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As renewable energy becomes more accessible, affordable optimization solutions have become a larger part of at home systems. Solar energy is one of the most common clean energy applications used by homeowners because of its increasing affordability. While many photovoltaic systems are statically mounted on roofs or in yards, many systems also employ some kind of solar tracking. Both single axis and dual axis solar tracking systems have been implemented and tested with multiple kinds of tracking methods. Two of the most accurate tracking strategies are utilizing light dependent resistors or using some kind of solar position calculation. This paper proposes a design for a solar tracking system that combines these two strategies, using a solar position algorithm to calculate the angle of the sun which is then corrected by light dependent resistors if necessary. This design is highly accurate as well as being robust in finding the sun regardless of weather conditions and geographical location. Data from two days of testing shows an average percent difference in solar energy output of 1.486% in the late evening and 0.883% near solar noon.

Background: Introduced in 2014, the diagnostic accuracy of the Lever Sign (LS) in detecting acute complete anterior cruciate ligament (ACL) lesions is not well documented. Purpose: To assess the diagnostic accuracy of the LS, Lachman’s Test (LT), and Drawer Test (DT) in the detection of acute ACL lesions, including a population with an intact ACL. Methods: We reviewed the records of 70 acute (< 72 hours postinjury) knee injuries. Deidentified records were collected from high school and collegiate athletic trainers using a standardized form. Statistical Analysis: The DT and LT were performed 69 times and the LS 42 times. A 2 x 2 contingency table including 95% confidence intervals (CI) were created. A receiver operating characteristic (ROC) curve was created and data from the knee inventory form were filtered for patient-perceived pain. Results: The LS yielded a sensitivity of .85 and specificity of .97. The LT and DT yielded a sensitivity of .75 and .60 and a specificity of .94 and .96. ROC curves demonstrated that the LS, LT and DT produced an area under the curve (AUC) of .88, .83, and .77. Last, the patient-perceived pain at a frequency of 40% when the LS was performed on an ACL lesion and a frequency of 13% when the test was performed and an ACL lesion was not present. No statistically significant differences were identified among the 3 tests. Conclusion: Although not statistically significant, the LS produced a better diagnostic accuracy than the LT and DT in the detection of acute complete ACL lesions. The LS had a decreased frequency of patient-perceived pain when performed, decreasing the chance of a false negative. We propose that clinicians can use the LS in the assessment of suspected ACL lesions.

The purpose of this study was to explore possible solutions to student interaction and product quality in a ninth grade English class by using strategies in cooperative learning. Reciprocal learning, jigsaw, and skills practice were used to promote student interaction and cooperation during a lesson on William Shakespeare's "Romeo and Juliet." The data reveals that the three student participants have the skills necessary to succeed and excel in cooperative learning strategies, and previous student achievements may not necessarily indicate an ability or inability to master a cooperative learning activity. Implications for using cooperative learning strategies in the classroom are discussed.