Fair Class-Based Downlink Scheduling with Revenue Considerations in Next Generation Broadband Wireless Access Systems

The success of emerging Broadband Wireless Access Systems (BWASs) will depend, among other factors, on their ability to manage their shared wireless resources in the most efficient way. This is a complex task due to the heterogeneous nature, and hence, diverse Quality of Service (QoS) requirements of different applications that these systems support. Therefore, QoS provisioning is crucial for the success of such wireless access systems. In this paper, we propose a novel downlink packet scheduling scheme for QoS provisioning in BWASs. The proposed scheme employs practical economic models through the use of novel utility and opportunity cost functions to simultaneously satisfy the diverse QoS requirements of mobile users and maximize the revenues of network operators. Unlike existing schemes, the proposed scheme is general and can support multiple QoS classes with users having different QoS and traffic demands. To demonstrate its generality, we show how the utility function can be used to support three different types of traffic, namely best-effort traffic, traffic with minimum data rate requirements, and traffic with maximum packet delay requirements. Extensive performance analysis is carried out to show the effectiveness and strengths of the proposed packet scheduling scheme.     

2-Aminophenyl diphenylphosphinite as an easily accessible ligand for heterogeneous palladium-catalyzed Suzuki-Miyaura reaction in water in the absence of any organic co-solvent

In this article, we have introduced application of 2-aminophenyl diphenylphosphinite as an easily accessible ligand for heterogeneous palladium-catalyzed Suzuki-Miyaura reaction in water in the absence of any organic co-solvent. By using 2-aminophenyl diphenylphosphinite as a ligand and Pd(OAc)₂ as the pre-catalyst, structurally different aryl halides (I, Br, Cl) were reacted efficiently with phenylboronic acid in water to produce their corresponding biphenyl products in good to excellent yields under heterogeneous conditions. The catalyst is recyclable and was recycled for seven runs for the reaction of bromobenzene with phenylboronic acid without appreciable loss of its catalytic activity.     

Selective recognition of organic pollutants in aqueous solutions with composite imprinted membranes

In this work, thin-layer composite membranes imprinted with desmetryn or ibuprofen were prepared and studied for selective recognition of the template compounds in aqueous solutions. The imprinted membranes were developed using photoinitiated copolymerization of 2-acrylamido-2-methyl-1-propane sulphonic acid and N,N'-methylene-bis-acrylamide, in the presence of desmetryn or via copolymerization of dimethylaminoethyl methacrylate, and trimethylopropane trimethacrylate, in the presence of ibuprofen, followed by deposition of the imprinted layers on the surface of porous microfiltration supports of various chemical nature. Atomic force microscopy was used to study the surface morphological characteristics of the developed membranes. Molecularly recognition properties of imprinted membranes were evaluated by measuring their capability to bind the template molecules from polycomponent aqueous solutions. It was shown that obtained membranes may be used as selective recognising elements of portative differential capacitor sensor device for express monitoring of the target molecules in water. The sensor performance is based on registration of the alteration of dielectric permeability of composite imprinted membrane at selective binding of template molecules, when the analyzed feed solution is filtered through the membrane sample.     

Quantum deficits and correlations of two superconducting charge qubits

Motivated by recent experiments [Y.A. Pashkin, T. Yamamoto, O. Astafiev, Y. Nakamura, D.V. Averin, J.S. Tsai, Nature 421 (2003) 823] that show coherent oscillations of two superconducting qubits system, we consider a system of two charge qubits coupled to a common stripline microwave resonator. We discuss the separable and entangled behavior as well as the quantum and classical information deficits. Numerical computation of these quantities is performed for several regimes. We find that for less entangled states the partner can extract much more information by means of classical communication and local operations.     

A one-pot, efficient, and odorless synthesis of symmetrical disulfides using organic halides and thiourea in the presence of manganese dioxide and wet polyethylene glycol (PEG-200)

Primary, secondary, tertiary, allylic, and benzylic halides are converted efficiently into symmetric disulfides in high yields using thiourea as the sulfur atom source. The reactions are odorless and are performed at 30-35 °C in wet PEG-200 using MnO₂ as an oxidant.     

Plumbagin,a Naturally Occurring Naphthoquinone: Its Isolation,Spectrophotometric Determination in Roots,Stems, and Leaves in Plumbago Europaea L.

A new method for isolation and spectrophotometric determination of plumbagin is presented. Plumbagin was isolated by thin layer chromatography (TLC) and column chromatography (CC) techniques, as an orange tinged yellow long crystalline substances. Plumbagin exhibits two absrop-tion maxima at 410 and 510 nm. Stability of the color, pK_a value, and the effect of pH were studied. Beer's law is obeyed over the range 0.9-45 ppm. The method is applied to the determination of plumbagin in roots, stems, and leaves of Plumbago europaea L. plant.     

Aluminium dodecatungstophosphate (AlPW12O40) as a highly efficient catalyst for the selective acetylation of -OH, -SH and -NH2 functional groups in the absence of solvent at room temperature

AlPW12O40 was found to be an effective catalyst for the selective acetylation of alcohols, thiols, and amines in the absence of solvent at room temperature.     

A density functional study of N NQR parameters of imidazole derivatives and extrapolation to PfHRP2–Fe-PPIX complex

In this paper, density functional theory (DFT) was used to calculate ¹⁴N nuclear quadrupole coupling constants (NQCC), χ, and asymmetry parameters, η, for a series of imidazole derivatives: imidazole, 5-methylimidazole and histidine. These calculations were carried out with the PW91P86 method via the Gaussian 98 package. A systematic theoretical investigation of the different environmental effects on (χ, η) values of amino ¹⁴N1 and imino ¹⁴N2 of imidazole ring of these compounds, reveals that the local surrounding of nitrogen atoms play an important role in determining their χ and η values. Our calculations in solution show that adding explicit solvent molecules to the polarizable continuum model (PCM) has a strong effect on (χ, η) values, thereby indicating that for long-range effects, PCM, is not sufficient to describe the whole solvent effects. We also evaluate the influence of [Fe³⁺ (S = 1/2)] on the (χ, η) values of proximal and remote nitrogens of an axial ligand and compare with those of free ligands. The results show that Fe³⁺ has a strong effect on the (χ, η) values of proximal nitrogen unlike remote nitrogen. Finally, our results predict (χ = 1.56 MHz, η = 0.690) for proximal nitrogen and (χ = 2.75 MHz, η = 0.169) for remote nitrogen in PfHRP2–Fe³⁺-PPIX complex.     

Synthesis of 5′-azido- and 5′-amino-2′,5′-dideoxynucleosides from quinazoline-2,4(1H,3H)-diones

Quinazoline-2,4(1H,3H)-diones 4 were silylated and condensed with methyl 5-azido-2,5-dideoxy-3-O-(4-methylbenzoyl)-α,β-D-erythro-pentofuranoside (3) using trimethylsilyl trifluoromethanesulfonate (TMS triflate) as the catalyst to afford the corresponding 5′-azidonucleosides 5 . 1-(5-Azido-2,5-dideoxy-α-D-erythro-pentofuranosyl)quinazoline-2,4(1H,3H)-diones 6 and the corresponding β anomers were obtained by treating 5 with sodium methoxide in methanol at room temperature. 6-Methyl-1-(5-amino-2,5-dideoxy-β-D-erythro-pentofuranosyl)quinazoline-2,4(1H,3H)-dione (8) was obtained by treatment of the corresponding azido derivative 7 with triphenylphosphine in pyridine, followed by hydrolysis with ammonium hydroxide.     

Determination of nanogram amounts of bromide and chloride by molecular emission cavity analysis based on gallium halide emission

By measuring the GaBr emission enhanced by iodide at 350 nm in a carbon cavity heated by a hydrogen/argon flame, 0–60 ng of bromide is determined with a detection limit of 0.5 ng μl^?1. In a similar way, gallium (0–20 ng) can be determined with a detection limit of 0.15 ng μl^?1. Interferences are reported. Chloride (0–1200 ng) is determined by means of GaCl emission; the detection limit is 50 ng μl^?1.