Seismic analyses of shallow tunnels by dynamic centrifuge tests and finite elements

The increments of internal forces induced in a tunnel lining during earthquakes can be assessed with several procedures at different levels of complexity. However, the substantial lack of well-documented case histories still represents a difficulty in order to validate any of the methods proposed in literature. To bridge this gap, centrifuge model tests were carried out on a circular aluminium tunnel located at two different depths in dense and loose dry sand. Each model has been instrumented for measuring soil motion and internal loads in the lining and tested under several dynamic input signals. The tests performed represented an experimental benchmark to calibrate dynamic analyses with different approaches to account for soil-tunnel kinematic interaction. © 2009 IOS Press.

Vibrations of coupled cylindrical-conical shells

The free vibrational characteristics of coupled conical-cylindrical shells is presented. The equations of motion for the cylindrical shell are solved using a wave approach while the equations of motion for the conical shells are solved using a power series solution. The use of both Donnell-Mushtari and Flügge equations of motion are investigated and their limitations are discussed. Results are presented in terms of natural frequencies for different boundary conditions and the purely torsional mode solution is described. The results from the analytical model presented are compared with those obtained from a finite element model solved with Nastran and other data available in literature.

Raman spectroscopy as a versatile tool for studying the properties of graphene.

Raman spectroscopy is an integral part of graphene research. It is used to determine the number and orientation of layers, the quality and types of edge, and the effects of perturbations, such as electric and magnetic fields, strain, doping, disorder and functional groups. This, in turn, provides insight into all sp(2)-bonded carbon allotropes, because graphene is their fundamental building block. Here we review the state of the art, future directions and open questions in Raman spectroscopy of graphene. We describe essential physical processes whose importance has only recently been recognized, such as the various types of resonance at play, and the role of quantum interference. We update all basic concepts and notations, and propose a terminology that is able to describe any result in literature. We finally highlight the potential of Raman spectroscopy for layered materials other than graphene.

Computational engineering design for micro-scale combustion devices: A thermally improved configuration

A multi-objective design optimisation study has been carried out with the objectives to improve the overall efficiency of the device and to reduce the fuel consumption for the proposed micro-scale combustor design configuration. In a previous study we identified the topology of the combustion chamber that produced improved behaviour of the device in terms of the above design criteria. We now extend our design approach, and we propose a new configuration by the addition of a micro-cooling channel that will improve the thermal behaviour of the design as previously suggested in literature. Our initial numerical results revealed an improvement of 2.6% in the combustion efficiency when we applied the micro-cooling channel to an optimum design configuration we identified from our earlier multi-objective optimisation study, and under the same operating conditions. The computational modelling of the combustion process is implemented in the commercial computational fluid dynamics package ANSYS-CFX using Finite Rate Chemistry and a single step hydrogen-air reaction. With this model we try to balance good accuracy of the combustion solution and at the same time practicality within the context of an optimisation process. The whole design system comprises also the ANSYS-ICEM CFD package for the automatic geometry and mesh generation and the Multi-Objective Tabu Search algorithm for the design space exploration. We model the design problem with 5 geometrical parameters and 3 operational parameters subject to 5 design constraints that secure practicality and feasibility of the new optimum design configurations. The final results demonstrate the reliability and efficiency of the developed computational design system and most importantly we assess the practicality and manufacturability of the revealed optimum design configurations of micro-combustor devices. Copyright © 2013 by ASME.

Effect of beta-irradiation on photoluminescence of MOCVD grown GaN

The effect of beta particles interaction on the optical properties of MOCVD grown GaN is reported. A significant change in luminescence properties of GaN is observed after exposing the material with 0.6 MeV beta particles with low dose of 10(12) cm(-2). The results obtained from photoluminescence measurements of irradiated GaN samples in low dose are found contradictory to those reported in literature for samples irradiated with heavy dose (> 10(15) cm(-2)) of electron. An increase in intensity of yellow luminescence has been observed with increasing dose of beta particles which is in disagreement to the already reported results in literature for heavily irradiated samples. A model has been proposed to sort out this inconsistency. The increase in YL intensity at low dose is attributed to the increase in concentration of VGaON complex whereas production of non-radiative VGaON clusters is assumed to justify the decrease in YL intensity at high dose.

Solving MIN UR problem by triangle evolution algorithm with archiving and niche techniques

In this paper, as an extension of minimum unsatisfied linear relations problem (MIN ULR), the minimum unsatisfied relations (MIN UR) problem is investigated. A triangle evolution algorithm with archiving and niche techniques is proposed for MIN UR problem. Different with algorithms in literature, it solves MIN problem directly, rather than transforming it into many sub-problems. The proposed algorithm is also applicable for the special case of MIN UR, in which it involves some mandatory relations. Numerical results show that the algorithm is effective for MIN UR problem and it outperforms Sadegh's algorithm in sense of the resulted minimum inconsistency number, even though the test problems are linear.

The effect of chain flexibility and chain mobility on radiation crosslinking of polymers

Radiation crosslinking of polymers mainly depends on the structure of polymer chain. The flexibility and mobility of chain directly influence the possibility of the reactive radicals recombination. Flexible chain is easier to crosslink than rigid-chain polymer. The latter must be crosslinked at high temperature, as most polymers can only crosslink above their melting point. Structural effect also influences the mechanism of radiation crosslinking of polymers. We find from the results in literature and in our laboratory that, the flexibility chain polymer mainly crosslinked with H type, but the rigid chain polymer mainly crosslinked with Y type. (C) 2001 Published by Elsevier Science Ltd.

C-13 NMR study on the aqueous structure of lanthanide citrate complexes

The aqueous complexation of lanthanide complexes of citrate in pH 7.4 solutions has been studied by using lanthanide-induced shift and relaxation times measurement methods. These results indicate that citrate coordinate via 3-hydroxyl and 3-carboxylate groups with lanthanide ions and form 1:2 (Ln/cit) isostructural complexes through lanthanide series. We suggest a new coordination geometry which is different from that described in literature.

Keats and the Holocaust: Notes towards a post-temporalism

Grovier, Kelly, 'Keats and the Holocaust: Notes towards a post-temporalism', Literature and Theology (2003) 17 (4) pp.361-373 RAE2008

W oczekiwaniu na Paruzję. Myśl eschatologiczna w prawosławnym piśmiennictwie słowiańskim do początku XVI wieku

Wydział Filologii Polskiej i Klasycznej: Instytut Filologii Słowiańskiej

Osobliwości środkowoeuropejskiej przestrzeni literackiej: ironiczni moraliści i ludyczni myśliciele

Autorka, stawiając pytanie o zasadność pojęcia Europy Środkowej, przypomina historię różnic poglądowych pomiędzy czeskimi a polskimi uczonymi na temat (nie)istnienia wspólnoty na tym terytorium: ci pierwsi w XIX wieku głosili ideę panslawizmu, w 30-tych latach XX wieku potrzebę syntezy kultur i literatur słowiańskich, a po II wojnie światowej przeciwstawiali słowiańskość Zachodowi, co wywoływało krytykę tych drugich. Stąd wynika odmienne rozumienie obszaru środkowoeuropejskiego – w Czechach przeważnie lokowanego w granicach Austro-Węgier, zaś w Polsce pojmowanego znacznie szerzej. Natomiast pewnego rodzaju spójny wyróżnik Europy Środkowej można znaleźć w literaturze, przytaczany bywa szczególnie gatunek powieści (np. Kafki, Haška, Musila, Gombrowicza), poprzedzony – jak przypomina autorka – polską gawędą i popularnym w Polsce szkicem fizjologicznym. Zawarty w nich element humoru, przeszedł w stadium satyry, a następnie groteski, tworząc dzięki temu niepowtarzalny odcień humoru środkowoeuropejskiego, często określanego jako drugi wyróżnik omawianego terytorium. Zdaniem autorki, środkowoeuropejska specyfika ściśle związana jest z kodem euroatlantyckim, a w tym właśnie kontekście zawsze powinna być rozpatrywana.

Religijne motywy w tworczości syberyjskiego pisarza Wiktora Astafjewa

Wydział Neofilologii: Instytut Filologii Rosyjskiej

Problemy strefy Euro

Oficjalne kredyty ratunkowe dla niektórych krajów w strefie euro nie mogą zastąpić tam reform, które – poprawiając sytuację gospodarczą – pozwolą odzyskać owym krajom zaufanie rynków finansowych. W literaturze wymienia się dwie główne strukturalne słabości wspólnej waluty (euro): 1. Jednolita polityka pieniądza nie jest w stanie uwzględnić odmienności sytuacji poszczególnych krajów, a wspólny pieniądz nie pozwala na dewaluację w obrębie strefy euro; 2. Strefa euro istnieje bez „unii politycznej”. Artykuł analizuje zasadność tych tez.

Sybilla współczesna. Motywy sybillińskie w literaturze XX wieku

The paper deals with some instances of exploiting the theme of the Sibyl in twentieth century literature, e.g. T.S. Eliot’s The Waste Land, J. Joyce’s Ulysses, M. Butor’s The Modifcation, P. Lagerkvist’s The Sibyl, W. Golding’s The Double Tongue.

„Uksiążkowić świat”, czyli kilka słów o liberaturze

Celem artykułu jest przybliżenie kwestii dotyczących nowego zjawiska w literaturze, choć swymi korzeniami sięgającego czasów bardzo odległych, mianowicie liberatury. Przedstawiam nie tylko podstawowe tezy związane z liberaturą, np. postrzeganie utworu jako integralnej całości, w której następuje stopienie słowa i przestrzeni, ale także swoistą ewolucję form literackich, prowadzącą do narodzin nowego nurtu. Sednem tego procesu jest położenie nacisku na współistnienie formy i treści, obecne już w poezji wizualnej wywodzącej się ze starożytności i średniowiecza, a przybierające na sile w twórczości autorów związanych z XX-wiecznymi ruchami awangardowymi. „Totalne” myślenie o literaturze zyskało najciekawszy wyraz w twórczości autorów liberatów: Zenona Fajfera, Katarzyny Bazarnik i Radosława Nowakowskiego (zarówno praktyków, jak i teoretyków liberatury), których sylwetki oraz dzieła przedstawiam pokrótce w niniejszym artykule.