478 research outputs found
Fire safety: A case study of technology transfer
Two basic ways in which NASA-generated technology is being used by the fire safety community are described. First, improved products and systems that embody NASA technical advances are entering the marketplace. Second, NASA test data and technical information related to fire safety are being used by persons concerned with reducing the hazards of fire through improved design information and standards. The development of commercial fire safety products and systems typically requires adaptation and integration of aerospace technologies that may not have been originated for NASA fire safety applications
Applications of aerospace technology in the public interest: Pollution measurement
This study of selected NASA contributions to the improvement of pollution measurement examines the pervasiveness and complexity of the economic, political, and social issues in the environmental field; provides a perspective on the relationship between the conduct of aerospace R and D and specific improvements in on site air pollution monitoring equipment now in use; describes the basic relationship between the development of satellite-based monitoring systems and their influence on long-term progress in improving environmental quality; and comments on how both instrumentation and satellite remote sensing are contributing to an improved environment. Examples of specific gains that have been made in applying aerospace R and D to environmental problem-solving are included
Solar heating system for recreation building at Scattergood School
The solar heating facility and the project involved in its construction are described. As such, it has both detailed drawings of the completed system and a section that discusses the bottlenecks that were encountered along the way
Applications of aerospace technology in industry, a technology transfer profile: Fire safety
The fire safety field is considered as being composed of three parts: an industry, a technology base, and a user base. An overview of the field is presented, including a perspective on the magnitude of the national fire safety problem. Selected NASA contributions to the technology of fire safety are considered. Communication mechanisms, particularly conferences and publications, used by NASA to alert the community to new developments in the fire safety field, are reviewed. Several examples of nonaerospace applications of NASA-generated fire safety technology are also presented. Issues associated with attempts to transfer this technology from the space program to other sectors of the American economy are outlined
Applications of aerospace technology in industry, a technology transfer profile: Lubrication
Technology transfer in the lubrication field is discussed in terms of the movement of NASA-generated lubrication technology into the private sector as affected by evolving industrial requirements. An overview of the field is presented, and NASA technical contributions to lubrication technology are described. Specific examples in which these technologies have been used in the private sector are summarized
Asymptotic behaviour of multiple scattering on infinite number of parallel demi-planes
The exact solution for the scattering of electromagnetic waves on an infinite
number of parallel demi-planes has been obtained by J.F. Carlson and A.E. Heins
in 1947 using the Wiener-Hopf method. We analyze their solution in the
semiclassical limit of small wavelength and find the asymptotic behaviour of
the reflection and transmission coefficients. The results are compared with the
ones obtained within the Kirchhoff approximation
Modelling for Robust Feedback Control of Fluid Flows
This paper addresses the problem of obtaining low-order models of fluid flows for the purpose of designing robust feedback controllers. This is challenging since whilst many flows are governed by a set of nonlinear, partial differential-algebraic equations (the Navier-Stokes equations), the majority of established control theory assumes models of much greater simplicity, in that they are firstly: linear, secondly: described by ordinary differential equations, and thirdly: finite-dimensional. Linearisation, where appropriate, overcomes the first disparity, but attempts to reconcile the remaining two have proved difficult. This paper addresses these two problems as follows. Firstly, a numerical approach is used to project the governing equations onto a divergence-free basis, thus converting a system of differential-algebraic equations into one of ordinary differential equations. This dispenses with the need for analytical velocity-vorticity transformations, and thus simplifies the modelling of boundary sensing and actuation. Secondly, this paper presents a novel and straightforward approach for obtaining suitable low-order models of fluid flows, from which robust feedback controllers can be synthesised that provide~\emph{a~priori} guarantees of robust performance when connected to the (infinite-dimensional) linearised flow system. This approach overcomes many of the problems inherent in approaches that rely upon model-reduction. To illustrate these methods, a perturbation shear stress controller is designed and applied to plane channel flow, assuming arrays of wall mounted shear-stress sensors and transpiration actuators. DNS results demonstrate robust attenuation of the perturbation shear-stresses across a wide range of Reynolds numbers with a single, linear controller
Directing Astroglia from the Cerebral Cortex into Subtype Specific Functional Neurons
Forced expression of single defined transcription factors can selectively and stably convert cultured astroglia into synapse-forming excitatory and inhibitory neurons
An Integrated TCGA Pan-Cancer Clinical Data Resource to Drive High-Quality Survival Outcome Analytics
For a decade, The Cancer Genome Atlas (TCGA) program collected clinicopathologic annotation data along with multi-platform molecular profiles of more than 11,000 human tumors across 33 different cancer types. TCGA clinical data contain key features representing the democratized nature of the data collection process. To ensure proper use of this large clinical dataset associated with genomic features, we developed a standardized dataset named the TCGA Pan-Cancer Clinical Data Resource (TCGA-CDR), which includes four major clinical outcome endpoints. In addition to detailing major challenges and statistical limitations encountered during the effort of integrating the acquired clinical data, we present a summary that includes endpoint usage recommendations for each cancer type. These TCGA-CDR findings appear to be consistent with cancer genomics studies independent of the TCGA effort and provide opportunities for investigating cancer biology using clinical correlates at an unprecedented scale. Analysis of clinicopathologic annotations for over 11,000 cancer patients in the TCGA program leads to the generation of TCGA Clinical Data Resource, which provides recommendations of clinical outcome endpoint usage for 33 cancer types
Novel lines of Pax6-/- embryonic stem cells exhibit reduced neurogenic capacity without loss of viability
<p>Abstract</p> <p>Background</p> <p>Embryonic stem (ES) cells can differentiate into all cell types and have been used extensively to study factors affecting neuronal differentiation. ES cells containing mutations in known genes have the potential to provide useful in vitro models for the study of gene function during neuronal differentiation. Recently, mouse ES cell lines lacking the neurogenic transcription factor Pax6 were reported; neurons derived from these <it>Pax6</it><sup>-/- </sup>ES cells died rapidly after neuronal differentiation in vitro.</p> <p>Results</p> <p>Here we report the derivation of new lines of <it>Pax6</it><sup>-/- </sup>ES cells and the assessment of their ability to survive and differentiate both in vitro and in vivo. Neurons derived from our new <it>Pax6</it><sup>-/- </sup>lines were viable and continued to elaborate processes in culture under conditions that resulted in the death of neurons derived from previously reported <it>Pax6</it><sup>-/- </sup>ES cell lines. The new lines of <it>Pax6</it><sup>-/-</sup>ES cells showed reduced neurogenic potential, mimicking the effects of loss of Pax6 in vivo. We used our new lines to generate <it>Pax6</it><sup>-/- </sup>↔ <it>Pax6</it><sup>+/+ </sup>chimeras in which the mutant cells survived and displayed the same phenotypes as <it>Pax6</it><sup>-/- </sup>cells in <it>Pax6</it><sup>-/- </sup>↔ <it>Pax6</it><sup>+/+ </sup>chimeras made by embryo aggregation.</p> <p>Conclusions</p> <p>We suggest that loss of Pax6 from ES cells reduces their neurogenic capacity but does not necessarily result in the death of derived neurons. We offer these new lines as additional tools for those interested in the generation of chimeras and the analysis of in vitro ES cell models of Pax6 function during neuronal differentiation, embryonic and postnatal development.</p
- …