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Desenvolvimento de equipamento óptico para avaliação nutricional em plantas: aplicação na cultura do milho

2026-05-05T16:33:28Z

Título: Desenvolvimento de equipamento óptico para avaliação nutricional em plantas: aplicação na cultura do milho Autor(es): Nogueira, Felipe Hermínio Meireles Abstract: The search for technologies that promote more sustainable and efficient practices is an increasingly important priority on the global agricultural scene. With this in mind, the use of spectroradiometry techniques to assess nitrogen concentration in maize crops has proved to be a promising alternative for conducting precision agriculture practices. In addition, the development of new instruments with optical sensors for agricultural applications has become increasingly important given the challenges of maintaining the sustainability of production systems. With this in mind, this work sought to improve elements of the use of MSPAT (Multispectral Soil Plant Analysis Tools) to determine reflectance. The improvements involved the development of a reference plate with sintered barium sulphate, new approaches using programming techniques, electronics and 3D printing. In addition, the performance of the optical instruments used to estimate leaf nitrogen in the maize crop was also assessed. With this in mind, an experiment was carried out in the experimental area of the Agricultural Electronics and Mechanisation Laboratory (LEMA), located at the Federal University of Ceará (UFC), with AG-1051 maize planted under treatments N0, N60, N90, N120, N150 and N180 (0, 60, 90, 120, 150 and 180 kg.ha-1 of N, respectively) with four replications, in two crop cycles and a Completely Randomized Design (CRD). The assessments took place during the V5, V10 and R2 phenological stages and were carried out using the MSPAT, SPAD and FieldSpec PRO FR 3 equipment. The spectroradiometer was used under the conditions provided by the dark-room of the UFC Geoprocessing Laboratory. The samples were then prepared for nitrogen (N) determination according to the methodology proposed by Kjeldah. In addition to leaf nitrogen, morphological parameters were also assessed throughout plant development, production, biomass and dry matter. The spectral indices (NRI, Normalise Ratio Index) were then correlated with the leaf N data and the individual bands were evaluated using Pearson's coefficient (r). Linear regression was then carried out (p-value < 0.01) with the NRI's to select the models, by optical instrument, that showed the best coefficient of determination (R²) with the leaf N data sets: i) at each stage of development, for the two crop cycles and ii) with the entire data set. Cross-validation (k-fold) was then carried out to assess the error parameters RMSE, MAE and adjusted coefficient of determination (R²adj.). The results for the best predictive models reveal different patterns for the selected bands between the data sets, as well as low generalisation capacity. However, it was possible to validate relevant models with MSPAT, SPAD and FieldSpec, which showed an R²adj. of 0.7871; 0.6959; 0.7199 and RMSE of 0.0425; 4.47; 0.0214 g.kg-1; respectively. From the model that showed the best performance with MSPAT, when using the NRI with the 900 and 560nm bands, the application in an agricultural area provided an RMSE of 2.73 g.kg-1 and MAE of 2.47 g.kg-1. However, it is clear that the use of new technologies has great potential for assessing leaf N in maize crops. Tipo: Dissertação

Desenvolvimento de barra alimentícia híbrida à base de pescado e macroalga marinha

2026-06-02T23:01:48Z

Título: Desenvolvimento de barra alimentícia híbrida à base de pescado e macroalga marinha Autor(es): Santos, Rayane Leite dos Abstract: The increasing demand for foods with high nutritional value, convenience, and alignment with contemporary trends in protein diversification has driven the development of innovative products. This study aimed to develop and evaluate a hybrid protein food bar formulated with Nile tilapia (Oreochromis niloticus) fillet flour and the marine macroalgae Gracilaria domingensis, considering physicochemical, techno-functional, sensory, and consumer perception aspects. Initially, prior to the development of the bars, an exploratory stage was conducted with consumers to define concepts and expectations, using the focus group method and online application of the Check-All-That-Apply (CATA) method, involving 302 participants, with the aim of identifying expectations, perceptions, and relevant attributes associated with the product concept. The terms most frequently associated with the proposed bar were “nutrition” (78.1%), “health” (62.6%), and “convenience” (52.6%). Among the main consumption drivers, taste (92.1%), price (64.6%), and appearance (55.3%) were highlighted. Regarding expected characteristics, the attributes most frequently cited were “nutritious” (74.8%), “healthy” (71.9%), “without fishy odor” (49.7%), and “high in fiber” (47.7%). Subsequently, the raw materials were acquired, processed, and converted into flour for physicochemical and techno-functional characterization. Tilapia flour exhibited high protein content (73.65 g·100 g−1), whereas G. domingensis flour presented 15.28 g·100 g−1 protein, high water absorption capacity (941.11%), and gel formation at concentrations as low as 4%, demonstrating functional complementarity between the ingredients. Based on these results, five hybrid food bar formulations were developed and subsequently evaluated by 80 consumers using CATA, a 9-point hedonic scale, the Just-About-Right (JAR) scale, and purchase intention analysis. No statistically significant differences were observed among formulations (p > 0.05). Sensory profiling highlighted fish aroma (5.96–6.52), fish flavor (4.67–4.99), soft texture (3.71–5.07), and sandy/grainy residual perception (4.81–5.70). In the JAR evaluation, fish odor (2.13–2.29) and sandy/grainy perception (2.05–2.16) were considered above the ideal level, whereas compact texture and flavor showed values closer to the ideal. In the hedonic evaluation, appearance achieved the highest scores (6.21–6.51), followed by flavor (6.03–6.32) and overall impression (6.08–6.37), indicating acceptance between “liked slightly” and “liked moderately.” Aroma (4.76–4.87), texture (4.81–5.03), and residual sensations (4.27–4.53) remained close to neutrality. Penalty analysis indicated a negative effect of attributes such as fish aroma (−3.7500), adhesiveness (−1.9028), and sandy/grainy residual perception (−1.1091), whereas softness (+0.2527) contributed positively to acceptance. Purchase intention scores ranged from 2.96 to 3.03 on a 5-point scale, with predominance of intermediate responses. The results are promising and indicate market potential, provided that sensory attributes, particularly odor and texture, are improved, in addition to further studies involving technological optimization. Tipo: Tese

Criação e manejo de Xylocopa frontalis e sua utilização comparativa na polinização do urucuzeiro (Bixa orellana)

2026-05-29T19:54:37Z

Título: Criação e manejo de Xylocopa frontalis e sua utilização comparativa na polinização do urucuzeiro (Bixa orellana) Autor(es): Silva, Felipe Jackson de Farias Abstract: We aimed to propose improvements to a rational nest model for bees of the genus Xylocopa, especially X. frontalis, as well as techniques for the rearing, multiplication, and management of this species, and its efficiency as a pollinator of the annatto tree (Bixa orellana), compared to three other native bee species (Augochloropsis sp., Melipona fasciculata, and Melipona flavolineata). The first colonized nests appeared few months after their installation in the study area. The number of galleries built per nest ranged from one to six (3.82 ± 1.4). The galleries had a total average length of 104.19 (±43.41) cm and an excavated volume of 327.15 (±136.29) cm³. Active nests were observed throughout the study period and were transported and relocated without abandonment. Regarding pollination, peak flower visits occured between 7:00 and 8:00 AM, with X. frontalis foraging earlier than other bees and making shorter flower visits. No statistically significant differences were detected in any fruit parameters between treatments. The treatment with free pollination showed the highest fruit set rate (37.5%), followed by a visit from M. flavolineata (25%), although no statistically significant difference was observed. We conclude that our rational nesting device is a suitable alternative for the rearing and management of Xylocopa frontalis and, presumably, other species of the genus for crop pollination or research purposes, without evidence of negative interference in the nesting biology of these bees. Xylocopa frontalis proved to be an efficient pollinator of Bixa orellana. Tipo: Tese

Avaliação do Auxílio Moradia da UFC no campus de Fortaleza no âmbito da Política Nacional de Assistência Estudantil (PNAES)

2026-05-29T03:21:18Z

Título: Avaliação do Auxílio Moradia da UFC no campus de Fortaleza no âmbito da Política Nacional de Assistência Estudantil (PNAES) Autor(es): Leão, Isabelle Silva Abstract: This dissertation evaluates the Housing Assistance Program of the Federal University of Ceará (UFC), at the Fortaleza campus, within the scope of the National Student Assistance Policy (PNAES), aiming to understand its contribution to the retention of students in situations of socioeconomic vulnerability in higher education. The study is based on the understanding that the expansion of access to higher education, especially through the quota policy, has changed the student profile of federal institutions and intensified the relevance of student assistance policies for undergraduate student retention. The research adopts an evaluative perspective inspired by Fourth Generation Evaluation and combines qualitative and quantitative approaches. To this end, documentary and institutional data regarding the beneficiaries of the program were mobilized, in addition to interviews with managers, staff members responsible for implementing the policy, and assisted students, with data processed through content analysis. The results show that the Housing Assistance Program plays a significant role in student retention by impacting material conditions of subsistence, mobility, academic continuity, and expectations of remaining at the university. At the same time, the study identifies tensions related to poverty, budget constraints, targeted assistance, management and operational challenges, partial lack of knowledge about PRAE services, and the increasing complexity of student demands. It is concluded that the program constitutes an important instrument for inclusion and student retention; however, its effectiveness depends on the institutional and budgetary strengthening of PNAES, as well as on information, monitoring, and evaluation strategies capable of reducing exclusions within the inclusion policy itself. Tipo: Dissertação