Echolocation beam shape in emballonurid bats, Saccopteryx bilineata and Cormura brevirostris

2012 ◽  
Vol 66 (11) ◽  
pp. 1493-1502 ◽  
Author(s):  
Lasse Jakobsen ◽  
Elisabeth K. V. Kalko ◽  
Annemarie Surlykke
Keyword(s):  
Beam Shape ◽  
Saccopteryx Bilineata

scholarly journals Dynamics of the echolocation beam during prey pursuit in aerial hawking bats

2015 ◽  
Vol 112 (26) ◽  
pp. 8118-8123 ◽  
Author(s):  
Lasse Jakobsen ◽  
Mads Nedergaard Olsen ◽  
Annemarie Surlykke
Keyword(s):  
Peripheral Vision ◽  
Fundamental Property ◽  
High Energy ◽  
Beam Shape ◽  
Saccopteryx Bilineata ◽  
Very High Energy ◽  
Myotis Daubentonii ◽  
Escape Behaviors ◽  
Very High ◽  
Beam Broadening

In the evolutionary arms race between prey and predator, measures and countermeasures continuously evolve to increase survival on both sides. Bats and moths are prime examples. When exposed to intense ultrasound, eared moths perform dramatic escape behaviors. Vespertilionid and rhinolophid bats broaden their echolocation beam in the final stage of pursuit, presumably as a countermeasure to keep evading moths within their “acoustic field of view.” In this study, we investigated if dynamic beam broadening is a general property of echolocation when catching moving prey. We recorded three species of emballonurid bats, Saccopteryx bilineata, Saccopteryx leptura, and Rhynchonycteris naso, catching airborne insects in the field. The study shows that S. bilineata and S. leptura maintain a constant beam shape during the entire prey pursuit, whereas R. naso broadens the beam by lowering the peak call frequency from 100 kHz during search and approach to 67 kHz in the buzz. Surprisingly, both Saccopteryx bats emit calls with very high energy throughout the pursuit, up to 60 times more than R. naso and Myotis daubentonii (a similar sized vespertilionid), providing them with as much, or more, peripheral “vision” than the vespertilionids, but ensonifying objects far ahead suggesting more clutter. Thus, beam broadening is not a fundamental property of the echolocation system. However, based on the results, we hypothesize that increased peripheral detection is crucial to all aerial hawking bats in the final stages of prey pursuit and speculate that beam broadening is a feature characterizing more advanced echolocation.

Study on MEMS Thermal Microactuators with Pedestal-Type Beam Shape and Au Electroplating

2013 ◽  
Vol 133 (4) ◽  
pp. 100-104 ◽  
Author(s):  
Kuniyuki Ochiai ◽  
Takahiro Osada ◽  
Hideo Muro
Keyword(s):  
Beam Shape

scholarly journals Beam-shape loss for multiple-beam digital array radars

2019 ◽  
Vol 2019 (19) ◽  
pp. 5593-5596
Author(s):  
Yuan Yao ◽  
Guangxin Wu
Keyword(s):  
Beam Shape ◽  
Multiple Beam ◽  
Shape Loss

scholarly journals Optimized beam shaping assembly for a 2.1-MeV proton-accelerator-based neutron source for boron neutron capture therapy

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Pablo Torres-Sánchez ◽  
Ignacio Porras ◽  
Nataliya Ramos-Chernenko ◽  
Fernando Arias de Saavedra ◽  
Javier Praena
Keyword(s):  
Boron Neutron Capture Therapy ◽  
Neutron Capture ◽  
Beam Shaping ◽  
Proton Accelerator ◽  
Neutron Capture Therapy ◽  
Beam Shape ◽  
New Era ◽  
Boron Neutron Capture ◽  
Optimal Beam ◽  
Beam Shaping Assembly

AbstractBoron Neutron Capture Therapy (BNCT) is facing a new era where different projects based on accelerators instead of reactors are under development. The new facilities can be placed at hospitals and will increase the number of clinical trials. The therapeutic effect of BNCT can be improved if a optimized epithermal neutron spectrum is obtained, for which the beam shape assembly is a key ingredient. In this paper we propose an optimal beam shaping assembly suited for an affordable low energy accelerator. The beam obtained with the device proposed accomplishes all the IAEA recommendations for proton energies between 2.0 and 2.1 MeV. In addition, there is an overall improvement of the figures of merit with respect to BNCT facilities and previous proposals of new accelerator-based facilities.

ORIENTATING MANIPULATION OF CYLINDRICAL PARTICLES WITH OPTICAL TWEEZERS

2008 ◽  
Vol 17 (04) ◽  
pp. 387-394 ◽  
Author(s):  
XIUDONG SUN ◽  
XUECONG LI ◽  
JIANLONG ZHANG
Keyword(s):  
Escherichia Coli ◽  
Carbon Nanotubes ◽  
Laser Beam ◽  
Optical Tweezers ◽  
Optical Trap ◽  
Polarization Direction ◽  
Beam Shape ◽  
E Coli ◽  
Potential Applications ◽  
Cylindrical Particles

Orientating manipulations of cylindrical particles were performed by optical tweezers. Vertical and horizontal manipulations of Escherichia coli (E. coli) were carried out by changing the trapping depth and the focused laser beam shape. It was found that carbon nanotubes bundles (CNTBs) could be rotated in the linear polarized optical trap until it orientated its long axis along the linear polarization direction of the laser beam. However, E.coli could not be orientated in this way. Corresponding mechanisms were discussed based on the anisomeric electric characters of CNTBs. These orientation technologies of cylindrical objects with optical trap have potential applications in assembling nano-electric devices.

Circular aerial arrays for radio astronomy

1961 ◽  
Vol 262 (1308) ◽  
pp. 84-99 ◽  
Keyword(s):  
Radio Astronomy ◽  
Side Lobe ◽  
Correction Function ◽  
Side Lobe Level ◽  
Circular Aperture ◽  
Circular Array ◽  
Polar Diagram ◽  
Beam Shape ◽  
Correction Process ◽  
Dimensional Distribution

A new type of aerial array suitable for high-resolution observations in radio astronomy is explored theoretically. The array consists of a large number of aerial elements equally Spaced round a circle and electrically connected in phase. The power polar diagram is calculated for the cases when the circle is effectively continuous, and when the separation between adjacent elements is appreciable. In both cases the side-lobe level is rather high for most radio astronomical purposes, for which a process of aerial correction is required. The function of the correction process is to readjust the relative weights of the different spatial Fourier components to provide a suitable beam shape. A general method of aerial correction is developed in which the two dimensional distribution of brightness directly recorded by scanning is cross-correlated with a circularly symmetrical correction function , a process which is desirably performed in the instrument itself. The correction process allows one to convert the polar diagram of a ring-shaped array into (for example) the diagram of a uniform circular aperture of the same radius. The principal theoretical characteristics of the circular array are briefly compared with those of the Mills cross. It is found that while the process of aerial correction or ‘tapering’ is technically more straightforward in the cross, the circular array has the following advantages: (1) the length of transmission line (and hence attenuation) between each element and receiver is halved; (2) the number of elements required to gain the same information is reduced, approximately in the ratio 4: π ; (3) the beam possesses circular or elliptical symmetry; and (4) the system offers the possibility of direct phase and amplitude calibration with the aid of a transmitter situated on a central tower.

Laboratory determination of beam-shape coefficients for use in generalized Lorenz–Mie theory

2001 ◽  
Vol 40 (10) ◽  
pp. 1699 ◽  
Author(s):  
Hubert Polaert ◽  
Gérard Gouesbet ◽  
Gérard Gréhan
Keyword(s):  
Mie Theory ◽  
Beam Shape ◽  
Laboratory Determination

A histological examination of the holding sacs and glandular scent organs of some bat species (Emballonuridae, Hipposideridae, Phyllostomidae, Vespertilionidae, and Molossidae)

2000 ◽  
Vol 78 (4) ◽  
pp. 613-623 ◽  
Author(s):  
William MR Scully ◽  
M B Fenton ◽  
A SM Saleuddin
Keyword(s):  
Electron Microscope ◽  
Sexual Dimorphism ◽  
Sebaceous Glands ◽  
Microscope Examination ◽  
Scent Gland ◽  
Light Microscope Level ◽  
Histological Techniques ◽  
Saccopteryx Bilineata ◽  
The Face ◽  
Scanning Electron

Using histological techniques at the light-microscope level, we examined and compared structure and sexual dimorphism of the wing sacs and integumentary glandular scent organs of 11 species of microchiropteran bats. The antebrachial wing sacs of the Neotropical emballonurids Peropteryx macrotis, Saccopteryx bilineata, and Saccopteryx leptura differed in size and location but lacked sudoriferous and sebaceous glands, confirming that they were holding sacs rather than glandular scent organs. Glandular scent organs from 11 species consisted of sebaceous and (or) sudoriferous glands in emballonurids (P. macrotis, S. bilineata, S. leptura, Taphozous melanopogon, Taphozous nudiventris), hipposiderids (Hipposiderous fulvus, Hipposiderous ater), the phyllostomid Sturnira lilium, the vespertilionid Rhogeessa anaeus, and molossids (Molossus ater and Molossus sinaloe). Glandular scent organs were located on the face (H. fulvus, H. ater), gular region (S. bilineata, P. macrotis, T. melanopogon, M. ater, M. sinaloe), chest (T. nudiventris), shoulder (S. lilium), or ears (R. anaeus). Glandular scent organs showed greater similarities within than between families, and typically were rudimentary or lacking in females. Scanning electron microscope examination revealed that the hairs associated with glandular areas of male T. melanopogon were larger and had a different cuticular-scale pattern than body hairs. These were osmetrichia, hairs specialized for holding and dispersing glandular products. In S. lilium, hairs associated with the shoulder scent-gland area were larger than body hairs but similar in cuticular-scale pattern.

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