Universidade Federal do Ceará
  • Fortaleza, Ceará, Brazil
Recent publications
The study of historic facades is an essential subject for the valorization and conservation of human cultural identity. The evaluation of the vulnerability of ancient c006Fnstructions requires the adoption of a specific and appropriate methodology depending on the purpose and scale of the analysis, demanding the identification of the main constructive aspects and the existing damages. From the literature survey, most of the vulnerability assessment is focused on the behaviour of the building as a whole and vulnerability assessment on dynamic actions. Brazil is the fifth largest country globally and has a wide variety of historical heritage. Thus, this research proposes a new methodology to evaluate the vulnerability of historic facades based on a building sample of the historic centre of Viçosa, Brazil. As vulnerability parameters were considered, the Facade Conservation State, Elements connected to the facade, Facade Geometry, Facade Openings, and Facade Orientation. The hierarchization of each vulnerability parameter was based on the expert's evaluation collected by a questionnaire and the Hierarchical Analytical Process. Results reveal that Facade Conservation State was the main influence parameter (0.80), followed by Facade Openings (0.50) and Facade Orientation (0.50). The proposed model was then validated to a set of 11 historic facades of Viçosa do Ceará.
Maize production (Zea mays) under rainfed conditions, although risky in semi-arid areas, is still widespread. In theses areas, rainfall events are concentrated over a short, irregular and discontinuous period, so that understanding these events has great relevance to the anning and agricultural management of maize. This study sought to understand the relationship between the frequency of different classes of dry spells formed during the rainy season and the occurrence of dry, normal and wet years in the semi-arid region. Also analysed was whether this same frequency is influenced by the incidence of long-duration El Niño and La Niña phenomena, and how all these factors interfere with maize productivity. For this, a trend analysis was then carried out between the frequency of dry spells, considering years classified as dry, normal and wet, and whether this number is also influenced by the occurrence of long-duration El Niño and La Niña events, and how the classes and temporal occurrence of dry spells influence maize productivity within the study region. The results show that crop achieving good results for dry spells of up to 15 days, after which productivity falls significantly. The greatest number of dry spells was found in regions of the semi-arid sertão that are further inland, especially more prolonged dry spells. Throughout the region, the highest probability of occurrence of dry spells is during the first and last month of the rainy season, with a high concentration of dry spells which vary from 6 to 20 days with no rain, indicating the need supementary irrigation, anting nearer the end of the season in years of normal or wet conditions, reducing the chances of the crop suffering from water stress.
The rhizospheric microbial community is affected by plant genera and genotypes. However, the rhizospheric effect on the microbial community from distinct plant species belonging to the same genus is poorly understood. This study hypothesized that the rhizospheric microbial community differs between plant species from the Phaseolus genus (i.e. P. acutifolius A. Gray, P. lunatus L., P. vulgaris L., P. microcarpus Mart., and P. filiformis Benth.) and that these differences could be related to phylogenetic differences found in these plant species. The redundancy analysis showed a distinct microbial community mainly when comparing P. lunatus and P. microcarpus. The microbial richness and diversity varied among plants, where P. lunatus showed the highest richness and diversity and P. microcarpus the lowest. The abundances of specific microbial phyla varied between the rhizosphere of Phaseolus species. Actinobacteria was abundant in the rhizosphere of P. acutifolius, P. vulgaris, and P. filiformis, while Acidobacteria was abundant in the rhizosphere of P. lunatus. This study revealed that each Phaseolus species recruits a distinct microbial community in the rhizosphere, with the rhizosphere community of the domesticated species P. lunatus being the most distinct.
Sedimentological analyses are essential to understand the system that dictates the sediment yield processes of a basin. Basins have their own characteristics according to climatic, geological, geomorphological, pedological, and phytogeographic influences, on the sediment yield at different scales. This study evaluated the hydrosedimentological aspects of the Rio Seridó hydrographic basin to understand the sediment yield behaviour in the drainage area at different scales. Primary and secondary data, such as imagery (remote sensing), geostatistical methods, hydrosedimentological modelling, and calculations, were used to produce thematic maps, to implement theoretical–methodological revisions of the objects, and determine the specific sediment yield. The sediment delivery ratio was utilized to model the sediment yield at the basin scale, which was calculated using Maner’s Equation and the Universal Soil Loss Equation from 1992 to 2015. The measured data comprised sediment collection, a bathymetric survey of reservoirs, and erosion pins in the drainage basin on a timescaleof up to 82 years. The modelled sediment yield of the basin (2.5 t ha⁻¹ y⁻¹) was comparable to the measurements performed in the semiarid regions for basins of the same scale. The average sediment yield in the reservoirs (2.15 t ha⁻¹ y⁻¹) was very close to the modelled value. Positive allometry was identified for areas of up to 400 km² in the upper, middle, and lower reaches. Positive allometry was observed with an increase in sediment yield in the drainage area. Globally, this pattern is rare in regions that have not experienced glaciation and this identification is tan important contribution of this research.
In arid and semiarid environments, evaporation is responsible for significant water losses from reservoirs. This condition is of special concern in the Brazilian Northeast region, as this is one of the most populous semiarid areas in the planet. The present study aims to assess the spatio-temporal variability of evaporation rates on the water surface of Pentecoste reservoir, located in the Brazilian semiarid region, by using both the hydrodynamic model Delft3D and a remote sensing technique (RS). While RS has already been used to evaluate the spatial distribution of evaporation rates in lakes, Delft3D was innovatively tested and applied for this purpose for the first time in this study. The calibration results showed an accurate reproduction of the water level variability (r 2 of 0.997), along with a satisfactory calibration of the reservoir's thermal structure for the full water column (MAE of 0.539 • C, RMSE of 0.572 • C, and NMAE of 0.008). Curves relating monthly evaporation rates with air temperature and wind speed showed strong correlation between those variables (r 2 of 0.817 for air temperature and 0.849 for wind speed). Also, the averaged evaporation rates modeled by Delft3D differed by less than 5% compared to RS. Regarding the spatial distribution results, for the wet period the evaporation patterns were similar to those of RS, while in the dry period RS provided a more stable evaporation pattern when compared to Delft3D. The innovative approach proposed in the present study can be used to better understand the evaporation dynamics in surface waters and optimize the location of damping evaporation structures, namely air diffusers, shading systems, and floating solar panels, which are important for improving water availability, not only in drylands.
Copper complexes are highly versatile species that find promising uses in broad fields such as catalysis, drug design, and bioinorganic applications. However, copper complexes display a rich chemical behavior in solution due to their oxidation-state dependent geometrical rearrangements that make it daunting to the inexperienced. This review summarizes the advances in the synthesis of copper complexes containing phenanthroline- and bipyridine-like ligands covering from the electronic aspects of Cu(I) and Cu(II) metal ions to the intricate mechanisms of helicate formation and generation of reactive oxygen species (ROS). To illustrate the complexity of Cu complexes and strategies to address it, we will focus on three main aspects of their chemistry: 1) their electronic/geometric structure relationships, 2) the formation and behavior of helicates, and 3) oxygen reaction chemistry with copper complexes. In the first case, g values from EPR spectroscopy are discussed as a powerful method to elucidate the molecular structure of different copper complexes using crystal field approximations and the R parameter. Also, we correlate these with the geometries and the electronic properties observed for different copper species. In the second case, we cover structural changes observed in helicates from the synthesis of tetracoordinate ligands to trimetallic species. We consider relevant equilibria in the helicates, and we discuss the chiral separation of diastereosimers and their properties. In addition, we summarize oxygen reduction by copper(I) complexes and the oxygen adducts determined for hydroxyl and peroxyl radicals in different solvents. Their water oxidation chemistry and the concept of “autoreduction” that many copper complexes have is addressed. Lastly, we revised photoinduced charge transfer activates the electron transfer mechanisms proposed for copper complexes onto support TiO2 receiving charge injection from copper photosensitizers for use in solar cells. We describe the generation of reactive oxygen species and their detection by EPR. While the reader may find different challenges in their research on coordination chemistry, these three illustrations provide solid examples of how ligand field theory, crystal structure, and spin characterization are used to solve concrete problems posed by Cu chemistry. We hope this review will help jumpstart the novice chemist into the fascinating chemistry of Cu complexes and provide new discussion and conceptual tools to more advanced researchers.
Soil organic matter (SOM) is a critical component of the soil system and a sensitive indicator of soil quality. We aimed to investigate the response of SOM pools to different land uses and management in irrigated croplands of the semi-arid region of northeast Brazil. Four sites irrigated under long-term (29 years) land uses were selected: banana (B1 and B2); elephant grass (EG)-perennial systems; maize and cowpea succession (MCP)-annual system; B1 was cropped for 17 years +2 years of maize and cowpea +17 years banana, while B2 was continuously cropped. A native forest (NF) site was selected as reference of steady state. Soil samples were collected at four depths in the rows and inter-rows of each management system. The higher decline in SOM fractions was perceived at 0-0.05 m depth and microbial indices (microbial biomass C and N, and basal respiration and metabolic quotient) were very sensitive indicators of soil quality. Perennial systems (B1 and EG) maintained the C and N stocks at higher levels equivalent to NF at the 0-0.40 m layer, while MCP and B2 had lower total organic carbon (TOC) (15 and 17%, respectively) and total nitrogen stocks (4.27 and 8.67%, respectively). Perennial cultivation with B1 and EG showed also the highest soil C and N microbial biomass and stratification ratio and, the lowest respiratory quotients, all indications of elevated soil C sequestration. In general, land use change from native forest to annual crops reduced plant residue input and increased soil disturbance, favoring higher SOM mineralization, while perennial crops and grasses were the most effective in increasing C and N stocks due to the maintenance of crop residues on the soil surface and the absence of soil tillage.
The increasing penetration of wind energy conversion systems (WECSs) based on the doubly-fed induction generator (DFIG) has raised serious concerns about the stability of modern power systems. One important issue is the frequency control of interconnected networks, which may become more complex owing to the low inertia of wind turbines. In this context, this work presents a novel frequency control approach that associates the grid-side converter (GSC) with a synchronverter. To assess the performance of the proposed solution, a thorough comparison with other well-known frequency control techniques is presented, that is, pitch angle control and switching angle controller (SAC). Simulation tests of the IEEE 14-bus modified test system are carried out in PSCAD/EMTDC® software to assess the behavior of a 165 MW wind farm (WF) when frequency variations occur. The results show that the classical control approaches can restore the system frequency within a time interval up to 63% shorter and a frequency dip lower than 13% when compared with WECSs that cannot provide frequency support. In turn, the synchronverter-based technique presents improved performance while attenuating a frequency dip by 45.7% and 56.9% when compared with the aforementioned strategies and WECSs without frequency support, respectively.
Aging is defined as a dynamic event influenced by biological, physiological, psychological, environmental, behavioral, and social processes intermingled. It can also be considered an age-dependent or age-progressive decline in physiological function, resulting in an elevated mortality rate and reduced reproductive function.
The dissolved oxygen (DO) level in the hypolimnion of lakes and reservoirs can reach anoxic conditions, which favor the release of phosphorus from the sediment bed to the water column. However, to estimate nutrient release from sediment is extremely important to quantify the duration of anoxia. In low latitude regions, the water-sediment layer is warmer than in temperate regions and eutrophication is usually more severe, potentially accelerating oxygen depletion and extending the anoxia period. Considering that the available equations to quantify the duration of anoxia were developed for temperate lakes, there is a need to effectively quantify this period in lakes and reservoirs located in other climate regions, such as the semiarid. In this study, the dynamics of thermal stratification was analyzed as a function of the Relative Water Column Stability coefficient (RWCS) and then correlated with DO dynamics for nineteen tropical semiarid reservoirs. RWCS values were higher during the rainy season, when anoxia duration was longer and the hypolimnion was thicker with respect to total water depth. Then, two new equations for quantification of anoxia duration, based on the equation originally developed for temperate climate, were adapted for the wet and dry seasons of the tropical semiarid region. The results showed that the proposed equations presented a better performance compared to the original one, which tends to underestimate anoxia in tropical semiarid reservoirs. This work intended to provide simple and locally adjusted tools to better quantify anoxic events and support the water quality and internal phosphorus load modeling for tropical semiarid reservoirs.
Resumo O crédito rural é o principal instrumento da política de teor agrícola brasileira, amparando e proporcionando aos agricultores mais investimento em suas produções. Quando comparado, porém, às demais, a região Nordeste requer maior atenção e, ademais, essa região também denota heterogeneidade. Assim, este estudo estimou o efeito do crédito rural destinado aos agricultores familiares (Pronaf) sobre a produção total das lavouras temporárias na Região, discriminando nas regiões de clima semiárido e não semiárido, além dos municípios com polos de irrigação e os que não têm. A base de dados foi obtida por intermédio das seguintes fontes: PAM, IBGE, BCB, MDA, INMET e Global Climate Monitor; no período de 2012 a 2017, em razão da disponibilidade de dados, e estes foram analisados com a aplicação de métodos para dados em painel com efeitos aleatórios. Os resultados mostraram que o crédito rural expressou efeito positivo sobre o valor bruto da produção durante o período analisado, apesar de o número de agricultores familiares não exprimir influência. Além disso, os municípios que têm polos de irrigação mostraram resultados melhores em relação aos demais grupos, em contraposição aos municípios localizados no semiárido.
Biocatalysis is one of the most promising technological alternatives to be applied in various industrial sectors, but its use in the commercial environment is limited. It is necessary to resort to techniques that improve its properties, one of which is immobilization. So the most used immobilization strategies, such as physical adsorption, trapping, covalent bonding, and cross-linking, are presented in this chapter. Then the support-free procedures, such as cross-linked enzyme crystals or cross-linked enzyme aggregates, will be highlighted. Besides, the analysis of support-free immobilization with magnetic properties will be presented and analyzed as well as the coimmobilizing enzymes in combi-CLEAs, in magnetic CLEA (m-CLEAS) and m-Combi-CLEAs, and cross-linked enzyme crystals (CLECs) and their equational reactions.
The flood-prone scenarios assessment contributes to detecting natural and climate change trends and it is a crucial component of integrated coastal zone management. However, the data acquisition with a high spatial and temporal resolution for a local scale is still a challenge considering that sea-level rise projections are usually represented by global scales. This contribution uses locally acquired topographic data for a flood-prone simulation (2100), presents a flood depth-damage function, and points out several obstacles for sea-level rise simulations. The input data is based on GNSS and RPAS surveys. The results showed multimedia videos and maps containing the optimistic, intermediate, and pessimistic scenarios for 2100. In the pessimistic scenario (0.80 m elevation), 45% of the vegetation and 67% of the islet would flood. The results showed the importance and barriers for flood-prone simulations. It is still necessary to advance in developing new methods able to combine multiple parameters, particularly for local and regional scales highlighting high spatial data-set to properly represent local impacts.
Objective to develop and assess a Knowledge, Attitude and Practice survey on healthy lifestyle in people with human immunodeficiency virus. Method a development study, with the elaboration of survey through of an integrative review and analysis of the guidelines; content and appearance analysis by 22 expert judges; and semantic analysis by 22 outpatients. The proportion of positive assessments of the items was measured, considering a percentage equal to or greater than 85%. Results the survey had three domains and seven axes: chronic diseases in people with human immunodeficiency virus; body weight control; healthy eating; physical exercise; avoiding smoking, alcohol and illicit drugs; stress control/reduction; antiretroviral and other medication compliance. Knowledge and attitude domains had 10 questions, and practice domains had 11. In the assessment by expert judges, nurses, doctors and nutritionists participated, with positive agreement of items above 85%. Patients underwent semantic analysis, with 100% positive agreement in the domains. Conclusion and implications for practice the survey had adequate evidence of validity, to be used by nurses and other health professionals, to support care, educational strategies and research with people living with the human immunodeficiency virus.
Resumo Objetivo desenvolver e avaliar um inquérito de Conhecimento, Atitude e Prática sobre estilo de vida saudável em pessoas com vírus da imunodeficiência humana. Método estudo de desenvolvimento, com elaboração do inquérito por meio de revisão integrativa e análise das diretrizes; análise de conteúdo e aparência por 22 juízes especialistas; e análise semântica por 22 pacientes em acompanhamento ambulatorial. Mensurada a proporção de avaliações positivas dos itens, considerando-se percentual igual ou maior a 85%. Resultados o inquérito teve três domínios e sete eixos: doenças crônicas em pessoas com vírus da imunodeficiência humana; controle do peso corporal; alimentação saudável; prática de exercício físico; evitar fumo, álcool e drogas ilícitas; controle/redução do estresse; adesão aos antirretrovirais e outros medicamentos. Domínios conhecimento e atitude tiveram 10 perguntas, e o de prática, 11. Na avaliação pelos juízes especialistas, participaram enfermeiros, médicos e nutricionista, com concordância positiva dos itens acima de 85%. Os pacientes fizeram a análise semântica, com concordância positiva nos domínios de 100%. Conclusão e implicações para a prática o inquérito teve evidência de validade adequada, para ser utilizado por enfermeiros e outros profissionais de saúde, para subsidiar a assistência, estratégias educativas e pesquisas com pessoas vivendo com o vírus da imunodeficiência humana.
There is a growing market for beverages made with mixed fruits, mainly tropical ones. The objective of this work was to develop blended nectars based on açai and cashew apple pulps and to evaluate them by using sensory consumer tests according to a response surface methodology. Nine formulations were prepared by using different total pulp concentrations and açai-to-cashew apple pulp ratios. The formulation with 30.0% of total pulp and an açai-to-cashew apple pulp ratio of 0.84 (that is to say, 13.7% of açai pulp and 16.3% of cashew apple pulp) was the most accepted by consumers (lowest pulp assayed). This mixed nectar showed high vitamin C and anthocyanin contents, and exhibited an attractive dark violet color, suggesting potential commercial success. The data obtained in this study can be used for large-scale production of new mixed fruit nectars, which suggests that they may represent an exciting option for consumers. © 2022 The Author(s). Published with license by Taylor & Francis Group, LLC.
In this work, we present an analytical model to describe atomic force microscopy force curves of standard linear solid and power-law viscoelastic materials by taking indenter geometry and finite thickness effects into account. We show that conical/pyramidal cantilevers are less susceptible to finite thickness effects than other shapes, such as spherical and flat punch indenters. This is confirmed by finite element modeling of the stress field distribution within the sample. We also perform a systematic error analysis for the cases where finite thickness samples are analyzed with an infinite thickness force model. In particular, we show that for spherical indenters and indentation depth up to 20% of sample thickness, the mechanical response of viscoelastic materials will wrongly mimic a purely elastic behavior even within timescales where viscoelastic relaxation should appear.
Purpose: To investigate whether there is a relationship between the volume of the maxillary sinus and individual parameters such as gender, side, posterior tooth absence, sinus membrane thickening, bony septa, vertical and sagittal skeletal patterns. Methods: The tomographic volume of the maxillary sinus from 211 individuals (422 sides) was evaluated using Horos DICOM Viewer Software. Bony septa and sinus membrane thickening were classified as absent or present. At the same time, loss of one or more teeth in the posterior region of the maxilla (except for the third molars) was considered. The t test was applied to analyze maxillary sinus volume according to gender, age, side, posterior tooth absence, sinus membrane thickening and bony septa. A one-way analysis of variance (ANOVA) with Tukey's post-hoc test was applied to compare sagittal and vertical patterns. Pearson's correlation coefficient was also used to verify the association between maxillary sinus volume, age and skeletal patterns. Results: Concerning the sagittal skeletal pattern, a statistically significant difference was observed between Classes II and III (p = 0.05) and it was confirmed by the Pearson's correlation coefficient (r = - 0.107/p = 0.029). No statistically significant differences were observed between the maxillary sinus volume according to gender (p = 0.06), side (p = 0.37), posterior tooth absence (p = 0.92), sinus membrane thickening (p = 0.47), bony septa (0.89) and vertical skeletal pattern (p = 0.67). No significant differences were observed with age (r = - 0.076/p = 0.109) and the vertical skeletal pattern (r = - 0.078/p = 0.108). Conclusion: Maxillary sinus volume was influenced by the sagittal skeletal pattern and was higher in Class III individuals.
This paper studies a control structure based on the generalized predictive control (GPC) able to deal with SISO/MIMO dead-time processes. An equivalent dead-time compensator structure is presented in order to analyze the controller properties, such as set-point tracking, robustness and disturbance rejection. From the equivalent structure, a set of simple tuning rules are derived. Such rules employ a reduced number of parameters which facilitates the tuning of the controller, especially for the case of MIMO processes. A simulation result shows the enhanced performance of the tuning strategy when compared with an example from the literature. Furthermore, an experiment was performed to show the effectiveness of the proposed tuning strategy on the temperature and humidity control of an in-house thermal chamber.
1. To sample bee communities, a combination of methods is necessary, the most common being hand netting (HN) and pan traps (PT). However, there has been little exploration into how vertical distribution of PT can improve their sampling efficiency, also taking the temporal variation of floral resources into account. 2. Here, we analysed the properties of bee communities sampled with PT at different heights (1.6 and 4.0 m) compared with PTs close to the ground, HN and large blue bucket trap (BB). In addition, we tested the effect of variation in the availability of floral resources on the performance of each method. Bees were collected in fragments of the Brazilian Caatinga. 3. We captured 60 bee species with PTs, HN and BB, with significant increases in the sample coverage with elevated bowls (BB = 56.7%, HN = 60.0%, PT0.3 m = 23.3%, PT1.6 m = 36.7%, PT4.0 m = 50.0%). Elevating the bowls increased the sampling of bees with larger body size. Considering the three heights, PTs registered similar richness compared to HN and BB, but differed in the composition of species and ecological traits. 4. When floral resource availability was greater, the abundance and richness of bees caught in PTs decreased, however, the elevated PT increased their ecological uniqueness (degree of uniqueness of the samples in terms of community composition). Thus, elevating PTs enables the capture of bees that forage at a specific height when floral resources increase. 5. Our results highlight the importance of the vertical distribution of PT for sampling bees, since it improves their performance and its complementarity with other methods.
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8,998 members
Alejandro Pedro Ayala
  • Departamento de Física
Fabio Costa
  • Departamento de Clínica Odontológica
Geancarlo Zanatta
  • Departamento de Física
Lidiany K A Rodrigues
  • Faculty of Pharmacy, Dentistry and Nursery
Ligia Regina Sansigolo Kerr
  • Departamento de Saúde Comunitária
Avenida da Universidade, 2853 Benfica, 60020-181, Fortaleza, Ceará, Brazil
Head of institution
Prof. Dr. José Cândido Lustosa Bittencourt de Albuquerque
+55 (85) 3366 7300
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