2,369 research outputs found
Modification of cold orographic clouds
December, 1970.Includes bibliographical references.Sponsored by by National Science Foundation 847.Sponsored by by National Science Foundation 1553.Sponsored by by National Science Foundation 11574.Bureau of Reclamation 14-06-D-6467
Interactions Between Convective Storms and Their Environment
The ways in which intense convective storms interact with their environment are considered for a number of specific severe storm situations. A physical model of subcloud wind fields and vertical wind profiles was developed to explain the often observed intensification of convective storms that move along or across thermal boundaries. A number of special, unusually dense, data sets were used to substantiate features of the model. GOES imagery was used in conjunction with objectively analyzed surface wind data to develop a nowcast technique that might be used to identify specific storm cells likely to become tornadic. It was shown that circulations associated with organized meso-alpha and meso-beta scale storm complexes may, on occasion, strongly modify tropospheric thermodynamic patterns and flow fields
Report from ionospheric science
The general strategy to advance knowledge of the ionospheric component of the solar terrestrial system should consist of a three pronged attack on the problem. Ionospheric models should be refined by utilization of existing and new data bases. The data generated in the future should emphasize spatial and temporal gradients and their relation to other events in the solar terrestrial system. In parallel with the improvement in modeling, it will be necessary to initiate a program of advanced instrument development. In particular, emphasis should be placed on the area of improved imaging techniques. The third general activity to be supported should be active experiments related to a better understanding of the basic physics of interactions occurring in the ionospheric environment. These strategies are briefly discussed
The retarding ion mass spectrometer on dynamics Explorer-A
An instrument designed to measure the details of the thermal plasma distribution combines the ion temperature-determining capability of the retarding potential analyzer with the compositional capabilities of the mass spectrometer and adds multiple sensor heads to sample all directions relative to the spacecraft ram directions. The retarding ion mass spectrometer, its operational modes and calibration are described as well as the data reduction plan, and the anticipated results
International Educatorsâ Perspectives on the Purpose of Science Education and the Relationship between School Science and Creativity
This is the author accepted manuscript. The final version is available from Taylor & Francis (Routledge) via the DOI in this record.Background: Creativity across all disciplines is increasingly viewed as a fundamental
educational capability. Science can play a potentially important role in the nurturing of
creativity. Research also suggests that creative pedagogy, including interdisciplinary
teaching with Science and the Arts, can engage students with science. Previous studies
into teachersâ attitudes to the relationship between science and creativity have been
largely situated within national educational contexts.
Purpose: This study, part of the large EU funded CREATIONs project, explores
educatorsâ perspectives on the relationship between Science and Creativity across
national contexts drawn from Europe and beyond.
Sample and Methods: 270 educators, broadly defined to include primary (age 4-11) and
secondary (age 11-18) teachers and trainee teachers, informal educators and teacher
educators, responded to a survey designed to explore perceptions of the relationship
between science and creativity. Respondents were a convenience sample recruited by
project partners and through online media. The elements of the survey reported here
included Likert-scale questions, open response questions, and ranking questions in the
form of an electronic self-administered questionnaire. Exploratory factor analysis was
used to develop a combined attitude scale labelled âscience is creativeâ, with results
compared across nationalities and phases of education. Open question responses were
analysed thematically to allow more nuanced interpretation of the descriptive statistical
findings.
Results: The findings show broad agreement internationally and across phases that
science is a creative endeavour, with a small number of educators disagreeing about the
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relationship between science and creativity in the context of school science. Those who
disagreed were usually secondary science teachers, from England, Malta or outside
Europe (primarily from the United States). The role of scientific knowledge within
creativity in science education was found to be contentious.
Conclusions: That educators broadly see science as creative is unsurprising, but initial
exploration of educatorsâ perspectives internationally shows some areas of difference.
These were especially apparent for educators working in formal education, particularly
relating to the role of knowledge with respect to creativity in science. With current
interest in STEAM education, further investigation to understand potential mediating
factors of national educational contexts on teachersâ perspectives with respect to the
role of disciplinary knowledge(s) in creativity and their interaction in interdisciplinary
teaching and learning, is recommended.European Commissio
Theory of Cylindrical Tubules and Helical Ribbons of Chiral Lipid Membranes
We present a general theory for the equilibrium structure of cylindrical
tubules and helical ribbons of chiral lipid membranes. This theory is based on
a continuum elastic free energy that permits variations in the direction of
molecular tilt and in the curvature of the membrane. The theory shows that the
formation of tubules and helical ribbons is driven by the chirality of the
membrane. Tubules have a first-order transition from a uniform state to a
helically modulated state, with periodic stripes in the tilt direction and
ripples in the curvature. Helical ribbons can be stable structures, or they can
be unstable intermediate states in the formation of tubules.Comment: 43 pages, including 12 postscript figures, uses REVTeX 3.0 and
epsf.st
Novel polyvinylpyrrolidones to improve delivery of poorly-water soluble drugs; from design to synthesis and evaluation
Polyvinylpyrrolidone is a widely used in tablet formulations with the linear form acting as a wetting agent and disintegrant whereas the cross-linked form is a super-disintegrant. We have previously reported that simply mixing the commercial cross-linked polymer with ibuprofen disrupted drug crystallinity with consequent improvements in drug dissolution behavior. In this study, we have designed and synthesized novel cross-linking agents containing a range of oligoether moieties which have then be polymerized with vinylpyrrolidone to generate a suite of novel excipients with enhanced hydrogen-bonding capabilities. The polymers have a porous surface and swell in most common solvents and in water; properties which suggest their value as disintegrants. The polymers were evaluated in simple physical mixtures with ibuprofen as a model poorly-water soluble drug. The results show that the novel PVPs induce the drug to become âX-ray amorphousâ, which increased dissolution to a greater extent than that seen with commercial cross-linked PVP. The polymers stabilize the amorphous drug with no evidence for recrystallization seen after 20 weeks storage
Three-body correlations in Borromean halo nuclei
Three-body correlations in the dissociation of two-neutron halo nuclei are
explored using a technique based on intensity interferometry and Dalitz plots.
This provides for the combined treatment of both the n-n and core-n
interactions in the exit channel. As an example, the breakup of 14Be into
12Be+n+n by Pb and C targets has been analysed and the halo n-n separation
extracted. A finite delay between the emission of the neutrons in the reaction
on the C target was observed and is attributed to 13Be resonances populated in
sequential breakup.Comment: 5 pages, 4 figures, submitted to PR
'You were quiet - I did all the marching': Research processes involved in hearing the voices of South Asian girls
This article is available open access through the publisherâs website at the link below. Copyright @ 2011
A B
Academic
Publishers.This article provides insights into the outcomes of reflection following two interview approaches used to explore narratives of the lived, individual experiences of South-Asian girls living in West London. In attempting to illuminate and re-present the cultural experiences as told by these girls, the choice of interview approach became critical in allowing the voices to be effectively heard (Rogers, 2005). This article therefore considers how a semi-structured interview approach offered valuable insights into the girls' experiences but became constraining for both researcher and participant in unveiling the complexity and depth of their lives. These constraints emerged through reflection by both participants and researcher. As a result of reflexivity during the research process, the researcher moved towards the use of research conversations during the second phase of the study. Ultimately the study revealed how the girls felt empowered by the opportunity to narrate their individual experiences and tell of their lives. In narrating their reflections on being part of the research, there was a clear recognition that the process facilitated the articulation of new voices and âmulti-voicednessâ (Moen, 2006
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