scholarly journals Computational Method for Quantifying Growth Patterns at the Adaxial Leaf Surface in Three Dimensions

2012 ◽  
Vol 159 (1) ◽  
pp. 27-39 ◽  
Author(s):  
Lauren Remmler ◽  
Anne-Gaëlle Rolland-Lagan
Weed Science ◽  
1996 ◽  
Vol 44 (3) ◽  
pp. 469-475 ◽  
Author(s):  
W. Mack Thompson ◽  
Scott J. Nissen ◽  
Robert A. Masters

Laboratory experiments were conducted to identify adjuvants that improve absorption of imazethapyr, 2,4-D amine, and picloram by leafy spurge. Adjuvants (0.25% v/v) included crop oil concentrate (COC), methylated seed oil (MSO), nonionic surfactant (NIS), organosilicones (Silwet L-77®, Sylgard® 309, Silwet® 408), 3:1 mixtures of acetylinic diol ethoxylates (ADE40, ADE65, ADE85) with Silwet L-77, ammonium sulfate (2.5 kg ha−1), and 28% urea ammonium nitrate (UAN, 2.5% v/v). Adjuvants were combined with14C-herbicide and commercially formulated herbicide product. Leaves were harvested 2 DAT, rinsed with 10% aqueous methanol to remove surface deposits of herbicide, and dipped in 9:1 hexane:acetone to solubilize cuticular waxes. Imazethapyr absorption increased by 38 to 68% when UAN was combined with COC, NIS, or MSO. Total absorption of imazethapyr plus COC, MSO, or NIS exceeded 86% 2 DAT when UAN was added. Urea ammonium nitrate reduced the amount of imazethapyr associated with the cuticular wax by 2.0%. Imazethapyr absorption was similar on both the abaxial and adaxial leaf surface when UAN was not added; however, 12% more imazethapyr was absorbed from the abaxial leaf surface than from the adaxial leaf surface when UAN was combined with Sylgard 309. Uptake of 2,4-D ranged from 54 to 78% and was greatest with Silwet 408 and 3:1 mixture of ADE40: Silwet L-77. Picloram absorption ranged from 3 to 19%. Buffering picloram treatment solutions to pH 7 and including 2.5 kg ha-1ammonium sulfate increased picloram absorption to 37%.


Phytotaxa ◽  
2019 ◽  
Vol 422 (2) ◽  
pp. 201-205 ◽  
Author(s):  
JOEL CALVO ◽  
ROSA I. MENESES

Werneria lanatifolia is described as a new species from the central Andes. It is a minute plant characterized by a lanate indumentum on the adaxial leaf surface and involucre. The new species is compared with the morphologically closest taxa and useful characters for its proper identification are provided. Detailed pictures of living plants, a distribution map, and a dichotomous key including the species allied to W. lanatifolia are also presented.


Author(s):  
Alexander R. Jung ◽  
Jürgen F. Mayer ◽  
Heinz Stetter

This paper presents a computational method for the calculation of unsteady three-dimensional viscous flow in turbo-machinery stages. The method is based on a Finite-Volume Navier-Stokes solver for structured grids in a multiblock topology. The meshes at the stator/rotor interface are overlapped by two grid cells. An implicit residual smoothing method applicable to global time-stepping is used to accelerate the solution process. The problem of periodic boundary treatment for unequal pitches is handled using a method of time-inclined computational domains for three dimensions. The method applies a time transformation to the stator domain and to the rotor domain and uses different time-steps in the two domains. The results of a numerical simulation of the flow in a transonic turbine stage with a pitch ratio of 1.364 are presented. The time-averaged solution is compared to experimental data and satisfactory agreement is stated. Complex 3D-unsteady flow phenomena (shock motion, vortex shedding) are observed. Unsteady blade pressure fluctuations at various positions in spanwise direction are shown and the fluctuations are found to vary considerably along span. Instantaneous distributions of static pressure, Mach number, and entropy are presented.


HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 554a-554
Author(s):  
Susan M. Stieve ◽  
Dennis P. Stimart

Eighteen commercially used white Antirrhinum majus (snapdragon) inbreds, a hybrid of Inbred 1 × Inbred 18 (Hybrid 1) and an F2 population (F2) of Hybrid 1 were evaluated for stomatal size and density and transpiration rate to determine their affect on postharvest longevity. Stems of each genotype were cut to 40 cm, placed in distilled water and discarded when 50% of florets wilted or browned. Postharvest longevity of inbreds ranged from 3.7 to 12.9 days; Hybrid 1 and the F2 averaged 3.0 and 9.1 days postharvest, respectively. Leaf impressions showed less than 3% of stomata were found on the adaxial leaf surface. Inbred abaxial stomatal densities ranged from 128.2 to 300.7 stomata mm-2; Hybrid 1 and the F2 averaged 155 and 197 stomata mm-2, respectively. Transpiration measurments on leaves of stems 24 hr after cutting were made with a LI-COR 1600 Steady State Porometer. Statistical analysis showed inbreds were significantly different based on postharvest longevity, stomatal size and density and transpiration of cut stems.


2021 ◽  
Author(s):  
Adriana Paluszny ◽  
Robin N. Thomas ◽  
M. Cristina Saceanu ◽  
Robert W. Zimmerman

<p>A finite-element based, quasi-static growth algorithm models mixed mode concurrent fracture growth in three dimensions, leading to the formation of non-planar arrays and networks. To model the fully coupled THM model, equations describing mechanical deformation as well as heat transfer in the matrix and in the fractures are introduced in the formulation, simultaneously accounting for the effect of fluid flow and stress-strain response. This results in five separate, but two-way coupled model equations: a thermoporoelastic mechanical model; two fluid flow equations, one for the rock matrix and one for the fractures; two heat transfer equations, similarly for both the matrix and fractures. Fractures are represented explicitly as discrete surfaces embedded within a volumetric domain [1]. Growth is computed as a set of vectors that modify the geometry of a fracture by accruing new fracture surfaces in response to brittle deformation. Fracture tip stress intensity factors drive fracture growth. This growth methodology is validated against analytical solutions for fractures under compression and tension [2]. Thermal effects on the apertures and growth patterns will be presented. Isolated fracture geometries are compared with selected experimental results on brittle media. Accurate growth is demonstrated for domains discretised by refined and coarse volumetric meshes. Fracture and volume-based growth rates are shown to modify fracture interaction patterns. Two-dimensional cut-plane views of fracture networks show how fractures would appear on the surface of the studied volume.</p><p><strong>REFERENCES</strong></p><p>[1] N. Thomas, A. Paluszny and R. W. Zimmerman. Growth of three-dimensional fractures, arrays, and networks in brittle rocks under tension and compression. Computers and Geotechnics, 2020. doi: 10.1016/j.compgeo.2020.103447</p><p>[2] Paluszny and R. W. Zimmerman. Numerical fracture growth modeling using smooth surface geometric deformation. Eng. Fract. Mech., 108, 19-36, 2013. doi: 10.1016/j.engfracmech.2013.04.012</p>


Open Biology ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 190057 ◽  
Author(s):  
Richard Kennaway ◽  
Enrico Coen

Differential growth is the driver of tissue morphogenesis in plants, and also plays a fundamental role in animal development. Although the contributions of growth to shape change have been captured through modelling tissue sheets or isotropic volumes, a framework for modelling both isotropic and anisotropic volumetric growth in three dimensions over large changes in size and shape has been lacking. Here, we describe an approach based on finite-element modelling of continuous volumetric structures, and apply it to a range of forms and growth patterns, providing mathematical validation for examples that admit analytic solution. We show that a major difference between sheet and bulk tissues is that the growth of bulk tissue is more constrained, reducing the possibility of tissue conflict resolution through deformations such as buckling. Tissue sheets or cylinders may be generated from bulk shapes through anisotropic specified growth, oriented by a polarity field. A second polarity field, orthogonal to the first, allows sheets with varying lengths and widths to be generated, as illustrated by the wide range of leaf shapes observed in nature. The framework we describe thus provides a key tool for developing hypotheses for plant morphogenesis and is also applicable to other tissues that deform through differential growth or contraction.


2010 ◽  
Vol 277 (1700) ◽  
pp. 3555-3561 ◽  
Author(s):  
Maxim V. Filatov ◽  
Jaap A. Kaandorp ◽  
Marten Postma ◽  
Robert van Liere ◽  
Kris J. Kruszyński ◽  
...  

In addition to experimental studies, computational models provide valuable information about colony development in scleractinian corals. Using our simulation model, we show how environmental factors such as nutrient distribution and light availability affect growth patterns of coral colonies. To compare the simulated coral growth forms with those of real coral colonies, we quantitatively compared our modelling results with coral colonies of the morphologically variable Caribbean coral genus Madracis. Madracis species encompass a relatively large morphological variation in colony morphology and hence represent a suitable genus to compare, for the first time, simulated and real coral growth forms in three dimensions using a quantitative approach. This quantitative analysis of three-dimensional growth forms is based on a number of morphometric parameters (such as branch thickness, branch spacing, etc.). Our results show that simulated coral morphologies share several morphological features with real coral colonies ( M. mirabilis , M. decactis, M. formosa and M. carmabi ). A significant correlation was found between branch thickness and branch spacing for both real and simulated growth forms. Our present model is able to partly capture the morphological variation in closely related and morphologically variable coral species of the genus Madracis .


Weed Science ◽  
1993 ◽  
Vol 41 (1) ◽  
pp. 87-93 ◽  
Author(s):  
Moritz Knoche ◽  
Martin J. Bukovac

The effect of oxyethylene (OE) chain length of three homologous series of nonionic surfactants (allinol, nonoxynol, octoxynol) on glyphosate uptake was markedly affected by the leaf surface fine-structure of sugarbeet and kohlrabi. Adaxial leaf surfaces of sugarbeet were covered with a layer of amorphous wax, whereas the adaxial surface of kohlrabi leaves was covered with fine crystalline wax. Foliar uptake of glyphosate (1 mM glyphosate, 20 mM glycine, pH 3.2) averaged 4% for sugarbeet without surfactant, but droplets were not retained by kohlrabi leaves in the absence of a surfactant. Glyphosate absorption with octoxynol (9 to 10 OE units, 0.5 g L−1) was rapid initially (0 to 2 h) and leveled off about 2 h after application in both species. Absorption by sugarbeet decreased from 12 to 3% as OE content of octoxynol was increased from 5 to 30 OE units. In contrast, surfactants of intermediate OE content (octoxynol, 16 OE units) induced the greatest uptake (17%) on kohlrabi. Leaf wetting was markedly affected by surfactant and leaf surface. As OE content of octoxynol increased from 5 to 30 OE units, droplet/leaf interface areas of 1-μl droplets decreased from 4 to 3 mm2 on the adaxial leaf surface of sugarbeet and from 61 to 2 mm2 on kohlrabi. Concurrently, the rate of droplet evaporation (1 μl) decreased from 1.0 to 0.7 nl s−1 on sugarbeet and 4.2 to 0.5 nl s−1 on kohlrabi leaves. The effect of OE content on enhancement of glyphosate uptake and wetting characteristics of spray solutions was similar within species for different hydrophobic moieties but differed markedly between species.


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