Synthesis of Cycloalk[b]indole Bearing Spiropiperidine Derivatives

The novel heterocyclic compounds that have cycloalk[b]indole moiety bearing spiropiperidinone and spiropiperidinedione ( 3a , 3b , 3c , 5a , 5b , 8a , 8b , and 10a ) were synthesized for the first time. The synthesis of spiropiperidinone and spiropiperidinedione structures was performed by a new method. These compounds are similar to sedative and hypnotic drugs such as methyprylon, glutethimide, and thalidomide.     

Electron-hole liquid in strained SiGe layers of silicon heterostructures

The electron-hole liquid has been found in strained SiGe thin films of Si/Si_1?x Ge_x/Si heterostructures. The density and binding energy of the electron-hole liquid have been determined. Owing to the presence of internal strains in the SiGe layer, the density and binding energy are significantly smaller than the respective quantities for the electron-hole liquid in a bulk single crystal of the solid solution of the same composition. The critical temperature of the transition from the exciton gas to the electron-hole liquid is estimated using the experimental data. The Mott transition (from the exciton gas to electron-hole plasma) occurs above the critical temperatures for high excitation intensities.     

Fabrication and characterization of enhanced hydrazine electrochemical sensor based on gold nanoparticles decorated on the vanadium oxide,ruthenium oxide nanomaterials,and carbon nanotubes composites

This work describes the synthesis of mixed oxide film of vanadium and ruthenium by pulsed deposition technique on multiwall carbon nanotubes and the decoration of gold nanoparticles on the mixed film. A ternary electrocatalyst has been developed for the electrochemical oxidation of hydrazine by combining two metal oxide mixtures with Au nanoparticles. Surface morphology and chemical composition of the electrode have been examined with SEM, EDX, HRTEM, EIS, and XRD. The peak current of hydrazine increased 9 times at the AuNPs/(VOx-RuOx)/CNT/GCE compared to the bare GCE, and the peak potential shifted to negative 848 mV. Linear sweep voltammetry (LSV) and amperometric techniques revealed that the AuNPs/(VOx-RuOx)/CNT/GCE displays linear concentration range 2.5–10000 µM (LSV) and the concentration range 0.03–100 µM (amperometry). The limit of detection (LOD) is 0.5 μM and 0.1 μM at (S/N = 3) for LSV and amperometric technique, respectively. The results obtained show a good RSD% of 2.1%–3.2% and reasonable recovery of 97%–108% of hydrazine detection.     

La3Ni2O6: a new double T'-type nickelate with infinite Ni1+/2+O2 layers

New mixed-valent, Ni1+/Ni2+, metastable nickelate, La3Ni2O6, was synthesized by low-temperature reduction of La3Ni2O7 with CaH2. The crystal structure of La3Ni2O6 (space group: I4/mmm, a = 3.9686(1) A and c = 19.3154(6) A) was determined from powder neutron diffraction data by Rietveld analysis. The structure can be described as an intergrowth of LaO2 fluorite and double infinite layer (LaNiO2)2 blocks and represents the n = 2 homologue of the T'-type series Lan+1NinO2n+2. Such double T'-type structural arrangement has never been observed before. The 3d9/3d8 electronic configuration of Ni1+/Ni2+ and the presence of NiO2 infinite layers resemble electronic and structural features of the superconducting cuprates. X-ray absorption spectroscopy supports the 1+/2+ oxidation state and planar coordination of Ni in agreement with the structure determination.     

Investigating pedestrian evacuation using ant algorithms

We have presented non-linear analytical formula for fusion–fission cross-sections. This is achieved by analysing many fusion–fission experiments of the compound nuclei of atomic number range \(23 \le Z \le 146\) available in literature. Our parametrised formula can reproduce the fusion–fission cross-sections which agree well with the experiments. Our parametrisations depend on the charges and masses of the compound nuclei and fission fragments only. These results can be used as a guideline for estimating the fusion–fission cross-sections in those cases where measurements do not exist and also for studying new nuclei which are not yet explored.     

Study on bi-directional pedestrian movement using ant algorithms

A cellular automata model is proposed to simulate bi-directional pedestrian flow. Pedestrian movement is investigated by using ant algorithms. Ants communicate with each other by dropping a chemical, called a pheromone, on the substrate while crawling forward. Similarly, it is considered that oppositely moving pedestrians drop ‘visual pheromones' on their way and the visual pheromones might cause attractive or repulsive interactions. This pheromenon is introduced into modelling the pedestrians' walking preference. In this way, the decision-making process of pedestrians will be based on ‘the instinct of following'. At some densities, the relationships of velocity–density and flux–density are analyzed for different evaporation rates of visual pheromones. Lane formation and phase transition are observed for certain evaporation rates of visual pheromones.     

Construction of Hexahydropyrido[3,2‐c]carbazole and Hexahydropyrrolo[3,2‐c]carbazole Skeletons for the Synthesis of Related Indole Alkaloids

Synthesis of tetracyclic hexahydropyrido[3,2‐c]carbazoles ( 9a and 9b ) and hexahydropyrrolo[3,2‐c]carbazoles ( 13a and 13b ) structures was achieved via a new synthetic approach for the synthesis of related indole alkaloids such as deethylaspidospermidine and deethylibophyllidine. Hexahydropyrrolo[3,2‐c]carbazole structure was constructed for the first time starting from ethyl 4‐oxo‐cyclohexanecarboxylate in seven steps. Some tetrahydrocarbazole derivatives ( 4 , 5 , 6 , 7 , 11 , and 12 ) were also synthesized.     

An X-ray and DFT Computational Study on 1-（Naphthalene-2-yl）-2-（1H-pyrazol-1-yl） ethanone O-butyl Oxime

The title compound, 1-(naphthalene-2-yl)-2-(1H-pyrazol-1-yl)ethanone O-butyl oxime, I, was synthesized. The crystal and molecular structures of I were determined by IR, 1H-NMR, mass spectrum, elemental analysis and X-ray single crystal diffraction. Molecular geometry from X-ray experiment of I in the ground state was compared using the Density Functional Theory (DFT) with B3LYP/6-311G(d,p) basis set. In addition, DFT calculation, molecular electrostatic potentials (MEP) and frontier molecular orbitals of I were performed at the B3LYP/6-311G(d,p) level of the theory.     

Selective and periodic inventory routing problem for waste vegetable oil collection

We consider a biodiesel production company that collects waste vegetable oil from source points that generate waste in large amounts. The company uses the collected waste as raw material for biodiesel production. The manager of this company needs to decide which of the present source points to include in the collection program, which of them to visit on each day, which periodic routing schedule to repeat over an infinite horizon and how many vehicles to operate such that the total collection, inventory and purchasing costs are minimized while the production requirements and operational constraints are met. For this selective and periodic inventory routing problem, we propose two different formulations, compare them and apply the better performing one on a real-world problem with 36 scenarios. We generate lower bounds using a partial linear relaxation model, and observe that the solutions obtained through our model are within 3.28% of optimality on the average. Several insights regarding the customer selection, routing and purchasing decisions are acquired with sensitivity analysis.     

A sensitive determination of dopamine in the presence of ascorbic acid using a nafion-coated clinoptilolite-modified carbon paste electrode

A selective dopamine determination using a nafion-coated clinoptilolite-modified carbon paste electrode in the presence of ascorbic acid was studied. Both cyclic voltammetry (CV) and differential pulse anodic stripping voltammetry (DPASV) were used for measurements of dopamine. To improve the selectivity of the clinoptilolite-modified carbon paste electrode in presence of a high concentration of ascorbic acid, the electrode surface was coated with nafion membrane. Experimental parameters affecting the determination of dopamine, including the clinoptilolite ratio, nafion membrane thickness, preconcentration time, preconcentration solution pH, stripping solution pH and interferences are discussed. The developed sensor has a wide linear range, a low detection limit, and good stability and reproducibility. The sensor offers a good alternative to existing analytical methods for dopamine, permits a relatively short analysis time, and is simple, selective and inexpensive.