Interaction effects within Langmuir layers and three-dimensional arrays of ε-Co nanoparticles

2006 ◽  
Vol 99 (8) ◽  
pp. 08C302 ◽  
Author(s):  
M. Sachan ◽  
N. D. Walrath ◽  
S. A. Majetich ◽  
K. Krycka ◽  
Chi-Chang Kao
Keyword(s):  
Three Dimensional ◽  
Interaction Effects ◽  
Co Nanoparticles

Streckziehen keramischer Grünfolien*/Stretch drawing of ceramic green tapes - Investigation of the factors influencing to the stretch drawing capacity of ceramic green tapes

2016 ◽  
Vol 106 (11-12) ◽  
pp. 847-850
Author(s):  
Q. Spiller ◽  
M. Baumeister ◽  
J. Prof. Fleischer
Keyword(s):  
Statistical Methods ◽  
Three Dimensional ◽  
Interaction Effects ◽  
Powder Technology ◽  
Factors Influencing ◽  
Statistische Methoden ◽  
Main Effects

Im Bereich der Pulvertechnologie stellt das Streckziehen keramischer Grünfolien eine wirtschaftliche Möglichkeit dar, dreidimensionale Halbzeuge herzustellen. Im Rahmen des AiF-Projekts „Inka“ werden die Einflüsse der Prozess- und Geometrieparameter auf die Streckziehfähigkeit von keramischen Grünfolien aus dem Werkstoff ZrO2 experimentell untersucht. Dabei kommen statistische Methoden zur Ermittlung der Haupt- und Wechselwirkungseffekte zum Einsatz.   In the field of powder technology stretch drawing is an economic way to produce three-dimensional semi-finished products. In the context of the AIF Project “Inka“ the influences of process and geometry parameters are experimental examined on stretch drawing capacity of ceramic green tapes of material ZrO2. Statistical methods are used to find out main effects and interaction effects.

Three-Dimensional Interaction Effects in an Internally Multicracked Pressurized Thick-Walled Cylinder— Part I: Radial Crack Arrays

1996 ◽  
Vol 118 (3) ◽  
pp. 357-363 ◽  
Author(s):  
M. Perl ◽  
C. Levy ◽  
J. Pierola
Keyword(s):  
Radial Crack ◽  
Crack Depth ◽  
Three Dimensional ◽  
Internal Surface ◽  
Interaction Effects ◽  
Life Assessment ◽  
Fatigue Life Assessment ◽  
Dimensional Interaction ◽  
Least Squares Fit ◽  
Wide Range

Under certain conditions, numerous internal surface cracks develop in pressurized thick-walled cylinders, both in the radial and longitudinal directions. For fatigue life assessment of such vessels, the 3-D interaction effects among these cracks on the prevailing stress intensity factors (SIFs) need evaluation. In Part I of this paper, radial crack arrays are considered exclusively. The mode I SIF distribution for a wide range of semi-circular and semi-elliptical cracks are evaluated. The 3-D analysis is performed via the finite element method with the submodeling technique, employing singular elements along the crack front. SIFs are evaluated for arrays of up to n = 180 cracks; for a wide range of crack depth to wall thickness ratios, a/t, from 0.05 to 0.6; and, for various ellipticities of the crack, i.e., the ratio of crack depth to semicrack length, a/c, from 0.2 to 2. Using a least-squares fit, two simple expressions for the most critical (n = 2) SIFs are obtained for sparse and dense crack arrays. The formulas, which are functions of a/t and a/c, are of very good engineering accuracy. The results clearly indicate that the SIFs are considerably affected by the interaction among the cracks in the array as well as the three-dimensionality of the problem. In Part II of this paper, the interaction effects between longitudinal coplanar cracks will be analyzed.

scholarly journals Computed Eccentricity Effects on Turbine Rim Seals at Engine Conditions With a Mainstream

1994 ◽  
Author(s):  
Zhou Guo ◽  
David L. Rhode ◽  
Fred M. Davis
Keyword(s):  
Reynolds Number ◽  
Temperature Rise ◽  
Three Dimensional ◽  
Computer Code ◽  
Interaction Effects ◽  
Navier Stokes ◽  
Radial Clearance ◽  
Turbine Wheel ◽  
Blade Root

A previously verified axisymmetric Navier-Stokes computer code was extended for three-dimensional computation of eccentric rim seals of almost any configuration. All compressibility and thermal/momentum interaction effects are completely, included, and the temperature, pressure and Reynolds number of the mainstream, coolant stream and turbine wheel are fixed at actual engine conditions. Regardless of the seal eccentricity, both ingress and egress are found between θ = −30° and 100°. which encompasses the location of maximum radial clearance at θ = 0°. All other θ locations within the rim seal show only egress, as does the concentric basecase for all circumferential locations. Further, the maximum ingress occurs near θ = 30° for all eccentricities. This is found to produce a blade root/retainer temperature rise from the concentric case of 390 percent at 50 percent eccentricity and a 77 percent rise at 7.5 percent eccentricity. In addition, the nature of an increased eccentricity causing a decreased seal effectiveness is examined, along with the corresponding increase of cavity-averaged temperature.

scholarly journals New Insights into the Electrocatalytic Mechanism of Methanol Oxidation on Amorphous Ni-B-Co Nanoparticles in Alkaline Media

Catalysts ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 749 ◽  
Author(s):  
Wu ◽  
Zhang ◽  
Zhang ◽  
Duan ◽  
Li ◽  
...  
Keyword(s):  
Methanol Oxidation ◽  
Amorphous Materials ◽  
Reaction Order ◽  
Chemical Reduction ◽  
Three Dimensional ◽  
Kinetic Studies ◽  
Alkaline Media ◽  
Methanol Oxidation Reaction ◽  
Oxidation Reactions ◽  
Co Nanoparticles

Despite an increased interest in sustainable energy conversion systems, there have been limited studies investigating the electrocatalytic reaction mechanism of methanol oxidation on Ni-based amorphous materials in alkaline media. A thorough understanding of such mechanisms would aid in the development of amorphous catalytic materials for methanol oxidation reactions. In the present work, amorphous Ni-B and Ni-B-Co nanoparticles were prepared by a simple chemical reduction, and their electrocatalytic properties were investigated by cyclic voltammetry measurements. The diffusion coefficients (D0) for Ni-B, Ni-B-Co0.02, Ni-B-Co0.05, and Ni-B-Co0.1 nanoparticles were calculated to be 1.28 × 10−9, 2.35 × 10−9, 4.48 × 10−9 and 2.67 × 10−9 cm2 s−1, respectively. The reaction order of methanol in the studied transformation was approximately 0.5 for all studied catalysts, whereas the reaction order of the hydroxide ion was nearly 1. The activation energy (Ea) values of the reaction were also calculated for the Ni-B and Ni-B-Co nanoparticle systems. Based on our kinetic studies, a mechanism for the methanol oxidation reaction was proposed which involved formation of an electrocatalytic layer on the surface of amorphous Ni–B and Ni-B-Co nanoparticles. And methanol and hydroxide ions could diffuse freely through this three-dimensional porous conductive layer.

Matrix and interaction effects on the magnetic properties of Co nanoparticles embedded in gold and vanadium

2013 ◽  
Vol 15 (1) ◽  
pp. 316-329 ◽  
Author(s):  
M. Ruano ◽  
M. Díaz ◽  
L. Martínez ◽  
E. Navarro ◽  
E. Román ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Interaction Effects ◽  
Co Nanoparticles

Wave-Current Interaction Effects on Airgap Calculations

2017 ◽  
Author(s):  
Elin Marita Hermundstad ◽  
Jan Roger Hoff ◽  
Nuno Fonseca ◽  
Rune Bjørkli
Keyword(s):  
Significant Influence ◽  
Three Dimensional ◽  
Interaction Effects ◽  
Offshore Structures ◽  
The Body ◽  
Linear Potential ◽  
Hydrodynamic Coupling ◽  
Motion Responses ◽  
Motion Modes ◽  
Current Interaction

The importance of wave-current interaction effects on the determination of mean drift forces on floating offshore structures is well documented. Wave-current interaction effects will also influence the first-order motions and loads as well as the diffracted and radiated waves around the structure. One of the significant contributions to the influence of wave-current interaction effects on the motion responses is the additional coupling between motion modes due to the current. These effects are well known from seakeeping calculations of ships with forward speed. A structure with fore-aft symmetry will have no hydrodynamic coupling between heave and pitch in regular waves only. Due to the presence of a current, the symmetry of the flow around the body is lost, resulting in hydrodynamic coupling between the modes. This will also occur for a moored structure with slowly varying motions in the horizontal plane. The most important couplings are from the heave motion into pitch and surge and from heave to roll and sway. These couplings are otherwise present only for asymmetric structures. Due to the presence of the heave resonance and cancellation periods, the motion responses in roll and pitch for a semi-submersible will be influenced by the wave-current interaction effects. Due to the differences in phase between the different motion modes, the hydrodynamic coupling may have significant influence on the rotational motions roll and pitch and thus significant influence on the prediction of airgap. This coupling between the heave and roll/pitch modes due to the current adds complexity to the numerical simulations since the structure responses are more sensitive to the actual orientation of the structure, mooring configuration etc. A three-dimensional linear potential flow code, MULDIF, has been developed by SINTEF Ocean. This code accounts for hydrodynamic interaction between waves and current from arbitrary directions. The code can be applied to single or multiple bodies in infinite or finite water depth. Verification studies have previously shown good agreement with other numerical codes, Hermundstad et.al. [1], Zhiyuan et.al [2]. Validation studies with emphasis on airgap and comparison with experimental results are presented and numerical results for airgap and upwell are visualized and discussed. It is demonstrated how MULDIF can be used in airgap studies.

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