scholarly journals Spray deposition within plant canopies

2000 ◽  
Vol 53 ◽  
pp. 248-252 ◽  
Author(s):  
B. Richardson ◽  
M. Newton
Keyword(s):  
Velocity Component ◽  
Spray Deposition ◽  
Horizontal Velocity ◽  
Pteridium Aquilinum ◽  
Fluorescent Tracer ◽  
Bracken Fern ◽  
Plant Canopies ◽  
Plane Normal ◽  
Horizontal Velocity Component ◽  
Arctostaphylos Patula

Spray deposition was measured within canopies of bracken fern (Pteridium aquilinum) and greenleaf manzanita (Arctostaphylos patula) following ground application of a spray mixture containing water a fluorescent tracer and surfactant A high proportion of spray (3538) reached the ground through manzanita canopies whereas only 113 reached the ground through a bracken canopy Spray deposition was closely linked to the quantity of foliage projected on a plane normal to the trajectory of droplets passing through the canopy Droplets that had trajectories with a significant horizontal velocity component were more effectively captured because of an increase in the quantity of foliage in their path

Response of Young Ponderosa Pines, Shrubs, and Ferns to Three Release Treatments

1994 ◽  
Vol 9 (1) ◽  
pp. 24-28
Author(s):  
Philip M. McDonald ◽  
Celeste S. Abbott ◽  
Gary O. Fiddler
Keyword(s):  
Pinus Ponderosa ◽  
Ponderosa Pine ◽  
Pteridium Aquilinum ◽  
Northern California ◽  
Bracken Fern ◽  
Growing Seasons ◽  
Arctostaphylos Patula ◽  
One Year

Abstract One-year-old Sierra chinkapin (Castanopsis sempervirens) sprouts, greenleaf manzanita (Arctostaphylos patula var. platyphylla) seedlings, and new fronds of bracken fern (Pteridium aquilinum var. pubescens), present in a 1-yr-old ponderosa pine (Pinus ponderosa var. ponderosa) plantation in northern California, were treated once with one of three herbicides (Velpar L, Escort, and Garlon 4) in fall 1986 and spring 1987 and their density and development compared among treatments and to a control. After 6 growing seasons, chinkapin sprouts in the control averaged more than 16,000 per acre, manzanita seedlings over 19,000, and bracken ferns more than 13,000 per acre. After 6 growing seasons, mean ponderosa pine diameter ranged from 2.03 in. in the Velpar treatment to 1.28 in. in the control. Cover of combined shrubs, also after six seasons, was about 3% with Velpar, 7% with Garlon, 20% with Escort, and 51% in the control. Bracken fern cover was greatest (13%) where foliage-active Garlon reduced competing shrubs, and least in the soil-active Velpar treatment (2%) and the control (3%), where heavy competition from shrubs precluded establishment. West. J. Appl. For. 9(1):24-28.

Comparison of Driving Rain Index Calculated According to EN 15927-3 to the CFD Simulation and Experimental Measurement

2016 ◽  
Vol 861 ◽  
pp. 239-246 ◽  
Author(s):  
Peter Juras ◽  
Miroslav Jakubcik
Keyword(s):  
Experimental Measurement ◽  
Velocity Component ◽  
Cfd Simulation ◽  
Rain Gauge ◽  
Horizontal Velocity ◽  
Building Science ◽  
Moisture Source ◽  
Horizontal Velocity Component ◽  
Building Facades ◽  
Driving Rain

Wind-driven rain or driving rain is a rain which has given a horizontal velocity component by the wind. It can be the important moisture source for building façades and has been of the great concern in building science. In this article, the normative method described in STN EN ISO 15927-3:2009, was used for calculation of driving rain impact on vertical surfaces. This amount of rain was compared to the CFD simulation for selected location and to the experimental measurement carried out by wind-driven rain gauge.

scholarly journals Wakes in stratified flow past a hot or cold two-dimensional body

1976 ◽  
Vol 75 (2) ◽  
pp. 233-256 ◽  
Author(s):  
G. E. Robertson ◽  
J. H. Seinfeld ◽  
L. G. Leal
Keyword(s):  
Velocity Component ◽  
Horizontal Velocity ◽  
Explicit Calculation ◽  
Two Dimensional ◽  
Line Heat Source ◽  
Oseen Flow ◽  
Horizontal Velocity Component ◽  
Self Similar ◽  
The Common ◽  
Jet Structure

This paper considers the general problem of laminar, steady, horizontal, Oseen flow at large distances upstream and downstream of a two-dimensional body which is represented as a line source of horizontal or vertical momentum, or as a line heat source or heat dipole. The fluid is assumed to be incompressible, diffusive, viscous and stably stratified. The analysis is focused on the general properties of the horizontal velocity component, as well as on explicit calculation of the horizontal velocity profiles and disturbance stream-function fields for varying degrees of stratification. For stable stratifications, the flow fields for all four types of singularities exhibit the common feature of multiple recirculating rotors of finite thicknesses, which leads to an alternating jet structure both upstream and downstream for the horizontal velocity component and to leewaves downstream in the overall flow. The self-similar formulae for the velocity, temperature and pressure at very large distances upstream and downstream are also derived and compared with the Oseen solutions.

scholarly journals Cavity Formation during Asymmetric Water Entry of Rigid Bodies

2021 ◽  
Vol 11 (5) ◽  
pp. 2029
Author(s):  
Riccardo Panciroli ◽  
Giangiacomo Minak
Keyword(s):  
Velocity Component ◽  
Water Entry ◽  
Rigid Bodies ◽  
Rigid Body Dynamics ◽  
The Body ◽  
Horizontal Velocity ◽  
Cavity Formation ◽  
Fluid Structure ◽  
Horizontal Velocity Component ◽  
The Stability

This work numerically evaluates the role of advancing velocity on the water entry of rigid wedges, highlighting its influence on the development of underpressure at the fluid–structure interface, which can eventually lead to fluid detachment or cavity formation, depending on the geometry. A coupled FEM–SPH numerical model is implemented within LS-DYNA, and three types of asymmetric impacts are treated: (I) symmetric wedges with horizontal velocity component, (II) asymmetric wedges with a pure vertical velocity component, and (III) asymmetric wedges with a horizontal velocity component. Particular attention is given to the evolution of the pressure at the fluid–structure interface and the onset of fluid detachment at the wedge tip and their effect on the rigid body dynamics. Results concerning the tilting moment generated during the water entry are presented, varying entry depth, asymmetry, and entry velocity. The presented results are important for the evaluation of the stability of the body during asymmetric slamming events.

ChemInform Abstract: Pteridanoside, the First Protoilludane Sesquiterpene Glucoside as a Toxic Component of the Neotropical Bracken Fern Pteridium aquilinum var. caudatum.

ChemInform ◽  
2010 ◽  
Vol 31 (3) ◽  
pp. no-no
Author(s):  
Uvidelio Francisco Castillo ◽  
Youji Sakagami ◽  
Miguel Alonso-Amelot ◽  
Makoto Ojika
Keyword(s):  
Pteridium Aquilinum ◽  
Bracken Fern ◽  
Toxic Component

Variability of the Horizontal Velocity Structure in the Upper 1600 m of the Water Column on the Equator at 10°W

2006 ◽  
Vol 36 (7) ◽  
pp. 1287-1304 ◽  
Author(s):  
Lucia Bunge ◽  
Christine Provost ◽  
Jonathan M. Lilly ◽  
Marc D’Orgeville ◽  
Annie Kartavtseff ◽  
...  
Keyword(s):  
Water Column ◽  
Velocity Component ◽  
Velocity Structure ◽  
Strong Dependence ◽  
Acoustic Doppler Current Profiler ◽  
Horizontal Velocity ◽  
Vertical Shear ◽  
Equatorial Atlantic ◽  
Entire Water Column ◽  
Current Profiler

Abstract This paper presents initial results from new velocity observations in the eastern part of the equatorial Atlantic Ocean from a moored current-meter array. During the “EQUALANT” program (1999–2000), a mooring array was deployed around the equator near 10°W that recorded one year of measurements at various depths. Horizontal velocities were obtained in the upper 60 m from an upward-looking acoustic Doppler current profiler (ADCP) and at 13 deeper levels from current meters between 745 and 1525 m. To analyze the quasiperiodic variability observed in these records, a wavelet-based technique was used. Quasiperiodic oscillations having periods between 5 and 100 days were separated into four bands: 5–10, 10–20, 20–40, and 40–100 days. The variability shows (i) a strong seasonality (the first half of the series is dominated by larger periods than the second one) and (ii) a strong dependence with depth (some oscillations are present in the entire water column while others are only present at certain depths). For the oscillations that are present in the entire water column the origin of the forcing can be traced to the surface, while for the others the question of their origin remains open. Phase shifts at different depths generate vertical shears in the horizontal velocity component with relatively short vertical scales. This is especially visible in long-duration events (>100 days) of the zonal velocity component. Comparison with a simultaneous lowered acoustic Doppler current profiler (LADCP) section suggests that some of these flows may be identified with equatorial deep jets. A striking feature is a strong vertical shear lasting about 7 months between 745 and 1000 m. These deep current-meter observations would then imply a few months of duration for the jets in this region.

scholarly journals Clastogenic effect of bracken fern (Pteridium aquilinum v. arachnoideum) diet in peripheral lymphocytes of human consumers: preliminary data

2003 ◽  
Vol 1 (1) ◽  
pp. 22-29 ◽  
Author(s):  
R. C. Recouso ◽  
R. C. Stocco dos Santos ◽  
R. Freitas ◽  
R. C. Santos ◽  
A. C. de Freitas ◽  
...  
Keyword(s):  
Preliminary Data ◽  
Pteridium Aquilinum ◽  
Bracken Fern ◽  
Peripheral Lymphocytes ◽  
Clastogenic Effect

scholarly journals INTOXICAÇÃO AGUDA PELA SAMAMBAIA (Pteridium aquilinum, L. Kuhn), EM BOVINOS DA RAÇA ABERDEEN ANGUS

2002 ◽  
Vol 7 (1) ◽  
Author(s):  
W. S. MARÇAL ◽  
L. GASTE ◽  
N. C. REICHERT NETTO ◽  
F. A. MONTEIRO
Keyword(s):  
Pteridium Aquilinum ◽  
Acute Intoxication ◽  
Bracken Fern ◽  
Nutrient Quality ◽  
Toxic Plant

Os autores descrevem a ocorrência de um surto de intoxicação aguda pela samambaia (Pteridium aquilinum, L. Kuhn), em bovinos da raça Aberdeen angus, criados numa propriedade rural localizada no município de Ortigueira, estado do Paraná. Um total de 14 animais vieram a óbito e a ocorrência do surto reacende a necessidade de encontrar soluções, mesmo que paliativas, para a prevenção de novos episódios. Segundo os autores, a superlotação de animais nos piquetes, tornaram as pastagens cultivadas muito baixas, favorecendo a procura pela samambaia, que mantinha-se mais viçosa e atraente ao consumo, o que possibilitou uma ingestão de grande quantidade em curto espaço de tempo. Acute intoxication by bracken fern (Pteridium aquilinum, L. Kuhn) In Aberdeen angus breed Abstract The present paper gives an account of a herd intoxication caused by the ingestion of bracken fern (Pteridium aquilinum,L. Kuhn) that took place in a farm at the region of Ortigueira, State of Paraná. Fourteen Aberdeen Angus bovines died of acute intoxication caused by the ingestion of large amounts of this toxic plant. Overpopulated and low nutrient quality pastured areas induce the large ingestion of bracken fern. Due to these reasons there is an urgent need for adequate solutions aiming to prevent the occurrence of such episodes.

scholarly journals A new pest management research facility Scions largescale precision track sprayer

2014 ◽  
Vol 67 ◽  
pp. 267-273
Author(s):  
S.F. Gous ◽  
T.M. Withers ◽  
A.J. Hewitt
Keyword(s):  
Large Scale ◽  
Spray Deposition ◽  
Management Research ◽  
Application Research ◽  
Pesticide Application ◽  
Research Facility ◽  
Liquid Pressure ◽  
Plant Canopies ◽  
Wide Range ◽  
Potential Use

A new large scale precision track sprayer has been developed and evaluated for spray deposition and pesticide application research under controlled conditions The spray room is fitted with a 4 m wide electrically driven boom suspended 4 m above ground running on a 12 m long Ibeam It is fitted with 9 independently controlled shut off valves and nozzles Sprays can be applied to live plant canopies up to 3 m tall within a 2 m times; 3 m sample area The number location and type of nozzle on the boom can be altered as can spray liquid pressure and boom speed in order to simulate a wide range of spray application scenarios Calibration of the largescale precision track sprayer has been undertaken for a range of droplet spectra from extremely coarse to very fine This paper documents the calibration results and discusses the potential use of this facility for pesticide application research

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