Investigation of the gas inlet velocity distribution in a fixed granular bed filter

Granular bed filter (GBF) technology can be applied for high-temperature gas cleanup in integrated gasification combined-cycle (IGCC) and pressurized fluidized-bed combustion (PFBC) advanced coal-fired power plants. The design of the gas inlet component of the granular bed filter is important to achieve a uniform gas distribution and higher usage rate of the filter media. Previous studies show that the gas velocity at the inlet is not uniformly distributed. This non-uniformity may lead to a lower usage rate of the filter media. In this study a baffle device is introduced to the inlet system in order to achieve a more uniform gas velocity distribution. A more uniform gas inlet distribution can be obtained by adjustment of the lengths and angles of the baffles. The gas velocities along the inlet and filtration surfaces are measured using a pitot tube. The uniformity of the gas velocity distribution can be characterized by looking at the distributions of the standard deviation of the gas velocity and the differences in the mean velocities between the two filtration surfaces.     

Exhaust hood for steam turbines-single-flow arrangement

In the past, increased attention was given to the development of an optimal shape for the inlet part of LP turbine casings in SKODA POWER. A double-flow design is typically used for high power output turbines. An optimized shape for the internal diffuser has been found, which transforms the kinetic energy of steam into increased pressure, thus effectively increasing the thermodynamic efficiency of the stage. Some conclusions have been drawn from laboratory experiments, others derived directly from on-site measurements at power plants. The conclusions from the development of double-flow turbines form the basis for the design of the single-flow turbine arrangement. Single-flow design is typically used for lower output turbines. There are still some limitations in applying this arrangement. The designer needs to resolve the bearing position and how to ensure access to them. Reinforcing the ribs and supports are used, therefore, to ensure the rigidity of the entire casing. The optimization of the single-flow diffuser shape is therefore the subject of the study presented below.     

Polymer-decorated Plasmonic Nanoparticles

The preparation and characterization of noble metal nanoparticles that are coated by organic shells for the covalent immobilization of biopolymers were described. Plasmonic nanoparticles demonstrate unique size-dependent optical and photothermal properties due to the collective oscillation of free electrons in their conduction bands. The intensity of absorption and scattering of noble metal nanoparticles is significantly higher than most absorbing and scattering organic molecular dyes, which makes them excellent candidates as contrast agents in imaging. Cylindrical gold nanorods also demonstrate a tunable photothermal response to near infrared light as a function of nanoparticle aspect ratio. Organic functional groups on the nanoparticles allow the coupling of organic molecules to their shells. Several synthetic approaches to couple biomolecules to metal nanoparticles and to use the hybrid assemblies for various bioanalytical applications have been reported.     

Magnetically Controllable Silver Nanocomposite with Multifunctional Phosphotriazine Matrix and High Antimicrobial Activity

A recently developed multi‐functional phosphotriazine‐based polymer is used as a matrix for embedding γ‐Fe₂O₃ nanoparticles as well as a suitable chemical template for surface modification with silver nanoparticles. For the primary magnetic modification, maghemite nanoparticles are surface modified with oleic acid in order to render them organophilic and to prevent the aggregation of the nanoparticles. This aggregation could occur as the polymer synthesis, based on reaction of phosphonitrilic chlorine and 1,4‐phenylenediamine, takes place in toluene. The surface active amine units of the polymer structure enable the reduction of silver cations to silver nanoparticles, which are well attached and finely dispersed on its surface. The developed nanocomposite represents one of the few magnetically controllable antibacterial agents based on silver nanoparticles. Magnetic measurements reveal the completely suppressed interactions among maghemite nanoparticles because of their perfect surface coating with an organic surfactant and fine dispersion inside the polymer matrix. This magnetic nanocomposite exhibits a high antibacterial and antifungal activity as proven by tests with nine bacterial strains and four candida (yeast genus) species. For the majority of the tested species, the minimum‐inhibition concentrations are below 100 mg L^?1, which is comparable to their equivalent minimum‐inhibition concentrations in colloidal silver systems.     

An adsorptive transfer technique coupled with brdicka reaction to reveal the importance of metallothionein in chemotherapy with platinum based cytostatics

The drugs based on platinum metals represent one of the oldest, but also one of the most effective groups of chemotherapeutic agents. Thanks to many clinical studies it is known that resistance of tumor cells to drugs is a frequent cause of chemotherapy failure. With regard to platinum based drugs, multidrug resistance can also be connected with increased expression of low-molecular weight protein metallothionein (MT). This study aimed at investigating the interactions of MT with cisplatin or carboplatin, using the adsorptive transfer technique coupled with differential pulse voltammetry Brdicka reaction (AdTS DPV Brdicka reaction), and a comparison of in vitro results with results obtained in vivo. The results obtained from the in vitro study show a strong affinity between platinum based drugs and MT. Further, we analyzed extracts of neuroblastoma cell lines treated with cisplatin or carboplatin. It is clear that neuroblastoma UKF-NB-4 cisplatin-resistant and cisplatin-sensitive cell lines unlikely respond to the presence of the platinum-based cytostatics cisplatin and carboplatin. Finally, we determined the level of MT in samples from rabbits treated with carboplatin and patients with retinoblastoma treated with the same drug.     

A model for cell-surface-exposed carbohydrate moieties suitable for structural studies by NMR spectroscopy

In the present study a synthetic glycolipid system is presented that can be readily incorporated into phospholipid micelles and that allows the study of cell-surface-exposed carbohydrate units by high-resolution NMR techniques. Here, we present an efficient route for the synthesis of glycolipid compounds that contain mannose, mannobiose, or mannotriose coupled either directly to an alkyl chain or through a poly(ethylene glycol) linker. Furthermore, we have validated our model system by measuring the binding of cyanovirin N (CV-N), a cyanobacterial protein that binds with nanomolar affinity to the terminal arms of high-mannose structures of the HIV surface-envelope glycoprotein gp120, to glycolipids the carbohydrate portions of which comprise the corresponding high-mannose moieties. From the results of chemical-shift mapping with uniformly (15)N-labelled CV-N, we conclude that binding to the protein occurs at sites similar to those involved in binding the nonconjugated carbohydrates. We characterized the insertion of the glycolipids into dodecylphosphocholine (DPC) micelles by measuring translational diffusion, and we observed that the diffusion constants of the glycolipids were very similar to those of the DPC micelles themselves, but significantly deviated from those of the free glycolipids. We also present experimental proof that the glycolipids remain inserted in the micelles while binding to CV-N. Finally, by addition of a ligand that had a higher affinity to CV-N but which was not attached did not couple to a lipid anchor, CV-N could be released from the glycolipid and, hence, from the micelle-associated state.     

Failure Resistance of the Historic Stone Bridge Structure of Charles Bridge. I: Susceptibility to Nonstress Effects

The monitoring of deformations of the stone structure of Charles Bridge in Prague proved the gravity and relevance of nonstress effects (temperature, moisture content) on cyclic deformations and permanent strain accompanied by a gradual disintegration of its stone masonry, growing tilt of the breast walls, and development of cracks in the masonry of the stone bridge structure. Each deformation cycle is accompanied by a gradual growth in permanent deformations. The “unmanifested” primary deformation due to, e.g., a temperature change causes a mechanical state of tension, and it is mainly the tensile stresses thus arising that contribute to the development of tensile cracks in the stone masonry.     

Proplant: Multiagent system for production planning

The so-called ''tribase'' acquaintance model of the agent's behavior is presented in this paper. This represents an extension of the twin-base model (Cao et al., 1997). Based on practical experience, the new model tries to cope with parallel processing, precedence constraints, and sparse resources. The idea of substituting the interagent negotiation processes by the periodical internal planning activity of the agents is stressed. A multiagent system, ProPlanT, as an application of the tribase model for the project-oriented production planning developed for TESLA TV company is described in detail. Three types of agents production planning agent (PPA), production management agent (PMA), and production agent (PA) are distinguished. The corresponding tribase models and potential role of metaagents are discussed.     

Combined exposure to cyanobacterial biomass, lead and the Newcastle virus enhances avian toxicity

Under environmental conditions, wild birds can be exposed to multiple stressors including natural toxins, anthropogenic pollutants and infectious agents at the same time.This experimental study was successful in testing the hypothesis that adverse effects of cyanotoxins, heavy metals and a non-pathogenic immunological challenge combine to enhance avian toxicity. Mortality occurred in combined exposures to naturally occurring cyanobacterial biomass and lead shots, lead shots and Newcastle vaccination as well as in single lead shot exposure. Mostly acute effects around day 10 were observed. On day 30 of exposure, there were no differences in the liver accumulation of lead in single and combined exposure groups. Interestingly, liver microcystin levels were elevated in birds co-exposed to cyanobacterial biomass together with lead or lead and the Newcastle virus. Significant differences in body weights between all Pb-exposed and Pb-non-exposed birds were found on days 10 and 20. Single exposure to cyanobacterial biomass resulted in hepatic vacuolar dystrophy, whereas co-exposure with lead led to more severe granular dystrophy. Haematological changes were associated with lead exposure, in particular. Biochemical analysis revealed a decrease in glucose and an increase in lactate dehydrogenase in single and combined cyanobacterial and lead exposures, which also showed a decreased antibody response to vaccination.The combined exposure of experimental birds to sub-lethal doses of individual stressors is ecologically realistic. It brings together new pieces of knowledge on avian health. In light of this study, investigators of wild bird die-offs should be circumspect when evaluating findings of low concentrations of contaminants that would not result in mortality on a separate basis. As such it has implications for wildlife biologists, veterinarians and conservationists of avian biodiversity.     

Dyeing of leather with microencapsulated acid dye

CI Acid Black 210 was microencapsulated into liposomic systems, and the effects of the microencapsulation on dyebath exhaustion, depth of shade, colour fastness properties and through‐dyeing of chrome‐tanned leather were studied. In comparison with the original dyestuff form, the microencapsulated dye showed a deeper shade and a greater depth of through‐dyeing. Exhaustion and colour fastness values were the same.