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Sistema óptico de projeção a laser para análise da superfície das pregas vocais em imagens laringoscópicas
(Universidade Federal de São Carlos, 2021-09-17) Medeiros, Jacilene Martins; Cirino, Giuseppe Antônio; https://lattes.cnpq.br/4223181147426711; https://lattes.cnpq.br/4171325648694103
When understanding the acoustic production of the human voice and its dysphonia, factors such as characteristics and dimensions of the vocal folds are relevant. Previous studies show that images of the glottic surface, seen through laryngoscopy technique, are shaped according to their geometric shapes and shades of color and brightness. However, clinical examinations in general are still performed subjectively and present challenges, especially regarding the detection of the position of anomalies. Therefore, the objective of this work is to propose an optical laser projection system, capable of detecting the surface characteristics of pathological vocal folds and estimating their quantitative parameters. This system comprises a structured white light source, a diffractive optical element (DOE) and a high-resolution camera, which together are able to project onto the photographed vocal folds a regular array of pixels measuring 12 x 12 light spots . Thus, by superimposing the DOE metric on vocal fold surface images, parameters such as position and dimension can be quantified. In order to minimize operating costs, the UPL DOE project was simulated and based on the scalar theory of Fourier diffraction. This master’s research analyzed the laryngoscopic images of 3 patients, p1, p2 and p3 , with polyps, cyst and leukoplakia, respectively. In addition to simulating the system, to validate the proposal, a prototype was developed, with a commercial UPL and molds of the glottic surface of each patient. The image processing, simulation and prototype were centered on the semi-automatic method of the watershed. Therefore, with a diffraction grating of 73 % efficiency, two polyps, a cyst and a leukoplakia were detected with dimensions of 9.73 x 8.82 ±10⁻⁵ mm and 24.06 x 8.97 .73 ±10⁻⁵ mm; 4.12 x 10.00 ±10⁻⁴ mm and 20.03 x 16.30 ±10⁻⁵ mm, respectively.. This study demonstrated that the proposed system can be considered a suitable tool for vocal fold surface analysis, either as a treatment or as prognosis of pathologies, seeking to improve the quality of life of patients.
Máscaras e respiradores: uma revisão sobre suas características e seus impactos ambientais, e a influência da pandemia de COVID-19
(Universidade Federal de São Carlos, 2021-09-17) Rocha, Thais Helena dos Santos; Urban, Roberta Cerasi; https://lattes.cnpq.br/7313670290572985; https://lattes.cnpq.br/2195671878162285
The COVID-19 pandemic brought an unprecedented use of masks and respirators for the healthcare workers and population. World Health Organization estimated the monthly needs of 129 billion masks. In order to prevent the spread of the disease, the widespread use of masks and respirators and their mismanagement may result in greater environmental contamination. The main objective of this work is to review the concepts of masks, respirators and polymeric materials, and to verify their environmental impacts, in addition to the possible strategies to minimize impacts. The masks and respirators are made of non-woven material, synthetic fibers (plastics), which filter particles, such as viruses, by the mechanisms of diffusion, direct interception, inertial deposition, sedimentation by gravitational force, and electrostatic deposition. These plastics objects can have negative consequences for the environment, such as animal entanglement, ingestion by animals, the release of microplastics and additives dangerous to health and the environment, persistence, among others. To reduce harmful impacts strategies should be adopted for pollution mitigation, such as improvements in waste management, recycling, reuse, use of sustainable plastics, public awareness of the use and disposal of plastics, and environmental remediation techniques: technologies for collecting plastics in aquatic environments and biotechnologies for the degradation of plastics.
Charge carrier dynamics and optoelectronic properties in quantum tunneling heterostructures
(Universidade Federal de São Carlos, 2021-09-17) Guarin Castro, Edgar David; Richard, Victor Lopez; https://lattes.cnpq.br/4492188799583104; https://lattes.cnpq.br/7147058400283331
Semiconductor quantum tunneling heterostructures offer a wide range of applications as photosensors, lasers, and circuit elements. However, fundamental questions related to energy transfer mechanisms and the correlation between some electrical and optical responses remain challenging. In order to provide insights into these problems, the nature of the carrier dynamics in these structures has been investigated by exploring the role of majority and minority carriers in the optoelectronic responses and the limiting factors responsible for their modulation. Thus, the transport and optical properties of different n-type samples built on Sb- and As-based double-barrier quantum well architectures have been analyzed using transport measurements and luminescence spectroscopies in continuous- and pulsed-wave mode. The characterization has been carried out by tuning various external parameters such as temperature, illumination, and magnetic fields. Our observations revealed resonant tunneling of carriers from cryogenics up to room temperature. The inclusion of III-V quaternary alloys enhances the photodetection of infrared wavelengths. Quaternary layers serve as absorbers that allow a thorough tuning of the photosensor capabilities. The optical response of the devices allowed unveiling complex dynamics of non-equilibrium carriers, pointing out the formation of independent electron and hole populations that do not thermalize. This characteristic enables the mapping of thermalization mechanisms of hot carriers along with the structures. In all cases, it was found that the optoelectronic characteristics of the devices are strongly intertwined. In this regard, bistable optical and transport characteristics associated with an intrinsic magnetoresistance of some samples can be modulated simultaneously with temperature and magnetic fields. Models were proposed to simulate the charge dynamics, discerning the main ingredients that control the electrical response and, in some cases, the photosensor abilities. These models were complemented considering coherent and incoherent transport channels, which demonstrates how the transport and optical attributes correlate to produce the peculiar quantum response. This approach allows discussing the role of minority carriers in the overall dynamics of the systems, the segmentation of the relaxation mechanisms, and the optimization of the optoelectronic properties. The results are intended to offer a comprehensive theoretical and experimental analysis of the complex quantum phenomena behind these quantum tunneling systems.
Dificuldades e desafios de estudantes na disciplina morfologia e sistemática dos vegetais avasculares no cenário de ensino não presencial emergencial: um enfoque nas atividades práticas
(Universidade Federal de São Carlos, 2021-09-17) Perboni, Jéssica Kunimatsu; Freitas, Denise de; https://lattes.cnpq.br/3330976062026878; Bagatini, Inessa Lacativa; https://lattes.cnpq.br/3904631503604006; https://lattes.cnpq.br/7334473731485522
The Covid-19 pandemic required the implementation of the Emergency Remote Teaching (ERT), which demanded the adjustment of the classes in a short time and impacted the routine of students and professors. Here we aimed to analyze the possible difficulties and challenges faced by students of the course of Morphology and Systematics of Avascular Plants in the new ERT scenario, focusing on practical/lab classes. This course, like most in the Biology curriculum, lacks software or materials available to supply the lab part. In this study, we applied online questionnaires at the beginning and at the end of the course, performed remote interviews and field diary records during synchronous classes. From 30 volunteer students enrolled, 9 answered the two questionnaires and were considered for analysis. For the analyses, we created categories based on the answers of the students in the field diary using the methodology of content analysis. The results indicated that the main difficulties and challenges that the students faced throughout the semester were related to the lack of face-to-face contact with colleagues and professors, the instability of internet connection, difficult access to technologies, the difficulty in staying focused on the classes and in organizing the tasks, in addition to the absence of an appropriate study environment. Regarding lab classes, a complementary difficulty was the lack of experiencing the observation of the organisms in a microscope or magnifying glass. To overcome the problems, the questionnaires and reports applied during the semester and the audio-visual didactic resources helped the students in the learning process. However, it was evident that some skills were not developed in the ERT scenario. Despite the difficulties of this atypical teaching scenario, the learning process was satisfactory in the perception of the students. This research may help professors teaching remote lab classes to overcome the main problems reported by students in future and similar remote teaching situations.