A spectral collocation technique based on integrated Chebyshev polynomials for biharmonic problems in irregular domains

In this paper, an integral collocation approach based on Chebyshev polynomials for numerically solving biharmonic equations [N. Mai-Duy, R.I. Tanner, A spectral collocation method based on integrated Chebyshev polynomials for biharmonic boundary-value problems, J. Comput. Appl. Math. 201 (1) (2007) 30–47] is further developed for the case of irregularly shaped domains. The problem domain is embedded in a domain of regular shape, which facilitates the use of tensor product grids. Two relevant important issues, namely the description of the boundary of the domain on a tensor product grid and the imposition of double boundary conditions, are handled effectively by means of integration constants. Several schemes of the integral collocation formulation are proposed, and their performances are numerically investigated through the interpolation of a function and the solution of 1D and 2D biharmonic problems. Results obtained show that they yield spectral accuracy

A second-order continuity domain-decomposition technique based on integrated Chebyshev polynomials for two-dimensional elliptic problems

This paper presents a second-order continuity non-overlapping domain decomposition (DD) technique for numerically solving second-order elliptic problems in two-dimensional space. The proposed DD technique uses integrated Chebyshev polynomials to represent the solution in subdomains. The constants of integration are utilized to impose continuity of the second-order normal derivative of the solution at the interior points of subdomain interfaces. To also achieve a C2 (C squared) function at the intersection of interfaces, two additional unknowns are introduced at each intersection point. Numerical results show that the present DD method yields a higher level of accuracy than conventional DD techniques based on differentiated Chebyshev polynomials

Ein Liederabend, April 5, 1988

This is the concert program of the Ein Liederabend performance on Tuesday, April 5, 1988 at 8:00 p.m., at the Concert Hall, 855 Commonwealth Avenue. Works performed were Mai non intensi by Giacomo Antonio Perti, Have you seen but a white lily grow? by Anonymous, c. 1617, Der Jüngling am Bachee by Franz Schubert, Danza, danza fanciulla gentile by Francesco Durante, Dove sei from "Rodelinda" by George Frideric Handel, Von ewiger Liebe by Johannes Brahms, Music for a while from "Oedipus" by Henry Purcell, Sweeter than Roses from "Pausanias" by H. Purcell, Der Musensohn by F. Schubert, Freudvoll und Leidvoll by Ludwig van Beethoven, Mädchenlied by J. Brahms, Am Bergbach by Edvard Grieg, Un moto di gioia by Wolfgang Amadeus Mozart, Mai by Gabriel Fauré, Notre amour by G. Fauré, and "El paño moruno," "Asturiana," and "Jota" from "Siete canciones populares españolas" by Manuel de Falla. Digitization for Boston University Concert Programs was supported by the Boston University Humanities Library Endowed Fund

Interesting species of the genus Helicopsyche von Siebold (Trichoptera: Helicopsychidae) from Vietnam

Three new species of the genus Helicopsyche von Siebold (Trichoptera: Helicopsychidae), H. botosaneanui, H. verrucaspinosa, and H. inusitata, from Vietnam are described, and 1 new country record, H. pathoumthongi Johanson and Malm, is reported. The male of H. boniata Malicky and Chantaramongkol is redescribed to facilitate comparisons with two of the new species

Concentration of Hot Water Extracts of Anthocyanins obtained from Muscadine Grape Pomace using Membrane-Osmotic Distillation

Anthocyanins are well known for their health-promoting benefits. The goal of this study was to evaluate a distillation-based membrane technology to concentrate aqueous anthocyanins extracted from muscadine grape pomace using polypropylene (PP) or ethylene chlorotrifluoroethylene (ECTFE) membranes. A hot water extraction method was utilized to extract the anthocyanins from the pomace. A pre-experimental run using DI water as feed was conducted to optimize the NaCl brine concentration for osmotic distillation and it was determined that 4M was the optimal concentration. The aqueous anthocyanins extraction was filtrated through a series of filter of different pore sizes before the distillation process. Membrane distillation (MD), osmotic distillation (OD), and membrane osmotic distillation (OMD) were all carried out over a 6-hour period to determine the optimal distillation process. Among the three processes, OMD demonstrated the highest permeate flux value, therefore, it was utilized to conduct the concentration using either PP or ECTFE membranes. The anthocyanins contents before and after the concentration process were measured by High Performance Liquid Chromatography machine. The result shows that OMD paired with ECTFE membrane concentrated the aqueous anthocyanins up to 196% but OMD with PP membrane exhibited a better performance. Concentrating the aqueous anthocyanin extract 280% over a 12-hour period. In addition, the quality of the concentrate was also investigated in terms of NaCl transferring across the membrane to the feed solution. only 0.02% - 0.03% of NaCl was transferred across the membrane to the feed side, indicating it is feasible to obtain concentrated anthocyanin extracts with low salt concentratio

Non-equilibrium behavior of the magnetization in the helimagnetic phases of the rare earth alloys R_{1-x}Y_{x} (R = Gd, Tb, Dy)

We have performed DC and AC magnetization measurements for the rare-earth magnetic alloy systems Gd_{0.62}Y_{0.38}, Tb_{0.86}Y_{0.14}, and Dy_{0.97}Y_{0.03}. These materials commonly exhibit a proper helical magnetic structure, and ferromagnetic structure at lower temperatures.In all of these materials, a difference between zero-field-cooled (ZFC) magnetization and field-cooled (FC) magnetization and a hysteresis loop in the M-H curve have been observed in the helimagnetic phases. The non-equilibrium behavior is possibly caused by a common nature, e. g., chiral domain structures. In addition to the above behavior, strong non-linearity of the magnetization and slow spin dynamics have been observed around the N'eel temperature only in Gd$_{0.62}$Y$_{0.38}$. The spin-glass like behavior observed in Gd_{0.62}Y_{0.38} could be related to a novel glassy state such as a helical-glass state.Comment: 7pages 4 figures, 20th International Conference on Magnetism (ICM2015