bluuebunny/crossref_metadata_2025 huggingface dataset:
The effect of craniokinesis on the middle ear of domestic chickens (Gallus gallus domesticus)
Authors: Claes Raf , Muyshondt Pieter G. G. , Van Hoorebeke Luc , Dhaene Jelle , Dirckx Joris J. J. , Aerts Peter
Published: November 2016

The avian middle ear differs from that of mammalians and contains a tympanic membrane, one ossicle (bony columella and cartilaginous extra‐columella), some ligaments and one muscle. The rim of the eardrum (closing the middle ear cavity) is connected to the neurocranium and, by means of a broad ligament, to the otic process of the quadrate. Due to the limited number of components in the avian middle ear, the possibilities of attenuating the conduction of sound seem to be limited to activity of the stapedius muscle. We investigate to what extent craniokinesis may impact the components of the middle ear because of the connection of the eardrum to the movable quadrate. The quadrate is a part of the beak suspension and plays an important role in craniokinesis. Micro‐computed tomography was used to visualize morphology and the effect of craniokinesis on the middle ear in the domestic chicken (Gallus gallus domesticus). Both hens and roosters are considered because of their difference in vocalization capacity. It is hypothesized that effects, if present, of craniokinesis on the middle ear will be greater in roosters because of their louder vocalization. Maximal lower jaw depression was comparable for hens and roosters (respectively 34.1 ± 2.6° and 32.7 ± 2.5°). There is no overlap in ranges of maximal upper jaw elevation between the sexes (respectively 12.7 ± 2.5° and 18.5 ± 3.8°). Frontal rotation about the transversal quadrato‐squamosal, and inward rotation about the squamosal‐mandibular axes of the quadrate were both considered to be greater in roosters (respectively 15.4 ± 2.8° and 11.1 ± 2.5°). These quadrate rotations did not affect the columellar position or orientation. In hens, an influence of the quadrate movements on the shape of the eardrum could not be detected either; however, craniokinesis caused slight stretching of the eardrum towards the caudal rim of the otic process of the quadrate. In roosters, an inward displacement of the conical tip of the tympanic membrane of 0.378 ± 0.21 mm, as a result of craniokinesis, was observed. This is linked to a flattening and slackening of the eardrum. These changes most likely go along with a deformation of the extra‐columella. Generally, in birds, larger beak opening is related to the intensity of vocalization. The coupling between larger maximal upper jaw lifting in roosters and the slackening of the eardrum suggest the presence of a passive sound attenuation mechanism during self‐vocalization.
The effects of cracks on the quantification of the cancellous bone fabric tensor in fossil and archaeological specimens: a simulation study
Authors: Bishop Peter J. , Clemente Christofer J. , Hocknull Scott A. , Barrett Rod S. , Lloyd David G.
Published: November 2016

Cancellous bone is very sensitive to its prevailing mechanical environment, and study of its architecture has previously aided interpretations of locomotor biomechanics in extinct animals or archaeological populations. However, quantification of architectural features may be compromised by poor preservation in fossil and archaeological specimens, such as post mortem cracking or fracturing. In this study, the effects of post mortem cracks on the quantification of cancellous bone fabric were investigated through the simulation of cracks in otherwise undamaged modern bone samples. The effect on both scalar (degree of fabric anisotropy, fabric elongation index) and vector (principal fabric directions) variables was assessed through comparing the results of architectural analyses of cracked vs. non‐cracked samples. Error was found to decrease as the relative size of the crack decreased, and as the orientation of the crack approached the orientation of the primary fabric direction. However, even in the best‐case scenario simulated, error remained substantial, with at least 18% of simulations showing a > 10% error when scalar variables were considered, and at least 6.7% of simulations showing a > 10° error when vector variables were considered. As a 10% (scalar) or 10° (vector) difference is probably too large for reliable interpretation of a fossil or archaeological specimen, these results suggest that cracks should be avoided if possible when analysing cancellous bone architecture in such specimens.
Dental pain in the medical emergency department: a cross‐sectional study
Authors: Currie C. C. , Stone S. J. , Connolly J. , Durham J.
Published: November 2016

The aim of this study was to examine the number of patients attending a medical emergency department (MED) with dental problems over a three‐year period. This cross‐sectional study was carried out as part of a service evaluation. Data were collected via a database search of patient attendances at the MED using free text and the 10th revision of the International Statistical Classification of Diseases and Related Health Problems (ICD‐10) for oral and dental diagnoses. Data were analysed using descriptive statistics, t‐test and chi‐squared tests. Over the three‐year period, there were 2504 visits to the MED for dental‐related complaints, accounting for 0·7% of all attendances. The majority of patients were male (53·9%), with a mean age of 29 (s.d. 19·4) years for men, and 32 (s.d. 19·7) years for females. The mean index of multiple deprivation per cent rank was 35·0%. The most common diagnosis was unspecified dental disorder. Ten per cent of dental attendances to MED were repeat attendances by the same patients. In conclusion, patient attendances at MED for dental problems account for 0.7% of all attendances. MED may not be the most appropriate place for these patients to attend, in terms of care pathways, and also for economic reasons. The reasons why patients attend MED for dental problems clearly warrant further research.
Microfinance, Financial Inclusion, and the Rhetoric of Reaction: The Evolution and Limitations of Microfinance in Brazil
Authors: Schönerwald Carlos , Vernengo Matías
Published: November 2016

Several political and academic circles have considered microfinance to be an important tool to promote economic development and the reduction of poverty. It became a worldwide phenomenon, and the practice disseminated in many developing countries such as Brazil. Even as many authors sing the praises of microfinance—in particular the success in developing countries—the actual experience has fallen short. The goal in this article is to provide a critical analysis of the recent practices of microfinance in Brazil. The article also presents the general characteristics of microcredit in Brazil within the context of the broader development strategy pursued, in particular since stabilization and the inception of neoliberal policies in the mid‐1990s. It is argued that microfinance plays an insidious role, making market‐friendly solutions for social problems more acceptable.
Renewable Energy in Central America: One Step Forward, One Step Back, and Another Tentative Step Forward Again
Authors: Hira Anil
Published: November 2016

We are at an historical crossroads. The latest IPCC report gives dire predictions about potential losses from climate change, ranging from high sea levels to deterioration of agricultural production. Although emissions are still concentrated in the North, the most‐rapid growth of emissions is occurring in the South, suggesting the need for major changes in the trajectory of its economic development. Massive aid flows for climate‐change mitigation and adaptation lack any clear framework. We begin the task by examining the evolution of Central American electricity systems, seeking to explain the exceptional ability of several countries wracked by conflict, weak institutions, and struggling economies to move toward renewable fuels. We use first‐person interviews, government documents and websites, and consultant and expert reports to examine the largely unrecognized achievements. The necessity of finding alternative energy is not in question, but how these countries overcame the financial, technical, and policy challenges should be of great interest and could potentially provide valuable lessons for other countries.
Canadian Mining Investments in Argentina and the Construction of a Mining–Development Nexus
Authors: Saguier Marcelo , Peinado Guillermo
Published: November 2016

This article explores the relations between Argentina and Canada through the mining sector during the political cycle of Kirchnerism (2003–2015). Mining has been a growing economic sector but also a source of social resistance capable of mobilizing a regulatory agenda that sets restrictions to this activity. State political agency has been central to managing these tensions. How has the state responded to the growth of the mining industry? What has been Canada's role in this process? The claim is that Kirchnerism's response to growing anti‐mining resistance in a context of macroeconomic tensions has been to reframe transnational mining as consistent with a national development outlook. We explore this argument by looking at changes at the material, discursive, and institutional dimensions of the mining–development nexus.
Online virtual worlds as anthropological field sites: Ethnographic methods training via collaborative research of Internet gaming cultures
Authors: SNODGRASS JEFFREY G.
Published: November 2016

Since 2008, at Colorado State University, I have been collaboratively researching virtual worlds with my students in experimental methods seminars. My “ethnographic research and teaching laboratory” (ERTL), ambitious in scope, conducts original and even cutting edge research, while teaching students field methods in the process. The research and teaching unfold primarily in Internet‐based games—such as World of Warcraft and Guild Wars 2—persistent online networked social spaces of hundreds and even thousands of players. As a teaching tool, online virtual worlds provide a convenient way to get students quickly into the “field,” with online games being for some students (based on their play experience or lack of it) akin to foreign cultures. In this article, I discuss strengths and also challenges of ERTL, illustrating in the process how my lab's linked research and teaching model illuminates one way forward for empirically minded anthropologists hoping to move beyond the lone ethnographer. [online gaming cultures, ethnographic laboratory, mixed methods]
Teaching the research process through student engagement: Cultural consensus analysis of HIV/AIDS
Authors: COPELAND TONI
Published: November 2016

Participation in research prepares students for planning and conducting future projects, as well as academic and professional success. This article presents results of a student‐involved research project exploring a cultural model of HIV/AIDS prevention and treatment among college students as an example of teaching anthropological methods through faculty‐directed research. This research provides information on how an “at‐risk” population understands HIV/AIDS, including misconceptions held. Results include what participants know about prevention, treatment, and services. In addition to presenting this shared model, variation in knowledge is discussed by exploring factors influencing competence. Also, student collaborators learn invaluable methods by actually conducting research. This teaching method is assessed through student outcomes, including how they applied this experience to future work. Students have completed additional research on a variety of topics using methods learned throughout, including conceptions of mental illnesses, expectations of farmers’ markets, and treatment seeking among the uninsured. [student engagement, HIV/AIDS, Mississippi]
A mechanism for sequence specificity in plant‐mediated interactions between herbivores
Authors: Huang Wei , Robert Christelle A. M. , Hervé Maxime R. , Hu Lingfei , Bont Zoe , Erb Matthias
Published: November 2016

Herbivore communities are shaped by indirect plant‐mediated interactions whose outcomes are strongly dependent on the sequence of herbivore arrival. However, the mechanisms underlying sequence specificity are poorly understood.

We examined the mechanisms that govern sequence‐specific effects of the interaction between two specialist maize herbivores, the leaf feeder Spodoptera frugiperda and the root feeder Diabrotica virgifera virgifera. In the field, S. frugiperda reduces D. v. virgifera abundance, but only when it arrives on the plant first.

In behavioral experiments, D. v. virgifera larvae continued feeding on plants that they had infested before leaf infestation, but refused to initiate feeding on plants that were infested by S. frugiperda before their arrival. Changes in root‐emitted volatiles were sufficient to elicit this sequence‐specific behavior. Root volatile and headspace mixing experiments showed that early‐arriving D. v. virgifera larvae suppressed S. frugiperda‐induced volatile repellents, which led to the maintenance of host attractiveness to D. v. virgifera.

Our study provides a physiological and behavioral mechanism for sequence specificity in plant‐mediated interactions and suggests that physiological canalization of behaviorally active metabolites can drive sequence specificity and result in strongly diverging herbivore distribution patterns.
Structure–function analyses of the Pth11 receptor reveal an important role for CFEM motif and redox regulation in rice blast
Authors: Kou Yanjun , Tan Yi Han , Ramanujam Ravikrishna , Naqvi Naweed I.
Published: November 2016

The interaction of Magnaporthe oryzae, the rice blast fungus, and rice begins when M. oryzae establishes contact with the host plant surface. On perception of appropriate surface signals, M. oryzae forms appressoria and initiates host invasion. Pth11, an important G‐protein‐coupled receptor necessary for appressorium formation in M. oryzae, contains seven transmembrane regions and a CFEM (common in several fungal extracellular membrane proteins) domain with the characteristic eight cysteine residues.

We focused on gaining further insight into the role of the CFEM domain in the putative surface sensing/response function of Pth11.

Increased/constitutive expression of CFEM resulted in precocious, albeit defective, appressoria formation in wild‐type M. oryzae. The Pth11C63A/C65A mutant, probably with disrupted disulfide bonds in the CFEM, showed delayed appressorium formation and reduced virulence. Furthermore, the accumulation of reactive oxygen species (ROS) was found to be altered in the pth11Δ strain. Strikingly, antioxidant treatment induced appressorium formation in pth11Δ. The Gα subunit MagB and the mitogen‐activated protein (MAP) kinase Pmk1 were required for the formation of antioxidant‐induced appressoria.

We conclude that the CFEM domain of Pth11 is required for proper development of the appressoria, appressoria‐like structures and pathogenicity. Highly regulated ROS homeostasis is important for Pth11‐mediated appressorium formation in M. oryzae.
Florid cemento‐osseous dysplasia: analysis of 47 Sudanese cases and review of the literature
Authors: Elbeshir E.I. , Mohammed Alhadad M.A.
Published: November 2016

Aim

We studied the prevalent cases of florid cemento‐osseous dysplasia (FCOD) in Sudanese patients reporting to Khartoum Dental Hospital, Sudan.

Material and methods

Case records of FCOD and osteomyelitis over a 3 years period were retrieved, reassessed for confirmation of diagnosis and evaluation.

Results

There were a total of 47 cases of FCOD and 35 (74.5%) of them fulfilled the criteria for initial diagnosis of FCOD. Out of 56 cases diagnosed with osteomyelitis, 12 (25.5%) cases fulfilled the criteria of FCOD, making a total of 47 cases of FCOD. Forty‐five patients were females and most of them were from western and northern areas of the Sudan. Thirty‐seven (78.7%) patients were symptomatic with pain, swellings, discharging sinuses and non‐healing sockets being the most frequent complaints, and extraction was the most common cause of infection and all symptomatic cases were exclusively in the mandible. In asymptomatic areas, sound teeth were vital and alveolar bone swellings were encountered in 23% of the cases. The mandible was affected in all cases and the maxilla in two‐thirds of the cases 64%. Diagnosis was made on the bases of clinical and radiographic features, and 12 cases were examined histologically and the diagnosis was confirmed. Asymptomatic cases received restorative and preventive management. Symptomatic cases were treated with antibiotics alone or in combination with surgery.

Conclusions

Until now, this is the largest series to be reported on prevalent cases of florid cemento‐osseous dysplasia in Sudan. Dentists must look for these lesions and adopt a preventive role to minimize complications that may arise thereof. The female predilection and distribution between two major ethnic groups warrant further investigations.
International Menu Costs and Price Dynamics
Authors: Schoenle Raphael
Published: November 2016

The pricing behavior of firms systematically differs across domestic and export markets. First, domestic producer prices change approximately twice as often, the probability of synchronized price adjustment across markets is 21% for upwards adjustments and 14% for downwards adjustments, the size of export price changes is substantially larger and there are strong seasonality effects. Second, economic fundamentals can only partially explain adjustment decisions and cross‐market synchronization. Third, I attribute the remaining unexplained part in adjustment decisions to differences in menu costs across countries. Model‐implied export menu costs are 1.5% of steady state revenues and three times domestic market menu costs.
Knowledge Search Pattern and Product Innovation of Firms in Low and High‐Technology Industrial Clusters: A Knowledge Relatedness Perspective
Authors: Wu Aiqi , Wang Cassandra C.
Published: November 2016

Geographical knowledge search and innovation have attracted much attention in recent years. Yet the existing literature placed much emphasis on the way firms search for new ideas and knowledge as well as the geographical dimensions of knowledge sourcing without taking accounting into the nature and characteristics of knowledge per se. We examine the relationship between knowledge search and product innovation in both low and high‐tech industry with a survey data from China. While both internal and external knowledge search are conducive to product innovation of high‐tech firms, only external knowledge search is valuable for low‐tech firms. External unrelated knowledge is significant for innovation of high‐tech firms whereas external related knowledge search is significantly enough for low‐tech firms. It highlights the importance of knowledge relatedness in innovation and appeals a shift of theoretical focus from ‘how to search’ and ‘where to search’ to ‘what to search’ in the process of innovation.
IMAGING DIAGNOSIS—MAGNETIC RESONANCE IMAGING OF A NEURONAL HETEROTOPIA IN THE BRAIN OF A CAT
Authors: DeJesus Antonia , Turek Bradley J. , Galban Evelyn , Suran Jantra Ngosuwan
Published: November 2016

A domestic shorthair kitten was presented for evaluation and further treatment of seizures. Magnetic resonance imaging of the brain revealed a large multilobulated mass in the third ventricle extending into the right lateral ventricle with secondary obstructive hydrocephalus. The mass was homogeneously isointense to gray matter on T2W, T2‐FLAIR, T2*W, T1W, and ADC images, and hyperintense on DW‐EPI. There was no appreciable contrast enhancement. Seizures were managed medically and with subsequent ventriculoperitoneal shunt placement. Clinical status later deteriorated and the cat was euthanized. Histopathology confirmed that the mass was the result of neuronal heterotopia. To the authors’ knowledge this is the first report of neuronal heterotopia in a cat.
Economic Policy as a Determinant of Development and More Efficient Business Operation in the Republic of Srpska
Authors: Mastilo Zoran
Published: November 2016

The Republic of Srpska needs a developing economic policy in order to make it a key determinant of more efficient business operation. The present economic policy is far from being like that, as it is more recession like given that it does not determine development yet. The economic policy of the Republic of Srpska has failed to perform its function years and especially for the incoming 2016, when, in addition to previous scope of welfare, which was defined as a target, it set to itself an additional goal to also finance pensions from the Budget in the coming period. The RS Government has gone even further and has even praised in public that in 2017 the Public Health Service would also be financed from the Budget, which will most certainly place an additional burden to an already strained Budget of the Republic of Srpska, whose 1/5 has been regularly replenished by using resources of International Monetary Fund. The Republic of Srpska, unlike many other countries worldwide, has abandoned Bismarck social insurance system and has adopted the Beverage system which is rarely applied worldwide. Such occurrence appears only when an economic system of a parent state cannot finance social rights out of its operations. Unfortunately, it has happened to the Republic of Srpska. Thus defined objectives and economic policy created in this way would not provide any positive growth rate, higher employment level, abatement of public debts nor cutting the deficit in any country, let alone in the RS. The said arguments will additionally contribute to poor living standard of citizens i.e. the citizens would experience even worse conditions than today, while only a small number of them would live in abundance. Such poor condition was not only caused by the global economic and financial crisis, but the culprits should be sought among those who have poorly planned, managed and spent scarce financial resources of the RS. Economic policy of the Republic of Srpska should spawn certain indicators, which would become a determinant of development and better business operation. It would considerably benefit to greater wealth of the Republic of Srpska and provide better living standard of its citizens.
Experimental Usage of Humanoid Robot for Energy Harvesting Study From Walking Motion
Authors: Cha Youngsu , Hong Seokmin
Published: November 2016

Human motions are good energy sources for energy harvesters to support wearable devices. Among them, walking motions have received considerable attention as energy sources due to their large kinetic energy. Most of the studies about energy harvesting from human walking have been tested in real human wearing energy harvesters. In this paper, we use a humanoid robot to study energy harvesting from walking motion. We quantitatively analyze the energy harvesting from walking through the repeatable motion of the humanoid robot. A knee pad is attached on the leg of the humanoid robot. We make a pocket on the knee pad and put a piezoelectric composite as an energy transducer into the pocket. We refer to a trajectory of knee angle during one walking cycle of human from literature. The knee motion is formulated by performing Fourier series fitting for programming the movement of the humanoid robot. Additionally, an electromechanical model is used to explain the electrical responses from the piezoelectric composite in the pocket during the motion of the humanoid robot. We estimate average power transferred from the piezoelectric composite to the load resistances during the knee motion by using the model and validate the theoretical predictions by comparing with experimental results.
Scattering of Lamb Waves by a Cylindrical Mass Attached to the Surface of a Plate
Authors: Golato Andrew , Santhanam Sridhar , Ahmad Fauzia , Amin Moeness G.
Published: November 2016

Defect classification is the logical next step after localization in a Lamb wave based Guided Wave Structural Health Monitoring (GWSHM) defect detection scheme. Lamb waves are a preferred wave mode in GWSHM; therefore, classification can be facilitated via understanding of the Lamb wave scattering characteristics of defects. Many defects can be modeled either as (part-) through holes or accumulated masses on the surface. We consider and analytically solve the scenario of an attached mass on the surface of a plate. The mass is treated as an elastic isotropic homogeneous cylinder and the scattering response is obtained for incident fundamental symmetric and antisymmetric waves. Propagation is modeled via Mindlin plate theory, utilizing infinite series of Bessel functions as potential functions. Boundary and continuity conditions provide a linear system of equations for the expansion coefficients of the potential functions, which, solved numerically, produce the scattering response of the defect.
Strain Estimation From Conductivity Changes in Piezoresistive Nanocomposites
Authors: Tallman T. N.
Published: November 2016

Carbon nanofiller-modified composites have incredible potential for self-sensing and structural health monitoring (SHM) because they are piezoresistive. That is, the electrical conductivity of a nanocomposite is inherently coupled with mechanical perturbations such as damage and strain. Because of the correspondence of strain and damage with conductivity changes, non-invasive conductivity imaging techniques such as electrical impedance tomography (EIT) can enable unprecedented insight into the mechanical state of a nanofiller-modified composite. Furthermore, because of the potential of nanocomposites for self-sensing and SHM, considerable effort has been dedicated to studying the effect of strain on nanocomposite conductivity. That is, these efforts seek to determine the change in conductivity of a nanocomposite for a prescribed strain. However, from a SHM perspective, knowing the inverse relation would be much more useful. In other words, for an observed conductivity change, what is the underlying strain state? In light of the potential of EIT to provide insight into the conductivity distribution of a strained nanocomposite, we herein develop a method of estimating the infinitesimal strain tensor of a piezoresistive nanocomposite for observed conductivity changes. This is done by formulating an inverse problem that seeks to minimize the difference between an observed conductivity and a piezoresistivity model that predicts nanocomposite conductivity as a function of the strain in the least-squares sense. Next, this approach is specialized to the finite element method such that the nodal displacements giving rise to an observed conductivity change can be ascertained. Lastly, this method is tested analytically with noisy data. It is found that the proposed method can accurately reproduce nodal displacements and therefore strains from conductivity data.
Thermally Adaptive Building Coverings: Theory and Application
Authors: Barrett Ronald M. , Barrett Ronald P.
Published: November 2016

The paper begins with a brief overview of historical building coverings. Thermadapt™ thermally adaptive buildings are introduced as a completely new class of shingles, siding and roofing. These elements physically change shape in response to thermal loading. In hot weather with high solar loading, the panels curl up and away from the building. As the temperature cools and the sun sets, the Thermadapt™ elements lie close to the building. In cool temperatures, the elements lie flat agains the building transferring solar energy. In extremely cold temperatures, high convexity inherently forms in the elements, forming a pocket of trapped dead air which forms a highly effective layer of insulation. Thermadapt™ elements are analytically modeled using Classical Laminated Plate Theory (CLPT). Although Thermadapt™ elements may use materials like shape memory alloys, cost concerns drive the use of coefficient of thermal expansion mismatch as the basic driving mechanism. A series of experiments were performed on a variety of Thermadapt™ elements using high CTE mismatch pairs of structural materials including graphite-epoxy and aluminum and Invar and aluminum pairings. Analytical estimates are shown to predict the performance of the Thermadapt™ panels with great accuracy with curvature levels measured and predicted in excess of 5 deg/m/°C. Analytical predictions using CLPT employed a lateral constraint, driving lateral curvature, κy, to zero by the use of stiff lateral constraint mechanisms like edge rolls and lateral corrugations. This constraint was shown to increase deflections by roughly 33% over the unconstrained elements which were simply allowed to encounter equal curvatures in x and y directions, or “doming.”
Joint Characteristic Effect on the Performance of Nonlinear Piezoelectric Energy Harvesters
Authors: Jahani Kamal , Aghazadeh Parisa
Published: November 2016

In this work, the effects of joint characteristics on the performance of a nonlinear piezoelectric energy harvester are investigated numerically. Large amplitude deflection unimorph beam with a tip mass and a nonlinear piezoelectric layer is considered as an energy harvester. By applying Euler-Lagrange equation and the Gauss’s law, mechanical and electrical equations of motion are obtained respectively, under two scenarios, i.e. with an ideal (rigid) joint and with a flexible one. A numerical approach is followed to investigate the effects of each nonlinear parameter of the harvester (stiffness, damping and piezoelectric coefficient) on harvested power. Results show that considering ideal joint between harvester and base structure leads to overestimating the maximum output power and the range of effective excitation frequency.
Demonstration of a Novel Smart Structural System for Pointing Control of Trusses
Authors: Shimada Takeshi , Ishimura Kosei , Kawano Taro
Published: November 2016

We designed and developed a novel smart structural system for pointing control of large-scale support structures, such as trusses. The system consists of a pointing control mechanism, an internal displacement-sensor, and a controller. Remarkable points of our system are (1) artificial thermal expansion of truss members is utilized as linear actuators, (2) elastic hinges are applied instead of boll joints, and (3) the internal displacement-sensor which does not need external jigs and has high measuring accuracy is applied. In this paper, we conducted the feasibility study and the experimental demonstration. As a result of the feasibility study, the proposed pointing control mechanism can produce several hundred arcseconds of the rotational displacements within three minutes, therefore it has potential for using in practical operations. As a result of the experimental demonstration, we confirmed that the hysteresis of the pointing control mechanism can be kept sufficiently small due to the absence of the sliding parts, and has high control accuracy and followability (the error RMS value for a circle of the radius of 500 μm is 3.6 %).
Modular SMA-Based Bi-Directional Rotational Actuator
Authors: Motzki Paul , Britz Rouven , Seelecke Stefan
Published: November 2016

State-of-the-art actuators that produce rotatory motion and torsional moment are based on either combustion engines, electro-motors, hydraulic or pneumatic machines. Each of these actuation methods has several drawbacks. All of these systems often come with high initial costs, big weight and need a lot of construction space because of their dimensions. Shape memory alloys are known for their superior energy density. That allows for the construction of very compact and light-weight actuator systems. In this paper, the design and construction of a light weight rotational actuator based on SMA wires is presented. The design is based on a modular concept, with each module contributing to the total rotational radius. This way, the actuator can be custom fitted to specific application needs.
Two-Dimensional Phononic Crystals With Acoustic-Band Negative Refraction
Authors: Sadeghi Hossein , Nemat-Nasser Sia
Published: November 2016

A two-dimensional phononic crystal (PC) can exhibit longitudinal-mode negative energy refraction on its lowest (acoustical) frequency pass band. The effective elastodynamic properties of a typical PC are calculated and it is observed that the components of the effective density tensor can achieve negative values at certain low frequencies on the acoustical branches for the longitudinal-mode pass-band, and that negative refraction may be accompanied by either positive or negative effective density. Furthermore, such a PC has a high anisotropy ratio at certain low frequencies, offering potential for application to acoustic cloaking where effective material anisotropy is essential.
Microfluidic Generation, Encapsulation and Characterization of Asymmetric Droplet Interface Bilayers
Authors: Nguyen Mary-Anne , Sarles Stephen A.
Published: November 2016

Our research focuses on creating smart materials that utilize synthetic cell membranes assembled at liquid interfaces for autonomic sensing, actuation, and energy conversion. Unlike single membrane assemblies, systems featuring many membranes have the potential to offer multi-functionality, greater transduction sensitivity, and even emergent behaviors in response to environmental stimuli, similar to living tissue, which utilizes networks of highly packed cells to accomplish tasks. Here, we present for the first time a novel microfluidic platform capable of generating a stream of alternating droplet compositions, i.e. A-B-A-B, and sequentially capturing these droplets in precise locations to enable the spontaneous formation of synthetic lipid bilayers between droplets of different compositions (i.e. A and B) in an enclosed substrate. This platform preserves a key feature of the droplet interface bilayer (DIB) method, which allows asymmetric conditions within and across the membrane to be prescribed by simply using droplets containing different species. In this work, we demonstrate the ability to assemble bilayers consisting of asymmetric lipid compositions and, separately, show that alternating droplets containing the same lipid type can also be used to control the direction of ion channel insertion. In the first study, A and B droplet types contain liposomes comprised of different lipid types, which are used to establish an asymmetric composition of the leaflets that make up the lipid bilayer. This asymmetry results in a dc, non-zero membrane potential, which we measure via membrane capacitance versus bias voltage. In the second study, alamethicin peptides are included in only one of the droplet types, which enable voltage-dependent insertion to occur only at one polarity. Cyclic voltammetry measurements are performed to confirm the direction of insertion of alamethicin channels in bilayers. Also, these results show the ability to perform simultaneously electrical measurements on multiple DIB, which increases the experimental capacity and efficiency of a microfluidic approach. The ability to produce alternating droplets in a high throughput manner with electrical access provides a system to investigate the effects of lipid asymmetry on the function of membrane proteins in a controlled model system.
Sensitivity Analysis for a Quantum Informed Ferroelectric Energy Model
Authors: Leon Lider S. , Smith Ralph C. , Oates William S. , Miles Paul
Published: November 2016

We perform global sensitivity analysis for parameters in a continuum energy model for ferroelectric materials, which is informed by density functional theory (DFT). Specifically, we use global sensitivity analysis to rank the sensitivity of phenomeno-logical parameters governing the Landau and electrostriction energy for single-domain ferroelectric lead titanate. These techniques include Pearson correlations constructed directly from input and output relations, Sobol sensitivity indices, and Morris indices.
Parametric Study of a Fluidic Artificial Muscle Actuated Electrohydraulic System
Authors: Chapman Edward , Jenkins Tyler , Bryant Matthew
Published: November 2016

Fluidic artificial muscles have the potential for a wide range of uses; from injury rehabilitation to high-powered hydraulic systems. Their modeling to date has largely been quasi-static and relied on the operator to adjust pressure so as to control force output and utilization while little work has been done to analyze the kinematics of the driving-systems involved in their operation. This paper utilizes an established electro-hydraulic model to perform a study of the components of a fluidic artificial muscle actuated climbing robot. Its purpose is to determine the effect of the robotic subsystems on function and efficiency for a small-scale system in order to extrapolate more general design and analysis schemes for future use. Its results indicate that important aspects to consider in design of the hydraulic system are system payload, operating pressure, pump selection, and FAM construction.
Modeling and Experiments on Liquid-Infused, Mechanically Activated Porous Materials
Authors: Razavi Reza , Sarles Stephen A.
Published: November 2016

The goal of our research is to develop new understanding regarding the design and fabrication of mechanically activated liquid-infused porous films. Our unique approach is to consider a thin, elastic material that features well-defined pores, which are plugged with an infusing liquid that preferentially wets to the walls of the pores. By tuning the geometry of the pores, liquid-filled pores can be rearranged into a configuration that creates an open pore by applying stretch to the solid material, and they close (i.e. heal) again when the stretch is removed. Impregnating the pores with liquid seeks to avoid limitations that prevent complete pore closure and allows for tailoring of the pore geometry to drive liquid redistribution in the pore. The specific objective of this research is to study the effects of pore geometry and liquid wetting for creating fully reversible, stretch-activated pores. Our approach is both computational and experimental: Surface Evolver software is utilized to predict minimal energy wetting states of liquid in various pore shapes, and experiments on porous elastomers infused with either water or mineral oil allow measurements of stretch-induced changes in wetting properties and porosity. Both modeling and experiments demonstrate that a tear-shaped pore, which consists of a circular pore that features a taper extending in a radial direction, can enable reversible opening and closing of the pore via liquid redistribution. Our results indicate that infusing liquids with lower surface tensions and lower contact angles on walls of the pore exhibit better reversibility during the application of stretch.
Semi-Active Control of Sound Radiated From an Elastic Circular Plate Integrated With Adaptive Tuned Vibration Absorbers
Authors: Hemmatian Masoud , Sedaghati Ramin
Published: November 2016

While adaptive tuning of vibration absorbers (ATVA) have been widely studied for vibration control applications, limited studies have been done to explore their potential for noise control applications. This study aims to utilize magnetorheological elastomer (MRE)-based ATVA to control the radiated sound from an elastic plate excited by a plane wave especially at low frequencies. Radiated sound from a clamped circular plate integrated with MRE-based ATVA is analytically studied using classical plate theory. Rayleigh integral approach is, then, used to express the transmitted sound pressure in terms of the plate’s displacement modal amplitude. A MRE-based ATVA under shear mode is investigated. The semi-active Skyhook controller is proposed to attenuate the transverse displacement of the plate and subsequently reduce the radiated sound. The controller determines the current input to the electromagnet and tunes the MRE-based ATVA with the desired stiffness.
Public Participatory Integrity Monitoring of the Great Wall Based on Smart Phones
Authors: Zhao Xuefeng , Wang Niannian , Wang Linan , Yu Yan , Li Mingchu , Ou Jinping
Published: November 2016

Some of The Great Wall relics are destroyed or even disappeared. The existing studies relied on field surveys are costly and time consuming. So a new cloud monitoring system based on smart phones is proposed. The system, which consists of three modules, image acquisition, questionnaire and real-time location, can realize rapid acquisition of information. Firstly, using smart phones, some photos of the Great Wall can be obtained. Then, the typical integrity damage information and location information can be obtained, including structure crack, human-caused destruction, the vegetation growth, etc. Secondly, analyzing the typical integrity damage information, the evaluation results are obtained. Then, the Great Wall information in the form of questionnaire is posted on the Great Wall integrity monitoring system. Mobile phone users who logged in the system can upload photos, and fill in the questionnaires. Through taking pictures and filling in the questionnaires, the required information can be obtained.
Nonlinear Parametric System Identification Using Hard Excitations
Authors: Abusoua Abdraouf , Daqaq Mohammed F.
Published: November 2016

This paper presents a new approach for the parametric identification of nonlinear systems. The approach is based on subjecting a nonlinear system to a strong high-frequency excitation and monitoring its influence on the slow modulation of the system’s response which occurs near its natural frequency. The identification procedure is outlined and numerically implemented on a Duffing-type system with unknown quadratic and cubic nonlinearities. The proposed technique is then implemented to identify the nonlinear parameters of three different experimental systems. Results demonstrate that the proposed approach predicts the nonlinear parameters with good accuracy.
Reduced Radius of Curvature Nitinol-on-Pt Bimorph Actuators Based on Reversible Shape Memory Effect
Authors: Knick Cory R. , Smith Gabriel L. , Srour Merric D. , Morris Christopher J.
Published: November 2016

In this work we discuss the design and fabrication of NiTi on Pt bimorph cantilever arrays that may be actuated by utilizing the martensite to austenite phase transformation of a sputtered thin film of equiatomic NiTi shape memory alloy (SMA). The cantilever devices were fabricated on a silicon wafer using standard micro fabrication techniques, and may therefore be applicable to microelectromechanical systems (MEMS) switch or actuator applications. This paper details the development of a co-sputtering process to yield a SMA film with controllable composition of Ni50Ti50 and transformation temperature around 60 °C. Shape memory effects were characterized and verified using Differential Scanning Calorimetry (DSC), which demonstrated a martensite-austenite phase change near 60 °C for a co-sputter deposited film onto a Si wafer at 600 °C for in-situ crystallization.

We used wafer stress versus temperature measurements as additional confirmation for the repeatable measurement of reversible phase transformation which completed by 80 °C upon heating. Up to 900 MPa completely reversible stress change was available for actuation during the thermally induced phase change. The tightest curling devices were based on a 600 nm NiTi film on 20 nm Pt and were actuated between a 200 μm curl at 25 °C and flat states when heated beyond 70 °C. Using a 532 nm (green), 440 mW laser, we also characterized actuation times of NiTi on Pt cantilever actuators from 4–240 milliseconds using optical intensities ranging from 2–24 W/cm2.
Carbon Nanotube Doping Effect on Structure and Optical Properties of Poly(3-Hexylthiophene) Tensile Strain Sensing Thin Films
Authors: Ryu Donghyeon
Published: November 2016

The poly(3-hexylthiophene) (P3HT)-based thin films were shown to perform multifunctional capability as a self-powered tensile strain sensor for structural health monitoring and an energy harvester. It was shown that carbon nanotubes (CNTs) could help alignment of molecules through non-covalent functionalization of CNTs via helical wrapping. P3HT molecules are expected to be better ordered thanks to the doped CNTs. In this study, doping effect of the CNT will be investigated on crystalline structures and optical properties of P3HT tensile sensing thin films. First, P3HT tensile strain sensing thin films with various doping concentrations of CNTs will be fabricated using the spin-coating technique. Second, the fabricated P3HT-based sensing thin films will be characterized using x-ray diffractometer and ultraviolet-visible spectrophotometer to understand the changes of P3HT molecules’ crystalline structures and optical properties at various strain levels, respectively.
Cured Shapes and Snap-Through Loads Analysis of Bi-Stable Polyimide Film Hybrid Composite Laminates
Authors: Hu Jianqiang , Dai Fuhong
Published: November 2016

Bi-stable composite laminates have potential in application on conformal, morphing and deployable structures due to their bi-stable, load-bearing, deformable and conformal characteristics. To expand their applications in multifunctional structures, other functional components (such as flexible sensors networks, flexible antennas and other large-area flexible electronic systems) are required to integrate into the bi-stable composite laminates. Polyimide (PI) film usually serves as the substrate of flexible electronics due to its excellent mechanical, thermal and chemical properties. In this study, the cured shapes and snap-through loads of the bi-stable polyimide film hybrid composite laminates are numerically and experimentally studied. The lay-ups of the bi-stable polyimide film hybrid composite laminate are [PI/02/902], [02/PI/902], [02/902/PI], [PI/02/902/PI], [PI/02/PI/902/PI], respectively. The results from the finite element analysis are compared with the experimental ones and show good agreements.
Study on the Snap-Through Behavior of Bistable Plates
Authors: Fei Yaying , Chen Lihua , Zhang Xiaozhi , Zhang Wei
Published: November 2016

This paper aims to analyze snap-through behavior of two-layer cross-ply bistable composite laminate square plates. The analyses consider the factors of laminate thickness, temperature and external applied force. In this study, the model was performed on the basis of the classical thin plate theory, the Von Kármán large deformation theory and Principle of Virtual Work. Afterwards the statics equilibrium equation was available. Subsequently the analysis was presented by adjusting the laminate thickness for these prior factors. Through the numerical simulations with Matlab® software, the curvatures in x-direction and y-direction were calculated to investigate the snap-through behavior. Two stable cylindrical configurations and an unstable saddle shape were given with different curvatures to show the equilibrium positions. Then the figures prove the external applied distributed force plays a vital role to the snap-through behavior. The results show that under macroscopic view, the ratio of side-length to thickness is three hundred or less, as the plates are thinner, the snap-through will appear more frequently, and the external forces will be less needed.