A multi-parent genetic algorithm for solving longitude–latitude-based 4D traveling salesman problems under uncertainty

In this study, we propose a mathematical model of a 4D clustered traveling salesman problem (CTSP) to address the cost-effective security and risk-related difficulties associated with the TSP. We used a multiparent-based memetic genetic algorithm to optimize paths between all clusters and proposed unique heuristic approaches to create clusters and reconnect them. We constructed a 4D CTSP considering multiple routes between two locations and multiple available vehicles on each route. Travel expenses and risks impact every itinerary; however, the behaviors of these costs and risks are always uncertain. We inspected various standard benchmark problems from (TSPLIB) using the proposed calculations. Real-life problems in the tourism industry motivate a longitude–latitude-based CTSP with risk constraints. Thus, we determined the risk of each path based on longitude and latitude. The contributions of this study are twofold: developing a genetic algorithm and heuristics based on mathematical modeling of a real problem.</p

IoT-based smart bin allocation and vehicle routing in solid waste management: A case study in South Korea

© 2022 Elsevier LtdIncreasing waste generation has become a real challenge because of population growth and rapid urbanization. Given this, most waste bins get overfilled easily because of the improper management of waste and the irregular cleaning of waste bins. The internet of things (IoT) is a remarkable modern technology that offers powerful resolutions to modernize traditional systems. In this study, the filling level of waste bins is considered in conjunction with IoT-based waste bins. This paper develops an integrated IoT-based smart bin allocation with a central monitoring system (CMS) and enhanced vehicle routing algorithm in solid waste management. This article proposes the time-dependent penalty concept to waste management authorities if these waste bins are not emptied in time after becoming full. To obtain the solution with faster execution time, an intelligent variable neighborhood search with ant colony optimization method (VNS- ACO) is developed. The proposed model is illustrated with some numerical data, and a sensitivity analysis is established with some parameters. Furthermore, the superiority of our developed VNS-ACO algorithm is established through testing on some traveling salesman problem (TSP) instances in the traveling salesman problem library (TSPLIB). Results have been compared with an advanced version of genetic algorithm (GA) and ACO methods.N

Manganese(IV) complex with a polydentate Schiff base ligand: synthesis, crystal structure, TDDFT calculation, electronic absorption and EPR spectral study

A six-coordinate Mn(IV) complex, [Mn(H2L)2] (1) [H4L = 2-methoxy-6-(tris(hydroxymethyl)methyliminomethyl)phenol], was synthesized and characterized by elemental analysis, single-crystal X-ray crystallography, FTIR, UV\u2013Vis electronic absorption, and EPR spectroscopy. The single-crystal structural determination reveals that the complex crystallizes in tetragonal space group P41212 and the tridentate Schiff base ligands are arranged in mer configuration chelating manganese, which exhibits as slightly distorted octahedral coordination sphere with a N2O4 chromophore. Weak hydrogen bonding interactions of uncoordinated hydroxyl groups result in a 2-D supramolecular structure. The UV\u2013Vis electronic absorption and IR spectral data of 1 have been compared with the results obtained by employing DFT and time-dependent density functional theory calculation using B3LYP, B3PW91, and MPW1PW91 functionals, with 6-31G (d-p) and LanL2MB basis sets. The results of these calculations are functional-dependent and, among those used, B3PW91 proved to better reproduce the experimental results

Oxalato-bridged oligonuclear complexes of cadmium(II)/lead(II) with bipyridine coligands: Synthesis, crystal structure, electronic spectra, density functional theory calculation and effect of organic compounds on the fluorescence property

A trinuclear [Cd3(ox)2(bipy)5](ClO4)2 (1) and a dinuclear [Pb2(ox)(bipy)2(NO3)2(H2O)2] (2) oxalatobridged complex, where ox = oxalate dianion and bipy = 2,20-bipyridine, have been synthesized and characterized by elemental analysis, IR spectroscopy and X-ray crystallography. Structural determination for complex 1 reveals a cationic species of C2 symmetry having two Cd(bipy)2 fragments connected through bridging oxalate to a central Cd(bipy) unit. Complex 2 is a neutral centrosymmetric species having two Pb (bipy)(NO3)(H2O) units connecting through the bridging oxalate. The dinuclear fragments through Hbonding as well as p\u2013p interactions result in a 2D supramolecular network. Since complex 1 exhibits intense fluorescence (kex = 284 nm, kem = 315, 329 and 356 nm) in methanol at room temperature with a fluorescence quantum yield Us = 0.41, it was tested in association with several aromatic compounds. The results show a pronounced fluorescence quenching and enhancement in presence of nitrobenzene and m-toluidine, respectively. The outcome from DFT calculations is discussed and compared with the experimental electronic, IR spectral and X-ray structural data

Synthesis, crystal structure, DFT/TDDFT calculation, photophysical properties and DNA binding studies of morpholino moiety ligand based two Cu(II) complexes in combination with carboxylates

Two Cu(II) compounds have been characterized by structure analyses and DFT/TD-DFT calculations. Both the complexes potentially bind with CT-DNA and corresponding binding constants are in the order of 105 M−1.</p

p-Toluate-bridged dinuclear Cu(II) complexes in combination with tridentate chelating ligand: Crystal structure, density functional theory calculation, DNA/protein binding and catecholase activity

The dinuclear Cu(II) complexes [Cu2(L1)2(mb)]⋅ClO4 (1) and [Cu2(L2)2(mb)]⋅ClO4 (2) (HL1 = 2-[(2-diethylaminoethylimino)methyl]phenol; HL2 = 2-[1-(2-diethylaminoethylimino)propyl]phenol; mb = 4-methylbenzoate) were synthesized and characterized using X-ray crystal structure analysis and spectroscopic methods. Complexes 1 and 2 are dinuclear with distorted square pyramidal Cu (II) geometries, where Schiff base coordinates with tridentate (N,N,O) chelating mode and mb bridges two metal centres. Optimized structures and photophysical properties of ligands and complexes were calculated using density functional theory and time-dependent density functional theory methods using B3LYP functional with 6-31G (d,p) and LanL2MB basis sets. Interactions of the complexes with bovine serum albumin (BSA) and human serum albumin (HSA) were studied using UV–visible absorption and fluorescence spectroscopies and the calculated values of association constants (M−1) are 1.7 × 105 (1–BSA), 5.7 × 105 (2–BSA), 1.6 × 105 (1–HSA) and 6.9 × 105 (2–HSA). Interactions of the complexes with calf thymus DNA were also investigated and the binding affinities are 1.4 × 105 and 1.6 × 105 M−1 for 1 and 2, respectively. Both complexes catalytically oxidize 3,5-di-tert-butylcatechol to 3,5-di-tert-butylbenzoquinone in the presence of molecular oxygen

Single-Ion Magnetic Behavior in Co-II-Co-III Mixed-Valence Dinuclear and Pseudodinuclear Complexes

Two CoII–CoIII mixed-valence complexes of molecularformulas [Co2(H2L)2(H2O)2][Co2(H2L)2(H2O)(m-phth)]·8(H2O) {1;H2L2–= 2-[(2-hydroxy-3-methoxybenzylidene)amino]-2-(hydroxymethyl)propane-1,3-diolato, m-phth = 1,3-benzene-dicarboxylate} and [Co4(H2L)4(H2O)2(ppda)]·2(dmf)·3.2(H2O) {2;ppda = 1,4-phenylenediacrylate; dmf = N,N-dimethyl-formamide} were synthesized and characterized by single-crys-tal X-ray diffraction and magnetic studies at low temperature.The structural determination reveals that 1 is composed of di-nuclear ion pairs, namely, a cationic [Co2(H2L)2(H2O)2]+(1+) andan anionic [Co2(H2L)2(H2O)(m-phth)]–(1–) unit. In each of these ions, the CoIIand CoIIIcenters present distorted octahedralgeometries. Compound 2 is a centrosymmetric tetranuclearcomplex comprising two symmetry-related dinuclear CoII–CoIIIunits bridged by ppda anions

Synthesis, characterization, TDDFT calculation and biological activity of tetradentate ligand based square pyramidal Cu(ii) complexes

Distorted square pyramidal complexes [Cu(L1)(H2O)]·ClO4 (1), [Cu(L2)(H2O)]·ClO4 (2) and [Cu(L3)(H2O)]·ClO4 (3) (HL1 = o-{[2-(2-aminoethylamino)ethylimino]methyl}phenol; HL2 = 2-{[2-(2-aminoethylamino)ethylimino]methyl}-6-methoxyphenol; HL3 = o-{1-[2-(2-aminoethylamino)ethylimino]ethyl}phenol) have been synthesized, and characterized by X-ray crystallography and spectroscopic analysis. All the complexes exhibit fluorescence at room temperature [λex = 267 nm, λem = 312, 329 and 357 nm, φ = 0.52 for 1; λex = 272 nm, λem = 312, 329 and 355 nm, φ = 0.46 for 2; λex = 265 nm, λem = 312, 356 and 377 nm, φ = 0.33 for 3]. The electronic structure and photophysical properties of the ligands and complexes were calculated by density functional theory (DFT) and time-dependent density functional theory (TD-DFT) methods using the B3LYP, B3PW91 and MPW1PW91 functionals, with 6-31G (d-p) and LanL2DZ basis sets. The results of TD-DFT calculations are functional-dependent and among the functionals, B3LYP was able to best reproduce the experimental results. Catecholase activity of 1-3 has been investigated using 3,5-di-tert butyl catechol (3,5-DTBC) as the model substrate and found that complexes are active for catalyzing the aerobic oxidation of 3,5-DTBC to 3,5-di-tert butyl benzoquinone (3,5-DTBQ). The compound with more distorted square pyramidal geometry shows a higher rate of catalytic activity. All the complexes have been tested for their anticancer activities in human breast (MCF7) cancer cell lines. Complexes show dose dependent suppression of cell viability with IC50 values 30, 68 and >100 μM for 1, 2 and 3, respectively. Anticancer activities of 1-3 and cisplatin were compared, and found that 1-3 were relatively less active than cisplatin