Filtration Effects Due to Bioassay Cage Design and Screen Type

Abstract

The use of bioassay cages in the efficacy assessment of pesticides, application techniques and technologies is common practice using numerous cage designs, which vary in both shape and size as well as type of mesh. The objective of this work was to examine various cage shapes and mesh types for their filtration effects on air speed, spray droplet size, and spray volume. Reductions in wind speed and droplet size seen inside the cages were measured by placing cages in a low-speed wind tunnel at air speeds of 0.5 m/ sec, 1 m/sec, 2 m/sec, and 4 m/sec and cage face orientations (relative to the air stream) of 0u, 10u, 22.5u, and 45u. Reduction in spray volume inside a select number of cages was also evaluated under similar conditions. Generally, greater air speed reductions were seen at lower external air speeds with overall reductions ranging from 30% to 88%, depending on cage type and tunnel air speed. Cages constructed with screens of lower porosities and smaller cylindrical-shaped cages tended to provide greater resistance to air flow and spray volume. Overall, spray droplet size inside the cages was minimally reduced by 0?10%. There was a 32?100% reduction in concentration of the spray volume applied relative to that recovered inside the bioassay cages depending on the cage geometry and screening material used. In general, concentration reductions were greatest at lower air speeds and for cages with lower porosity screens. As a result of this work, field researchers involved in assessing the efficacy of vector control applications will have a better understanding of the air speed and spray volume entering insect bioassay cages, relative to the amount applied, resulting in better recommended application techniques and dosage levels.

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Document Details

Document Type
Technical Report
Publication Date
Jan 01, 2010
Accession Number
ADA534957

Entities

People

  • Bradley K. Fritz
  • Jane Bonds
  • Muhammad Qamar Farooq
  • Todd Walker
  • W. C> Hoffmann

Organizations

  • Navy Entomology Center of Excellence

Tags

Communities of Interest

  • Biomedical

DTIC Thesaurus Topics

  • Air Flow
  • Bioassay
  • Fibers
  • Filtration
  • Flow
  • Fluid Dynamics
  • Geometry
  • Materials
  • Measurement
  • Orientation (Direction)
  • Pest Control
  • Pesticides
  • Porosity
  • Public Health
  • Stainless Steel
  • Test Methods
  • Wind Tunnels

Fields of Study

  • Agricultural and Food sciences

Readers

  • Combustion and Flow Dynamics.
  • Mathematics or Statistics
  • Tribology (the study of the boundary interaction between sliding surfaces, lubrication, wear and friction).