2,252 research outputs found
Aero/fluids database system
The AFAS Database System was developed to provide the basic structure of a comprehensive database system for the Marshall Space Flight Center (MSFC) Structures and Dynamics Laboratory Aerophysics Division. The system is intended to handle all of the Aerophysics Division Test Facilities as well as data from other sources. The system was written for the DEC VAX family of computers in FORTRAN-77 and utilizes the VMS indexed file system and screen management routines. Various aspects of the system are covered, including a description of the user interface, lists of all code structure elements, descriptions of the file structures, a description of the security system operation, a detailed description of the data retrieval tasks, a description of the session log, and a description of the archival system
Approximate analysis and stability of pressure oscillations in ramjets
This paper summarizes work accomplished during the past five years on analysis of stability related to
recent experimental results on combustion instabilities in dump combustors. The primary purpose is to provide
the information in a form useful to those concerned with design and development of operational systems. Thus
most substantial details are omitted; the material is presented in a qualitative fashion
Preliminary base heating environments for a generalized ALS LO2/LH2 launch vehicle, appendix 1 and 2
A secondary objective of contract NAS8-39141 is to provide base heating assessments, as required, to support Advanced Launch System (ALS) preliminary launch vehicle and propulsion system design studies. The ALS propulsion systems integration working group meeting (No. 3) recently completed in San Diego, California, focused attention on the need for base heating environment determination to provide preliminary requirements for LO2/LH2 propulsion systems currently being considered for ALS. We were requested to provide these environments for a range of possible propellant mixture and nozzle area ratios. Base heating environments can only be determined as a function of altitude when the engine operating conditions and vehicle base region geometry (engine arrangement) are known. If time dependent environments are needed to assess thermal loads, a trajectory must also be provided. These parameters are not fixed at this time since the ALS configurations and propulsion operating conditions are varied and continue to be studied by Phase B contractors. Therefore, for this study, a generalized LO2/LH2 system was selected along with a vehicle configuration consisting of a seven-engine booster and a three-engine core. MSFC provided guidance for the selection. We also selected a limited number of body points on the booster and core vehicles and engines for the environment estimates. Environments at these locations are representative of maximum heating conditions in the base region and are provided as a function of altitude only. Guidelines and assumptions for this assessment, methodology for determining the environments, and preliminary results are provided in this technical note. Refinements in the environments will be provided as the ALS design matures
Base heating methodology improvements, volume 1
This document is the final report for NASA MSFC Contract NAS8-38141. The contracted effort had the broad objective of improving the launch vehicles ascent base heating methodology to improve and simplify the determination of that environment for Advanced Launch System (ALS) concepts. It was pursued as an Advanced Development Plan (ADP) for the Joint DoD/NASA ALS program office with project management assigned to NASA/MSFC. The original study was to be completed in 26 months beginning Sep. 1989. Because of several program changes and emphasis on evolving launch vehicle concepts, the period of performance was extended to the current completion date of Nov. 1992. A computer code incorporating the methodology improvements into a quick prediction tool was developed and is operational for basic configuration and propulsion concepts. The code and its users guide are also provided as part of the contract documentation. Background information describing the specific objectives, limitations, and goals of the contract is summarized. A brief chronology of the ALS/NLS program history is also presented to provide the reader with an overview of the many variables influencing the development of the code over the past three years
SRB Environment Evaluation and Analysis. Volume 3: ASRB Plume Induced Environments
Contract NAS8-37891 was expanded in late 1989 to initiate analysis of Shuttle plume induced environments as a result of the substitution of the Advanced Solid Rocket Booster (ASRB) for the Redesigned Solid Rocket Booster (RSRB). To support this analysis, REMTECH became involved in subscale and full-scale solid rocket motor test programs which further expanded the scope of work. Later contract modifications included additional tasks to produce initial design cycle environments and to specify development flight instrumentation. Volume 3 of the final report describes these analyses and contains a summary of reports resulting from various studies
Social Assessment of Section 3 of the A465 Heads of the Valleys Road: Brynmawr to Tredegar
The aim of this report is to provide a social assessment of the impacts of Section 3 of the A465 Heads of the Valleys Road: Brynmawr to Tredegar, using a mixed methods approach which adapts and builds on the UK WebTAG appraisal guidance units 4.1 and 4.2. We define social assessment in this document as a study of the social and distributional impacts which estimate the impacts of the implemented scheme at the point of opening rather than a detailed ex-ante appraisal. In the absence of detailed ex-ante appraisal, this report sets a baseline from which future evaluation may be conducted. This is the first application of a new mixed methods approach to social assessment of the impacts of transport infrastructure investment in the UK. It was commissioned by the Welsh Government in specific recognition of the need for improved guidance in this area of project delivery. The results reported here, along with its accompanying annexes, also contribute to greater understanding of social and distributional impacts, which builds upon and extends the current quantitative approach in WelTAG / WebTAG. This will hopefully lead to better understanding of the wider social effects of transport projects in order to inform future considerations as to how new transport schemes affect wellbeing
The ecology of peer review: Person-centred, strength-based, and self-determination perspectives
The peer-review system, commonly considered critical for research integrity and rigour, has been criticised for being slow, exclusionary and exploitive. Concerns include the high profits of academic publishers as well as the growing number of insecurely employed academic staff who report high levels of stress and burnout. The consequence has been a decline in willing reviewers, publication delays, and potential damage to the career trajectories of early career researchers and PhD candidates at institutions that rely on metrics of academic impact as measures of academic performance. Rather than overhaul the system and undermine current benefits, this critical review adopts an ecological lens to posit an approach that is humanistic, transparent, and above all things, kind. This approach frames an applied perspective on how to improve peer-review moving forward
Functional and Morphological Studies of Mitochondria Exposed to Undecagold Clusters: Biologic Surfaces Labeling with Gold Clusters
This study reports morphological and functional alterations observed in respiring isolated mitochondria when they are exposed to nonpenetrating, positive electrostatically charged synthetic undecagold clusters. Modification of the undecagold clusters positive charges change or prevent the functional effects and the binding to the outside surface of the mitochondria. The mitochondrial functional alterations are dependent on the oxidative phosphorylation capacity of the isolated organelles. The results of these experiments indicate that artificial undecagold may be useful to explore the molecular mechanisms of biological energy transducers which require electric charges separation, ionic fluxes, and electric surface properties
NLS cycle 1 and NLS 2 base heating technical notes. Appendix 3: Preliminary cycle 1 NLS base heating environments. Cycle 1 NLS base heating environments. NLS 2 650K STME base heating environments
A preliminary analysis of National Launch System ascent plume induced base heating environments has been completed to support the Induced Environments Panel's objective to assist in maturing the NLS vehicle (1.5 stage and heavy launch lift vehicle) design. Environments during ascent have been determined from this analysis for a few selected locations on the engine nozzles and base heat shield for both vehicles. The environments reflect early summer 1991 configurations and performance data and conservative methodology. A more complete and thorough analysis is under way to update these environments for the cycle 1 review in January 1992
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