ALBERT

Beschreibung: The development of this paper was inspired by the increase in the number of different eco-label like quality assurance schemes established in the European Union in the past few years. These schemes are flooding the market and the researchers raise the question, is there enough credibility in these schemes? This piece of research is based on 58 eco-labeling like food schemes and dissects them into the building blocks of the different factors that makes a scheme credible and analyses the structure of these blocks as well as a literature survey on the perceptions of both the consumers and producers to these schemes. The sort of credibility structure that the building blocks of the schemes (ownership, stakeholder dialogue, traceability, transparency, etc.) have created was discussed and it was questioned if they meet the expectations of the consumers. The main findings of the research indicate that although small groups of consumers may be satisfied with a number of the different schemes, the majority of them fall short of providing a credible quality assurance scheme. Improvements were suggested such as involving a more diverse range of stakeholders and expanding the responsibility of processors and retailers. An alternative to the current form of labeling is also discussed.

Beschreibung: Selbstverständlich schafft Windenergie Arbeitsplätze. Betrachtet man die Studie des Bremer Energie-Institutes näher, so zeigen sich einige methodische Schwächen und wenig plausible Annahmen. Von einer "nüchternen Analyse" kann deswegen nicht gesprochen werden.

Beschreibung: New energy efficiency policies have been introduced around the world. Historically, most energy models were reasonably equipped to assess the impact of classical policies, such as a subsidy or change in taxation. However, these tools are often insufficient to assess the impact of alternative policy instruments. We evaluate the so-called engineering economic models used to assess future industrial energy use. Engineering economic models include the level of detail commonly needed to model the new types of policies considered. We explore approaches to improve the realism and policy relevance of engineering economic modeling frameworks. We also explore solutions to strengthen the policy usefulness of engineering economic analysis that can be built from a framework of multidisciplinary cooperation. The review discusses the main modeling approaches currently used and evaluates the weaknesses in current models. We focus on the needs to further improve the models. We identify research priorities for the modeling framework, technology representation in models, policy evaluation, and modeling of decision-making behavior.

Beschreibung: This book presents important new research on applied eco-efficiency concepts throughout Europe. The aim of eco-efficiency is to achieve market-based measures of environmental protection, in order to enhance the prospects for sustainable development and achieve positive economic and ecological benefits. The distinguished authors discuss a number of themes surrounding eco-efficiency including the necessary conditions for technological dissemination and ecological modernization, and the role of government in enabling businesses and society to participate actively in this process. In particular, they highlight the application of existing European-based policies concerning material flows and energy. The authors also investigate some new concepts of sustainable development and provide a useful introduction to material flows analysis. In further chapters they study the emerging regulatory policies for eco-efficiency, and examine the issues of sustainable business and consumption strategies.

Beschreibung: Transnational corporations' (TNCs) economic operations cover numerous countries and can be diverted between several continents. These units have reached a level of significance, having not only economic, but also social and environmental implications. This justifies that they shall be treated separately as a social phenomenon, when considering strategies for the development towards sustainability. This paper presents the concept of Responsible Corporate Governance (RCG), as a strategy to "govern" TNCs. RCG is suggested as a stakeholder based policy instrument, which aims at allocating responsibilities to societal actors aiming at corporate accountability. RCG recognises that the process of societal change is strongly based on what can be called as bottom up-processes. Learning processes take place through the interaction of the different societal members, which eventually leads to macro changes. Therefore, governing TNCs towards sustainability improvements is considered to be a collective process including all stakeholders. Firstly, the paper places the concept of RCG in the ongoing debate of political modernization based on the fact that society develops overtime and the political system must correspondingly modernize. In this context, political overload developed as a consequence of increased resource interdependencies is explained and as a resolution, network approach is discussed. Secondly, demands on the orientation of the TNCs in terms of accountability and innovative action are brought forward. Here, the paper also lists down corporate elements (stakeholder empowered corporate governance, management and performance evaluation systems, transparency enhancement and accountability verification), which need to be in place to attain an accountable orientation in the society. Following, using an analytical framework, the orientation and capabilities of each societal actor (environmental non-governmental organisations, financial institutions, intergovernmental organisations) to affect improvements in the corporate responsibility elements are investigated and recommendations for their effective orientation are listed.

Beschreibung: In jedem Unternehmen gibt es Potenziale, um die eigene wirtschaftliche Position zu verbessern und sich gegen zukünftige Krisen abzusichern. Technische, organisatorische oder soziale Innovationen sind der Schlüssel zur dauerhaften Sicherung ihrer Wettbewerbsposition. Diese Broschüre soll kleinen und mittelständischen Unternehmen helfen, Bereiche zu finden, in denen Innovationspotenziale vorhanden sind. Anhand erster Maßnahmen, so genannten Innovationsschritten, werden Ansatzpunkte entwickelt, wie mit möglichst geringem (Zeit- und Kosten-) Aufwand gezielt die eigene Wettbewerbsposition gestärkt werden kann. Sie wendet sich an Unternehmensleitung oder Umweltmanagementbeauftragte und gibt ihnen einen ersten Ein- bzw. Überblick und konkrete Vorschläge, wie sie die Zukunftsfähigkeit ihres Unternehmens verbessern können. Damit hat diese Broschüre konkrete Hilfestellungen für den Praktiker im Unternehmen im Fokus. Mögliche Ansatzpunkte, geeignete Wege sowie passende Instrumente werden für einzelne Bereiche aufgezeigt und erläutert.

Beschreibung: Diese Studie untersucht die Medien, die sanktionsbereiten Konsumenten Informationen über die Verantwortung von Unternehmen als Orientierungshilfe für den Einkauf anbieten. Im Brennpunkt stehen dabei sozial-ökologisch orientierte Einkaufsführer, die vergleichende Unternehmensbewertungen mit dem Ziel anbieten, Verbrauchern eine Informationsgrundlage für positive und negative Sanktionen zu geben, um einen positiven Profilierungswettbewerb in Gang zu setzen. Dabei gilt das besondere Interesse dem Übergang vom Printmedium zum Internetauftritt. Ziel der Untersuchung ist eine Analyse fördernder und hemmender Faktoren für den Erfolg, die für die Praxis nützlich sein soll.

Beschreibung: Infrastrukturen und Infrastrukturpolitik nehmen einen entscheidenden Einfluss auf die Nachhaltigkeit eines Landes. Betrachtet man die (Fehl-) Entwicklungen des letzten Jahrhunderts in den Industrieländern, so ist zu erkennen, dass die derzeitigen Energie-, Verkehrs- und Wasserinfrastrukturen selbst den Anforderungen einer ökonomischen Nachhaltigkeit nicht gewachsen sind. Ihre sozialen und ökologischen Folgen wurden zudem meist vernachlässigt und spielten bei Entscheidungsprozessen nur eine nachrangige Rolle. Große Herausforderungen liegen vor den Industrieländern, wenn sie nachhaltige Infrastrukturen schaffen wollen - und gar eine Leitbildfunktion für Schwellen- und Entwicklungsländer im 21. Jahrhundert einnehmen möchten. Denn durch die Intensivierung der weltweiten Austauschbeziehungen werden die nicht-nachhaltigen Infrastrukturkonzepte und -politiken der Industrieländer zunehmend auf Entwicklungsländer übertragen. Eine Umorientierung muss deshalb auch im Süden erfolgen. Dieses Wuppertal Paper bietet am Beispiel der drei wichtigen Sektoren Energie, Verkehr und Wasser Ansätze einer nachhaltigen Infrastrukturpolitik. Dazu gehören sowohl globale Lösungsstrategien als auch spezifische Instrumente für die Länder des Nordens oder des Südens. Im Rahmen von sektoralen Fallstudien werden die Schwellenländer Brasilien (Energie), China (Verkehr) und Indonesien (Wasser) betrachtet. Zudem werden Strategien und Erfolgsfaktoren für eine an Nachhaltigkeitszielen orientierte Transferpolitik skizziert, wobei auch auf die Bedeutung von Bildung und die Rolle internationaler Finanzinstitutionen (am Beispiel der Weltbank) eingegangen wird. Um die großen Herausforderungen einer globalen nachhaltigen Entwicklung zu bewältigen, schlägt dieses Papier vor, mehrere Strategien parallel zu verfolgen. Im Norden sind die gegenwärtigen ressourcenintensiven, nicht-nachhaltigen Infrastrukturen zu überdenken. Im Süden sollte der Pfad der "nachholenden Entwicklung" verlassen und im Sinne eines ökologischen "leapfrogging" der Sprung in post-fossile Infrastrukturen angestrebt werden, um nicht die Fehler des Nordens zu wiederholen. Länderspezifische Lösungen sollten dabei an die Stelle eines Imports nicht-angepasster Infrastrukturen treten. Der Transfer und Austausch von Ideen, Konzepten und Lösungen kann dabei einen wesentlichen Beitrag leisten, wobei eine unidirektionale Entwicklungszusammenarbeit von Nord nach Süd nicht ausreicht. Auch Süd-Süd oder Süd-Nord-Kooperationen eröffnen wichtige Chancen. Zudem ist der industrieländerzentrische, Technologie orientierte Ansatz einer einfachen Optimierung der supply-side zu verlassen zugunsten einer Handlungsstrategie, die ein nachhaltiges demand-side-management integriert.

Beschreibung: An increasing number of publications about theoretical approaches and new findings illustrate the relevance of the topic environmental risk assessment. The actual discussion about high oil prices is not incorporated under this headline; but it should be, as natural resource scarcity is a crucial economic factor. In practical experience, more and more banks, insurance companies as well as investors realize that there are certain areas with a high correlation between sustainable development and corporate success, corporate risk exposure and corporate performance. In this discussion one of the most obvious topics are risks related to climate change. According to the findings of surveys evaluated in this paper climate change starts to affect economic development and companies' performance in various ways. Over the next decade, economic losses due to climate change are estimated by US$ 150 billion per year. As result world's business leaders have described climate change as the biggest challenge of the 21st century. Hence, the incorporation of climate change as a risk factor is essential, but risks related to climate change feature a severe issue of complex structure and uncertainty; traditional risk assessment tools appear in the light of not being able to either reflect the multifaceted system nor provide sufficient outcomes. Environmental risk assessments in general so far have mainly emphasized - if at all - on actual and possible impacts of the release of materials or emissions (external effects). But an overall sustainable risk assessment has also to take into account the risks related to the inflow of materials. The main reason for neglecting the inflow risks from an environmental perspective can be seen in the fact that these risks seem to be less tangible and more uncertain. Nevertheless, in a world where economic development and the use of natural resources is not uncoupled yet, a steadily increasing economic power will result in a continually rising extraction of resources. As all resources are limited, the risk of scarcity will rise; and the example of water illustrates that it already exists. Indeed, scarcity is not tangible for all kind of resources from a present point of view. Hence, a specified analysis is needed considering different market and supply conditions. A comprehensive analysis of environmental risks needs to encompass risks affecting the output as well as the input side of a value chain. This paper enlarges the discussion on environmental risk assessments upon the input dimension using the example of carbon risks. Firstly, carbon risks are defined as risks related to climate change at the corporate level with a focus on the input as well as the output dimension. Secondly, an analysis of the current discussion on the topic of carbon risk evaluates the status quo of scientific work in this field. Thirdly, in terms of developing a practically oriented tool, the Value-at-Risk approach and it's application to measure input oriented carbon risks are scrutinized. The results discuss how future volatility and market prices can be utilized to describe the uncertainty resulting from markets acknowledging and pricing oil scarcity as a risk factor. Finally recommendations with a focus on strategic management decisions and financial performance analysis are given and further research opportunities are drawn. The conclusion is; once markets have acknowledged the depletion mid-point as a measure of oil scarcity, natural scarcity will result in a significant higher Value-at-Risk. The Value-at-Risk of one barrel of crude oil could then be as high as US$ 15.5 in the short term and even US$ 17.2 in the long term. The scope of this paper is neither intended to predict one likely development nor to demonstrate how this tool can actually work in terms of forecasting single companies' performance. But in order to point the way ahead, this paper provides scenarios for potential future developments and sets a frame for risk assessments due to oil scarcity.

Beschreibung: Der neoliberalen Globalisierung liegen Rationalitätsmuster zugrunde, die weder neu, noch liberal sind. Dies gilt für herrschaftliches Denken über Natur (als Ressource) ebenso wie für den sich verstärkenden Zugriff auf Naturgüter und die Ausblendung reproduktiver Elemente aus der Debatte über Umgangsweisen mit Natur. Mit Blick auf Landnutzung und Livelihood wird lokale Vielfalt durch Globalisierung zerstört. Der Absolutheitsanspruch eines weltweit entfesselten Marktes mit seinem grenzenlos freien Wettbewerb untergräbt das Recht auf- und die Möglichkeit zu je eigener, der Lokalität gemäßer Naturnutzung. Wenn immer mehr Menschen ihrer an die jeweiligen Lokalitäten gebundenen Produktionsmittel beraubt werden, können sich Gesellschaften nicht von innen heraus nachhaltig entwickeln.

Beschreibung: This paper examines the connection between globalisation, with its growth in world trade links, and certain ecological effects especially concerning "North-South" relations. Although world trade in the mid-nineties was significantly uncoupled from growth trends in the world economy, so that since then it has increased nearly three times faster than the global GDP, certain indicators of energy use and CO2 emissions have not developed proportionately to world trade; globalisation evidently does not lead to a situation where pressures on the environment are increasing to the same extent worldwide. This de-linking may, however, result in the kind of shifts that we examine here with reference to the material trade flows of the European Union. It will be shown that, in the course of globalisation, the countries of the EU have increasingly shifted environmental burdens on to the countries of the South, especially in the form of ecological rucksacks of imported raw materials, while at the same time reducing the pressure on their own domestic environment by extracting fewer material resources. Furthermore, goods whose production places intensive pressure on the environment (industrial emissions into the atmosphere and water, heavy metal emissions, etc.) have been increasingly imported from newly industrializing or developing countries. The greater covering of material requirements from foreign resources has served not so much the EU's internal consumption as its own production of export goods; this shows that the EU has an increasing share in the resource requirement of other economies. The paper concludes that it is absolutely necessary to consider the international dimension in any strategy for more productive use of resources in industrial countries. In the long term, the EU's resource use should also be reduced in absolute terms. This will also be necessary in order to reduce the pressure on the environment due to imports and exports.

Beschreibung: Die "Ökonomie der Aufmerksamkeit" hat zur Herausbildung spezifischer Märkte für Kommunikations-, Media- und Marketingdienstleistungen geführt. Ein dynamisch wachsender Markt ist der Markt für Live-Kommunikation, der in dieser Arbeit vertiefend untersucht wird. Hierbei werden drei Fragen diskutiert: 1. Was sind die treibenden Faktoren und Trends der Live-Kommunikation? 2. Nach welchen Maßstäben werden Events, insbesondere im Bereich der Unternehmenskommunikation, beauftragt? 3. Welche Chancen bestehen in diesem Markt, Events für Nachhaltigkeit als Marktsegment zu etablieren und zu stärken? Bei der Beantwortung dieser Fragen werden aktuelle Trendstudien ausgewertet, aber auch auf Untersuchungen und Fallstudien zurückgegriffen, die im Rahmen des Projektes "Eventkultur und Nachhaltigkeit" durchgeführt wurden. Die Autoren kommen zu dem Ergebnis, dass die Markt- und Trendstudien eine wichtige Orientierungsfunktion für die Eventwirtschaft haben. Aus der Perspektive eines kulturökonomischen Ansatzes wird kritisiert, dass diese Orientierungsfunktion auf Marken und Marketingtechniken beschränkt ist und der Einfluss der gesellschaftlichen Wertbildung auf die Marketingpraxis ausgeblendet bleibt. Nachhaltige Ziele und Inhalte werden mit den Mitteln des Event-Marketings erst vereinzelt vermittelt. Aus diesen ersten Aktivitäten kann aber ein neuer Kommunikationsmarkt entstehen, wenn seitens der Nachhaltigkeitsakteure eine Verständigung über Kriterien und Anforderungen an dieses Marketinginstrument erfolgt sowie der Symbolebene in der Nachhaltigkeitskommunikation eine stärkere Beachtung geschenkt wird. Informationsbündelung und symbolisches Management sind wichtige Ansatzpunkte, um in der Marketingpraxis von Unternehmen, öffentlichen Einrichtungen, Verbänden, NGOs und von Kommunikations- und Eventagenturen eine nachhaltige Eventkultur zu verankern.

Beschreibung: We observe two near-limb solar filament eruptions, one of 2000 February 26 and the other of 2002 January 4. For both we use 195 A Fe XII images from the Extreme-Ultraviolet Imaging Telescope (EIT) and magnetograms from the Michelson Doppler Imager (MDI), both of which are on the Solar and Heliospheric Observatory (SOHO). For the earlier event we also use soft X-ray telescope (SXT), hard X-ray telescope (HXT), and Bragg Crystal Spectrometer (BCS) data from the Yohkoh satellite, and hard X-ray data from the BATSE experiment on the Compton Gamma Ra.v Observatory (CGRO). Both events occur in quadrupolar magnetic regions, and both have coronal features that we infer belong to the same magnetic cavity structures as the filaments. In both cases, the cavity and filament first rise slowly at approx.10 km/s prior to eruption and then accelerate to approx.100 km/s during the eruption, although the slow-rise movement for the higher altitude cavity elements is clearer in the later event. We estimate that both filaments and both cavities contain masses of approx.10(exp 14)-10(exp 15) and approx.10(exp 15)-10(exp 16) g, respectively. We consider whether two specific magnetic reconnection-based models for eruption onset, the "tether cutting" and the "breakout" models, are consistent with our observations. In the earlier event, soft X-rays from SXT show an intensity increase during the 12 minute interval over which fast eruption begins, which is consistent with tether- cutting-model predictions. Substantial hard X-rays, however, do not occur until after fast eruption is underway, and so this is a constraint the tether-cutting model must satisfy. During the same 12 minute interval over which fast eruption begins, there are brightenings and topological changes in the corona indicative of high-altitude reconnection early in the eruption, and this is consistent with breakout predictions. In both eruptions, the state of the overlying loops at the time of onset of the fast-rise phase of the corresponding filament can be compared with expectations from the breakout model, thereby setting constraints that the breakout model must meet. Our findings are consistent with both runaway tether-cutting-type reconnection and fast breakout-type reconnection, occurring early in the fast phase of the February eruption and with both types of reconnection being important in unleashing the explosion, but we are not able to say which, if either, type of reconnection actually triggered the fast phase. In any case, we have found specific constraints that either model, or any other model, must satisfy if correct.

Beschreibung: This custom bibliography from the NASA Scientific and Technical Information Program lists a sampling of records found in the NASA Aeronautics and Space Database. The scope of this topic includes primarily nuclear thermal and nuclear electric technologies, to enable spacecraft and instrument operation and communications, particularly in the outer solar system, where sunlight can no longer be exploited by solar panels. This area of focus is one of the enabling technologies as defined by NASA s Report of the President s Commission on Implementation of United States Space Exploration Policy, published in June 2004.

Beschreibung: The Analysis and Management branch of the Power and Propulsion Office at NASA Glenn Research Center is responsible for performing complex analyses of the space power and In-Space propulsion products developed by GRC. This work quantifies the benefits of the advanced technologies to support on-going advocacy efforts. The Power and Propulsion Office is committed to understanding how the advancement in space technologies could benefit future NASA missions. They support many diverse projects and missions throughout NASA as well as industry and academia. The area of work that we are concentrating on is space technology investment strategies. Our goal is to develop a Monte-Carlo based tool to investigate technology impacts in space electric power systems. The framework is being developed at this stage, which will be used to set up a computer simulation of a space electric power system (EPS). The outcome is expected to be a probabilistic assessment of critical technologies and potential development issues. We are developing methods for integrating existing spreadsheet-based tools into the simulation tool. Also, work is being done on defining interface protocols to enable rapid integration of future tools. Monte Carlo-based simulation programs for statistical modeling of the EPS Model. I decided to learn and evaluate Palisade's @Risk and Risk Optimizer software, and utilize it's capabilities for the Electric Power System (EPS) model. I also looked at similar software packages (JMP, SPSS, Crystal Ball, VenSim, Analytica) available from other suppliers and evaluated them. The second task was to develop the framework for the tool, in which we had to define technology characteristics using weighing factors and probability distributions. Also we had to define the simulation space and add hard and soft constraints to the model. The third task is to incorporate (preliminary) cost factors into the model. A final task is developing a cross-platform solution of this framework.

Beschreibung: Recent studies have shown that strong correlations are observed between the low frequencies (1-10 Hz) of quasiperiodic oscillations (QPOs) and the spectral power law index of several Black Hole (BH) candidate sources, in low hard states, steep power-law (soft) states and in transition between these states. The observations indicate that the X-ray spectrum of such state (phases) show the presence of a power-law component and are sometimes related to simultaneous radio emission indicated the probable presence of a jet. Strong QPOs (less than 20% rms) are present in the power density spectrum in the spectral range where the power-law component is dominant ( i.e. 60-90% ). This evidence contradicts the dominant long standing interpretation of QPOs as a signature of the thermal accretion disk. We present the data from the literature and our own data to illustrate the dominance of power-law index-QPO frequency correlations. We provide a model, that identifies and explains the origin of the QPOs and how they are imprinted on the properties of power-law flux component. We argue the existence of a bounded compact coronal region which is a natural consequence of the adjustment of Keplerian disk flow to the innermost sub-Keplerian boundary conditions near the central object and that ultimately leads to the formation of a transition layer (TL) between the adjustment radius and the innermost boundary. The model predicts two phases or states dictated by the photon upscattering produced in the TL: (1) hard state, in which the TL is optically thin and very hot (kT approx. greater than 50 keV) producing photon upscattering via thermal Componization; the photon spectrum index Gamma appprox.1.5 for this state is dictated by gravitational energy release and Compton cooling in an optically thin shock near the adjustment radius; (2) a soft state which is optically thick and relatively cold (approx. less than 5 keV); the index for this state, Gamma approx. 2.8 is determined by soft-photon upscattering and photon trapping in converging flow into BH. In the TL model for corona the QPO frequency vnu(sub high) is related to the gravitational (close to Keplerian) frequency nu(sub K) at the outer (adjustment) radius and nu(sub low) is related to the TL s normal mode (magnetoacoustic) oscillation frequency nu(sub MA). The observed correlations between index and low and high QPO frequencies are readily explained in terms of this model. We also suggest a new method for evaluation of the BH mass using the index-frequency correlation.

Beschreibung: Future space nuclear power systems will require radiator technology to dissipate excess heat created by a nuclear reactor. Large radiator fins with circulating coolant are in development for this purpose and an investigation of how to make them most efficient is underway. Maximizing the surface area while minimizing the mass of such radiator fins is critical for obtaining the highest efficiency in dissipating heat. Processes to develop surface roughness are under investigation to maximize the effective surface area of a radiator fin. Surface roughness is created through several methods including oxidation and texturing. The effects of atomic oxygen impingement on carbon-carbon surfaces are currently being investigated for texturing a radiator surface. Early studies of atomic oxygen impingement in low Earth orbit indicate significant texturing due to ram atomic oxygen. The surface morphology of the affected surfaces shows many microscopic cones and valleys which have been experimentally shown to increase radiation emittance. Further study of this morphology proceeded in the Long Duration Exposure Facility (LDEF). Atomic oxygen experiments on the LDEF successfully duplicated the results obtained from materials in spaceflight by subjecting samples to 4.5 eV atomic oxygen from a fixed ram angle. These experiments replicated the conical valley morphology that was seen on samples subjected to low Earth orbit.

Beschreibung: The amount of chemical propellant required to accomplish certain NASA s planned missions is too immense such that the spacecraft will never be able to lift off. To address this concern, electric propulsion systems have been chosen as the primary propulsion systems for some NASA s future missions, including DAWN and JIMO. Research Center is a proposed engine for the JIMO mission, which will visit three of Jupiter s icy moons. Optimizing thruster s lifetime and efficiency are the two foci for the engineers on the Ion Team. One qualitative study of the engine s efficiency can be accomplished by examining the ratio of doubly- to singly-charged ions in the ion beam of the engine. Thrust efficiency directly relates to this ratio. The bulk of this project is to redesign and build an EXB probe to obtain this qualitative measurement. Once this probe is built, it can be installed in a vacuum tank (VF 65 in building 301) behind the exit plane of the HiPEP engine to collect data. Current chemical propulsion technology cannot address the needs of some deep space The HiPEP (High Power Electric Propulsion) engine being developed at NASA Glenn Research Center is a proposed engine for the JIMO mission, which will visit three Jupiter's icy moons.

Beschreibung: This custom bibliography from the NASA Scientific and Technical Information Program lists a sampling of records found in the NASA Aeronautics and Space Database. The scope of this topic includes technologies for the crew exploration vehicle. This area of focus is one of the enabling technologies as defined by NASA s Report of the President s Commission on Implementation of United States Space Exploration Policy, published in June 2004.

Beschreibung: Power spectrum estimation and evaluation of associated errors in the presence of incomplete sky coverage; nonhomogeneous, correlated instrumental noise; and foreground emission are problems of central importance for the extraction of cosmological information from the cosmic microwave background (CMB).

Beschreibung: Observations show that solar activity is distributed nonaxisymmetrically, concentrating at preferred longitudes.

Beschreibung: This viewgraph presentation reviews the design and development of the Disturbance Reduction System (DRS). The colloidal microthrusters will allow for precise, quiet spacecraft position and attitude control. The DRS will be attached to ESAS's SMART-2 spacecraft.

Beschreibung: The Palomar Integral Field Spectrograph was used to probe a variety of environments in nine nearby galaxies that span a range of morphological types, luminosities, metallicities, and infrared-to-blue ratios.

Beschreibung: We observe two near-limb solar filament eruptions, one of 2000 February 26 and the other of 2002 January 4. For both we use 195 Angstroms, Fe XII images from the Extreme-Ultraviolet Imaging Telescope (EIT) and magnetograms from the Michelson Doppler Imager (MDI), both of which are on the Solar arid Heliospheric Observatory (SOHO). For the earlier event we also use soft X-ray telescope (SXT), hard X-ray telescope (HXT), and Bragg Crystal Spectrometer (BCS) data from the Yohkoh satellite, and hard X-ray data from the BATSE experiment on the Compton Gamma Ray Observation, (CGRO). Both events occur in quadrupolar magnetic regions, and both have coronal features that we infer belong to the same magnetic cavity structures as the filaments. In both cases, the cavity and filament first rise slowly at approximately 10 kilometers per second prior to eruption and then accelerate to approximately 100 kilometers per second during the eruption, although the slow-rise movement for the higher altitude cavity elements is clearer in the later event. We estimate that both filaments and both cavities contain masses of approximately 10(exp 14)-10(exp 15) and approximately 10(exp 15)-10(exp 16)g, respectively. We consider whether two specific magnetic reconnection-based models for eruption onset, the tether cutting and the breakout models, are consistent with our observations. In the earlier event, soft X-rays from SXT show an intensity increase during the 12 minute interval over which fast eruption begins, which is consistent with tether-cutting-model predictions. Substantial hard X-rays, however, do not occur until after fast eruption is underway, and so this is a constraint the tether-cutting model must satisfy. During the same 12 minute interval over which fast eruption begins, there are brightenings and topological changes in the corona indicative of high-altitude reconnection early in the eruption, and this is consistent with breakout predictions. In both eruptions, the state of the overlying loops at the time of onset of the fast-rise phase of the corresponding filament can be compared with expectations from the breakout model, thereby setting constraints that the breakout model must meet. Our findings are consistent with both runaway tether-cutting-type reconnection and fast breakout-type reconnection, occurring early in the fast phase of the February eruption and with both types of reconnection being important in unleashing the explosion, but we are not able to say which, if either, type of reconnection actually triggered the fast phase. In any case, we have found specific constraints that either model, or any other model, must satisfy if correct.

Beschreibung: The ion thruster is one of the most promising solar electric propulsion (SEP) technologies to support future Outer Planet missions (place provided link below here) for NASA's Office of Space Science. Typically, ion thrusters are used in high Isp- low thrust applications that require long lifetimes, as well as, higher efficiency over state-of-the-art chemical propulsion systems.Today, the standard for ion thrusters is the SEP Technology Application Readiness (NSTAR) thruster. Jet Propulsion Laboratory's (JPL's) extended life test (ELT) of the DS 1 flight spare NSTAR thruster began in October 1998. This test successfully demonstrated lifetime of the NSTAR flight spare thruster, which will provide a solid basis for selection of ion thrusters for future Code S missions. The NSTAR ELT was concluded on June 30,2003 after 30,352 hours. The purpose of the Next Generation Ion (NGI) activities is to advance Ion propulsion system technologies through the development of NASA's Evolutionary Xenon Thruster (NEXT). The goal of NEXT is to more than double the power capability and lifetime throughput (the total amount of propellant which can be processed) while increasing the Isp by 30% and the thrust by 120%.

Beschreibung: A back-and-forth orbit integration technique, developed for our previous investigation of the splitting of the parent of the sungrazers C/1882 R1 and C/1965 S1, is now applied in an effort to understand the history and orbital evolution of the Kreutz sungrazer system, starting with the birth of two subgroups, which show prominently among the bright members and whose inception dates back to the progenitor's breakup into two superfragments. The integration technique is used to reproduce the motion of comet C/1843 D1 - the second brightest sungrazer known and presumably the most massive surviving piece of superfragment I - from the motion of C/1882 R1 - the brightest sungrazer on record and arguably the most massive surviving piece of superfragment II. Running the orbit of C/1882 R1 back to A.D. 326, the progenitor comet is found to have split at a heliocentric distance of 50 AU and nearly 30 yr before perihelion. The superfragments acquired separation velocities of similar to8 m s(-1) in opposite directions. Using the same technique, we show next that (1) the motions of two additional sungrazers, C/1880 C1 and C/1887 B1, are matched extremely well if these objects shared a common parent with C/1843 D1, and (2) C/1963 R1 (Pereyra), the second brightest subgroup I member on record, is more closely related to subgroup II objects (such as C/1882 R1 and C/1965 S1) than to C/1843 D1. This finding raises serious doubts about the major role of the subgroups in the system's orbital history and offers an incentive for considering an alternative dynamical scenario. The fragmentation models for C/1963 R1 and two additional bright sungrazers, C/1945 X1 and C/1970 K1, suggest that (1) these comets may have been the most massive pieces of the fragment populations formed from their respective disintegrating parents, and (2) the course of evolution of the Kreutz system at the upper end of the mass spectrum may be better ascertained from the distribution of the sungrazers' arrival times than from the sources of subgroups. If so, the fragment hierarchy should be determined primarily by the cascading nature of the fragmentation process, which was recently shown by Sekanina to control the evolution of minor fragments as well. The sungrazer system's estimated age is in any case very short, less than 1700 yr.

Beschreibung: We report detections of X-rays from HH 80 and HH 81 with the ACIS instrument on the Chandra X-Ray Observatory.

Beschreibung: The processes and mechanisms involved in the rotation and alignment of interstellar dust grains have been of great interest in astrophysics ever since the surprising discovery of the polarization of starlight more than half a century ago. Numerous theories, detailed mathematical models, and numerical studies of grain rotation and alignment with respect to the Galactic magnetic field have been presented in the literature. In particular, the subject of grain rotation and alignment by radiative torques has been shown to be of particular interest in recent years. However, despite many investigations, a satisfactory theoretical understanding of the processes involved in subject, we have carried out some unique experiments to illuminate the processes involved in the rotation of dust grains in the interstellar medium. In this paper we present the results of some preliminary laboratory experiments on the rotation of individual micron/submicron-sized, nonspherical dust grains levitated in an electrodynamic balance evacuated to pressures of approximately 10(exp -3) to 10(exp -5) torr. The particles are illuminated by laser light at 5320 A, and the grain rotation rates are obtained by analyzing the low-frequency (approximately 0 - 100 kHz) signal of the scattered light detected by a photodiode detector. The rotation rates are compared with simple theoretical models to retrieve some basic rotational parameters. The results are examined in light of the current theories of alignment.

Beschreibung: The objective of this study is to conduct a unified computational analysis for computing design parameters such as axial thrust, convective and radiative wall heat fluxes for regeneratively cooled liquid rocket engine nozzles, so as to develop a computational strategy for computing those parameters through parametric investigations. The computational methodology is based on a multidimensional, finite-volume, turbulent, chemically reacting, radiating, unstructured-grid, and pressure-based formulation, with grid refinement capabilities. Systematic parametric studies on effects of wall boundary conditions, combustion chemistry, radiation coupling, computational cell shape, and grid refinement were performed and assessed. Under the computational framework of this study, it is found that the computed axial thrust performance, flow features, and wall heat fluxes compared well with those of available data and calculations, using a strategy of structured-grid dominated mesh, finite-rate chemistry, and cooled wall boundary condition.

Beschreibung: Recent studies have shown that strong correlations are observed between the low frequencies (1-10 Hz) of quasi-periodic oscillations (QPOs) and the spectral power law index of several black hole (BH) candidate sources, in low (hard) states, steep power law (soft) states, and transitions between these states. The observations indicate that the X-ray spectra of such state (phases) show the presence of a power-law component and are sometimes related to simultaneous radio emission, indicating the probable presence of a jet. Strong QPOs (〉20% rms) are present in the power density spectrum in the spectral range where the power-law component is dominant (i.e., 60%90%). This evidence contradicts the dominant, long-standing interpretation of QPOs as a signature of the thermal accretion disk. We present the data from the literature and our own data to illustrate the dominance of power-law index-QPO frequency correlations. We provide a model that identifies and explains the origin of the QPOs and how they are imprinted on the properties of the power-law flux component. We argue for the existence of a bounded compact coronal region that is a natural consequence of the adjustment of the Keplerian disk flow to the innermost sub-Keplerian boundary conditions near the central object and that ultimately leads to the formation of a transition layer (TL) between the adjustment radius and the innermost boundary. The model predicts two phases or states dictated by the photon upscattering produced in the TL: (1) a hard state, in which the TL is optically thin and very hot (kT approximately greater than 50 keV), producing photon upscattering via thermal Comptonization (the photon spectrum index Gamma approximates 1.7 for this state is dictated by gravitational energy release and Compton cooling in an optically thin shock near the adjustment radius), and (2) a soft state that is optically thick and relatively cold (kT approximately less than 5 keV the index for this state, Gamma approximates 2.8, is determined by soft-photon upscattering and photon trapping in a converging flow into the BH). In the TL model for the corona, the QPO frequency V(sub high) is related to the gravitational (close to Keplerian) frequency V(sub K) at the outer (adjustment) radius and v(sub low) is related to the TL's normal mode (magnetoacoustic) oscillation frequency v(sub MA) . The observed correlations between index and low and high QPO frequencies are readily explained in terms of this model. We also suggest a new method for evaluation of the BH mass using the index-frequency correlation.

Beschreibung: The Constellation-X mission will address the questions: "What happens to matter close to a black hole?" and "What is Dark Energy?" These questions are central to the NASA Beyond Einstein Program, where Constellation-X plays a central role. The mission will address these questions by using high throughput X-ray spectroscopy to observe the effects of strong gravity close to the event horizon of black holes, and to observe the formation and evolution of clusters of galaxies in order to precisely determine Cosmological parameters. To achieve these primary science goals requires a factor of 25-100 increase in sensitivity for high resolution spectroscopy. The mission will also perform routine high- resolution X-ray spectroscopy of faint and extended X-ray source populations. This will provide diagnostic information such as density, elemental abundances, velocity, and ionization state for a wide range of astrophysical problems. This has enormous potential for the discovery of new unexpected phenomena. The Constellation-X mission is a high priority in the National Academy of Sciences McKee-Taylor Astronomy and Astrophysics Survey of new Astrophysics Facilities for the first decade of the 21st century.

Beschreibung: Previous observations of the luminous Seyfert 1 galaxy 1H 0419-577 have found its X-ray spectrum to range from that of a typical Seyfert 1 with 2-10 keV power law index Gamma approx. 1.9 to a much flatter power law of Gamma approx. 1.5 or less. We report here a new XMM-Newton observation which allows the low state spectrum to be studied in much greater detail than hitherto. We find a very hard spectrum (Gamma approx. 1.0), which exhibits broad features that can be modelled myth the addition of an extreme relativistic Fe K emission line or with partial covering of the underlying continuum by a substantial column density of near-neutral gas. Both the EPIC and RGS data show evidence for strong line emission of OVII and OVIII requiring an extended region of low density photoionised gas in 1H 0419-577. Comparison with an earlier XMM-Newton observation when 1H 0419-577 was 'X-ray bright' indicates the dominant spectral variability occurs via a steep power law component.

Beschreibung: We present new XMM-Newton results on the field around the NGC346 star cluster in the SMC. This continues and extends previously published work on Chandra observations of the same field. The two XMM-Newton observations were obtained, respectively, six months before and six months after the previously published Chandra data. Of the 51 X-ray sources detected with XMM-Newton, 29 were already detected with Chandru. Comparing the properties of these X-ray sources in each of our three datasets has enabled us to investigate their variability on times scales of a year. Changes in the flux levels and/or spectral properties were observed for 21 of these sources. In addition, we discovered long-term variations in the X-ray properties of the peculiar system HD5980, a luminous blue variable star, that is likely to be a colliding wind binary system, which displays the largest luminosity during the first XMM-Newton observation.

Beschreibung: We present new interstellar dust models which have been derived by simultaneously fitting the far ultraviolet to near infrared extinction, the diffuse infrared emission, and, unlike previous models, the elemental abundances in dust for the diffuse interstellar medium. We found that dust models consisting of a mixture of spherical graphite and silicate grains, polycyclic aromatic hydrocarbon (PAH) molecules, in addition to porous composite particles containing silicate, organic refractory, and water ice, provide an improved .t to the UV-to-infrared extinction and infrared emission measurements, while consuming the amounts of elements well within the uncertainties of adopted interstellar abundances, including B star abundances. These models are a signi.cant improvement over the recent Li & Draine (2001, ApJ, 554, 778) model which requires an excessive amount of silicon to be locked up in dust: 48 ppm (atoms per million of H atoms), considerably more than the solar abundance of 34 ppm or the B star abundance of 19 ppm.

Beschreibung: Traditional methods of actuating spacecraft in sparse aperture arrays use propellant as a reaction mass. For formation flying systems, propellant becomes a critical consumable which can be quickly exhausted while maintaining relative orientation. Additional problems posed by propellant include optical contamination, plume impingement, thermal emission, and vibration excitation. For these missions where control of relative degrees of freedom is important, we consider using a system of electromagnets, in concert with reaction wheels, to replace the consumables. Electromagnetic Formation Flight sparse apertures, powered by solar energy, are designed differently from traditional propulsion systems, which are based on V. This paper investigates the design of sparse apertures both inside and outside the Earth's gravity field.

Beschreibung: The X-ray and gamma-ray spectrum of rotation-powered millisecond pulsars is investigated in a model for acceleration and pair cascades on open field lines above the polar caps. Although these pulsars have low surface magnetic fields, their short periods allow them to have large magnetospheric potential drops, but the majority do not produce sufficient pairs to completely screen the accelerating electric field. In these sources, the primary and secondary electrons continue to accelerate to high altitude and their Lorentz factors are limited by curvature and synchrotron radiation reaction. The accelerating particles maintain high Lorentz factors and undergo cyclotron resonant absorption of radio emission, that produces and maintains a large pitch angle, resulting in a strong synchrotron component. The resulting spectra consist of several distinct components: curvature radiation from primary electrons dominating from 1 - 100 GeV, synchrotron radiation from primary and secondary electrons dominating up to about 100 MeV, and much weaker inverse-Compton radiation from primary electrons a t 0.1 - 1 TeV. We find that the relative size of these components depends on pulsar period, period derivative, and neutron star mass and radius with the level of the synchrotron component also depending sensitively on the radio emission properties. This model is successful in describing the observed X-ray and gamma-ray spectrum of PSR J0218+4232 as synchrotron radiation, peaking around 100 MeV and extending up to a turnover around several GeV. The predicted curvature radiation components from a number of millisecond pulsars, as well as the collective emission from the millisecond pulsars in globular clusters, should be detectable with AGILE and GLAST. We also discuss a hidden population of X-ray-quiet and radio-quiet millisecond pulsars which have evolved below the pair death line, some of which may be detectable by telescopes sensitive above 1 GeV. Subject headings: pulsars: general - radiation mechanisms: nonthermal - stars: neutron - gamma rays: theory

Beschreibung: We report the results of a search for burst oscillations during thermonuclear X-ray bursts from the low mass X-ray binary (LMXB) EXO 0748-676. With the proportional counter array (PCA) onboard the Rossi X-ray Timing Explorer (RXTE) we have detected a 45 Hz oscillation in the average power spectrum of 38 thermonuclear X-ray bursts from this source. We computed power spectra with 1 Hz frequency resolution for both the rising and decaying portions of 38 X-ray bursts from the public RXTE archive. We averaged the 1 Hz power spectra and detected a significant signal at 45 Hz in the decaying phases of the bursts. The signal is detected at a significance level of 4 x 10 (exp -8) similar signal was detected in the rising intervals. The oscillation peak is unresolved at 1 Hz frequency resolution, indicating an oscillation quality factor, Q = nu (sub 0)/Delta nu (sub fwhm) greater than 45, and the average signal amplitude is approximately equal to 3% (rms) The detection of 45 Hz burst oscillations from EXO 0748-676 provides compelling evidence that this is the neutron star spin frequency in this system. We use the inferred spin frequency to model the widths of absorption lines from the neutron star surface and show that the widths of the absorption lines from EXO 0748-676 recently reported by Cottam et al. are consistent with a 45 Hz spin frequency as long as the neutron star radius is in the range from about 9.5 - 15 km. With a known spin frequency, precise modelling of the line profiles from EXO 0748-676 holds great promise for constraining the dense matter equation of state.

Beschreibung: The goal of the Orbiting Wide-field Light-collectors (0WL) mission is to study the origin and physics of the highest energy particles known in nature, the ultra- high energy cosmic rays (UHECRs). The OWL mission consists of telescopes with UV sensitive cameras on two satellites operating in tandem to view in stereo the development of the giant particle showers induced in the Earth s atmosphere by UHECRs. This paper discusses the characteristics of the 0WL mission.

Beschreibung: We present RHESSI observF5oss of three homologous flares, which occurred between April 14 and 16, 2002. We find that the RHESSI images of all three flares at energies between 6 and 25 keV had some common features: (1) A. separate coronal source up to approx. 30 deg. above the flare loop appeared in the early impulsive phase and stayed stationary for several minutes. (2) Before the flare loop moved upward; previously reported by others, the flare loop-top centroid moved downward for 2-4 minutes during the early impulsive phase of the Ears: falling by 13 - 30% of its initial height with a speed between 8 and 23 km/s. We conclude that these features are associated with the formation and development of a current sheet between the loop-top and the coronal source. In the April 14-15 flare, we find that the hard X-ray flux (greater than 25 keV) is correlated with the rate at which the flare loop moves upward, indicating that the faster the loop grows, the faster the reconnection rate, and therefore, the greater the flux of accelerated electrons. Subject headings: Sun: L'iaies-Sun: X-1-ay-s -

Beschreibung: We report on Chandra ACE observations of the ultracompact AM CVn binary ES Cet. This object has a 10.3 minute binary period and is the most compact of the confirmed AM CVn systems. We have, for the first time, unambiguously detected the X-ray counterpart to ES Cet. In a 20 ksec ACIS-S image a point-like X-ray source is found within 1 sec. of the catalogued optical position. The mean countrate in ACIS-S is 0.013/s, and there is no strong evidence for variability. We folded the X-ray data using the optical ephemeris of Warner & Woudt, but did not detect any significant modulation. If an approx. = 100% modulation similar to those seen in the ultracompact candidates V407 Vu1 and Rx J0806.3+1527 were present then we would have detected it. The upper limit (3(sigma)) to any modulation at the putative orbital period is approx. 40% (rms). We extract the first X-ray spectrum from ES Cet, and find that it is not well described by simple continuum models. We find suggestive evidence for discrete spectral components at approx. 470 and 890 eV, that can be modelled as gaussian emission lines. In comparison with recent X-ray detections of nitrogen and neon in another AM CVn system (GP Com), it appears possible that these features may represent emission lines from these same elements; however, deeper spectroscopy will be required to confirm this. Our best spectral model includes a black body continuum with kT = 0.8 keV along with the gaussian lines. The 0.2 - 5 keV X-ray flux was approx. 7 x 10(exp -14) ergs/sq cm s. The luminosity implied by this flux for any reasonable distance is much smaller than that expected for a mass accretion rate as high as m = 10(exp -8) solar mass/yr, suggesting that the bulk of the accretion luminosity is below 100 eV and not seen with Chandra. We discuss the implications of our results for the nature of ES Cet.