Finite element analysis of inviscid subsonic boattail flow

A finite element code for analysis of inviscid subsonic flows over arbitrary nonlifting planar or axisymmetric bodies is described. The code solves a novel primitive variable formulation of the coupled irrotationality and compressible continuity equations. Results for flow over a cylinder, a sphere, and a NACA 0012 airfoil verify the code. Computed subcritical flows over an axisymmetric boattailed afterbody compare well with finite difference results and experimental data. Interative coupling with an integral turbulent boundary layer code shows strong viscous effects on the inviscid flow. Improvements in code efficiency and extensions to transonic flows are discussed

Efficient solution of the Euler and Navier-Stokes equations with a vectorized multiple-grid algorithm

A multiple-grid algorithm for use in efficiently obtaining steady solutions to the Euler and Navier-Stokes equations is presented. The convergence of the explicit MacCormack algorithm on a fine grid is accelerated by propagating transients from the domain using a sequence of successively coarser grids. Both the fine and coarse grid schemes are readily vectorizable. The combination of multiple-gridding and vectorization results in substantially reduced computational times for the numerical solution of a wide range of flow problems. Results are presented for subsonic, transonic, and supersonic inviscid flows and for subsonic attached and separated laminar viscous flows. Work reduction factors over a scalar, single-grid algorithm range as high as 76.8

Supply-Chain Management Issues In The Oil And Gas Industry

The oil and gas industry is involved in a global supply-chain that includes domestic and international transportation, ordering  and inventory visibility and control, materials handling, import/export facilitation and information technology. Thus, the industry offers a classic model for implementing supply-chain management techniques. In a supply-chain, a company is linked to its upstream suppliers and downstream distributors as materials, information, and capital flow through the supply-chain.  The purpose of this paper is to investigate the role of supply-chain management in the oil and gas industry. This paper also discusses the application of the Uniform Commercial Code (UCC) to supply-chain management issues. Then, several strategies are examined for improving supply-chains in the oil and gas industry. Finally, two case studies are introduced to show how improving supply-chain logistics in the oil and gas industry can improve efficiency and the bottom line

Intensity Of Energy Use In The U.S.A.: 1949 - 2003

The particular role that energy plays in the economy of a country, and the relationship between energy consumption and economic growth are of interest to researchers, analysts, and policymakers. Energy consumption can be seen as either a cause of, or a symptom of economic growth. Therefore, understanding the nature of the interactions between energy consumption and gross domestic product (GDP) can help guide energy policies. This paper examines the energy-GDP relationship in the U.S.A. One common method used in analyzing the energy-GDP relationship is energy intensity (also called the intensity of energy use (IEU)), which is the amount of energy required to produce a unit of income (GDP). The paper begins with a substantial literature review of energy intensity studies from around the world. A summary of the findings is discussed, including the factors that were found to directly influence the intensity of energy use. The Kuznets environmental curve is then presented and used in developing a model for the IEU. The model is then tested with data for the U.S.A. from 1949 – to 2003. The results show that energy consumption is very sensitive to energy prices, which in turn impacts the GDP, and that the IEU has declined in the U.S.A. for the period tested, fitting the downward slopping segment of the Kuznets curve.  These results imply that energy conservation policies are desirable

Empirical Study Of The Relationship Between Energy Consumption And Gross Domestic Product In The U.S.A.

The role of energy in the economy is an important issue. There is a general belief and agreement amongst economists, researchers, analysts, and policymakers, that energy consumption is related to economic activity and plays a key role in the process of economic development. However, the precise nature of this relationship between energy consumption and economic growth remains debatable. While some ambiguity has remained regarding the direction of causation--- whether from energy to economy or from economy to energy --- the importance of the energy –GDP interaction is well recognized. Energy use is a necessary input to economic growth and is also a function of growth.  This paper begins with a literature review of the work that has been done to date on the energy-GDP relationship in several countries. Then, an analysis of the historical data for the U.S.A. from 1949 – 2003 is presented along with mathematical models.  The contributions from this paper are that first, we clarify that energy conservation policies will not harm the U.S. economy. Second, we employed a macroeconomic model based on Multiple Model Estimation to determine the relationship between energy consumption and GDP in the United States for the stated time period.  Our model suggests that the causation goes both ways: from energy to the components of GDP, and from GDP to energy consumption

The Impact of Corporate Governance on Voluntary Information Disclosures of Quoted Firms in Nigeria: An Empirical Analysis

Through annual reports, the company provides a lot of voluntary information which is very vital to stakeholders and in corporate governance. The main objective of this study is to empirically investigate the impact of corporate governance on voluntary information disclosures of quoted companies in Nigeria using data from 385 annual reports from a sample of 35 quoted companies during 1999 – 2009. The study also adopted Pre and Post approach to study the significant difference on information disclosures during pre and post corporate governance codes era in Nigeria. A content analysis of the annual reports of sampled companies was carried out with the use of a disclosure checklist developed by the researcher. Multiple regression is employed to test the hypothesis of the study. The study reveals that corporate governance has significant impact on financial reporting of quoted firms in Nigeria and that the level of voluntary disclosure has significantly improved after the introduction of corporate governance codes in Nigeria. Keywords: Corporate governance, voluntary information disclosures, Disclosure index, financial reporting.

Seminal Caspase 3, Cytochrome C and Total Atioxidant capacity in Nigerian male subjects undergoing infertility evaluation

Male factor infertility may be responsible for about half of cases of infertility. This study evaluated the activities of caspase 3, cytochrome c and total antioxidant capacity in normospermic males investigated for infertility. Seminal plasma cytochrome c, caspases3 and total antioxidant capacity were determined by Enzyme linked Immunosorbent assay technique. Sixty (60) infertile males aged 39.6±0.28 and 30 males aged 38.9±0.52 with proven fertility were enrolled. The activities of cytochrome c (p<0.002) and caspase 3 (p<0.01) were significantly higher in infertile but normospermic than controls. There was however no significant different in the level of total antioxidant capacity between the groups. The levels of cytochrome c (p<0.001) and caspase 3 (p<0.02) were significantly higher in the subjects with primary infertility than secondary infertility. Cytochrome c and caspase 3 correlated negatively with sperm morphology in normospermic infertile males. Seminal fluid caspase 3 and cytochrome c activities were higher in normospermic but infertile males than control subjects. The implication of these findings on fertility potential of the male subjects is discussed.Keywords: Seminal caspase 3, cytochrome c, infertility, normospermia and total antioxidant capacityAfr. J. Biomed. Res. Vol. 22 (January, 2019); 59- 6

Efficacy of Cognitive Restructuring Techniques on Affluenza Syndrome of Nigerian Youths

Affluenza which is perceived as a culture that places a high value on and being addicted to wealth is a social condition that affects the cognitions, emotions and academic behavior of youths in our contemporary society. These youths are negatively influenced by the affluence and wealth of their parents to the detriment of their academic pursuit. This study is therefore carried out to ascertain the effects of cognitive restructuring (Rational Emotive Therapy (RET), confrontation (CON) and Thought Stopping (TS) in bringing sanity and discipline on Nigerian youths by curbing their affluenza syndrome. The study adopted quasi experimental design. Two research hypotheses guided the study. The sample is made up of 48 students from Imo State University Owerri, Nigeria 2014/2015 academic year struck by affluenza syndrome. Data were collected using researcher- made questionnaire titled “Affluenza Syndrome Identification Questionnaire” (ASIQ). Data collected were analyzed using Analysis of Covariance (ANCOVA). The result showed that the three techniques of Cognitive Restructuring Treatment Package-RET, CON and TS were very effective in lowering the level of affluenza syndrome in participants. The result also reveals that there is no gender effect on affluenza syndrome of participants. A finding that translates to the fact that both male and female participants benefited maximally from the three treatment approaches. Useful recommendations were made based on the findings from the study

Anesthesia for deep brain stimulation in traumatic brain injury-induced hemidystonia.

Deep brain stimulation in an awake patient presents several unique challenges to the anesthesiologist. It is important to understand the various stages of the procedure and the complexities of anesthetic management in order to have a successful surgical outcome and provide a safe environment for the patient

Axisymmetric Calculations of a Low-Boom Inlet in a Supersonic Wind Tunnel

This paper describes axisymmetric CFD predictions made of a supersonic low-boom inlet with a facility diffuser, cold pipe, and mass flow plug within wind tunnel walls, and compares the CFD calculations with the experimental data. The inlet was designed for use on a small supersonic aircraft that would cruise at Mach 1.6, with a Mach number over the wing of 1.7. The inlet was tested in the 8-ft by 6-ft Supersonic Wind Tunnel at NASA Glenn Research Center in the fall of 2010 to demonstrate the performance and stability of a practical flight design that included a novel bypass duct. The inlet design is discussed here briefly. Prior to the test, CFD calculations were made to predict the performance of the inlet and its associated wind tunnel hardware, and to estimate flow areas needed to throttle the inlet. The calculations were done with the Wind-US CFD code and are described in detail. After the test, comparisons were made between computed and measured shock patterns, total pressure recoveries, and centerline pressures. The results showed that the dual-stream inlet had excellent performance, with capture ratios near one, a peak core total pressure recovery of 96 percent, and a large stable operating range. Predicted core recovery agreed well with the experiment but predicted bypass recovery and maximum capture ratio were high. Calculations of offdesign performance of the inlet along a flight profile agreed well with measurements and previous calculations