The mammals of Angola

Scientific investigations on the mammals of Angola started over 150 years ago, but information remains scarce and scattered, with only one recent published account. Here we provide a synthesis of the mammals of Angola based on a thorough survey of primary and grey literature, as well as recent unpublished records. We present a short history of mammal research, and provide brief information on each species known to occur in the country. Particular attention is given to endemic and near endemic species. We also provide a zoogeographic outline and information on the conservation of Angolan mammals. We found confirmed records for 291 native species, most of which from the orders Rodentia (85), Chiroptera (73), Carnivora (39), and Cetartiodactyla (33). There is a large number of endemic and near endemic species, most of which are rodents or bats. The large diversity of species is favoured by the wide range of habitats with contrasting environmental conditions, while endemism tends to be associated with unique physiographic settings such as the Angolan Escarpment. The mammal fauna of Angola includes 2 Critically Endangered, 2 Endangered, 11 Vulnerable, and 14 Near-Threatened species at the global scale. There are also 12 data deficient species, most of which are endemics or near endemics to the countryinfo:eu-repo/semantics/publishedVersio

Small laser Doppler velocimeter based on the self-mixing effect in a diode laser

A very small and simple velocimeter is presented consisting of a diode laser with a gradient-index lens in front of it. The basis of the velocity measurement is the mixing that occurs when light, scattered back by the moving object into the laser cavity, interferes with light inside the laser. This mixing induces large fluctuations of the laser intensity with the Doppler frequency. These fluctuations can be detected either with a photodiode or by measuring the voltage across the diode laser. As an illustration of the performance of the velocimeter, velocity measurements of a rotating disk covered with white paper are described. The differences arising because of using a single-mode or a multilongitudinal mode laser were calculated and verified in experiments. The advantage of the use of a multimode laser is that differential measurements of the distance between laser and moving object are also possible

Active Gust Load Alleviation by Combined Actuation of Trailing Edge and Leading Edge Flap at Transonic Speeds

Gust load analysis plays a substantial role in the certification process of aircraft. Active gust load alleviation techniques exhibit a high potential in significantly reducing the transient gust loads and thus the overall structural weight. In this paper, two dynamic actuator concepts are studied by means of CFD methods on a generic wing-fuselage aircraft configuration. The concepts comprise spanwise segmented trailing edge flaps (TEF) and leading edge flaps (LEF), which are already existent on the research model for high-lift and maneuvering purposes. Simulations based on Euler and RANS equations are utilized to assess the aerodynamic potential of the actuators regarding alleviation of critical idealized "1-cos" type vertical gusts. 2D simulations of a representative wing section are considered in an extended parametric study to derive an initial guess for the required actuation deflections on the aircraft configuration. An iterative analysis of spanwise varying actuator amplitudes is conducted in order to obtain strong control authority over the wing bending moment (WBM) and wing torsional moment (WTM). It is shown that the TEFs are promising in terms of mitigation of gust induced WBM and the LEFs are able to compensate the WTM induced by the deflected TEFs. Unsteady phenomena are identified at large TEF deflections resulting in unfavorable response of the aircraft. The transient behavior of the force coefficients shows significant dependencies on the flap scheduling. Only small improvements are achieved through segmented flap actuation compared to continuous flap actuation for the limited investigated setups

Pulsed-laser Doppler flowmetry provides basis for deep perfusion probing

A setup for pulsed-laser Doppler flowmetry ~LDF! measurements has been built and tested. Measurements were carried out comparing continuous-wave and pulsed LDF. With pulsed LDF a higher peak power can be injected into the tissue without exceeding the safety limits. This enables a much larger spacing between the locations of illumination and detection. Thus, the penetration depth, and thus the measurement volume, can be enlarged using the pulsed-LDF method. This method will allow, e.g., monitoring of the cerebral perfusion