3,774 research outputs found
Novel U-Shaped D-A-D π-conjugated Systems with Mechanochromic Properties: An Experimental and Theoretical Vibrational Spectroscopic Investigation
Π-conjugated compounds have been widely studied in the last few decades due to their huge field of application in organic electronics. Specifically, stimuli-responsive Π-conjugated materials which are sensitive to external stimulus (i.e., temperature, pressure, etc) have several uses like sensors, probes and security inks, for example.1 In this work, we study two U-shape Donor-Acceptor-Donor (D-A-D) systems that are found to exhibit interesting thermal- and pressure-dependent properties. 2 They consist on two different conformers of phenothiazine-dibenzo[a,j]phenazine-phenothiazine which differs from the position of the phenothiazine respect to the dibenzophenzaine central core. Compound 1R is the equatorial-equatorial conformer and 1Y is the axial-axial conformer (Figure 1). The dibenzophenzaine group acts as an electron-acceptor whereas the phenothiazine unit acts as an electron-donor. It has been reported that this U-shape D-A-D compound shows a multi-active color changing in 3 steps and their luminescence changes with temperature, pressure and acid exposition.2 In this work, we aim to elucidate how the external stimuli (i.e. temperature, pressure, acid ambient) affects the molecular structure at both intra- and intermolecular level. To this end, we use UV-Vis absorption, Raman (Figure 1) and Infrared spectroscopy experiments in combination with DFT calculations.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
Practical issues on the sales of loan portfolios
Este artículo analiza las operaciones de venta de carteras de créditos
(hipotecarios y al consumo) en situación de incumplimiento que
recientemente vienen realizando las entidades financieras españolas
a fondos de inversión oportunistas internacionales. Este análisis se
aborda desde una perspectiva mercantil, procesal y fiscal y con un
enfoque eminentemente práctico. Dentro de este enfoque práctico, y
para facilitar su lectura, se sigue el orden del proceso de venta de una
cartera y la posterior toma de control de la gestión por el inversor.
El artículo comienza abordando los aspectos más relevantes de la negociación
del contrato de compraventa: determinación de su objeto
—adquisición de la plena titularidad de los créditos de la cartera o de
sus resultas— y de su precio, la gestión de la cartera desde la fecha de
corte, declaraciones y garantías más habituales del vendedor, delimitación
de los créditos defectuosos y régimen de saneamiento de vicios, notificación
de la cesión a los deudores y entrega de documentación de los
créditos necesaria para su reclamación, según el tipo de procedimiento
judicial que se inste en cada caso. Tras ello se analizan otros aspectos,
como la sucesión procesal del comprador en los procesos judiciales de
reclamación y la ejecución de los créditos de la cartera, poniendo el
acento en el régimen legal previsto para la adjudicación y cesión de
remate de bienes del deudor, en los riesgos de sucesión de empresa y en
la incidencia del concurso sobre los procedimientos de reclamación.This article analyzes the recent sales of non-performing loans (mortgage
loans and consumer credits) by Spanish financial institutions to
opportunistic international investment funds. The analysis is from a
commercial, procedural and tax perspective, with an eminently practical
approach. From this practical approach, and as an aid to the
reader’s understanding, the order of the article follows the sale process
of a portfolio and the subsequent takeover of its management by
the investor.
The article begins by considering the most relevant aspects of the contract
of sale: determination of the subject-matter —acquisition of the
full ownership of the portfolio’s loans or of its results—, and its price;
portfolio management from the cut-off date, most common reps and
warranties of the seller, definition of doubtful loans and regulation of
claims for defects, notification of the assignment to the debtors and
provision of the necessary documentation on the loans that must be
submitted with the claims, depending on the type of proceedings initiated
by the creditor. We then proceed with the analysis of other
aspects, such as the succession of the buyer in the legal proceedings to
collect the debt-claims, the enforcement and foreclosure of the portfolio
credits, focusing on the legal regulations applicable to the auction
and award of the debtor’s assets, taking into account the risks of the
transfer of the undertakings and the effect of the insolvency on the
claim proceedings
Arrays de sensores interferométricos recirculantes de fibra óptica
Two discrete interferometric sensors' arrays have been analysed from time división multiplexing of recirculating crossed loop structures based on singlemode optical fiber. Intensity impulsive responses for both arrays have been obtained and compared under different design considerations, calculating Ihe system coupling constants, signial to interference noise ratio, input pulse repetition rate and duty cycle for each case. First experimental results are shown in this paper and very simple temperature and pressure sensing applicalions are suggested from here
Parametric macromodeling of integrated inductors for RF circuit design
Nowadays, parametric macromodeling techniques are widely used to describe electromagnetic structures. In this contribution, the application of such parametric macromodeling techniques to the design of integrated inductors and radio-frequency circuit design is investigated. In order to allow such different operations, a new modeling methodology is proposed, which improves the modeling accuracy when compared to former techniques. The new methodology is tailored to the unique characteristics of the devices under study. The obtained parametric macromodel is then used in a synthesis methodology and in the design of a voltage controlled oscillator in a 0.35-μm CMOS technologyMinisterio de Economía y Competitividad TEC2013-45638-C3- 3-RJunta de Andalucía P12-TIC-148
PT-Symmetric Quantum Theory Defined in a Krein Space
We provide a mathematical framework for PT-symmetric quantum theory, which is
applicable irrespective of whether a system is defined on R or a complex
contour, whether PT symmetry is unbroken, and so on. The linear space in which
PT-symmetric quantum theory is naturally defined is a Krein space constructed
by introducing an indefinite metric into a Hilbert space composed of square
integrable complex functions in a complex contour. We show that in this Krein
space every PT-symmetric operator is P-Hermitian if and only if it has
transposition symmetry as well, from which the characteristic properties of the
PT-symmetric Hamiltonians found in the literature follow. Some possible ways to
construct physical theories are discussed within the restriction to the class
K(H).Comment: 8 pages, no figures; Refs. added, minor revisio
Osteitis condensante de clavícula
La osteítis condensante de clavícula es una lesión ósea infrecuente, benigna y de
etiología desconocida. Se caracteriza por esclerosis densa y homogénea de la porción infero-medial
clavicular con obliteración de la cavidad medular sin afectación de la articulación esternoclavicular.
Hasta ahora sólo se había descrito en mujeres, en el presente trabajo presentamos
un caso en un paciente varón. Se discute el diagnóstico diferencial con otras entidades que producen
afectación similar y proponemos la TC como método diagnóstico de elección, defendiendo
el tratamiento conservador.Condensing osteitis of the clavicle is a benign and uncommon bone lesion of
unknown cause, characterized by homogeneously dense sclerotic patch with obliteration of the
marrow cavity at the medial end of the clavicle without involvement of the sternoclavicular
joint. To date it had been described only in women. In this work we report a case in a male patient.
The differential diagnosis with other disorders of similar findings is discussed. We propose
CT-scan as the elective diagnostic test and we defend the conservative treatment
Quantifying the contamination by old main-sequence stars in young moving groups: the case of the Local Association
The associations and moving groups of young stars are excellent laboratories
for investigating stellar formation in the solar neighborhood. Previous results
have confirmed that a non-negligible fraction of old main-sequence stars is
present in the lists of possible members of young stellar kinematic groups. A
detailed study of the properties of these samples is needed to separate the
young stars from old main-sequence stars with similar space motion, and
identify the origin of these structures. We used stars possible members of the
young (~ 10 - 650 Myr) moving groups from the literature. To determine the age
of the stars, we used several suitable age indicators for young main sequence
stars, i.e., X-ray fluxes and other photometric data. We also used
spectroscopic data, in particular the equivalent width of the lithium line Li I
and Halpha, to constrain the range of ages of the stars. By combining
photometric and spectroscopic data, we were able to separate the young stars
(10 - 650 Myr) from the old (> 1 Gyr) field ones. We found, in particular, that
the Local Association is contaminated by old field stars at the level of ~30%.
This value must be considered as the contamination for our particular sample,
and not of the entire Local Association. For other young moving groups, it is
more difficult to estimate the fraction of old stars among possible members.
However, the level of X-ray emission can, at least, help to separate two age
populations: stars with <200 Myr and stars older than this. Our results are
consistent with a scenario in which the moving groups contain both groups of
young stars formed in a recent star-formation episode and old field stars with
similar space motion. Only by combining X-ray and optical spectroscopic data is
it possible to distinguish between these two age populations.Comment: 7 pages, 7 figures. Accepted for publication in A&
Intermediate Band Solar Cell with Extreme Broadband Spectrum Quantum Efficiency
We report, for the first time, about an intermediate band solar cell implemented with InAs/AlGaAs quantum dots whose photoresponse expands from 250 to ~ 6000 nm. To our knowledge, this is the broadest quantum efficiency reported to date for a solar cell and demonstrates that the intermediate band solar cell is capable of producing photocurrent when illuminated with photons whose energy equals the energy of the lowest band gap. We show experimental evidence indicating that this result is in agreement with the theory of the intermediate band solar cell, according to which the generation recombination between the intermediate band and the valence band makes this photocurrent detectable
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