Strain Measurement in a Specimen Subjected to Out-of-Plane Movement: Using an Open-Source Digital Image Correlation-Based Tool

Structural health monitoring (SHM) helps engineers maintain structures, enhance their safety, and operate them cost-effectively. Digital image correlation (DIC) techniques applied to SHM are noncontact techniques; they are also fast, accurate, and simple to implement. The goal of this investigation was to determine the smallest strain accurately measurable by a standard opensource DIC-based tool, in a specimen subjected to out-of-plane movement (toward or away from sensor). The investigation builds upon an initial study which determined the smallest accurately measurable strains using the same DIC-based tool in a specimen that was not subjected to controlled out-of-plane specimen movement. This initial study was motivated by initially undetected damage at low strains in connections of the Storstrøm Bridge in Denmark. Timely identifi cation of this damage would have prevented its spread, resulting in lower repair costs. It was observed in this initial study that the minute out-of-plane specimen movements that inadvertently occurred even in the controlled conditions of the laboratory created noise in the DIC-based strain measurements. Hence, before implementing this technique in a real-world structure, it is desirable to determine the bounds of out-of-plane displacement of the system within which it is practical to use this technique to measure strain. A cantilevered plate specimen was transversely loaded in the laboratory, and the longitudinal strain was measured at a selected location at different values of out-of-plane displacement of the specimen toward the sensor, using the open-source DIC-based tool. DIC-based strains were compared against those measured by conventional strain gauges. The smallest strains accurately measurable using DIC techniques, over a range of specimen out-of-plane displacement amplitudes, were determined

Coefficient of Friction and Subjective Assessment of Slippery Work Surfaces

Research was conducted to determine how well subjects could distinguish between surfaces with different coefficient of friction (COF) values and to evaluate how well subjective ratings of slipperiness correlated with the actual COF values. Thirty-three ironworkers experienced in working and walking on steel surfaces and 23 university students inexperienced with these tasks participated in the study. Subjective slipperiness ratings for a variety of climbing and walking conditions were obtained from the subjects. It was found that subjects could identify differences in the slipperiness of four types of steel coatings tested in the study. There was a high correlation between the subjective ratings and the measured COF values. Subjects did not slip at a COF of 0.41 but did lose footing at a COF of 0.20.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline

Habilidades funcionais, nível de actividade, integração na comunidade e saúde em idosos institucionalizados em lar: resultados preliminares

São escassos os estudos portugueses que avaliam o nível de funcionalidade, o nível de actividade e a saúde em idosos institucionalizados em lar. Objectivos: Estimar os meses de institucionalização dos idosos e as causas que conduziram à institucionalização em lar, bem como o número de idosos que partilha o seu quarto com outros. Estimar as Habilidades Funcionais dos idosos, o tipo de actividades relatadas, dentro e fora da instituição (Nível de Actividade e Integração na Comunidade) e o grau de saúde (objectiva e subjectiva). Analisar a relação entre estas quatro dimensões e analisar a relação destas com algumas variáveis demográficas (idade, género). Métodos: 35 idosos institucionalizados em lar (idade média=80.20 anos; DP=6.263) completaram o Questionário de Informação Pessoal (QIP; Fernándes-Ballesteros, 1995; Maia et al., 2013). Para a análise dos dados recorremos ao SPSS 21. Resultados: A grande generalidade dos idosos está institucionalizada há mais de 16 meses, por motivos maioritariamente de saúde (65,7%), partilha o quarto com terceiros (71.4%) e é autónoma, não necessitando de ajuda (56.7%) em actividades como o cuidado pessoal, comer, vestir/despir, andar, levantar/deitar. Quando se trata das actividades mais complexas, como a administração de dinheiro, uso do telefone ou ida às compras, o grau de dependência aumenta (27.6% dos sujeitos necessitam de muita ajuda e 35.2% de alguma ajuda). Verifica-se que 72.9% da população está inactiva, visto limitar-se a ver televisão ou a ouvir rádio e apenas 14.3% dos idosos se dedicam a actividades fora da Instituição. Os actos religiosos têm uma larga adesão (88.6%). 79.4% dos idosos reporta problemas de mobilidade e 35.3% problemas de foro psicológico. Verifica-se que 45.7% percepcionam a saúde como má, com as mulheres a percepcionarem a sua saúde mais negativamente do que os homens. Nenhum dos idosos, de ambos os géneros, percepciona a sua saúde como boa ou excelente (0%). A dimensão Nível de Actividade apresenta uma correlação positiva com a dimensão Integração na Comunidade (r=.448*). O género apresenta uma correlação significativa com a dimensão Habilidades Funcionais (rho=.383*) e com a dimensão Saúde (r=.414*). O estado civil apresentou uma correlação positiva com as Habilidades Funcionais (rho=.419*) e o grau de escolaridade apresentou uma correlação negativa e com a dimensão Saúde (r=-.446*). Conclusões: Na nossa amostra a institucionalização é causada maioritariamente devido a problemas de saúde. A maioria dos idosos partilha o seu quarto o que pode afectar a sua intimidade e bem-estar. Apesar da maioria dos idosos ser funcionalmente autónoma, a grande generalidade apresenta uma vida pautada pela inactividade e por fracos laços com o exterior. As mulheres percepcionam a sua saúde mais negativamente do que os homens. Importa assim, desenvolver estratégias que conduzam a um envelhecimento activo destes idosos

Final Coastal Lakes Aquatic Plant Survey Report

Invasive, non-indigenous plants can degrade water quality and fish habitat when they invade lakes, ponds, and streams. Changes in plant community architecture in lakes due to invasion by canopy-forming invasive aquatic plants can result in loss of native plant biodiversity and reduction of the structural complexity of the underwater habitat

Alaska Aquatic Plant Survey Report 2005

Invasive, non-indigenous plants can degrade water quality and fish habitat when they invade lakes, ponds, and streams. Changes in plant community architecture in lakes due to invasion by canopy-forming invasive aquatic plants can result in loss of native plant biodiversity and reduction of the structural complexity of the underwater habitat

2005 Diamond Lake Submersed Aquatic Vegetation Survey

Diamond Lake is a large natural lake having a surface area of some 3214 acres (1300.7 hectares) and a maximum depth of 52 feet (15.8 meters). It is located within the Umpqua National Forest in the Southern Cascade Mountains of Oregon, at an elevation of over 5000 feet (\u3e1524 meters). Diamond Lake is a high-use waterbody that supports angling, public campgrounds, recreational boating, swimming, and water skiing. The human activity associated with the lake has been a significant contributor to the economy of southern Oregon since the early part of the twentieth century. Historically Diamond Lake was fishless but since 1910 the lake has been managed as a popular trophy trout fishery. The unauthorized introduction of the tui chub (Gila bicolor) into the lake in the 1930s caused disruption of the food web and a decline in the fishery. In 1954, the Oregon Game Commission constructed a canal near the Lake Creek outlet, lowered the lake level, and treated Diamond Lake with rotenone, to eradicate tui chub. The lake was restocked with trout following the successful rotenone treatment and a fishery was maintained for several decades. In 1992, tui chub were reintroduced, through accidental introduction or intentional illegal stocking, and again caused a decline in the trout fishery. Originally mesotrophic, Diamond Lake Diamond Lake productivity increased over the last century to a eutrophic state, and is currently included on the Oregon Department of Environmental Quality (ODEQ) 303(d) list of water quality limited water bodies for pH and algae. The lake had severe blooms of the cyanobacteria (blue-green algae) Anabaena flos-aquae, which produce neurotoxins, in the summers of 2001, 2002, and 2003. Microcystis aeruginosa, another toxin producing cyanobacterium species, was also present in the 2003 bloom. Diamond Lake was closed to some public uses (wading, swimming, water skiing, and boating) during portions of all three summers due to public health and safety concerns. Algae blooms and declining trout fishery have been attributed to alteration of the food web by the tui chubs. The chubs spawn early and consume the zooplankton in the lake, which reduces grazing pressure on phytoplankton. Since the lake is nitrogen limited, nitrogen-fixing cyanobacteria dominate the phytoplankton community. Therefore, the chubs reduce the quality of the trout fishery by reducing food available for trout and impact water quality by facilitating cyanobacteria blooms, which can be toxic. In response to the impact of the tui chub on Diamond Lake the US Forest Service and Oregon Department of Fish and Wildlife are collaborating in a tui chub eradication effort. The eradication plan includes a 2.4-m (8 ft) drawdown of the lake in the winter and spring of 2006 and a rotenone treatment of remaining lake volume in 2006 to kill any remaining fish. The US Forest Service prepared an EIS for the drawdown and rotenone treatment. Potential impacts of the drawdown on littoral aquatic plant communities were identified in the EIS. The US Forest Service conducted a qualitative survey to develop a species list for the lake. The survey described here provides a quantitative, pretreatment measure of cover and biomass of aquatic plants in Diamond Lake. Follow-up sampling, using similar methods, will permit assessment of changes in the plant community following drawdown and refilling of the lake

Coastal Lakes Aquatic Plant Survey Report

Invasive, non-indigenous plants can degrade water quality and fish habitat when they invade lakes, ponds, and streams. Changes in plant community architecture in lakes due to invasion by canopy-forming invasive aquatic plants can result in loss of native plant biodiversity and reduction of the structural complexity of the underwater habitat. Differences in photosynthetic biochemistry between non-indigenous and native plants can result in large diurnal pH and dissolved oxygen concentrations

Prometheus: A Cyclical Theme In Literature and History

The mythological figure of Prometheus will stand at the center of this presentation. This report will focus on Prometheus by Johann Wolfgang von Goethe, and Im Westen Nichts Neues (English title: All\u27s Quiet on the Western Front) by Erich Maria Remarque, in order to exhibit the actualization of various elements of the Promethean myth in later German history. Starting with an analysis of Goethe\u27s poem, I will consider the way German writers have appropriated and reworked the Prometheus myth. In this observation the similarities and disparities between the myth of Prometheus and the lives and works of Goethe and Remarque (and their public reception) as well as the consequential effects on social and philosophical thought in contemporary German culture, will be presented. In this presentation the argument will be posed that Goethe and Remarque performed the functions of Promethean archetypes. At the conclusion of the presentation, the audience will be asked to think critically as to what this theme implies in modern cultures. In contemporary societies around the world political social activists, writers, etc. are persecuted. Those who openly declare new philosophies or ideologies that are seemingly strange or unfamiliar are considered, without closer inspection, to be false, or radical, in some manner or another. Goethe\u27s works are picked apart centuries later, as Prometheus\u27 entrails. Erich Maria Remarque\u27s Im Westen Nichts Neues was burned during the infamous Bücherverbrennungin 1933, due to the declaration by the Main Office for Press and Propaganda of the German Student Association, that it, along with hundreds of other literary works by just as many authors were un-German. It is the hope of this presenter that members of the audience will take this insight into consideration when presented with new and seemingly foolish, or strange, information