Fundamental and applied research on core engine/combustion noise of aircraft engines

Some results of a study of the importance of geometrical features of the combustor to combustion roughness and resulting noise are presented. Comparison is made among a perforated can flame holder, a plane slotted flame holder and a plane slotted flame holder which introduces two counter swirling streams. The latter is found to permit the most stable, quiet combustion. Crosscorrelations between the time derivative of chamber pressure fluctuations and far field noise are found to be stronger than between the far field noise and the direct chamber pressure signal. Temperature fluctuations in the combustor nozzle are also found to have a reasonably strong crosscorrelation with far field sound

A Meta-Analysis of Political Advertising

Political advertising is one of the dominant media for reaching voters. Previous metaanalyses (Allen & Burrell, 2002; Lau, Sigelman, Heldman, & Babbitt, 1999) found little or no net benefit to negative versus positive ads. However, this finding does not reveal whether ads have effects (both or neither could be persuasive). A meta-analysis revealed that political spots increased issue knowledge, influenced perceptions of the candidates’ character, altered attitudes, and affected candidate preference; influenced agenda-setting, and altered vote likelihood (turnout). One moderator variable was detected: The effect size for learning was larger for studies of students than non-students; however, the effect size for both sub-groups was significant. On the other hand, political ads had larger effects on attitudes for non-students than students

Addressing Barriers to Breast Cancer Screening: Where to Intervene to Increase Mammogram Completion Rates

Methods: Study sought to determine if an intervention would aid in increasing mammogram screening rates in the Jefferson Family Medicine Associates practice.https://jdc.jefferson.edu/patientsafetyposters/1061/thumbnail.jp

Value Control for System Design

Value and cost are created and therefore controlled by the designer. Design decisions made so as to achieve the proper balance of costs and performance will yield the greatest utility value to a system. Good value may be achieved by developing a cost model and a performance requirements model in detail sufficient to permit trade-offs to be made by the individual designer

Sonify Your Lesson Using aQWERTYon

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Is alcohol dependence best viewed as a chronic relapsing disorder?

This 'For Debate' paper starts by recognizing the growing trend towards considering alcohol dependence as a chronic relapsing disorder. We argue that the adoption of this model results from focusing on those in treatment for alcohol dependence rather than considering the larger number of people in the general population who meet criteria for alcohol dependence at some point in their lives. The majority of the general population who ever experience alcohol dependence do not behave as though they have a chronic relapsing disorder: they do not seek treatment, resolve their dependence themselves and do not relapse repeatedly. We suggest that caution is therefore needed in using the chronic relapsing disorder label. Our primary concerns are that this formulation privileges biological aspects of dependence to the detriment of psychological and social contributions, it inhibits much-needed developments in understanding alcohol dependence and leads to inefficient distributions of public health and clinical care resources for alcohol dependence. We invite debate on this issue

Childhood physical abuse and adulthood mortality in treatment-seeking male veterans with combat-related PTSD

Posttraumatic stress disorder (PTSD) has been associated with increased overall risk for mortality as well as deaths death due to behavioral causes in combat veterans. In addition, adverse childhood experiences, including childhood physical abuse, have been associated with many of the leading causes of death in adults. The present study investigated childhood physical punishment experiences in 1,866 U.S. military male combat veterans who had been in residential PTSD treatment in order to explore whether such experiences were related to increased risk for mortality or cause of death in this population. It was hypothesized that more physical punishment would be related to increased mortality and behaviorally-caused deaths. Possible confounding variables such as depression and substance use disorders were also taken into account in the analyses. One-way ANOVAs comparing groups found no significant differences in mortality or cause of death based on childhood physical punishment experiences. Possible explanations for these findings are discussed and treatment implications are explored