bluuebunny/crossref_metadata_2025 huggingface dataset:
Introduction to the Special Issue: Globalisation, Knowledge and Institutional Change: Towards an Evolutionary Perspective to Economic Development
Authors: Morrison Andrea , Cusmano Lucia
Published: March 2015

This special issue aims at advancing the debate about the interpretative power of evolutionary perspectives on economic development and institutional change. In the introduction, we argue that the interpretative power of the current evolutionary approach can be improved by elaborating an ‘augmented’ perspective to economic development, which explicitly integrates the role of institutions and the dynamics of natural resource sectors (e.g. agro‐food) into the analysis. We maintain that such a theoretical and empirical advancement can help to define a conceptual framework that is more suitable to analyse innovation‐driven change, differentiated development patterns, opportunities and constraints for developing countries in the globalised knowledge economy. A collection of papers that adopt this perspective are discussed in order to prove the interpretative power of this approach in a variety of development contexts.
An analysis of first‐time blood donors return behaviour using regression models
Authors: Kheiri S. , Alibeigi Z.
Published: March 2015

Background and Objectives

Blood products have a vital role in saving many patients' lives. The aim of this study was to analyse blood donor return behaviour.

Materials and Methods

Using a cross‐sectional follow‐up design of 5‐year duration, 864 first‐time donors who had donated blood were selected using a systematic sampling. The behaviours of donors via three response variables, return to donation, frequency of return to donation and the time interval between donations, were analysed based on logistic regression, negative binomial regression and Cox's shared frailty model for recurrent events respectively.

Results

Successful return to donation rated at 49·1% and the deferral rate was 13·3%. There was a significant reverse relationship between the frequency of return to donation and the time interval between donations. Sex, body weight and job had an effect on return to donation; weight and frequency of donation during the first year had a direct effect on the total frequency of donations. Age, weight and job had a significant effect on the time intervals between donations.

Conclusion

Aging decreases the chances of return to donation and increases the time interval between donations. Body weight affects the three response variables, i.e. the higher the weight, the more the chances of return to donation and the shorter the time interval between donations. There is a positive correlation between the frequency of donations in the first year and the total number of return to donations. Also, the shorter the time interval between donations is, the higher the frequency of donations.
The CO2 concentrating mechanism and photosynthetic carbon assimilation in limiting CO2: how Chlamydomonas works against the gradient
Authors: Wang Yingjun , Stessman Dan J. , Spalding Martin H.
Published: March 2015

The CO2 concentrating mechanism (CCM) represents an effective strategy for carbon acquisition that enables microalgae to survive and proliferate when the CO2 concentration limits photosynthesis. The CCM improves photosynthetic performance by raising the CO2 concentration at the site of ribulose‐1,5‐bisphosphate carboxylase/oxygenase (Rubisco), simultaneously enhancing carbon fixation and suppressing photorespiration. Active inorganic carbon (Ci) uptake, Rubisco sequestration and interconversion between different Ci species catalyzed by carbonic anhydrases (CAs) are key components in the CCM, and an array of molecular regulatory elements is present to facilitate the sensing of CO2 availability, to regulate the expression of the CCM and to coordinate interplay between photosynthetic carbon metabolism and other metabolic processes in response to limiting CO2 conditions. This review intends to integrate our current understanding of the eukaryotic algal CCM and its interaction with carbon assimilation, based largely on Chlamydomonas as a model, and to illustrate how Chlamydomonas acclimates to limiting CO2 conditions and how its CCM is regulated.
Field evaluation of allelopathic plant extracts alongside herbicides on weed management indices and weed–crop regression analysis in maize
Authors: Ihsan Muhammad Zahid , Khaliq Abdul , Mahmood Azhar , Naeem Muhammad , El‐Nakhlawy Fathy , Alghabari Fahad
Published: March 2015

Synthetic herbicides are posing problems owing to the development of weed resistance and emerging debate on their associated health hazards and ecological threats. Allelopathic manipulations are evolving as applicable substitutes for weed management in agroecosystems. In order to assess the efficacy of potential allelopathic water extracts from different plant species, field experiments were conducted during 2010 and 2011. Sorghum bicolor L., Helianthus annuus L., Brassica napus L., Oryza sativa L., Zea mays L. and Morus alba L. aqueous extracts in different combinations alone or along with a reduced dose of herbicide were evaluated for weed suppression in a maize crop. A weedy check and two herbicidal treatments, S‐metolachlor + atrazine (pre‐emergence) and atrazine alone (early postemergence), were included for comparison. Sorghum, brassica or sunflower tank‐mixed with 25% of the recommended dose of atrazine significantly suppressed the total weed density and dry biomass, along with a concomitant decrease in the crop resistance indices and treatment efficacy indices over the control. The weed density and dry biomass that were recorded at 60 days after sowing showed a strong negative correlation, while the leaf area index, crop growth rate, dry matter accumulation and net assimilation rate predicted a strong positive correlation, with the stover and grain yield of maize.
Na+ channel function, regulation, structure, trafficking and sequestration
Authors: Chen‐Izu Ye , Shaw Robin M. , Pitt Geoffrey S. , Yarov‐Yarovoy Vladimir , Sack Jon T. , Abriel Hugues , Aldrich Richard W. , Belardinelli Luiz , Cannell Mark B. , Catterall William A. , Chazin Walter J. , Chiamvimonvat Nipavan , Deschenes Isabelle , Grandi Eleonora , Hund Thomas J. , Izu Leighton T. , Maier Lars S. , Maltsev Victor A. , Marionneau Celine , Mohler Peter J. , Rajamani Sridharan , Rasmusson Randall L. , Sobie Eric A. , Clancy Colleen E. , Bers Donald M.
Published: March 2015

This paper is the second of a series of three reviews published in this issue resulting from the University of California Davis Cardiovascular Symposium 2014: Systems approach to understanding cardiac excitation–contraction coupling and arrhythmias: Na+ channel and Na+ transport. The goal of the symposium was to bring together experts in the field to discuss points of consensus and controversy on the topic of sodium in the heart. The present review focuses on Na+ channel function and regulation, Na+ channel structure and function, and Na+ channel trafficking, sequestration and complexing.
A Robust Controller of Multi DOF-Cooperating Planar Robotic Manipulators Using a Tuned PID Approach
Authors: Al-Ani Dhafar , Afshari Hamed H. , Habibi Saeid
Published: March 2015

Usually, a dynamic system with impact conditions is an interesting problem with practical applications in the fields of dynamics, vibrations, and control. One difficulty in controlling robotics (i.e., a multi DOF two-cooperating or two-link planar) is the subject to impact between the end-effectors of manipulators is that the dynamics (i.e., equations of motion) are different when the system status changes suddenly from a non-contact state to a contact state. In this paper, a Tuned PID controller with different design scenarios is developed to regulate the states of two dynamic systems that collide. Further, in this work, three types of errors are used to compare among different cases that are; (1) the steady state error, (2) the root mean square error, and (3) the final value error. The results of the Tuned PID controller are compared to those obtained by a classical PID controller. The PID controller is tuned using the Ziegler–Nicholas approach. The simulation results of the robotic manipulators confirmed the theoretical effectiveness of the proposed controller, based on MATLAB/Simulink. Unlike the classical PID results (i.e., the impact-induced force is found to be 2.0 N), the Tuned PID controller successfully determined the impact-induced force as same as the desired force (i.e., 0.6 N). Moreover, the Tuned PID satisfied all other desired design values.
Design the High-Speed Micro-Motion Controller for Peck Drilling With the LuGre Friction Model
Authors: Huang Cong-Sheng , Yeh Syh-Shiuh , Hsu Pau-Lo
Published: March 2015

Micro-motion control on the peak drilling, particularly in 3C industry processing, is difficult for the spindle to precisely follow the high-frequency commands, mainly because the repetitive motion distance is very small and it passes through zero velocity frequently to cause serious problems of friction. Experimental results indicate that the axis is nearly unmoved by applying traditional controllers in practice. By applying the static friction compensation constructed under constant-speed operations, results indicate that it is suitable only when the motion command is slowly-varying in a low frequency range. In this paper, the LuGre model is adopted and a systematic approach is proposed to obtain corresponding modeling coefficients. Results indicate that by applying the controller with the LuGre model, the bandwidth of the velocity loop is greatly improved from 394Hz to 663.7Hz, and the position loop is greatly improved from 9.5 Hz to 113.8 Hz. The LuGre model has also been realized on a DYNA 1007 CNC machine to prove its feasibility. Moreover, the tracking error of its peck drilling is improved 67.5% in RMS and the maximum peak error improvement is 72.0%.
A Novel Ball End Magnetorheological Finishing Process
Authors: Singh Anant Kumar , Jha Sunil , Pandey Pulak M.
Published: March 2015

A novel ball end magnetorheological finishing process was developed for performing stable and controllable finishing operation on flat as well as 3D free form features of magnetic or non-magnetic materials. The main innovation in this process was generating a magnetic flux density at the end of a cylindrical tool that facilitates the shaping of the magnetorheological polishing fluid in a fashion to resemble like a ball nose cutter. A 4-axis motion controller program directs the resembled polishing fluid to follow the surface to be finished. This paper focuses on the various stages of the development of a novel finishing process. This leads to significant improvement in process performance in terms of smooth controllable functionality, percentage reduction in surface roughness, surface textures at microscopic level of the workpiece surfaces. In the initial stage of development, the magnetorheological cylindrical finishing tool was made to rotate as a whole during the finishing operation with all its constituent components like inner core, magnetic coil and outer core. In this stage, there was no provision of cooling magnetic coil because magnetic coil was rotated with the rotation of the finishing tool during finishing operation. Therefore, it was difficult to incorporate any cooling arrangement over the outer surface of magnetic coil to cool it continuously. Hence, the tool was limited to shorter time of finishing operation due to continuous heating of magnetic coil. Also, some other additional limitations were noticed such as constraint on magnetic coil to produce higher magnetic field, noise and vibration during the finishing operation. These limitations resulted in low effectiveness of finishing operation. To overcome these specific limitations which were observed after initial development of finishing setup, the limitations were overcome by redesigning of cylindrical finishing tool with stationary magnetic coil (integrated with cooling coils) and only central core was allowed to rotate during operation without the outer core. This resulted in smooth rotational motion of the tool without much noise and vibration during finishing operation. The experiments were performed on flat magnetic material workpiece using the modified magnetorheological cylindrical finishing tool. The surface finish obtained was 23.7 nm from the initial surface roughness of 126.1 nm in 30 min with continuous cooling of magnetic coil.
Dynamic Modeling of a Transient Engine Test Cell for Cold Engine Testing Applications
Authors: Souflas I. , Pezouvanis A. , Mason B. , Ebrahimi K. M.
Published: March 2015

The increasing complexity in the development and manufacturing process of internal combustion engines leads to a higher demand for more effective testing and monitoring methods. Cold engine testing becomes progressively the main End-of-Line test which is used nowadays from automotive engine manufacturers with the purpose of determining the integrity of engine assembly. The present work is focused on the development of a detailed physics-based, lumped-parameter, dynamic model of a single cylinder internal combustion engine coupled with an alternating current transient dynamometer for cold engine testing applications. The overall transient engine test cell model is described based on a two-inertia system model consisting of the engine, the dynamometer and the coupling shaft. The internal combustion engine is modelled based on First Law of Thermodynamics and Second Newton’s Law for rotational bodies. The transient dynamometer is actually an alternating current three-phase induction motor which is modelled according to direct-quadrature axis approach, and its drive unit which is responsible for controlling the speed of the motor using indirect field orientation scheme. The engine and dynamometer are connected through a coupling shaft which is modelled as a compliant member with damping. The model is validated against experimental measurements such as engine cylinder pressure, engine excitation torque and alternating currents of the induction motor. All of the experimental measurements were recorded from an identical single cylinder transient engine test cell using a highly advanced instrumentation system. The described model serves as an ideal platform for developing innovative model-based fault detection and diagnosis techniques for cold engine testing applications. In conclusion, this is presented successfully for two simulated fault cases, a process fault and a sensor fault, proving the functionality and usefulness of the model.
A Study on Mechanical Behavior of Dental Hard Tissues and Dental Restorative Materials by Three-Point Bending Test
Authors: Chun K. J. , Kim C. Y. , Lee J. Y.
Published: March 2015

Dental restorative materials including amalgam, dental ceramic, gold alloy, dental resin, zirconia, and titanium alloy are used to reconstruct damaged teeth, as well as to recover their function. In this study, the mechanical properties of various dental restorative materials were determined using test specimens of identical shape and dimension under the same three-point bending test condition, and the test results were compared to enamel and dentin. The maximum bending force of enamel and dentin was 6.9 ± 2.1 N and 39.7 ± 8.3 N, and the maximum bending deflection was 0.12 ± 0.02 mm and 0.25 ± 0.03 mm, respectively. The maximum bending force of amalgam, dental ceramic, gold alloy, dental resin, zirconia, and titanium alloy were 1.9 ± 0.4 N, 2.7 ± 0.6 N, 66.9 ± 4.1 N, 2.7 ± 0.3 N, 19.0 ± 2.0 N, and 121.3 ± 6.8 N, respectively, and the maximum bending deflection was 0.20 ± 0.08 mm, 0.28 ± 0.07 mm, 2.53 ± 0.12 mm, 0.37 ± 0.05 mm, 0.39 ± 0.05 m, and 2.80 ± 0.08 mm, respectively. The dental restorative materials that possessed greater maximum bending force than that of enamel were gold alloy, zirconia, and titanium alloy. Gold alloy and titanium alloy had greater maximum bending force than dentin. The dental restorative materials that possessed greater maximum bending deflection than that of enamel were all of the dental restorative materials, and the dental restorative materials that possessed greater maximum bending deflection than that of dentin were all of the dental restorative materials except amalgam. The appropriate dental restorative materials for enamel are gold alloy and zirconia and for dentin is gold alloy concerning the maximum bending force and the maximum bending deflection. These results are expected to aid dentists in their choice of better clinical treatment and to contribute to the development of dental restorative materials that possess properties that are most similar to the mechanical properties of dental hard tissue.
Synthesis of Path Generation Compliant Mechanisms Using Variable Width Spline Curves
Authors: Zhou Hong , Ahmed Nisar
Published: March 2015

Path generation is to guide a point tracing a prescribed path. Compliant mechanisms (CMs) have been synthesized for path generation mechanisms. In this paper, each connection in a synthesized CM is represented as a variable width spline curve and the entire synthesized CM is modeled as a set of variable width spline curves. The synthesis of a path generation CM is systemized as the optimization of control parameters of a set of variable width spline curves. A variable width spline curve is a center spline curve with variable perpendicular width. The center spline curve is for the shape description of its represented connection while variable width is for the size of the connection. The shape and size of a variable width spline curve is defined by its interpolation circles. The locations of interpolation circles are utilized as interpolation nodes of the center spline curve for connection shape and the diameters of interpolations circles are interpolated for connection size. The centers of all interpolation circles in a synthesized CM form a network of nodes. The network of nodes decides the topology of the synthesized CM and can be classified based on degree of genus (DOG). The presented synthesis approach is demonstrated by synthesizing CMs with different DOGs to generate curved paths.
Application of Microforming to Create Chondrocyte Home Sites in a Natural Cartilage Matrix
Authors: Vandenberg Theodore W. , Nehme Christopher R. , James Thomas P.
Published: March 2015

Articular cartilage degeneration is a central pathological feature of osteoarthritis. Cartilage in the adult does not regenerate in vivo and, as a result, cartilage damage in osteoarthritis is irreversible. With our ever-aging population, osteoarthritis has become a leading cause of disability and unfortunately, no optimal treatments for osteoarthritis are currently available. To address this problem, a research community is focused on the development of both natural and synthetic biodegradable tissue scaffolds. The scaffolds must contain depressions or holes for the purpose of chondrocyte seeding and growth in order to create an implantable construct. In addition to chondrocytes, cartilage tissue consists of the extracellular matrix (ECM). Studies of many tissue types have established that ECM plays an important role in regulating cell behavior and controlling processes such as tissue differentiation and tumor progression. Unlike most natural tissues, adult cartilage ECM is exceptionally dense and lacking in vascularity, which makes it difficult for chondrocytes to be transplanted directly into the matrix. Current methods of creating cell home sites through chemical decellularization of the ECM degrade the mechanical integrity of the cartilage tissue. The research conducted here used a mechanical, rather than chemical, method to create cell home sites. A novel micropunching machine was developed to fabricate 200 μm diameter holes in cartilage, thereby creating a porous natural scaffold while maintaining a healthy ECM. Equine articular cartilage slices were harvested from the cadaver’s back knee joint and cryo-sectioned into 100 μm thick slices. Using die clearances of 3.7%, 6.8%, and 8.9%, the results indicate that micro-scale holes can be mechanically punched in cartilage tissue. The maximum punching force showed a slight trend of decreasing as die clearance increased, but there was no statistical significance. Punching force, as well as hole size, was highly dependent on sample hydration. Upon inspection, the resulting hole sizes were approximately 50 μm to 150 um, indicating 25% to 75% shrinkage in reference to the male punch diameter. Finally, the resulting hole shape was observed to be slightly non-circular and the edges of the hole exhibited a raggedness, which was indicative of the cartilage tearing during hole punching.
Mechanical Properties of Glass Fiber Reinforced Polyoxymethylene Composites by Direct Fiber Feeding Injection Molding
Authors: Mathurosemontri Suchalinee , Uawongsuwan Putinun , Ichikawa Hiroaki , Inoya Hiroyuki , Hamada Hiroyuki
Published: March 2015

In this study, the short glass fiber reinforced polyoxymethylene composites were fabricated by direct fiber feeding injection molding (DFFIM). The processing parameters such as number of fiber, matrix feeding speed and screw rotational speed are study the effect on fiber content, fiber length and mechanical properties. Fiber orientation and fiber distribution are observed by scanning electron microscope. The maximum and minimum fiber content are 34.1 and 11.5 wt.%, respectively. The increasing of number of fiber and screw rotational speed and the decreasing of matrix feeding speed lead to the increasing of fiber content. Tensile modulus increase when fiber content increase. However, tensile strength do not increase when fiber content is over 23.3 wt.% due to poor orientation and distribution of glass fiber.
Design of a Reconfiguration Mechanism for an Electric Stair-Climbing Wheelchair
Authors: Quaglia Giuseppe , Franco Walter , Nisi Matteo
Published: March 2015

In this paper is described a new solution for a stair-climbing wheelchair: a device that allows disabled people to autonomously overcome architectural barriers. The paper presents the evolution of a project introduced in previous works. The aim is to obtain a wheelchair able to move both in structured and unstructured environments and overcome single steps or an entire staircase.

The innovative aspect of this work is the introduction of a hybrid solution, with a locomotion system based on wheels and an idle track for the vehicle stability.

The locomotion group permits to overcome obstacles through an original architecture based on an epicycloidal transmission. The control logic manages the motors that drive independently the two degrees of freedom of the transmission and allows to switch from an advancing mode to a climbing one.

The wheelchair must be able to move in different environments, such as flat ground or stairs, which require different specifications, sometimes in contrast. For this reason the main part of the work regards the design of a reconfiguration mechanism able to prepare the wheelchair for different working conditions.

First of all the relative positions between the elements that compose the wheelchair structure in different configuration are studied in order to optimize the performances especially in terms of regularity.

Then several possible solutions for the reconfiguration mechanism are presented and qualitatively evaluated, in order to choose the one that satisfy the design specifications.
Estimation of Anchor Points for Fully-Constrained and Redundant Planar Cable Robots
Authors: Gungor Gokhan , Torres-Mendez Sergio J. , Fidan Baris , Khajepour Amir
Published: March 2015

Cable-based robots generally perform better than other parallel robots with rigid links in terms of wider workspace and higher acceleration of end effector because of lightweight of robot links. Cable based robots allow an easy mounting and remounting for outside applications; however, this requires a precise assembly of components at the cable anchor points. In this study, firstly a parametric model is developed for estimation of position errors of anchor points for fully-constrained and redundant planar cable robots. A novel method based on inclusion of virtual cables facilitates the linear separation of the uncertain parameters from the input-output signals for redundant planar robots. In addition, the adaptive law (parameter estimator) updates the estimated parameters using the least squares algorithm. The simulation results show that the least squares method reduces the time of estimation convergence compared to gradient algorithms. Furthermore, the least squares method allows simple persistent excitation signals to estimate parameters.
Electrochemical Model Based Fault Diagnosis of Li-Ion Battery Using Fuzzy Logic
Authors: Muddappa Vinay K. S. , Anwar Sohel
Published: March 2015

There is a strong urge for advanced diagnosis method, especially in high power battery packs and high energy density cell design applications, such as electric vehicle (EV) and hybrid electric vehicle segment, due to safety concerns. Accurate and robust diagnosis methods are required in order to optimize battery charge utilization and improve EV range. Battery faults cause significant model parameter variation affecting battery internal states and output. This work is focused on developing diagnosis method to reliably detect various faults inside lithiumion cell using electrochemical model based observer and fuzzy logic algorithm, which is implementable in real-time. The internal states and outputs from battery plant model were compared against those from the electrochemical model based observer to generate the residuals. These residuals and states were further used in a fuzzy logic based residual evaluation algorithm in order to detect the battery faults. Simulation results show that the proposed methodology is able to detect various fault types including overcharge, over-discharge and aged battery quickly and reliably, thus providing an effective and accurate way of diagnosing Li-Ion battery faults.
Modeling Cell Deformation in CTC Microfluidic Filters
Authors: Zhang Zhifeng , Xu Jie , Chen Xiaolin
Published: March 2015

Circulating tumor cells (CTCs) are metastatic cancer cells in the circulatory system. Researchers have recently realized that CTCs can serve as excellent biomarkers for early cancer detection, which can greatly increase the chances for successful follow up treatment. Among CTC detection methods, a new method called CTC-chip is promising to make future early cancer diagnosis a routine inspection. Using size effect and cell deformability, deformation-based CTC filter is reported to be an inexpensive and effective solution. Cancer cell deformation mechanism is believed to be important in CTC-chip design. Most existing CTC-chips use Young-Laplace model to describe cell deformation. However, the deformation behavior of cancer cell under high velocities is observed to be very different from the static Young-Laplace model according to our present research. In this study, we characterize the detailed cell deformation process when they are passing through CTC microfluidic channels using volume of fluids (VOF) model simulation. Our study provides valuable information for future high throughput CTC chip design.
Machining Quality and Tool Wear While Drilling 3D Woven Carbon/Epoxy Composites Using Core Drills With Diamond Grains
Authors: Cadorin Nicolas , Zitoune Redouane , Seitier Philippe
Published: March 2015

Advanced carbon fiber reinforced polymers (CFRP) are extensively used in aerospace, automotive and civil applications. Optimization of drilling parameters of these materials is an issue of great economical importance. This paper presents an experimental investigation of drilling of a 3D woven carbon/epoxy with diamond coated core drills and its wear mechanisms. Based on full factorial experimental design, the machinability range was identified. The influence of the machining parameters on the thrust forces and the machining quality was also investigated. The results show that the generated damage on the wall of the hole is uniformly distributed and is not affected by the fiber orientation. Analysis of wear mechanisms has indicated that grain removal and grain smoothing were the main mechanisms of wear of core drills with electro deposited diamond grains. These mechanisms of wear were investigated using tool mass and optical images. It was found that the manufacturing quality of the core drills has an important role on its efficiency. Core drills (electro deposited diamond grains) offer excellent wear resistance compared to twist drills during drilling of CFRP.
Design and Optimization of Multi-Modal Vibration Energy Harvesters Using Slitted Beams
Authors: Dawoud Mina , Hegazi Hesham , Arafa Mustafa
Published: March 2015

The objective of this work is to design cantilever beams possessing close vibration modes to enable harvesting energy from variable frequency sources of base motion. In this context, the geometry of two-dimensional cantilever beams is designed to obtain closely spaced harvestable modes of vibration. A number of internal slits are made inside the beam, whose outer contour and mass distribution are altered in such a way to obtain the desired frequency spacing. The beam carries two permanent magnets that oscillate past stationary pickup coils in order to convert the mechanical motion into electric power. Optimum design results of the shape and geometrical parameters of the system are presented towards controlling the natural frequencies, their spacing and the output power. Simulations of the system dynamics are supported by experimental validation.
Analytical Models to Determine the Electric Field Characteristics of a Multi-Electrode Impedimetric Immunosensor in a Digital Microfluidic Device
Authors: Blume Steffen O. P. , Schertzer Michael J. , Ben Mrad Ridha , Sullivan Pierre E.
Published: March 2015

The level of integration of digital microfluidics is continually increasing to include the system path from fluid manipulation and transport, on to reagent preparation, and finally reaction detection. Digital microfluidics therefore has the capability to encompass all steps of common biochemical protocols. Reported here is a set of analytical models for the design of a coplanar interdigitated multi-electrode array to be used as an impedimetric immunosensor in a digital microfluidic device for on-chip chemical reaction detection. The models are based on conformal mapping techniques, and are compared to results obtained from finite element analysis to discuss limitations of the model. The analytical models are feasible and inexpensive surrogates for numerical simulation methods.
Five Bar Planar Manipulator Simulation and Analysis by Bond Graph
Authors: Jian Shengqi , Yin Cheng , Rolland Luc , James Lesley
Published: March 2015

This work focuses on the bond graph modelling method and its application on multi-body system, especially on the five-bar parallel robot. Five-bar parallel robot is comprised of four arms, two revolute actuators and five revolute joints. This paper adopts five-bar parallel robot in symmetric configuration as simulation object. As it will be used as a pickup and placing machine, its workspace is fixed on Cartesian coordinate. The relationship between the two rotating angles and end effector’s desire position is built by inverse kinematics. Bond graph is used to describe moment, torque, velocity, angle relationships. In this project, the dynamic performances between arms, motors at robot basement and end effector will be researched. In this paper, an investigation about how to use bond graph to model DC (direct current) servo motor and an integrated motion control system is carried out. During a typical end effector point-point displacement, the torque change between arms is plotted. Finally, 3-D animation experiment is conducted. Experiment results show that bond graph can simulate robot dynamics performance without having to make a large number of equations. It is able to simulate and solve five-bar kinematics problem in the process.
Active Vibration Control of a Composite Sandwich Plate
Authors: Ferrari Giovanni , Capriotti Margherita , Amabili Marco , Garziera Rinaldo
Published: March 2015

The active vibration control of a rectangular sandwich plate by Positive Position Feedback is experimentally investigated. The thin walled structure, consisting of carbon-epoxy outer skins and a Nomex paper honeycomb core, has completely free boundary conditions. A detailed linear and nonlinear characterization of the vibrations of the plate was previously performed by our research group [1, 2]. Four couples of unidirectional Macro Fiber Composite (MFC) piezoelectric patches are used as strain sensors and actuators. The positioning of the patches is led by a finite element modal analysis, in the perspective of a modal control strategy aimed at the lowest four natural frequencies of the structure. Numerical and experimental verifications estimate the resulting influence of the control hardware on the modal characteristics of the plate. Experimental values are also extracted for the control authority of the piezoelectric patches in the chosen configuration. Single Input – Single Output (SISO) and MultiSISO Positive Position Feedback algorithms are tested and the transfer function parameters of the controller are tuned according to the previously known values of modal damping. A totally experimental procedure to determine the participation matrices, necessary for the Multiple-Input and Multiple-Output configuration, is developed. The resulting algorithm proves successful in selectively reducing the vibration amplitude of the first four vibration modes in the case of a broadband disturbance. PPF is therefore used profitably on laminated composite plates in conjunction with strain transducers, for the control of the low frequency range up to 100 Hz. The relevant tuning procedure moreover, proves straightforward, despite the relatively high number of transducers. The rigid body motions which arise in case of free boundary conditions do not affect the operation of the active control.
A Torsion Based Shear Mode Piezoelectric Energy Harvester for Wireless Sensor Modules
Authors: Kulkarni V. , Ben-Mrad R. , Prasad S. Eswar
Published: March 2015

Energy harvesting devices are growing in popularity for their ability to capture the ambient energy surrounding a system and convert it into usable electrical energy. With an increasing demand for portable electronics and wireless sensors in a number of sectors, energy harvesting has the potential to create self-powered sensor systems operating in inaccessible locations. This paper discusses a torsion based piezoelectric energy harvester that utilizes superior shear mode piezoelectric properties to harvest energy from vibrations. Mathematical expressions are used to determine optimized geometry configurations for the harvester. Using these expressions, a harvester design is presented for use with wireless sensor networks.
Frequency Analysis of a Trailing Vortex Flow Subjected to External Turbulence
Authors: Ahmadi-Baloutaki Mojtaba , Carriveau Rupp , Ting David S-K.
Published: March 2015

The frequency response of a trailing vortex downstream the free end of a NACA0015 wing section has been studied in a closed loop wind tunnel. The wing spanning approximately half height of the wind tunnel section was fixed to a dynamic load cell at the base. The flow cases studied have constant angle of attack of 10 degrees and constant Reynolds number of 160,000 based on the wing chord length while two levels of 0.5 and 4.6% free-stream turbulence were introduced to the flow. Lift and drag forces acting on the wing section were quantified using a load cell while an X-probe hot-wire was used to measure the turbulence parameters in the near-field wake region. The tip vortex was captured with sufficient accuracy. The effect of free-stream turbulence on the vortex structure has been discussed in detail by characterizing several turbulence parameters via time-averaging and frequency analysis of the turbulence signal.
Revision Technique of Curved Textile Machine Parts by Expert
Authors: Chottikampon Kontawat , Mathurosemontri Suchalinee , Sirisuwan Porakoch , Yang Yuqiu , Kuwahara Noriaki , Hamada Hiroyuki
Published: March 2015

In this research, a needle bar was studied to approach the techniques and manufactures of this product by learning via the expert. Although the fixed of the pins on the brass bar is the only one step to make a needle bar, the fixed method is so complicate. It requires the fineness and high skill from manufacturer. The soldering process was used for fixed pins and brass bar together. However, the effect of heat transfer from soldering process on brass bar revealed the curve of specimen. The hitting technique was used to modify the curve. This technique is very useful. The curved of needle bar was improved and became too straight.
Effects of Mechanical Vibration on Multilayering of Cultured Osteoblasts
Authors: Shiraishi Toshihiko , Ishii Akinori , Morishita Shin
Published: March 2015

This paper describes the mechanism of cell proliferation promotion by mechanical vibration focusing on multilayering of cultured osteoblasts. After osteoblasts were cultured under the mechanical vibration of 0.5 G and 12.5 Hz, the saturated cell density reached approximately twice as high as control. In the vibration group, multilayer formation of osteoblasts was observed by fluorescent microscopy in contrast with almost single layer in the control group. Fluorescent staining demonstrated that the expression of N-cadherin, which plays an important role of cell-cell adhesion, was lower under mechanical vibration than control. Therefore, the application of mechanical vibration to osteoblasts can downregulate the expression of N-cadherin, resulting in weakening of cell-cell adhesion and multilayer formation followed by promotion of cell proliferation.
Vibration Control of a Cantilever Beam by Metal-Core Flexoelectric and Piezoelectric Fibers
Authors: Zhang X. F. , Li H. , Tzou H. S.
Published: March 2015

Flexoelectric effect occurs in the solid crystalline dielectrics of symmetry or centro-symmetric crystals, which shows the electromechanical coupling of the polarization response and the strain gradient or the stress and the electric field gradient. Thus, a generic stress expression induced by the converse flexoelectric effect is established first in this study. The generic stress expression is simplified to a cantilever beam to evaluate the vibration control effect due to the converse flexoelectric effect. Flexoelectric fiber embedded with a metal core is placed into the cantilever beam to generate inhomogeneous electric field. When the flexoelectric fiber is actuated with the applied voltage, stress induced by the actuator is obtained with the electric field gradient, which results in a control bending moment to the beam. Static displacement control of the cantilever beam is established and the control effect is related to the fiber location and size of the flexoelectric fiber and the metal core. Cases show that the control effect is enhanced when the flexoelectric fiber is far away from the neural surface of the beam. Besides, the control effect can enhance with thinner fiber thickness. Since the piezoelectricity is similar to the flexoelectricity, comparison of the vibration control induced by the piezoelectric fiber is also discussed. The results show that the control effect of the flexoelectric fiber is more effective than the piezoelectric fiber in the cantilever beam.
Comparison of Ball Bearing Model Performance With and Without Centrifugal and Gyroscopic Forces
Authors: Kurvinen Emil , Sopanen Jussi , Mikkola Aki
Published: March 2015

Bearing performance significantly affects the dynamic behaviors and estimated working life of a rotating system. A common bearing type is the ball bearing, which has been under investigation in numerous published studies. The complexity of the ball bearing models described in the literature varies as models with or without the inclusion of centrifugal forces or the gyroscopic moments of the rolling elements are equally proposed. Naturally, model complexity is related to computational burden. In particular, the inclusion of centrifugal forces and gyroscopic moments significantly increases the system degrees of freedom and lengthens solution time. On the other hand, for low or moderate rotating speeds, these effects can be neglected without significant loss of accuracy.

The objective of this paper is to present guidelines for the appropriate selection of a suitable bearing model for a case study. To this end, two ball bearing models were implemented. One considers high-speed forces, and the other neglects them. Both models were used to study a single structure, and the simulation results were compared. The bearing behavior is studied at different shaft rotation speeds and the simulation results are used to determine when the model containing the centrifugal and gyroscopic forces should be used.
Analysis of the Influence of Fretting on the Fatigue Life of Interference Fitted Joints
Authors: Croccolo D. , De Agostinis M. , Fini S. , Morri A. , Olmi G.
Published: March 2015

The present paper deals with the fatigue behaviour of shaft hub interference fitted joints. The investigation is carried out by means of a down-scaled ad-hoc specimen, which has been developed by the authors in order to perform accelerated fatigue tests. The specimen is similar to those suggested by standard ISO 1143, but it consists of two parts, joined together by shrink fitting. In a previous work, the authors compared the performances of a plain specimen manufactured according to ISO 1143 and those of the shrink fitted specimen. Both the plain and the shrink fitted specimens were made of C40 EN 10083 low carbon steel. The outcome of that research was that shrink fitting determines a degradation of the fatigue response of the assembly, with respect to those of the plain specimen. Moreover, such decrease cannot be predicted by means of FEA alone, since it is partly due to fretting phenomena. In fact, fretting takes place on the mating surface between the shaft and the hub, and especially in the vicinity of the end of the contact. The present paper deals with the observation of failed and survived specimens by means of optical and SEM microscopes, in order to determine the actual tribological characteristics of the contact surface. For instance, the amplitude of the sliding zone observed experimentally is compared with that given by FEA for different choices of the contact formulation. Since fretting is often associated with the presence of secondary fatigue cracks, which do not propagate, the authors set up an experimental method for locating the secondary cracks prior to sectioning the specimen for microscope observation.
Control of Autonomous Robots Using Principles of Neuromodulation in ROS Environment
Authors: Muhammad Cameron , Samanta Biswanath
Published: March 2015

Decision making of a vertebrate in response to the sensory signals from the environment is regulated by the neuromodulatory systems in its brain. A vertebrate’s behaviors like focusing attention, cautious risk-aversion and curiosity-seeking exploration are influenced by these neuromodulators. The paper presents an autonomous robotic control approach based on vertebrate neuromodulation and its implementation on multiple open-source hardware platforms. A simple neural network is used to model the neuromodulatory functions for generating context based behavioral responses to sensory signals. The neural network incorporates three types of neurons — attention focusing cholinergic and noradrenergic (ACh/NE), curiosity-seeking dopaminergic (DA), and risk aversive serotonergic (5-HT) neurons. The implementation of the neuronal model on multiple relatively simple autonomous robots is illustrated through the interesting behavior of the robots adapting to changes in the environment. The implementation is done in open-source, open-access robotics software framework of Robot Operating System (ROS).
Effect of Heel to Toe Walking on Time Optimal Walking of a Biped During Single Support Phase
Authors: Farizeh Tara , Sadigh Mohammad Jafar
Published: March 2015

Dynamic modeling of a biped has gained lots of attention during past few decades. While stability and energy consumption were among the first issues which were considered by researchers, nowadays achieving maximum speed and improving pattern of motion to reach that speed are the important targets in this field. Walking model of bipeds usually includes two phases, single support phase (SSP), in which only the stance foot is in contact with the ground while the opposite leg is swinging; and double support phase (DSP) in which the swing leg is in contact with the ground in addition to the rear foot. It is common in the simplified model of walking to assume the stance leg foot, flat during the entire SSP; but one may know that for human walking, there is also a sub-phase during SSP in which the heel of stance foot leaves the ground while the whole body is supported by toe link. Actually in this sub phase the stance leg foot rotates around the toe joint. This paper is trying to study the effect of toe-link and heel to toe walking model on dynamic and specially speed of walking compare to flat foot model.
ROM of Electrostatically Actuated MEMS Resonators Under Simultaneous Resonances
Authors: Caruntu Dumitru I. , Reyes Christian
Published: March 2015

This paper deals with MEMS resonator sensors under double electrostatic actuation. The system consists of a MEMS cantilever between two parallel fixed plates. The frequencies of actuation are near natural frequency and near half natural frequency. The frequency response of the simultaneous resonance of the structure is investigated using Reduced Order Model (ROM) method.
Voltage Response of MEMS Resonators Under Simultaneous Resonances
Authors: Caruntu Dumitru I. , Reyes Christian
Published: March 2015

This paper deals with MEMS resonator sensors under double electrostatic actuation. The system consists of a MEMS cantilever between two parallel fixed plates. The frequencies of actuation are AC near natural frequency, and AC half natural frequency. The voltage response of the structure is investigated, and parameter influences reported.
Determination of Slung Load Divergence Speed Using Airload Measurement and Simulation
Authors: Liberi Brandon , Kelley William , Pirau Sorin , Raghav Vrishank , Komerath Narayanan
Published: March 2015

The speed at which a slung load can be carried under an aircraft is often limited by the onset of divergent oscillations. Simulations using highly-resolved airloads maps are described, in an effort to determine divergence speed. Airloads are obtained using the Continuous Rotation technique, which converts the discrete-attitude static airload measurements problem to a periodic problem amenable to closed-form analytical description. Free-swing tests of scaled models are performed in a wind tunnel with and without initial perturbations, to capture quantitative and qualitative records from encoders and from video, also capturing the likely modes that amplify. Results are presented for a cuboid and a porous box, the latter with and without one side closed. The roll divergence mechanism, the coupling of roll and yaw frequency, seen in swing tests is clearly observed in simulations run on the cuboid, both when yaw is forced and when the model is free.