Handbook on Hypergolic Propellant Discharges and Disposal

The efficiency of all treatment methods formerly or currently used in treating chemical wastes is assessed with emphasis on the disposal of hypergolic propellants. Maximum focus is on the space shuttle propellants MMH and N2O4. Except for hydrogen peroxide oxidizers, all the propellants are nitrogen based and can be potentially reduced to valuable plant nutrients. In theory, all the propellants can be reduced to carbon, hydrogen, nitrogen, and oxygen, except of fuming nitric acid which contains a small amount of fluorine. Appendices cover: (1) a general design criteria for disposal ponds; (2) thermal aspects of reaction in dilute solution; (3) gas bubble growth, detachment, and rise (4) absorption scrubber fundamentals and descriptions; (5) separation of a propellant vapor from a helium stream by permeation; and (6) atmospheric emission limits

Viewpoint consistency in Z and LOTOS: A case study

Specification by viewpoints is advocated as a suitable method of specifying complex systems. Each viewpoint describes the envisaged system from a particular perspective, using concepts and specification languages best suited for that perspective. Inherent in any viewpoint approach is the need to check or manage the consistency of viewpoints and to show that the different viewpoints do not impose contradictory requirements. In previous work we have described a range of techniques for consistency checking, refinement, and translation between viewpoint specifications, in particular for the languages LOTOS and Z. These two languages are advocated in a particular viewpoint model, viz. that of the Open Distributed Processing (ODP) reference model. In this paper we present a case study which demonstrates how all these techniques can be combined in order to show consistency between a viewpoint specified in LOTOS and one specified in Z. Keywords: Viewpoints; Consistency; Z; LOTOS; ODP

Does corporate strategy matter?

A revisionist view that corporate strategy does not matter has gained considerable influence in recent years. This view largely stems from empirical results of early variance decomposition studies that found negligible corporate effects associated with profitability differences between businesses. Our analysis of the variance decomposition literature shows this view to be incorrect. Not only do the studies as a group show that factors at the corporate level of organizations contribute to profitability differences, but also evidence suggests that factors specifically associated with corporate strategy contribute to corporate effects. Corporate strategy in fact does matter. Copyright Ó 2001 John Wiley & Sons, Ltd

Modelling the impact of liner shipping network perturbations on container cargo routing: Southeast Asia to Europe application

Understanding how container routing stands to be impacted by different scenarios of liner shipping network perturbations such as natural disasters or new major infrastructure developments is of key importance for decision-making in the liner shipping industry. The variety of actors and processes within modern supply chains and the complexity of their relationships have previously led to the development of simulation-based models, whose application has been largely compromised by their dependency on extensive and often confidential sets of data. This study proposes the application of optimisation techniques less dependent on complex data sets in order to develop a quantitative framework to assess the impacts of disruptive events on liner shipping networks. We provide a categorization of liner network perturbations, differentiating between systemic and external and formulate a container assignment model that minimises routing costs extending previous implementations to allow feasible solutions when routing capacity is reduced below transport demand. We develop a base case network for the Southeast Asia to Europe liner shipping trade and review of accidents related to port disruptions for two scenarios of seismic and political conflict hazards. Numerical results identify alternative routing paths and costs in the aftermath of port disruptions scenarios and suggest higher vulnerability of intra-regional connectivity

Diagenetic responses to sea-level change: Integration of field, stable isotope, paleosol, paleokarst, fluid inclusion, and cement stratigraphy research to determine history and magnitude of sea-level fluctuation

Abstract Quantifying the history of changes in sea level is an important constraint for modeling sedimentary systems. Integration of diagenetic evidence for subaerial exposure with stratigraphic evidence of paleotopography is important for determining the history of relative changes in sea level. Surfaces of subaerial exposure can develop on marine strata from aggradation of sediment into the subaerial realm, from eustatic sea-level falls, or from uplift. Surfaces of subaerial exposure that result from aggradation alone can be distinguished from those that result from eustatic fall or uplift. If exposure surfaces directly overlie strata of subtidal origin or drape significant paleotopography, aggradation alone must be ruled out. The minimum relative fall in sea level can be quantified by tracing surfaces of subaerial exposure over reconstructed paleotopography or by determining the depth to which vadose-zone diagenesis occurred. Paleosols, paleokarst, trends in stable isotopes, calcite cement stratigraphy, calcite cement fabrics, and fluid inclusions provide diagenetic records that are useful in identifying ancient surfaces of subaerial exposure and determining the position of ancient vadose zones. Paleosols can be identified using the preserved records of desiccation and wetting, subaerial processes, and plant activity. Studies from the Pennsylvanian Holder Formation of New Mexico illustrate that paleosols can be laterally variable in nature and can be used to demonstrate a relative fall in sea level of at least 30 m (100 ft). Paleosol features can develop well below the subaerial surface, so caution must be used in applying this technique. Paleokarst is another useful record of subaerial exposure. Some karstification results in surface landforms, terra rossa paleosols, or vertical voids in which there is a clear relationship to an ancient surface of subaerial exposure. The depth of penetration of these karst features that developed in the vadose zone can be used as a minimum estimate of relative sea-level fall. For karst cavities that cannot be directly associated with a specific surface of subaerial exposure, the age of sediment fills or regional distribution of cavities can provide the most direct link to a particular surface of subaerial exposure. Whole-rock trends of relatively negative δ13C, relatively positive δ18O, and a baseline shift in δ18O can also reflect ancient surfaces of subaerial exposure. Variability of data from the Holder Formation shows that the trends predicted are not the result of stabilization in a homogeneous, relatively negative δ13C zone but the result of patchy cementation and replacement in a solution of heterogeneous carbon isotopic composition. Preservation of the most negative carbon signatures depends on sampling the highest volumes of soil-precipitated phases and those in closest proximity to organic structures in soils. Calcite cements with meniscus or pendant fabrics preserve a record of vadose diagenesis. Vertical pinchout of calcite-cement compositional zones may reflect surfaces of subaerial exposure. The lateral variability of such cements in the Pennsylvanian Holder Formation and the Lansing-Kansas City Groups of Kansas shows that such cements develop best in paleotopographically high settings. Fluid inclusions can provide a record of diagenesis in the vadose zone. Fluid inclusions trapped in the vadose zone are marked by variable ratios of vapor to liquid and all-liquid fluid inclusions. The distribution of such inclusions in Miocene rocks of Spain demonstrate a relative fall in sea level of at least 50-55 m (160-180 ft)

Diagenetic responses to sea-level change: Integration of field, stable isotope, paleosol, paleokarst, fluid inclusion, and cement stratigraphy research to determine history and magnitude of sea-level fluctuation

Abstract Quantifying the history of changes in sea level is an important constraint for modeling sedimentary systems. Integration of diagenetic evidence for subaerial exposure with stratigraphic evidence of paleotopography is important for determining the history of relative changes in sea level. Surfaces of subaerial exposure can develop on marine strata from aggradation of sediment into the subaerial realm, from eustatic sea-level falls, or from uplift. Surfaces of subaerial exposure that result from aggradation alone can be distinguished from those that result from eustatic fall or uplift. If exposure surfaces directly overlie strata of subtidal origin or drape significant paleotopography, aggradation alone must be ruled out. The minimum relative fall in sea level can be quantified by tracing surfaces of subaerial exposure over reconstructed paleotopography or by determining the depth to which vadose-zone diagenesis occurred. Paleosols, paleokarst, trends in stable isotopes, calcite cement stratigraphy, calcite cement fabrics, and fluid inclusions provide diagenetic records that are useful in identifying ancient surfaces of subaerial exposure and determining the position of ancient vadose zones. Paleosols can be identified using the preserved records of desiccation and wetting, subaerial processes, and plant activity. Studies from the Pennsylvanian Holder Formation of New Mexico illustrate that paleosols can be laterally variable in nature and can be used to demonstrate a relative fall in sea level of at least 30 m (100 ft). Paleosol features can develop well below the subaerial surface, so caution must be used in applying this technique. Paleokarst is another useful record of subaerial exposure. Some karstification results in surface landforms, terra rossa paleosols, or vertical voids in which there is a clear relationship to an ancient surface of subaerial exposure. The depth of penetration of these karst features that developed in the vadose zone can be used as a minimum estimate of relative sea-level fall. For karst cavities that cannot be directly associated with a specific surface of subaerial exposure, the age of sediment fills or regional distribution of cavities can provide the most direct link to a particular surface of subaerial exposure. Whole-rock trends of relatively negative δ13C, relatively positive δ18O, and a baseline shift in δ18O can also reflect ancient surfaces of subaerial exposure. Variability of data from the Holder Formation shows that the trends predicted are not the result of stabilization in a homogeneous, relatively negative δ13C zone but the result of patchy cementation and replacement in a solution of heterogeneous carbon isotopic composition. Preservation of the most negative carbon signatures depends on sampling the highest volumes of soil-precipitated phases and those in closest proximity to organic structures in soils. Calcite cements with meniscus or pendant fabrics preserve a record of vadose diagenesis. Vertical pinchout of calcite-cement compositional zones may reflect surfaces of subaerial exposure. The lateral variability of such cements in the Pennsylvanian Holder Formation and the Lansing-Kansas City Groups of Kansas shows that such cements develop best in paleotopographically high settings. Fluid inclusions can provide a record of diagenesis in the vadose zone. Fluid inclusions trapped in the vadose zone are marked by variable ratios of vapor to liquid and all-liquid fluid inclusions. The distribution of such inclusions in Miocene rocks of Spain demonstrate a relative fall in sea level of at least 50-55 m (160-180 ft)

Recommendations for Safe Separation Distances from the Kennedy Space Center (KSC) Vehicle Assembly Building (VAB) Using a Heat-Flux-Based Analytical Approach (Abridged)

The NASA Engineering and Safety Center (NESC) was requested to provide computational modeling to support the establishment of a safe separation distance surrounding the Kennedy Space Center (KSC) Vehicle Assembly Building (VAB). The two major objectives of the study were 1) establish a methodology based on thermal flux to determine safe separation distances from the Kennedy Space Center's (KSC's) Vehicle Assembly Building (VAB) with large numbers of solid propellant boosters containing hazard division 1.3 classification propellants, in case of inadvertent ignition; and 2) apply this methodology to the consideration of housing eight 5-segment solid propellant boosters in the VAB. The results of the study are contained in this report