Analysis and simulation of new approximation equations for boundary-layer flow on curved surfaces

An accurate and computationally efficent simulation of viscous flow fields exhibiting streamline curvature effects is important for the basic understanding and optimal design of a variety of mechanical systems. Examples include flow part airfoils, marine crafts, and automobiles or flow in diffusors and curved ducts. In this paper a new set of second-order boundary-layer equations is derived for steady incompressible two-dimensional or axisymmetric flow in regions where the streamlines stay approximately parallel to the curved surface. The performances of the new approximation equations and commonly used second-order boundary-layer equations are evaluated in two case studies. First, in a well-defined computer experiment, results from the two different sets of approximation equations are compared with a solution of the full Navier—Stokes equations for laminar flow past a representative body with longitudinal curvature. Then, turbulent flow versions of the new and traditionally used second-order boundary-layer equations are compared with experimental data sets for a representative axisymmetric body with strong longitudinal and transverse curvatures.     

A State Language for the Sequencing in a Hybrid Electric Vehicle

The application of a state language to the real-time control of a hybrid electric vehicle is explained. The state language has been developed both as a specification aid to the system designer and as a means for the programmer to produce microcomputer software. A translator program, which was developed on a VAX minicomputer, preprocesses the state language into a software module to be compiled by the standard Intel PL/M 86 compiler.     

Application of liquid-metal MHD generators to the LMFBR

The feasibility of coupling two-phase liquid-metal magnetohydrodynamic generators (LMMHD) to liquid-metal fast breeder reactors (LMFBR) is examined. Important constraints on the LMFBR-LMMHD system that were not accounted for in earlier studies have been included.A LMMHD cycle coupled to a gas turbine cycle yielded an overall cycle efficiency of 35.2% which is less than the efficiency of 36.2% when the gas turbine cycle is utilized by itself. However, a LMMHD cycle coupled to a steam cycle shows a slight advantage (38.9–39.8% overall cycle efficiencies for generator efficiencies varying from 80 to 90%) over the conventional steam cycle (38.5% efficiency).     

Transcranial ultrasound focus reconstruction with phase and amplitude correction

Therapeutic and diagnostic ultrasound procedures performed noninvasively through the skull require a reliable method for maintaining acoustic focus integrity after transmission through layered bone structures. This study used a multiple-element, phased-array transducer to reconstruct ultrasound foci through the human skull by amplitude and phase correction. It was previously demonstrated that adaptive phase correction using a multiple-element, focused transducer array yields a significant correction to an acoustic field that has been distorted by the heterogeneities of the skull bone. The introduction of amplitude correction, in a regime in which acoustic pressures from individual transducer array elements are adjusted to be normalized at the focus, has demonstrated a 6% (-0.27 dB) average decrease in acoustic sidelobe acoustic intensity relative to the focal intensity and a 2% (-0.09 dB) average decrease in the full-width-at-half-maximum (FWHM) of the acoustic intensity profile at the focus. These improvements come at the expense of significant ultrasound intensity loss--as much as 30% lower (-1.55 dB)--at the focus because the amplitude correction method requires that, at constant power, a larger proportion of energy is absorbed or reflected by regions of the skull that transmit less energy. In contrast, a second correction method that distributes pressure amplitudes such that the sections of the skull which transmit more ultrasound energy are exposed with higher ultrasound intensities has demonstrated an average sidelobe intensity decrease of 3% (-0.13 dB) with no change in the FWHM at the focus. On average, there was a 2% (0.09 dB) increase in the acoustic intensity at the focus for this inverse amplitude correction method. These results indicate that amplitude correction according to the transmission properties of various segments of the skull have a clear effect on ultrasound energy throughput into a target site within the brain parenchyma.     

Efficacy and onset of action of fluticasone propionate aqueous nasal spray on nasal symptoms, eosinophil count, and mediator release after nasal allergen challenge in patients with seasonal allergic rhinitis

In order to determine if peripheral blood stem cells (PBSC) collected after priming with G-CSF in AML in first complete remission (CR) can be used for autologous transplantation and to evaluate the efficacy of early intensification therapy as in vivo purging, we studied 35 consecutive patients with AML in first CR. After standard induction and consolidation chemotherapy, 24 of them were treated with one (10 patients) or two (14 patients) cycles of high-dose cytarabine plus etoposide prior to PBSC collection. G-CSF was used as the priming agent. Of the 35 patients scheduled for peripheral blood stem cell transplantation (PBSCT), three relapsed before transplantation, and the 32 remaining underwent PBSCT. High-dose therapy consisted of either total body irradiation plus cyclophosphamide or busulphan plus cyclophosphamide. The median number of CD34+ cells infused was 3.24 x 10(6)/kg (range 0.15-14). The median times to reach a PMN count of 0.5 x 10(9)/l and a platelet count of 50 x 10(9)/l were 12 (8-28) and 30 (11-345) days, respectively. There was no transplant-related mortality. Twelve patients relapsed between 2 and 21 months post-PBSCT. With a median follow-up of 28 months, actuarial disease-free survival (DFS) is 52.41 +/- 9% in the intent-to-treat group and 57.4 +/- 9.8% in patients who underwent PBSCT. The probability of DFS is significantly higher for patients who receive early intensification therapy prior to both PBSC collection and PBSCT as compared with patients that do not: 68.8 +/- 10.27% vs 35.5 +/- 12.6%, P = 0.0418. These results indicate the feasibility of PBSCT in AML using G-CSF-mobilized PBSC. The use of intensification treatment as 'purging in vivo' prior both to collection of PBSC and PBSCT significantly reduces the risk of relapse in this group of patients.     

选择合适的无线技术(一):频谱、通信距离和网络拓扑

当今有许多不同的无线标准和协议在使用,要为任何特定的应用选择合适的技术可能很困难.在这篇文章中,我们将探讨一些需要考虑的关键标准,并评介四个流行的选项:Wi-Fi?技术(无线保真)、蓝牙低功耗(Bluetooth? Low Energy)技术、专有射频(RF)和来自连接性标准联盟(Connectivity Standa...