Coordination polymers: Challenges and future scenarios for capture and degradation of volatile organic compounds

Over the past few decades, coordination polymers/metal organic frameworks (CPs/MOFs) have drawn a great deal of attention for diverse applications due to their advantages of intrinsically tunable chemical structure, flexible architecture, high pore volume, high surface area, multifunctional properties, etc. To date, numerous CPs/MOFs have been developed and employed for the treatment and control of gaseous pollutants, such as volatile organic compounds (VOCs), through capture, sorptive removal, and catalytic degradation. Nevertheless, there are also some key drawbacks and challenges for the practical application of these systems (e.g., poor selectivity, high energy (and fiscal) cost, high synthesis cost, low capacity, and difficulties in regeneration and recycling). In this review, recent developments in CPs/MOFs research are described with their associated mechanisms for capture, sorptive removal, and catalytic degradation of VOCs. To this end, we discuss the key variables and challenges for afforded abatement of VOCs through CPs/MOFs technologies. Hopefully, this review will help the scientific community set future directions for the advancement of CPs/MOFs techniques for the effective management of diverse environmental issues.

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Rough Cluster Quality Index Based on Decision Theory

Quality of clustering is an important issue in application of clustering techniques. Most traditional cluster validity indices are geometry-based cluster quality measures. This paper proposes a cluster validity index based on the decision-theoretic rough set model by considering various loss functions. Experiments with synthetic, standard, and real-world retail data show the usefulness of the proposed validity index for the evaluation of rough and crisp clustering. The measure is shown to help determine optimal number of clusters, as well as an important parameter called threshold in rough clustering. The experiments with a promotional campaign for the retail data illustrate the ability of the proposed measure to incorporate financial considerations in evaluating quality of a clustering scheme. This ability to deal with monetary values distinguishes the proposed decision-theoretic measure from other distance-based measures. The proposed validity index can also be extended for evaluating other clustering algorithms such as fuzzy clustering.     

Applications of Rough Genetic Algorithms

This paper describes rough genetic algorithms based on the notion of interval values. A gene in a rough genetic algorithm can be represented using an interval. The paper explains how this generalization facilitates development of new genetic operators and evaluation measures. Various operations of rough genetic algorithms are illustrated using a simple document retrieval example. An experiment involving classification of interval-valued traffic patterns demonstrates the usefulness of rough genetic algorithms for real-world applications. A discussion on further extensions of rough genetic algorithms to rough sets is also included.     

Learning Layered Motion Segmentations of Video

We present an unsupervised approach for learning a layered representation of a scene from a video for motion segmentation. Our method is applicable to any video containing piecewise parametric motion. The learnt model is a composition of layers, which consist of one or more segments. The shape of each segment is represented using a binary matte and its appearance is given by the rgb value for each point belonging to the matte. Included in the model are the effects of image projection, lighting, and motion blur. Furthermore, spatial continuity is explicitly modeled resulting in contiguous segments. Unlike previous approaches, our method does not use reference frame(s) for initialization. The two main contributions of our method are: (i) A novel algorithm for obtaining the initial estimate of the model by dividing the scene into rigidly moving components using efficient loopy belief propagation; and (ii) Refining the initial estimate using α β-swap and α-expansion algorithms, which guarantee a strong local minima. Results are presented on several classes of objects with different types of camera motion, e.g. videos of a human walking shot with static or translating cameras. We compare our method with the state of the art and demonstrate significant improvements.     

Streamflow Response to Climate Change in the Brahmani River Basin,India

Climate change can significantly affect the water resources availability by resulting changes in hydrological cycle. Hydrologic models are usually used to predict the impacts of landuse and climate changes and to evaluate the management strategies. In this study, impacts of climate change on streamflow of the Brahmani River basin were assessed using Precipitation Runoff Modeling System (PRMS) run under the platform of Modular Modeling System (MMS). The plausible hypothetical scenarios of rainfall and temperature changes were used to assess the sensitivity of streamflow to changed climatic condition. The PRMS model was calibrated and validated for the study area. Model performance was evaluated by using joint plots of daily and monthly observed and simulated runoff hydrographs and different statistical indicators. Daily observed and simulated hydrographs showed a reasonable agreement for calibration as well as validation periods. The modeling efficiency (E) varied in the range of 0.69 to 0.93 and 0.85 to 0.95 for the calibration and validation periods, respectively. Simulation studies with temperature rise of 2 and 4°C indicated 6 and 11% decrease in annual streamflow, respectively. However, there is about 62% increase in annual streamflow under the combined effect of 4°C temperature rise and 30% rainfall increase (T4P30). The results of the scenario analysis showed that the basin is more sensitive to changes in rainfall as compared to changes in temperature.     

High temperature oxidation of Nb-10 at. % W alloy

By means of the “interruption kinetic technique”, as applied to oxidation of tungsten under 0.048 bar O₂, the oxygen diffusion coefficient in growing WO_8−x has been determined for the temperature range of 568–908°C and may be expressed as: D = 6.83 × 10⁻² exp (−29,890/RT), with the activation energy given in cal/mole. Calculations are made to show the influence of temperature on the concentration of oxygen vacancies in WO_3−x, on their free energy of formation and on the ionic conductivity in WO_3−x. From the kinetic data of W oxidation at 800°C, prior to interruption-annealing, values of oxygen diffusion coefficients due to oxygen transport via lattice and short-circuit paths have been calculated as functions of time for growing WO_3−x. A simplified oxidation model is used for evaluation of the oxidation rate constant of W at 800°C.     

Effects of alprostadil and prazosin on motility, viability and membrane integrity of human sperm

PURPOSE: We evaluated the effects of alprostadil, prazosin hydrochloride, and alprostadil/prazosin hydrochloride, agents used in the clinical treatment of male erectile dysfunction, on the motility, viability and membrane integrity of human sperm. MATERIALS AND METHODS: Ten healthy volunteers provided semen samples that were incubated with 0.4 mg./ml. alprostadil, 0.1 and 0.2 mg./ml. prazosin hydrochloride and 0.4 mg./ml. alprostadil plus 0.1 mg./ml. prazosin hydrochloride for 2 hours. Control incubations included polyethylene glycol 1450, the formulation vehicle for the clinical use of alprostadil and prazosin, and Ham's F-10 buffer. Serial evaluations of percent sperm motility, percent viability, membrane function (by hypo-osmotic swelling test) and several computer generated measurements of sperm motion, including straight line velocity, curvilinear velocity, linearity and amplitude of lateral head displacement, were made. RESULTS: None of the agents had a significant impact on the percentage of motile or viable sperm or on sperm membrane function. Incubation with 0.2 mg./ml. prazosin reduced straight line velocity and curvilinear velocity significantly compared with the other agents. These changes were most likely a direct result of the viscosity of the 0.2 mg./ml. prazosin solution and not a cellular or metabolic effect on the sperm. CONCLUSIONS: Alprostadil and prazosin hydrochloride at doses used in transurethral therapy for erectile dysfunction have no effect on the motility, viability and membrane integrity of human sperm.     

Electrical transport properties of bulk amorphous Gex Se1−x

d. c. -Conductivity measurements have been made as a function of temperature (80–330 K) on bulk amorphous samples of Ge_xSe_1?x (0.1 ? x ?0.7), in order to identify the conduction mechanism and to observe the effect of selenium -doping on the d. c.-conductivity of germanium. It is found that for samples with a low concentration of selenium (0. 5? x ? 0. 7 ), conduction in the high temperature region (330-180 K) is due to thermally assisted tunneling of electrons in the localized states at the conduction band edge, and in the low temperature region (80–190 K), conduction takes place through variable range hopping in the localized states near the Fermi level. The addition of selenium is found to increase the amorphicity of the samples. In the samples with a relatively high content of selenium (0.1 ? x ? 0.4), conduction in the entire temperature range of investigation is due to the thermally assisted tunneling of holes in the localized states at the valence band edge.     

Strain field in dilute alloys

Kanzaki lattice static method is generalized to evaluate impurity-induced strain field in the dilute alloys. The displacements of nearest neighbours of impurity are found positive and negative, however, their magnitudes are found decreasing away from the impurity.     

Statistical,Evolutionary, and Neurocomputing Clustering Techniques: Cluster-Based vs Object-Based Approaches

Modern day computers cannot provide optimal solution to the clustering problem. There are many clustering algorithms that attempt to provide an approximation of the optimal solution. These clustering techniques can be broadly classified into two categories. The techniques from first category directly assign objects to clusters and then analyze the resulting clusters. The methods from second category adjust representations of clusters and then determine the object assignments. In terms of disciplines, these techniques can be classified as statistical, genetic algorithms based, and neural network based. This paper reports the results of experiments comparing five different approaches: hierarchical grouping, object-based genetic algorithms, cluster-based genetic algorithms, Kohonen neural networks, and K-means method. The comparisons consist of the time requirements and within-group errors. The theoretical analyses were tested for clustering of highway sections and supermarket customers. All the techniques were applied to clustering of highway sections. The hierarchical grouping and genetic algorithms approaches were computationally infeasible for clustering a larger set of supermarket customers. Hence only Kohonen neural networks and K-means techniques were applied to the second set to confirm some of the results from previous experiments.