A phenomenological study of the experiences and teaching strategies of private music instructors working with elementary school students

The lack of consistent elementary musical education in the United States has sustained a steady demand for private music instruction. Private instruction, however, does not usually align with the general music education standards, or the school requirements. There is a lack of research about private music instructors’ role in music education for elementary-aged students. The purpose of this study was to explore the experiences and teaching strategies of private music instructors who supplement elementary students\u27 school-based music education. The two research questions were RQ1: What are the experiences of private music instructors who supplement elementary students\u27 school-based music education? RQ2: What are the teaching strategies used by private music instructors who supplement elementary students\u27 school-based music education? The theoretical framework of this study was based on the California Music Standards, and the methodology was qualitative phenomenology. Four topics were discovered through the literature review process: music education and mathematic disciplines; music education and cognitive benefits; music education and student engagement; music education and accessibility. Participants were chosen through a convenience sampling procedure. Five private music instructors answered open-ended questions in one-to-one Zoom interviews lasting 55-90 minutes. Interviews were recorded and transcribed. The data was analyzed using HyperRESEARCH. The analysis identified seven themes which addressed the two research questions: (a) Private music instructors believe themselves to be the only source of music education; (b) Private music instructors prioritize getting to know their students; (c) Private music instructors believe that music lessons benefits to students can extend beyond music skill; (d) Private music instructors see themselves as significant role models in their students’ lives; (e) Private music instructors rely on individualized teaching strategies and creative approaches; (f) Private music instructors must navigate difficult relationships with their students’ parents; (g) Private music instructors teach to outcomes. Based on the seven themes, the researcher offered conclusions and implications for educational leaders, private music instructors, and policy makers. A recommendation is made to modify the California Music Standards to help private music instructors integrate them into their instructio

Investigation of DSR Test Methods to Determine Binder Low Temperature Properties

The low temperature rheology of bituminous binders is of great interest because low temperature cracking is one of the primary asphalt pavement failure modes observed in cold-climate places such as Nebraska. Low temperature binder characterization/grading has been primarily conducted using the bending beam rheometer (BBR), while the dynamic shear rheometer (DSR) can alternatively be used to characterize the low temperature properties of binders with the recent advancement of DSR equipment that can cover a wide range of testing temperatures. This study investigates alternative testing-analysis methods using the DSR to determine low temperature asphalt binder properties that have been measured by the BBR. Toward that end, twelve different binders from four sources satisfying three different PG grading criterion common in Nebraska were selected. The binder samples were tested in the frequency domain at temperatures ranging from 60°C to -30°C under PAV-aged conditions using DSR. The 8-mm parallel plate geometry was primarily employed for the testing, while four binders were randomly selected and tested using the 4-mm parallel plate to investigate the influence of geometry on the results. BBR experiments were also performed as a parallel for each binder. Three methods were used to analyze and compare the data from the two different experiments (i.e., DSR and BBR) where each method utilizes a different scheme for converting the frequency domain results to time domain data to compare with the BBR results. The three methods are: (1) Western Research Institute’s (WRI) methodology; (2) NCHRP methodology; and (3) UNL’s mechanistic approach. It was observed that the DSR testing is quite promising, and sample preparation is crucial to obtain reliable-repeatable results. Moreover, in the proposed UNL’s mechanistic approach, it was observed that a single shift factor for creep compliance may account for different testing conditions, differences in physical hardening and temperature-dependent effects. The approach was then extended to seven additional binders to further examine its feasibility, and it was observed that the predictions from the proposed approach match well with the experimental values

New Mixture Additives for Sustainable Bituminous Pavements

In an effort to improve mechanical properties of asphalt concrete, an exploratory research using mixture additives was attempted. Two different types of additives on two material scales were used: asphalt concrete (AC) level and binder level. At the start of this study, the effect of natural cornhusk fibers on the resistance of two types of AC mixtures on cracking were tested for hot-mix asphalt (HMA) and cold-mix asphalt (CMA). The results showed slight improvements in cracking resistance in cornhusk reinforced HMA, and in the case of the CMA, marshal flow. Overall, based on the test results, cornhusk-reinforced HMA and CMA may not significantly improve critical mechanical properties given the added cost of fibers. In addition, cornhusk fibers proved difficult to properly disperse in HMA and CMA when mixed in laboratory. However, when fibers were mixed in an asphalt production plant, the fibers appeared to become more distributed. The second part of this study, two different types of carbon nano-fillers (F1 and F2) with different surface properties and sizes were added to two different asphalt binders: the base binder and the polymer modified binder. Also, mastic samples were prepared by replacing parts of the limestone filler by the carbon nano-fillers. It was observed that the nanoscale additives interacted with the binder quite differently. Additive F1 did not show a drastic improvement in the mechanical properties, fatigue resistance, and rutting resistance of the base and polymer modified binder at the mastic and the binder scale; however, additive F2 improved all the above- mentioned properties. From the experimental investigation, it can be inferred that part of the polymer modification can be replaced by additive F2. Although additive F1 showed a minimal change, it could be useful in improving the secondary application of the pavement, such as the electrical conductivity, thermal conductivity, and absorption of radiation for energy storage, which was not the scope of this study but appears worthy to investigate

Hemolysis in needles.

Hemolysis, the major cause for specimen rejection in clinical laboratories is defined as the rupture of red blood cell membranes, resulting in the release of hemoglobin into the plasma. Blood flow in needles causes hemolysis resulting in complications such as incorrect assay results [13,14], repeated painful blood draws [4,9,13] and also the release of hemoglobin into the plasma, which is toxic to the kidneys [18]. Hemolysis mainly occurs due to high fluid stresses that act on the red blood cells in blood flow through the needle [22]. Highest stresses during blood draws act near the downstream edge of the needle entrance. In this project, the needle has been modified with a more rounded entrance to reduce the effect of the stresses acting near the tip. Experiments were also performed with needles of beveled entrance to reduce the hemolysis. This thesis discusses in detail, experiments conducted with 16G and 20G standard and modified needles in both reverse and normal orientations at three different pressures. Blood was drawn into a syringe, then the needle is attached to it and the assembly is placed in a fixture. The fixture was designed to hold the syringe in place and apply desired pressure on the syringe. The blood flowing out of the syringe was collected in a test tube and this process was repeated for all the combinations of pressures and needle orientations viz. normal and reverse. The collected test tubes were then centrifuged and the plasma was removed and analyzed in a spectrophotometer. Results were tabulated and graphs were plotted to compare the hemolysis in the test and control needles. ANOVA p-values clearly indicated that the rounded entrance significantly reduced hemolysis compared to the standard needles for the 20G size in the reverse orientation at all three pressures (p-values at 20psi, 35psi and 50psi were 0.053, 4.60E-08 and 1.00E-08, respectively). There was also a significant relation between the 16G with rounded entrance and the standard needles in the reverse orientation (p-values were 0.017, 0.004 and 0.001 at l5psi, 30psi and 45psi, respectively), but no significant relation for the 16G needles with beveled entrance

A Metric for Measuring Customer Turnover Prediction Models

The interest for data mining techniques has increased tremendously during the past decades, and numerous classification techniques have been applied in a wide range of business applications. Hence, the need for adequate performance measures has become more important than ever. In this application, a cost-benefit analysis framework is formalized in order to define performance measures which are aligned with the main objectives of the end users, i.e., profit maximization. A new performance measure is defined, the expected maximum profit criterion. This general framework is then applied to the customer churn problem with its particular cost-benefit structure. The advantage of this approach is that it assists companies with selecting the classifier which maximizes the profit. Moreover, it aids with the practical implementation in the sense that it provides guidance about the fraction of the customer base to be included in the retention campaign

Research on High-RAP Asphalt Mixtures with Rejuvenators - Phase II

A previous study by the authors have demonstrated effectiveness of three rejuvenators: R1 (triglyceride/fatty acid: agriculture-tech based), R2 (aromatic extract: petroleum-tech based), and R3 (tall oil: green-tech based) on rejuvenating properties of the aged binder. In that study, it was observed that the rejuvenators made high-RAP mixtures softer and more compliant, which may increase the rutting potential, while they simultaneously improve cracking resistance of the high-RAP materials. Research outcomes and findings from the previous study resulted in consequential research needs for more specific investigation of high-RAP mixtures with rejuvenators in order to achieve realistic implementation into future high-RAP paving projects in Nebraska. This study thus aimed to investigate the effects of type, dosage, and treating methods of rejuvenators when they are added in aged asphalt materials. To meet the goal, we used the three rejuvenators (R1, R2, and R3) by conducting various binder-level and mixture-level tests in this study. For the binder-level testing, the performance grading (PG) method was used to primarily determine proper dosages targeting desired binder grades, and two chemical tests (i.e., Fourier Transform Infrared and Saturates-Aromatics-Resins-Asphaltenes analysis) were also conducted to examine chemical characteristics altered by rejuvenation and further aging process. The selected dosage levels from the binder testing were then applied to asphalt concrete (AC) mixture-level performance evaluation by conducting two tests: flow number for rutting and semicircular bending fracture with and without moisture conditioning for cracking. AC mixtures treated with rejuvenators at the dosage levels selected from the binder PG testing showed improved fracture resistance compared to unrejuvenated mixtures. Test-analysis results also indicated that PG binder testing, although it can successfully determine the proper dosage range of rejuvenators, is limited by only assessing the effects of rejuvenators in mechanical properties, which can be better aided by integrating chemical characterization that provides a more in-depth material-specific rejuvenation process. In addition, it appears that rejuvenation methods (e.g., blending and/or curing) can alter performance of aged mixtures. Therefore, the selection of rejuvenators and their implementation into practice should be carried out by considering multiple aspects not only by its PG recovery

Chemical-Rheological Evaluation of the Short-Term and Long-Term Effectiveness of Binder Rejuvenators

Many previous studies have investigated how rejuvenators affect/alter mechanical/chemical characteristics of aged binders. However, it has not been actively examined how the rejuvenated binders will perform for the next round of service after the rejuvenation was made. A better understanding of the short-term and long-term effect of rejuvenating agents in RAP blended asphalt mixtures is necessary to achieve more appropriate selection and use of rejuvenating agents

Optimizing Chemical & Rheological Properties of Rejuvenated Bitumen

Bitumen has long been a material used in the construction of roadways, yet new pavement only consists of low fractions of recycled materials due to poor compatibility of aged bitumen and new materials. Thus, rejuvenators, chemical additives, have been used in an attempt to re-balance the chemical composition and restore the physical properties of aged bitumen back to its virgin state. A fundamental understanding of how one particular rejuvenator, soybean oil, revitalizes bitumen was investigated using a multi-scale approach. Fourier-transform infrared spectroscopy (FTIR) was used to determine the changes in chemical properties of pure and rejuvenated virgin and aged samples. Samples were artificially short term aged using a rolling thin film oven (RTFO) procedure or long term aged using a pressure aging vessel (PAV). Rejuvenator concentrations were tested at both 7.5% and 15%. FTIR results reveal carbonyl (IC=O), sulfoxide (IS=O), branched aliphatic (IB), and aromatic (IAr) indices decrease in RTFO and PAV samples from rejuvenation with soybean oil, suggesting that the aging process in the aged bitumen has been reversed. A linear amplitude sweep (LAS), a mechanical procedure using a dynamic shear rheometer (DSR), was employed to investigate rheological properties. LAS analysis of PAV samples manifests fatigue resistances of bitumen samples increase at every applied shear strain as a result of increasing concentration of rejuvenator. The relation of FTIR and LAS results indicates rejuvenation of aged bitumen with soybean oil reverses the aging process at a molecular level and, as a result, increases the fatigue life of the bitumen