Dynamic economic dispatch using Lbest-PSO with dynamically varying sub-swarms

Dynamic economic dispatch (DED) is one of the major planning problem in a power system. It is a non-linear optimization problem with various operational constraints, which includes the constraints of the generators operating characteristics and the system constraints. Its principal aim is to minimize the cost of power production of all the participating generators over a time horizon of 24 h, while satisfying the system constraints. This problem deals with non-convex characteristics if generation unit valve-point effects are taken into account. The paper intends to solve the DED problem with valve-point effects, using our modified form of Local-best variant of Particle Swarm Optimization (Lbest PSO) algorithm. We have tested our algorithm on 5-unit, 10-unit and 110-unit test system with non-smooth fuel cost functions to prove the effectiveness of the suggested method over different state of the art methods.     

Extending Petri net to reduce control strategies of railway interlocking system

In our previous articles we gave step by step refinement process towards the development of safety properties of moving block interlocking system (MBRIS). The refinement process started from abstraction to fuzzy based safety properties using Z and then fuzzy multi agent specification language. However, one dimensional control of train passing through a switch and level crossing were not discussed. This paper reduces the existing two dimensional controls along the switch and level crossing to one dimensional for shifting it to a train only. For example, in the existing model the train movement along components switches and level crossings depends on both the train and components control. Whereas, in one dimensional control train is the only authority to control a switch and level crossing required for its desired operation. For this reduction, concurrent and mobile agent concepts are required. Therefore, we integrate mobile agent concepts with Petri nets to develop the mobile Petri net (MPN) a new class of PNs. This supports both mobility and concurrency. Further, we prove that the collection of different MPNs in a connected network is a PN. This proof allowed us to use the properties of PN to verify the system. Finally, we use MPN to model the safety properties of MBRIS along the switch and level crossing. This provides one dimensional control to a train along a switch and level crossing which increases the safety of the railway interlocking system. Moreover, we use reachability graph (RG) to verify the switch and level crossing models.     

Generation of higher degree chaos by controlling harmonics of the modulating signal in EDFRL

Erbium doped fiber ring lasers (EDFRL) are being used to generate optical chaos for secure communication by modulating the cavity loss/pump power or exploiting nonlinearities. The security level in chaotic communication depends on degree of chaos quantified by the Lyapunov exponent and its variability which is determined by the number of tuneable system parameters which were limited to five main parameters, i.e. modulation index, modulation frequency, pump power, cavity gain and loss. In this study we have increased the number of tuneable parameters using square, triangular and sum of harmonics waveforms. We have analysed the effect on degree of chaos of phase and duty cycle of square modulating signal with gradual addition of harmonics. For the given cavity parameters, the Lyapunov exponents can be increased by more than fifteen times using square wave modulating signal and a duty cycle of 60%. The electrical parameters identified make generation of new chaotic sequences more flexible in a field deployed EDFRL chaotic system.     

Crystal Structure and Raman Spectroscopic Study of K5[CuO2][CO3]

Air and moisture sensitive K₅[CuO₂][CO₃] was prepared via the azide/nitrate route from stoichiometric mixtures of the precursors CuO, KN₃, KNO₃ and K₂CO₃. According to the single‐crystal X‐ray analysis of the crystal structure [P4/nbm, Z = 2, a = 7.4067(5), c = 8.8764(8) Å, R₁ = 0.053, 433 independent reflections] K₅[CuO₂][CO₃] represents an ordered superstructure of Na₅[NiO₂][CO₃]. The structure contains isolated [CuO₂]^3– dumbbells and CO₃^2– anions, with the latter not connected to the transition element. Raman spectroscopic measurements confirm the presence of CO₃^2– in the structure.     

Thermodynamic Study of the Binding of Mercury Ion to Human Growth Hormone at Different Temperatures

The interaction of human growth hormone (hGH) with the divalent mercury ion was studied by isothermal titration calorimetry at two temperatures of 27 °C and 37 °C in aqueous solutions. We found that there is a set of two identical and non-interacting binding sites for Hg²⁺ ions. The intrinsic dissociation equilibrium constant and the molar enthalpy of binding are 4.2 mmol⋅L⁻¹ and −14.8 kJ⋅mol⁻¹ at 27 °C and 5.1 mmol⋅L⁻¹ and −14.2 kJ⋅mol⁻¹ at 37 °C, respectively. The results obtained indicate that the stability of the protein increases due to the binding of mercury ions using the extended solvation theory.     

Colorimetric analysis of water and sand samples performed on a mobile phone

Analysis of water and sand samples was done by reflectance measurements using a mobile phone. The phone's screen served as light source and front view camera as detector. Reflected intensities for white, red, green and blue colors were used to do principal component analysis for classification of several compounds and their concentrations in water. Analyses of colored solutions and colorimetric reactions based on widely available chemicals were performed. Classification of iron(III), chromium(VI) and sodium salt of humic acid was observed using reflected intensities from blue and green light for concentrations 2-10 mg/l. Addition of complex forming sodium salt of ethylenediaminetetraacidic acid enabled the discrimination of Cu(II) ions in the 2-10 mg/l concentration range based on reflection of red light. An alternate method using test strips for copper solutions with the phone as reader also demonstrated a detection limit of 2 mg/l. Analysis of As(III) from 25 to 400 μg/l based on reflection of red light was performed utilizing the bleaching reaction of tincture of iodine containing starch. Enhanced sensitivity to low concentrations of arsenic was obtained by including reflected intensities from white light in the analysis. Model colored sand samples representing discoloration caused by the presence of arsenic in groundwater were analyzed as a complementary method for arsenic detection.     

Recent Developments to Cope the Antibacterial Resistance via β-Lactamase Inhibition

Antibacterial resistance towards the β-lactam (BL) drugs is now ubiquitous, and there is a major global health concern associated with the emergence of new β-lactamases (BLAs) as the primary cause of resistance. In addition to the development of new antibacterial drugs, β-lactamase inhibition is an alternative modality that can be implemented to tackle this resistance channel. This strategy has successfully revitalized the efficacy of a number of otherwise obsolete BLs since the discovery of the first β-lactamase inhibitor (BLI), clavulanic acid. Over the years, β-lactamase inhibition research has grown, leading to the introduction of new synthetic inhibitors, and a few are currently in clinical trials. Of note, the 1, 6-diazabicyclo [3,2,1]octan-7-one (DBO) scaffold gained the attention of researchers around the world, which finally culminated in the approval of two BLIs, avibactam and relebactam, which can successfully inhibit Ambler class A, C, and D β-lactamases. Boronic acids have shown promise in coping with Ambler class B β-lactamases in recent research, in addition to classes A, C, and D with the clinical use of vaborbactam. This review focuses on the further developments in the synthetic strategies using DBO as well as boronic acid derivatives. In addition, various other potential serine- and metallo- β-lactamases inhibitors that have been developed in last few years are discussed briefly as well. Furthermore, binding interactions of the representative inhibitors have been discussed based on the crystal structure data of inhibitor-enzyme complex, published in the literature.     

Degenerate Cauchy–Goursat problem for 2-D steady isentropic Euler system with van der Waals gas

This study concerns with the existence–uniqueness of local classical sonic-supersonic solution to a degenerate Cauchy–Goursat problem that arises in transonic phenomena. The flow is governed by 2-D steady isentropic Euler system with a polytropic van der Waals gas. The idea of characteristic decomposition has been used to convert the Euler system into a new system involving the angle variables $(𝛩,\mu )$. To overcome the parabolic degeneracy caused at the sonic curve, the partial hodograph transformation and a variety of dependent–independent variables have been introduced to transform the nonlinear system into a linear one with explicit singularity–regularity structure. The uniform convergence of the sequences $(W^{(m)},Z^{(m)})$ has been discussed by employing the mathematical induction. Eventually, the inversion of the solution from partial hodograph plane to the original plane has been established.     

Tuning the Photocatalytic Performance of Ruthenium(II) Polypyridine Complexes Via Ligand Modification for Visible-Light-Induced Phosphorylation of Tertiary Aliphatic Amines

Tuning the redox potential of commonly available photocatalyst to improve the catalytic performance or expand its scope for challenging synthetic conversions is an ongoing demand in synthetic chemistry. Herein, the excited state properties and redox potential of commercially available [Ru(bpy)₃]²⁺ photocatalyst were tuned by modifying the structure of the bipyridine ligands with electron-donating/withdrawing units. The visible-light-mediated photoredox phosphorylation of tertiary aliphatic amines was demonstrated under mild conditions. A series of cross-dehydrogenative coupling reactions were performed employing the Ru^II complexes as photocatalyst giving the corresponding α-aminophosphinoxides and α-aminophosphonates via carbon-phosphorus (C−P) bond formation.