For many of the Pb-free solders required under the European RoHS directive, there is now sufficient information, primarily in the form of the results of accelerated thermal cycling of various levels of severity, to develop acceleration models for the creep-fatigue of these solders. In this paper the parameters for the SAC405/305, SAC205, SAC105 and SnAg to replace the parameters for eutectic Sn...

background: previous studies have shown detrimental effects of muscle fatigue on balance. also they have reported the effects of kinesio taping (kt) on postural control, joint support, and muscle function. however, no studies have been conducted so far to assess the immediate effects of kt after local muscle fatigue on balance. therefore, the aim of this study was to determine whether kt improv...

Fatigue failures caused by cyclic stresses are commonly modeled by Birnbaum-Saunders (B-S) and Weibull distributions. Sometimes, materials with high cycle fatigue exhibit bimodal failure rates which are difficult to model with Weibull distribution. The objective of this paper is to investigate a general Birnbaum-Saunders (GB-S) distribution which covers diverse hazard rates such as increasing, ...

background: fatigue is considered as a major problem in hemodialysis patients and can impair their quality of life. the purpose of this study was to investigate the effectiveness of acupressure on fatigue in hemodialysis patients. materials and methods: this is a clinical trial study in which 96 hemodialysis patients participated. patients were randomly assigned into acupressure, placebo, and c...

Person and situational determinants of cognitive ability test performance and subjective reactions were examined in the context of tests with different time-on-task requirements. Two hundred thirty-nine first-year university students participated in a within-participant experiment, with completely counterbalanced treatment conditions and test forms. Participants completed three test sessions of...

Fatigue damage is considered to be one of the most critical phenomenon, contributing to the failure of an aircraft structure. Understanding the fatigue mechanism is essential for considering the different technical conditions that influence the fatigue life of structures. In recent years, fatigue tests are accelerated in order to reduce the testing time of materials/structures being developed, ...

The useful life of an LED is presently determined by the IESNA LM80-08 lumen maintenance standard. Even though an LED system has many components, the current industry practice rates LED system lifetime based on a single component, namely, the LED. LED system life is one of the least understood parameters, especially in application environments. As a result, any lifetime claim for a complete LED...

When we talk about environmental justice, we mean calling a halt to the poisoning of our poorest communities, from our rural areas to our inner cities. We don’t have a person to waste and pollution clearly wastes human lives and natural resources. When our children’s lives are no longer damaged by lead poisoning, we will stop wasting the energy and intelligence that could build a stronger and m...