A comparison of computer-generated lift and drag polars for a Wortmann airfoil to flight and wind tunnel results

Computations of drag polars for a low-speed Wortmann sailplane airfoil are compared to both wind tunnel and flight results. Excellent correlation is shown to exist between computations and flight results except when separated flow regimes were encountered. Wind tunnel transition locations are shown to agree with computed predictions. Smoothness of the input coordinates to the PROFILE airfoil analysis computer program was found to be essential to obtain accurate comparisons of drag polars or transition location to either the flight or wind tunnel results

Orthotic management of cerebral palsy : recommendations from a consensus conference

An international multidisciplinary group of healthcare professionals and researchers participated in a consensus conference on the management of cerebral palsy, convened by the International Society for Prosthetics and Orthotics. Participants reviewed the evidence and considered contemporary thinking on a range of treatment options including physical and occupational therapy, and medical, surgical and orthotic interventions. The quality of many of the reviewed papers was compromised by inadequate reporting and lack of transparency, in particular regarding the types of patients and the design of the interventions being evaluated. Substantial evidence suggests that ankle-foot orthoses (AFOs) that control the foot and ankle in stance and swing phases can improve gait efficiency in ambulant children (GMFCS levels I-III). By contrast, little high quality evidence exists to support the use of orthoses for the hip, spine or upper limb. Where the evidence for orthosis use was not compelling consensus was reached on recommendations for orthotic intervention. Subsequent group discussions identified recommendations for future research. The evidence to support using orthoses is generally limited by the brevity of follow-up periods in research studies; hence the extent to which orthoses may prevent deformities developing over time remains unclear. The full report of the conference can be accessed free of charge at www.ispoint.org

A Biosystematic Study of \u3cem\u3eHeterotheca\u3c/em\u3e section \u3cem\u3ePityopsis\u3c/em\u3e

A biosystematic study of the section Pityopsis of the genus Heterotheca was undertaken. Cytological, morphological, chromatographic, and hybridization studies were utilized to provide a basis for taxonomic treatment of the taxa. The species were divided into two broad groups; the Heterotheca graminifolia group (H. adenolepis, H. aspera, H. graminifolia, H. microcephala var. microcephala and var. aequilifolia, and H. oligantha) and the H. pinifolia group (H. falcata, H. flexuosa, H. pinifolia, and H. ruthii) Heterotheca ruthii appears to be intermediate between the two groups and is closely related to H. oligantha. Cytology indicates the diploid species (N=9) are prominent with only H. adenolepis (both diploids and tetraploid), H. graminifolia, and H. oligantha being tetraploids (N=8). Pollen measurements were obtained showing tetraploids being significantly larger (except for H. adenolepsis). Paper chromatographs were somewhat inconclusive but generally followed the other taxonomic evidence for the section. It is thought that H. graminifolia was derived via autopolyploidy from H. microcephala. Heterotheca adenolepsis is thought to have been derived from an allopolyploid hybrid between H. aspera and H. microcephala. Heterotheca oligantha has a limited range in Florida and Alabama but appears closely related to H. graminifolia and H. ruthii. Heterotheca pinifolia, H. falcata, H. flexuosa, and H. ruthii apparently were derived from one or more primitive ancestors which migrated from an Appalachian center of origin to the Coastal Plain, became geographically separated and evolved into the four entities listed above. Heterotheca ruthii appears to be the most primitive of the four species. All are limited in rang with H. ruthii found only in the Hiwassee Gorge of East Tennessee; H. flexuosa in a few counties in Florida: H. pinifolia in a few counties in the Sand Hills of Georgia and North and South Carolina, and H. falcata in sand areas in five northeastern states. These four species have relatively few genetic barriers but are widely separated geographically

Mutualism : a means for creating an architecture of relationships

This study explores the idea of mutualism as a process of combining apparently oppositional elements into interdependent relationships. This combination creates an architectural system which provides greater value to its component parts and simultaneously establishes a larger more coherent whole. It is through this process that a zone of combination is achieved, a zone that is perhaps more real and which speaks to the complex fluidity of contemporary life. The method chosen for the exploration of this thesis involves the design of an architectural design/build school which focuses on a hands on approach to education to be located in downtown Chattanooga Tennessee

An electrical probe of the phonon mean-free path spectrum

Most studies of the mean-free path accumulation function (MFPAF) rely on optical techniques to probe heat transfer at length scales on the order of the phonon mean-free path. In this paper, we propose and implement a purely electrical probe of the MFPAF that relies on photo-lithographically defined heater-thermometer separation to set the length scale. An important advantage of the proposed technique is its insensitivity to the thermal interfacial impedance and its compatibility with a large array of temperature-controlled chambers that lack optical ports. Detailed analysis of the experimental data based on the enhanced Fourier law (EFL) demonstrates that heat-carrying phonons in gallium arsenide have a much wider mean-free path spectrum than originally thought

Postcard from James H. Morton to G. W. D. Bowers

Postcard from James H. Morton to G. W. D. Bowers. The handwritten note is dated 23 February 1909. There is a transcript of the correspondence in the item PDF

Design of Accelerated Fatigue Tests for Flame Free Refrigeration Fittings

Refrigerant leakage from failed braze joints is a multi-billion dollar problem for the global HVAC&R industry. Leaks are typically caused due to mechanical fatigue from extreme pressure cycling, temperature cycling including exposure to freeze/thaw cycles, or vibrational wear induced from rotating electrical machinery. Three tests to accelerate mechanical fatigue were devised to simulate real world extreme conditions to determine possible failure modes of refrigerant components. The first test is a freeze/thaw test which simulates ice buildup and defrost observed during heat pump operation. Field failures of brazed joints have been detected due to water being trapped in tight spaces and expanding during freezing, causing high stress on brazed joints and joining methods. The second test is a combined thermal/pressure shock test designed to simulate abrupt temperature and pressure changes due to start/stop cycles and frost/defrost mode changes. The third test is a vibration test, designed to simulate vibrational loads induced from rotating components in the system. The test article is a flame-free tube fitting designed to work with refrigerants. Six different fitting sizes designed to connect tubes between 6.35 mm and 28.5 mm were subjected to the three tests described above