Empirical source noise prediction method with application to subsonic coaxial jet mixing noise

A general empirical method, developed for source noise predictions, uses tensor splines to represent the dependence of the acoustic field on frequency and direction and Taylor's series to represent the dependence on source state parameters. The method is applied to prediction of mixing noise from subsonic circular and coaxial jets. A noise data base of 1/3-octave-band sound pressure levels (SPL's) from 540 tests was gathered from three countries: United States, United Kingdom, and France. The SPL's depend on seven variables: frequency, polar direction angle, and five source state parameters: inner and outer nozzle pressure ratios, inner and outer stream total temperatures, and nozzle area ratio. A least-squares seven-dimensional curve fit defines a table of constants which is used for the prediction method. The resulting prediction has a mean error of 0 dB and a standard deviation of 1.2 dB. The prediction method is used to search for a coaxial jet which has the greatest coaxial noise benefit as compared with an equivalent single jet. It is found that benefits of about 6 dB are possible

Online learning : towards enabling choice

Education is rapidly evolving from an opportunity that was provided mainly for an elite to one that is available to a mass markets and as such is prone to the forces generated by this environment. Where, in the established pattern, commercial interest was limited mainly to the use of skills developed during the educational process, the future model of educational provision will involve extensive commercial activity in the production, delivery and marketing of material. Already there are a number of commercial companies offering framework products enabling "off the shelf solutions" for the construction and delivery of web based courses in any subject area. The commercialisation of education is underway and it is inevitable that it will be viewed, by entrepreneurs and customers alike, as any other commercial product. It would seem reasonable that the consumer should be able to evaluate the performance of these new modes of working in a similar manner to other commercial products. This paper draws together current thinking on the problems associated with evaluating computer and communication based learning

Tabulation and summary of thermodynamic effects data for developed cavitation on ogive-nosed bodies

Thermodynamic effects data for developed cavitation on zero and quarter caliber ogives in Freon 113 and water are tabulated and summarized. These data include temperature depression (delta T), flow coefficient (C sub Q), and various geometrical characteristics of the cavity. For the delta T tests, the free-stream temperature varied from 35 C to 95 C in Freon 113 and from 60 C to 125 C in water for a velocity range of 19.5 m/sec to 36.6 m/sec. Two correlations of the delta T data by the entrainment method are presented. These correlations involve different combinations of the Nusselt, Reynolds, Froude, Weber, and Peclet numbers and dimensionless cavity length

Correlations by the entrainment theory of thermodynamic effects for developed cavitation in venturis and comparisons with ogive data

A semi-empirical entrainment theory was employed to correlate the measured temperature depression, Delta T, in a developed cavity for a venturi. This theory correlates Delta t in terms of the dimensionless numbers of Nusselt, Reynolds, Froude, Weber and Peclet, and dimensionless cavity length, L/D. These correlations are then compared with similar correlations for zero and quarter caliber ogives. In addition, cavitation number data for both limited and developed cavitation in venturis are presented

Emic and Etic Perspectives on HR Practice for Managing Human Resource Issues Affected by the Prevalence of Informal Networks in Arab Countries

Whilst research on Wasta has been improving in quantity and quality, there is still much more to know about the interactions between the different parties in Wasta transactions, the role of power in this process and how it impacts HR functions. As such, this research aims to address this gap by exploring the use of Wasta in human resources (HR) functions, drawing on 17 semi-structured interviews with HR, recruitment and line managers working in the Jordanian banking sector. This paper focuses on the roles of trust and power in the organizational transactions in which Wasta is positioned and identifies recruitment and selection (R&S) as one of the main human resource (HR) practices and procedures that are affected by Wasta. The findings shed light on the impact of Wasta on HRM practice on the micro and macro levels, highlighting the complex socio-economic needs for this practice which, whilst they might be beneficial on the micro level in terms of securing employment for job seekers and benefits for organizations in the Wasta exchange process, can also have some substantive negative outcomes in the forms of social and economic exclusion of others outside the Wasta network. By doing so, it develops the conceptualization beyond the often-simplistic view of Wasta as a negative (and sometimes positive) practice as viewed by previous research extending it to a practice that could have either impact on different stakeholder

Spectroscopy of quasar candidates from the case low-dispersion survey

Case Low-Dispersion Northern Sky Survey. Thirteen of them are quasars, ranging in redshift from 0.0786 to 2.67, with a median redshift of 2. CSO 203 is a broad absorption-line quasar, and CSO 38 may have substantial associated absorption in the cores of emission lines. Several other objects show some intervening absorption, and all of them are bright enough to make the follow-up studies practical. CSO 251 is a bright (~15m), previously uncataloged quasar. The remaining objects are Galactic stars, five subdwarfs, and one hot white dwarf (CSO 160)

Older adults' attitudes towards deprescribing and medication changes: a longitudinal sub-study of a cluster randomised controlled trial.

To investigate the association between older patients' willingness to have one or more medications deprescribed and: (1) change in medications, (2) change in the appropriateness of medications and (3) implementation of prescribing recommendations generated by the electronic decision support system tested in the 'Optimising PharmacoTherapy In the Multimorbid Elderly in Primary CAre' (OPTICA) trial. A longitudinal sub-study of the OPTICA trial, a cluster randomised controlled trial. Swiss primary care settings. Participants were aged ≥65 years, with ≥3 chronic conditions and ≥5 regular medications recruited from 43 general practitioner (GP) practices. Patients' willingness to have medications deprescribed was assessed using three questions from the 'revised Patient Attitudes Towards Deprescribing' (rPATD) questionnaire and its concerns about stopping score. Medication-related outcomes were collected at 1 year follow-up. Aim 1 outcome: change in the number of long-term medications between baseline and 12 month follow-up. Aim 2 outcome: change in medication appropriateness (Medication Appropriateness Index). Aim 3 outcome: binary variable on whether any prescribing recommendation generated during the OPTICA medication review was implemented. We used multilevel linear regression analyses (aim 1 and aim 2) and multilevel logistic regression analyses (aim 3). Models were adjusted for sociodemographic variables and the clustering effect at GP level. 298 patients completed the rPATD, 45% were women and 78 years was the median age. A statistically significant association was found between the concerns about stopping score and the change in the number of medications over time (per 1-unit increase in the score the average number of medications use was 0.65 higher; 95% CI: 0.08 to 1.22). Other than that we did not find evidence for statistically significant associations between patients' agreement with deprescribing and medication-related outcomes. We did not find evidence for an association between most measures of patient agreement with deprescribing and medication-related outcomes over 1 year. NCT03724539