Economic Analysis of Automotive-Derived Engine-Generator Sets as Energy Conversion Systems at Small Landfills

This study is an economic analysis of the cost and longevity of modified automotive engine-generator sets as an economical method for small landfills to produce electricity. Internal combustion engines are common in landfill gas to electricity projects, but automotive engines have not been carefully studied yet represent a less expensive alternative to industrial internal combustion engines. The energy conversion system at the Watauga County Landfill in Boone, North Carolina, is composed of two 93 kW KSD Enterprises-General Motors Vortec (8.1 liters) engines attached to a Taylor Power Systems generator. Interviews with the managers of landfill projects using automotive-derived engine generator sets were conducted by phone and via email. The questions included the landfills’ cost of energy conversion systems, revenue, payback period, funding sources, operations, and engine oil and landfill gas testing methods. The findings indicate that small landfills benefit from the economics of this appropriate technology

Electronic structure and dosage correlation of 1,4-benzodiazepines

Density functional theory was used to calculate the electronic structure of 20 selected 1,4-benzodiazepine derivatives. Certain parameters were extracted from the theoretical calculations, including the proton affinity of N1, the total energy, HOMO and LUMO energies, the total positive atomic charge, dipole moment and molecular volume. These parameters were used for the correlation with the minimum effective dose acting on human. The correlation was performed by applying linear least square method. Seven parameters were found to afford good fit. Clorazepate, one of the benzodiazepines, was studied extensively, it contains a carboxylate group, which can act as an ordinary molecule or zwitterions, where the ionisable proton migrates to N1. The energy gap between the two forms was found to be strongly dependent on the solvent dielectric constant

Theoretical calculation of the exchange coupling constant in some polymeric nickel(II) complexes using range-separated functionals

The magnetic parameters (J, g) of two nickel(II) 1D polymers (Ni(en)(ox) and Ni(ox) (ampy)2; where en = ethylene diamine, ox = oxalate, ampy = 4-amino-pyridine) were calculated using 6-311+G* basis set and six range-separated DFT functionals (CAM-B3LYP, LC-BLYP, wB97, wB97X, wB97X-D3 and B2T-PLYP) together with the hybrid B3LYP method for sake of comparison. We found that the wB97, CAM-B3LYP and wB97X-D3 methods gave approximate value of J for compound 1 and the B2T-PLYP method was found to be the best method for compound 2. The g values were calculated by the coupled perturbed approach. However, we assume that a higher approximation is needed in order to give satisfactory results for g. A new equation has been proposed to relate the experimental susceptibility to the J and g parameters. The Curie-Weiss law was included in this equation resulting in a good explanation of the steep part of the experimental curve below 20 K

On the electronic structure of 5g

Quasi-relativistic SCF Xα calculations are reported for the hypothetical complexes math, EF6 (E = element 125) and the 5f1 ion NpO22+. The calculations indicate that the E(125) complexes have a 5g1 outer electronic configuration with good agreement with previous predictions. The ligand field energy diagram for g1 system in Oh sysmmetry is discussed in relation to the obtained Xα results