Numerical study of air staging in a coke oven heating system

The air staging to combustion approach introduced to a coke oven heating system as a primary method of nitrogen oxide (NO) formation reduction is considered in this paper. To numerically investigate the thermal and prompt NO formation, a heating flue model representing the most popular Polish coke oven battery was used. The model was developed and experimentally validated as a transient coupled model for the representative heating flue and the two coke ovens. Numerical simulations were performed to estimate the amount of NO passing into the atmosphere during the operation of such a heating system with and without the secondary air inlets. Various strategies for the secondary air distribution along the flue gas flow as well as the secondary air velocity were studied. The results of the numerical investigation demonstrated the substantial positive effect of the considered air staging on NO formation reduction.     

Organizing Security Patterns

Early software systems communicated in predefined ways, so they were easy to secure. However, the old ways of ensuring software systems' security and reliability are inadequate on the Internet. Although building secure systems is difficult, retrofitting existing systems to introduce security is even harder. For example, sendmail, the most popular mail transfer agent, has been plagued with security vulnerabilities ever since the Morris worm first exploited it in 1988.     

Estradiol-mimetic probes. Preparation of 17 alpha-(6-aminohexynyl)estradiol biotin, fluorescein and acridinium conjugates

3-O-tert-Butyldimethylsilyl-17 alpha-(6-mesyloxyhexynyl)estradiol was converted to the azide in 60-70% yield with NaN3/DMPU, then reduced to the corresponding amine (> 95% yield). Acylation with the N-hydroxysuccinimide esters of biotin, 5-carboxyfluorescein and 10-(3-sulfopropyl)-N-tosyl-N-(3- carboxypropyl)acridinium-9-carboxamide gave the title conjugates. The KDs of the tracers with an estradiol antibody ranged from 97-197 nM.     

O-(fluoresceinylmethyl)hydroxylamine (OFMHA): a fluorescent reagent for detection of damaged nucleic acids

5- and 6-O-(Fluoresceinylmethyl)hydroxylamine (OFMHA, 5a, b) were prepared from the corresponding bis-pivaloyl-protected hydroxymethylfluoresceins (1a, b) in 50-70% yield. The hydroxylamine derivatives reacted smoothly with the abasic sites present in acid/heat stressed calf thymus DNA.     

Accompanying Elements in Sphalerite in Pyrometallurgical Process of Zinc and Lead Production

The primary raw materials used in the imperial smelting process (ISP) are Zn and Pb concentrates. Dust generated in the course of ISP is recycled. The identified sphalerite grains indicate the presence of Pb, Fe, Cd sulfides, Fe and Zn oxides, as well as accompanying elements (Ca, Mn, Cu, As, Se, Ag, Sn, and Sb). The tests performed have demonstrated the differentiation in the content of the accompanying elements in sphalerite present in both charge mixture as well as in dusts. This differentiation may be an indication of the migration of these element from sphalerite to the products or to waste during the process.     

Comparison study of macro and micro scale AC and DC conductivity measurements with Impedance Spectroscopy and Atomic Force Microscopy techniques applied in PBZT ceramics

Ferroelectric materials systematically enter into the structure of microelectronic devices. The ability to increase the packing density of the ferroelectric structures, and thus the piezoelectric coefficients of the final device, is primarily limited by the fact that such tiny ferroelectric structures may not preserve their microscopic properties at macroscopic scale. A problem of current interest in ferroelectric research is to get to know how to modify the domain structure and the piezoelectric properties of the material, if the polycrystalline material consists of grains and grain boundaries, in which electrical properties differ significantly. In this paper, we have combined the Impedance Spectroscopy (IS), as a method for detecting such inequality in the form of separated impedances, and Atomic Force Microscopy (AFM), as techniques for direct local engineering and investigation of grain and grain boundaries conductivity. We would like to present hitherto unreported connection between values of electrical parameters obtained by both methods.     

Urban Computing and Mobile Devices

Learn about projects on participant-environment interaction, the leveraging of information from mobile sensors, user authentication, and urban computing navigation.     

Adsorption of Homopolymer Chains on a Strip-Patterned Surface: A Monte Carlo Study

In this study we investigated the process of chemisorption of polymers on solid surfaces. The formation of a strongly adsorbed polymer film was studied by Monte Carlo simulations. The adsorbing planar surface was patterned with strip-like repulsive sites. The polymer chains were represented by a sequence of schematically constructed objects (united atoms) and we considered star-branched macromolecules with f = 3 arms of equal length. The chains were studied at good solvent conditions and thus the excluded volume was the only potential of interaction between the polymers. A Metropolis-like sampling algorithm was employed in order to calculate the properties of the adsorbed chains. The influence of the chain length, the system density and the type of the pattern on the adsorbing surface on size of chains and the structure of the polymer film were determined and discussed. We found that the roughness of the polymer film surface depends non-monotonics on the number of polymer beads in the system. The shape of this surface reflects the pattern imposed on the substrate.     

Electrochemical preparation of composite coatings of 3,4-etylenodioxythiophene (EDOT) and 4-(pyrrole-1-yl) benzoic acid (PyBA) with heteropolyanions

The possibility of incorporating 4-(pyrrole-1-yl) benzoic acid, (PyBA), and heteropolyacids (SiMo₁₂) during the electrodeposition of poly (3,4-ethylenedioxythiophene), PEDOT, is demonstrated in the paper. The formed novel composite material was applied on the electrode surface as a moderately thin (ca. 0.9–1 μm thick) PEDOT/PyBA/SiMo₁₂ coating. The physicochemical identity of our composite coating was established with the use of electrochemical, spectroscopic, and microscopic techniques. The fact that carboxylate-containing PyBA units link with positively charged and PEDOT structures tend to improve the overall stability and adherence of composite coatings to glassy carbon and stainless steel. The PEDOT/PyBA composite serves as a stable host matrix for large negatively charged silicium heteropolymolybdates inorganic species. Consequently, due to the formation of denser polymeric structures and due to the existence of electrostatic repulsion effects, the large polyanion-containing composite coatings are capable of blocking the access of smaller pitting-causing anions (chlorides) to the surface of stainless steel.