Die Wechselwirkung Laurin- und Stearinsäure/Ni-NiO-System des Katalysators

The Interaction between Lauric and Stearic Acid and the Ni-NiO Catalyst System The reactivity of the Ni-NiO catalytic system of following degrees of reduction: 0, 35–65 and 100% Ni with the pure chemical quality lauric and stearic acids during the catalyst passivating conditions 75–115°C were followed in the time period 0–100 hours. The quantity of interaction product of nickel salts of fatty acids in the catalyst is controlled both of the initial reactivity of the Ni-NiO system with the fatty acids and of the kinetics of the zero reaction order. Although the lauric acid is expressively more reactive than the stearic acid, the activity of the in this way prepared catalysts tested in hydrogenation of free fatty acids did not show significant differences.     

A comparative performance study of common and popular task‐centric programming frameworks

Programmers today face a bewildering array of parallel programming models and tools, making it difficult to choose an appropriate one for each application. An increasingly popular programming model supporting structured parallel programming patterns in a portable and composable manner is the task‐centric programming model. In this study, we compare several popular task‐centric programming frameworks, including Cilk Plus, Threading Building Blocks, and various implementations of OpenMP 3.0. We have analyzed their performance on the Barcelona OpenMP Tasking Suite benchmark suite both on a 48‐core AMD Opteron 6172 server and a 64‐core TILEPro64 embedded many‐core processor. Our results show that the OpenMP offers the highest flexibility for programmers, and this flexibility comes to a cost. Frameworks supporting only a specific and more restrictive model, such as Cilk Plus and Threading Building Blocks, are generally more efficient both in terms of performance and energy consumption. However, Intel's implementation of OpenMP tasks performs the best and closest to the specialized run‐time systems. Copyright © 2013 John Wiley & Sons, Ltd.     

Aggregation behaviour of some β-cyclodextrin-based side-chain azo amphiphilic polyurethanes

New β-cyclodextrin-based side-chain azo amphiphilic polyurethanes were prepared. Aggregation behaviour was studied by employing steady-state fluorescence and UV–Vis spectroscopy techniques and, determination of the hydrodynamic diameter of micellar aggregates in N,N-dimethyl formamide and N,N-dimethyl formamide/ethanol mixture solutions was done. An apparent polarity evidenced by increasing I ₁/I ₃ ratio with the increasing concentration of polyurethanes except the polyurethanes with stronger intra- and intermolecular hydrogen bonding of hard segments was obtained. Pyrene resides predominantly in the interfacial region in micellar aggregates that is sensitive to polarity changes due to solvent penetration. Apparent critical micelle concentration due to the presence of β-cyclodextrin was determined by steady-state fluorescence and UV–Vis spectroscopy techniques which ranged between 10^?2 and 10^?1 g/L. Binding constants from both spectroscopy techniques were determined. The values of hydrodynamic diameter for the amphiphilic poly(ether urethane)s show that their aggregation behaviour is different in function of chemical composition, type and content of hard segment and hydrophobe/hydrophile ratio.     

Detection and Localization of Delaminations in Thin Carbon Fiber Reinforced Composites with the Ultrasonic Polar Scan

In this paper, the hybrid compliance-stiffness matrix method for simulating wave propagation in (delaminated) multilayered media with viscoelastic anisotropy has been confronted with high-quality amplitude and phase experiments on delaminated composites, obtained using the ultrasonic polar scan setup (UPS) in transmission by considering harmonic as well as pulsed ultrasound. Results are presented for multiple thin carbon/epoxy laminates with an artificial edge delamination induced by a foil insert, showing a good agreement between experimental recording and numerical modeling. The obtained results further reveal the feasibility of the harmonic UPS to detect and even locate the depth-position of multiple delaminations in fiber reinforced composites. Considering that the harmonic UPS method does not rely on the detection of different echoes like the classical C-scan, but rather expounds the conditions for efficient stimulation of guided waves in the solid, the method is found to be highly suited for inspecting thin composite materials for the presence of delaminations.     

Poly[N-(2-hydroxypropyl)methacrylamide]-based tissue-embedding medium compatible with MALDI mass spectrometry imaging experiments

Traditional tissue-sectioning techniques for histological samples utilize various embedding media to stabilize the tissue on a sectioning target and to provide a smooth cutting surface. Due to the ion suppression effect in MALDI ionization and number of background peaks in the low-mass region, these media are not suitable for mass spectrometry imaging (MSI) experiments. To overcome this, droplets of water are often used to mount the tissue on a sectioning target, but the ice block formed around the tissue does not provide a good support for sectioning of fragile samples. In this work, we propose a novel embedding media, compatible with MALDI ionization and MSI experiments, based on poly[N-(2-hydroxypropyl)methacrylamide] (pHPMA). Using a reversible addition-fragmentation chain transfer polymerization technique, well-defined pHPMA polymer with narrow mass distribution was prepared. Benefits of the resulted pHPMA-based embedding media were tested on different tissue samples.     

The effect of heat treatment temperature on the interfacial shear strength of C/C composites

This paper investigates the effect of heat treatment temperature on the interfacial shear strength (IFSS) of carbon/carbon composites reinforced with polyacrylonitrile-based fibers. A series of single fiber push-out tests were performed on specimens heat treated at 1800, 2100, and 2400 °C, using a nanoindenter with a flat ended conical tip. The microstructure was characterized using polarized light and transmission electron microscopy and the debonded fiber/matrix interface was examined using scanning electron microscopy. Wavelet analysis of the load–displacement data was used as an additional tool to investigate the initiation and progression of debonding. Compared to 1800 °C, heat treatment at 2400 °C was associated with a decrease in IFSS, from 12 to 7 MPa. Transmission electron microscopy study showed that the microstructure of the fiber/matrix interphase remained amorphous even with heat treatment at 2400 °C. The decrease in the IFSS can be partly attributed to the reorganization of the graphene sheets in the matrix in the vicinity of fiber/matrix interphase. The thermal expansion mismatch between fiber and pyrocarbon matrix is another possible reason for the observed decrease in the IFSS.     

Probing enzyme promiscuity of SGNH hydrolases

Several hydrolases of the SGNH superfamily, including the lipase SrLip from Streptomyces rimosus (Q93MW7), the acyl-CoA thioesterase I TesA from Pseudomonas aeruginosa (Q9HZY8) and the two lipolytic enzymes EstA (from P. aeruginosa, O33407) and EstP (from Pseudomonas putida, Q88QS0), were examined for promiscuity. These enzymes were tested against four chemically different classes of a total of 34 substrates known to be hydrolysed by esterases, thioesterases, lipases, phospholipases, Tweenases and proteases. Furthermore, they were also analysed with respect to their amino acid sequences and structural homology, and their phylogenetic relationship was determined. The Pseudomonas esterases EstA and EstP each have an N-terminal domain with catalytic activity together with a C-terminal autotransporter domain, and so the hybrid enzymes EstA(N)-EstP(C) and EstP(N)-EstA(C) were constructed by swapping the corresponding N- and C-terminal domains, and their hydrolytic activities were compared. Interestingly, substrate specificity and kinetic measurements indicated a significant influence of the autotransporter domains on the catalytic activities of these enzymes in solution. TesA, EstA and EstP were shown to function as esterases with different affinities and catalytic efficacies towards p-nitrophenyl butyrate. Of all the enzymes tested, only SrLip revealed lipase, phospholipase, esterase, thioesterase and Tweenase activities.     

HVAC system optimization with CO2 concentration control using genetic algorithms

This study describes the use of genetic algorithms (GAs) for operating standard HVAC systems (HVAC—heating, ventilation and air conditioning) in order to optimize performance, primarily with regard to power saving. Genetic algorithms were introduced as an instrument for solving optimization problems. Analytic optimization procedures are widely used in other fields of engineering, but they are difficult to operate within HVAC systems, because the range of the research is usually too broad, the problems are not linear but rather discontinuous, and they mostly have complex limitations. This is why for this type of system genetic algorithms are used, since they have the qualities of robustness and efficiency that are crucial for finding the optimal solution. A simulation is conducted in order to demonstrate how much power can be saved by using the suggested method of CO₂ concentration control in a standard HVAC system. In addition to Matlab Simulink, the suggested method is verified with Energy software.     

The structure of maladaptive personality traits in childhood: A step toward an integrative developmental perspective for DSM-V.

The present study describes the construction of a taxonomy of trait-related symptoms in childhood, the Dimensional Personality Symptom Item Pool (DIPSI), and examines the replicability of the taxonomy's higher order structure across maternal ratings of referred (N = 205) and nonreferred (N = 242) children and self-ratings of adolescents (N = 453). The DIPSI's 4 higher order factors--that is, Emotional Instability, Disagreeableness, Introversion, and Compulsivity--showed clear correspondence with the dimensions of personality pathology found in adulthood (Dimensional Assessment of Personality Pathology-Basic Questionnaire; W. J. Livesley, 1990; Schedule for Nonadaptive and Adaptive Personality; L. A. Clark, 1993). These 4 factors can be further organized into 2 superfactors, representing Internalizing and Externalizing Traits, demonstrating empirical and conceptual relationships with psychopathology models in childhood and adulthood. The implications for the assessment and conceptualization of early trait pathology are discussed in the context of an integrative developmental perspective on the construction of the Diagnostic and Statistical Manual of Mental Disorders-Fifth Edition. (PsycINFO Database Record (c) 2010 APA, all rights reserved)