Analytical Study of Gravity Effects on Laminar Diffusion Flames

A mathematical model is presented for the description of axisymmetric laminar-jet diffusion flames. The analysis includes the effects of inertia, viscosity, diffusion, gravity and combustion. These mechanisms are coupled in a boundary layer type formulation and solutions are obtained by an explicit finite difference technique. A dimensional analysis shows that the maximum flame width radius, velocity and thermodynamic state characterize the flame structure. Comparisons with experimental data showed excellent agreement for normal gravity flames and fair agreement for steady state low Reynolds number zero gravity flames. Kinetics effects and radiation are shown to be the primary mechanisms responsible for this discrepancy. Additional factors are discussed including elipticity and transient effects

Characterization of the space shuttle reaction control system engine

A computer program was developed and written in FORTRAN 5 which predicts the transient and steady state performance and heat transfer characteristics of a pulsing GO2/GH2 rocket engine. This program predicts the dynamic flow and ignition characteristics which, when combined in a quasi-steady state manner with the combustion and mixing analysis program, will provide the thrust and specific impulse of the engine as a function of time. The program also predicts the transient and steady state heat transfer characteristics of the engine using various cooling concepts. The computer program, test case, and documentation are presented. The program is applicable to any system capable of utilizing the FORTRAN 4 or FORTRAN 5 language

Press coverage of Corporate Social Responsibility Performance in Ghana

The work examines the role press reports on corporate social responsibility (CSR) play in the reputation-building of two telecom companies (MTN and Vodafone) in Ghana. Content in 480 editions of Accra-based Daily Graphic and Business and Financial Times were analyzed from January to December, 2015. Findings show that 102 CSR stories were published by the newspapers at 40.2 and 59.8 per cent respectively. Similarly, most of the stories were positive and published on pages inside while not more than two stories existed on the front pages in each case. The insignificant front-page exposure suggests that these telecom companies should upgrade their credential in terms of the impact their CSR activities make on their audiences. Â

Lowest 2\u3csup\u3e+\u3c/sup\u3e, \u3cem\u3eT\u3c/em\u3e = 2 States in \u3csup\u3e20\u3c/sup\u3eMg and \u3csup\u3e20\u3c/sup\u3eF

A recent experiment located the lowest 2+ state in 20Mg and discovered that the corresponding 2+, T = 2 state in 20F does not fit expectations of the isobaric multiplet mass equation without a d term.We have calculated the energies of the ground and 2+ states in 20Mg and the 2+ in 20F in a potential model, using shell-model spectroscopic factors. We conclude that this important 20F state has likely never been observed, and suggest a reaction to find it

On the pathwidth of almost semicomplete digraphs

We call a digraph {\em $h$-semicomplete} if each vertex of the digraph has at most $h$ non-neighbors, where a non-neighbor of a vertex $v$ is a vertex $u \neq v$ such that there is no edge between $u$ and $v$ in either direction. This notion generalizes that of semicomplete digraphs which are $0$-semicomplete and tournaments which are semicomplete and have no anti-parallel pairs of edges. Our results in this paper are as follows. (1) We give an algorithm which, given an $h$-semicomplete digraph $G$ on $n$ vertices and a positive integer $k$, in $(h + 2k + 1)^{2k} n^{O(1)}$ time either constructs a path-decomposition of $G$ of width at most $k$ or concludes correctly that the pathwidth of $G$ is larger than $k$. (2) We show that there is a function $f(k, h)$ such that every $h$-semicomplete digraph of pathwidth at least $f(k, h)$ has a semicomplete subgraph of pathwidth at least $k$. One consequence of these results is that the problem of deciding if a fixed digraph $H$ is topologically contained in a given $h$-semicomplete digraph $G$ admits a polynomial-time algorithm for fixed $h$.Comment: 33pages, a shorter version to appear in ESA 201

Stress ulcer prophylaxis in trauma patients

INTRODUCTION: A number of issues concerning stress ulcer prophylaxis remain unresolved despite numerous randomized, controlled trials and several meta-analyses. The role of stress ulcer prophylaxis, particularly in trauma patients, is further complicated by the lack of trials utilizing clinically important bleeding as an endpoint. Given the lack of consensus regarding stress ulcer prophylaxis in trauma patients, prescribing practices at Level I trauma centers in the United States were assessed. MATERIALS AND METHODS: A survey was developed that contained questions related to institutional prescribing and evaluation of stress ulcer prophylaxis. The survey was intended to delineate these practices at the 188 Level I trauma centers (at the time of the present survey) in the United States. RESULTS: One hundred and nineteen surveys were returned, yielding a response rate of 63%. Eighty-six percent stated that medications for stress ulcer prophylaxis are used in a vast majority of trauma patients admitted to the intensive care unit. Sixty-five percent stated that there is one preferred medication. For these institutions, histamine-2-blockers were the most popular at 71%. Thirty-nine percent stated that greater than 50% of patients remain on stress ulcer prophylaxis following discharge from the intensive care unit. CONCLUSION: The lack of consensus with regards to appropriate stress ulcer prophylaxis is apparent in this survey of Level I trauma centers. For those institutions with a preferred agent, histamine-2-blockers were most common

Analyses for the description of rocket and airbreathing propulsion system combustion chamber and nozzle flows Annual report

Calculations of rocket and air breathing propulsion system combustion chamber and nozzle flow performanc

Tribute to Frederick W. Whiteside, Jr.

A series of tributes to Frederick W. Whiteside, Jr., a professor at the University of Kentucky College of Law

Acceptance and use of a smartphone application in cirrhosis

Background and AimsThe development of cirrhosis‐related smartphone applications for remote monitoring is increasing. Whether patients with cirrhosis will welcome such new technology, however, is uncertain.MethodsWe prospectively enrolled patients with cirrhosis (N = 102) to determine predictors of acceptance and utilization of a smartphone application for cirrhosis management using a 12‐item Technology Acceptance Model (TAM) survey. Patients were then shown the EncephalApp© and evaluated for their willingness to download and use the application.ResultsPatients had a median age of 61.3 years and 63.7% had a history of hepatic decompensation. Intention to use the hypothetical application was associated with perceived usefulness (β: 0.4, 95% CI: 0.3‐0.5) and the presence of a caregiver (β: 1.1, 95% CI: 0.2‐2.0). Of the eligible participants, 71% agreed to download the EncephalApp© and the decision was influenced by computer anxiety, behavioural intent, caregiver presence and disease state factors. Actual usage was 32% and not associated with baseline characteristics or the technology acceptance model.ConclusionsPatient acceptance of smartphone applications for the management of cirrhosis is high and related to their attitudes towards technology and the presence of a caregiver. However, usage was low. Future research must employ behavioural interventions to optimize uptake and utilization of remote monitoring technology.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/155977/1/liv14494_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/155977/2/liv14494.pd