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 Educators’ 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 teachers’ 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 educators’ 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 ‘science is creative’, 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 3 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 educators’ 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 teachers’ 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 “X-ray amorphous”, 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