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https://www.readbyqxmd.com/read/28340526/an-experimental-study-on-flow-and-heat-transfer-characteristics-of-ethanol-polyalphaolefin-nanoemulsion-flowing-through-circular-minichannels
#1
Vu Trinh, Jiajun Xu
This work experimentally studied the convective flow and heat transfer characteristics of a novel nanostructured heat transfer fluid: "ethanol/polyalphaolefin nanoemulsion" flowing through 12 circular minichannels of 1-mm diameter each. Ethanol/polyalphaolefin nanoemulsion is a thermodynamically stable system formed by dispersing ethanol into a mixture of "polyalphaolefin (PAO)" and surfactants. In this study, ethanol/PAO nanoemulsion is used as the working fluid to study the effect of ethanol nanodroplets on its convective flow and heat transfer characteristics...
December 2017: Nanoscale Research Letters
https://www.readbyqxmd.com/read/28339277/turbulence-nonlinearities-shed-light-on-geometric-asymmetry-in-tokamak-confinement-transitions
#2
I Cziegler, A E Hubbard, J W Hughes, J L Terry, G R Tynan
A comprehensive study of fully frequency-resolved nonlinear kinetic energy transfer has been performed for the first time in a diverted tokamak, providing new insight into the parametric dependences of edge turbulence transitions. Measurements using gas puff imaging in the turbulent L-mode state illuminate the source of the long known but as yet unexplained "favorable-unfavorable" geometric asymmetry of the power threshold for transition to the turbulence-suppressed H mode. Results from the recently discovered I mode point to a competition between zonal flow (ZF) and geodesic-acoustic modes (GAM) for turbulent energy, while showing new evidence that the I-to-H transition is still dominated by ZFs...
March 10, 2017: Physical Review Letters
https://www.readbyqxmd.com/read/28339257/erratum-model-for-plane-turbulent-couette-flow-phys-rev-lett-75-2956-1995
#3
Peter W Egolf, Daniel A Weiss
This corrects the article DOI: 10.1103/PhysRevLett.75.2956.
March 10, 2017: Physical Review Letters
https://www.readbyqxmd.com/read/28339251/distinct-turbulence-saturation-regimes-in-stellarators
#4
G G Plunk, P Xanthopoulos, P Helander
In the complex 3D magnetic fields of stellarators, ion-temperature-gradient turbulence is shown to have two distinct saturation regimes, as revealed by petascale numerical simulations and explained by a simple turbulence theory. The first regime is marked by strong zonal flows and matches previous observations in tokamaks. The newly observed second regime, in contrast, exhibits small-scale quasi-two-dimensional turbulence, negligible zonal flows, and, surprisingly, a weaker heat flux scaling. Our findings suggest that key details of the magnetic geometry control turbulence in stellarators...
March 10, 2017: Physical Review Letters
https://www.readbyqxmd.com/read/28335222/effects-of-atomization-injection-on-nanoparticle-processing-in-suspension-plasma-spray
#5
Hong-Bing Xiong, Cheng-Yu Zhang, Kai Zhang, Xue-Ming Shao
Liquid atomization is applied in nanostructure dense coating technology to inject suspended nano-size powder materials into a suspension plasma spray (SPS) torch. This paper presents the effects of the atomization parameters on the nanoparticle processing. A numerical model was developed to simulate the dynamic behaviors of the suspension droplets, the solid nanoparticles or agglomerates, as well as the interactions between them and the plasma gas. The plasma gas was calculated as compressible, multi-component, turbulent jet flow in Eulerian scheme...
May 20, 2016: Nanomaterials
https://www.readbyqxmd.com/read/28334026/exploring-the-link-between-multiscale-entropy-and-fractal-scaling-behavior-in-near-surface-wind
#6
Miguel Nogueira
The equivalency between the power law behavior of Multiscale Entropy (MSE) and of power spectra opens a promising path for interpretation of complex time-series, which is explored here for the first time for atmospheric fields. Additionally, the present manuscript represents a new independent empirical validation of such relationship, the first one for the atmosphere. The MSE-fractal relationship is verified for synthetic fractal time-series covering the full range of exponents typically observed in the atmosphere...
2017: PloS One
https://www.readbyqxmd.com/read/28332446/scaling-effects-in-spiral-capsule-robots
#7
Liang Liang, Rong Hu, Bai Chen, Yong Tang, Yan Xu
Spiral capsule robots can be applied to human gastrointestinal tracts and blood vessels. Because of significant variations in the sizes of the inner diameters of the intestines as well as blood vessels, this research has been unable to meet the requirements for medical applications. By applying the fluid dynamic equations, using the computational fluid dynamics method, to a robot axial length ranging from 10(-5) to 10(-2) m, the operational performance indicators (axial driving force, load torque, and maximum fluid pressure on the pipe wall) of the spiral capsule robot and the fluid turbulent intensity around the robot spiral surfaces was numerically calculated in a straight rigid pipe filled with fluid...
April 2017: Proceedings of the Institution of Mechanical Engineers. Part H, Journal of Engineering in Medicine
https://www.readbyqxmd.com/read/28332407/unsteady-computational-fluid-dynamics-in-front-crawl-swimming
#8
Mathias Samson, Anthony Bernard, Tony Monnet, Patrick Lacouture, Laurent David
The development of codes and power calculations currently allows the simulation of increasingly complex flows, especially in the turbulent regime. Swimming research should benefit from these technological advances to try to better understand the dynamic mechanisms involved in swimming. An unsteady Computational Fluid Dynamics (CFD) study is conducted in crawl, in order to analyse the propulsive forces generated by the hand and forearm. The k-ω SST turbulence model and an overset grid method have been used...
March 23, 2017: Computer Methods in Biomechanics and Biomedical Engineering
https://www.readbyqxmd.com/read/28331386/phylogenetic-analysis-of-the-genus-laparocerus-with-comments-on-colonisation-and-diversification-in-macaronesia-coleoptera-curculionidae-entiminae
#9
Antonio Machado, Eduardo Rodríguez-Expósito, Mercedes López, Mariano Hernández
The flightless Entiminae weevil genus Laparocerus is the species-richest genus, with 237 species and subspecies, inhabiting Macaronesia (Madeira archipelago, Selvagens, Canary Islands) and the continental 'Macaronesian enclave' in Morocco (one single polytypic species). This is the second contribution to gain insight of the genus and assist in its systematic revision with a mitochondrial phylogenetic analysis. It centres on the Canarian clade, adding the 12S rRNA gene to the combined set of COII and 16S rRNA used in our first contribution on the Madeiran clade (here re-analysed)...
2017: ZooKeys
https://www.readbyqxmd.com/read/28322436/modelling-hydraulic-transport-and-anaerobic-uptake-by-paos-and-gaos-during-wastewater-feeding-in-ebpr-granular-sludge-reactors
#10
David G Weissbrodt, Christof Holliger, Eberhard Morgenroth
New-generation bioprocesses using granular sludge aim for a high-rate removal of nutrients from wastewater with low footprint. Achieving enhanced biological phosphorus removal (EBPR) relies on the design of sludge beds and wastewater feeding conditions to optimally load the biomass and to select for polyphosphate- (PAOs) over glycogen-accumulating organisms (GAOs) and other heterotrophs. A hydraulic-metabolic mathematical model was developed to elucidate the impact of hydraulic transport patterns and environmental conditions on the PAO/GAO competition during up-flow feeding through an EBPR granular sludge bed...
March 21, 2017: Biotechnology and Bioengineering
https://www.readbyqxmd.com/read/28322219/two-dimensional-turbulence-in-symmetric-binary-fluid-mixtures-coarsening-arrest-by-the-inverse-cascade
#11
Prasad Perlekar, Nairita Pal, Rahul Pandit
We study two-dimensional (2D) binary-fluid turbulence by carrying out an extensive direct numerical simulation (DNS) of the forced, statistically steady turbulence in the coupled Cahn-Hilliard and Navier-Stokes equations. In the absence of any coupling, we choose parameters that lead (a) to spinodal decomposition and domain growth, which is characterized by the spatiotemporal evolution of the Cahn-Hilliard order parameter ϕ, and (b) the formation of an inverse-energy-cascade regime in the energy spectrum E(k), in which energy cascades towards wave numbers k that are smaller than the energy-injection scale kin j in the turbulent fluid...
March 21, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28321688/an-ethical-descriptive-framework-for-judgment-of-actions-and-decisions-in-the-construction-industry-and-engineering-part-i
#12
Omar J Alkhatib, Alaa Abdou
The construction industry is usually characterized as a fragmented system of multiple-organizational entities in which members from different technical backgrounds and moral values join together to develop a particular business or project. The greatest challenge in the construction process for the achievement of a successful practice is the development of an outstanding reputation, which is built on identifying and applying an ethical framework. This framework should reflect a common ethical ground for myriad people involved in this process to survive and compete ethically in today's turbulent construction market...
March 20, 2017: Science and Engineering Ethics
https://www.readbyqxmd.com/read/28321519/cardiac-autonomic-function-in-type-1-and-type-2-myotonic-dystrophy
#13
Piotr Bienias, Anna Łusakowska, Michał Ciurzyński, Zuzanna Rymarczyk, Katarzyna Irzyk, Michał Konwerski, Kamil Ciąpała, Paweł Kowalski, Anna Kamińska, Piotr Pruszczyk
OBJECTIVE: The aim of this study was to evaluate cardiac autonomic nervous system function using Holter-derived and standard electrocardiographic parameters in patients with myotonic dystrophy (dystrophia myotonica, DM) and no clinically overt heart involvement. METHODS: Eighty-four DM patients without conditions potentially influencing cardiac autonomic function were enrolled in the study: 44 with DM type 1 and 40 with DM type 2 (mean age 34.9 ± 11.5 and 47...
March 20, 2017: Clinical Autonomic Research: Official Journal of the Clinical Autonomic Research Society
https://www.readbyqxmd.com/read/28317480/novel-insights-into-complex-cardiovascular-pathologies-using-4d-flow-analysis-by-cardiovascular-magnetic-resonance-imaging
#14
Adam James Lewandowski, Betty Raman, Rajarshi Banerjee, Matteo Milanesi
BACKGROUND: It is essential that we are able to assess variations in blood flow in order to fully understand cardiovascular function in disease pathologies and for identification of individuals at long-term risk of cardiovascular disease development. Qualitative and quantitative assessments of blood flow by imaging modalities have been limited, and much of the accurate quantification has relied on invasive measures. METHODS: This review discusses how four-dimensional velocity cardiovascular magnetic resonance (4D flow CMR) offers increasing potential for the non-invasive assessment of blood flow in the heart and major blood vessels such as the aorta...
March 17, 2017: Current Pharmaceutical Design
https://www.readbyqxmd.com/read/28306291/new-paradigm-for-turbulent-transport-across-a-steep-gradient-in-toroidal-plasmas
#15
H S Xie, Y Xiao, Z Lin
First principles gyrokinetic simulation of the edge turbulent transport in toroidal plasmas finds a reverse trend in the turbulent transport coefficients under strong gradients. It is found that there exist both linear and nonlinear critical gradients for the nonmonotonicity of transport characteristics. The discontinuity of the transport flux slope around the turning gradient shows features of a second order phase transition. Under a strong gradient the most unstable modes are in nonground eigenstates with unconventional mode structures, which significantly reduces the effective correlation length and thus reverse the transport trend...
March 3, 2017: Physical Review Letters
https://www.readbyqxmd.com/read/28303015/spatio-temporal-dynamics-of-a-planktonic-system-and-chlorophyll-distribution-in-a-2d-spatial-domain-matching-model-and-data
#16
Davide Valenti, Giovanni Denaro, Rosalia Ferreri, Simona Genovese, Salvatore Aronica, Salvatore Mazzola, Angelo Bonanno, Gualtiero Basilone, Bernardo Spagnolo
Field data on chlorophyll distribution are investigated in a two-dimensional spatial domain of the Mediterranean Sea by using for phytoplankton abundances an advection-diffusion-reaction model, which includes real values for physical and biological variables. The study exploits indeed hydrological and nutrients data acquired in situ, and includes intraspecific competition for limiting factors, i.e. light intensity and phosphate concentration. As a result, the model allows to analyze how both the velocity field of marine currents and the two components of turbulent diffusivity affect the spatial distributions of phytoplankton abundances in the Modified Atlantic Water, the upper layer of the water column of the Mediterranean Sea...
March 16, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28302189/temporal-dynamics-of-rituals-in-obsessive-compulsive-disorder
#17
Robert W Bond, Stephen J Guastello, Andrea D Guastello
Obsessive-compulsive disorder (OCD) is characterized by obsessions, defined as intrusive and persistent thoughts, and compulsions, defined as repetitive ritualistic behaviors that attempt to neutralize the anxiety associated with the obsessions. The present study investigated the patterns of symptoms as they occur over time in order to generate new insights about the triggers to symptoms. Fourteen adult participants who met the DSM-5 criteria for OCD completed 7-day logbooks of daily activities including the times when they engaged in compulsive rituals...
April 2017: Nonlinear Dynamics, Psychology, and Life Sciences
https://www.readbyqxmd.com/read/28299809/bedside-screening-with-the-use-of-pocket-size-imaging-device-can-be-useful-for-ruling-out-carotid-artery-stenosis-in-patients-scheduled-for-cardiac-surgery
#18
Dominika Filipiak-Strzecka, Jarosław D Kasprzak, Ewa Szymczyk, Paulina Wejner-Mik, Piotr Lipiec
BACKGROUND: Patients (pts) scheduled for coronary artery bypass grafting, burdened with high risk of carotid stenosis, are recommended to undergo duplex ultrasonography (DUS) of carotid arteries. PURPOSE: To validate pocket-size imaging device (PSID) equipped with linear probe as an easily accessible tool enabling bedside screening for carotid artery stenosis (CAS). METHODS: A total of 100 pts (60 men, mean age 69±11 years) with multivessel coronary artery disease underwent bedside DUS of carotid arteries with the use of PSID performed by a cardiology resident trained in DUS...
March 16, 2017: Echocardiography
https://www.readbyqxmd.com/read/28297963/enhanced-settling-of-nonheavy-inertial-particles-in-homogeneous-isotropic-turbulence-the-role-of-the-pressure-gradient-and-the-basset-history-force
#19
M A T van Hinsberg, H J H Clercx, F Toschi
The Stokes drag force and the gravity force are usually sufficient to describe the behavior of sub-Kolmogorov-size (or pointlike) heavy particles in turbulence, in particular when the particle-to-fluid density ratio ρ_{p}/ρ_{f}≳10^{3} (with ρ_{p} and ρ_{f} the particle and fluid density, respectively). This is, in general, not the case for smaller particle-to-fluid density ratios, in particular not for ρ_{p}/ρ_{f}≲10^{2}. In that case the pressure gradient force, added mass effects, and the Basset history force also play important roles...
February 2017: Physical Review. E
https://www.readbyqxmd.com/read/28297949/criticality-and-turbulence-in-a-resistive-magnetohydrodynamic-current-sheet
#20
Alexander J Klimas, Vadim M Uritsky
Scaling properties of a two-dimensional (2d) plasma physical current-sheet simulation model involving a full set of magnetohydrodynamic (MHD) equations with current-dependent resistivity are investigated. The current sheet supports a spatial magnetic field reversal that is forced through loading of magnetic flux containing plasma at boundaries of the simulation domain. A balance is reached between loading and annihilation of the magnetic flux through reconnection at the current sheet; the transport of magnetic flux from boundaries to current sheet is realized in the form of spatiotemporal avalanches exhibiting power-law statistics of lifetimes and sizes...
February 2017: Physical Review. E
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