318 research outputs found
Examination of saturation coverage of polygons using random sequential adsorption algorithm
The goal of random sequential adsorption (RSA), a time-dependent packing
method, is to create a regular or asymmetric covering of an empty space that
can fit in the allocated space without overlapping. The density of coverage
tends to reach a limit in the infinite-time limit. We attempt to estimate
saturated packing of oriented 2-D polygons, including squares(4-sides), regular
pentagons (5-sides), regular hexagons (6-sides), regular heptagons (7-sides),
regular octagons (8-sides), regular nonagons (9-sides), regular decagons
(10-sides), and regular dodecagons (12-sides), in this study. We obtained
results that are consistent with previous, extrapolation-based studies1. We
utilised the "separating axis theorem" to determine if there is overlap between
arriving polygons and those that have previously been placed. Saturation as a
lower limit is considered to have been reached when RSA addition becomes
excessively slow, according to us.Comment: 12 Pages, 4 Figure
Elastic-plastic analysis of pressure vessels and rotating disks made of functionally graded materials using the isogeometric approach
An NURBS-based isogeometric analysis for elastic-plastic stress in a cylindrical pressure
vessel is presented. The vessel is made of a ceramic/metal functionally graded material, i.e.
a particle-reinforced composite. It is assumed that the material plastic deformation follows
an isotropic strain-hardening rule based on the von Mises yield criterion. The mechanical
properties of the graded material are modelled by the modified rule of mixtures. Selected
finite element results are also presented to establish the supporting evidence for validation of
the isogeometric analysis. Similar analyses are performed and solutions for spherical pressure
vessel and rotating disk made of FGMs are also provided
Random sequential adsorption of aligned regular polygons and rounded squares: Transition in the kinetics of packing growth
We study two-dimensional random sequential adsorption (RSA) of flat polygons
and rounded squares aligned in parallel to find a transition in the asymptotic
behavior of the kinetics of packing growth. Differences in the kinetics for RSA
of disks and parallel squares were confirmed in previous analytical and
numerical reports. Here, by analyzing the two classes of shapes in question we
can precisely control the shape of packed figures and thus localize the
transition. Additionally, we study how the asymptotic properties of the
kinetics depend on the packing size. We also provide accurate estimations of
saturated packing fractions. The microstructural properties of generated
packings are analyzed in terms of the density autocorrelation function.Comment: 7 pages, 9 figure
CNC Gel Rheology Meets Mechanical Characteristics
Rheology was used to study the microstructure of cellulose nanocrystal suspensions and hydrogels before, during, and after disturbance. Rheological testing is classified into two types: linear and nonlinear tests. These tests can be carried out with either oscillatory or rotational shear deformations. This manuscript includes recent research on cellulose nanocrystals using rheology to familiarize readers with the generality of these nanoparticles and their flow behavior in aqueous media, as well as to provide a comprehensive overview of current efforts in the literature addressing these materials
Effect of foliar application of α-tocopherol and pyridoxine on vegetative growth, flowering, and some biochemical constituents of Calendula officinalis L. plants
A field experiment was conducted during 2010 at the Experimental Farm of Fajr, SB University of Kerman, Iran. The aim was to study the effects of foliar spray of α-tocopherol (0, 50, 100 part per million (ppm)) and pyridoxine (0, 50, 100 ppm) on vegetative growth, flowering parameters, and some chemical constituents of Calendula officinalis L. plants. Most parameters were significantly affected by application of two vitamins which were used in this study. The obtained results could be summarized as follows; pyridoxine at 100 ppm recorded the best value of leaf area, stem height, chlorophyll b, reducing sugars and hyperoside content; no significant difference was found between plants treated with vitamins in terms of chlorophyll a, root length, fresh weight and dry weight of root; the treatment with α-tocopherol at 100 ppm resulted in the highest yield of seed, fresh and dry aerial parts, as compared to control plants; maximum values of carotenoid were obtained by the application of pyridoxine at 50 ppm; and application of both vitamins led to the reduction of flower diameter.Keyswords: Calendula officinalis L., α-tocopherol, pyridoxin
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