Design of dissipative linear phase filters

Set of design curves eliminates work involved in designing linear phase filters by being normalized in such a way as to apply to low, band, and high-pass filters of any bandwidth. Similar curves for any number of poles are plotted by solving a system of simultaneous equations

An integral turbulent kinetic energy analysis of free shear flows

Mixing of coaxial streams is analyzed by application of integral techniques. An integrated turbulent kinetic energy (TKE) equation is solved simultaneously with the integral equations for the mean flow. Normalized TKE profile shapes are obtained from incompressible jet and shear layer experiments and are assumed to be applicable to all free turbulent flows. The shear stress at the midpoint of the mixing zone is assumed to be directly proportional to the local TKE, and dissipation is treated with a generalization of the model developed for isotropic turbulence. Although the analysis was developed for ducted flows, constant-pressure flows were approximated with the duct much larger than the jet. The axisymmetric flows under consideration were predicted with reasonable accuracy. Fairly good results were also obtained for the fully developed two-dimensional shear layers, which were computed as thin layers at the boundary of a large circular jet

The wall shear stress produced by the normal impingement of a jet on a flat surface

A method for the theoretical determination of the wall shear stress under impinging jets of various congurations is presented. Axisymmetric and two-dimensional incompressible jets of a wide range of Reynolds numbers and jet heights are considered. Theoretical predictions from this approach are compared with available wall shear stress measurements. These data are critically evaluated based on the method of measurement and its applicability to the boundary layer under consideration. It was found that impingement-region wall shear stress measurements using the electrochemical method in submerged impinging liquid jets provide the greatest accuracy of any indirect method. A unique wall shear stress measurement technique, based on observing the removal of monosized spheres from well-characterized surfaces, was used to conrm the impinging jet analysis presented for gas jets. The technique was also used to determine an empirical relation describing the rise in wall shear stress due to compressibility eects in impinging high-velocity jets

Unintended Consequences of Public Policy and Government Regulation on Supply Chain Structure, Conduct, and Performance

Supply chains, and the firms within them, change their behaviors in response to industry conditions so they can provide efficiency, effectiveness, strategic enablement, and customer utility. Social and economic policies enacted to promote social welfare by correcting market failures can alter these conditions. While these policies may serve their intended purposes, they may also create unintended consequences that may make managing logistics, operations, and supply chains more challenging. This dissertation contributes to the nascent body of knowledge concerning the intended and unintended consequences of policy on supply chain management by examining three unique contextual settings using different methodologies and levels of analysis. In the first essay, I examine the impacts of relationship-focused regulations on supply chain collaboration. Using a grounded theory approach, I theorize new barriers to collaboration unique to this regulatory context using data from multiple interviews with executives from suppliers and distributors in the beer industry supply chain. I find that regulations meant to promote social welfare by constraining the flow of alcohol to consumer also constrain choice in supply chain relationships that negatively affect supply chain collaboration. In the second essay, I examine how capacity-limiting structural regulation in healthcare, specifically certificate of need (CON) laws, interacts with case complexity to affect hospital operational performance. Using a hybrid estimation approach to analyze a unique data set collected from multiple sources, I tested a conceptual model developed using the structure-conduct-performance (SCP) framework and the complex adaptive systems (CAS) perspective. I find that indicate that CON does reduce costs but also worsens quality. I also find that these relationships are intensified by case complexity. In the third essay, I examine whether nuclear verdicts over $10 million resulting from harm caused by large truck crashes result in improved industry-level motor carrier safety performance. Drawing on institutional theory to hypothesize the effects of nuclear verdicts on safety performance and insurance spending. I test these hypotheses using autoregressive distributed lag time series econometric models. I find that nuclear verdicts may result in improvements in industry safety but may also result in increased insurance spending. Collectively, these essays demonstrate multiple perspectives of how policies can affect supply chain behaviors and performance at the individual-, firm-, and industry-level that may be undesirable or unexpected. Findings from these essays offer important insights for researchers, practitioners, and policymakers

PREDICTORS OF READINESS TO INITIATE INSULIN THERAPY IN PATIENTS WITH TYPE 2 DIABETES WHEN ORAL MEDICATIONS FAIL TO CONTROL HYPERGLYCEMIA

Type 2 diabetes (T2DM) has reached epidemic levels worldwide during the past two decades. It affects nearly 26 million adults in the U.S. Advances in both the treatments for T2DM and guidelines for its optimal management are extensive. Despite these advances, barely half of type 2 diabetics achieve recommended glycemic targets. Specific Aims: The specific aims were to: Describe the available research on clinical inertia and interventions that have been implemented to reduce it. Analyze various behavioral theories that explain and predict self-care practices in diabetes in order to develop a conceptual model on which to base an investigation of predictors of readiness to initiate insulin therapy in type 2 diabetics. Determine predictors of readiness to initiate insulin therapy in patients with T2DM when oral medications fail to control hyperglycemia using the conceptual model based on Self-Determination Theory (SDT) as a framework. Results: A review of research articles published from 1990 to 2010 concluded that clinical inertia of primary care providers treating T2DM resulted in a majority of patients experiencing unnecessary chronic uncontrolled hyperglycemia. Behavioral theories were analyzed for their ability to predict self-care behaviors in type 2 diabetics. A conceptual model was developed based on the major constructs of SDT in order to guide the design of study to investigate predictors of readiness to begin insulin therapy in T2DM. Finally, a descriptive, correlational study was performed to determine readiness to initiate insulin therapy in patients with T2DM when oral medications fail to control hyperglycemia. Results of the study revealed that participants who had a friend or family using insulin were 5.5 times more likely to rate their readiness to initiate insulin as high than those who had neither (p=.020). In addition, those with greater negative beliefs and attitudes toward insulin therapy were more likely to rate their readiness to initiate insulin as low (p=.012). A majority (58%) of participants rated their readiness to begin insulin therapy as immediate if it would give them better control over their hyperglycemia. The study also confirmed findings from previous studies that clinical inertia was present in this setting

High school chemistry students\u27 learning of the elements, structure, and periodicity of the periodic table: contributions of inquiry-based activities and exemplary graphics

The main research question of this study was: How do selected high school chemistry students\u27 understandings of the elements, structure, and periodicity of the Periodic Table change as they participate in a unit study consisting of inquiry-based activities emphasizing construction of innovative science graphics? The research question was answered using a multiple case study/mixed model design which employed elements of both qualitative and quantitative methodologies during data collection and analyses. The unit study was conducted over a six-week period with 11th-grade students enrolled in a chemistry class. A purposive sample of six students from the class was selected to participate in interviews and concept map coconstruction (Wandersee & Abrams, 1993) periodically across the study. The progress of the selected students of the case study was compared to the progress of the class as a whole. The students of the case study were also compared to a group of high school chemistry students at a comparative school. The results show that the students from both schools left traditional instruction on the periodic table (lecture and textbook activities) with a very limited understanding of the topic. It also revealed that the inquiry-based, visual approach of the unit study helped students make significant conceptual progress in their understanding of the periodic table. The pictorial periodic table (which features photographs of the elements), used in conjunction with the graphic technique of data mapping, enhanced students understanding of the patterns of the physical properties of the elements on the periodic table. The graphic technique of compound mapping helped students learn reactivity patterns between types and groups of elements on the periodic table. The recreation of the periodic table with element cards created from the pictorial periodic table helped students progress in their understanding of periodicity and its key concepts. The Periodic Table Literacy Rubric (PTLR) proved to be a valuable tool for assessing students’ conceptual progress, and helped to identify a critical juncture in the learning of periodicity. In addition, the PTLR rubric\u27s historical-conceptual design demonstrates how the history of science can be used to inform today\u27s science teaching