DESE Research (United States)

Na sepse, a resposta imune do hospedeiro pode desencadear o desequilíbrio entre a coagulação e a fibrinólise, ocasionando uma síndrome clínica associada a piores prognósticos, na qual coexistem manifestações hemorrágicas e trombóticas, comumente definida como Coagulação Intravascular Disseminada (CIVD).

Meteoroids pose one of the largest risks to spacecraft outside of low Earth orbit. To correctly predict the rate at which meteoroids impact and damage spacecraft, environment models must describe the mass, directionality, velocity, and density distributions of meteoroids. NASA’s Meteoroid Engineering Model (MEM) is one such model; MEM 3 is an updated version of the code that better captures the correlation between directionality and velocity and incorporates a bulk density distribution. This paper describes MEM 3 and compares its predictions with the rate of large particle impacts seen on the Long Duration Exposure Facility and the Pegasus II and III satellites.

A unique model-reference-based control system architecture has been devised that greatly improves a closed-loop control system's ability to function in the event of a malfunction, including malicious intervention. This architecture, called the ICAR (Integral Command Augmentation for Robustness) loop, was first applied to make missile autopilots more robust to unanticipated changes and disturbances. The ICAR loop, which features a feed-forward/feedback topology, monitors the system and corrects the control signal to the system, if necessary. The ICAR loop has the important characteristic that it is totally transparent in normal operation and does not alter the performance of the in-place control system. It only becomes active when the system being controlled changes and/or its operation deviates from its intended transient response. The ICAR loop generates a signal to restore the system response to its originally intended character. The novel idea of this paper is to exploit the robustness feature of the ICAR loop as a diagnostic and system-resilience mechanism for satellite cyber-security. The ICAR loop can be implemented as a standalone device. This makes it particularly easy to implement it as a completely separate and independent computing unit. This idea could further extended to implement the ICAR loop as an analog device thus overcoming total dependence on digital monitoring and protection technologies. ICAR loop application with a satellite attitude control system is shown in a series of operational examples. For a hypothetical satellite, different malfunction scenarios are presented encompassing a variety of ways that computation-related processes can fail due to cyber-attack and the ICAR loop's remedial role. The ICAR loop's powerful capability to successfully provide a detection and operational resilience capability is demonstrated. The malfunctions considered span a range of origin and illustrate the ICAR loop's ability to defend against disturbances caused by cyber-attack.

This paper discusses the importance of fusion propulsion for interplanetary space travel, illustrates why the magnetoinertial fusion parameter space may facilitate the most rapid, economic path for development, justifies the choice of pulsed Z pinch, and provides a potential development path leading up to a technical readiness level 9 system. Round trips of less than one year to Mars are only possible using fusion propulsion systems. Such a system will require an onboard nuclear fission reactor for reliable startups, and so fission and fusion developments for space are mutually beneficial. The paper reviews the more than 50 year history of fusion research and summarizes results from a recent study of the fusion parameter space for terrestrial power, which suggests magnetoinertial fusion can provide the smallest, most economical approach for a fusion propulsion system. Emerging experimental data and theory show pulsed Z-pinch fusion solves some of the most deleterious instabilities and scales to fusion breakeven within reach of current pulsed power facilities. The paper illustrates a potential development path to a technical readiness level 9 flight system, starting from an assumed technical readiness level 2 for the current state of fusion propulsion.

Fondée en 1007 pour devenir la capitale du royaume Berbère des Hammadides, la Qalʽa des Banī Ḥammād est la première ville du Maghreb central connue pour son rôle de métropole après la conquête arabe. Elle est le symbole d’une période marquée par l’essor urbain et le développement de la vie intellectuelle. En 1091, elle perd définitivement son statut de capitale au profit de la nouvelle métropole maritime, Béjaia/Bgayet. La Qalʽa resta néanmoins une grande métropole économique et garda son pr...

Z-pinch and Dense Plasma Focus (DPF) are two promising techniques for bringing fusion power to the field of in-space propulsion. A design team comprising of engineers and scientists from UAHuntsville, NASA's George C. Marshall Space Flight Center and the University of Wisconsin developed concept vehicles for a crewed round trip mission to Mars and an interstellar precursor mission. Outlined in this paper are vehicle concepts, complete with conceptual analysis of the mission profile, operations, structural and thermal analysis and power/avionics design. Additionally engineering design of the thruster itself is included. The design efforts adds greatly to the fidelity of estimates for power density (alpha) and overall performance for these thruster concepts

Abstract In an integrated product development environment that includes several vendor tools, diverse and incompatible configuration management mechanisms and authorization management mechanisms across tools can lead to inefficiencies in the design process. We describe in this document a common model of configuration management and authorization that may be adopted for an integrated product development environment. We specified a common minimal set of configuration management mechanisms and authoriza‐tion management mechanisms that must be provided by the tools to support the proposed configuration and authorization models. We implemented a pilot program of the configuration management and authorization management models using Intergraph Corporation's Document Manager 2.0 (DM2) software system. This pilot implementation proves the plausability and usability of the model.

Twenty-nine focus groups were conducted among men and women in five regions of Zaire to identify motivations for and obstacles to voluntary surgical contraception (VSC) for women. Both male and female participants believe that VSC is justified only for medical reasons related to difficulties with pregnancy or childbirth, and not for economic hardship. Women feel great pressure, especially from the husband's family, to produce many children, and fear they might be abandoned after being sterilized, even if their husband had previously consented to VSC. Men also perceive the major consequence of VSC to be marital conflict and dissolution. However, women who had had the procedure--primarily for medical reasons--expressed high levels of satisfaction with the operation. At the same time, they stress the need for confidentiality, suggesting that VSC remains controversial. Also examined are reasons for introducing VSC programs in a country such as Zaire.