bluuebunny/crossref_metadata_2025_split huggingface dataset:
Application of Modified Couple Stress Theory and Homotopy Perturbation Method in Investigation of Electromechanical Behaviors of Carbon Nanotubes
Authors: Fakhrabadi Mir Masoud Seyyed 
Published: October 2016

AbstractThe paper presents the size-dependant behaviors of the carbon nanotubes under electrostatic actuation using the modified couple stress theory and homotopy perturbation method. Due to the less accuracy of the classical elasticity theorems, the modified couple stress theory is applied in order to capture the size-dependant properties of the carbon nanotubes. Both of the static and dynamic behaviors under static DC and step DC voltages are discussed. The effects of various dimensions and boundary conditions on the deflection and pull-in voltages of the carbon nanotubes are to be investigated in detail via application of the homotopy perturbation method to solve the nonlinear governing equations semi-analytically.
Efficient and Stable Exponential Runge-Kutta Methods for Parabolic Equations
Authors: Zhu Liyong 
Published: October 2016

AbstractIn this paper we develop explicit fast exponential Runge-Kutta methods for the numerical solutions of a class of parabolic equations. By incorporating the linear splitting technique into the explicit exponential Runge-Kutta schemes, we are able to greatly improve the numerical stability. The proposed numerical methods could be fast implemented through use of decompositions of compact spatial difference operators on a regular mesh together with discrete fast Fourier transform techniques. The exponential Runge-Kutta schemes are easy to be adopted in adaptive temporal approximations with variable time step sizes, as well as applied to stiff nonlinearity and boundary conditions of different types. Linear stabilities of the proposed schemes and their comparison with other schemes are presented. We also numerically demonstrate accuracy, stability and robustness of the proposed method through some typical model problems.
On the Factors Affecting the Accuracy and Robustness of Smoothed-Radial Point Interpolation Method
Authors: Hamrani Abderrachid , Belaidi Idir , Monteiro Eric , Lorong Philippe 
Published: October 2016

AbstractIn order to overcome the possible singularity associated with the Point Interpolation Method (PIM), the Radial Point Interpolation Method (RPIM) was proposed by G. R. Liu. Radial basis functions (RBF) was used in RPIM as basis functions for interpolation. All these radial basis functions include shape parameters. The choice of these shape parameters has been and stays a problematic theme in RBF approximation and interpolation theory. The object of this study is to contribute to the analysis of how these shape parameters affect the accuracy of the radial PIM. The RPIM is studied based on the global Galerkin weak form performed using two integration technics: classical Gaussian integration and the strain smoothing integration scheme. The numerical performance of this method is tested on their behavior on curve fitting, and on three elastic mechanical problems with regular or irregular nodes distributions. A range of recommended shape parameters is obtained from the analysis of different error indexes and also the condition number of the matrix system. All resulting RPIM methods perform very well in term of numerical computation. The Smoothed Radial Point Interpolation Method (SRPIM) shows a higher accuracy, especially in a situation of distorted node scheme.
Similarity Solution for the Synchronous Grouting of Shield Tunnel Under the Vertical Non-Axisymmetric Displacement Boundary Condition
Authors: Zou Jinfeng , Zuo Songqing 
Published: October 2016

AbstractSimilarity solution is investigated for the synchronous grouting of shield tunnel under the vertical non-axisymmetric displacement boundary condition in the paper. The synchronous grouting process of shield tunnel was simplified as the cylindrical expansion problem, which was based on the mechanism between the slurry and stratum of the synchronous grouting. The stress harmonic function on the horizontal and vertical ground surfaces is improved. Based on the virtual image technique, stress function solutions and Boussinesq's solution, elastic solution under the vertical non-axisymmetric displacement boundary condition on the vertical surface was proposed for synchronous grouting problems of shield tunnel. In addition, the maximum grouting pressure was also obtained to control the vertical displacement of horizontal ground surface. The validity of the proposed approach was proved by the numerical method. It can be known from the parameter analysis that larger vertical displacement of the horizontal ground surface was induced by smaller tunnel depth, smaller tunnel excavation radius, shorter limb distance, larger expansion pressure and smaller elastic modulus of soils.
A Two-Year Longitudinal Assessment of Ophthalmologists’ Perceptions after Implementing an Electronic Health Record System
Authors: Ehrlich Joshua , Michelotti Monica , Blachley Taylor , Zheng Kai , Couper Mick , Greenberg Grant , Kileny Sharon , Branford Greta , Hanauer David , Weizer Jennifer 
Published: October 2016

SummaryObjectives To understand the attitudes and perceptions of ophthalmologists toward an electronic health record (EHR) system, before and after its clinical implementation.Methods Ophthalmologists at a single large academic ophthalmology department were surveyed longitudinally before and after implementation of a new EHR system. The survey measured ophthalmologists’ attitudes toward implementation of a new EHR. Questions focused on satisfaction, efficiency, and documentation. All attending physicians (between 56 and 61 at various time points) in the University of Michigan Department of Ophthalmology and Visual Sciences were surveyed. We plotted positive responses to survey questions and assessed whether perceptions followed a J-curve with an initial decrease followed by an increase surpassing pre-implementation levels.Results Survey responses were received from 32 (52%) ophthalmologists pre-implementation, and 28 (46%) at 3 months, 35 (57%) at 7 months, 40 (71%) at 13 months and 39 (67%) at 24 months post-implementation. After EHR implementation respondents were more likely to express concerns about their ability to create high-quality documentation (p<0.01) and the impact of an electronic health record on meaningful patient interaction (p<0.01). Physicians did not report a significant change in the amount of time spent documenting outside of regular clinical work hours (p=0.54) or on their clinic efficiency and workflow (p=0.97). There was no significant change in overall job satisfaction during the study period (p=0.69). We did not observe a J-curve for any of the survey responses analyzed.Conclusions As ophthalmology practices continue to transition to EHRs, adapting them to their specific culture and needs is important to maintain efficiency and user satisfaction. This study identifies areas of concern to ophthalmologists that may be addressed through education of physicians and customization of software as other practices move forward with EHR implementation.Citation: Ehrlich JR, Michelotti M, Blachley TS, Zheng K, Couper MP, Greenberg GM, Kileny S, Branford GL, Hanauer DA, Weizer JS. A two-year longitudinal assessment of ophthalmologists’ perceptions after implementing an electronic health record system.
Between Earth and Sky
Authors: Martinon Jean-Paul 
Published: October 2016

Africa. Who are you?I deliberately don’t say here, “What are you?” As we know, the interrogative pronoun “what” is an attempt to grab the essence of something. As Heidegger says: “whatness [Wassein], comprises what one commonly calls… the idea or mental representation by means of which we propose to… grasp what a thing is.” As such, questions starting with the interrogative pronoun “what” are eminently violent because they reduce the object of inquiry to a thing that can be held in one’s hand; that can make sense as a totality; that can be conceptualized with one idea. The history of philosophy— from Plato to Augustine, from Descartes to Lenin, all the way to Kwame Nkrumah, for example—is littered with the question “What…?”; with these violent attempts at grabbing the essence of something. Africa’s history is also littered with these attempts at reducing a continent to an essence or concept. These attempts are absurdly grandiose (pinning down “the idea” of Africa, for example) and ridiculously small (analyzing the minutiae of life in a village, for example). In all cases, they try to envision Africa as an object to be possessed by any means and I know that we can’t carry on doing that..
Frantz Fanon: Philosophy, Praxis, and the Occult Zone
Authors: Pithouse Richard 
Published: October 2016

In 2011, Achille Mbembe asserted that “the human has consistently taken on the form of waste within the peculiar trajectory race and capitalism espoused in South Africa.” He added that the end of apartheid had shifted rather than undone the lines of exclusion and dispute. Since the massacre on the platinum mines in 2012 it has become widely accepted that the state is resorting to repressive measures to enforce these lines and contain the dispute that they occasion. With notable exceptions academic philosophy, and theory more broadly, has offered remarkably little illumination of the widening distance between the promise of national liberation and democracy and the often bitter realities of contemporary South Africa. [i] Achille Mbembe ‘Democracy as Community Life’ Johannesburg Workshop in Theory & Criticism, 2011 http://jwtc.org.za/volume_4/achille_mbembe.htm
Systemic Delivery of Bone Marrow Mesenchymal Stem Cells for In Situ Intervertebral Disc Regeneration
Authors: Cunha Carla , Almeida Catarina R. , Almeida Maria Inês , Silva Andreia M. , Molinos Maria , Lamas Sofia , Pereira Catarina L. , Teixeira Graciosa Q. , Monteiro António T. , Santos Susana G. , Gonçalves Raquel M. , Barbosa Mário A. 
Published: October 2016

Abstract
Cell therapies for intervertebral disc (IVD) regeneration presently rely on transplantation of IVD cells or stem cells directly to the lesion site. Still, the harsh IVD environment, with low irrigation and high mechanical stress, challenges cell administration and survival. In this study, we addressed systemic transplantation of allogeneic bone marrow mesenchymal stem cells (MSCs) intravenously into a rat IVD lesion model, exploring tissue regeneration via cell signaling to the lesion site. MSC transplantation was performed 24 hours after injury, in parallel with dermal fibroblasts as a control; 2 weeks after transplantation, animals were killed. Disc height index and histological grading score indicated less degeneration for the MSC-transplanted group, with no significant changes in extracellular matrix composition. Remarkably, MSC transplantation resulted in local downregulation of the hypoxia responsive GLUT-1 and in significantly less herniation, with higher amounts of Pax5+ B lymphocytes and no alterations in CD68+ macrophages within the hernia. The systemic immune response was analyzed in the blood, draining lymph nodes, and spleen by flow cytometry and in the plasma by cytokine array. Results suggest an immunoregulatory effect in the MSC-transplanted animals compared with control groups, with an increase in MHC class II+ and CD4+ cells, and also upregulation of the cytokines IL-2, IL-4, IL-6, and IL-10, and downregulation of the cytokines IL-13 and TNF-α. Overall, our results indicate a beneficial effect of systemically transplanted MSCs on in situ IVD regeneration and highlight the complex interplay between stromal cells and cells of the immune system in achieving successful tissue regeneration.
A model providing long‐term data sets of energetic electron precipitation during geomagnetic storms
Authors: van de Kamp M. , Seppälä A. , Clilverd M. A. , Rodger C. J. , Verronen P. T. , Whittaker I. C. 
Published: October 2016

AbstractThe influence of solar variability on the polar atmosphere and climate due to energetic electron precipitation (EEP) has remained an open question largely due to lack of a long‐term EEP forcing data set that could be used in chemistry‐climate models. Motivated by this, we have developed a model for 30–1000 keV radiation belt driven EEP. The model is based on precipitation data from low Earth orbiting POES satellites in the period 2002–2012 and empirically described plasmasphere structure, which are both scaled to a geomagnetic index. This geomagnetic index is the only input of the model and can be either Dst or Ap. Because of this, the model can be used to calculate the energy‐flux spectrum of precipitating electrons from 1957 (Dst) or 1932 (Ap) onward, with a time resolution of 1 day. Results from the model compare well with EEP observations over the period of 2002–2012. Using the model avoids the challenges found in measured data sets concerning proton contamination. As demonstrated, the model results can be used to produce the first ever >80 year long atmospheric ionization rate data set for radiation belt EEP. The impact of precipitation in this energy range is mainly seen at altitudes 70–110 km. The ionization rate data set, which is available for the scientific community, will enable simulations of EEP impacts on the atmosphere and climate with realistic EEP variability. Due to limitations in this first version of the model, the results most likely represent an underestimation of the total EEP effect.
Structure of magma reservoirs beneath Merapi and surrounding volcanic centers of Central Java modeled from ambient noise tomography
Authors: Koulakov Ivan , Maksotova Gulzhamal , Jaxybulatov Kayrly , Kasatkina Ekaterina , Shapiro Nikolai M. , Luehr Birger‐G. , El Khrepy Sami , Al‐Arifi Nassir 
Published: October 2016

AbstractWe present a three‐dimensional model of the distribution of S‐wave velocity in the upper crust to a depth of 20 km beneath Central Java based on the analysis of seismic ambient noise data recorded by more than 100 seismic stations in 2004 associated with the MERAMEX project. To invert the Rayleigh wave dispersion curves to construct 2‐D group‐velocity maps and 3‐D distributions of S‐wave velocity, we have used a new tomographic algorithm based on iterative linearized inversion. We have performed a series of synthetic tests that demonstrate significantly higher resolution in the upper crust with this model compared to the local earthquake travel‐time tomography (LET) model previously applied for the same station network. Beneath the southern flank of Merapi, we identify a large low‐velocity anomaly that can be split into two layers. The upper layer reflects the ∼1 km thick sedimentary cover of volcanoclastic deposits. The deeper anomaly at depths of ∼4–8 km may represent a magma reservoir with partially molten rock that feeds several volcanoes in Central Java. Beneath the Merapi summit, we observe another low‐velocity anomaly as deep as 8 km that may be associated with the active magma reservoir that feeds the eruptive activity of Merapi. In the southern portion of the study area, in the lower crust, we identify a low‐velocity anomaly that may represent the top of the pathways of volatiles and melts ascending from the slab that was previously inferred from the LET model results. We observe that this anomaly is clearly separate from the felsic magma reservoirs in the upper crust.
Spawning superplumes from the midmantle: The impact of spin transitions in the mantle
Authors: Shahnas M. H. , Pysklywec R. N. , Yuen D. A. 
Published: October 2016

AbstractThe formation of large‐scale upwellings with lateral extents of several hundreds of kilometers, reaching up to ∼10,000 km or more, still remains a hotly debated topic. Some seismic imaging studies based on high‐resolution data suggest that the main superplumes underneath Africa and South‐central Pacific are clusters, composed of several individual plumes rather than being a single large mantle upwelling. The iron spin transition in the lower mantle minerals may present a new idea on the origin and the formation of such superplumes, notably sourcing such features in the midmantle. Stagnation of both cold sinking slabs and hot rising plumes can be caused by density and viscosity variation due to the spin transition in iron in ferropericlase (Fp) and a possible spin‐dependent bulk modulus hardening in bridgmanite silicate perovskite (Pv). This process produces intermittent downward spin transition‐induced midmantle avalanches (SIMMA) of the cold sinking flow as well as upward spin transition‐induced midmantle superplume avalanches (SIMMSA) of the rising hot plumes, triggered at the spin transition‐induced thermal boundary layer at around 1600 km depth. Our high‐resolution axi‐symmetric models reveal that the hot upwellings, trapped below ∼1600 km depth, can suddenly penetrate into the upper levels in the mantle and spread laterally for hundreds of kilometres. Owing to the upward penetration of the midmantle‐rooted superplumes, as broad as ∼1500 km across, a large amount of heat can be delivered to the upper mantle and base of the lithosphere with implications for large volcanic episodes.
The change in contact angle at unsaturated CO2‐water conditions: Implication on geological carbon dioxide sequestration
Authors: Jafari Mohammad , Jung Jongwon 
Published: October 2016

AbstractThe performance of a geologic carbon storage site strongly depends on the capillary pressure of sealing rock and formations. While wettability of minerals is a key factor in capillary pressure, published contact angles are inconsistent. This study explores the discrepancy of published contact angles in order to reduce the uncertainty of measured laboratory contact angles, and understand the variation of contact angles at unsaturated CO2‐water conditions. A ratio of droplet dimension and triple line (or contact line) are used to explain the observed wide range of contact angles and the variation of contact angle at unsaturated conditions. Results show that the shape factor has a good agreement with contact angle change during CO2 dissolution in water. Silica substrate has clear two pinned and slip stages of triple line during CO2 droplet dissolution, which cause contact angle on silica substrate to increase from 34.5° to 42.1°. However, mica substrate has the repeated pinned and slip stages due to the heterogeneity of mica surface, which cause contact angle to increase dramatically from 25.4° to 68.1°. Thus, both the impact of the unsaturated CO2‐water conditions on the wide range of contact angle and the heterogeneity of mineral surface should be considered when one estimates capillary pressure based on contact angle in geological CO2 sequestration.
Tectonic structure of the Mid‐Atlantic Ridge near 16°30′N
Authors: Parnell‐Turner Ross , Schouten Hans , Smith Deborah K. 
Published: October 2016

AbstractThe 16°30'N area of the Mid‐Atlantic Ridge represents an area of present‐day detachment faulting. Here we present shipboard bathymetric, magnetic and gravity data acquired up to 65 km from the ridge axis that reveal a varied tectonic history of this region. Magnetic data are used to calculate spreading rates and examine spreading rate variability along and across the axis. Bathymetric and gravity data are used to infer the crustal structure. A central magnetic anomaly 40% narrower than expected is observed along much of the study area. Misalignment between modern‐day spreading center and magnetic anomalies indicates tectonic reorganization of the axis within the past 780 ka. Observed magnetic anomalies show a pattern of anomalous skewness consistent with rotation of magnetic vectors probably associated with detachment faulting. Relatively thin crust north of a small (∼7 km) nontransform offset coincides with a weakly magmatic spreading axis. In contrast, to the south a robust axial volcanic ridge is underlain by thicker crust. Variations in crustal structure perpendicular to the axis occur over tens of kilometers, indicating processes which occur over timescales of 1–2 Ma.
Reconciling mantle wedge thermal structure with arc lava thermobarometric determinations in oceanic subduction zones
Authors: Perrin Alexander , Goes Saskia , Prytulak Julie , Davies D. Rhodri , Wilson Cian , Kramer Stephan 
Published: October 2016

AbstractSubduction zone mantle wedge temperatures impact plate interaction, melt generation, and chemical recycling. However, it has been challenging to reconcile geophysical and geochemical constraints on wedge thermal structure. Here we chemically determine the equilibration pressures and temperatures of primitive arc lavas from worldwide intraoceanic subduction zones and compare them to kinematically driven thermal wedge models. We find that equilibration pressures are typically located in the lithosphere, starting just below the Moho, and spanning a wide depth range of ∼25 km. Equilibration temperatures are high for these depths, averaging ∼1300°C. We test for correlations with subduction parameters and find that equilibration pressures correlate with upper plate age, indicating overriding lithosphere thickness plays a role in magma equilibration. We suggest that most, if not all, thermobarometric pressure and temperature conditions reflect magmatic reequilibration at a mechanical boundary, rather than reflecting the conditions of major melt generation. The magma reequilibration conditions are difficult to reconcile, to a first order, with any of the conditions predicted by our dynamic models, with the exception of subduction zones with very young, thin upper plates. For most zones, a mechanism for substantially thinning the overriding plate is required. Most likely thinning is localized below the arc, as kinematic thinning above the wedge corner would lead to a hot fore arc, incompatible with fore‐arc surface heat flow and seismic properties. Localized subarc thermal erosion is consistent with seismic imaging and exhumed arc structures. Furthermore, such thermal erosion can serve as a weakness zone and affect subsequent plate evolution.
Reverse flow events and small‐scale effects in the cusp ionosphere
Authors: Spicher A. , Ilyasov A. A. , Miloch W. J. , Chernyshov A. A. , Clausen L. B. N. , Moen J. I. , Abe T. , Saito Y. 
Published: October 2016

AbstractWe report in situ measurements of plasma irregularities associated with a reverse flow event (RFE) in the cuspFregion ionosphere. The Investigation of Cusp Irregularities 3 (ICI‐3) sounding rocket, while flying through a RFE, encountered several regions with density irregularities down to meter scales. We address in detail the region with the most intense small‐scale fluctuations in both the density and in the AC electric field, which were observed on the equatorward edge of a flow shear, and coincided with a double‐humped jet of fast flow. Due to its long‐wavelength and low‐frequency character, the Kelvin‐Helmholtz instability (KHI) alone cannot be the source of the observed irregularities. Using ICI‐3 data as inputs, we perform a numerical stability analysis of the inhomogeneous energy‐density‐driven instability (IEDDI) and demonstrate that it can excite electrostatic ion cyclotron waves in a wide range of wave numbers and frequencies for the electric field configuration observed in that region, which can give rise to the observed small‐scale turbulence. The IEDDI can seed as a secondary process on steepened vortices created by a primary KHI. Such an interplay between macroprocesses and microprocesses could be an important mechanism for ion heating in relation to RFEs.