An evaluation of Space Shuttle STS-1 payload bay acoustic data and comparison with predictions

During the first launch (STS-1) of the Space Shuttle orbiter vehicle, sound pressure levels were measured at several locations in the payload bay of the vehicle and on the exterior surface. The data were obtained in order to provide validation for prediction procedures for interior and exterior sound pressure levels and to determine, independently, the acoustic environment in the payload bay during actual launch conditions

An evaluation of Space Shuttle STS-3 payload bay acoustic data and comparison with predictions

Acoustic data collected inside the payload bay and over the exterior of the orbiter collected during the third launch (STS 3) were analyzed and evaluated

An evaluation of Space Shuttle STS-2 payload bay acoustic data and comparison with predictions

Space average sound pressure levels computed from measurements at 18 locations in the payload bay of the Space Shuttle orbiter vehicle during the STS-2 launch were compared with predicted levels obtained using the PACES computer program. The comparisons were performed over the frequency range 12.5 Hz to 1000 Hz, since the test data at higher frequencies are contaminated by instrumentation background noise. In general the PACES computer program tends to overpredict the space average sound levels in the payload bay, although the magnitude of the discrepancy is usually small. Furthermore the discrepancy depends to some extent on the manner in which the payload is modeled analytically, and the method used to determine the "measured' space average sound pressure levels. Thus the difference between predicted and measured sound levels, averaged over the 20 one third octave bands from 12.5 Hz to 1000 Hz, varies from 1 dB to 3.5 dB

Evaluation of aero Commander propeller acoustic data: Static operations

Acoustic data are analyzed from a series of ground tests performed on an Aero Commander propeller-driven aircraft with an array of microphones flush-mounted on one side of the fuselage. The analyses were concerned with the propeller blade passage noise during static operation at several different engine speeds and included calculations of the magnitude and phase of the blade passage tones, the amplitude stability of the tones, and the spatial phase and coherence of the tones. The results indicate that the pressure field impinging on the fuselage represents primarily aerodynamic (near field) effects in the plane of the propeller at all frequencies. Forward and aft of the propeller plane aerodynamic effects still dominate the pressure field at frequencies below 200 Hz; but at higher frequencies, the pressure field is due to acoustic propagation from an equivalent center located about 0.15 to 0.30 blade diameters inboard from the propeller hub

Evaluation of Aero Commander sidewall vibration and interior acoustic data: Static operations

Results for the vibration measured at five locations on the fuselage structure during static operations are presented. The analysis was concerned with the magnitude of the vibration and the relative phase between different locations, the frequency response (inertance) functions between the exterior pressure field and the vibration, and the coherent output power functions at interior microphone locations based on sidewall vibration. Fuselage skin panels near the plane of rotation of the propeller accept propeller noise excitation more efficiently than they do exhaust noise

An evaluation of Space Shuttle STS-3 payload bay acoustic data and comparison with predictions

Acoustic data inside the payload bay and over the exterior of the orbiter were collected. The data were used to evaluate the Payload Acoustic Environment for Shuttle (PACES) computer program

A new stall-onset criterion for low speed dynamic-stall

The Beddoes/Leishman dynamic-stall model has become one of the most popular for the provision of unsteady aerofoil data embedded in much larger codes. The underlying modeling philosophy was that it should be based on the best understanding, or description, of the associated physical phenomena. Even though the model was guided by the flow physics, it requires significant empirical inputs in the form of measured coefficients and constants. Beddoes provided these for a Mach number range of 0.3–0.8. This paper considers one such input for a Mach number of 0.12, where, from the Glasgow data, it is shown that the current stall-onset criterion, and subsequent adjustments, yield problematic results. A new stall criterion is proposed and developed in the best traditions of the model. It is shown to be very capable of reconstructing the Glasgow's data for stall onset both the ramp-up and oscillatory tests

Modes of climate variability and associated bird communities in India

Birds are sensitive to climate variability and change. This pilot study explores variations in bird communities in India under contrasting phases of the El NinoSouthern Oscillation (ENSO) and Indian Ocean Dipole (IOD). Statistical analyses were performed using monthly bird data for the years 1990-2015 in Goa and Tamil Nadu. Monthly precipitation, temperature, the Oceanic Nino Index and the Dipole Mode Index were used as explanatory variables for species richness (SR) and counts of three marker species (Brahminy Kite, Indian Pond Heron and Lesser Whistling Duck). Due to highly autocorrelated series, small sample sizes and many test permutations there is greater likelihood of Type I errors when interpreting correlation results. However, pooling bird data by climate mode and state revealed that SR was generally greater under El Nino or negative IOD (locally wet conditions) than under La Nina or positive IOD (locally dry conditions). In Goa, the Brahminy Kite, Indian Pond Heron and Lesser Whistling Duck had significantly higher counts during El Nino than La Nina events. In Tamil Nadu, there were significantly more Kites under negative than positive IOD phases. Regional variations in sensitivity may reflect species-dependent factors such as food availability and security of nesting sites. Further research is needed to establish causal mechanisms between climate mode and SR as well as into the combined effects of ENSO and IOD on bird communities across South Asia

Wettest December in the Lake District for over 200 years

Wettest December in the Lake District for over 200 year

Practice implications of an antimicrobial stewardship intervention in a tertiary care teaching hospital, Qatar

Background: Antibiotic misuse is a worldwide public health problem and has been associated with increased morbidity, length of hospital stay, mortality, healthcare costs, and most importantly antibiotic resistance. Aims: We aimed to evaluate the compliance of antibiotic prescribing with national guidelines, assess how educational interventions can best be utilized to make impact and fill gaps for optimal antibiotic utilization, and to identify facilitators and barriers to implementing ASPs in Qatar. Methods: Six cross-sectional baseline audits of antibiotic prescribing were conducted over a two-week period at a tertiary care teaching hospital. A sub-analysis of prescriptions with follow up has followed. An educational intervention utilizing the PDSA (Plan-Do-Study-Act) tool was implemented to address gaps identified. A repeated audit was done to assess the impact of change. Lastly, interviews were conducted to recognize perceived facilitators and barriers for ASP implementation, identify strategies to overcome barriers, and evaluate the effectiveness of educational interventions. Results: The most common indication for antibiotic prescribing was febrile neutropenia (20.7%). The most frequently used class of antibiotics was carbapenems (21.4%). Sixty percent of prescriptions complied with guidelines. The rationale behind choosing not to adhere to guidelines was not documented in 37.2% of cases. Suboptimal documentation in records was targeted through our intervention. The audit post intervention showed slight improvement in documentation. Facilitators and barriers included: collaboration and communication among teams, compliance with guidelines, interventions documented by clinical pharmacists, and electronic system errors. Conclusions: Effective communication, continuous documentation in records, and repetitive education promote rational antibiotic prescribing and enhance ASPs.This report was made possible by a UREP award [UREP18-033-3-010] from the Qatar National Research Fund (a member of The Qatar Foundation)