Acoustic radiation from lined, unflanged ducts: Duct termination impedance program

For abstract, see N75-28849

A theoretical approach to sound propagation and radiation for ducts with suppressors

The several phenomena involved in theoretical prediction of the far-field sound radiation attenuation from an acoustically lined duct were studied. These include absorption by the suppressor, termination reflections, and far-field radiation. Extensive parametric studies show that the suppressor absorption performance can be correlated with mode cut-off ratio or angle of propagation. The other phenomena can be shown to depend explicitly upon mode cut-off ratio. A complete system can thus be generated which can be used to evaluate aircraft sound suppressors and which can be related to the sound source through the cut-off ratio-acoustic power distribution. Although the method is most fully developed for inlet suppressors, several aft radiated noise phenomena are also discussed. This simplified suppressor design and evaluation method is summarized, the recent improvements in the technique are presented, and areas where further refinement is necessary are discussed. Noise suppressor data from engine experiments are compared with the theoretical calculations

Acoustic radiation from lined unflanged ducts: Directivity index program

For abstract, see N75-28849

On the two-dimensional atmospheric turbulence response of an airplane

Two dimensional gust response analysis of aircraft to atmospheric turbulenc

Analytical and experimental studies of an optimum multisegment phased liner noise suppression concept

Results are presented from detailed analytical studies made to define methods for obtaining improved multisegment lining performance by taking advantage of relative placement of each lining segment. Properly phased liner segments reflect and spatially redistribute the incident acoustic energy and thus provide additional attenuation. A mathematical model was developed for rectangular ducts with uniform mean flow. Segmented acoustic fields were represented by duct eigenfunction expansions, and mode-matching was used to ensure continuity of the total field. Parametric studies were performed to identify attenuation mechanisms and define preliminary liner configurations. An optimization procedure was used to determine optimum liner impedance values for a given total lining length, Mach number, and incident modal distribution. Optimal segmented liners are presented and it is shown that, provided the sound source is well-defined and flow environment is known, conventional infinite duct optimum attenuation rates can be improved. To confirm these results, an experimental program was conducted in a laboratory test facility. The measured data are presented in the form of analytical-experimental correlations. Excellent agreement between theory and experiment verifies and substantiates the analytical prediction techniques. The results indicate that phased liners may be of immediate benefit in the development of improved aircraft exhaust duct noise suppressors

Influences of 12-Hour Shifts on Unhealthy Eating Habits of Acute Care Nurses

Shift work is a necessary part of a nurses’ work schedule to patients who need 24 hours of continuous care. Eating habits of nurses are influenced by working long hours, not having adequate time to take a meal break, and not having access to healthy food choices which can cause stress and exhaustion and results in weight gain and obesity. The purpose of this quantitative logistic regression analysis, guided by the health belief model and the theory of planned behavior, was to determine if there was a relationship between shift work and the unhealthy eating habits/obesity rates of acute care nurses. Data were gathered from the Nurses’ Study 3, which includes information from nurses or nursing students from the United States and Canada. The sample was 8988 nurses who worked 12-hour shifts and more than 20 hours per week. The results demonstrated that the relationship between working 12-hour shifts and unhealthy eating was not statistically significant (p = 0.39) the relationship between working 12-hour shifts and obesity rates were not statistically significant (p = 0.32). Further studies are needed to determine how often nurses eat or eat while working during their shift because of perceived inability to take scheduled breaks because of workloads. The study findings provide evidence for health professionals to examine their eating habits and modify healthy eating behaviors to maintain a healthy lifestyle. When nurses learn to care for themselves, nurses are positive role models for their patients by encouraging healthy lifestyles which effects positive social change

A review of salt transport in porous media : assessment methods and salt reduction treatments

It is an unpalatable fact that while objects can deteriorate through lack of care and attention, they can also deteriorate as a result of inappropriate and misguided interventions. This is particularly the case with regard to salt-related deterioration problems. A successful treatment outcome using aqueous salt reduction methods demands an understanding of the transport processes involved as well as detailed information regarding the characteristics and specific situation of the individual object. The use of poultice materials to reduce the salt content of salt deteriorated objects is a long established technique in conservation. However, due to the complex nature of salt problems within historic structures the result of such interventions can be variable and unpredictable. The amount and depth to which salts are mobilised, and where they are transported to, is dependent on the inter-relationship between the poultice and the substrate, the drying conditions and also the initial salt distribution. This paper examines the current scientific understanding of salt and moisture transport processes, and the extent to which this knowledge can feed back into the practical arena, to aid the conservator. Moreover, areas where further research is required are identified. In particular, the importance of pre- and post treatment investigations is highlighted, showing how, in combination with knowledge of salt and moisture transport mechanisms, these can give useful indications regarding treatment options. The role of selective salt extraction and the post treatment behaviour of residual salts are discussed

A comparison study examining maternal perception of outcomes of delivery and future pregnancies in Parirenyatwa Hospital, Zimbabwe and the Queen Alexandra Hospital, Portsmouth, England.

Poster presenting a comparative study examining maternal perception of outcomes of delivery and future pregnancies in Parirenyatwa Hospital, Zimbabwe and the Queen Alexandra Hospital, Portsmouth, England; Poster Global Health

Social and Psychological Factors Associated with Health Care Transition for Young Adults Living with Sickle Cell Disease

Introduction: Due to advances in disease management, mortality rates in children with sickle cell disease (SCD) have decreased. However, mortality rates for young adults (YA) increased, and understanding of social and psychological factors is critical. The aim of this study was to explore factors associated with health care transition experiences for YA with SCD. Method: This was a qualitative descriptive study. A 45-minute semistructured interview was conducted with 13 YA (M = 21.5 years, SD = 1.73). Results: Results suggest that social and psychological factors and self-management experiences influence health care transition. Eight themes emerged: “need for accessible support”; “early assistance with goal setting”; “incongruence among expectations, experiences, and preparation”; “spiritual distress”; “stigma”; “need for collaboration”; “appreciation for caring providers”; and “feeling isolated.” Discussion: Consideration of cultural contexts will guide nurses in supporting health care transition. Designing culturally relevant interventions that address unique needs for YA living with SCD is warranted

Complementary and Alternative Medicine Mind-Body Approaches Used Among Racially and Ethnically Diverse Adolescents

Purpose The aim of this paper is to examine complementary and alternative medicine (CAM) use among racially and ethnically diverse adolescents. Greater understanding of CAM use among this group is warranted to better inform health care providers in delivering a culturally relevant health promotion approach. Design and methods A secondary data analysis was conducted using the 2012 Child Complementary and Alternative Medicine Supplement of the National Health Interview Survey (CAM-NHIS) data, which was collected from a national sample of adolescents aged 12–17 years. A logistic regression test was employed to investigate the predictors associated with CAM use among racially and ethnically diverse adolescents. Results While Black and Hispanic adolescents were the least likely to use CAM compared to their White counterparts, families with higher incomes, higher education attainment, and adolescents who experienced pain were more likely to use CAM. Conclusions Findings suggest the need for future research to gain a greater understanding of CAM use among racially and ethnically diverse adolescents, and insights into how health disparities impact CAM use. Greater understanding of how CAM use intersects with health beliefs and outcomes is also warranted. Practice implications Based on the CAM-NHIS survey, few racially and ethnically diverse adolescents have reported use of CAM. Development of culturally appropriate instruments and methods to assess CAM use among racially and ethnically diverse adolescents may yield specific data for this population. Informed health care providers can advocate for improved access to CAM for minority adolescents and alter disparate use