Search results for: Matheus Fernando Pereira

Authors: Jorge Olivares, Fernando Maass, Pablo Martin

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Fractional derivatives have been considered recently as a way to solve different problems in Engineering. In this way, second kind modified Bessel functions are considered here. The order α fractional differential equations of second kind Bessel functions, Kᵥ(x), are studied with simple initial conditions. The Laplace transform and Caputo definition of fractional derivatives are considered. Solutions have been found for ν=1/3, 1/2, 2/3, -1/3, -1/2 and (-2/3). In these cases, the solutions are the sum of two hypergeometric functions. The α fractional derivatives have been for α=1/3, 1/2 and 2/3, and the above values of ν. No convergence has been found for the integer values of ν Furthermore when α has been considered as a rational found m/p, no general solution has been found. Clearly, this case is more difficult to treat than those of first kind Bessel Function.

Keywords: Caputo, modified Bessel functions, hypergeometric, linear fractional differential equations, transform Laplace

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Authors: Danilo López, Edwin Rivas, Fernando Pedraza

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Currently, one of the major challenges in wireless networks is the optimal use of radio spectrum, which is managed inefficiently. One of the solutions to existing problem converges in the use of Cognitive Radio (CR), as an essential parameter so that the use of the available licensed spectrum is possible (by secondary users), well above the usage values that are currently detected; thus allowing the opportunistic use of the channel in the absence of primary users (PU). This article presents the results found when estimating or predicting the future use of a spectral transmission band (from the perspective of the PU) for a chaotic type channel arrival behavior. The time series prediction method (which the PU represents) used is ANFIS (Adaptive Neuro Fuzzy Inference System). The results obtained were compared to those delivered by the RNA (Artificial Neural Network) algorithm. The results show better performance in the characterization (modeling and prediction) with the ANFIS methodology.

Keywords: ANFIS, cognitive radio, prediction primary user, RNA

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Authors: Matheus Borges Carneiro, Fabiane Leticia Lizarelli, José Carlos De Toledo

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The evolution of quality management by companies was strongly enabled by, among others, ISO 9001 certification, which is considered a crucial requirement for several customers. Likewise, performance measurement provides useful insights for companies to identify the reflection of their decision-making process on their improvement. One of the most used performance measurement models is the balanced scorecard (BSC), which uses four perspectives to address a firm’s performance: financial, internal process, customer satisfaction, and learning and growth. Studies related to ISO 9001 and business performance have mostly adopted a quantitative approach to identify the standard’s causal effect on a firm’s performance. However, to verify how this influence may occur, an in-depth analysis within a qualitative approach is required. Therefore, this paper aims to verify the impact of ISO 9001:2015 on Brazilian firms’ performance based on the balanced scorecard perspective. Hence, nine certified companies located in the Southeast region of Brazil were studied through a multiple case study approach. Within this study, it was possible to identify the positive impact of ISO 9001 on firms’ overall performance, and four Critical Success Factors (CSFs) were identified as relevant on the linkage among ISO 9001 and firms’ performance: employee involvement, top management, process management, and customer focus. Due to the COVID-19 pandemic, the number of interviews was limited to the quality manager specialist, and the sample was limited since several companies were closed during the period of the study. This study presents an in-depth analysis of how the relationship between ISO 9001 certification and firms’ performance in a developing country is.

Keywords: balanced scorecard, Brazilian firms’ performance, critical success factors, ISO 9001 certification, performance measurement

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Authors: Paulo Fernando Silva Filho, Elcio Hideiti Shiguemori

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The selection of specific landmarks for an Unmanned Aerial Vehicles’ Visual Navigation systems based on Automatic Landmark Recognition has significant influence on the precision of the system’s estimated position. At the same time, manual selection of the landmarks does not guarantee a high recognition rate, which would also result on a poor precision. This work aims to develop an automatic landmark selection that will take the image of the flight area and identify the best landmarks to be recognized by the Visual Navigation Landmark Recognition System. The criterion to select a landmark is based on features detected by ORB or AKAZE and edges information on each possible landmark. Results have shown that disposition of possible landmarks is quite different from the human perception.

Keywords: clustering, edges, feature points, landmark selection, X-means

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Authors: Nicole Kalemba, Fernando Campa-Planas, Ana-Beatriz Hernández-Lara, Maria Victória Sánchez-Rebull

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The purpose of this paper is to determine the effects of service quality on US airlines’ economic performance. In order to cover this goal, it has been considered four different indexes of service quality in the air transportation industry, and also two indicators of economic performance, revenues and return on investment (ROI). Data from American airline companies over a period that covers from 2006 to 2013 have been used in order to determine if airlines’ profitability increases when service quality improves. Considering the effects on airlines’ profitability, the results confirm the positive and significant influence of service quality on the ROI of the companies in our study. Meanwhile, a non-significant effect was found for airline revenues related to quality. No previous research in this area has been done and these findings could encourage airline companies to invest in quality as far as this policy can have a return on their profitability.

Keywords: airlines, economic performance, key performance indicators, quality

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Authors: Luis Fernando Pinedo-Lomeli, Rosa Martha Lopez-Gutierrez, Jose Antonio Michel-Macarty, Cesar Cruz-Hernandez, Liliana Cardoza-Avendaño, Humberto Cruz-Hernandez

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Robots are working in industry and services performing repetitive or dangerous tasks, however, when flexible movement capabilities and complex tasks are required, the use of many robots is needed. Also, productivity can be improved by reducing times to perform tasks. In the last years, a lot of effort has been invested in research and development of collective control of mobile robots. This interest is justified as there are many advantages when two or more robots are collaborating in a particular task. Some examples are: cleaning toxic waste, transportation and manipulation of objects, exploration, and surveillance, search and rescue. In this work a study of collective movements of mobile robots is presented. A solution of collisions avoidance is developed. This solution is levered on a communication implementation that allows coordinate movements in different paths were avoiding obstacles.

Keywords: synchronization, communication, robots, legos

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Authors: Andressa dos Santos Nicolau, João P. da S.C Algusto, Claudio Márcio do N. A. Pereira, Roberto Schirru

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In case of abnormal situations, the nuclear power plant (NPP) operators must follow written procedures to check the condition of the plant and to classify the type of emergency. In this paper, we proposed a Real Time Expert System in order to improve operator’s performance in case of transient or accident with reactor shutdown. The expert system’s knowledge is based on the sequence of events (SoE) of known accident and two emergency procedures of the Brazilian Pressurized Water Reactor (PWR) NPP and uses two kinds of knowledge representation: rule and logic trees. The results show that the system was able to classify the response of the automatic protection systems, as well as to evaluate the conditions of the plant, diagnosing the type of occurrence, recovery procedure to be followed, indicating the shutdown root cause, and classifying the emergency level.

Keywords: emergence procedure, expert system, operator support, PWR nuclear power plant

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Authors: Ciro Sobrinho Campolina Martins, Halison da Silva Pereira, Vitor Mainenti Leal Lopes

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Unmanned Aerial vehicles (UAVs) has been used in a wide range of applications, from precise agriculture monitoring for irrigation and fertilization to military attack missions. Long range performance is required for many of these applications. Tailless aircrafts are commonly used as long-range configurations and, due to its small amount of stability, the airfoil shape design of its wings plays a central role on the performance of the airplane. In this work, a new family of flying wing airfoils is designed for low Reynolds number flows, typical of small-middle UAVs. Camber, thickness and their maximum positions in the chord are variables used for the airfoil geometry optimization. Aerodynamic non-dimensional coefficients were obtained by the well-established Panel Method. High efficient airfoils with small pitch moment coefficient are obtained from the analysis described and its aerodynamic polars are plotted.

Keywords: airfoil design, flying wing, low Reynolds number, tailless aircraft, UAV

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Authors: Carlos H. Ferreira, Joana R. Pereira

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In recent decades, calls for sustainable architecture based on environmental policies have been frequent. Despite a vast number of documents, technical procedures, and publications involving these themes, conceptions, and even architectural practice are often distanced from critical and methodological reflection on the relationship between environment and architecture. Among the various issues that we could consider in this relationship, we highlight in this article the relevance of water in the environment and in the architectural design. From documentary references and works carried out, we seek contributions to a better systematization and framing of water in architectural thinking. We distinguish, on the one hand, more conceptual issues that involve the environmental relationship of water, involving its cycle, relevance in the landscape, and infrastructural commitments. On the other hand, we highlight a more operative component, focusing on the place of water in the design process, from its perception in space-shape dimensions to more specific technical requirements that involve the interdisciplinary boundaries of architecture. In both approaches to water in architectural design, we seek to contribute to greater sensitivity and efficiency in the art of designing a more sustainable future.

Keywords: sustainability, environment, water, resilience design

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Authors: Adriana Souza M. Batista, Cláubia Pereira, Luiz O. Faria

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The irradiation of polymeric materials has received much attention because it can produce diverse changes in chemical structure and physical properties. Thus, studying the chemical and structural changes of polymers is important in practice to achieve optimal conditions for the modification of polymers. The effect of gamma irradiation on the crystalline structure of poly(vinylidene fluoride) (PVDF) has been investigated using differential scanning calorimetry (DSC) and X-ray diffraction techniques (XRD). Gamma irradiation was carried out in atmosphere air with doses between 100 kGy at 3,000 kGy with a Co-60 source. In the melting thermogram of the samples irradiated can be seen a bimodal melting endotherm is detected with two melting temperature. The lower melting temperature is attributed to melting of crystals originally present and the higher melting peak due to melting of crystals reorganized upon heat treatment. These results are consistent with those obtained by XRD technique showing increasing crystallinity with increasing irradiation dose, although the melting latent heat is decreasing.

Keywords: differential scanning calorimetry, gamma irradiation, PVDF, X-ray diffraction technique

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Authors: Joao Paulo Matheus, Renan Fangel

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Rheumatoid arthritis is a chronic, inflammatory, systemic and progressive disease that affects the synovial joints bilaterally, causing definitive orthopedic damage. It has a higher prevalence in postmenopausal female patients. It is a disabling disease that causes joint deformities that may compromise the functionality of the affected segment. The aim of this study was to evaluate the influence of low-intensity therapeutic laser on the perception of pain and quality of life in patients with rheumatoid arthritis. This is a randomized clinical study involving 6 women with a mean age of 56.8+6.3 years. Exclusion criteria: patients with acute pain, chronic infectious disease, underlying acute or chronic underlying disease. An AsGaAl laser with 808nm wavelength, 100mW power, beam output area of 0.028cm2, power density of 3.57W/cm2 was used. The laser was applied at pre-defined points in the interphalangeal and metacarpophalangeal joints, totaling 24 points, 2 times a week, for 4 weeks, totaling 8 sessions. The Pain Inventory (IBD) and Visual Analogue Scale (VAS) were used for the analysis of pain and for the WHOQOL-bref quality of life assessment. There was no statistical difference between the onset (5.67±2.66) and the final (4.67±3.78) of treatments (p=0.70). There was also no statistical difference between the beginning (5.67±2.66) and the final (4.67±3.78) of the treatments in the VAS analysis (p=0.68). The overall mean quality of life obtained by the questionnaire at the start of treatment was 42.3±7.6, while at the end of treatment it was 58.5±7.6 (p=0.01) and the domains of the questionnaire with significant differences were: psychological domain 42.9±6.8 and 66.7±12.9 (p=0.004), social domain 39.9±5.7 and 68.1±6.3 (p=0,0005) and environmental domain 36.3±7.3 and 56.3±12.5 (p=0.003). It can be concluded that the low-intensity therapeutic laser did not produce significant changes in the painful period of rheumatoid arthritis patients. However, there was an improvement in patients' quality of life in the psychological, social and environmental aspects.

Keywords: laser therapy, pain, quality of life, rheumatoid arthritis

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Authors: Paulo Cesar Pereira Junior, Alexandre Monteiro, Rafael da Luz Ribeiro, Antonio Carlos Sobieranski, Aldo von Wangenheim

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In this paper, we present a comparison between convolutional neural networks and classical computer vision approaches, for the specific precision agriculture problem of weed mapping on sugarcane fields aerial images. A systematic literature review was conducted to find which computer vision methods are being used on this specific problem. The most cited methods were implemented, as well as four models of convolutional neural networks. All implemented approaches were tested using the same dataset, and their results were quantitatively and qualitatively analyzed. The obtained results were compared to a human expert made ground truth for validation. The results indicate that the convolutional neural networks present better precision and generalize better than the classical models.

Keywords: convolutional neural networks, deep learning, digital image processing, precision agriculture, semantic segmentation, unmanned aerial vehicles

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Authors: Fernando Miguel Campos, Carlos Ferreira, João Pestana, Pedro Campos, Nils Ehrenberg, Wojciech Hydzik

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The current trend of organizations offering their workers open-office spaces and co-working offices has been primed for stimulating teamwork and collaboration. However, this is not always valid as these kinds of spaces bring other types of challenges that compromise workers productivity and creativity. We present an approach for improving creativity and productivity at the workspace by redesigning an office chair that incorporates subtle technological elements that help users focus, relax and being more productive and creative. This sheds light on how we can better design interactive furniture for such popular contexts, as we develop this new chair through a multidisciplinary approach using ergonomics, interior design, interaction design, hardware and software engineering and psychology.

Keywords: creativity, co-working, ergonomics, human-computer interaction, interaction, interactive furniture, productivity

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Authors: Henrique C. C. Andrade, Ana Beatriz C. G. Silva, Fernando Luiz B. Ribeiro, Samir Maghous, Jose Claudio F. Telles, Eduardo M. R. Fairbairn

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The present paper aims at developing a parallel computational model for numerical simulation of poromechanics analyses of heterogeneous reservoirs. In the context of macroscopic poroelastoplasticity, the hydromechanical coupling between the skeleton deformation and the fluid pressure is addressed by means of two constitutive equations. The first state equation relates the stress to skeleton strain and pore pressure, while the second state equation relates the Lagrangian porosity change to skeleton volume strain and pore pressure. A specific algorithm for local plastic integration using a tangent operator is devised. A modified Cam-clay type yield surface with associated plastic flow rule is adopted to account for both contractive and dilative behavior.

Keywords: finite element method, poromechanics, poroplasticity, reservoir analysis

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Authors: Bruno Valverde Chahaira, Matheus Jeronimo Low Lopes, Marta Beatriz Tanaka Ferdinandi

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This paper proposes to dissect the meanings and / or directions of the State, in order, to present the State models to elaborate a conceptual framework about its function in the legal scope. To do so, it points out the possible contracts established between the State and the Society, since the general principles immanent in them can guide the models of society in force. From this orientation arise the contracts, whose purpose is by the effect to modify the status (the being and / or the opinion) of each of the subjects in presence - State and Society. In this logic, this paper announces the fiduciary contracts and “veredicção”(portuguese word) contracts, from the perspective of semiotics discourse (or greimasian). Therefore, studies focus on the issue of manifest language in unilateral and bilateral or reciprocal relations between the State and Society. Thus, under the biases of the model of the communicative situation and discourse, the guidelines of these contractual relations will be analyzed in order to see if there is a pragmatic sanction: positive when the contract is signed between the subjects (reward), or negative when the contract between they are broken (punishment). In this way, a third path emerges which, in this specific case, passes through the subject-third sector. In other words, the proposal, which is systemic in nature, is to analyze whether, since the contract of the welfare state is not carried out in the constitutional program on fundamental rights: education, health, housing, an others. Therefore, in the structure of the exchange demanded by the society according to its contractual obligations (others), the third way (Third Sector) advances in the empty space left by the State. In this line, it presents the modalities of action of the third sector in the social scope. Finally, the normative communication organization of these three subjects is sought in the pragmatic model of discourse, namely: State, Society and Third Sector, in an attempt to understand the constant dynamics in the Law and in the language of the relations established between them.

Keywords: access to justice, state, social rights, third sector

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Authors: Claudia Marcela Munoz Gonzalez, Diego Fernando Hernandez Losada, Hugo Alberto Herrera Fonseca

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The project owner's role in the public-private investment consists of controlling and verifying the correct execution of the project's objectives and resources. Likewise, it is a discipline little explored in the academic field, whereby this work wishes to contribute with a model of good practices based on the project management methodology proposed by the Project Management Body of Knowledge® Guide. In the same way, highlight what are the controls that an integral project owner should take into account in its exercise and application, through the stages in which its contract runs. This proposal aims to structure its practice and integrate its functions according to a project management methodology. In addition, these practices will be applied in a case study of projects in the agricultural sector, particularly in the construction of irrigation district in Cundinamarca, Colombia.

Keywords: controls, construction of irrigation district, PMBOK®, project owner

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Authors: Generoso Pamittan Jr., Freddielyn Pontemayor

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Through the years, the purpose of tattoos in the Philippines, has changed from being tribal and traditional-ritualistic to personal and individualistic. Hence it is interesting to know the stories and meanings behind tattoos of particular individuals. Using the frames of Anabela Pereira’s concept of ‘body art’ as ‘visual language’, this paper scrutinizes the tattoos of selected Filipino LGBTs to (1) unfold the stories behind their body symbols, (2) describe the meanings and significance of their tattoos, and (3) determine the dominant themes that are common among the tattoos of the selected LGBTs. Semi-structured interviews were conducted with selected respondents to obtain in-depth information about the tattoos. Photos of tattoos were also taken, with respondents’ consent, to describe and analyze the details of tattoos’ patterns/ designs. Based on the interviews and analysis, most of the immediate relatives of the selected LGBTs were initially against the idea of having tattoos because of social stigma. However, the LGBT respondents considered their tattoos as symbols of their penchant for something (arts, cooking, etc.), expression of their personality and life’s aspirations, assertion of their identity amidst heteronormative tendencies and symbols that constantly remind them of the significant people and milestones in their lives.

Keywords: body art, body tattoo, gender, identity, LGBT, tattoo

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Authors: Priscila M. Lima, Corine A. P. de Almeida, Muriele R. de Lima, Fernando J. C. Magalhães Filho

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This work characterized the preliminary treatment in WWTPs in the state of Mato Grosso Do Sul (Brazil) and analyzed aspects of operation and maintenance of solid waste retained, and was evaluated the interference of this step in treatment efficiency beyond the relationship between solid waste generation with rainfall and seasonality in the region of each WTPs. The results shown that the standard setting in the preliminary treatment consists of grid along with Sand Trap, followed by Parshall that is used in 94.12% of WWTPs analyzed, and in 5.88% of WWTPs it was added the air-lift to the Sand Trap. Was concluded that the influence of rainfall, flow and seasonality associated with the rate of waste generation in the preliminary treatment, had little relation to the operation and maintenance of the primary treatment. But in some cases, precipitation data showed increased rainfall converging with increased flow and solid waste generation.

Keywords: pretreatment, sewage, solid waste, wastewater

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Authors: Juliana V. Pereira, Adriana S. M. Batista, Jefferson P. Nascimento, Clascídia A. Furtado, Luiz O. Faria

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The combination of the properties of graphene oxide (OG) and PVDF homopolymer makes their combined composite materials as multifunctional systems with great potential. Knowledge of the molecular structure is essential for better use. In this work, the degradation of PVDF polymer exposed to gamma irradiation in oxygen atmosphere in high dose rate has been studied and compared to degradation of PVDF/OG composites. The samples were irradiated with a Co-60 source at constant dose rate, with doses ranging from 100 kGy to 1,000 kGy. In FTIR data shown that the formation of oxidation products was at the both samples with formation of carbonyl and hydroxyl groups amongst the most prevalent products in the pure PVDF samples. In the other hand, the composites samples exhibit less presence of degradation products with predominant formation of carbonyl groups, these results also seen in the UV-Vis analysis. The results show that the samples of composites may have greater resistance to the irradiation process, since they have less degradation products than pure PVDF samples seen by spectroscopic techniques.

Keywords: gamma irradiation, PVDF, PVDF/OG composites, spectroscopic techniques

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Authors: Lilia M. Fernando, Matthew K. Vasher, Evangelyn C. Alocilja

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This paper describes the development of a DNA-based nanobiosensor to detect the dengue virus in mosquito using electrically active magnetic (EAM) nanoparticles as the concentrator and electrochemical transducer. The biosensor detection encompasses two sets of oligonucleotide probes that are specific to the dengue virus: the detector probe labeled with the EAM nanoparticles and the biotinylated capture probe. The DNA targets are double hybridized to the detector and the capture probes and concentrated from nonspecific DNA fragments by applying a magnetic field. Subsequently, the DNA sandwiched targets (EAM-detector probe–DNA target–capture probe-biotin) are captured on streptavidin modified screen printed carbon electrodes through the biotinylated capture probes. Detection is achieved electrochemically by measuring the oxidation–reduction signal of the EAM nanoparticles. Results indicate that the biosensor is able to detect the redox signal of the EAM nanoparticles at dengue DNA concentrations as low as 10 ng/ul.

Keywords: dengue, magnetic nanoparticles, mosquito, nanobiosensor

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Authors: Sara Pereira-Nogueira, Tim Worbs, Marc Permanyer-Bosser, Reinhold Förster

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While the entry mechanism of lymphocytes into the lymph node via the blood are well described, it is still largely unknown how cells enter lymph nodes that arrive via afferent lymphatics. In order to address this, our group has established a micro-injection technique in mice through which cells are delivered directly into the lymphatic vessel immediately afferent to the popliteal lymph node. Injected cells can then be tracked via multi-colour fluorescence or 2-photon microscopy, and their localization can be analysed within the popliteal or downstream lymph nodes by immunohistology. Since naïve B cells express the chemokine receptor CXCR5 we intra-lymphatically co-injected B cells derived from wildtype and Cxcr5-deficient mice. While CXCR5 does not play a role in guiding B cells out of the subcapsular sinus, it affects their positioning within the lymph node parenchyma, since CXCR5-deficient B cells are impaired in migrating into the B cell follicle. The knowledge obtained by studying B-cell migration may prove beneficial in clinical settings regarding tumor metastasis or autoimmune diseases.

Keywords: afferent lymphatics, B cell migration, chemokine, intra-lymphatic injection

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Authors: Suzy Pereira, Alberto Rocha, Ana Almeida, Catarina Figueiredo, Helena Fonseca, Leonor Moreira, Carla Blum Vestena, Cristina Costa-Lobo

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The socio-educational support to parents, through parental education intervention programs, is part of European social policies, aiming to respond to the needs of education, promotion of well-being and development of children and young people. The purpose of this research is to evaluate the impact of the Positive Parenting Program on the subjective well-being of the parents of gifted children. The Positive Parenting Program is authored and is conducted by the National Association of Study and Intervention in Giftedness, Portuguese Association. The central question to be explored in this research is: Does the promotion of positive parenting in parents of gifted children have a positive impact on the subjective well-being? The sample consisted of 30 parents, non-probabilistic sampling of convenience, of which 15 parents belong to the intervention group and the rest to the control group. One dimension will be evaluated - subjective well-being, through the PANAS questionnaire - before and after the sessions of this program. The aim is to contribute to the understanding of the process and results of the positive parenting program in parents of gifted children.

Keywords: positive parenting, subjective well-being, giftedness, parental education intervention programs

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Authors: Cesar Hernández, Diego Giral, Fernando Santa

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The spectral handoff is important in cognitive wireless networks to ensure an adequate quality of service and performance for secondary user communications. This work proposes a benchmarking of performance of the three spectrum handoff models: VIKOR, SAW and MEW. Four evaluation metrics are used. These metrics are, accumulative average of failed handoffs, accumulative average of handoffs performed, accumulative average of transmission bandwidth and, accumulative average of the transmission delay. As a difference with related work, the performance of the three spectrum handoff models was validated with captured data of spectral occupancy in experiments realized at the GSM frequency band (824 MHz-849 MHz). These data represent the actual behavior of the licensed users for this wireless frequency band. The results of the comparative show that VIKOR Algorithm provides 15.8% performance improvement compared to a SAW Algorithm and, 12.1% better than the MEW Algorithm.

Keywords: cognitive radio, decision making, MEW, SAW, spectrum handoff, VIKOR

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Authors: M. Ezati Kooshki , H. Pourmohamad

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Leaf spring dampers are used for commercial vehicles and heavy tracks. The main function of this damper in these vehicles is protection against damage and providing comfort for drivers by creating suspension between road and vehicle. This paper presents a new device, circular leaf spring damper, which is frequently used on vehicles, aiming to gain seismic protection of structures. Finite element analyses were conducted on several one-story structures using finite element software (Abaqus, v6.10-1). The time history analysis was conducted on the records of Kobe (1995) and San Fernando (1971) ground motions to demonstrate the advantages of using leaf spring in structures as compared to simple bracing system. This paper also suggests extending the use of this damper in structures, considering its large control force despite high cycle fatigue properties and low prices.

Keywords: bracing system, finite element analysis, leaf spring, seismic protection, time history analysis

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Authors: Luis Rodrigo Valencia Pérez, Juan Manuel Peña Aguilar, Adelina Morita Alexander, Alberto Lamadrid Alvarez, Héctor Fernando Valencia Pérez

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Financial education is among the areas of opportunity in the Spanish-speaking from an early age to high school, through mobile devices such as cell phones and tablets using ludic and fun applications like interactive games, children can learn money management and investment through time, thereby fostering the habit of saving and/or sound management of cash and family business resources, having interaction with an uncontrolled environment such as the involvement of other players in the external decisions of the environment in which the game is play. The application proposed in Phase 1 (design and development) was designed in multi-user environments, under methodologies of hybrid programming for any platform on the market and designed under CMMI standards that allow for quality production over time, following up on these improvements counting with continuous user feedback and usage statistics.

Keywords: mobile educational games, ludic games, children, multiuser, design and software development

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Authors: Gabriel Wosiak, Jeyse da Silva, Sthefany S. Sena, Renato N. de Andrade, Ernesto Pereira

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The bubble formation during hydrogen production by electrolysis and several electrochemical processes is an inherent phenomenon and can impact the energy consumption of the processes. In this work, it was reported both experimental and computational results describe the effect of bubble displacement, which, under the cases investigated, leads to the formation of a convective flow in the solution. The process is self-sustained, and a solution vortex is formed, which modifies the bubble growth and covering at the electrode surface. Using the experimental data, we have built a model to simulate it, which, with high accuracy, describes the phenomena. Then, it simulated many different experimental conditions and evaluated the effects of the boundary conditions on the bubble surface covering the surface. We have observed a position-dependent bubble covering the surface, which has an effect on the water-splitting efficiency. It was shown that the bubble covering is not uniform at the electrode surface, and using statistical analysis; it was possible to evaluate the influence of the gas type (H2 and O2), current density, and the bubble size (and cross-effects) on the covering fraction and the asymmetric behavior over the electrode surface.

Keywords: water splitting, bubble, electrolysis, hydrogen production

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Authors: Fernando P. Silva, Valter J. S. Leite, Erivelton G. Nepomuceno

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In this paper, a nonlinear controller design for an omnidirectional mobile is presented. The robot controller consists of an inner-loop controller and an outer-loop controller, the first is designed using state feedback (robust allocation) and the second controller is designed based on Robust Multi Inversion (RMI) approach. The objective of RMI controller is rendering the robust inversion of the dynamic, when the model is affected by uncertainties. A model nonlinear MIMO of an omni-directional robot (small-league of Robocup) is used to simulate the RMI approach. The parameters of linear and nonlinear model are varied to cause modelling uncertainties among the model and the real model (real system) generating an error in inner-loop controller signal that must be compensated by RMI controller. The simulation test results show that the RMI is capable of compensating the uncertainties and keep the system stable and controlled under uncertainties.

Keywords: robust multi inversion, omni-directional robot, robocup, nonlinear control

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Authors: Wagner Pereira, Alphonse Kelecom

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Mining can impact the environment, and the major impact of some mining activities is the radiological impact. In human populations, such impact is well studied and regulated. For biota, this assessment always had as focus the protection of human food chain. The protection of biota itself is a new approach, still developing. In order to contribute to this new approach, fish collecting was carried out in areas of naturally occurring radioactive materials (NORM), where a uranium mine is in decommissioning phase. The activity concentrations were analyzed, in Bq/kg wet weight, for Uranium (Unat), Th-232 and Ra-226 in the lambari fish Astyanax bimaculatus L. (omnivorous fish) and in the traíra fish Hoplias malabaricus Bloch, 1794 (carnivorous fish). Seven composite samples (that is: a sufficient number of individuals to reach at least 2 kg of fresh weight) were collected every six months between 2013 and 2015. The mean activity concentrations (AC) for uranium ranged from 1.12 (lambari) to 0.60 (lungfish). For Th, variations ranged from 0.30 to 0.05 (lambari and traíra, respectively). Finally, the Ra-226 means ranged between 0.08 and 0.03. No temporal trends of accumulation could be identified. Systematically, the AC values of radionuclides were higher in omnivorous fish when compared to the carnivore ones.

Keywords: biota dose, NORM, fish, environmental protection

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Authors: Nini Johana Marín Rodríguez, William Fernando Oquendo Patino

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In this work, we model a coupled system where we explore the effects of steady and random behavior on a linear system like an extension of the classic Strogatz model. This is exemplified by modeling a couple love dynamics as a linear system of two coupled differential equations and studying its stability for four types of lovers chosen as CC='Cautious- Cautious', OO='Only other feelings', OP='Opposites' and RR='Romeo the Robot'. We explore the effects of, first, introducing saturation, and second, adding a random variation to one of the CC-type lover, which will shape his character by trying to model how its variability influences the dynamics between love and hate in couple in a long run relationship. This work could also be useful to model other kind of systems where interactions can be modeled as linear systems with external or internal random influence. We found the final results are not easy to predict and a strong dependence on initial conditions appear, which a signature of chaos.

Keywords: differential equations, dynamical systems, linear system, love dynamics

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Authors: Fernando G. Torres, Omar P. Troncoso

Abstract:

A wide range of bacteria synthesizes and secretes polymeric substances composed of a mixture of high-molecular-mass heteropolysaccharides. Nostoc commune cyanobacteria grow in colonial spherules of 10-20 mm in diameter. These spherules are filled with an internal gel made from a variety of polysaccharides known as Nostoc commune exopolysaccharides (NCE). In this paper, we report the use of these exopolysaccharides as a raw material for the preparation of a solid polymer electrolyte. Ammonium iodide and 1-butyl-3-methylimidazolium chloride ([Bmim]Cl) salts were used to provide NCE films with ionic conductivity. In addition, a carboxymethylation treatment was used to further increase the conductivity of NCE films. The structural characterization of the NCE films was assessed by FTIR, XRD, and DSC tests. Broadband dielectric spectroscopy (BDS) and dielectric thermal analysis (DETA) were used to evaluate the ionic conductivity of the samples. The results showed that NCE can be used to prepare solid polymer electrolyte films and that carboxymethylation improves their ionic conductivity. These NCE films can be used in the development of novel energy storage devices such as flat batteries or supercapacitors.

Keywords: polymer electrolyte, Nostoc commune, cyanobacteria, exopolysaccharides

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