mount bidkhan stratovolcano is located in the central iranian volcanic belt. it is composed of several types of pyroclastic deposits, lava flows and intrusive bodies. textural and chemical characteristics of plagioclase phenocrysts from the eruptive products volcanic edifice, record complex magma mixing events over the lifetime of the volcano. evidences such as xenocrystic high al+ti clinopyrox...

We consider a supersymmetric SO(10) model with a SU(3) symmetry of flavour in which fermion masses emerge via the see-saw mixing with superheavy fermions in 16+16 representations. In this model the dangerous D = 5 operators of proton decay are naturally suppressed and flavour-changing supersymmetric effects are under control. The mass matrices for all fermion types (up and down quarks, charged ...

By using recent results from graph theory, including the Strong Perfect Graph Theorem, we obtain a unifying framework for a number of tractable classes of constraint problems. These include problems with chordal microstructure; problems with chordal microstructure complement; problems with tree structure; and the “all-different” constraint. In each of these cases we show that the associated mic...

A graph G is perfect if for every induced subgraph H, the chromatic number of H equals the size of the largest complete subgraph of H, and G is Berge if no induced subgraph of G is an odd cycle of length at least 5 or the complement of one. The “strong perfect graph conjecture” (Berge, 1961) asserts that a graph is perfect if and only if it is Berge. A stronger conjecture was made recently by C...

Our proof (with Robertson and Thomas) of the strong perfect graph conjecture ran to 179 pages of dense matter; and the most impenetrable part was the final 55 pages, on what we called “wheel systems”. In this paper we give a replacement for those 55 pages, much easier and shorter, using “even pairs”. This is based on an approach of Maffray and Trotignon.

A c-ary Perfect Factor is a set of uniformly long cycles whose elements are drawn from a set of size c, in which every possible v-tuple of elements occurs exactly once. In the binary case, i.e. where c = 2, these perfect factors have previously been studied by Etzion, [2], who showed that the obvious necessary conditions for their existence are in fact sufficient. This result has recently been ...

The application of stable isotope analysis to ecology requires estimating the contribution of different isotopic sources to the isotopic signatures of an animal's tissues using mixing models. These models make the physiologically unrealistic assumption that assimilated nutrients are disassembled into their elemental components and that these atoms are then reassembled into biomolecules. We quan...

This study was carried out to deal with reducing feed cost and provide high quality poultry for the local breed of quail through provision mixer machines equipped fermentation equipment. Mixing using is much faster, accurate less energy consuming compered manual mixing. Poultry mixing machine designed, fabricated tested. The consists two function as fermented liquid spray. design computations h...