Energy harvesting from vibrations with a nonlinear oscillator

In this paper we present a nonlinear electromagnetic energy harvesting device that has a broadly resonant response. The nonlinearity is generated by a particular arrangement of magnets in conjunction with an iron-cored stator. We show the resonant response of the system to both pure-tone excitation and narrow-band random excitation. In addition to the primary resonance, the super-harmonic resonances of the harvester are also investigated and we show that the corresponding mechanical up-conversion of the excitation frequency may be useful for energy harvesting. The harvester is modeled using a Duffing-type equation and the results compared to the experimental data.</jats:p

Perceptions of student affairs and services practitioners in Ontario’s post-secondary institutions: An examination of colleges and universities

Student affairs and services divisions and the partnerships and collaborations in which they engage with faculty, students, and the community form the structural centre of institutions’ approaches to student support. Although past research has identified areas typically associated with the student affairs and services portfolio and factors that influence the organizational structure, little is known about how staff perceive their institutions’ organizational structures relative to supporting student success. The purpose of this study was to understand student affairs and services staff members’ perceptions of the role organizational structure plays in their day-to-day work supporting student success in colleges and universities in Ontario. Although staff commented on their institutions’ formal organizational structures (referring to titles, reporting lines, and breadth of portfolio), their comments focused more specifically on how they saw the nature of their work and changes they have experienced in supporting student success as student bodies become more diverse. &nbsp;Les divisions des services aux étudiants et des affaires étudiantes, de même que les partenariats et collaborations qu’elles forment avec la faculté, les étudiants et la communauté façonnent le centre structurel des approches des établissements envers le soutien des étudiants. Bien qu’une précédente recherche ait identifié des domaines typiquement associés au dossier des affaires étudiantes et des services aux étudiants, ainsi qu’à des facteurs qui influencent la structure organisationnelle, on n’en sait pas beaucoup quant à la perception du personnel de ces établissements envers les structures organisationnelles de leur établissement et leur façon d’appuyer la réussite des étudiants. L’objet de cette étude était de comprendre les perceptions du personnel des affaires étudiantes et des services aux étudiants envers le rôle de la structure organisationnelle dans leur travail quotidien de soutien à la réussite des étudiant(e)s des collèges et universités de l’Ontario. Bien que le personnel ait formulé des remarques sur les structures organisationnelles de leur établissement (les titres, les liens hiérarchiques et l’ampleur des services offerts), leurs commentaires ont ciblé plus précisément leur perception quant à la nature de leur travail et les changements qu’ils ont subi en appuyant la réussite des étudiants en raison d’une population étudiante de plus en plus diversifiée

An optimized tuned mass damper/harvester device

Much work has been conducted on vibration absorbers, such as tuned mass dampers (TMD), where significant energy is extracted from a structure. Traditionally, this energy is dissipated through the devices as heat. In this paper, the concept of recovering some of this energy electrically and reuse it for structural control or health monitoring is investigated. The energy-dissipating damper of a TMD is replaced with an electromagnetic device in order to transform mechanical vibration into electrical energy. That gives the possibility of controlled damping force whilst generating useful electrical energy. Both analytical and experimental results from an adaptive and a semi-active tuned mass damper/harvester are presented. The obtained results suggest that sufficient energy might be harvested for the device to tune itself to optimise vibration suppression

Reply to “Comment on ‘Electron-induced bond breaking at low energies in HCOOH and glycine: The role of very short-lived σ anion states’ ”

Rescigno et al. [Phys. Rev. A 80, 046701 (2009)] criticized our theoretical treatment of dissociative electron attachment in formic acid in which we show that this process can be explained by electron attachment into the temporary negative ion state formed by occupation of the σ*(OH) orbital. We argue that their objections do not hold up to scrutiny

Reply to “Comment on ‘Electron-induced bond breaking at low energies in HCOOH and glycine: The role of very short-lived σ anion states’ ”

Rescigno et al. [Phys. Rev. A 80, 046701 (2009)] criticized our theoretical treatment of dissociative electron attachment in formic acid in which we show that this process can be explained by electron attachment into the temporary negative ion state formed by occupation of the σ*(OH) orbital. We argue that their objections do not hold up to scrutiny

Meth­yl(phen­yl)phosphinic acid

The crystal structure of the title compound, C7H9O2P, displays O—H⋯O hydrogen bonding , which links individual mol­ecules related via the c-glide plane and translational symmetry along the crystallographic b-axis direction into continuous chains

An experimental and theoretical study of transient negative ions in Mg, Zn, Cd and Hg

A range of experimental and theoretical techniques have been applied to the study of transient negative ions (resonances) formed in electron scattering from the Group II metals Mg, Zn, Cd, and Hg at incident electron energies below the first ionization potential. A wealth of resonance structures have been observed and from the experimental observations and theoretical information, classifications are proposed for some of these negative ion states