The aerodynamic challenges of SRB recovery

Recovery and reuse of the Space Shuttle solid rocket boosters was baselined to support the primary goal to develop a low cost space transportation system. The recovery system required for the 170,000-lb boosters was for the largest and heaviest object yet to be retrieved from exoatmospheric conditions. State-of-the-art design procedures were ground-ruled and development testing minimized to produce both a reliable and cost effective system. The ability to utilize the inherent drag of the boosters during the initial phase of reentry was a key factor in minimizing the parachute loads, size and weight. A wind tunnel test program was devised to enable the accurate prediction of booster aerodynamic characteristics. Concurrently, wind tunnel, rocket sled and air drop tests were performed to develop and verify the performance of the parachute decelerator subsystem. Aerodynamic problems encountered during the overall recovery system development and the respective solutions are emphasized

System analysis approach to deriving design criteria (loads) for Space Shuttle and its payloads. Volume 1: General statement of approach

Space shuttle, the most complex transportation system designed to date, illustrates the requirement for an analysis approach that considers all major disciplines simultaneously. Its unique cross coupling and high sensitivity to aerodynamic uncertainties and high performance requirements dictated a less conservative approach than those taken in programs. Analyses performed for the space shuttle and certain payloads, Space Telescope and Spacelab, are used a examples. These illustrate the requirements for system analysis approaches and criteria, including dynamic modeling requirements, test requirements control requirements and the resulting design verification approaches. A survey of the problem, potential approaches available as solutions, implications for future systems, and projected technology development areas are addressed

Enhanced product functionality with life cycle units

Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich.This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.Cycle economy is not only ecologically reasonable but also a chance for new business. Selling utilization instead of selling products is advantageous once additional costs for information processing and logistics are less than costs for underutilized capacity. A competitive provider offers product functionality in quality, time and location as required by the user. Lifetime component monitoring is conditional for this performance. Modern microelectronic technology enables the acquisition of component deterioration with sensorial devices, information processing and storing with microcontrollers and initiating appropriate actions such as maintenance. The architecture of a microsystem called the life cycle unit (LCU) for product and component monitoring is introduced and specified. Product examples illustrate some application areas.DFG, SFB 281, Demontagefabriken zur Rückgewinnung von Ressourcen in Produkt- und Materialkreisläufe

System analysis approach to deriving design criteria (Loads) for Space Shuttle and its payloads. Volume 2: Typical examples

The achievement of an optimized design from the system standpoint under the low cost, high risk constraints of the present day environment was analyzed. Space Shuttle illustrates the requirement for an analysis approach that considers all major disciplines (coupling between structures control, propulsion, thermal, aeroelastic, and performance), simultaneously. The Space Shuttle and certain payloads, Space Telescope and Spacelab, are examined. The requirements for system analysis approaches and criteria, including dynamic modeling requirements, test requirements, control requirements, and the resulting design verification approaches are illustrated. A survey of the problem, potential approaches available as solutions, implications for future systems, and projected technology development areas are addressed

How Spanish speakers express norms using generic person markers

Language is one powerful vehicle for transmitting norms—a universal feature of society. In English, people use “you” generically (e.g., “You win some you lose some”) to express and interpret norms. Here, we examine how norms are conveyed and interpreted in Spanish, a language that—unlike English—has two forms of you (i.e., formal, informal), distinct generic person markers, and pro-drop, allowing for an examination of underlying conceptual tendencies in how the structure of language facilitates the transmission of norms. In Study 1a-b (N = 838) Spanish speakers used informal generic-you and the generic person marker “se” (but not formal-you) to express norms (vs. preferences). In Study 2 (N = 300), formal you, informal you, and impersonal “se” had persuasive force over personal endorsements (e.g., “I”), informing Spanish speaker’s interpretation of unfamiliar norms. Our findings add to a growing literature on how subtle linguistic shifts reflect and influence cognitive processes

Estimating the Effect of Palliative Care Interventions and Advance Care Planning on ICU Utilization: A Systematic Review

OBJECTIVE: We conducted a systematic review to answer three questions: 1) Do advance care planning and palliative care interventions lead to a reduction in ICU admissions for adult patients with life-limiting illnesses? 2) Do these interventions reduce ICU length of stay? and 3) Is it possible to provide estimates of the magnitude of these effects? DATA SOURCES: We searched MEDLINE, EMBASE, Cochrane Controlled Clinical Trials, and Cumulative Index to Nursing and Allied Health Literature databases from 1995 through March 2014. STUDY SELECTION: We included studies that reported controlled trials (randomized and nonrandomized) assessing the impact of advance care planning and both primary and specialty palliative care interventions on ICU admissions and ICU length of stay for critically ill adult patients. DATA EXTRACTION: Nine randomized controlled trials and 13 nonrandomized controlled trials were selected from 216 references. DATA SYNTHESIS: Nineteen of these studies were used to provide estimates of the magnitude of effect of palliative care interventions and advance care planning on ICU admission and length of stay. Three studies reporting on ICU admissions suggest that advance care planning interventions reduce the relative risk of ICU admission for patients at high risk of death by 37% (SD, 23%). For trials evaluating palliative care interventions in the ICU setting, we found a 26% (SD, 23%) relative risk reduction in length of stay with these interventions. CONCLUSIONS: Despite wide variation in study type and quality, patients who received advance care planning or palliative care interventions consistently showed a pattern toward decreased ICU admissions and reduced ICU length of stay. Although SDs are wide and study quality varied, the magnitude of the effect is possible to estimate and provides a basis for modeling impact on healthcare costs

The Functional Connectivity Landscape of the Human Brain

Functional brain networks emerge and dissipate over a primarily static anatomical foundation. The dynamic basis of these networks is inter-regional communication involving local and distal regions. It is assumed that inter-regional distances play a pivotal role in modulating network dynamics. Using three different neuroimaging modalities, 6 datasets were evaluated to determine whether experimental manipulations asymmetrically affect functional relationships based on the distance between brain regions in human participants. Contrary to previous assumptions, here we show that short- and long-range connections are equally likely to strengthen or weaken in response to task demands. Additionally, connections between homotopic areas are the most stable and less likely to change compared to any other type of connection. Our results point to a functional connectivity landscape characterized by fluid transitions between local specialization and global integration. This ability to mediate functional properties irrespective of spatial distance may engender a diverse repertoire of cognitive processes when faced with a dynamic environment.</p