2,061 research outputs found
Geotechnical Evaluations of a Tailings Dam for Use by a Molybdenum and Copper Mine Project in Southern Idaho
A proposed mining project in Boise County, Idaho for the extraction of copper, molybdenum, and silver deposits, required investigations into a possible tailings dam construction that will be built using the processed material from the mine. The mine is located southwest of Lowman Idaho, northeast of Pioneerville Idaho, and directly north of Jackson Peak Mountain. The total area for the proposed project is approximately 12 square kilometers and the estimated material to be excavated is about 1.99 billion cubic meters (BCM) (USDA 2013). Typical investigations into the construction of a tailings dam consist of identifying the types of ore contained within the mine, identifying a suitable location for the dam based on topography, and conducting an analysis of the geotechnical aspects of constructing the dam. In this project, construction of the tailings dam will adequately model a cut and fill operation where the excavated waste material will be used to construct the tailings dam. Construction of the tailings dam will happen in stages, with a starter dam followed by successive additions to accommodate the need for reservoir capacity. Several aspects such as excavation depth, the types of excavated soil and rock, the ore processing methods, and mechanical properties of the waste material, have been considered for properly conducting an analysis of the tailings dam. Also, aspects including the slope stability of the tailings dam, seepage velocities through the tailings dam, and slope stability after a seismic event have also be studied. This paper discusses the geotechnical aspects of the tailings dam construction including the stability of the dam under both hydrological and seismic conditions
A Practical Framework to Assess the Sustainability and Resiliency of Civil Infrastructure
Research within civil engineering is focusing on newer ideas and philosophies such as sustainability and resiliency (S&R). This is evident in the development of frameworks for assessing the sustainability or the resiliency of civil infrastructures. Several frameworks have been developed by researchers to quantify the S&R of civil infrastructures. It is evident that the S&R are not mutually exclusive, and it is important to assess these aspects at the same time and that frameworks are able to accommodate simultaneous assessments. While there are other frameworks that follow a unified approach to S&R assessments, they do not account for the risk of the hazard as part of the framework. In the proposed framework, an attempt was made to include the risk of the hazard as part of the assessment to gain a realistic perspective of the hazard impact. This paper presents explicit steps to use the framework, along with an example of using the framework in assessing an earthen dam subjected to two types of hazards, earthquakes and floods. The novel aspects of this framework revolve around the simplicity and flexibility of the framework. Major input parameters are user-defined, which allows for a wide range of variables to be considered when determining the overall quality of the infrastructure
Smitin, a novel smooth muscle titin–like protein, interacts with myosin filaments in vivo and in vitro
Smooth muscle cells use an actin–myosin II-based contractile apparatus to produce force for a variety of physiological functions, including blood pressure regulation and gut peristalsis. The organization of the smooth muscle contractile apparatus resembles that of striated skeletal and cardiac muscle, but remains much more poorly understood. We have found that avian vascular and visceral smooth muscles contain a novel, megadalton protein, smitin, that is similar to striated muscle titin in molecular morphology, localization in a contractile apparatus, and ability to interact with myosin filaments. Smitin, like titin, is a long fibrous molecule with a globular domain on one end. Specific reactivities of an anti-smitin polyclonal antibody and an anti-titin monoclonal antibody suggest that smitin and titin are distinct proteins rather than differentially spliced isoforms encoded by the same gene. Smitin immunofluorescently colocalizes with myosin in chicken gizzard smooth muscle, and interacts with two configurations of smooth muscle myosin filaments in vitro. In physiological ionic strength conditions, smitin and smooth muscle myosin coassemble into irregular aggregates containing large sidepolar myosin filaments. In low ionic strength conditions, smitin and smooth muscle myosin form highly ordered structures containing linear and polygonal end-to-end and side-by-side arrays of small bipolar myosin filaments. We have used immunogold localization and sucrose density gradient cosedimentation analyses to confirm association of smitin with both the sidepolar and bipolar smooth muscle myosin filaments. These findings suggest that the titin-like protein smitin may play a central role in organizing myosin filaments in the contractile apparatus and perhaps in other structures in smooth muscle cells
Who says we are bad people? The impact of criticism source and attributional content on responses to group-based criticism.
addresses: University of Exeter, UK. [email protected]: Journal Article; Randomized Controlled Trial; Research Support, Non-U.S. Gov'tCopyright © 2010 SAGE Publications. Author's draft version; post-print. Final version published by Sage available on Sage Journals Online http://online.sagepub.com/We investigated the interplay between the source of criticism and the attributional content of their message on behavioral responses to group-based criticism. Studies 1 and 2 revealed that outgroup critics were more effective when their criticism included internal attributions (to the ingroup's character) rather than external attributions (the ingroup's circumstances), whereas there was no effect of attributional content for ingroup critics (a significant Source x Content interaction). Study 3 explored the role of audiences in responses to outgroup criticism. The results indicated that the positive effects of internal versus external attributions were only evident when an outgroup audience was witness to participants' responses. Furthermore, these effects were mediated through concerns about the ingroup's image. Together, these patterns suggest that responses to criticism depend not just on the identity of the critic but also on what the critic says and who is watching. People may be surprisingly responsive to outgroup criticism-particularly when inaction might lead others to perceive them as "bad people.
Investigation on influence of antimony tin oxide/silver nanofluid on direct absorption parabolic solar collector
The Inert Gas Effect On The Rate Of Evaporation Of Zinc And Cadmium
An experimental study has been made to investigate the effect of argon and helium on the rate of evaporation of zinc and cadmium under one atmosphere pressure at temperatures ranging from 500 to 850°C. The experimental results were compared with the maximum rates calculated using the effusion formula as well as with values obtained using two different types of equations based on kinetic theory, diffusion theory, and empirical data. Equations have been derived for expressing the rate of evaporation of zinc and cadmium in both argon and helium as functions of temperature of the liquid zinc and cadmium. It was found that the rates of evaporation of zinc and cadmium were higher in helium than in argon, with the difference increasing with increasing temperature. It was also found that the experimental results obtained in argon agree with the calculated values better than those obtained in helium. © 1980 The Minerals, Metals & Materials Society - ASM Materials - The Materials Information Society
An Emerging Pattern of Declining Growth Rates in Belugas of the Beaufort Sea: 1989–2008
Standardized, hunter-based sampling of harvested beluga whales was initiated in the three main harvesting areas of the Mackenzie River delta (Shallow Bay, Kendall Island, Kugmallit Bay) in 1980 and near Paulatuk, Northwest Territories, in 1989. Standard length and sex of landed whales have been recorded for 90 to 110 belugas per year since 1980, and ages have been determined since 1988. Hunters select larger and older belugas; males outnumbered females 2.0 to 1 between 1980 and 1989, 3.0 to 1 between 1990 and 1999, and 3.6 to 1 between 2000 and 2009. Age classes younger than 10 growth layer groups (GLGs) were essentially absent from harvests both in the Delta and near Paulatuk. Asymptotic lengths, calculated using GLG counts from teeth of 839 males and 225 females sampled over 16 seasons (1989, 1993 – 2008), were 435.3 cm (SE 2.0) for males and 380.1 cm (SE 1.8) for females. Males were 14.5% longer than females. Belugas landed in the Delta and Paulatuk were mainly mature adults (by hunter selection). Mature belugas landed by Paulatuk hunters were younger and shorter than those taken in the Delta because of age and sex segregation in the hunting areas. There was no difference in the size-at-age relationships for belugas landed at Paulatuk vs the Delta. The linear trend in size-at-age indicated a decline of 0.08% (SE 0.038%) per year, or 1.75% over the 19 year time series. The 314 male belugas landed in the Delta between 2000 and 2007 showed statistically significant differences in blubber thickness among years, but only a slight downward trend over this short period. Mean blubber was thickest in 2002 and 2003 and thinnest in 2005. The thinness of belugas in 2005, and subtle changes in growth of the belugas over the time series, may reflect ecosystem changes that have reduced the availability or quality and quantity of their prey in recent years. Further research, including isotope and fatty acid profiling, would be helpful in substantiating the declining trend in growth and elucidating the causative factors.Des échantillons standardisés provenant de pêcheurs ayant capturé des bélugas ont été prélevés dans trois lieux de capture principaux du delta du fleuve Mackenzie (baie Shallow, île Kendall et baie Kugmallit) en 1980 et près de Paulatuk, dans les Territoires du Nord-Ouest, en 1989. La longueur standard et le sexe des baleines débarquées ont été enregistrés dans le cas de 90 à 110 bélugas par année depuis 1980, et les âges ont été déterminés depuis 1988. Les pêcheurs choisissent les bélugas qui sont plus gros et plus âgés. Le nombre de mâles a dépassé le nombre de femelles dans une mesure de 2,0 contre 1 entre 1980 et 1989, de 3,0 contre 1 entre 1990 et 1999, et de 3,6 contre 1 entre 2000 et 2009. Les classes d’âge plus jeunes que dix groupes de couches d’accroissement (GCA) étaient pour ainsi dire absentes des récoltes du delta et de la proximité de Paulatuk. Les longueurs asymptotiques, calculées au moyen des dénombrements de GCA à partir des dents de 839 mâles et de 225 femelles échantillonnés au cours de 16 saisons (1989, 1993-2008) étaient de 435,3 cm (ET de 2,0) chez les mâles et de 380,1 cm (ET de 1,8) chez les femelles. Les mâles étaient plus longs que les femelles dans une mesure de 14,5 %. Les bélugas débarqués dans le delta et à Paulatuk étaient surtout des adultes en pleine maturité (en raison du choix des pêcheurs). Les bélugas adultes débarqués par les pêcheurs de Paulatuk étaient plus jeunes et moins longs que ceux capturés dans le delta en raison de la ségrégation entre les sexes et de l’âge dans les zones de pêche. Il n’y avait pas de différence dans les relations en fonction de la taille selon l’âge pour les bélugas débarqués à Paulatuk par rapport à ceux débarqués au delta. La tendance linéaire dans la taille selon l’âge a fait ressortir un déclin de 0,08 % (ET de 0,038 %) par année, soit 1,75 % pour la série temporelle de 19 ans. Les 314 bélugas mâles débarqués dans le delta entre 2000 et 2007 ont affiché d’importantes différences statistiques sur le plan de l’épaisseur du lard au fil des ans, mais seulement une faible tendance à la baisse pendant cette courte période. L’épaisseur moyenne du lard était à son point le plus élevé en 2002 et en 2003, et à son point le plus faible en 2005. La maigreur des bélugas en 2005 et les changements mineurs sur le plan de la croissance des bélugas au cours de la série temporelle pourraient être le reflet de changements caractérisant l’écosystème, changements qui ont eu pour effet de réduire la disponibilité ou la qualité et la quantité des proies des baleines ces dernières années. Des recherches plus poussées, prenant notamment la forme du profilage des isotopes et des acides gras, aideraient à valider la tendance à la baisse en matière de croissance et à élucider les facteurs causals
Optimisation of thermo-optical properties of SiO2/Ag–CuO nanofluid for direct absorption solar collectors
Senior Civil Engineering Students’ Views on Sustainability and Resiliency
In recent years, civil engineering education and workforce development have evolved to include a greater emphasis on sustainability and resiliency. Sustainability balances economic, ecological, and societal needs by being responsive to community impact, human health, and the environment. Resilient infrastructure lasts, retaining functional and structural capacity and supporting interconnected transportation, energy, water, and social systems after a distress event. While many undergraduate civil engineering programs address sustainability, it tends to be limited to individual courses, and resiliency concepts are rarely incorporated. To address these shortcomings, we are incorporating sustainability and resiliency conceptual threads and activities throughout our curriculum, from our first-year engineering course through senior design.
To understand the effectiveness of this initiative, at the beginning of this project we conducted interviews with senior civil engineering students to collect baseline data on our current students’ views and understanding of sustainability and responsibility. Thematic analysis of these interviews suggests that there is significant variability in students’ understanding of sustainability, with some students recognizing that sustainability involves tradeoffs between economic, environmental, and societal needs, while others tended to conflate sustainability with environmentalism. While students reported encountering sustainability in a portion of their undergraduate courses, they generally did not learn about how sustainability related to much of their technical coursework such as structures, soils, or transportation. Most current students have little conceptual understanding of resiliency which is not surprising given that it is not addressed in any substantial way in our current curriculum. This provides clear evidence of the need for greater exposure to both sustainability and resiliency and understanding the relationship between these practices as part of the undergraduate civil engineering curriculum.
By incorporating sustainability and resiliency throughout the undergraduate civil engineering curriculum, students will be better prepared to address these topics as part of their senior design projects, and in their future careers
Ringed Seals and Sea Ice in Canada’s Western Arctic: Harvest-Based Monitoring 1992–2011
We examined the relationship between ringed seal body condition and reproduction and spring sea ice conditions in prime ringed seal habitat in Canada’s western Arctic during 1992 – 2011. Since 1970, ice conditions in east Amundsen Gulf and west Prince Albert Sound have shown only a slight trend toward earlier ice clearance (breakup) in spring (3 – 7 days per decade) (p < 0.10) and no trend toward later freeze-up or increased variability in timing of spring ice clearance. A subsistence harvest – based sample of 2281 ringed seals was obtained during 1992 – 2011 from Masoyak, a traditional hunting camp located on the northwest shore of west Prince Albert Sound and less than 5 km from east Amundsen Gulf. The results revealed a statistically significant trend of decreasing mean annual body condition of ringed seals (using an index of length-mass-blubber depth [LMD]: adults, 0.14 m1.5/kg0.5/y; subadults, 0.24 m1.5/kg0.5/y) over the past two decades. A parallel result was that mean annual body condition of adults and subadults was correlated with the timing of fast ice clearance in spring (later ice clearance = worse condition). This correlation was most obvious in the extreme ice years in all sex/age groupings and was statistically significant for subadults. In mature females sampled since 1992, annual ovulation rates averaged 92.4 ± 16.3% (SD) and were greater than 80%, and mostly at 100%, in all years but two. Failure to ovulate was obvious in 2005, the most extreme late ice clearance year in our series, when only 30.0% of the mature adult females sampled ovulated. At the same time, values for seal body condition indices (adult females, LMD = 11.3; adult males, LMD = 12.4) and percent pups in the harvest (3.3%) were among the lowest recorded, and spring ice clearance was 38 d later than the 1992 – 2011 average. While this and previous studies indicate that the seal population in this core habitat has recovered from natural and extreme-year sea ice fluctuations over the past four decades, the potentially magnified effect of several consecutive extreme ice years, compounded by the concurrent decline in seal body condition that we have now detected over the past 20 years, is of particular concern.Nous avons examiné le lien qui existe entre l’état corporel du phoque annelé, l’état de reproduction de ce phoque et l’état de la glace de mer printanière dans son habitat d’élection de l’ouest de l’Arctique canadien et ce, entre 1992 et 2011. Depuis 1970, l’état de la glace dans l’est du golfe Amundsen et dans l’ouest du détroit de Prince-Albert n’a affiché qu’une petite tendance vers une débâcle printanière plus hâtive (de 3 à 7 jours par décennie) (p < 0,10) et aucune tendance vers un englacement plus tardif ou une variabilité accrue caractérisant la période de la débâcle du printemps. Un échantillon recueilli à partir de 2 281 phoques annelés ayant fait l’objet d’une récolte de subsistance a été obtenu entre 1992 et 2011 à Masoyak, un camp de chasse traditionnel situé sur la côte nord-ouest de l’ouest du détroit de Prince-Albert et à moins de cinq kilomètres de l’est du golfe Amundsen. Les résultats ont permis de constater une tendance statistiquement significative sur le plan de la décroissance de l’état corporel annuel moyen des phoques annelés (en fonction d’un indice de la profondeur et de la longueur de la masse du petit lard [LMD] : reproducteurs, 0,14 m1,5/kg0,5/a; préreproducteurs, 0,24 m1,5/kg0,5/a) au cours des deux dernières décennies. Un résultat parallèle a permis de corréler l’état corporel annuel moyen des reproducteurs et des préreproducteurs à la période d’une débâcle printanière rapide (débâcle tardive = pire état). Cette corrélation était plus évidente au cours des années où la glace était extrême chez tous les groupements en fonction du sexe ou de l’âge, et elle était statistiquement significative chez les préreproducteurs. Parmi les femelles matures échantillonnées depuis 1992, les taux d’ovulation annuels atteignaient 92,4 ± 16,3 % (DS) en moyenne, et étaient plus grands que 80 %, et à près de 100 % au cours de toutes les années, sauf deux. L’anovulation était évidente en 2005, ce qui correspondait à l’année de notre série où la débâcle a été la plus tardive, lorsque seulement 30,0 % des femelles adultes et matures qui avaient été échantillonnées ont ovulé. En même temps, les valeurs relatives aux indices de l’état corporel des phoques (femelles adultes, LMD = 11,3; mâles adultes, LMD = 12,4) et au pourcentage de petits faisant partie de la récolte (3,3 %) figuraient parmi les valeurs les plus basses à n’avoir jamais été enregistrées, et la débâcle printanière était plus tardive de 38 jours par rapport à la moyenne de 1992-2011. Bien que cette étude et des études antérieures laissent croire que la population de phoques de cet habitat important a réussi à se remettre des fluctuations naturelles et extrêmes des conditions de glace des quatre dernières décennies, l’effet potentiellement grossissant de plusieurs années consécutives de glace extrême, allié au déclin concurrent de l’état corporel des phoques que nous avons décelé au cours des 20 dernières années, présente une source d’inquiétude particulière
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