ± 15.2 min) and exercise alone administered for the same duration and at the same time of night. Thus, the data suggest that late night bright light followed by early morning exercise can have an additive circadian phase-shifting effect.The final version of this article, as published in Journal of Circadian Rhythms, can be viewed online at: http://www.jcircadianrhythms.com/article/10.5334/jcr.137
Memorandum from A. E. Demaray to E. C. Finney
No full textFour letters of correspondence about the purchase of Bright Angel Trail between A. E. Demaray, Acting Director of the Grand Canyon National Park; E. C. Finney, Department of the Interior First Assistant Secretary; Carl T. Hayden, Representative (AZ); and Stephen T. Mather, Director of the National Park Service
Automatic Cell Viability Determination In Bright-Field Microscope Images
No full textQuantification of non-viable cells in bright-field microscope images allows for an in vitro assessment of the viability of cultured cells. The identification and quantification of non-viable cells in a cell culture is conventionally achieved with viability stains. A disadvantage of viability stains is that they might be invasive and even toxic to a cell culture. For this purpose, a non-invasive keypoint-based cell viability determination method without the use of viability stains, has been developed. This method formulates unstained non-viable cell detection as a supervised, binary pattern recognition problem and presents a set of features that are suitable for distinguishing between unstained viable and non-viable cells in bright-field micrographs. Experimental results for a representative sample of micrographs are compared with the ground truth non-viable cell count obtained from fluorescent micrographs. Despite the low contrast and high variability in appearance of cells in bright-field images, the method yield a classification rate in excess of 88% for non-viable versus viable-suspended cells and of more than 65% for nonviable versus viable-adherent cells . Thus, the developed method has been proven to be a feasible alternative for cell viability determination in bright-field micrographs.Computer Simulation for Science and EngineeringApplied mathematicsElectrical Engineering, Mathematics and Computer Scienc
A catalog of Scolytidae (Coleoptera), supplement 4 (2011-2019) with an annotated checklist of the world fauna (Coleoptera: Curculionoidea: Scolytidae)
No full textIncludes bibliographical references and index.This contribution consists of two parts. The first part is the fourth supplement to the 1992 Catalog of the Scolytidae and Platypodidae (Coleoptera) of the World (Wood and Bright 1992) and summarizes the additions and corrections that have affected the nomenclature of the family for the years 2011 through 2019. New synonymy proposed in this supplement: Dryocoetes caryi Hopkins (=Dryocoetes sechelti Swaine); Lymantor decipiens (LeConte) (=Lymantor alaskanus Wood). New combinations proposed in this supplement: Ancipitis scabrior (Schedl) from Xyleborus; Beaverium obstipus (Schedl) from Xyleborus; Beaverium rufus (Schedl) from Xyleborus; Cyclorhipidion inaqualis (Schedl) from Xyleborus; Debus amphicranoiodes (Hagedorn) from Xyleborus; Euwallacea pseudorudis (Schedl) from Xyleborus; Euwallacea sublinearis (Eggers) from Xyleborus; Planiculus subdolosus (Schedl) from Xyleborus; Pseudowebbia bakoensis (Browne) from Webbia; Pseudowebbia quattuordecimspinatus (Sampson) from Webbia. New status proposed in this supplement: Dendroctonus barberi Hopkins is removed from synonymy with Dendroctonus brevicomis LeConte and placed as a subspecies of D. brevicomis; Euwallacea kuroshio Gomez and Hulcr, Xyleborus whitfordiodendrus (Schedl) and E. fornicatior (Eggers) are placed as subspecies of Euwallacea fornicatus (Eichhoff). New name proposed in this supplement: Ambrosiophilus incertissimus for Xyleborus incertus Schedl 1969, not Schedl 1963. New distribution records are given for 130 species. The second part of this paper is a checklist of the world Scolytidae (Coleoptera) consisting of 280 genera, of which 17 are fossils, and 7829 species, of which 61 are fossils. Generic and specific names that are currently recognized are listed along with their synonyms, if any. Generic names are listed in alphabetical order, followed by the included species, also in alphabetical order. The known distribution of every species is given. The cut-off date is December 31, 2019
Operational Performance Improvements to BRIght Target Explorer Constellation
No full textThe BRIght Target Explorer (BRITE)-Constellation is composed of six nano-satellites funded by Austria, Canada, and Poland, and each of them is equipped with an optical telescope that observes stars with visual magnitude +3.5 or brighter. BRITE-Constellation has provided numerous images of bright stars from Low Earth Orbit, which will eventually lead to investigation of origin of the Universe.
This thesis presents the contribution of the author to BRITE mission, especially in BRITE Operations. The author performed antenna steering experiments on UniBRITE and BRITE-Toronto, to improve data downlink. To improve scientific data collection from BRITE satellites, the author computed available observation time for multiple targets every orbit, which resulted in collection of twice the amount of scientific data. Also, the author increased the available observation time for each target from 32 minutes to 48 minutes by improving the performance of the star tracker on-board BRITE-Toronto.M.A.S
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