bluuebunny/crossref_metadata_2025 huggingface dataset:
Building Innovation and Sustainability in Programs of Research
Authors: Villarruel Antonia M.
Published: November 2017

Purpose

Innovation and sustainability are two important concepts of impactful programs of research. While at first glance these concepts and approaches may seem at odds, they are synergistic.

Approach

We examine the social, political, and policy context as it relates to innovation and sustainability. We present an exemplar of a program of research and discuss factors to consider in developing innovative and sustainable programs of research.

Conclusions

Innovation is an important component of sustainable programs of research. Understanding the social and political context and addressing relevant policy issues are factors to be considered in both innovation and sustainability.

Clinical Relevance

Innovation and sustainability, important components of research, are also central to clinical practice. Open communication between researchers and clinicians can support the acceleration of innovations and the integration of evidence‐based findings in practice.
Need for reassurance in self‐care of minor illnesses
Authors: Gustafsson Silje , Sävenstedt Stefan , Martinsson Jesper , Wälivaara Britt‐Marie
Published: November 2017

Aims and objectives

This study describes people's need for reassurance in self‐care of minor illnesses.

Background

Self‐care and active surveillance are advocated as important strategies to manage minor illnesses. Reassurance influences patient satisfaction and confidence in the practicing of self‐care.

Design

This study is a descriptive and interpretive qualitative study.

Methods

Twelve persons with experience in self‐care and receiving self‐care advice were recruited, and data were collected using semi‐structured interviews between September–December 2014. Data were analysed using qualitative content analyses.

Results

Having previous experience and the ability to actively manage symptoms using self‐care interventions was described as reassuring. Participants became stressed and concerned when the symptoms persisted and interventions lacked the desired effect, which often resulted in a decision to consult. Participants wanted to feel that the nurse was an actual person, who was sympathetic, present and understanding, when they received self‐care advice. The nurse's assessment and reasoning of the symptoms facilitated care‐seekers’ assessments of risk, and clear and concrete advice on how to manage the symptoms exerted a calming effect. Patients needed to trust that the nurse understood their situation to embrace the advice, and being invited to return created a feeling that the nurse had listened and taken them seriously.

Conclusions

Reassurance has the potential to allay doubts and fears to build confidence, which influences self‐care and consultation behaviour. Personal presence in the encounter, receiving an assessment and an explanation of the symptoms and precise advice are reassuring.

Relevance to clinical practice

The needs of nursing care may persist despite the absence of medical needs. The encounter between the nurse and care‐seeker is a unique possibility for reassurance and confidence that a minor illness is self‐limiting in its nature, and self‐care interventions provide relief and comfort.
Efficacy of medroxyprogesterone acetate treatment and retreatment for atypical endometrial hyperplasia and endometrial cancer
Authors: Tamauchi Satoshi , Kajiyama Hiroaki , Utsumi Fumi , Suzuki Shiro , Niimi Kaoru , Sakata Jun , Mizuno Mika , Shibata Kiyosumi , Kikkawa Fumitaka
Published: November 2017

Aim

Medroxyprogesterone acetate (MPA) is used to preserve fertility in patients with Grade 1 endometrial cancer without myometrial invasion (G1EA) and those with atypical endometrial hyperplasia (AEH). However, the efficacy of retreatment with MPA has not been sufficiently established for patients who experience recurrence but wish to retain their fertility. This study aimed to show the effectiveness of MPA treatment and retreatment for AEH and G1EA.

Methods

A total of 39 patients received MPA treatment between 2005 and 2015, including nine with G1EA and 30 with AEH. The patients received high‐dose (600 mg/day) MPA for 26 weeks. If a complete response was not achieved, MPA treatment was continued. After complete remission, if there was a recurrence, the patient was offered a choice of a hysterectomy or retreatment with MPA. The gynecologic and obstetric outcomes were retrospectively analyzed.

Results

The median age was 34 years, and the median body mass index was 23.3 kg/m2. The median follow‐up period was 52 months. Complete response rates for the initial treatment were 89% for G1EA and 93% for AEH. Recurrence occurred in 88% of patients with G1EA (7/8) and 50% of those with AEH (14/28). Seven patients with G1EA and 11 with AEH received MPA retreatment, and 100% and 92% of these achieved a complete response. During the study period, a total of 14 pregnancies were recorded with 10 live births.

Conclusion

MPA can be effective for G1EA and AEH treatment even when they recur.
Technical Quality of Complete Dentures: Influence on Masticatory Efficiency and Quality of Life
Authors: Tôrres Ana Clara Soares Paiva , Maciel Amanda de Queiroz , de Farias Danielle Bezerra , de Medeiros Annie Karoline Bezerra , Vieira Flávia Patrícia Tavares Veras , Carreiro Adriana da Fonte Porto
Published: November 2017

Purpose

To evaluate the effect of the technical quality of conventional complete dentures (CD) on masticatory efficiency and quality of life (QoL) of denture wearers during a 1‐year follow‐up.

Materials and Methods

A prospective clinical trial with 32 edentulous patients (mean age of 60.2 years) wearing mandibular and maxillary dentures was conducted. All patients were evaluated wearing their preexisting dentures and after 3, 6, and 12 months postinsertion of new dentures. A reproducible method for objective evaluation of the technical quality of CDs was employed. Masticatory efficiency was evaluated by the colorimetric method using beads as artificial testing food. The oral health impact on patient QoL was measured using the OHIP‐EDENT (Oral Health Impact Profile in Edentulous Adults) questionnaire. The nonparametric Wilcoxon test was applied to reveal any differences in technical quality between the preexisting and new dentures. The Friedman test was used to detect differences in masticatory efficiency and oral health impact on QoL. Spearman's correlation was applied to reveal correlation between the variables.

Results

Comparing preexisting and new dentures, significant improvement was found in technical quality between the dentures (p < 0.001). There was no statistically significant difference in masticatory efficiency. A significant decrease was found in the total OHIP‐EDENT scores after denture replacement. A positive correlation was found between technical quality and OHIP in the new denture wearers (p = 0.011).

Conclusions

According to the results of this study, denture quality significantly improved patients’ oral health‐related QoL; however, insertion of new dentures did not influence masticatory efficiency.
Competition and Cooperation in International Commercial Arbitration: The Birth of a Transnational Legal Profession
Authors: Grisel Florian
Published: November 2017

This paper revisits the sociology of international commercial arbitration on the basis of unexploited archives and data. This material casts new light on the competition between “grand old men” and “young technocrats” in the 1980s and 1990s, a theme that has structured the analysis of international commercial arbitration since the pioneering work of Yves Dezalay and Bryant G. Garth (Dealing in Virtue). In contrast, the data show that the crucial transformative period actually took place between the 1950s and 1970s, when a relatively well-defined group of individuals emerged as the leading arbitrators at the International Chamber of Commerce. These individuals— the “secant marginals”—succeeded in constructing a cooperative interface (rather than competition) between otherwise separate legal systems and professions. In doing so, they created the conditions necessary for the emergence of a new transnational legal profession. At a more general level, the article proposes an alternative narrative of globalization, wherein actors operating at the intersection of various systems, create new arenas of governance on the basis of inter-system cooperation.
Management of urethral stricture: High‐pressure balloon dilation versus optical internal urethrotomy
Authors: Kumano Yohei , Kawahara Takashi , Mochizuki Taku , Takamoto Daiji , Takeshima Teppei , Kuroda Sinnnosuke , Teranishi Jun‐ichi , Makiyama Kazuhide , Miyoshi Yasuhide , Yumura Yasushi , Yao Masahiro , Uemura Hiroji
Published: November 2017

Objective

Urethral stenosis is a disease in which the lumen of the urethra becomes constricted by fibrosis. Such stenoses have been treated by urethral dilation using a bougie and optical internal urethrotomy (OIU). Recently, high‐pressure balloon dilation (BD) has been developed as a new treatment method for urethral stenosis. The present study compared the effectiveness of urethral dilation by BD and OIU.

Methods

Twenty‐two patients of urethral stenosis were treated at Yokohama City University Medical Center between 2005 and 2015. Of these, 13 underwent BD, whereas OIU was performed in 9. BD was performed at 30 atm twice for 5 min each time. In OIU, an endoscopic knife was used to cut out the stenotic lesion in 3 directions. The endpoint was set as restenosis, which required additional surgical treatment, including BD, OIU, and the use of a urethral bougie.

Results

The causes of urethral stricture were endoscopic surgery (n = 7; 31.8%), development after total prostatectomy (n = 4; 18.2%), iatrogenic reasons associated with catheter insertion (n = 5; 22.7%), development after a prostate needle biopsy (n = 3; 13.6%), and unknown (n = 3; 13.6%). The site of the stenotic lesion site was the anastomosis (n = 3; 13.6%), bladder neck (n = 6; 27.3%), prostatic urethra (n = 4; 18.2%), anterior urethra (n = 7; 31.8%), and membranous urethra (n = 2; 9.1%). The stenosis‐free rate was 84% for those undergoing BD and 22% for those receiving OIU. The median stenosis‐free time was significantly longer after BD than OIU (1675 vs. 244 days, respectively; P < .01).

Conclusion

The stenosis‐free time was significantly longer after BD than OIU.
Opportunities and hurdles of edible insects for food and feed
Authors: Dobermann D. , Swift J. A. , Field L. M.
Published: November 2017

Entomophagy, the consumption of insects, is promoted as an alternative sustainable source of protein for humans and animals. Seminal literature highlights predominantly the benefits, but with limited empirical support and evaluation. We highlight the historical significance of entomophagy by humans and key opportunities and hurdles identified by research to date, paying particular attention to research gaps. It is known that insects present a nutritional opportunity, being generally high in protein and key micronutrients, but it is unclear how their nutritional quality is influenced by what they are fed. Research indicates that, in ideal conditions, insects have a smaller environmental impact than more traditional Western forms of animal protein; less known is how to scale up insect production while maintaining these environmental benefits. Studies overall show that insects could make valuable economic and nutritional contributions to the food or feed systems, but there are no clear regulations in place to bring insects into such supply systems. Future research needs to examine how the nutritional value of insects can be managed systematically, establish clear processing and storage methodology, define rearing practices and implement regulations with regard to food and feed safety. Each of these aspects should be considered within the specifics of concrete supply and value chains, depending on whether insects are intended for food or for feed, to ensure insects are a sound economic, nutritional and sustainable protein alternative – not just a more expensive version of poultry for food, or soya for feed.
Exosomes: biology, therapeutic potential, and emerging role in musculoskeletal repair and regeneration
Authors: Cobelli Neil J. , Leong Daniel J. , Sun Hui B.
Published: November 2017

Exosomes are nanovesicles secreted from cells that play key roles in intercellular communication. They carry unique content derived from parental cells and are capable of transferring this cargo between cells. The role and function of exosomes largely depends on the origin and functional status of the parental cells. Emerging evidence indicates that exosomes are associated with biological processes and pathogenesis of certain diseases. These nanovesicles offer great potential as biomarkers, enabling the monitoring and diagnosis of various diseases in a noninvasive manner. Furthermore, as an efficient vehicle of biomolecular intercellular transfer, exosomes are under intensive investigation for their potential for drug delivery and carriers for gene therapy. Here, we first summarize the basic biology and function of exosomes, followed by a discussion of their clinical potential, including the use of exosomes for disease diagnosis, treatment, and drug delivery. The review will highlight the potential of exosomes derived from stem cells in regenerative medicine, with a focus on musculoskeletal tissues. We conclude by sharing our views on the challenges, opportunities, and future directions for the use of exosomes as a therapeutic treatment for the repair and regeneration of musculoskeletal tissues.
Outcomes of oral lichen planus and oral lichenoid lesions treated with topical corticosteroid
Authors: Gonzalez‐Moles MA , Bravo M , Gonzalez‐Ruiz L , Ramos P , Gil‐Montoya JA
Published: November 2017

Objective

To determine corticosteroid treatment effectiveness in patients with oral lichen planus/oral lichenoid lesions (OLP/OLL).

Material and Methods

Twenty‐one patients with OLP and eighty‐one patients with OLL received 0.05% clobetasol propionate (CP) or 0.05% triamcinolone acetonide (TA) in aqueous solution (AS) or orabase (OB), evaluating responses to treatment and follow‐up compliance.

Results

Lesions were atrophic (72 of 102; 70.6%), extensive (58 of 100; 58%), producing eating difficulties (62 of 102; 60.8%), and spontaneous pain (30 of 102; 29.4%); 50 patients (49%) received CP‐AS. The mean ± SD percentage of follow‐ups attended was 43 ± 32%. Symptom remission was achieved in 46% of patients receiving CP‐AS, 36.36% of those receiving TA‐AS, 20% of those receiving CP‐OB, and 25% of those receiving TA‐OB. Follow‐up compliance was poor in 66.7% of patients. Among 51 patients with continuous symptoms, 64.7% evidenced total remission at treatment completion; among 33 with intermittent symptoms, 73.1% had outbreaks 2–3 times/year and 51.5% controlled outbreaks with <6 corticosteroid applications. Adverse effects were observed in seven patients (6.8%) (moon face, hirsutism, capillary fragility) in induction stage, subsiding with dose; among 15 patients under maintenance treatment for >6 months, one showed hypothalamic–pituitary–adrenal (HPA) axis inhibition but not adrenal insufficiency.

Conclusions

Our treatment proved highly effective and safe. Recall programs are desirable to enhance follow‐up compliance.
Post‐metamorphic allometry in the earliest acrotretoid brachiopods from the lower Cambrian (Series 2) of South China, and its implications
Authors: Zhang Zhiliang , Zhang Zhifei , Holmer Lars E. , Chen Feiyang
Published: November 2017

The earliest growth of post‐metamorphic (post‐larval) shells in two species of Eohadrotreta is described from the Cambrian Shuijingtuo Formation of South China. Two different growth patterns can be observed by quantifying developmental variations in size and shape of successive stages of post‐metamorphic shell growth (including the pedicle foramen forming stage, pedicle foramen enclosing stage and intertrough increasing stage) of Eohadrotreta zhenbaensis and Eohadrotreta? zhujiahensis. The pedicle foramen is never enclosed within the metamorphic shell of E. zhenbaensis, while the enclosed pedicle foramen of E.? zhujiahensis is located directly outside the metamorphic shell after the pedicle foramen enclosing stage. A strongly allometric growth pattern of E. zhenbaensis is demonstrated by the early enclosure of the pedicle foramen; an accelerated lengthening of the ventral intertrough is associated with the development of a more complex dorsal median septum during the intertrough increasing stage. By contrast, E.? zhujiahensis demonstrates possible paedomorphic development by delayed enclosure of pedicle foramen and an associated decreased lengthening of ventral intertrough during the intertrough increasing stage. This ontogenetic developmental sequence represents the marginal accretionary formation and growth of the pedicle foramen, which resembles that of linguloid brachiopods. Furthermore, the developmental process of the pedicle foramen of Eohadrotreta seems to recapitulate the likely evolutionary transition from the Botsfordiidae, with open delthyrium, to the Acrotheloidea, with an enclosed foramen. This study provides a unique opportunity to obtain a complete understanding of the ontogenetic development of the earliest acrotretoids, and casts new light on the phylogeny of lingulate brachiopods.
Genetic diversity of reintroduced tree populations in restoration plantations of the Brazilian Atlantic Forest
Authors: Zucchi Maria I. , Sujii Patricia S. , Mori Gustavo M. , Viana João P. G. , Grando Carolina , Silvestre Ellida de Aguiar , Schwarcz Kaiser D. , Macrini Camila M. , Bajay Miklos M. , Araújo Fabiano L. , Siqueira Marcos V. B. M. , Alves‐Pereira Alessandro , de Souza Anete P. , Pinheiro José B. , Rodrigues Ricardo R. , Brancalion Pedro H. S.
Published: November 2017

Long‐term ecological success of large‐scale restoration programs planned for the next decades will rely on genetic diversity (GD) of reintroduced or colonizing species, a limiting factor in highly fragmented landscapes. In small and isolated natural remnants or restoration areas, substantial reduction in population's size or connectivity may lead to local extinctions due to the accumulation of deleterious recessive alleles and ongoing reduction of fecundity, plant vigor, recruitment success, and adaptive potential. Despite the paramount role of GD for species persistence, its levels in restoration programs are poorly known. We assessed the GD of four model tree species (different succession stages, dispersal, and pollination syndromes) from the Brazilian Atlantic Forest, comparing two high‐diversity restoration plantations, one forest fragment and one conserved remnant. Contrary to the expectation that the plantation strategies adopted in the restoration programs could result in genetic composition homogenization, we found that restoration areas established heterogeneous genetic groups with similar levels of neutral GD and inbreeding to those observed in natural forest remnants. This pattern was consistent across the four functionally different tree species, despite some species idiosyncrasies. For instance, we observed lower allelic richness in early successional species in restoration sites, suggesting that some species may be more prone to reintroduction with lower GD. Thus, we advocate the use of high GD levels in restoration to support biodiversity conservation in human‐modified landscapes, thus reinforcing the role of ecological restoration for recovering the diversity of genes—the basic constituent of biodiversity.
Strain measurements on compliant knitted mesh used in space antennas, by means of 2D Fourier analysis
Authors: de Salvador W. , Marotta E. , Salvini P.
Published: November 2017

The paper presents a strain measurement technique to be applied on repetitive knitted nets. The application of the procedure is focused on large deployable reflectors used in space applications. Manufacturing of these structures involves knitting of thin metallic wires. Besides space antennas, the method herein developed is advantageous for many other types of knitted tissues such as elastic coatings, elastic bandages for medical applications, or any other woven fabric requiring a defined elastic behaviour. All of them display an almost regular repetitive pattern whose variations due to imposed loads are the core of the method. Deformation of such kind of structural elements must be analysed in two dimensions, because the knitting causes an accentuated orthotropic behaviour. Strain measurement is tricky and requires special computational techniques. Indeed, the application of standard experimental methods and indirect strain determination, through well‐established image analysis algorithm, can be totally unsuccessful or unsuitable because of the lack of continuity of these structures. The paper presents a method based on two‐dimensional Fourier analysis. Numerical examples, supported by some experimental evidences, confirm the feasibility of the technique. Furthermore, a newly proposed frequency zooming algorithm, based on fast Fourier transform, makes the computational costs of the indirect strain measurement affordable.
An informal justification for selected degree‐of‐freedom formulae
Authors: Cashing Doug
Published: November 2017

This article offers some less‐than‐rigorous explanations for the notion of degrees of freedom, and for the particular formulae to be used when computing those values.
Young people's perspectives on the mobility of Australian English accents
Authors: STARKS DONNA , TAYLOR‐LEECH KERRY , WILLOUGHBY LOUISA
Published: November 2017

This paper draws on lines of sociolinguistic theory that have arisen in response to globalisation and current thinking about mobilities in the social sciences. Using the constructs of space, scale and centre‐periphery, we set out to analyse 564 Australian high school students’ responses to a questionnaire item which asked: ‘If you moved to another country, how important would it be for you to keep your Australian accent?’ Our exploration of the students’ responses through these lenses reveals the diverse ways in which young people imagine the mobility of their own accents and also how they situate the Australian accent more broadly.
Porous Materials Under Shock Loading as a Two-Phase Mixture: The Effect of the Interstitial Air
Authors: Resnyansky A. D.
Published: November 2017

Deformation and mixing of solid particles in porous materials are typical consequences under shock compression and are usually considered as the major contributors to energy dissipation during shock compression while a contribution from the interaction between the solid and gaseous phases attracts less attention. The present work illustrates the phase interaction process by mesomechanical hydrocode modeling under different conditions of the interstitial gaseous phase. A two-phase analytical approach focusing on the role of thermal nonequilibrium between the phases and an advanced two-phase model complement the mesomechanical analysis by demonstrating a similar trend due to the effect of pressure in the interstitial air.
Scale-Resolving Simulations of Bypass Transition in a High-Pressure Turbine Cascade Using a Spectral Element Discontinuous Galerkin Method
Authors: Garai Anirban , Diosady Laslo T. , Murman Scott M. , Madavan Nateri K.
Published: November 2017

The application of a new computational capability for accurate and efficient high-fidelity scale-resolving simulations of turbomachinery is presented. The focus is on the prediction of heat transfer and boundary layer characteristics with comparisons to the experiments of Arts et al. (1990, “Aero–Thermal Investigation of a Highly Loaded Transonic Linear Turbine Guide Vane Cascade,” von Karman Institute for Fluid Dynamics, Rhode St. Genese, Belgium, Technical Note No. 174.) for an uncooled, transonic, linear high-pressure turbine (HPT) inlet guide vane cascade that includes the effects of elevated inflow turbulence. The computational capability is based on an entropy-stable, discontinuous Galerkin (DG) spectral element approach that extends to arbitrarily high orders of spatial and temporal accuracy. The suction side of the vane undergoes natural transition for the clean inflow case, while bypass transition mechanisms are observed in the presence of elevated inflow turbulence. The airfoil suction-side boundary layer turbulence characteristics during the transition process thus differ significantly between the two cases. Traditional simulations based on the Reynolds-averaged Navier–Stokes (RANS) fail to predict these transition characteristics. The heat transfer characteristics for the simulations with clean inflow agree well with the experimental data, while the heat transfer characteristics for the bypass transition cases agree well with the experiment when higher inflow turbulence levels are prescribed. The differences between the clean and inflow turbulence cases are also highlighted through a detailed examination of the characteristics of the transitional and turbulent flow fields.
Droplet Coalescence and Departure on a Vibrating Film During Humid Air Condensation
Authors: Huber Ryan A. , Derby Melanie M.
Published: November 2017

This paper investigates an approach to collect evaporated water from a moist air stream, a scenario found in many power plant cooling towers which utilize evaporation to cool, thereby resulting in evaporative water losses. For example, a 500 MW power plant may lose about 27m3/h (7133 gal/h) of water to evaporation during operation. When a cooled surface is placed in a warm humid environment, water condenses on the surface. The condensed liquid forms a thermal resistance, thereby reducing the condensation rate and water collected. The concept presented in this paper is to vibrate the cooled surface, thereby rapidly removing more droplets than gravity alone. With forced movement and through droplet coalescence, new droplets can nucleate in the space created by departing water droplets. Droplet nucleation, coalescence, and departure were investigated on vibrating and stationary Teflon films (contact angle 105°) in an environmental chamber at 30°C and 50% RH. Film vibrations of approximately 100 Hz were investigated. Droplet departure diameters were approximately 2–3 mm diameter on the vibrating surface and 6 mm on the stationary surface.
Experimental Study of Nonlinear Vibration Energy Harvesting of a Bistable Composite Laminate
Authors: Emam Samir A. , Hobeck Jared , Inman Daniel J.
Published: November 2017

This study is at attempt to explore the nonlinear behavior of bistable composite laminates for vibration energy harvesting. Asymmetric four-ply [0/90/0/90] carbon-fiber plate with two cylindrical stable equilibria supported at its center and free at all boundaries is used for the experimental testing. Macro-fiber composite (MFC) patches are attached to the plate to transform the mechanical vibration energy into electrical energy. The mechanical bistable property of the plate makes it possible to snap from one stable equilibrium state to the other. This snapthrough motion is highly nonlinear and associated with large-amplitude vibrations. The experimental tests aim at exploiting the nonlinearity due to the snapthrough motion to enhance the energy extraction. First, the resonant frequencies and damping of the plate are identified. A primary-resonance excitations of the first mode are carried out using two schemes: amplitude sweep and frequency sweep. In the first case, amplitude sweep, the excitation frequency is kept fixed at the resonant frequency and the amplitude of excitation is increased. The time history and FFT of the response as well as the output voltage are measured and reported. In the second case, frequency sweep, the excitation frequency is varied around the resonant frequency while the excitation amplitude is kept fixed. In both cases, the response shows a small-amplitude single-well vibrations at low excitation amplitudes and chaotic and periodic snapthrough motion as the amplitude and frequency of excitation are varied. The snapthrough motion has been found to greatly enhance the energy extraction capability. This study can serve as a motive for more testing and modeling efforts in order to understand the complex nonlinear behavior of bistable composite laminates and exploit it for vibration energy harvesting.
Application of Swarm Intelligence to a Vibration Monitoring System
Authors: Hiura Takuya , Morishita Shin
Published: November 2017

The technology of swarm intelligence has been applied to a mechanical vibration monitoring system composed of a network of units equipped with sensors and actuators. The expression of “swarm intelligence” was first used in 1988 in the context of cellular robotic systems, where lots of simple agents may generate self-organized patterns through mutual interactions. There are various examples of the swarm intelligence in the natural environment, a swarm of ants, birds or fish. In this sense, the network of agents in a swarm may have some kind of intelligence or higher function than those appeared in a simple agent, which is defined as the swarm intelligence. The concept of swarm intelligence may be applied in diverse engineering fields such as flexible pattern recognition, adaptive control system, or intelligent monitoring system, because some kind of intelligence may emerge on the network without any special control system. In this study, a simulation model of a five degree-of-freedom lumped mass-spring system was prepared as an example of a mechanical dynamic system. Five units composed of a displacement sensor and a variable damper as actuator were assumed to be placed on each mass of the system. Each unit was connected to each other to exchange the information of state variables measured by sensors on each unit. Because the network of units configured as a mutual connected neural network, a kind of artificial intelligence, the network of units may memorize the several expected vibration-controlled patterns and may produce the signal to the actuators on the unit to reduce the vibration of target system. The simulation results showed that the excited vibration was reduced autonomously by selecting the position where the damping should be applied.
Control Design for High-Fidelity Cyber-Physical Systems With Applications to Experimental Fluid-Structure Interaction Studies
Authors: Waghela Rajmohan , Bryant Matthew
Published: November 2017

A cyber-physical system (CPS) combines active actuation, sensing, and a control algorithm to virtually replicate a physical structure with desired inertia, stiffness, and damping properties. The interaction of a CPS with a fluid flow can be used to study complex fluid-structure interaction phenomena. This paper highlights some of the control design challenges associated with the design of CPS and elaborates on issues pertaining to performance and lag. A model for including the interaction force and a potential work-around to inertia compensation are presented. Finally, a case study compares classical PID control with H∞ based model-matching control design.
Experimental Investigation for Enhancing the Output Power of a Piezoelectric Energy Harvester
Authors: Zargarani Anahita , Mahmoodi S. Nima
Published: November 2017

This paper investigates an experimental approach for enhancing the output power of a piezoelectric energy harvester. The proposed method adopts inductance to reduce the effect of the piezoelectric harvester’s impedance, and boost the output power. Four electrical circuits for a piezoelectric beam harvester are investigated experimentally; Simple Resistive Load (SRL), Inductive Load (IL), Standard AC-DC, and Inductive AC-DC circuits. The results show that the adaptation of inductor in the IL and Inductive AC-DC improves the output power compared to the SRL and Standard AC-DC respectively. The Inductive AC-DC circuit is shown to increase the output power by 6.7% in comparison to the existing standard AC-DC circuits.
Design Optimization of a Bi-Fold Magnetorheological Damper Subject to Impact Loads
Authors: Saleh Muftah , Sedaghati Ramin , Bhat Rama
Published: November 2017

Dynamic range (ratio of the maximum on-state damping force to the off-state damping force), is an important index characteristic of the performance of the Magnetorheological Energy Absorbers (MREAs). In high speed impact, the dynamic range may fall into the uncontrollable zone (≤ 1) due to the increase in the off-state damping force which is associated with the transition of the flow from laminar to turbulent condition. Therefore, it is of paramount importance to design optimize the MREA in order to increase its dynamic range while accommodating the geometry, MR fluid flow and magnetic field constraints. In this study, a design optimization problem has been formulated to optimally design a bi-fold MREA to comply with the helicopter crashworthiness specifications for lightweight civilian helicopters. It is required to have a minimum dynamic range of 2 at 5 m/s impact velocity while satisfying the constraints imposed due to the geometry, volume of the device, magnetic field and the flow of the magnetorheological fluid in the MR valve. Meanwhile in order to comply with the helicopter crashworthiness requirement, the MREA device should be designed to generate 15 kN field-off damping force at the design impact velocity if the MREA is to be integrated with skid landing gear systems. The magneto-static analysis of the MREA valve has been conducted analytically using simplified assumptions in order to obtain the relation between induced magnetic flux in the MR fluid gaps in active regions versus the applied current and MREA valve geometrical parameters.

Both Bingham plastic models, with and without minor loss factors, have been utilized to derive the dynamic range and the results are compared in terms of the generated off-state damping force, on-state damping force, and dynamic range. The Bingham plastic model with minor loss coefficients was found to be more accurate due to the turbulent condition in the MREA caused by the impact. Finally, the performance of the optimized bi-fold MREA has been evaluated under different impact speeds.
Modeling of Stiffness Characteristics in a Prosthetic Foot
Authors: Tryggvason H. , Starker F. , Lecomte C. , Jonsdottir F.
Published: November 2017

The key goal of prosthetic foot design is to mimic the function of the lost limb. A passive spring and damper system can imitate the behavior of an ankle for low level activity, e.g. walking at slow to normal speeds and relatively gentle ascents/descents. In light of this, a variety of constant stiffness prosthetic feet are available on the market that serve their users well. However, when walking at a faster pace and ascending/descending stairs, the function of the physiological ankle is more complex and the muscular activity contributes to the stride in different ways.

One of the challenges in prosthetic device design is to achieve the appropriate range of stiffness of the arrangement of joints and spring elements for different tasks, as well as varying loading of the prosthetic device. This calls for an adaptive mechanism that mimics the stiffness characteristics of a physiological foot by applying real-time adaptive control that changes the stiffness reactively according to user’s needs. The goal of this paper is to define the stiffness characteristics of such a device through modeling.

The research is based on a finite element model of a well-received prosthetic foot design, which is validated by mechanical measurements of the actual product. We further enhance the model to include a secondary spring/dampener element. Various smart material technologies are considered in the design to provide control of flexibility and damping rate of the ankle joint movement. The reactive control of the secondary element allows the simulated prosthetic foot to adapt the ankle joint to imitate the behavior of the physiological ankle during different activities and in different phases of the gait cycle.
The Use of Magneto-Rheological Fluids for Simulating Arterial Pulse Waveforms
Authors: Tantiyartyanontha Takdanai , Shin Eric , Koo Jeong-Hoi , Yang Tae-Heon
Published: November 2017

Creating a multi-variance human pulsation simulator is crucial for deeper understanding of human pulsation system and developing useful medical devices. Current pulsatile systems are bulky, complex, and expensive. In order to address these disadvantages, this project intends to develop a simple and cost-effective pulsatile simulator using Magneto-Rheological fluids whose flow can be controlled by magnetic fields instantly. It also intends to evaluate its effectiveness in generating various arterial blood pulsation patterns. To this end, a test setup consisting of tubing, an electromagnet, and sensors along with MR fluids was constructed. Using Pulse Width Modulation (PWM) techniques, the electromagnet produced control signals to regulate the flow motion. The output pressure changes (perceived human pulsation) were measured using a pressure sensor installed in the tubing. Using the test setup, a series of testing was performed to measure arterial pulsations by varying the duty cycles of PWM signals. The results show that the pulsatile system was capable of replicating various human pulsation waveforms.
Preparation of Highly Loaded Piezo-Composite Foams With High Expansion and Low Permittivity
Authors: Petrossian Gayaneh , Ameli Amir
Published: November 2017

The sensitivity of piezoelectric/polymer composite materials is inversely proportional to their dielectric permittivity. Introducing a cellular structure into these composites can decrease the permittivity while enhancing their mechanical flexibility. Foaming of highly filled polymer composites is however challenging. Polymers filled with high content of dense additives such as lead zirconate titanate (PZT) exhibit significantly decreased physical foaming ability. This can be attributed to difficulty in gas diffusion, decreased fraction of the matrix available, the reduced number of nucleated cells and the difficulty in cell growth. Here, both CO2 foaming and Expancel foaming were examined as potential methods to fabricate low-density thermoplastic polyurethane (TPU)/ PZT composite foams. While composites containing up to only 10vol.% PZT could be foamed using CO2, Expancel foaming could successfully yield highly-expanded composite foams containing up to 40vol.% (80wt.%) PZT. Dispersed Expancel particles in TPU/PZT composites acted as the blowing agent, activated by subjecting the samples to high temperatures using a hot press. Using Expancel, foams with expansion ratios of up to 9 were achieved. However, expansion ratios of greater than 4 were not of interest due to their poor structural integrity. The density of solid samples ranged from 1.8 to 3.3 g.cm−3 and dropped by a maximum of 80%, even for the highest PZT content, at an expansion ratio of 4. As the expansion increased, the dielectric permittivity of both CO2-foamed and Expancel-foamed TPU/PZT composites decreased significantly (up to 7.5 times), while the dielectric loss and electrical conductivity were affected only slightly. This combination of properties is suitable for high-sensitivity and flexible piezoelectric applications.
Synapse-Inspired Variable Conductance in Biomembranes: A Preliminary Study
Authors: Najem Joseph S. , Taylor Graham J. , Collier Charles P. , Sarles Stephen A.
Published: November 2017

Memristors are solid-state devices that exhibit voltage-controlled conductance. This tunable functionality enables the implementation of biologically-inspired synaptic functions in solid-state neuromorphic computing systems. However, while memristors are meant to emulate an intricate signal transduction process performed by soft biomolecular structures, they are commonly constructed from silicon- or polymer-based materials. As a result, the volatility, intricate design, and high-energy resistance switching in memristive devices, usually, leads to energy consumption in memristors that is several orders of magnitude higher than in natural synapses. Additionally, solid-state memristors fail to achieve the coupled dynamics and selectivity of synaptic ion exchange that are believed to be necessary for initiating both short- and long-term potentiation (STP and LTP) in neural synapses, as well as paired-pulse facilitation (PPF) in the presynaptic terminal. LTP is a phenomenon mostly responsible for driving synaptic learning and memory, features that enable signal transduction between neurons to be history-dependent and adaptable. In contrast, current memristive devices rely on engineered external programming parameters to imitate LTP. Because of these fundamental differences, we believe a biomolecular approach offers untapped potential for constructing synapse-like systems. Here, we report on a synthetic biomembrane system with biomolecule-regulated (alamethicin) variable ion conductance that emulates vital operational principals of biological synapse. The proposed system consists of a synthetic droplet interface bilayer (DIB) assembled at the conjoining interface of two monolayer-encased aqueous droplets in oil. The droplets contain voltage-activated alamethicin (Alm) peptides, capable of creating conductive pathways for ion transport through the impermeable lipid membrane. The insertion of the peptides and formation of transmembrane ion channels is achieved at externally applied potentials higher than ∼70 m V. Just like in biological synapses, where the incorporation of additional receptors is responsible for changing the synaptic weight (i.e. conductance), we demonstrate that the weight of our synaptic mimic may be changed by controlling the number of alamethicin ion channels created in a synthetic lipid membrane. More alamethicin peptides are incorporated by increasing the post-threshold external potential, thus leading to higher conductance levels for ion transport. The current-voltage responses of the alamethicin-based synapse also exhibit significant “pinched” hysteresis — a characteristic of memristors that is fundamental to mimicking synapse plasticity. We demonstrate the system’s capability of exhibiting STP/PPF behaviors in response to high-frequency 50 ms, 150 mV voltage pulses. We also present and discuss an analytical model for an alamethicin-based memristor, classifying that later as a “generic memristor”.
A Metameric Crawling Robot Enabled by Origami and Smart Materials
Authors: Angatkina Oyuna , Chien Brian , Pagano Alexander , Yan Tongxi , Alleyne Andrew , Tawfick Sameh , Wissa Aimy
Published: November 2017

Metamerism, in biology, occurs when a creature has multiple segments, which are similar in structure and configured in series. True metamerism means that these connected segments include a repetition of all organs and muscle tissues. Earthworms are examples of true metameric creatures. Animals use metameric structures to increase maneuverability and enable multiple modes (gaits) of locomotion along with other functions. This work presents the design of a crawling robot that is inspired by the crawling gait and true metamerism of earthworms. The building block of each segment is a bistable origami structure that extends and contracts its length. The robot moves forward by using directional friction on its feet to enable forward motion and turning. [1]. Using a series of connected origami building blocks provides the robot with a modular metameric structure. This paper presents a true metameric robot design where different segments can be detached and reattached to one another but remain fully functional in each state. The docking system uses shape memory alloy (SMA) wire coils as actuators for a clutching mechanism to disengage the different segments. A directional magnetic arrangement is used to reattach the segments. The actuation architecture exploits the bistability of the origami building blocks to improve the power efficiency of the robot. Future work includes implementing a control algorithm to plan the paths of the different segments and allow for autonomous segmentation and docking in various operational environments.
An Optimal Method for Periodic Structures Design
Authors: Riva Emanuele , Cazzulani Gabriele , Belloni Edoardo , Braghin Francesco
Published: November 2017

Periodic structures provide filtering behavior for vibrations, as a result of the repetition in space of unit blocks, or unit cells. In general, they are characterized by an internal mechanical impedance mismatch, so that waves are reflected and transmitted every time a discontinuity is present. The global behavior given by waves superposition is their cancellation, only for specific frequency ranges, generally called stop-bands or band-gaps. The variation of non-dimensional parameters shows how these attenuation regions move in the frequency domain: the correspondent diagrams are the main tools for the design problem and are known as band-maps. The selection of the geometrical, physical and elastic properties of the unit cell is therefore dependent on the designer experience and nothing can be said about the optimality of the proposed solution. Numerical methods are used for the selection of the best cell geometry, in order to get optimal attenuation. Generally, this is a time consuming approach. In this paper, an new method is presented, based on how the waves are reflected and transmitted at cells interface. Both beam and rod case studies are investigated. The algorithm allows matching between band-gap central frequency and the desired value, while the designed attenuation is optimal there, under certain physical and geometrical constraints. Moreover, the design of the bandgap location has been decoupled from the design of the magnitude of attenuation. This approach is purely analytic, therefore the computational efforts required are minimum. In order to validate the analytical model, a passive periodic beam has been manufactured. Its real frequency response is therefore compared to the expected one.
Identifiability and Active Subspace Analysis for a Polydomain Ferroelectric Phase Field Model
Authors: Leon Lider S. , Smith Ralph C. , Oates William S. , Miles Paul
Published: November 2017

We consider subset selection and active subspace techniques for parameters in a continuum phase-field polydomain model for ferroelectric materials. This analysis is necessary to mathematically determine the parameter subset or subspace critically affecting the response, prior to model calibration using either experimental or synthetic data constructed using density functional theory (DFT) simulations. For the 180° domain wall model, we employ identifiability analysis using a Fisher information matrix methodology, and subspace selection to determine the active subspace. We demonstrate the implementation and interpretation of techniques that accommodate the model structure and discuss results in the context of identifiable parameter subsets and active subspaces quantifying the strongest influence on the model output. Our results indicate that the governing domain wall gradient energy exchange parameter is most identifiable.