The impact of customer behavior models on revenue management systems

Computational Management Science - Revenue management (RM) can be considered an application of operations research in the transportation industry. For these service companies, it is a difficult...     

Gliclazide as novel carrier in construction of PVC-based La(III)-selective membrane sensor

A PVC-based sensor for La³⁺ ions based on N-[hexahydrocyclopentapyrol-2((1H)yl)amino]carbonyl]-4-methyl benzene sulfonamide (gliclazide) as a novel carrier was prepared. The electrode exhibits a Nernstian response for La³⁺ over a wide concentration range (1.0×10⁻¹-1.0×10⁻⁶ M) with a slope of 20.1 mV per decade. The limit of detection is 8.0×10⁻⁷ M. The sensor has a very short response time (<15 s) and a useful working pH range of 4.0-8.0. The proposed membrane sensor shows excellent discriminating ability towards La³⁺ ions with regard to several alkali, alkaline earth, transition and heavy metal ions. The electrode was successfully applied for determination of La³⁺ in binary mixtures.     

Novel ferrocene modified poly(amide ether amide)s and investigation of physical and thermal properties

A new diamine containing ferrocene group with preformed ether and amide units was prepared via reaction of 1,1′-ferrocenedicarbonyl chloride with two moles of 2,6-bis(5-amino-1-naphthoxy)pyridine. Polycondensation reactions of the prepared diamine with different aromatic and aliphatic diacid chlorides in the presence of trimethylchlorosilane (TMSCl) resulted in preparation of novel ferrocene modified poly(amide ether amide)s. The monomer and polyamides were characterized and the effect of trimethylchlorosilane (TMSCl) as activating agent on the polymerization reaction was studied. The physical and thermal properties of the polyamides including inherent viscosity, solubility, thermal stability and behavior, flame-retardancy and crystallinity of the polymers were studied. The polymers showed good thermal stability and flame-retardancy, and also improved solubility in polar aprotic solvents.     

Impedimetric biosensor based on bimetallic AgPt nanoparticle-decorated carbon nanotubes as highly conductive film surface

Journal of Solid State Electrochemistry - In the present study, an ultrasensitive impedimetric aptasensor for the quantitative detection of diclofenac (DCF) was fabricated based on a novel signal...     

Metabolites from the biodegradation of 1,6‐hexanediol dibenzoate,a potential green plasticizer,by Rhodococcus rhodochrous

Metabolites from the biodegradation of a potential plasticizer 1,6‐hexanediol dibenzoate in the presence of n‐hexadecane as a co‐substrate by the common soil organism Rhodococcus rhodochrous were identified using GC/MS and Fourier transform mass spectroscopy (FTMS) techniques. Trimethylsilylation of compounds from the biodegradation broth permitted detection of the following metabolites: 1‐hexadecyl benzoate, 6‐benzoyloxyhexanoic acid, 4‐benzoyloxybutanoic acid, 6‐benzoyloxyhexan‐1‐ol and benzoic acid. The presence of these metabolites was confirmed by repeating the biodegradation with 1,6‐hexanediol di[²H₅]benzoate, by measurement of their exact masses in FTMS and by comparison with available authentic materials. The results show that biodegradation of 1,6‐hexanediol dibenzoate by R. rhodochrous does not lead to the accumulation of persistent metabolites as has been reported for commercial dibenzoate plasticizers. Copyright © 2009 John Wiley & Sons, Ltd.     

Synthesis new Co–Mn mixed oxide catalyst for the production of light olefins by tuning the catalyst structure

In order to increase the catalyst activity for Fischer–Tropsch synthesis (FTS), the preparation methods of two new catalysts were studied. The chemically identical bimetallic Co–Mn/Al₂O₃ catalysts were synthesized by different synthetic methods: (a) via thermal decomposition of the complex [Co_1.33Mn_0.667(C₇H₃NO₄)₂(H₂O)₅].2H₂O ( 1 ) and (b) by the impregnation technique. The complex was characterized by the single‐crystal analysis, elemental analysis, and Fourier‐transform infrared (FT‐IR) spectroscopy. Both catalysts were characterized by powder X‐ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X‐ray spectrometry (EDS), Brunauer–Emmett–Teller (BET) specific surface area, hydrogen temperature‐programmed reduction (H₂‐TPR), and H₂‐chemisorption. The catalysts' activity was investigated for the Fischer–Tropsch synthesis in a fixed bed microreactor. Higher activity was obtained for the catalyst prepared by thermal decomposition of the inorganic precursor due to its small particle size, superior dispersion, and higher surface area. The results show that the catalyst prepared thermal decomposition has 21% ethylene, 10% propylene, and 50% C₅⁺ selectivity, while methane selectivity of this catalyst is 11% at 250°C. On the other hand, the catalyst obtained by the impregnation method displays 15% ethylene, 8% propylene, 29% C₅⁺_, and 29% methane selectivity at the same temperature.     

Dissecting the effect of anions on Hg2+ detection using a FRET based DNA probe

Many biosensors have been developed to detect Hg(2+) using thymine-rich DNA. While sensor response to various cations is often studied to demonstrate selectivity, the effect of anions has been largely overlooked. Anions may compete with DNA for metal binding and thus produce a false negative result. Anions cannot be added alone; the cation part of a salt may cause DNA compaction and other effects, obscuring the role of anions. We find that the sensitivity of a FRET-based Hg(2+) probe is independent of Na(+) concentration. Therefore, by using various sodium salts, any change in sensitivity can be attributed solely to the effect of anions. Halide salts, sulfides, and amines are strong inhibitors; anions containing oxo or hydroxyl groups (e.g. nitrate, sulfate, phosphate, carbonate, acetate, and citrate) do not interfere with Hg(2+) detection even at 100 mM concentration. Mercury hydrolysis and its diffusion into polypropylene containers can also strongly affect the detection results. We conclude that thymine-rich DNA should be useful for Hg(2+) detection in many environmental water samples.