Publications by authors named "Adoum Mahamat"
Bayfol HX200 photopolymer is a holographic recording material used in a variety of applications such as a holographic combiner for a heads-up display and augmented reality, dispersive grating for spectrometers, and notch filters for Raman spectroscopy. For these systems, the thermal properties of the holographic material are extremely important to consider since temperature can affect the diffraction efficiency of the hologram as well as its spectral bandwidth and diffraction angle. These thermal variations are a consequence of the distance and geometry change of the diffraction Bragg planes recorded inside the material.
View Article and Find Full Text PDFBackground: A longitudinal Anopheles gambiae s.l. insecticide resistance monitoring programme was established in four sentinel sites in Chad 2008-2010.
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- Volume-phase holographic (VPH) gratings are crucial for applications in fields like optical communication, imaging, and astronomy.
- The paper discusses a VPH grating designed to efficiently operate across red, green, and blue wavelengths, achieving 98% efficiency at 532 nm and at least 75% efficiency in the 400-700 nm range for unpolarized light.
- Fabrication optimization focuses on using a 12 μm thick layer of dichromated gelatin with specific properties to enhance performance and tolerance.
The search for the earliest fossil evidence of the human lineage has been concentrated in East Africa. Here we report the discovery of six hominid specimens from Chad, central Africa, 2,500 km from the East African Rift Valley. The fossils include a nearly complete cranium and fragmentary lower jaws.
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