bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hydraulic Instability Onset Detection in Kaplan Turbines by Monitoring Shaft Vibrations
Authors: Pennacchi P. , Borghesani P. , Chatterton S. , Vania A. 
Published: September 2013

Design of hydraulic turbines has often to deal with hydraulic instability. It is well-known that Francis and Kaplan types present hydraulic instability in their design power range. Even if modern CFD tools may help to define these dangerous operating conditions and optimize runner design, hydraulic instabilities may fortuitously arise during the turbine life and should be timely detected in order to assure a long-lasting operating life.
In a previous paper, the authors have considered the phenomenon of helical vortex rope, which happens at low flow rates when a swirling flow, in the draft tube conical inlet, occupies a large portion of the inlet. In this condition, a strong helical vortex rope appears. The vortex rope causes mechanical effects on the runner, on the whole turbine and on the draft tube, which may eventually produce severe damages on the turbine unit and whose most evident symptoms are vibrations. The authors have already shown that vibration analysis is suitable for detecting vortex rope onset, thanks to an experimental test campaign performed during the commissioning of a 23 MW Kaplan hydraulic turbine unit.
In this paper, the authors propose a sophisticated data driven approach to detect vortex rope onset at different power load, based on the analysis of the vibration signals in the order domain and introducing the so-called “residual order spectrogram”, i.e. an order-rotation representation of the vibration signal. Some experimental test runs are presented and the possibility to detect instability onset, especially in real-time, is discussed.
Dynamic Characteristics of Fluid Force Induced by Swirling Leakage Flow Between Rotational and Stationary Disks
Authors: Sugiyama Takayuki , Kaneko Shigehiko 
Published: September 2013

Axial self-excited vibration may be induced in a balance piston by fluid with a tangential velocity component that flows into the piston orifices. To avoid such vibration, knowledge of the dynamic characteristics of axial self-excited vibration induced by swirling leakage flow is required at the design stage.
In this research, the effect of axial rotation and swirl strength on the added fluid force coefficients is clarified by modeling the piston orifice as the combination of rotational and stationary disks, and deriving the unsteady fluid force generated by swirling leakage flow between the disks.
As a result, reduction of the relative velocity in the circumferential direction is shown to destabilize the oscillatory system. In particular, the effect of swirl strength on the fluid force coefficient is found to be larger in the case of the divergent channel than in the case of the parallel flow path.
Determination of State Space Matrices for Active Vibration Control Using ANSYS Finite Element Package
Authors: Daraji A. H. , Hale J. M. 
Published: September 2013

This paper concerns optimal placement of discrete piezoelectric sensors and actuators for active vibration control, using a genetic algorithm based on minimization of linear quadratic index as an objective function. A new method is developed to get state space matrices for simple and complex structures with bonded sensors and actuators, using the ANSYS finite element package taking into account piezoelectric mass, stiffness and electromechanical coupling effects.
The state space matrices for smart structures are highly important in active vibration control for the optimisation of sensor and actuator locations and investigation of open and closed loop system control response, both using simulation and experimentally.
As an example, a flexible flat plate with bonded sensor/actuator pairs is represented in ANSYS using three dimensional SOLID45 elements for the passive structure and SOLID5 for the piezoelectric elements, from which the necessary state space matrices are obtained.
To test the results, the plate is mounted as a cantilever and two sensor/actuator pairs are located at the optimal locations. These are used to attenuate the first six modes of vibration using active vibration reduction based on a classical and optimal linear quadratic control scheme. The plate is subject to forced vibration at the first, second and third natural frequencies and represented in ANSYS using a proportional derivative controller and compared with a Matlab model based on ANSYS state space matrices using linear quadratic control. It is shown that the ANSYS state space matrices describe the system efficiently and correctly.
Beyond Hands-on-Learning: Fostering Creativity in Student Competitive Teams
Authors: Siddique Zahed 
Published: September 2013

Engineering educators and practitioners have suggested that collaborative-competitive team design events promote innovation. These competitions are popular, and they attract sponsors and participants. Beyond being popular, they are believed to provide rich learning opportunities for students. We are currently investigating combining student centered learning to have a more appropriate mix of theory and experience (hands-on activities) to provide a complete experiential learning environment to foster innovation and creativity.
In this paper we investigate the theoretical models that can be used to model the Sooner Racing Team (SRT) of University of Oklahoma. Experiential Learning is the foundation to develop the competencies of students engaged in SRT. The SRT is setup as a learning organization and relies on peer-learning to facilitate developing innovation related meta-competencies.
Controlled Buckling of Piezoelectric Beams for Direct Energy Harvesting From Passing Vehicles
Authors: Karami M. Amin , Inman Daniel J. 
Published: September 2013

A piezoelectric device is introduced and modeled to directly interact with the tires of passing vehicles and generate electrical power for roadside applications. Piezoelectric beams are vertically placed on the surface of the road to generate energy from the load of passing vehices. A metal cap is connected to the top end of the bimorphs. The vertical motion of the metal cap is limited by the containing fixture of the device. Tires of the passing vehicles pass over the metal cap and force the bimorph into buckling. The buckling of the piezoelectric beam generates significant amount of power. By controlling the extent of deformation of the beam we make sure that the beam is not damaged by the buckling. To this end, the amount of axial recession of the metal cap (equal to axial deformation of the beam) is precision controlled by the containing fixture. When the beam deflects it axially shrinks due to geometric nonlinearities. This lowers the metal cap. After a certain amount of deformation the metal cap rests on the containing fixture and the tire load is no more transmitted to the piezoelectric beam.
In this paper the performance of the proposed energy harvesting device is analytically modeled. Geometric nonlinearities and piezoelectric couplings have been included in the model. The vibrations of the device are transient. Power is generated when the tire pushes down the metal cap and when the metal cap springs back after the tire has passed. The design criteria for the device are discussed. It is demonstrated that the device can be realized with commonly used piezoelectric patches and can generate hundreds of milliwatts from the moving traffic. The device is not prone to resonance and generates notable amounts of power from passing of each tire. It therefore can be used as a self-sufficient sensor for traffic control.
Effects of Process Parameters on the Properties of Replicated Polymeric Parts
Authors: Trotta Gianluca , Bellantone Vincenzo , Surace Rossella , Fassi Irene 
Published: September 2013

The increasing demand for small and even micro scale parts is boosting the development of reliable micro system technologies. Micro-fabrication process capabilities should expand to encompass a wider range of materials and geometric forms, by defining processes and related process chains that can satisfy the specific functional and technical requirements of new emerging multi-material products, and ensure the compatibility of materials and processing technologies throughout these manufacturing chains. Micro injection moulding is the process of transferring the micron or even submicron precision of microstructured metallic moulds to a polymeric products. It represents one of the key technologies for micro manufacturing because its mass production capability and relatively low production cost. Polymers have relatively low cost, and offer good mechanical and thermal strength, electrical insulation, optical transparency, chemical stability and biocompatibility.
In this work the authors investigate the micro injection moulding process parameters on the overall quality of a miniaturized dog-bone shaped specimen. The aim of the experimentation is to calibrate the process and set the machine for the correct filling of the component. A set of injection parameters are selected for study by experimental plan and simulation tool and then discussed. Simulation results are used to better understand the polymer flow behaviour during the filling phase. A commercial software is used and input data, collected during the micro injection moulding process, are included using as performance indicators flow front position and moulded mass. Process simulation can provide, at the present time, mostly qualitative input to the designer and process engineer. Two different polymers materials are tested and evaluated in relation to the process replication capability: Polyoxymethylene (POM) and Liquid Cristal Polymer (LCP). Finally, the moulding factors with significant statistical effects are identified. The holding pressure and holding time for POM and the holding pressure and injection velocity for LCP show the highest influence on achieving high part mass.
An Interactive Tool for the Participatory Design of Product Interface
Authors: Barbieri Loris , Angilica Agostino , Bruno Fabio , Muzzupappa Maurizio 
Published: September 2013

The importance of participatory design (PD) is progressively increasing thanks to its capacity to explore a wide variety of concepts, thus increasing the opportunity to create a successful product. In fact the design process should not be a solo activity, as designers often need inputs and other points of view, especially from end-users.
According to the ultimate idea of PD, end-users are actively involved in the various activities of the product development to ensure that their needs and desires are satisfied.
This paper presents a novel approach to the participatory design of product interfaces in a user-centered design (UCD) process. The approach is based on an interactive tool that allows end-users to design custom user interfaces of household appliances taking advantage of their own needs and experiences.
The tool incorporates the analytical and more abstract knowledge of the designers codified in the form of aesthetical, technological and manufacturing constraints (i.e., limitations in the number and geometry of interface components, a limited number of colors, a discretization of the area where interface widgets are placed). This solution allows the end-users to directly design their favorite interface without the interference of any other subject. Through an accurate analysis of the choices done by the users, the designers are able to access to the deepest level of the users’ expression in order to catch their latent needs and tacit knowledge.
The tool has been designed in order to make possible to immediately perform usability tests on the designed interface by using a Mixed Reality prototype.
The paper describes the development of the tool and proposes a methodology that has been specifically addressed to include this tool in a design process based on UCD principles. Both the tool and the methodology are presented through the description of a case-study related to the redesign of a washing machine dashboard. Experimental results show that the proposed tool can be an effective support to design product interfaces during PD sessions.
Managing Dilemmas Embodied in 21st Century Engineering
Authors: Ahmed Salman , Xiao Minting , Panchal Jitesh H. , Allen Janet K. , Mistree Farrokh 
Published: September 2013

In this session we describe in four parts the pedagogy and out-comes of a course Designing for Open Innovation designed to empower 21st century engineering students to develop competencies associated with innovating in an inter-connected technologically flat world:
1. Competencies for Innovating in the 21st Century, [1].
2. Developing Competencies In The 21st Century Engineer, [2].
3. Identifying Dilemmas Embodied in 21st Century Engineering, [3].
4. Managing Dilemmas Embodied in 21st Century Engineering - this paper.
In the first paper we describe the core characteristics of the engineering in an interconnected world and identify the key competencies and meta-competencies that 21st century engineers will need to innovate and negotiate solutions to issues associated with the realization of systems.
In the second paper, we describe our approach to fostering learning and the development of competencies by an individual in a group setting. We focus on empowering the students to learn how to learn as individuals in a geographically distanced, collaborative group setting.
We assert that two of the core competencies required for success in the dynamically changing workplace are the competencies to first identify and then to manage dilemmas. In the third paper, we illustrate how students have gone about identifying dilemmas and in the fourth paper how they have attempted to manage dilemmas. In papers three and four students have briefly described the challenges that they faced and their takeaways in the form of team learning and individual learning.
In this the last of four papers in this session, we focus on how students learned to manage dilemmas associated with the realization of complex, sustainable, socio-techno-eco systems, namely, energy policy design. The example involves the identification of a bridging fuel that balances environmental, economic and socio-cultural concerns. The principal outcome is clearly not the result attained but a student’s ability to learn how to learn as illustrated through the development of personal competencies in a collaborative learning framework and environment.
Experimental Optimization of a Discrete Robot Exhibiting Hysteresis
Authors: Kirsch Karl , Kean Michael , Cipra Raymond J. 
Published: September 2013

Discrete joint manipulators are a potential alternative to common continuous joint robots used in industry today. Applications of a discrete joint manipulator include proximity positioning tasks, space exploration, camera placement, and automation systems. Discrete robots are potentially useful for small scale robots because it is difficult to implement sensors and motors at small scales. This work discusses the results obtained with an experimental 7 link robot designed for an 8 × 12 inch grid.
Results show that a discrete robot can successfully be used for proximity positioning tasks. The performance depends on the location of discrete points relative to the desired points and also on the repeatability of the experimental manipulator. Results obtained via a vision system demonstrate the potential capabilities of the planar discrete manipulator. Results include subsets of end-effector positions in the gridspace and training results.
Higher-Pair Reuleaux-Triangle in Square and its Derived Mechanisms
Authors: Figliolini Giorgio , Rea Pierluigi , Grande Salvatore 
Published: September 2013

This paper deals with the formulation of a mathematical procedure for the motion analysis of mechanisms, which are derived by the higher-pair Reuleaux-triangle in square, which curve-triangle shows a rounded vertex.
In particular, the trajectory of the center of the modified Reuleaux triangle, the fixed and moving centrodes, the trajectory of any moving point, with particular reference to the center of the rounded corner of the curve-triangle, have been obtained in algebraic form. Exact square trajectories can be also obtained for specific rounded corners.
Graphical Synthesis of Fourbar Mechanisms by Three-Position, Instant-Center Specification
Authors: Thompson Thomas J. 
Published: September 2013

In four-bar mechanism synthesis, solutions to both the three-position and four-position synthesis problems are well-known. However, certain practical synthesis problems also require consideration of the instantaneous center of velocity for one of the precision positions. Examples are the double-wishbone front suspension of an automobile (camber in jounce and rebound, along with roll center), and four-bar prosthetic knee (standing stability, flexion length, and sitting cosmetic advantage).
Because specifying the location of the instant center constrains the solution by one free choice per dyad, it reduces the number of free choices available in a three-position problem from two to one. Thus, center point and circle point solutions to the three-position, instant center specified synthesis (TPICS) problem are located along point-pair solution curves similar to the Burmester curves in four-position synthesis.
The purpose of this paper is to present a direct, graphical method for finding pivot locations in three-position, instant-center synthesis of four-bar mechanisms. The method uses pole triangle theory to determine pivot locations along center point and circle point curves. A summary of a previously-presented computational method is included.
As an example, both the graphical and the computational method are used to generate TPICS center-point curves for an automotive front suspension.
Evaluating the Directed Method for Bioinspired Design
Authors: Glier Michael W. , Tsenn Joanna , Linsey Julie S. , McAdams Daniel A. 
Published: September 2013

Bioinspired design, the practice of looking to nature to find inspiration for engineering design, is becoming an increasingly desired approach to design. It allows designers to tap a wealth of time-tested solutions to difficult problems in a domain rarely considered by designers. Only recently have researchers developed organized, systematic methods for bioinspired design. These methods include BioTRIZ, an extension of functional modeling for bioinspired design, engineering-to-biology keyword translation tools, and specialized design tools like DANE and SAPPHIRE. These organized methods are currently active research efforts. Traditionally, however, bioinspired design has been conducted without the benefit of any organized method. Without the support of formal methods, designers have relied on the “directed method” of bioinspired design. The directed method approach simply directs designers to consider how nature might approach a problem in order to help designers find solutions. This paper presents an experiment to explore the impact upon idea generation of simply contemplating how nature would solve a design problem. This experiment is foundationally important to bioinspired engineering design method research. The results of this experiment serve as a fundamental baseline and benchmark for the comparison of more systematic, and often more involved, bioinspired design methods.
A group of 121 novice designers are given one of two design problems and instructed to either generate solutions using the “directed method,” considering how nature would solve the problem, or to generate solutions without being prompted to use any method. Based on the findings presented here, the directed method offers designers no advantage in the average number of non-redundant ideas the designers can produce, the average quality of their solutions, the average solution novelty, or the variety of solutions proposed. Overall, this investigation finds no significant difference in idea generation between the directed method and the control condition. In conclusion, systematic and organized methods for bioinspired design should instead be sought to effectively leverage nature’s design knowledge.
Numerical Investigation and Experimental Lab Setting-Up for Analysis of Gas Turbine Combustor Dilution Process
Authors: Amano R. S. , Gupta Alka , Ibrahim Mohamed S. , Rux Andrew , Lang Mark , Moll Travis 
Published: September 2013

A gas turbine combustor dilution process is modeled numerically using both 2-D and 3-D approaches, then an experimental set-up was designed and built for validation using standard air ducts. The combustor model is used to test various air cooling strategies with the goal of uniformly diluting combustion gas before it enters the turbine section. The high temperature combustion gas (simulated as hot air) is cooled by introducing a lower temperature secondary air flow through perforated plates. First a 2-D simulation was conducted to compare between introducing the dilution air from smaller but large number of holes or larger but smaller number of holes. It was found that the larger holes are more effective especially when pressure drop is taken into consideration. Then a 3-D simulation was run with larger holes for different configurations and the experimental set up was constructed accordingly. The temperature profile at the exit of the dilution section is considered the criteria for testing the uniformity of temperature after the dilution process, and it will be measured in the experimental work.
This paper presents a brief discussion on the importance of cooling combustion exit gas uniformly before it enters the turbine section. With this in mind, a testing concept is derived in order to gauge methods of improving this cooling. Detailed design specifications and initial conclusions are also outlined. Initial conclusions have yielded a desired primary airflow of 6 m/s (19.7 ft/s) and primary duct diameter of 0.4 m (16 in). With this information it was determined that the flow rate required by the fan is 1.727 m3/s (3660 CFM).
Confronting bad husbandry
Authors: Henderson Kathryn 
Published: September 2013

THIS series gives readers the opportunity to consider and contribute to discussion of some of the ethical dilemmas that can arise in veterinary practice. Each month, a case scenario is presented, followed by discussion of some of the issues involved. In addition, a possible way forward is suggested; however, there is rarely a cut‐and‐dried answer in such cases, and readers may wish to suggest an alternative approach. This month's dilemma, ‘Confronting bad husbandry’, was submitted and is discussed by Kathryn Henderson. Readers with comments to contribute are invited to send them as soon as possible, so that they can be considered for publication in the next issue. Discussion of the dilemma ‘Honesty and euthanasia’, which was published in the July/August issue of In Practice, appears on page 487.The series is being coordinated by Siobhan Mullan, of the University of Bristol. It is hoped it will provide a framework that will help practices find solutions when facing similar dilemmas.
Epigenetic Approaches for Chemosensitization of Refractory Diffuse Large B-Cell Lymphomas
Authors: Steinhardt James J. , Gartenhaus Ronald B. 
Published: September 2013

Abstract
Summary: Diffuse large B-cell lymphoma (DLBCL) is the most common form of non-Hodgkin lymphoma, with the greatest challenge for improving patient survival being the management of chemorefractory disease upon relapse. Epigenetic dysregulation has been correlated with more-aggressive malignancies and chemoresistance. In this issue of Cancer Discovery, Clozel and colleagues show the potential for low-dose DNA methyltransferase inhibitors as both a rational and an effective neoadjuvant approach for chemosensitization in DLBCL. Cancer Discov; 3(9); 968–70. ©2013 AACR.
See related article by Clozel et al., p. 1002