Instituto Federal Of Pernambuco Ifpe

São Pedro, Brazil

Instituto Federal Of Pernambuco Ifpe

São Pedro, Brazil
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Silva C.P.N.,Federal University of Pernambuco | Machado G.G.,Federal University of Pernambuco | de Oliveira E.M.F.,Federal University of Pernambuco | de Oliveira M.R.T.,Federal University of Pernambuco | And 2 more authors.
Microwave and Optical Technology Letters | Year: 2017

Instantaneous frequency measurement (IFM) systems have been developed during the last decades, and new designs came across trying to keep the system as compact as possible. In this paper, the authors present compact interferometers based on Hilbert fractal geometry for a 4-bit IFM system. The interferometers operate in the range 4.66–6.38 GHz, using a Wilkinson power divider connected to two microstrip lines, which one of these is the Hilbert fractal curve. The design and simulations to be presented were done in a full wave EM simulator. Measured and simulating results are presented and compared. © 2017 Wiley Periodicals, Inc. Microwave Opt Technol Lett 59:1153–1157, 2017. © 2017 Wiley Periodicals, Inc.

De Souza H.V.L.,Federal University of Pernambuco | Rodrigues R.L.,Federal Rural University of Pernambuco | De Melo Filho I.J.,Instituto Federal Of Pernambuco Ifpe | Gomes A.S.,Federal University of Pernambuco
Iberian Conference on Information Systems and Technologies, CISTI | Year: 2017

Understanding the learning strategies conceived by self-directed learners has become a major challenge to be found in contexts supported by sub-domains of learning. For this objective to be achieved it is necessary to understand the different approaches that dimension the phenomenon, to explore the technologies created for this purpose and to discuss the results and limitations obtained through the research. Therefore, this paper aims to present an ongoing doctoral research that investigates the current solutions recommended by the literature to make it possible to create a process of identification of strategies of self-directed learners in ubiquitous learning environments. © 2017 AISTI.

De Souza H.V.L.,Federal University of Pernambuco | Rodrigues R.L.,Federal Rural University of Pernambuco | De Melo Filho I.J.,Instituto Federal Of Pernambuco Ifpe | Gomes A.S.,Federal University of Pernambuco
Iberian Conference on Information Systems and Technologies, CISTI | Year: 2017

This paper presents a preliminary systematic mapping of the literature in order to identify what are the methods used by researchers to evaluate characteristics of self-directed learning in ubiquitous environments. We use systematic review procedures proposed by Kitchenham et. al. (2007) (Marshall and Brereton, 2013) to develop the methodological approach contained in sections. The results show that no studies were found that direct use of methods to contextualize the phenomenon clearly, generate virtual spaces with SDL and recommend performance measurement techniques in real time by analyzing the data interaction of learners. © 2017 AISTI.

Silvestre P.,Federal University of Pernambuco | Higino A.,Federal University of Pernambuco | Karman R.,Federal University of Pernambuco | Celia J.,Federal University of Pernambuco | Medeiros R.,Instituto Federal Of Pernambuco Ifpe
CEUR Workshop Proceedings | Year: 2017

This article is focusing to discuss how we can work with digital games at school and how to produce games, considering what Huizinga (2000), defends which is the game is something inherent in the human being, that is, we use the games to play or to learning. And to discuss aboutthe prejudice of race, present in our society. So, the article aims, from the reflection of Laws 10639/03 and 11645/08 which deal with the teaching of African culture in schools, trying to demystify some issues such as the vision of black people in society, his contributions to our culture. So the game To Equal for Equal, is focusing simulate situations where the prejudice is experienced by a family.

Silva P.P.J.C.D.O.,Federal University of Pernambuco | Silva P.P.J.C.D.O.,Instituto Federal Of Pernambuco Ifpe | Araujo P.L.B.,Federal University of Pernambuco | da Silveira L.B.B.,Highplastic Industria de Plasticos Ltda | Araujo E.S.,Federal University of Pernambuco
Radiation Physics and Chemistry | Year: 2017

Polycarbonate (PC) is an engineering polymer which presents interesting properties. This material has been also used in medical devices, which is frequently exposed to gamma radiosterilization and to chemical agents. This may produce significant changes in polymer structure, leading to failure in service. The present work brings about a new approach on environmental stress cracking (ESC) processes elucidation in 100 kGy gamma-irradiated PC, by evaluating the diffusion process of methanol or 2-propanol in test specimens and determining the diffusion parameters on solvent-irradiated polymer systems. A comparison of diffusion parameters for both solvents indicated that methanol has a considerable ESC action on PC, with diffusion parameter of 7.5×10−14±1% m2 s−1 for non-irradiated PC and 7.8×10−14±2.8% m2 s−1 for PC irradiated at 100 kGy. In contrast, 2-propanol did not act as an ESC agent, as it did promote neither swelling nor cracks in the test specimens. These results were confirmed by visual analysis and optical microscopy. Unexpectedly, structural damages evidenced in tensile strength tests suggested that 2-propanol is as aggressive as methanol chemical for PC. Moreover, although some manufacturers indicate the use of 2-propanol as a cleaning product for PC artifacts, such use should be avoided in parts under mechanical stress. © 2016 Elsevier Ltd

Alves E.U.,Federal University of Paraiba | Santos-Moura S.S.,Federal University of Paraiba | De Moura M.F.,Federal Rural University of Pernambuco | Silva R.S.,Federal University of Paraiba | Galindo E.A.,Instituto Federal Of Pernambuco Ifpe
Ciencia Rural | Year: 2017

Crataeva tapia L. is a fruit native to the Brazilian savanna, the caatinga, and is used in the production of soft drinks and other beverages. Given the importance of this species and the lack of knowledge about its seeds, this research aimed to evaluate the physiological quality of C. tapia L. seeds subjected to different environments and drying periods. Seeds were dried for the following time periods: 0 (no drying), 24, 48, 72, 96, and 120 hours, in the laboratory environment (25°C and 90% RH) and in a greenhouse (30°C and 80% RH). After the drying period, seeds from each of the treatments were used for determining the water content, germination, and vigor (using tests for emergence, first count of germination and emergence, rate of germination and emergence, length, and seedling dry weight). The experimental design was completely randomized and a factorial 2×6 scheme (local environment × drying periods) was used with four replicate sets of seeds. The data were subjected to analysis of variance and polynomial regression using quadratic models. The germination and seed vigor reduced as the drying periods increased. For optimum results, the seeds of C. tapia L. must be dried in the laboratory for a period of 48 hours. In addition, their desiccation resistance was classified as intermediate. © 2017, Universidade Federal de Santa Maria. All rights reserved.

Do Nascimento Oliveira C.A.,Federal University of Pernambuco | Gonzalez C.H.,Federal University of Pernambuco | Filho O.O.,Federal University of Pernambuco | Da Silva N.J.,Instituto Federal Of Pernambuco Ifpe | And 3 more authors.
Materials Research | Year: 2015

Shape memory alloys (SMAs) present some characteristics, which make it unique material to be use in applications that require strength and shape recovery. This alloys was been used to manufacture smart actuators for mechanical industry devices and several other applications in areas as medicine, robotics, aerospace, petroleum and gas industries. However it is important to know the actuators response to external stimulus (heat source, electrical current and/or external stress) in these technological applications. This work investigated the thermomechanical behaviors of helical actuators produced from Ti-Ni alloy commercial wires. Initially, the wire was subjected to some heat treatment and characterized by differential scanning calorimeter (DSC), scanning electron microscopy (SEM), optical microscopy (OM) and Energy dispersive spectroscopy. Then two heat treatments were selected to obtain the helical actuators. The actuators were tested in an apparatus developed to apply an external traction stress in helical actuators during thermal cycles. Two wires were tested in a dynamic mechanical analyzer (DMA). The results were analyzed in comparison with thermoplastic properties obtained in thermomechanical tests. The analysis took into consideration the wiring forming process, the precipitates formation, the stress fields generated by dislocations and reorientation of martensite variants during the actuators training process.

Silva E.M.,Instituto Federal Of Pernambuco Ifpe | Da Costa M.F.,Federal University of Pernambuco | Barletta M.,Federal University of Pernambuco
Journal of Coastal Research | Year: 2013

The monitoring of seawater physico-chemistry using automated buoys is well developed for large oceanic scales. Accessible and easy to handle small-scale monitoring buoys and land-based receivers are still missing in coastal water monitoring. River basins, reservoirs and estuaries are the most stressed aquatic environments as a result of their intensive use. These water bodies, and adjacent coastal waters, are priority candidates for continuous and reliable water quality monitoring. Environmental Agencies establish monitoring programs that involve water sampling and laboratorial analysis. Small-scale automated monitoring systems work with relatively low costs if simple materials and readily available technologies are used. We propose the development of a monitoring system that involves small plastic buoys/moorings with temperature and salinity probes, signal emitter/receptor devices, and Programmable Logic Controller (PLC) with wireless communication. The proposed technologies already exist, but need to be developed to work together in inhospitable environments as salt water and high temperatures. It is indicated for the continuous monitoring of shallow water bodies within coastal conservation units, municipal water reservoirs and even by environmental agencies in an upstream/downstream design to monitor water intake and effluents discharges from industries and water treatment plants. Private users may also be interested in installing the system if they are responsible for the maintenance of the water quality of coastal environments. Cheaper and efficient water quality monitoring is key to the building of meaningful time series that can be statistically treated to allow predictions of water quality changes. © Coastal Education & Research Foundation 2013.

Espinosa-Espinosa M.,Catalonia Technology Center of Telecomunications | Llamas-Garro I.,Catalonia Technology Center of Telecomunications | De Oliveira B.G.M.,Instituto Federal Of Pernambuco Ifpe | De Melo M.T.,Federal University of Pernambuco | Kim J.-M.,Chonbuk National University
Mediterranean Microwave Symposium | Year: 2016

This paper presents a building block approach for the design of frequency identification receivers. The devices are based on a Reconfigurable Discriminator (RD) for frequency measurement, operating from 1 to 4 GHz. The RD is a two-port device used to identify the frequency of an unknown signal. The devices use RF switches, which are implemented with PIN diodes to select different bits used for frequency identification. © 2015 IEEE.

da Silva N.V.,Instituto Federal Of Pernambuco Ifpe | Costa R.G.,Federal University of Paraiba | de Medeiros G.R.,Instituto Nacional do Semiarido INSA | de Medeiros A.N.,Instituto Federal Of Pernambuco Ifpe | And 3 more authors.
Archivos de Zootecnia | Year: 2014

It was evaluated the carcass characteristics of 40 sheeps of Santa Inês breed, uncastrated, with initial average weight of 17.41 ± 1.27 kg and average age of 120 days and slaughtered with body weight of 32 kg or 105 days of confinement. The animals were placed in individual stalls and fed with diets containing increasing levels (0, 20, 40 and 60 %) of corn replacement by guava agroindustrial by-product. It was used the lineation completely at random with four treatments and ten repetitions. It occurred a diet effect over the weight and the percentage of carcasses and retail cuts. The replacement of 60 % of corn by guava agroindustrial by-product provided smaller hot carcass weight (11.91 kg) and cold carcass (11.81 kg), lower hot carcass yield (42.08 %) and cold carcass weight (41.72 %), lower rib eye area (9.94 cm2), and muscle (0.33 g/cm), and higher content of gastrointestinal tract (7.43 kg). It is estimated that the inclusion of up to 40 % of guava agroindustrial by-product in the diet replacing the corn is relevant to attaining carcasses with characteristics appropriate to the consumer market, especially where this food resource is available.

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