Search results for: Anderson Peccin da Silva

Authors: Maria Konstadinou, Etienne Alderlieste, Anderson Peccin da Silva, Ben Arntz, Leonard van der Bijl, Wouter Verschueren

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The shear strength and compression properties of stiff Boom clay from Belgium at the depth of about 30 m has been investigated by means of cone penetration and laboratory testing. The latter consisted of index classification, constant rate of strain, direct, simple shear, and unconfined compression tests. The Boom clay samples exhibited strong swelling tendencies. The suction pressure was measured via different procedures and has been compared to the expected in-situ stress. The undrained shear strength and OCR profile determined from CPTs is not compatible with the experimental measurements, which gave significantly lower values. The observed response can be attributed to the presence of pre-existing discontinuities, as shown in microscale CT scans of the samples. The results of this study demonstrate that the microstructure of the clay prior to testing has an impact on the mechanical behaviour and can cause inconsistencies in the comparison of the laboratory test results with in-situ data.

Keywords: boom clay, laboratory testing, overconsolidation ratio, stress-strain response, swelling, undrained shear strength

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Authors: Teles de Sales Bezerra, Saulo Aislan da Silva Eleuterio, José Anderson Rodrigues de Souza, Jeronimo Silva Rocha

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Propagation in radio frequency is a constant concern in the application of Wireless Sensor Networks (WSN), the behavior of an environment determines how good the quality of signal reception. The objective of this paper is to analyze the behavior of a WSN in an environment for agriculture where environmental variables are present and correlate the capture of values received signal strength (RSSI) with a propagation model.

Keywords: propagation, WSN, agriculture, quality

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Authors: José Anderson Rodrigues de Souza, Teles de Sales Bezerra, Saulo Aislan da Silva Eleuterio, Jeronimo Silva Rocha

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Mobile devices are increasingly occupying sectors of society and one of its most important features is mobility. However, the use of mobile devices is subject to the lifetime of the batteries. Thus, the use of energy batteries has become an important issue in the study of wireless network technologies. In this context, new solutions that enable aggregate energy efficiency not only through energy saving, and principally they are evaluated from a more realistic model of energy discharge, if easy adaptation to existing protocols. This paper presents a study on the energy needed and the lifetime for Wireless Sensor Networks (WSN) using a heterogeneous network and applying the LEACH protocol.

Keywords: wireless sensor networks, energy efficiency, heterogeneous, LEACH protocol

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Authors: Teles de Sales Bezerra, Saulo Aislan da Silva Eleuterio, José Anderson Rodrigues de Souza, Ítalo de Pontes Oliveira

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This paper presents a analysis of performance the Received Strength Signal Indicator (RSSI) to Wireless Sensor Networks, with a finality of investigate a behavior of ZigBee devices operating into real environments. The test of performance was realize using two Series 1 ZigBee Module and two modules of development Arduino Uno R3, evaluating in this form a measurements of RSSI into environments like places of sports, preservation forests and water reservoir.

Keywords: wireless sensor networks, RSSI, Arduino, environments

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Authors: Anderson S. Fonseca, Italo F. S. Da Silva, Robert D. A. Santos, Mayara G. Da Silva, Pedro H. C. Vieira, Antonio M. S. Sobrinho, Victor H. B. Lemos, Petterson S. Diniz, Anselmo C. Paiva, Eliana M. G. Monteiro

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In Brazil, the National Electric Energy Agency (ANEEL) establishes that electrical energy companies are responsible for measuring and billing their customers. Among these regulations, it’s defined that a company must bill your customers within 27-33 days. If a relocation or a change of period is required, the consumer must be notified in writing, in advance of a billing period. To make it easier to organize a workday’s measurements, these companies create a reading plan. These plans consist of grouping customers into reading groups, which are visited by an employee responsible for measuring consumption and billing. The creation process of a plan efficiently and optimally is a capacitated clustering problem with constraints related to homogeneity and compactness, that is, the employee’s working load and the geographical position of the consuming unit. This process is a work done manually by several experts who have experience in the geographic formation of the region, which takes a large number of days to complete the final planning, and because it’s human activity, there is no guarantee of finding the best optimization for planning. In this paper, the GBKMeans method presents a technique based on K-Means and genetic algorithms for creating a capacitated cluster that respects the constraints established in an efficient and balanced manner, that minimizes the cost of relocating consumer units and the time required for final planning creation. The results obtained by the presented method are compared with the current planning of a real city, showing an improvement of 54.71% in the standard deviation of working load and 11.97% in the compactness of the groups.

Keywords: capacitated clustering, k-means, genetic algorithm, districting problems

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Authors: Natalie Malone

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This study explores the role of a public library in the creation of social spaces for vulnerable populations. The data stems from a longitudinal ethnographic study of the Anderson Library community, which included field notes, artifacts, and interview data. Thematic analysis revealed multiple meanings and thematic relationships within and among the data sources -interviews, field notes, and artifacts. Initial analysis suggests the Anderson Library serves as a space for vulnerable populations, with the sub-themes of fostering interpersonal communication to create a social space for children and fostering interpersonal communication to create a social space for parents and adults. These findings are important as they illustrate the potential of public libraries to serve as community empowering institutions.

Keywords: capital, immigrant families, public libraries, space, vulnerable

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Authors: Caio Marcelo Nunes, Anderson da Silva Soares, Gustavo Teodoro Laureano, Clarimar Jose Coelho

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This paper presents a methodology to pixel recognition in aerial images using fuzzy $c$-means algorithm. This algorithm is a alternative to recognize areas considering uncertainties and inaccuracies. Traditional clustering technics are used in recognizing of multispectral images of earth's surface. This technics recognize well-defined borders that can be easily discretized. However, in the real world there are many areas with uncertainties and inaccuracies which can be mapped by clustering algorithms that use fuzzy sets. The methodology presents in this work is applied to multispectral images obtained from Landsat-5/TM satellite. The pixels are joined using the $c$-means algorithm. After, a classification process identify the types of surface according the patterns obtained from spectral response of image surface. The classes considered are, exposed soil, moist soil, vegetation, turbid water and clean water. The results obtained shows that the fuzzy clustering identify the real type of the earth's surface.

Keywords: aerial images, fuzzy clustering, image processing, pattern recognition

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Authors: Estela Mayra de Moura Vianna, Thiago José Tavares Ávila, Bruno Morais Silva, Diego Henrique Bezerra, Paulo Henrique Gomes Silva, Alan Pedro da Silva

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The Brazilian Federal Constitution defines the access to information as a crucial right of the citizen and the Law on Access to Public Information, which regulates this right. Accordingly, the Fiscal Responsibility Act, 2000, amended in 2009 by the “Law of Transparency”, began demanding a wider disclosure of public accounts for the society, including electronic media for public access. Thus, public entities began to create "Transparency Portals," which aim to gather a diversity of data and information. However, this information, in general, is still published in formats that do not simplify understanding of the data by citizens and that could be better especially available for audit purposes. In this context, a proposal of ontology about Brazilian Transparency Portal can play a key role in how these data will be better available. This study aims to identify and implement in ontology, the data model about Transparency Portal ecosystem, with emphasis in activities that use these data for some applications, like audits, press activities, social government control, and others.

Keywords: audit, government transparency, ontology, public sector

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Authors: Hugo Manoel Olivera Da Silva, Ricardo Silva Thé Pontes

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In this work, is presented an analysis of the Brazilian regulation on human exposure to electromagnetic fields, which provides limits to electric fields, magnetic and electromagnetic fields. The regulations for the electricity sector was in charge of the Agência Nacional de Energia Elétrica-ANEEL, the Brazilian Electricity Regulatory Agency, that made it through the Normative Resolution Nº 398/2010, resulting in a series of obligations for the agents of the electricity sector, especially in the areas of generation, transmission, and distribution.

Keywords: adverse effects, electric energy, electric and magnetic fields, human health, regulation

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Authors: José Luiz da Silva Neto, Renato Sipelli Silva, Érick Aragão Ribeiro

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The automation of industrial processes plays a vital role in industries today, becoming an integral and important part of the industrial process and modern production. The process control systems are designed to maximize production, reduce costs and minimize risks in production. However, these systems are generally not deployed methodologies and planning. So that this article describes the development of an automation system of a kitchen preparation of chemicals in the textile industry based on a retrofitting methodology that provides more quality into the process at a lower cost.

Keywords: automation, textile industry, kitchen chemical, information integration

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Authors: Mahesh Koti

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In this paper, we present a quantum transport study of a quantum dot in steady state in the presence of static gate potential. We consider a quantum dot coupled to the two metallic leads. The quantum dot under study is modeled through Anderson Impurity Model (AIM) with hopping parameter modulated through voltage drop between leads and the central dot region. Based on the Landauer's formula derived from Nonequilibrium Green's Function and Single Electron Theory, the essential ingredients of transport properties are revealed. We show that the results out of two approaches closely agree with each other. We demonstrate that Landauer current response derived from single electron approach converges with non-zero interaction through gate potential whereas Landauer current response derived from Nonequilibrium Green's Function (NEGF) hits a pole.

Keywords: Anderson impurity model (AIM), nonequilibrium Green's function (NEGF), Landauer's formula, single electron analysis

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Authors: Amanda Rithieli Pereira Dos Santos, Rute Quelvia De Faria, Álvaro De Oliveira Cardoso, Anderson Rodrigo Da Silva, Érica Leão Fernandes Araújo

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The study of the kinetics of drying has great importance for the mathematical modeling, allowing to know about the processes of transference of heat and mass between the products and to adjust dryers managing new technologies for these processes. The present work had the objective of studying the kinetics of drying of soybean seeds and adjusting different statistical models to the experimental data varying cultivar and temperature. Soybean seeds were pre-dried in a natural environment in order to reduce and homogenize the water content to the level of 14% (b.s.). Then, drying was carried out in a forced air circulation oven at controlled temperatures of 38, 43, 48, 53 and 58 ± 1 ° C, using two soybean cultivars, BRS 8780 and Sambaíba, until reaching a hygroscopic equilibrium. The experimental design was completely randomized in factorial 5 x 2 (temperature x cultivar) with 3 replicates. To the experimental data were adjusted eleven statistical models used to explain the drying process of agricultural products. Regression analysis was performed using the least squares Gauss-Newton algorithm to estimate the parameters. The degree of adjustment was evaluated from the analysis of the coefficient of determination (R²), the adjusted coefficient of determination (R² Aj.) And the standard error (S.E). The models that best represent the drying kinetics of soybean seeds are those of Midilli and Logarítmico.

Keywords: curve of drying seeds, Glycine max L., moisture ratio, statistical models

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Authors: Manasa Kalla, Narasimha Raju Chebrolu, Ashok Chatterjee

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We have studied the quantum transport properties of a single molecular transistor in the presence of an external magnetic field using the Keldysh Green function technique. We also used the Anderson-Holstein-Caldeira-Leggett Model to describe the single molecular transistor that consists of a molecular quantum dot (QD) coupled to two metallic leads and placed on a substrate that acts as a heat bath. The phonons are eliminated by the Lang-Firsov transformation and the effective Hamiltonian is used to study the effect of an external magnetic field on the spectral density function, Tunneling Current, Differential Conductance and Spin polarization. A peak in the spectral function corresponds to a possible excitation. In the presence of a magnetic field, the spin-up and spin-down states are degenerate and this degeneracy is lifted by the magnetic field leading to the splitting of the central peak of the spectral function. The tunneling current decreases with increasing magnetic field. We have observed that even the differential conductance peak in the zero magnetic field curve is split in the presence electron-phonon interaction. As the magnetic field is increased, each peak splits into two peaks. And each peak indicates the existence of an energy level. Thus the number of energy levels for transport in the bias window increases with the magnetic field. In the presence of the electron-phonon interaction, Differential Conductance in general gets reduced and decreases faster with the magnetic field. As magnetic field strength increases, the spin polarization of the current is increasing. Our results show that a strongly interacting QD coupled to metallic leads in the presence of external magnetic field parallel to the plane of QD acts as a spin filter at zero temperature.

Keywords: Anderson-Holstein model, Caldeira-Leggett model, spin-polarization, quantum dots

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Authors: Alex Kizuk

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This paper studies the trope or meme of the Siren in terms of what long-standing cultural continuities can be found in college classrooms today. Those who have raised children may remember reading from Hans Christian Anderson's 'The Little Mermaid' (1836), not to mention regaling them with colorful Disneyesque versions when they were younger. Though Anderson tempered the darker first ending of the story to give the little mermaid more agency in her salvation—a prognostic developed in Disney adaptations—nonetheless, the tale pivots on an image of a 'heavenly realm' that the mermaid may eventually come to know or comprehend as a beloved woman on dry land. Only after 300 years, however, may she hope to see that 'which lives forever' and 'rises through thin air, up to the shining stars. Just as [sea-people] rise through the water to see the lands on earth.' What students today can see in this example is a trope of the agonistic soul in a hard-won disembarkation at a harbour of knowledge--where the seeker after truth may come to know through persistence (300 years)—all that is good and true concerning human life. This paper discusses several such examples from the Great Books and popular culture to suggest that teaching in the world of the 21st century could do worse than accede to some such perennial seeking.

Keywords: the Great Books, tradition, popular culture, 21st century directions in teaching

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Authors: Jamal Abd Awadallak, Thiago Olinek Reinehr, Eduardo Raizer, Deise Molinari, Edson Antonio, Camila da Silva da Silva

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The hydrolysis of soy oil catalyzed by 1,3-specific enzyme (Lecitase Ultra) in a well-stirred bioreactor was studied. Two forms of applications of the ultrasound were evaluated aiming to increase reaction rates, wherein the use of probe ultrasound associated with the use of surfactant to pre-emulsify the substrate showed the best results. Two different reaction periods were found: the first where the ultrasound has great influence on reaction rates, and the second where ultrasound influence is minimal. Studies on the time of pre-emulsification, surfactant concentration and enzyme concentration showed that the initial rate of hydrolysis depends on the interfacial area between the oil phase and the aqueous phase containing the enzyme.

Keywords: specific enzyme, free fatty acids, Hydrolysis, lecitase ultra, ultrasound

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Authors: Dora Martins, Susana Silva, Cândida Silva

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Human Resources Management (HRM) has been recognized by academics and practitioners as an important element in organizations. Therefore, this paper explores the best practices of HRM and seeks to understand the level of participation in the development of these practices by human resources managers in the hospitality industry and compare it with other industries. Thus, the study compared the HRM practices of companies in the hospitality sector with HRM practices of companies in other sectors, and identifies the main differences between their HRM practices. The results show that the most frequent HRM practices in all companies, independently of its sector of activity, are hiring and training. When comparing hospitality sector with other sectors of activity, some differences were noticed, namely in the adoption of the practices of communication and information sharing, and of recruitment and selection. According to these results, the paper discusses the major theoretical and practical implications. Suggestions for future research are also presented.

Keywords: exploratory study, human resources management practices, human resources manager, hospitality companies, Portuguese companies

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Authors: Silvania M. P. Silva, Ricardo A. Mazaro, Gemilde M. Queiroz, Josefa Barbosa, Lucas S. Victorino, Grasiela J. Silva

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The Minas Gerais sweets have a remarkable personality, perceived on the original usage of fruits, sweets, and cheeses in the Brazilian gastronomic landscape, as a unique representation of Minas Gerais. This memory-related and feeling-oriented food is one of the treasures common to all Brazilians. It is mandatory to mention its Portuguese roots for the use of honey, as well as sugar cane and its countless possibilities. This work will show that this heritage is predominantly Portuguese, born in Portuguese convents and that it crossed the Atlantic. Through a historical survey, visits to mining towns known for their sweet culture and material collected in these places, we present the protagonists of this journey of flavors: the Portuguese cake makers (boleiras), who brought the knowledge, ingredients, and the dream of a better life in the crowded mines of gold and opportunities, helping to form a new Minas Gerais knowledge with their delicacies.

Keywords: sweets from portugal, convent sweets, minas gerais, brazil

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Authors: Adriana Anselmo Oliveira

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The present project showcases a tile work from the Franco-Portuguese artist Maria Helena Vieira da Silva (1908-1992). It is a set of 8 panels composed of figurative and geometric tiles, with extra tiles framing nearby doors and windows in a study room in the (UFRRJ, Universidade Federal Rural do Rio de Janeiro). The aforementioned work was created between 1942 and 1943, during the artist's 6 year exile in the Brazilian city. This one-of-a-kind tileset was designed and made by Vieira da Silva between 1942 and 1943. Over the years, several units were lost, which led to their replacement in the nineties. However, these replacements don't do justice to the original work of art. In 2007, a project was initiated to fully repair and maintain the set. Three panels are removed and restored, but the project is halted. To this day, the three fully restored panels remain in boxes. In 2016 a new restoration project is submitted by the (Faculdade de Belas Artes da Universidade de Lisboa) in collaboration with de (Fundacão Árpád Szenes-Vieira da Silva). There are many varied opinions on restoring and conserving older pieces of art, however, we have the moral duty to safeguard the original materials used by the artist along with the artists original vision and also to care for the future generations of students who will use the space in which the tile-work was inserted. Many tiles have been replaced by white tiles, tiles with a divergent colour pallet and technique, and in a few cases, the incorrect place or way around. These many factors make it increasingly difficult to maintain the artists original vision and destroy and chance of coherence within the artwork itself. The conservative technician cannot make new images to fill the empty spaces or mark the remaining images with their own creative input. with reliable photographic documentation that can provide us with the necessary vision to allow us to proceed with an accurate reconstruction, we have the obligation to proceed and return the piece of art to its true form, as in its current state, it is impossible to maintain its original glory. Using the information we have, we must find a way to differentiate the original tiles from the reconstructions in order to recreate and reclaim the original message from the artist. The objective of this project is to understand the significance of tiles in Vieira da Silva's art as well as the influence they had on the artist's pictorial language since the colour definition on tile work is vastly different from the painting process as the materials change during their merger. Another primary goal is to understand what the previous interventions achieved besides increasing the artworks durability. The main objective is to submit a proposal that can salvage the artist's visual intention and supports it for posteriority. In summary, this proposal goes further than the usual conservative interventions as it intends to recreate the original artistic worth, prioritising the aesthetics and keeping its soul alive.

Keywords: Vieira da Silva, tiles, conservation, restoration

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Authors: Catharina O. Vianna Dias da Silva, Amanda F. Batista, Ana Clara C. Burgos Lessa, Carolina S. Lucchesi Ramacciotti, Maria Clara B. de Andrade, Roberto de B. Silva

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This article aims to analyze the bioethical aspects related to the historical practices of experiments on humans that occurred in Nazi Germany during the period of World War II (1939-1945). The method was based on the bibliographic review of articles published in databases such as SciELO and Pubmed. In the discussion, historical and humanistic aspects that contributed to the construction of a genocidal culture practiced during this period were analyzed. Additionally, an ethical question arises: should the information acquired during this dark period be used by science? After analysis, it was found that these Nazi experiments went over medical and ethical principles, being a deplorable milestone in history. It was also concluded that, although they generated potentially 'useful' results in the scientific field, they should be discarded as an ethical question of principle, of never daring to validate such a deplorable way of obtaining knowledge.

Keywords: Nazism, bioethics, human experimentation, human rights, genocide, torture, medicine

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Authors: Samuel Hyellamada Jerry

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This study focused on assessing conservation priorities within the Karlahi Forest Reserve of Fufore Local Government in Adamawa State. The main objective was to identify specific areas within the forest reserve that require immediate conservation attention. The research employed remote sensing and GIS techniques to achieve this goal. By overlaying the IDRIS Silva module results, a spatial distribution map was generated, highlighting the cumulative priority areas within and outside the forest. Among the total vegetated area of 26.38 km² in the Karlahi Forest Reserve, the analysis revealed that 16.16 km² were classified as high-priority conservation zones. Additionally, 4.59 km² and 5.63 km² were identified as medium and low-priority areas, respectively. In light of these findings, it is recommended that conservation efforts incorporate detailed land cover information and regular assessments of species diversity. Furthermore, strict adherence to national and state policies regarding forest reserves and parks is crucial for effective conservation management.

Keywords: priority, Karlahi, forest, reserve, IDRISI Silva, species diversity

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Authors: Carolina Beres, Laurine Da Silva, Danielle Pereira, Ana Ribeiro, Renata Tonon, Caroline Mellinger-Silva, Karina Dos Santos, Flavia Gomes, Lourdes Cabral

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The health benefits of bioactive compounds such as phenolics are well known. The main source of these compounds are fruits and derivates. This study had the objective to study the bioacessibility of phenolic compounds from grape pomace and juçara dried extracts. For this purpose both characterized extracts were submitted to a simulated human digestion and the total phenolic content, total anthocyanins and antioxidant scavenging capacity was determinate in digestive fractions (oral, gastric, intestinal and colonic). Juçara had a higher anthocianins bioacessibility (17.16%) when compared to grape pomace (2.08%). The opposite result was found for total phenolic compound, where the higher bioacessibility was for grape (400%). The phenolic compound increase indicates a more accessible compound in the human gut. The lyophilized process had a beneficial impact in the final accessibility of the phenolic compounds being a more promising technique.

Keywords: bioacessibility, phenolic compounds, grape, juçara

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Authors: Sterling C. DeVerter

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In recent decades, there has been continually growing concern amongst scholars and political leaders towards the global resurgence of nationalism, particularly in Europe, the United States, and China. However, very few studies have attempted to empirically examine the relationship between religion and nationalism at the level of the individual, and none are known to have done so quantitatively. Building on Tajfel's and Turner's (1978) Social Identity Theory (SIT), and Anderson (1991) and Marx (2003), this study will employ SIT and regression analysis to compare the sources and patterns of nationalistic sentiment among European respondents in eight countries to the average levels of self-reported religiosity, religious participation, age, education, and income levels. Survey reports from the International Social Survey Programme were the primary quantitative data sources. It was hypothesized that the increase in nationalism across Europe follows this same evolution as first identified by Anderson, and is positively correlated to the reduction in reported religiosity. However, this study failed to reject the null, there was no substantial ( < .035) correlation between nationalistic sentiment and any of the measures of religiosity, nor were there any substantial correlations between nationalistic sentiment and either of the three control variables ( < .008). Across all countries examined, it was discovered that inclusionary nationalism has slightly declined (-5.08%), while exclusionary nationalism had increased substantially (+17.25%). The combined trend reflected an overall rise in nationalism across the time period and a forecast that suggests the current levels are also elevated. The primary implications include the demand to readdress the notion of religion and nationalism, and the correlation between the two, as well as the current nationalism trends in terms of support or non-support for future political and social movements.

Keywords: European Union, secularization, nationalism, social identity theory

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Authors: Rajendra Kumar

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We study the Electronic spectral density of a double coupled quantum dots sandwich between superconducting leads, where one of the superconducting leads (QD1) are connected with left superconductor lead and (QD1) also connected right superconductor lead. (QD1) and (QD2) are coupling to each other. The electronic spectral density through a quantum dots between superconducting leads having s-wave symmetry of the superconducting order parameter. Such junction is called superconducting –quantum dot (S-QD-S) junction. For this purpose, we have considered a renormalized Anderson model that includes the double coupled of the superconducting leads with the quantum dots level and an attractive BCS-type effective interaction in superconducting leads. We employed the Green’s function technique to obtain superconducting order parameter with the BCS framework and Ambegaoker-Baratoff formalism to analyze the electronic spectral density through such (S-QD-S) junction. It has been pointed out that electronic spectral density through such a junction is dominated by the attractive the paring interaction in the leads, energy of the level on the dot with respect to Fermi energy and also on the coupling parameter of the two in an essential way. On the basis of numerical analysis we have compared the theoretical results of electronic spectral density with the recent transport existing theoretical analysis. QDs is the charging energy that may give rise to effects based on the interplay of Coulomb repulsion and superconducting correlations. It is, therefore, an interesting question to ask how the discrete level spectrum and the charging energy affect the DC and AC Josephson transport between two superconductors coupled via a QD. In the absence of a bias voltage, a finite DC current can be sustained in such an S-QD-S by the DC Josephson effect.

Keywords: quantum dots, S-QD-S junction, BCS superconductors, Anderson model

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Authors: André C. Silva, Izabela L. A. Moraes, Elenice M. S. Silva, Carlos M. Silva Filho

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In Brazil, most soils are acidic and low in essential nutrients required for the growth and development of plants, making fertilizers essential for agriculture. As the biggest producer of soy in the world and a major producer of coffee, sugar cane and citrus fruits, Brazil is a large consumer of phosphate. Brazilian’s phosphate ores are predominantly from igneous rocks showing a complex mineralogy, associated with carbonites and oxides, typically iron, silicon and barium. The adopted industrial concentration circuit for this type of ore is a mix between magnetic separation (both low and high field) to remove the magnetic fraction and a froth flotation circuit composed by a reverse flotation of apatite (barite’s flotation) followed by direct flotation circuit (rougher, cleaner and scavenger circuit). Since the 70’s fatty acids obtained from vegetable oils are widely used as lower-cost collectors in apatite froth flotation. This is a very effective approach to the apatite family of minerals, being that this type of collector is both selective and efficient (high recovery). This paper presents Jatropha curcas L. oil (JCO) as a renewable and sustainable source of fatty acids with high selectivity in froth flotation of apatite. JCO is considerably rich in fatty acids such as linoleic, oleic and palmitic acid. The experimental campaign involved 216 tests using a modified Hallimond tube and two different minerals (apatite and quartz). In order to be used as a collector, the oil was saponified. The results found were compared with the synthetic collector, Fotigam 5806 produced by Clariant, which is composed mainly by soy oil. JCO showed the highest selectivity for apatite flotation with cold saponification at pH 8 and concentration of 2.5 mg/L. In this case, the mineral recovery was around 95%.

Keywords: froth flotation, jatropha curcas, microflotation, selectivity

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Authors: H. N. S. Silva, S. N. Silva

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Introduction: 88.3% of physicians decided to choose a ‘no-code’ or a DNR order if hospitalized and would choose to die less aggressively at home. However, their wishes were mostly over ridden. Objective: To assess the attitudes of nurses towards the end-of-the-life care they would like to receive for themselves and their attitudes towards terminal illnesses. Methods: A mixed method approach was used. A closed and open-ended questionnaire was administered to 73 participants and 5 registered nurses, who have more than 10 years of experience, working in hospitals both in Sri Lanka and abroad, were interviewed. Results: 94.1% of the participants stated that they would like to die at home, spending their last hours at home surrounded by their loved ones and engaging in religious activities but 57.7% of unmarried nurse said they would agree on euthanasia if they had a terminal disease, and also 66.2% of them stated they would agree in DNR order if they happen to be admitted to the ICU, but 82.5% wanted to diagnose if they had a terminal illness or cancer but did not agree on euthanasia. Qualitative analysis confirmed the findings and revealed that despite having adequate confidence about the hospital care, nurses would choose to die at home, surrounded by their loved once and engaging in religious activities. Euthanasia was believed to be inappropriate as it is religiously incorrect and as death is a natural process. Conclusion: The perception of death among nurses depends on their religious belief.

Keywords: death, do not resuscitate, euthanasia, nurses

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Authors: Dirson Santos De Campos, Deller James Ferreira, Anderson Cavalcante Gonçalves, Uyara Ferreira Silva

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Rubrics to learning research provide many evaluation criteria and expected performance standards linked to defined student activity for learning and pedagogical objectives. Despite the rubric being used in education at all levels, academic literature on rubrics as a tool to support research in SQL Education is quite rare. There is a large class of SQL queries is syntactically correct, but certainly, not all are semantically correct. Detecting and correcting errors is a recurring problem in SQL education. In this paper, we usthe Rubric Abstract Framework (RAF), which consists of steps, that allows us to map the information to measure student performance guided by didactic objectives defined by the teacher as long as it is contextualized domain modeling by rubric. An empirical study was done that demonstrates how rubrics can mitigate student difficulties in finding logical errors and easing teacher workload in SQL education. Detecting and correcting logical errors is an important skill for students. Researchers have proposed several ways to improve SQL education because understanding this paradigm skills are crucial in software engineering and computer science. The RAF instantiation was using in an empirical study developed during the COVID-19 pandemic in database course. The pandemic transformed face-to-face and remote education, without presential classes. The lab activities were conducted remotely, which hinders the teaching-learning process, in particular for this research, in verifying the evidence or statements of knowledge, skills, and abilities (KSAs) of students. Various research in academia and industry involved databases. The innovation proposed in this paper is the approach used where the results obtained when using rubrics to map logical errors in query formulation have been analyzed with gains obtained by students empirically verified. The research approach can be used in the post-pandemic period in both classroom and distance learning.

Keywords: rubric, logical error, structured query language (SQL), empirical study, SQL education

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Authors: Jean C. G. Silva, Kaline N. Ferreira, Rennio F. Sena, Flavio L. H. Silva

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The Prosopis juliflora (called algaroba in Northeastern Region of Brazil) is a species of medium to large size that can reach 18 meters high, being typical of arid and semi-arid regions by to requirement less water to survive; this is a fundamental attribute from its adaptation. It's considered of multiple uses, because the trunk, the fruit, and the algaroba pods are utilized for several purposes, among them, the production of wood from lumber mill, charcoal, alcohol, animal and human consumption, being hence, a culture of economic and social value. The use of waste Prosopis juliflora can be carried out for like pyrolysis and gasification processes, in order to energy production in those regions where it is grown. Thus this study aims to characterize the residue of the algaroba pods and evaluate the kinetic parameters, activation energy (Ea) and pre-exponential factor (k0), the devolatilization process through the data obtained from TG/DTG curves with different levels of heating rates. At work was used the heating rates of 5 K.min-1, 10 K.min-1, 15 K.min-1, 20 K.min-1 and 30 K.min-1, in inert nitrogen atmosphere (99.997%) under a flow of 40 ml.min-1. The kinetic parameters were obtained using the methods of Friedman and Ozawa-Flynn-Wall.

Keywords: activation energy, devolatilization, kinetic parameters, waste

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Authors: Carolina Silva, João Nuno Oliveira, Rui Sousa, João Paulo Silva

Abstract:

This study uses genetic algorithms to solve a job scheduling problem in a weaving factory. The underline problem regards an NP-Hard problem concerning unrelated parallel machines, with sequence-dependent setup times. This research uses real data regarding a weaving industry located in the North of Portugal, with a capacity of 96 looms and a production, on average, of 440000 meters of fabric per month. Besides, this study includes a high level of complexity once most of the real production constraints are applied, and several real data instances are tested. Topics such as data analyses and algorithm performance are addressed and tested, to offer a solution that can generate reliable and due date results. All the approaches will be tested in the operational environment, and the KPIs monitored, to understand the solution's impact on the production, with a particular focus on the total number of weeks of late deliveries to clients. Thus, the main goal of this research is to develop a solution that allows for the production of automatically optimized production plans, aiming to the tardiness minimizing.

Keywords: genetic algorithms, textile industry, job scheduling, optimization

Procedia PDF Downloads 121

Authors: C. A. C. Castro, D. C. Urashima, E. P. Silva, P. M. L. Silva

Abstract:

Since 1920, the industry has almost completely changed the rivets production techniques for the manufacture of permanent welding join production of structures and manufacture of other products. The welding arc is the process more widely used in industries. This is accomplished by the heat of an electric arc which melts the base metal while the molten metal droplets are transferred through the arc to the welding pool, protected from the atmosphere by a gas curtain. The GMAW (Gas metal arc welding) process is influenced by variables such as: Current, polarity, welding speed, electrode, extension, position, moving direction; type of joint, welder's ability, among others. It is remarkable that the knowledge and control of these variables are essential for obtaining satisfactory quality welds, knowing that are interconnected so that changes in one of them requiring changes in one or more of the other to produce the desired results. The optimum values are affected by the type of base metal, the electrode composition, the welding position and the quality requirements. Thus, this paper proposes a new methodology, adding the variable vibration through a mechanism developed for GMAW welding, in order to improve the mechanical and metallurgical properties which does not affect the ability of the welder and enables repeatability of the welds made. For confirmation metallographic analysis and mechanical tests were made.

Keywords: vibration, joining, weldability, GMAW

Procedia PDF Downloads 396

Authors: André C. Silva, Mariana R. Barros, Elenice M. S. Silva, Douglas. Y. Marinho, Diego F. Lopes, Débora N. Sousa, Raphael S. Tomáz

Abstract:

Modern agriculture requires productivity, efficiency and quality. Therefore, there is need for agricultural limestone implementation that provides adequate amounts of calcium and magnesium carbonates in order to correct soil acidity. During the limestone process, fine particles (with average size under 400#) are generated. These particles do not have economic value in agricultural and metallurgical sectors due their size. When limestone is used for agriculture purposes, these fine particles can be easily transported by wind generated air pollution. Therefore, briquetting, a mineral processing technique, was used to mitigate this problem resulting in an agglomerated product suitable for agriculture use. Briquetting uses compressive pressure to agglomerate fine particles. It can be aided by agglutination agents, allowing adjustments in shape, size and mechanical parameters of the mass. Briquettes can generate extra profits for mineral industry, presenting as a distinct product for agriculture, and can reduce the environmental liabilities of the fine particles storage or disposition. The produced limestone briquettes were subjected to shatter and water action resistance tests. The results show that after six minutes completely submerged in water, the briquettes where fully diluted, a highly favorable result considering its use for soil acidity correction.

Keywords: agglomeration, briquetting, limestone, soil acidity correction

Procedia PDF Downloads 356