A Non-standard discrete model for the solution of first order Ordinary Differential Equations using minimally characterized interpolating function

We present a new set of one step finite difference schemes for the numerical solution of  First order differential equations using a combination of an interpolation function and a modification of the resulting schemes by replacing step size  with a suitable function of   as required by the second non-standard modeling rule. The resulting schemes have been applied to some initial value problems and the schemes have been found to possess  desirable qualitative properties. KEYWORDS Nonstandard methods, Hybrid, Interpolation functions, Non-standard modeling rules, Standard Finite difference method

A new Numerical Integrator for the Solution of Problems Arising from Some Dynamical Systems

In this paper, we developed a new Numerical Integrator for solving oscillatory and exponential problems that can be represented by  Ordinary Differential Equation. This integrator was applied in solving some physical problems including the dynamic and aerospace routing problem. The results obtained showed that the numerical integrator is suitable for the simulation of these  problems. KEYWORDS: Dynamic Aerospace problem, Numerical  Integrator, Algorithms, Oscillatory and Exponential problems. Dynamical systems

Construction of new Non-standard Finite Difference Schemes for the Solution of a free un-damped Harmonic Oscillator Equation

In this paper we discussed the numerical solution to the model of a freely suspended spring with a mass attached. Suitable nonstandard finite difference schemes were developed  for the solution of the resulting dynamical system which follows a free un-damped harmonic oscillator. The result of the numerical experiment  on the schemes are illustrated  with 3D graphs . Keywords: Numerical methods , Non-Local Approximations,  Non-standard finite difference schemes, Qualitative properties, Free un-damped Harmonic Oscillator,  Monotonicity of solution

HIVAN and medication use in chronic dialysis patients in the United States: analysis of the USRDS DMMS Wave 2 study

BACKGROUND: The use and possible effects of factors known to improve outcomes in patients with human immunodeficiency virus associated nephropathy (HIVAN), namely of angiotensin converting enzyme inhibitors (ACE) and antiretroviral therapy, has not been reported for a national sample of dialysis patients. METHODS: We conducted a historical cohort study of the United States Renal Data System (USRDS) Dialysis Morbidity and Mortality Study (DMMS) Wave 2 to identify risk factors associated with increased mortality in these patients. Data were available for 3374 patients who started dialysis and were followed until March 2000. Cox Regression analysis was used to model adjusted hazard ratios (AHR) with HIVAN as a cause of end stage renal disease (ESRD) and its impact on mortality during the study period, adjusted for potential confounders. RESULTS: Of the 3374 patients who started dialysis, 36 (1.1%) had ESRD as a result of HIVAN. Only 22 (61%) of patients with HIVAN received antiretroviral agents, and only nine patients (25%) received combination antiretroviral therapy, and only 14% received ACE inhibitors. Neither the use of multiple antiretroviral drugs (AHR, 0.62, 95% CI, 0.10, 3.86, p = 0.60), or ACE inhibitors were associated with a survival advantage. Patients with HIVAN had an increased risk of mortality (adjusted hazard ratio, 4.74, 95% Confidence Interval, 3.12, 7.32, p < 0.01) compared to patients with other causes of ESRD. CONCLUSIONS: Medications known to improve outcomes in HIV infected patients were underutilized in patients with HIVAN. Adjusted for other factors, a primary diagnosis of HIVAN was associated with increased mortality compared with other causes of ESRD

Preparation and Characterization of Biochar and Activated Carbon Derived from Cashew Bagasse Waste

Biochar and Activated carbon derived from cashew bagasse waste are veritable materials produced from agro-waste. They are currently under-utilized owing to paucity of information in their recycling methods which reduces agricultural waste from the environment. This study investigates the use of under-utilized cashew bagasse waste in the production of biochar and activated carbon using pyrolysis and chemical activation methods, respectively. Cashew bagasse waste was pyrolysed at 4000C for 20mins at a heating rate of 100C per mins. The biochar produced was allowed to cool at room temperature for 30 mins. It was further reduced to smaller size particles using euro premium grinder and later sieved with 10 mesh sieve size prior to its application. The biochar was chemically activated using 0.3M Orthophosphoric acid (H3PO4) as activating agent at an impregnation ratio of 1:2.36(w/w). It was heated at 1000C to form a paste and later placed in muffle furnace at 5000C for 30 mins. This was allowed to cool and washed with distilled water until a neutral pH was obtained and later oven dried at 1050C for 24 hours to a constant weight to produce activated carbon. The produced activated carbon was kept in air tight containers prior to analysis. Characterization of pH, bulk density, moisture content, dry matter, volatile matter, and fixed carbon were determined for biochar and activated carbon. Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy (SEM) analysis was performed to determine the functional groups and surface morphology of biochar and activated carbon, respectively. The Data obtained were analyzed using descriptive statistics and ANOVA at P value < 0.05. The results showed that significant differences (p<0.05) were observed in the characterized parameters determined. The biochar and activated carbon has pH: (7.68±0.06 and 6.13±0.03); Bulk density :( 0.18±0.01 and 0.20±0.01) %; Moisture content: (6.67±0.33 and 16.00±0.58)%; Dry matter (93.33±0.33 and 84.00±0.58) %; Volatile matter (68.67±3.18 and 29.67±5.21) %; Fixed carbon (30.24±3.20 and 69.32±5.16) %, respectively. FTIR Analysis showed that biochar and activated carbon were more polar and also contained specific bonds. SEM analysis also indicated that biochar and activated carbon have porous structures. This study, therefore, revealed that chemically activated carbon had better characteristics than biochar produced through pyrolysis method

Rationale for Utilization of Hydrogel Rectal Spacers in Dose Escalated SBRT for the Treatment of Unfavorable Risk Prostate Cancer

In this review we outline the current evidence for the use of hydrogel rectal spacers in the treatment paradigm for prostate cancer with external beam radiation therapy. We review their development, summarize clinical evidence, risk of adverse events, best practices for placement, treatment planning considerations and finally we outline a framework and rationale for the utilization of rectal spacers when treating unfavorable risk prostate cancer with dose escalated Stereotactic Body Radiation Therapy (SBRT)

Extraction of castor oil from castor seed for optimization of biodiesel production

. This research was carried out to optimize biodiesel production from castor oil using 24 full factorial central composite design (CCD). Transesterification method was used for the biodiesel production from castor using KOH & NaOH were used as catalysts. Physico-chemical properties including density, kinematic viscosity, acid value, saponification value, iodine value and pour point. The results were determined both on the castor oil and biodiesel produced. The predicted optimum conditions for the production of castor oil biodiesel are; reaction time of 60 minutes at the temperature of 60˚C, catalyst concentration of 3.5 g and a methanol /oil molar ratio of 5:1. The biodiesel yield was 99.76% and the result of the measured properties of biodiesel was compared with the international standards of EN14214 and ASTM D6751. The weight composition of the fatty acid and methyl ester were both determined by the Gas Chromatography (GCMS