scholarly journals Form Birefringence Effect of Ultradrawn Polyethylene Determined by Two Dimensional Composite Structural Model

1991 ◽  
Vol 23 (10) ◽  
pp. 1149-1155
Author(s):  
Masaru Matsuo ◽  
Tetsuya Ogita
Keyword(s):  
Structural Model ◽  
Two Dimensional ◽  
Form Birefringence ◽  
Birefringence Effect

scholarly journals Preferred ion diffusion pathways and activation energies for Ag in the crystal structure of stephanite, Ag5SbS4

2009 ◽  
Vol 73 (1) ◽  
pp. 17-26 ◽  
Author(s):  
M. Leitl ◽  
A. Pfitzner ◽  
L. Bindi
Keyword(s):  
Crystal Structure ◽  
Electron Density ◽  
Structural Model ◽  
Careful Analysis ◽  
Type Locality ◽  
Two Dimensional ◽  
Ionic Conductors ◽  
Ion Diffusion ◽  
Unit Cell Parameters ◽  
Cell Parameters

The crystal structure of stephanite fromthe type locality, Freiberg District, Saxony, Germany, was refined in the space group Cmc21, up to a final R index of 0.0427. Unit-cell parameters are: a 7.8329(6) Å, b 12.458(1) Å, c 8.5272(7) Å, V 832.1(1) Å3; Z = 4. The previously reported structural model is confirmed, but a higher-precision refinement was achieved herein by the introduction of thirdorder non-harmonic Gram-Charlier tensors for one Ag atom. In the structure of stephanite, Sb forms isolated SbS3 pyramids, which typically occur in sulphosalts, and Ag occupies sites with coordination ranging fromtriangular to almost tetrahedral. Both the Sb–S and Ag–S bond distances closely match the values commonly observed in the structures of other Ag sulphosalts and sulphides.The use of non-harmonic parameters for Ag allowed a better description of the electron density related to Ag, which is usually difficult to refine in good ionic conductors. A careful analysis of the energy barriers between the Ag sites defines preferred ion-diffusion pathways within the crystal structure of stephanite. The diffusion of Ag ions occurs preferentially along the sites Ag1 and Ag2, giving rise to two-dimensional nets of Ag atoms in which the ion conduction probably takes place.

A two-dimensional/three-dimensional hybrid structural model of the vocal folds

2011 ◽  
Vol 130 (4) ◽  
pp. 2550-2550
Author(s):  
Douglas Cook ◽  
Pradeep George ◽  
Margaret Julias
Keyword(s):  
Structural Model ◽  
Three Dimensional ◽  
Vocal Folds ◽  
Two Dimensional

Turbulence characteristics of the boundary layer on a rotating disk

1994 ◽  
Vol 266 ◽  
pp. 175-207 ◽  
Author(s):  
Howard S. Littell ◽  
John K. Eaton
Keyword(s):  
Boundary Layer ◽  
Shear Stress ◽  
Reynolds Stress ◽  
Structural Model ◽  
Rotating Disk ◽  
Two Dimensional ◽  
Mean Flow ◽  
Velocity Correlation ◽  
Dimensional Boundary ◽  
The Mean

Measurements of the boundary layer on an effectively infinite rotating disk in a quiescent environment are described for Reynolds numbers up to Reδ2 = 6000. The mean flow properties were found to resemble a ‘typical’ three-dimensional crossflow, while some aspects of the turbulence measurements were significantly different from two-dimensional boundary layers that are turned. Notably, the ratio of the shear stress vector magnitude to the turbulent kinetic energy was found to be at a maximum near the wall, instead of being locally depressed as in a turned two-dimensional boundary layer. Also, the shear stress and the mean strain rate vectors were found to be more closely aligned than would be expected in a flow with this degree of crossflow. Two-point velocity correlation measurements exhibited strong asymmetries which are impossible in a two-dimensional boundary layer. Using conditional sampling, the velocity field surrounding strong Reynolds stress events was partially mapped. These data were studied in the light of the structural model of Robinson (1991), and a hypothesis describing the effect of cross-stream shear on Reynolds stress events is developed.

Analogical recognition of shape and structure in design drawings

2008 ◽  
Vol 22 (2) ◽  
pp. 117-128 ◽  
Author(s):  
Patrick W. Yaner ◽  
Ashok K. Goel
Keyword(s):  
Structural Model ◽  
Line Drawing ◽  
Source Model ◽  
Two Dimensional ◽  
Structural Components ◽  
Levels Of Abstraction ◽  
Shape Representations ◽  
Source Case ◽  
Multiple Levels

AbstractWe describe a method for constructing a structural model of an unlabeled target two-dimensional line drawing by analogy to a known source model of a drawing with similar structure. The source case is represented as a schema that contains its line drawing and its structural model represented at multiple levels of abstraction: the lines and intersections in the drawing, the shapes, the structural components, and connections of the device are depicted in the drawing. Given a target drawing and a relevant source case, our method of compositional analogy first constructs a representation of the lines and the intersections in the target drawing, then uses the mappings at the level of line intersections to transfer the shape representations from the source case to the target; next, it uses the mappings at the level of shapes to transfer the full structural model of the depicted system from the source to the target.

scholarly journals Enhancement of thrust reverser cascade performance using aerodynamic and structural integration

2004 ◽  
Vol 108 (1090) ◽  
pp. 621-628 ◽  
Author(s):  
J. Butterfield ◽  
H. Yao ◽  
M. Price ◽  
C. Armstrong ◽  
S. Raghunathan ◽  
...  
Keyword(s):  
Structural Model ◽  
Three Dimensional ◽  
Operating Conditions ◽  
Product Development Process ◽  
Structural Performance ◽  
Two Dimensional ◽  
Operational Conditions ◽  
Structural Integration ◽  
Thrust Reverser ◽  
Reverse Thrust

AbstractThis paper focuses on the design of a cascade within a cold stream thrust reverser during the early, conceptual stage of the product development process. A reliable procedure is developed for the exchange of geometric and load data between a two dimensional aerodynamic model and a three dimensional structural model. Aerodynamic and structural simulations are carried out using realistic operating conditions, for three different design configurations with a view to minimising weight for equivalent or improved aerodynamic and structural performance. For normal operational conditions the simulations show that total reverse thrust is unaffected when the performance of the deformed vanes is compared to the un-deformed case. This shows that for the conditions tested, the minimal deformation of the cascade vanes has no significant affect on aerodynamic efficiency and that there is scope for reducing the weight of the cascade. The pressure distribution through a two dimensional thrust reverser section is determined for two additional cascade vane configurations and it is shown that with a small decrease in total reverse thrust, it is possible to reduce weight and eliminate supersonic flow regimes through the nacelle section. By increasing vane sections in high pressure areas and decreasing sections in low pressure areas the structural performance of the cascade vanes in the weight reduced designs, is improved with significantly reduced levels of vane displacement and stress.

scholarly journals Interlamellar amino functionalization of kaolinite

1997 ◽  
Vol 75 (11) ◽  
pp. 1766-1772 ◽  
Author(s):  
James J. Tunney ◽  
Christian Detellier
Keyword(s):  
Thermal Analysis ◽  
Thermal Decomposition ◽  
Nmr Spectroscopy ◽  
Structural Model ◽  
Hydroxyl Group ◽  
Two Dimensional ◽  
Amino Groups ◽  
Surface Hydroxyl ◽  
Silicate Surface ◽  
Ir Analysis

The interlamellar surface of kaolinite has been modified with molecules possessing amino functionalities. Either the dimethyl sulfoxide intercalate of kaolinite (Kao/DMSO) or the N-methylformamide intercalate of kaolinite (Kao/NMF) were used as starting materials. One of the products, an ethanolamine functionalized kaolinite (Kao–EOA) was resistant to thermal decomposition in both air and N2 atmospheres up to temperatures greater than 150 °C. Based on results from thermal analysis, IR analysis, 13CCP/MAS NMR spectroscopy, and elemental analysis, a structural model is proposed in which every third interlayer surface hydroxyl group on the aluminol (Al-OH) surface of kaolinite is either replaced with an interlayer Al-OCH2CH2NH2 group or is strongly H-bonded to an aminoalcohol molecule. A mixture of both types of linkages could coexist. The amino groups that point away from this surface are each keyed into the -(SiO−)6 macro-rings of the adjacent silicate surface, resulting in an amino-functionalized ordered two-dimensional organo-mineral assembly. Keywords: kaolinite, halloysite, organo-mineral nanocomposites, clay functionalization, supramolecular assemblies.

Une généalogie des organisations de partis

Res Publica ◽  
1984 ◽  
Vol 26 (2) ◽  
pp. 119-141
Author(s):  
Daniel-Louis Seiler
Keyword(s):  
Social Integration ◽  
Structural Model ◽  
Party Competition ◽  
Vote System ◽  
Two Dimensional ◽  
Party Organizations ◽  
Governmental Power ◽  
Set Up

The first aim of the article is to present the lineage of party organizations integrating several "classical" approaches. Therefore a second aim is to set up a structural model able to catch the evolution of any typeof modern party organization.One assumes that Party Structure is an invariable element which subsumes several organizational translations. Same are protopartisan translations : leagues, armed and unarmed f actions, parliamentary groups.  Some are partisan translations : modern party organizations.  This assumptions means a corollary: organizations tend to adapt to the kind of party competition they have to afford in order to have accessto governmental power. The model combines the assumptions in a two dimensional matrix.The first dimension is concerned with the organization's major historical goal. It takes three values : a) to elect of MP's ; b) to promote a Weltanschauung; c) to elect the President.The second deals with mobilization and takes three values : adapted 1 ° to the age of «Registration Societies» ; 2° the age of «One man, one vote system» ; 3° the post McLuhan age of electronic media.The combination of the dimensions gives three lineages: Cadre Parties including Notability Parties, Voters Parties and Indirect Parties; Mass Parties including Activist Parties and Social Integration Parties; MachineParties.

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