Drexel University

About: Drexel University is a education organization based out in Philadelphia, Pennsylvania, United States. It is known for research contribution in the topics: Population & Poison control. The organization has 26770 authors who have published 51438 publications receiving 1949443 citations. The organization is also known as: Drexel & Drexel Institute.

Some New Results on Edge Effect in Symmetric Composite Laminates

Abstract: An improved numerical (finite element) procedure is developed to investigate the stress field in symmetrically laminated composites of finite dimensions Emphasis is placed on assessing the singular behavior of stresses in regions close to ply-interfaces and the exposed free edge An accurate evaluation of these stresses will help to better understand the failure process of composite laminates Mechanical load in the form of uniaxial tension and environmental variables such as temperature and humidity exposures are considered in the formulation Results tor lam inates under uniaxial tension are presented in this paper; thermal and hygroscopic stresses will be reported in a subsequent paper

The Effects of Time Constraints on Consumers' Judgments of Prices and Products

Abstract: This article examines how time constraints influence consumers' product evaluations over different levels of price information. To understand the effects of time constraints (time pressure), a conceptual framework incorporating both the motivational and the resource effects of time constraints on consumers' information processing is developed. Using price as the attribute information to be evaluated, specific hypotheses about the effects of time constraints on the relationship between price and consumers' perceptions of quality and monetary sacrifice are proposed. The results of a replicated experiment show that perceptions of quality and monetary sacrifice exhibit different response patterns depending on the time constraints, price levels, and subjects' motivations to process information. Additional analyses provide insights into how these two perceptions are integrated to form perceptions of value.

History and Systematic Review of Wear and Osteolysis Outcomes for First-generation Highly Crosslinked Polyethylene

Abstract: Background Highly crosslinked polyethylene (HXLPE) was introduced to reduce wear and osteolysis in total joint arthroplasty. While many studies report wear and osteolysis associated with HXLPE, analytical techniques, clinical study design and followup, HXLPE formulation and implant design characteristics, and patient populations differ substantially among investigations, complicating a unified perspective.

Adolescents living the 24/7 lifestyle: effects of caffeine and technology on sleep duration and daytime functioning.

Abstract: OBJECTIVE. Adolescents may not receive the sleep they need. New media technology and new, popular energy drinks may be implicated in sleep deficits. In this pilot study we quantified nighttime technology use and caffeine consumption to determine effects on sleep duration and daytime behaviors in adolescents. We hypothesized that with increased technology use, adolescents increase caffeine consumption, resulting in insufficient sleep duration. PATIENTS AND METHODS. Subjects were recruited from a pediatric office in a proximal suburb of Philadelphia, Pennsylvania. Inclusion criteria for this study were middle and high school subjects aged 12 to 18 years old. The questionnaire, Adolescent Sleep, Caffeine Intake, and Technology Use, was developed by the investigators to measure adolescents9 intake of caffeinated drinks, use of nighttime media-related technology, and sleep behaviors. Descriptive statistics characterized the subjects, their caffeine and technology use, and sleep variables. Regression models assessed the relationships between caffeine, technology use, and sleep variables, having adjusted for age, race, gender, and BMI. RESULTS. Sleep was significantly related to the multitasking index. Teenagers getting 8 to 10 hours of sleep on school nights tended to have 1.5- to 2-fold lower multitasking indices compared with those getting less sleep. Thirty-three percent of the teenagers reported falling asleep during school. Caffeine consumption tended to be 76% higher by those who fell asleep. The log-transformed multitasking index was significantly related to falling asleep during school and with difficulties falling asleep on weeknights. CONCLUSIONS. Many adolescents used multiple forms of technology late into the night and concurrently consumed caffeinated beverages. Subsequently, their ability to stay alert and fully functional throughout the day was impaired by excessive daytime sleepiness. Future studies should measure more than television hours when evaluating the impact of nighttime activities on sleep patterns in adolescents.