3,153 research outputs found
USB environment measurements based on full-scale static engine ground tests
Flow turning parameters, static pressures, surface temperatures, surface fluctuating pressures and acceleration levels were measured in the environment of a full-scale upper surface blowing (USB) propulsive lift test configuration. The test components included a flightworthy CF6-50D engine, nacelle, and USB flap assembly utilized in conjunction with ground verification testing of the USAF YC-14 Advanced Medium STOL Transport propulsion system. Results, based on a preliminary analysis of the data, generally show reasonable agreement with predicted levels based on model data. However, additional detailed analysis is required to confirm the preliminary evaluation, to help delineate certain discrepancies with model data, and to establish a basis for future flight test comparisons
Multimode Memories in Atomic Ensembles
The ability to store multiple optical modes in a quantum memory allows for
increased efficiency of quantum communication and computation. Here we compute
the multimode capacity of a variety of quantum memory protocols based on light
storage in ensembles of atoms. We find that adding a controlled inhomogeneous
broadening improves this capacity significantly.Comment: Published version. Many thanks are due to Christoph Simon for his
help and suggestions. (This acknowledgement is missing from the final draft:
apologies!
Who Are The Difficult Employees? Psychopathological Attributions Of Their Co-workers
On a given workday, over 700 workers are attacked, 43,800 employees are harassed and 16,400 are threatened (Hynes, 2001). Yet the literature focuses upon environmental causes; none attempt to identify personal characteristics of the uncivil, deviant or maladaptive employee. This study helps fill this void by exploring the personality correlates of uncivil employee behavior. These employees violate mutual norms of respect, negatively affect organizational performance, and are thus the prototypical difficult employee. Utilizing a unique psycho-pathological approach, the DSM-IV (Diagnostic Statistical Manual) was used as the basis for defining and assessing the perceived personality correlates of these employees’ behaviors. Results suggest that narcissistic traits are the modal descriptors for the Difficult Employee, regardless of hierarchical role (boss, peer, subordinate). Implications are discussed with suggestions for future research
Teaching an Engineering Systems Doctoral Seminar: Concepts and Structure
This paper describes the current state of the evolving engineering systems doctoral seminar in
the Engineering Systems Division (ESD) at MIT. This subject is required for all first year
engineering systems doctoral students. It is intended to bring them into the culture of ESD, and
to establish a common base on which subsequent subjects can build. It is the first of three
required subjects that make up the core of the ESD doctoral program. The seminar is intended
to provide students with the foundations and context of engineering systems, largely focused on
providing an appreciation for the many facets of socio-technical complexity. We discuss the
seminar’s pedagogy, learning objectives, assignments and readings, and provide insights gained
from teaching the course
Ultrastructural studies of microconidium formation
Ultrastructural studies of microconidium formatio
Initial Top-Level Characterization of the Air Force Sustainment System
This draft white paper presents an initial top-level characterization of the Air Force sustainment system. The first part of the paper gives an overview of the proposed conceptual framework for system characterization. The second part presents an initial top-level characterization of the system, by using this framework, and offers some preliminary suggestions or recommendations. Finally, next steps in the research process are outlined, placing the paper in the larger context of the task on system characterization and transformation
Lattice Boltzmann Model for Axisymmetric Multiphase Flows
In this paper, a lattice Boltzmann (LB) model is presented for axisymmetric
multiphase flows. Source terms are added to a two-dimensional standard lattice
Boltzmann equation (LBE) for multiphase flows such that the emergent dynamics
can be transformed into the axisymmetric cylindrical coordinate system. The
source terms are temporally and spatially dependent and represent the
axisymmetric contribution of the order parameter of fluid phases and inertial,
viscous and surface tension forces. A model which is effectively explicit and
second order is obtained. This is achieved by taking into account the discrete
lattice effects in the Chapman-Enskog multiscale analysis, so that the
macroscopic axisymmetric mass and momentum equations for multiphase flows are
recovered self-consistently. The model is extended to incorporate reduced
compressibility effects. Axisymmetric equilibrium drop formation and
oscillations, breakup and formation of satellite droplets from viscous liquid
cylindrical jets through Rayleigh capillary instability and drop collisions are
presented. Comparisons of the computed results with available data show
satisfactory agreement.Comment: 17 pages, 11 figures, to be published in Physical Review
Efficient spatially-resolved multimode quantum memory
We propose a method that enables efficient storage and retrieval of a
photonic excitation stored in an ensemble quantum memory consisting of
Lambda-type absorbers with non-zero Stokes shift. We show that this can be used
to implement a multimode quantum memory storing multiple frequency-encoded
qubits in a single ensemble, and allowing their selective retrieval. The
read-out scheme applies to memory setups based on both
electromagnetically-induced transparency and stimulated Raman scattering, and
spatially separates the output signal field from the control fields
Specific IgE Response to Purified and Recombinant Allergens in Latex Allergy
Background
In recent years, allergy to natural rubber latex has emerged as a major allergy among certain occupational groups and patients with underlying diseases. The sensitization and development of latex allergy has been attributed to exposure to products containing residual latex proteins. Although improved manufacturing procedures resulted in a considerable reduction of new cases, the potential risk for some patient groups is still great. In addition the prevalent cross-reactivity of latex proteins with other food allergens poses a major concern. A number of purified allergens and a few commercial kits are currently available, but no concerted effort was undertaken to evaluate them. Methods
We studied 11 purified latex allergens, Hev b 1 to Hev b 10, and Hev b 13 along with several crude allergen extracts and two commercial ImmunoCAP assays to evaluate specific IgE antibody in the sera from latex allergic patients and controls. Health care workers and spina bifida patients with clinical symptoms of latex allergy, spina bifida patients without latex allergy, and non-atopic health care workers have been studied. Results
The results suggest that Hev b 2, 5, 6, and 13 together identified over 80 percent health care workers with latex allergy, while Hev b 6 along with Hev b 1 or 3 detected specific IgE antibody in all sera studied from patients with spina bifida and latex allergy. The ImmunoCAP results using both Hev b 5 amplified and non-amplified closely agreed with the clinical diagnosis of latex allergy in health care workers and in spina bifida. Conclusion
Although the purified allergens and crude extracts reacted diversely with IgE from different patient groups, the results indicated that use of certain combinations of purified recombinant antigens will be useful in commercial kits or in in-house assays for detecting specific IgE antibody in the sera. The results suggest that a combination of Hev b 2, 3, 5, 6, and 13 together detected specific IgE in 80% of the sera from latex allergic patients. Both ImmunoCAPs correctly identified over 95% of latex allergic patients, however, showed reactivity with a few normal control subject
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