University of Central Florida

About: University of Central Florida is a education organization based out in Orlando, Florida, United States. It is known for research contribution in the topics: Laser & Population. The organization has 18822 authors who have published 48679 publications receiving 1234422 citations. The organization is also known as: UCF.

Well-aligned arrays of vertically oriented ZnO nanowires electrodeposited on ITO-coated glass and their integration in dye sensitized solar cells

Abstract: We report on the effects of post-growth hydrothermal treatment and thermal annealing on properties of vertically aligned ZnO nanowires arrays (NWs). The samples were electrochemically deposited (ECD) on indium–tin oxide (ITO)-coated glass substrates and subjected to post-growth hydrothermal treatment (HT) at 150 °C and, for the purpose of comparison, to conventional thermal annealing (CTA) in a furnace at 150, 400, and 600 °C in air. Sample characterization was realized using X-ray diffraction (XRD), SEM, TEM, selected-area electron diffraction (SAED) and photoluminescence (PL). Thermal annealing does not induce significant changes of morphology, but influences the structural and optical properties. At the same time we found that the HT induces more significant improvement of properties of ZnO nanowires arrays (ZnO NWs) on ITO. The results show that the ECD ZnO NWs are single-crystalline with hexagonal structure and c-axis perpendicular to ITO substrate. Only one peak at about 379 nm was observed in the photoluminescence spectra at room temperature which showed an intensity increase after hydrothermal treatment. This corresponds to the increase of the optical quality of ZnO NWs. The best optical quality for ZnO NWs was found after the hydrothermal treatments at 150 °C in our experiment. The high-quality electrodeposited NW layers have been used, after sensitization with the highly absorbing D149 dye, as a photoanode in dye sensitized solar cells (DSCs) and the impact of post-growth treatment of the nanowires on DSCs performances has been evaluated. The photocurrent of the solar cells increased significantly after HT or CTA at 150 °C leading to a maximum overall photovoltaic conversion efficiency (PCE) of 0.66% at 100 mW/cm2, based on short-circuit photocurrent density, open-circuit voltage and fill factor of 3.283 mA/cm2, 0.606 V and 33.3%, respectively. The obtained results are interesting in view of the low layer roughness and pave the way for implementation of high-quality electrodeposited ZnO NW arrays in DSCs fabrication.

Police Education, Experience, and the Use of Force

Abstract: Police researchers have devoted a considerable amount of empirical attention to testing the impact college education has on police performance. The counterargument to the education debate is that experience, in learning the police craft, is what contributes to differences in performance. The current study adds to both lines of research by examining the impact of education and experience on one of the core features of the police role: the use of coercion. The findings indicate that varying levels of education and experience are related to differences in the use of coercion in encounters with citizens. Encounters involving officers with any college education result in significantly less verbal force compared to those with a high school education. However, only those encounters involving officers with a 4-year degree result in significantly less physical force. Finally, encounters involving officers with greater experience result in less verbal and physical force.

Evaluation of Nursing Work Effort and Perceptions About Blood Glucose Testing in Tight Glycemic Control

Abstract: Background Tight glycemic control is important in critically ill patients and involves insulin infusions and monitoring of blood glucose levels. Hourly measurements of blood glucose levels and adjustments of intravenous insulin doses require additional work by nurses. Objectives To evaluate the nursing work incurred with and nursing perceptions about tight glycemic control and blood glucose monitoring. Methods A variety of intensive care units were studied. Surveys were used to gain information about nurses' perceptions. Time-in-motion observations were used to determine the time taken to measure blood glucose levels and adjust insulin doses. Results Nurses thought that tight glycemic control was important and that the work associated with it was substantial. Nurses thought that easier and automated forms of blood glucose monitoring are needed. They preferred using an arterial catheter to obtain blood samples to avoid excessive finger sticks. The total number of blood glucose measurements was 77 954. The mean time taken for hourly blood glucose monitoring and adjustment of insulin doses was 4.72 minutes. The estimated costs of time spent on glycemic control during a 1-year period were $182 488 for nurses' salaries and $58 500 for supplies. Conclusions Although most nurses endorse tight glycemic control, the work associated with it is burdensome and costly. Because up to 2 hours might be required for tight glycemic control for a single patient in a 24-hour period, the costs in time and money are high. Easier clinical methods for monitoring blood glucose levels are needed.