On the nature of the fragment environment created by the range destruction or random failure of solid rocket motor casings

Given here are predictions of fragment velocities and azimuths resulting from the Space Transportation System Solid Rocket Motor range destruct, or random failure occurring at any time during the 120 seconds of Solid Rocket Motor burn. Results obtained using the analytical methods described showed good agreement between predictions and observations for two specific events. It was shown that these methods have good potential for use in predicting the fragmentation process of a number of generically similar casing systems. It was concluded that coupled Eulerian-Lagrangian calculational methods of the type described here provide a powerful tool for predicting Solid Rocket Motor response

Centaur in-tank explosion flow fields within STS and Titan 4 payload spaces

Explosions are examined which result from the mixing of liquid hydrogen and liquid oxygen (LH2-LO2) such that the reactants are confined by the missile (CBM) body. Explosion which were confined by the ground surface (CBGS) were also studied, with results reported elsewhere. Initial attempts to predict the reported PYRO experimental results were unsuccessful. A new reaction energy addition hypothesis was then developed and tested. The results obtained provide reasonable agreement with the experiments both in the near and far field. Calculations were performed to predict the environment which would occur at the Galileo Radioisotope Thermoelectric Generator (RTG) location given a Centaur G' upper stage and an STS launch vehicle. It was concluded that the principle threat to the RTG in this environment would be the impact of a slug of LH2. No analyses were conducted to assess the response of the Galileo RTG to such an environment. It was shown that the flow field resulting from the failure of the Centaur G' tankage was benign. It was concluded that while the cryogen particle velocity was very high, the flow field density was extremely low. As a result, the dynamic pressure was a trivial eight psia

Summary of miscellaneous hazard environments for hypothetical Space Shuttle and Titan IV launch abort accidents

The various analyses described here were aimed at obtaining a more comprehensive understanding and definition of the environments in the vicinity of the Radioisotope Thermal Generator (RTG) during certain Space Transportation System (STS) and Titan IV launch abort accidents. Addressed here are a number of issues covering explosion environments and General Purpose Heat Source Radioisotope Thermoelectric Generator (GPHS-RTG) responses to those environments

Correlating Architecture Maturity and Enterprise Systems Usage Maturity to Improve Business/IT Alignment

This paper compares concepts of maturity models in the areas of Enterprise Architecture and Enterprise Systems Usage. We investigate whether these concepts correlate, overlap and explain each other. The two maturity models are applied in a case study. We conclude that although it is possible to fully relate constructs from both kinds of models, having a mature architecture function in a company does not imply a high Enterprise Systems Usage maturity

Developing an inter-enterprise alignment maturity model: research challenges and solutions

Business-IT alignment is pervasive today, as organizations strive to achieve competitive advantage. Like in other areas, e.g., software development, maintenance and IT services, there are maturity models to assess such alignment. Those models, however, do not specifically address the aspects needed for achieving alignment between business and IT in inter-enterprise settings. In this paper, we present the challenges we face in the development of an inter-enterprise alignment maturity model, as well as the current solutions to counter these problems

Validating adequacy and suitability of business-IT alignment criteria in an inter-enterprise maturity model

Aligning requirements of a business with its information technology is currently a major issue in enterprise computing. Existing literature indicates important criteria to judge the level of alignment between business and IT within a single enterprise. However, identifying such criteria in an inter-enterprise setting – or re-thinking the existing ones – is hardly addressed at all. Business-IT alignment in such settings poses new challenges, as in inter-enterprise collaborations, alignment is driven by economic processes instead of centralized decision-making processes. In our research, we develop a maturity model for business-IT alignment in inter-enterprise settings that takes this difference into account. In this paper, we report on a multi-method approach we devised to confront the validation of the business-IT alignment criteria that we included in the maturity model. As independent feedback is critical for our validation, we used a focus group session and a case study as instruments to take the first step in validating the business-IT alignment criteria. We present how we applied our approach, what we learnt, and what the implications were for our model

A CORAVEL radial-velocity monitoring of giant Ba and S stars: spectroscopic orbits and intrinsic variations

This paper provides orbital parameters for 38 barium stars and 10 extrinsic S stars derived from a decade-long CORAVEL monitoring. Lower bounds on the orbital period (generally exceeding 10 y) have been obtained for 10 more systems. Mira S, SC and (Tc-poor) C stars have also been monitored and show intrinsic radial-velocity variations due to atmospheric phenomena. Tentative orbital solutions are proposed for 3 stars (S UMa, X Cnc, BD-08:1900) where the velocity and photometric periods are different. Three stars (RZ Peg, SS Vir and R CMi) exhibit radial-velocity variations synchronous with the light variations. Pseudo-orbital solutions have been derived for those stars. In the case of RZ Peg, a line-doubling phenomenon is observed near maximum light, and probably reflects the shock wave propagating through the photosphere.Comment: Astronomy & Astrophysics Supplements, 20 pages, 8 figures, 8 tables (LaTeX). Also available at: http://obswww.unige.ch/~udry/cine/barium/barium.htm

A unified approach to mapping and clustering of bibliometric networks

In the analysis of bibliometric networks, researchers often use mapping and clustering techniques in a combined fashion. Typically, however, mapping and clustering techniques that are used together rely on very different ideas and assumptions. We propose a unified approach to mapping and clustering of bibliometric networks. We show that the VOS mapping technique and a weighted and parameterized variant of modularity-based clustering can both be derived from the same underlying principle. We illustrate our proposed approach by producing a combined mapping and clustering of the most frequently cited publications that appeared in the field of information science in the period 1999-2008