Influence of Brownian Motion, Thermophoresis and Magnetic Effects on a Fluid Containing Nanoparticles Flowing over a Stretchable Cylinder

The influence of Brownian motion and thermophoresis on a fluid containing nanoparticles flowing over a stretchable cylinder is examined.The classical Navier-Stokes equations are considered in a porous frame.In addition,the Lorentz force is taken into account.The controlling coupled nonlinear partial differential equations are transformed into a system of first order ordinary differential equations by means of a similarity transformation.The resulting system of equations is solved by employing a shooting approach properly implemented in MATLAB.The evolution of the boundary layer and the growing velocity is shown graphically together with the related profiles of concentration and temperature.The magnetic field has a different influence(in terms of trends)on velocity and concentration.

High-resolution digital beamforming of UWB signals based on Carathéodory representation for delay compensation and array extrapolation

To realize high-resolution digital beamforming(DBF)of ultra-wideband(UWB) signals, we propose a DBF method based on Carath ′eodory representation for delay compensation and array extrapolation. Delay compensation by Carath ′eodory representation could achieve high interpolation accuracy while using the single channel sampling technique. Array extrapolation by Carath ′eodory representation reformulates and extends each snapshot, consequently extends the aperture of the original uniform linear array(ULA) by several times and provides a better realtime performance than the existing aperture extrapolation utilizing vector extrapolation based on the two dimensional autoregressive(2-D AR) model. The UWB linear frequency modulated(LFM) signal is used for simulation analysis. Simulation results demonstrate that the proposed method is featured by a much higher spatial resolution than traditional DBF methods and lower sidelobes than using Lagrange fractional filters.

Thymoma： current diagnosis and treatment

Objective To review the presentation, diagnosis, staging and treatment of thymoma. Data sources Data were obtained from papers on thymoma published in English within the last 30 years. No formal systematic review was conducted, but an effort was made to be comprehensive. Study selection Studies were selected if they contained data relevant to the topic addressed in the particular section. In particular, standards adopted by the International Thymic Malignancies Interest Group through a formal process of achieving worldwide consensus are featured. Because of the limited length of this article, we have frequently referenced recent reviews that contain a comprehensive amalgamation of literature rather than the actual source papers. Results Thymomas are rare malignant tumors. They account for about half （47%） of anterior mediastinal tumors. About one third of these are associated with myasthenia gravis. Computed tomography with intravenous contrast is the standard diagnostic modality. Thymomas appear as round or oval masses in early stages but irregular shapes with calcifications occurring in later stages. They can invade surrounding structures including mediastinal fat, pleura, major blood vessels and nerves. Fine needle aspiration, core needle biopsy or open biopsy is used to obtain tissue diagnosis. Masaoka-Koga classification is currently used to stage thymomas. All thymomas should be considered for resection due to their malignant potential. A complete resection is a major prognostic factor and every effort should be made to achieve this even if this means resection and reconstruction of a major thoracic structure. Median sternotomy is the standard approach for thymoma resection. A number of minimally invasive techniques are used in selective centers. While stage I and II tumors undergo primary surgery, preoperative chemotherapy appears to increase the chances of complete resection for stage III and IVa tumors. Postoperative radiation could be considered for patients with residual disease. Excellent 5 and 10-year survival rates are noted for completely resected early stage thymomas. Conclusions Thymic malignancies are rare tumors. Standards have recently been achieved to allow better communication and promote collaborative research. Surgical resection is the mainstay of treatment, but a multimodality approach is useful for many patients.

Null steering antenna beamforming utilizing space-time adaptive processing

A new architecture of null steering antenna based upon the technology of space-time adaptive processing（STAP） with optimized parameters is proposed. The new STAP antenna is comprised of multiple channels and each channel is a transversal filter. So separate sensor element for the reference signal is not required because the antenna gets the reference signal from the first sensor of the auxiliary array. Furthermore, the least mean square（LMS） algorithm is employed to calculate the weight vector. Detailed analysis about the relationship between noise power and output error is investigated. Compared with the traditional null steering antenna in space or space-time domain, the new approach obtains more freedom degrees and can suppress both the wideband and narrowband interferences more efficiently with deeper nulls. Simulation results shows that the proposed architecture outperforms the conventional STAP techniques for interference suppression.