Comparison of unitary transforms using Franson interferometry

Unknown unitary transforms may be compared to each other in a way which makes it possible to obtain an unambiguous answer, indicating that the transforms are different, already after a single application of each transform. Quantum comparison strategies may be useful for example if we want to test the performance of individual gates in a quantum information or quantum computing network. It is then possible to check for errors by comparing the elements to a master copy of the gate, instead of performing a complete tomography of the gate. In this paper we propose a versatile linear optical implementation based on the Franson interferometer with short and long arms. A click in the wrong output port unambiguously determines that the tested gate is faulty. This set-up can also be used for a variety of other tasks, such as confirming that the two transforms do not commute or do not anticommute.     

Incremental elastic compliance and electric resistance of a cylinder with partial loss in the cross-sectional area

Motivated by material science applications, the paper focuses on quantitative characterization and comparison of two microstructural elements typical for lamellar materials - crack and contacting area - in the context of their effect on macroscopic elastic and conductive (thermal or electrical) properties of a body of finite size. The problem is solved in axisymmetric formulation - axial load or axial heat flux is applied to a circular cylinder containing a centered crack, either internal or external. The latter case corresponds to the welding of two halves of the cylinder at the center. The changes in the elastic and conductive properties of the cylinder due to these types of cracks are obtained in explicit analytical form. It is shown that the contributions of internal and external cracks into elastic and conductive properties are similar if the relative loss in the cross-sectional between two parts of the cylinder is up to 70% for elasticity problem and up to 85% for conductivity problem. We also show that the changes in elastic compliance and conductive properties generated by both microstructural elements are interrelated by cross-property connection identical to one obtained for an unbounded material.     

Coupling the BEM/TBEM and the MFS for the numerical simulation of acoustic wave propagation

The coupling of the boundary element method (BEM)/the traction boundary element method (TBEM) and the method of fundamental solutions (MFS) is proposed for the transient analysis of acoustic wave propagation problems in the presence of multi-inclusions to overcome the limitations posed by each method. The full domain is divided into sub-domains which are modeled using the BEM/TBEM and the MFS, and the sub-domains are coupled with the imposition of the required boundary conditions. The accuracy of the proposed algorithms, using different combinations of BEM/TBEM and MFS, is verified by comparing the solutions against reference solutions. The applicability of the proposed method is shown by simulating the acoustic behavior of a rigid acoustic screen in the vicinity of a dome and by computing the acoustic attenuation provided by a fluid-filled thin inclusion separating two railway tracks in an underground train station.     

Silica nanoparticles as a tool for fluorescence collection efficiency enhancement

In this work we demonstrate enhancement of the fluorescence collection efficiency for chlorophyll-containing photosynthetic complexes deposited on SiO₂ spherical nanoparticles. Microscopic images of fluorescence emission reveal ring-like emission patterns associated with chlorophyll-containing complexes coupled to electromagnetic modes within the silica nanoparticles. The interaction leaves no effect upon the emission spectra of the complexes, and the transient behavior of the fluorescence also remains unchanged, which indicates no influence of the silica nanoparticles on the radiative properties of the fluorophores. We interpret this enhancement as a result of efficient scattering of electromagnetic field by the dielectric nanoparticles that increases collection efficiency of fluorescence emission.     

The Aral Sea and the Dead Sea: Disparate lakes with similar histories

In spite of significant differences in their sizes, depths, salinity and other properties, the Aral Sea and the Dead Sea share many features, as illustrated by a comparison of the histories of both water bodies. Fifteenth and early sixteenth century maps, based on the ‘Geography’ of Ptolemy, contain both lakes. The first successful limnological surveys of the lakes were made in the same year 1848, when Alexey Butakov explored the Aral Sea and William Lynch mapped the Dead Sea. Paintings and drawings by Taras Shevchenko (Aral Sea) and David Roberts (Dead Sea) document the landscapes around the lakes in the first half of the 19th century. The water balance of both lakes has been strongly negative in the past decades, leading to a decreased water surface area and volume for both lakes, their increased salinity and deterioration of their local infrastructures. Complex and expensive mitigation schemes have been proposed for both lakes, based on the import of large quantities of water from distant sources via canals or pipelines (i.e. Siberian rivers or Caspian Sea to supply water to the Aral Sea, Mediterranean Sea or Red Sea, to be connected with the Dead Sea). Less dramatic solutions to improve the local situations already have resulted in improved water quality in the Aral Sea, and partial restoration of its fisheries. In contrast, the Dead Sea remains much too saline to support higher forms of life. Nevertheless, a biblical prophecy predicts that even this most hypersaline of all lakes will eventually be teeming with fish of many kinds.     

Alleviation of Osmotic Stress Effects by Exogenous Application of Salicylic or Abscisic Acid on Wheat Seedlings

The aim of the study was to assess the role of salicylic acid (SA) and abscisic acid (ABA) in osmotic stress tolerance of wheat seedlings. This was accomplished by determining the impact of the acids applied exogenously on seedlings grown under osmotic stress in hydroponics. The investigation was unique in its comprehensiveness, examining changes under osmotic stress and other conditions, and testing a number of parameters simultaneously. In both drought susceptible (SQ1) and drought resistant (CS) wheat cultivars, significant physiological and biochemical changes were observed upon the addition of SA (0.05 mM) or ABA (0.1 μM) to solutions containing half-strength Hoagland medium and PEG 6000 (−0.75 MPa). The most noticeable result of supplementing SA or ABA to the medium (PEG + SA and PEG + ABA) was a decrease in the length of leaves and roots in both cultivars. While PEG treatment reduced gas exchange parameters, chlorophyll content in CS, and osmotic potential, and conversely, increased lipid peroxidation, soluble carbohydrates in SQ1, proline content in both cultivars and total antioxidants activity in SQ1, PEG + SA or PEG + ABA did not change the values of these parameters. Furthermore, PEG caused a two-fold increase of endogenous ABA content in SQ1 and a four-fold increase in CS. PEG + ABA increased endogenous ABA only in SQ1, whereas PEG + SA caused a greater increase of ABA content in both cultivars compared to PEG. In PEG-treated plants growing until the harvest, a greater decrease of yield components was observed in SQ1 than in CS. PEG + SA, and particularly PEG + ABA, caused a greater increase of these yield parameters in CS compared to SQ1. In conclusion, SA and ABA ameliorate, particularly in the tolerant wheat cultivar, the harmful effects and after effects of osmotic stress induced by PEG in hydroponics through better osmotic adjustment achieved by an increase in proline and carbohydrate content as well as by an increase in antioxidant activity.     

Towards modelling of construction,renovation and demolition activities: Norway's dwelling stock, 1900–2100

The activities of construction, renovation and demolition related to the dwelling (housing) stock have a strong impact on both material and energy demands. A deeper understanding of the dynamics driving these activities is a precondition for a more consistent way to address material and energy demands. The method presented herein is based on a dynamic material flow analysis and is applied to the Norwegian dwelling stock. Input data to the model are population and socio-economic lifestyle indicators such as the average number of persons per dwelling and the average size of dwellings; these determine the size of the floor area stock. Parameters such as the lifetime of dwellings and renovation intervals complete the input set. Outputs of the model are the stock and flows of floor area for the period 1900–2100. Analysis of the renovation activity is given particular attention. Several scenarios are considered in order to test the model's sensitivity to input's uncertainties. Results are compared with statistical data, where the latter are available. The main conclusion is that in the coming decades renovation is likely to overtake construction as the major activity in the Norwegian residential sector.

Les activités de construction, de rénovation et démolition relatives au parc de logements ont un fort impact sur la demande de matériaux et d'énergie. Une meilleure compréhension de la dynamique qui anime ces activités est une condition préalable à une méthode plus cohérente de traitement des demandes de matériaux et d'énergie. La méthode présentée ici repose sur une analyse dynamique des flux de matériaux telle qu'elle est appliquée au parc de logements en Norvège. Les données fournies au modèle sont des indicateurs du mode de vie de la population et des indicateurs socio-économiques comme le nombre moyen de personnes par logement et la taille moyenne des logements; ces indicateurs déterminent la superficie des logements. Des paramètres comme la durée de vie des logements et les intervalles de rénovation complètent les données d'entrée. Les résultats du modèle sont le parc de logements et sa superficie pour la période 1900–2100. L'analyse de l'activité de rénovation reçoit une attention particulière. Plusieurs scénarios sont envisagés afin de mettre à l'épreuve la sensibilité du modèle par rapport aux incertitudes des entrées. Les résultats sont comparés aux données statistiques lorsque ces dernières sont disponibles. La conclusion principale réside dans le fait que dans les prochaines décennies, le secteur de rénovation risque de dépasser celui de la construction en tant qu'activité majeure du secteur résidentiel norvégien.

Mots clés: parc de bâtiments, construction, démographie, démolition, prévisions, logement, analyse des flux de matériaux, rénovation, parc résidentiel, Norvège     

Synthesis and electrochemical characterization of new optoelectronic materials based on conjugated donor-acceptor system containing oligo-tri(heteroaryl)-1,3,5-triazines

A series of novel oligoarylenes based on donor-acceptor system, containing triazine moiety as an electron-transporting central core, have been prepared by electrochemical polymerization. The redox behaviour of poly(2,4,6-tri[p-(2-(3,4-ethylenedioxythienyl))-phenyl]-1,3,5-triazine) was studied by cyclic voltammetry and triple in situ ESR/UV-vis-NIR spectroelectrochemistry to get more details on the type of charge carriers within the film. To obtain desired oligoarylenes, triazine-core monomers possessing various electrochromic side groups have been synthesized by the Stille cross-coupling methodology. The structures have been confirmed by ¹H NMR, ¹³C NMR, and elemental analysis. Monomers show good chemical stability in common organic solvents such as chloroform, dichloromethane or toluene and also exhibit excellent thermal stability over wide range of temperatures. Furthermore, their photophysical properties have been established with the use of fluorescence spectroscopy. Electrochemical results accompanied with fluorescence spectroscopy suggest that these derivatives of triazine can be successfully used in the fabrication of organic light-emitting diodes (OLEDs).     

Structural evolution in copper layers during sliding under different lubricant conditions

Friction and wear of copper rubbed in a wide range of loads and sliding velocities were studied. The results of friction and wear experiments in PAO-4 lubricant are presented as the Stribeck curve where the boundary, mixed and elasto-hydrodynamic lubrication regimes are considered. The structural state of surface layers in different lubricant regimes is studied by optical and scanning electron microscopy and X-ray photoelectron spectroscopy analyses. The dominant friction and wear mechanisms in different lubrication regimes are discussed. Severe plastic deformation of subsurface layers under friction is correlated with the nanocrystalline structure obtained by different methods of grain refinement.