Damage progression tests were performed in the NASA Glenn Spiral Bevel Gear Fatigue Rig. Six gear sets with varying levels of tooth damage were tested, and vibration-based gear condition indicators, amount of debris generated, and oil temperatures were measured. The damage state was documented with photographs taken at inspection intervals throughout the test and was quantified with a numerical...

Classical reliability assessment methods have predominantly focused on probability and statistical theories, which are insufficient in assessing the operational reliability of individual mechanical equipment with time-varying characteristics. A new approach to assess machinery operational reliability with normalized lifting wavelet entropy from condition monitoring information is proposed, whic...

Monitoring natural gas transmission in a pipeline network is important to maintain the supply and demand balance transactions distribution. Gas pressure, temperature, flowrate, properties must be monitored during process. These variables, also known as operational conditions, need simulated carefully understand dynamics behavior over time. Commonly used physical equations, such thermodynamic or...

Condition-based maintenance (CBM) seeks to implement a policy wherein maintenance management decisions are based on the identification of the current condition of monitored machinery. It involves not only collecting data but also comparing them with reference values and, if necessary generating alerts based on preset operational limits. This approach is adopted by a system responsible for monit...

We provide a broad characterization of the supply chain settings in which perfect coordination can be achieved with a simple wholesale pricing scheme based on constant unit wholesale prices or a single quantity discount scheme. We confine ourselves to two-echelon chains with a single supplier servicing a network of retailers who compete with each other by selecting retail prices (Bertrand compe...

the highly substituted pyridine derivatives are found to exhibit diverse pharmacological activities. they are also emerged as potential medicinal leads in developing therapeutic agents for the treatment of various diseases. in this work, a series of 2-amino-3,5-dicarbonitrile-6-thio-pyridine derivatives have been synthesized at room temperature via one-pot, multi-component reaction of various a...

(diacetoxyiodo)benzene has been used as an efficient catalyst for an improved and rapid one-pot synthesis of biscoumarin derivatives in excellent yield under reflux condition using water as a environmentally benign reaction medium. this aqua mediated knoevenagel condensation of various aromatic and hetero-aromatic aldehydes with 4-hydroxycoumarin using catalytic amount of (diacetoxyiodo)benzene...

This study aimed to examine the relative effect of feedback and operational experience on children's rule learning in a balance scale task, in which 88 children under the age of 7 years were asked to judge the state of equilibrium under four conditions. In the Control condition, children were required to observe the scale and predict which side would tilt down or keep balance, without feedback ...