Otimização no tempo de análise de um veio de transmissão, por meio de uma aplicação online, para a correta tomada de decisões

Mestrado de dupla diplomação com a UTFPR - Universidade Tecnológica Federal do ParanáVeios são componentes essenciais na engenharia mecânica, usados em máquinas para sustentar outros elementos mecânicos e transmitir potência, como em aerogeradores, que ganham cada vez mais espaço ao redor do mundo na geração de energia de maneira renovável. Para evitar a falha por fadiga em tais componentes, é necessário verificar o fator de segurança e fazer a análise ainda na fase de projeto, pois falhas podem ter um efeito cascata e trazer danos a toda à estrutura em que está conectado, para um aerogerador, isso pode resultar em problemas em toda a caixa de engrenagens ou na própria nacele. Os cálculos referentes à fadiga, são repetitivos e ocupam demasiado tempo do engenheiro ou projetista responsável. Para isso, este trabalho pretende desenvolver uma aplicação web, utilizando o framework web Django, que com critérios de análise confiáveis possa diagnosticar o projeto de veios de seção transversal circular, maciços, dúcteis e de aço carbono, que estejam sob cargas fletoras e/ou torcionais. Assim, será possível para qualquer usuário com acesso à internet, identificar, ainda na fase de projeto, uma provável falha devido à fadiga, ou conferir se um veio atuante está ou não respeitando a faixa de segurança. Em seguida, será realizado um estudo de caso, no qual, uma seção crítica de um veio de alta velocidade de um aerogerador será analisado em consonância com o procedimento proposto, também será possível comparar a diferença de tempo investido para o cálculo manual e o automatizado pela aplicação. Além dos resultados particulares que oferecerá o trabalho, será possível identificar que a aplicação desenvolvida auxilia e deixa mais prática simulações com possíveis alterações na geometria ou material do veio analisado, facilitando a tomada de decisões, diminuindo os erros acidentais de projeto e otimizando o tempo envolvido no processo de análise de um veio em relação a sua resistência à fadiga.Shafts are essential components in mechanical engineering, used in machines to support other mechanical elements and transmit power, as in wind turbines, which are increasingly gaining more space around the world in renewable energy generation. To avoid fatigue failure in such components, is necessary to verify the safety factor and perform the analysis during the design phase, as failures can have a cascade effect and bring damage to the entire structure to which is connected, for a wind turbine this can result in problems for the gearbox or the nacelle itself. The calculations referring to fatigue are repetitive and cost too much time for the responsible engineer or designer. For that, this work intends to develop a web application, using the Django web framework, which with reliable analysis criteria can diagnose the design of circular cross-section, solid, ductile and carbon steel shafts, under bending and/or torsional loads. So, it will be possible for any user with internet access to identify, during the design phase, a probable failure due to fatigue or to verify whether an active shaft is in or out the respective safety range. Then, a case study will be carried out, in which a critical section of a high-speed wind turbine shaft will be analyzed in line with the proposed procedure, it will also be possible to compare the difference in time invested for manual calculation and the automated one, made by the application. In addition to the results that the work will offer, it will be possible to identify that the developed application assists and makes simulations with possible changes in the geometry or material of the analyzed shaft more practical, facilitating decision-making, reducing accidental design errors, and optimizing the time involved in the process of analyzing a shaft in relation to its resistance to fatigue

Forced Imbibition - a Tool for Determining Laplace Pressure, Drag Force and Slip Length in Capillary Filling Experiments

When a very thin capillary is inserted into a liquid, the liquid is sucked into it: this imbibition process is controlled by a balance of capillary and drag forces, which are hard to quantify experimentally, in particularly considering flow on the nanoscale. By computer experiments using a generic coarse-grained model, it is shown that an analysis of imbibition forced by a controllable external pressure quantifies relevant physical parameter such as the Laplace pressure, Darcy's permeability, effective pore radius, effective viscosity, dynamic contact angle and slip length of the fluid flowing into the pore. In determining all these parameters independently, the consistency of our analysis of such forced imbibition processes is demonstrated.Comment: 4 pages, 5 figure

Dynamics of the photoinduced insulator-to-metal transition in a nickelate film

The control of materials properties with light is a promising approach towards the realization of faster and smaller electronic devices. With phases that can be controlled via strain, pressure, chemical composition or dimensionality, nickelates are good candidates for the development of a new generation of high performance and low consumption devices. Here we analyze the photoinduced dynamics in a single crystalline NdNiO$_3$ film upon excitation across the electronic gap. Using time-resolved reflectivity and resonant x-ray diffraction, we show that the pump pulse induces an insulator-to-metal transition, accompanied by the melting of the charge order. Finally we compare our results to similar studies in manganites and show that the same model can be used to describe the dynamics in nickelates, hinting towards a unified description of these photoinduced phase transitions.Comment: 17 pages, 6 figure

Incidence of delayed and missed diagnoses in whole-body multidetector CT in patients with multiple injuries after trauma

Background: Whole-body CT (WBCT) is the imaging modality of choice during the initial diagnostic work-up of multiple injured patients in order to identify serious injuries and initiate adequate treatment immediately. However, delayed diagnosed or even missed injuries have been reported frequently ranging from 1.3% to 47%. Purpose: To highlight commonly missed lesions in WBCT of patients with multiple injuries. Material and Methods: A total of 375 patients (age 42.8 +/- 17.9 years, ISS 26.6 +/- 17.0) with a WBCT (head to symphysis) were included. The final CT report was compared with clinical and operation reports. Discrepant findings were recorded and grouped as relevant and non-relevant to further treatment. In both groups, an experienced trauma radiologist read the CT images retrospectively, whether these lesions were missed or truly not detectable. Results: In 336 patients (89.6%), all injuries in the regions examined were diagnosed correctly in the final reports of the initial CT. Forty-eight patients (12.8%) had injuries in regions of the body that were not included in the CT. Fourteen patients (3.7%) had injuries that did not require further treatment. Twenty-five patients (6.7%) had injuries that required further treatment. With secondary interpretation, 85.4% of all missed lesions could be diagnosed in retrospect from the primary CT data-set. Small pancreatic and bowel contusions were identified as truly non-detectable. Conclusion: In multiple traumas, only a few missed injuries in initial WBCT reading are clinically relevant. However, as the vast majority of these injuries are detectable, the radiologist has to be alert for commonly missed findings to avoid a delayed diagnosis

Kepler-424 b: A "lonely" hot Jupiter that found a companion

Peer reviewedFinal Accepted Versio

Magnetostratigraphy and paleomagnetic poles from Late Triassic-earliest Jurassic strata of the Newark basin: Discussion and reply

The Discussion of Lucas and others underscores the potential usefulness of magnetostratigraphy for correlation between red beds of the broadly coeval Chinle Group of the western interior and the Newark Supergroup of eastern North America. Detailed magnetostratigraphic correlation between the Newark and the Chinle is very likely to change significantly, however, with the addition of new data from both of these units, and hence such an attempt as proposed in the Discussion may be premature

Exploring Lip Segmentation Techniques in Computer Vision: A Comparative Analysis

Lip segmentation is crucial in computer vision, especially for lip reading. Despite extensive face segmentation research, lip segmentation has received limited attention. The aim of this study is to compare state-of-the-art lip segmentation models using a standardized setting and a publicly available dataset. Five techniques, namely EHANet, Mask2Former, BiSeNet V2, PIDNet, and STDC1, are qualitatively selected based on their reported performance, inference time, code availability, recency, and popularity. The CelebAMask-HQ dataset, comprising manually annotated face images, is used to fairly assess the lip segmentation performance of the selected models. Inference experiments are conducted on a Raspberry Pi4 to emulate limited computational resources. The results show that Mask2Former and EHANet have the best performances in terms of mIoU score. BiSeNet V2 demonstrate competitive performance, while PIDNet excels in recall but has lower precision. Most models present inference time ranging from 1000 to around 3000 milliseconds on a Raspberry Pi4, with PIDNet having the lowest mean inference time. This study provides a comprehensive evaluation of lip segmentation models, highlighting their performance and inference times. The findings contribute to the development of lightweight techniques and establish benchmarks for future advances in lip segmentation, especially in IoT and edge computing scenarios

Nonlinear terahertz control of the lead halide perovskite lattice

Lead halide perovskites (LHPs) have emerged as an excellent class of semiconductors for next-generation solar cells and optoelectronic devices. Tailoring physical properties by fine-tuning the lattice structures has been explored in these materials by chemical composition or morphology. Nevertheless, its dynamic counterpart, phonon-driven ultrafast material control, as contemporarily harnessed for oxide perovskites, has not yet been established. Here, we use intense THz electric fields to obtain direct lattice control via nonlinear excitation of coherent octahedral twist modes in hybrid CH3NH3PbBr3 and all-inorganic CsPbBr3 perovskites. These Raman-active phonons at 0.9 to 1.3 THz are found to govern the ultrafast THz-induced Kerr effect in the low-temperature orthorhombic phase and thus dominate the phonon-modulated polarizability with potential implications for dynamic charge carrier screening beyond the Fröhlich polaron. Our work opens the door to selective control of LHP’s vibrational degrees of freedom governing phase transitions and dynamic disorder

Secondary prevention of venous thromboembolism: Predictors and outcomes of guideline adherence in a long-term prospective cohort study.

Background Prevention of recurrent venous thromboembolism (VTE) is considered a main goal of VTE management. However, the extent to which physicians adhere to the recommendations from evidence-based guidelines is unknown. Aim From a large, prospective clinical cohort, we aimed to (1) quantify the adherence of treatment recommendations to evidence-based guidelines and establish its predictors, and (2) estimate its impact on clinical outcomes and costs in patients with VTE. Methods We included 6'243 consecutive patients with VTE treated at the university outpatient unit. Detailed clinical characteristics and treatment recommendations were recorded. Adherence of treatment recommendations to evidence-based guidelines at risk assessment was assessed in terms of duration of anticoagulant treatment. Data on death were obtained from the Swiss Central Compensation Office. Health care claims data recorded between 2014 and 2019 were retrieved from Helsana, one of the largest Swiss health insurance companies. Results The adherence to evidence-based guidelines was 36.1%. Among patients with non-adherence, overtreatment was present in 70.1%. Significant patient-related predictors of guideline adherence were (a) age above 50 years, (b) male sex, (c) pulmonary embolism, (d) unprovoked VTE, (e) multiple VTE, (f) laboratory tests not ordered, and (g) various cardiovascular comorbidities. Non-adherence was not significantly associated with mortality, hospitalization, admission to nursing home, and costs. Conclusions The adherence to evidence-based guidelines was low, and several unrelated predictors appeared. Although these results need to be confirmed in other settings, they highlight the need for implementation of evidence-based guidelines in clinical practice