Accession Number : ADP014406


Title :   Magnetic Material Arrangement In Apis Mellifera Abdomens


Corporate Author : PONTIFICIA UNIVERSIDADE CATOLICA DO RIODE JANEIRO (BRAZIL)


Personal Author(s) : Esquivel, Darci M ; Wajnberg, Eliane ; Cernicchiaro, Geraldo R ; Acosta-Avalos, Daniel ; Garcia, B E


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/p014406.pdf


Report Date : Apr 2002


Pagination or Media Count : 5


Abstract : Honeybees are the most studied insects in the magnetic orientation research field. Experiments on the magnetic remanence of honeybees have shown the presence of magnetite nanoparticles aligned transversely to the body axis on the anterodorsal abdomen horizontal plane. These results support the hypothesis of ferromagnetic sensors for the magnetoreception mechanism. An Electron Paramagnetic Resonance (EPR) study identified isolated magnetite nanoparticles and aggregates of these particles with a low temperature transition (52 K - 91 K). Hysteresis curves of Apis mellifera abdomens organized parallel and perpendicular to the applied magnetic field were obtained from 5K to 310K. At low temperatures, the hysteresis curves indicate a preferential orientation of the magnetic easy axis parallel to the body axis. The saturation (J sub s) and remanent (J sub r) magnetizations, coercive field (H sub c) and initial susceptibility (X) were obtained. Results were interpreted based on the presence of magnetite nanopartieles with 50 K and 120 K mean blocking temperatures.


Descriptors :   *MAGNETIC FIELDS , *FERROMAGNETIC MATERIALS , *ABDOMEN , *MAGNETITE , LOW TEMPERATURE , ORIENTATION(DIRECTION) , PARTICLES , TRANSITIONS , HORIZONTAL ORIENTATION , COERCIVE FORCE , ELECTRON PARAMAGNETIC RESONANCE , BRAZIL , INSECTS


Subject Categories : Anatomy and Physiology
      Properties of Metals and Alloys
      Electricity and Magnetism


Distribution Statement : APPROVED FOR PUBLIC RELEASE