Unitary treatment of infrared singularities

Infrared singularities are treated to all orders by a unitary approximation of the time-evolution operator. The method allows the renormalization of the ultraviolet divergencies. It has been tested in QED bremsstrahlung processes.     

Exploring the intra-frame energy conservation capabilities of the horizontal simple packing algorithm in IEEE 802.16e networks: an analytical approach

The power saving capabilities of the mobile devices in broadband wireless networks constitute a challenging research topic that has attracted the attention of researchers recently, while it needs to be addressed at multiple layers. This work provides a novel analysis of the intra-frame energy conservation potentials of the IEEE 802.16e network. Specifically, the power saving capabilities of the worldwide interoperability for microwave access downlink sub-frame are thoroughly studied, employing the well-known simple packing algorithm as the mapping technique of the data requests. The accurate mathematical model, cross-validated via simulation, reveals the significant ability to conserve energy in this intra-frame fashion under different scenarios. To the best of our knowledge, this is the first work providing intra-frame power-saving potentials of IEEE 802.16 networks. Additionally, this is the first study following an analytic approach.     

Enforcing Effective Rates for Packet-Level QoS Control in IP Networks: Theory and Validation Based on Real Traffic Data

This paper presents experimental results aiming at underpinning a traffic engineering framework for traffic control and resource management in IP-based networks, which has significant theoretical qualities. Initially, the paper reviews the major components of a packet level traffic control framework: (a) a general traffic shaping algorithm for effective rate enforcement (b) mechanisms for aggregating, splitting and policing streams shaped with this algorithm, and (c) a calculus for quantitative end-to-end QoS. Following the illustration of the theoretical concepts the paper focuses on aspects pertaining to the applicability of the framework. Specifically, we study the impact of the shaping delay and we provide insight into the issue of enforcing effective rates to traffic streams. These studies take into account results from simulating the shaping algorithm, which are based on analyzing, processing and simulating real traffic traces collected from an HTTP server. Moreover, traffic modeling conclusions related to the proposed shaping algorithm, are derived and presented.     

Chemiluminescent evaluation of peroxide value in olive oil

A method is described for the evaluation of the peroxide value (PV, meq. O₂ kg⁻¹) in olive oil. The method is based on the chemiluminogenic energy-transfer reaction of bis(2,4,6-(trichlorophenyl)oxalate (TCPO) with hydrogen peroxide or total peroxides in the presence of Mn(II) as catalyst and 9,10-dimethylanthracene as fluorophore. The procedure developed allows the evaluation of PV within the range of 0.6-100 meq. O₂ kg⁻¹ (CL intensity = 1.76 × PV (meq. O₂ kg⁻¹) + 23.2, r² = 0.994, n = 9) and relative standard deviation within the range 1-5% by using a simple manual measurement.     

New refractive index method for measurement of alcoholic strength of small volume samples

A study of the correlation between the refractive index (RI) method adopted by the European Community (EC) and a reference pycnometric method for the measurement of alcoholic strength was undertaken. A new RI method with greater accuracy was also developed. Alcoholic strength measured by both RI methods presented a relatively constant negative bias compared with results by the pycnometric method. Differences found between the RI methods and the pycnometric method were 0.6-0.9% (v/v) when RI was measured by the EC method and 0.4-0.5% (v/v) when the new RI method developed in our laboratory was used. Statistical analysis of the results showed that differences between the 2 RI methods and the reference pycnometric method were statistically significant at the 95% confidence level. Correction factors are proposed for the accurate use of measurements of alcoholic strength obtained for small volume samples.     

Randwertprobleme und Methode der inneren Parallelen: eine gemeinsame Erweiterung zweier Ungleichungen von Pólya

Zusammenfassung Die Methode der inneren Parallelen von Makai und Pólya wird hier auf das Randwertproblem (3) angewendet. Die sich ergebenden Schranken (11) und (11) für das FunktionalQ() enthalten als Grenzfälle die von Pólya [9] erhaltenen Schranken (2) und (1) für die Torsionssteifigkeit (Fall=0) bzw. für den Grundton einer Membran (Fall ₁.

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Summary We apply here the method of interior parallels of Makai and Pólya to the boundary value problem (3). The resulting bounds (11) and (11) for the functionalQ() contain as limit cases the bounds (2) and (1) obtained by Pólya [9] for torsional rigidity (case=0) and for the lowest eigenfrequency of a membrane (case ₁).

     

Some applications of the adjoint to lattice regular measures

Summary In this paper, the principal role is played by the adjoint of a certain bounded linear mapping, whose domain and range are Banach spaces of lattice regular measures. First, the general properties of the adjoint are investigated and it is shown, in particular, how this mapping yields generalizations of many results in Stone-ech Theory, especially matters related to embeddibility. Then, the investigation continues with the mapping properties of the adjoint, and a variety of applications is given to Topological Measure Theory, strong measure repleteness, tightness, and relative compactness.     

Visible light photocatalysis with platinized rutile TiO2 for aqueous organic oxidation

Platinized rutile TiO2 samples containing varying concentrations of Pt were synthesized using Kemira (KE, BET surface area 50 m2/g, from Finland), and Toto HT0270 (HT, BET surface area 2.9 m2/g, from Japan) as the starting materials by solution mixing followed by sintering the precursors. Photocatalytic activities were established for phenol oxidation under visible light (wavelength >400 nm). Our results show optimal performance for 8 wt % platinized KE (8 wt % Pt/KE) and (1/2) wt % platinized HT rutile samples. The specific roles of O2 and visible light were examined using the 8 wt % Pt/KE sample in either N2 gas ambient or no illumination. Separately, 8 wt % platinized SiO2 was tested to compare its performance with that of platinized rutile TiO2. Several other chemicals containing different functional groups (formic acid, salicylic acid, 4-chlorophenol, 2,4,6-trichlorophenol, diethyl phosphoramidate) were selected for photooxidation tests with (1/2) wt % platinized HT rutile. X-ray diffraction reveals Pt metal clusters segregating on the surface of rutile TiO2 particles with increasing Pt weight percent. The Pt cluster surface area broadly increases, while the effective optical band gap steadily decreases with platinization of the rutile samples. These results suggest that Pt clusters on the surface of rutile TiO2 particles serve to mediate electron transfer from rutile to O2, thus facilitating photooxidation of organic chemicals.     

157-nm Laser ablation of polymeric layers for fabrication of biomolecule microarrays

A new methodology for protein microarray fabrication is proposed based on the ablation of polymer film using laser at 157 nm (F₂). The polymer has been selected among others with the criterion of negligible protein adsorption. Improved results have been obtained by pretreatment of the polymer surface with an inert protein. The use of 157-nm laser radiation allowed very good depth control during the polymeric layer ablation process. In addition the importance of laser ablation at 157 nm is based on the fact that irradiated surfaces indicate limited chemical change due to the fact that laser ablation at 157 nm is only photochemical, thus avoiding excessive surface heating and damage. Results of protein microarray fabrication are presented to illustrate the viability of the proposed method.     

Stability,monotonicity and invariant quantities in general polling systems

Consider a polling system withK1 queues and a single server that visits the queues in a cyclic order. The polling discipline in each queue is of general gated-type or exhaustive-type. We assume that in each queue the arrival times form a Poisson process, and that the service times, the walking times, as well as the set-up times form sequences of independent and identically distributed random variables. For such a system, we provide a sufficient condition under which the vector of queue lengths is stable. We treat several criteria for stability: the ergodicity of the process, the geometric ergodicity, and the geometric rate of convergence of the first moment. The ergodicity implies the weak convergence of station times, intervisit times and cycle times. Next, we show that the queue lengths, station times, intervisit times and cycle times are stochastically increasing in arrival rates, in service times, in walking times and in setup times. The stability conditions and the stochastic monotonicity results are extended to the polling systems with additional customer routing between the queues, as well as bulk and correlated arrivals. Finally, we prove that the mean cycle time, the mean intervisit time and the mean station times are invariant under general service disciplines and general stationary arrival and service processes.