Nonclassical dynamic modeling of nano/microparticles during nanomanipulation processes.

Since the manipulation of particles using atomic force microscopy is not observable in real-time, modeling the manipulation process is of notable importance, enabling us to investigate the dynamical behavior of nanoparticles. To model this process, previous studies employed classical continuum mechanics and molecular dynamics simulations which had certain limitations; the former does not consider size effects at the nanoscale while the latter is time consuming and faces computational restrictions. To optimize accuracy and computational costs, a new nonclassical modeling of the nanomanipulation process based on the modified couple stress theory is proposed that includes the size effects.

Prediction of insomnia severity based on cognitive, metacognitive, and emotional variables in college students.

Objective: Insomnia is the most common sleep disorder whose origin is attributed to various variables. The current study aims to predict the symptoms of insomnia by investigating some of its predictors.

Methods: Numerous variables such as depression and anxiety symptoms, worry, pre-sleep arousal (cognitive arousal and somatic arousal), dysfunctional cognitions, and metacognitive beliefs about sleep were assessed as insomnia predictors.