Estudo numérico em vigas de madeira submetidas a altas temperaturas

Mestrado de dupla diplomação com a UTFPR - Universidade Tecnológica Federal do ParanáEste trabalho tem como objetivo principal investigar o comportamento de vigas de madeira submetidas à flexão em temperatura ambiente e também em condições térmicas variadas, para temperaturas constantes em toda a secção transversal e sob tempos de exposição ao fogo. As simulações numéricas foram realizadas com o uso do software Ansys em conformidade com as propriedades definidas para o material. Foram desenvolvidos três modelos de cálculo numérico via elementos finitos, o primeiro realizando uma análise mecânica com carga incremental à temperatura ambiente, o segundo para análise mecânica com carga incremental em diferentes valores de temperatura constante e o terceiro para uma análise térmica de exposição à curva de incêndio ISO834 acoplada à análise mecânica com carga incremental. Foi realizada uma simulação numérica de um ensaio experimental e as demais simulações contemplaram 2 geometrias de viga, cada uma delas analisadas em 6 valores de temperatura constante e 6 tempos de exposição diferentes. Para analises a respeito do máximo carregamento aplicado, do momento resistente, da espessura de carbonização e da taxa de carbonização, conforme necessário. Os resultados obtidos numericamente foram comparados com o ensaio experimental fornecendo resultados coerentes, e com o método simplificado proposto pelo Eurocódigo 1995-1-2 que no geral mantém-se a favor da segurança ao determinar as propriedades de resistência da madeira por meio do método da secção reduzida.The main objective of this work is to investigate the behavior of wooden beams submitted to bending for room temperature and also for varied thermal conditions, under constant temperatures across the entire cross section and under exposure to fire. The numerical simulations were performed using the Ansys software, in accordance with the proprieties defined of the material. Three numerical calculation models by finite elements were developed, the first performing a mechanical analysis with increment load at room temperature, the second for a mechanical analysis with an increment load at different values of constant temperature and the third for a thermal analysis of exposure to the curve of fire ISO834 coupled to mechanical analysis with incremental load. Was realized the numerical simulation of an experimental test, and the others for 2 beam geometries, each of which was analyzed at 6 constant temperature values and 6 different exposure times. Analyzes were made regarding the maximum applied load, the resistant moment, the carbonization thickness and the carbonization rate, as necessary. The results obtained numerically were compared with the experimental test providing coherent results, and with the simplified method proposed by Eurocode 1995-1-2 which in general remains in favor of safety when determining the strength properties of the wood through the method of reduced section

Dental size and frequency of anomalies in the teeth of a small-bodied population of mid-late holocene Micronesians, Palau Micronesia.

The aim of this study was to compare the size of the teeth of a sample of small-bodied fossil humans from the island of Palau, Micronesia, with modern and fossil human populations from mainland southern Africa. Four modern human population groups and a sample of Holocene human remains were examined for comparison. These included Zulus, Tswanas, Khoisan and Europeans, from the Dart Collection, University of the Witwatersrand. Several measurements of the different tooth classes were obtained from the modern population groups and compared to the Palauan sample using Univariate and Bivariate statistical methods. In addition, frequencies of anomalies were recorded for the entire modern human Dart Collection (n. 3000), and a sample of Holocene human skeletons (n. 69) for comparison with the Palauan material. The Palauans have been found to have absolutely and relatively very large teeth compared to modern and Holocene population groups. Their mesiodistal diameter (MD) and buccolingual diameter (BL) exceed the normal range of modern human populations, whereas the same measurements at the cervical enamel junction are smaller. Total root length and crown height of the Palauans are equal to those of modern humans. Estimating body size from tooth size is thus shown to be unreliable, indicating that tooth size should be viewed in relation to other factors, such as diet, which may lead to phenomena like island dwarfism. Frequencies of third molar agenesis, incisiform canines, caniniform premolars and rotated premolars were very high in the Palauan sample: third molar agenesis, incisiform canines, caniniform premolars and rotated premolars. These anomalies are mostly due to crowding, which results in erupting teeth looking like their neighbours, or failing to develop at all, as in the case of third molars, which free up space for the remaining teeth to develop

Gestão da manutenção para uma empresa com frota de caminhões e máquinas agrícolas

This work through a qualitative exploratory approach suggests the adoption of maintenance management tools applied to a company transporting, harvesting and detachment maize, using the study of maintenance practices, performance indicators and consolidated quality tools. Considering the major difficulties of the organization and hoping that uncomplicated tools can be consolidated more easily, causing less cultural impact, models and approaches have been presented that can be used in the prioritization of equipment, process mapping, activity standardization, design of maintenance schedules, and implementation of basic indicators.UFU - Universidade Federal de UberlândiaTrabalho de Conclusão de Curso (Graduação)Este trabalho, através de uma abordagem qualitativa exploratória, sugere a adoção de ferramentas de gestão da manutenção aplicadas à uma empresa de transporte, colheita e despendoamento de milho, utilizando-se do estudo das práticas de manutenção, indicadores de desempenho e ferramentas de qualidade já consolidados. Observadas as maiores dificuldades da organização, e esperando que ferramentas descomplicadas possam consolidar-se mais facilmente - ocasionando menor impacto cultural - foram apresentados modelos e abordagens que poderão ser utilizados na priorização de equipamentos, mapeamento de processos, padronização de atividades, desenho de cronogramas de manutenção, e implementação de indicadores básicos

Novos registros de mastodontes (Mammalia: Proboscidea) para Minas Gerais, Brasil: descrição, datação e ecologia alimentar

Proboscidea is one of the large mammals groups present in the Brazilian fossil record, represented in the country by the mastodon Notiomastodon platensis (Ameghino, 1888). In contribution to all studies that aim to understand their taxonomy, feeding diet, chronology and paleoenvironmental and paleoclimatic aspects in which they lived, this work objective was obtain information about mastodons recorded in the Campina Verde town and in the vicinity of Montes Claros and Francisco Sá, providing new data and analyzes that include: (1) the detailed morphological description of the specimens obtained, (2) the radiocarbon dating and stable carbon and oxygen isotopes analysis of the specimen from Campina Verde. The material description corroborated the exclusive occurrence of the species N. platensis in Brazil. The stable isotopes analysis, in turn, reveals a mixed-feeder with high proportion of grass on its diet (δ13C ‰ 0.53), which indicates the existence of an open savana for the region of Campina Verde town during the end from the Pleistocene period (19,890 ± 45 years), similar to the results found in other locations in the Brazilian Intertropical Region, however comparatively colder and wetter when we analyzed the oxygen values (δ18O ‰ 23,81), which may be a reflection of a humidity corridor from the Amazon region.CNPq - Conselho Nacional de Desenvolvimento Científico e TecnológicoTrabalho de Conclusão de Curso (Graduação)Proboscidea é um dos grupos de grandes mamíferos presentes no registro fossilífero brasileiro, representado no país pelo mastodonte Notiomastodon platensis (Ameghino, 1888). Em contribuição a todos os estudos que buscam compreender sua taxonomia, hábitos alimentares, cronologia e aspectos paleoambientais e paleoclimáticos em que viveram, este trabalho objetivou obter informações sobre os mastodontes registrados no município de Campina Verde e na região dos municípios de Montes Claros e Francisco Sá, aportando novos dados e análises que incluem: (1) a descrição morfológica detalhada dos espécimes obtidos, (2) a datação absoluta e a análise de isótopos estáveis de carbono e oxigênio do espécime oriundo de Campina Verde. A descrição do material corroborou com a ocorrência exclusiva da espécie N. platensis em território brasileiro. A análise de isótopos estáveis, por sua vez, revelou uma dieta mista, composta predominantemente por plantas C4 (δ13C 0,53‰), o que indica a existência de um ambiente com fitofisionomia aberta para a região do município de Campina Verde durante o final da época pleistocênica (19.890±45 anos), similar aos resultados encontrados em outras localidades da Região Intertropical Brasileira, porém comparativamente mais ameno e úmido quando analisamos os valores de oxigênio (δ18O 23,81‰), o que pode ser reflexo de um corredor de umidade oriundo da região amazônica

Disponibilidade no ambiente e ingestão de resíduos sólidos antrópicos por tartarugas-verde (Chelonia mydas) no Litoral do Paraná .

Orientadora: Silvia Pedroso MelegariCoorientadora: Camila DomitMonografia (Graduação) - Curso de Oceanografia, Centro de Estudos do Mar, Universidade Federal do Paraná.Dentre as espécies mais impactadas por resíduos sólidos antrópicos estão as tartarugas-verde (Chelonia mydas), devido a dieta primariamente herbívora com alto consumo de gramas-marinhas e algas, acarretando em maior probabilidade de ingestão destes resíduos que se assemelham aos seus alimentos. O Complexo Estuarino de Paranaguá (CEP), no litoral do Paraná, é uma importante área de forrageio para juvenis de C. mydas. No entanto, nesta região existe um complexo portuário e áreas intensamente urbanizadas com gestão deficiente de resíduos sólidos. Neste contexto, este estudo buscou avaliar a disponibilidade dos resíduos sólidos nas praias adjacentes ao CEP, além da ingestão e seletividade destes resíduos por C. mydas, em duas fases do pós-recrutamento (Fase I e II) entre os anos 2014 e 2015. O levantamento da disponibilidade dos resíduos no ambiente ocorreu por meio de monitoramentos visuais em cinco quilômetros de costa no município de Pontal do Paraná. Os fragmentos de resíduos sólidos de até 30 cm foram quantificados e classificados quanto ao tipo e cor. As quantidades totais, médias e a composição dos resíduos (tipos e cores) foram analisadas estatisticamente em relação a variação sazonal e espacial. Os tratos digestórios de 48 exemplares de C. mydas encalhadas mortas na região foram triados e os fragmentos de resíduos sólidos encontrados quantificados e classificados com os mesmos parâmetros usados para resíduos sólidos disponíveis. Correlacionou-se o número total e massa dos resíduos ingeridos em relação ao comprimento curvilíneo de carapaça (CCC) da espécie e, calculou-se também a frequência de ingestão e proporções dos tipos e cores de resíduos ingeridos para a amostra total, nas fases do pós-recrutamento e sazonalidade. Avaliou-se a seletividade para as duas fases do pós-recrutamento confrontando a quantidade total de cada tipo de resíduo ingerido com sua proporção disponível no ambiente. Foram contabilizados 43.652 itens de resíduos sólidos disponíveis no ambiente, compostos principalmente de plásticos coloridos rígidos (20,6%) e flexíveis (15,7%) e houve variação sazonal e espacial (p<0,05). O CCC dos indivíduos variou entre 29,8 e 57,0 cm, destas, 41 tiveram todos os compartimentos do trato digestivo analisados. Do total, 93,8% de C. mydas ingeriram resíduos sólidos e uma correlação negativa entre o CCC e o número total de resíduos ingeridos foi observada, indicando que os indivíduos na Fase I ingerem maior quantidade de resíduos sólidos. A categoria mais ingerida foi plástico flexível transparente, entretanto o índice de seleção destacou forte seletividade para plásticos flexíveis pretos e possível rejeição a canudinhos brancos nas duas fases do pós-recrutamento. A alta taxa de ingestão de resíduos demonstra que C. mydas pode ser considerada sentinela ambiental para a poluição por resíduos sólidos e encontram-se vulneráveis a este impacto no litoral do Paraná e também durante sua fase de vida oceânica. Desta forma são necessárias medidas mitigadoras relacionadas à redução na produção, consumo e descarte inadequado de resíduos sólidos, principalmente aqueles com maior dispersão e resiliência no ambiente marinho e mais atrativos para ingestão pela fauna

Growth and development of the third permanent molar in Paranthropus robustus from Swartkrans, South Africa

Third permanent molars (M3s) are the last tooth to form but have not been used to estimate age at dental maturation in early fossil hominins because direct histological evidence for the timing of their growth has been lacking. We investigated an isolated maxillary M3 (SK 835) from the 1.5 to 1.8-million-year-old (Mya) site of Swartkrans, South Africa, attributed to Paranthropus robustus. Tissue proportions of this specimen were assessed using 3D X-ray micro-tomography. Thin ground sections were used to image daily growth increments in enamel and dentine. Transmitted light microscopy and synchrotron X-ray fluorescence imaging revealed fluctuations in Ca concentration that coincide with daily growth increments. We used regional daily secretion rates and Sr marker-lines to reconstruct tooth growth along the enamel/dentine and then cementum/dentine boundaries. Cumulative growth curves for increasing enamel thickness and tooth height and age-of-attainment estimates for fractional stages of tooth formation differed from those in modern humans. These now provide additional means for assessing late maturation in early hominins. M3 formation took ≥ 7 years in SK 835 and completion of the roots would have occurred between 11 and 14 years of age. Estimated age at dental maturation in this fossil hominin compares well with what is known for living great apes

Reassessment of the TM 1517 odonto-postcranial assemblage from Kromdraai B, South Africa, and the maturational pattern of Paranthropus robustus

Objectives The Pleistocene taxon Paranthropus robustus was established in 1938 following the discovery at Kromdraai B, South Africa, of the partial cranium TM 1517a and associated mandible TM 1517b. Shortly thereafter, a distal humerus (TM 1517g), a proximal ulna (TM 1517e), and a distal hallucial phalanx (TM 1517k) were collected nearby at the site, and were considered to be associated with the holotype. TM 1517a‐b represents an immature individual; however, no analysis of the potentially associated postcranial elements has investigated the presence of any endostructural remnant of recent epiphyseal closure. This study aims at tentatively detecting such traces in the three postcranial specimens from Kromdraai B. Materials and Methods By using μXCT techniques, we assessed the developmental stage of the TM 1517b's C‐M3 roots and investigated the inner structure of TM 1517g, TM 1517e, and TM 1517k. Results The M2 shows incompletely closed root apices and the M3 a half‐completed root formation stage. The distal humerus was likely completely fused, while the proximal ulna and the distal hallucial phalanx preserve endosteal traces of the diaphyseo‐epiphyseal fusion process. Discussion In the hominin fossil record, there are few unambiguously associated craniodental and postcranial remains sampling immature individuals, an essential condition for assessing the taxon‐specific maturational patterns. Our findings corroborate the original association of the craniodental and postcranial remains representing the P. robustus type specimen. As with other Plio‐Pleistocene hominins, the odonto‐postcranial maturational pattern of TM 1517 more closely fits an African great ape rather than the extant human pattern

A hominin first rib discovered at the Sterkfontein Caves, South Africa.

First ribs - the first or most superior ribs in the thorax - are rare in the hominin fossil record, and when found, have the potential to provide information regarding the upper thorax shape of extinct hominins. Here, we describe a partial first rib from Member 4 of the Sterkfontein Caves, South Africa. The rib shaft is broken away, so only the head and neck are preserved. The rib is small, falling closest to small-bodied Australopithecus first ribs (AL 288-1 and MH1). Given that it was recovered near the StW 318 femur excavation, which also represents a small individual, we suggest that the two may be associated. Three-dimensional geometric morphometric analyses were used to quantify the rib fragment morphology and compare it to extant hominoid and other fossil hominin ribs. While only the proximal end is preserved, our analyses show that South African Australopithecus share derived features of the proximal first rib more closely resembling A. afarensis and later hominins than great apes.NCS2016

The TM 1517 odontoskeletal assemblage from Kromdraai B, South Africa, and the maturational pattern of Paranthropus robustus

The holotype of Paranthropus robustus was discovered by R. Broom in 1938 in an outcrop of bone breccia at the cave site of Kromdraai B, in Gauteng, South Africa [1]. It consists of the left half of a cranium (TM 1517a) and an associated right mandibular corpus (TM 1517b), both bearing teeth, and of seven isolated teeth (a LLP3, a LLP4 and the series URP3-M3 labelled as TM 1517c). A few weeks later, close to the block containing the cranial remains, Broom identified four postcranial elements: the distal end of a right humerus (TM 1517g), the partial proximal end of a right ulna (TM 1517e), and two toe bones (TM 1517k and TM 1517o), all at the time attributed to the same young individual represented by the cranial remains. However, the distal foot phalanx TM 1517o was subsequently attributed to a baboon. While the holotype has been variously referred to as a 'young female', a 'young adult', as 'probably male and immature', or as a 'late adolescent', it certainly represents a dentally immature individual. Since these early descriptions, no study has explored the possibility that the associated postcranial remains preserve evidence of active bone growth or recent epiphyseal closure. Clearly, however, such information would either strengthen, or challenge the idea that the craniodental and postcranial remains belong to a single P. robustus individual and, importantly, might provide the first evidence about the odontoskeletal maturational pattern of this fossil taxon. Accordingly, we performed a micro-XCT-based study aimed at characterising the inner structure of the distal humerus TM 1517g, the proximal ulna TM 1517e and the distal hallucial phalanx TM 1517k. Our 2-3D analyses show that the distal humerus was likely completely fused, while the proximal ulna still displays a faint remnant of fusion, and the distal hallucial phalanx shows evidence of still growing bone. These findings, as well as the observation that the distal humerus and the proximal ulna fit anatomically and morpho-dimensionally [2], provide support for the original attribution of the cranial and the three postcranial remains from Kromdraai B to a single individual representing the P. robustus type specimen. Using extant human dental standards, the age at death estimate of TM 1517 is of 16.5±3 years if based on the LM2 (not fully closed distal apices) and LM3 root developmental stages (root formation stage between half and three-quarters completed). The skeletal age ranges between 14 and 18 years, for a male, and between 11 and 15 years, for a female individual. When a chimpanzee dental growth pattern is considered, TM 1517 fits the c. 10.5 years 'older juvenile' group [3], while chimpanzee skeletal maturity standards place it between 7.95 and 13.5 years. Interestingly, in humans fusion of the distal hallucial phalanx commonly slightly precedes that of the distal humerus. However, a sequence of distal humerus-distal hallucial phalanx-proximal ulna fusion, as displayed by TM 1517, is usually observed in Pan. Taken together, this new evidence for TM 1517 more closely resembles the chimpanzee condition for maturational patterning. This finding is broadly in line with the evidence observed for Australopithecus sediba [4] and Homo erectus from Nariokotome [5]. Nevertheless, since P. robustus seems characterised by sexual bimaturism (with the males experiencing prolonged growth), the uncertain sex attribution of TM 1517 still represents a limiting interpretative factor