Turbulent Drag Reduction of polyelectrolyte (DNA) solutions: relation with the elongational viscosity

We report measurements of turbulent drag reduction of two different polyelectrolyte solutions: DNA and hydrolyzed Polyacrylamide. Changing the salt concentration in the solutions allows us to change the flexibility of the polymer chains. For both polymers the amount of drag reduction was found to increase with the flexibility. Rheological studies reveal that the elongational viscosity of the solutions increases simultaneously. Hence we conclude that the elongational viscosity is the pertinent macroscopic quantity to describe the ability of a polymer to cause turbulent drag reduction

The relationships of the leadership styles of superintendents and fiscal conditions with district student performance across Ohio

This study investigated the relationships of the leadership styles of superintendents and the fiscal conditions of local school districts with student performance across Ohio. To examine these relationships the Bolman and Deal survey instrument, Leadership Behavior Description Questionnaire-Self, was utilized to collect data from superintendents to assess their perception of their leadership style. The fiscal conditions of the school districts were placed on predictability and sustainability continuums based upon state percentage basic aid and annual percentage change in per pupil expenditure over five Ohio state biennial funding cycles (1997--2007). Control variables for the study include district size, socio-economic status, locale and per pupil expenditure. Surveys were sent to superintendents serving the 614 public school districts across Ohio. Responses were received from 241 superintendents. 174 surveys were utilized for an inclusive analysis and 83 qualified for the primary study. An ancillary analysis was completed to investigate more deeply the relationships between district fiscal condition-predictability and district student performance with the study variables. Descriptive statistics were utilized as were linear multiple regression models to provide the statistical analysis.;Major research findings indicate: (1) Superintendents across Ohio champion the multi-framed leadership style (35%) followed by the single frame (27%) and the paired and the no-frame style (19%) equally; (2) Within these styles the structural frame (30.2%) was utilized the most, followed by the human-resource (26.3%), the symbolic and political (17.1%) equally and the no-frame (9.3%); (3) None of the study variables were found to be significant with leadership styles; (4) As a school district\u27s fiscal condition-sustainability increases, so does the district expenditure per pupil and the district fiscal condition-predictability; (5) As a school district\u27s fiscal condition-predictability increases, so does the number of students qualifying for the free/reduced lunch program and the district fiscal condition-sustainability. However, as the school district also becomes smaller, the district expenditure per pupil becomes less and the district is more likely to be urban than suburban; and (6) As a school district\u27s student performance increases its fiscal condition-predictability and fiscal condition-sustainability becomes lower.;Recommendations from this study include: (1) Implementation of professional development activities for superintendents that includes an understanding in leadership styles along with an increased awareness of their personal leadership style; and (2) opportunities provided for federal, state and local funding policy makers to gain an awareness of the relationships between a school district\u27s dependency on state basic aid and the district student performance

Managers\u27 Perception of Alcohol Service Training Programs

In order to serve alcoholic beverages in a responsible manner, most managers turn to alcohol server training programs to provide effective standardized training for the alcohol server. Whether or not the programs are perceived by hospitality managers as effective has not been established. The author presents the results of a study of Oklahoma hospitality managers who perceive alcohol server training as becoming less effective

Real-Time, Multiple Pan/Tilt/Zoom Computer Vision Tracking and 3D Positioning System for Unmanned Aerial System Metrology

The study of structural characteristics of Unmanned Aerial Systems (UASs) continues to be an important field of research for developing state of the art nano/micro systems. Development of a metrology system using computer vision (CV) tracking and 3D point extraction would provide an avenue for making these theoretical developments. This work provides a portable, scalable system capable of real-time tracking, zooming, and 3D position estimation of a UAS using multiple cameras. Current state-of-the-art photogrammetry systems use retro-reflective markers or single point lasers to obtain object poses and/or positions over time. Using a CV pan/tilt/zoom (PTZ) system has the potential to circumvent their limitations. The system developed in this paper exploits parallel-processing and the GPU for CV-tracking, using optical flow and known camera motion, in order to capture a moving object using two PTU cameras. The parallel-processing technique developed in this work is versatile, allowing the ability to test other CV methods with a PTZ system using known camera motion. Utilizing known camera poses, the object\u27s 3D position is estimated and focal lengths are estimated for filling the image to a desired amount. This system is tested against truth data obtained using an industrial system