Kinetic investigation of the radical polymerization of N-acryloylpiperidine in solution

The kinetics of free radical polymerizations of N-acryloylpiperidine (NAPi) were studied in benzene (Bz) using 2,2′-azobisisobutyronitrile (AIBN) as initiator. The activation energy was determined to be 111.7 kJ mol^?1. The overall rate of polymerization of the NAPi-AIBN-Bz system at 60°C was investigated as a function of monomer and initiator concentrations. Deviation from normal kinetics was observed with an order of 1.48 with respect to the monomer. The observed dependence of the rate constants k_p/k on monomer concentration could not be explained by the diffusion theory or the theory of electron donor-acceptor (EDA) complexes. The observed data have, however, been satisfactorily interpreted by the ‘hot’ radical theory.     

Multiple network alignment on quantum computers

Comparative analyses of graph-structured datasets underly diverse problems. Examples of these problems include identification of conserved functional components (biochemical interactions) across species, structural similarity of large biomolecules, and recurring patterns of interactions in social networks. A large class of such analyses methods quantify the topological similarity of nodes across networks. The resulting correspondence of nodes across networks, also called node alignment, can be used to identify invariant subgraphs across the input graphs. Given \(k\) graphs as input, alignment algorithms use topological information to assign a similarity score to each \(k\) -tuple of nodes, with elements (nodes) drawn from each of the input graphs. Nodes are considered similar if their neighbors are also similar. An alternate, equivalent view of these network alignment algorithms is to consider the Kronecker product of the input graphs and to identify high-ranked nodes in the Kronecker product graph. Conventional methods such as PageRank and HITS (Hypertext-Induced Topic Selection) can be used for this purpose. These methods typically require computation of the principal eigenvector of a suitably modified Kronecker product matrix of the input graphs. We adopt this alternate view of the problem to address the problem of multiple network alignment. Using the phase estimation algorithm, we show that the multiple network alignment problem can be efficiently solved on quantum computers. We characterize the accuracy and performance of our method and show that it can deliver exponential speedups over conventional (non-quantum) methods.     

A universal quantum circuit scheme for finding complex eigenvalues

We present a general quantum circuit design for finding eigenvalues of non-unitary matrices on quantum computers using the iterative phase estimation algorithm. In addition, we show how the method can be used for the simulation of resonance states for quantum systems.     

Graphical Control Interface for Construction and Maintenance Equipment

This paper discusses graphical interfaces to improve equipment control in construction and facility∕infrastructure maintenance environments. Most large construction and maintenance machines are difficult to control because of insufficient visual feedback to equipment operators. In many emerging applications such as hazardous waste cleaning, it is also necessary to control such equipment from a distance using teleoperation techniques. Initial evidence indicates that real-time updated graphical representation of equipment and work environments can enhance equipment control by providing better spatial perception to the equipment operator. Real-time simulation and task planning with graphical models can also ensure safe and reliable operation of equipment. However, graphical control interfaces require careful design for successful results as it is very difficult to generate exact graphical models of unstructured and dynamic environments such as construction and maintenance. Design of graphical control interfaces for construction equipment also requires knowledge in various technological areas. In this paper, design issues and principles for graphical control interfaces for construction and maintenance equipment are presented. The usefulness of graphical control interfaces is also presented through performance tests of a teleoperated clinker clearing robot for power plant maintenance.     

Detection of breast abnormalities in digital mammograms using the electromagnetism-like algorithm

Multimedia Tools and Applications - The detection of abnormalities in the breast at an early stage can be so helpful for breast cancer treatment. Currently, mammography is the cheapest and the most...     

Performance analysis and optimization of high capacity pulse tube refrigerator

High capacity pulse tube refrigerator (HCPTR) is a new generation of cryocoolers tailored to provide more than 250 W of cooling power at cryogenic temperatures. The most important characteristics of HCPTR when compared to other types of pulse tube refrigerators are a powerful pressure wave generator, and an accurate design. In this paper the influence of geometrical and operating parameters on the performance of a double inlet pulse tube refrigerator (DIPTR) is studied. The model is validated with the existing experimental data. As a result of this optimization, a new configuration of HCPTR is proposed. This configuration provides 335 W at 80 K cold end temperature with a frequency of 50 Hz and COP of 0.05.     

Optical anisotropy in self-assembled InAs nanostructures grown on GaAs high index substrate

We present a study of the optical properties of InAs self-assembled nanostructures grown by molecular beam epitaxy on GaAs(11N)A substrates (N?=?3-5). Photoluminescence (PL) measurements revealed good optical properties of InAs quantum dots (QDs) grown on GaAs(115)A compared to those grown on GaAs(113)A and (114)A orientations substrate. An additional peak localized at 1.39 eV has been shown on PL spectra of both GaAs(114)A and (113)A samples. This peak persists even at lower power density. Supporting on the polarized photoluminescence characterization, we have attributed this additional peak to the quantum strings (QSTs) emission. A theoretical study based on the resolution of the three dimensional Schr?dinger equation, using the finite element method, including strain and piezoelectric-field effect was adopted to distinguish the observed photoluminescence emission peaks. The mechanism of QDs and QSTs formation on such a high index GaAs substrates was explained in terms of piezoelectric driven atoms and the equilibrium surfaces at edges.