Analyses of Morphological Properties of a Generalized Miura Origami Structure

2017 ◽  
Vol 139 (9) ◽  
Author(s):  
Wei Ye ◽  
Feng Wei ◽  
Jin Yi ◽  
Zhu Chang'an
Keyword(s):  
Limit State ◽  
Morphological Properties ◽  
Spherical Trigonometry ◽  
Fold Structure ◽  
Horizontal Length ◽  
Longitudinal Length ◽  
Angle Difference ◽  
Severe Change ◽  
The Relationship

In this paper, we generalize Miura origami and propose a method for analyzing a generalized Miura origami structure. Morphological properties of the generalized Miura origami element during the deploy motion are analyzed using the proposed method, which mainly utilizes the principle of spherical trigonometry and is verified in the folding limit state. The longitudinal length, horizontal length, and height of the generalized Miura origami element are defined and obtained using the proposed method. Results show the relationship between the range of deployment and the element parameters as well as the changes of the folding plane angles in the deployment process. During the deploy motion, both the longitudinal and horizontal length increased while the height decreased. However, the change speed of horizontal length decreased, whereas those of longitudinal length and height initially increased and then decreased. The increment of the folding element angle difference Δα reduced folding range and put off the severe change time of longitudinal length and height. The length parameters Ka, Kb, and Kab had slight effects on the results, but their changes did not alter the change trends. These results are useful to the design of fold structure and analysis of errors in standard Miura-ori structures.

Geometric Analysis of a Foldable Barrel Vault With Origami

2013 ◽  
Vol 135 (11) ◽  
Author(s):  
Jianguo Cai ◽  
Yixiang Xu ◽  
Jian Feng
Keyword(s):  
Geometric Analysis ◽  
Radius Of Curvature ◽  
Spherical Trigonometry ◽  
Longitudinal Length ◽  
Relationship Of ◽  
The Relationship

This paper investigates the geometry of a foldable barrel vault with modified Miura-ori patterns, which displays a curvature during the motion. The principal of spherical trigonometry was used to obtain the relationship of the inclined angles between adjacent folded papers of Miura-ori. Then, the radius, span, rise, and longitudinal length of the foldable barrel vault in all configurations throughout the motion are determined. The results show that the radius of curvature grows exponentially and the span increases during deployment. Furthermore, the rise increases first, followed by a decrease with increasing deployment angle.

Studies on Leukemogenic and Sarcomagenic Viruses

1970 ◽  
Vol 28 ◽  
pp. 156-157
Author(s):  
Leon Dmochowski
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Morphological Properties ◽  
Mode Of Development ◽  
Relationship Of ◽  
The Relationship

Electron microscopy has proved to be an invaluable discipline in studies on the relationship of viruses to the origin of leukemia, sarcoma, and other types of tumors in animals and man. The successful cell-free transmission of leukemia and sarcoma in mice, rats, hamsters, and cats, interpreted as due to a virus or viruses, was proved to be due to a virus on the basis of electron microscope studies. These studies demonstrated that all the types of neoplasia in animals of the species examined are produced by a virus of certain characteristic morphological properties similar, if not identical, in the mode of development in all types of neoplasia in animals, as shown in Fig. 1.

scholarly journals Kinematics around the B335 protostar down to au scales

2019 ◽  
Vol 631 ◽  
pp. A64 ◽  
Author(s):  
Per Bjerkeli ◽  
Jon P. Ramsey ◽  
Daniel Harsono ◽  
Hannah Calcutt ◽  
Lars E. Kristensen ◽  
...  
Keyword(s):  
Morphological Properties ◽  
Young Stellar Objects ◽  
Continuum Emission ◽  
Small Scale ◽  
Short Baseline ◽  
Stellar Objects ◽  
Spatially Resolved ◽  
Long Baseline ◽  
The Relationship ◽  
The Continuum

Context. The relationship between outflow launching and the formation of accretion disks around young stellar objects is still not entirely understood, which is why spectrally and spatially resolved observations are needed. Recently, the Atacama Large Millimetre/sub-millimetre Array (ALMA) carried out long-baseline observations towards a handful of young sources, revealing connections between outflows and the inner regions of disks. Aims. Here we aim to determine the small-scale kinematical and morphological properties of the outflow from the isolated protostar B335 for which no Keplerian disk has, so far, been observed on scales down to 10 au. Methods. We used ALMA in its longest-baseline configuration to observe emission from CO isotopologues, SiO, SO2, and CH3OH. The proximity of B335 provides a resolution of ~3 au (0.03′′). We also combined our long-baseline data with archival observations to produce a high-fidelity image covering scales up to 700 au (7′′). Results. 12CO has an X-shaped morphology with arms ~50 au in width that we associate with the walls of an outflow cavity, similar to what is observed on larger scales. Long-baseline continuum emission is confined to <7 au from the protostar, while short-baseline continuum emission follows the 12CO outflow and cavity walls. Methanol is detected within ~30 au of the protostar. SiO is also detected in the vicinity of the protostar, but extended along the outflow. Conclusions. The 12CO outflow does not show any clear signs of rotation at distances ≳30 au from the protostar. SiO traces the protostellar jet on small scales, but without obvious rotation. CH3OH and SO2 trace a region <16 au in diameter, centred on the continuum peak, which is clearly rotating. Using episodic, high-velocity, 12CO features, we estimate the launching radius of the outflow to be <0.1 au and dynamical timescales of the order of a few years.

scholarly journals The universal aspect ratio of vortices in rotating stratified flows: experiments and observations

2012 ◽  
Vol 706 ◽  
pp. 34-45 ◽  
Author(s):  
Oriane Aubert ◽  
Michael Le Bars ◽  
Patrice Le Gal ◽  
Philip S. Marcus
Keyword(s):  
Aspect Ratio ◽  
Salt Water ◽  
Boussinesq Equations ◽  
Companion Paper ◽  
Buoyancy Frequency ◽  
Coriolis Parameter ◽  
Aspect Ratios ◽  
Horizontal Length ◽  
The Law ◽  
The Relationship

AbstractWe validate a new law for the aspect ratio $\ensuremath{\alpha} = H/ L$ of vortices in a rotating, stratified flow, where $H$ and $L$ are the vertical half-height and horizontal length scale of the vortices. The aspect ratio depends not only on the Coriolis parameter $f$ and buoyancy (or Brunt–Väisälä) frequency $\bar {N} $ of the background flow, but also on the buoyancy frequency ${N}_{c} $ within the vortex and on the Rossby number $\mathit{Ro}$ of the vortex, such that $\ensuremath{\alpha} = f \mathop{ [\mathit{Ro}(1+ \mathit{Ro})/ ({ N}_{c}^{2} \ensuremath{-} {\bar {N} }^{2} )] }\nolimits ^{1/ 2} $. This law for $\ensuremath{\alpha} $ is obeyed precisely by the exact equilibrium solution of the inviscid Boussinesq equations that we show to be a useful model of our laboratory vortices. The law is valid for both cyclones and anticyclones. Our anticyclones are generated by injecting fluid into a rotating tank filled with linearly stratified salt water. In one set of experiments, the vortices viscously decay while obeying our law for $\ensuremath{\alpha} $, which decreases over time. In a second set of experiments, the vortices are sustained by a slow continuous injection. They evolve more slowly and have larger $\vert \mathit{Ro}\vert $ while still obeying our law for $\ensuremath{\alpha} $. The law for $\ensuremath{\alpha} $ is not only validated by our experiments, but is also shown to be consistent with observations of the aspect ratios of Atlantic meddies and Jupiter’s Great Red Spot and Oval BA. The relationship for $\ensuremath{\alpha} $ is derived and examined numerically in a companion paper by Hassanzadeh, Marcus & Le Gal (J. Fluid Mech., vol. 706, 2012, pp. 46–57).

scholarly journals The effect of subsidising firms on voting behaviour: Evidence from Flemish elections

2012 ◽  
Vol 1 (1) ◽  
pp. 30 ◽  
Author(s):  
Caroline Buts ◽  
Marc Jegers ◽  
Dimi Jottier
Keyword(s):  
Government Spending ◽  
Local Level ◽  
Limit State ◽  
Government Expenditure ◽  
Financial Statements ◽  
Regional Government ◽  
International Consensus ◽  
General Government ◽  
Election Results ◽  
The Relationship

Despite an international consensus on the importance to limit State aid spending, large amounts of resources are still devoted to a wide variety of subsidies to firms. A sizable literature studies the relationship between general government spending and the proximity of elections, mostly documenting a positive link. In addition, other studies verify whether this strategy of increasing government expenditure pays off in terms of number of votes. We focus on one type of government spending that can be quite vulnerable to becoming ‘targeted spending’, i.e. subsidies to firms. We empirically test the relationship between the amount of subsidies granted to firms at the local level and local support for incumbent parties in the regional government. To that end, we make use of subsidy data derived from financial statements on 2008 and Flemish election results of 2004 and 2009. We find that the total amount of subsidies as well as subsidies per capita granted in 2008 positively correlate to support for incumbent parties 2009, meaning that voters appear to reward subsidy granting politicians.

High Rayleigh number convection in a porous medium containing a thin low-permeability layer

2014 ◽  
Vol 756 ◽  
pp. 844-869 ◽  
Author(s):  
Duncan R. Hewitt ◽  
Jerome A. Neufeld ◽  
John R. Lister
Keyword(s):  
Porous Medium ◽  
Rayleigh Number ◽  
Lower Boundary ◽  
Low Permeability ◽  
One Dimensional ◽  
Horizontal Length ◽  
The Relationship ◽  
Geological Formations ◽  
Rayleigh Benard ◽  
Steady Convection

AbstractPorous geological formations are commonly interspersed with thin, roughly horizontal, low-permeability layers. Statistically steady convection at high Rayleigh number $\def \xmlpi #1{}\def \mathsfbi #1{\boldsymbol {\mathsf {#1}}}\let \le =\leqslant \let \leq =\leqslant \let \ge =\geqslant \let \geq =\geqslant \def \Pr {\mathit {Pr}}\def \Fr {\mathit {Fr}}\def \Rey {\mathit {Re}}\mathit{Ra}$ is investigated numerically in a two-dimensional porous medium that is heated at the lower boundary and cooled at the upper, and contains a thin, horizontal, low-permeability interior layer. In the limit that both the dimensionless thickness $h$ and permeability $\Pi $ of the low-permeability layer are small, the flow is described solely by the impedance of the layer $\Omega = h/\Pi $ and by $\mathit{Ra}$. In the limit $\Omega \to 0$ (i.e. $h \to 0$), the system reduces to a homogeneous Rayleigh–Darcy (porous Rayleigh–Bénard) cell. Two notable features are observed as $\Omega $ is increased: the dominant horizontal length scale of the flow increases; and the heat flux, as measured by the Nusselt number $\mathit{Nu}$, can increase. For larger values of $\Omega $, $\mathit{Nu}$ always decreases. The dependence of the flow on $\mathit{Ra}$ is explored, over the range $2500 \leqslant \mathit{Ra} \leqslant 2\times 10^4$. Simple one-dimensional models are developed to describe some of the observed features of the relationship $\mathit{Nu}(\Omega )$.

scholarly journals The Relationship between the Morphology and Elasticity of Natural Rubber Foam Based on the Concentration of the Chemical Blowing Agent

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1091
Author(s):  
Supitta Suethao ◽  
Saree Phongphanphanee ◽  
Jirasak Wong-ekkabut ◽  
Wirasak Smitthipong
Keyword(s):  
Mechanical Properties ◽  
Morphological Structure ◽  
Morphological Properties ◽  
Heterogeneous Structure ◽  
Compression Force ◽  
Soft Or ◽  
Blowing Agent ◽  
Chemical Agents ◽  
The Difference ◽  
The Relationship

Concentrated natural latex was used to produce a rubber foam that is porous, elastic and well ventilated. The mechanical properties can be either soft or firm, depending on the formulation of the latex used. Briefly, concentrated natural latex was mixed with chemical agents to make the rubber foam on a laboratory scale using the Dunlop process. In this work, we changed the concentration of the chemical blowing agent in the latex. The morphological properties of the rubber foam were characterised using scanning electron microscopy, and the mechanical properties, or elasticity, were studied using compression experiments and the Mooney–Rivlin calculation. The results show that the concentration of the chemical blowing agent affects the morphological properties of the rubber foam but not the mechanical properties, indicating the heterogeneous structure of the rubber foam. The thermodynamic parameters (∆G and ∆S) and the internal energy force per compression force (Fu/F) of the rubber foam with various amounts of chemical blowing agent were also investigated. This study could be applied in the foam industry, particularly for pillow, mattress and insulation materials, as the present work shows the possible novel control of the morphological structure of the rubber foam without changing its mechanical properties. The difference in cell sizes could affect the airflow in rubber foam.

Buckling of longitudinally stiffened plates in bending and compression

1989 ◽  
Vol 16 (5) ◽  
pp. 607-614 ◽  
Author(s):  
Mark A. Bradford
Keyword(s):  
Limit State ◽  
Local Buckling ◽  
Test Results ◽  
Pure Bending ◽  
Uniform Compression ◽  
Longitudinal Stiffener ◽  
Optimum Position ◽  
Buckling Coefficient ◽  
The Relationship ◽  
Web Plates

The nonlinear stiffness equations that predict local and post-local buckling of plates and plate assemblies are given. These equations are validated by accurate predictions of independent test results. The elastic local buckling of longitudinally stiffened web plates in combined bending and compression is considered. Graphs which may be used to predict the optimum position of a stiffener are presented. The relationship between the area and second moment of area of a stiffener of finite dimensions that optimizes the local buckling coefficient is given for various eccentricities of end load. The post-local buckling of a longitudinally stiffened plate in uniform compression and pure bending is also considered. It is shown that the provision of a longitudinal stiffener, of proportions to enforce a node at the plate–stiffener junction, enhances significantly the postbuckling response of the plate with regard to the serviceability limit state, particularly for the case of pure bending. Key words: bending, compression, finite strips, local buckling, plates, postbuckling, stiffeners, webs.

scholarly journals Morphometric evaluation and measurements of primary pterygium by anterior segment optical coherence tomography and its relation with astigmatism

2021 ◽  
Vol 13 ◽  
pp. 251584142110201
Author(s):  
Anuradha Raj ◽  
Renu Dhasmana ◽  
Harsh Bahadur
Keyword(s):  
Optical Coherence Tomography ◽  
Corneal Thickness ◽  
Anterior Segment ◽  
Cross Sectional Study ◽  
Optical Coherence ◽  
Cross Sectional ◽  
Horizontal Length ◽  
The Mean ◽  
The Relationship ◽  
Primary Pterygium

Purpose: To evaluate the relationship between measurements and various morphometric parameters of primary pterygium on anterior segment optical coherence tomography(AS-OCT) and refractive and keratometric astigmatism. Methods: In this cross-sectional study, patients with primary pterygium were included. The AS-OCT parameters of pterygium consisting of epithelial thickness near apex(µm), apical or head thickness(µm), its thickness at limbus(µm), horizontal length of pterygium(mm), central corneal thickness (µm) and maximum pterygium thickness(mm) were evaluated. Results: Sixty three patients comprising of 63 eyes with a primary pterygium were studied. The mean keratometric and refractive astigmatism were 1.69 ± 3.15 Diopter(D) and0.5 ± 1.4D, respectively. There was a significant association between pterygium grade and stocker’s line with keratometric astigmatism ( p = 0.02, 0.00) respectively. Vertical and horizontal length on slit lamp and horizontal length on AS-OCT showed significant association with keratometric astigmatism ( p = 0.05, 0.00,0.00), respectively. Limbal thickness on AS-OCT showed significant positive correlation with refractive astigmatism ( r = 0.29, p = 0.02). Conclusion: The pterygium grade influences the keratometric astigmatism. Increased limbal thickness of pterygium on AS-OCT leads to more refractive astigmatism.

Analysis of Small Non-Sand Concrete Pile Grouting Pressure Based on Unified Strength Theory

2012 ◽  
Vol 166-169 ◽  
pp. 3095-3099
Author(s):  
Huai Feng Tong
Keyword(s):  
Stress State ◽  
Principal Stress ◽  
Limit State ◽  
Intermediate Principal Stress ◽  
Plastic State ◽  
Strength Theory ◽  
Unified Strength Theory ◽  
Grouting Pressure ◽  
Concrete Pile ◽  
The Relationship

Analysis of stress state of soil around the pile and grouting pressure of small non-sand concrete pile is given based on the expansion elastic theory of cylindrical cavity and the unified strength theory, the grouting pressure formula is obtained in the elastic limit state and elastic-plastic state of soil around the pile considered the intermediate principal stress, and the relationship is obtained between the grouting pressure and the plastic radius; When the soil around the pile is in different stress state, the correlativity of crack and densification of grouting is analyzed, and the relationship between the grouting pressure and the plastic radius is discussed with the right coefficient of the intermediate principal stress and initial press under different values. The obtained results have provided efficient analysis means for grouting optimal design of post-processing technology with small non-sand concrete pile.

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