The Journal of Engineering and Exact Sciences

An efficient Protocol for Enhanced Flynet Communication in Presence of Partitioning

Tahar Allaoui — 2024-10-27

This paper presents an adaptive fault-tolerant resource allocation protocol tailored for FlyNet, a dynamic aerial network characterized by its mobility and three-dimensional operational space. Addressing the challenges of network partitioning and resource allocation in aerial networks, the proposed algorithm dynamically adjusts to the network's changing topology, ensuring consistent and efficient resource management. Through robust fault tolerance mechanisms, the protocol enhances FlyNet's reliability, maintaining seamless communication and optimal resource utilization even amid node mobility and disruptions. Simulation results demonstrate the algorithm's effectiveness in adapting to dynamic environments, maximizing resource utilization, and minimizing communication delays.

Application of Business Intelligence in the Brazilian Educational System

Carlos Grimm Moniz Junior — 2024-10-29

In this article, we will discuss an application of Business Intelligence (BI) in analyzing data from the Brazilian educational system, specifically working with INEP (The Instituto Brasileiro de Geografia e Estatística — IBGE). This paper then discusses BI implementation's positive contributions and critical challenges in this domain. From the construction of an integrated BI system, our study aimed to offer a helpful tool that was easy to handle and touched on visuals such as dashboards, tables, and graphs to help us understand and manage the educational scenery throughout Brazil. The methodology used has been applied, with case studies and bibliographical research, based on data analysis techniques such as ETL (Extract, Transform, Load) and Data Warehousing. This is all leveraged to interactive dashboards, which should enable data-driven decisions and forge the way for advanced analytics like data mining.

Pythagorean Theorem: From the school context to professional practice in determining alignments and areas of urban lots

Janilce de Araújo Barros — 2024-10-27

When addressing a given subject, teachers often face questions about the origin and purpose of the material presented. Often, due to a lack of in-depth knowledge, they are unable to adequately answer these questions, presenting the content in a manner that is disconnected from its historical and practical context. This article aims to explore the use of the Pythagorean Theorem, from its introduction in elementary school to its application in various professional areas, with an emphasis on Civil Engineering and Architecture. The focus is not only on its theoretical demonstration and calculation of dimensions, but also on its role in the creation of constructive forms developed by engineers and architects. The choice of the Theorem is due to its historical relevance in the development of Mathematics and its applicability in future content in different professions. The study includes a brief historical contextualization of the Theorem, an analysis of its application in elementary school, with practical exercises extracted from textbooks, and an approach applied to civil construction, especially in the delimitation and description of urban and rural areas. The results indicate that the Pythagorean Theorem plays a fundamental role in the graphical representation of property boundaries, helping to define their sides and angles, particularly through the use of the right triangle, an essential figure for determining boundaries and areas in urban and rural subdivision documents.

Viscoelastic Fluid Flow Model for Hydrodynamic Behaviour of Magnetorheological Fluid in Valve and Shear Modes for a Damper System

Adelani Ismail Adeleke — 2024-07-02

In this present study, the flow behaviour of magnetorheological fluid in valve and shear modes for damping system is modelled and analysed. The fluid is modelled as viscoelastic fluid flowing between two parallel plates in pressure driven flow mode, and also as direct shear mode. In the work, the post-yield shear thinning or thickening behaviour of magnetorheological fluids are accounted for. The velocity and pressure distributions in the unsteady magnetorheological fluid flow between the electrodes of the damper are obtained by solving the momentum equation of the magnetorheological fluid flow using the Laplace transform method. There is an excellent agreement between the results of the present model and the results of the experimental studies. The adopted viscoelastic flow model describes that the rheological behaviour of the fluid is separated into distinct pre-yield and post-yield regimes. The fluid flow velocity, velocity gradient, and shear stresses have all been shown to be enhanced by an increase in the pressure drop. The viscosity of the fluid increases with an increase in the volume fraction of particles in the fluid, which causes the resistance of the fluid to flow to increase and thereby, reduces the fluid flow velocity. Fluid flow velocity is decreased as a result of increasing magnetic field strength. The design of clutches, rotary brakes, dampers, shock absorbers, prosthetic devices, polishing and grinding tools, etc. will all benefit greatly from the adoption of the current model.

An essay on the foundations of variational methods: Exploring Sobolev Spaces for boundary integral equations

Rômulo Damasclin Chaves dos Santos — 2024-07-01

This work addresses the uniqueness and regularity of solutions to integral equations associated with elliptic boundary value problems in irregular domains. Traditional results often assume smooth (Lipschitz) boundaries, but this study extends these results to more general domains with irregular boundaries. By leveraging Sobolev spaces, particularly fractional Sobolev spaces , and the properties of the Slobodetskii norm, we develop a robust theoretical framework. Our main theorem demonstrates that, under suitable conditions, has a unique solution in , and this solution inherits the regularity properties from the function . The results provide significant advancements in the mathematical understanding of boundary value problems in non-smooth domains, with potential applications in various fields of physics and engineering.

Improvements in the manufacture of benzoic acid obtained by catalytic oxidation of toluene

João Guilherme Rocha Poço — 2024-11-05

This study investigates improvements in benzoic acid production through the catalytic oxidation of toluene with cobalt octoate. The oxidation process, which occurs under controlled conditions with temperatures ranging from 130 °C to 165 °C, typically results in a conversion rate of 50% toluene with a selectivity of 80% over benzoic acid. However, various by-products such as benzyl alcohol, benzaldehyde, and benzyl benzoate are also formed, which reduces the overall yield. The work identifies methods to minimize these byproducts, particularly benzyl benzoate, which forms in the distillation column. One strategy investigated involved using additives to inhibit the esterification reaction that produces benzyl benzoate, aiming to improve the selectivity of the oxidation process. Experimental results show that maintaining reaction temperatures between 135 °C and 145 °C in combination with using sodium benzoate as an additive effectively reduces the formation of benzyl benzoate and increases the yield of benzoic acid. Furthermore, increasing the O₂/toluene ratio increases the oxidation efficiency.

Sentiment analysis of Algerian Arabic dialect on social media Using Bi-LSTM recurrent neural networks

Abdelghani BOUZIANE — 2024-10-27

This paper presents a sentiment analysis approach using Bidirectional Long Short-Term Memory (Bi-LSTM) Recurrent Neural Networks to train predictive models for sentiment analysis on social media, particularly focusing on Algerian Arabic Dialect. The method leverages word-to-vector embedding for word representation and incorporates natural language understanding of emojis to improve semantic interpretation. The model achieves a high accuracy of 94%, demonstrating its effectiveness in analyzing sentiments in online discussions. The originality lies in applying Bi-LSTM to handle multilingual challenges on social platforms. The findings have practical implications for business, policymaking, and public sentiment evaluation, while also contributing positively to fostering informed online discourse.

Vibration analysis using the theory of exponential shear deformation for laminated plates

Khaled Bendahane — 2024-10-27

In this research, the free vibration response of laminated composite plates is studied using a refined exponential shear strain theory. The most interesting feature of this theory is that it allows exponential distributions of transverse shear strains, and verifies zero-shear boundary conditions on the plate surfaces without the use of shear correction factors. Some stiffness constants are written as a series. The number of independent unknowns in the present theory is four, compared with five in other shear deformation theories. The equations of motion are obtained from Hamilton's principle and Navier's method is used to determine the exact solution for antisymmetric cross-laminated plates. The numerical results found in the present analysis for free vibration are presented and compared with those available in the literature. The proposed theory is not only accurate, but also effective in predicting the fundamental frequencies of laminated composite plates.

Niobium Pentoxide as an Acid Catalyst: An Overview

Ana Paula de Melo Guedes — 2024-10-27

The global chemical industry is under increasing pressure to adopt more sustainable practices, as most chemical products exceed environmental safety limits. Given that chemical production largely relies on catalytic processes, the development of solid acid catalysts has become crucial for more sustainable production. Among these catalysts, niobium pentoxide stands out due to its strong acid sites, which remain active in the presence of water, and its stability under hydrothermal conditions. Recent studies have demonstrated that these solids maintain their catalytic activity even in the presence of strong bases, making them unique catalysts. This review explores the potential of niobium pentoxide as an acid catalyst, addressing advances in synthesis techniques, surface modifications, and combinations with other materials to enhance its catalytic performance in sustainable applications, such as biomass conversion and biofuel production, opening new pathways for the production of greener chemicals. Finally, the future perspectives of niobium pentoxide - based catalysts in green chemistry are discussed.

Evaluation of Evaporative Cooling and Mechanical/Natural Ventilation strategies for the design of air conditioning systems for classrooms, considering different climate change scenarios for Viçosa (MG)

Anderson Ferreira Barros — 2024-07-07

The design of air conditioning and ventilation systems aims to achieve thermal comfort and Indoor Air Quality (IAQ) with energy efficiency. Thermal comfort directly influences people's concentration and productivity indoors. In schools and universities, environments with densely occupied classrooms, this factor becomes important in the performance of academic activities. In these environments, it is important to maintain indoor temperatures and humidity within ranges that provide thermal comfort, and to promote air renewal in order to guarantee Indoor Air Quality. Considering the scenarios of climate change and global warming, with the tendency for average temperatures to rise and the growing need to save energy, promoting thermal comfort in these environments is becoming more challenging. In this context, this work analyzed how Evaporative Cooling (EC) and Mechanical/Natural Ventilation (MVN) techniques could be used as strategies to promote thermal comfort in a classroom in the city of Viçosa (MG). Based on a survey of the room's hourly thermal load, the capacities of EC and MVN systems to maintain the room's temperature between 22 and 35 ^oC for two relative humidity ranges, between 40% and 60%, and between 40% and 80%, were analyzed. The analysis was carried out for nine climate scenarios, one for today, four for 2050 and four for 2080. All future scenarios considered global warming at different levels. The results showed that EC, based on different climate scenario models, for the present and projected for the future, was able to keep the internal temperature of the room below 27 ^oC for the current climate scenario and below 31 ^oC for the most pessimistic climate scenario for 2050, in all situations keeping the internal relative humidity below 80%.