bluuebunny/crossref_metadata_2025 huggingface dataset:
Integrated Risk Assessment and Management Methods Are Necessary for Effective Implementation of Natural Hazards Policy
Authors: Johnson David R.
Published: January 2019

A transdisciplinary, integrated risk assessment and risk management process is particularly beneficial to the development of policies addressing risk from natural hazards. Strategies based on isolated risk assessment and management processes, guided by traditional “predict, then act” methods for decision making, may induce major regret if future conditions diverge from predictions. Analytic methods designed to identify robust solutions—those that perform satisfactorily over a broader range of future conditions—are more suitable for management of natural hazards risks, for at least three major reasons discussed within. Such approaches benefit from co‐production of knowledge to collaboratively produce adaptive, robust policies through an iterative process of dialogue between analysts, decisionmakers, and other stakeholders: exploring tradeoffs, searching for futures in which current plans are likely to fail, and developing adaptive management strategies responsive to evolving future conditions. The process leads to more effective adoption of risk management policies by ensuring greater feasibility of solutions, exploring a wide range of plausible future conditions, generating buy‐in, and giving a voice to actors with a diversity of perspectives. The second half of the article presents Louisiana's coastal master planning process as an exemplary model of participatory planning and integrated risk assessment and management. Louisiana planners have adopted a decision framework that incorporates insights from modern methods for decision making under deep uncertainty to effectively address the deep uncertainties and complexities characteristic of a variety of natural hazards and long‐range planning problems.
Body orientation contributes to modelling the effects of gravity for target interception in humans
Authors: La Scaleia Barbara , Lacquaniti Francesco , Zago Myrka
Published: January 2019

Key points

It is known that interception of targets accelerated by gravity involves internal models coupled with visual signals.

Non‐visual signals related to head and body orientation relative to gravity may also contribute, although their role is poorly understood.

In a novel experiment, we asked pitched observers to hit a virtual target approaching with an acceleration that was either coherent or incoherent with their pitch‐tilt.

Initially, the timing errors were large and independent of the coherence between target acceleration and observer's pitch. With practice, however, the timing errors became substantially smaller in the coherent conditions.

The results show that information about head and body orientation can contribute to modelling the effects of gravity on a moving target. Orientation cues from vestibular and somatosensory signals might be integrated with visual signals in the vestibular cortex, where the internal model of gravity is assumed to be encoded.

Interception of moving targets relies on visual signals and internal models. Less is known about the additional contribution of non‐visual cues about head and body orientation relative to gravity. We took advantage of Galileo's law of motion along an incline to demonstrate the effects of vestibular and somatosensory cues about head and body orientation on interception timing. Participants were asked to hit a ball rolling in a gutter towards the eyes, resulting in image expansion. The scene was presented in a head‐mounted display, without any visual information about gravity direction. In separate blocks of trials participants were pitched backwards by 20° or 60°, whereas ball acceleration was randomized across trials so as to be compatible with rolling down a slope of 20° or 60°. Initially, the timing errors were large, independently of the coherence between ball acceleration and pitch angle, consistent with responses based exclusively on visual information because visual stimuli were identical at both tilts. At the end of the experiment, however, the timing errors were systematically smaller in the coherent conditions than the incoherent ones. Moreover, the responses were significantly (P = 0.007) earlier when participants were pitched by 60° than when they were pitched by 20°. Therefore, practice with the task led to incorporation of information about head and body orientation relative to gravity for response timing. Instead, posture did not affect response timing in a control experiment in which participants hit a static target in synchrony with the last of a predictable series of stationary audiovisual stimuli.
Aristotelian phronesis as a key factor for leadership in the knowledge-creating company according to Ikujiro Nonaka
Authors: Scalzo Germán , Fariñas Guillermo
Published: January 2019

Some Western organizational studies scholars have proposed that Aristotelian Phronesisrepresents a way of including practical reason in research on business topics such as decision-making, knowledge management, ethics and leadership. Ikujiro Nonaka, a Japanese scholar with notable theoretical and practical contributions to knowledge creation in organizations and with extensive experience in Japanese corporations, has joined this group of academics. As an Eastern thinker, he takes on a Western classical tradition, namely the virtue of Phronesis, making an important contribution to the application of ethical notions to business practice, in this case knowledge management. To locate his conceptualization of Aristotelian practical wisdom, we briefly describe his theory of knowledge creation, pointing to phroneticleadership skills as essential drivers of knowledge creation in organizations. Furthermore, we assess Nonaka’s incorporation of practical rationality from the point of view of the Western classical tradition.To conclude, we discuss the scope and limits of the use of Phronesisin Nonaka´s contribution, and ultimately suggest that incorporating the will helps us to understand prudence as a virtue and not just as an intellectual habit.
“This is not a cake recipe”: Historicity as an element for the understanding and transformation of a waste management activity at a university hospital in Brazil
Authors: Rodrigues Paniza Maurício Donavan , Cassandre Marcio Pascoal
Published: January 2019

This work analyzes how the expansive learning cycle is covered by a work group, from the intervention of a Change Laboratory, held in a waste management activity at a university hospital. The theoretical basis is derived from the Cultural-Historical Activity Theory and documentary research was used as methodology. In the learning movement, the workers realized that the organization of activity was and still is insufficient to meet the demands of the hospital and society. The intervention did not provoke structural transformation in the activity. But the historicity present in the learning experience allowed the apprentices to be aware of themselves and the importance of waste management, either from a functional or a social viewpoint.
THE TIME, SPACE AND MATTER OF LEADING: AN ARENDTIAN FRAMEWORK FOR LEADERSHIP LEARNING
Authors: Jørgensen Kenneth Mølbjerg
Published: January 2019

This paper develops an ethical framework of leadership learning from Hannah Arendt’s writing. The intention is to identify important principles of a framework of leadership leading that help empower actors to lead themselves and to engage, interact, influence and inspire others through their appearances. It is argued that true leadership learning is directed initiating new beginnings through political actions. Such actions rely on spaces of freedom, which are spaces where people in organizations are answerable to each other and oneself. Three dimensions in this “spacing” are considered important: spaces of thinking, spaces of acting and spaces of judging They constitute three domains of freedom, which may help organizing and guiding leadership learning activities.
Factores asociados a la práctica reflexiva en estudiantes de pedagogía
Authors: Salinas-Espinosa Álvaro Luis , Rozas-Assael Tamara , Cisternas-Alarcón Pablo , González-Ugalde Carlos
Published: January 2019

Este artículo describe la frecuencia con la cual estudiantes de pedagogía realizan prácticas reflexivas, y analiza factores que pueden explicar esta frecuencia. Para ello se empleó una perspectiva cuantitativa que incluyó una encuesta a una muestra de 650 estudiantes de 134 programas de formación de profesores en Chile. Los resultados muestran que los factores más importantes para explicar la práctica reflexiva se relacionan con el supervisor. Los factores relacionados con los compañeros de estudio y con la discusión sobre la profesión docente contribuyen menos a la práctica reflexiva.
ICT for Inclusion. A Student Voice Research Project in Spain
Authors: Susinos-Rada Teresa , Calvo-Salvador Adelina , Rodríguez-Hoyos Carlos , Saiz-Linares Ángela
Published: January 2019

This article is the result of a research project developed over 4 years (2011-15) in 13 schools in the region of Cantabria (Spain). In this research, students from different levels of education designed and implemented school improvement processes within a model of the student voice (SV) inspired by the pedagogy of participation and inclusion. This paper describes some of these experiences mediated by technology (photographs, 2.0 devices and video) in order to analyse what opportunities these devices offer as a means for contributing to a more participative and democratic school, where the student voice is a tool for change.
Ontología crítica de las prácticas formativas en medicina y enfermería
Authors: Martínez-Posada Jorge Eliécer , Hernández-Molina Nelly , Hernández-Molina Luz Mery
Published: January 2019

Artículo resultado de investigación de dos tesis doctorales en ciencias de la educación, relacionadas con las prácticas de formación en enfermería y medicina, con el objetivo de visibilizar el entramado de relaciones entre los discursos y las prácticas discursivas presentes en la educación de médicos y enfermeras en Colombia, entre 1992 y 2014. Se hizo uso de la arqueología y la genealogía como herramientas metodológicas que permitieron mostrar grandes cambios, asociados a las condiciones de salud, que en el ámbito universitario visibilizan las prácticas que tienen lugar en el orden curricular.
Etnografía con los movimientos de lucha por el derecho a la vivienda en el sur de Europa: retos metodológicos en la investigación colaborativa para la acción social
Authors: Olmos Alcaraz Antonia , Cota Ariana S , Álvarez Veinguer Aurora , Sebastiani Luca
Published: January 2019

Stop Desahucios 15M Granada (Andalucía-Estado Español) es un movimiento que nace en 2011 en el Sur de Europa ante la ausencia de alternativas habitacionales para un gran número de personas que hipotecaron sus vidas y ante la incapacidad del Estado de ofrecer soluciones prácticas a dicho problema. A partir de este ecosistema de acción social, compartiremos los pasos que estamos dando para sumergirnos en nuevas formas de hacer-habitar una investigación etnográfica desde “el común”, lo colaborativo y la producción colectiva del conocimiento junto al movimiento de lucha por el derecho a la vivienda Stop Desahucios 15-M Granada. Comenzaremos con unas breves coordenadas sobre los lugares desde donde vivimos-investigamos, para después compartir los procesos activados que denominamos dispositivos de escucha (grupos de debate, proyecto transmedia) junto al grupo. Un proceso de coinvestigación atravesado por la voluntad de descolonizar la práctica etnográfica recurriendo al pluriversalismo metodológico y a la centralidad del proceso de subjetivación política.
Los Mayores y el territorio de Jenoy (Pasto, Colombia): quehacer etnográfico y etnoliteratura de resistencia
Authors: Ceballos Rosero Franco
Published: January 2019

El presente documento, desde un quehacer etnográfico indisciplinado, de largo aliento y solidario, presenta una mirada del proceso de reconstrucción identitaria y territorial del pueblo originario de Jenoy (Colombia), trece años después de la declaratoria como zona de desastre del territorio aledaño al volcán Galeras en 2005 (Decreto 4106), y la orden de reubicación de la población humana asentada en la zona de amenaza volcánica alta en 2008 (Decreto 3905); todo ratificado por la jurisprudencia constitucional en 2015 (Sentencia T-269), a pesar de la legítima oposición comunitaria (Art. 16, Ley 21 de 1991). La construcción del documento se propone desde una etnografía literaria o etnoliteratura, fundamentada en la memoria oral y territorial de los Mayores. Son herramientas suyas el diálogo, la solidaridad y los caminos.
La práctica pedagógica en la investigación en educación matemática desde la perspectiva de los egresados
Authors: Valbuena Duarte Sonia , Conde Carmona Robinson Junior , Padilla Escorcia Iván Andrés
Published: January 2019

Este texto tuvo como objetivo describir la práctica pedagógica del formador de formadores como actuación comunicativa en su relación con la investigación en educación matemática en un programa que forma docentes de matemáticas. Para recabar la información se hizo uso de diversas técnicas e instrumentos; dentro de estas, anotamos aquí: observaciones no participantes, registros en diarios de campo y entrevista a los docentes a cargo de las asignaturas referentes a investigación del programa académico y a docentes ya egresados del mismo programa que ejercen la profesión en una institución educativa. Esto, para analizar, desde diferentes puntos de vista, la progresión y el alcance en que se encuentra el programa en la formación en investigación desde la práctica pedagógica, y compararlo con los referentes que la literatura reporta como parte fundante en la formación y requerimientos de un docente investigador, quien se forma a través de la práctica pedagógica que establece la propuesta curricular de una licenciatura en Matemáticas en Colombia.
Los talleres “epistémico-corporales” como herramientas reflexivas sobre la práctica etnográfica
Authors: Ruiz Trejo Marisa , García Dauder (S.)
Published: January 2019

Los planteamientos de la antropología del sur global y las epistemologías feministas han permitido nuevas reflexiones sobre la práctica etnográfica. Desde dicho marco, proponemos los talleres como metodologías privilegiadas para la “reflexividad fuerte”, colectiva y encarnada, sobre el quehacer etnográfico, no solo sobre “el saber qué”, sino sobre el “saber cómo” y sobre aspectos de la investigación tradicionalmente desechados. En el artículo, conjugamos la descripción de los ejercicios de los talleres, las reflexiones colectivas surgidas de ellos, y tres artefactos teóricos para su análisis: las “prácticas corporales en investigación”, la “articulación comprometida” y las “epistemologías del fuera de campo”. Como resultado, analizamos el papel del cuerpo y las emociones en el proceso de investigación; las redes y vínculos que se generan, cómo y desde dónde nos comprometemos con lo que investigamos; las relaciones de poder y las violencias epistémicas en la práctica investigadora, y los dilemas, encuentros y desencuentros entre investigación y activismo.
Pre-Surgical Planning of Screw-Position Arrangement for the Femur Fractures With a Custom APP
Authors: Chung Chen-Yuan , Lai Jiing-Yih , Young He-Kai , Gao Han-Yuan
Published: January 2019

Several types of implants, plates, and screws have been developed for corresponding bone fractures at different sites. To understand the mechanical behavior of a bone plate and to provide surgeons with suggestions for selecting screw positions, this study aimed to create an APP to provide pre-surgical planning using a computed tomography (CT)-based finite element model. This model was validated using a compression test of synthetic sawbones. Furthermore, the specific APP was established using the COMSOL application builder to calculate the stress and strain of the implant under different screw positions. This APP reveals how the number and location of screws affect the stress distribution of the implant. It can provide clinicians with preliminary reference information before surgery.
Study of the Effect of Large Deformation Through a Finite Deformation Based Constitutive Model for Metallic Glasses
Authors: Kulkarni Shank S. , Bhandakkar Tanmay K.
Published: January 2019

A thermodynamically consistent constitutive model of metallic glass is presented by extending the infinitesimal deformation model of Huang et al. [Huang, R., Suo, Z., Prevost, J. H., and Nix,W. D., 2002.Inhomogeneous deformation in metallic glasses,J. Mech. Phys. Solids, 40, 1011–1027] to finite deformation. The underlying theory behind the model is the free volume theory with free volume concentration as the order parameter affected through the processes of diffusion, annihilation and creation. The main assumptions of the model include multiplicative decomposition of deformation gradient and additive decomposition of free energy. The former comprises of elastic, inelastic dilatational component associated with excess free volume concentration and isochoric plastic part while the latter consists of contributions from elastic deformation and free volume concentration. The plastic part evolves according to Mises-theory and the local free volume concentration. Homogeneous simple shear is the model problem solved using the present model and compared with the infinitesimal deformation theory to examine the effect of large deformation on stresses in metallic glasses.
Composite Fabric Blankets for Plastic Gears
Authors: Kini S. , Fuentes Aznar A. , Ghoneim H.
Published: January 2019

Two approaches for increasing the load capacity of plastic gears in general are proposed and investigated: modifying the conventional involute profile of the gear tooth surfaces by applying a parabolic-crowned profile, and introducing a composite fabric, which blankets the surface of the teeth. The investigation is carried out using the finite element method (IGD/ANSYS). A five-tooth model is applied for the gears, and nylon and carbon/nylon are adopted for the materials. The evolution of maximum contact and bending stresses is evaluated over two cycles of meshing for both the pure plastic (nylon) gears and the gears with the composite surface blanket (carbon/nylon) to investigate the process of transfer of load between consecutive pairs of teeth and detect possible edge contacts. The results indicate that selecting the proper parabolic-crowned profile helps to alleviate the contact stress, and more specifically, to reduce the peaks of contact stresses due to edge contacts at the tip of the teeth. The results also indicate that there are an optimum parabolic-crowned profile and an optimum thickness of the composite blanket, which render the lowest maximum level of contact stresses over the cycle of meshing and bending stresses at the fillet. However, this preliminary research work suggests that, for the case considered, the novel idea of composite blanket is inconclusive — though the blanket may protect the plastic core, it itself becomes vulnerable to failure. The idea is being explored more, and the results will be disseminated in a future work.
Temperature and Heat Flux Data-Logger for Use in Tunnel Ovens: An International Partnered Project
Authors: Watt Alexander , Wichert Jason , Staniszewski Justine , Nakles Nathaniel , English Yvonne , Bright Mike , Havet Michel , Bardy Erik , Reuber Mark
Published: January 2019

The Grove City College (GCC) European Study Center (ESC) is a program that allows mechanical and electrical engineering students to study abroad in the junior and senior year fall semester, respectively, and graduate in four years. The ESC is activity partners with a local institution called Oniris, which specializes in food science engineering, and veterinary science (an affiliate with the French Ministry of Agriculture). Electrical engineering students that participate in the program carry out their yearlong capstone design project (Senior Experience in Electrical Design (SEED)) in partnership with Oniris. For the 2016–2017 academic year, participating electrical engineering students completed a project titled Ultra-Low-Cost Flexible Sensor Array, or “Low-Cost Array” (LCA), designed for commercial tunnel-style ovens. The LCA features low cost ($200), flexible programmability, and ease of use (based on the widely available Arduino). The purpose of the project was to develop a low-cost data-logger to operate inside tunnel-style ovens to record temperature from thermocouples (and other analog signals, i.e. heat flux) for thirty minutes in an environment up to 250 °C. This study evaluates the LCA compared to other data-logging systems, and its performance in high temperature environments by a series of experiments. In addition, an idea of its commercialization potential was explored by interviewing industrialists and academics on-site. Experimental results showed that: (1) data logged from the system were close to values recorded by current systems used for both temperature and heat flux measurements, and (2) the system performed well at 240 °C for thirty minutes (maximum temperature of oven). In addition, the interviews revealed that although most interest was in a tunnel-style oven data-logger, it seems feasible to incorporate changes to satisfy needs for other markets, especially those of a general-purpose data-logger.
Maxwell-Voigt and Voigt Models for Vibration Isolation: Influence of Fractional Damping and Time Delay
Authors: Kaul Sudhir
Published: January 2019

This paper presents results from a follow-up study of fractional damping and time delay. Fractional damping has been used in the literature to demonstrate certain advantages over integer-order damping in many applications involving viscoelastic characteristics. It is observed that fractional damping can be used to influence stability boundaries, natural frequencies and vibration amplitudes, thus providing modeling flexibility in predicting the response of an isolated system during preliminary design. Additionally, time delay or lag is known to be inherent in a damped system, therefore a direct representation of time delay in modeling the damping force is expected to enhance model fidelity. This paper investigates the use of Voigt and Maxwell-Voigt models that incorporate fractional damping and time delay. In this paper, fractional damping has been particularly introduced to investigate possible improvements in the frequency response. Results indicate that fractional damping can be used to significantly enhance the capability of the Voigt model. The influence of the fractional order is found to be analogous to the damping ratio in an integer-order model. Fractional order is seen to exhibit a somewhat limited influence on the Maxwell-Voigt model. However, attributes such as the peak frequency and maximum amplitude are seen to be directly influenced by the fractional order. Although time delay is seen to exhibit an influence on the frequency response, it needs to be limited within useful bounds. Overall, it is observed that fractional order and time delay can be used to improve the accuracy of the Voigt and Maxwell-Voigt models. These enhanced models can be used for the design and development of elastomeric isolators and vibration isolation systems.
CyberManufacturing System: A Solution for Sustainable Manufacturing
Authors: Song Zhengyi , Moon Young
Published: January 2019

CyberManufacturing System (CMS) is emerging as a new manufacturing paradigm and an integrated management approach, and it is capable of providing on-demand, data-driven, highly-collaborative, knowledge-intensive and sustainability-oriented manufacturing solutions. The recent developments in the Internet of Things, Cloud Computing, Service-Oriented Technologies, and Machine Learning, all contribute to the development of CMS. In CMS, each manufacturer is able to package their resources and capabilities into services and make them available to customers through pay-per-use pricing strategy. Associated capabilities such as computing and simulation resources, application software, know-hows, and expertise also become accessible to worldwide users via the Internet.

The manufacturing community is searching for sustainable manufacturing solutions to address environmental degradation and natural resource depletion issues. Sustainable manufacturing systems need to be socially and environmentally responsible as well as economically viable. CMS possesses advanced features — such as resource sharing, servitization and self-manage capabilities — suitable for addressing sustainability issues. This paper presents a framework of the CMS paradigm and performance analysis from the perspective of sustainability. An architecture is proposed to elaborate the constitutions of CMS and to make manufacturing operations transparent. Two case studies are used to illustrate (i) how initial manufacturing requests can be processed and met by a collection of production services and (ii) how the effectiveness of the proposed framework in addressing sustainability issues can be evaluated.
Determination of Thermal Parameters of a Work-Roll in Warm Rolling Using Inverse Modeling
Authors: Yadav Vinod
Published: January 2019

Thermal parameters of a work-roll play an important role in the modeling of the rolling process, due to periodic thermal loading. The knowledge of thermal parameters is also vital in understanding the fatigue life of the work-roll and the thermal crown. However, estimation of the thermal parameters viz., thermal conductivity, thermal diffusivity and convective heat transfer coefficients at both, inner and outer roll periphery is tough to realize during the rolling process. Various methods employed earlier for measuring the thermal properties of work-rolls in the rolling process requires intrusion in the surface of the work-rolls, mainly to embed the thermocouples inside the rolls. These methods are easy to implement, but it is really hard to achieve truthful estimation. A possible way out is to measure the average thermal parameters of a work roll in the rolling process by utilizing the measured temperature at two specified locations on the work-roll surface. In this work, an inverse method is proposed to estimate the thermal properties and convective heat transfer coefficients of a roll in the rolling process. The inverse method makes use of a direct model of temperature determination considering plane strain problem, which is based on the integral transform method. For minimizing the error between the computed and experimentally recorded data, a quasi-Newton method is used. In lieu of shop floor experiments, a finite element method (FEM) based package ABAQUS 6.10 is used to obtain the temperature distribution in the work-roll. Further, an additive white Gaussian error is added in the FEM simulated measurements to assess the inverse method for stability towards mild measurements. The inverse estimation is successfully validated and can be used in shop floor for the online determination of thermal parameters of the work-rolls in the rolling process.
A Hybrid Thermal Management System With Negative Parasitic Losses for Electric Vehicle Battery Packs
Authors: Arora Shashank , Tammi Kari
Published: January 2019

Parasitic power requirement is a key criterion in selection of suitable battery thermal management system (TMS) for EV applications. This paper presents a hybrid TMS with negative parasitic requirements, designed by integrating phase change material (PCM) with thermoelectric devices. The proposed system does not require any power consumption to maintain tight control over battery cell temperature during aggressive use and repetitive cycling. In addition, it can recover a portion of waste heat produced during the typical operation of EV battery packs.

Commercially available LiFeP04 20 Ah pouch cell has been chosen as a test battery sample for validating the conceptual design presented herein. The commercial battery cells, submerged in a PCM-filled polycarbonate casing, are subjected to a cyclic discharge process to elucidate their heat generation characteristics at 27 °C. Charging and discharging is conducted at 0.5C and 1C, respectively. A thermoelectric circuit is used to recover the heat energy absorbed by the PCM and to convert it to electrical energy. The manuscript further details some of the major findings of this experiment.
Longer Passage of Airflow in Multiple Packed-Bed Thin Tanks Versus in a Short Big Tank for Improved Thermal Storage Performance
Authors: Wang Yan , Li Peiwen , Wang Zhifeng , Yang Bei , Yuan Guofeng , Tang Wenxun
Published: January 2019

A very challenging issue about solar thermal power generation is the use of a high temperature heat transfer fluid (water, oils, or molten salts) for heat transfer and thermal storage material, which may freeze at night or cold weather. When choosing air as the heat transfer fluid, the problem of freezing is eliminated. In order to increase the performance of thermal storage system which uses air as the heat transfer fluid passing through a packed bed (by ceramic spheres of Al2O3), multiple small-diameter tanks are considered to replace a single large-diameter tank with the same packed-bed volume and airflow rate in this paper. Analysis about the thermal storage performance in a short big tank and in cascade thin tanks has been made for comparison. A long passage of airflow and faster flow speed of air in the cascade thin tanks has been found significantly beneficial to thermal storage. Results about the increased thermal storage performance and increased pressure loss will be presented. Longer passage of airflow made it possible to have a longer time of high temperature of outflow air during discharging period. And faster speed of the fluid enhanced the heat transfer between air and thermal storage material. The total effective energy and thermal storage efficiency of cascade thin-tank thermal energy storage (TES) are higher. The thermal storage efficiency in the two types of thermal storage arrangement was compared for optimal design. The obtained results are of great significance to the development of using air as heat transfer fluid and rocks or ceramic spheres as the thermal storage material for thermal storage system in concentrated solar thermal power plants.
Extracting Substantial Free Energy From Static Ambient Potential Energy Using Distance, Time-Lapse Chaos, and Coriolis Principles
Authors: Surjaatmadja Jim B.
Published: January 2019

Extracting free energy has long been a goal of science but is mostly considered impossible to achieve. Natural processes having independent movement, such as rivers and wind, are often used but provide varied effectiveness. However, coordinated instability within a statically pressurized ambience can be used to extract a significant percentage of the ambient potential energy. This method creates two pathways between two adjacent points, one being a chaotic or Coriolis swirling path and the other being a direct path, thereby creating a pressure difference between the two adjacent points, which can be harvested to reduce the kinetic energy input required to perform the process.

While some refer to the proposed benefits as “perpetual motion,” it is necessary to understand that 55 to 80% of the required kinetic energy would still be mechanically generated; therefore, they could be better referred to as “coordinated chaos” or a “Coriolis energy extractor” to save energy [1].

This paper studies direct returns—extracting energy directly from a static (not dynamic) ambient energy. While such returns might not be substantial in normal activities, in deepwater or underground applications (e.g., oil or gas wells), they can be significant, often equating to a 20–45% reduction in fuel use or pollutant generation. In operations that use 20,000 horsepower, this could represent a savings of 4,000 horsepower or 10,000,000 Btu/hr with no associated financial costs.
Applications of the Monte Carlo Method for Estimating the Reliability of Components Under Multiple Cyclic Fatigue Loadings
Authors: Le Xiaobin
Published: January 2019

In reliability-based mechanical design, reliability replaces the traditional factor of safety as the measurement index of the safety of mechanical components. More than 90% of metal components under cyclic fatigue loadings in industries fail because of fatigue. The P-S-N curve fatigue theory (Probability - Stress level - Number of cycles) is one of the current important fatigue theories. It is very important to know how to determine the reliability of components under different loading-induced cyclic stresses for reliability-based mechanical design. The Monte Carlo method is a powerful numerical simulation in almost every field such as optimization, numerical integration, and generating draws from a probability distribution. Literature reviews show the Monte Carlo method is successfully implemented to estimate the reliability of components under single loading-induced cyclic stress. However, there is little literature about implementing the Monte Carlo method to estimate the reliability of components under multiple loading-induced cyclic stress by using the P-S-N curve fatigue theory. The purpose of this paper is to develop a new Monte Carlo computational algorithm to calculate the reliability of components under several cyclic loadings using the P-S-N curve fatigue theory. Two key concepts in the widely-accepted Miner rule in fatigue theory are that fatigue damage is linear cumulative and the fatigue damage because of different cyclic stress is independent. Based on these two key concepts, this paper has successfully developed a new Monte Carlo computational algorithm to calculate the reliability of components under multiple loading-induced cyclic stresses using the P-S-N curve fatigue theory. The results obtained by the developed computational algorithm is validated by results obtained from two published methods. The results by the developed computational algorithm is again validated by the K-D probabilistic model. Based on validation studies, the relative differences in the results between the proposed method and the published methods are in the range of 0.66% to 2.98%. Therefore, the developed Monte Carlo computational algorithm is validated and can provide an acceptable estimation of the reliability of components under several cyclic fatigue loadings using the P-S-N curve fatigue theory.
An Energy-Regenerative Suspension System
Authors: Lato Thomas , Zhao Huiyong , Zhao Lin , He Yuping
Published: January 2019

This paper presents an energy-regenerative suspension device that is able to harvest some of the wasted energy that is generated in a suspension system. For a traditional road vehicle suspension system, shock absorbers are mainly dissipating energy to reduce vibration. The dissipated energy may be collected to improve the fuel economy of road vehicles. In this research, CarSim and Simulink are used to simulate and determine the harvestable energy in a conventional shock absorber under different operating conditions. A conceptual energy-regenerative absorber is designed and tested using a fabricated prototype. A variable speed motor is implemented to adapt the change of stroke length of a mechanism due to the various road roughness. Instruments, e.g., laser tachometer, pressure gauge, ammeter, voltmeter, and stopwatch, are used to collect data. The simulation and prototype testing results indicate that the proposed energy-regenerative suspension device could harvest dissipated energy to improve vehicle fuel economy.
Multi-Stable Magnetic Spring-Based Energy Harvester Subject to Harmonic Excitation: Comparative Study and Experimental Evaluation
Authors: Nguyen Hieu , Bardaweel Hamzeh
Published: January 2019

The work presented here investigates a unique design platform for multi-stable energy harvesting using only interaction between magnets. A solid cylindrical magnet is levitated between two stationary magnets. Peripheral magnets are positioned around the casing of the energy harvester to create multiple stable positions. Upon external vibration, kinetic energy is converted into electric energy that is extracted using a coil wrapped around the casing of the harvester. A prototype of the multi-stable energy harvester is fabricated. Monostable and bistable configurations are demonstrated and fully characterized in static and dynamic modes. Compared to traditional multi-stable designs the harvester introduced in this work is compact, occupies less volume, and does not require complex circuitry normally needed for multi-stable harvesters involving piezoelectric elements. At 2.5g [m/s2], results from experiment show that the bistable harvester does not outperform the monostable harvester. At this level of acceleration, the bistable harvester exhibits intrawell motion away from jump frequency. Chaotic motion is observed in the bistable harvester when excited close to jump frequency. Interwell motion that yields high displacement amplitudes and velocities is absent at this acceleration.
Infrared Thermography to Measure Heat Transfer of a Heated Curved Thin Sheet
Authors: Zhong Liang , Wang Gaofeng , Xia Yifan
Published: January 2019

Heat transfer measurements on a heated curved thin sheet are performed by infrared thermography. The evolution of the temperature field is recorded to calculate the heat flux by using the two-dimensional unsteady heat balance equation. The thermal conduction term is estimated by the projection relationship between the curved surface of the thin sheet and the horizontal plane. Natural convection is neglected during the estimation of this heat flux. Unlike the traditional means of heat flux measurement, this method is non-intrusive and can measure the heat flux distribution within a curved space, allowing an easier evaluation of the errors due to radiation and tangential conduction. An electrical resistance foil with known power are applied as the heating source to compare the calculated heating power with the actual recorded power, the max relative error for different heating powers is about 10 %, which verified of the feasibility of the method. Considering possible applications, three different domestic gas cookers are used to heat three different curved thin pans, and then, in each case, the heat flux of the burners is analyzed. From the heat flux distribution of the three gas cookers, some heating characteristics such as heating power, maximum and average heating flux are investigated to help optimize the designs of the gas cookers, avoiding local overheating and low uniformity of heat distribution.
A New Design of Cycloidal Planetary Reducer With Internal Cycloidal Profile
Authors: Mao He , Liu Guanyi , Zeng Deqiang , Cao Yaning , He Kai , Du Ruxu
Published: January 2019

Compared with other speed reducers, the two-stage cycloidal planetary one also known as RV reducer has higher precision, higher mechanical efficiency, higher loading capacity as well as long service life. These characteristics make it attractive for industrial applications, especially for robotics applications and machine tools, where high precision and large torque transmission are required. The traditional RV reducer uses cycloidal drive which is comprised of the cycloidal wheel and the pins. It has some disadvantages in the pin design, because of small clearance between the pin and the cycloidal wheel, the collision between the pin and the cycloidal wheel may lead to unstable stress in the key parts and output velocity fluctuation. This paper presents an innovative cycloidal planetary reducer using internal meshing principle instead of external meshing between cycloidal wheel and pins in traditional RV reducer. In the new design of the reducer, the internal teeth with cycloidal profile are processed inside the reducer housing, meshing with two pin holders which are placed at the inner side of the cycloidal teeth to achieve transmission. The pin holder is a new integral structure of pins integrated on a round plate. Then a comparison study is conducted through establishment of system dynamics analysis. The transmission characteristics and meshing force of both the new type of reducer and the traditional RV reducer are analyzed under the same condition of reduction ratio. The results show the new reducer improves on these shortcomings, its transmission performance is competitive as compared to traditional RV reducer. What’s even better is that its output speed is more stable, and the contact force between the pin position on the pin holder and the internal cycloidal teeth inside the reducer housing is smaller, as well as the contact frequency is obviously decreased.
Inspiring Learning: Assessment of Friction in a Real-World Model Using the Moving Frame Method in Dynamics
Authors: Rykkje Thorstein R. , Leinebø Daniel , Bergaas Erlend Sande , Skjelde Andreas , Impelluso Thomas J.
Published: January 2019

This project conducts research in energy dissipation. It also demonstrates the power of the new Moving Frame Method (MFM) in dynamics to inspire undergraduate students to embark on research in engineering. The MFM is founded on Lie Group Theory to model rotations of objects, Cartan’s moving frames to model the change of a frame in terms of the frame, and a new notation from the discipline of geometrical physics. The MFM presents a consistent notation for single bodies, linked systems and robotics. This work demonstrates that this new method is accessible by undergraduate students. The MFM structures the equations of motion on the Special Euclidean Group and the Principle of Virtual work. A restriction on the virtual angular velocities to enable variational methods empowers the method. This work implements an explicit fourth order Runge-Kutta numerical integration scheme. It assesses the change in mechanical energy. In addition, this work researches the energy losses due to friction in a system of linked rigid bodies. This research also builds the physical hardware and compares the theory and experiment using 3D visualization. The authors built the structure to observe the actual motion and approximate the energy loss functions. This project demonstrates the power of WebGL to supplement analyses with visualization.
Improving Motion Stability of the Plane 3-RPR Parallel Manipulator at Singular Configuration
Authors: Li Yu-Tong , Wang Yu-Xin
Published: January 2019

Kinematic parameters have significant influences on the motion stability of parallel manipulators at singular configureations. Taking the plane 3-RPR parallel manipulator as an example, the motion stability at different types of singular configurations corresponding to the angular speed and velocity of the movable platform are investigated. At first, the second order of uncoupled dynamics equation for the 3-RPR parallel manipulator is established with the aid of the second class Lagrange approach. According to the Lyapunov first approximate stability criterion, the approximate conditions for the 3-RPR parallel manipulator with a stabile motion at singular configurations are determined based on the Gerschgorin circle theorem. Next, the exact Hurwitz criterion is utilized to study the motion stability and the load capability of the manipulator corresponding to the angular speed and velocity of the movable platform, as well as the directions of the external forces at two kinds of singular configurations: with a gained rotation-type DOF, and with a gained translation-type DOF, respectively. The results show that increasing both the angular speed and the velocity of the mass center of the movable platform can efficiently improve the motion stability of the 3-RPR parallel manipulator at singular configurations.
Determining Cutting Pressure Coefficients for Aluminum 6061-T6 Using a Small Number of Drilling Experiments
Authors: Seif Charbel Y. , Hage Ilige S. , Hamade Ramsey F.
Published: January 2019

Cutting pressure models have long been utilized for calculating machining force components both tangential and normal. This work lists literature-reported closed form analytical models for torque and thrust of material cutting pressures. Typically, these models are equations formulated in terms of process parameters including mainly cutting speed (V, m/min), feed (f, mm/rev), and tool rake angle (α, degrees). This work aims to benefit from the variation in rake angle and cutting speeds encountered along the lip cutting edge of a standards twist drill to generate normal and tangential cutting pressure empirical models for aluminum 6061-T6 material based on a limited number of drilling feed rate and spindle speed combinations. To isolate the 10mm twist drill bit cutting edge forces, drilling experiments were conducted utilizing 2.5mm pre-cored workpieces. Cutting lip edge toque and thrust data were collected from conducted series of drilling experiments with total number of 10 varying combinations of feed rate and spindle speeds.

Values of cutting pressure in terms of feed, speed, and rake angle parameters were identified using a custom-developed MATLAB® code. Minimized is the difference between the cutting pressure-based closed form torque and thrust models versus the experimentally collected cutting lip torque and thrust measurements. Based on this MATLAB® code, cutting feed, speed and rake angle parameters found around −0.2, −0.1 and 1.5 respectively based on a convergence criteria of 10−10 and maximum iteration number of 1000. These optimized cutting pressure parameters were found to predict well the collected experimental forces and were found to be in line with parameter values as reported in the literature.
Theoretical Analysis of Moisture Condensation on a Cold Heat Sink
Authors: Yan Run , Ma Hongbin
Published: January 2019

This paper presents a theoretical model of the moisture condensation of ambient air flowing over a cold heat sink. When ambient air flows over a cold heat sink, three-dimensional conservation equations of momentum, energy, and mass should be used to predict the heat and mass transfer of ambient air to determine the condensation rate. In this paper, a simplified model is developed to predict moisture condensation from ambient air flowing over a cold heat sink under the boundary condition of a constant baseplate temperature. The model can be used to predict effects of inlet velocity, relative humidity, incoming flow temperature, and fin geometry. The model demonstrates that the increasing inlet velocity and relative humidity could help to enhance the condensation rate. The model can also be used to reveal the variation of condensation rate over cold fins in terms of fin geometry parameters. The significance of this model is that it can be readily applied to predict mass and heat transfer behavior in phase change processes incurred from ambient air flowing over complex geometries of cold surfaces.