Einsatz von alternativen Reaktionsmedien für eine umweltverträglichere chemische Produktion

Use of alternative reaction media for an environmentally safer chemical production. The way in which a chemical reaction is carried out and the composition of the reaction mixture diotate the degree of difficulty of downstream processing operations, not only in terms of energy consumption but also with respect to environmental pollution. A specific environmental protection that is an integral part of the production process must therefore begin with the examination of the chemical rection step. Restructuring a process from a reaction engineering point of view includes two important aspects of which the technical implementation has not yet been systematically examined and which therefore should promise a significant potential for innovation. These are the integration of modern separation operations in the chemical reactor with the aim of shifting the chemical equilibrium and the choice of an alternative reaction medium; although the latter also serves the same purpose, it can bring about a significant reduction in environmental pollution. This aspect is the focus of this paper, in which the advantages of molten salts, supercritical fluids and microemulsions as alternative reaction media are discussed.     

Artists portray human faces with the Fourier statistics of complex natural scenes

When artists portray human faces, they generally endow their portraits with properties that render the faces esthetically more pleasing. To obtain insight into the changes introduced by artists, we compared Fourier power spectra in photographs of faces and in portraits by artists. Our analysis was restricted to a large set of monochrome or lightly colored portraits from various Western cultures and revealed a paradoxical result. Although face photographs are not scale-invariant, artists draw human faces with statistical properties that deviate from the face photographs and approximate the scale-invariant, fractal-like properties of complex natural scenes. This result cannot be explained by systematic differences in the complexity of patterns surrounding the faces or by reproduction artifacts. In particular, a moderate change in gamma gradation has little influence on the results. Moreover, the scale-invariant rendering of faces in artists' portraits was found to be independent of cultural variables, such as century of origin or artistic techniques. We suggest that artists have implicit knowledge of image statistics and prefer natural scene statistics (or some other rules associated with them) in their creations. Fractal-like statistics have been demonstrated previously in other forms of visual art and may be a general attribute of esthetic visual stimuli.     

Tracking of moving interfaces in sedimentation processes using electrical impedance tomography

Sedimentation monitoring is widely used to control and optimize industrial processes. In this paper we propose a novel computational method for sedimentation monitoring using electrical impedance tomography (EIT). EIT measurements consist of electric current and voltage measurements that are made on the surface of the sedimentation tank and therefore they do not interfere with the sedimentation process. The proposed computational method is based on shape estimation and state estimation formulation of the EIT problem. The sedimentation is parameterized by the locations of the phase interfaces and conductivities of the phase layers. Three different evolution models for the state parameters are considered and the state estimates are computed using the extended Kalman filter algorithm. The performance of the method and the models are evaluated using simulated data from a six electrode EIT measurement configuration. From the results a promising performance of the method can be seen.     

Comparative Analyses of Medicinal Chemistry and Cheminformatics Filters with Accessible Implementation in Konstanz Information Miner (KNIME)

High-throughput virtual screening (HTVS) is, in conjunction with rapid advances in computer hardware, becoming a staple in drug design research campaigns and cheminformatics. In this context, virtual compound library design becomes crucial as it generally constitutes the first step where quality filtered databases are essential for the efficient downstream research. Therefore, multiple filters for compound library design were devised and reported in the scientific literature. We collected the most common filters in medicinal chemistry (PAINS, REOS, Aggregators, van de Waterbeemd, Oprea, Fichert, Ghose, Mozzicconacci, Muegge, Egan, Murcko, Veber, Ro3, Ro4, and Ro5) to facilitate their open access use and compared them. Then, we implemented these filters in the open platform Konstanz Information Miner (KNIME) as a freely accessible and simple workflow compatible with small or large compound databases for the benefit of the readers and for the help in the early drug design steps.     

The Pro-Inflammatory Deletion Allele of the NF-κB1 Polymorphism Is Characterized by a Depletion of Subunit p50 in Sepsis

The functionally important NF-κB1 promoter polymorphism (−94ins/delATTG) significantly shapes inflammation and impacts the outcome of sepsis. However, exploratory studies elucidating the molecular link of this genotype-dependent pattern are lacking. Accordingly, we analyzed lipopolysaccharide-stimulated peripheral blood mononuclear cells from both healthy volunteers (n = 20) and septic patients (n = 10). All individuals were genotyped for the −94ins/delATTG NF-κB1 promoter polymorphism. We found a diminished nuclear activity of the NF-κB subunit p50 in ID/DD genotypes after 48 h of lipopolysaccharide stimulation compared to II genotypes (p = 0.025). This was associated with higher TNF-α (p = 0.005) and interleukin 6 concentrations (p = 0.014) and an increased production of mitochondrial radical oxygen species in ID/DD genotypes (p = 0.001). Although ID/DD genotypes showed enhanced activation of mitochondrial biogenesis, they still had a significantly diminished cellular ATP content (p = 0.046) and lower mtDNA copy numbers (p = 0.010) compared to II genotypes. Strikingly, these findings were mirrored in peripheral blood mononuclear cells taken from septic patients. Our results emphasize the crucial aspect of considering NF-κB subunits in sepsis. We showed here that the deletion allele of the NF-κB1 (−94ins/delATTG) polymorphism was associated with the lower nuclear activity of subunit p50, which, in turn, was associated with aggravated inflammation and mitochondrial dysfunction.     

Determination of optimal cutting edge geometry on a stamped orthotropic circular electrical steel sheet

Today engineers involved in the stamping process used for high-volume production of rotor and stator laminations are faced with a great challenge to achieve extremely narrow dimensional and geometrical tolerance on their products. Because materials are produced by different suppliers, adjustments of technological parameters to the emerging differences are required to maintain the high quality of products. An upgraded engineering method was developed in which electrical steel sheet of semi-finish grade was not treated traditionally, but as a 3D body with orthotropic material behaviour. The round profile of the cutting edge was studied from the experimental and numerical point of view. If the completely round punch was used, the profile of the cutting edge appeared as a non-round shape. With additional FEM analyses a new profile of punch was designed as a non-round shape to be able to provide much better circularity. FEM simulation showed that 10 times lower profile deviations were found on the workpiece shaped by the new cutting element profile.     

Closed-loop control of hydraulic telescopic handler

Automatization is supposed to improve working conditions and safety in the construction industry, as it already did in manufacturing industries. This paper presents the development of a robotic control system for a commercially available hydraulic telescopic handler. The target application for the telescopic handler is semi-automated assembly of facade panels. The base handler was upgraded with two additional hydraulic axes, position sensors and closed-loop control system, while the original handler safety assurance mechanisms were preserved. The control approach is based on a PI controller with velocity feedforward and valve overlap compensation. The direct and inverse kinematic models of handler mechanism were developed to enable control of end-effector motion along a straight line in the Cartesian coordinate system. The motion performances were evaluated following the ISO 9283 standard with payload of 2000 kg. Results show the repeatability of positioning bellow 7.0 mm and the straight line tracking error smaller than 63 mm.     

Using Analog Predistortion for Linearizing Class A–C Power Amplifiers

An analog 5th order, complex-valued polynomial predistortion IC has been built to linearize the behavior of RF power amplifiers. The predistorter can be used either at baseband or low IF frequencies and it was tested using a simple IF amplifier that could be biased to operate in classes A, AB, B and C. Intermodulation products can be reduced by 20 to 30 dB in classes A and AB over a bandwidth of several MHz. In classes B and C the shape of nonlinearity is such that a low-order polynomial predistortion function is not sufficient for linearizing them.