Permeation of hydrocarbons through organosilane crosslinked LDPE

The importance of polymeric transportation systems has been steadily increasing over the years. It is a useful material in numerous applications, such as packaging, oil and gas pipes, and household items. One particular aspect of polyethylene (PE) is the permeability of small molecules, such as low‐molecular‐weight hydrocarbons. In the present study, PE sheets were crosslinked by grafting and subsequent hydrolysis of organosilanes during a reactive extrusion process. The formation of a network structure was characterized by sol/gel analysis and by rheological measurements. It is shown that as a result of crosslinking the permeation of linear alkanes through the PE is reduced. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45374.     

Large‐Scale Nano Piezo Force Position Arrays as Ultrahigh‐Resolution Micro‐ and Nanoparticle Tracker

Defining the position of an object on a planar substrate by force sensors is a common technology nowadays. Many products are commercialized worldwide, which make use of force sensors, especially, for instance, touchpads. Here advanced lithography processes together with piezoelectric materials are demonstrated to fabricate an extremely high resolution force sensor. The approach combines a large array of nanoscale piezoelectric lines fabricated on Si wafer by phase‐shift lithography and atomic‐layer‐deposition‐based spacer lithography techniques. These key lithography methods are utilized to fabricate ultralong (cm range) nanolines on the wafer scale. ZnO and P(VDF‐TrFE) are selected here as materials for piezoelectric signal generators. The detection mechanisms are explained and simulations combined with experimental data are demonstrated to prove the concept. The signal generated when an object approaches one single line is in the nanoampere range. The result enables a new and simple path for a device fabrication, which defines the position with micro‐ and nanometer resolution and can be used, for example, as micro‐ and nanoparticle trackers.     

Changed incidence and case-fatality rates of first-ever stroke between 1970 and 1993 in Tartu, Estonia

Double blind tests to check the correlation between pulse diagnosis and liver function tests were performed. Blood tests including T-Bil, D-Bil, SGOT and SGPT of 70 chemical factory workers were compared with pulse analysis. Special attention was paid to the indicators of liver and lung meridians for pulse diagnosis. It was found that using the criterion (1) C1 > or = 3+ and C1 + C4 > or = 4+ (hyperfunction) and (2) C1 < or = 3-(hypofunction) as abnormal liver meridian (for C1, every 5% above normal give one +, every 5% below normal give one-; for C4 every 10% above normal give one +, every 10% below normal give one -). The correlation or agreement between the blood tests and the pulse diagnosis was very high (noncorrelation chance checked by X2-test, P < 0.001, degree of agreement checked by Kappa test Ka = 0.61 which means a substantial relationship). Suggestions such as more tests, more criteria and precautions for future study are also proposed.     

Learning to learn during visual discrimination in group housed dwarf goats (Capra hircus).

Using an automated learning device, we investigated "learning to learn" by dwarf goats (Capra hircus) in what was for them a familiar environment and normal social settings. Nine problems, each consisting of four discriminable black symbols, each with one S+ and three different S-, were presented on a computer screen. Mean daily learning success improved over the course of the first four problems, and the improvement was maintained throughout the remaining five problems. The number of trials to reach the learning criterion decreased significantly beginning with problem four. Such results may be interpreted as evidence that the goats were developing a learning set. In the present case, the learning set appeared to have two components. One involved gaining familiarity and apparent understanding of the learning device and the basic requirements of the discrimination task. The second component involved learning potential error factors to be ignored, as well as learning commonalities that carried over from one problem to the next. Among the error factors, evidence of apparent preferences for specific symbols was seen, which had a predictable effect on performances. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Muscle fibre recruitment can respond to the mechanics of the muscle contraction.

This study investigates the motor unit recruitment patterns between and within muscles of the triceps surae during cycling on a stationary ergometer at a range of pedal speeds and resistances. Muscle activity was measured from the soleus (SOL), medial gastrocnemius (MG) and lateral gastrocnemius (LG) using surface electromyography (EMG) and quantified using wavelet and principal component analysis. Muscle fascicle strain rates were quantified using ultrasonography, and the muscle-tendon unit lengths were calculated from the segmental kinematics. The EMG intensities showed that the body uses the SOL relatively more for the higher-force, lower-velocity contractions than the MG and LG. The EMG spectra showed a shift to higher frequencies at faster muscle fascicle strain rates for MG: these shifts were independent of the level of muscle activity, the locomotor load and the muscle fascicle strain. These results indicated that a selective recruitment of the faster motor units occurred within the MG muscle in response to the increasing muscle fascicle strain rates. This preferential recruitment of the faster fibres for the faster tasks indicates that in some circumstances motor unit recruitment during locomotion can match the contractile properties of the muscle fibres to the mechanical demands of the contraction.     

How temporal distance changes novices' attitudes towards unconventional arts.

The authors suggest that, just like other attitudes, attitudes toward art may be malleable, and may thus also depend on situational factors. In particular, the authors propose that thinking styles vary within the situation and that an abstract versus concrete thinking style has an influence on attitudes toward conventional (e.g., Mona Lisa by da Vinci) versus unconventional (e.g., Fat Corner by Beuys) artworks. Construal Level Theory predicts that when people think about the distant future they automatically start thinking in a more abstract way, relative to when people think about the near future, which is supposed to elicit a concrete thinking style. In an experiment, the authors asked participants to think about their lives a year from now or tomorrow. Afterward, in an allegedly unrelated task, participants were asked to evaluate conventional and unconventional artworks. Results showed that participants that had thought about distant events and presumably thought more abstractly were more likely to include unconventional artworks into the category of arts than participants that had thought about near events, and thus presumably thought in more concrete terms. Implications for applied settings are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Visual Abstractions of Solvent Pathlines near Protein Cavities

Water is known to play a crucial role in protein structure, flexibility and activity. The use of molecular dynamics simulations allows detailed studies of complex protein‐solvent interactions. Cluster analysis and density‐based approaches have been successfully used for the identification and analysis of conserved water molecules and hydration patterns of proteins. However, appropriate tools for analysing long‐time molecular dynamics simulations with respect to tracking and visualising the paths of solvent molecules are lacking. Our method focuses on visualising the solvent paths entering and leaving cavities of the protein and allows to study the route and dynamics of the exchange of tightly bound internal water molecules with the bulk solvent. The proposed visualisation also represents dynamic properties such as direction and velocity in the solvent. Especially, by clustering similar path‐lines with respect to designated properties the visualisation can be abstracted to represent the principal paths of solvent molecules through the cavities. Its application in the analysis of long‐time scale molecular dynamics simulations not only confirmed conjectures based on previous manual observations made by chance, but also led to novel insights into the dynamical and structural role of water molecules and its interplay with protein structure.     

Hydrodechlorination of chloroorganic compounds in ground water by palladium catalysts: Part 1. Development of polymer-based catalysts and membrane reactor tests

A polymer-based catalytic membrane reactor was developed and applied for hydrodechlorination of chlorobenzene as a model compound of ground and waste water contaminants. The catalytically active membrane consists of a non-porous, thin film (about 3–7 μm) of poly(dimethylsiloxane) (PDMS) loaded with nano-sized Pd clusters. They were built-in either directly or as nano-sized, supported catalysts. A composite membrane, consisting of porous poly(acrylonitrile) (PAN) support and a Pd-loaded thin PDMS film, was fabricated on a coating machine. Defect-free membrane envelopes of 0.1 m² were produced and fitted into a membrane test cell. Gaseous hydrogen as reductant for hydrodechlorination is fed from the membrane’s back side directly to the catalyst, embedded in the PDMS layer. The chemical reactions at the Pd surface are accompanied by absorption of chlorobenzene from the water phase into the PDMS layer and desorption of benzene and HCl back to the water phase. The specific activity of supported catalysts decreased only slightly by PDMS incorporation, e.g., from 31 l/g(Pd) min for Pd/Fe on titania to 16 l/g(Pd) min for the same catalyst built-in a 7 μm thick supported PDMS membrane and measured in the membrane test cell. Directly built-in Pd clusters are less active and more difficult to prepare on a larger scale. Some catalyst deactivation was observed and may be balanced by development of more suited nano-sized supported catalysts.