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dos Santos R.L.,IFPE | Freire F.J.,Federal Rural University of Pernambuco | de Azevedo V.M.,Federal Rural University of Pernambuco | da Rocha A.T.,Federal Rural University of Pernambuco | Tavares J.A.,IPA
Revista Brasileira de Engenharia Agricola e Ambiental | Year: 2013

The use of gypsum in context of exchangeable acidity in subsurface has provided the improvement of root environment, positive influence on crop yields. Therefore, the aim of this study was to evaluate the potential of the mined gypsum from the Araripe region in increasing the exchangeable Ca and also the reduction of exchangeable Al in subsurface, and increase in biomass production of varieties of elephant grass. The experiment was composed of three varieties of elephant grass, such as, Cameroon, Gramafante and Roxo in the presence and absence of mined gypsum through a factorial arrangement (3 × 2), with treatments arranged in 4 randomized blocks. The levels of Ca2+, S-SO4 2-, Al3+ and also its saturation were not affected by the application of mined gypsum in the soil subsurface layer. The application of mined gypsum reduced the pH of the soil subsurface layer. The growing of Cameroon variety promoted the increase in soil pH, reducing the Al saturation. The Cameroon and Gramafante had high dry matter yields, but only the Cameroon variety presented response to application of gypsum, which reached 33 Mg ha-1.

Pinto F.C.,IFPE | Silva Da Silveira D.,Federal University of Pernambuco | Dornelas J.S.,Federal University of Pernambuco | Lopes C.S.,Federal University of Pernambuco
Proceedings - 2015 41st Latin American Computing Conference, CLEI 2015 | Year: 2015

The process of change that is happening in the contemporary world reaches inevitably the public sector. The search for more effective management to provide quality and efficient services to citizens has been the target to be reached by moderns governments. Within this perspective the study of information systems on public organizations is strategic. In this sense, this paper aims to investigate transparency in the electronic system of purchases of the Federal Government of Brazil, the ComprasNet, with the perspective of usability. In other words, this study evaluated whether the non-functional requirement of usability has been contemplated in the ComprasNet system interfaces to meet the transparency criteria. This article is designed from a qualitative exploratory approach about the use of ComprasNet. To achieve the goal, it was performed semi-structured interviews and a field research using the observation method with system users. As a result of this research, we found that the deficiency in the ComprasNet use is caused, in most cases, by the lack of usability rules in their interfaces. In addition, the present study suggests changes in interfaces that will improve the usability of the system and in its transparency. © 2015 IEEE.

Magalhaes A.G.,Federal Rural University of Pernambuco | Rolim M.M.,Federal Rural University of Pernambuco | Duarte A.S.,IFPE | Pedrosa E.M.R.,Federal Rural University of Pernambuco | Silva E.F.D.F.E.,Federal Rural University of Pernambuco
Engenharia Agricola | Year: 2015

The aim of this study was to evaluate chemical attributes alterations of a clay-loam textured soil and dry mass accumulation of maize submitted to application of cassava wastewater doses in three assessment periods. The experiment was conducted under greenhouse using a completely randomized experimental design in a factorial 5 × 3, with four replicates. The analyzed factors of research were doses of cassava wastewater (0; 12.6; 25.2; 50.4; 75.6 m3 ha-1) and assessment periods (20, 40 and 52 days after germination). The following parameters were determined: electric conductivity of soil saturation extract, pH in water, content of available P, content of exchangeable K+, Ca2+, Mg2+ and Na+ of soil, dry mass of leaves and stem. The application of cassava wastewater on soil enables increase of pH, electric conductivity of saturation extract, contents of available P, contents of exchangeable K+ and Na+ and dry mass of leaves and stem. However, only pH and content of exchangeable K+ of soil, the electric conductivity of saturation extract and dry mass of leaves and stem are influenced by assessment period.

Almeida D.R.,IFPE | Moraes A.,Federal University of Paraiba | Moraes A.,Federal University of Campina Grande | Andrade W.L.,Federal University of Campina Grande | Machado P.D.L.,Federal University of Campina Grande
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2015

In model-based testing, test cases are generated from a specification model. To avoid an exhaustive search for all possible test cases that can be obtained, usually an expensive and infeasible activity, test case generation may be guided by a test selection criterion. The objective of a test selection criterion is to produce a minimal test suite and yet effective to reveal faults. However, the choice of a criterion is not straightforward specially for real-time systems, because most criteria presented in the literature are general-purpose. Moreover, the relationship between general-purpose and specific criteria for real-time systems is not clear. In this paper, we investigate the criteria that can be applied for test case generation in the scope of model-based testing of real-time systems, specifically of Timed Input-Output Symbolic Transition Systems (TIOSTS) models. We formalize a family of 19 test selection criteria ordered by strict inclusion relation for TIOSTS models. The family combines general-purpose data-flow-oriented and transition-based criteria with specific reactive and real-time systems criteria. We also perform an empirical study to compare the effectiveness of selected criteria. Results of the empirical study indicate that failure detection capability of the generated test suite may vary, but differences are not significant for time failures. We conclude that more effective criteria for the modelbased testing of real-time systems are still needed. © Springer International Publishing Switzerland 2015.

Barreto M.T.L.,IFPE | Magalhaes A.G.,Federal Rural University of Pernambuco | Rolim M.M.,Federal Rural University of Pernambuco | Pedrosa E.M.R.,Federal Rural University of Pernambuco | And 2 more authors.
Revista Brasileira de Engenharia Agricola e Ambiental | Year: 2014

The aim of this study was to evaluate the growth and nutrient accumulation in maize plants fertilized with cassava wastewater. The experiment was carried out under greenhouse from March to May 2011. The experimental design was completely randomized, in a factorial 2 (soil types: sandy loam and clay loam) × 4 (doses of cassava wastewater: 0; 11.2; 22.4 and 44.8 m3 ha-1) arrangement, with eight replications. The variables analysed consisted of: plant height, stem diameter, number of leaves, fresh and dry mass of shoot and N, P, K, Ca and Mg content in leaf tissue. The use of cassava wastewater contributed to reduce plant height and increase both fresh mass of shoots and potassium content in leaf tissue. Increase in shoot fresh was higher in sandy loam soil.

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