NASA SBIR abstracts of 1990 phase 1 projects

The research objectives of the 280 projects placed under contract in the National Aeronautics and Space Administration (NASA) 1990 Small Business Innovation Research (SBIR) Phase 1 program are described. The basic document consists of edited, non-proprietary abstracts of the winning proposals submitted by small businesses in response to NASA's 1990 SBIR Phase 1 Program Solicitation. The abstracts are presented under the 15 technical topics within which Phase 1 proposals were solicited. Each project was assigned a sequential identifying number from 001 to 280, in order of its appearance in the body of the report. The document also includes Appendixes to provide additional information about the SBIR program and permit cross-reference in the 1990 Phase 1 projects by company name, location by state, principal investigator, NASA field center responsible for management of each project, and NASA contract number

Documenting the Origin of Compositional Diversity of Subduction Zone Magmatism, Alicudi, Aeolian Arc (Southern Tyrrhenian Sea, Italy) Using in situ Plagioclase Data

Processes that generate magma compositional diversity are important to document because composition affects degree of explosivity, which impacts hazard mitigation. Magnesium to silicon rich magmas are produced by processes such as magma recharge, assimilation, and fractional crystallization (RAFC) that occur in subvolcanic magma chamber(s). This study evaluates how magma chamber processes contribute to compositional diversity at Alicudi Volcano, Italy. Analytical and petrographic data from ten samples that span the subaerial history include whole rock major and trace elements and strontium/neodymium isotopes, and plagioclase textural types, major and trace elements, and strontium isotopes; numerical modeling was also conducted. Integration of these data suggests that recharge, assimilation, storage at different levels below the volcano, and homogenization occur in Alicudi’s magmatic system. Magma bodies shoaled and coalesced as the volcanic system matured. Understanding the physical and geochemical constraints of magma formation in plumbing systems enhances eruption prediction and hazard mitigation

Cavity dynamics of water entry for spheres and ballistic projectiles

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2009.Includes bibliographical references.The free surface impact of solid objects has been investigated for well over a century. This canonical problem has many facets that may be studied: object geometry, surface treatment, and diameter; impact speed and angle; and fluid viscosity and surface tension. The problem is further enriched with the consideration of varying mass ratios and rotational velocities. This thesis uses advanced high-speed imaging and visualization techniques to discover underlying physics and further our understanding of these phenomena through improvements to analytical solutions describing criterion such as cavity formation, depth of deep seal, and trajectory for all impact parameters studied. The topic is extended to the impact of high-speed projectiles or bullets. Through experimentation the trajectory, cavity size, and forces acting on the projectiles are elucidated. Experimentation coupled with improvements to an existing cavitation model lead to an improved bullet design that forms a narrower cavity and achieves higher speeds. Industrial applications include ship slamming, extreme waves and weather on oil platforms, sprayed adhesives, paint aerosols and ink jet printing. In the field of naval hydrodynamics there is particular interest as these problems relate to the study of the water entry of mines and bullets, and the underwater launching of torpedos and missiles. Physical insight can also be applied to sports performance research relating to the water entry of athletes, reducing drag of swimmers near the free surface, decreasing cavity formation for divers, and the entry and exit of oars in rowing.(cont.) This thesis examines the effect of several key parameters on the water entry physics of spheres at relatively low Froude numbers including: hydrophobic vs. hydrophilic surfaces, mass ratio and rotational velocity. Physical models that predict the depth of deep seal and the effect of dynamic and static wetting angle on cavity formation will be discussed. Theories are derived from physical parameters witnessed through high-speed video image sequences using advanced image processing techniques. New phenomena have been witnessed via these techniques including a wedge of fluid that crosses the cavity in the case of transverse rotational velocity. Furthermore, the images reveal the forces acting on the sphere through the entire trajectory, which adds valuable information for future theoretical models. The discussion continues with the water entry of bullets, which produce water vapor cavities large enough to engulf the projectile (i.e. supercavitation). The effects of speed, geometry and angle of attack on the formation of the subsurface cavity are analyzed through an improved physical model and full scale experimentation. The analytical model is then used to improve the design of projectile geometry to allow for more efficient travel inside the cavity and experimentally validated.by Tadd Trevor Truscott.Ph.D

A Survey on Audio-Video based Defect Detection through Deep Learning in Railway Maintenance

Within Artificial Intelligence, Deep Learning (DL) represents a paradigm that has been showing unprecedented performance in image and audio processing by supporting or even replacing humans in defect and anomaly detection. The Railway sector is expected to benefit from DL applications, especially in predictive maintenance applications, where smart audio and video sensors can be leveraged yet kept distinct from safety-critical functions. Such separation is crucial, as it allows for improving system dependability with no impact on its safety certification. This is further supported by the development of DL in other transportation domains, such as automotive and avionics, opening for knowledge transfer opportunities and highlighting the potential of such a paradigm in railways. In order to summarize the recent state-of-the-art while inquiring about future opportunities, this paper reviews DL approaches for the analysis of data generated by acoustic and visual sensors in railway maintenance applications that have been published until August 31st, 2021. In this paper, the current state of the research is investigated and evaluated using a structured and systematic method, in order to highlight promising approaches and successful applications, as well as to identify available datasets, current limitations, open issues, challenges, and recommendations about future research directions

Building information modeling – A game changer for interoperability and a chance for digital preservation of architectural data?

Digital data associated with the architectural design-andconstruction process is an essential resource alongside -and even past- the lifecycle of the construction object it describes. Despite this, digital architectural data remains to be largely neglected in digital preservation research – and vice versa, digital preservation is so far neglected in the design-and-construction process. In the last 5 years, Building Information Modeling (BIM) has seen a growing adoption in the architecture and construction domains, marking a large step towards much needed interoperability. The open standard IFC (Industry Foundation Classes) is one way in which data is exchanged in BIM processes. This paper presents a first digital preservation based look at BIM processes, highlighting the history and adoption of the methods as well as the open file format standard IFC (Industry Foundation Classes) as one way to store and preserve BIM data

On the popularization of digital close-range photogrammetry: a handbook for new users.

Εθνικό Μετσόβιο Πολυτεχνείο--Μεταπτυχιακή Εργασία. Διεπιστημονικό-Διατμηματικό Πρόγραμμα Μεταπτυχιακών Σπουδών (Δ.Π.Μ.Σ.) “Γεωπληροφορική