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Search Results: 1 - 10 of 1684 matches for " Isaac; "
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Newton’s Method and an Exact Opposite That Average into Halley’s Method  [PDF]
Isaac Fried
Applied Mathematics (AM) , 2017, DOI: 10.4236/am.2017.810103
Abstract:
This note is mainly concerned with the creation of oppositely converging and alternatingly converging iterative methods that have the added advantage of providing ever tighter bounds on the targeted root. By a slight parametric perturbation of Newton’s method we create an oscillating super-linear method approaching the targeted root alternatingly from above and from below. Further extension of Newton’s method creates an oppositely converging quadratic counterpart to it. This new method requires a second derivative, but for it, the average of the two opposite methods rises to become a cubic method. This note examines also the creation of high order iterative methods by a repeated specification of undetermined coefficients.
Newton, Halley, Pell and the Optimal Iterative High-Order Rational Approximation of √N  [PDF]
Isaac Fried
Applied Mathematics (AM) , 2018, DOI: 10.4236/am.2018.97059
Abstract:
In this paper we examine single-step iterative methods for the solution of the nonlinear algebraic equation f (x) = x2 - N = 0 , for some integer N, generating rational approximations p/q that are optimal in the sense of Pell’s equation p2 - Nq2 = k for some integer k, converging either alternatingly or oppositely.
Entropy of Living versus Non-Living Systems  [PDF]
Isaac C. Sanchez
Journal of Modern Physics (JMP) , 2011, DOI: 10.4236/jmp.2011.27077
Abstract: Using a careful thermodynamic analysis of unfertilized and fertilized eggs as a paradigm, it is argued that neither classical nor statistical thermodynamics is able to adequately describe living systems. To rescue thermodynamics from this dilemma, the definition of entropy for a living system must expand to acknowedge the latent genetic information encoded in DNA and RNA.As a working supposition, it is proposed that gradual unfolding (expression) of genetic information contributes a negative entropy flow into a living organism that alleviates apparent thermodynamic inconsistencies. It is estimated that each coding codon in DNA intrinsically carries about -3k in negative entropy. Even prior to the discovery of DNA and the genetic code, negative entropy flow in living systems was first proposed by Erwin Schrödinger in 1944.
Cardiac Immobilization in Beating Heart Surgery Using Pericardial Bands  [PDF]
Srikrishna Sirivella, Isaac Gielchinsky
World Journal of Cardiovascular Surgery (WJCS) , 2012, DOI: 10.4236/wjcs.2012.22005
Abstract: A novel technique of stabilization of the coronary targets with autogenous pericardial bands is described in off pump coronary revascularizations. Pericardial bands are placed across the coronary targets and snared to the pericardial well for local cardiac immobilization. This technique can be used as an alternate to mechanical stabilizers for immobilization of the coronary targets.
Hemodynamic Changes during Off-Pump Coronary Ar-tery Bypass Graft Surgery: Experience Using Pericardial Bands for Target Stabilization  [PDF]
Srikrishna Sirivella, Isaac Gielchinsky
World Journal of Cardiovascular Surgery (WJCS) , 2013, DOI: 10.4236/wjcs.2013.38045
Abstract: Background: The off-pump coronary artery bypass graft surgery (OPCAB) may produce significant hemodynamic instability necessitating conversion to on-pump surgery. This study evaluated the hemodynamic parameters in patients undergoing OPCAB using pericardial bands for stabilization of the coronary target sites. Methods: In 250 patients undergoing OPCAB the hemodynamic parameters including continuous cardiac output and systemic venous oxygen saturation (SvO2) were recorded at baseline after pericardiotomy, during each coronary artery anastomosis at 3, 5, 10, 15 min, and after release of the pericardial bands used for target stabilization. Vasopressors were used to maintain mean arterial pressure (MAP) > 60 mmHg. Results: SvO2 and cardiac index (CI) decreased significantly after target stabilization and during all coronary anastomoses with greater decreases noted during obtuse marginal branch of left circumflex (OM) anastomosis. The MAP and heart rate were maintained without significant change but central venous pressure increased significantly during all coronary anastomoses. The significant increase in pulmonary capillary wedge pressure and mean pulmonary artery pressure were noted only during anastomosis of the left anterior descending artery. The highest dose of vasopressor was used during OM anastomosis. Conclusions: During OPCAB surgery using pericardial bands for coronary target stabilization, MAP was maintained constantly, but SvO2 and CI decreased immediately after target stabilization and reduced further during all coronary artery anastomoses. During OM anastomosis SvO2 and CI were significantly lower as compared to that of LAD and right coronary artery. Careful monitoring and management of hemodynamic variables are warranted to avoid conversion to on-pump technique.
An Assessment of Heavy-Metal Contamination in Soils within Auto-Mechanic Workshops Using Enrichment and Contamination Factors with Geoaccumulation Indexes  [PDF]
Isaac A. Ololade
Journal of Environmental Protection (JEP) , 2014, DOI: 10.4236/jep.2014.511098
Abstract:

Soil characterization and heavy metals in different layers (0 - 15 cm; 15 - 30 cm and 30 - 45 cm depth) of automobile mechanic waste dumps were studied. The soils showed remarkably high levels of all the metals above background concentrations with most (Ni, Cu, Fe, Cr and Cd) decreasing with soil depth. The distribution pattern were in the following order Fe > Cu > Zn > Pb > Cr > Ni > Cd. Across all the sampling locations and profiles, Fe and Cd showed the highest (476.4 μg·g-1) and least (37.5 μg·g-1) mean concentrations respectively. Pollution load index (PLI) and index of geoaccumulation (Igeo) revealed overall high and moderate contamination respectively but the enrichment factors (EFs) for Pb Ni and Cd are severe. The inter-element relationship revealed the identical source of elements in the soils of the studied area. The accuracy of the results has been cheeked using the standard reference material; SRM (PACS-2). The mechanic waste dumps represent potential sources of heavy metal pollution to environment. The elevated levels of heavy metals in these soil profiles constitute a serious threat to both surface and groundwater.

Early and Long Term Outcomes of Corrective Operations for Tetralogy of Fallot: An Experience of Two Centers  [PDF]
Srikrishna Sirivella, Isaac Gielchinsky
World Journal of Cardiovascular Surgery (WJCS) , 2014, DOI: 10.4236/wjcs.2014.411027
Abstract: Objectives: Pulmonary valve insufficiency and right ventricular dysfunction may contribute to early and late morbidity and mortality after repair of Tetralogy of Fallot. Right ventricular dysfunction may be attributed to ventriculotomy incision, especially, when it is combined with a transannular patch as employed in the transventricular repair. Transatrial/transpulmonary approach without ventriculotomy and an attempt to preserve the pulmonary valve has been advocated as a method potentially diminishing such adverse events. The prevalence of associated morbidity and mortality and analysis of the results of various surgical approaches for repair of Tetralogy of Fallot formed the basis of this study. Methods: Nine hundred and ninety five patients during 20 yearS period (from 1992 and 2012) with primary diagnosis of Tetralogy of Fallot that underwent total repair operations in two medical centers were analyzed. The mean age of the patients was 2.9 ± 6.9 SE, with female/male ratio of 0.25. The mean long follow-up was 94 months ± 112 SD. Results: Repair via ventriculotomy with transannular patch was the most common technique (n = 627, 63%), followed by infundibulotomy without transannular patch (20%) and transatrial/transpulmonary approach without ventriculotomy (15%). The operative and long term mortality were 3.2% and 4.4%; 2% and 3.1%; 2% and 2.7% respectively. The overall operative and long term mortality for repairs was 2.9% and 3.4%, with high 3.94% and 6.6% respectively for repairs with right ventricular pulmonary valve conduit. There was statistically significant correlation between the type of repair and mortality risk. Use of transannular patch with ventriculotomy was associated with significant increase in overall mortality risk and operative mortality compared with ventriculotomy without transannular patch. [Odds ratio, 2.10; 95% confidence interval: 1.29-3.64]. Operations that have been performed before 2000 have resulted in increased operative risk compared with those performed after 2000. [Odds ratio 1.45; 95% confidence interval: 1.03-2.01]. Conclusions: Overall mortality for Tetralogy of Fallot repair was low. The repair by ventriculotomy with transannular patch was the most common technique and was associated with higher mortality. Repairs through infundibulotomy without transannular patch and repair without ventriculotomy were less common, but were associated with lower mortality. Current advances in management, anatomical substrate of the lesion, choice of a repair and surgical expertise may all determine the mortality risk.
Transition to Certification Schemes and Implications for Market Access: GlobalGAP Perspectives in Kenya  [PDF]
Isaac Maina Kariuki
Agricultural Sciences (AS) , 2014, DOI: 10.4236/as.2014.512120
Abstract: Voluntary pre-farm certification schemes especially GlobalGAP are increasingly defining market access for smallholders in developing countries. Their strict demand for financial and technical competencies and concerns for producer welfare and environmental conservation imply that transition to certified production could spell smallholders’ exit or shift to alternative markets for no-compliance. But what factors motivate successful transition to certification and does alternative market access exist for the unsuccessful transition? Multinomial logit estimates reveal training and higher farm assets base as key indicators of successful certification and organized production. However, a large cultivated land resource favours certification but disfavours transition to organized production. The results point to sensitivity of certification schemes to expertise on technical information and assets that enhance cultivation of quality, reliable and hygienic produce and economies of scale in farming. The transition to organized production seems efficient if technical knowledge and assets that enhance cultivation of quality, reliable and hygienic produce are present. The results imply that farmer expertise, farm assets and land resource are critical barriers for farmers transiting to certification schemes. This calls for concerted mitigation if smallholders in developing countries are to benefit from the lucrative premium markets in Western Europe.
Dynamics of Unsteady MHD Convective Flow with Thermophoresis of Particles and Variable Thermo-Physical Properties past a Vertical Surface Moving through Binary Mixture  [PDF]
Isaac Lare Animasaun
Open Journal of Fluid Dynamics (OJFD) , 2015, DOI: 10.4236/ojfd.2015.52013
Abstract: The dynamics of unsteady magnetohydrodynamic convective fluid flow with radiation and thermophoresis of particles past a vertical porous plate moving through a binary mixture in an optically thin environment is investigated. The approximate form of the radiative heat flux is considered as the fourth power of temperature. Chemical reaction that occurs as the chemically reacting fluid flow through binary mixture is accounted for in energy and species concentration equations. Exponential space dependent heat source is introduced to generate additional heat energy across the fluid domain. The corresponding influence of heat energy is properly accounted for. It is assumed that viscosity and thermal conductivity vary as a linear function of temperature. The governing boundary layer equations are converted to nonlinear ordinary differential equations using similarity variables. A novel method of obtaining root finding starting with three guesses in shooting techniques is presented. The corresponding nonlinear coupled ordinary differential equations is solved numerically by shooting technique along with quadratic interpolation scheme. Graphical results of the dimensionless velocity, temperature and concentration distributions are shown for certain pertinent parameters controlling the fluid flow. The quadratic interpolation method is found to produce better estimated values of \"\", which satisfy the degree of accuracy and proportional to the physical quantities.
Heavy Metal Profile of Oreochromis niloticus Harvested from E-Waste Polluted Vials and Associated Fungi  [PDF]
Adeyemi Isaac Sanusi
Advances in Microbiology (AiM) , 2016, DOI: 10.4236/aim.2016.68056
Abstract: This study was designed to investigate the possible variation in bioaccumulation of heavy metals (lead, cadmium, zinc, cobalt, chromium, nickel, and manganese) in the tissue of harvested Oreochromis niloticus (tilapia) and the associated fungi from vials treated with soil from e-waste dumpsite and soil without e-waste. E-waste is electronic waste which contains valuable metals as well as potential environmental contaminants. The heavy metals in soil and fish samples were determined using flame atomic absorption spectrophotometer (AAS) after homogeneity and digestion of samples. The associated fungi were identified using standard microbiological methods. The genera of the associated fungi were: Penicillium, Candida, Articulospora, Aspergillus, Aspergillus, Aspergillus, Rhizopus, Mucor, Zoopage, Varicosporium and Rhodoturula. The quantity of fungi isolated from each pollution treatments showed that the number of fungi were inversely proportional to the quantity of e-waste soil pollution and directly proportional to the quantity of soil without e-waste pollution. The occurrence of the fungi species revealed that the untreated (control) vial had the highest occurrence (191) while the lowest occurrence (103)
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