7,374 research outputs found
Analysis, design, and test of acoustic treatment in a laboratory inlet duct
A suppression prediction program based on the method of modal analysis for spinning mode propagation in a circular duct was used in the analytical design of optimized, multielement, Kevlar bulk-absorber treatment configurations for an inlet duct. The NASA-Langley ANRL anechoic chamber using the spinning mode synthesizer as a sound source was used to obtain in-duct spinning mode measurements, radial mode measurements, and far-field traverses, as well as aerodynamic measurements. The measured suppression values were compared to predicted values, using the in-duct, forward-traveling, radial-mode content as the source for the prediction. The performance of the treatment panels was evaluated from the predicted and measured data. Although experimental difficulties were encountered at the design condition, sufficient information was obtained to confirm the expectation that it is the panel impedance components which are critical to suppression at a single frequency, not the particular construction materials. The agreement obtained between measurement and prediction indicates that the analytical program can be used as an accurate, reliable, and useful design tool
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Elephantiasis nostras verrucosa: an atypical presentation following intrapelvic lymphoma
Elephantiasis nostras verrucosa is a progressively debilitating and disfiguring disease commonly presenting with verrucous, cobblestone-like papules, nodules, or plaques with nonpitting edema in the lower extremities. Histopathology is marked by hyperkeratosis and dermal or subcutaneous fibrosis as a result of chronic lymphedema. Risk factors include obesity, recurrent cellulitis, chronic venous insufficiency, congestive heart failure, scleroderma, radiation, trauma, and tumors. We report a 72-year-old man who presented to the dermatology clinic for an 11-year history of edematous legs, occasionally associated with ulcerations. The findings developed within a year of intrapelvic non-Hodgkin lymphoma and progressed gradually over 10 years after lymphoma remission. Physical examination revealed atypical features including compressible cysts and pitting edema extending from the lower legs to the thighs bilaterally. The patient was noncompliant for the recommended compressive devices and the condition progressively worsened over the course of 7 months of follow-up. Early interdisciplinary management using compressive devices and a lymphatic pump are recommended. Underlying causative factors should be assessed with regular follow-up to optimize treatment outcomes
The psoriatic epidermal lesion and anagen hair growth may share the same "switch-on" mechanism.
Based on striking parallels between the cell kinetics in the epidermal lesion of psoriasis and the proliferation of hair matrix keratinocytes during the anagen phase of the hair growth cycle, the hypothesis is proposed that both phenomena may share the same "switch-on" mechanism. Particular emphasis is placed on a comparison between the Koebner phenomenon in psoriasis and wounding-induced anagen hair growth. In discussing alternative theoretical models for the proposed common "switch-on" mechanism, some useful experimental tools are suggested. Research into the mechanisms which control epithelial proliferation in psoriasis and hair growth may provide new insights into other growth processes, such as embryonic organogenesis and neoplasia, in which similar epithelial-mesenchymal interactions play a pivotal role
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Cutibacterium (formerly Propionibacterium) acnes clavicular infection.
Cutibacterium (formerly Propionibacterium) acnes13, 16 is a slow growing, gram-positive bacteria that is naturally found in higher concentrations as skin flora on the chest and back, as well as in other areas with greater numbers of hair follicles.25, 37 Most of the reported cases of C. acnes shoulder girdle infection follow arthroplasty surgery,18, 20, 26, 27, 32, 35 which then often requires debridement, administration of intravenous antibiotics, and surgical revision of the implanted device.12, 15, 21, 28-30 In a recent study, 56% of 193 shoulder revisions had a positive culture, 70% of which grew C. acnes.30 Despite the relatively common presumed association of C. acnes humeral osteomyelitis with prosthetic infection, infection of the scapula or clavicle secondary to C. acnes is rare.4, 23, 36 Osteomyelitis of the clavicle involving any organism is also an uncommon event that can arise spontaneously via presumed hematogenous spread, or secondary to open fractures or internal fixation.6, 33 The most commonly found organism in clavicular osteomyelitis is Staphylococcus aureus.9 We here report two cases of clavicular infection secondary to C. acnes that were not associated with implants
Antiferroquadrupolar Order in the Magnetic Semiconductor TmTe
The physical properties of the antiferroquadrupolar state occurring in TmTe
below TQ=1.8 K have been studied using neutron diffraction in applied magnetic
fields. A field-induced antiferromagnetic component k = (1/2,1/2,1/2) is
observed and, from its magnitude and direction for different orientations of H,
an O(2,2) quadrupole order parameter is inferred. Measurements below TN ~= 0.5
K reveal that the magnetic structure is canted, in agreement with theoretical
predictions for in-plane antiferromagnetism. Complex domain repopulation
effects occur when the field is increased in the ordered phases, with
discontinuities in the superstructure peak intensities above 4 T.Comment: 6 pages, 6 figures, Presented at the International Conference on
Strongly Correlated Electrons with Orbital Degrees of Freedom (ORBITAL 2001),
September 11-14, 2001 (Sendai, JAPAN). To appear in: Journal of the Physical
Society of Japan (2002
Ring-Pattern Dynamics in Smectic-C* and Smectic-C_A* Freely Suspended Liquid Crystal Films
Ring patterns of concentric 2pi-solitons in molecular orientation, form in
freely suspended chiral smectic-C films in response to an in-plane rotating
electric field. We present measurements of the zero-field relaxation of ring
patterns and of the driven dynamics of ring formation under conditions of
synchronous winding, and a simple model which enables their quantitative
description in low polarization DOBAMBC. In smectic C_A* TFMHPOBC we observe an
odd-even layer number effect, with odd number layer films exhibiting order of
magnitude slower relaxation rates than even layer films. We show that this rate
difference is due to much larger spontaneous polarization in odd number layer
films.Comment: 4 RevTeX pgs, 4 eps figures, submitted to Phys. Rev. Let
Causes of Litigation in Workers\u27 Compensation Programs
By applying econometric analyses to case data from two states, Falaris, Link and Staten identify the economic incentives influencing the probability of litigation in workers\u27 compensation cases, and the probability that a contested case is pursued to verdict.https://research.upjohn.org/up_press/1075/thumbnail.jp
High-pressure transport properties of CeRu_2Ge_2
The pressure-induced changes in the temperature-dependent thermopower S(T)
and electrical resistivity \rho(T) of CeRu_2Ge_2 are described within the
single-site Anderson model. The Ce-ions are treated as impurities and the
coherent scattering on different Ce-sites is neglected. Changing the
hybridisation \Gamma between the 4f-states and the conduction band accounts for
the pressure effect. The transport coefficients are calculated in the
non-crossing approximation above the phase boundary line. The theoretical S(T)
and \rho(T) curves show many features of the experimental data. The seemingly
complicated temperature dependence of S(T) and \rho(T), and their evolution as
a function of pressure, is related to the crossovers between various fixed
points of the model.Comment: 9 pages, 10 figure
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