Fatigue characterization of mechanical components in service

The quickly identify of fatigue limit of a mechanical component with good approximation is currently a significant practical problem not yet resolved in a satisfactory way. Generally, for a mechanical component, the fatigue strength reduction factor ( ? i) is difficult to evaluate especially when it is in service. In this paper, the procedures for crack paths individuation and consequently damage evaluation (adopted in laboratory for stressed specimens with planned load histories) are applied to mechanical components, already failed during service. The energy parameters, proposed by the authors for the evaluation of the fatigue behavior of the materials [1-5], are defined on specimens derived from a flange bolts. The flange connecting pipes at high temperature and pressure. Due to the loss of the seal, the bolts have been subjected to a hot flow steam addition to the normal stress. The numerical analysis coupled experimental analysis (measurement of surface temperature during static and dynamic tests of specimens taken from damaged tie rods), has helped to determine the causes of failure of the tie rods. The determination of an energy parameter for the evaluation of the damage showed that factors related to the heat release of the material (loaded) may also help to understand the causes of failure of mechanical components

Kindness is not 86’d: the spirit of hospitality in a world of COVID-19

Beginning in March of 2020, individuals started the practice of the unfamiliar act of social distancing. Along with the uncertainty of the virus, many of us are left apprehensive about the future. Having consensual physical contact with other people and enjoying the company of others in the flesh releases chemicals in the brain and body (e.g. endorphins, serotonin and oxytocin) that give us feelings of happiness and even love (Dewan, 2020). Humans generally thrive from social interaction—making self-isolation feel unnatural. The option of enjoying a glass of Barolo and a charcuterie board, while engaging in meaningful conversation with the bartender at a local restaurant, is temporarily unavailable. For centuries, many have leaned on the shoulders of hospitality personnel for company, laughter and guidance. What have the restaurants, hotels, distributors, suppliers and other members of the hospitality community been doing during this time? While hospitality establishments start to reopen, it is crucial to remember how an overwhelming amount of those in the hospitality business have been aiding the community in extraordinary measures.Published versio

Positive Surgical Margins in the 10 Most Common Solid Cancers.

A positive surgical margin (PSM) following cancer resection oftentimes necessitates adjuvant treatments and carries significant financial and prognostic implications. We sought to compare PSM rates for the ten most common solid cancers in the United States, and to assess trends over time. Over 10 million patients were identified in the National Cancer Data Base from 1998-2012, and 6.5 million had surgical margin data. PSM rates were compared between two time periods, 1998-2002 and 2008-2012. PSM was positively correlated with tumor category and grade. Ovarian and prostate cancers had the highest PSM prevalence in women and men, respectively. The highest PSM rates for cancers affecting both genders were seen for oral cavity tumors. PSM rates for breast cancer and lung and bronchus cancer in both men and women declined over the study period. PSM increases were seen for bladder, colon and rectum, and kidney and renal pelvis cancers. This large-scale analysis appraises the magnitude of PSM in the United States in order to focus future efforts on improving oncologic surgical care with the goal of optimizing value and improving patient outcomes

Good People: How Coworker Competence and Support Influence Engagement and Contextual Performance

Organizational structures are flattening; as a consequence, relationships with coworkers are becoming increasingly influential in the workplace (Cascio, 2003; Nijssen & Pauuwe, 2012). Based on the Stereotype Content Model (Fiske, Cuddy, Glick, & Xu, 2002), I argue that two perceptions of coworkers, competence and warmth (i.e., support), relate to employee engagement and subsequent performance. Applying the Job Demands-Resources Model (Demerouti, Bakker, Nachreiner, & Schaufeli, 2001), I hypothesized that perceptions of coworker competence and support, two job resources, predict employee emotional and social engagement. These claims were partially supported. Using a longitudinal structural equation model, I found that coworker support predicted both social and emotional engagement, while coworker competence significantly predicted social engagement. I also found that emotional and social engagement yield organizational citizenship behaviors. Accordingly, I hypothesized that emotional and social engagement fully mediate the relationships of coworker competence and support with organizational citizenship behaviors. Coworker support indirectly resulted in organizational citizenship behaviors through both emotional and social engagement However, coworker competence only produced organizational citizenship behaviors via social engagement. The current study also introduces a new scale for measuring coworker competence, an important, yet largely ignored concept in organizational literature.Psychology, Department o