129 research outputs found

    Enlargement of Submicron Gas‐Borne Particles by Heterogeneous Condensation for Energy‐Efficient Aerosol Separation

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    To improve the efficiency of aerosol separation, a process sequence for particle enlargement by condensation of water vapor on their surface is suggested. The presented method makes use of packed columns in non-equilibrium operation to achieve supersaturation, which is required for droplet growth. Although this method is known for several years, it is not widely used in industrial processes and still needs accurate investigations for consolidation and establishment. The simulation tool AerCoDe3.0 for predicting saturation and particle growth in packed columns allows investigating the thermal energy consumption under various operation conditions. Based on the results obtained in this study, optimized arrangements of columns, which are applicable as preconditioning step for existing particle separators, are proposed

    Calcitization of aragonitic bryozoans in Cenozoic tropical carbonates from East Kalimantan, Indonesia

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    © The Author(s) 2016. Open Access. This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The file attached is the published version of the article

    Genetic Analysis of a Novel Human Adenovirus with a Serologically Unique Hexon and a Recombinant Fiber Gene

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    In February of 1996 a human adenovirus (formerly known as Ad-Cor-96-487) was isolated from the stool of an AIDS patient who presented with severe chronic diarrhea. To characterize this apparently novel pathogen of potential public health significance, the complete genome of this adenovirus was sequenced to elucidate its origin. Bioinformatic and phylogenetic analyses of this genome demonstrate that this virus, heretofore referred to as HAdV-D58, contains a novel hexon gene as well as a recombinant fiber gene. In addition, serological analysis demonstrated that HAdV-D58 has a different neutralization profile than all previously characterized HAdVs. Bootscan analysis of the HAdV-D58 fiber gene strongly suggests one recombination event

    Signal transduction controls heterogeneous NF-ÎșB dynamics and target gene expression through cytokine-specific refractory states

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    Cells respond dynamically to pulsatile cytokine stimulation. Here we report that single, or well-spaced pulses of TNFα (>100 min apart) give a high probability of NF-ÎșB activation. However, fewer cells respond to shorter pulse intervals (<100 min) suggesting a heterogeneous refractory state. This refractory state is established in the signal transduction network downstream of TNFR and upstream of IKK, and depends on the level of the NF-ÎșB system negative feedback protein A20. If a second pulse within the refractory phase is IL-1ÎČ instead of TNFα, all of the cells respond. This suggests a mechanism by which two cytokines can synergistically activate an inflammatory response. Gene expression analyses show strong correlation between the cellular dynamic response and NF-ÎșB-dependent target gene activation. These data suggest that refractory states in the NF-ÎșB system constitute an inherent design motif of the inflammatory response and we suggest that this may avoid harmful homogenous cellular activation

    The challenge of measuring sulfuric acid aerosols : number concentration and size evaluation using a condensation particle counter (CPC) and an electrical low pressure impactor (ELPI+)

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    In this study, two different methods for the measurement of the sulfuric acid aerosol which is formed in wet flue gas cleaning processes have been investigated. The condensation particle counter (UFCPC, PALAS GmbH) provides information about the number concentration. With the electrical low pressure impactor (ELPI+, Dekati Ltd.) also the size evaluation is possible. Both measurement methods reveal number concentrations above 108cm-3 under well controlled conditions in a pilot plant and the good conformance of the both methods is shown. With the ELPI+ the effect of dilution on the size of the volatile aerosol can be observed. The predicted trend of an existing simulation tool can be verified: the higher the sulfuric acid concentration, the larger are the droplet sizes. The number concentration, however, doesnD́t change considerably when altering the sulfuric acid concentration. © 2013 Elsevier Ltd

    Collection and generation of sulfuric acid aerosols in a wet electrostatic precipitator

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    Wet electrostatic precipitators (WESPs) are considered to be a possible technology for the control of sulfuric acid mist. The performance of a lab-scale WESP was investigated as a precipitator for sulfuric acid aerosol droplets produced under controlled conditions in a pilot plant. It was found that for higher levels of residual SO2 in the flue gas, WESP collection efficiencies were greatly reduced due to aerosol formation inside the WESP. Investigations showed a strong correlation of aerosol emission from the WESP with incoming SO2 concentration and operating voltage. It is suspected that the reactive species produced in the nonthermal plasma of the corona discharge oxidize the SO2 to SO3 which forms sulfuric acid. This causes supersaturation with subsequent homogeneous nucleation and thus aerosol formation
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