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Journal articles on the topic 'Faibles angles de diffusion'

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Author: Grafiati

Published: 10 December 2022

Last updated: 28 January 2023

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1

Rhaiem, H. Ben, D. Tessier, and Ch H. Pons. "Comportement hydrique et évolution structurale et texturale des montmorillonites au tours d'un cycle de dessiccation-humectation: partie I. Cas des montmorillonites calciques." Clay Minerals 21, no. 1 (March 1986): 9–29. http://dx.doi.org/10.1180/claymin.1986.021.1.02.

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RésuméL'évolution structurale et texturale ainsi que le comportement hydrique de deux montmorillonites-Ca (Wyoming et grecque) ont été éudiés par microscopic électronique à transmission (MET) et plus précisément par analyse de la diffusion aux petits angles des rayons X (DPAX). L'étude au MET a permis de montrer qu'à faible contrainte, le matériau est formé par un réseau de particules déformables délimitant des pores de grandes dimensions (~2μm). L'étude en DPAX des mêmes systèmes soumis à une contrainte de type succion a montré que: 1. Lors de la première dessiceation il y a d'abord déformation du réseau sans regroupement des particules (p ⩽ 1 bar), puis regroupement des particules face-face pour former des particules de plus grande épalsseur (p > 1 bar). On montre aussi que l'eau est essentiellement extraite de la porosité interparticulaire. 2. Lors de la réhydratation, on met en évidence qu'après dessiccation le système perd une grande partie de son aptitude à, reprendre de l'eau et que cette perte est d'autant plus importante que le niveau de dessiccation préalable a été élevé. Ceci est dû au falt qu'une partie de la porosité est réduite fi des espaces ayant la propriété de l'espace interfoliaire.

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2

Ruel, L., A. Rahmouni, A. Luciani, A. Gaston, and P. Brugières. "Estimation de la perfusion cerebrale par imagerie de diffusion a facteurs b faibles." Journal de Radiologie 86, no. 10 (October 2005): 1405. http://dx.doi.org/10.1016/s0221-0363(05)75706-1.

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3

Nallet, F. "Introduction à la diffusion aux petits angles." École thématique de la Société Française de la Neutronique 11 (2010): 17–42. http://dx.doi.org/10.1051/sfn/201011003.

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4

Pardo, B., F. Bridou, and M. Maaza. "Réflectométrie X et diffusion aux petits angles." Le Journal de Physique IV 06, no. C4 (July 1996): C4–351—C4–366. http://dx.doi.org/10.1051/jp4:1996432.

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5

Glättli, H. "La diffusion de neutrons aux petits angles." Le Journal de Physique IV 11, PR9 (November 2001): Pr9–19—Pr9–32. http://dx.doi.org/10.1051/jp4:2001902.

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6

Langlois, Simon. "Les réseaux personnels et la diffusion des informations sur les emplois." Articles 18, no. 2 (April 12, 2005): 213–45. http://dx.doi.org/10.7202/055748ar.

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L'auteur propose une approche déductive pour montrer comment la structure et le contenu des réseaux personnels de relations sociales affectent l'accès à l'information sur les offres d'emplois dans une organisation. L'analyse porte sur les conditions qui affectent l'utilisation des différents champs de relations sociales (relations de sociabilité, relations occupationnelles et relations indirectes) à l'intérieur des réseaux personnels, sur les rapports entre les informateurs et les répondants et sur la longueur des chaînes d'informations. Deux résultats en particulier pourront retenir l'attention : la position de classe ne suffit pas à expliquer l'accès à certains types de relations et les liens forts jouent un rôle important dans la diffusion d'informations sur les emplois alors que les liens faibles ne semblent caractériser qu'un certain type d'occupations, les cadres et les administrateurs.

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7

Jelali, M., A. Vignaud, L. Ruel, M. Bouanane, P. Brugière, A. Luciani, H. Kobeiter, Y. Allory, A. de Lataille, and A. Rahmouni. "Imagerie de diffusion a faibles valeurs de B Dans le cancer de la prostate." Journal de Radiologie 88, no. 10 (October 2007): 1454–55. http://dx.doi.org/10.1016/s0221-0363(07)81404-1.

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8

Cinque, L., L. Lombardi, and A. Rosenfeld. "Evaluating digital angles by a parallel diffusion process." Pattern Recognition Letters 16, no. 10 (October 1995): 1097–104. http://dx.doi.org/10.1016/0167-8655(95)00056-m.

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9

Lairez, D. "Introduction à la diffusion de neutrons aux petits angles." Journal de Physique IV (Proceedings) 103 (February 2003): 253–90. http://dx.doi.org/10.1051/jp4:200300010.

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10

Lazarian, Alex, and Siyao Xu. "Diffusion of Cosmic Rays in MHD Turbulence with Magnetic Mirrors." Astrophysical Journal 923, no. 1 (December 1, 2021): 53. http://dx.doi.org/10.3847/1538-4357/ac2de9.

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Abstract As the fundamental physical process with many astrophysical implications, the diffusion of cosmic rays (CRs) is determined by their interaction with magnetohydrodynamic (MHD) turbulence. We consider the magnetic mirroring effect arising from MHD turbulence on the diffusion of CRs. Due to the intrinsic superdiffusion of turbulent magnetic fields, CRs with large pitch angles that undergo mirror reflection, i.e., bouncing CRs, are not trapped between magnetic mirrors, but move diffusively along the turbulent magnetic field, leading to a new type of parallel diffusion, i.e., mirror diffusion. This mirror diffusion is in general slower than the diffusion of nonbouncing CRs with small pitch angles that undergo gyroresonant scattering. The critical pitch angle at the balance between magnetic mirroring and pitch-angle scattering is important for determining the diffusion coefficients of both bouncing and nonbouncing CRs and their scalings with the CR energy. We find nonuniversal energy scalings of diffusion coefficients, depending on the properties of MHD turbulence.

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11

Shreeve, R. P., Y. Elazar, J. W. Dreon, and A. Baydar. "Wake Measurements and Loss Evaluation in a Controlled Diffusion Compressor Cascade." Journal of Turbomachinery 113, no. 4 (October 1, 1991): 591–99. http://dx.doi.org/10.1115/1.2929120.

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The results of two component laser-Doppler velocimeter (LDV) surveys made in the near wake (to one fifth chord) of a controlled diffusion (CD) compressor blade in a large-scale cascade wind tunnel are reported. The measurements were made at three positive incidence angles from near design to angles thought to approach stall. Comparisons were made with calibrated pressure probe and hot-wire wake measurements and good agreement was found. The flow was found to be fully attached at the trailing edge at all incidence angles and the wake profiles were found to be highly skewed. Despite the precision obtained in the wake velocity profiles, the blade loss could not be evaluated accurately without measurements of the pressure field. The blade trailing edge surface pressures and velocity profiles were found to be consistent with downstream pressure probe measurements of loss, allowing conclusions to be drawn concerning the design of the trailing edge.

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12

Lairez, D. "Bonnes pratiques de la diffusion de neutrons aux petits angles." École thématique de la Société Française de la Neutronique 11 (2010): 43–69. http://dx.doi.org/10.1051/sfn/201011004.

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13

Halsey, T. C. "Can Characteristic Surface Angles be Stable in Diffusion-Limited Aggregation?" Europhysics Letters (EPL) 4, no. 3 (August 1, 1987): 315–21. http://dx.doi.org/10.1209/0295-5075/4/3/010.

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14

Yu, Hang. "Research on Diffusion Effect of Sewage Marine Discharge from Different Angles." Applied Mechanics and Materials 675-677 (October 2014): 551–55. http://dx.doi.org/10.4028/www.scientific.net/amm.675-677.551.

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The sewage diffusion is an environmental material for protecting marine environment. It plays an important role in port engineering. Its effect under deep water was carried out between different diffuser design parameters based on the hydraulic model test, and YangKou port sewage marine disposal project phase II was taken as an example. For this project, jet angle was controlled to be 0 degree, and horizontal angle was controlled to be 0 degree. It not only can ensure that sewage fully diluted mixed, also can avoid the premature convergence and sewage lifting. It is feasible for selecting large angle nozzle under deep water and there are some technical bases have been provided for other sewage marine disposal project.

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15

Baete, Steven H., Martijn A. Cloos, Ying-Chia Lin, Dimitris G. Placantonakis, Timothy Shepherd, and Fernando E. Boada. "Fingerprinting Orientation Distribution Functions in diffusion MRI detects smaller crossing angles." NeuroImage 198 (September 2019): 231–41. http://dx.doi.org/10.1016/j.neuroimage.2019.05.024.

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16

Sun, Jie, Wei Qiao, and Shuai Liu. "Fractal Diffusion Limited Aggregation of Soot Particles Based on Fuzzy Membership Functions." International Journal of Bifurcation and Chaos 29, no. 05 (May 2019): 1950073. http://dx.doi.org/10.1142/s0218127419500731.

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In this paper, the membership function in fuzzy systems is used in the Diffusion Limited Aggregation (DLA) model to investigate the fractal diffusion of soot particles from diesel engine emissions. The transformation of the morphology of soot particle aggregates and the control of fractal diffusion of soot particles are investigated by analyzing the nonlinear relationship between the motion steps and angles of diffusing particles. The simulation results demonstrate that the morphology of the aggregates varies from loose to compact by changing the particles’ motion steps and angles in membership functions. Meanwhile, the Ballistic Aggregation (BA)-like aggregates are obtained. Furthermore, the control of the morphology of soot particle aggregates is realized, which makes the settlement of the aggregates become easier. This will provide a reference for further understanding the growth mechanism of soot particle diffusion and enhancing the purification technology of the soot particles.

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17

Secondulfo, Laura, Melissa T. Hooijmans, Joep J. Suskens, Valentina Mazzoli, Mario Maas, Johannes L. Tol, Aart J. Nederveen, and Gustav J. Strijkers. "A diffusion tensor-based method facilitating volumetric assessment of fiber orientations in skeletal muscle." PLOS ONE 17, no. 1 (January 27, 2022): e0261777. http://dx.doi.org/10.1371/journal.pone.0261777.

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Background The purpose of this study was to develop a DTI-based method to quantitatively assess fiber angles and changes therein in leg muscles in order to facilitate longitudinal studies on muscle fiber architectural adaptations in healthy subjects. Methods The upper legs of five volunteers were scanned twice on the same day. The right lower legs of five volunteers were scanned twice with the ankle in three positions, i.e. -15° dorsiflexion, 0° neutral position, and 30° plantarflexion. The MRI protocols consisted of a noise scan, a 3-point mDixon scan and a DTI scan. Fiber-angle color maps were generated for four muscles in the upper legs and two muscles in the lower leg. Voxel-wise fiber angles (θ) were calculated from the angle between the principal eigenvector of the diffusion tensor and a reference line defined between the origo and insertion points of each muscle. Bland-Altman analysis, intraclass correlation coefficient (ICC), coefficient of variation (CV%), minimal detectable change (MDC), standard error (SE) and Friedman test were used for assessing the feasibility of this method and in order to have an indication of the repeatability and the sensitivity. Results Bland-Altman analysis showed good repeatability (CV%<10 and 0.7≤ICC≤0.9) with exception of the Tibialis Anterior (TA) muscle in dorsiflexion position(CV%: 12.2) and the Semitendinosus (ST) muscle (left leg) (CV%: 11.4). The best repeatability metrics were found for the SOL muscle in neutral position (CV%: 2.6). Changes in average θ in TA and SOL with ankle positions were observed in accordance with expected agonist and antagonist functions of both muscles. For example, for the anterior left compartment the change in fiber angle Δθ with respect to the neutral position Δθ = -1.6° ± 0.8° and 2.2° ± 2.8° (p = 0.008), for dorsiflexion and plantarflexion, respectively. Conclusion Our method facilitates fast inspection and quantification of muscle fiber angles in the lower and upper leg muscles in rest and detection of changes in lower-leg muscle fiber angles with varying ankle angles.

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18

HUSSAIN, M. S., A. H. DOGAR, A. QAYYUM, and S. A. ABBASI. "ANGULAR DISTRIBUTION OF TUNGSTEN MATERIAL AND ION FLUX DURING NANOSECOND PULSED LASER DEPOSITION." Surface Review and Letters 23, no. 03 (May 3, 2016): 1650004. http://dx.doi.org/10.1142/s0218625x16500049.

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Tungsten thin films were prepared by pulsed laser deposition (PLD) technique on glass substrates placed at the angles of 0[Formula: see text] to 70[Formula: see text] with respect to the target surface normal. Rutherford backscattering Spectrometry (RBS) analysis of the films indicated that about 90% of tungsten material flux is distributed in a cone of 40[Formula: see text] solid angle while about 54% of it lies even in a narrower cone of 10[Formula: see text] solid angle. Significant diffusion of tungsten in glass substrate has been observed in the films deposited at smaller angles with respect to target surface normal. Time-of-flight (TOF) measurements performed using Langmuir probe indicated that the most probable ion energy decreases from about 600 to 91[Formula: see text]eV for variation of [Formula: see text] from 0[Formula: see text] to 70[Formula: see text]. In general ion energy spread is quite large at all angles investigated here. The enhanced tungsten diffusion in glass substrate observed at smaller angles is most probably due to the higher ion energy and ion assisted recoil implantation of already deposited tungsten.

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19

Okabayashi, Akira, and Takao Morinari. "Anisotropic diffusion of conduction electron under antiferromagnetic spin configuration." International Journal of Modern Physics B 30, no. 31 (December 5, 2016): 1650226. http://dx.doi.org/10.1142/s021797921650226x.

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We consider a conduction electron that couples with the localized spins, which are close to the antiferromagnetic ordered state. We show that the hopping of the conduction electron is possible even if the neighboring spins are almost antiparallel, and the difference in the relative angles between the neighboring spins leads to anisotropic diffusion of the conduction electron. Our calculation supports the presence of the spinmotive force in antiferromagnets.

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20

Brusset, H. "La structure colloïdale des charbons (Diffusion des rayons X aux petits angles)." Bulletin des Sociétés Chimiques Belges 57, no. 7-9 (September 1, 2010): 373–80. http://dx.doi.org/10.1002/bscb.19480570711.

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21

D’Arrigo, G., and C. Spinella. "High Resolution Measurements of Two-dimensional Dopant Diffusion in Silicon." Microscopy and Microanalysis 6, no. 3 (May 2000): 237–45. http://dx.doi.org/10.1017/s1431927600000398.

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AbstractWe report detailed experimental results on the electrochemical selective etching of doped Si. By using transmission electron microscopy analyses and spreading resistance measurements we investigated the dependence of the etching selectivity on the different parameters of the electrochemical cell, i.e., bias voltage and chemical solution. In B-doped samples immersed in buffered HF, the increase of bias voltage from 0.5 to 1 V produces a slight improvement of the etching selectivity and a B concentration as low as 1 × 1017 cm−3 can be successfully delineated at 1 V. A further improvement is achieved by using HF:HNO3:CH3COOH or HF:HCl chemical mixtures for which the delineation sensitivity approaches the value of 1 × 1016 cm−3. In buffered HF As-doped regions can be delineated to a concentration of 2 × 1017 cm−3, independently of the bias voltage, in the range 2–4 V. These results were used to measure the 2D doping diffusion profiles in silicon wafers patterned with polycrystalline Si strips and implanted with As or B, by using different tilt and twist angles. The high resolution of the electrochemical delineation allowed us to evaluate very accurately the effects of the implant angles on the lateral doping distribution.

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22

Kim, Woo-Yul, Santhosh Senguttuvan, and Sung-Min Kim. "Effect of Rotor Spacing and Duct Diffusion Angle on the Aerodynamic Performances of a Counter-Rotating Ducted Fan in Hover Mode." Processes 8, no. 11 (October 23, 2020): 1338. http://dx.doi.org/10.3390/pr8111338.

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The aerodynamic performance of a counter-rotating ducted fan in hover mode is numerically analyzed for different rotor spacings and duct diffusion angles. The design of the counter-rotating fan is inspired by a custom-designed single rotor ducted fan used in a previous study. The numerical model to predict the aerodynamic performance of the counter-rotating ducted fan is developed by adopting the frozen rotor approach for steady-state incompressible flow conditions. The relative angle between the front and the rear rotor is examined due to the usage of the frozen rotor model. The results show that the variation of thrust for the different relative angles is extremely low. The aerodynamic performances are evaluated by comparing the thrust, thrust coefficient, power coefficient, and figure of merit (FOM). The thrust, thrust coefficient, and FOM slightly increase with increasing rotor spacing up to 200 mm, regardless of the duct diffusion angle, and reduce on further increase in the rotor spacing. The duct diffusion angle of 0° generates about 9% higher thrust and increases the FOM by 6.7%, compared with the 6° duct diffusion angle. The duct diffusion angle is highly effective in improving the thrust and FOM of the counter-rotating ducted fan, rather than the rotor spacing.

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23

D’Arrigo, G., and C. Spinella. "High Resolution Measurements of Two-dimensional Dopant Diffusion in Silicon." Microscopy and Microanalysis 6, no. 3 (May 2000): 237–45. http://dx.doi.org/10.1007/s100050010027.

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Abstract We report detailed experimental results on the electrochemical selective etching of doped Si. By using transmission electron microscopy analyses and spreading resistance measurements we investigated the dependence of the etching selectivity on the different parameters of the electrochemical cell, i.e., bias voltage and chemical solution. In B-doped samples immersed in buffered HF, the increase of bias voltage from 0.5 to 1 V produces a slight improvement of the etching selectivity and a B concentration as low as 1 × 1017 cm−3 can be successfully delineated at 1 V. A further improvement is achieved by using HF:HNO3:CH3COOH or HF:HCl chemical mixtures for which the delineation sensitivity approaches the value of 1 × 1016 cm−3. In buffered HF As-doped regions can be delineated to a concentration of 2 × 1017 cm−3, independently of the bias voltage, in the range 2–4 V. These results were used to measure the 2D doping diffusion profiles in silicon wafers patterned with polycrystalline Si strips and implanted with As or B, by using different tilt and twist angles. The high resolution of the electrochemical delineation allowed us to evaluate very accurately the effects of the implant angles on the lateral doping distribution.

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24

Abdulkarim, Assist Prof Dr Jassim M., Prof Dr Jamal Y. Al Abass, Paiman S. Salih, Shadi B. Ahmed, and Hanin N. Al-Kalany. "Impact of the Nozzle Angles on Counterflow Diffusion Flame to Strain Rate Variations." International Journal of Advanced Engineering Research and Science 3, no. 10 (2016): 197–205. http://dx.doi.org/10.22161/ijaers/3.10.31.

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25

YANG, Jun, Xitian PI, Liguo ZHANG, Xiangshao LIU, Jing YANG, Yi CAO, Wenxian ZHANG, and Xiaolin ZHENG. "Diffusion Characteristics of a T-type Microchannel with Different Configurations and Inlet Angles." Analytical Sciences 23, no. 6 (2007): 697–703. http://dx.doi.org/10.2116/analsci.23.697.

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26

Teixeira, J. "Remarques sur la notion de cohérence en diffusion de neutrons aux petits angles." École thématique de la Société Française de la Neutronique 11 (2010): 7–15. http://dx.doi.org/10.1051/sfn/201011002.

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27

Ilbas, Mustafa, and Serhat Karyeyen. "Turbulent diffusion flames of a low-calorific value syngas under varying turbulator angles." Energy 138 (November 2017): 383–93. http://dx.doi.org/10.1016/j.energy.2017.07.073.

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28

Tsui, Yeng-Yung, and Chia-Kang Wang. "Calculation of Laminar Separated Flow in Symmetric Two-Dimensional Diffusers." Journal of Fluids Engineering 117, no. 4 (December 1, 1995): 612–16. http://dx.doi.org/10.1115/1.2817311.

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This study is concerned with numerical analysis of laminar separated flow in symmetric, two-dimensional, straight-walled diffusers. With Reynolds numbers Re = 56 and 114 and expansion ratios ER = 3 and 4, totally, there are four cases considered. At the low Reynolds number and the low expansion ratio the flow in the diffuser is nearly symmetric to the center line, irrespective of the diffusion angle. As Reynolds number or expansion ratio increases, a large recirculation region forms at one side wall and a small one at the other side. For the case with Re = 114 and ER = 4 the small recirculating flow disappears at small diffusion angles and a third recirculating flow appear in the same side of the small main recirculation region for large diffusion angles. The pressure recovery reaches its peak value somewhere downstream of the reattachment point of the large recirculating flow. The effectiveness of the diffuser deteriorates as the diffusion angle increases, apart from that at Re = 56 the effectiveness increases from θ = 15 to 30 deg. Symmetric flow solutions can be obtained by incorporating a symmetric relaxation method. The pressure recovery is higher for the symmetric flow than that for the asymmetric flow owing to the weaker recirculating strength in the former.

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29

Schmitt, Boris, Katsiaryna Fedarava, Jan Falkenberg, Kai Rothaus, Narendra K. Bodhey, Carolin Reischauer, Sebastian Kozerke, et al. "Three-dimensional alignment of the aggregated myocytes in the normal and hypertrophic murine heart." Journal of Applied Physiology 107, no. 3 (September 2009): 921–27. http://dx.doi.org/10.1152/japplphysiol.00275.2009.

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Several observations suggest that the transmission of myocardial forces is influenced in part by the spatial arrangement of the myocytes aggregated together within ventricular mass. Our aim was to assess, using diffusion tensor magnetic resonance imaging (DT-MRI), any differences in the three-dimensional arrangement of these myocytes in the normal heart compared with the hypertrophic murine myocardium. We induced ventricular hypertrophy in seven mice by infusion of angiotensin II through a subcutaneous pump, with seven other mice serving as controls. DT-MRI of explanted hearts was performed at 3.0 Tesla. We used the primary eigenvector in each voxel to determine the three-dimensional orientation of aggregated myocytes in respect to their helical angles and their transmural courses (intruding angles). Compared with controls, the hypertrophic hearts showed significant increases in myocardial mass and the outer radius of the left ventricular chamber ( P < 0.05). In both groups, a significant change was noted from positive intruding angles at the base to negative angles at the ventricular apex ( P < 0.01). Compared with controls, the hypertrophied hearts had significantly larger intruding angles of the aggregated myocytes, notably in the apical and basal slices ( P < 0.001). In both groups, the helical angles were greatest in midventricular sections, albeit with significantly smaller angles in the mice with hypertrophied myocardium ( P < 0.01). The use of DT-MRI revealed significant differences in helix and intruding angles of the myocytes in the mice with hypertrophied myocardium.

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30

Quairel, Françoise, and Marie-Noëlle Auberger. "La diffusion de la RSE par la relation fournisseurs." Revue internationale P.M.E. 20, no. 3-4 (February 16, 2012): 69–94. http://dx.doi.org/10.7202/1008524ar.

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Les grands textes et références internationales confient aux grandes entreprises la responsabilité de diffuser les valeurs environnementales et sociales dans leur sphère d’influence. Cette vision « messianique » de leur responsabilité les conduit à promouvoir des pratiques RSE au sein de leur chaîne d’approvisionnement, notamment auprès de leurs fournisseurs et sous-traitants PME. Dans une vision managériale, elles demandent à leurs fournisseurs de signer des codes de conduite et autres clauses contractuelles pour se protéger des risques liés à un comportement non responsable. Quelle que soit la vision, les grandes entreprises sont considérées comme des acteurs majeurs de la diffusion de pratiques socialement et environnementalement responsables pour les PME de leur chaîne d’approvisionnement. À partir de cinq études de cas de grands groupes industriels considérés comme socialement responsables et à partir d’une enquête auprès de PME françaises, cet article se propose d’analyser les facteurs, freins ou leviers qui expliquent l’influence exercée sur les PME par la gestion « durable » de la relation fournisseurs. Il cherche à répondre à la question : dans quelle mesure les PME sont-elles poussées à adopter des politiques RSE par les grandes entreprises clientes ? Dans les pays développés comme la France, cette influence est faible, même lorsque les grands clients se disent engagés dans la RSE. Nous avons dégagé les principaux déterminants de cette influence : le degré de formalisation et surtout de contrôle des engagements demandés au fournisseur, le degré des contradictions entre les exigences économiques de prix toujours plus bas et les exigences de conformité avec les codes de conduite ou autres standards, la nature de la relation commerciale entre les acteurs basée sur un rapport de force économique dans une approche de stricte conformité ou basée sur la confiance, les relations personnelles et le partenariat gagnant-gagnant. Les grandes entreprises, même proactives, ne sont que de faibles leviers de la diffusion de la RSE chez leurs fournisseurs PME parce que tous ces facteurs jouent faiblement ou comme des freins, ce qui traduit une mise en œuvre encore très partielle des objectifs annoncés de développement durable au sein des services achat. Les objectifs et l’engagement du chef d’entreprise dans la PME constituent des facteurs clés pour l’adoption de stratégies RSE dans les PME et donc pour aller au-delà de la stricte conformité et transformer les exigences RSE du client en opportunités. Nous proposons huit types de réponses stratégiques des PME fournisseurs aux exigences de leurs clients en fonction des facteurs dégagés ci-dessous.

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31

Auvray, L., and A. Brûlet. "Diffusion de neutrons aux petits angles appliquée aux études d'interfaces et de systèmes confinés." École thématique de la Société Française de la Neutronique 12 (2007): 179–205. http://dx.doi.org/10.1051/sfn:20070014.

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32

Ma, G. F., H. F. Zhang, H. Li, and Z. Q. Hu. "Contact angles and diffusion of molten Bi–Sn alloy on amorphous and crystalline Fe78B13Si9." Materials Letters 63, no. 18-19 (July 2009): 1605–7. http://dx.doi.org/10.1016/j.matlet.2009.04.026.

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33

Lairez, D., and J. Pelta. "Diffusion de neutrons aux petits angles : application à l'étude des macromolécules biologiques en solution." Journal de Physique IV (Proceedings) 130 (November 2005): 39–62. http://dx.doi.org/10.1051/jp4:2005130003.

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34

Su, Zhenpeng, Fuliang Xiao, Huinan Zheng, and Shui Wang. "Combined radial diffusion and adiabatic transport of radiation belt electrons with arbitrary pitch angles." Journal of Geophysical Research: Space Physics 115, A10 (October 2010): n/a. http://dx.doi.org/10.1029/2010ja015903.

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35

Geerts, L., P. Bovendeerd, K. Nicolay, and T. Arts. "Characterization of the normal cardiac myofiber field in goat measured with MR-diffusion tensor imaging." American Journal of Physiology-Heart and Circulatory Physiology 283, no. 1 (July 1, 2002): H139—H145. http://dx.doi.org/10.1152/ajpheart.00968.2001.

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Cardiac myofiber orientation is a crucial determinant of the distribution of myocardial wall stress. Myofiber orientation is commonly quantified by helix and transverse angles. Accuracy of reported helix angles is limited. Reported transverse angle data are incomplete. We measured cardiac myofiber orientation postmortem in five healthy goat hearts using magnetic resonance-diffusion tensor imaging. A novel local wall-bound coordinate system was derived from the characteristics of the fiber field. The transmural course of the helix angle corresponded to data reported in literature. The mean midwall transverse angle ranged from −12 ± 4° near the apex to +9.0 ± 4° near the base of the left ventricle, which is in agreement with the course predicted by Rijcken et al. (18) using a uniform load hypothesis. The divergence of the myofiber field was computed, which is a measure for the extent to which wall stress is transmitted through the myofiber alone. It appeared to be <0.07 mm−1 throughout the myocardial walls except for the fusion sites between the left and right ventricles and the insertion sites of the papillary muscles.

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36

Liu, Tianshu. "Optimum Bifurcating-Tube Tree for Gas Transport." Journal of Fluids Engineering 127, no. 3 (March 2, 2005): 550–53. http://dx.doi.org/10.1115/1.1899168.

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This paper describes optimality principles for the design of an engineering bifurcating-tube tree consisting of the convection and diffusion zones to attain the most effective gas transport. An optimality principle is formulated for the diffusion zone to maximize the total diffusion mass-transfer rate of gas across tube walls under a constant total-volume constraint. This optimality principle produces a new diameter distribution for the diffusion zone in contrast to the classical distribution for the convection zone. In addition. this paper gives a length distribution for an engineering tree based on an optimality principle for minimizing the total weight of the tree under constraints of a finite surface and elastic criteria for structural stability. Furthermore, the optimum branching angles are evaluated based on local optimality principles for a single bifurcating-tube branch.

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37

Negendank, Maik, Constanze Weber, Soeren Mueller, and Walter Reimers. "Coextrusion and Mechanical Characterization of Aluminum Coated Mg-Profiles." Key Engineering Materials 554-557 (June 2013): 767–75. http://dx.doi.org/10.4028/www.scientific.net/kem.554-557.767.

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Due to their low density and high specific strengths Mg-alloys provide an excellent potential to be used for light weight constructions. However, their equilibrium potential is very low resulting in relatively low corrosion resistance, especially in contact with other, more noble metals. In order to separate Mg from a corrosive environment hybrid billets with Al-alloy coating and AZ31-core were coextruded. Thus, the extrusion and coating of Mg-profiles can be done in a single production step, resulting in aluminum coated Mg-profiles. The influence of the extrusion ratio as well as of different die angles on the formation of diffusion layers at the interface was investigated. Furthermore the phases formed in the diffusion zones were analyzed using EDS and synchrotron XRD. Additionally, FEM-simulations were conducted in order to reveal the material flow of core and shell material during the forming process and to identify differences in using different die angles. The FEM-results were verified by comparison with the real extrusion experiments. Finally, the shear strengths of the produced compounds were evaluated in push-out tests.

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Hsu, E. W., A. L. Muzikant, S. A. Matulevicius, R. C. Penland, and C. S. Henriquez. "Magnetic resonance myocardial fiber-orientation mapping with direct histological correlation." American Journal of Physiology-Heart and Circulatory Physiology 274, no. 5 (May 1, 1998): H1627—H1634. http://dx.doi.org/10.1152/ajpheart.1998.274.5.h1627.

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Functional properties of the myocardium are mediated by the tissue structure. Consequently, proper physiological studies and modeling necessitate a precise knowledge of the fiber orientation. Magnetic resonance (MR) diffusion tensor imaging techniques have been used as a nondestructive means to characterize tissue fiber structure; however, the descriptions so far have been mostly qualitative. This study presents a direct, quantitative comparison of high-resolution MR fiber mapping and histology measurements in a block of excised canine myocardium. Results show an excellent correspondence of the measured fiber angles not only on a point-by-point basis (average difference of −2.30 ± 0.98°, n = 239) but also in the transmural rotation of the helix angles (average correlation coefficient of 0.942 ± 0.008 with average false-positive probability of 0.004 ± 0.001, n = 24). These data strongly support the hypothesis that the eigenvector of the largest MR diffusion tensor eigenvalue coincides with the orientation of the local myocardial fibers and underscore the potential of MR imaging as a noninvasive, three-dimensional modality to characterize tissue fiber architecture.

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39

Sanger, N. L., and R. P. Shreeve. "Comparison of Calculated and Experimental Cascade Performance for Controlled-Diffusion Compressor Stator Blading." Journal of Turbomachinery 108, no. 1 (July 1, 1986): 42–50. http://dx.doi.org/10.1115/1.3262023.

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The midspan section of a previously reported controlled-diffusion compressor stator has been experimentally evaluated in cascade. Measurements were taken over a range of incidence angles for blade chord Reynolds numbers from 470,000 to 690,000. Blade chord length was 12.7 cm, aspect ratio was 2.0, and solidity was 1.67. Measurements included conventional cascade performance parameters as well as blade surface pressures. Computations were made for the inviscid flow field, surface boundary layers, and loss for several of the blade inlet angle conditions, and compared against corresponding data.

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40

Jiang, Lei, Songyan Li, Jiqian Wang, Limin Yang, Qian Sun, and Zhaomin Li. "Surface Wettability of Oxygen Plasma Treated Porous Silicon." Journal of Nanomaterials 2014 (2014): 1–6. http://dx.doi.org/10.1155/2014/526149.

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Oxygen plasma treatment on porous silicon (p-Si) surfaces was studied as a practical and effective means to modify wetting properties of as-fabricated p-Si surfaces, that is, contact angles of the p-Si materials. P-Si samples spanning a wide range of surface nanostructures have been fabricated which were subjected to a series of oxygen plasma treatments. Reduction of the p-Si surface contact angles has been systematically observed, and the surface activation rate constant as a function of different pore geometries has been analyzed to achieve an empirical equation. The underlying diffusion mechanisms have been discussed by taking into account of different pore diameters of p-Si samples. It is envisaged that such an approach as well as the corresponding empirical equation may be used to provide relevant process guidance in order to achieve precise control of p-Si contact angles, which is essential for many p-Si applications especially in biosensor areas.

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41

FEHRIBACH, J. D. "Diffusion-reaction-conduction processes in porous electrodes: the electrolyte wedge problem." European Journal of Applied Mathematics 12, no. 1 (February 2001): 77–96. http://dx.doi.org/10.1017/s0956792501004454.

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This work studies mathematical issues associated with steady-state modelling of diffusion- reaction-conduction processes in an electrolyte wedge (meniscus corner) of a current-producing porous electrode. The discussion is applicable to various electrodes where the rate-determining reaction occurs at the electrolyte-solid interface; molten carbonate fuel cell cathodes are used as a specific example. New modelling in terms of component potentials (linear combinations of electrochemical potentials) is shown to be consistent with tradition concentration modelling. The current density is proved to be finite, and asymptotic expressions for both current density and total current are derived for suffciently small contact angles. Finally, numerical and asymptotic examples are presented to illustrate the strengths and weaknesses of these expressions.

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42

Wang, En Yu, Jing Qin, Xing Xiang, and Jin Xiang Wu. "Influence of Jet Angle on Diffusion Flames in Centrifugal Field." Applied Mechanics and Materials 694 (November 2014): 181–86. http://dx.doi.org/10.4028/www.scientific.net/amm.694.181.

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Diffusion combustion of propane and air in a rotational combustor was simulated by three-dimensional numerical model based on FLUENT. Influence of centrifugal field on the flame shapes and temperatures were discussed under various jet angles changing in the plane perpendicular to the rotational axis. The flame is compressed when the value of jet angle θ is less 90°, otherwise, the flame is stretched when |θ|>90°. When θ<90°, the deflection of flame becomes larger with an increase of θ. As contrasted to positive θ cases, the zones of high temperature in combustion chamber corresponding to negative are larger, and the maximal flame temperatures are likewise larger. The negative jet angle is useful to flame stability. External fluid is an important factor influence the distribution of temperature in combustion chamber.

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43

Sinha, Usha, Shantanu Sinha, John A. Hodgson, and Reggie V. Edgerton. "Human soleus muscle architecture at different ankle joint angles from magnetic resonance diffusion tensor imaging." Journal of Applied Physiology 110, no. 3 (March 2011): 807–19. http://dx.doi.org/10.1152/japplphysiol.00923.2010.

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The orientation of muscle fibers influences the physiological cross-sectional area, the relationship between fiber shortening and aponeurosis shear, and the total force produced by the muscle. Such architectural parameters are challenging to determine particularly in vivo in multicompartment structures such as the human soleus with a complex arrangement of muscle fibers. The objective of this study was to map the fiber architecture of the human soleus in vivo at rest in both neutral and plantarflexed ankle positions using an MRI-based method of diffusion tensor imaging (DTI). Six subjects were imaged at 3 Tesla with the foot at rest in the two ankle positions. Eigenvalues, fractional anisotropy (FA), and eigenvector orientations of fibers in the different soleus subcompartments were evaluated after denoising of the diffusion tensor. The fiber architecture from DTI was similar to earlier studies based on a 3D fiber model from cadavers. The three eigenvalues of the diffusion tensor increased by ∼14% on increasing the joint plantarflexion angle in all of the soleus subcompartments, whereas FA showed a trend to decrease in the posterior and marginal soleus and to increase in the anterior soleus. The angle change in the lead eigenvector between the two foot positions was significant: ∼41° for the posterior soleus and ∼48° for the anterior soleus. Fibers tracked from the subcompartments support these changes seen in the eigenvector orientations. DTI-derived, subject-specific, muscle morphological data could potentially be used to model a more complete description of muscle performance and changes from disease.

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Belloni, L. "La Diffusion de Neutrons aux Petits Angles : mécanique statistique des liquides et traitement des données." École thématique de la Société Française de la Neutronique 11 (2010): 71–88. http://dx.doi.org/10.1051/sfn/201011005.

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Yu, Hang. "Research on Diffusion Effect from Different Angles of Yangkou Sewage Marine Discharge Engineering Phase I." Advanced Materials Research 1065-1069 (December 2014): 3182–86. http://dx.doi.org/10.4028/www.scientific.net/amr.1065-1069.3182.

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The sewage diffusion is an environmental material for protecting marine environment. It plays an important role in port engineering. Its effect under deep water was carried out between different diffuser design parameters based on the hydraulic model test, and YangKou port sewage marine disposal project phase I was taken as an example. For this project, jet angle was controlled to be 0 degree, and horizontal angle was controlled to be 0 degree. It not only can ensure that sewage fully diluted mixed, also can avoid the premature convergence and sewage lifting. It is feasible for selecting large angle nozzle under deep water and there are some technical bases have been provided for other sewage marine disposal project.

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Kagaya, Takashi, and Yoshihito Kohsaka. "Existence of Non-convex Traveling Waves for Surface Diffusion of Curves with Constant Contact Angles." Archive for Rational Mechanics and Analysis 235, no. 1 (July 16, 2019): 471–516. http://dx.doi.org/10.1007/s00205-019-01426-0.

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47

Dai, Houping, Dongdong Chen, and Zhoushun Zheng. "Modelling the Sintering Neck Growth Process of Metal Fibers under the Surface Diffusion Mechanism Using the Lattice Boltzmann Method." Metals 9, no. 5 (May 27, 2019): 614. http://dx.doi.org/10.3390/met9050614.

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In this paper, the sintering neck growth process of metal fibers under the surface diffusion mechanism is simulated by using the Lattice Boltzmann method (LBM). The surface diffusion model is developed considering the geometrical characteristic of metal fibers. Then, the LBM scheme is constructed for solving the developed surface diffusion model. The sintering neck growth process of two metal fibers with different fiber angles is simulated by LBM. The simulated morphologies of sintering metal fibers well agree with ones obtained by experiments. Moreover, the numerical simulation results show that the sintering neck radius of two metal fibers is increased with the increase of fiber angle, which implies that the initial geometrical characteristic plays an important role in the sintering neck formation and growth of metal fibers.

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48

Elazar, Y., and R. P. Shreeve. "Viscous Flow in a Controlled Diffusion Compressor Cascade With Increasing Incidence." Journal of Turbomachinery 112, no. 2 (April 1, 1990): 256–65. http://dx.doi.org/10.1115/1.2927642.

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A detailed two-component LDV mapping of the flow through a controlled diffusion compressor cascade at low Mach number ( ~ 0.25) and Reynolds number of about 7 × 105, at three inlet air angles from design to near stall, is reported. It was found that the suction-side boundary layer reattached turbulent after a laminar separation bubble, and remained attached to the trailing edge even at the highest incidence, at which losses were 3 to 4 times the minimum value for the geometry. Boundary layer thickness increased to fill 20 percent of the blade passage at the highest incidence. Results for pressure-side boundary layer and near-wake also are summarized. Information sufficient to allow preliminary assessment of viscous codes is tabulated.

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Lubchich, A. A., A. G. Yahnin, E. E. Titova, A. G. Demekhov, V. Yu Trakhtengerts, J. Manninen, and T. Turunen. "Longitudinal drift of substorm electrons as the reason of impulsive precipitation events and VLF emissions." Annales Geophysicae 24, no. 10 (October 20, 2006): 2667–84. http://dx.doi.org/10.5194/angeo-24-2667-2006.

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Abstract. Using the data from satellite CRRES and three geostationary LANL spacecraft, the propagation of an electron cloud from midnight to the evening sector is investigated. An electron cloud was injected during a weak isolated substorm that developed on a quiet geomagnetic background. It is found that within the local time sector from 03:00 until at least 08:00 MLT, the propagation of electrons at perpendicular pitch-angles is well described by a simple model of drift in the dipole magnetic field. The flux levels in the field-aligned electrons increase simultaneously with the flux at perpendicular pitch angles, which is attributed to the pitch angle diffusion by the whistler mode. This pitch-angle diffusion leads to precipitation of electrons from a drifting cloud and an increase in the ionospheric electron density, simultaneously observed above Tromsø, Norway, by the EISCAT UHF radar in the morning sector (04:40–05:25 MLT). The precipitation develops as quasi-periodic pulses with a period of about 100 s. We discuss the models of pulsating precipitation due to the whistler cyclotron instability and show that our observations can be explained by such a model.

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Choi, Junho, Wei-Ting Hsu, Li-Syuan Lu, Liuyang Sun, Hui-Yu Cheng, Ming-Hao Lee, Jiamin Quan, et al. "Moiré potential impedes interlayer exciton diffusion in van der Waals heterostructures." Science Advances 6, no. 39 (September 2020): eaba8866. http://dx.doi.org/10.1126/sciadv.aba8866.

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The properties of van der Waals heterostructures are drastically altered by a tunable moiré superlattice arising from periodically varying atomic alignment between the layers. Exciton diffusion represents an important channel of energy transport in transition metal dichalcogenides (TMDs). While early studies performed on TMD heterobilayers suggested that carriers and excitons exhibit long diffusion, a rich variety of scenarios can exist. In a moiré crystal with a large supercell and deep potential, interlayer excitons may be completely localized. As the moiré period reduces at a larger twist angle, excitons can tunnel between supercells and diffuse over a longer lifetime. The diffusion should be the longest in commensurate heterostructures where the moiré superlattice is completely absent. Here, we experimentally demonstrate the rich phenomena of interlayer exciton diffusion in WSe2/MoSe2 heterostructures by comparing several samples prepared with chemical vapor deposition and mechanical stacking with accurately controlled twist angles.

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