Manitoba Hydro's diversion of the Churchill River at Southern Indian Lake, part of a multi-million dollar hydro-electric development in northern Manitoba, will have extensive economic, social and environmental implications. The impact that the project may have on slush-ice formation in the estuary at the Port of Churchill is one such implication. Previous studies have suggested that reduced flows on the lower Churchill River may alleviate the problem of slush-ice formation which physically terminates the navigation season at Churchill. A reduction in the formation of slush ice would make feasible an average tow week extension of the navigation season. The primary objective of this study was to assess the effect of the Churchill River diversion on the length of the navigation season at the Port of Churchill. A secondary objective was to determine the relationship between the physical variables (slush ice and sedimentation) and the economic variable (insurance coverage) that influence the length of the navigation season. A field trip to Churchill was made in late July, 1973 to collect data. Interviews with hydrologists, ice observers, and National Harbours Board personnel were conducted at this time. In the data analysis, October Churchill River discharges and meteorological data on climatic factors were correlated with dates of Churchill harbour closure due to slush ice for the period 1928-1972......

Slush-ice chilling has been applied to catfish fillets by processors for several years. However, little is known about the effect of this system on fillets’ safety and quality. Salmonella counts were reduced (P≤0.05) between 0.55 - 0.83 log CFU/g by slush ice treatments (0% - 4.5% salt), regardless of salt concentration. Salmonella counts for slush ice treated fillets were less (P≤0.05) than for untreated fillets during refrigerated storage. However, Salmonella reduction was similar (P>0.05) among all treatments after 12 days of storage. Sensory evaluation showed that a 24 h-slush-ice treatment negatively affected (P≤0.05) the texture, drip, and odor of fillets during storage at 2 ± 2°C. Lightness (61.7), hue (80.6), and chroma (10.1) values were similar (P>0.05) between slush-ice fillets and water-chilled fillets. Psychotrophs, coliforms, and E. coli counts (5.1, 1.6 and /g, respectively) were similar (P>0.05) among fillets collected before and after 24 h in slush ice.

The objective of this study was to determine the consumer acceptability of fruit slushes prepared with either sucralose or sugar. Subjects (n=105) were given samples of fruit slushes and asked to complete an acceptability test and survey. The sensory characteristics measured included the overall liking of the product, flavor, texture, and color using a scale of 1=dislike extremely to 5=like extremely. Subjects? daily fruit consumption patterns and knowledge of nutrition were also solicited and analyzed. On average, there were no differences (P>0.05) in sensory characteristics between the two products. Overall, participants moderately liked both products. Flavor scores of the sucralose and sugar products were 4.5 and 4.4, respectively. Twenty-nine percent of panelists extremely liked both fruit products. Twenty-three percent of panelists liked both products, but preferred (P<0.05) the slush prepared with sucralose. Enhancing the nutritional content of a fruit slush product with sucralose will still provide an acceptable product and maintain the same sensory characteristics as the sugar product.

Wheyruit slush formulas were evaluated prior to consumer testing of pre-selected formulated beverages. Varying ingredients were prepared in accordance to a factorial design of maximum use of whey and minimum use of additional ingredients. Whey was obtained from the Mississippi State University Dairy Processing Plant and evaporated. The evaporated sweet whey was combined with blueberries, cherry concentrate, Splenda®, water and ice. Sensory tests were conducted to evaluate appearance, flavor and overall acceptability of formulations. Panelists were asked to participate in a survey to elaborate personal perceptions of the products. Formulation of 125mL whey and 30g blueberries had the higher acceptability score, but was not different from the beverage with 150mL whey and 30g blueberries. These two formulas were tested for chemical analysis. Adequate levels of antioxidants, total phenolics and neutral pH were observed. Results from proximate analysis showed minimal caloric levels with low presence of protein and carbohydrate.

Bering Sea storms regularly bring adverse environmental conditions, including large waves and storm surges of up to 4 m, to the west coast of Alaska. These conditions can cause flooding, erosion and other damage that affects marine subsistence activities and infrastructure in the low-lying coastal communities. Storm impacts also include interactions with sea ice in various states: large floes, shore-fast ice, the acceleration of sea-ice formation in frazil or slush state, and the formation of slush-ice berms. Slush-ice berms are accumulations of slush ice that develop under the right wind, water level, water and air temperature, and snow conditions. During a strong wind event, large amounts of slush may be formed and pushed onto the shore, where the slush can accumulate, solidify and protect communities from flooding and erosion. Slush ice berms can also be problematic, restricting access to the coast and presenting other hazards. Residents of Shishmaref and Shaktoolik, communities on the west coast of Alaska, observed the formation of slush-ice berms during storms that occurred in 2007, 2009 and 2011. These formations are important to the communities, and it would be useful to develop the capacity to predict their occurrence. However, scientific work has not been conducted on this phenomenon, with the result that a physical conceptual model describing the formation of slush-ice berms does not exist. In recognition of this need, a project thesis was designed, and had as its main objective to identify and document the environmental and synoptic weather conditions that lead to these types of events, and to develop a descriptive physical conceptual model of slush-ice berm formation. A key to this work was the engagement of traditional knowledge holders and local observers to gather data and information about slush ice and slush-ice berm formation, along with the specific dates when these events took place. This dissertation is organized around three major elements: development of a conceptual model of slush-ice berm formation; presenting the traditional knowledge gathered that led to the development of this model; and documenting the methods and tools used to engage traditional knowledge holders and local observers in this process. In this dissertation, the knowledge from traditional knowledge holders on slush ice formation is presented in the context of feeding into a physical scientific process – specifically, developing a descriptive physical conceptual model of slush-ice berm formation. It is expected that this type of research will contribute to slush-ice berm forecasting which would aid communities’ safety by improving assessment of environmental risk. / Graduate

Thèse (M. Eng.) -- Université du Québec à Chicoutimi, 2002. / Bibliogr.: f. 154-192. Document électronique également accessible en format PDF. CaQCU

Slush is a two phase flow of solid particles (crystals) and liquid at the triple point temperature, and constitutes an appealing alternative to liquid propellants for space launchers. The crystals give to the mixture higher density and lower specific enthalpy than liquid, enabling reduced tank volume storage and larger fuel holding time. However, the presence of solid crystals significantly modifies the thermo-hydraulics of the fuel transport, and requires novel predictive tools and diagnostic techniques for efficiently exploiting slush propellants. This thesis contributes to both aspects. In particular, this work studied the flow pressure losses and the heat transfer of solid-liquid mixtures in pipelines, combining experimental and numerical methods. Hydraulic and thermal flow features were analyzed separately with substitute mixtures chosen to mimic the behavior of slush flows in engine fuel feed systems. A dedicated facility was designed and built. The pipeline mounted conventional probes for pressure, temperature and mass flow rate measurements. Moreover, a capacitance-based density meter was developed and validated to measure the mixture's solid content. Optical flow visualization and image processing routines were combined to retrieve particulate phase distribution and velocity fields. The experimental work was complemented with 3D Unsteady Reynolds Averaged Navier Stokes simulations in OpenFOAM. The simulations coupled the Euler-Euler approach with the granular kinetic theory for the treatment of the solid dispersed phase. The model was validated with the experimental results on the pressure drop, heat transfer and solid volume fraction.The resulting physical insights and the proposed empirical correlations on the pressure drop and heat transfer in solid-liquid flows contribute to move a step forward towards slush propelled space launchers. / Doctorat en Sciences de l'ingénieur et technologie / info:eu-repo/semantics/nonPublished

In environmental impact assessment (EIA), accident risk should be considered as one impact. However, few studies have compared assessed risk levels with documented accidents. There is thus a need for assessing accuracy of risk assessment methodologies. The aim of this study was to develop and examine a risk assessment guideline based on environmental assessment. The guideline examination was carried out along the railway and the road between Kiruna and Narvik, Northern Scandinavia. The examined hazards were avalanches, debris flows, rock falls, slush flows, torrents, moose and reindeer. Documented accidents were quantified into an accident level. For each hazard type, six sections/sites were assessed. The propensities of these hazards were analysed through environmental assessments, especially by utilising geomorphology. Then, the accident densities along the sections/sites were compared with assessed accident phase indices describing risk and hazard in both spatial and temporal dimensions. The average uncertainty factors for both the risk and the hazard indices were about 5. This implies a fairly good precision. Risk and hazard indices were also rated and compared to the accident density rates. Thereafter, railway and road information was split up as different proposal alternatives in an EIA context. The total risk for each proposal was compared with the total accident density. The risk assessment guideline proved to be cost-efficient, rapid and relatively reliable in comparing accident risk.

In environmental impact assessment (EIA), accident risk should be considered as one impact. However, few studies have compared assessed risk levels with documented accidents. There is thus a need for assessing accuracy of risk assessment methodologies. The aim of this study was to develop and examine a risk assessment guideline based on environmental assessment. The guideline examination was carried out along the railway and the road between Kiruna and Narvik, Northern Scandinavia. The examined hazards were avalanches, debris flows, rock falls, slush flows, torrents, moose and reindeer. Documented accidents were quantified into an accident level. For each hazard type, six sections/sites were assessed. The propensities of these hazards were analysed through environmental assessments, especially by utilising geomorphology. Then, the accident densities along the sections/sites were compared with assessed accident phase indices describing risk and hazard in both spatial and temporal dimensions. The average uncertainty factors for both the risk and the hazard indices were about 5. This implies a fairly good precision. Risk and hazard indices were also rated and compared to the accident density rates. Thereafter, railway and road information was split up as different proposal alternatives in an EIA context. The total risk for each proposal was compared with the total accident density. The risk assessment guideline proved to be cost-efficient, rapid and relatively reliable in comparing accident risk.