Drag and Propulsive Characteristics of Air-Cooled Engine-Nacelle Installations for Large Airplanes, Special Report

An investigation is in progress in the NACA full-scale wind tunnel to determine the drag and propulsive efficiency of nacelle sizes. In contrast with the usual tests with a single nacelle, these tests were conducted with nacelle-propeller installations on a large model of a 4-engine airplane. Data are presented on the first part of the investigation, covering seven nacelle arrangements with nacelle diameters from 0.53 to 1.5 times the wing thickness. These ratios are similar to those occurring on airplane weighing from about 20 to 100 tons. The results show that the drag, the propulsive efficiency, and the overall efficiency of the various nacelle arrangements as functions of the nacelle size, the propeller position, and the airplane lift coefficient. The effect of the nacelles on the aerodynamic characteristics of the model are shown for both propeller-removed and propeller-operating conditions

Drag and Propulsive Characteristics of Air-Cooled Engine-Nacelle Installations for Large Airplane

An investigation was conducted in the NACA full-scale wind tunnel to determine the drag and the propulsive efficiency of nacelle-propeller arrangements for a large range of nacelle sizes. In contrast with usual tests with a single nacelle, these tests were conducted with nacelle-propeller installations on a large model of a four-engine airplane. Data are presented on the first part of the investigation, covering seven nacelle arrangements with nacelle diameters from 0.53 to 1.5 times the wing thickness. These ratios are similar to those occurring on airplanes weighing from about 20 to 100 tons. The results show the drag, the propulsive efficiency, and the over-all efficiency of the various nacelle arrangements as functions of the nacelle size, the propeller position, and the airplane lift coefficient. The effect of the nacelles on the aerodynamic characteristics of the model is shown for both propeller-removed and propeller-operating conditions

Studies on the mechanism of phagocytosis. II. The interaction of macrophages with anti-immunoglobulin IgG-coated bone marrow-derived lymphocytes

We have examined the effect of the distribution of anti-immunoglobulin IgG molecules on the surface of bone marrow-derived lymphocytes upon the interaction of these cells with macrophages. Lymphocytes which were diffusely coated with antibodies to surface immunoglogulin were ingested by macrophages. Lymphocytes which had the same number of anti-immunoglobulin IgG molecules redistributed to one pole of the surface bound to the macrophages' Fc receptors but were not ingested. These results confirm our previous hypothesis that ingestion of an immunologically coated particle requires the sequential, circumferential binding of specific receptors on the plasma membrane of a phagocytic cell to immunologic ligands distributed over the entire particle surface. Macrophages which had bound capped lymphocytes by the macrophages' Fc receptors removed the immune complex caps from the lymphocyte surface without destroying the lymphocytes. These lymphocytes remained attached to the macrophage surface. The finding that macrophages can phagocytize immune complexes from the surface of a cell without destroying the cell to which these complexes are attached may be important in understanding the effects of antigens and antibodies on cells participating in a humoral immune response, in identifying the mechanisms by which chronic viral infections are established, and in defining the roles of blocking antibodies in tumor immunity

Studies on the mechanism of phagocytosis. I. Requirements for circumferential attachment of particle-bound ligands to specific receptors on the macrophage plasma membrane

These experiments were designed to evaluate the role of macrophage plasma membrane receptors for the third component of complement (C) and for the Fc portion of IgG in the ingestion phase of phagocytosis. Sheep erythrocyte (E) were coated with anti-E IgG [E(IgG)]; these E(IgG) were then attached to cultivated monolayers of mouse peritoneal macrophages under conditions which reversibly inhibit ingestion of E(IgG). The E(IgG)-macrophage complexes were further incubated under similar conditions with an antimacrophage IgG fraction which blocks Fc receptor-mediated ingestion but has no effect upon ingestion mediated by other phagocytic receptors. When these cultures were subsequently incubated under conditions optimal for particle ingestion, phagocytosis of the IgG-coated erythrocytes did not occur; the erythrocytes remained bound to the Fc receptors of the macrophage plasma membrane. To determine whether ligands must cover the entire surface of an attached particle to permit ingestion of that particle, C-coated E [E(IgM)C] were bound to the C receptors of thioglycollate-induced (activated) macrophages at 4 degrees C. E(IgM)C-macrophage complexes were then trypsinized at 4 degrees C, a procedure which resulted in cleavage of erythrocyte-bound C3b molecules to a form of C3 not recognized by the macrophage receptors for C3b. Under the conditions used, trypsin did not affect the attachment of E(IgM)C to the macrophage surface or the macrophage receptors for C3b. When these trypsin treated E(IgM)C-macrophage complexes were incubated at 37 degrees C, the bound E(IgM)C were not ingested; the erythrocytes remained attached to the macrophage plasma membrane via the macrophage's C receptors. These results indicate that attachment of a particle to specific receptors on the macrophage plasma membrane is not sufficient to trigger ingestion of that particle. Rather, ingestion requires the sequential, circumferential interaction of particle-bound ligands with specific plasma membrane receptors not involved in the initial attachment process

Developing Conceptual and Methodological Foundations in Community Engagement

We describe the efforts of two related undergraduate projects to promote lasting social change in marginalized communities in the Dominican Republic and Nicaragua. The projects represent a test of the premise that undergraduate projects can engage academically based strategies and transcend good intentions to achieve effective community partnerships to improve health and health care. The projects proceed from a perspective and theory of marginalization and its consequences. Specifically, marginalization undermines individual and collective capacity to meet basic needs and efforts to thrive. Through strengthening social infrastructure, communities can overcome the effects of marginalization. Project work begins with annual medical clinics and, with the permission of community residents, team members conduct ethnographic descriptions of the communities and their health and health care concerns and resources. We use social network analysis (SNA) and geographic information system (GIS) techniques to describe social infrastructure. Working from those foundations, both projects have enabled increased social infrastructure. To date, we have observed increased communication among community residents, facilitated the development of community-endorsed five-year plans, and established partnerships with regional and international groups

Compactification with Flux on K3 and Tori

We study compactifications of Type IIB string theory on a K3 \times T^2/Z_2 orientifold in the presence of RR and NS flux. We find the most general supersymmetry preserving, Poincare invariant, vacua in this model. All the complex structure moduli and some of the Kahler moduli are stabilised in these vacua. We obtain in an explicit fashion the restrictions imposed by supersymmetry on the flux, and the values of the fixed moduli. Some T-duals and Heterotic duals are also discussed, these are non-Calabi-Yau spaces. A superpotential is constructed describing these duals.Comment: Discussion of susy breaking vacua significantly altere

A specific case in the classification of woods by FTIR and chemometric: discrimination of Fagales from Malpighiales

Fourier transform infrared (FTIR) spectroscopic data was used to classify wood samples from nine species within the Fagales and Malpighiales using a range of multivariate statistical methods. Taxonomic classification of the family Fagaceae and Betulaceae from Angiosperm Phylogenetic System Classification (APG II System) was successfully performed using supervised pattern recognition techniques. A methodology for wood sample discrimination was developed using both sapwood and heartwood samples. Ten and eight biomarkers emerged from the dataset to discriminate order and family, respectively. In the species studied FTIR in combination with multivariate analysis highlighted significant chemical differences in hemicelluloses, cellulose and guaiacyl (lignin) and shows promise as a suitable approach for wood sample classification