A note on efficient signaling of bargaining power

Strategic delay and restricted offers are two modes of signaling bargaining power in alternating offers bargaining games. This paper shows that when both modes are available, the best signaling strategy of the “strong” type of the informed player consists of a pure strategic delay followed by an offer on the whole pie. There is no signaling motivation for issue-by-issue bargaining when the issues are perfectly substitutable. Received: July 1996/Final version: August 1999     

General properties of Bertrand curves in Riemann–Otsuki space

In this paper we studied the general properties of Bertrand curves and their characterizations in Riemann–Otsuki space.     

Poly(cyclohexene oxide)/clay nanocomposites by photoinitiated cationic polymerization via activated monomer mechanism

Poly(cyclohexene oxide) (PCHO)/clay nanocomposites were prepared by in situ photoinitiated activated monomer cationic polymerization. The polymerization of cyclohexene oxide through the interlayer galleries of the clay can provide distribution of the clay layers in the polymer matrix homogenously and results in the formation of PCHO/clay nanocomposites. The exfoliated structures were characterized by X‐ray diffraction spectroscopy, thermogravimetric analysis, transmission electron microscopy, and atomic force microscopy. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 5328–5335, 2009     

Contribution of nitrification and denitrification to nitrous oxide emissions from soils after application of biogas waste and other fertilizers

The attribution of nitrous oxide (N₂O) emission to organic and inorganic N fertilizers requires understanding of how these inputs affect the two biological processes, i.e. denitrification and nitrification. Contradictory findings have been reported when the effects of organic and inorganic fertilizers on nitrous oxide emission were compared. Here we aimed to contribute to the understanding of such variation using ¹⁵N‐labelling techniques. We determined the processes producing N₂O, and tested the effects of soil moisture, N rates, and the availability of organic matter. In a pot experiment, we compared soil treated with biogas waste (BGW) and mineral ammonium sulphate (Min‐N) applied at four rates under two soil moisture regimes. We also tested biogas waste, conventional cattle slurry and mineral N fertilizer in a grassland field experiment. During the first 37 days after application we observed N₂O emissions of 5.6 kg N₂O‐N ha^?1 from soils supplied with biogas waste at a rate of 360 kg N ha^?1. Fluxes were ca. 5‐fold higher at 85% than at 65% water holding capacity (WHC). The effects of fertilizer types and N rates on N₂O emission were significant only when the soil moisture was high. Organic fertilizer treated soils showed much higher N₂O emissions than those receiving mineral fertilizer in both, pot and field experiment. Over all the treatments the percentage of the applied N emitted as N₂O was 2.56% in BGW but only 0.68% in Min‐N. In the pot experiment isotope labelling indicated that 65–95% of the N₂O was derived from denitrification for all fertilizer types. However, the ratio of denitrification/nitrification derived N₂O was lower at 65% than at 85% WHC. We speculate that the application of organic matter in conjunction with ammonium nitrogen first leads to a decrease in denitrification‐derived N₂O emission compared with soil receiving mineral fertilizer. However, at later stages when denitrification becomes C‐limited, higher N₂O emissions are induced when the soil moisture is high. Copyright © 2009 John Wiley & Sons, Ltd.     

Derivation of Korteweg–de Vries flow equations from nonlinear Schrödinger equation

We perform a multiple scales analysis on the nonlinear Schrödinger (NLS) equation in the Hamiltonian form together with the Hamiltonian function. We derive, as amplitude equations, Korteweg–de Vries (KdV) flow equations in the bi-Hamiltonian form with the corresponding Hamiltonian functions.     

Legendre polynomial solutions of high-order linear Fredholm integro-differential equations

In this study, a Legendre collocation matrix method is presented to solve high-order Linear Fredholm integro-differential equations under the mixed conditions in terms of Legendre polynomials. The proposed method converts the equation and conditions to matrix equations, by means of collocation points on the interval [−1, 1], which corresponding to systems of linear algebraic equations with Legendre coefficients. Thus, by solving the matrix equation, Legendre coefficients and polynomial approach are obtained. Also examples that illustrate the pertinent features of the method are presented and by using the error analysis, the results are discussed.     

Determination of low level nitrite and nitrate in biological, food and environmental samples by gas chromatography-mass spectrometry and liquid chromatography with fluorescence detection

Gas chromatography-mass spectrometry (GC-MS) and liquid chromatography with fluorescence detection (LC-FL) methods have been proposed for the determination of low level nitrite and nitrate in biological, food and environmental samples. The methods include derivatization of aqueous nitrite with 2,3-diaminonaphthalene (DAN), enzymatic reduction of nitrate to nitrite, extraction with toluene and chromatographic analyses of highly fluorescent 2,3-naphthotriazole (NAT) derivative of nitrite by using GC-MS in selected-ion-monitoring (SIM) mode and LC-FL. Nitrite and nitrate ions in solid samples were extracted with 0.5 M aqueous NaOH by sonication. The recoveries of nitrite and nitrate ions based on GC-MS and LC-FL results were 98.40% and 98.10% and the precision of these methods, as indicated by the relative standard deviations (RSDs) were 1.00% for nitrite and 1.20% for nitrate, respectively. The limits of detection of the GC-MS in SIM mode and LC-FL methods based on S/N = 3 were 0.02 and 0.29 pg/ml for nitrite and 0.03 and 0.30 pg/ml for nitrate, respectively.     

Determination of selected polychlorinated biphenyls in water samples by ultrasound-assisted emulsification-microextraction and gas chromatography-mass-selective detection

Ultrasound-assisted emulsification-microextraction (USAEME) procedure was developed for the determination of selected polychlorinated biphenyls (PCBs) in 10 mL of water samples by gas chromatography-mass-selective detection. After determination of the most suitable solvent and extraction time, several other parameters including solvent volume, centrifugation time and ionic strength of the sample were optimized using a 2³ factorial experimental design. The optimized USAEME procedure used 200 μL of chloroform as extraction solvent, 10 min of extraction with no ionic strength adjustment at 25 °C and 5 min of centrifugation at 4000 rpm. The limits of detection ranged from 14 ng L⁻¹ (for PCB153) to 30 ng L⁻¹ (for PCB101). Recoveries of PCBs from fortified distilled water are over 80% for three different fortification levels between 0.1 and 5 μg L⁻¹ and relative standard deviations of the recoveries are below 10%. The performance of the proposed method was compared with those involving traditional liquid-liquid extraction (LLE) and solid phase extraction (SPE) on the real water samples (i.e., tap and well water as well as domestic and industrial wastewaters, etc.) and comparable efficiencies were obtained. The proposed USAEME procedure has been demonstrated to be viable, simple, rapid and easy to use for residue analysis of PCBs in water samples.     

Selective metal sensor phthalocyanines bearing non-peripheral functionalities: Synthesis,spectroscopy, electrochemistry and spectroelectrochemistry

A novel alcohol-soluble ionophore ligand and its non-peripherally tetrasubstituted functional 1,8,15,22-tetrakis(6-hydroxyhexylsulfanyl) metallophthalocyanines M[Pc(α-SC₆H₁₂OH)₄] (M = Cu(II), Zn(II), Co(II); Pc = phthalocyanine) are reported. The aggregation and cation binding behaviors of the phthalocyanine compounds in the presence of soft Ag^I and Pd^II metal ions were investigated by using UV–Vis spectroscopy. The new compounds have been characterized by elemental analysis, IR, ¹H, ¹³C NMR, UV/Vis spectroscopy, ESI and MALDI–TOF–MS mass spectra. Voltammetric and in-situ spectroelectrochemical studies show that while copper and zinc phthalocyanine complexes give well-defined ring-based reduction and oxidation processes, the cobalt phthalocyanine gives both metal-based and ring-based redox processes which have reversible and diffusion controlled character.     

On Darboux helices in Euclidean 4‐space

The notion of Darboux helix in Euclidean 3‐space was introduced and studied by Yayl? et al. 2012. They show that the class of Darboux helices coincide with the class of slant helices. In a special case, if the curvature functions satisfy the equality κ² + τ² = constant, then these curves are curve of the constant precession. In this paper, we study Darboux helices in Euclidean 4‐space, and we give a characterization for a curve to be a Darboux helix. We also prove that Darboux helices coincide with the general helices. In a special case, if the first and third curvatures of the curve are equal, then Darboux helix, general helix, and V₄‐slant helix are the same concepts.