When is RPⁿ×Spin(n) Diffemorphic to Sⁿ×SO(n) and how

We show that the spaces in the title, whose corresponding homotopy groups are isomorphic, are homotopy equivalent only when n = 3 or n = 7. We produce an explicit diffeomorphism in the only non trivial case, n = 7.</p

Konzeption und prototypische Realisierung eines Informationssystems für das Prozeßmonitoring und -controlling

Durch die Überwachung der aktuellen Prozeßstatus (Prozeßmonitoring) sowie die Verdichtung und Gegenüberstellung dieser Istdaten mit Solldaten (Prozeßcontrolling) wird die Bewertung der Prozeßqualität möglich. Zur informationstechnischen Unterstützung dieser Aufgaben dienen Prozeßinformationssysteme. In diesem Arbeitsbericht werden nach einer Einordnung dieser Aufgaben in einem Vorgehensmodell des Prozeßmanagements Intention und Aufbau von Prozeßinformationssystemen beschrieben. Konkretisiert werden die Ausführungen durch die Vorstellung des Prototypen PISA, dessen Architektur und Funktionalität erläutert werden.<br/

Исследования по применению флокулянтов для интенсификации работы сгустительного и обезвоживающего оборудования

Наведено результати лабораторних досліджень та промислових випробувань використання різних флокулянтів для інтенсифікації роботи згущувального та зневоднювального обладнання на ГЗФ "Самсонівська" ПАТ "Краснодонвугілля" і ВАТ "ЦЗФ "Добропільська". Виявлено фактори, які необхідно враховувати при виборі синтетичних флокулянтів та режимів флокуляції для інтенсифікації процесів згущення та зневоднення шламів.Приведены результаты лабораторных исследований и промышленных испытаний использования различных флокулянтов для интенсификации работы сгустительного и обезвоживающего оборудования на ГОФ "Самсоновская" ПАО "Краснодонуголь" и ОАО "ЦОФ "Добропольская". Выявлены факторы, которые необходимо учитывать при выборе синтетических флокулянтов и режимов флокуляции для интенсификации процессов сгущения и обезвоживания шламов.The results of laboratory and industrial tests of various flocculant using for the intensification of the thickening and dewatering equipment for МDF "Samsonovskaya" PJSC "Krasnodoncoal" and JSC "CDF" Dobropilska" are shown. The factors which are necessary for consideration at choosing a synthetic flocculants and flocculation regimes to intensify the process of thickening and dewatering of sludge are revealed

Phyllobacterium catacumbae sp. nov., a member of the order 'Rhizobiales' isolated from Roman catacombs

Two strains were isolated from tuff, a volcanic rock that forms the walls of the Roman Catacombs of Saint Callixtus in Rome, Italy. A polyphasic approach using nutritional and physiological tests, reactions to antibiotics, fatty acid profiles, DNA base ratios, DNA-DNA reassociation and 16S rRNA gene sequence comparisons showed that the two isolates belong to a novel species within the genus Phyllobacterium. The species Phyllobacterium catacumbae sp. nov. is proposed. The type strain is CSC19T (=CECT 5680T=LMG 22520T).V. J. and L. L. received fellowships from the Spanish Ministry of Education and Science (MEC), I3P programme and J. M. G. is supported by an MEC contract from the ‘Ramón y Cajal’ program. This study was supported by EC project EVK4-CT2000-00028 and MEC project BTE2002-04492-C02-01.Peer Reviewe

Robust conveniently sealable container for high-temperature single-crystal growth out of reactive melts with high vapor pressure

The high-temperature crystal growth of intermetallics often asks for sealing of the materials in a protective atmosphere. Here, we report on the development of a convenient sealing method for alkali-containing melts, with high vapor pressure and reactivity. Our newly designed container made of high-temperature resistant steel can be sealed manually and reliably without any air exposure of the containing material. The closed container may be heated in air up to at least 1150 ∘C. The containers were applied for the development and optimization of a high-temperature self-flux growth of KFe1-x Ag1+y Ch2 (Ch = Se, Te) single crystals. Their crystal structure and the low-temperature electrical resistance are presented. The successful growths of these air-sensitive materials out of a reactive self-flux confirm the reliability of the container

Approval Voting on Dichotomous Preferences

The aim of this paper is to find normative foundations of Approval Voting. In order to show that Approval Voting is the only social choice function that satisfies anonymity, neutrality, strategy-proofness and strict monotonicity we rely on an intermediate result which relates strategy-proofness of a social choice function to the properties of Independence of Irrelevant Alternatives and monotonicity of the corresponding social welfare function. Afterwards we characterize Approval Voting by means of strict symmetry, neutrality and strict monotonicity and relate this result to May's Theorem. Finally, we show that it is possible to substitute the property of strict monotonicity by the one efficiency of in the second characterization.This research was undertaken with support from the fellowship 2001FI-00451 of the Generalitat de Catalunya and from the research grant BEC2002-02130 of the Ministerio de Ciencia y Tecnología of Spain

Cohomogeneity one manifolds and selfmaps of nontrivial degree

We construct natural selfmaps of compact cohomgeneity one manifolds with finite Weyl group and compute their degrees and Lefschetz numbers. On manifolds with simple cohomology rings this yields in certain cases relations between the order of the Weyl group and the Euler characteristic of a principal orbit. We apply our construction to the compact Lie group SU(3) where we extend identity and transposition to an infinite family of selfmaps of every odd degree. The compositions of these selfmaps with the power maps realize all possible degrees of selfmaps of SU(3).Comment: v2, v3: minor improvement

Derivation of determinantal structures for random matrix ensembles in a new way

There are several methods to treat ensembles of random matrices in symmetric spaces, circular matrices, chiral matrices and others. Orthogonal polynomials and the supersymmetry method are particular powerful techniques. Here, we present a new approach to calculate averages over ratios of characteristic polynomials. At first sight paradoxically, one can coin our approach "supersymmetry without supersymmetry" because we use structures from supersymmetry without actually mapping onto superspaces. We address two kinds of integrals which cover a wide range of applications for random matrix ensembles. For probability densities factorizing in the eigenvalues we find determinantal structures in a unifying way. As a new application we derive an expression for the k-point correlation function of an arbitrary rotation invariant probability density over the Hermitian matrices in the presence of an external field.Comment: 36 pages; 2 table

Facies Distribution, Sequence Stratigraphy, Chemostratigraphy, and Diagenesis of the Middle-Late Triassic Al Aziziyah Formation, Jifarah Basin, NW Libya

This study presents the depositional facies, sequence stratigraphy, chemostratigraphy and diagenetic evolution of the Middle-Late Triassic Al Aziziyah Formation, Jifarah Basin northwest Libya. Eight measured sections were sampled and analyzed. High-resolution stable carbon isotope data were integrated with an outcrop-based sequence stratigraphic framework, to build the stratigraphic correlation, and to provide better age control of the Al Aziziyah Formation using thin section petrography, cathodoluminescence (CL) microscopy, stable isotope, and trace element analyses. The Al Aziziyah Formation was deposited on a gently sloping carbonate ramp and consists of gray limestone, dolomite, and dolomitic limestone interbedded with rare shale. The Al Aziziyah Formation is predominantly a 2nd-order sequence (5-20 m.y. duration), with shallow marine sandstone and peritidal carbonate facies restricted to southernmost sections. Seven 3rd-order sequences were identified (S1-S7) within the type section. North of the Ghryan Dome section are three mainly subtidal sequences (S8-S10) that do not correlate to the south. Shallowing upward trends define 4th-5th order parasequences, but correlating these parasequences between sections is difficult due to unconformities. The carbon isotope correlation between the Ghryan Dome and Kaf Bates sections indicates five units of δ13C depletion and enrichment (sequences 3-7). The enrichment of δ13C values in certain intervals most likely reflects local withdrawal of 12C from the ocean due to increased productivity, as indicated by the deposition of organic-rich sediment, and/or whole rock sediment composed of calcite admixed with aragonite. The depletion of δ13C is clearly associated with exposure surfaces and with shallow carbonate facies. Heavier δ18O values are related to evaporetic enrichment of 18O, whereas depletion of δ18O is related to diagenesis due to freshwater input. Al Aziziyah Formation diagenetic events indicate: 1) initial meteoric and shallow burial; 2) three types of dolomite D1, D2 and D3 were most likely formed by microbial, seepage reflux and burial processes, respectively; and 3) diagenetic cements cannot be related to the arid, mega-monsoonal climate of the Triassic and most likely formed subsequently in a humid, meteoric setting