44,535 research outputs found
The Small Size of the Small Scale Market: The Early-Stage Labor Market for Highly Skilled Nanotechnology Workers
We examine the labor market for the highly trained in nanotechnology and the response of universities toward providing training. We draw comparisons with the labor market and university response in bioinformatics. The demand analysis is based on position announcements in Science in 2002 compared to 2005. We also analyze online position announcements in late 2005 and early 2006. Our analysis leads us to conclude that at the present time the market is small and growing for positions in academe and at FFRDC's, small and stable for positions at firms. Our analysis of training leads to the conclusion that the pipeline is being filled primarily through a principal investigator approach, where a student is attached to one faculty member's lab, rather than to a formal program. The fundamental difference between nanotechnology and bioinformatics in this respect may be due to differences in the opportunities available to universities and faculty. Working Paper 07-0
Blade loss transient dynamics analysis, volume 1. Task 2: TETRA 2 theoretical development
The theoretical development of the forced steady state analysis of the structural dynamic response of a turbine engine having nonlinear connecting elements is discussed. Based on modal synthesis, and the principle of harmonic balance, the governing relations are the compatibility of displacements at the nonlinear connecting elements. There are four displacement compatibility equations at each nonlinear connection, which are solved by iteration for the principle harmonic of the excitation frequency. The resulting computer program, TETRA 2, combines the original TETRA transient analysis (with flexible bladed disk) with the steady state capability. A more versatile nonlinear rub or bearing element which contains a hardening (or softening) spring, with or without deadband, is also incorporated
The Knowledge Production Function for University Patenting
We estimate a knowledge production function for university patenting using an individual effects negative binomial model. We control for R&D expenditures, research field and the presence of a TTO office. We distinguish between three kinds of researchers who staff labs: faculty, postdoctoral students and PhD students. We also examine whether PhDs and postdoctoral scholars contribute equally to patent activity or whether there is a differential effect depending upon visa status. We find patent counts relate positively and significantly to the number of faculty, number of PhD students and number of postdocs. Our results also suggest that not all graduate students and postdocs contribute equally to patenting but that contribution is mediated by visa status. Working Paper 07-0
Blade loss transient dynamics analysis, volume 2. Task 2: TETRA 2 user's manual
This is the user's manual for the TETRA 2 Computer Code, a program developed in the NASA-Lewis Blade Loss Program. TETRA 2 calculates a turbine engine's dynamic structural response from applied stimuli. The calculation options are: (1) transient response; and (2) steady state forced response. Based on the method of modal syntheses, the program allows the use of linear, as well as nonlinear connecting elements. Both transient and steady state options can include: flexible Bladed Disk Module, and Nonlinear Connecting Elements (including deadband, hardening/softening spring). The transient option has the additional capability to calculate response with a squeeze film bearing module. TETRA 2 output is summarized in a plotfile which permits post processing such as FFT or graphical animation with the proper software and computer equipment
Towards Other Planetary Systems (TOPS): A technology needs identification workshop
The workshop identified a strong commonality between the technology needs for NASA's TOPS program and the technology needs that were identified for NASA's astrophysics program through its Astrotech 21 survey. The workshop encourages NASA to have the Solar System Exploration and Astrophysics Div. work cooperatively to share in technology studies that are common to both programs, rather than to conduct independent studies. It was also clear, however, that there are technology needs specific to TOPS, and these should be pursued by the Solar System Exploration Div. There are two technology areas that appear to be particularly critical to realizing the ultimate performance that is being sought under the TOPS program, these areas are metrology and optics. The former is critical in calibration and verification of instrument performance, while the latter is needed to provide optical systems of sufficient quality to conduct a search for and characterization of other planetary systems at the more extreme levels of performance identified in TOPS program
Integrated Expert Management Knowledge on OSI Network Management Objects
The management of modern telecommunications networks must satisfy
ever-increasing operational demands. We propose a study for the improvement
of intelligent administration techniques in telecommunications networks.
This task is achieved by integrating knowledge base of expert system within the
management information used to manage a network. For this purpose, an extension
of OSI management framework specifications language has been added
and investigated. For this goal, we shall use the language Guidelines for the
Definition of Managed Objects (GDMO) and a new property named RULE
which gathers important aspects of the facts and the knowledge base of the embedded
expert system. Networks can be managed easily by using this proposed
integration
The importance of electron-electron interactions in the RKKY coupling in graphene
We show that the carrier-mediated exchange interaction, the so-called RKKY
coupling, between two magnetic impurity moments in graphene is significantly
modified in the presence of electron-electron interactions. Using the
mean-field approximation of the Hubbard- model we show that the
-oscillations present in the bulk for
non-interacting electrons disappear and the power-law decay becomes more long
ranged with increasing electron interactions. In zigzag graphene nanoribbons
the effects are even larger with any finite rendering the long-distance
RKKY coupling distance independent. Comparing our mean-field results with
first-principles results we also extract a surprisingly large value of
indicating that graphene is very close to an antiferromagnetic instability.Comment: 4 pages, 3 figure
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