Performance analysis and multi-objective optimization of an organic Rankine cycle with binary zeotropic working fluid employing modified artificial bee colony algorithm

From a thermal point of view, zeotropic mixtures are likely to be more efficient than azeotropic fluids in low-temperature power cycles for reduction in exergy destruction occurring during heat absorption/rejection processes due to their suitable boiling characteristics. In this study, comprehensive energetic and exergetic analyses are mathematically performed for an organic Rankine cycle (ORC) system employing a potential binary zeotropic working fluid, namely R717/water. For this purpose, initially mass, energy, and exergy balance equations are derived. With regard to the similarity in molar mass of R717 (17.03 g mol^?1) and water (18.01 g mol^?1), there is no need to alter the size of the ORC components such as turbine and pump. In order to achieve the optimal thermal and exergy efficiencies of the ORC system, modified version a powerful and relatively new optimization algorithm called artificial bee colony (ABC) is used taking into account different effective constraints. The main motivation behind using ABC lies on its robustness, reliability, and convergence rate speed in dealing with complicated constrained multi-objective problems. Convergence rates of the algorithm for optimal calculation of the efficiencies are presented. Subsequently, due to the importance of exergy concept in ORC systems, exergy destructions occurring in the components are computed. Finally, the impacts of pressure, temperature, mass fraction, and mass flow rate on the ORC thermal and exergy efficiencies are discussed.

     

Unique solvability of a linear problem with perturbed periodic boundary values

We investigate the problem with perturbed periodic boundary values

New formulas for approximation of π and other transcendental numbers

We derive many new formulas for the approximation of π. The formulas make use of a sequence of iteration functions called the basic family; a nontrivial determinantal generalization of Taylor's theorem; other ingredients; as well as several new results presented in the present paper. In one scheme, one evaluates members of the basic family, for an appropriately selected function, all at the same input. This scheme generates almost a fixed and preselected number of digits in each successive evaluation. The computation amounts to the evaluation of a homogeneous linear recursive formula and is equivalent to the computation of special Toeplitz matrix determinants. The approximations of π obtained via this scheme are within simple algebraic extensions of the rational field. In a second scheme, the fixed-point iteration is applied to any fixed member of the basic family, while selecting an appropriate function. In this scheme for each natural number we prove convergence of order m, starting from the initial point. We report on some preliminary computational results obtained via Maple. Analogous formulas can be used to approximate other transcendental numbers. For instance, we also give a formula for the approximation of e. In fact, our results give new formulas and arbitrary high-order methods for the approximation of roots of certain analytic functions. This revised version was published online in June 2006 with corrections to the Cover Date.     

Thermodynamic Studies of Insulin Loading into a Glucose Responsive Hydrogel Based on Chitosan‐polyacrylamide‐polyethylene Glycol

The insulin therapy constitutes the preferred treatment for Diabetes Mellitus (DM). The traditional insulin therapy, which consists of daily subcutaneous insulin injections to control blood glucose level, is not able to regulate the blood glucose level precisely. In this research, to facilitate the diabetic patient life, an intelligent drug delivery system based on a biodegrable biopolymer to control the insulin release, was designed. In this system, chitosan‐polyethylene glycol hydrogel and glucose oxidize play the role of drug carrier and glucose biosensor, respectively. To increase the hydrogel drug loading capacity, hydrogels with different PEG content were synthesized and insulin was loaded by swelling‐diffusion method into them. The loaded hydrogels were characterized by Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM), High performance liquid chromatography (HPLC), and Thermogravimetric analysis (TGA). Finally, the thermodynamic study for insulin loading process was performed to investigate the stability of the drug in the system.     

Seed Priming with Non-thermal Plasma Modified Plant Reactions to Selenium or Zinc Oxide Nanoparticles: Cold Plasma as a Novel Emerging Tool for Plant Science

Plasma Chemistry and Plasma Processing - This research explored the capability of seed priming with the non-thermal plasma to modify reactions of Melissa officinalis, an important medicinal plant,...     

Cu–S‐(propyl)‐2‐aminobenzothioate on magnetic nanoparticles: highly efficient and reusable catalyst for synthesis of polyhydroquinoline derivatives and oxidation of sulfides

Cu–S‐(propyl)‐2‐aminobenzothioate supported on functionalized Fe₃O₄ magnetic nanoparticles is reported as a reusable and highly efficient nanocatalyst for the one‐pot synthesis of polyhydroquinoline derivatives and also for selective oxidation of sulfides to sulfoxides. The prepared nanoparticles were characterized using Fourier transform infrared spectroscopy, vibrating sample magnetometry, thermogravimetric analysis, transmission and scanning electron microscopies, energy‐dispersive X‐ray spectroscopy, X‐ray diffraction, inductively coupled plasma atomic emission spectroscopy and atomic absorption spectroscopy. The nanocatalyst was easily recovered using an external magnet and reused several times without significant loss of its catalytic efficiency. Copyright © 2016 John Wiley & Sons, Ltd.     

Performance evaluation of fast Fourier-transform continuous cyclic-voltammetry pesticide biosensor

In this work, a method for the fast monitoring of OPs in flow-injection systems was evaluated. The fast Fourier transform continuous cyclic-voltammetry (FFTCCV) at the carbon-paste electrode in a flowing solution system was used for determination of OPs. In this method the S/N ratio is enhanced by using of fast Fourier transform of the analyte and signal integration. FFTCCV can be considered as a new sensitive, accurate and fast method for determination of drugs and some pesticides. However, in order to obtain better sensitivity for a specific target, experimental parameters should be optimized. Response surface methodology (RSM) was applied to optimize three effective parameters (enzyme activity, multiwall carbon nanotube quantity and acidic sol–gel quantity). The optimum values for the tested parameters were enzyme amount H0.169 U cm⁻², multiwall carbon nanotube (MWCNT) 0.607 mL and acidic sol–gel 1.012 mL. The optimum feed pH, feed flow rate, ATChCl concentration and sweeping-rate were found to be 7.4, 0.34 mL min⁻¹, 0.750 mM and 10 V s⁻¹, respectively. The long-term stability of this flow-through system was 80% of its initial response after 120 days. Based on an incubation time of 12 min, it was found that the detection limit for paraoxon was equal to 1.7 × 10⁻⁷ mg L⁻¹ (6.2 × 10⁻¹³ M). The developed biosensor exhibited good repeatability and reproducibility. This study provides a new, modern, sensitive tool for the analysis of organophosphate pesticides.