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Especially at transonic flow conditions the leading edge shape influences the performance of a fan profile. At the same time the leading edge of a fan profile is highly affected by erosion during operation. This erosion leads to a deformation of the leading edge shape and a reduction of the chord length. In the present experimental and numerical study, the aerodynamic performance of an original fan profile geometry is compared to an eroded fan profile with a blunt leading edge (BLE) and a chord length reduced by about 1%. The experiments are peiformed at a linear fan blade cascade in the Transonic Cascade Wind Tunnel of DLR in Cologne. The inflow Mach number during the tests is 1.25 and the Reynolds number 1.5 x 106. All tests are carried out at a low inflow turbulence level of 0.8%. The results of the investigation show that losses are increased over the whole operating range of the cascade. At the aerodynamic design point (ADP) the losses raise by 25%. This significant loss increase can be traced back to the increase of the shock losses at the leading edge. The change in shock structure is investigated and described in detail by means of particle image velocimetry (PIV) measurements and Schlieren imaging. Additionally, the unsteady fluctuation of the shock position is measured by a high-speed shadowgraphy. Then the frequency range of the fluctuation is obtained by a Fourier analysis of the time resolved shock position. Furthermore, liquid crystal measurements are performed in order to analyze the influence of the leading edge shape on the development of the suction side boundary layer. The results show that for the original fan blade the transition occurs at the shock position on the blade suction side by a separation bubble whereas the transition onset is shifted upstream for the fan blade with the BLE. [ABSTRACT FROM AUTHOR]

Lymphedema are characterized by interstitial edema leading to swelling of extremities. They can be divided into primary and secondary lymphedema. Developmental abnormalities of the lymphatic system are responsible for the primary form of lymphedema. The secondary form of lymphedema is caused by damage of the lymphatic system due to external factors. Lymphedema can rarely be observed in patients with tuberous sclerosis complex (TSC), which is a neurocutaneous syndrome caused by pathogenic variants in the genes TSC1 or TSC2. Patients with TSC usually present with neurological manifestations and the development of multiple benign tumors of ectodermal origin. Typical onset for several symptoms is during the first year of life and in some cases lesions can be detected prenatally. Epilepsy is one of the most common manifestations, affecting up to 90% of TSC patients, and is associated with developmental delay. Early pharmacotherapy improves long term patient outcome. Trio exome sequencing was performed in a 3 weeks old girl with congenital lymphedema of the right lower extremity. Using a filter for de novo variants, the heterozygous missense variant c.2524C>T, p.(Gln842Ter) in TSC1 (NM_000368.4) could be identified. After the first onset of infantile spams at age 7 months treatment with vigabatrin was started immediately. We propose to include TSC1 and TSC2 analysis in the diagnostic work-up of patients with (isolated) congenital lymphedema as early diagnosis facilitates consequent treatment strategies potentially improving the prognosis of TSC patients., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Conventional laser cooling relies on repeated electronic excitations by near-resonant light, which constrains its area of application to a selected number of atomic species prepared at moderate particle densities. Optical cavities with sufficiently large Purcell factors allow for laser cooling schemes, avoiding these limitations. Here, we report on an atom-cavity system, combining a Purcell factor above 40 with a cavity bandwidth below the recoil frequency associated with the kinetic energy transfer in a single photon scattering event. This lets us access a yet-unexplored regime of atom-cavity interactions, in which the atomic motion can be manipulated by targeted dissipation with sub-recoil resolution. We demonstrate cavity-induced heating of a Bose-Einstein condensate and subsequent cooling at particle densities and temperatures incompatible with conventional laser cooling.

A novel regime of atom-cavity physics is explored, arising when large atom samples dispersively interact with high-finesse optical cavities. A stable far-detuned optical lattice of several million rubidium atoms is formed inside an optical ring resonator by coupling equal amounts of laser light to each propagation direction of a longitudinal cavity mode. An adjacent longitudinal mode, detuned by about 3 GHz, is used to perform probe transmission spectroscopy of the system. The atom-cavity coupling for the lattice beams and the probe is dispersive and dissipation results only from the finite photon-storage time. The observation of two well-resolved normal modes demonstrates the regime of strong cooperative coupling. The details of the normal mode spectrum reveal mechanical effects associated with the retroaction of the probe upon the optical lattice.