An integrated process of oxidative coupling of methane and pyrolysis of naphtha in a scaled‐up unit

A heat‐effective ‘integrated’ process of C₂H₄ production, incorporating exothermic oxidative coupling of methane (OCM) carried out in the catalytic section of a flow tubular reactor, and endothermic pyrolysis of naphtha carried out in the postcatalytic section of the same reactor, studied earlier in a small silica reactor, was examined now in a scaled‐up unit with a stainless‐steel (1H18N9T) reactor (volume 400 cm³, Li/MgO catalyst bed 165 cm³). It was demonstrated that depending on the operating conditions, such an integrated process could be realized over a wide range of the relative contribution of the two component processes, leading always to an increase in the C₂H₄ yield, as compared with OCM or pyrolysis alone. A high degree of additivity of the yields of all products was observed in all cases, independently of the relative contribution of OCM and pyrolysis. Such results indicated that in the scaled‐up unit with a stainless‐steel reactor, the interactions between the component processes and products were only negligible under experimental conditions. The overall balance of CH₄, being consumed in OCM and formed in pyrolysis, was negative, equal to zero, or positive, depending on the relative contribution of the component processes. The integrated process could be based, therefore, either on CH₄ and naphtha as raw materials or exclusively on naphtha, with the recirculation of the excess of CH₄ to the OCM section. Copyright © 2004 Society of Chemical Industry     

New technique of nondestructive assessment of concrete strength using artificial intelligence

A new technique of nondestructively assessing the compression strength of concrete, which employs artificial neural networks, is presented. A data set based on results of testing concretes (with a 28-day strength of 24–105 MPa) by different nondestructive methods was used to train and test an artificial neural network. The methodology of neural identification of the strength is described. The obtained results, including those of the practical verification of the technique, are reported.     

Aspartame as a texturizing agent in foodstuffs

Rheological studies of aqueous aspartame blends with d-fructose, d-glucose, maltose and sucrose revealed that only sucrose-aspartame blends provided an increase in the viscosity. Polarimetric studies of the blends together with computer MM+ simulations involving energy optimization for such blends and for solutions of saccharides showed that the energies of hydration of sucrose and aspartame are similar and higher than those for aqueous solutions of other saccharides. The hydration coats of these species are least organized. The results showed the formation of a common hydration coat for both solutes. The hydrodynamic shape of the resulting aggregate is responsible for the increase in viscosity of these blends. Other saccharides formed hydrates that remained independent of the hydrated aspartame.     

A Constructive Approach to Stabilizability and Stabilization of a Class of nD Systems

This paper presents a constructive approach to the problem of output feedback stabilizability and stabilization of a class of linear multidimensional (nD, n>2) systems, whose varieties of the ideals generated by the reduced minors are infinite with respect to not more than two variables. The main idea of the proposed approach is to decompose the variety of an nD system in this class into a union of several varieties, each of which is defined by polynomials in just two variables. The new method can be considered as a combination of Gröbner bases and existing results on two-dimensional (2D) digital filter stability tests and on stabilizability and stabilization of 2D systems. An example is illustrated.     

Environmental impact of combustion

Large amounts of fuels, burned in various types of furnaces are one of the main sources of pollution in the environment. Flue gases pollute the atmosphere and the associated ashes pollute soil and water. To compare the influence of various fuels burned in different installations on the environment, one universal index would be helpful. Such a coefficient, which represents the harmfulness of combustion processes of a particular fuel in a particular installation, is defined in this paper. This coefficient takes into account the composition of the fuel, the thermal efficiency of the installation, the type and process efficiency of creation of harmful compounds in the combustion chamber, efficiency of cleaning devices, ability of emitter to propagate pollutants into the atmosphere, as well as the relative toxicity of various components. Finally methods of calculation of propagation of pollutants in the atmosphere are introduced. All these factors are essential for a reliable assessment and comparison of fuel and installations. An individual coefficient of harmfulness could be calculated for each compound present in the flue gases as well as a total coefficient for all compounds. Each compound created in the combustion processes is the source of many types of environmental impact. It could have significant influences on human health, plants and animals as well as for example on the corrosion process taking place in many different installations. We have to take into consideration that the result of a combustion process could appear in many different places, sometimes distant from the place of the process itself. All these results should be analyzed and introduced into the universal coefficient of “harmfulness” of specific compound. Economic parameters and methods are important and therefore are also introduced into the assessment method presented in the paper. In this way we are able to compare the values of extremely different phenomena such as a human health and corrosion.     

Grid Infrastructure Monitoring Service Framework Jiro/JMX Based Implementation

The paper describes a grid infrastructure monitoring service based on Jiro and JMX. Involvement of those technologies gives the programmer ease of instrumentation, dynamic configuration and simple to use discovery and notification mechanisms. Moreover, building the system over existing standards accepted by the IT industry makes this process stable in longer period of time. The goals of the autors of the service's concept were not only to provide the user with yet another front-end for SNMP, but also to let the system resolve typical problems by involving existing or forthcoming technologies supporting declarative way of programming. Being structured as a framework, the system allows the user to describe rules that define the actions taken by the system and conditions, upon which the actions should be taken. The system is currently developed further by the Distributed Systems Research Group at the University of Mining and Metallurgy in Kraków.     

Inhibitors of Matriptase‐2 Based on the Trypsin Inhibitor SFTI‐1

A series of 17 new analogues of trypsin inhibitor SFTI‐1 were designed and synthesized to obtain matriptase‐2 inhibitors. A number of the modified bicyclic peptides displayed much higher affinity towards matriptase‐2 than towards the highly homologous matriptase‐1. Replacement of Lys5 by Arg in the wild‐type SFTI‐1 led to an 11‐fold increase in the matriptase‐2 inhibitory activity. Replacement of Arg2 by its enantiomer (D ‐arginine) slightly lowered the inhibition of matriptase‐2, but almost completely abolished the affinity towards matriptase‐1, thus yielding the most selective matriptase‐2 inhibitor. This is the first report describing inhibitors of the recently discovered matriptase‐2 based on the SFTI‐1 structure. The results showed that SFTI‐1 is a promising scaffold for the design of potent and selective inhibitors of this enzyme.     

Use of the subcutaneous venous network of the forearm to create an arteriovenous fistula

The reconstruction of vascular access in patients with kidney allograft failure is a challenging problem. A case of a 62‐year‐old man with transplanted kidney insufficiency is described. The patient was initially dialyzed with a wrist radial‐cephalic arteriovenous fistula. In the post‐transplantation period, the enormously dilated venous part of the anastomosis was ligated and the part of the vein suspected of being the source of bacteremia was excised. The man was referred to our department due to kidney allograft failure for vascular access creation. During preoperative assessment, we unexpectedly found a soft thrill on the forearm. Doppler ultrasound confirmed fistula patency, although the blood supply was not sufficient to perform dialysis. Angiography showed the blood flow from the radial artery to the cephalic vein, through a complicated vessel system consisting of inter alia a dilated vein of the subcutaneous venous network. We successfully used this vein as the vascular access outflow for fistula recreation. In conclusion, making use of veins of the subcutaneous venous network of the forearm for creation of a native fistula should be considered in selected cases.     

Intrinsic Kinetics of Carbon Dioxide Degradation of YBa2Cu3O7-x

The intrinsic kinetics, unaffected by diffusional and masstransfer effects, of the CO₂ degradation of superconducting particles have been determined using a nonisothermal technique. Below 900°C, the carbonization of YBa₂Cu₃O_{7- x} leads to formation of BaCO₃, Y₂Cu₂O₅, CuO, and Cu₂O. A further increase in temperature results in formation of BaCuO₂ from BaCO₃ and CuO. The carbonization rate shows the 1.5th-order dependence on the amount of unreacted YBa₂Cu₃O_{7- x} for the temperature range of 550° to 815°C. The activation energy of carbonization was determined to be 95.1 kJ · mol⁻¹.     

miR-31-5p-Modified RAW 264.7 Macrophages Affect Profibrotic Phenotype of Lymphatic Endothelial Cells In Vitro

Cardiac lymphatic vessel (LyV) remodeling as a contributor to heart failure has not been extensively evaluated in metabolic syndrome (MetS). Our studies have shown structural changes in cardiac LyV in MetS that contribute to the development of edema and lead to myocardial fibrosis. Tissue macrophages may affect LyV via secretion of various substances, including noncoding RNAs. The aim of the study was to evaluate the influence of macrophages modified by miR-31-5p, a molecule that regulates fibrosis and lymphangiogenesis, on lymphatic endothelial cells (LECs) in vitro. The experiments were carried out on the RAW 264.7 macrophage cell line and primary dermal lymphatic endothelial cells. RAW 264.7 macrophages were transfected with miR-31-5p and supernatant from this culture was used for LEC stimulation. mRNA expression levels for genes associated with lymphangiogenesis and fibrosis were measured with qRT-PCR. Selected results were confirmed with ELISA or Western blotting. miR-31-5p-modified RAW 264.7 macrophages secreted increased amounts of VEGF-C and TGF-β and a decreased amount of IGF-1. The supernatant from miR-31-5p-modified RAW 264.7 downregulated the mRNA expression for genes regulating endothelial-to-mesenchymal transition (EndoMT) and fibrosis in LECs. Our results suggest that macrophages under the influence of miR-31-5p show the potential to inhibit LEC-dependent fibrosis. However, more studies are needed to confirm this effect in vivo.