This paper reports the development of an unconstrained sensing technique for monitoring the respiration and heartbeats during sleep using a polyvinylidene fluoride (PVDF) piezopolymer film sensor with the aim that the sensor can be used on the ordinary bed together with the condition that the use of the sensor does not interfere the daily sleep of the patient under measurement. A PVDF film is used as the sensory material in the sensor system. The film is placed under the sheet at the location of the thorax to pick up the fluctuation of the pressure on the bed caused by the respiratory movement and heartbeats. Wavelet multiresolution decomposition analysis is used for the detection of respiration and heartbeat from the sensor output. It is shown that the respiration and heartbeats can simultaneously be detected by the sensor with the use of the wavelet multiresolution decomposition analysis.
SUMMARYIn this paper, we present a generalized prismatic hybrid meshing method for viscous flow simulations. One major difficulty in implementing a robust prismatic hybrid meshing tool is to handle boundary layer mesh collisions, and normally an extra data structure (e.g. quadtree in two-dimensional and octree in threedimensional) is required. The proposed method overcomes this difficulty via an heuristic approach, and it only relies on constrained delaunay triangulation/tetrahedralization (CDT). No extra data structures are required. Geometrical reasoning is used to approximate the maximum marching distance of each point by walking through the CDT. This is combined with post-processing of marching vectors and distance and prohibition of multilevel differences to form an automatic and robust mechanism to remove boundary layer mesh collisions. Benefiting from the matureness of CDT techniques, the proposed method is robust, efficient and simple to implement. Its capability is demonstrated by generating quality prismatic hybrid meshes for industrial models with complex geometries. The proposed method is believed to be able considerably reduce the effort to implement a robust hybrid prismatic mesh generator for viscous flow simulations.
Aryl hydrocarbon receptor (AhR) nuclear translocator (Arnt) gene has been isolated and characterized from a mouse genomic DNA library. The gene is about 60 kilobases long and split into 22 exons. An unusual exon/ intron junctional sequence was found in the 11th intron of the gene that begins with GC at its 5-end. The exon/ intron arrangement of mArnt gene differs greatly from those of the other members of the same basic-helix-loophelix/PAS family. The gene is TATA-less and has several transcription start sites. The promoter region of the mArnt gene is GC-rich and contains a number of putative regulatory DNA sequences such as two GC-boxes, a cAMP-responsive element, E-box, AP-1 site, and CAATbox. Deletion experiments revealed that all these DNA elements made substantial contributions to a high level of expression of the gene, except for the cAMP-responsive element. Of all, two GC-boxes displayed the most dominant enhancing effects. It was demonstrated that there exist specific factors binding to these DNA elements in the nuclear extracts of HeLa cells. Among them, Sp1 and Sp3, and CAAT-box binding factor-A were identified to bind the GC-boxes and CAAT-box, respectively. Expression of MyoD in HeLa cells stimulated the Arnt promoter activity by binding to the E-box.Aryl hydrocarbon receptor (AhR) 1 nuclear translocator (Arnt) is a member of the basic-helix-loop-helix/PAS family of heterodimeric transcription factors, which include AhR, hypoxia-inducible factor 1␣ (HIF-1␣), Drosophila Trachealess (Trh), and single-minded protein (Sim) (1-5). Recent molecular cloning and biochemical studies have demonstrated that in the nuclei, Arnt forms a heterodimer with AhR that is activated by binding with a ligand such as 2,3,7,8-tetrachlorodibenzo-p-dioxin to activate expression of the genes for a group of drugmetabolizing enzymes through binding to the xenobiotic response element sequence upstream of the genes (6). In addition, the AhR-Arnt heterodimer is also considered to mediate the various biological effects such as teratogenesis, tumor promotion, epithelial dysplasia, and immunosuppression by aromatic environmental pollutants usually represented by 2,3,7,8-tetrachlorodibenzo-p-dioxin, the most toxic chemical, although the target genes for the heterodimer in these effects remain to be elucidated (6). Arnt also forms a homodimer that binds the E-box and potentially activates the genes driven by the promoter containing the E-boxes (7). It has recently been reported that Arnt forms heterodimeric complexes with HIF-1␣ and HIF-1␣-like factor to regulate genes involved in the response to hypoxic conditions (2), and disruption of the Arnt gene by homologous recombination resulted in embryonic death of mice because of abortive angiogenesis and defective responses to glucose and oxygen deprivation (8). Taken together, these results suggest that Arnt plays a central role in transcriptional regulation by the bHLH-PAS transcription factors as a key partner molecule in the formation of transcription/ regulation-competent dimers. It wo...
This paper documents the construction of a Virtual Engine, with particular reference to its geometry and conceptual description.. The phrase Virtual Engine denotes a system which allows simulations of whole gas-turbine engines to be undertaken at any desired level of fidelity or physical modeling. In order to be of any practical use, the system must allow the computations to be setup as automatically as possible and needs to contain provisions for the exchange of boundary data between adjacent computational domains — e.g. solid-gas interfaces. The paper illustrates the application of the system to the representation and analysis of a modern commercial turbofan engine.
The main role of the intake is to provide a sufficient mass flow to the engine face and a sufficient flow homogeneity to the fan. Intake-fan interaction off design represents a critical issue in the design process because intake lines are set very early during the aircraft optimization. The offdesign operation of an aero-engine, strictly related to the intake flow field, can be mainly related to two different conditions. When the plane is in near ground position, vorticity can be ingested by the fan due to crosswind incidence. During the flight, distortions occur due to incidence. In these conditions, the windward lip is subjected to high acceleration followed by strong adverse pressure gradients, high streamline curvature, and cohabitation of incompressible and transonic flow around the lip. All these features increase the risk of lip stall in flight at incidence or in crosswind near ground operation and increase the level of forcing seen by the fan blades because of the interaction with nonuniform flow from the intake. This work deals with the study of two sources of distortions: ground vortex ingestion and flight at high incidence conditions. A test case representative of a current installation clearance from the ground has been investigated and the experimental data available in open literature validated the computational fluid dynamics (CFD) calculations. An intake, representative of a realistic civil aero-engine configuration flying at high incidence, has been investigated in powered and aspirated configurations. Distortion distributions have been characterized in terms of total loss distributions in space and in time. The beneficial effect of the presence of fan in terms of distortion control has been demonstrated. The mutual effect between fan and incoming distortion from the intake has been assessed in terms of modal force and distortion control. CFD has been validated by means of comparisons between numerical results and experimental data which have been provided. Waves predicted by CFD have been compared with an actuator disk approach prediction. The linear behavior of the lower disturbance frequency coming from distortion and the waves reflected by the fan has been demonstrated.
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