2,348 research outputs found
Comportamento da renda e da mão-de-obra nas comunidades remanescentes dos quilombos de Oriximiná.
bitstream/item/57318/1/Oriental-Doc86.pd
Efficient fully blade-coated perovskite solar cells in air with nanometer-thick bathocuproine buffer layer
Fully printed perovskite solar cells (PSCs) were fabricated in air with all constituent layers, except for electrodes, deposited by the blade coating technique. The PSCs incorporated, for the first time, a nanometer-thick printed bathocuproine (BCP) hole blocking buffer using blade coating and deposited at relative humidity up to 50%. The PSCs with a p-i-n structure (glass/indium tin oxide (ITO)/poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS)/CH3NH3PbI3/[6,6]-phenyl-C61-butyric acid methyl ester (PCBM)/BCP/Ag) delivered a maximum power conversion efficiency (PCE) of 14.9% on an active area of 0.5 cm2 when measured under standard test conditions. The PSCs with a blade coated BCP delivered performance of 10% and 63% higher (in relative terms) than those incorporating a spin coated BCP or without any BCP film, respectively. The atomic force microscopy (AFM) showed that blade coated films were more homogeneous and acted also as a surface planarizer leading to a reduction of roughness which improved BCP/Ag interface lowering charge recombination. The demonstration of 15% efficient devices with all constituent layers, including nanometer-thick BCP (∼ 10 nm), deposited by blade coating in air, demonstrates a route for industrialization of this technology
Fermion localization on degenerate and critical branes
In this work we analyze the localization of fermions on degenerate and
critical Bloch branes. This is done directly on physical coordinates, in
constrast to some works that has been using conformal coordinates. We find the
range of coupling constants of the interaction of fermions with the scalar
fields that allow us to have normalizable fermion zero-mode localized on the
brane on both, critical and degenerate Bloch branes. In the case of critical
branes our results agree with those found in [Class. Quantum Grav. \textbf{27}
(2010) 185001]. The results on fermion localization on degenerate Bloch branes
are new. We also propose a coupling of fermions to the scalar fields which
leads to localization of massless fermion on both sides of a double-brane.Comment: 16 pages, 6 figure
Twist Deformations of the Supersymmetric Quantum Mechanics
The N-extended Supersymmetric Quantum Mechanics is deformed via an abelian
twist which preserves the super-Hopf algebra structure of its Universal
Enveloping Superalgebra. Two constructions are possible. For even N one can
identify the 1D N-extended superalgebra with the fermionic Heisenberg algebra.
Alternatively, supersymmetry generators can be realized as operators belonging
to the Universal Enveloping Superalgebra of one bosonic and several fermionic
oscillators. The deformed system is described in terms of twisted operators
satisfying twist-deformed (anti)commutators. The main differences between an
abelian twist defined in terms of fermionic operators and an abelian twist
defined in terms of bosonic operators are discussed.Comment: 18 pages; two references adde
A ligand-based system for receptor-specific delivery of proteins
Gene delivery using vector or viral-based methods is often limited by technical and safety barriers. A promising alternative that circumvents these shortcomings is the direct delivery of proteins into cells. Here we introduce a non-viral, ligand-mediated protein delivery system capable of selectively targeting primary skin cells in-vivo. Using orthologous self-labelling tags and chemical cross-linkers, we conjugate large proteins to ligands that bind their natural receptors on the surface of keratinocytes. Targeted CRE-mediated recombination was achieved by delivery of ligand cross-linked CRE protein to the skin of transgenic reporter mice, but was absent in mice lacking the ligand\u2019s cell surface receptor. We further show that ligands mediate the intracellular delivery of Cas9 allowing for CRISPR-mediated gene editing in the skin more efficiently than adeno-associated viral gene delivery. Thus, a ligand-based system enables the effective and receptor-specific delivery of large proteins and may be applied to the treatment of skin-related genetic diseases
A Transfer Matrix Method for Resonances in Randall-Sundrum Models
In this paper we discuss in detail a numerical method to study resonances in
membranes generated by domain walls in Randall-Sundrum-like scenarios. It is
based on similar works to understand the quantum mechanics of electrons subject
to the potential barriers that exist in heterostructures in semiconductors.
This method was used recently to study resonances of a three form field and
lately generalized to arbitrary forms. We apply it to a lot of important
models, namely those that contain the Gauge, Gravity and Spinor fields. In many
cases we find a rich structure of resonances which depends on the parameters
involved.Comment: 25 pages, 17 figure
Utilização de método voltamétrico para estudo da defesa induzida de plantas de algodão submetidas ao ataque de lagarta.
Na publicação: Rafaela. G. da Silv
Desplazamiento climático y resiliencia: modelos de atención a familias afectadas por el invierno en el Caribe colombiano : el caso del sur del Atlántico (2010-2011)
Parte I. Descripción de la problemática -- Capítulo 1. El desplazamiento climático: una mirada desde el desarrollo compatible con el clima -- Capítulo 2. Ola invernal de 2010-2011 en el departamento del Atlántico -- Capítulo 3. Análisis institucional y respuestas a la ola invernal 2010-2011 -- Parte II. Implementación de un modelo de la resiliencia con desplazados climáticos -- Capítulo 4. Buscando alternativas de acción -- Capítulo 5. Momento aplicado de la investigación -- Tipo de investigación -- Capítulo 6. Modelo de intervención -- Parte III. Resultados y lecciones aprendidas -- Capítulo 7. Factores personales de resiliencia en desplazados climáticos -- Capítulo 8. Recomendaciones para políticas públicas.Universidad del Norte, Centro de Investigaciones en Desarrollo Human
Description of the Immatures of the Ant, Myrmelachista catharinae
The Neotropical ant genus Myrmelachista Roger comprises 69 described species and subspecies, and still is a poorly studied group. Larvae play a paramount role in colony nutrition in social hymenopterans and bear considerable value in the reconstruction of group phylogenies, however, they are generally neglected. Larvae of different instars of Myrmelachista catharinae Mayr (Hymenoptera: Formicidae) are herein described in detail by light and scanning electron microscopy. The number of larval instars was estimated as three based on the frequency distribution of maximum head capsule widths. The described larvae confirmed some traits typical of the genus: general shape of body and mandibles, general aspect and distribution of body hairs, and the number of sensilla on the palps and galea. Differently from other Myrmelachista larvae previously described, M. catharinae presented two distinct kinds of second instars, some additional types of body hairs, different number of antennal sensilla, and a distinct labrum shape. M. catharinae presented ten pairs of spiracles, which is the first record for this genus
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