bluuebunny/crossref_metadata_2025 huggingface dataset:
An Optimization Study on the Marketing of Outfit Short Video Content - Taking Xiaohongshu as an Example
Authors: He Dan Dan , Shia An-Shin , Bao Jie
Published: January 2025

Numerous short video platforms have emerged amidst contemporary digital trends, among which Xiaohongshu (XHS) stands out as a social e-commerce platform primarily focused on lifestyle sharing. The outfit-related short video content on XHS has garnered extensive attention and popularity among users. This study aims to analyze the marketing of XHS’s outfit short videos from the perspective of users, based on the five dimensions of the AISAS model: Attention, Interest, Search, Action, and Share. It delves into aspects such as user behavior and content characteristics. A total of 332 questionnaires were distributed through various online platforms, of which 10 were invalid, leaving 322 valid questionnaires, resulting in an effective response rate of 96%. The findings propose five optimization suggestions: implementing a personalized recommendation mechanism, enhancing product storytelling, focusing on user interaction and participation, collaborating with shopping apps, and providing authentic and effective product evaluations. These recommendations hold significant guidance for content creators and brand merchants of outfit short videos on the XHS platform and also offer insights for the marketing optimization of social media and short video platforms.
Concept Analysis of Adaptive Learning Strategy in English Language Teaching (ALS-ELT)
Authors: Mark N. Saldivar, John , Bernadeth L. Fernandez,
Published: January 2025

Adaptive Learning Strategies (ALS) are revolutionary forces in the ever-changing educational landscape, where varied learning contexts and technological breakthroughs converge. This study aimed to acquire a nuanced understanding of the concept while providing empirical support and new information on the usefulness and effects of ALS on language learning outcomes.  Research articles from open-access databases such as Google Scholar, CrossRef, and OpenAlex published from 2019-2024 were carefully analyzed using Walker and Avant’s eight-step analysis. Keywords utilized were adaptive learning, knowledge translation, and English language teaching. The 17 research articles analyzed determined five attributes of adaptive learning pedagogy: enhanced motivation and involvement, personalization and customization, improvement in language proficiency and communication skills, support for autonomous and independent learning, and technological integration and innovation. Antecedents included five themes: learner needs and context, availability of technology and resources, teacher training and proficiency, administrability support and policy alignment, and student motivation and engagement. Consequences also generated five themes: personalized learning experiences, enhanced technological integration and innovative learning tools, effective implementation of ALS, institutional commitment to ALS adoption, active student participation, and improved learning outcomes. Adaptive learning strategy in English language teaching (ELT) effectively engages students by aligning content with their interests and providing relevant challenges, fostering active participation and motivation. Individualized learning paths and real-time feedback enhance learning outcomes, improving language proficiency and communication skills. The seamless incorporation of technology, such as language learning apps and AI-driven tools, enables personalized experiences and data-driven adaptation, promoting student autonomy and independence.
The COVID-19 Pandemic and its Impact on Consumers' Food Habits
Authors: Damani Zamir , Topi Dritan
Published: January 2025

In January 2020, starting as a flu outbreak in China, COVID-19 was soon declared a pandemic, posing a significant threat to public health on a global scale. Albania experienced the initial impacts at the beginning of March 2020, resulting in the first confirmed cases and subsequent governmental measures that affected the entire population. The government implemented a lockdown, necessitating the cessation of operations for all schools and universities due to transportation restrictions and isolation protocols designed to mitigate the spread of the virus. During the first wave of the Pandemic, Albania distinguished itself as one of the countries that effectively managed the crisis. Social distancing measures considerably affected the coordination system, leading to challenges in food supply for families, particularly in urban areas—disruptions within the agri-food supply chain complicated food distribution to markets in sufficient quantities to meet consumer demands. Throughout 2020 and subsequent years, developed countries adopted an online and offline commerce model, deviating from practices established before the COVID-19 pandemic. Food catering services experienced significant growth during the lockdown compared to the pre-pandemic period. These services flourished by implementing various preventive and control measures calibrated to the scale of the COVID-19 pandemic. In Tirana, the capital city, stringent measures impeded both market and governmental efforts to ensure food supply for residents. The unplanned participation of various entities in online food trading facilitated the resolution of this issue. This period proved to be a pivotal opportunity for individuals globally to conceive future solutions.
The Importance of In-group Favoritism in Explaining Voting for PRRPs: A Study of Minority and Majority Groups in France, Germany and the Netherlands
Authors:   Oxford University, van Oosten Sanne
Published: January 2025

The voting behavior of racial and ethnic minorities is a topic that attracts much speculation, with some claiming that racial and ethnic minorities do vote for Populist Radical Right Parties (PRRPs) and some claiming they do not. In the European Union, where saving data on individual’s race and ethnicity is prohibited, it is very difficult to contribute to these conversations with real facts. Do ethnic minorities and majorities tend to vote for PRRP and what explains their (lack of) support? Thanks to a novel yet costly sampling method, I surveyed racial/ethnic minority and majority voters in France, Germany and the Netherlands and asked them about their propensity to vote for Rassemblement National (RN) in France, Alternative für Deutschland (AfD) in Germany, and Partij voor de Vrijheid (PVV) in the Netherlands. I compare racial/ethnic minority groups, including Muslims, with majority groups and test the mechanisms that might predict their support for PRRPs. My findings indicate Muslims are among the least likely to vote for PRRPs, though the difference with voters without a migration background is only significant in the Netherlands. When testing what explains the propensity to vote for PRRPs, I find that indicators of in-group favoritism usually explain support to larger extent than out-group hate. Though anti-immigration attitudes predict PRRP voting in all three countries, in-group favoritism explanations explain PRRP voting to a slightly stronger extent. In France and Germany, the ethnocentrism scale predicts voting for RN/AfD more than immigration attitudes do. In the Netherlands, feeling accepted as belonging in the Netherlands explains voting for the PVV the most. Amongst Muslim French, German and Dutch voters, in-group favoritism, or the lack thereof, explains voting for PRRPs as well. French Muslims who feel more attached to France are more likely to vote for RN. German Muslims who do not believe in religious freedom for Muslims are more likely to vote for AfD. This also applies to Dutch Muslims, though immigration attitudes also predict voting for the PVV: the more a Dutch Muslim is against immigration, the more likely they are to vote PVV. Generally, this study makes a case for expanding the standard predictors of PRRP voting towards more indicators of in-group favoritism for the majority in-group, while for Muslims PRRP voting is more driven by policy attitudes. Feeling close or distant towards ethnic in- or out-groups does not predict PRRP voting in any of the cases. These findings contribute to our understanding of PRRP voting in Europe.

Keywords: Populism, Muslims, race, ethnicity, voting behavior, France, Germany, Netherlands, RN, AfD, PVV.
Low Lice Prevalence in On-Cage Laying Hen Free of Treatment, Under Sub-humid Tropical Condition
Authors: González-Alvarez V. H. , Bracamontes-Guzmán L. A. , Herrera-Pérez J. , Martínez-Aispuro J. A. , Ayala-Monter M. A.
Published: January 2025

Egg production, in response to animal welfare concerns has shifted towards the use of open environments and there has been increasing interest in egg production systems with access to pasture. However, ectoparasite infestation is one of the main health problems affecting poultry. The objective of this research was to determine the prevalence of ectoparasite species (lice) in cage-free ISA Brown laying hens in a tropical sub-humid environment. Ninety hens of 45 weeks of age and an average weight of 1,850 g were inspected, of which 44 were found to be positive for a prevalence of about 50%. According to the taxonomic keys used, the specimens were identified as the louse Menacanthus stramineus. A low prevalence of lice in free of cage hens without ectoparasiticide treatment, was observed. Future studies are suggested to compare prevalences in other production units, as well as to evaluate possible clinicopathological conditions and their repercussions on the productive performance of the birds.
Rekal Remineralizer as an Alternative to Potassium Fertilization in Soybean Cultivation
Authors: Brasil Eliana Paula Fernandes , Leandro Wilson Mozena , Couto Charlismila Amorim do , Teles Thiago Augusto Sampaio , Costa Adriana Rodolfo da , Castro João Paulo Vilela , Araújo Isadora de Lima , Aguiar Junior Célio Gomes de
Published: January 2025

The agricultural sector seeks regional solutions to reduce environmental impact and to develop practices that consider the assumptions of the circular bioeconomy, in addition, to meeting the objectives set out in the 2030 agenda of the United Nations. In this context, Brazil leads research with soil remineralizers to contribute to regenerative agriculture and to have greater sovereignty in the use of natural inputs. This study aimed to evaluate the efficiency of the remineralizer of Rekal soils in soybean commercial areas in the State of Goiás, verifying the availability and mobility of potassium in soils compared to using soluble source (KCl). The methodology adopted was the application of doses of a Rekal remineralizer in four commercial areas in the municipalities of Santa Rita do Novo Destino/GO, Mimoso de Goiás/GO, and Niquelândia/GO, in rainfed and irrigated systems. The experimental design was the same for all experimental fields, randomized blocks made with four experimental treatments and four replications. The treatments were constituted of the farm standard using KCl (potassium chloride), as the only supplier of K2O demand, and three different doses of a Rekal remineralizer of soils. The parameters evaluated were the determination of the residual potassium content in the soil at three depths (0 to 10 cm, 0 to 20 cm, and 20 to 40 cm); determination of potassium leaf concentrations; determination of potassium concentrations in the grains; yield and weight of one thousand grains (PMG). The remineralizer of Rekal soils did not show significant differences, compared to the use of KCl (potassium chloride), in the variables of potassium content (soil, leaf, and grain) productivity and PMG in different productive environments in a commercial study of soybean cultivation in the Cerrado Goiano.
Analisis Regresi Berganda pada Faktor - Faktor yang Mempengaruhi Burnout Syndrome pada Perawat Jiwa di Yogyakarta
Authors: Mulyanti Mulyanti , Abdilah Yanuar Lutfhi , Fadilah Tania Yan , Prananda Laura , Oktaviani Vegy , Ediyono Suryo
Published: January 2025

Jumlah perawat jiwa di Indonesia masih sedikit dan tidak seb&ing dengan peningkatan terjadinya gangguan jiwa yang saat ini terjadi di masyarakat. Tanggung jawab dalam memberikan asuhan keperawatan serta adanya tuntutan pekerjaan dapat menjadi stressor sehingga akan menyebabkan terjadinya kejenuhan (burnout syndrome). Penelitian ini bertujuan untuk menganalisis penyebab terjadinya burnout syndrome pada perawat jiwa. Penelitian ini deskriptif korelatif dengan pendekatan crossectional. Sebanyak 109 perawat jiwa menjadi sampel penelitian. Adapun teknik sampling yang digunakan adalah purposive sampling. Pengambilan data menggunakan kuesioner. Metode analisis data yang digunakan regresi linear berganda. Hasil penelitian didapatkan karakteristik responden penelitian, 35–45 tahun, perempuan, sudah menikah, berpendidikan D3 Keperawatan, masa kerja lebih dari 15 tahun, spiritual well being dalam kategori sedang, beban kerja sedang, dukungan keluarga baik, burnout syndrome kategori rendah. Berdasarkan hasil penelitian didapatkan persamaan regresi yaitu Y = 60,668 – 0,477X1 + 0,75X2 – 0,345X3 – 0,539X4 – 0,188X5 + e. Pada hasil pengujian asumsi klasik didapatkan data terdistribusi normal, data linear, tidak ada gejala multikolinearitas dan autokorelasi. Urutan variabel yang paling berpengaruh adalah dukungan sosial (-0,539), masa kerja (0,477), beban kerja (-0,345), dukungan keluarga (-0,188), spiritual well being (0,75). Nilai koefisien determinasi sebesar 0,146 yang artinya variabel independent mampu menjelaskan variabel dependent sejumlah 14,6%, sedangkan 85,4% dipengaruhi oleh faktor lain.
Motivasi dan Kepuasan Kerja Tenaga Kesehatan di Puskesmas Padang Bulan Kota Medan
Authors: Hasibuan Indah Doanita , Harahap Jesi Wanda , Rahmawati Nurul , Hasibuan Ira Sri Mawarni , Laoli Ananda Nurmairani
Published: January 2025

Motivasi karyawan dan kepuasan kerja merupakan aspek penting dalam pengelolaan sumber daya manusia. Para profesional layanan kesehatan harus melakukan yang terbaik sebagai pemimpin layanan kesehatan. Oleh karena itu, sangat penting untuk memenuhi kebutuhan tenaga kesehatan dan memastikan kepuasan terhadap pekerjaannya. Tujuan penelitian ini adalah untuk menganalisis motivasi dan kepuasan kerja tenaga medis di Puskesmas Padang Bulan serta mengidentifikasi faktor utama penyebab motivasi dan ketidakpuasan karyawan. Penelitian ini memakai metode pendekatan kualitatif deskriptif dikarenakan tujuan penelitian ini merupakan untuk mendeskripsikan ataupun mendapatkan data ataupun informasi. Penelitian ini menggunakan teknik purposive, untuk memperoleh data yang diperlukan, maka teknik yang digunakan dalam penelitian ini menggunakan observasi dan wawancara mendalam. Berdasarkan dari hasil dan pembahasan penelitian motivasi karyawan berada dalam kondisi baik, hal ini disebabkan faktor- faktor yang menjadi motivasi kerja terkait gaji yang sesuai, lingkungan, dan fasilitas yang sudah terpenuhi sehingga meningkatkan motivasi kinerja karyawan di puskesmas Padang Bulan. Sedangkan kepuasan kerja karyawan terdapat pengaruh positif dan signifikan yang disebabkan adanya rasa keharmonisan terhadap sesama karyawan, adanya pengawasan serta adanya peluang kemajuan bagi karyawan yang berkinerja tinggi. Faktor terpenting memotivasi petugas layanan kesehatan adalah kepuasan kebutuhan mereka akan gaji yang memadai, lingkungan kerja yang memadai, dan kondisi kerja yang memadai. Faktor-faktor yang berhubungan dengan kepuasan kerja antara lain hubungan kerja yang harmonis antara karyawan dan timnya, pengawasan yang suportif dan konstruktif dari atasan, serta peluang kemajuan bagi karyawan yang berkinerja tinggi.
Hubungan Tingkat Pengetahuan Umum dengan Pencegahan Luka Diabetik pada Penderita Diabetes Melitus
Authors: Amelya Ferdiana , Sudaryanto Agus
Published: January 2025

Diabetes melitus merupakan penyakit kronis yang ditandai dengan kadar gula darah di atas normal. International Diabetic Federation (IDF) menyatakan Indonesia menjadi negara yang masuk dalam 5 besar dengan penderita diabetes terbesar, rata-rata usia yang menderita penyakit terebut antara 20-79 tahun. Kurangnya pendidikan kesehatan dan pengetahuan tentang perilaku yang dapat mencegah terjadinya diabetes menjadi salah satu penyebab tingginya penderita diabetes di Indonesia. Penelitian ini bertujuan untuk mengetahui hubungan tingkat pengetahuan dengan perilaku pencegahan luka diabetik pada pasien diabetes melitus. Penelitian ini menggunakan metode Literature Review dengan mengambil beberapa artikel menggunakan media online seperti PubMed, Google Schoolar, dan Science Direct, serta metode dalam seleksi artikel berdasar PRISMA. Proses penyortiran menggunakan metode “boolean searching” dengan penambahan kata AND atau OR. Proses pencarian dan seleksi artikel dalam bahasa Indonesia atau bahasa Inggris sehingga didapatkan 5 artikel sebagai bahan dalam studi ini dengan 6 tahun (2019-2024) sebagai batasan waktu publikasi. Berdasarkan review, hasil yang didapatkan dari 5 artikel disebutkan bahwa terdapat hubungan antara tingkat pengetahuan dan pendidikan kesehatan dengan perilaku pencegahan terjadinya luka diabetik. Pengetahuan seseorang mempunyai pengaruh yang besar terhadap perilakunya, sehingga penyakit dan potensi komplikasinya dapat dicegah atau dihindari.
Predicting Schistosoma Haematobium Risk Distribution in Zambia Using Geographic Information System (GIS) and Remote Sensing (RS) Technologies
Authors: Chimfwembe Kingford , Mutesu Lillian Mambwe
Published: January 2025

Introduction: This study explores the spatial distribution and climatic influences on schistosomiasis in Zambia using remote-sensed data, specifically focusing on the Normalized Difference Vegetation Index (NDVI) and maximum temperature (Tmax).
Material and Methods: By analysing prevalence data over a decade (2002-2012) and employing Geographic Information System (GIS) and Remote Sensing (RS) technologies, we identified regions conducive to the transmission of the disease.
Results: The findings revealed significant variability in schistosomiasis prevalence across Zambia. Climatic cut-offs for schistosomiasis transmission were established, highlighting NDVI values between 134 - 153 and Tmax ranges of 19.4 – 27.6°C as optimal for sustaining transmission.
Conclusion: The study underscores the pressing need for comprehensive control strategies that extend beyond school-based treatments, addressing the broader community and targeting at-risk populations. Furthermore, the established climatic cut-offs provide a framework for future research and public health initiatives aimed at reducing the burden of schistosomiasis in Zambia. This work emphasizes the intricate relationship between climate, health interventions, and disease dynamics, calling for adaptive strategies in the face of climate change.
Application of Nonlinear Optimization in Flight Path Reconstruction of a Sub-scale Aircraft
Authors: Clecio Fischer  , Luiz Carlos Sandoval Góes  , Éder Alves de Moura  , Vítor Paixão Fernandes  , Leonardo Murilo Nepomuceno  , Roberto Gil Annes da Silva
Published: January 2025

One key challenge in working with free-flight test data is ensuring its compatibility with the dynamic systems of sub-scale unmanned aircraft. This is crucial to avoid errors in measurements, bias, or scaling issues that could compromise the integrity of the estimated results. We refer to this initial processing step as data compatibility checking, a rigorous process that forms the foundation of our research.Typically, this verification process involves flight path data reconstruction (FPR) predicated on estimating the aircrafts flight kinematics. The predominant methodologies encompass the stochastic approach, the Extended Kalman Filter (EKF), and the deterministic approach, employing the Output Error Method (OEM). In this research, we propose to approach the problem from the perspective of a nonlinear optimizer to estimate the reconstruction of data derived from free-flight tests of a sub-scale aircraft.The nonlinear optimizer we employ in this research was designed to verify the authenticity of the data representing the aircraft's actual flight. It does this by comparing the measurements of attitude angles, accelerations, and velocities with the expected kinematic behavior of the aircraft. This rigorous evaluation process ensures that the reconstructed data is as close to the actual flight as possible, enhancing the reliability of our results.The sub-scale model deployed in these tests was engineered to emulate the dynamic characteristics of a full-scale aircraft, utilizing the Froude number criterion for appropriate scaling. The chosen aircraft for this project was a Cessna 177B, and the sub-scale aircraft was developed by the Aeronautical Systems Laboratory (LSA) at the Aeronautics Institute of Technology (ITA).This study will delineate the outcomes achieved through FPA employing OEM techniques and compare these results with the studies derived from the proposed nonlinear estimation method.
Data-Driven Modeling of Cold-Formed Steel Bolted Angle Connections under Axial Tension using Artificial Neural Networks
Authors: Ruan de Alencar Carvalho  , Francisco Evangelista Junior
Published: January 2025

Given that steel is one of the main structural materials in civil engineering, it is important to understand its mechanical properties and failure mechanisms. L-shaped laminated steel elements, known as angles, are commonly bolted to other metal elements to make connections in steel structures. When these elements are connected by only one of its legs and are subjected to axial tension, the failure of the angle can be caused by rupture of the section where the holes are located. In this case, there is influence of complex phenomena such as shear lag, therefore a reduction factor is applied to the resistance of the section. The general theme of this work is the use of Artificial Neural Networks (ANN) as an approach to the study of the load capacity of cold-formed steel bolted angles connected by one leg and under axial tension. Although this class of techniques do not provide a simple regression equation, they are powerful tools in Machine Learning (ML), having the ability to model any arbitrarily complex nonlinear problem. In this work, a dataset is built with samples from different numerical and experimental works, collecting steel angles geometric parameters, tensile strength of the material and ultimate capacity regarding net section failure. The data-driven models are trained with 80% of the data, tested with 20%, validated with 5-fold cross-validation and their hyperparameters are tuned with Bayesian Optimization. Feature generation, selection, and importance algorithms are implemented, hoping to achieve more accurate, less complex and more interpretable models. ML models predictions are compared with the ones given by the equations of Eurocode-3, Brazilian NBR 14762, American Iron and Steel Institute (AISI) and Australasian AS/NZS Standards. The comparison shows mostly superior results in the ANN models, proving the competitiveness and effectiveness of Machine Learning techniques and data-driven modeling.
A low-cost space-time finite element for free-surface flows under total Lagrangian description
Authors: Darcy Hannah Falcão Rangel Moreira  , Rodolfo André Kuche Sanches
Published: January 2025

In this work, we propose a position-based space-time finite element formulation for incompressible Newtonian flows under a total Lagrangian description. This formulation is suggested within the context of finite strain free-surface flows and differs from the traditional finite element approach for fluid dynamics by utilizing current nodal positions as the main variables instead of nodal velocities. In contrast to time-marching methods, space-time formulations involve applying the finite element technique not only to the spatial domain but also to the temporal domain. The proposed approach employs a finite element discretization that can be unstructured or structured in space, but is always structured in time. Thus, the space-time shape functions are expressed as a tensor product of linear shape functions in the spatial direction and specially designed quadratic shape functions in the temporal direction. Consequently, the space-time domain is divided into time slabs that are solved progressively, with the final velocities and positions from the previous time slab serving as initial conditions for the current one, thereby reducing the dimension of the discrete system of equations. The proposed shape functions in the temporal direction yield a system of equations of the same size as standard time-marching methods, but with advantages stemming from the space-time discretization: different stability and high-frequency dissipation can be achieved based on the selection of the time test functions. To solve the incompressible problem stably, we employ mixed equal-order position-pressure finite elements with Petrov-Galerkin/pressure stabilization (PSPG). This formulation possesses several significant features that justify its development: 1) the space-time formulation facilitates dynamic re-meshing by permitting the spatial discretization at the end of one time slab to differ entirely from the spatial discretization at its beginning, thus extending its applicability to flows with undefined distortion and topological changes; 2) by considering positions as variational parameters, it becomes straightforward to couple with Lagrangian hyper-elastic solid solvers, which may also be formulated in terms of positions or displacements in a monolithic way. Numerical examples conducted to validate the formulation demonstrate its robustness and efficiency for finite strain free surface flows, including phenomena such as dam breaks with smooth surfaces and sloshing.
Airfoil lift finite element computations using H1 (Ω) and H(div,Ω) approximation spaces
Authors: Sérgio Gustavo Ferreira Cordeiro  , Carlos Henrique Chama Puga  , Giovane Avancini  , Francisco Teixeira Orlandini  , Nathan Shauer  , Philippe Remy Bernard Devloo
Published: January 2025

Computing the lift generated by an airfoil is crucial in aircraft design, especially for aircraft performance prediction, aircraft stability/control, and optimization of airfoil shape for improving efficiency. The problem of incompressible flow around an airfoil is studied herein as a weakly irrotational flow, resulting a div-curl problem in a 2D double-connected domain. The original div-curl problem is ill-posed because it is defined over a multiply-connected domain. Traditionally, a cut in the original domain and additional constrain for the velocity potential and velocity potential gradient at the cut are required for the numerical solution, which applies a rotational correction method based on Helmholtz decomposition of vector fields. The lift coefficient can be finally computed from the numerical solution of the problem. In the present work, the lift of an airfoil is computed from finite element solutions using different approximation spaces: The conventional H1 (Ω) potential-field space and a special class of H(div,Ω) velocity-field space, i.e., the divergence-free space. Accurate analysis using both approximations is performed with h-refinement strategies. The lift coefficient computed from the analysis is compared against available reference solutions. The computational performance and accuracy of the lift computation using the two different approaches are discussed. Finally, the difference in the velocity solution obtained using H1 (Ω) and H(div,Ω) spaces is presented, which can be interpreted as a new posteriori error estimator for the problem.
Ck-Generalized FEM with enhanced consistency: application to the static linear elastic rod deformation problem
Authors: Diego Amadeu Furtado Torres
Published: January 2025

The Ck-Generalized Finite Element Method (Ck-GFEM) in its original version considers Partition of Unity (PoU) functions defined as Shepard ones, which delivers zeroth order consistency in the absence of uniform polynomial extrinsic enrichment of degree one, at least. Such a feature can make Ck-GFEM unfavorable against the conventional G/XFEM when comparing the degrees-of-freedom (dof) amount for a certain error level. This inconvenience can be overcome through intrinsic enrichment using the Moving Least Squares Method (MLSM), which allows the construction of PoU functions with enhanced polynomial reproducibility despite the cost of demanding the widening of the associated supports. In this context, the present work summarizes some results for the static rod deformation problem, for the linear elasticity, considering different classes of PoU functions and different extrinsic enrichment functions, through an approach that adjusts the k-order of continuity and the p-polynomial degree of the ansatz independently, for some kinds of loads distributions which leads to different classes of solutions.
Analysis of the fluid-structure interaction of a 2D model of the savonius rotor, using immersed boundary and fourier pseudospectral methods
Authors: Mylena Carvalho Silva  , Andreia Aoyagui Nascimento
Published: January 2025

Savonius rotors are a unique type of vertical axis wind turbine (VAWT) characterized by its S shape, with low rotational speed, low noise and good automatic start-up capability. This turbine has a great profile forsmall businesses and residences. The present work presents a simplified modeling of the fluid-structure interaction problem of a Savonius rotor, using the Fourier pseudospectral method (FPSM) coupled to the immersed bound-ary method (IBM), considering the Newtonian fluid, incompressible flow, without heat transfer and gravitational effects, with constant and two-dimensional (2D) properties. The results presented address the flow over a freely rotating vertical turbine, which allows the analysis of the evolution of the moment coefficient (Cm ) in relation to temporal evolution, azimuthal position (θ) and the blade tip speed ratio (λ).
Improving the energy efficiency of residential buildings in Brazil by changing the geometry of ceramic bricks
Authors: Ivo Almino Gondim  , Hipólito José Campos de Sousa  , Alexandre Araújo Bertini
Published: January 2025

The performance of a building's thermal and energy systems is greatly affected by its building envelope. In Brazil, residential buildings typically utilize masonry walls with coatings, and the materials used, such as the block models, have a significant impact on their energy efficiency. However, cost is a limiting factor when it comes to improving performance. One way to modify thermal properties without significantly increasing manufacturing inputs is to explore new geometries of ceramic blocks. This study introduces a new ceramic block geometry for structural masonry, adapted from a commonly used 14cm thick commercial model in Brazil. The thermal properties of this new model are evaluated numerically using Abaqus software. Additionally, the study presents the findings of an energy simulation conducted on housing models in cities like Fortaleza, Brasília, and Curitiba using Energyplus software. The results show potential for reducing energy consumption in colder months while having a minimal impact on energy consumption in hotter climates, while still maintaining a comfortable temperature.
Study of the Influence of Buildings on the Performance of Micro Wind Turbines in Urban Environments through Computational Simulations
Authors: Andreia Aoyagui Nascimento  , ANA CAROLINA FINOTTI AZEREDO
Published: January 2025

In urban areas, where space is limited, micro wind turbines can be installed on rooftops or structures near buildings. Studying the flow around cylinders near a flat wall is important for understanding how the presence of buildings affects the performance of these micro wind turbines and how they can be optimized to operate in urban environments. This study employs the Pseudospectral Fourier method coupled with the Immersed Boundary method in simulations involving flow around a circular-based cylinder near a wall. This work presents simulations that demonstrate the influence of local Reynolds number with the introduction of a wall, as well as the influence of varying the distance between the cylinder and the wall, referred to as "GAP," on the formation of the vortex wake. The results are compared with other works: experimental and numerical.
Using Computational Fluid Dynamics to investigate heat exchanges between the environment and photovoltaic panels
Authors: Thauã Albert da Graça Santos  , Nuccia Carla Arruda de Sousa
Published: January 2025

Given the increasing demand for energy sources with lower environmental impact, solar panels play an important role in diversifying energy sources and in the process of decarbonizing the electrical grid. Their electricity production is based on the photovoltaic effect; however, only a portion of the energy from solar radiation is utilized, with the rest being reflected or transferred to the environment in the form of heat, increasing the temperature of the panel and causing an energy efficiency loss, since the performance of the panels is influenced by the operating temperature.Therefore, our study aims to investigate the heat exchanges by natural convection that occur between solar panels and the surroundings, disregarding radiation. The analysis was conducted using Computational Fluid Dynamics with the OpenFOAM software, which employs the Finite Volume Method to discretize the governing equations. We sought to evaluate the effects of varying the inclination of the panel on the surrounding temperature.The CFD modeling consists of three stages: pre-processing, processing, and post-processing. In the pre-processing stage, the Gmsh software was used to create the computational domain, a simplified 2D model of 4 m x 4 m around the panel with a length of 2 m, a temperature of 80 °C, and presenting different inclinations. Then, the domain was discretized through the division into an unstructured mesh of finite volumes with progressive refinement near the panel.Wall conditions were assigned for the ground and the panel, and free flow conditions for the surroundings. The fluid was defined as air, with dynamic viscosity of 1.849 × 10^-5 kg/m∙s, specific heat at constant pressure of 1000 J/kg∙K, Prandtl number of 0.7296, and temperature of 25°C. In the processing stage, the transient state solver, buoyantPimpleFoam, was used for transient and turbulent flows of compressible fluids for heat transfer, including the K-epsilon turbulence model.In the post-processing stage, the Paraview software was used to map temperature and velocity fields. The results show the formation of air flows and the gradual propagation of temperature to the environment from the panel through thermal plumes. The increase in the panel's inclination contributed to raising the average temperature of the surroundings. The natural convection from the panel caused the formation of air flows due to the buoyancy effects that occur with the variation of the fluid's density.
Cost and CO2 emission optimization of steel-concrete composite floor systems with composite tubular trusses
Authors: Chayana Morgner Gomes da Silva  , Luciano Dal Secco Silveira Amorim  , Adenílcia Fernanda Grobério Calenzani  , Élcio Cassimiro Alves
Published: January 2025

The objective of this study is to propose a formulation for the topological and dimensional optimization of composite floor systems, which comprise composite trusses, while considering both the costs and environmental impacts generated due to the consumption of materials from this structural system. To address this optimization problem, the Bonobo algorithm (BO) will be employed. For the structural analysis, the bar element was implemented with 2 nodes and 3 degrees of freedom per node to obtain displacements and efforts arising from the application of the vertical actions considered (dead and live load). Structural verification will adhere to the guidelines outlined in Brazilian standards for tubular structures, steel structures and composite steel and concrete structures. The models studied address examples from the literature in order to verify and compare solutions from an economic and environmental perspectives, identifying which factors impact the final solutions found.
Optimal Design of Prestressed Steel and Concrete Composite Beams
Authors: Elcio Cassimiro Cassimiro  , Lucas Augusto Soares Chamoun  , Abner Endrye Pimentel de Almeida  , Lorenzo Augusto Ruschi e Luchi
Published: January 2025

The application of prestressing techniques is typically associated with concrete structures and has been relatively underexplored in the context of concrete-steel composite beams. The objective of this study is to propose a formulation for the optimal design of prestressed steel and concrete composite beams. The objective function will analyze the costs and final CO2 emissions of the beam. As constraints, the guidelines outlined in NBR 8800:2008 for steel structures and NBR 6118:2021 for prestressing in concrete structures will be adhered to. To solve the optimization problem, the Ant Colony Algorithm (ACO) will be employed. Additionally, a parametric analysis will be conducted and compared with examples proposed in the literature, aiming to identify the key factors that impact the final solution.
Time domain analysis of a pultruded composite cooling tower under dynamic wind loads
Authors: João Paulo Dias de Souto Pereira  , Eliane Maria Lopes Carvalho  , Janine Domingos Vieira
Published: January 2025

Pultruded glass fiber reinforced polymer (pGFRP) profiles have been used in cooling tower frame structures for decades. Its advantageous properties such as high strength-to-mass ratio and corrosion resistance make it well-suited for the highly humid environment of cooling towers. On the other hand, pGFRP also has a relatively low modulus of elasticity, about 10% that of steel, which makes the structures more flexible. This results in low natural frequencies and brings the risk of resonance to dynamic loads such as wind fluctuation. The present study assesses the response of a pGFRP cooling tower under dynamic wind loads. A finite element (FE) model of the structure was developed to obtain its modal properties and assess the structure’s dynamic response. A spectral representation method was implemented in Python to generate artificial wind fluctuation time series, which were input into the FE model to produce the fluctuating component of the wind drag force. The results show that, despite the flexibility, the structure satisfies the serviceability limit states and can be safely exposed to dynamic wind loads, benefitting from the material’s favorable properties.
Numerical modeling for the structural analysis of the unbuilt Praça Maior design by Oscar Niemeyer for the University of Brasília
Authors: Leonardo da Silveira Pirillo Inojosa  , Márcio Augusto Roma Buzar
Published: January 2025

Many established architectural works follow the structural component as a guiding parameter of the project. The architectural works of Oscar Niemeyer are renowned for their seamless integration of structure and design  "once the structure is finished, architecture is already present, simple and beautiful" (NIEMEYER, 2002). The structural elements are deliberately showcased, adding to the overall aesthetic of the building. Niemeyer was responsible for Brasilia's most significant public buildings, including the National Congress, the Metropolitan Cathedral, and the Planalto Palace. However, there are numerous unrealized projects, preserved in history through sketches and even detailed plans. One such project is 1962 Niemeyer's design for the Main Square of the University of Brasilia, which featured a distinguished architectural complex composed of four blocks - Auditorium, Museum, Library, and Rectory. In this article, we explore the relationship between structures and architectural engineering by modeling structural systems and conducting numerical analysis using the software SAP2000. The main objective of this investigation is to determine how the structural system played a key role in the architectural conception of Oscar Niemeyer for this iconic project. The study aims to offer an analysis of the relationship between form and function, with a focus on how the structural elements of the project influenced its overall design and aesthetic result.
Dynamic Analysis of Slender Buildings under Wind Loading
Authors: Rafael Mundim Dias Pequeno  , Leandro Lopes da Silva  , Jeferson Wilian Dossa Fernandes
Published: January 2025

This dissertation project aims to understand and compare methods that simulate the dynamic characteristics of atmospheric wind loads acting on slender structures, with a focus on NBR 6123 and the Synthetic Wind Method. The amount of research conducted on this topic since the 1960s has led to significant advancements in understanding the dynamic behavior of wind. This progress has facilitated the development of methodologies for quantifying its impact on buildings and the continuous refinement of these methodologies up to the present day. In this context, it is possible to encounter two key approaches: NBR 6123 (2023), developed by the Brazilian Association of Technical Standards, and the Synthetic Wind Method, initially proposed by Franco (1993). The Brazilian standard provides two methods to determine maximum values of variables such as acceleration, displacement, and forces for structures subjected to wind, without describing how these values vary over time. Despite advances in wind engineering studies and methodologies, the procedure described in the 1988 version of the standard remained unchanged in its 2023 update. On the other hand, the Synthetic Wind Method, first published in 1993 and subsequently refined until 2014, works by decomposing the fluctuating component of wind into harmonic functions. This approach not only allows to obtain absolute maximum values but also provides the structural response over time. To address this, a comparative study is planned between NBR 6123 (2023) and the most updated version of the Synthetic Wind Method. Additional relevant methods may also be included in the analysis to identify the limitations, advantages, and disadvantages of each approach.
A permutation algorithm for stacking sequence optimization of composite laminates
Authors: Renata de Araujo Braga  , Elias Saraiva Barroso
Published: January 2025

Structures made of fiber-reinforced composite material are used in many industries, such as automotive, naval, aeronautical, and construction civil. Laminated structures are produced by thin layers of composite material, such as carbon fiber-reinforced laminates, which have high strength and stiffness. These composites are stacked in different orientations in order to provide superior mechanical properties compared to other conventional structures. Due to the number of variables, the conventional design methodology based on trial and error is not attractive, and it is advantageous to use optimization techniques. When designing laminated structures, strength, stiffness, and performance constraints must be satisfied. Using optimization techniques, it is possible to find an optimal lamination scheme that meets the established prerequisites. In this type of structure, the arrangement of the layers and the orientation of the fibers can have a significant impact on the final performance of the structure. The permutation problem in optimization refers to determining the most effective sequence of layers and fiber orientations that meets the design requirements. This work proposes the implementation of a heuristic optimization technique based on design variable permutation. In this specific combinatorial optimization problem, the quantity of layers of each type (i.e. orientation) is known a prior, and the optimal arrangement of these layers is to be evaluated. The algorithm is implemented in Octave language and is demonstrated in optimization of laminated plates.
Arc-shaped elements in 2D program of frames subjected to thermal loading
Authors: Letícia Amorim Melo  , Fernanda Gabriella Batista Santos Oliveira  , Luis Fernando Sampaio Soares
Published: January 2025

This research deals with the creation of a 2D frame program that includes circumferential and parabolical arc-shaped elements subjected to thermal loading. It was based on the Finite Element Method and written in Fortran. The elements have two nodes each and three degrees of freedom per node (both in-plane translations and out-of-plane rotation). The matrices were derived using Virtual Work and some integrals demanded a numerical approximation, where a Gaussian Quadrature approach was employed. The algorithm was checked against results found in books and papers, usual software where curves need to be approximated using a great number of straight elements, and structures designed and solved by the authors using traditional methods. The results for rotations, displacements, reactions, bending, normal and shear forces are seen to be very precise at a less demanding input data in comparison to others programs.
Development of a finite element program for acoustics
Authors: Daniele Kempner Schultz  , Eduardo Lenz Cardoso
Published: January 2025

Acoustic is the study of mechanical waves in solids, liquid and gases. Altougth the differential equations describing these problems are well known, with analytical solutions for simple geometries and/or loads, there are no closed solution for general problems. Thus, it is common to sougth on numerical procedures to address such problems.This work addresses the simulation of mechanical waves in loseless air using the linear finite element method. Solution in both time and frequency domains are discussed and compared to theoretical results.
Matrix structural analysis of beams on elastic supports: implementation in Python
Authors: Maysa Arouche Ribeiro Curvelo  , Felipe Alexander Vargas Bazán  , Jesaías Santos Silva  , Paulo César de Oliveira Queiroz  , George Fernandes Azevedo
Published: January 2025

Technological resources have made it possible to model natural phenomena and engineering problems more accurately, thus allowing better results. This article presents the computational implementation of a procedure for matrix structural analysis of beams. Both rigid and elastic supports were considered to represent the contact between the structural model and the external environment. A computational code was created in Python language. The matrix method allows a detailed analysis of the structural response. The developed code calculates stiffness matrices and force vectors of beam elements, which are assembled into a global stiffness matrix and a global force vector, and the equilibrium equation system is then solved. Results such as nodal displacements and slopes, support reactions, and internal forces are obtained. Different support conditions, namely fixed, hinged, and elastic supports, as well as different loading conditions, were investigated for beams. Results highlight that the presence of elastic supports can significantly affect the overall structural behavior of the system. By incorporating these effects into the analysis, more accurate predictions of structural response can be obtained, leading to safer and more economical solutions. The article provides a basis for further investigation of the behavior of complex structural systems. The use of Python language can be justified as it provides a versatile and efficient platform for conducting structural analysis and is suitable for future advances in the field of structural engineering.