7,160 research outputs found
Application of a low order panel method to complex three-dimensional internal flow problems
An evaluation of the ability of a low order panel method to predict complex three-dimensional internal flow fields was made. The computer code VSAERO was used as a basis for the evaluation. Guidelines for modeling internal flow geometries were determined and the effects of varying the boundary conditions and the use of numerical approximations on the solutions accuracy were studied. Several test cases were run and the results were compared with theoretical or experimental results. Modeling an internal flow geometry as a closed box with normal velocities specified on an inlet and exit face provided accurate results and gave the user control over the boundary conditions. The values of the boundary conditions greatly influenced the amount of leakage an internal flow geometry suffered and could be adjusted to eliminate leakage. The use of the far-field approximation to reduce computation time influenced the accuracy of a solution and was coupled with the values of the boundary conditions needed to eliminate leakage. The error induced in the influence coefficients by using the far-field approximation was found to be dependent on the type of influence coefficient, the far-field radius, and the aspect ratio of the panels
Electrostatic forces for personnel restraints
The feasibility of utilizing electrostatic forces for personnel retention devices on exterior spacecraft surfaces was analyzed. The investigation covered: (1) determination of the state of the art; (2) analysis of potential adhesion surfaces; (3) safety considerations for personnel; (4) electromagnetic force field determination and its effect on spacecraft instrumentation; and (5) proposed advances to current technology based on documentation review, analyses, and experimental test data
WHY SIZE MATTERS: FLASH FICTION IN HIGH SCHOOL ENGLISH
This action research project explores the value of flash fiction in the secondary classroom. Flash fiction draws heavily on oral traditions such as the joke, and the fable, to present complete stories in fewer than 1500 words. The form has flourished in recent years, particularly on the internet, where literary journals such as The Vestal Review, SmokeLong Quarterly, and Toasted Cheese, publish engaging, and provocative stories. By examining how students react to the unique characteristics of flash fiction, teachers can make the most this valuable and abundant resource.
This article describes how students at a public secondary charter school responded to a unit on flash fiction. Data from writing assignments and online discussions during the unit show that the unit on flash fiction helped students become more engaged readers and more confident writers. An analysis of the flash fiction that students chose to study suggests that flash fiction may enable teachers to differentiate lessons more precisely based on gender, interest, and ability. Specifically, flash fiction may be particularly appealing to male students who do not consider reading a masculine activity. Methods for teaching flash fiction in conjunction with online threaded discussion forums are also discussed as a method of integrating the study of literature with new literacy skills required in online environment
Reclaiming human machine nature
Extending and modifying his domain of life by artifact production is one of
the main characteristics of humankind. From the first hominid, who used a wood
stick or a stone for extending his upper limbs and augmenting his gesture
strength, to current systems engineers who used technologies for augmenting
human cognition, perception and action, extending human body capabilities
remains a big issue. From more than fifty years cybernetics, computer and
cognitive sciences have imposed only one reductionist model of human machine
systems: cognitive systems. Inspired by philosophy, behaviorist psychology and
the information treatment metaphor, the cognitive system paradigm requires a
function view and a functional analysis in human systems design process.
According that design approach, human have been reduced to his metaphysical and
functional properties in a new dualism. Human body requirements have been left
to physical ergonomics or "physiology". With multidisciplinary convergence, the
issues of "human-machine" systems and "human artifacts" evolve. The loss of
biological and social boundaries between human organisms and interactive and
informational physical artifact questions the current engineering methods and
ergonomic design of cognitive systems. New developpment of human machine
systems for intensive care, human space activities or bio-engineering sytems
requires grounding human systems design on a renewed epistemological framework
for future human systems model and evidence based "bio-engineering". In that
context, reclaiming human factors, augmented human and human machine nature is
a necessityComment: Published in HCI International 2014, Heraklion : Greece (2014
Blood Libel: Radical Islam\u27s Conscription of the Law of Defamation into a Legal Jihad against the West - and How to Stop It
Two Amino Acid Residues Contribute to a Cation-Ï€ Binding Interaction in the Binding Site of an Insect GABA Receptor
Cys-loop receptor binding sites characteristically possess an "aromatic box," where several aromatic amino acid residues surround the bound ligand. A cation-Ï€ interaction between one of these residues and the natural agonist is common, although the residue type and location are not conserved. Even in the closely related vertebrate GABA_A and GABA_C receptors, residues in distinct locations perform this role: in GABA_A receptors, a Tyr residue in loop A forms a cation-Ï€ interaction with GABA, while in GABA_C receptors it is a loop B residue. GABA-activated Cys-loop receptors also exist in invertebrates, where they have distinct pharmacologies and are the target of a range of pesticides. Here we examine the location of GABA in an insect binding site by incorporating a series of fluorinated Phe derivatives into the receptor binding pocket using unnatural amino acid mutagenesis, and evaluating the resulting receptors when expressed in Xenopus oocytes. A homology model suggests that two aromatic residues (in loops B and C) are positioned such that they could contribute to a cation-Ï€ interaction with the primary ammonium of GABA, and the data reveal a clear correlation between the GABA EC_(50) and the cation-Ï€ binding ability both at Phe206 (loop B) and Tyr254 (loop C), demonstrating for the first time the contribution of two aromatic residues to a cation-Ï€ interaction in a Cys-loop receptor
Addressing the Healthcare Needs of an Ageing Population The Need for an Integrated Solution
All stakeholders involved in healthcare are well aware of the ticking time bomb of our ageing world with demand exceeding supply even within the most affluent of countries. The Director- General of the World Health Organisation (WHO) has recently drawn global attention to the fact that even in low income countries people are living longer; however pointedly adds that longevity is not enough. To benefit society as a whole there needs to be a refocus on how later years in life are significant to the older person; with attention to dignity and good health [1]
Amine-terminated nanoparticle films: pattern deposition by a simple nanostencilling technique and stability studies under X-ray irradiation
Exploring the surface chemistry of nanopatterned amine-terminated nanoparticle films.</p
Potential flow theory and operation guide for the panel code PMARC
The theoretical basis for PMARC, a low-order potential-flow panel code for modeling complex three-dimensional geometries, is outlined. Several of the advanced features currently included in the code, such as internal flow modeling, a simple jet model, and a time-stepping wake model, are discussed in some detail. The code is written using adjustable size arrays so that it can be easily redimensioned for the size problem being solved and the computer hardware being used. An overview of the program input is presented, with a detailed description of the input available in the appendices. Finally, PMARC results for a generic wing/body configuration are compared with experimental data to demonstrate the accuracy of the code. The input file for this test case is given in the appendices
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