On the problem of supersonic gas flow in two-dimensional channel with the oscillating upper wall

In the present paper we solve the problem of supersonic gas flow in two-dimensional channel with the moving upper wall making oscillations according to the harmonic law. In order to get a numerical solution for gas dynamics equations we have implemented a difference scheme with space and time approximation of the first order and one with space approximation of the second order. Depending on a type of harmonic law and initial gas inflow conditions, the peculiarities of angle-shock wave propagation in moving curvilinear domains have been investigated. It has been determined that the increase of oscillation amplitude causes the increase of shock wave intensity. It has been shown that under particular oscillation amplitude the moving wall has practically no effect on the flow within the domain

Aggressive PDACs show hypomethylation of repetitive elements and the execution of an intrinsic IFN program linked to a ductal cell of origin

Pancreatic ductal adenocarcinoma (PDAC) is characterized by extensive desmoplasia, which challenges the molecular analyses of bulk tumor samples. Here we FACS-purified epithelial cells from human PDAC and normal pancreas and derived their genome-wide transcriptome and DNA methylome landscapes. Clustering based on DNA methylation revealed two distinct PDAC groups displaying different methylation patterns at regions encoding repeat elements. Methylation(low) tumors are characterized by higher expression of endogenous retroviral (ERV) transcripts and dsRNA sensors which leads to a cell intrinsic activation of an interferon signature (IFNsign). This results in a pro-tumorigenic microenvironment and poor patient outcome. Methylation(low)/IFNsign(high) and Methylation(high)/IFNsign(low) PDAC cells preserve lineage traits, respective of normal ductal or acinar pancreatic cells. Moreover, ductal-derived Kras(G12D)/Trp53(−/−) mouse PDACs show higher expression of IFNsign compared to acinar-derived counterparts. Collectively, our data point to two different origins and etiologies of human PDACs, with the aggressive Methylation(low)/IFNsign(high) subtype potentially targetable by agents blocking intrinsic IFN-signaling

Modelling human choices: MADeM and decision‑making

Research supported by FAPESP 2015/50122-0 and DFG-GRTK 1740/2. RP and AR are also part of the Research, Innovation and Dissemination Center for Neuromathematics FAPESP grant (2013/07699-0). RP is supported by a FAPESP scholarship (2013/25667-8). ACR is partially supported by a CNPq fellowship (grant 306251/2014-0)

Dynamic Simulation of Innovative Aircraft Air Conditioning

The development of innovative air conditioning systems for passenger aircrafts requires the application of dynamic simulation. FLECS, the "Functional Model Library of the Environmental Control System", was programmed to support such development processes of environmental control systems (ECS). FLECS offers a library with generic models from small ECS components up to the whole aircraft cabin. Fundamental to FLECS is the functional simulation in a MATLAB/Simulink environment based on a generalized volume and generalized resistances – mass flow resistances as well as heat flow resistances. Based on these generalized elements, specialised components like isobaric volumes and fan components were derived. Using measured datasets recorded during a test flight of an Airbus A340-600, a set of duct components as well as a cabin model was validated. The measured data was matched in both cases by the simulated response of the system. The validated duct components and the cabin model were used to simulate the control behaviour of an ECS. The cabin model of this simulation consisted of 2 zones of a single aisle aircraft. A highly dynamic test case was defined. The simulated behaviour of the system was plausible and could be well interpreted.Hamburger Behörde für Wirtschaft, Verkehr und Innovatio

Dynamische Simulation des Kühlaggregates eines Flugzeugs

In dieser Veröffentlichung wird ein dynamisches Simulationsmodell eines Kühlaggregats eines Flugzeugs beschrieben. Das Simulationsmodell berücksichtigt alle relevanten Komponenten: den Kompressor, die Turbine, das Gebläse und die verschiedenen Wärmetauscher. Die genannten Komponenten werden durch Kennfelder beschrieben. Die Dynamik der Simulation des Kühlaggregats basiert auf der dynamischen Beschreibung der Wärmetauscher. Den Wärmetauschern wird eine Masse bzw. eine Wärmekapazität zugeordnet. Der Wärmeübergang im Wärmetauscher von der Luft auf die Trennwand zwischen den Luftströmen wird durch einen Faktor alpha*A beschreiben. Der Faktor alpha*A (Produkt aus Wärmeübergangskoeffizient und Austauschfläche) lässt sich mit Hilfe einer Effizienzkurve berechnen. Für diese Rechnung sind keine Daten der Geometrie des Wärmetauschers erforderlich. Das Simulationsmodell des Kühlaggregats wurde mit Industriedaten verifiziert. Weiterhin wurde das Kühlaggregat in eine Simulation der Temperaturregelung der Kabine eingebaut. Die Simulation zeigt plausible Ergebnisse. Es wird gezeigt, dass der Einfluss der Dynamik des Kühlaggregats auf das Regelverhalten des Gesamtsystems nicht vernachlässigt werden kann.Hamburger Behörde für Wirtschaft, Verkehr und Innovatio

FLECS: Functional Library of the Environmental Control System – A Simulation Tool for the Support of Industrial Processes

An Environmental Control System (ECS) in an aircraft ensures the correct air temperature and pressure for passengers and crew. The ECS development process requires the simulation of the ECS system functionality in order to find an optimum system configuration and to support sizing of components. FLECS, the "Functional Model Library of the Environmental Control System", is programmed to support this development process. It offers a library of generic models of ECS components and the aircraft cabin. The library is based on the commercial standard simulation software MATLAB/Simulink. FLECS allows the simulation of a network topology of a system, combining heat and mass flows. Fundamental to the simulation are generalized volume and generalized resistance elements – mass flow resistances as well as heat flow resistances for conduction, convention and radiation. The mass flow of predominantly dry air may contain water vapor and CO2. A highly dynamic sample simulation from FLECS components was compared with results from another verified simulation program: Both results were in good agreement. Various Graphical User Interfaces (GUI) in FLECS support everyday use in the industrial environment

New observations of Phobos, Deimos, and their shadows with the HRSC/SRC on Mars Express

In the past year, many new observations of Phobos and Deimos have been carried out by the HRSC (High Resolution Stereo Camera) and the SRC (Super Resolution Channel) on the Mars Express spacecraft. A total of 3 Phobos flyby maneuvers were executed within one November week (2005) alone. In addition, the Phobos shadow was captured twice, in orbits 2239 and 2345, as it moved across the surface. As we reported previously, the earlier observations were used to determine the astrometric positions of the two satellites with accuracies of 0.5 - 5 km (Phobos) and 1.0 km (Deimos). These positional data differed substantially from the various available predictions, a fact which motivated the beginning of renewed Phobos and Deimos orbit modeling efforts. On the observational side, efforts were made to refine the astrometric measurements: for the HRSC observations carried out in the second half of this year, the planning software was upgraded, to maximize the number of background stars in the images for improved camera pointing control. The new data can be used to confirm and further improve the accuracy of the satellite orbit models. These models bear important implications on tidal dissipation and internal structure of Mars