5,365 research outputs found
Design and fabrication of metallic thermal protection systems for aerospace vehicles
A program was conducted to develop a lightweight, efficient metallic thermal protection system (TPS) for application to future shuttle-type reentry vehicles, advanced space transports, and hypersonic cruise vehicles. Technical requirements were generally derived from the space shuttle. A corrugation-stiffened beaded-skin TPS design was used as a baseline. The system was updated and modified to incorporate the latest technology developments and design criteria. The primary objective was to minimize mass for the total system
Immunohistochemical characterization of the 'intimal proliferation' phenomenon in Sneddon's syndrome and essential thrombocythaemia
Cellular changes were immunocytochemically characterized in skin vessels of five patients with idiopathic generalized racemose livedo (Sneddon's syndrome), and one patient with localized racemose livedo associated with essential thrombocythaemia. Antibodies against alpha-smooth muscle-actin, tropomyosin, desmin, vimentin, factor VIII-related antigen, human endothelial cells (CD31), human macrophages (CD68), and HLA-DR positive cells (CR3/43) were used. Conventional light microscopy showed, in all cases, intimal thickening of ascending arteries and arterioles as a result of an accumulation of cells and extracellular hyalinized material. None of the specimens showed infiltration with polymorphonuclear leucocytes or macrophages. The cells in the region of the intimal hyperplasia showed intense positive immunostaining for alpha-smooth muscle actin and tropomyosin. Staining for the intermediate filament desmin was localized to the resident smooth muscle cells of the media, whereas staining for vimentin was found in all types of cells in both the intima and media. Positive immunostaining for factor VIII-related antigen and CD31 was strictly confined to the endothelial cells lining the narrowed lumina of the vessels. No positive staining with either antibody was observed in totally occluded vessels. Cells in the subintimal space did not show reactivity for CD68 in any of the specimens, but two cases showed solitary cells with positive staining for HLA-DR in this region. There were no differences in staining pattern between Sneddon's syndrome and essential thrombocythaemia with any of the antibodies. Our results support the assumption that the 'intimal proliferation' in both diseases is caused by colonization of the subendothelial space with contractile cells of possible smooth muscle origin.(ABSTRACT TRUNCATED AT 250 WORDS
Design and fabrication of elevon cove thermal protection systems for aerospace vehicles
The design study of a lightweight, effective, reuseable seal for use along the elevon cove of shuttle-type reentry and hypersonic cruise vehicles is presented. The study deals primarily with membrane seals, both metallic and non-metallic. This type of seal spans the cove gap between the wing and elevon, and does not depend on spring tension to maintain contact along a flexing wing span. Technical requirements and criteria were generally derived from the space shuttle and utilized for seal design
The Companions of St. Paul
In treating a subject of this kind it is natural to ask the question: whom should we consider companions of the Apostle Paul? If we were to consider all those men and women who at various times were his coworkers and friends, we would have a work which would fill volumes. For this reason I will deal with those men only who were his companions and coworkers on his var1ous Journeys. It is not my purpose to treat all of them biographically for large books have been written about some or his companions, Luke, the beloved physician for example. It is my purpose to fix in the mind of the reader an association between the names which we so often hear in connection with the New Testament, especially in the letters of St. Paul, and the field of the activity of these men
Mimicry and ultrastructural analogy between the semi-aquatic grasshopper Paulinia acuminata (Orthoptera: Pauliniidae) and its foodplant, the water-fern Salvinia auriculata (Filicatae: Salviniaceae)
The semi-aquatic grasshopper Paulinia acuminata is mimetically protected by a striking similarity to its foodplant, the floating fern Salvinia auriculata. A SEM study of the cuticula of young grasshopper nymphs and the Salvinia leaf surface reveals a similar ultrastructure of epicuticular waxes which makes both organisms extremely water repellent
Le degre d'interdependance internationale des prix en France et en Italie = The degree of international interdependence affecting prices in France and in Italy. II/367/1/72-F, May 1972
Obtaining Record Linkage Consent: Results from a Wording Experiment in Germany
Many sample surveys ask respondents for consent to link their survey information with
administrative sources. There is significant variation in how linkage requests are
administered and little experimental evidence to suggest which approaches are useful for
achieving high consent rates. A common approach is to emphasize the positive benefits of
linkage to respondents. However, some evidence suggests that emphasizing the negative
consequences of not consenting to linkage is a more effective strategy. To further examine
this issue, we conducted a gain-loss framing experiment in which we emphasized the benefit
(gain) of linking or the negative consequence (loss) of not linking one’s data as it related to
the usefulness of their survey responses. In addition, we explored a sunk-prospective costs
rationale by varying the emphasis on response usefulness for responses that the respondent
had already provided prior to the linkage request (sunk costs) and responses that would be
provided after the linkage request (prospective costs). We found a significant interaction
between gain-loss framing and the sunk-prospective costs rationale: respondents in the
gain-framing condition consented to linkage at a higher rate than those in the loss-framing
condition when response usefulness was emphasized for responses to subsequent survey
items. Conversely, the opposite pattern was observed when response usefulness was
emphasized for responses that had already been provided: loss-framing resulted in a higher
consent rate than the gain-framing, but this result did not reach statistical significance
Data Analysis Techniques for Fan Performance in Highly-Distorted Flows from Boundary Layer Ingesting Inlets
The design of a unique distortion-tolerant fan for a high-bypass ratio boundary-layer ingesting propulsion system has been completed and a rig constructed and tested in the NASA Glenn 8x6 wind tunnel. Processing the data from the experiment presented some interesting challenges because of the complexity of the experimental setup and the flow through the test rig. The experiment was run in three phases, each of which employed a unique complement of inlet throat and fan face instrumentation to avoid the blockage that would have resulted from simultaneously installing all of the rakes. The measurement from the individual test points were subsequently combined to compute the overall stage performance. A CFD model of the experiment was used to gain understanding of the flow field and to test some of the techniques proposed for interpolating and extrapolating the measurements into regions where measurements were not made. This capability became extremely useful when it was discovered that there was an unexpected total temperature distortion in the tunnel. The CFD model was modified by inserting a total temperature profile at the upstream boundary that mimicked the measured distortion where measurements were available and that CFD solution was used to investigate methods to infer the complete total temperature field at the fan face
Modal Sosial sebagai Strategi Bertahan Hidup Buruh Tani di Desa Kopiwangker, Kecamatan Langowan Barat, Minahasa
This research aims to determine and describe how farm-workers can survive by social strategy as their strategy. From the three elements of social capital, that's trust, norms, and networks, which one has the greater influence for a survival strategy of Kopiwangker farm-workers in village. This research was conducted over five months, from February until June 2016 started from preparation until making research reports. This study has used primary data and secondary data. The number of respondents is 30 respondents of whom are farm-workers. The sampling method which used in this research is purposive sampling and data analysis method used is descriptive qualitative which quantified using the Likert Scale. The results of this research indicate that social capital can be a survival strategy for Kopiwangker village farm-workers, especially on the elements of the network (patron-client networks) because it has the highest score, that is 450. But according to several informants that ever happened was also a problem among some farm-workers (as clients) and patrons, but always can be resolved
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