Symmetric Tardos fingerprinting codes for arbitrary alphabet sizes

Fingerprinting provides a means of tracing unauthorized redistribution of digital data by individually marking each authorized copy with a personalized serial number. In order to prevent a group of users from collectively escaping identification, collusion-secure fingerprinting codes have been proposed. In this paper, we introduce a new construction of a collusion-secure fingerprinting code which is similar to a recent construction by Tardos but achieves shorter code lengths and allows for codes over arbitrary alphabets. We present results for ‘symmetric’ coalition strategies. For binary alphabets and a false accusation probability , a code length of symbols is provably sufficient, for large c ₀, to withstand collusion attacks of up to c ₀ colluders. This improves Tardos’ construction by a factor of 10. Furthermore, invoking the Central Limit Theorem in the case of sufficiently large c ₀, we show that even a code length of is adequate. Assuming the restricted digit model, the code length can be further reduced by moving from a binary alphabet to a q-ary alphabet. Numerical results show that a reduction of 35% is achievable for q = 3 and 80% for q = 10.      

Organosilane self-assembled monolayer growth from supercritical carbon dioxide in microstructured optical fiber capillary arrays

Microstructured optical fibers form a new class of extreme aspect ratio templates that are well-suited for precise, designed spatial organization of materials and molecules at dimensions down to the nanoscale. The extreme aspect ratios of the nanoscale to microscale pores in the templates necessitates new approaches to fabrication of nanowires, nanotubes, and self-assembled monolayers within them. High-pressure fluids, which have lower viscosities than liquids and no surface tension, are well-suited for penetrating such extreme aspect ratio capillaries. Here we report an approach to fabricating self-assembled monolayers within microstructured optical fibers using near supercritical or supercritical carbon dioxide. An AFM-based "shaving" technique has been developed to characterize the monolayers formed in capillaries that are too small to allow for characterization by conventional approaches.     

Nonisocyanate based polyurethane/silica nanocomposites and their coating performance

A series of silica nano-particles with different size were prepared by sol–gel technique, then surface modification by using cyclic carbonate functional organoalkoxysilane (CPS) was performed. Various amounts of carbonated silica particles directly added into carbonated soybean oil (CSBO) and carbonated polypropylene glycol (CPPG) resin mixture to prepare polyurethane–silica nanocomposite coating compositions by nonisocyanate route using an aliphatic diamine as a curing agent. Cupping, gloss, impact, and taber abrasion tests were performed on aluminum panels coated with those nano-composite formulations and tensile tests, thermogravimetric and SEM analyses were conducted on the free films prepared from the same coating formulations. An increase in abrasion resistance of CSBO-CPPG resin combination with the addition of silica was observed. In addition, the maximum weight loss of CSBO-CPPG resin combination was shifted to higher temperatures with incorporation of silica nano-particles The positive effect of modified silica particles on thermal stability of CSBO-CPPG system could be explained in such a way that PPG chains are able to disperse particles in the medium throughout the interactions between ether linkages and silanol groups.     

Thermodynamic analysis of the copper production step in a copper–chlorine cycle for hydrogen production

The hybrid copper–chlorine (Cu–Cl) thermo/electrochemical cycle for decomposing water into its constituents is a novel method for hydrogen production. The process involves a series of closed-loop chemical reactions. The cycle is assumed driven in an environmentally benign manner using nuclear energy. The cycle involves five steps of which three are thermally driven chemical reactions and one has an electrochemical reaction. In the present study, the electrochemical reaction, copper (Cu) production step, is described with its operational and environmental conditions, and analyzed thermodynamically. Various parametric studies are carried out on energetic and exergetic aspects of the step, considering variable reaction and reference-environment temperatures. At a reaction temperature of 45 °C, the reaction heat of the Cu production step is 140,450 kJ/kmol H₂. At a constant reaction temperature of 45 °C, the exergy destruction of the step varies between 50 kJ/kmol H₂ and 7000 kJ/kmol H₂ when the reference-environment temperature increases from 0 °C to 30 °C. At a reaction temperature of 45 °C and a reference-environment temperature of 25 °C, the exergy efficiency of this step is 99% and decreases with increasing reference-environment and/or reaction temperatures.     

Application of Impedimetric and Voltammetric Genosensor for Detection of a Biological Warfare: Anthrax

A strategy for the detection of anthrax, which is a potential biological weapon by using an electrochemical genosensing technology, is investigated. An alkanathiol‐linked or unlabeled capture probe related to B. anthracis is immobilized onto gold or graphite electrode surface. A 101‐mer anthrax target is used for hybridization. The extent of hybridization between probe and target sequences is determined by using differential pulse voltammetry (DPV) and electrochemical impedance spectrometry (EIS). EIS analysis are based on electron transfer resistance (R_ct) in the presence of [Fe(CN)₆]^3?/4? and DPV measurements are based on transduction of both guanine oxidation and Meldola's blue (MDB) reduction signal as hybridization indicator. The response of the probe‐modified electrodes which was interacted with a noncomplementary sequence was the same as the responses of probe‐modified surface and proved the specifity of the hybridization with the target. According to these results the developed genosensors based on EIS and DPV techniques can be employed for rapid and selective detection of B. anthracis.     

Resonant tunneling properties of inverted Morse double quantum barrier

We study resonant tunneling characteristics of inverted Morse double quantum barrier structures. The effect of electric bias and structure parameters is calculated by using non-equilibrium Green's function method. Results for the transmission coefficients are compared with the structure parameters. Our results show that the widths of the wells and heights of barriers have a significant effect on the transmission properties. We found that the resonant peak of the transmission coefficient decreases with increasing electric field bias. Moreover, resonant energy level increases with increasing barrier height and increasing width parameters.     

Bright,dark optical and other solitons to the generalized higher-order NLSE in optical fibers

In this paper, we study the generalized higher-order nonlinear Schrödinger equation analytically. We use two integral schemes for conducting this study. Dark, bright, combined dark–bright optical, singular soliton, soliton-like and trigonometric function solutions are successfully constructed. We give the constraint conditions for the existence of valid solutions. The 2D, 3D and the contour graphs for the dark and bright solitons are plotted.     

Dynamic phase transition in the kinetic spin-2 Blume–Emery–Griffiths model in an oscillating field

We extend our recent paper [M. Keskin, O. Canko, M. Erta?, J. Exp. Theor. Phys. (Sov. Phys. JETP) 105 (2007) 1190.] to present a study, within a mean-field approach, the stationary states of the kinetic spin-2 Blume–Emery–Griffiths model in the presence of a time-dependent oscillating magnetic field by using the Glauber-type of stochastic dynamics. We found 20 fundamental types of dynamic phase diagrams where exhibit more complex and richer phase diagrams than our recent paper. Especially, the obtained dynamic phase diagrams show the dynamic triple, quadruple and dynamic double critical end points besides dynamic tricritical points that depending on interaction parameters. The phase diagrams also exhibit a disordered (d) and the ferromagnetic-2 (f₂) phases, and the f₂+d, f₂+fq, fq+d, f₂+f₁+fq and f₂+fq+d, where f₁ are fq the ferromagnetic-1 and ferroquadrupolar or simply quadrupolar phases respectively, coexistence phase regions that strongly depend on interaction parameters.