A model for the onset of oscillations near the stopping angle in an inclined granular flow

We propose an explanation for the onset of oscillations seen in numerical simulations of dense, inclined flows of inelastic, frictional spheres. It is based on a phase transition between disordered and ordered collisional states that may be interrupted by the formation of force chains. Low frequency oscillations between ordered and disordered states take place over weakly bumpy bases; higher-frequency oscillations over strongly bumpy bases involve the formation of particle chains that extend to the base and interrupt the phase change. The predicted frequency and amplitude of the oscillations induced by the unstable part of the equation of state are similar to those seen in the simulations and they depend upon the contact stiffness in the same way. Such oscillations could be the source of sound produced by flowing sand

The state of commercial augmentative biological control: plenty of natural enemies, but a frustrating lack of uptake

Augmentative biological control concerns the periodical release of natural enemies. In com- mercial augmentative biological control, natural enemies are mass-reared in biofactories for release in large numbers to obtain an immediate control of pests. The history of commercial mass production of natural enemies spans a period of roughly 120 years. It has been a successful, environmentally and eco- nomically sound alternative for chemical pest control in crops like fruit orchards, maize, cotton, sugar cane, soybean, vineyards and greenhouses. Currently, aug- mentative biological control is in a critical phase, even though during the past decades it has moved from a cottage industry to professional production. Many efficient species of natural enemies have been discovered and 230 are commercially available today. The industry developed quality control guidelines, mass production, shipment and release methods as well as adequate guidance for farmers. However, augmentative biological control is applied on a frustratingly small acreage. Trends in research and application are reviewed, causes explaining the limited uptake are discussed and ways to increase application of augmentative biological control are explored

Tribological behaviour of polymer bearings under dry and water lubrication

This study attempts to evaluate the performance of polymer journal bearings (PET and UHMWPE) sliding against Inconel stainless steel in both dry and lubricated condition. Four types of ‘lubricant’ are included: distilled water; demineralized water; tap water and river water. The tests were carried out in a so called “Stribeck” configuration with a projected pressure of about 0.3 MPa at room temperature and sliding speed ranging from 0 to 1.07 m/s respectively. The study indicates that polymer bearings with four types of water lubricant give better tribological behaviour compared to those in dry sliding contact. Besides, with water lubrication, UHMWPE shows low friction at starting, but it does not go down much over the course of the tests. Meanwhile, although PET indicates quite higher friction at the beginning, it then shows a clearly decreasing trend

Molecular Diagnostics in Advanced NSCLC: Trying to Maximize a Non-Ideal Situation

10.1097/JTO.0b013e31811f479dJournal of Thoracic Oncology28782

On Large Ensembles: A Cross-Cultural Content Analysis of English and Chinese-language Articles

This article reports a cross-cultural analysis of journal articles pertaining to large ensembles published in English and Chinese languages from 2007–17. Topics addressed in the articles included issues of equity and access, the value of large ensembles in young people’s lives and to the field of music education, the development of large ensemble music education in Asia, and implications for the field of conductor-teacher preparation. Three conceptually distinct but interrelated themes emerged: power, participation, and pedagogy. “Power” refers to the authority, command, and influence commonly associated with conductors. “Participation” refers to issues of access, recruitment, retention, attrition, and other sociological issues related to participation in large ensembles. “Pedagogy” refers to calls for changes in the teaching and delivery of large ensemble programs. The article closes with recommendations for international research and pedagogical development concerning music education’s large ensembles

Electrical and Structural Analysis of CNT-Metal Contacts in Via Interconnects

Vertically aligned carbon nanotubes grown by plasmaenhanced chemical vapor deposition offer a potentially suitable material for via interconnects in next-generation integrated circuits. Key performance-limiting factors include high contact resistance and low carbon nanotube packing density, which fall short of meeting the requirements delineated in the ITRS roadmap for interconnects. For individual carbon nanotube s, contact resistance is a major performance hurdle since it is the dominant component of carbon nanotube interconnect resistance, even in the case of vertically aligned carbon nanotube arrays. In this study, we correlate the carbon nanotube-metal interface nanostructure to their electrical properties in order to elucidate growth parameters that can lead to high density and low contact resistance and resistivity