scholarly journals Wing loading, not terminal velocity, is the best parameter to predict capacity of diaspores for secondary wind dispersal

2020 ◽  
Vol 71 (14) ◽  
pp. 4298-4307 ◽  
Author(s):  
Wei Liang ◽  
Zhimin Liu ◽  
Minghu Liu ◽  
Xuanping Qin ◽  
Carol C Baskin ◽  
...  
Keyword(s):  
Shape Index ◽  
Terminal Velocity ◽  
Wind Dispersal ◽  
Wing Loading ◽  
Dispersal Capacity ◽  
Secondary Dispersal ◽  
Lift Off ◽  
Best Parameter ◽  
The Relationship ◽  
Primary Dispersal

Abstract Lift-off velocity may be the most useful surrogate to measure the secondary dispersal capacity of diaspores. However, the most important diaspore attribute determining diaspore lift-off velocity is unclear. Furthermore, it is not known whether terminal velocity used to characterize the primary dispersal capacity of diaspores can also be used to predict their secondary wind dispersal capacity. Here, we investigate how diaspore attributes are related to lift-off velocity. Thirty-six species with diaspores differing in mass, shape index, projected area, wing loading, and terminal velocity were used in a wind tunnel to determine the relationship between diaspore attributes and lift-off velocity. We found that diaspore attributes largely explained the variation in lift-off velocity, and wing loading, not terminal velocity, was the best parameter for predicting lift-off velocity of diaspores during secondary wind dispersal. The relative importance of diaspore attributes in determining lift-off velocity was modified by both upwind and downwind slope directions and type of diaspore appendage. These findings allow us to predict diaspore dispersal behaviors using readily available diaspore functional attributes, and they indicate that wing loading is the best proxy for estimating the capacity for secondary dispersal by wind.

scholarly journals Effect of genotype, age of hens and K/k allele on eggshell quality

2011 ◽  
Vol 56 (No. 5) ◽  
pp. 242-249 ◽  
Author(s):  
Z. Ledvinka ◽  
L. Zita ◽  
M. Hubený ◽  
E. Tůmová ◽  
M. Tyller ◽  
...  
Keyword(s):  
Growth Rate ◽  
Egg Production ◽  
Statistical Significance ◽  
Live Weight ◽  
Shape Index ◽  
Feed Mixture ◽  
Eggshell Quality ◽  
Feather Growth ◽  
Two Factors ◽  
The Relationship

We assessed the influence of the particular genotype, age of layers, feather growth-rate gene, and their mutual interactions on selected indicators of eggshell quality in six groups of hens of the laying type Dominant. The following genotypes were examined in the experiment: Barred Plymouth Rock, Dominant BPR 951 (K) strain, slow-feathering; Barred Plymouth Rock, Dominant BPR 901 (k) strain, fast-feathering; Blue Plymouth Rock, Dominant BLPR 954 (K) strain, slow-feathering; Blue Plymouth Rock, Dominant BLPR 894 (k) strain, fast-feathering; crossbreds of the above strains in the F<sub>1</sub> generation Dominant D 107 blue (K), slow-feathering and Dominant D 107 blue (k), fast-feathering. The layers were fed a feed mixture NP1 (16.64 % CP) from the 20<sup>th</sup> week of age and a feed mixture NP2 (15.02% CP) from the 42<sup>nd</sup> week. Husbandry conditions met the regular requirements of laying hens. Egg production and live weight of hens were monitored for the duration of the experiment (12 months). Eggshell quality was examined at the layers' age of 27, 35 and 56 weeks. The average hen-day egg production for the duration of the experiment (12 months) was not significantly influenced by the particular genotype or the feather growth-rate gene. The varying representation of the feather growth-rate gene significantly (P &le; 0.001) influenced the live weight; similarly, the relationship between the genotype and the representation of K/k alleles was significant. The average egg weight was influenced statistically significantly (P &le; 0.001) by the age of hens, their genotype (P &le; 0.05), feather growth-rate gene (P &le; 0.001), and the relationship between the age and genotype (P &le; 0.001). The age of hens, genotype, and the interaction of these two factors affected the egg shape index, as did the incidence of the feather growth-rate gene within the population (with a statistical significance of P &le; 0.001). The age, genotype and the feather growth-rate gene incidence within the population also significantly affected the eggshell quality indicators. In the eggshell to egg ratio, eggshell thickness and strength, an interaction was determined between the age of hens and their particular genotype. The eggshell colour was also significantly (P &le; 0.001) affected by hens' age, genotype (P &le; 0.001), as well as by the feather growth-rate gene (P &le; 0.001). No significant interaction between the age and the genotype was found for this indicator.

Automatic Planning of Smooth Trajectories for Pick-and-Place Operations

1991 ◽  
Author(s):  
Clément M. Gosselin ◽  
Ammar Hadj-Messaoud
Keyword(s):  
Joint Space ◽  
Inverse Kinematic ◽  
Planning Problem ◽  
Inverse Kinematic Problem ◽  
Polynomial Solutions ◽  
Joint Coordinates ◽  
Pick And Place ◽  
Lift Off ◽  
The Relationship ◽  
Third Derivative

Abstract This paper proposes some new polynomial solutions to the trajectory planning problem encountered in pick-and-place operations. When a robotic manipulator is used for such operations, it is possible to plan the required trajectory in joint space, provided that the inverse kinematic problem has been solved for the initial and final configurations — and possibly for a lift-off and a set-down configuration — and that the workspace is free of obstacles. Polynomial solutions to this problem can be found in the literature. However, they usually provide continuity up to the second derivative only, leading to a discontinuous jerk. The solutions derived in this paper preserve the continuity of the third derivative of the joint coordinates, thereby ensuring smooth trajectories with smooth variations of the actuator currents. Moreover, whenever possible, unique polynomial expressions valid between the initial and final configurations are used in order to simplify the logic. Polynomial formulations without lift-off and set-down configurations are first presented. Then, these intermediate configurations are introduced, leading to a new set of solutions. A global algorithm is then discussed in order to clearly indicate the relationship between the different solutions. Finally, an example illustrating the application to a pick-and-place operation is solved.

scholarly journals Methods of Controlling Lift - off in Conductivity Invariance Phenomenon for Eddy Current Testing

2020 ◽  
Author(s):  
Zhongwen Jin ◽  
Yuwei Meng ◽  
Rongdong Yu ◽  
Ruochen Huang ◽  
Mingyang Lu ◽  
...  
Keyword(s):  
Linear Relationship ◽  
Eddy Current ◽  
Coating Thickness ◽  
Test Sample ◽  
Common Point ◽  
Coil Design ◽  
Current Testing ◽  
Lift Off ◽  
Two Parameters ◽  
The Relationship

<p>Previously, a conductivity invariance phenomena (CIP) has been discovered – at a certain lift-off, the inductance change of the sensor due to a test sample is immune to conductivity variations, i.e. the inductance – lift-off curve passes through a common point at a certain lift-off, termed as conductivity invariance lift-off. However, this conductivity invariance lift-off is fixed for a particular sensor setup, which is not convenient for various sample conditions. In this paper, we propose using two parameters in the coil design – the horizontal and vertical distances between the transmitter and the receiver to control the conductivity invariance lift-off. The relationship between these two parameters and the conductivity invariance lift-off is investigated by simulation and experiments and it has been found that there is an approximate linear relationship between these two parameters and the conductivity invariance lift-off. This is useful for applications where the measurements have restrictions on lift-off, e.g. uneven coating thickness which limits the range of the lift-off of probe during the measurements. Therefore, based on this relationship, it can be easier to adjust the configuration of the probe for a better inspection of the test samples.</p>

scholarly journals Tomato Phenotypic Diversity Determined by Combined Approaches of Conventional and High-Throughput Tomato Analyzer Phenotyping

Plants ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 197 ◽  
Author(s):  
Amol N. Nankar ◽  
Ivanka Tringovska ◽  
Stanislava Grozeva ◽  
Daniela Ganeva ◽  
Dimitrina Kostova
Keyword(s):  
Phenotypic Diversity ◽  
Hierarchical Cluster ◽  
Shape Index ◽  
Fruit Shape ◽  
Strong Positive Correlation ◽  
Correlation Networks ◽  
Vegetative Traits ◽  
The Relationship ◽  
Shape And Size ◽  
Tomato Analyzer

Morphological variation in vegetative and fruit traits is a key determinant in unraveling phenotypic diversity. This study was designed to assess phenotypic diversity in tomatoes and examine intra- and intervarietal groups’ variability using 28 conventional descriptors (CDs) and 47 Tomato Analyzer (TA) descriptors related to plant and fruit morphometry. Comprehensive phenotyping of 150 accessions representing 21 countries discerned noticeable variability for CD vegetative traits and TA quantified fruit features, such as shape, size, and color. Hierarchical cluster analysis divided the accessions into 10 distinct classes based on fruit shape and size. Multivariate analysis was used to assess divergence in variable traits among populations. Eight principal components with an eigenvalue >1 were identified by factor analysis, which contributed 87.5% variation to the total cumulative variance with the first two components contributing 32.0% and 18.1% variance, respectively. The relationship between vegetative and fruit descriptors was explained by respective CD and TA correlation networks. There was a strong positive correlation between fruit shape and size whereas negative correlations were between fruit shape index, internal eccentricity, and proximal end shape. The combined approach of CD and TA phenotyping allowed us to unravel the phenotypic diversity of vegetative and reproductive trait variation evaluated at pre- and post-harvest stages.

Long-distance wind dispersal of tree seeds

1995 ◽  
Vol 73 (7) ◽  
pp. 1036-1045 ◽  
Author(s):  
D. F. Greene ◽  
E. A. Johnson
Keyword(s):  
Seed Dispersal ◽  
Conservation Biology ◽  
Plant Conservation ◽  
Dispersal Distance ◽  
Wind Dispersal ◽  
Source Strength ◽  
Long Distance ◽  
Model Predictions ◽  
Tree Seeds ◽  
The Relationship

Long-distance seed dispersal figures prominently in most plant conservation biology arguments, yet we possess little more than anecdotes concerning the relationship among deposition (seeds/m2), source strength (seeds/m2), and distance. In this paper we derive two simple models for long-distance deposition. The models are tested at the scale of 100–1600 m from the source and found to be within 5-fold of the observed deposition. There is no discernable decline in deposition for the range 300–1600 m. While we hesitate to extend model predictions to greater distances, both the models and the empirical results allow us to assert that rare wind-dispersed species in woodlots (dispersal distance around 1 km) are effectively isolated from one another at the temporal scale of 1000 years. Key words: plant conservation biology, wind dispersal of seeds, metapopulations.

Effects of habitat fragmentation on the genetic diversity and differentiation of Dendrolimus punctatus (Lepidoptera: Lasiocampidae) in Thousand Island Lake, China, based on mitochondrial COI gene sequences

2018 ◽  
Vol 109 (1) ◽  
pp. 62-71 ◽  
Author(s):  
K. Lv ◽  
J.-R. Wang ◽  
T.-Q. Li ◽  
J. Zhou ◽  
J.-Q. Gu ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Habitat Fragmentation ◽  
Geographic Distance ◽  
Haplotype Diversity ◽  
Shape Index ◽  
Coi Gene ◽  
Fragmented Landscape ◽  
Dispersal Capacity ◽  
Island Populations ◽  
High Dispersal

AbstractThousand Island Lake (TIL) is a typical fragmented landscape and an ideal model to study ecological effects of fragmentation. Partial fragments of the mitochondrial cytochrome oxidase subunit I gene of 23 island populations of Dendrolimus punctatus in TIL were sequenced, 141 haplotypes being identified. The number of haplotypes increased significantly with the increase in island area and shape index, whereas no significant correlation was detected between three island attributes (area, shape and isolation) and haplotype diversity. However, the correlation with number of haplotypes was no longer significant when the ‘outlier’ island JSD (the largest island) was not included. Additionally, we found no significant relationship between geographic distance and genetic distance. Geographic isolation did not obstruct the gene flow among D. punctatus populations, which might be because of the high dispersal capacity of this pine moth. Fragmentation resulted in the conversion of large and continuous habitats into isolated, small and insular patches, which was the primary effect on the genetic diversity of D. punctatus in TIL. The conclusion to emphasize from our research is that habitat fragmentation reduced the biological genetic diversity to some extent, further demonstrating the importance of habitat continuity in biodiversity protection.

Physical Cleaning Enhancement Using Advanced Spray with Uniform Droplet Control

2012 ◽  
Vol 195 ◽  
pp. 195-197 ◽  
Author(s):  
Ying Hsueh Chang Chien ◽  
Matt Yeh ◽  
Scott Ku ◽  
C.M. Yang ◽  
C.C. Chen ◽  
...  
Keyword(s):  
Semiconductor Device ◽  
Droplet Diameter ◽  
Particle Removal ◽  
Physical Force ◽  
Cleaning Efficiency ◽  
Lift Off ◽  
The Moment ◽  
The Relationship ◽  
Uniform Droplet ◽  
Droplet Control

In semiconductor device manufacturing, single wafer processors are widely used in not only BEOL process but also in FEOL process for 2X devices to improve the cleaning efficiency and get the higher productivity. Because the scaled down devices require the minimum substrate loss in the cleaning steps, the physical force by a dual fluid spray is still the main position to improve the cleaning efficiency at the moment comparing with chemical effects as the dissolution of contaminants and/or the lift off of particles. Sato, et al., reported that the relationship between particle removal and droplet characteristics linked to the droplet energy densityEdas following equation [. The kinetic energyEkof droplet is calculated from droplet diameterdand velocityv, as shown in Equation 1.

Different supramolecular architectures mediated by different weak interactions in the crystals of three N-aryl-2,5-dimethoxybenzenesulfonamides

2017 ◽  
Vol 73 (10) ◽  
pp. 833-844 ◽  
Author(s):  
K. Shakuntala ◽  
S. Naveen ◽  
N. K. Lokanath ◽  
P. A. Suchetan ◽  
M. Abdoh
Keyword(s):  
Hydrogen Bonds ◽  
Crystal Structures ◽  
Intermolecular Interactions ◽  
Weak Interactions ◽  
Three Dimensional ◽  
Shape Index ◽  
Intramolecular Interactions ◽  
Molecular Conformations ◽  
Supramolecular Architectures ◽  
The Relationship

The synthesis and evaluation of the pharmacological activities of molecules containing the sulfonamide moiety have attracted interest as these compounds are important pharmacophores. The crystal structures of three closely related N-aryl-2,5-dimethoxybenzenesulfonamides, namely N-(2,3-dichlorophenyl)-2,5-dimethoxybenzenesulfonamide, C14H13Cl2NO4S, (I), N-(2,4-dichlorophenyl)-2,5-dimethoxybenzenesulfonamide, C14H13Cl2NO4S, (II), and N-(2,4-dimethylphenyl)-2,5-dimethoxybenzenesulfonamide, C16H19NO4S, (III), are described. The asymmetric unit of (I) consists of two symmetry-independent molecules, while those of (II) and (III) contain one molecule each. The molecular conformations are stabilized by different intramolecular interactions, viz. C—H...O interactions in (I), N—H...Cl and C—H...O interactions in (II), and C—H...O interactions in (III). The crystals of the three compounds display different supramolecular architectures built by various weak intermolecular interactions of the types C—H...O, C—H...Cl, C—H...π(aryl), π(aryl)–π(aryl) and Cl...Cl. A detailed Hirshfeld surface analysis of these compounds has also been conducted in order to understand the relationship between the crystal structures. The d norm and shape-index surfaces of (I)–(III) support the presence of various intermolecular interactions in the three structures. Analysis of the fingerprint plots reveals that the greatest contribution to the Hirshfeld surfaces is from H...H contacts, followed by H...O/O...H contacts. In addition, comparisons are made with the structures of some related compounds. Putative N—H...O hydrogen bonds are observed in 29 of the 30 reported structures, wherein the N—H...O hydrogen bonds form either C(4) chain motifs or R 2 2(8) rings. Further comparison reveals that the characteristics of the N—H...O hydrogen-bond motifs, the presence of other interactions and the resultant supramolecular architecture is largely decided by the position of the substituents on the benzenesulfonyl ring, with the nature and position of the substituents on the aniline ring exerting little effect. On the other hand, the crystal structures of (I)–(III) display several weak interactions other than the common N—H...O hydrogen bonds, resulting in supramolecular architectures varying from one- to three-dimensional depending on the nature and position of the substituents on the aniline ring.

scholarly journals Superhydrophobic frictions

2019 ◽  
Vol 116 (17) ◽  
pp. 8220-8223 ◽  
Author(s):  
Timothée Mouterde ◽  
Pascal S. Raux ◽  
Christophe Clanet ◽  
David Quéré
Keyword(s):  
Terminal Velocity ◽  
Water Repellent ◽  
Viscous Liquids ◽  
The Relationship

Contrasting with its sluggish behavior on standard solids, water is extremely mobile on superhydrophobic materials, as shown, for instance, by the continuous acceleration of drops on tilted water-repellent leaves. For much longer substrates, however, drops reach a terminal velocity that results from a balance between weight and friction, allowing us to question the nature of this friction. We report that the relationship between force and terminal velocity is nonlinear. This is interpreted by showing that classical sources of friction are minimized, so that the aerodynamical resistance to motion becomes dominant, which eventually explains the matchless mobility of water. Our results are finally extended to viscous liquids, also known to be unusually quick on these materials.

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