Numerical Simulation of a High Mach Number Jet Flow

The recent efforts to develop accurate numerical schemes for transition and turbulent flows are motivated, among other factors, by the need for accurate prediction of flow noise. The success of developing high speed civil transport plane (HSCT) is contingent upon our understanding and suppression of the jet exhaust noise. The radiated sound can be directly obtained by solving the full (time-dependent) compressible Navier-Stokes equations. However, this requires computational storage that is beyond currently available machines. This difficulty can be overcome by limiting the solution domain to the near field where the jet is nonlinear and then use acoustic analogy (e.g., Lighthill) to relate the far-field noise to the near-field sources. The later requires obtaining the time-dependent flow field. The other difficulty in aeroacoustics computations is that at high Reynolds numbers the turbulent flow has a large range of scales. Direct numerical simulations (DNS) cannot obtain all the scales of motion at high Reynolds number of technological interest. However, it is believed that the large scale structure is more efficient than the small-scale structure in radiating noise. Thus, one can model the small scales and calculate the acoustically active scales. The large scale structure in the noise-producing initial region of the jet can be viewed as a wavelike nature, the net radiated sound is the net cancellation after integration over space. As such, aeroacoustics computations are highly sensitive to errors in computing the sound sources. It is therefore essential to use a high-order numerical scheme to predict the flow field. The present paper presents the first step in a ongoing effort to predict jet noise. The emphasis here is in accurate prediction of the unsteady flow field. We solve the full time-dependent Navier-Stokes equations by a high order finite difference method. Time accurate spatial simulations of both plane and axisymmetric jet are presented. Jet Mach numbers of 1.5 and 2.1 are considered. Reynolds number in the simulations was about a million. Our numerical model is based on the 2-4 scheme by Gottlieb & Turkel. Bayliss et al. applied the 2-4 scheme in boundary layer computations. This scheme was also used by Ragab and Sheen to study the nonlinear development of supersonic instability waves in a mixing layer. In this study, we present two dimensional direct simulation results for both plane and axisymmetric jets. These results are compared with linear theory predictions. These computations were made for near nozzle exit region and velocity in spanwise/azimuthal direction was assumed to be zero

Diabetes Mellitus Prevalence and Burden Among Community Acquired Pneumonia Patients

This work aimed at measuring the prevalence of Diabetes Mellitus among community acquired pneumonia (CAP) patients and declaring its effect on CAP patient\u27s outcome. Both community acquired pneumonia and diabetes mellitus are common in Egypt, and patients with associated CAP and DM need special care and supervision. This prospective study was carried out on 108 CAP patients admitted to Abassia Chest Hospital during the period from January 2016 to December 2016. Clinical and radiological diagnosis of pneumonia and DM diagnosis were performed. DM recorded a prevalence of 39.8% among community acquired pneumonia patients. Disturbed level of consciousness is more frequent among diabetic patients than non diabetics. Diabetic patients recorded higher rate of hospital admission, longer duration of hospital stay, higher rate of ICU admission and more sever pneumonia than among non diabetic patients. CURB-65 score showed significant positive correlation with HbA1c of the patients. Associated community-acquired pneumonia and diabetes mellitus is frequent in our locality and labor a double burden on the affected patients leading to poorer prognosis, higher rate of hospitalization with longer duration of hospital stay and ICU admission. So CAP patients with DM need intimate care

Autonomic management of software defined networks : DAIM can provide the environment for building autonomy in distributed electronic environments - using OpenFlow networks as the case study

University of Technology Sydney. Faculty of Engineering and Information Technology.Next generation networks need to support a broad range of services and functionalities with capabilities such as autonomy, scalability, and adaptability for managing networks complexity. In present days, network infrastructures are becoming increasingly complex and challenging to administer due to scale and heterogeneous nature of the infrastructures. Furthermore, among various vendors, services, and platforms, managing networks require expert operators who have expertise in all different fields. This research relied on distributed active information model (DAIM) to establish a foundation which will meet future network management requirements. The DAIM is an information model for network solutions which considers challenges of autonomic functionalities, where the network devices can make local and overall network decisions by collected information. The DAIM model can facilitate networks management by introducing autonomic behaviours. The autonomic behaviours for communication networks lead networks to be self-managed and emerge as promising solutions to manage networks complexity. Autonomic networks management aims at reducing the workload on network operators from low-level tasks. Over the years, researchers have proposed a number of models for developing self-managed network solutions. One such example is the common information model (CIM), which is described as the managed environment that attempts to merge and extend the existing conventional management and also uses object-oriented constructs for overall network representation. However, the CIM has limitations coping in complex distributed electronic environments with multiple disciplines. The goal of this research is defined as development of a network architecture or a solution based on the DAIM model, which is effectively distribute and automate network’s functions to various network devices. The research first looks into the possibilities of local decision-making and programmability of network elements for distributed electronic environments with an intention to simplify network management by providing abstracted network infrastructures. After investigating and implementing different elements of the DAIM model in network forwarding devices by utilising virtual network switches, it discovers that a common high-level interface and framework for network devices are essential for the development of network solutions which will meet future network requirements. The outcome of this research is the development of (DAIM OS) specification. The DAIM OS is a network forwarding device operating system which is compliant with the DAIM model when it comes to network infrastructure management and provides a high-level abstracted application programming interface (DAIM OS API) for creating network service applications. Through the DAIM OS, network elements will be able to adapt to ever changing environments to meet the goals of service providers, vendors, and end users. Furthermore, the DAIM OS API aims to reduce complexity and time of network service applications development. If the developed DAIM OS specification is implemented and if it functions as predicted in the design analyses; that will result in a significant milestone in the development of distributed network management. This dissertation has an introduction in chapter 1 followed by five parts in order to draw a blueprint for information model as a distributed independent computing environment for autonomic network management. The five parts include lending weight to the proposition, gaining confidence in the proposition, drawing conclusions, supporting work and lastly is appendices. The introduction in chapter 1 includes motivations for the research, main challenges of the research, overall objectives, and review of research contributions. After that, to lend weight to the proposition as the first part of the dissertation, there is chapter 2 which presents the background and literature review, and chapter 3 which has a theoretical foundation for the proposed model. The foundation consists of a generic architecture for complex network management and agents to aggregate distributed network information. Moreover, chapter 3 is probably more about a state of the art in software engineering than about real implementation to engineer autonomic network management. The second part of the dissertation is to gain confidence in the proposition which includes attempting to implement the DAIM model in chapter 4 with some tests to report good performance regarding convergence and robustness for the service configuration process of network management. Also, the second part has a specification of true abstraction layers in chapter 5. The specification of true abstraction layers proposes a high-level abstraction for forwarding networking devices and provides an application program interface for network service applications developed by network operators and service providers. The implementation in chapter 4 is supported by the fourth part of the dissertation in chapter 10 which supports the theoretical foundation, designing, modelling, and developing the distributed active information model via simulation, emulation and real environments. The third part of this dissertation provides the way to draw conclusions as shown in chapter 7 which has the overall research summary, validation of the propositions, contributions and discussion, limitations and finally recommendations for future works. Finally are the appendices in Appendix A, Appendix B, Appendix C and Appendix D which provide a developing code of the core DAIM model and show different setting up for testbed environments

A nouvelle approach for predicting the shear cracking angle in RC and PC beams using artificial neural networks

The truss model for predicting shear resistance of reinforced concrete beams has usually been criticized because of its underestimation of the concrete shear strength especially for beams with low shear reinforcement. Two challengers are commonly encountered in any truss model and are responsible for its inaccurate shear strength prediction. First: the cracking angle is usually assumed empirically and second the shear contribution of the arching action is usually neglected. This research introduces a nouvelle approach, by using Artificial Neural Network (ANN) for accurately evaluating the shear cracking angle of reinforced and prestressed concrete beams. The model inputs include the beam geometry, concrete strength, the shear reinforcement ratio and the prestressing stress if any. ..

Multidimensional Binary Vector Assignment problem: standard, structural and above guarantee parameterizations

In this article we focus on the parameterized complexity of the Multidimensional Binary Vector Assignment problem (called \BVA). An input of this problem is defined by $m$ disjoint sets $V^1, V^2, \dots, V^m$, each composed of $n$ binary vectors of size $p$. An output is a set of $n$ disjoint $m$-tuples of vectors, where each $m$-tuple is obtained by picking one vector from each set $V^i$. To each $m$-tuple we associate a $p$ dimensional vector by applying the bit-wise AND operation on the $m$ vectors of the tuple. The objective is to minimize the total number of zeros in these $n$ vectors. mBVA can be seen as a variant of multidimensional matching where hyperedges are implicitly locally encoded via labels attached to vertices, but was originally introduced in the context of integrated circuit manufacturing. We provide for this problem FPT algorithms and negative results ($ETH$-based results, $W$[2]-hardness and a kernel lower bound) according to several parameters: the standard parameter $k$ i.e. the total number of zeros), as well as two parameters above some guaranteed values.Comment: 16 pages, 6 figure

Novel patient-centered approach to facilitate same-day discharge in patients undergoing elective percutaneous coronary intervention

Background Same‐day discharge ( SDD ) after elective percutaneous coronary intervention is safe, less costly, and preferred by patients, but it is usually performed in low‐risk patients, if at all. To increase the appropriate use of SDD in more complex patients, we implemented a “patient‐centered” protocol based on risk of complications at Barnes‐Jewish Hospital. Methods and Results Our objectives were as follows: (1) to evaluate time trends in SDD ; (2) to compare (a) mortality, bleeding, and acute kidney injury, (b) patient satisfaction, and (c) hospital costs by SDD versus no SDD ( NSDD ); and (3) to compare SDD eligibility by our patient‐centered approach versus Society for Cardiovascular Angiography and Interventions guidelines. Our patient‐centered approach was based on prospectively identifying personalized bleeding, mortality, and acute kidney injury risks, with a personalized safe contrast limit and mitigating those risks. We analyzed Barnes‐Jewish Hospital's National Cardiovascular Data Registry Cath PCI Registry data from July 1, 2009 to September 30, 2015 (N=1752). SDD increased rapidly from 0% to 77% ( P &lt;0.001), independent of radial access. Although SDD patients were comparable to NSDD patients, SDD was not associated with adverse outcomes (0% mortality, 0% bleeds, and 0.4% acute kidney injury). Patient satisfaction was high with SDD . Propensity score–adjusted costs were 7331 lower/ SDD patient ( P <0.001), saving an estimated 1.8 million annually. Only 16 patients (6.95%) met the eligibility for SDD by Society for Cardiovascular Angiography and Interventions guidelines, implying our patient‐centered approach markedly increased SDD eligibility. Conclusions With a patient‐centered approach, SDD rapidly increased and was safe in 75% of patients undergoing elective percutaneous coronary intervention, despite patient complexity. Patient satisfaction was high, and hospital costs were lower. Patient‐centered decision making to facilitate SDD is an important opportunity to improve the value of percutaneous coronary intervention. </jats:sec

Theoretical and Experimental Sets of Choice Anode/Cathode Architectonics for High-Performance Full-Scale LIB Built-up Models

To control the power hierarchy design of lithium-ion battery (LIB) built-up sets for electric vehicles (EVs), we offer intensive theoretical and experimental sets of choice anode/cathode architectonics that can be modulated in full-scale LIB built-up models. As primary structural tectonics, heterogeneous composite superstructures of full-cell-LIB (anode//cathode) electrodes were designed in closely packed flower agave rosettes TiO2@C (FRTO@C anode) and vertical-star-tower LiFePO4@C (VST@C cathode) building blocks to regulate the electron/ion movement in the three-dimensional axes and orientation pathways. The superpower hierarchy surfaces and multi-directional orientation components may create isosurface potential electrodes with mobile electron movements, in-to-out interplay electron dominances, and electron/charge cloud distributions. This study is the first to evaluate the hotkeys of choice anode/cathode architectonics to assemble different LIB–electrode platforms with high-mobility electron/ion flows and high-performance capacity functionalities. Density functional theory calculation revealed that the FRTO@C anode and VST-(i)@C cathode architectonics are a superior choice for the configuration of full-scale LIB built-up models. The integrated FRTO@C//VST-(i)@C full-scale LIB retains a huge discharge capacity (~ 94.2%), an average Coulombic efficiency of 99.85% after 2000 cycles at 1 C, and a high energy density of 127 Wh kg−1, thereby satisfying scale-up commercial EV requirements