Polyvinyl Chloride, commonly known as PVC is a common and effective construction material. PVC is also one of the most common types of plastic. In 2008, global production and consumption of PVC was approximately 34.5 million tons. The construction industry is responsible for about 70% of the world's consumption of PVC. The largest construction use of PVC is for pipe and conduit. Modern construction, especially structures built for data services depend heavily upon PVC conduit for underground pathways to distribute electricity and data. PVC is also at the center of a fierce effort by environmental groups who would like to see it eliminated completely. If environmentalists are successful in their efforts to eliminate PVC; builders will be left without a material that is crucial for many applications. Seven alternative conduit materials have been identified as potential replacements for PVC electrical conduit. PVC electrical conduit is commonly used in commercial, industrial, and civil construction. This thesis undertook to study the four major electrical contractors in the state of Utah which employ more than one hundred electricians. Because major electrical contractors use large quantities of PVC conduit, electricians working for these contractors were surveyed to determine their preferences of alternative materials. A questionnaire was distributed and received 112 responses, which represent 6.5% of the total population. This study found that PVC was the most used, most preferred, easiest to install and was perceived as the least expensive conduit material. Polypropylene and High Density Polyethylene were rated next highest, but were also the least commonly used of the alternative materials. The other materials, which include: Nylon, Fiberglass, Fiberglass Reinforced Epoxy, Polyurethane Coated Steel, and Galvanized Steel were also examined. Many of the respondents expressed displeasure by the effort to eliminate PVC and the vast majority felt that green certification for construction did not justify elimination. These responses indicate that more needs to be done to introduce alternative conduit materials to users of PVC and educate them about the value of the alternatives. This study represents an important step in evaluating the value of PVC conduit and its alternatives.

Hazard recognition and risk perception are two important factors that are a focus of most safety training programs. According to previous research, unrecognized hazards could lead to underestimation of risks, which ultimately could lead to injuries and fatalities. The primary objective of this research was to assess hazard recognition and safety risk perception skills in the electrician trade among electricians in unions. Another goal of this study was to find possible correlation between level of engagement in safety training and hazard recognition and risk perception skills. The research objectives were accomplished by gathering data from sixty-seven apprentices and journeymen across the United States. Each individual was asked to find identify hazards and to assess the risk associated with each hazard. both groups of apprentices and journeymen are similar to each other in terms of hazard recognition and both are significantly different than an expert group.The result also shows that apprentices perceive the risk not significantly different than the expert group. The result will help understand the impact of the level of engagement of safety training on hazard recognition and risk perception skills of their workers. The result could also help electrical unions identify performance gaps in their training and ultimately improve safety behaviors with union electricians.

This study examines how teaching is interactionally accomplished within a vocational program for students studying to become electricians. The data is drawn from video recordings of classroom lectures as well as hands-on instructions at construction work sites. The analysis of the classroom explores how the students exploit poetics and sequential structures of language including especially the Initiative-Response-Evaluation sequence tosupport, challenge or undermine teaching and to build alliances with or against peers. The analysis of the construction work sites focusses on how the teacher and the students use multimodal resources to create situations for teaching and learning. The analysis of the classroom focusses on how students launch different initiatives that compete with the instructional activities in the classroom. These initiatives emerge from and reveal the broad meaning potential inherent in linguistic forms. The analysis shows how structures and roles that are constitutive of the classroom as well as the emergent professional identity of the electrician provide resources for maintaining, challenging or even dissolving instruction.The analysis of the construction work site shows how artefacts, postures, talk, and spatial configurations are handled in relation to place, mobility, and action. In stark contrast with the classroom, students at the construction site compete for the teacher's attention and assistance. The analysis includes descriptions of collaborative moments between the teacher and the students as well situations where the teacher is interrupted and challenged by the students. Three frames are deployed to convey meaning, a professional, a mundane, and an educational. The professional frame involves higher or lesser degrees of manifested professional visions on part of the teacher as well the students. The mundane frame is characterized by playfulness which in turn can jeopardize the professional agenda. Instructions provide a tool for re-establishing an instructional setting where work related tasks can be executed.

Made available in DSpace on 2016-06-02T20:18:14Z (GMT). No. of bitstreams: 1 3866.pdf: 6310029 bytes, checksum: 1dbae2c10aceb4a83b1489edc0b7fb1d (MD5) Previous issue date: 2011-10-24 / Universidade Federal de Minas Gerais / Electrical energy is an essential good that may affect people s life and the economy. Overhead line workers and construction electricians are the workers responsible for the availability of this good. To perform their occupational tasks these workers are exposed to fatal accidents and musculoskeletal overload. Although of high rates of accidents and musculoskeletal injuries among these workers, few studies evaluated the presence of risk factors in the occupational settings of line workers and electricians. In this sense, it is necessary to identify the risk factors in the electricians activities (Study 1), quantify the exposure using valid direct methods (Study 2, 3 and 5) and verify the importance of the found results for clinical applications (Study 4 and 5). Study 1 was developed to determine the prevalence of musculoskeletal symptoms among line workers and to identify the risk factors for musculoskeletal disorders. The results of this study showed postural overload and high prevalence of musculoskeletal symptoms at shoulders and neck. Based on these results, Study 2 was purposed to quantify the postural overload in the five main tasks performed by line workers. Loading and unloading the ladder on the vehicle support was deeply investigated by means of posture and force measurements in Study 3, due its higher frequency in line workers schedule. Postures and movements were recorded by four inclinometer sensors at a sampling rate of 20Hz. Inclinometer sensors were previously calibrated and them attached at workers head, upper back and right and left upper arms. Study 2 and 3 identified that line workers are exposed to shoulder and neck awkward postures during all evaluated tasks. However, both studies were performed in simulated settings. By this way, Study 4 was developed to verify if the postures recorded in the simulated conditions are representative of the posture recorded in occupational environment. The results of Study 4 showed that whether the tasks are possible to be reproduced in simulated conditions the postural overload is representative of occupational overload. Besides the representativeness, Study 5 focused the comparison between posture exposure among Brazilian and Norwegian electricians to verify whether the same job type evaluated by the same method under the same procedures would present the same overload disregard the culture differences. The results of this study would allow inferring about external validity of the recordings. According to the found results, Brazilian and Norwegian posture exposure is similar. The results of Study 5 also indicated the high postural overload that these workers are submitted. Therefore, the present thesis showed the need for ergonomic interventions to reduce biomechanical risk factors presented at electricians work activity and the representativeness of the found results to occupational environmental conditions and to other populations. / A disponibilidade de energia elétrica é um serviço básico que afeta diretamente a vida e a economia da população. Para a manutenção deste serviço, eletricistas das empresas de distribuição de energia e eletricistas de construção são expostos aos riscos de acidentes fatais e à alta sobrecarga musculoesquelética. Apesar do reconhecimento dos altos índices de acidentes e de lesões musculoesqueléticas nestes trabalhadores, poucos estudos que avaliam a exposição destes sujeitos aos fatores de risco presentes no ambiente ocupacional estão disponíveis na literatura. Neste sentido, é necessário conhecer os fatores de risco presentes na atividade ocupacional (Estudo 1), quantificá-los por medidas diretas válidas (Estudos 2, 3 e 5) e verificar a importância dos resultados encontrados para a prática clínica (Estudos 4 e 5). O Estudo 1 foi desenvolvido para determinar a prevalência de sintomas musculoesqueléticos em eletricistas de distribuição e identificar os fatores de risco para desordens musculoesqueléticas presentes nas atividades mais freqüentemente desenvolvidas por estes. Os resultados deste estudo mostraram alta prevalência de sintomas musculoesqueléticos em ombros e cervical associados à alta sobrecarga postural, identificada por observação. Com base nestes resultados foi proposto o Estudo 2 para quantificar a sobrecarga postural a que estes trabalhadores estão submetidos durante cinco das atividades freqüentemente realizadas. Maior detalhamento da atividade de remoção e reposição da escada foi realizado no Estudo 3, que envolveu, além do registro postural, a medida da força e esforço requeridos. As posturas e movimentos da cabeça, tronco superior, cervical e ombros direito e esquerdo foram registrados por inclinometria por meio de 4 transdutores previamente calibrados e fixos na cabeça, tronco superior e braços direito e esquerdo, respectivamente. Os Estudos 2 e 3 identificaram a exposição dos eletricistas de distribuição a posturas inadequadas para ombros e cervical nas atividades avaliadas. No entanto, como estes dois estudos foram realizados em ambiente simulado, foi realizado o Estudo 4, para verificar a representatividade destes resultados encontrados em ambiente simulado quando comparados ao registro realizado em ambiente ocupacional real. Os resultados do Estudo 4 mostraram que as atividades desenvolvidas em ambiente simulado podem apresentar a mesma sobrecarga postural do ambiente ocupacional desde que a atividade possa ser simulada. Além da representatividade, no Estudo 5 foi realizada a comparação da exposição postural entre eletricistas de construção Brasileiros e Noruegueses, para verificar se o mesmo tipo de trabalho, avaliado pelo mesmo instrumento a partir dos mesmos procedimentos, indicam a mesma exposição independente da cultura, o que permite inferir sobre a validade externa dos resultados encontrados. De acordo com os resultados encontrados, a exposição de eletricistas Brasileiros e Noruegueses é similar. Os resultados do Estudo 5 também indicam a alta sobrecarga postural a que os eletricistas de construção estão expostos. Portanto, a presente tese revelou a necessidade de intervenções ergonômicas para redução dos fatores de riscos biomecânicos presentes na atividade de eletricistas e a representatividade dos resultados encontrados para situações ocupacionais reais e para outras populações.