Quantum interference effects in resonant Raman spectroscopy of single- and triple-layer MoTe2_2 from first principles

We present a combined experimental and theoretical study of resonant Raman spectroscopy in single- and triple-layer MoTe$_2$. Raman intensities are computed entirely from first principles by calculating finite differences of the dielectric susceptibility. In our analysis, we investigate the role of quantum interference effects and the electron-phonon coupling. With this method, we explain the experimentally observed intensity inversion of the $A^\prime_1$ vibrational modes in triple-layer MoTe2 with increasing laser photon energy. Finally, we show that a quantitative comparison with experimental data requires the proper inclusion of excitonic effects.Comment: Main Text (5 Figures, 1 Tables) + Supporting Information (6 Figures

Prevalence And Clinical Significance Of Potential Drug-drug Interactions In Diabetic Patients Attended In A Tertiary Care Outpatient Center, Brazil

The aim of this study is to investigate the prevalence of potential drug-drug interactions (PDDIs), as well as classifying them in relation to level of severity, scientific evidence, time of onset, and potential clinical impact in adult and older adult patients with diabetes mellitus 2 (DM2). This cross-sectional study was conducted in a tertiary care outpatient center. The consecutive sample was made up of 140 patients with DM2. The Anatomical-Therapeutic-Chemical Classification was used for classifying the classes of medications. The PDDIs were analyzed using the DRUG-REAXA (R) system. The relationships between PDDI and the associated factors were ascertained using a multiple logistic regression model. The prevalence of total PDDI was 75 %, and the prevalence of major severity PDDI was 20.7 %. Simvastatin (30.8 %), captopril/enalapril (12.8 %), and oral anti-diabetics/insulin (12.8 %) were the medications which were most involved in the major PDDI, bringing relevant potential clinical impacts such as rhabdomyolysis, hyperkalemia, and important glycemic alterations. Polypharmacy was associated with PDDI (adjusted odds ratio = 10.46, 95 % confidence interval = 4.10-26.71). Diabetics were highly exposed to clinically significant PDDI. It is important that health professionals should be aware of the risks related to PDDI, so that measures may be implemented in order to assure safe care for the patient.36328328

Portuguese colonial architectural archives at the Arquivo Histórico Ultramarino, mid 19th century - 1975

The Arquivo Histórico Ultramarino (AHU - Overseas Historical Archive) holds Portuguese architectural and also engineering archival records created and managed by the Colonial Public Offices seated in Lisbon, dating back to the end of the 16th century to 1975. The archives from the offices that performed duties in the Portuguese colonies remained there, even after their independence from Portugal. Until recently, records dated from the mid 19th century onwards were poorly identified, a panorama that changed over the last decade. These records are related to Angola, Cabo Verde, Guinea-Bissao, São Tomé and Príncipe, Mozambique, previous Portugese possessions in India, Macao and East Timor. The AHU hosted two funded projects by the Portuguese Foundation to Science and Technology (FCT) submitted by the Centre for Socioeconomic and Territorial Studies from the Lisbon University Institute (DINÂMIA'CET-IUL). The participation of the AHU in both projects allowed processing these records bulk. The first one was “The Colonial Urbanization Offices”, a three year project which benefited from the collaboration of five archival fellowships during nearly two years. The second project is the “Coast to Coast”, has a similar duration to the previous and will be ongoing until December 2019, with the contribution of an archival fellowship. Two archivists of the AHU participated in these projects as well, supervising the archival processing as researchers.info:eu-repo/semantics/publishedVersio

Robotic Tankette for Intelligent BioEnergy Agriculture: Design, Development and Field Tests

In recent years, the use of robots in agriculture has been increasing mainly due to the high demand of productivity, precision and efficiency, which follow the climate change effects and world population growth. Unlike conventional agriculture, sugarcane farms are usually regions with dense vegetation, gigantic areas, and subjected to extreme weather conditions, such as intense heat, moisture and rain. TIBA - Tankette for Intelligent BioEnergy Agriculture - is the first result of an R&D project which strives to develop an autonomous mobile robotic system for carrying out a number of agricultural tasks in sugarcane fields. The proposed concept consists of a semi-autonomous, low-cost, dust and waterproof tankette-type vehicle, capable of infiltrating dense vegetation in plantation tunnels and carry several sensing systems, in order to perform mapping of hard-to-access areas and collecting samples. This paper presents an overview of the robot mechanical design, the embedded electronics and software architecture, and the construction of a first prototype. Preliminary results obtained in field tests validate the proposed conceptual design and bring about several challenges and potential applications for robot autonomous navigation, as well as to build a new prototype with additional functionality.Comment: 9 pages, 15 figure

Jamming and percolation in the random sequential adsorption of a binary mixture on the square lattice

We study the competitive irreversible adsorption of a binary mixture of monomers and square-shaped particles of linear size $R$ on the square lattice. With the random sequential adsorption model, we investigate how the jamming coverage and percolation properties depend on the size ratio $R$ and relative flux $F$. We find that the onset of percolation of monomers is always lower for the binary mixture than in the case with only monomers ($R=1$). Moreover, for values $F$ below a critical value, the higher is the flux or size of the largest species, the lower is the value of the percolation threshold for monomers.Comment: Submitted to a special issue of Journal of Physics A: Mathematical and Theoretical to mark the 70th Birthday of Robert M. Zif

Missão Polyedros: um diálogo entre a arte analógica e a digital e o ensino de geometria espacial através de atividades gamificadas

As tecnologias digitais, sobretudo os games, são importantes ferramentas para o estímulo de habilidades e competências artísticas, culturais e curriculares que, quando aliadas ao processo de ensino e aprendizagem, resultam em inúmeros benefícios para alunos e professores de um modo geral. O problema está no fato de que muitos docentes ainda não têm formação adequada para utilizar artefatos digitais, e muitos dos softwares e games educacionais existentes ainda são insuficientes e carentes de interfaces gráficas, funcionalidades, recursos, entre outros parâmetros, quando comparados com os comerciais. O objetivo é de apresentar um estudo sobre o ensino de geometria espacial, através de atividades gamificadas, estabelecendo diálogos entre a arte analógica e a digital, e o ensino de Geometria espacial com alunos do terceiro ano do Ensino Médio de uma escola pública. Dos resultados obtidos, destacam-se o comportamento participativo e o engajamento dos discentes, que se mostraram interessados em compreender o que estava sendo ministrado, graças às mecânicas de jogo empregadas. Os resultados mostraram que, quando aliada à utilização das Tecnologias Digitais da Informação e Comunicação (TDIC) ou a materiais concretos, a gamificação emerge como uma alternativa com grande potencial. Entretanto, por si só, ela não transforma a sala de aula nem garante o sucesso na execução de atividades, razão pela qual é necessária uma boa metodologia e o controle de turma por parte do professor, assim como a colaboração dos alunos para que haja uma aprendizagem tranquila e eficaz.Digital technologies are important tools to motivate artistic, cultural and curricular skills. When added to the teaching and learning process, they result in many benefits for teachers and students. Many teachers, however, still do have not the appropriate instruction to use digital artifacts, and most of the educational software and games are still insufficient and have poor graphical interfaces, resources and others parameters when compared to the commercial ones. The goal of this article is to present a study about spatial geometry’s teaching, through gamified activities, establishing dialogues between analogue and digital arts, in the teaching of third grade high school students from a public school. The results prove the participative behavior and the engagement of students, who have showed interest in understanding what was being taught, thanks to the game mechanics used. The results also show that when allied to Digital Technologies of Information and Comunication (TDIC), or other concrete materials, the gamification process emerges as an alternative with strong potential. However, by itself, it does not transform the classroom nor guarantees the success of the activities. For these reasons, a good methodology and classroom control by the teacher, as well as the collaboration of students, for a quiet and effective learning, is mandatory.info:eu-repo/semantics/publishedVersio

Propagating Surface Plasmons and Dispersion Relations for Nanoscale Multilayer Metallic-Dielectric Films

22 page(s

Unipolar resistive switching in metal oxide/organic semiconductor non-volatile memories as a critical phenomenon

Diodes incorporating a bilayer of an organic semiconductor and a wide bandgap metal oxide can show unipolar, non-volatile memory behavior after electroforming. The prolonged bias voltage stress induces defects in the metal oxide with an areal density exceeding 10(17) m(-2). We explain the electrical bistability by the coexistence of two thermodynamically stable phases at the interface between an organic semiconductor and metal oxide. One phase contains mainly ionized defects and has a low work function, while the other phase has mainly neutral defects and a high work function. In the diodes, domains of the phase with a low work function constitute current filaments. The phase composition and critical temperature are derived from a 2D Ising model as a function of chemical potential. The model predicts filamentary conduction exhibiting a negative differential resistance and nonvolatile memory behavior. The model is expected to be generally applicable to any bilayer system that shows unipolar resistive switching. (C) 2015 Author(s).Dutch Polymer Institute (DPI), BISTABLE [704]; Fundacao para Ciencia e Tecnologia (FCT) through the research Instituto de Telecommunicacoes (IT-Lx); project Memristor based Adaptive Neuronal Networks (MemBrAiNN) [PTDC/CTM-NAN/122868/2010]; European Community Seventh Framework Programme FP7', ONE-P [212311]; Dutch Ministry of Education, Culture and Science (Gravity Program) [024.001.035]info:eu-repo/semantics/publishedVersio

Effect of boundary conditions on diffusion in two-dimensional granular gases

We analyze the influence of boundary conditions on numerical simulations of the diffusive properties of a two dimensional granular gas. We show in particular that periodic boundary conditions introduce unphysical correlations in time which cause the coefficient of diffusion to be strongly dependent on the system size. On the other hand, in large enough systems with hard walls at the boundaries, diffusion is found to be independent of the system size. We compare the results obtained in this case with Langevin theory for an elastic gas. Good agreement is found. We then calculate the relaxation time and the influence of the mass for a particle of radius $R_s$ in a sea of particles of radius $R_b$. As granular gases are dissipative, we also study the influence of an external random force on the diffusion process in a forced dissipative system. In particular, we analyze differences in the mean square velocity and displacement between the elastic and inelastic cases.Comment: 15 figures eps figures, include