42 research outputs found
Understanding Copyright & Transformative Fair Use
Slides and workshop examples from a session, Understanding Copyright & Transformative Fair Use, given at the Rhode Island Library Association Annual Conference, RILA 2015, on May 28, 2015 in Newport, Rhode Island.
This interactive workshop will outline the basics of copyright and fair use, emphasizing the notion of transformative fair use as highlighted in recent court decisions. The majority of the session will be devoted to real-life scenarios, and audience members will be able to analyze texts, images, video, and sound recordings to determine whether the proposed use is fair. You’ll also learn about handy alternatives for situations when fair use does not apply
Open Everything: How to Find Free, Reusable Content Online
Slides and handout from a session, Open Everything: How to Find Free, Reusable Content Online, given at the Rhode Island Library Association Annual Conference, Color Outside the Lines, on May 25, 2016 in Warwick, Rhode Island.
How can you help your patrons locate open materials to support their school work, personal development, and creative activities? What is the difference between content that is free to access versus free to reuse? What does it mean when content has an open license like Creative Commons? Where are the best places online to look for open e-books, learning materials, images, sound and music, video, historical and cultural materials, and software? We\u27ll explain the different kinds of open, give a quick tour of where on the Web to look for open materials, and send you away with a guide to additional resources that you can explore on your own
Copyright, Fair Use, and Education: Your Rights as a Student, Faculty Member, and Researcher
Slides, handouts, and classroom examples from a presentation, Copyright, Fair Use, and Education: Your Rights as a Student, Faculty Member, and Researcher, offered at the University of Rhode Island Libraries on February 24 and February 25, 2014.
Learn how Fair Use can help you incorporate copyrighted works (written material, images, video, etc.) into your research, teaching, and academic projects. Have questions about Fair Use and Copyright? Please bring them to these interactive sessions!
Part of the University Libraries\u27 Search Savvy Seminar series
What Are They Doing Anyway?: Library as Place and Student Use of a University Library
Objective - To determine student use of library spaces, the authors recorded student location and behaviors within the Library, to inform future space design.
Methods - The case study method was used with both quantitative and qualitative measures. The authors had two objectives to guide this assessment of library spaces: 1) To determine what library spaces are being used by students and whether students are working individually, communally, or collaboratively and 2) To determine whether students use these spaces for learning activities and/or social engagement.
Results - After data collection and analysis, the authors determined students are using individual or communal spaces almost equally as compared with collaborative group spaces. Data also revealed peak area usage and times.
Conclusion - Observed student individual and social work habits indicate further need for spaces with ample electrical outlets and moveable tables. Further study is recommended to see whether additional seating and renovated spaces continue to enhance informal learning communities at URI and whether the Library is becoming a “third place” on campus
Recommended from our members
On the molecular pathways supporting the development of structurally coloured cuticle in Hibiscus trionum
Evolving from a single ancestor that appeared between 250 and 125 million years ago, flowering plants are the most diverse group of plants with about 78% of plant species. The staggering diversity of flowering plants is often correlated with their capacity of adaptation to the diversity of niche space offered by numerous different animal pollinators displaying many different sensory and behavioural traits. In response to selective pressure to attract pollinators, flowers have developed many strategies such as the production of volatile compounds, thermal patterns, visual cues, and rewards amongst others. In 2009, observations of the proximal adaxial part of Hibiscus trionum petals revealed the presence of structural colours. They are mainly characterised by the specific reflection of blue and UV-light in an angle dependant manner (also known as iridescence). Further observations of the cuticle showed the presence of nano-scaled striations acting as a grating like surface responsible for the diffraction of light. Computational modelling, and existing knowledge in material physics, suggests that the development of such a structure is induced by the buckling of the petal cuticle.
In this PhD, the molecular pathways and mechanisms underpinning the production of nanoscaled petal ridges were investigated in Hibiscus trionum. Liquid extraction surface analyses coupled with mass spectrometry were conducted on striated and non-striated tissues, allowing us to highlight the importance of the cuticle chemistry in the development of nano-scaled ridges. The abundance of a specific cutin monomer and the reticulation of the cutin network appeared to be crucial for the buckling of the cuticle. Further investigation using transcriptomic analyses of distal and proximal petal tissues before and after the development of striations revealed the importance of SHN3 and DEWAX transcription factors in the modulation of the cuticle chemistry of the petals. The upregulation of SHN3 and DEWAX expression in the proximal petal region suggested that cuticle buckling could be enabled by a relative abundance of cutin and a decrease in the wax content of the cuticle. Further transcriptomic
III analyses revealed the up regulation of numerous genes involved in pectin catabolism in the proximal petal region, consistently with the production of a compliant, softer cell wall for the development of striations. Mutant screen experiments identified 2 mutant lines characterised by the presence of smooth patches of cells and the presence of conical cells in one of them. Further characterisation of the mutant phenotypes suggested the importance of the cell shape and the thickness of the cuticle to achieve proper bucking. Finally, the adhesion properties of structurally coloured cuticle were briefly studied by testing the gripping capacity of Leptinotarsa decemlineata on replicas of the structurally coloured cuticle of Paeonia mascula petals. Wettability was also investigated by measuring the contact angle of water droplets on similar replicas. Together, these results demonstrate that structurally coloured cuticle resulting from nano-scaled striation decreases the grip ability of L. decemlineata, potentially by a decrease in the contact surface between the setose pads and the cuticle.The European Commission: Marie Skłodowska Curie Actions: Plant inspired Material and Surfaces (PLAMATSU) Innovative training network (ITN)
Analyse des instabilités aéroélastiques dans les turbines spatiales : étude du flottement dans des configurations récentes de turbines à traversanalyse aérodynamique des écoulements subsoniques soumis à un mode de structure vibratoire imposé
Modern turbomachines are designed towards thinner, lighter and highly loaded blades. This gives rise to increased sensitivity to flow induced vibrations such as flutter, which leads to structure failure in a short period of time if not sufficiently damped. Although numerical tools are more and more reliable, flutter prediction still depends on a large degree on simplified models. In addition, the critical nature of flutter, resulting in poor welldocumented real cases in the open literature, and the lack of experimental database typical of engine flows make its apprehension even more challenging. In that context, the present thesis is dedicated to study flutter in recent turbines through aerodynamic analysis of subsonic or supersonic flows in response to a prescribed vibratory mode of the structure. The objective is to highlight some mechanisms potentially responsible for flutter in order to be in better position when designing blades. The strategy consists in leading both experimental and numerical investigations. The experimental part is based on a worldwide unique annular turbine sector cascade employed for measuring the aeroelastic response by means of the aerodynamic influence coefficient technique. The cascade comprises seven low pressure gas turbine blades one of which can oscillate in a controlled way as a rigid body. Aeroelastic responses are measured at various mechanical and aerodynamic parameters: pure and combined modeshapes, reduced frequency, Mach number, incidence angle. In addition to turbulence level measurements, the database aims at assessing the influence of these parameters on the aerodynamic damping, at validating the linear combination principle and at providing input for numerical tools. The numerical part is based on unsteady computations linearized in the frequency domain and performed in the traveling wave mode. The focus is put on two industrial space turbines: 2D computations are performed on an integrally bladed disk, also called blisk; its very low viscous material damping results in complex motions with combined modes and extremely high reduced frequency. The blisk operates at low subsonic conditions without strong non-linearities. Although the blades have been predicted aeroelastically stable, an original methodology based on elementary decompositions of the blade motion is presented to identify the destabilizing movements. The results suggest that the so-called classical flutter is surprisingly prone to occur. Moreover, the aerodynamic damping has been found extremely sensitive to the interblade phase angle and cut-on/cut-off conditions.• 3D computations are then performed on a supersonic turbine, which features shockwaves and boundary layer separation. In contrast, the blade motion is of elementary nature, i.e. purely axial. The blades have been predicted aeroelastically unstable for backward traveling waves and stable for forward traveling waves. The low reduced frequencies allow quasi-steady analysis, which still account for flutter mechanisms: the shock wave motion establishes the boundary between stable and unstable configurations.Les aubes des turbomachines modernes sont de plus en plus fines, légères et chargées aérodynamiquement. Cette tendance accroît l'apparition de phénomènes aéroélastiques tel que le flottement qui conduit à la rupture si l'amortissement est insuffisant. Bien que les outils numériques soient de plus en plus robustes, la fiabilité de sa prédiction demeure insuffisante. La nature critique du phénomène et le manque de données expérimentales pour des écoulements typiques de l'industrie encouragent des travaux de recherche. Dans ce contexte, la présente thèse est dédiée à l'étude du flottement dans des configurations récentes de turbine à travers l'analyse aérodynamique des écoulements subsoniques ou supersoniques soumis à un mode de structure vibratoire imposé. L'objectif est de fournir des éléments de compréhension des mécanismes potentiellement générateurs de flottement pour une meilleure intégration lors de la conception des aubes. L’approche consiste à mener des travaux expérimentaux et numériques. La partie expérimentale s'appuie sur un secteur de grille annulaire constitué de sept aubes dont une peut osciller de manière contrôlée. Les fluctuations de pressions instationnaires générées sont mesurées avec la technique dite des coefficients d'influence pour différents paramètres mécaniques et aérodynamiques : déformées modales pures et combinées, fréquence réduite, nombre de Mach, angle d'incidence. Complétée par des mesures de niveau de turbulence, la base de données vise à évaluer l'influence de ces paramètres sur la réponse aéroélastique, à valider le principe de superposition linéaire et à soutenir les codes numériques. La partie numérique se base sur des calculs instationnaires linéarisés dans le domaine fréquentiel en utilisant la technique dite des "ondes propagatives" (traveling wave mode).Deux cas de turbines spatiales industrielles sont étudiés.• Des calculs 2D sont réalisés sur une turbine monobloc ou blisk. L'amortissement mécanique quasi-nul entraîne des déformées complexes avec couplage de modes et des fréquences réduites très élevées. Bien que les aubes soient prédites stables, une méthodologie basée sur des décompositions géométriques élémentaires est présentée afin d'identifier les contributions déstabilisantes. Les résultats aboutissent étonnamment aux conclusions de la théorie du flottement classique : la torsion est une source potentielle d'instabilité. De plus, le coefficient d'amortissement aérodynamique a été trouvé extrêmement sensible au déphasage interaube et aux fréquences de coupure (modes cut-on/cut-off).• Des calculs 3D sont ensuite réalisés sur une turbine supersonique. L'écoulement présente des ondes de chocs avec décollement de la couche limite et le mouvement de l'aube est de nature élémentaire, i.e. purement axial. Les aubes ont été prédites instables pour les modes rétrogrades et stables pour les modes propagatifs. En dépit des fortes hypothèses, des analyses quasi-stationnaires rendent compte des mécanismes de flottement : la phase entre le mouvement du choc et l'excitation établit la frontière entre configurations stable et instable
Contribution to Numerical and Experimental Studies of Flutter in Space Turbines. Aerodynamic Analysis of Subsonic or Supersonic Flows in Response to a Prescribed Vibratory Mode of the Structure.
Modern turbomachines are designed towards thinner, lighter and highly loaded blades. This gives rise to increased sensitivity to flow induced vibrations such as flutter, which leads to structure failure in a short period of time if not sufficiently damped. Although numerical tools are more and more reliable, flutter prediction still depends on a large degree on simplified models. In addition, the critical nature of flutter, resulting in poor well-documented real cases in the open literature, and the lack of experimental database typical of engine flows make its apprehension even more challenging. In that context, the present thesis is dedicated to study flutter in recent turbines through aerodynamic analysis of subsonic or supersonic flows in response to a prescribed vibratory mode of the structure. The objective is to highlight some mechanisms potentially responsible for flutter in order to be in better position when designing blades. The strategy consists in leading both experimental and numerical investigations. The experimental part is based on a worldwide unique annular turbine sector cascade employed for measuring the aeroelastic response by means of the aerodynamic influence coefficient technique. The cascade comprises seven low pressure gas turbine blades one of which can oscillate in a controlled way as a rigid body. Aeroelastic responses are measured at various mechanical and aerodynamic parameters: pure and combined modeshapes, reduced frequency, Mach number, incidence angle. In addition to turbulence level measurements, the database aims at assessing the influence of these parameters on the aerodynamic damping, at validating the linear combination principle and at providing input for numerical tools. The numerical part is based on unsteady computations linearized in the frequency domain and performed in the traveling wave mode. The focus is put on two industrial space turbines: 2D computations are performed on an integrally bladed disk, also called blisk; its very low viscous material damping results in complex motions with combined modes and extremely high reduced frequency. The blisk operates at low subsonic conditions without strong non-linearities. Although the blades have been predicted aeroelastically stable, an original methodology based on elementary decompositions of the blade motion is presented to identify the destabilizing movements. The results suggest that the so-called classical flutter is surprisingly prone to occur. Moreover, the aerodynamic damping has been found extremely sensitive to the interblade phase angle and cut-on/cut-off conditions. 3D computations are then performed on a supersonic turbine, which features shock waves and boundary layer separation. In contrast, the blade motion is of elementary nature, i.e. purely axial. The blades have been predicted aeroelastically unstable for backward traveling waves and stable for forward traveling waves. The low reduced frequencies allow quasi-steady analysis, which still account for flutter mechanisms: the shock wave motion establishes the boundary between stable and unstable configurations.QC 20111209</p
Analyse des instabilités aéroélastiques dans les turbines spatiales : étude du flottement dans des configurations récentes de turbines à traversanalyse aérodynamique des écoulements subsoniques soumis à un mode de structure vibratoire imposé
Modern turbomachines are designed towards thinner, lighter and highly loaded blades. This gives rise to increased sensitivity to flow induced vibrations such as flutter, which leads to structure failure in a short period of time if not sufficiently damped. Although numerical tools are more and more reliable, flutter prediction still depends on a large degree on simplified models. In addition, the critical nature of flutter, resulting in poor welldocumented real cases in the open literature, and the lack of experimental database typical of engine flows make its apprehension even more challenging. In that context, the present thesis is dedicated to study flutter in recent turbines through aerodynamic analysis of subsonic or supersonic flows in response to a prescribed vibratory mode of the structure. The objective is to highlight some mechanisms potentially responsible for flutter in order to be in better position when designing blades. The strategy consists in leading both experimental and numerical investigations. The experimental part is based on a worldwide unique annular turbine sector cascade employed for measuring the aeroelastic response by means of the aerodynamic influence coefficient technique. The cascade comprises seven low pressure gas turbine blades one of which can oscillate in a controlled way as a rigid body. Aeroelastic responses are measured at various mechanical and aerodynamic parameters: pure and combined modeshapes, reduced frequency, Mach number, incidence angle. In addition to turbulence level measurements, the database aims at assessing the influence of these parameters on the aerodynamic damping, at validating the linear combination principle and at providing input for numerical tools. The numerical part is based on unsteady computations linearized in the frequency domain and performed in the traveling wave mode. The focus is put on two industrial space turbines: 2D computations are performed on an integrally bladed disk, also called blisk; its very low viscous material damping results in complex motions with combined modes and extremely high reduced frequency. The blisk operates at low subsonic conditions without strong non-linearities. Although the blades have been predicted aeroelastically stable, an original methodology based on elementary decompositions of the blade motion is presented to identify the destabilizing movements. The results suggest that the so-called classical flutter is surprisingly prone to occur. Moreover, the aerodynamic damping has been found extremely sensitive to the interblade phase angle and cut-on/cut-off conditions.• 3D computations are then performed on a supersonic turbine, which features shockwaves and boundary layer separation. In contrast, the blade motion is of elementary nature, i.e. purely axial. The blades have been predicted aeroelastically unstable for backward traveling waves and stable for forward traveling waves. The low reduced frequencies allow quasi-steady analysis, which still account for flutter mechanisms: the shock wave motion establishes the boundary between stable and unstable configurations.Les aubes des turbomachines modernes sont de plus en plus fines, légères et chargées aérodynamiquement. Cette tendance accroît l'apparition de phénomènes aéroélastiques tel que le flottement qui conduit à la rupture si l'amortissement est insuffisant. Bien que les outils numériques soient de plus en plus robustes, la fiabilité de sa prédiction demeure insuffisante. La nature critique du phénomène et le manque de données expérimentales pour des écoulements typiques de l'industrie encouragent des travaux de recherche. Dans ce contexte, la présente thèse est dédiée à l'étude du flottement dans des configurations récentes de turbine à travers l'analyse aérodynamique des écoulements subsoniques ou supersoniques soumis à un mode de structure vibratoire imposé. L'objectif est de fournir des éléments de compréhension des mécanismes potentiellement générateurs de flottement pour une meilleure intégration lors de la conception des aubes. L’approche consiste à mener des travaux expérimentaux et numériques. La partie expérimentale s'appuie sur un secteur de grille annulaire constitué de sept aubes dont une peut osciller de manière contrôlée. Les fluctuations de pressions instationnaires générées sont mesurées avec la technique dite des coefficients d'influence pour différents paramètres mécaniques et aérodynamiques : déformées modales pures et combinées, fréquence réduite, nombre de Mach, angle d'incidence. Complétée par des mesures de niveau de turbulence, la base de données vise à évaluer l'influence de ces paramètres sur la réponse aéroélastique, à valider le principe de superposition linéaire et à soutenir les codes numériques. La partie numérique se base sur des calculs instationnaires linéarisés dans le domaine fréquentiel en utilisant la technique dite des "ondes propagatives" (traveling wave mode).Deux cas de turbines spatiales industrielles sont étudiés.• Des calculs 2D sont réalisés sur une turbine monobloc ou blisk. L'amortissement mécanique quasi-nul entraîne des déformées complexes avec couplage de modes et des fréquences réduites très élevées. Bien que les aubes soient prédites stables, une méthodologie basée sur des décompositions géométriques élémentaires est présentée afin d'identifier les contributions déstabilisantes. Les résultats aboutissent étonnamment aux conclusions de la théorie du flottement classique : la torsion est une source potentielle d'instabilité. De plus, le coefficient d'amortissement aérodynamique a été trouvé extrêmement sensible au déphasage interaube et aux fréquences de coupure (modes cut-on/cut-off).• Des calculs 3D sont ensuite réalisés sur une turbine supersonique. L'écoulement présente des ondes de chocs avec décollement de la couche limite et le mouvement de l'aube est de nature élémentaire, i.e. purement axial. Les aubes ont été prédites instables pour les modes rétrogrades et stables pour les modes propagatifs. En dépit des fortes hypothèses, des analyses quasi-stationnaires rendent compte des mécanismes de flottement : la phase entre le mouvement du choc et l'excitation établit la frontière entre configurations stable et instable