Report of an exploratory study: Safety and liability considerations for photovoltaic modules/panels

An overview of legal issues as they apply to design, manufacture and use of photovoltaic module/array devices is provided and a methodology is suggested for use of the design stage of these products to minimize or eliminate perceived hazards. Questions are posed to stimulate consideration of this area

Prediction of remaining life of power transformers based on left truncated and right censored lifetime data

Prediction of the remaining life of high-voltage power transformers is an important issue for energy companies because of the need for planning maintenance and capital expenditures. Lifetime data for such transformers are complicated because transformer lifetimes can extend over many decades and transformer designs and manufacturing practices have evolved. We were asked to develop statistically-based predictions for the lifetimes of an energy company's fleet of high-voltage transmission and distribution transformers. The company's data records begin in 1980, providing information on installation and failure dates of transformers. Although the dataset contains many units that were installed before 1980, there is no information about units that were installed and failed before 1980. Thus, the data are left truncated and right censored. We use a parametric lifetime model to describe the lifetime distribution of individual transformers. We develop a statistical procedure, based on age-adjusted life distributions, for computing a prediction interval for remaining life for individual transformers now in service. We then extend these ideas to provide predictions and prediction intervals for the cumulative number of failures, over a range of time, for the overall fleet of transformers.Comment: Published in at http://dx.doi.org/10.1214/00-AOAS231 the Annals of Applied Statistics (http://www.imstat.org/aoas/) by the Institute of Mathematical Statistics (http://www.imstat.org

A Resource Manual for Facilitating Effective Instructional Strategies for At-Risk Junior High Students

The purpose of this project was to develop a resource manual to facilitate effective instructional strategies for at-risk junior high school students. To accomplish this purpose, current research and literature related to at-risk student characteristics, their special needs, and programs and strategies developed to assist them was reviewed. Additionally, on site visits to selected programs and interviews with teachers and administrators were conducted. At-risk students are young people who lack motivation to do well in school or work. They live marginally outside the socially accepted code for children and youth. School systems which have large numbers of at-risk students need to be flexible and creative in developing programs to meet the needs of these students. Parents and community members need to become knowledgeable and more involved with supporting programs for at-risk students

Siple Dome Deep Ice Core Glaciochemistry and Regional Survey - A Contribution to the WAIS Initiative

Our project focuses on the analysis and interpretation of major ions and methanesulfonate (in conjunction with the Univ. of Miami) from a deep ice core at Siple Dome, Antarctica. In addition, this study investigates the regional glaciochemical variability on Siple Dome, continuing work begun during the 1994 field season. The first field season for this project was conducted during the 1996/97 austral season. Because this project closely follows work begun in 1994, selected glaciochemical results from 1994 are presented, along with reports that detail Siple Dome research to present

Team Projects And Peer Evaluations

The authors assign semester- or quarter-long team-based projects in several Computer Science and Finance courses. This paper reports on our experience in designing, managing, and evaluating such projects. In particular, we discuss the effects of team size and of various peer evaluation schemes on team performance and student learning. We report statistical measures of the students’ peer evaluations – do they always rate each other strongly or weakly? What are the means and ranges? More importantly, we discuss why we introduced these peer evaluations, and what effect they have had on student commitment and performance. We discuss a small number of cases where student participation was poor, and relate this to the peer evaluation process

Automatic Crack Detection Algorithm for Vibrothermography Sequence-of-Images Data

Vibrothermography (Sonic IR, thermosonics) is a technique for finding cracks through frictional heat given off in response to vibration. Vibrothermography provides a sequence of infrared images as output of the inspection process. A fast and accurate automatic crack‐detection algorithm for the sequence‐of‐images data will greatly increase the productivity of vibrothermography method. Matched filtering is a technique widely used in signal detection, and it is the optimal linear filter to maximize the signal‐to‐noise ratio in the presence of additive uncorrelated stochastic noise. Based on key features from images of known cracks, we can construct a three‐dimensional matched filter to detect cracks from the vibrothermography data. In this paper, we evaluate the matched filter developed from a vibrothermography inspection sequence‐of‐images. The probability of detection for the matched filter detection algorithm is then compared with the probability of detection for a simpler detection algorithm that is based on a scalar measure of the amount of heat generated in an inspection. Our results show the matched filter algorithm provides improved detection capability when a flaw signature is known approximately

Blood cadmium is elevated in iron deficient U.S. children: a cross-sectional study

Abstract Background Cadmium (Cd), a widespread environmental contaminant, and iron deficiency (ID), the most common nutrient deficiency in the world, are known risk factors for neurodevelopmental delays, as well as other disorders, in infants and children. Studies assessing the cumulative effects of these factors are lacking in children, despite concerns of increased uptake of metals in the presence of ID. Here we sought to determine if blood and urine Cd levels were elevated in ID children compared to non-ID children. Methods Data for 5224 children, aged 3–19 years, were obtained from the 1999–2002 NHANES. ID was defined as ≥2 of 3 abnormal iron indicators (low serum ferritin [SF], high free erythrocyte protoporphyrin [FEP], low % transferrin saturation [TSAT]); ID anemia (IDA) was defined as ID plus low hemoglobin (Hgb). Logistic regression was used to evaluate associations between ID, IDA, and abnormal iron indicators and categories of blood and urine Cd. Results Adjusted odds of ID, IDA, low SF, and low TSAT were associated with increasing category of blood Cd but not urine Cd. Adjusted ORs (95% CI) for blood Cd ≥0.5 μg/L versus < LOD were = 1.74 (1.30-2.34), 4.02 (1.92-8.41), 4.08 (2.36-5.89) and 1.78 (1.32-2.39), for ID, IDA, low SF, and low TSAT, respectively. Age and sex specific analyses of blood Cd and ID/abnormal iron indicators revealed that the observed associations were strongest in females aged 16–19 years. Conclusions Given their shared neurotoxic effects in children, and that many people live in areas with high burdens of both ID and Cd, more research into the complex relationships between nutrient deficiencies and environmental toxicants is vital.http://deepblue.lib.umich.edu/bitstream/2027.42/109497/1/12940_2013_Article_710.pd