From Pyrene to Large Polycyclic Aromatic Hydrocarbons

Studies of polycyclic aromatic hydrocarbons have shown that the overall size, periphery, and functionalization of PAHs are crucial parameters which significantly alter their electronic structure and chemical reactivity. Therefore, the major direction of this thesis is the synthesis and characterization of extended PAHs: (i) with different functional groups improving their processability, (ii) with different periphery changing their chemical reactivity, (iii) with inclusions of different metal ions, which influence their physical properties. • The cyclodehydrogenation reaction has been proposed for to synthesise polyphenylene ribbons with preplanarized (dibenzo[e,l]pyrene) moieties in the aromatic core with up to 10 nm linear size. The synthetic strategy employed is discussed in Chapter 2 and is based on stoichiometrically controlled DIELS-ALDER cycloaddition. All molecules possessed very good solubility in common organic solvents allowing their characterization by standard analytical techniques. • A new concept was developed to extend PAH’s core. Here the introduction of “zigzag” sites, discussed in Chpater 3 was shown to lower the HOMO-LUMO gap and to result in higher chemical reactivities. This allowed, in Chapters 3, 4 and 5, further functionalization of PAH and enlargement of their aromatic cores up to 224 atoms. Despite the size of these novel molecules, extraordinary solubilities in common organic solvents were obtained due to distortions from planarity of the aromatic cores by bulky tert-butyl groups, which hampered the usually very pronounced aggregation tendency of extended π-systems. All extended PAHs posses the small HOMO-LUMO gap together with good electron affinities making them potential candidates for application in organic FETs. • Another alternative synthetic route has been proposed to obtain extended the metal-PAH complexes. Using the quinoxaline methodology in Chapter 5 three new phenanthroline ligands (up to 60 skeletal atoms) have been synthesized and characterized. Four different (Ru(II), Cu(II) and Pt(II)) complexes were synthesized, allowing to construct a range of large metal complexes by varying the metal as well as the number and nature of ligands

The foreclosure crisis in 2008: predatory lending or household overreaching?

At least early in the financial crisis, the high rate of foreclosures seemed to be due more to households' overreaching than to predatory lending. A disproportionate number of those being foreclosed on were well-educated, well-off and relatively young people.Foreclosure ; Mortgage loans ; Housing - Finance

Периодизация иммиграционной политики Европейского Союза: от истоков к современности

У статті досліджуються етапи становлення імміграційної політики Європейського Союзу. Вводиться періодизація формування спільної політики ЄС у сфері управління міграцією. Запропоновано чотири періоди формування імміграційної політики ЄС, кожний з яких характеризується прийняттям важливих документів, що внесли значні зміни у компетенції інституцій ЄС та винесли регулювання питань міграції на наднаціональний рівень.Основним висновком є те, що жодна країна не в змозі справитися з викликами міграції самотужки, в ізоляції від своїх сусідів, яким доводиться стикатися з подібними проблемами. Це призвело до співробітництва між державами-членами в напрямку обміну досвідом та ідеями щодо управління міграцією, проте питання чи потрібно встановлювати єдині міграційні процедури на рівні ЄС впродовж довгого часу викликали гострі дискусії.На сьогодні регулювання міграційних потоків в Євросоюзі - це політичний процес, який у правовому сенсі координується на основі правового доробку ЄС та національного законодавства держав-членів. Перенесення міграційної політики на наднаціональний рівень дозволяє простежувати зміни, проведені на національних рівнях та реагувати на сучасні виклики міграційного характеру без істотних затримок.The historical development of the European Union’s immigration policy has been described in the article. The main four phases of common immigration policy of the EU have been examined. Each phase is characterized by the adoption of important agreements and programs. In particular, the principles of Amsterdam Treaty and the Treaty of Lisbon and five-year program have been analyzed in the paper: Tampere (1999), The Hague (2004), Stockholm (2009) and guidelines Ypres (2014). The program contains guidelines for a common politics on the topics of protection of fundamental rights, privacy, minority rights and rights of groups of people in need of special protection, as well as a citizenship of the European Union. Such different spheres as domestic and public security, migration (European pact on immigration and asylum), the combat against the organized crime, and even family law, private law, inheritance law and others have been described in the program. The Ypes guidelines don’t constitute a program any more, but they rather guide focusing on the objective of transposition, implementation and consolidation of the existing legal instruments and measures. The guidelines point out the necessity to adopt a holistic approach to migration, making the best possible use of the regular migration, affording protection to those who need it, combating irregular migration and managing borders effectively.The need for the formation of the migration policy is becoming more apparent in view of the fact that globalization increases due to migration flows and its effectiveness depends largely on the cooperation with other Member States, countries of origin and transit countries.Nowadays, regulation of migration flows in the EU is a political process, which is legally coordinated from the acquit of the EU and national legislation of the Member States. Transfer of the migration policy to the supranational level allows tracking changes, made at the national level, in order to respond to the challenge of migration character without significant delay.The main conclusion of the article is that, on the one hand, immigration has become a relevant issue in all the EU countries. On the other hand, as a consequence of different timing of immigration, different socio-economic contexts and varying governmental migration and integration policies, different forms of migration, with different governmental policies of migration and integration, and with different types of migrants have evolved. Such different starting positions should be taken into account when studying the consequences of the immigration and the presence of migrants in society.В статье исследуются этапы становления иммиграционной политики Европейского Союза. Вводится периодизация формирования общей политики ЕС в сфере управления миграцией. Предложено четыре периода формирования иммиграционной политики ЕС, каждый из которых характеризуется принятием важных документов, что внесли значительные изменения в компетенции институтов ЕС и вынесли регулирования вопросов миграции на наднациональный уровень.Основным выводом является то, что ни одна страна не в состоянии справиться с вызовами миграции самостоятельно, в изоляции от своих соседей, которым приходится сталкиваться с подобными проблемами. Это привело к сотрудничеству между государствами-членами в направлении обмена опытом и идеями по управлению миграцией, однако вопрос нужно ли устанавливать единые миграционные процедуры на уровне ЕС в течение длительного времени вызывали острые дискуссии.На сегодня регулирование миграционных потоков в Евросоюзе - это политический процесс, который в правовом смысле координируется на основе правового поля ЕС и национального законодательства государств-членов. Перенос миграционной политики на наднациональный уровень позволяет прослеживать изменения, проведенные на национальном уровне и реагировать на современные вызовы миграционного характера без существенных задержек

Optimizing the Stark-decelerator beamline for the trapping of cold molecules using evolutionary strategies

We demonstrate feedback control optimization for the Stark deceleration and trapping of neutral polar molecules using evolutionary strategies. In a Stark-decelerator beamline pulsed electric fields are used to decelerate OH radicals and subsequently store them in an electrostatic trap. The efficiency of the deceleration and trapping process is determined by the exact timings of the applied electric field pulses. Automated optimization of these timings yields an increase of 40 % of the number of trapped OH radicals.Comment: 7 pages, 4 figures (RevTeX) (v2) minor corrections (v3) no changes to manuscript, but fix author list in arXiv abstrac

Renormalization Group Theory for a Perturbed KdV Equation

We show that renormalization group(RG) theory can be used to give an analytic description of the evolution of a perturbed KdV equation. The equations describing the deformation of its shape as the effect of perturbation are RG equations. The RG approach may be simpler than inverse scattering theory(IST) and another approaches, because it dose not rely on any knowledge of IST and it is very concise and easy to understand. To the best of our knowledge, this is the first time that RG has been used in this way for the perturbed soliton dynamics.Comment: 4 pages, no figure, revte

Grey-box model identification via evolutionary computing

This paper presents an evolutionary grey-box model identification methodology that makes the best use of a priori knowledge on a clear-box model with a global structural representation of the physical system under study, whilst incorporating accurate blackbox models for immeasurable and local nonlinearities of a practical system. The evolutionary technique is applied to building dominant structural identification with local parametric tuning without the need of a differentiable performance index in the presence of noisy data. It is shown that the evolutionary technique provides an excellent fitting performance and is capable of accommodating multiple objectives such as to examine the relationships between model complexity and fitting accuracy during the model building process. Validation results show that the proposed method offers robust, uncluttered and accurate models for two practical systems. It is expected that this type of grey-box models will accommodate many practical engineering systems for a better modelling accuracy

Strain-induced partially flat band, helical snake states, and interface superconductivity in topological crystalline insulators

Topological crystalline insulators in IV-VI compounds host novel topological surface states consisting of multi-valley massless Dirac fermions at low energy. Here we show that strain generically acts as an effective gauge field on these Dirac fermions and creates pseudo-Landau orbitals without breaking time-reversal symmetry. We predict the realization of this phenomenon in IV-VI semiconductor heterostructures, due to a naturally occurring misfit dislocation array at the interface that produces a periodically varying strain field. Remarkably, the zero-energy Landau orbitals form a flat band in the vicinity of the Dirac point, and coexist with a network of snake states at higher energy. We propose that the high density of states of this flat band gives rise to interface superconductivity observed in IV-VI semiconductor multilayers at unusually high temperatures, with non-BCS behavior. Our work demonstrates a new route to altering macroscopic electronic properties to achieve a partially flat band, and paves the way for realizing novel correlated states of matter.Comment: Accepted by Nature Physic

The Mass of the Black Hole in the Seyfert 1 Galaxy NGC 4593 from Reverberation Mapping

We present new observations leading to an improved black hole mass estimate for the Seyfert 1 galaxy NGC 4593 as part of a reverberation-mapping campaign conducted at the MDM Observatory. Cross-correlation analysis of the H_beta emission-line light curve with the optical continuum light curve reveals an emission-line time delay of 3.73 (+-0.75) days. By combining this time delay with the H_beta line width, we derive a central black hole mass of M_BH = 9.8(+-2.1)x10^6 M_sun, an improvement in precision of a factor of several over past results.Comment: 22 pages, 3 tables, 5 figures, accepted for publication in Ap

NGC 5548 in a Low-Luminosity State: Implications for the Broad-Line Region

We describe results from a new ground-based monitoring campaign on NGC 5548, the best studied reverberation-mapped AGN. We find that it was in the lowest luminosity state yet recorded during a monitoring program, namely L(5100) = 4.7 x 10^42 ergs s^-1. We determine a rest-frame time lag between flux variations in the continuum and the Hbeta line of 6.3 (+2.6/-2.3) days. Combining our measurements with those of previous campaigns, we determine a weighted black hole mass of M_BH = 6.54 (+0.26/-0.25) x 10^7 M_sun based on all broad emission lines with suitable variability data. We confirm the previously-discovered virial relationship between the time lag of emission lines relative to the continuum and the width of the emission lines in NGC 5548, which is the expected signature of a gravity-dominated broad-line region. Using this lowest luminosity state, we extend the range of the relationship between the luminosity and the time lag in NGC 5548 and measure a slope that is consistent with alpha = 0.5, the naive expectation for the broad line region for an assumed form of r ~ L^alpha. This value is also consistent with the slope recently determined by Bentz et al. for the population of reverberation-mapped AGNs as a whole.Comment: 24 pages, 3 tables, 7 figures, accepted for publication in Ap