Easy Development and Integration of Science Gateways with Vine Toolkit

Science Gateways are web portal environments targeted for a given community and dedicated to specific scientific needs. Scientists require a different set of tools, applications, visualizations, data integration patterns, to be able to satisfy unique requirements of different research domains. To enable users to benefit from remote computational and storage resources, a web portal framework should support an easy integration and access to the e-Infrastructure. In this paper we present results of our research and development activities leading to the release of the Vine Toolkit framework integrated with Adobe Flex/BlazeDs technologies. It offers a set of unified and abstract APIs for different Grid middleware and a rich graphic presentation layer. Additionally, it automates the integration process with portal frameworks, such as Liferay or GridSphere. Vine Toolkit introduces a concept of subprojects which extend core APIs or define new low level components and web applications. This way, a Science Gateway prototyping process is definitely shortened. Consequently, it allows programmers to build software components that can be reused in a simple manner for different Science Gateways.     

New analytical benchmarks for topology optimization and their implications. Part I: bi-symmetric trusses with two point loads between supports

Extending some results by Sokó? and Lewiński (Struct Multidisc Optim 42:835–853, 2010), the optimal topology of bi-symmetric trusses with two symmetrically placed pointloads is determined analytically, and verified by highly accurate numerical calculations. It is rather remarkable that Michell’s best-known classical solution had to wait over hundred years for its generalization from one to two point loads. Some implications of these solutions, including properties of so-called O-regions, are also discussed.     

On calibration of orthotropic elastic-plastic constitutive models for paper foils by biaxial tests and inverse analyses

In this paper two procedures are developed for the identification of the parameters contained in an orthotropic elastic-plastic-hardening model for free standing foils, particularly of paper and paperboard. The experimental data considered are provided by cruciform tests and digital image correlation. A simplified version of the constitutive model proposed by Xia et al. (Int J Solids Struct 39:4053?C4071, 2002) is adopted. The inverse analysis is comparatively performed by the following alternative computational methodologies: (a)?mathematical programming by a trust-region algorithm; (b)?proper orthogonal decomposition and artificial neural network. The second procedure rests on preparatory once-for-all computations and turns out to be applicable economically and routinely in industrial environments.     

An object-oriented implementation of a solver of the time-dependent Schrödinger equation using the CUDA technology

We present a set of C++ classes which allow one to use the graphics card processor?s cores for quantum ab initio simulations, i.e. a direct solving of the time-dependent Schrödinger equation, gaining the benefits from the parallel architecture of the graphical processor units. We use the Chebyshev polynomial and FFT algorithm. The solution is based on NVIDIA CUDA technology. The speed-up factor in the test runs of our classes performed using the graphics card processor can even be of order of 300 in comparison with the test runs using only the single core of CPU. Not only the Schrödinger equation can be integrated using the presented solver. With only small changes it can be used for solving the nonlinear Gross–Pitaevskii equation of BEC?s dynamics, the heat equation, the diffusion equation or other parabolic partial differential equations of second order.¹Program summaryProgram title: QnDynCUDACatalogue identifier: AELE_v1_0Program summary URL: http://cpc.cs.qub.ac.uk/summaries/AELE_v1_0.htmlProgram obtainable from: CPC Program Library, Queen?s University, Belfast, N. IrelandLicensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.htmlNo. of lines in distributed program, including test data, etc.: 101 359No. of bytes in distributed program, including test data, etc.: 3 165 228Distribution format: tar.gzProgramming language: C++, C for CUDAComputer: Graphics card with CUDA technology recommendedOperating system: No limits (tested on 32-bit and 64-bit Windows and 64-bit Linux)Has the code been vectorized or parallelized?: Yes, number of processors used – one CPU core and all CUDA cores of the selected processor of graphics cardRAM: Dependent on user?s parameters, typically between several tens of megabytes and several gigabytes (this concerns also the graphics card?s memory)Supplementary material: Test input and output files (approx. 3.4 Gigabytes) are availableClassification: 2.7, 6.5Nature of problem: Solving the time-dependent Schrödinger equation.Solution method: FFT and Chebyshev polynomial algorithm, CUDA technology.Running time: Every test example included in the distribution package takes approximately an hour or so if the GPU is engaged and a day or so if only CPU is used.     

Solvent selection for CO<Subscript>2</Subscript> capture from gases with high carbon dioxide concentration

Amine absorption processes are widely used to purify both refinery and process gases and natural gas. Recently, amine absorption has also been considered for application to CO₂ removal from flue gases. It has a number of advantages, but there is one major disadvantage-high energy consumption. This can be solved by using an appropriate solvent. From a group of several dozen solutions, seven amine solvents based on primary amine, tertiary amine and sterically hindered amine were selected. For the selected solutions research was conducted on CO₂ absorption capacity, an absorption rate and finally a solvent vapor pressure. Furthermore, tests on an absorber-desorber system were also performed. In this study the most appropriate solvent for capturing CO₂ from flue gases with higher carbon dioxide concentrations was selected.     

Polypropylene‐based composites containing sorbitol‐based nucleating agent and siloxane‐silsesquioxane resin

Composites based on isotactic polypropylene (iPP) modified with a sorbitol derivative (NX8000) and siloxane‐silsesquioxane resin containing reactive phenyl groups (SiOPh) were prepared by melt extrusion. These iPP‐based formulations were investigated to evaluate the influence of such additives on the crystallization behavior and morphology, as well as on thermal and mechanical properties. The addition of sorbitol fastens crystallization kinetics of iPP and leads to higher transparency of iPP films. Upon the incorporation of siloxane‐silsesquioxane resin, no further effect on iPP crystallization kinetics is evidenced by calorimetry, optical microscopy, and X‐ray diffraction analysis. Transparency of iPP‐based composites is improved upon the addition of sorbitol, but decreased when SiOPh is added to the formulation. The composites are also stiffer, compared to neat polypropylene with a decreased elongation at break and increased Young's modulus values, with increasing amounts of fillers. The effect of the siloxane‐silsesquioxane resin on properties of iPP/NX8000/SiOPh composites was explained taking into account compatibility of the components and morphology of the composites. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43476.     

In vitro evaluation of polymeric formulations designed for use in alveolar osteitis

In this article, we present a potential use of biodegradable polymers as a drug‐delivery system designed for alveolar osteitis (AO) management. The release characteristics of lidocaine hydrochloride from alginate or hyaluronate xerogels, which covered the microcrystalline chitosan scaffold, were examined as drug carriers, wound dressings, and potential devices in bone regeneration. The materials were characterized by Fourier transform infrared spectroscopy to confirm that there was no additional covalent bonding between the polymeric membranes and the anesthetic agent. Surface‐eroding matrices (ca. 120 μm) encapsulated the main substance, and the morphologies of all of the structures were measured by scanning electron microscopy. Positive results were obtained, and the data suggested an important impact of materials selection on the physicochemical properties and drug release. Additionally, the mechanical properties, such as the hardness, adhesiveness, springiness, and cohesiveness, of the tested materials were evaluated. A study of the swelling confirmed one of the assumptions that the materials could be used as a potential wound dressing and emphasized the resistance of the materials in the condition imitating the movement of the masticatory system. A cytotoxicity test of the formulations was performed to prove the materials’ nontoxicity. The aim of this study was to design and propose an in vitro evaluation of a new drug formulation as a potential application for the treatment of AO. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 42991.     

Discrete time congestion controllers for multi-source connection-oriented communication networks

In this article, a new, discrete time, non-linear flow control strategy for a connection-oriented, multi-source communication network is proposed. The strategy effectively exploits the Smith principle in order to avoid data loss in the network, and to ensure full utilisation of the bottleneck link available bandwidth. The desirable properties of the proposed control strategy are preserved, even though the connection round trip times may be determined imprecisely. Furthermore, an enhanced strategy, which employs extra feed-forward bandwidth compensation, and reduces the influence of the available bandwidth variations on the steady state queue length in the network, is introduced. Finally, the proposed strategy is modified to be appropriate for application when the number of active connections changes during the control process, and new conditions for no data loss and full bandwidth utilisation are formulated and strictly proved. Since the modified strategy allows for arbitrary resource allocation among the controlled virtual circuits, the max–min fairness criteria can be satisfied.     

Frisch scheme identification for dynamic diagonal bilinear models

The article addresses the problem of dynamic system identification in the errors-in-variables framework for a class of discrete-time time-invariant input–output bilinear models when subjected to a white input signal. The proposed algorithm is based on an extension of the bias-compensated least squares method and utilises the Frisch scheme equations to determine the parameter vector together with the variances of the input and output noise sequences. The appropriateness of the approach is analysed and its performance evaluated when compared to other errors-in-variables identification techniques by means of a Monte Carlo simulation. The results obtained demonstrate the accuracy of the proposed method and the performance in terms of noise robustness is also observed.