Ice nuclei measurements from solid rocket motor effluents

The ice crystal forming nuclei (IN) measured in solid rocket motor (SRM) exhaust products is discussed in relation to space shuttle exhaust. Preliminary results from laboratory investigations and flight preparations for March 1978 Titan launch are discussed. The work necessary to provide adequate measurements of IN and cloud condensation nuclei (CCN) in the stabilized ground clouds from SRM's is studied

Fostering Liberatory Teaching: A Proposal for Revising Instructional Assessment Practices

Appraises the assumptions that drive standard evaluation methods and compares them to those assumptions that undergird more critical approaches to teaching. Presents an alternative teacher evaluation instrument and explains how it more accurately measures what is said and believed to be effective teaching. Offers statistical evidence supporting the instrument and suggests further steps to foster teaching practice

Airborne measurements of cloud forming nuclei and aerosol particles at Kennedy Space Center, Florida

Results of airborne measurements of the sizes and concentrations of aerosol particles, ice nuclei, and cloud condensation nuclei that were taken at Kennedy Space Center, Florida, are presented along with a detailed description of the instrumentation and measuring capabilities of the University of Washington airborne measuring facility (Douglas B-23). Airborne measurements made at Ft. Collins, Colorado, and Little Rock, Arkansas, during the ferry of the B-23 are presented. The particle concentrations differed significantly between the clean air over Ft. Collins and the hazy air over Little Rock and Kennedy Space Center. The concentrations of cloud condensation nuclei over Kennedy Space Center were typical of polluted eastern seaboard air. Three different instruments were used to measure ice nuclei: one used filters to collect the particles, and the others used optical and acoustical methods to detect ice crystals grown in portable cloud chambers. A comparison of the ice nucleus counts, which are in good agreement, is presented

The Magellanic Bridge: The Nearest Purely Tidal Stellar Population

We report on observations of the stellar populations in twelve fields spanning the region between the Magellanic Clouds, made with the Mosaic-II camera on the 4-meter telescope at the Cerro-Tololo Inter-American Observatory. The two main goals of the observations are to characterize the young stellar population (which presumably formed in situ in the Bridge and therefore represents the nearest stellar population formed from tidal debris), and to search for an older stellar component (which would have been stripped from either Cloud as stars, by the same tidal forces which formed the gaseous Bridge). We determine the star-formation history of the young inter-Cloud population, which provides a constraint on the timing of the gravitational interaction which formed the Bridge. We do not detect an older stellar population belonging to the Bridge in any of our fields, implying that the material that was stripped from the Clouds to form the Magellanic Bridge was very nearly a pure gas.Comment: 19 pages, 9 figures. Accepted to Ap

Airborne measurements of cloud-forming nuclei and aerosol particles in stabilized ground clouds produced by solid rocket booster firings

Airborne measurements of cloud volumes, ice nuclei and cloud condensation nuclei, liquid particles, and aerosol particles were obtained from stabilized ground clouds (SGCs) produced by Titan 3 launches at Kennedy Space Center, 20 August and 5 September 1977. The SGCs were bright, white, cumulus clouds early in their life and contained up to 3.5 g/m3 of liquid in micron to millimeter size droplets. The measured cloud volumes were 40 to 60 cu km five hours after launch. The SGCs contained high concentrations of cloud condensation nuclei active at 0.2%, 0.5%, and 1.0% supersaturation for periods of three to five hours. The SGCs also contained high concentrations of submicron particles. Three modes existed in the particle population: a 0.05 to 0.1 micron mode composed of aluminum-containing particles, a 0.2 to 0.8 micron mode, and a 2.0 to 10 micron mode composed of particles that contained primarily aluminum

Reinventing the University: Finding the Place for Basic Writers

A poststructuralist critique of basic writing placement and pedagogy, this paper argues that our notions of good writing (i.e., the criteria by which we as English professors and compositionists authorize and place students) come not from some general or transcendent standards, but rather from the practices by which we self-authorize within our own discourse community. Using Bartholomae and Petrosky\u27s curriculum presented in Facts, Artifacts, Counterfacts as a point of departure, I propose a language-centered curriculum which uses discourse itself as the subject of the semester-Jong project wherein students eventually learn to critique our practices and create their own discourse communities. This modification, the author argues, comes closer to empowering students to be the agents of their own authorization and placement at the academy

A precise determination of chlorinity of sea water using the Ag-AgCl indicator electrode

A knowledge of the relative currents of the oceans depends to a large extent upon a knowledge of the distribution of mass. Measurements of temperature and cblorinity are made to furnish the necessary data for the computations of the density

Special focus: personal writing

This introduction to a special section of College English treats the nature, role, and problematics of personal academic discourse and professional work. It address the place of personal writing in professional contexts and aims to clarify the myriad denotations of the personal in academic discourse and to suggest viable criteria for evaluating the effectiveness of personal writing\u27s contributions to knowledge-making in English studies

Clinicians’ views on cognitive assessment with Aboriginal Australians

Background: A shortage of standardised cognitive assessment tools for use with Aboriginal Australians is evident. Clinicians also miss the range of guidelines necessary to inform test selection and interpretation for all Aboriginal clients. This mixed methods study examines clinicians’ confidence, views and current practices when conducting cognitive assessments with Aboriginal Australian clients. Methods: Clinicians were asked about factors that influence their likelihood of using standardised testing in Aboriginal vs non-Indigenous Australian people. Twenty-one health professionals with experience conducting cognitive assessments with Aboriginal and non-Aboriginal Australians participated. Clinicians were presented with a series of different scenarios per the client’s level of education and language of origin via an online survey. Clinicians rated their likelihood and confidence using standardised cognitive assessment for each scenario. Open-ended questions captured clinicians’ views and information about their current clinical practices. Results: Clients’ age, education and language of origin influence the likelihood of clinicians’ use of standardised cognitive assessment measures with Aboriginal people. Overall, clinicians reported feeling only slightly more confident working with non-Indigenous clients than Aboriginal clients. Qualitative data indicate a lack of consistency regarding test selection. Conclusion: Clinicians expressed concerns about the validity of available cognitive assessment tools for use with Aboriginal Australians and the absence of evidence to assist decision-making. Cited barriers included language, educational attainment and cultural factors