bluuebunny/crossref_metadata_2025 huggingface dataset:
Restoration of macroinvertebrates, fish, and habitats in streams following mining subsidence: replicated analysis across 18 mitigation sites
Authors: Nuttle Tim , Logan Marisa N. , Parise David J. , Foltz David A. , Silvis Joshua M. , Haibach Mark R.
Published: February 2017

Human activities have led to declines in stream functioning and stream restoration seeks to reverse this trend. Longwall coal mining, an underground full‐extraction method, can cause surface subsidence, affecting streams by creating a series of deep pools that trap sediment, reduce habitat diversity, and impair macroinvertebrate and fish communities. Mining effects on streams must be mitigated to maintain the functions, values, and foreseeable uses of streams. Gate cutting is a procedure that alleviates pooling by reestablishing the stream grade, accompanied by procedures that stabilize the channel, restore substrates, and enhance in‐stream and riparian habitats. We evaluated effectiveness of gate cuts at restoring streams affected by subsidence pooling at 18 independent restoration sites over two mines in southwestern Pennsylvania, U.S.A. At each site, sampling stations were established to monitor effects of mining subsidence and its restoration on macroinvertebrates, fish communities, and habitats. We tested for effects of sequential interventions (subsidence and restoration) on biological and habitat variables in a replicated before–after design, controlling for potentially confounding temporal effects (sample month and antecedent effective precipitation). All biological indices and substrate‐related habitat indices declined following subsidence but improved following restoration. Macroinvertebrate indicex and taxa richness, substrates, and riparian vegetation continued to improve with time following restoration. Whereas other studies have concluded that biological communities may take many years to respond to restoration, these results indicate that where macroinvertebrate and fish communities are altered by subsidence pooling, they can be effectively restored using gate cuts to pre‐mining levels within relatively short time periods.
Two spheres of regulation: Balancing social and economic goals
Authors: Eckert Sandra
Published: February 2017

Independent regulatory authorities hold comprehensive policy mandates that cover both economic and social goals. They take on various roles in market regulation, competition policy, consumer protection, and labor inspection. This article questions whether policymakers are driven by different rationales when delegating the realization of social, as opposed to economic goals, and analyzes how regulators accommodate their various roles in practice. The conceptual framework links the literature on delegation and organizational models. Comparative analysis of postal policy in France, Germany, and the United Kingdom covers a serious area of potential conflict between social and economic regulation. Variation in delegation points to the relevance of instrumental considerations, but also to the politics of institutional arrangements. Variation in regulatory practice shows that organizational models make a difference in accommodating conflict. The article makes a strong case that social and economic regulation need to be addressed as two distinct, yet interacting spheres. © 2017 John Wiley & Sons Australia, Ltd
Just Existing Is Resisting: The Everyday Struggle against the Expansion of GM Crops in Spain
Authors: Herrero Amaranta , Binimelis Rosa , Wickson Fern
Published: February 2017

The attempt to have coexistence between organic, conventional and genetically modified (GM) crops has generated unresolved frictions between agro‐food models based on different practices, values, worldviews and cultures. This article explores forms of everyday resistance that have emerged against the domineering power and spread of GM maize in Spain, the gateway nation for GM crops in Europe. Drawing on multi‐sited ethnographic work and interviews, we describe six practices by which social actors throughout the agro‐food system are resisting the expansion of GM maize and forming some unlikely alliances. We conclude that a myriad of practical resistance actions are taking place, from actors in both alternative and conventional food systems, as they fight for their survival against the political power and uncontrolled biological spread of GM crops. These practices challenge the regulatory concept of the possibility of a harmonious coexistence between the systems and highlight how an everyday struggle is required for non‐GM maize actors to continue to exist.
Developing a Conceptual Model of STEAM Teaching Practices
Authors: Quigley Cassie F. , Herro Dani , Jamil Faiza M.
Published: February 2017

STEAM, where the “A” represents arts and humanities, is considered a transdisciplinary learning process that has the potential to increase diverse participation in science, technology, engineering, and math (STEM) fields. However, a well‐defined conceptual model that clearly articulates essential components of the STEAM approach is needed to conduct empirical research on STEAM's efficacy–in particular, the teaching content that should be considered when enacting STEAM teaching practices. This paper proposes a conceptual model of STEAM, providing educators with the opportunity to teach effectively using transdisciplinary inquiry. The instructional content domain of the model includes problem‐based delivery, discipline integration, and problem‐solving skills.
Identification of the novel HLA‐B*13:83 allele by polymerase chain reaction sequence‐based typing in a Chinese cord blood donor
Authors: He J. , Chen N.‐Y. , Han Z.‐D. , Zhang W. , Zhu F.‐M.
Published: February 2017

HLA‐B*13:83 differs from HLA‐B*13:01:01 by 2 nucleotide substitutions at positions 103 and 106.
An integrated approach to control glyphosate‐resistant Ambrosia trifida with tillage and herbicides in glyphosate‐resistant maize
Authors: Ganie Z A , Lindquist J L , Jugulam M , Kruger G R , Marx D B , Jhala A J
Published: February 2017

Glyphosate‐resistant Ambrosia trifida is a competitive and difficult‐to‐control annual broad‐leaved weed in several agronomic crops in the Midwestern United States and Ontario, Canada. The objectives of this study were to compare treatments for control of glyphosate‐resistant A. trifida with tillage followed by pre‐emergence (PRE) and/or post‐emergence (POST) herbicides in glyphosate‐resistant maize and to determine the impact of A. trifida escapes on maize yield. Field experiments were conducted in 2013 and 2014 in grower fields infested with glyphosate‐resistant A. trifida. Tillage prior to maize sowing resulted in 80–85% control compared with no tillage. Tillage followed by PRE application of saflufenacil plus dimethenamid‐P with or without atrazine resulted in 99% control compared with ≤86 and 96% control with PRE herbicides alone at 7 and 21 days after application respectively. Tillage or POST‐only herbicides resulted in 4–14 A. trifida plants m−2, whereas a PRE and POST programme had <3 plants m−2. Maize yield was greatest (13.1–14.2 tonnes ha−1) with tillage followed by PRE and POST herbicide programme. The relationship between maize yield and late‐season density of A. trifida escapes showed a 50% maize yield reduction irrespective of control measures when A. trifida density was 8.4 plants m−2. It was concluded that the combination of tillage with PRE and/or POST herbicides reduced A. trifida density and biomass accumulation early in the season and provided an integrated approach for effective management.
INVESTIGATING THE “SCIENCE” IN “EASTERN RELIGIONS”: A METHODOLOGICAL INQUIRY
Authors: Barua Ankur
Published: February 2017

This article explores some of the understandings of “science” that are often employed in the literature on “science and Eastern religions.” These understandings crucially shape the raging debates between the avid proponents and the keen detractors of the thesis that Eastern forms of spirituality are uniquely able to subsume the sciences into their metaphysical–axiological horizons. More specifically, the author discusses some of the proposed relations between “science” and “Eastern religions” by highlighting three themes: (a) the relation between science and metaphysics, (b) the relation between science and experience, and (c) the European origins of science. The analysis of these relations requires a methodological inquiry into some of the culturally freighted valences of “science,” “metaphysics,” and “experience.”
Comparison of the herb layer composition in stands of several tree species in the Louny region
Authors: Viewegh Jiří , Miltner Stanislav , Matějka Karel , Podrázský Vilém
Published: February 2017

Influence of introduced northern red oak stands (Quercus rubra L.) on herb understory with comparison with herb understory of autochthonous Sessile oak (Quercus petraea agg. L) and Scots pine (Pinus sylvestris L.) was observed in Louny region area on 14 plots. The analysis of the ground vegetation was performed using classical phytosociological methods. Significant changes were not determined in the site character, when comparing particular tree species stands, the differences consisted especially in the natural regeneration of tree species. Northern red oak showed a tendency of more fast penetration in the neighboring stands.
Parasternal intercostal muscle activity during methacholine‐induced bronchoconstriction
Authors: MacBean Victoria , Pringle Claire L. , Lunt Alan C. , Sharp Keith D. , Ali Ashraf , Greenough Anne , Moxham John , Rafferty Gerrard F.
Published: February 2017

New Findings

What is the central question of this study?

The parasternal intercostal electromyogram (EMGpara) is known to provide an accurate, non‐invasive index of respiratory load–capacity balance. Although relationships between EMGpara and both airflow obstruction and hyperinflation have been shown, the independent contribution of each factor has not been examined.

What is the main finding and its importance?

Reductions in airway calibre and inspiratory capacity along with increases in EMGpara were induced via methacholine challenge. A strong inverse relationship was observed between EMGpara and airway obstruction, with no influence of inspiratory capacity. These data suggest that EMGpara is more strongly influenced by airway calibre than by changes in end‐expiratory lung volume during airway challenge testing.

Neural respiratory drive, measured via the parasternal intercostal electromyogram (EMGpara), provides a non‐invasive index of the load–capacity balance of the respiratory muscle pump. Previous studies in patients with obstructive lung disease have shown strong relationships between EMGpara and the extent of both airflow obstruction and hyperinflation. The relative influence of the two factors has not, however, been described. Airflow obstruction was induced via methacholine challenge testing in 25 adult humans. Forced expiratory volume in 1 s (FEV1) and surface EMGpara during tidal breathing were measured after each dose, with 20 of the participants also undergoing measurements of inspiratory capacity (IC) at each stage. Linear mixed model analysis was used to assess dose‐wise changes in FEV1 and EMGpara, and thereafter to determine the influence of changes in FEV1 and IC on change in EMGpara. Median (interquartile range) FEV1 decreased significantly [from 96.00 (80.00–122.30) to 67.80 (37.98–92.27)% predicted, P < 0.0001] and EMGpara increased significantly [from 5.37 (2.25–8.92) to 6.27 (3.37–19.60) μV, P < 0.0001] from baseline to end of test. Linear mixed model analysis showed a significant interaction between methacholine dose and induced change in EMGpara, with an increase in EMGpara of 0.24 (95% confidence interval 0.11–0.37) μV per methacholine dose2. Change in FEV1 further influenced this relationship [increase in slope of 0.002 (0.004–0.001) μV dose−2 per % predicted fall in FEV1, P = 0.011], but not with change in IC. These data suggest that bronchoconstriction exerts a more potent influence on levels of EMGpara than changes in end‐expiratory lung volume during methacholine challenge.
Neuronal sodium channels: emerging components of the nano‐machinery of cardiac calcium cycling
Authors: Veeraraghavan Rengasayee , Györke Sándor , Radwański Przemysław B.
Published: February 2017

Excitation–contraction coupling is the bridge between cardiac electrical activation and mechanical contraction. It is driven by the influx of Ca2+ across the sarcolemma triggering Ca2+ release from the sarcoplasmic reticulum (SR) – a process termed Ca2+‐induced Ca2+ release (CICR) – followed by re‐sequestration of Ca2+ into the SR. The Na+/Ca2+ exchanger inextricably couples the cycling of Ca2+ and Na+ in cardiac myocytes. Thus, influx of Na+ via voltage‐gated Na+ channels (NaV) has emerged as an important regulator of CICR both in health and in disease. Recent insights into the subcellular distribution of cardiac and neuronal NaV isoforms and their ultrastructural milieu have important implications for the roles of these channels in mediating Ca2+‐driven arrhythmias. This review will discuss functional insights into the role of neuronal NaV isoforms vis‐à‐vis cardiac NaVs in triggering such arrhythmias and their potential as therapeutic targets in the context of the aforementioned structural observations.

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Protein kinase A regulates C‐terminally truncated CaV1.2 in Xenopus oocytes: roles of N‐ and C‐termini of the α1C subunit
Authors: Oz Shimrit , Pankonien Ines , Belkacemi Anouar , Flockerzi Veit , Klussmann Enno , Haase Hannelore , Dascal Nathan
Published: February 2017

Key points

β‐Adrenergic stimulation enhances Ca2+ entry via L‐type CaV1.2 channels, causing stronger contraction of cardiac muscle cells.

The signalling pathway involves activation of protein kinase A (PKA), but the molecular details of PKA regulation of CaV1.2 remain controversial despite extensive research.

We show that PKA regulation of CaV1.2 can be reconstituted in Xenopus oocytes when the distal C‐terminus (dCT) of the main subunit, α1C, is truncated.

The PKA upregulation of CaV1.2 does not require key factors previously implicated in this mechanism: the clipped dCT, the A kinase‐anchoring protein 15 (AKAP15), the phosphorylation sites S1700, T1704 and S1928, or the β subunit of CaV1.2. The gating element within the initial segment of the N‐terminus of the cardiac isoform of α1C is essential for the PKA effect.

We propose that the regulation described here is one of two or several mechanisms that jointly mediate the PKA regulation of CaV1.2 in the heart.

β‐Adrenergic stimulation enhances Ca2+ currents via L‐type, voltage‐gated CaV1.2 channels, strengthening cardiac contraction. The signalling via β‐adrenergic receptors (β‐ARs) involves elevation of cyclic AMP (cAMP) levels and activation of protein kinase A (PKA). However, how PKA affects the channel remains controversial. Recent studies in heterologous systems and genetically engineered mice stress the importance of the post‐translational proteolytic truncation of the distal C‐terminus (dCT) of the main (α1C) subunit. Here, we successfully reconstituted the cAMP/PKA regulation of the dCT‐truncated CaV1.2 in Xenopus oocytes, which previously failed with the non‐truncated α1C. cAMP and the purified catalytic subunit of PKA, PKA‐CS, injected into intact oocytes, enhanced CaV1.2 currents by ∼40% (rabbit α1C) to ∼130% (mouse α1C). PKA blockers were used to confirm specificity and the need for dissociation of the PKA holoenzyme. The regulation persisted in the absence of the clipped dCT (as a separate protein), the A kinase‐anchoring protein AKAP15, and the phosphorylation sites S1700 and T1704, previously proposed as essential for the PKA effect. The CaVβ2b subunit was not involved, as suggested by extensive mutagenesis. Using deletion/chimeric mutagenesis, we have identified the initial segment of the cardiac long‐N‐terminal isoform of α1C as a previously unrecognized essential element involved in PKA regulation. We propose that the observed regulation, that exclusively involves the α1C subunit, is one of several mechanisms underlying the overall PKA action on CaV1.2 in the heart. We hypothesize that PKA is acting on CaV1.2, in part, by affecting a structural ‘scaffold’ comprising the interacting cytosolic N‐ and C‐termini of α1C.
Three-Dimensional Numerical Investigation of Thermodynamic Performance Due to Conjugate Natural Convection From Horizontal Cylinder With Annular Fins
Authors: Senapati Jnana Ranjan , Dash Sukanta Kumar , Roy Subhransu
Published: February 2017

Entropy generation due to natural convection has been computed for a wide range of Rayleigh numbers based on fin spacing, RaS in the entire laminar range 5≤RaS≤108, and diameter ratio 2 ≤ D/d ≤ 5 for an isothermal horizontal cylinder fitted with vertical annular fins. Entropy generation in the tube-fin system is predominantly due to heat transfer rather than fluid friction. The results demonstrate that the degree of irreversibility is higher in the case of the finned configuration when compared with the unfinned one. With the deployment of a merit function combining the first and second laws of thermodynamics, we have tried to show the thermodynamic performance of finned cylinder with natural convection. So, we have defined the ratio (I/Q)finned/(I/Q)unfinned which gets its minimum value at optimum fin spacing where heat transfer is maximum. A detailed view of the entropy generation around the finned cylinder has been shown for various S/d (fin spacing to tube diameter ratio) at a particular D/d (fin to tube diameter ratio) and Rayleigh number, which explains the nature and reason of entropy production.
Conjugate Mixed Convection Heat Transfer From a Shrouded Vertical Nonisothermal Heat Sink
Authors: Das Biplab , Giri Asis , Debnath Suman
Published: February 2017

A computational analysis of conjugate mixed convection heat transfer from shrouded vertical nonisothermal heat sink on a horizontal base is performed. The overall Nusselt number and the product of friction factor (f) and Reynolds number (Re) are found to vary significantly with the spacing of heat sink as well as with the clearance between shroud and heat sink. By increasing the fin conductance by 200%, an enhancement of Nusselt number is noted to be around 58%, while the same Nusselt number enhancement is 134% for isothermal fin, within the range of parametric studies. The fRe value for smaller fin spacing shows a maximum with clearances, while the same for higher fin spacing remains the same or increases with clearances. Finally, overall Nusselt number and friction factor are well correlated with the governing parameters of the problem.
Anisotropic Thermal Response of Packed Copper Wire
Authors: Wereszczak Andrew A. , Emily Cousineau J. , Bennion Kevin , Wang Hsin , Wiles Randy H. , Burress Timothy B. , Wu Tong
Published: February 2017

The apparent thermal conductivity of packed copper wire test specimens was measured parallel and perpendicular to the axis of the wire using laser flash, transient plane source, and transmittance test methods. Approximately 50% wire packing efficiency was produced in the specimens using either 670- or 925-μm-diameter copper wires that both had an insulation coating thickness of 37 μm. The interstices were filled with a conventional varnish material and also contained some remnant porosity. The apparent thermal conductivity perpendicular to the wire axis was about 0.5–1 W/mK, whereas it was over 200 W/mK in the parallel direction. The Kanzaki model and an finite element analysis (FEA) model were found to reasonably predict the apparent thermal conductivity perpendicular to the wires but thermal conductivity percolation from nonideal wire-packing may result in their underestimation of it.
Numerical Study of Laser Shock Peening Effects on Alloy 600 Nozzles With Initial Residual Stresses
Authors: Kim Ji-Soo , Nam Hyun-Suk , Kim Yun-Jae , Kim Ju-Hee
Published: February 2017

This paper investigates the effect of initial residual stress and prestrain on residual stresses due to laser shock peening for Alloy 600 using numerical simulation. For simulation, the strain rate dependent Johnson–Cook hardening model with a Mie–Grüneisen equation of state is used. Simulation results are compared with published experimental data, showing good agreement. It is found that the laser shock peening (LSP) process is more effective for higher initial tensile residual stress and for larger initial prestrain in terms of compressive stress at the near surface. However, the effective depth decreases with increasing initial tensile residual stress and initial prestrain.
Nonlinear Dynamic Analysis of a Rotor-Labyrinth Seal-Bearing-Foundation System
Authors: Zhang Enjie , Jiao Yinghou , Chen Zhaobo , Mo Wenchao
Published: February 2017

Steam turbine rotors are subjected to various excitation forces originated from inner structure and outer environment. Unbalance forces, nonlinear oil film forces, nonlinear seal forces, and base excitation are drastically influence the dynamic behaviors of the rotor system. A mathematical model of rotor system, including the coupled effects of these excitation forces, is established by applying the Lagrange’s equations. The axial flow velocity and leakage mass flow, which vary with the structure of labyrinth seal and with inlet/outlet pressure ratio, are calculated using the two-control-volume model. The axial mean flow velocity is then introduced into the Muszynska’s nonlinear seal forces model. The nonlinear oil-film forces are also obtained based on the short bearing theory. The equations of motion are solved by Runge-Kutta numerical integration. The influences of inlet pressure and seal strip number on axial mean flow velocity and leakage mass flow are analyzed. The effects of rotational speed, foundation movements and inlet pressure on the nonlinear dynamic characteristics of the labyrinth seal-bearing-rotor system are investigated. The bifurcation diagrams, axis orbits and spectrum cascades are used to analyze the nonlinear dynamic behaviors of the system.
Assisted Mobility Gait Training System
Authors: Shaw Erik , Vasquez Pablo , Kondo Ryosuke , Ung Kevin , Farrer Zachary , Fagerberg Evan , Baker Jack , Yergeau Bryan , Harrison Matthew , McCusker James , Zenouzi Mansour
Published: February 2017

Gait training is a rehabilitation process which helps patients improve their ability to walk or stand. Current gait training methods require patients to be in hospitals or rehabilitation facilities to acquire data on their recovery progress; there is no method of monitoring patient’s walking pattern continuously. Patients can fall into bad habits when they are not with their physician. Assisted Mobility Gait Training System is a redesigned walker that wirelessly provides data to patients and healthcare professionals throughout the rehab process. With continuous monitoring of data, patients can obtain live feedback about their walking pattern when they are outside a hospital setting.

Assisted Mobility Gait Trainer combines tele-medicine and out-patient monitoring to improve the gait rehabilitation process. Portability and ease of use allows the device to be used as an outpatient monitoring tool decreasing recovery time and healthcare visitations. Data acquisition and progress monitoring are achieved through load cells and a Microsoft Kinect 2 that collects data regarding the patient’s gait. Imaging arrays within the Microsoft Kinect 2, including an RGB camera, infrared emitter, and depth sensor, monitor limb trajectories. Angle of rotation of each joint is obtained through the use of blob detection and trigonometry, specifically a variation of the dot product. Use of the camera, load cells, and wheel encoder ensures there is minimal set up time, other than turning on the system. Four load cells in each leg measure the force applied to the gait trainer, which allows physicians to identify if the patient is utilizing one leg more than the other, as well as determining if the patient becomes less reliant on the walker over time. Gait speed and distance traveled during use is measured by a wheel encoder. Data collected is sent into cloud storage where it is processed and saved. Saved data is then electronically communicated to the healthcare professional and the patient in two separate user interfaces. Healthcare professionals are able to help patients gage their rehabilitation progress more efficiently. Patients benefit by receiving feedback regarding their gait while they are not at a rehab facility, which assists against patients falling into of bad habits during the rehabilitation process.
Mechanical Response of Different Lattice Structures Fabricated Using the CLIP Technology
Authors: Saigal Anil , Tumbleston John R. , Vogel Hendric
Published: February 2017

In the rapidly growing field of additive manufacturing (AM), the focus in recent years has shifted from prototyping to manufacturing fully functional, ultralight, ultrastiff end-use parts. This research investigates the mechanical behavior of octahedral, octet, vertex centroid, dode, diamond, rhombi octahedron, rhombic dodecahedron and solid lattice structured polyacrylate fabricated using Continuous Liquid Interface Production (CLIP) technology based on 3D printing and additive manufacturing processes. The compressive stress-strain behavior of the lattice structures observed is typical of cellular structures which include a region of nominally elastic response, yielding, plastic strain hardening to a peak in strength, followed by a drop in flow stress to a plateau region and finally rapid hardening associated with contact of the deformed struts with each other as part of densification. It was found that the elastic modulus and strength of the various lattice structured materials are proportional to each other. In addition, it was found that the octahedral, octet and diamond lattice structures are amongst the most efficient based on the measured specific stiffness and specific strength.
Study of Tool Geometry Effect on Environmental Impact
Authors: Jha Nand K.
Published: February 2017

The effect of tool geometry on the quality of the machined part has been an important consideration. Here the effect of tool geometry from energy minimization angle has been studied for sustainable manufacturing. The greenhouse gas (GHG) emission has been analyzed in terms of rake angle (α) and shear plane angle (φ). A numerical study of tool geometry and its effect on eco-indicators has been presented. The shear force (Fs) decreases as rake angle increases. The reduction in horse power requirement will affect the GHG emissions. It has been quantified how much CO2 is emitted in air during machining. The other toxic gases like NOx, SO2, CH4, and mercury (Hg) emissions have also been quantified. The friction force (F) declines very rapidly as rake angle (α) increases and reduce the lubricant requirement. The total specific energy (TSE) is summation of specific process energy (SPE) and specific constant energy (SCE).
A Multi-Wavelength Light Interference Method for the Measurement of Lubricating Film Thickness
Authors: Chen Yingjun , Wu Xiaodong , Huang Ping
Published: February 2017

A multi-wavelength light interference method for the measurement of lubricating film thickness was proposed for the improvement of convenience and accuracy of monochromatic light interferometry. Through the successive analysis of the hypothetical curves and the revised curves of three-wavelength light interference, the procedures of this method were discussed in detail. Then three-wavelength light interference method was applied to measure the lubricating film thickness of base oil under a specific condition. In comparison with the numerical results of Hamrock-Dowson formula, it was concluded that the multi-wavelength light interference method is applicable for the measurement of lubricating film thickness. With this method, the only requirement is the images which captured in stationary and purposed conditions, and higher measurement accuracy can be achieved.
Implementation of an Open-Architecture Control for CNC Systems Based on Open-Source Electronics
Authors: Correa Jorge , Toombs Nicholas , Ferreira Placid M.
Published: February 2017

Open control architectures have many advantages including increased computational resources and flexibility of reconfiguration of new manufacturing units. This paper proposes an open architecture for the control of CNC systems based on open source electronics. The software architecture in this paper is a component-based approach where each component has an independent finite state machine (FSM) model. The hardware architecture is a multiprocessor distributed controller, with different levels of processing, and adaptable for different hardware specifications. A discussion of the basic control algorithms, with examples of implementation to the open source platform Arduino, is presented as part of the methodology. Other results in this paper include the preliminary test of the control to a two-axis CNC stage and a mathematical model of the control-loop in Simulink. The architecture in this paper has the potential of transforming CNC in open source electronics from device-oriented systems to systems where users can design their controls for special purpose machines.
Experimental Study of the Effect of Serrations on Axial Flow Fan Blade Trailing Edge
Authors: Nath Dhyanjyoti Deb , Viswanath K. , Patel Ankit Bhai
Published: February 2017

Rotor wakes shed from a compressor rotor impinge on downstream blades and is a major source of rotor-stator interaction noise and much research has been dedicated on wake attenuation. Serrated trailing edges is one such wake attenuation technique where the vortices produced at the serrated trailing edges enhance mixing and create a more uniform flow at stator inlet. The present paper investigates the effect of serrations on the trailing edge of a forced vortex axial fan blade. Experimental investigations were carried out at rotor outlet using pneumatic probes and fast response pressure sensors. It is found that total and static pressures reduce in serrated blades due to reduced turning and hence reduced work input. The absolute tangential velocity wake deficit decreases in serration valleys and improvement in axial velocity wake deficit is also found. Improvements as large as 19% and 18% decrease in absolute tangential velocity and axial velocity wake deficit are found at certain radii. The spanwise shape of the wake is altered by the serrations and a wake pattern undulating in the spanwise direction is observed. These are expected to bring down the circumferential variation of the velocity and its phase before entering the next row of blades and bring down the tonal noise.
On the Difference of Subsurface Deformation Obtained by Image Correlation Technique From That of Plane Strain Deformation in Orthogonal Metal Cutting
Authors: Zhang Dong , Zhang Xiao-Ming , Ding Han
Published: February 2017

Subsurface deformation in orthogonal metal cutting process is nowadays widely determined by image correlation techniques. To get clearer images of the cutting process, two methods were usually adopted to reduce workpiece material side flow in the literature. One is inducing a weak inclination angle of the cutting tool; the other is to restrict material side flow by a piece of thick glass. However, the differences between the subsurface deformation determined by observing the side surfaces in these two methods and that of plane strain deformation has not been studied yet. Therefore, this paper aims to study the differences of subsurface deformation obtained by these two methods quantitatively through numerical methods. It is found that the restrict side flow method surpasses the inducing an inclination angle method; inducing an inclination angle method will produce larger discrepancy than the side surface of typical orthogonal cutting which stands for observing the side surface directly. Besides, restrict material side flow method surpasses inducing an inclination angle method in the aspect of strain distribution across the width direction. To reduce the differences further, a new method called split-workpiece method based on the bonded-interface technique is proposed in this paper. To validate the effectiveness of this method, numerical comparisons between the subsurface deformation produced by the proposed method and that of the plane strain deformation are made. The results show that the subsurface deformation produced by the proposed method is much closer to that of plane strain deformation than the previous two methods.
Enhancing the Sport Performance and Quality Life of Athletes by Applying of WBV Method
Authors: Pop Petru A. , Lazar Liviu , Marcu Florin M.
Published: February 2017

The mechanical vibrations’ therapy is widely used as a non-conservative and safe physical method for patients diagnosed with osteoporosis, postmenopausal women and sportsmen training, also during athletes’ recovery and rehabilitation phase.

This paper has the main goal in assessing the benefic effects of whole-body-vibration (WBV) therapy applied to professional sportsmen as a complementary alternative of training that can improve their sport performance and quality life. The experiment applied on a group of ten volunteers’ athletes from our university, with the ages between of 19 to 29 years and appropriate weight and height, which signed a statement on by self-agreement to participate in this study. The WBV trial performed via a proper dynamic vibration installation during of two months, where the subjects were sitting in a bed with upper limbs on their thighs and inferior limbs extended to provide support for the spine in a fixed support. The installation comprised a vibration bed with direct control of vibration signal and an electronic analyzing system for acquisition and interpretation of vibration data, which allowing an automat control of rotation frequency, alarm and safety system, and visualization on-line the measurement process. The electric motor of vibrating bed can generate predictable vibration values on three axes that used two types of tri-axial vibration sensors, one accelerometer fixed on bed and the second that is an implant accelerometer on the anterior face of the thigh of evaluated subject. Each mechanical vibration training session has performed with a frequency of 45 Hz during of 16 minutes, consisted in eight series with 60 seconds, and one-minute breaks in between. The evaluation of data has made by assessing the values of subjects recorded at the initial stage and at final therapy, which supposed to control the objective parameters, as standing long jump, standing high jump and intensity of exercise performed during of physical efforts.

The results of vibration trial stressed that the subjects had a significant increase of sport performances after vibration training at each parameter assessing, which means that WBV can be a viable alternative method used of sportsmen to improve their athletic performance and quality life.
Failure Prognosis Based on Adaptive State Space Models
Authors: Bai Guangxing , Abdolsamadi Amirmahyar , Wang Pingfeng
Published: February 2017

This paper presents a generic data-driven failure prognosis method based on adaptive state space models for engineering systems, which integrates adaptive model recognition with a dynamic system model for remaining useful life prediction. The developed approach employs a statistical learning framework for adaptively learning of time-series degradation performance, and then a Bayesian technique for self-updating of data-driven models to adapt the operational or environmental changes. With the developed approach, the prognosis technique can eliminate the dependence to system specific models and be adaptive to system performance changes due to degradation or variation of system operational conditions, thereby yielding accurate remaining useful life predictions. The developed methodology is demonstrated by an engineering case study.
Structure Design and Performance Simulation on Liquid Lubricated Bearing System in Microgravity Environment
Authors: Ji Fenzhu , Zhang Mengjie , Du Farong , Xu Zheng
Published: February 2017

Nowadays, there are more works focused on the design and implementation of space mechanics under harsh environmental conditions, such as absence of a gravitational field. Precisely, the reliability and life of space mechanical components is still not adequate. Therefore, the deep-space exploration brings a challenge on lubrication system of space equipment. Centrifugal lubricators, oozing flow lubricators, wick feed systems and porous lubricant reservoirs are most common liquid lubrication systems used in space devices. But the oil amount is not sufficient. Additionally, it is needed to develop efficient supplementary lubrication systems to achieve future long-term space missions since the lacking of oil. In this paper, we propose liquid lubricating bearing system with built-in oil storage chamber for conquering lacking of oil. We also build the theoretical models for through vibration displacement and frequency of rolling element, bending deformation and vibration frequency of the elastomeric shaft, and the radiation energy of chamber’s inner surface respectively. These models are evaluated by numerical simulations. We tested and measured some parameters of oil flowing in system. The simulation and experimental results indicate that, 1) the rolling element has a through vibration displacement when bearing running; 2) the micro deformation and vibration of the elastomeric shaft are caused by the through vibration displacement; 3) the vibration energy of elastomeric shaft is transmitted to lubricating oil stored in chamber. Overall, the oil could be supplied to bearing race and friction surface through connecting oil hole drilled in the elastomeric shaft. The oil flowing performance varies with the diameter and inclination angle of the connecting oil hole.
Mechanical Characteristics and Design Method for Bolted Circular Flange Joints Subjected to External Tensile Loads
Authors: Sawa Shunichiro , Ishimura Mitsutoshi , Sekiguchi Yasuhisa , Sawa Toshiyuki
Published: February 2017

The characteristics of bolted circular flange joints tightened with bolt number N are analyzed using FEM such as the interface stress distributions in initial clamping state, those in operation and the load factor under tensile loadings. Then the effects of the bolt pitch circle diameter D and the bolt number N on the load factor and the interface stress distributions are examined. The FEM results of the load factor and a load when the interfaces starts to separate are fairly coincided with the experimental results. The value of the load factor is the smaller and it is less than 0.1. In addition, it decreases as the value of D increases. Another objective is to demonstrate a new design method and two typical cases are described. One is a problem how to determine the bolt nominal diameter when the bolt strength grade, bolt number N, the interface stress for keeping the joint function and external load are provided and the other is how to determine the bolt strength when the bolt nominal diameter, interface stress and external load are provided. The measured tightening coefficient Q is introduced in the design and the bolt strength is evaluated using the newly introduced equivalent stress taking account the shear stress due to torque in bolt initial tightening. Using the obtained nominal diameter, the bolt maximum stress, the bolt stress amplitude and the critical stress at the bearing surfaces are checked. The availability of the method is shown with the flowchart for design.
Analysis of the Tool Deflection in End Milling of Titanium
Authors: Hasenfratz Christian , Abele Eberhard
Published: February 2017

The world’s increasing demand for intercontinental mobility is leading to a steady growth in aircraft sales, with Airbus forecasting a total demand for 32,600 passenger aircraft until the year 2034. However, this demand arises not solely due to increased passenger numbers but also due to the need of replacing current aircraft as a consequence of their increasing service life. Since fuel consumption accounts for about one-third of operating costs, airlines need efficient jet engines to meet reduced noise emissions and fuel consumption demands in order to withstand international cost pressures. The development of new aircraft types focuses on the aspect of weight reduction. The aerospace industry is characterized not only by innovations in material science and technology, but also by increased integral construction of individual components for the sake of weight reduction.

Integral components are characterized by deep cavities and consist of difficult-to-cut materials to achieve weight reduction, presenting challenges for manufacturing technology. The most commonly encountered manufacturing technology for integral components is high performance cutting (HPC), using tools with a large overhang, whereby the process chain consists of two stages: roughing and finishing. However, manufacturing of integral components pushes HPC milling to its productivity limits. The interaction between work piece and end mill in the form of radial cutting forces leads to tool deflection and therefore limits the manufacturing of deep cavities. The present experimental study contributes to the analysis of tool deflection in the end milling of integral components, e.g., a blade integrated disk made of titanium for the aerospace industry.

The goal is to identify and describe tool deflection during milling and to analyze its interdependence with form deviation, as well as the local and global tool load.

A dynamometer is used to measure the global load on the tool and an experimental setup is designed and implemented to measure tool deflection and to identify the influence of the tool holder on total tool deflection. To determine tool deflection, the tool’s stiffness is determined by a reference measurement. Tool stiffness is utilized to determine tool deflection during the process and the results are illustrated for a range of technology parameters and tool wear. Tool deflection leads to a form deviation of the finished component as well as to changing contact conditions of the cutting edge, leading to increased tool wear. This study aims at providing a basic understanding of the relationship between milling force, tool deflection and form deviation under the influence of technology parameters and tool wear.
Knee Internal Forces in Moderate Squat Exercise
Authors: Caruntu Dumitru I. , Salinas Jose Mario
Published: February 2017

This paper deals with internal forces of human knee during moderate squat exercise. The moderate squat exercise consists of a descending phase from standing to the lowest position (largest flexion angle) in which no significant contact between thigh and calf occurs, and an ascending phase back to standing position. This research predicts the internal forces such as muscle forces, contact forces, and ligamentous forces. The ligamentous structures in this research consist of Anterior Cruciate Ligament (ACL), Posterior Cruciate Ligament (PCL), Lateral Collateral Ligament (LCL), and Medial Collateral Ligament (MCL). The ligaments are modeled as nonlinear elastic strips (they do not carry compression forces). An optimization technique was used to determine the muscle and contact forces present in the knee during the squat exercise.
Additively Manufactured Components With Embedded Instrumentation
Authors: Davis Matthew , Middendorf John , Garg Naman , Ohanian Osgar John
Published: February 2017

Additively manufactured components enable complex structures to be rapidly fabricated and tested for use in the automotive and aerospace industries. Additive manufacturing capabilities have expanded to include a variety of plastics, metal alloys, and fiber-reinforced polymers. There is interest in quantifying the residual stresses in components that have been manufactured using 3D printing processes in order to refine fabrication parameters and improve the performance of component design. Luna Innovations has developed and demonstrated methods to embed high definition fiber optic sensing (HD-FOS) technology into components that have been additively manufactured using ABS plastic as well as a cobalt chrome alloy. This technology enables characterization of internal residual stresses and provides a method for lifetime health monitoring of these printed components using the strain and temperature sensors installed during printing. The sensing technology utilizes the Rayleigh backscatter pattern contained in an optical fiber to determine the strain or temperature, with a high spatial resolution of 1.28 mm, along a fiber that can be embedded inside a printed component. HD-FOS technology was used to measure internal residual strains within layers of varying depths of an ABS printed block, showing a parabolic strain profile with a peak at 9,600 microstrain. In addition to characterizing the printing process, a method has been demonstrated to embed a distributed temperature sensor into a metallic additively manufactured component. This enables the temperature of the part to be measured while it is in use, providing data on the heat transfer through the component. Additive manufacturing has enabled embedding fiber optic sensors in new configurations that were previously unobtainable.
Non-Destructive and Failure Responses of Cervical Spine Artificial Disc Surgery for Military Applications
Authors: Yoganandan Narayan , Moore Jason , Baisden Jamie L. , Pintar Frank A. , McEntire B. Joseph , Chancey Valeta Carol
Published: February 2017

Ossification patters, non-destructive and failure responses of cervical artificial discs were determined using an in vivo Caprine model. The animals were anesthetized, discectomies were done at C3–C4, and Bryan disc, ProDisc-C, or anterior discectomy and fusion with plating (ACDF) was done. They were euthanized after monitoring for six months. Non-destructive loads were applied to the excised cervical columns in flexion, extension and lateral bending, combined with compression. The failure test was done under compression-flexion. X-rays and computed tomography scans were used to determine fusion. Force-displacement data for both artificial discs were grouped based on the presence or absence of heterotopic ossifications. They were compared with the ACDF specimens. Heterotopic ossifications occurred in both discs. Patterns of ossification were similar to those reported in civilian patients. Force-displacement responses of ossified spines were stiffer in all modes for both discs. However, differences were non-uniform. Biomechanical corridors are presented for all cases. The present preliminary study should be extended to discern the role of the disc type, loading mode and spinal level in future research.