bluuebunny/crossref_metadata_2025 huggingface dataset:
Thermal Ageing Mitigation of FRP Composites Using Vascular Networks
Authors: Boba Katarzyna , Bond Ian , Trask Richard
Published: December 2014

Incorporation of multifunctionality to fibre reinforced polymer composite materials delivers many benefits. One example includes improved longevity of components through increasing permissible temperatures of operation, which could be achieved via in-situ cooling. As the temperature of composite components approaches the glass transition temperature (Tg) of the matrix, thermal stress induced ageing greatly increases [1], [2], thus the incentive for integrated cooling.

In order to assess the damage, which could be caused by exposure to elevated temperatures, isothermal ageing was performed at a temperature 15°C lower than the materials Tg (2200 hours at 110°C). Material used in this study is a carbon/epoxy prepreg system (Gurit, SE70), with a Tg of 126°C when cured at 110°C. Results have shown a significant drop in Short Beam Shear (SBS) Strength starting after exposure for 1700h and increase in fibre bridging seen in mode I Double Cantilever Beam (DCB) testing. Fracture surface analysis using SEM indicated that fibres were generally less well bonded to the matrix, with visible changes began occurring as early as 1000h exposure. These results indicate that extended exposure of a material at near Tg temperatures has a detrimental effect on material properties. To mitigate against this phenomenon, a series of tests were performed on SBS and DCB specimens in a raised temperature (110°C) environment, which incorporated in-situ cooling. The specimens were placed in an oven at 110°C and were cooled down to a constant temperature of 60°C via the internal vascular cooling arrangement. Further testing is underway to assess the inhibition of ageing and maintenance of the original composite material by active cooling using embedded vascular networks.
Experimental Analysis and Validation of a Circular Dielectric Electroactive Polymer Actuator Operating Against Various Loading Conditions
Authors: Hodgins Micah , Rizzello Gianluca , York Alexander , Seelecke Stefan
Published: December 2014

Dielectric Electroactive Polymers (DEAP) are a favorable actuator technology and are receiving much attention because of their lightweight, high energy density, high energy efficiency, scalability and low noise features. In order to take steps using this technology effectively, real world models should be developed and more testing of the actuators needs to be done. The performance of a DEAP actuator against any given load should be tested and measured. This will aid in the optimization of material properties and structural design of the actuator system. In order to test and analyze the actuators under their operational conditions more comfortably, a versatile loading test bench should be developed. This would allow for more dynamic real life testing of the actuator under expected operating conditions of any particular application.

In this work, a test setup is built to characterize and apply programmable loading forces to the DEAP in the same setup. Here a DEAP actuator is tested while coupled with a constant load. The load was applied by controlling the current in an electromagnetic linear motor. This was successful in showing the reasonable matching between the actuator force characteristic and the actual stroke for different levels of load. In the future more complex loads and actuators will be tested to mimic what the actuator will experience in various applications.
A Combined Modal-Wave Based Control of Membranes Using Irrational Transfer Functions
Authors: Sirota Lea , Halevi Yoram
Published: December 2014

This paper considers the development of closed loop regulation algorithm for membranes, based on the traveling wave approach. The membrane is modeled by a combination of modal decomposition in one spatial axis and transfer functions in the other. The transfer functions are irrational and are shown to represent the wave motion in the system. A dedicated closed loop control algorithm is designed to eliminate the wave reflections in the control axis, achieving by this attenuation of external disturbances. The resulting controllers are irrational as well, and approximations are used to implement them.
Energy Harvesting for Marine-Wildlife Monitoring
Authors: Shafer Michael W. , Morgan Eric
Published: December 2014

Bio-logging devices are systems mounted to an animal that measure parameters associated with the animal or its environment. These devices date back to the 1930’s in their simplest form, while modern devices use suites of digital sensors, microcontrollers, and wireless data communication. Despite these advances, there has always been a fundamental relationship between power consumption and the amount of science that can be conducted. There are now a number of commercially available devices that use solar cells to supplement their daily energy budget, but supplemental solar power is not useful for species that are nocturnal, subterranean, aquatic, or spend significant time beneath dense forest canopies. As such, there have been calls from the marine biology community for devices that could harvest power from their environments. For these marine species, alternative energy harvesting techniques are required. Here we explore a new application for energy harvesting as a power source for marine wildlife bio-logging tags. Marine animals cover wide swaths of the ocean, making tracking and data collection challenging. Tagging these animals with devices that track their location and/or collect data about the animal or its surroundings require large batteries and have limited life spans due to high power requirements for satellite data relays. With limited solar irradiance at depth making solar power less attractive, we review and explore other forms of energy that could be harvested, such as energy from fluid flow and hydrostatic pressure cycles. We investigate the energy potential from a number of sources and compare these values with the requirements of current bio-logging systems to assess required transduction efficiencies. The application of energy harvesting on animal tags could result in nearly indefinite life systems allowing for data collection from a single animal over the course of many years.
A Three Dimensional Iterative Panel Method for Bio-Inspired Multi-Body Wings
Authors: Dhruv Akash , Blower Christopher J. , Wickenheiser Adam M.
Published: December 2014

The continuing growth of Unmanned Aerial Vehicle (UAV) use in reconnaissance and surveillance has led to an increased demand for novel flight systems that improve vehicle flight capabilities in cluttered and turbulent environments. Bio-inspired wings with feather-like flaps have been proposed to enable bird-scale UAVs to fly robustly in such environments. This paper presents the development of a three-dimensional iterative constant strength doublet Adaptive Panel Method (APM) for calculating the flight characteristics of a multi-body wing operating in any of its possible configurations. A three-dimensional wake relaxation algorithm is incorporated into the model, which enables accurate wake shapes and down-stream roll-up for each flap configuration to be derived. Wake modeling is shown to improve the accuracy of the pressure distributions induced by the wake-body interactions. The flight coefficients calculated using this method are validated by experimental values obtained from a low speed suction wind tunnel operating at a Reynolds number of 300,000. Finally, it is shown that the APM aids in determining accurate surface loads for the preliminary design process of multi-body wings.
Identification of Breathing Fatigue Cracks in Nonlinear Structures
Authors: Yan Guirong , Zhao Kai , Fang Chen , Feng Ruoqiang
Published: December 2014

Fatigue cracks often occur in structural components due to dynamic loadings acting on them, such as wind loads and ground motion. If the static deflection due to dead loads is smaller than the vibration amplitude caused by dynamic loadings, these fatigue cracks alternately open and close with time, exhibiting a breathing-like behavior. This type of crack leads to a smaller change in structural dynamic characteristics than open cracks, and thus it is more difficult to be detected. If undetected timely, these fatigue cracks may lead to a catastrophic failure of the overall structure. Considering that breathing cracks introduce bilinearity into the structure, the present authors first developed a simple and efficient system identification method for bilinear systems by separating the global responses into two parts and performing Fourier transform on each set of separated data [1]. By applying this method, the natural frequency of each stiffness region can be identified. Then, breathing fatigue cracks can be detected by looking for the difference in the identified natural frequency between stiffness regions [1]. That approach is only applicable to the cases where the intact structure is linear. This study is to extend the approach in [1] to the cases when the intact structure is nonlinear, e.g., a structure with large displacements (geometrical nonlinearity). Once breathing cracks occur, there will exist both bilinearity (caused by breathing cracks) and cubic nonlinearity (caused by large displacements). To detect fatigue cracks in this case, Hilbert transform is proposed to be employed to process the separated data, instead of employing Fourier transform as in [1]. This approach has been successfully validated by numerical simulations.
Optimization of a Composite Morphing Wing With Shape Memory Alloy Torsional Actuators
Authors: Saunders Robert , Hartl Darren , Herrington Joshua , Hodge Logan , Mabe James
Published: December 2014

Shape memory alloy (SMA) actuators have recently been developed in the form of torsional tubes that can undergo large twisting deformations. Wing twisting has been investigated as a means to reduce induced drag in cruise conditions in small aircraft, but the actuation hardware required to generate wing twist at larger scales is prohibitively cumbersome. Replacing conventional actuators with SMA torque tubes provides a way to minimize weight of the twisting system but wing structural design then becomes more challenging. This analysis-driven design study examines an SMA torque tube as applied to the twisting wing design problem. A composite skin is considered to maximize wing performance under combined twist and aerodynamic loads. The SMA has been analyzed using a 3-D thermo-mechanical constitutive model while a preliminary study was performed to determine a composite lamina with appropriate unidirectional properties. An optimization was then completed to find an ideal composite layup. This optimization also included the design of a passive torque tube used to properly balance the twist generated by the SMA against that required in the wing. Localized buckling in the twisted wing was also considered and avoided. The product of this optimization was a composite wing that twisted while considering constraints of stress on the SMA. To validate the controllable use of SMA actuators, testing was completed on a scaled wing model fitted with a rapid prototype shell.
Design and Fabrication of a Functionally Modified Bimorph Actuator
Authors: Fujamade Johnson , Williams Frances , Myers Oliver , Plastied Brandon , Bahoura Messaoud , Hall Asha , Riddick Jaret
Published: December 2014

In recent years, the use of microelectromechanical systems (MEMS) devices has led to high performing actuators for various applications, including unmanned air vehicles (UAVs) for defense applications. The incorporation of MEMS technology in this field has resulted in miniaturized UAVs with the capability of carrying out sophisticated reconnaissance and relaying real time information remotely; however, maneuverability of these devices around obstacles is still a challenge. This paper presents the design and fabrication of a functionally modified bimorph actuator with enhanced UAV aerodynamics and maneuverability. The actuator is a metal-based MEMS device consisting of stainless steel, lead zirconate titanate (PZT), and titanium/platinum electrodes. COMSOL analysis was performed to examine optimal device design parameters and is presented in this paper. The design consists of off-axis PZT segments on a bimorph PZT layer which results in bend twist coupling. A detailed description of the fabrication process flow developed based on the optimization of the device design is also given. MEMS processing technology was incorporated to produce a torsional cantilever beam that produces angular and linear displacement for superior UAV maneuverability and its performance is also presented in this paper.
Modeling and Validation of Additively Manufactured Porous Nitinol Implants
Authors: Rahmanian Rasool , Andani Mohsen Taheri , Walker Jason , Habeland Christoph , Elahinia Mohammad , Dean David , Miller Michael
Published: December 2014

Bone implants are long term solutions for bone loss. Currently, two issues have been identified as reducing the long term stability of bone implants. The first issue is stiffness mismatch between the implant and the surrounding bony structure. The current materials used for manufacturing bone implants are much stiffer than the surrounding host bone. The second issue concerns bone-implant integration; the fact is that the bone needs an appropriate surface on which to attach and accept or deliver a load. Additive manufacturing techniques using Nitinol may provide the ability to fabricate bone implants with predetermined pore size and stiffness. This work brings the concept of stiffness tailoring to reality, taking advantage of additive manufacturing technique to fabricate engineering porosity to modify the stiffness. Based on the simulation and test results, it is shown that implants can be made with the stiffness in the range of the stiffness of the bone. The same capabilities can be used to affect a rough surface onto which bone is more likely to attach.
Efficient Methods of Harvesting Energy From Ultra-Short Duration Shock Loading
Authors: Rastegar Jahangir , Feng Dake , Pereira Carlos
Published: December 2014

Harvesting energy from high-shock pulse events such as those experienced during high velocity impact and firing setback acceleration in munitions using piezoelectric-based harvesters and converting it to usable electrical energy is not new. However, efficient collection of the generated charges and its transfer to an electrical storage device such as a capacitor for pulse events with very short duration, such as those that last a small fraction of a millisecond such as 50–100 microseconds is challenging. Another challenge for such piezoelectric-based harvesters is their hardening to survive high levels of shock loading, sometimes in excess of 100–200,000 Gs. In this paper, the basic design and operation of two such piezoelectric-based energy harvesters and their charge collection and storage electronics are described. The novel methods described are shown to achieve this goal with very high efficiency. The paper also describes the development of test-beds to simulate electrical charge generation of the energy harvesting power sources during high velocity impact and munitions firing for use in the design and evaluation of the developed charge collection and storage electronics.
Application of Piezoelectric Dynamic Force Sensor for Tool State Assessment in Manufacturing Process
Authors: Dominik Ireneusz , Flaga Stanislaw , Konieczny Jaroslaw , Snamina Jacek
Published: December 2014

In the paper the problem of examining of a damaged tool in the manufacturing process is presented by the example of the identification of a damaged die for creating a screw drive on a screw head. The operation of the screw head production is known as cold heading. One of the production stage is when a die cuts the head of the screw blank into an appropriate shape. Unfortunately, the die is often damaged before reaching its limit. In this case, the faulty semi-finished products are further processed because the cold heading is only the first operation required to produce a screw. If screws made of high-quality pure stainless steel are considered the economic loss is significant.

The measurement automatic systems for identification of damaged dies can be found in the newest machines but they are in minority in comparison to the older ones which work without such systems. It was the reason why attempt was made to construct the prototype diagnostic system for die state assessment, which is presented in the article.
The Design and Specifications of Service Friendly Shape Memory Driven Valve Systems
Authors: Czechowicz Alexander , Langbein Sven
Published: December 2014

Shape memory alloys (SMA) can be utilized as electrical activated drives for valve applications. By using the high actuation forces and medium strokes in combination with SMA intrinsic sensor functions, smart and versatile valve elements for multi-purpose applications can be designed. The sensoric functions, based on the change of the electrical characteristics of the SMA drive, allow to detect the system’s condition as well as the system’s fatigue. The paper systematizes the usability of the intrinsic sensor function with particular emphasis on service potentials. The paper focuses the development of a service friendly valve which allows health monitoring over the lifetime as well as failure diagnostics.
Thermal-Mechanical ICN-SMG Gels for Smart Devices
Authors: Gong Jin , Kabir M. Hasnat , Furukawa Hidemitsu
Published: December 2014

Transparent shape memory gels (SMGs) were developed in our group recently. They are smart materials having the ability to return from a deformed state (temporary shape) to their original (permanent) shapes upon application of a temperature change, which is named the shape memory. One of medical applications of SMGs is tried to use as a smart bandage material. The shape memory property of SMGs is good for fixing, removing and repeating, while their poor ductility is not good for wrapping. In order to improve the ductility of SMGs, a new network structure named as the inter-crosslinking network (ICN), which is composed of both flexible and easily broken chains and rod-like and durable chains, is introduced into the SMGs. Seven SMGs having ICN structure (ICN-SMGs) were synthesized by changing the ratio of monomers and the amount of crosslinker. The dependence of the mechanical properties on synthesis conditions and temperature changing of samples were investigated. The thermal-mechanical ICN-SMG showing the highest mechanical properties with the maximum stress of 4.6 MPa and the maximum strain of 7.4 (elongation 740%) was prepared. The Young’s modula of ICN-SMGs change quickly and reversibly between high temperature and low temperature from 0°C to 80°C. The water content was also discussed. The prepared ICN-SMGs in this paper have the water content in the range of 45∼72wt%. A trial medical bandage for treatment of broken finger was also made by the ICN-SMGs. It works well just by changing the temperature to wrap it around the finger and remove it after healing. The thermal-mechanical ICN-SMGs are supposed to be a very promising medical material for the future.
Damage Mapping in Composites With Phase Gradient
Authors: Darnton Aaron , Ruzzene Massimo
Published: December 2014

Lamb wave based methods for structural health monitoring and non-destructive evaluation have shown promise in composite and laminated structure applications. Many methods have been considered, but exploitation of the phase of the propagating wave is a recent addition. Utilizing the phase alleviates the ambiguity of many amplitude and modal analysis approaches. This paper considered two-dimensional damage analogs in analytical simulations, numerical simulations and experimental studies. Additionally, this paper addresses the importance of proper filtering for successful spatial domain reconstruction. The phase gradient approach was successful in cases where modal filtering yielded good results. In the case where modal filtering did not successfully reconstruct the time-space domain wave, the phase gradient approach could not be employed, underscoring the need for robust modal filtering techniques.
Autonomous Scour Monitoring of Bridges and Embankments Using Bio-Inspired Whisker Flow Sensor Arrays
Authors: Swartz R. Andrew , Rajbandari Baibhav , Winter Benjamin D.
Published: December 2014

Detection of damage to the boundary conditions of structures can be equally important as detection of structural damage. Civil structures sit on foundations which are, ideally, constant over time and are integral to collapse prevention. Any processes that compromise the foundations or the soil around them also constitutes damage to the structure. Bridge structures as well as embankments near roadways and viaducts can be particularly prone to this kind of attack when high-velocity water flows transport sediment away from the bridge foundation (scour). This process can be difficult to detect because 1) it happens out of sight, underwater; and 2) scour holes tend to grow and shrink at time progresses and materials are either carried away or deposited by the water. In this study, use of a buried-rod scour detection system based on magnetostrictive and magnetic flow sensor arrays is investigated. For buried-rod scour detection systems, an array of small, flexible, strain-sensitive rod sensors is distributed around the foundations which generate dynamic signals they are waterborne and static signals when buried. The pattern of static and dynamic signals reveals the depth of scour around the structure. Magnetostrictive sensors are appealing for this application due to their robustness. In this paper the effectiveness signal processing and scour detection algorithms are explored for water-coupled magnetostrictive whisker sensors of varying geometries to determine their sensitivity and the thresholds for false alarms and missed alert conditions at varying flow rates. Experimental laboratory data is utilized for this study.
Modeling Magneto-Active Elastomer Composites Using the Finite Element Method
Authors: Sheridan Robert , Tedesco Carrie , von Lockette Paris , Frecker Mary
Published: December 2014

Magneto-active elastomers (MAE) are a new branch of smart materials that consist of hard-magnetic particles such as barium ferrite in an elastomer matrix. Under the application of a uniform magnetic field, the MAE material undergoes large deformation as the material bends due to magnetic torques acting on the distribution of hard-magnetic particles. This behavior demonstrates the potential of MAEs to act as remote actuators. MAEs vary from magnetorheological elastomers (MRE) which use soft-magnetic iron particles in place of the hard-magnetic particles and they are driven by magnetic interactions between particles.

In this work, MAEs were fabricated using 30% v/v 325 mesh M-type barium ferrite (BaM) particles in Dow Corning HS II silicone elastomers. Prior to curing, the samples were placed in a uniform (∼2 Tesla) magnetic field to align the magnetic particles and produce a magnetization oriented in the direction of the applied magnetic field. The specimens were bonded to a passive poldymethylsiloxane (PDMS) substrate to form a two-segment accordion structure where the MAEs with magnetization, M, were placed in opposing orientations a prescribed distance apart. The application of a uniform magnetic field perpendicular to the magnetization of the undeformed MAEs would result in a bend (on the PDMS) that is dependent upon the orientation of the magnetic particles and the direction of the applied field. This behavior of the composite structure highlights the ability of the MAE material to perform work.

Experimental testing of the MAEs used a two-segment accordion structure with fixed boundary-conditions on both ends of the PDMS substrate and a uniform magnetic field was applied to the structure. The resulting deformation roughly represented either a mountain or valley fold (dependent upon the orientation of the applied field). The resulting axial force was observed and compared to computational simulations which utilized numerical techniques to develop approximate solutions. This procedure was repeated with a prescribed displacement on one of the two fixed boundary conditions to induce bending prior to the application of a uniform magnetic field. Results show a decrease in magnetic work potential with increases in the aforementioned prescribed displacement; results also show an increase in magnetic work potential with increases in the applied magnetic field.
Fluidic Flexible Matrix Composites for Volume Management in Prosthetic Sockets
Authors: Mercier Melina , Shirley Corin , Stafford Shelby , Hitzke Sydney , Byju Achu , Kevorkian Chris , Madigan Michael , Philen Michael
Published: December 2014

Persons with transfemoral and transtibial protheses experience changes in the volume of their residual limb during the course of the day. These changes in volume unavoidably lead to changes in quality of fit of the prosthesis, skin irritations, and soft tissue injuries. The associated pain and discomfort can become debilitating by reducing one’s ability to perform daily activities. While significant advancements have been made in prostheses, the undesirable pain and discomfort that occurs due to the volume change is still a major challenge that needs to be solved. The goal of this program is to develop smart prosthetic sockets that can accommodate for volume fluctuations in the residual limb. In this research, fluidic flexible matrix composite wafers (f2mc) are integrated into the prosthetic socket for volume regulation. The f2mc’s are flexible tubular elements embedded in a flexible matrix. These tubular elements are connected to a reservoir, and contain an internal fluid such as air or water. Fluid flow between the tubes and reservoir is controlled by valves. The f2mc’s can achieve more than 300% increase in volume and potentially several orders of magnitude of change in stiffness. Experimental results for a prosthetic socket demonstrate that the flexible matrix composite wafers can achieve changes in volume when pressurized.
Phenomenological Models of Solid State Actuators for Network Based System Modelling
Authors: Ziske Johannes , Ehle Fabian , Neubert Holger
Published: December 2014

Smart materials, such as thermal or magnetic shape memory alloys, provide interesting characteristics for new solid state actuators. However, their behavior is highly nonlinear and determined by strong hysteresis effects. This complex behavior must be adequately considered in simulation models which can be applied for efficient actuator design and optimization. We present a new phenomenological lumped element model for magnetic shape memory alloys (MSM). The model takes into account the two-dimensional hysteresis of the magnetic field induced strain as a function of both the compressive stress and the magnetic flux density. It is implemented in Modelica. The model bases on measured limiting hysteresis surfaces which are material specific. An extended Tellinen hysteresis modeling approach is used to calculate inner hysteresis trajectories in between the limiting surfaces. The developed model provides sufficient accuracy with low computational effort compared to finite element models. Thus, it is well suited for system design and optimization based on network models. This is demonstrated with exemplary models of MSM based actuators. System models and simulation results are shown and evaluated for different topologies.
Behavioral and Network Modeling for Efficient Design of Adaptive Systems
Authors: Schneider Peter , Köhler Andreas , Reitz Sven , Jancke Roland
Published: December 2014

Adaptive systems usually implement the entire cycle of measurement and data acquisition, signal conditioning and processing as well as process control. Especially, for the design of adaptive signal processing and control algorithms detailed insight into the interaction between the system components is of crucial importance. System level simulations are a suitable way to gain insight and to support algorithm design and test. However, an adequate mathematical representation of the system behavior is needed to take advantage of this method. In the paper a generic methodology for behavioral modelling is introduced. Important steps of the modelling process are described and illustrated by two examples. For a gyro sensor system the combination of different modeling methods is demonstrated. Network modeling and in particular an approach for the construction of network models for magnetic systems is discussed for an electromagnetic switching device.
Flexible Multiwall Carbon Nano-Tubes/Conductive Polymer Composite Electrode for Supercapacitor Applications
Authors: Lee Ka Yeung Terence , Naguib Hani , Lian Keryn
Published: December 2014

The present paper investigates three types of electrically conductive polymers (ECPs), namely polyaniline, polypyrrole and poly(3,4-ethylenedioxythiophene) PEDOT composite with multi-walled carbon nanotubes (CNTs) for supercapacitor applications. Their capacitive performance has been evaluated in both three electrodes half-cell and two electrodes cell setup. The nanocomposite were fabricated by polymerizing pseudocapacitive conductive polymer onto the MWCNT surface through the in-situ chemical polymerization approach. The composites were aimed to be optimized through varying the ECPs to MWCNT ratios. Half-cell electrochemical study was conducted to determine the optimal proportion of MWCNT and ECP in this parametric study. Two electrodes cell electrochemical study unveiled the potential device’s energy storage performance. MWCNT was found to act as the framework for the polymerization of the ECP into a tubular structure. Among the three composites, Ppy/MWCNT composite showed superior supercapacitor characteristics at scan rates of up to 500mV/s.
Piezoelectric MEMS Energy Harvesters
Authors: Yeo Hong Goo , Yeager Charles , Ma Xiaokun , Ramirez J. Israel , Sun Kaige G. , Rahn Christopher , Jackson Thomas N. , Trolier-McKinstry Susan
Published: December 2014

The development of self-powered wireless microelectromechanical (MEMS) sensors hinges on the ability to harvest adequate energy from the environment. When solar energy is not available, mechanical energy from ambient vibrations, which are typically low frequency, is of particular interest. Here, higher power levels were approached by better coupling mechanical energy into the harvester, using improved piezoelectric layers, and efficiently extracting energy through the use of low voltage rectifiers. Most of the available research on piezoelectric energy harvesters reports Pb(Zr,Ti)O3 (PZT) or AlN thin films on Si substrates, which are well-utilized for microfabrication. However, to be highly reliable under large vibrations and impacts, flexible passive layers such as metal foil with high fracture strength would be more desirable than brittle Si substrates for MEMS energy harvesting. In addition, metallic substrates readily enable tuning the resonant frequency down by adding proof masses. In order to extract the maximum power from such a device, a high level of (001) film orientation enables an increase in the energy harvesting figures of merit due to the coupling of strong piezoelectricity and low dielectric permittivity.

Strongly {001} oriented PZT could be deposited by chemical solution deposition or RF magnetron sputtering and ex situ annealing on (100) oriented LaNiO3 / HfO2 / Ni foils. The comparatively high thermal expansion coefficient of the Ni facilitates development of a strong out-of-plane polarization. 31 mode cantilever beam energy harvesters were fabricated using strongly {001} textured 1∼3 μm thick PZT films on Ni foils with dielectric permittivity of ∼ 350 and low loss tangent (<2%) at 100 Hz. The resonance frequency of the cantilevers (50∼75 Hz) was tuned by changing the beam size and proof mass. A cantilever beam with 3 μm thickness of PZT film and 0.4 g proof mass exhibited a maximum output power of 64.5 μW under 1 g acceleration vibration with a 100 kΩ load resistance after poling at 50 V (EC ∼ 16 V) for 10 min at room temperature. Under 0.3g acceleration, the average power of the device is 9 μW at a resonance frequency of ∼70 Hz. Excellent agreement between the measured and modeled data was obtained using a linear analytical model for an energy harvesting system, using an Euler-Bernoulli beam model. It was also demonstrated that up to an order of magnitude more power could be harvested by more efficiently utilizing the available strain using a parabolic mode shape for the vibrating structure. Additionally, voltage rectifying electronics in the form of ZnO thin film transistors are deposited directly on the cantilever. This relieves the role of voltage rectification from the interfacing circuitry and provides a technique improved harvesting relative to solid state diode rectification because the turn-on bias can be reduced to zero.
Muscle-Like Characteristics With an Engineered Metastructure
Authors: Wu Z. , Harne R. L. , Wang K. W.
Published: December 2014

Combining adaptable supporting structure, large compliance, and intricate energy management, skeletal muscle is a natural system that exhibits numerous attractive characteristics. Recent mechanical modeling of muscle suggests some of the intriguing macroscale features are due to the assembly of nanoscale, metastable cross-bridge constituents. Inspired by the multifunctionality and versatility of muscle’s architectural composition, this research investigates a new paradigm of modular structure-material development to achieve significant system adaptivity by utilizing building blocks possessing metastability. The proposed, assembled systems belong to the class of metastructures, a new concept for engineering adaptive structures from basic, functional units in ways such that the systems exhibit unprecedented characteristics resulting from a synergy of their elements. A modular and metastable building block is created to emulate the effective passive functionality of muscle’s cross-bridge. Analytical and experimental results reveal that metastructures assembled from the metastable modules may supply unique changes in reaction force when the end displacement is prescribed, adapting not only the magnitude of force but also the direction, in addition to yielding a multitude of globally stable topologies. The investigations provide clear evidence that a metastructure may realize orders of magnitude change in stiffness for a constant system shape, and also enables the variation in required energy expense to globally deform the system. From these findings, the metastructural design framework represents a major leap forward in adaptive structures and material systems and has the potential to find broad future application.
Asymmetrical degradation behaviors in amorphous InGaZnO thin-film transistors under various gate and drain bias stresses
Authors: Lee Daeun , Jeong Chan-Yong , Song Sang-Hun , Xiao-Shi Jin , Kim Jong In , Lee Jong-Ho , Kwon Hyuck-In
Published: December 2014

The asymmetrical degradation behaviors of amorphous indium–gallium–zinc oxide thin-film transistors are studied comprehensively under various gate and drain bias stresses. The transfer curve moves to the negative direction after bias stresses are applied, and different types of asymmetrical degradation are observed depending upon the magnitude of the applied gate and drain bias stresses. After the application of gate-to-source (VGS) and drain-to-source (VDS) bias stresses of (VGS = 16 V, VDS = 16 V) and (VGS = 22 V, VDS = 10 V), the forward mode transfer curve exhibits a more negative shift compared to that of the reverse mode, whereas opposite results are observed under the stress condition of (VGS = 10 V, VDS = 25 V). From the two-dimensional simulation results and the separately extracted subgap density of states in the source and drain sides of the thin film transistors before and after the application of various bias stresses, the local high electric field-induced nonuniform generation rate of the subgap states near the conduction band edge is considered to be the dominant mechanism causing the asymmetrical degradation of the devices under various gate and drain bias stresses. The generation of the subgap states is observed at different locations depending upon the magnitude of the applied gate and drain bias stresses.
Point Two USA: Marketing an Innovation in Equestrian Safety
Authors: Dyer Robert F. , Irizarry Rolando P.
Published: December 2014

Safety is a growing concern in all sports, with the equestrian sector statistically more dangerous than most. Point Two USA hopes to make horse riding and competition a safer sport for all ages, riding levels, and disciplines with its innovative air vests, which use an inflatable air bag similar to those required in modern automobiles. Air vests are used to reduce the severity and frequency of injuries; however, no technology or equipment can eliminate all injuries associated with horse riding. After a strong entry in the United Kingdom in 2009, Point Two needs to formulate a comprehensive marketing plan for the larger U.S. market to expand its customer base to anyone getting on a horse who desires a safer ride. Its U.S. subsidiary has been primarily marketing with the same approaches used in the United Kingdom, heavily targeting English saddle riders in specific riding disciplines, such as eventing and dressage, both amateur and professional. The challenge for Point Two is how it can make headway in more mainstream riding markets, including recreation or pleasure riders, novice riders, and those who ride using Western saddles, which is very popular in the United States.
Complete Genome Sequence of Bovine Papillomavirus Genotype 13 from Local Yellow Cattle in Hainan Province, China
Authors: Pang Feng , Shi Qiaoyun , Du Li , Zhao Tianjing , Cheng Ying , Jiao Hanwei , Zhao Jianguo , Wang Manchuriga , Rong Hui , Zhou Hailong , Wang Fengyang
Published: December 2014

Here, we present the complete genome sequence of bovine papillomavirus genotype 13 isolated from local yellow cattle in Hainan, China. The genome is 7,961 bp and contains six early genes and two late genes. This analysis provides important information for the research of bovine papillomavirus (BPV) in China.
Full-Length Genome Sequence of a Variant Porcine Epidemic Diarrhea Virus Strain, CH/GDZQ/2014, Responsible for a Severe Outbreak of Diarrhea in Piglets in Guangdong, China, 2014
Authors: Song Deping , Chen Yanjun , Peng Qi , Huang Dongyan , Zhang Tiansheng , Huang Tao , Zhang Fanfan , Zhou Xinrong , Tang Yuxin
Published: December 2014

The full-length genome sequence of a variant porcine epidemic diarrhea virus (PEDV) strain, CH/GDZQ/2014, was determined. The isolate was a variant strain with a relatively far relationship with the PEDV strains previously identified in the same area between 2011 and 2012 and was genetically distinct from the CV777-based vaccine strain currently being used in China.
Draft Genome Sequence of Streptomyces fradiae ATCC 19609, a Strain Highly Sensitive to Antibiotics
Authors: Bekker Olga B. , Klimina Ksenia M. , Vatlin Aleksey A. , Zakharevich Natalia V. , Kasianov Artem S. , Danilenko Valery N.
Published: December 2014

We report here a sequence of the genome of the
Streptomyces fradiae
ATCC 19609 strain, initially isolated from the soil, which produces tylosin.
S. fradiae
is highly sensitive to different classes of antibiotics, compared to the sensitivities of other bacteria. We have identified 9 groups of genes directly or indirectly involved in the resistome formation.
Draft Genome Sequence of an Aniline-Degrading Bacterium,
Burkholderia
sp. K24
Authors: Lee Sang-Yeop , Yun Sung Ho , Choi Chi-Won , Lee Dong-Gi , Choi Jong Soon , Kahng Hyung-Yeel , Kim Seung Il
Published: December 2014

Burkholderia
sp. K24 is an aniline-degrading soil bacterium that utilizes aniline and its analogues as sole carbon and nitrogen sources. Here, we report the draft genome sequence of this strain that consists of 8,344,181 bp, with a G+C content of 61.7%.
Molecular Characterization of Genome Sequences of Beak and Feather Disease Virus from the Australian Twenty-Eight Parrot (
Barnardius zonarius semitorquatus
)
Authors: Sarker Subir , Das Shubhagata , Ghorashi Seyed A. , Forwood Jade K. , Raidal Shane R.
Published: December 2014

Three complete genomes of beak and feather disease virus (BFDV) were recovered from wild twenty-eight parrots (
Polytelis anthopeplus monarchoides
). The genomes consisted of 1,996 bp with 1,934 identical sites and a typically content stem-loop structure between ORF1 and ORF2. This is the first report of BFDV infection as well as the complete genome sequences for this host species globally.
Draft Genome Sequence of Anoxybacillus flavithermus Strain 25, Isolated from the Garga Hot Spring in the Barguzin Valley, Baikal Region, Russian Federation
Authors: Rozanov Aleksey S. , Bryanskaya Alla V. , Kotenko Anastasia V. , Malup Tatiana K. , Peltek Sergey E.
Published: December 2014

Anoxybacillus flavithermus
strain 25 was isolated from a sediment sample from the Garga hot spring in the Barguzin Valley, Baikal Region, Russian Federation (54°19′3.72″N, 110°59′38.4″E). The sequenced and annotated genome is 2,838,680 bp and encodes 3,009 genes.
Draft Genome Sequence of the Anti-Algal Marine Actinomycete
Streptomyces
sp. JS01
Authors: Zhang Huajun , Zhang Su , Peng Yun , Li Yi , Chen Zhangran , Zheng Wei , Xu Hong , Yu Zhiming , Zheng Tianling
Published: December 2014

Streptomyces
sp. JS01 is the producer of an anti-algal compound that shows inhibitory activity against a harmful algal species
Phaeocystis globosa
and can also produce a red pigment. Its genome sequence will allow for the characterization of the anti-algal compound and the molecular mechanisms underlying its beneficial properties.
Draft Genome Sequence of the Versatile Alkane-Degrading Bacterium
Aquabacterium
sp. Strain NJ1
Authors: Masuda Hisako , Shiwa Yuh , Yoshikawa Hirofumi , Zylstra Gerben J.
Published: December 2014

The draft genome sequence of a soil bacterium,
Aquabacterium
sp. strain NJ1, capable of utilizing both liquid and solid alkanes, was deciphered. This is the first report of an
Aquabacterium
genome sequence.
Effect of Acupuncture at Ht7 on Heart Rate Variability: An Exploratory Study
Authors: Huang Huanlin , Zhong Zheng , Chen Junqi , Huang Yong , Luo Jixuan , Wu Junxian , Liao Hanbo , Zhen Erchuan , Lin Renyong , Fasmer Ole Bernt , Wik Gustav
Published: December 2014

Objective

To explore the effect of acupuncture at HT7 on heart rate variability (HRV) in healthy volunteers.

Methods

120 subjects were divided into four groups using a random number table. The following groups of acupuncture interventions were used: HT7 verum acupuncture; HT7 non-penetrating sham acupuncture; acupuncture at a sham point; and no acupuncture. HRV was recorded 10 min before, during and after each stimulation using an Actiheart ECG recorder.

Results

The HT7 verum acupuncture group had higher very-low frequency, low frequency and high frequency components of HRV compared with the control groups during but not after acupuncture. The HT7 verum acupuncture group also had higher SD of normal intervals compared with the sham needling and no acupuncture control groups.

Conclusions

Our preliminary study suggests, subject to limitations, that acupuncture at HT7 could affect cardiac autonomic neural regulation in healthy subjects, manifest as increased HRV, most likely via the parasympathetic system.

Trial Registration Number

ChiCTR-TRC-08000302.
Image-guided scapulothoracic arthroscopy for removing firearm projectiles
Authors: Ejnisman Benno , Andreoli Carlos Vicente , Carvalho Cassiano Diniz , Pochini Alberto De Castro
Published: December 2014

Scapulothoracic arthroscopy is gaining recognition among arthroscopic procedures as it is considered a relatively low morbidity procedure; also, continuing studies of this technique are making it safer. Scapulothoracic arthroscopy can be used for removal of a foreign body. This case report describes the removal of a firearm projectile using image-guided arthroscopy, highlighting the anatomical aspects and characteristics of the surgical technique. In this case, the patient recovered uneventfully, with complete remission of symptoms in 30 days, returning to his usual activities within 2 months after surgery.
Occipital calcified pseudoneoplasms of the neuraxis (CAPNON): understanding a rare pathology
Authors: Lyapichev Kirill , Bregy Amade , Shah Ashish H , Shah Kinjal , Desai Mehul B , Petito Carol , Komotar Ricardo J
Published: December 2014

Calcifying pseudoneoplasms of the neuraxis (CAPNON) are rare and typically benign lesions that can occur anywhere within the central nervous system. Aetiology of this lesion is unclear and surgical removal is usually curative. We present a 24-year-old male patient with a history of occipital migraines who was admitted after sudden onset seizure and loss of vision. CT and MRI demonstrated a small calcifying lesion in the right temporo-occipital lobe. The patient underwent gross total resection of the tumour mass and pathological analysis revealed a CAPNON. The preoperative diagnosis of CAPNON remains difficult due to unspecific radiological findings, yet a clear understanding of characteristic pathological findings and prognosis of CAPNON remains paramount.
Successful treatment of central retinal artery thromboembolism with ocular massage and intravenous acetazolamide
Authors: Duxbury Oliver , Bhogal Pervinder , Cloud Geoffrey , Madigan Jeremy
Published: December 2014

A 67-year-old woman presented with left-sided headache and blurred vision, worse during hypertensive episodes. CT angiography showed a 4 mm left internal carotid artery (ICA) aneurysm incorporating the ophthalmic artery. She passed a test balloon occlusion, so the aneurysm was coil occluded, without immediate complication. Four days postprocedure she experienced sudden loss of vision in the left eye and funduscopy showed central retinal artery occlusion secondary to emboli from the coiled aneurysm. She was treated promptly with intravenous acetazolamide and ocular massage and regained full visual acuity. Thromboembolism to the eye during or after neurointerventional treatment is a relatively rare but devastating complication. This report demonstrates the effectiveness of combined intravenous acetazolamide and ocular massage in dealing with this complication when delivered promptly.