A multiple exp-function method for the three model equations of shallow water waves

Nonlinear Dynamics - In this study, we consider three model equations of shallow water waves. Shallow water equations model the propagation of strongly nonlinear waves up to breaking and run-up in...     

Trends in labor efficiency among American hospital markets

The health care sector is one of the most labor intensive sectors of the economy. As a major player in health service delivery, hospitals must closely examine their largest cost — labor expenses. This study evaluates trends in the efficiency of health care labor among urban hospital markets. More specifically, it assesses the hypothesis that technological changes and market and regulatory pressures have increased aggregate labor efficiency. Using data envelopment analysis (DEA), this study evaluates labor efficiency in 1989 and 1993 in 298 metropolitan statistical areas (MSAs) with two or more hospitals. Results of this study suggest that between 1989 and 1993, hospital markets generally demonstrated higher labor inefficiencies. The U.S. health care system could save approximately $16.6 billion in 1993 by eliminating hospitals' excessive use of health care provider labor.     

Assessing efficiency of public health and medical care provision in OECD countries after a decade of reform

Central European Journal of Operations Research - The objective of this study was to examine the change in efficiency of health care systems of 34 OECD countries between 2000 and 2012, a period...     

Assessment of hospital efficiency under health transformation program in Turkey

The purpose of this research is to explore the operational performance of the Ministry of Health’s general public hospitals following the implementation of the Health Transformation Program in Turkey. This study adopts the Malmquist index to analyze the operational performance of the 352 Ministry of Health’s general hospitals during the period 2005–2008. The result show that the operational performance of these hospitals regardless of the attributes present a common tendency that the performance of 2005–2007 progressed as compared to the previous year, while that of 2008 has regressed as compared to 2007.     

Study of the gas chromatographic behavior of selected alcohols and amines

The gas chromatographic behavior of selected linear and non-linear alcohols and amines was investigated using four capillary columns containing phenyl substitution levels of 0%, 5%, and 50% and 50% cyanopropyl substitution. In a previous study, the positions of specific compounds inside the capillary column were iteratively modeled using only two thermodynamic parameters (ΔH and ΔS). The present study addresses the validation of the two-parameter model for retention time prediction for selected alcohols and amines using thermodynamic data obtained from as few as two data points. The difference between predicted and observed retention times under different temperature conditions was generally less than 1% of the experimental value and the predicted order of elution was correct in the used model.     

Simultaneous Determination of the Endogenous Free ��-Lipoic Acid and Dihydrolipoic Acid in Human Plasma and Erythrocytes by RP-HPLC with Electrochemical Detection

A highly sensitive, precise, and accurate reversed-phase high-performance liquid-chromatography/electrochemical detection method for simultaneous determination of the endogenous free ??-lipoic acid and dihydrolipoic acid in biological matrices was developed and validated. The two analytes were extracted from the samples with acetonitrile/10% metaphosphoric acid solution_(aqueous) (50/50 v/v). To determine the total lipoic acid, samples were treated with tris(2-carboxyethyl)phosphine solution in phosphate buffer, pH 2.5 with 85% orthophosphoric acid prior to deproteination. The two analytes were separated on a C₁₈ (150 × 4.6 mm, 5 ??m) analytical column using acetonitrile-50 mM phosphate buffer, pH 2.5 with 85% orthophosphoric acid (35/65 v/v) as the isocratic mobile phase pumped at a flow rate of 2.0 mL min^?1 at the column oven temperature of 35 °C. The column eluents were monitored at a potential of 0.9 V. These analytes were efficiently resolved in <7 min. The present method was sufficiently robust and specific for simultaneous determination of the two analytes and demonstrated acceptable values for linearity (r ² = 0.999 in the range of 0.1?C500 and 0.25?C1,000 ng mL^?1 for ??-lipoic acid and dihydrolipoic acid, respectively), recovery (>97%), precision (RSD% <2), and sensitivity (on column limit of detection, 150 and 375 fg for ??-lipoic acid and dihydrolipoic acid, respectively and limit of quantification: 0.5 and 1.25 pg for ??-lipoic acid and dihydrolipoic acid, respectively), indicating that the proposed method was more sensitive, precise, economical, and versatile, and has higher throughput than the previously reported methods for simultaneous determination of the two analytes.     

Determination of lead separated selectively with ion exchange method from solution onto BCW in Sirnak, East Anatolia of Turkey

There are approximately 82 million of tons asphaltites reserves in ?irnak, East Anatolia of Turkey. The present study was investigated to employ ashes of S?rnak BCW (burned coal waste) as an ion exchange in removal of important toxic metal, Lead (Pb), in high yields by adsorption. The ion exchange characteristics of lead onto BCW from aqueous solution were investigated with respect to the changes in pH of solution, adsorbent dosage, initial metal ion concentration, contact time and temperature of solution. For the adsorption of lead, the Langmuir isotherm model fitted to equilibrium data better than the Freundlich isotherm model. Thermodynamic functions, the change of free energy (ΔG°), enthalpy (ΔH°) and entropy (ΔS°) of adsorption were also calculated for lead. These parameters showed that the adsorption was feasible, spontaneous and exothermic at 293–333 K. Experimental data were also evaluated in terms of kinetic characteristics of adsorption. The batch kinetic data were correlated to the pseudo-first order and pseudo-second order models. The data fitted better to the pseudo-second order equation. The activation energy of systems was determined. Experimental data have shown that BCW that was used in unmodified form; as low cost, readily available ion exchange; can be used for removal of lead from industrial waste waters. Analysis was determined using Flame Atomic Absorption Spectrometry (FAAS).     

The relaxed Newton method derivative: Its dynamics and non-linear properties

The dynamic behaviour of the one-dimensional family of maps f(x)=_c2[(a−1)x+_c1]^{−λ/(α−1)}$f\left(x\right)=c_2{[(a-1)x+c_1]}^{-\lambda /(\alpha -1)}$ is examined, for representative values of the control parameters a,_c1$a,c_1$, _c2$c_2$ and λ$\lambda$. The maps under consideration are of special interest, since they are solutions of the relaxed Newton method derivative being equal to a constant a$a$. The maps f(x)$f\left(x\right)$ are also proved to be solutions of a non-linear differential equation with outstanding applications in the field of power electronics. The recurrent form of these maps, after excessive iterations, shows, in an _xn$x_n$ versus λ$\lambda$ plot, an initial exponential decay followed by a bifurcation. The value of λ$\lambda$ at which this bifurcation takes place depends on the values of the parameters a,_c1$a,c_1$ and _c2$c_2$. This corresponds to a switch to an oscillatory behaviour with amplitudes of f(x)$f\left(x\right)$ undergoing a period doubling. For values of a$a$ higher than 1 and at higher values of λ$\lambda$ a reverse bifurcation occurs. The corresponding branches converge and a bleb is formed for values of the parameter _c1$c_1$ between 1 and 1.20. This behaviour is confirmed by calculating the corresponding Lyapunov exponents.     

Liquid–liquid extraction of scandium with nalidixic acid in dichloromethane

The extraction behavior of nalidixic acid (HNA) in CH₂Cl₂ has been studied for various di- and trivalent metal ions such as Cu(II), Fe(II), Ni(II), Mn(II), Sb(II), Co(II), Sc(III), Y(III), Nd(III) and Eu(III) from aqueous buffer solutions of pH 1–7 with 0.1 mol dm⁻³ nalidixic acid in dichloromethane. Separation factors of Sc(III) from these metals has shown that its clean separation is possible at pH 3.4–4. The parameters affecting the extraction of Sc(III) were optimized. The composition of the extracted adduct was determined by slope analysis method that came out to be Sc(NA)₃. Extraction of Sc(III) was studied in the presence of various cations and anions. Among the anions studied only fluoride, citrate and oxalate have significant interference whereas, Fe(III) has reduced the extraction to 53% that can be removed by using ascorbic acid as reducing agent. The proposed extraction system proved good stability up to six extraction-stripping stages for the extraction of Sc(III).     

Retention time prediction of compounds in Grob standard mixture for apolar capillary columns in temperature-programmed gas chromatography

This paper presents an extension of a previous investigation in which the behavior of nonpolar compounds in temperature-programmed gas chromatographic runs was predicted using thermodynamic (entropy and enthalpy) parameters derived from isothermal runs. In a similar manner, entropy and enthalpy parameters were determined for a Grob standard mixture of compounds with widely varying chemical characteristics. These parameters were used to predict the retention times and chromatographic behaviors of the compounds on four gas chromatography capillary columns: three that had phenyl-based stationary phases (with degrees of substitution of 0%, 5% and 50%) and one with (50%) cyanopropyl substitution. The predictions matched data empirically obtained from temperature-programmed chromatographic runs for all of the compounds extremely well, despite the wide variations in polarity of both the compounds and stationary phases. Thus, the results indicate that such simulations could greatly reduce the time and material costs of chromatographic optimizations.