Air quality in the metropolitan area of Sidi Bel Abbes (Algeria) through the lichens species as bio-indicators

The air quality in towns and cities is increasingly deteriorating as human activities increase but no actions have been taken in Algeria to limit air pollution. There are no regulations for controlling pollutant emissions and no specialist treatment center for treating diseases and allergies caused by  air pollution. To access urban air quality lichens species were used for bio-monitoring   12 stations spread across Sidi Bel Abbés city (Western  Algeria). The use of living organisms, in this case lichens, for evaluating the quality of air is a preferred method.  European lichenologists developed a new environmental quality assessment protocol using mapping lichen diversity and  lichens are very often used as bio- accumulators. The selected species are generally those growing on tree trunks, and having a broad geographic distribution. The lichen species most often used are thallus foliaceus or fruticose forms such as Parmelia caperata, P. sulcata, Hypogymnia physodes, Xanthoria parietina, Evernia prunastri, Pseudevernia furfuracea. These lichens species have large adsorption surfaces for major pollutants.  In this work we evaluate the air quality by applying lichen index based on German environmental engineers to map air pollution  in the city of Sidi Bel Abbes

14 GHz longitudinally detected electron spin resonance using microHall sensors

In this work we developed a home-made LOngitudinally Detected Electron Spin Resonance (LODESR) spectrometer based on a microsize Hall sensor. A coplanar waveguide (CPW)-resonator is used to induce microwave-excitation on the sample at 14 GHz. We used InSb cross-shaped Hall devices with active areas of (10 mu m x 10 mu m) and (5 mu m x 5 mu m). Signal intensities of the longitudinal magnetization component of DPPH and YIG samples of volumes about (10 mu m)(3) and (5 mu m)(3), are measured under amplitude and frequency modulated microwave magnetic field generated by the CPW-resonator. At room temperature, 10(9) spins/G root Hz sensitivity is achieved for 0.2 mT linewidth, a result which is still better than most of inductive detected LODESR sensitivities. (C) 2017 Elsevier Inc. All rights reserved