Experimental Investigation of Average Heat-Transfer and Friction Coefficients for Air Flowing in Circular Tubes Having Square-Thread-Type Roughness

An investigation of forced-convection heat transfer and associated pressure drops was conducted with air flowing through electrically heated Inconel tubes having various degrees of square-thread-type roughness, an inside diameter of 1/2 inch, and a length of 24 inches. were obtained for tubes having conventional roughness ratios (height of thread/radius of tube) of 0 (smooth tube), 0.016, 0.025, and 0.037 over ranges of bulk Reynolds numbers up to 350,000, average inside-tube-wall temperatures up to 1950deg R, and heat-flux densities up to 115,000 Btu per hour per square foot. Data The experimental data showed that both heat transfer and friction increased with increase in surface roughness, becoming more pronounced with increase in Reynolds number; for a given roughness, both heat transfer and friction were also influenced by the tube wall-to-bulk temperature ratio. Good correlation of the heat-transfer data for all the tubes investigated was obtained by use of a modification of the conventional Nusselt correlation parameters wherein the mass velocity in the Reynolds number was replaced by the product of air density evaluated at the average film temperature and the so-called friction velocity; in addition, the physical properties of air were evaluated at the average film temperature. The isothermal friction data for the rough tubes, when plotted in the conventional manner, resulted in curves similar to those obtained by other investigators; that is, the curve for a given roughness breaks away from the Blasius line (representing turbulent flow in smooth tubes) at some value of Reynolds number, which decreases with increase in surface roughness, and then becomes a horizontal line (friction coefficient independent of Reynolds number). A comparison of the friction data for the rough tubes used herein indicated that the conventional roughness ratio is not an adequate measure of relative roughness for tubes having a square-thread-type element. The present data, as well as those of other investigators, were used to isolate the influence of ratios of thread height to width, thread spacing to width, and the conventional roughness ratio on the friction coefficient. A fair correlation of the friction data was obtained for each tube with heat addition when the friction coefficient and Reynolds number were defined on the basis of film properties; however, the data for each tube retained the curve characteristic of that particular roughness. The friction data for all the rough tubes could be represented by a single line for the complete turbulence region by incorporating a roughness parameter in the film correlation. No correlation was obtained for the region of incomplete turbulence

Best Practice in Developing Critical Analyses: An Empirical Study of Self-Efficacy from an Interdisciplinary Perspective

Despite substantial usage of case study analyses as learning tools in diverse fields of study, business graduate students often arrive with little to no prior knowledge in how to effectively use this tool. Using the Sams efficacy model (2009) strategic to business education this study identified a dearth in the usage of case study analyses in business graduate courses and also provides a step-by-step process to increase critical analysis and efficacy through the usage of case studies. Findings demonstrate that critical analysis is developed through a combination of teaching tools through additive strategies to impact more learning modalities at the graduate education level. A counter-intuitive finding was that formative written feedback did not significantly increase the development of case study analyses skills; this finding supports the additive model. This research brings forward universal best practices for developing critical analysis, as self-efficacy in business applications also increases

Refan program. Phase 1: Summary report

The Refan Program is aimed at a large reduction in aircraft approach and takeoff noise in the vicinity of airports caused by the JT3D-powered 707's and DC-8's and the JT8D-powered 727's, 737's and DC-9's. These aircraft represent a major part of the existing commercial fleet. The noise reductions can be achieved by engine and nacelle modifications in the form of aircraft retrofit kits. Engine turbomachinery noise is reduced by replacing the current two-stage fan with a larger single-stage fan and by nacelle acoustic treatment. Jet noise is reduced by the reduction on jet velocity caused by additional turbine work extraction to drive the larger bypass fan. The predicted net effect of these modifications on installed performance is large noise reductions on both approach and takeoff, increased takeoff thrust, decreased takeoff field length, and maintained or improved aircraft range depending on the amount of acoustic treatment included. The Refan Program is being conducted in two phases under contracts with one engine and two airframe companies. Results of the Phase I work are summarized in this report which describes the refan nacelle configurations studied, the airplane modifications required to install the nacelles, and the resulting airplane performance and noise reductions predicted for all five aircraft

Notes on scandal : lobbying reforms and public opinion in Canada

Dissertation supervisor: Dr. James W. Endersby.Includes vita.Political scandal is a topic that receives wide media coverage and speculation. While political scandals have tendency to set off a firestorm of press coverage, scandals also may have great implications for democracy. A common conversation associated with political scandals has been that of lobbying reforms to reduce undue influence over the policy process. Scandals may also lead to negative feelings about political efficacy and confidence in government institutions which can threaten the democratic health of a polity. Using a combination of original data gathered from provincial news sources in Canada and public opinion from the CES, this study reaches several conclusions. The first conclusion is that political scandals increase the adoption of lobbying policies in Canadian provinces. Political scandals, such as the groundbreaking Canadian Sponsorship Scandal, are also found to have deep implications on political efficacy, confidence in government, and feelings about politicians. Finally, this study suggests that while provincial-level political scandals play an important role in provincial adoptions of lobbying policy, provincial scandals do not impact evaluations of federal politics.Includes bibliographical references (pages 145-159)

Whole Blood Activation Results in Enhanced Detection of T Cell and Monocyte Cytokine Production by Flow Cytometry

An excellent monitor of the immune balance of peripheral circulating cells is to determine their cytokine production patterns in response to stimuli. Using flow cytometry a positive identification of cytokine producing cells in a mixed culture may be achieved. Recently, the ability to assess cytokine production following a wholeblood activation culture has been described. We compared whole blood culture to standard PBMC culture and determined the individual cytokine secretion patterns for both T cells and monocytes via flow cytometry. For T cells cytokine assessment following PMA +ionomycin activation: (1) a significantly greater percentages of T cells producing IFNgamma and IL-2 were observed following whole-blood culture; (2) altered T cell cytokine production kinetics were observed by varying whole blood culture times. In addition, a four-color cytometric analysis was used to allow accurate phenotyping and quantitation of cytokine producing lymphocyte populations. Using this technique we found IFNgamma production to be significantly elevated in the CD3+/CD8+ T cell population as compared to the CD3+/CD8- population following five hours of whole blood activation. Conversely, IL-2 and IL-10 production were significantly elevated in the CD3+/CD8- T cell population as compared to the CD3+/CD8+ population. Monocyte cytokine production was assessed in both culture systems following LPS activation for 24 hours. A three-color flow cytometric was used to assess two cytokines in conjunction with CD 14. The cytokine pairs used for analysis were IL-1a/IL-12, and IL-10ITNFa. Nearly all monocytes were stimulated to produce IL-1a, IL-12 and TNFalpha equally well in both culture systems. Monocyte production of IL-10 was significantly elevated following whole blood culture as compared to PBMC culture. IL-12 producing monocytes appeared to be a distinct subpopulation of the IL-1a producing set, whereas IL-10 and TNFa producing monocytes were largely mutually exclusive. IL-10 and TNFa producing monocytes may represent functionally different monocyte subsets with distinct functions. Whole blood culture eliminates the need to purify cell populations prior to culture and may have significant utility for the routine monitoring of the cytokine balances of the peripheral blood T cell and monocyte populations. In addition, there are distinct advantages to performing whole-blood (WB) activation as compared to PBMC activation. These advantages would include retaining all various cell-cell interactions as well as any soluble factors present in serum that influence cell activation. It is likely that the altered cytokine production observed following whole blood culture more accurately represents the in-vivo immune balance

Whole Blood Activation Results in Altered T Cell and Monocyte Cytokine Production Profiles by Flow Cytometry

An excellent monitor of the immune balance of peripheral circulating cells is to determine their cytokine production patterns in response to stimuli. Using flow cytometry, a positive identification of cytokine producing cells in a mixed culture may be achieved. Recently, the ability to assess cytokine production following a whole-blood activation culture has been described. In this study, whole blood activation was compared to traditional PBMC activation and the individual cytokine secretion patterns for both T cells, T cell subsets and monocytes was determined by flow cytometry. RESULTS: For T cell cytokine assessment (IFNg/IL-10 and IL-21/L-4) following PMA +ionomycin activation: (1) a Significantly greater percentages of T cells producing IFNgamma and IL-2 were observed following whole-blood culture and (2) altered T cell cytokine production kinetics were observed by varying whole blood culture times. Four-color analysiS was used to allow assessment of cytokine production by specific T cell subsets. It was found that IFNgamma production was significantly elevated in the CD3+/CD8+ T cell population as compared to the CD3+/CD8- population following five hours of whole blood activation. Conversely, IL-2 and IL-10 production were Significantly elevated in the CD3+/CD8- T cell population as compared to the CD3+/CD8+ population. Monocyte cytokine production was assessed in both culture systems following LPS activation for 24 hours. A three-color flow cytometric was used to assess two cytokines (IL-1a/IL-12 and TNFa/IL-10) in conjunction with CD14. Nearly all monocytes were stimulated to produce IL-1a, IL-12 and TNFa. equally well in both culture systems, however monocyte production of IL-10 was significantly elevated in whole blood culture as compared to PBMC culture. IL-12 producing monocytes appeared to be a distinct subpopulation of the IL-1a producing set, whereas IL-10 and TNFa producing monocytes were largely mutually exclusive. IL-10 and TNFa producing monocytes may represent distinct monocyte subsets with unique functions. CONCLUSIONS: Whole blood culture eliminates the need to purify cell populations prior to culture and may have Significant utility for the routine monitoring of the cytokine balances of the peripheral blood T cell and monocyte populations. In addition, there are distinct advantages to performing whole-blood (WB) activation as compared to PBMC activation. These advantages would include retaining all various cell-cell interactions as well as any soluble factors present in serum that influence cell activation. In this study, alterations in cytokine production are demonstrated between whole blood and PBMC activation. It is likely that whole blood activation more accurately represents the in-vivo immune balance than PBMC activation

Examining the Effectiveness of Marketing Practices of a Nonprofit Institution of Higher Education: Internal Service Provider

Abstract - Quality education is the sum of Institutions of Higher Education’s (IHE) parts, including classroom instruction and internal services, that are key to a student’s success during and after college. The purpose of this study is to address an understudied sector in the nonprofit marketing literature (i.e., Institutions of Higher Education internal service providers). The current study extends Dakouan et al. (2019) work by examining the marketing efforts of an IHE’s career services center’s effectiveness in creating awareness and increasing attendance at career events. The study focuses on outbound marketing strategies addressing the research question “to what extent are outbound marketing strategies successful in creating awareness and increasing attendance at IHE’s career fairs?” Data were collected over three academic years through an intercept survey provided at career fairs and through a database of social media and digital marketing analytics at a medium-sized university located in the Southeastern United States. Frequency analyses were used to determine the effectiveness of marketing strategies in bringing awareness and increasing attendance to IHE career fairs. Further, attendance data were compared between results of frequency analyses of outbound marketing strategies. The findings revealed that only two effective forms of outbound communications used by the subject IHE’s career center were personal selling by faculty and email blast. Findings also revealed that social and internet marketing strategies used by the subject IHE career center were not effective. The results have implications as to a need for continual marketing research of trends in marketing best practices. The findings demonstrated the need for adding inbound marketing strategies(Dakouan et al., 2019) and hiring and/or training staff in marketing research, social media, and internet marketing skills. From the study’s findings, it was concluded that Filip’s(2012) study was supported. Thus, to create awareness and increase attendance at events provided by an IHE’s internal services providers, strategically applied marketing best practices are necessary

SoTL Best Practices: 21st Century College Students’ Perceptions of Learning Styles and Instructional Design Materials’ Influence on the Successful Completion of Assignments

There is a long history of interest in individual differences in learning styles. Beginning in the 1960s, academic research endeavors began examining the concept of personalizing teaching as the best scholarship of teaching and learning best practice (SoTL). This current series of interconnected empirical studies take a fresh look at SoTL by examining students’ self-perception of their learning styles and whether their perceptions relate to how they learn. Today’s college students are growing up in the information age of the 21st Century. Many educators believe that a best practice is to focus on delivering personalized instructional material through technology. Thus, the current mixed methods study adds value to SoTL research by examining these concepts through a representative sample of the subject university in the United States. To assure the reliability and validity of the complex series of three integrated studies, research assistants were trained by a researcher experienced in experimental and survey designs. Data were analyzed using SPSS27®. The study\u27s findings indicated that focusing instructional materials on individual learning styles does not equate to learning success; in fact, the data showed no relationship. The data showed that a combined instructional delivery methodology (kinetic and audio) had a positive influence on learning success. The findings revealed that explicit instructions with or without audio were the most effective in leading to students’ ability to follow instructions successfully. Managing students’ self-perceptions of learning styles is important to assure successful learning experiences. Findings, conclusions, implications, recommendations, and limitations are presented herein