Mini Max Wallpaper

Mini Max company formulated a problem for the automatic calculation of the number of wallpaper rolls necessary for decorating a room with wallpaper. The final goal is the development of a web-based calculator open for use to both Mini Max staff and the general public. We propose an approach for reducing the studied problem to the one-dimensional cutting-stock problem. We show this in details for the case of plain wallpapers as well as for the case of patterned wallpapers with straight match. The one-dimensional cutting-stock problem can be formulated as a linear integer programming problem. We develop an approach for calculating the needed number of wallpapers for relatively small problems, create an algorithm in a suitable graphical interface and make different tests. The tests show the efficiency of the proposed approach compared with the existent (available) wallpapers’ calculators

Shear Alignment and Instability of Smectic Phases

We consider the shear flow of well-aligned one-component smectic phases, such as thermotropic smectics and lamellar diblock copolymers, below the critical region. We show that, as a result of thermal fluctuations of the layers, parallel ($c$) alignment is generically unstable and perpendicular ($a$) alignment is stable against long-wavelength undulations. We also find, surprisingly, that both $a$ and $c$ are stable for a narrow window of values for the anisotropic viscosity.Comment: To appear in PRL. Revtex, 1 figure

DNA methylation patterns of Brachypodium distachyon chromosomes and their alteration by 5-azacytidine treatment

Sequential immunolocalisation of 5-methylcytosine (5-MeC) and fluorescence in situ hybridisation with chromosome-specific BAC clones were performed on Brachypodium distachyon mitotic metaphase chromosomes to determine specific DNA methylation patterns of each chromosome in the complement. In the majority of cells examined, chromosomes Bd4 and Bd5, which bear the loci of 5S and 35S ribosomal DNA, respectively, had characteristic 5-MeC patterns. In contrast, the distribution of 5-MeC along the metacentric chromosome pairs Bd1, Bd2 and Bd3 was more variable. There were numerous differences in distribution of methylated sites between homologous chromosomes as well as between chromosome arms. Some chromosome sites, such as pericentromeric regions, were highly methylated in all chromosomes. Additionally, the influence of a hypomethylating agent, 5-azacytidine, on B. distachyon chromosome methylation patterns was confirmed. It was found that some chromosome pairs underwent demethylation more easily than others, but there was no apparent regularity in demethylation of particular chromosome segments

Comparative analysis of selected CAD enviroments used for calculations of electrical machines design

W pracy przedstawiono wyniki badań numerycznych obliczeń częstotliwości własnych wybranych elementów maszyny elektrycznej. Obliczenia przeprowadzono w dwóch środowiskach wykorzystujących metodę elementów skończonych (MES) - Autodesk Inventor oraz COMSOL. Wyniki obliczeń dla wybranych częstotliwości zaprezentowano w formie graficznej. Obliczenia wykazały, że dla stosunkowo prostych struktur w obliczeniach tego typu możliwe jest wykorzystanie modułów MES zaimplementowanych jako rozszerzenie systemów wspomagających proces projektowania CAD. Uzyskiwane wyniki są zadawalające. W przypadku konieczności dokładnego modelowania zjawisk wytrzymałościowych w konstrukcjach o złożonej strukturze i geometrii pożądaną dokładność zapewniają obliczenia prowadzone z wykorzystaniem dedykowanych pakietów.This paper presents the results of numerical experiment of calculation of natural frequencies of the electrical machine selected parts. Calculations were carried out in two environments using finite element method (FEM) - Autodesk Inventor and COMSOL. The results of calculations for selected frequencies are presented in graphical form. The experiment showed that for relatively simple structures for the calculations of this type can be used MES modules implemented as an extension of systems supporting CAD design process. The results obtained are satisfactory. For accurate modeling of strength in structures with complex geometry, structure and provide the desired accuracy of calculations performed using a dedicated package

Numerical modelling of influence of the asymmetry of the mmf compesation windings on magnetic field distribution

A numerical model of a DC machine with compensation and commutation windings connected into parallel circuit limbs was presented in this paper. The influence of the current distribution asymmetry in above mentioned limbs on the commutation process was analysed. Selected results of numerical calculations were presented