bluuebunny/crossref_metadata_2025 huggingface dataset:
Axial Force Reduction in Friction Stir Welding of AA6061-T6 at Right Angle
Authors: Imani Yousef , Guillot Michel
Published: March 2015

Invented in 1991, friction stir welding (FSW) is a new solid state joining technique. This process has many advantages over fusion welding techniques including absence of filler material, shielding gas, fumes and intensive light, solid state joining, better microstructure, better strength and fatigue life, and etc. The difficulty with FSW is in the high forces involved especially in axial direction which requires use of robust fixturing and very stiff FSW machines. Reduction of FSW force would simplify implementation of the process on less stiff CNC machines and industrial robots. In this paper axial welding force reduction is investigated by use of tool design and welding parameters in FSW of 3.07 mm thick AA6061-T6 sheets at right angle. Attempt is made to reduce the required axial force while having acceptable ultimate tensile strength (UTS). It is found that shoulder working diameter and shoulder angle are the most important parameters in the axial force determination yet pin angle has minor effect. According to the developed artificial neural network (ANN) model, proper selection of shoulder diameter and angle can lead to approximately 40% force reduction with acceptable UTS. Regions of tool design and welding parameters are found which result in reduced axial force along with acceptable UTS.
Biomechanics of Trunk During Walking Carrying Load on One Hand Using Nonlinear Methods
Authors: Yadav Vikas , Gudavalli Maruti Ram , Raju P. K. , Marghitu Dan
Published: March 2015

Activities of daily living include carrying objects using one hand. Carrying a load using one hand can alter the loading on the musculoskeletal system as well as the walking pattern. The objective of this pilot study was to quantify the ground reaction forces, electromyographic (EMG) activity of trunk muscles, and trunk motion during walking. Nine human volunteers with no symptoms of pain were recruited from the student and employee population of an academic institution. Data were recorded from 8 volunteer subjects. Participants were asked to walk at self-selected speed back and forth at their comfortable speed carrying loads varying from 0 to 25 pounds on right hand on a wooden walking platform for 30 steps/cycles. Motion data were recorded from T1, L1, L3, and S1 vertebrae at a sampling frequency of 120 Hz. Range of Motion (ROM), Correlation Dimension (CoD), and Approximate Entropy (ApEn) was computed using custom written MatLab programs. EMG data were recorded from six muscle groups bilaterally (right and left): Erector Spinae, Multifidus, Latissimus Dorsi, Internal Obliques, External Obliques and Rectus Abdominis at a frequency of 1200 Hz. Root mean square EMG values, Mean and Median Frequency of the EMG data were calculated to observe the effect of increasing load on muscle fatigue using custom developed MatLab program. Ground reaction force (GRF) data were collected using a force plate and the associated 1st peak force (Fz1), 2nd Peak force (Fz3) and minimum force (Fz2) between the two peak forces were calculated during gait cycle. The ROM values had a range from 2.6–3.2 deg. for Lumbar lateral bending (LB), 6.7–8.7 deg. for Thoracic LB. Approximate Entropy (ApEn) values ranged from 0.20–0.40 for Lumbar LB motion and 0.30–0.50 for Thoracic LB motion. Correlation Dimension (CoD) values ranged from 1.20–1.40 for lumbar LB and 1.20–1.30 for Thoracic LB. Normalized GRF increased during walking with increased load. Significance difference (P<0.05) were found for vGRF with increase in load. Motion and EMG data did not reveal any significant differences.
Error Reduction and Performance Improvement of Palpation for Human Soft Tissues Based on 3D Indentation System
Authors: Li Zhimeng , Sakuma Atsushi
Published: March 2015

In recent years, breast cancer has been a terror killer for women because of the high incidence rate. More and more researchers began to study breast cancer and made an effort to search an effective method for diagnosing breast cancer accurately. The stage achievement was reported by Li et al for AFM indentation study of breast cancer cells [1], which provided a famous method about measuring the elastic modulus to detect breast cancer. In addition, there are some common methods for the diagnosis of breast cancer, such as finger palpation, echo and mammography. However, due to the inaccuracy and pain, these methods have defects very obviously. Furthermore, it is said that palpation is most important method to reduce the mortality of the cancer in early diagnosis. However, the practical realization of the mechanical palpation system is desired since the palpation by human contains inaccuracy. Especially, three-dimensional evaluation is useful for precise diagnosis which can evaluate human body. Sakuma et al. firstly recommended Young’s modulus measurement using equivalent indentation strain in spherical indentation testing for soft flat material [2], which is also applied to evaluate the human skin successfully [3]. In this paper, three-dimensional palpation method for human body tissue based on Hertzian contact theory is proposed at first, and error reduction procedure of the method is also discussed for the improvement of identification ability of it.
Design of Bioabsorbable Polymeric Humeral Fracture Fixation Device
Authors: Hazlett Lauren , Becker Gabriella , Calvis Allyn , Verzi Mary , Paliwal Manish
Published: March 2015

Approximately 55,500 proximal humeral fractures require surgical fixation annually. The current standard for internal humeral fracture fixation involves implantation of rigid metallic devices to prevent dislocation of bone fragments. However, these devices have high stiffness characteristics which can cause stress shielding in bone. A second method of fixation, called biological fixation, decreases stiffness which reduces stress shielding by utilizing more flexible devices. This approach tends leads to increased incidences of delayed healing and nonunion of fracture fragments. Therefore, this device design implements two bioabsorbable polymers in two distinct layers that degrade at different rates. The purpose of this design is to provide rigid fixation during the initial fracture healing phase followed by a period of biological fixation, allowing for functional healing along with a reduction in stress shielding over time compared to current devices. The bioabsorbable property permits the device to remain in situ, thus eliminating the need for removal surgery and reducing the risk of surgical site infection. Using finite element analysis, the design has been demonstrated to exhibit varying axial, torsional, and flexural stiffness over time. The final device was fabricated by injection molding, and tested for flexural stiffness. In addition, the polymers were tested for stiffness at specific time intervals over the course of the degradation period. All stiffness tests were performed under simple three point loads. A Nikon 3200 camera (Nikon Inc., Melville, NY) was used to sequentially image the material samples and plate throughout each load application. The flexural stiffness of the device was determined by utilizing Digital Image Correlation analysis in Matlab (MathWorks, Inc.) to analyze surface displacements between image frames. The success of the device was determined by comparing the observed difference in stiffness to standard stiffness values for humeral fixation devices currently available on the market. A substantial decrease in stiffness combines the benefits of rigid and biological fixation devices as well as eliminates the complications associated with each, providing an improved solution for proximal humeral fractures.
Wavelet Transform for Human Gait With an Asymmetric Load
Authors: Berceanu Cosmin , Marghitu Dan , Gudavalli Maruti Ram , Raju P. K. , Yadav Vikas
Published: March 2015

The objective of this research is to evaluate the trunk kinematic data of asymptomatic human volunteers using the discrete wavelet transform. Five human volunteers with mean age of 29.6 (SD=7.4), height (m) 1.73 (SD=6.4), and weight (kg) 69.3 (SD=6.6) were recruited from the student and employee population of an academic institution. Participants were asked to walk back and forth at their comfortable speed carrying loads on one hand, on the right hand side of 0, 5, 10, 15, 20 and 25 pounds on a wooden walking platform for a maximum of 30 steps (cycles). Participants walked with self-selected speed. Motion data were recorded from T1, L1, L3, and S1 vertebrae at a frequency of 120 Hz. Three trials of data have been recorded for each participant. Using wavelet decomposition technique (five levels, Daubechies’s wavelet functions) we observed that the energy components corresponding to the levels 2, 3, 4 and 5 changed with respect of load. Comparing the no load (0 lbs) with maximum load (25 lbs), the energy of the lumbar signal decreased with 44.71% for level 2, 50.13% for level 3, 48.45 % for level 4 and 41.33 % for level 5 in average for all subjects.
Development of an Abdominal Aortic Aneurysm Ruptures Mechanism Using a Geometric Analytical Technique
Authors: Embong A. H. , Al-Jumaily A. M. , Mahadevan G. , Lowe A. , Sugita S.
Published: March 2015

Current ultrasound approaches practice probe for diagnosing instantaneous abdominal aortic aneurysms (AAA) based on arterial tissue deformation. However, tracking the progression of potential aneurysms, and predicting the risk of rupture is based on the diameter of the aneurysm and is still an insufficient method: Larger diameter aneurysms do not always lead to ruptures, and smaller diameter aneurysms unexpectedly rupture. In order to improve diagnostic accuracy of ultrasound imaging techniques, this paper presents geometric analyses of patient-specific instant deformations as a means to develop an aneurysm rupture mechanism. Segmented AAA images were used to analyze dependent elements that contribute to a three-dimensional (3-D) aneurysm reconstructive model using proposed Patient-Specific Aneurysm Rupture Predictor (P-SARP) method. The outcomes indicate that the proposed technique has the ability to associate the distortion of wall deformation with geometric analyses. This method can positively be integrated with established ultrasound techniques for improvements in the accuracy of future diagnoses of potential AAA ruptures.
Modeling and Position Control of a Magnetic Levitation System Calculating Eddy Current Based Damping Force
Authors: Nojoumian M. A. , Khodabakhsh M. , Vossoughi G. R.
Published: March 2015

In this paper a magnetic levitation system is modeled and an eddy current based damping force is identified and used for position control of the levitated object in the system. In the magnetic levitation technology, contactless manipulation of a levitated object is done by use of magnetic fields. Also, the eddy-current based force is used to damp the motion of the levitated object. Eddy-current is generated in a plate which is placed underneath the levitated object due to the change of current in an electromagnet and the motion of the levitated object.

First, using finite element method (FEM), the magnetic levitation system is modeled and the eddy-current based force acting on the levitated object is obtained. The thickness of the plate and the magnetic dipole moment of the levitated object are optimized so that the maximum value of the eddy current based force is gained. The effect of the eddy-current based force on the 2-D motion of the levitated object is studied. Also a controller using the damping effect of the eddy force is designed to control the position of the levitated object in one particular dimension. Results show that the controller can effectively regulate the position of the levitated object.
Modeling and Analysis of Flexible Multistage Rotor Systems With Water-Lubricated Rubber Bearings
Authors: Liu Shibing , Yang Bingen
Published: March 2015

Flexible multistage rotating systems that are supported by water-lubricated rubber bearings (WLRB) have many engineering applications, including power generation, mining, water services, waste treatment, oil and gas industries, and industrial processes. Due to the flexibility of rotating shafts in these applications, dynamic modeling and vibration analysis is essentially important to optimal design and reliable operation of this kind of rotor systems.

This paper presents a new model of WLRBs, with the focus on determination of bearing dynamic coefficients. Conventional bearing models are normally of pointwise type, and are invalid for WLRBs that have a large length-to-diameter ratio. The bearing model proposed in this work considers spatially distributed bearing forces, and for the first time, addresses the issue of mixed lubrication, which involves interaction effects of shaft vibration, elastic deformation of rubber material and fluid film pressure. With the bearing model, the dynamic response of a flexible multistage rotating system with WLRBs is described by a Distributed Transfer Function Method (DTFM). The steady-state response of the rotor system due to unbalanced mass is then computed by the DTFM, and compared with experimental data, yielding the dynamic stiffness coefficients of WLRBs. It is shown that the proposed bearing model and DTFM formulation is useful in vibration analysis and optimal design of WLRB-supported flexible multistage rotor systems.
4D Mitral Valve Motion Analysis Using Multi-Plane Cine Cardiac MRI Reconstructions for Functional Classification of Patients With Mitral Regurgitation
Authors: Rao Abhiram , Menon Prahlad G.
Published: March 2015

Mitral regurgitation (MR) is a common consequence of ventricular remodeling in heart failure (HF) patients with systolic dysfunction and is associated with diminished survival rates. Characterization of patient-specific anatomy and function of the regurgitant mitral valve (MV) can enhance surgical decision making in terms of medical device choice and deployment strategy for minimally invasive endovascular approaches for MV repair. As a first step toward pre-operative planning for MV repair, we examine the feasibility of using cardiac magnetic resonance (CMR) images acquired in multiple orientations to resolve leaflet function and timing. In this study, MV motion of a HF patient with ischemic heart disease exhibiting both adverse ventricular remodeling and MR was compared pre-operatively against a normal control from the Sunnybrook cardiac database, starting with manually segmented 2D MV contours from cine CMR images acquired in multiple orientations. We find that MV motion analysis from CMR imaging is feasible and anatomical reconstruction using oriented segmentations from a combination of imaging slices acquired in multiple orientations can help overcome inherent limitations of CMR image data in terms of resolving small anatomical features, owing to finite slice-thicknesses and partial volume effects.
Amplitudes Decay in the Nonlinear Oscillators of Mixed Linear and Cubic Stiffness Components
Authors: Al-Shudeifat Mohammad A. , Burton Thomas D.
Published: March 2015

New formulas for obtaining the accurate amplitudes decay of the energy, velocity and displacement in the Duffing oscillator of odd-power stiffness components are derived here. The derivation is based on the new transformation proposed recently in the literature. These new formulas are found to be highly accurate in locating the decay envelopes of the energy, velocity and displacement regardless of the system physical parameters and the initial condition. In addition, the formulas are also found to be applicable to the damped double-well Duffing oscillator as long as the oscillation simultaneously occurs between the two stable equilibrium positions.
Effect of Combined Motion on Force Transmission of a Flexible Instrument
Authors: Khatait J. P. , Brouwer D. M. , Aarts R. G. K. M. , Herder J. L.
Published: March 2015

The force transmission of a flexible instrument through an endoscope is deteriorated due to friction between the contacting surfaces. Friction force along the axial direction can be reduced by combining the translation motion input with rotational motion input at the proximal end of the instrument. The effect of the combined motion on the force transmission is studied for a flexible instrument through a curved rigid tube. A mathematical formula is derived for the reduction in friction force along the axial direction due to the combined motion input. The force transmission of a flexible instrument through a curved rigid tube is analysed using the capstan equation. The ratio of the input and output forces is compared for the combined motion with that of the translation motion only. A ratio ζ is defined to measure the reduction in the friction force along the axial direction due to the combined motion input. The analytical result shows the reduction in the friction force for the combined motion input. A flexible multibody model is set up and various simulations are performed with different motion inputs. The simulation result showed a reduction in the value of ζ in accordance with the analytical result for the given velocity ratio. The results are further validated with the experimental results. The simulation and experimental results show an agreement with the analytical solutions. The knowledge of force transmission with a combination of motions can be used to increase the force fidelity of a flexible instrument in applications like robotic surgery with a flexible instrument.
Lumped Thermal Model of a Newborn Lamb and a Liquid Ventilator in Total Liquid Ventilation
Authors: Nadeau Mathieu , Micheau Philippe , Robert Raymond , Vandamme Jonathan , Mousseau Julien , Tissier Renaud , Avoine Olivier , Germim Pamela Samanta , Sage Michaël , Praud Jean-Paul , Walti Hervé
Published: March 2015

Total liquid ventilation (TLV) is an emerging and promising mechanical ventilation method in which the lungs are filled with a breathable liquid. Perfluorocarbon (PFC) is the predominant liquid of choice due to its high O2 and CO2 solubility. In TLV, a dedicated liquid ventilator ensures gas exchange by renewing a tidal volume of PFC, which is temperature-controlled, oxygenated and free of CO2. A fundamental difference between TLV and conventional mechanical ventilation relates to the fact that PFCs are approximately 1500 times denser than air. This high density provides PFCs with a large heat capacity, turning the lungs into an efficient heat exchanger with circulating blood. The originality of this study is the development of a lumped thermal model of the body as a heat exchanger coupled to a liquid ventilator. The model was validated with an animal experimentation on a newborn lamb with the Inolivent-5.0 liquid ventilator prototype. TLV was initiated with a fast hypothermia induction, followed successively by a slow posthypothermic rewarming, a fast rewarming and finally a second fast hypothermia induction. Results demonstrate that the model was able to aptly predict, in every phase, the temperature of the lungs, the eardrum, the rectum as well as the various compartments of the liquid ventilator.
The Development of a Dynamic Adaptive Driving Simulator
Authors: Tudor Sarah M. , Carey Stephanie L. , Dubey Rajiv V.
Published: March 2015

The ability to drive a car is an important skill for individuals with a spinal cord injury to maintain a high quality of life, particularly their freedom and independence. However, driving with a physical disability often requires the installation of an adaptive driving system to control steering, gas, and braking. The two main types of adaptive driving controls are mechanical and electrical, also known as drive by wire (DBW). DBW controls work by converting electric signals to mechanical actuators. Driving simulators are useful tools for adaptive driving systems because they allow users to test different control devices, to practice driving without the dangers of being on the road, and can be used as a safe way to evaluate disabled drivers. This study focused on the development of a dynamic driving simulator using DBW controls because most studies focus on mechanical controls and not DBW controls and often use static simulators.

The simulator was developed using the Computer Assisted Rehabilitation Environment (CAREN) virtual reality system. The CAREN system (Motek Medical, Amsterdam, Netherlands) includes a six degree of freedom motion base, an optical motion capture system, a sound system, and a 180-degree projection screen. The two DBW controls, a lever device to control the gas and brake and a small wheel device to control steering, sent an electric signal to a Phidget board, which interfaced with the CAREN system. Several different driving scenarios were created and imported into CAREN’s D-Flow software. A program was developed in D-Flow to control the scene and motion of the platform appropriately based on the DBW controls via the Phidget. The CAREN system dynamically controlled the motion platform based on the user’s input. For example, if the user applied the brake suddenly, the user felt a deceleration from the motion platform moving backwards. The driving simulator showed the capability to provide dynamic feedback and, therefore, may be more realistic and beneficial than current static adaptive driving simulators. The dynamic adaptive driving simulator developed may improve driving training and performance of persons with spinal cord injuries. Future work will include testing the system with and without the dynamics from the moving platform to see how this type of feedback affects the user’s driving ability in the virtual environment.
Hand Grasping Assistance Device
Authors: Garcia Alejandra P. , Andrews Ryan P. , Johnson Logen M. , Santacroce Joseph F. , McCusker James , Dow Douglas E.
Published: March 2015

Stroke can result in Hemiparesis, often resulting in the disuse of impaired limbs and the increased use of the unimpaired limbs. Disuse leads to muscle atrophy, contracture and stiffening of the joints, which impedes daily living and quality of life. Physical therapy can maintain or increase motor function following stroke, but the impaired limb may still have less motor function than the unimpaired limb, leading to further disuse. Thus negating the gains accomplished by therapy. The development of devices that assist motor function of the impaired limbs during daily activities would promote use and help maintain any progress from physical therapy. Automated motion assistance can overcome spasticity by allowing a user to perform a specific task multiple times, thus reducing the stiffness developed in the fingers.

The purpose of this study was to develop prototype modules of a glove-like system for hand grasping assistance. The full system could be used during therapy sessions or worn to assist with activities of daily living. The force sensors positioned in the glove on the front and back of each fingertip would be used to determine whether an attempt is being made to grasp or to let go of an object. The system controls motors that wind or unwind cables that run along the forearm and connect independently to the glove for each finger. The modules were designed and assembled for testing. A simulation model was built for analysis. The early results appear promising, but further testing will be required to make developments toward the full system to assist with hand motor function.
Validation Data and Model Development for Nuclear Fuel Assembly Response to Seismic Loading
Authors: Weichselbaum Noah A. , Abkenar Morteza , Vanella Marcos , Manzari Majid T. , Balaras Elias , Bardet Philippe M.
Published: March 2015

A joint experimental and numerical campaign is conducted to provide validation datasets for high-fidelity fluid-structure interaction models of nuclear fuel assemblies during seismic loading. A refractive index matched flow loop is operated on a six-degree-of-freedom shake table and instrumented with non-intrusive optical diagnostics. The test section can house up to three full height fuel assemblies. To guarantee reproducible and controlled initial conditions, special care is given to the test section inlet plenum; in particular it is designed to minimize secondary pulsatile flow that may arise due to ground acceleration. A single transparent surrogate 6×6 fuel subassembly is used near prototypical Reynolds number, Re = 105 based on hydraulic diameter. To preserve dynamic similarity of the model with prototype, the main dimensionless parameters are matched and custom spacer grids are designed. Special instruments are developed to characterize fluid and structure response and to operate in this challenging shaking environment. In parallel to the above experiments we also conducted fully coupled large-eddy simulations, where the equations for the fluid and the structure are simultaneously advanced in time using a partitioned scheme. To deal with the highly complex geometrical configuration, which also involves large displacements and deformations we utilize a second order accurate, immersed boundary formulation, where the geometry is immersed in a block-structured grid with adaptive mesh refinement. To explore a wide parametric range we will consider several subsets of the experimental configuration. A typical computation involves 60K cores, on leadership high performance computing facilities (i.e. IBM Blue-Gene Q – MIRA).
Investigation of Upper Cervical Spine Injury due to Frontal and Rear Impact Loading Using Finite Element Analysis
Authors: Mustafy Tanvir , Moglo Kodjo , Adeeb Samer , El-Rich Marwan
Published: March 2015

Predicting neck response and injury resulting from motor vehicle crashes is essential for improving occupant protection, effective prevention, and in the evaluation and treatment of spinal injuries. Injury mechanism of upper cervical spine due to frontal/rear-end impacts was studied using Finite Element (FE) analyses. A FE model of ligamentous (devoid of muscles) occipito-C3 cervical spine was developed. Time and rate-dependent material laws were used for assessing bone and ligament failure. Frontal and rear-end impact loads at two rates of 5G and 10G accelerations were applied to analyze the model response in terms of stress distribution, intradiscal pressure change, and contact pressure in facet joints. Failure occurrence and initiation instants were investigated. Frontal and rear-end impacts increased stresses significantly producing failure in most components for both rates. However, transverse ligament and C2-vertebral endplate only failed under rear-end impact. No failure occurred in cortical bone, dens, disc, anterior or posterior longitudinal ligaments. The spine is more prone to injury under rear-end impact as most of the spinal components failed and failure started earlier. Ligaments and facet joints are the most vulnerable components of the upper cervical spine when subjected to frontal/rear end impacts and injury may occur at small ranges of displacement/rotation.
Investigation of Lumbosacral Spine Anatomical Variation Effect on Load-Partitioning Under Follower Load Using Geometrically Personalized Finite Element Model
Authors: Naserkhaki Sadegh , Jaremko Jacob L. , Kawchuk Greg , Adeeb Samer , El-Rich Marwan
Published: March 2015

The spinal load sharing and mechanical stresses developed in the spine segments due to mechanical loads are dependent on the unique spinal anatomy (geometry and posture). Variation in spinal curvature alters the load sharing of the lumbar spine as well as the stiffness and stability of the passive tissues. In this paper, effects of lumbar spine curvature variation on spinal load sharing under compressive Follower Load (FL) are investigated numerically. 3D nonlinear Finite Element (FE) models of three ligamentous lumbosacral spines are developed based on personalized geometries; hypo-lordotic (Hypo-L), normal (Normal-L) and hyper-lordotic (Hyper-L) cases. Analysis of each model is performed under Follower Load and developed stress in the discs and forces in the collagen fibers are investigated.

Stresses on the discs vary in magnitude and distribution depending on the degree of lordosis. A straight hypo-lordotic spine shows stresses more equally distributed among discs while a highly curved hyper-lordotic spine has stresses concentrated at lower discs. Stresses are uniformly distributed in each disc for Hypo-L case while they are concentrated posteriorly for Hyper-L case. Also, the maximum force in collagen fibers is developed in the Hyper-L case. These differences might be clinically significant related to back pain.
Electromyography (EMG) Controlled Assistive Rehabilitation System
Authors: Forshaw Robert V. , Snow Nicholas W. , Wolff Jared M. , Zenouzi Mansour , Dow Douglas E.
Published: March 2015

Electromyography (EMG) is a method for monitoring the electrical activity of skeletal muscles. The EMG signal is used to diagnose neuromuscular diseases and muscular injuries. EMG can also be utilized as an indicator of user intent for a muscle contraction for a specific motion. This input signal could be used to control powered exoskeleton prostheses. Limbs with impaired motor function tend to have increased disuse that may result in further muscle weakness. Therapy and other physical activities that increase the use of an impaired limb may contribute to some recovery of motor function. A device that helps to perform activities of daily living may increase usage and enhance recovery. The objective of this project is to make developments toward an EMG controlled assistive rehabilitation system that monitors EMG signals of the bicep and triceps muscles, and drives a motor to assist with arm motion. A motor is used to develop torque that would assist rotations of the arm about the elbow. A pair of EMG sensors (one pair near the biceps and the other near the triceps muscle) transmits electrical activity of the arm to a microcontroller (Raspberry Pi, Raspberry Pi Foundation, United Kingdom). For the prototype, the EMG signal is sampled and rectified within a moving time window to determine the root mean squared (VRMS) value. This value is used by the microcontroller to generate a pulse-width modulated (PWM) signal that controls the motor. Sensors for the motor provide information to an algorithm on the microcontroller. The generated PWM signal is based on the Vrms values for the EMG signal. Testing and analysis has shown a correlation between the EMG Vrms amplitude and muscle generated torque. The EMG controlled assistive rehabilitation system shows promise for assisting motor function for rotations about the elbow. Further algorithmic development is needed to determine the appropriate amount of assistance from the motor for the motor function indicated by user intent.
Accurate Force Control in a Miniature Gripper With a Single SMA Wire
Authors: Rezaeian Ayyoub , Yousefi-Koma Aghil
Published: March 2015

In this paper, a shape memory alloy wire is used as an actuator in a gripper. Additionally, a fuzzy controller is developed to control the force produced by the gripper. Fuzzy logic employed in the controller is used to tune the PID controller gains and improve the performance of the conventional PID controller. The performances of the proposed fuzzy PID controller and the conventional PID controller are compared with experiment tests. The experimental results verified the effectiveness of the proposed controller for the various command forces.
Transition Metal Manganites Prepared by a Green and Low-Temperature Wet Chemistry Route, Investigated by XPS
Authors: Diodati Stefano , Minelli Arianna , Dolcet Paolo , Gross Silvia
Published: March 2015

In the present contribution, three transition metal manganites, namely the copper manganite CuMnO2 and the zinc manganites ZnMnO3 and ZnMn2O4, were investigated through X-ray photoelectron spectroscopy (XPS). The chosen synthesis route involved the combination of coprecipitation of oxalates from an aqueous solution and hydrothermal processing at a mild temperature (180 °C). The precipitates were then separated and dried for 4 h at 80 °C, yielding crystalline nanostructured powders without the need for calcination. Along with survey scans of the analyzed samples, detailed spectra of the C 1s, O1s, Mn 2p, Mn 3p, Mn LMM as well as Cu 2p, Cu 3p, Cu LMM, Zn 2p and Zn LMM (depending on the sample in question) were collected. The data obtained from these analyses is discussed.
The weakening summer circulation in the Northern Hemisphere mid-latitudes
Authors: Coumou Dim , Lehmann Jascha , Beckmann Johanna
Published: March 2015

Smaller differences and greater extremes

Has recent rapid warming in the Arctic affected weather elsewhere in the world? Coumou
et al.
find that some key measures of atmospheric circulation in the Northern Hemisphere have weakened during the summer. This change has been caused by the reduction of the temperature difference between mid-latitudes and the North Pole. As summertime circulation has decreased in intensity, episodes of hot weather have become more persistent because there are fewer storms to bring cooler conditions.

Science
, this issue p.
324
Complete Genome Sequence of Paenibacillus polymyxa Strain Sb3-1, a Soilborne Bacterium with Antagonistic Activity toward Plant Pathogens
Authors: Rybakova Daria , Wetzlinger Ute , Müller Henry , Berg Gabriele
Published: March 2015

The genome of
Paenibacillus polymyxa
Sb3-1, a strain that shows antagonistic activities against pathogenic fungi and bacteria, consists of one 5.6-Mb circular chromosome and two plasmids of 223 kb and 8 kb. The genome reveals several genes that potentially contribute to its antagonistic and plant growth promotion activity.
Complete Genome Sequence of Emerging Porcine Circovirus Types 2a and 2b from India
Authors: Bhattacharjee Uttaran , Ahuja Anuj , Sharma Indu , Karam Amarjit , Chakraborty Amit Kumar , Ghatak Sandeep , Puro Kekungu , Das Samir , Shakuntala Ingudam , Giri Sarbani , Pegu R. K. , Laha R. , Pattanayak A. , Ngachan S. V. , Sen Arnab
Published: March 2015

We report here the first characterized complete genome sequence of porcine circovirus types 2a and 2b from northeastern states of India. These isolates may serve as a potential reference for the Indian strains of porcine circovirus types 2a and 2b.
Complete Genome Sequence of Bacillus amyloliquefaciens Strain BH072, Isolated from Honey
Authors: Zhao Xin , de Jong Anne , Zhou Zhijiang , Kuipers Oscar P.
Published: March 2015

The genome of
Bacillus amyloliquefaciens
strain BH072, isolated from a honey sample and showing strong antimicrobial activity against plant pathogens, is 4.07 Mb and harbors 3,785 coding sequences (CDS). Several gene clusters for nonribosomal synthesis of antimicrobial peptides and a complete gene cluster for biosynthesis of mersacidin were detected.
Draft Genome Sequences of Vibrio renopiscarius Strains CECT 8603
T
and CECT 8604, Two Marine
Gammaproteobacteria
Isolated from Cultured Gilthead Sea Bream (Sparus aurata)
Authors: Arahal David R. , Rodrigo-Torres Lidia , Lucena Teresa , Pujalte María J.
Published: March 2015

Vibrio renopiscarius DCR 1-4-2
T
(CECT 8603
T
) and DCR 1-4-12 (CECT 8604) were isolated from healthy gilthead sea bream (
Sparus aurata
) from Mediterranean fish farms (Castellón, Spain). Their draft genome sequences (30 and 44 contigs, respectively) have 4.3 Mbp and a G+C content of 45.2 mol% and contain almost 3,700 protein-encoding genes.
Genome Sequence of the Urethral Catheter Isolate Pseudomonas aeruginosa MH19
Authors: Vorhölter Frank-Jörg , Tielen Petra , Wibberg Daniel , Narten Maike , Schobert Max , Tüpker Reinhilde , Blom Jochen , Schatschneider Sarah , Winkler Anika , Albersmeier Andreas , Goesmann Alexander , Pühler Alfred , Jahn Dieter
Published: March 2015

Pseudomonas aeruginosa
is a frequent agent of complicated catheter-associated urinary tract infections (CAUTIs). Here, we present the improved 7.1-Mb draft genome sequence of
P. aeruginosa
MH19, which was isolated from a patient with an acute hospital-acquired CAUTI. It includes unique genes not represented in other
P. aeruginosa
genomes.
Long working hours and physical activity
Authors: Angrave David , Charlwood Andy , Wooden Mark
Published: March 2015

Background

It is widely believed that persons employed in jobs demanding long working hours are at greater risk of physical inactivity than other workers, primarily because they have less leisure time available to undertake physical activity. The aim of this study was to test this hypothesis using prospective data obtained from a nationally representative sample of employed persons.

Methods

Longitudinal data from the Household, Income and Labour Dynamics in Australia Survey (93 367 observations from 17 893 individuals) were used to estimate conditional fixed effects logistic regression models of the likelihood of moderate or vigorous physical exercise for at least 30 min, at least four times a week.

Results

No significant associations between long working hours and the incidence of healthy levels of physical activity were uncovered once other exogenous influences on activity levels were controlled for. The odds of men or women who usually work 60 or more hours per week exercising at healthy levels were 6% and 11% less, respectively, than those of comparable persons working a more standard 35–40 h/week; however, neither estimate was significantly different from 0 at 95% CI.

Conclusions

The findings suggest that there is no trade-off between long working hours and physical activity in Australia. It is argued that these findings are broadly consistent with previous research studies from Anglo-Saxon countries (where long working hours are pervasive) that employed large nationally representative samples.
First record of the tritylodontid cynodont Oligokyphus and cynodont postcranial bones from the McCoy Brook Formation of Nova Scotia, Canada
Authors: Fedak Tim J. , Sues Hans-Dieter , Olsen Paul E.
Published: March 2015

A fragment of a right dentary with one postcanine tooth from the Upper Triassic (Rhaetian) Scots Bay Member of the McCoy Brook Formation at Wasson Bluff, Nova Scotia, Canada, represents the first record of the tritylodontid cynodont Oligokyphus from the early Mesozoic of eastern North America. In addition, three dissociated postcranial bones from the same horizon and locality are referable to derived cynodont therapsids. One of these elements, a nearly complete right humerus, can be assigned to Tritylodontidae. Two other bones, an ulna and incomplete ischium, belong to indeterminate derived cynodonts but show no features allowing more precise taxonomic identification. The presence of Oligokyphus in the McCoy Brook Formation provides additional evidence for the remarkably wide geographic distribution of many latest Triassic and Early Jurassic continental tetrapods.
How animals glide: from trajectory to morphology
Authors: Socha John J. , Jafari Farid , Munk Yonatan , Byrnes Greg
Published: March 2015

Animals that glide produce aerodynamic forces that enable transit through the air in both arboreal and aquatic environments. The relative ease of gliding compared with flapping flight has led to a large diversity of taxa that have evolved some degree of flight capability. Glide paths are curved, reflecting the changing forces on the animal as it progresses through its aerial trajectory. These changing forces can be under control of the glider, which uses specific aspects of anatomy to modulate lift, drag, and rotational moments on the body. However, gliders share no single anatomical or behavioral feature, and some species are unspecialized for gliding, producing aerodynamic forces using posture and orientation alone. Animals use gliding in a broad range of ecological roles, suggesting that multiple performance metrics are relevant for consideration, but we are only beginning to understand how gliders produce and control their flight from takeoff to landing. In this review, we focus on the physical aspects of how glide trajectories are produced, and additionally discuss the range of morphologies and postures that are used to control aerial movements across the broad diversity of animal gliders.
Low Leakage and Highly Noise Immune FinFET-Based Wide Fan-In Dynamic Logic Design
Authors: Mahor Vikas , Pattanaik Manisha
Published: March 2015

Wide fan-in dynamic logic OR gate has always been an integral part of high speed microprocessors. However, low noise immunity of wide fan-in dynamic logic gate is always an issue of concern. For maintaining high noise immunity, various large sized PMOS keeper-based dynamic OR gates are proposed in the literature. These designs allow large leakage through them for maintaining high noise immunity which unnecessarily increases the power dissipation. This can be a critical issue for microprocessors used in battery operated devices. Independent gate (IG) FinFET devices are known to reduce leakage current through them using back gate biasing technique. In this paper, a novel FinFET-based wide fan-in dynamic OR gate has been proposed with effective leakage control and high noise immunity. This work reports a maximum leakage power reduction up to 70% while maintaining up to 90% higher noise immunity as compared to standard dynamic OR gate at low keeper size. This work also mathematically illustrates the effective leakage reduction capability of FinFET as compared to CMOS and hence proves its preference over CMOS in wide fan-in dynamic OR gate.
Earnings Management During Lockup in Explaining IPO Operating Underperformance
Authors: Liao Tsai-Ling , Huang Chih-Jen , Liu Hsiao-Chi
Published: March 2015

This study examines the relationship between initial public offering (IPO) managers' earnings management behavior during lockup (measured with discretionary accruals, DAs) and operating performance following lockup expiration (measured with operating return on assets, OPROAs). Based on a U.S. IPO sample, the results indicate that DAs during lockup are significantly higher than after lockup expiration. In addition, the reversal effect of DAs results in a negative association of DAs in lockup with post-lockup OPROAs. This negative relation is primarily concentrated in small-sized, non-venture backed, high-tech, and hot-market issued IPOs and is consistent with prior findings that such IPO firms have poorer post-issue performance. The overall evidence supports the role of managerial earnings management behavior during lockup in explaining post-IPO operating underperformance.
Lp–Lq estimates for homogeneous operators
Authors: Ioku Norisuke , Metafune Giorgio , Sobajima Motohiro , Spina Chiara
Published: March 2015

We prove precise [Formula: see text]–[Formula: see text] estimates for the semigroup generated by [Formula: see text] in [Formula: see text].
Semiclassical states for a static supercritical Klein–Gordon–Maxwell–Proca system on a closed Riemannian manifold
Authors: Clapp Mónica , Ghimenti Marco , Micheletti Anna Maria
Published: March 2015

We establish the existence of semiclassical states for a nonlinear Klein–Gordon–Maxwell–Proca system in static form, with Proca mass [Formula: see text] on a closed Riemannian manifold. Our results include manifolds of arbitrary dimension and allow supercritical nonlinearities. In particular, we exhibit a large class of three-dimensional manifolds on which the system has semiclassical solutions for every exponent [Formula: see text] The solutions we obtain concentrate at closed submanifolds of positive dimension as the singular perturbation parameter goes to zero.
On a bicomplex induced by the variational sequence
Authors: Krupka Demeter , Moreno Giovanni , Urban Zbyněk , Volná Jana
Published: March 2015

The construction of a finite-order bicomplex whose morphisms are the horizontal and vertical derivatives of differential forms on finite-order jet prolongations of fibered manifolds over one-dimensional bases is presented. In particular, relationship between the morphisms and classes entering the variational sequence and the associated finite-order bicomplex is studied. Properties of classes entering the infinite-order bicomplex, induced from the finite-order variational sequences by means of an infinite canonical construction, are formulated as a remark, insisting further research.
Deforming geometric transitions
Authors: Rossi Michele
Published: March 2015

After a quick review of the wild structure of the complex moduli space of Calabi-Yau 3-folds and the role of geometric transitions in this context (the Calabi-Yau web) the concept of deformation equivalence for geometric transitions is introduced to understand the arrows of the Gross–Reid Calabi-Yau web as deformation-equivalence classes of geometric transitions. Then the focus will be on some results and suitable examples to understand under which conditions it is possible to get simple geometric transitions, which are almost the only well-understood geometric transitions both in mathematics and in physics.
AN ECONOMY-WIDE ANALYSIS OF CLIMATE CHANGE IMPACTS ON AGRICULTURE AND FOOD SECURITY IN BANGLADESH
Authors: BANERJEE ONIL , MAHZAB MOOGDHO , RAIHAN SELIM , ISLAM NABIUL
Published: March 2015

Bangladesh is one of the most vulnerable countries to climate change (CC) with higher temperatures reducing crop yields and sea level rise decreasing arable land supply. The Government of Bangladesh aspires to offer its people a comparable standard of living to that of middle-income countries by 2021. Bangladesh's population will reach 247 million by 2050 and GDP is projected to grow annually by 7.9%. With increasing population density, greater demand for resources, and CC impacts, adaptation and mitigation strategies will be required for agricultural output to meet growing food demand. We develop a dynamic computable general equilibrium model linked with a food security module to explore CC impacts on agriculture and food security. Although CC impacts had a relatively small effect on GDP, reducing it by $29,925 million Taka (-0.11%) by 2030, agricultural sector impacts were felt more acutely, reducing output by -1.23%, increasing imports by 1.52%, and reducing total caloric consumption by 17%, with some households remaining underfed due to inequitable food distribution. Evidence generated here can guide policy to ensure economic growth contributes to meeting national development and food security targets.
Selective sodium-dependent glucose transporter 1 inhibitors block glucose absorption and impair glucose-dependent insulinotropic peptide release
Authors: Dobbins Robert L. , Greenway Frank L. , Chen Lihong , Liu Yaping , Breed Sharon L. , Andrews Susan M. , Wald Jeffrey A. , Walker Ann , Smith Chari D.
Published: March 2015

GSK-1614235 and KGA-2727 are potent, selective inhibitors of the SGLT1 sodium-dependent glucose transporter. Nonclinical (KGA-2727) and clinical (GSK-1614235) trials assessed translation of SGLT1 inhibitor effects from rats to normal human physiology. In rats, KGA-2727 (0.1 mg/kg) or vehicle was given before oral administration of 3- O-methyl-α-d-glucopyranose (3- O-methylglucose, 3-OMG) containing 3-[3H]OMG tracer. Tracer absorption and distribution were assessed from plasma, urine, and fecal samples. SGLT1 inhibition reduced urine 3-OMG recovery and increased fecal excretion. SGLT1 inhibitor effects on plasma glucose, insulin, gastric inhibitory peptide (GIP), and glucagon-like peptide-1 (GLP-1) concentrations were also measured during a standard meal. Incremental glucose, insulin, and GIP concentrations were decreased, indicating downregulation of β-cell and K cell secretion. Minimal effects were observed in the secretion of the L cell product, GLP-1. With the use of a three-way, crossover design, 12 healthy human subjects received placebo or 20 mg GSK-1614235 immediately before or after a meal. Five minutes into the meal, 3-OMG was ingested. Postmeal dosing had little impact, yet premeal dosing delayed and reduced 3-OMG absorption, with an AUC0–10 of 231 ± 31 vs. 446 ± 31 μg·h−1·ml−1, for placebo. Recovery of tracer in urine was 1.2 ± 0.7 g for premeal dosing and 2.2 ± 0.1 g for placebo. Incremental concentrations of insulin, C-peptide, and GIP were reduced for 2 h with premeal GSK-1614235. Total GLP-1 concentrations were significantly increased, and a trend for increased peptide YY (PYY) was noted. SGLT1 inhibitors block intestinal glucose absorption and reduce GIP secretion in rats and humans, suggesting SGLT1 glucose transport is critical for GIP release. Conversely, GLP-1 and PYY secretion are enhanced by SGLT1 inhibition in humans.