bluuebunny/crossref_metadata_2025 huggingface dataset:
REGENERAÇÃO NATURAL DA FLORESTA OMBRÓFILA DENSA APÓS OITO ANOS DE ABANDONO DE ATIVIDADES AGRÍCOLAS EM MIRACATU, VALE DO RIBEIRA, SP
Authors: Moura Claudio de , Waldir Mantovani
Published: November 2018

Este trabalho descreveu o processo de sucessão da vegetação em regeneração natural de uma área de floresta suprimida para introdução da bananicultura na Estação Ecológica Juréia-Itatins após oito anos de abandono das atividades agrícolas. Foram efetuados os levantamentos florísticos e fitossociológicos em cinco parcelas de 10 x 25 m, onde todos os indivíduos de porte arbustivo-arbóreo ≥ 1 m de altura foram coletados e registrados a altura e perímetro das plantas e as espécies foram classificadas em síndromes de dispersão e grupos sucessionais. A estrutura da floresta foi analisada por meio dos parâmetros fitossociológicos usuais, índice de diversidade de Shannon (H’) e equabilidade (J’). Foram amostrados 1.440 indivíduos de 149 espécies e 59 famílias,sendo Melastomataceae (29), Myrtaceae (15), Fabaceae (10) e Rubiaceae (9) as famílias de maior riqueza, predominando espécies pioneiras e secundárias iniciais (36,91%) e zoocóricas (54,36%). As espécies com os maiores valores de cobertura foram Tibouchina pulchra, Leandra variabilis, Miconia cinnamomifolia e Piptocarpha macropoda. L. variabilis apresentou maior densidade absoluta (2.568 ind./ha) e relativa (24,21%). T. pulchra apresentou a maior dominância absoluta e relativa, com 10,04 m²/ha e 37,72%, respectivamente. Na estrutura da floresta, destacaram-se as espécies pioneiras. A diversidade (H’ = 3,330 nat. ind-1) e equabilidade (J’ = 0,666) obtidas são equivalentes a áreas de mesma idade. A regeneração natural é uma forma promissora de recuperação ambiental em condições semelhantes, pois permite a formação de uma floresta secundária com elevada riqueza de espécies e densidade de indivíduos, além de erradicar de 91,93 a 100% das bananeiras anteriormente introduzidas.
CRESCIMENTO E SOBREVIVÊNCIA DE QUATRO ESPÉCIES DE Eucalyptus spp. EM CANOINHAS – SC
Authors: Bonfatti Júnior Eraldo Antonio , Lengowski Elaine Cristina
Published: November 2018

O presente trabalho teve como objetivo analisar o crescimento e taxa de sobrevivência de um plantio florestal experimental com quatro espécies do gênero Eucalyptus, E. dunnii, E. benthamii, E. cloesiana e E. saligna, na cidade de Canoinhas – SC. O talhão florestal contém 10 linhas com 25 árvores cada, a um espaçamento 3 m x 3 m em área de 2.250 m2 com idade de 5 anos. O censo florestal foi realizado com trena e fita métrica para a medição do diâmetro e hipsômetro para a medição em altura. As medições foram realizadas nos anos de 2012, 2013, 2014, 2015 e 2016. Foram calculados a taxa de sobrevivência, o Incremento Médio Anual – IMA e o Incremento Corrente Anual – ICA ao longo dos anos. Também foram avaliadas a distribuição diamétrica e a altura média para cada espécie. Os melhores IMAs foram de E. benthamii, E. dunnii e E. saligna, respectivamente 46,21, 42,87 e 40,77 m3.ha-1.ano-1. A espécie com o pior desempenho foi E. cloesiana com 12,24 m3.ha-1.ano-1. As espécies E. benthamii, E. dunnii e E. saligna atingiram a idade técnica de corte. As taxas de sobrevivência foram de 96% para E. dunniii, 94% para E. saligna, 82% para E. benthamii e 80% para E. cloesiana. Os resultados permitem dizer que a espécie E. cloesiana é a menos adaptada para o clima do local de estudo, com baixa taxa de sobrevivência e menor crescimento.
BIRDS CONSUMING FRUITS OF Varronia curassavica Jacq. (BORAGINACEAE) IN SOUTHEASTERN BRAZIL
Authors: Antunes Alexsander Zamorano , João Batista Baitello  , Campagnoli Mariana Lopes
Published: November 2018

The Tropical Black Sage Varronia curassavica Jacq. is a widespread shrub in Brazil, which has become invasive in some parts of the world. We recorded 24 bird species consuming its fruits and potentially dispersing its seeds at Alberto Löfgren State Park, state of São Paulo, southeastern Brazil. It was first cultivated at this location, and despite the fact that it already is spreading naturally, the shrub remains restricted to more altered sites and does not constitute a threat to local biota.
RENDIMENTO DO PROCESSAMENTO DE TRÊS ESPÉCIES FLORESTAIS AMAZÔNICAS
Authors: Freitas Nayanna de Nazaré Brito , Santos Iêdo Souza , Pereira Paulo Cezar Gomes
Published: November 2018

A crescente procura da matéria-prima vem ocasionando o encarecimento do produto, desse modo, as empresas devem possuir um processo de desdobramento que obtenha melhor aproveitamento, levando ao aumento do rendimento na produção. O objetivo deste trabalho foi avaliar o coeficiente de rendimento volumétrico de três espécies florestais amazônicas: Hymenolobium petraeum, Goupia glabra e Manilkara spp. Foram selecionadas cinco toras de madeira aleatoriamente para cada espécie analisada, o volume da madeira em tora foi obtido pelos métodos de Smalian e Francon. Posteriormente, foi obtido o volume da madeira processada, medindo-se as dimensões de cada peça serrada correspondente a cada uma das toras. O cálculo de rendimento foi determinado pela razão entre o volume de madeira serrada e o volume da madeira em tora. A análise estatística foi realizada através do teste de Tukey com o intuito de avaliar as médias levando em consideração um delineamento inteiramente casualizado, utilizando o programa ASSISTAT Versão 7.7. O rendimento médio das três espécies estudadas foi equivalente a 50,83%, valor satisfatório para as condições da região, a qual não apresenta nível de automação elevado e nem mão de obra qualificada.
BIOSSÓLIDO EM SUBSTRATOS PARA PRODUÇÃO DE MUDAS DE Handroanthus chrysotrichus
Authors: Arruda Suellen Batista de , Silva Francisca Alcivania de Melo , Ferraz Marcelo Viera , Silva Reginaldo Barboza da , Bim Ocimar José Batista
Published: November 2018

A reutilização como substrato tem sido uma das estratégias para disposição final de lodos de esgoto, sendo importantes os estudos sobre seu uso com espécies florestais em diferentes classes texturais de solos. Objetivou-se avaliar a qualidade de mudas de Handroanthus chrysotrichus utilizando como substrato diferentes proporções de compostos à base de resíduos da agroindústria do palmito e lodo de esgoto em duas classes de solos (Cambissolo háplico e Latossolo Amarelo distrófico). O experimento foi realizado no viveiro de mudas da UNESP – Campus Experimental de Registro – SP, em delineamento inteiramente casualizado – DIC em esquema fatorial 2 x 5, com duas texturas de solo (média e argilosa) e cinco proporções de composto (100:0; 80:20; 60:40; 40:60 e 20:80%) com dez repetições. Foram avaliados: diâmetro de coleto (D), altura da parte aérea (H), massa seca de raiz – MSR, massa seca da parte aérea – MSPA, massa seca total – MST, (H/D); (MSPA/MSR), Índice de Qualidade de Dickson – IQD e macronutrientes na parte aérea das mudas. A adição de biossólido aumentou as concentrações de matéria orgânica, fósforo, potássio, cálcio e magnésio dos substratos, melhorando sua fertilidade. O desenvolvimento máximo das mudas foi obtido com as proporções 47% e 40% de biossólido/solo, para o Latossolo e Cambissolo, respectivamente. O biossólido formulado à base de lodo de esgoto e resíduos da agroindústria do palmito foi capaz de suprir as necessidades nutricionais do ipê-amarelo, sendo desnecessária a adição de adubos químicos.
INFLUÊNCIA DA ALTURA E DIÂMETRO DAS CEPAS NA REBROTA DE Eucalyptus SPP
Authors: Luz Danusia Silva , Freitas Luis Carlos de , Prates Caio Jander Nogueira , Barros Ana Paula da Silva
Published: November 2018

Muitas espécies de Eucalyptus apresentam alta capacidade de regeneração das cepas após o abate da árvore, o que permite conduzir o povoamento em mais de uma rotação. Sendo assim, o objetivo deste trabalho foi avaliar a influência da altura de corte e diâmetro das cepas no vigor das brotações de Eucalyptus spp. O estudo foi realizado em um povoamento de Eucalyptus spp, com espaçamento de 2,5 X 2,5 metros. A área em estudo pertence a uma empresa de base florestal, situada no município de Barra do Choça – BA. As alturas das cepas foram medidas com auxílio de uma régua graduada, sendo a altura dos brotos, mensurada por meio de uma trena. Os diâmetros das cepas e brotos foram quantificados por meio de uma suta. Os dados obtidos foram rodados no programa estatístico SAEG versão 9.1, sendo os parâmetros avaliados pela correlação de Spearman. A altura da cepa mostrou baixa correlação com o quantitativo de brotação. O diâmetro da cepa não mostrou correlação com o número de brotos. Não houve correlação significativa para o diâmetro da cepa e a altura do maior broto. Não houve correlação entre diâmetro da cepa e diâmetro dos brotos. Apesar da importância no planejamento silvicultural, principalmente para pequenos e médios produtores florestais, observa-se uma escassez de trabalhos mais recentes na área em questão.
VASCULAR FLORA CHECKLIST OF THE IBICATU ECOLOGICAL STATION, PIRACICABA, SÃO PAULO, BRAZIL
Authors: Corrêa Laíne Silveira , Scatigna André Vito , Gissi Danilo Soares , Silva Danielle Muniz da , Cota Matheus Martins Teixeira , Souza Vinícius Castro , Ivanauskas Natália Macedo , Tamashiro Jorge Yioshio , Rodrigues Ricardo Ribeiro
Published: November 2018

Small forest fragments are recognized as relevant for the preservation of the São Paulo State Semideciduous Seasonal Forest. Our research presents an updated checklist of the vascular flora of the small fragment of legally protected forest, located in the São Paulo State countryside, known as Ibicatu Ecological Station, with the main goal of discussing its importance for local and regional biodiversity conservation. We used the walking method, for a qualitative floristic survey, and botanical material was collected in reproductive and vegetative state. We sampled 187 species typical of the semideciduous seasonal forest, distributed in different eight life forms, with predominance of non-woody life forms, especially herbs and epiphytes. We identified 11 endangered species, including Peperomia hydrocotyloides, considered extinct from the São Paulo State, and some exotic and invasive species. We consider that this small forest fragment present rich vascular flora typical of the São Paulo countryside, in different life forms, and it is essential for local and regional biodiversity. This study added 102 species to the previously published checklist, emphasizing the importance of floristic surveys that include all life forms.
LAGARTOS DA FLORESTA ESTADUAL DE PEDERNEIRAS, ESTADO DE SÃO PAULO, BRASIL
Authors: Araujo Cybele de Oliveira , Figueiredo Caio Collachite , Martinez Rosângela Aparecida Marques
Published: November 2018

Apesar de a fauna de répteis do estado de São Paulo ser considerada a mais conhecida no país, ainda existem consideráveis lacunas amostrais, sobretudo em remanescentes de vegetação natural presentes na região central do estado. Nesse contexto, o objetivo deste estudo foi gerar informações sobre a diversidade de lagartos na Floresta Estadual de Pederneiras, uma unidade de conservação na região central do estado de São Paulo que apresenta talhões de reflorestamento e fragmentos de floresta estacional semidecidual. O levantamento das espécies foi conduzido mensalmente de janeiro/2012 a março/2013, totalizando 70 dias de inventário. A amostragem foi realizada por meio de armadilhas de interceptação e queda, encontro ocasional e procura visual. Foram registradas na localidade cinco espécies de lagartos pertencentes a cinco gêneros e quatro famílias (Dactyloidae, Gymnophthalmidae, Mabuyidae e Teiidae). Este estudo contribui para ampliar o conhecimento sobre a diversidade de répteis na Mata Atlântica, um dos hotspots mundiais prioritários para a conservação biológica.
"Click" chemistry as a tool to create novel biomaterials: a short review
Authors: Barbosa Mariana , Martins Cristina , Gomes Paula
Published: November 2018

In recent years, there has been a growing demand for novel strategies for biomedical applications. Chitosan is a typical cationic amino-containing polysaccharide that has been widely used due to its unique properties. The grafting modification of chitosan has been explored as an interesting method to develop multifunctional novel chitosan hybrid materials for drug delivery, tissue engineering, and other biomedical applications. Recently, “click” chemistry has been introduced into the synthesis of polymeric materials with well-defined and complex chain architectures. The Huisgen’s 1,3-dipolar cycloaddition reaction between alkynes and azides yielding triazoles is the principal example of a “click” reaction. Bioconjugation, surface modification, and orthogonal functionalization of polymers were successfully performed through this chemoselective reaction. In recent literature interest has been shown in this cycloaddition for the modification of polysaccharides, however, only a few chitosan graft copolymers have been synthesized by this technique.
Editorial
Authors: Silva Lucas F.M. da
Published: November 2018

The Faculty of Engineering of the University of Porto (FEUP) offers since 2014 a course on Transferable Skills for Engineering: Scientific Publication and Writing. It is expected that the course participants may publish articles with more success through a more systematic writing and more appropriate choice of the journal in terms of content and impact on the scientific community. Apart from writing and choosing the journal, the student will also be competent in terms of paper revisions and corrections. The student will gain knowledge of issues related to publishing, the type of journal, in which databases the paper is indexed, the impact of the paper, the basic steps of writing a scientific article, the proper search of articles published in bibliographic databases and the ethical issues of plagiarism.
Environmental life-cycle assessment of a military explosive production unit: a preliminary approach
Authors: Costa Daniele , Galante Erick , Andrade Izabela , Cunha Jéssica
Published: November 2018

It is generally known that plants of the chemical industry have great potential to generate environmental impacts and health hazards. However, systematic measurements of these impacts are not common. Life Cycle Assessment (LCA) is a tool that allows quantitative environmental impacts evaluation and it was applied in a preliminary approach to analyze selected subsystems in a RDX (1,3,5-trinitroperhydro-1,3,5-triazine) military production unit. LCA was applied through analysis of the plant data in the free software OpenLCA, using ELCD (European Reference Lyfe Cycle Database) and the TRACI (Tool for the Reduction and Assessment of Chemical and other environmental Impacts) method. As a result, the following impact categories were assessed: acidification, ecotoxicity, eutrophication, global warming, human health, ozone depletion, photochemical oxidation and resource depletion.
Study and overview on WBAN under IEEE 802.15.6
Authors: Kurunathan John Harrison
Published: November 2018

WBAN (wireless body area networks) is an upcoming technology which stands to be a base for wearable and implantable sensors. The IEEE 802.15.6 formulates the physical and medium access for body area networks. The Body area networks can be implemented in several applications like health monitoring, ambient living environments and consumer electronics. This paper gives a clear overview about the functions of WBAN. The medium access layers and the physical layers of IEEE 802.15.6 are deeply examined and studied in this work. The access mechanisms of the protocol are explained in this paper. A clear literature review has also been stated to know the current state of art of this technology. The future possibilities and area to be explored also has been defined in this work.
SimTwo as a simulation environment for flight robot dynamics evaluation
Authors: Amaral Guilherme , Costa Paulo
Published: November 2018

Aerial Robots has become very popular in robotics groups. This ongoing interest is driven by a significant number of potential end-user applications where it is necessary to reduce human intervention. The validation of control/cooperation algorithms not always is an easy task and requires a large number of humans to keep tests safety. Is present in this paper the simulation of a quadrotor model in SimTwo simulation environment and evaluated the flight dynamic of the robot. To do that was developed a control layer responsible to the hovering maneuver and “go to” position function. The results prove that the objectives were achieved successfully and the simulation was validated. The navigation simulation is left as future work.
Performance of passive Direct Methanol Fuel Cell: modelling and experimental studies
Authors: Berns Beatriz A. , Torres Mariana F. , Oliveira Vânia B. , Pinto Alexandra M. F. R.
Published: November 2018

Low methanol and water crossover with high methanol concentrations are essential requirements for a passive Direct Methanol Fuel Cell (DMFC) to be used in portable applications. Therefore, it is extremely important to clearly understand and study the effect of the different operating and configuration parameters on the cell’s performance and both methanol and water crossover. In the present work, a detailed experimental study on the performance of an in-house developed passive DMFC with 25 cm2 of active membrane area is described. Tailored membrane electrode assemblies (MEAs) with different structures and combinations of gas diffusion layers (GDL) and membranes, were tested in order to select optimal working conditions at high methanol concentration levels without sacrificing performance. The experimental polarization curves were successfully compared with the predictions of a steady state, one-dimensional model accounting for coupled heat and mass transfer, along with the electrochemical reactions occurring in the passive DMFC developed by the same authors.
Simulated Annealing with Gaussian Probability Density Function for Transmission Expansion Planning
Authors: Gomes Phillipe
Published: November 2018

Simulated Annealing (SA) is a powerful tool for optimization problems that have several local optima. This tool has the ability to escape from a local optima accepting relatively bad solutions for a period and searching for good solutions in your neighborhood. This paper describes the use of SA based on Gaussian Probability Density Function as a decision support criteria in resolution of Transmission Expansion Planning (TEP) problem. This method consists in starting from an initial solution with all possible circuits added and over the iterations removing, replacing or adding new circuits. The method proved to be a reasonable computational effort and proved able to find optimal values known in the literature.
Cognitive Working Performance in Moderate Cold Thermal Environment: a systematic review
Authors: Zlatar Tomi
Published: November 2018

Presence of cold thermal environment represents significant risk factors high latitudes, during winter seasons and in a large number of industrial activities, influencing the cognitive working performance. The aim of this work is to contribute with a systematic review on cognitive working performance in moderate cold thermal environment, by classifying different studies conducted in that area. By using appropriate keywords and searching electronic databases, a systematic review of English articles has been conducted. Only articles related to cognitive working performance in moderate cold thermal environment were included. Nine experimental articles were included. The number of participants varied from 6 to 22 subjects. The findings of this systematic review indicate that moderate cold environment influence the cognitive performance by decreasing working performance, reaction time, executive function and attention and it remain decreased for some time after cold exposure, even when the core and skin temperature get stabilized.
A Low Cost Auto-filling and Refrigeration Rate Regulated Liquid Nitrogen Controller for Near Infrared Instruments
Authors: Anugu Narsireddy , Amorim António , Garcia Paulo , Gordo Paulo , Frederico Tiago , Abreu Jorge
Published: November 2018

Liquid Nitrogen is one of the key refrigerating elements in cooling near infrared science instruments to reduce the dark, readout noises and thermal emissions in the near infrared originated from the instrument structure. Usually, a small liquid nitrogen tank connected to the near infrared instrument is auto filled from a large Dewar in order to maintain required low temperatures during the experiment for several hours. The detectors used in these instruments are quite expensive and they need to be cooled down steadily (< 2K/min) to avoid mechanical damage. The steady state cooling of the detector is the key requirement to be considered while cooling down the detector. In this paper, a controller is developed to auto-fill the liquid nitrogen tank and also to keep the refrigeration rate of the detector below 2K/min. A systematic survey of auto-filling controllers is studied. The auto-filling of liquid nitrogen from Dewar to tank is implemented with a standard on-off controller. To address the critical refrigeration rate of the detector, two approaches are studied: a) by fixed time pumping; b) by feedback the detector cooling rate. In this work we have used inexpensive equipment to develop this controller. It is very successfully used for GRAVITY acquisition camera, a near infrared instrument for European Southern Observatory. This controller has been stable and efficient for our experiment. This low cost controller can be used for any student laboratory and research.
Recent Progress in Long-term Stability of Perovskite Solar Cells
Authors: Emami Seyedali , Andrade Luísa , Mendes Adélio
Published: November 2018

Perovskite solar cells made a huge breakthrough among the nanostructured thin film photovoltaics. They exhibited certified power conversion efficiency (PCE) as high 24 % in 2015. A vast amount of research were spent on improvement of PCE and lowering the fabrication process temperature, resulting in outstanding outcomes in these areas. In contrast, the long-term stability and commercialization of these devices were not well studied. The review briefly summaries the challenges of perovskite solar cells in the road of stabilization and commercialization.
Model-based Predictive Control implementation for Cooperative Adaptive Cruise Control
Authors: Lopes António , Araújo Rui Esteves
Published: November 2018

The automation of road vehicles has become a necessity to improve the efficiency and safety of this system. In a vehicle formation it is important to maintain a safety distance between the vehicles. The control of a vehicle spacing distance and longitudinal velocity can be achieved through the implementation of a model-based predictive controller. This implementation of a cooperative adaptive cruise control allows the access of another vehicle state information through vehicular communication technology and promote state prediction and ultimately system stability. The optimization algorithm performs the computation of the control input in a control horizon window and ensures that the spacing error takes only positive values. The results of the proposed controller are evaluated through the computational tool Simulink in the two-vehicle platoon. The controller is implemented in the precedent vehicle. To assess the performance of the proposed controller different control parameters and constraints were used.
Single Lap Joints Numerical Modelling and Comparison with Experimental Testing
Authors: Braga Daniel F. O. , Da Silva Lucas F. M. , Moreira Pedro M. G. P.
Published: November 2018

Adhesive bonding is a joining technique which has been extensively employed in structural design as its ability to join different types of materials allows higher freedom for designers when choosing materials. One of the most common joint configuration used is the single lap joint configuration. In this work a set of experimental procedures were undertaken to characterize a structural adhesive and model the behaviour of a single lap joint manufactured using this adhesive. Two types of surface preparations were used to study its effect in single lap joint strength.
Editorial
Authors: Campilho Aurélio
Published: November 2018

This Special Issue on Electrical and Computer Engineering includes selected papers from the 1st edition of the Symposium on Electrical and Computer Engineering (ECE 2015), one of the symposia included in the 1st Doctoral Congress in Engineering, held at FEUP, 11-12 June, 2015. ECE 2015 was an important forum for presenting the research activities of ECE students, particularly from the Doctoral Program in Electrical and Computer Engineering, at FEUP (PDEEC). ECE 2015 received a total of 42 two-page abstracts. The review process was carried out by members of the Symposium Scientific Committee and other reviewers. Each abstract was reviewed by at least two reviewers, and checked by the Program Committee. 37 abstracts were finally accepted and appear in the Symposium book of abstracts. From the 37 abstracts, 17 were presented in four oral sessions, and 20 in one poster session. We were very pleased to include two keynote talks: “The Internet of Things - Latest Trends and Future Perspectives” by Carlos Azeredo Leme, University of Lisbon, Portugal; “A Perspective on Virtual Radio Access Networks” by Luís M. Correia, University of Lisbon, Portugal. Six papers were invited to submit extended versions to this special issue, that were further reviewed and published in this issue.We would like to sincerely thank the authors for submitting these extended versions, and we thank the special issue reviewers for the careful evaluation and feedback provided to the authors. We also would like to express our gratitude to Luís Miguel Costa, for supporting the organization of this Special issue of the U.Porto Journal of Engineering.Finally, we are very pleased to give the readership of this Special Issue on ECE examples of the research developed by PDEEC students, from a vast area covered by the Electrical and Computer Engineering at FEUP and at the associated research institutes and research centers.
A Reconfigurable Custom Machine for Accelerating Cellular Genetic Algorithms
Authors: Santos P. V. , Alves José Carlos , Ferreira João Canas
Published: November 2018

In this work we present a reconfigurable and scalable custom processor array for solving optimization problems using cellular genetic algorithms (cGAs), based on a regular fabric of processing nodes and local memories. Cellular genetic algorithms are a variant of the well-known genetic algorithm that can conveniently exploit the coarse-grain parallelism afforded by this architecture. To ease the design of the proposed computing engine for solving different optimization problems, a high-level synthesis design flow is proposed, where the problem-dependent operations of the algorithm are specified in C++ and synthesized to custom hardware. A spectrum allocation problem was used as a case study and successfully implemented in a Virtex-6 FPGA device, showing relevant figures for the computing acceleration.
Multimedia Content Classification Metrics for Content Adaptation
Authors: Fernandes Rui , Andrade M. T.
Published: November 2018

Multimedia content consumption is very popular nowadays. However, not every content can be consumed in its original format: the combination of content, transport and access networks, consumption device and usage environment characteristics may all pose restrictions to that purpose. One way to provide the best possible quality to the user is to adapt the content according to these restrictions as well as user preferences. This adaptation stage can be best executed if knowledge about the content is known a-priori. In order to provide this knowledge we classify the content based on metrics to define its temporal and spatial complexity. The temporal complexity classification is based on the Motion Vectors of the predictive encoded frames and on the difference between frames. The spatial complexity classification is based on different implementations of an edge detection algorithm and an image activity measure.
Indoor Localization Using Barely Perceptible Audio Signals
Authors: Moutinho João , Freitas Diamantino , Araújo Rui Esteves
Published: November 2018

This paper presents a new approach to an audio-based indoor localization system. By using audio signals emitted by a public address sound system, mobile devices may globally localize themselves in an indoor environment where global navigation satellite systems are not viable or reliable. The use of data hiding techniques such as spread spectrum coding or echo hiding has allowed to convey information to a receiver avoiding people’s perception of the added audio content. Results demonstrate a relatively quite good localization with centimetre accuracy and precision and successful data transmission using barely perceptible audio signals.
Comparative Analysis of Constructive Heuristic Algorithms for Transmission Expansion Planning
Authors: Gomes Phillipe Vilaça , Saraiva João Tomé
Published: November 2018

Transmission Expansion Planning (TEP) is a complex optimization problem that has the purpose of determining how the transmission capacity of a network should be enlarged, satisfying the increasing demand. This problem has combinatorial nature and different alternative plans can be designed so that many algorithms can converge towards local optima. This feature drives the development of tools that combine high robustness and low computational effort. This paper presents a comparative analysis and a detailed review of the main Constructive Heuristic Algorithms (CHA) used in the TEP problem. This kind of tools combine low computational effort with reasonable quality solutions and can be associated with other tools to use in a subsequent step in order to improve the final solution. CHAs proved to be very effective and showed good performance as the test results will illustrate.
Analysing the Critical Orientation of Seismic Loading in 3D Buildings: Preliminary Results for Constant Lateral Forces
Authors: Skoulidou Despoina , Romão Xavier
Published: November 2018

The angle of seismic excitation has been proven to be an important factor when analysing the 3D behaviour of buildings. However, modern earthquake-related standards only cover partially the effects of this factor and practicable results of relevant studies are still limited. The proposed paper focuses on the determination of the critical angle of incidence based on the building's structural characteristics. An analytical expression is developed to define the critical angle for the case of single storey buildings and a special category of multi storey buildings under constant lateral forces assuming linear elastic behaviour of the structures.
Grillage Modeling Approach Applied to Simple-span Slab-girder Skewed Bridges for Dynamic Analysis
Authors: López Chávez Miriam Guadalupe , Arêde António , Jara Guerrero José Manuel , Delgado Pedro , Varum Humberto
Published: November 2018

This study involves the applicability of a simplified modeling technique to simple-span slab-girder skewed bridges for dynamic analysis, based on grillage modeling strategies. To evaluate the applicability of this technique, skew angles ranging from 0° to 60° are studied. The ability to capture vibration modes of grillage models is compared with three-dimensional (3-D) finite element (FE) models, using shell and frame elements. The effect of the skew angle in the grillage modeling technique of the bridge's deck and the grillage model accuracy associated with the orientation of the transverse grillage members (TGMs) are studied. The grillage modeling technique eliminates shell elements to model the slab, reducing the number of degrees of freedom and the computational time in the bridge model, but, although its simplicity, demonstrates good ability to capture the vibration modes.
Lignin Valorization: Concentration of Model Phenolic Compounds by Nanofiltration
Authors: Gomes Elson Dinis , Pinto P. C. R. , Rodrigues Alírio E.
Published: November 2018

Lignin is a biopolymer found in plants which can be valorized as a source of value added compounds by breaking its structure in the constituting monomers. A model solution was prepared with seven phenolic compounds, including vanillin and syringaldehyde, usually found after alkaline lignin oxidation. The model solution was concentrated by nanofiltration membranes with low molecular weight cut-off (MWCO). Two membranes (DOW NF270 and KOCH MPS-34) were tested for permeate fluxes and phenolic compound rejection. Significant reduction of the volume mixture was achieved with high permeate fluxes as well as high rejections (above 90%) for the phenolic compounds studied. The membrane with the best performance was the DOW NF270 with maintained high rejections while having higher permeate fluxes resulting in higher productivity when compared with the other membrane KOCH MPS-34 also tested.
Rescuing the Environment: Turning (Micro)plastics into Energy Through Gasification
Authors: Ramos Ana , Rouboa Abel
Published: November 2018

Plastics are a common residue of our activities and, when incorrectly disposed, high quantities of this type of products end up in the environment, namely through landfilling and dumping into the aquatic compartments. Therefore, water streams and basins are contaminated threatening wildlife, which ultimately can entail human toxicity by means of the food-chain effect. One of the major concerns relies on microplastics which, due to its size and nature, constitute a more difficult to handle residue.This paper presents an endeavour to control, reduce or even mitigate the presence of plastic debris in the environment, with the benefit of converting them into energy or other valuable commodities for the actual society. Gasification can be seen as one of the most effective techniques for this purpose, featuring a more environmental friendly scheme for treating this kind of residues, avoiding their overspread throughout Nature, as well as complying with environmental policies.
Power Transformer Failure Prediction: Classification in Imbalanced Time Series
Authors: Oliveira Eduardo E , Miguéis Vera L. , Guimarães Luís , Borges José
Published: November 2018

This paper describes a study on applying data mining techniques to power transformer failure prediction. The data set used consisted not only on DGA tests, but also in other tests done to the transformer’s insulating oil. This dataset presented several challenges, such as highly imbalanced classes (common in failure prediction problems), and the temporal nature of the observations.To overcome these challenges, several techniques were applied for prediction and better understand the dataset. Pre-processing and temporality incorporation in the dataset is discussed. For prediction, a 1-class and 2-class SVM, decision trees and random forests, as well as a LSTM neural network were applied to the dataset.As the prediction performance was low (high false-positive rate), we conducted a test to ascertain if the amount of data collected was sufficient. Results indicate that the frequency of data collection was not adequate, hinting that the degradation period was shorter than the periodicity of data collection.
Cohesive Properties of Environmentally Degraded Epoxy Adhesives
Authors: Viana G. , Costa M. , Banea M. D. , Silva L. F. M. da
Published: November 2018

Adhesives are increasingly being used in the aerospace and automotive industries. They allow for light weight vehicles, fuel savings and reduced emissions. However, the environmental degradation of adhesive joints is a major setback in its wider implementation. Moisture degradation of adhesive joints includes plasticization, attacking of the interface, swelling of the adhesive and consequent creation of residual stresses. The main factors affecting the strength of adhesive joints under high and low temperatures are the degradation of the adhesive mechanical properties and the creation of residual stresses.To model the long term mechanical behaviour of adhesive joints, the temperature and moisture dependent properties of the adhesives must be known. However, few studies focus on the combined moisture and temperature degradation, which difficults the prediction of the long term mechanical behaviour of these joints. In this study the prediction of moisture and temperature dependent cohesive properties of a structural adhesive is analysed.
Alkali-Activated Fly Ashes: Influence of Curing Conditions on Mechanical Strength
Authors: Almeida Filipe , Cristelo Nuno , Miranda Tiago , Vieira Castorina S. , Lopes Maria De Lurdes , Castro Fernando
Published: November 2018

Alkaline activation of fly ashes is a procedure that enables an alternative binder which has been receiving much interest by several research groups particularly on the manufacturing of mortars and concretes. The properties of the materials that are developed during the alkaline activation are influenced by the curing conditions (temperature and relative humidity). Another relevant facet related to the curing procedures is the possibility of carbonation occur, which may have an impact on the mechanical strength of the alkaline cements. In this research, several sets of curing conditions were tested to understand which one results in a higher strength and reveals carbonation. Uniaxial compressive strength tests were conducted to assess mechanical behavior. The outcome suggests that higher temperature and low relative humidity yields higher mechanical strength.
Prediction of Joint Strength and Effect of the Surface Treatment on the Single Overlap Adhesive Joints
Authors: Giesteira Filipe A. G. , Marques E. A. S. , Carbas R. J. C. , Silva L. F. M. da
Published: November 2018

A two-component high-ductility adhesive (acrylic and catalyst based), SikaFast® - 5211 NT, was used to bond single overlap joints with mild steel adherends and 25 mm of overlap. One joint configuration used treated bonding surfaces while the other was did not employ treatment of the adherend surfaces, with the aim of studying the influence of the material surface treatment. The specimens were tensile tested in a INSTRON® universal testing machine and the non-treated surface have shown a strength four times lower than the treated surface. Several analytical methods were used to predict joint strength, with two methods achieving reasonably accurate failure load predictions.
Chemical Vapour Deposition of Hexagonal Boron Nitride for Two Dimensional Electronics
Authors: Sompalle Balaji , Borme Jérôme , Cerqueira Fátima , Sun Tangyou , Campos Rui , Alpuim Pedro
Published: November 2018

Hexagonal boron nitride (h-BN) has potential applications in protective coatings, single photon emitters and as substrate for graphene electronics. In this paper, we report on the growth of h-BN by chemical vapor deposition (CVD) using ammonia borane as the precursor. Use of CVD allows controlled synthesis over large areas defined by process parameters, e.g. temperature, time, process chamber pressure and gas partial pressures. Furthermore, independently grown graphene and h-BN layers are put together to realize enhancement in electronic properties of graphene.
Hydric Resistance in Ceramic Samples with Contact Interfaces
Authors: Azevedo Antônio , Sousa Ricardo , Guimarães Ana Sofia , Freitas Vasco P. de
Published: November 2018

Knowledge of the humidity transport inside materials and building construction elements present a high role in the characterization of their behavior in service. It is a vary complex phenomena, where monolithic elements are considered since the existence of interface or layers contributes to the change of the moisture transport across the interface. This work presents an experimental analysis of the moisture transport considering the interface ceramic bricks. This preliminary experimental work consists of quantifying, analyzing and deepening the knowledge of hydric resistance in the interface of "contact" through ceramic brick test samples with different densities. In addition, this work also comprises an attempt to create a prediction model for the hydric resistance. The results describe the influence of hydric resistance in the interface as a function of the distance from the interface to the water plane.
Planning Models for Distribution Grid
Authors: Arias Piedy Agamez
Published: November 2018

planning and expansion models of the electrical grid to guarantee mainly the energy supply for current and future loads and the technical and operational criteria of the grid, requiring for this, to make an orderly sequence of investments along the planning horizon. Nevertheless, the ongoing integration of distributed generation and energy storage devices has been leading to consider some changes on those models focus to deal with the complexity those integrations bring with them. In this context, this paper presents a brief review of distribution planning and expansion models with the perspective of identifying approaches, objective functions used, uncertainties analyzed, the computational and evolutionary techniques used, the dimension of the grid under analyses, among other aspects considered to solve the planning and expansion problem. This document will provide a background to find out the further works in this field.
Occupational Vibration in Urban Bus and Influence on Driver’s Lower Limbs
Authors: Cvetkovic M. , Baptista J. Santos , Vaz M. A. Pires
Published: November 2018

The whole-body vibration occurs in many occupational activities, promoting discomfort in the working environment and inducing a variety of psycho – physical changes where consequences as a permanent dysfunction of certain parts of the organism may occur. The main goal of this short systematic review is finding the articles with the most reliable results relating whole-body vibrations to buses and, to compare them with the results of drivers’ lower limbs musculoskeletal disease which occurs as a consequence of many year exposure. PRISMA Statement Methodology was used and thereby 27 Scientific Journals and 25 Index - Database were searched through where 3996 works were found, of which 24 were included in this paper. As a leading standard for analysis of the whole-body vibration the ISO 2631 – 1 is used, while in some papers as an additional standard the ISO 2631-5 is also used for the sake of better understanding the vibrations. Furthermore, the European Directive 2002/44 / EC is included where a daily action exposure to the whole-body vibrations is exactly deter-mined. All the results presented in the paper were compared with the aforesaid standards. After having searched the databases, papers that deal with research of the impact of the vibration on the driver’s lower limbs did not contain any information’s on the described problem.
Dimensioning Studies for Reversible Hydro Power Plants in Portuguese Islands
Authors: Fonseca Nuno , Madureira André , Lopes João Peças , Matos Manuel
Published: November 2018

This work is within the scope of set of consultancy studies made for Portuguese islands. It focuses on the integration of Pumped Storage Power in isolated islands. The paper starts to address several power systems circumstances about two Portuguese islands on the energetic level. For each of these islands, an independent examination of the conditions to install a reversible hydro power plant is accomplished. Therefore, the energy volume to be stored due to excess of renewable generation and the ideal power and number of the pumps and turbines to be installed were identified and evaluated for the sake of using the produced energy surplus as to be pumped and later generated. The paper enhances the importance of storing energy in the operation of isolated and small systems with considerable amount of intermittent power resources as well as the conditions for the viability of installing new exploitations of this kind.
Atherosclerotic lesions of brachiocephalic arteries and issues of surgical correction of symptomatic and asymptomatic carotid stenosis
Authors: Glushkov N. I. , Ivanov M. A. , Artemova A. S. , Apresyan A. Yu. , Gorovaya A. D. , Uryupina А. A.
Published: November 2018

The objective of the study was to evaluate the results of carotid endarterectomy in patients with symptomatic and asymptomatic course of hemodynamically significant stenosis of carotid arteries.

Material and methods. The work was based on observations of 88 patients: the main group included 28 patients with asymptomatic lesion, the control group – 60 patients with symptomatic critical carotid stenosis.

Results. There was a predominance of contralateral carotid stenosis, changes in vertebral arteries in the control group. Features of atherosclerotic lesion of carotid arteries associated with the severity of metabolic disorders, perioperative fluctuations of hemodynamics, time of clamping of carotid arteries.

Conclusion. Aggressive course of symptomatic carotid stenosis requires correction of metabolic disorders in the perioperative and in the distant periods, as well as monitoring of hemodynamic abnormalities.
Role of preoperative x-ray endovascular interventions for improvement of resectability of colorectal liver metastases
Authors: Tarazov P. G. , Granov D. A. , Polikarpov A. A. , Sergeev V. I. , Kozlov A. V. , Polekhin А. S. , Moiseenko A. V. , Rozengauz Е. V.
Published: November 2018

The objective was of the study to evaluate the role of preoperative x-ray endovascular interventions – transcatheter arterial chemoembolization (TACE) and portal vein embolization (PVE) – for improvement of resectability of colorectal liver metastases.

Material and methods. Between 1997 and 2017, we treated 11 patients who simultaneously had large-volume (60–70 %) of right liver lobe colorectal metastases and small future remnant liver. The treatment was started from 1–4 cycles of TACE to reduce or stabilize the rapid growth of the tumor. In case of good effect, we performed PVE and then we performed liver resection.

Results. There were no major complications of TACE or PVE. After 1–4 cycles of TACE, the volume of metastases showed partial decrease or stabilization. The following PVE allowed to increase the future remnant volume of the left liver lobe up to a safe 40–45 %. Right – sided hemihepatectomy was performed in 6 patients and extended right-sided hemihepatectomy in 5 patients. There were no postoperative mortality or severe complications. At present, 4 patients are alive without recurrence during 1.5–8 years, and 4 other patients received endovascular treatment for local recurrence are alive during 1.5–5 years. The 3 patients died from tumor progression during 13–30 months. CONCLUSION. In patients with simultaneously extensive for resection volume of right liver lobe metastases and small left liver lobe, the primary treatment with TACE is reasonable. Only after the documentation of tumor decrease or stabilization, it is necessary to determine the timing of PVE and following major liver resection. This order of treatment procedures allows to improve resectability in cases with extensive, large-volume, rapidly grown malignant liver lesions.