5,186 research outputs found
Automated fiber placement composite manufacturing: The mission at MSFC's Productivity Enhancement Complex
Automated fiber placement is a manufacturing process used for producing complex composite structures. It is a notable leap to the state-of-the-art in technology for automated composite manufacturing. The fiber placement capability was established at the Marshall Space Flight Center's (MSFC) Productivity Enhancement Complex in 1992 in collaboration with Thiokol Corporation to provide materials and processes research and development, and to fabricate components for many of the Center's Programs. The Fiber Placement System (FPX) was developed as a distinct solution to problems inherent to other automated composite manufacturing systems. This equipment provides unique capabilities to build composite parts in complex 3-D shapes with concave and other asymmetrical configurations. Components with complex geometries and localized reinforcements usually require labor intensive efforts resulting in expensive, less reproducible components; the fiber placement system has the features necessary to overcome these conditions. The mechanical systems of the equipment have the motion characteristics of a filament winder and the fiber lay-up attributes of a tape laying machine, with the additional capabilities of differential tow payout speeds, compaction and cut-restart to selectively place the correct number of fibers where the design dictates. This capability will produce a repeatable process resulting in lower cost and improved quality and reliability
Distributed microprocessors in a tactical universal modem
The distributed microprocessor system associated with a wideband signal conversion unit (WBSCU) is described. Multiple embedded 8086 and 2901 microprocessors, supported by dedicated hardware modules, perform the required real time operations for both transmit and receive functions. Commands from a host computer determine the configuration of the WBSCU via the IEEE 488 bus. Each of the four WBSCU channels is assigned to process a specified IF waveform; each channel configures its own resources and, in some cases, borrows resources from other channels. The processed waveform data is communicated from individual channels to redundant global memories. Data flow between the user community and global memories occurs via redundant 1553 buses through intelligent Bus Interface Units. Each WBSCU channel contains one 2901 bit slice machine and one 8086 microprocessor. The 2901 provides high speed processing capability for the most time critical operations. The 8086 is used for lower speed processing tasks where its high level language capability can be better exploited. Each 8086 has a global bus for wideband interprocessor communication, and a local bus for 8086/2901, master/slave communication. Software architecture consists of a control and communications structure governing mode dependent signal processing tasks
Systematic review and meta-analysis of the sero-epidemiological association between Epstein Barr virus and multiple sclerosis
Peer reviewedPublisher PD
Working and Caring for Children with Chronic Illness/Disability: Stories of Disconnection, Cruelty and "Clayton's Support"
This paper reports the findings of an exploratory, qualitative study of the life and work of people who are, concurrently, parents of a child with chronic illness/disability, and working full time. Nine women shared their experiences about the demands of caring for a child with chronic illness/disability while working full time. In light of the demands constantly placed on these women as they manage their multiple roles, it was of particular interest that their stories shared feelings of disconnectedness from others, as well as frank recollections of the cruelty and thoughtlessness of partners, family, friends, colleagues and strangers. They also reported their experiences with "Clayton's support" - the support you get when you are not getting support. These stories are shared in an effort to ameliorate the continuing challenges faced by these women
Three StoriesâAnd a Writerâs Tale: A Creative Writing Case Study of Workplace Bullying
I present a creative writing case study of workplace bullying using three stories: Story 1âThe Writing Context contextualizes the case studyâs development in an Australian higher education institution; Story 2âThe Writing Process describes the creative writing process, including interpretation of public domain secondary empirical sources enmeshed with a writerâs imagination; and Story 3âThe Writing Product presents a creative writing case study of workplace bullying. Interleaved with these three stories of context, process, and product are fragments of my more reflective and reflexive storyâA Writerâs Taleâshared to assist reader understanding of some of the ambiguous, paradoxical, and pernicious outcomes of workplace bullying, while also offering insights into the challenges facing those choosing to use creative writing in their scholarly work
Reflections from an Action Researcher: Why We Do What We Do
"My reflections from the field are shared in an effort to assist others. I
commence by describing a social problem that was the focus of an action
research project. I then articulate the paradigmatic, methodological and
method choices made. I share extracts of data collected during different
stages of the project to illustrate cycles of learning, reflection, and the development
of actionable knowledge. What is important for researchers
who are contemplating choosing action research is to understand the
philosophy behind their decisions; that they think carefully about âwhy
we do what we doâ in order to fully realise the outcomes of co-learning,
developing actionable knowledge and, ultimately, making change." (author's abstract
Conceptual Fragmentation and the Rise of Eliminativism
Pluralist and eliminativist positions in philosophy â and other disciplines â have proliferated in recent decades. This paper emphasises the sheer scale of this movement: we start by summarising twenty debates which have been affected, thus illustrating how often debates have been transformed by the introduction of pluralist and/or eliminativist thinking. We then provide an explanation of why this shift of philosophical terrain has occurred, an explanation which in turn predicts that its reach will extend to other debates currently unaffected, and for good reasons. We go on to detail the landscape of various different pluralist and eliminativist positions one may favour. We ultimately argue for pluralism at the meta-level: whether one should implement (some stripe of) pluralism or eliminativism depends on the context of discussion and the details of the debate at hand. We use this analysis to dissolve debates between âpluralistsâ and âeliminativistsâ in various domains
Working in teams : the influence of rhetoric-from sensemaking to sadness
At a time when teams are increasingly and routinely being used in Public Administration (PA) organizations, the prevailing wisdom about teams continues to confirm that teams axiomatically bring increases and improvements in effectiveness, productivity and communication. There has been relatively little critical address of whether these benefits actually accrue, nor what the experience of team members actually is. The PA literature, in particular, remains silent on this important issue. This paper shares findings from an exploratory phenomenological study. Members of teams in organizations were interviewed and asked about their experiences of working in teams. In contrast to the current wisdom, not only did team members not report the anticipated improvements and benefits, their stories tended to highlight the negative influence that the rhetoric surrounding teams might have on individuals. This paper shares the responses of team members to that rhetoric, revealing themes of "Teams, Rhetoric and Sensemaking," a challenge to the notion of "Teams as One Big Happy Family?" while identifying "Teams as Crucibles of Resignation and Sadness." These findings indicate the continuing need for further research into understanding the experience of individuals within various team and organizational structures, especially as they operate in PA organizations.<br /
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