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No description available.

Thesis (M.S.)--Oregon State University, 1985. / Typescript (photocopy). Includes bibliographical references (leaves 121-127). Also available online.

Snow efficiently scavenges organic contaminants from the atmosphere. Those chemicals can be released in short, concentrated pulses during spring snowmelt, potentially affecting both aquatic and terrestrial environments. In order to investigate the behavior of organic contaminants in melting snow laboratory experiments were conducted using artificial snow spiked with the organic target substances naphthalene, phenanthrene, pyrene, benzo(ghi)perylene, lindane, and atrazine. The behavior of those substances during melting is dependent on their partitioning between the different phases present within the bulk snow. Very water soluble organic chemicals, such as atrazine, are preferentially released at an early stage of melting similar to inorganic ions. This first chemical flush becomes more pronounced when a deep, aged, and relatively homogeneous snow pack is exposed to intense melting. Hydrophobic substances attached to particles, such as high molecular weight polycyclic aromatic hydrocarbons, are often released at the very end of the melt period. Dirt cones at the surface of a deep snow pack amplify this late chemical enrichment. Whereas chemicals that are clearly hydrophilic or hydrophobic are likely to be released in pulse loads, the snowmelt behavior of chemicals with intermediate partitioning properties, such as lindane, is more dependent on the varying snow pack and melt characteristics. A notable fraction of volatile chemicals may transfer from the melting snow pack to the lower atmosphere due to evaporation. Shallow snow covers in temperate regions with depths below 10cm that are exposed to recurrent melt phases during the winter are less likely to lead to pulse releases. When the melt water runs off as overland flow over frozen ground, pollutants are directly transferred into catchment streams, and their water quality is affected most. Melt water flow along the soil subsurface dilutes and buffers organic contaminant loads. The findings of this laboratory study may assist in the development of contaminant fate models that includes snowmelt processes. The results may further help to explain observations of organic contaminants in natural snow environments.

The Swedish winters 2009/10 and 2010/11 were rich in snow and many roofs collapsed, mainly largespan frames. Investigations were made and the amount of snow was not the primary cause, insteadthere were several other causes. One of these was that in some cases roofs were shoveled in anunfavorable manner which affected the load patterns negatively, so causing the roofs to collapse.Most people lack the knowledge of how shoveling will affect the roof. Had there been an increasedunderstanding regarding shoveling, some roofs could have been prevented from collapsing. Through both qualitative and quantitative research in the form of interviews and calculations thetheoretically best ways to shovel a selection of roof types is presented in the report. The roofstructures covered are 3-compartment, continuous and Gerberspliced metal roof decks. Thecalculations only concern the bending moments in the decks. The results show that differentmethods are required depending on the type of structure. Therefore it is very important to knowwhat kind of a building is to be shoveled. To ensure that this information should be easy to understand and apply, a template has beendesigned with tips and advice for the structural engineer on how to establish a plan for shoveling.The plan for shoveling should then be passed on to the property owner with instructions, tips andadvice on how to attend to his property before, during and after the snow has fallen.

Snow efficiently scavenges organic contaminants from the atmosphere. Those chemicals can be released in short, concentrated pulses during spring snowmelt, potentially affecting both aquatic and terrestrial environments. In order to investigate the behavior of organic contaminants in melting snow laboratory experiments were conducted using artificial snow spiked with the organic target substances naphthalene, phenanthrene, pyrene, benzo(ghi)perylene, lindane, and atrazine. The behavior of those substances during melting is dependent on their partitioning between the different phases present within the bulk snow. Very water soluble organic chemicals, such as atrazine, are preferentially released at an early stage of melting similar to inorganic ions. This first chemical flush becomes more pronounced when a deep, aged, and relatively homogeneous snow pack is exposed to intense melting. Hydrophobic substances attached to particles, such as high molecular weight polycyclic aromatic hydrocarbons, are often released at the very end of the melt period. Dirt cones at the surface of a deep snow pack amplify this late chemical enrichment. Whereas chemicals that are clearly hydrophilic or hydrophobic are likely to be released in pulse loads, the snowmelt behavior of chemicals with intermediate partitioning properties, such as lindane, is more dependent on the varying snow pack and melt characteristics. A notable fraction of volatile chemicals may transfer from the melting snow pack to the lower atmosphere due to evaporation. Shallow snow covers in temperate regions with depths below 10cm that are exposed to recurrent melt phases during the winter are less likely to lead to pulse releases. When the melt water runs off as overland flow over frozen ground, pollutants are directly transferred into catchment streams, and their water quality is affected most. Melt water flow along the soil subsurface dilutes and buffers organic contaminant loads. The findings of this laboratory study may assist in the development of contaminant fate models that includes snowmelt processes. The results may further help to explain observations of organic contaminants in natural snow environments.

The objective of this study is the investigation of the mechanism responsible for the squeal vibrations excited when bodies with fairly rough surfaces are rubbed on a cold dry slightly compacted snow bed. To this end, signals were recorded and analyzed when the snow surface was rubbed by the ends of baseball bats, the ends of circular wood rods, and by the thick sole of a rubber boot. It is argued that the vibration modes are confined in the rubbing bodies and that the role of the snow bed is limited to providing the right conditions for the stick-slip effect to be applicable at the rubbing interface. An attempt is made to account for the reported very intense sound emission from a sheared very cold snow bed in terms of coherent snow granule column vibrations around the shearing body, as in the case of a sheared singing sand bed.

Thesis (doctoral)--Universität Hamburg, 1985. / Includes bibliographical references (p. 172-184).

The areal coverage of echoes from snow as a function of height and intensity has been measured using an automated method, for 183 hours of records from the winter of 1963 - 64. The shape of these plots against height averaged over the whole winter season is found to be identical to the shape measured previously for a season of rain echoes whose tops were below 40 thousand feet. [...]