Crosslinking of addition copolymers from tricyclononenes bearing (CH3)3Si‐ and (C2H5O)3Si‐groups as a modification of membrane gas separation materials

Here, we report the synthesis and the study of gas‐transport properties of crosslinked highly permeable copolymers from Si‐containing norbornene derivatives. The initial high‐molecular‐weight copolymers were prepared via addition copolymerization of 3‐trimethylsilyltricyclo[4.2.1.0^2,5]non‐7‐ene (TCNSi1) with 3‐triethoxysilyltricyclo[4.2.1.0^2,5]non‐7‐ene (TCNSiOEt) in good or high yields using a Pd‐catalyst. The obtained copolymers included up to 10 mol% of TCNSiOEt units bearing reactive Si–O–C‐containing substituents. The crosslinking was readily realized by using simple sol–gel chemistry in the presence of Sn‐catalyst. The formed crosslinked copolymers were insoluble in common organic solvents. Permeability coefficients of various gases (He, H₂, O₂, N₂, CO₂, CH₄, C₂H₆, C₃H₈, n‐C₄H₁₀) in these copolymers before and after crosslinking were determined and the influence of the incorporated TCNSiOEt units as well as the crosslinking on gas transport properties were established. As a result, it was found that only a small reduction of gas‐permeability was observed when TNCSiOEt units were incorporated into the main chains, and the copolymers were crosslinked. At the same time, the selectivity for C₄H₁₀/CH₄ pair was increased. The suggested approach has allowed obtaining crosslinked polymers from Si‐containing monomers without a loss of the main membrane characteristics. POLYM. ENG. SCI., 59:2502–2507, 2019. © 2019 Society of Plastics Engineers     

Efficient morse decompositions of vector fields

Existing topology-based vector field analysis techniques rely on the ability to extract the individual trajectories such as fixed points, periodic orbits, and separatrices that are sensitive to noise and errors introduced by simulation and interpolation. This can make such vector field analysis unsuitable for rigorous interpretations. We advocate the use of Morse decompositions, which are robust with respect to perturbations, to encode the topological structures of a vector field in the form of a directed graph, called a Morse connection graph (MCG). While an MCG exists for every vector field, it need not be unique. Previous techniques for computing MCG's, while fast, are overly conservative and usually results in MCG's that are too coarse to be useful for the applications. To address this issue, we present a new technique for performing Morse decomposition based on the concept of tau-maps, which typically provides finer MCG's than existing techniques. Furthermore, the choice of tau provides a natural tradeoff between the fineness of the MCG's and the computational costs. We provide efficient implementations of Morse decomposition based on tau-maps, which include the use of forward and backward mapping techniques and an adaptive approach in constructing better approximations of the images of the triangles in the meshes used for simulation.. Furthermore, we propose the use of spatial tau-maps in addition to the original temporal tau-maps. These techniques provide additional trade-offs between the quality of the MCGs and the speed of computation. We demonstrate the utility of our technique with various examples in the plane and on surfaces including engine simulation data sets.     

The SCOPE dynamic model for emulsion polymerization II. Comparison with experiment and applications

Paper I provides the underlying theoretical framework for the SCOPE dynamic model of emulsion copolymerization. The present paper compares the model predictions for styrenemethyl methacrylate copolymerizations with experimental measurements made at a variety of polymerization conditions. The SCOPE model predicts conversion–time profiles reasonably well over wide ranges of initiator concentration, monomer concentration and monomer composition. In addition, the model accurately predicts number average molecular weights and copolymer compositions over the entire range of monomer composition. Like previous investigations of this system, the present study suggests that free radical desorption from polymer particles plays a dominant role on the copolymerization kinetics: Simple case II Smith-Ewart kinetics do not apply. The model for this system was applied to understand how changing reaction conditions could effect polymer properties such as particle size and molecular weight distributions. The power of the SCOPE model is illustrated by using it to predict conversion profiles, temperature profiles and copolymer properties for some large-scale versions of these recipes.     

Temporal dynamics and drivers of lake ecosystem metabolism using high resolution observations in a shallow,tropical, eutrophic lake (Laguna Lake,Philippines)

The physical, chemical, and biological dynamics under changing atmospheric conditions of Laguna Lake, Philippines were analyzed from intensive observations. Diel measurements were conducted for 48 continuous hours for both dry and wet tropical seasons in addition to fine resolution long-term monitoring. Results revealed significant vertical and diel variations of lake variables in spite of a shallow water depth (2.5 m) caused by the intense surface heating from solar irradiance (~800 W m^?2) and accentuated by the lake's high turbidity (16–32 ftu). Late afternoon land-lake breeze (~5–7 m s^?1) regularly breaks daytime thermal stratification, and convective cooling at night maintains isothermal condition until dawn of the next day. The stratified condition demonstrated a wind-driven, density-induced 2-layer current pattern with a windward moving epilimnion (~4 folds faster) and a compensating hypolimnetic flow in the general lake circulation direction. Laguna Lake was observed to have a dominating diel cycle but also undergoes significant seasonal limnological variations brought primarily by climate, hydrology, and its interaction with the adjacent sea. Significantly correlated variations of pH, chlorophyll-a and DO in the dry season were indicative of the higher biological activity associated with the intrusion of polluted waters from Metro Manila. The non-occurrence of thermal over-turn was observed to be regularly followed by bottom hypoxic conditions (2–4 mg L^?1), indicative of the eutrophic condition of the lake and the importance of diel wind-induced mixing in the bottom supply of DO. Laguna Lake was found to be predominantly net heterotrophic (GPP:R < 1, NEP < 0).     

Technique of problem solving as a predictor of achievement in a mechanics course.

The Balance Problems Test, giving a choice of problem-solving techniques (use of principles versus use of facts), was studied as a predictor of mechanical achievement as assessed by final grade in the Airplane and Engines Mechanics course and by scores on two mechanical job-knowledge tests. "1. Final grade in the A. & E. course is positively related to the number of problems correctly solved in the BPT and to the tendency to prefer principles over facts in their solution. 2. The BPT… is as good or a better predictor of final mechanical school grade than any one of five standard scores studied… ." (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Personality adjustment and the study of abnormal psychology.

Rorschach story-completion test and autobiographical data were obtained from 21 students in an abnormal psychology class and 22 students in a history class, both at the beginning and the end of the semester. Comparisons of the pre- and post-test data "support the belief that, (a) as a group, students studying abnormal psychology differ in personality from those not enrolled in the course, and (b) while the study of abnormal psychology has little immediate effect on personality ad ustment, measurable changes occur which appear to be related to course experience." (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

非织造布推动俄罗斯轻工业发展

非织造布推动俄罗斯轻工业发展近年来,受金融危机的影响,俄罗斯的轻工业面临着诸多挑战,相关人士预测非织造布将为轻工业的发展注入活力。俄罗斯工业和贸易部部长Denis Manturov在近期发布的一份声明中称,由于俄罗斯国民经济逐渐摆脱了金融危机的阴影并获得进一步的发展,且主要消费行业对非织造布产品的需求不断增长,2019年俄罗斯的非织造布行业或会创造新的历史纪录。     

Effect of Processing on Release from an Inert, Heterogeneous Matrix

Matrixes containing 40% ephedrine hydrochloride and hydrogenated castor oil are prepared by two processes: (a) compression of a physical mixture and (b) compression of a congealed melt. The release from the melt matrix is slower than from the matrix prepared by compression of a physical mixture. applied pressure on the release profile is studied. For matrixes prepared by both processes as the applied pressure is increased, the release rate is slower; however, this effect is more pronounced for the physical mixture matrix. The effect of comminution of the medicinal compound on release profile is considered. mixture the fastest release occurs from the finer particles suggesting a boundary layer diffusion. In matrixes produced by the melt process as the particle size is decreased, the release is slowed presumably because of an increased tortuosity and more intimate contact between the ephedrine hydrochloride and the hydrogenated castor oil, which produces mass transfer by matrix diffusion.     

World trends of importance to intelligent robotic CIM systems

The reduction to practice of the concept of computer-integrated manufacturing (CIM) has moved painfully slowly in the more than 20 years since it came into being. However, within the past five years a very important world trend has emerged, namely a major commitment on the part of industry toward realistic and substantial accomplishment, in practice, of full computer-based integration of the overall system of manufacturing. With the emergence of the goal of accomplishing fully robotic operation of the technological system of manufacturing, and of the concept of the intelligent manufacturing system, the overall trend has now become one toward realization, in practice, of the computer-integrated intelligent robotic manufacturing system. That trend has generated important corollary trends which fall into two main categories, namely, enabling technologies for integration of the system of manufacturing and enabling technologies for imparting artificial intelligence to that system, both of which are required for accomplishing fully robotic operation of the technological system of manufacturing.     

Future directions in pediatric and clinical child psychology.

Examined future directions in pediatric and clinical child psychology, utilizing a "Delphi" survey of 80 experts. Experts were asked to identify future trends in research, training, and clinical service. Findings suggest considerable overlap for the two subspecialties. Differences were predominantly related to the characteristics of the settings within which the professionals practiced. Implications with regard to research, training, and clinical service are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)