Correlation of part-span damper losses through transonic rotors operating near design point

The design-point losses caused by part-span dampers (PSD) were correlated for 21 transonic axial flow fan rotors that had tip speeds varying from 350 to 488 meters per second and design pressure ratios of 1.5 to 2.0. For these rotors a correlation using mean inlet Mach number at the damper location, along with relevant geometric and aerodynamic loading parameters, predicts the variation of total pressure loss coefficient in the region of the damper to a good approximation

Secondary flow spanwise deviation model for the stators of NASA middle compressor stages

A model of the spanwise variation of deviation for stator blades is presented. Deviation is defined as the difference between the passage mean flow angle and the metal angle at the outlet of a blade element of an axial compressor stage. The variation of deviation is taken as the difference above or below that predicted by blade element, (i.e., two-dimensional) theory at any spanwise location. The variation of deviation is dependent upon the blade camber, solidity and inlet boundary layer thickness at the hub or tip end-wall, and the blade channel aspect ratio. If these parameters are known or can be calculated, the model provides a reasonable approximation of the spanwise variation of deviation for most compressor middle stage stators operating at subsonic inlet Mach numbers

The role of follow-on contracts in government-sponsored research and development

Role of follow-on contracts in government sponsored research and developmen

An experimental investigation of internal area ruling for transonic and supersonic channel flow

A simulated transonic rotor channel model was examined experimentally to verify the flow physics of internal area ruling. Pressure measurements were performed in the high speed wind tunnel at transonic speeds with Mach 1.5 and Mach 2 nozzle blocks to get an indication of the approximate shock losses. The results showed a reduction in losses due to internal area ruling with the Mach 1.5 nozzle blocks. The reduction in total loss coefficient was of the order of 17 percent for a high blockage model and 7 percent for a cut-down model

Off-design correlation for losses due to part-span dampers on transonic rotors

Experimental data from 10 transonic fan rotors were used to correlate losses created by part-span dampers located near the midchord position on the rotor blades. The design tip speed of these rotors varied from 419 to 425 m/sec, and the design pressure ratio varied from 1.6 to 2.0. Additional loss caused by the dampers for operating conditions between 50 and 100 percent of design speed were correlated with relevant aerodynamic and geometric parameters. The resulting correlation predicts the variation of total-pressure-loss coefficient in the damper region to a good approximation

Development and Validation of a Tool to Measure Patient Assessment of Clinical Compassion

Importance: Clinician compassion is a vital element of health care quality. Currently, there appears to be no validated and feasible method for health care organizations to measure patient assessment of clinician compassion on a large scale. Objective: To develop and validate a tool for measuring patient assessment of clinician compassion that can be used in conjunction with the Clinician and Group Consumer Assessment of Healthcare Providers and Systems (CG-CAHPS) survey. Design, Setting, and Participants: This prospective cohort study took place from June 1 to August 30, 2018, at a US academic health care system among a pilot cohort consisting of 3325 adult patients and a validation cohort consisting of 3483 adult patients, both of whom had an outpatient clinic visit and completed the CG-CAHPS survey. Main Outcomes and Measurements: After a comprehensive literature review, 12 candidate survey items were developed. Face and construct validity were performed. Candidate items were disseminated to patients in conjunction with the CG-CAHPS survey in a series of 2 studies: (1) exploratory factor analysis in one cohort to determine the factor structure and the most parsimonious set of items; and (2) validity testing in a second cohort using confirmatory factor analysis. Reliability was tested using Cronbach α. Convergent validity was tested with patient assessment of clinician communication and overall satisfaction questions from CG-CAHPS survey. Results: Overall, 6493 patient responses were analyzed. The mean (SD) age was 60 (15) years, 4239 patients (65.3%) were women, and 5079 (78.2%) were white. Exploratory factor analyses identified a 5-item compassion measure to be the most parsimonious. Confirmatory factor analyses found good fit. The compassion measure demonstrated good internal consistency (α = 0.94) and convergent validity (clinician communication: ρ = 0.44; overall satisfaction: ρ = 0.52) but reflected a patient experience domain (compassionate care) distinct from what is currently captured in the CG-CAHPS survey. Conclusions and Relevance: A simple 5-item tool to measure patient assessment of clinician compassion was developed and validated for use in conjunction with CG-CAHPS survey

Garnet–monazite rare earth element relationships in sub-solidus metapelites: a case study from Bhutan

A key aim of modern metamorphic geochronology is to constrain precise and accurate rates and timescales of tectonic processes. One promising approach in amphibolite and granulite-facies rocks links the geochronological information recorded in zoned accessory phases such as monazite to the pressure–temperature information recorded in zoned major rock-forming minerals such as garnet. Both phases incorporate rare earth elements (REE) as they crystallize and their equilibrium partitioning behaviour potentially provides a useful way of linking time to temperature. We report REE data from sub-solidus amphibolite-facies metapelites from Bhutan, where overlapping ages, inclusion relationships and Gd/Lu ratios suggest that garnet and monazite co-crystallized. The garnet–monazite REE relationships in these samples show a steeper pattern across the heavy (H)REE than previously reported. The difference between our dataset and the previously reported data may be due to a temperature-dependence on the partition coefficients, disequilibrium in either dataset, differences in monazite chemistry or the presence or absence of a third phase that competed for the available REE during growth. We urge caution against using empirically-derived partition coefficients from natural samples as evidence for, or against, equilibrium of REE-bearing phases until monazite–garnet partitioning behaviour is better constrained

The Physics Case for the New Muon (g-2) Experiment

This White Paper briefly reviews the present status of the muon (g-2) experiment and the physics motivation for a new effort. The present comparison between experiment and theory indicates a tantalizing $3.4 \sigma$ deviation. An improvement in precision on this comparison by a factor of 2--with the central value remaining unchanged--will exceed the ``discovery'' threshold, with a sensitivity above $6 \sigma$. The 2.5-fold reduction improvement goal of the new Brookhaven E969 experiment, along with continued steady reduction of the standard model theory uncertainty, will achieve this more definitive test. Already, the (g-2) result is arguably the most compelling indicator of physics beyond the standard model and, at the very least, it represents a major constraint for speculative new theories such as supersymmetry or extra dimensions. In this report, we summarize the present experimental status and provide an up-to-date accounting of the standard model theory, including the expectations for improvement in the hadronic contributions, which dominate the overall uncertainty. Our primary focus is on the physics case that motivates improved experimental and theoretical efforts. Accordingly, we give examples of specific new-physics implications in the context of direct searches at the LHC as well as general arguments about the role of an improved (g-2) measurement. A brief summary of the plans for an upgraded effort complete the report.Comment: 18 pages, 7 figure

Development of a CCD for ultraviolet imaging using a CCD photocathode combination

CCD in the electron-in mode, coupled with a bi-alkali photocathode to produce UV photon conversion, provides the following desirable features: (1) high UV response of the bi-alkali photocathode; (2) excellent imaging quality of a CCD area array; and (3) high signal-to-noise ratio due to the EBS (electron bombarded silicon) gain of the CCD operating in a tube configuration. This paper describes the rationale and progress made in developing a CCD for use as an UV imager