On friction and surface cracking during sliding of ice on ice

2003 ◽  
Vol 49 (166) ◽  
pp. 391-396 ◽  
Author(s):  
Maurine Montagnat ◽  
Erland M. Schulson
Keyword(s):  
Fresh Water ◽  
Kinetic Coefficient ◽  
Salt Water ◽  
The Other ◽  
Surface Cracks ◽  
Experimental Conditions ◽  
Water Ice ◽  
Surface Cracking ◽  
Double Shear ◽  
Deformation Features

AbstractAs a complement to earlier measurements on the friction of both granular fresh-water ice and S2 columnar salt-water ice, new experiments were performed on the friction of S2 columnar fresh-water ice sliding against itself at low velocities (5 × 10−7 to 5 × 10−1 m s−1) and at −10°C, using the same double-shear device as was used earlier. The results showed that under a given set of experimental conditions the kinetic coefficient of friction of S2 fresh-water ice compares favorably with that of the other two variants.The experiments also revealed friction-induced surface cracks and recrystallized grains.These deformation features are explained, respectively, in terms of fracture mechanics and an earlier model of dynamic recrystallization in ice.

Rheotaxis of Elvers of the American Eel (Anguilla rostrata) in the Laboratory to Water from Different Streams in Nova Scotia

1968 ◽  
Vol 25 (8) ◽  
pp. 1591-1602 ◽  
Author(s):  
S. G. Miles
Keyword(s):  
Organic Matter ◽  
Nova Scotia ◽  
Fresh Water ◽  
Stream Water ◽  
Salt Water ◽  
The Other ◽  
Anguilla Rostrata ◽  
American Eel ◽  
Heat Stable ◽  
Experimental Apparatus

In an experimental apparatus, elvers of the American eel (Anguilla rostrata) showed a stronger positive rheotaxis to fresh water than to salt water. The attractiveness of the fresh water was due to dissolved and particulate organic matter; these components were bio-degradable, heat stable, and nonvolatile. Four streams near Halifax, Nova Scotia, were tested, and were found to differ greatly in their attraction of elvers. Elvers were collected from each of three of these streams, and were not found to be attracted to their own stream water; elvers from one stream gave a greater rheotactic response than elvers from the other streams. The presence of adult eels in the water rendered it more attractive, whereas the presence of elvers made it less so.

Round Turbulent Thermals, Puffs, Starting Plumes and Starting Jets in Uniform Crossflow

2003 ◽  
Author(s):  
F. J. Diez ◽  
L. P. Bernal ◽  
G. M. Faeth
Keyword(s):  
Fresh Water ◽  
Salt Water ◽  
Water Channel ◽  
Reynolds Numbers ◽  
Ccd Cameras ◽  
Experimental Conditions ◽  
Time Resolved ◽  
Buoyant Flows ◽  
Video Images ◽  
Density Ratios

The self-preserving properties of round turbulent thermals, puffs, starting plumes and starting jets, in unstratified and uniform crossflow, were investigated experimentally. The experiments involved dye-containing fresh water (for nonbuoyant flows) and salt water (for buoyant flows) sources injected vertically downward into crossflowing fresh water within a water channel. Time-resolved video images of the flows were obtained using CCD cameras. Experimental conditions were as follows: source exit diameters of 3.2 and 6.4 mm, source Reynolds numbers of 2,500–16,000, source/ambient velocity ratios of 4–35, source/ambient density ratios (for buoyant flows) of 1.073 and 1.150, volumes of injected source fluid (for thermals and puffs) comprising 16–318 source diameters, streamwise (vertical) penetration distances of 0–200 source diameters and 0–13 Morton length scales (for buoyant flows) and crosstream (horizontal) penetration distances of 0–620 source diameters. Near-source behavior varied significantly with source properties but the flows generally became turbulent for streamwise distances within 5 source diameters from the source and became self-preserving for streamwise distances from the source greater than 40–50 source diameters. Crosstream motion satisfied the no-slip convection approximation. Streamwise motion for self-preserving conditions satisfied the behavior of corresponding self-preserving flows in still fluids: round thermals and puffs in still fluids for round thermals and puffs in crossflow and two-dimensional line thermals and puffs in still fluids for round starting plumes and jets in crossflow. The no-slip convection approximation for crossflow motion combined with self-preserving approximations for streamwise motion was also effective for predicting flow trajectories at self-preserving conditions for steady round turbulent plumes and jets in crossflow.

Effectiveness of sealers in counteracting alkali-silica reaction in plain and air-entrained laboratory concretes exposed to wetting and drying, freezing and thawing, and salt water

2002 ◽  
Vol 29 (2) ◽  
pp. 289-300 ◽  
Author(s):  
Marc-André Bérubé ◽  
Dominique Chouinard ◽  
Michel Pigeon ◽  
Jean Frenette ◽  
Luc Boisvert ◽  
...  
Keyword(s):  
Salt Water ◽  
Linseed Oil ◽  
The Other ◽  
Alkali Silica Reaction ◽  
Freezing And Thawing ◽  
Wetting And Drying ◽  
Surface Cracking ◽  
Air Content ◽  
High Alkali ◽  
Freezing And Thawing Cycles

Low- and high-alkali, plain and air-entrained large concrete cylinders, 255 mm in diameter by 310 mm in length, were made with a highly alkali–silica reactive limestone. After curing, a number of cylinders were sealed with silane, oligosiloxane, polysiloxane, linseed oil, or epoxy, with others subjected to 179 freezing and thawing cycles in humid air (one cycle per day). All cylinders were then subjected to 14-day exposure cycles, including in the most severe case periods of humid storage in air, drying, wetting in salt water, and freezing and thawing cycles. All low-alkali specimens did not either expand or develop surface cracking, even those with a deficient air void system and exposed to freezing and thawing cycles. All unsealed high-alkali cylinders subjected early to a series of freezing and thawing cycles did not significantly expand during these cycles, but presented high expansion afterwards. Wetting and drying significantly reduced alkali–silica reaction (ASR) expansion compared with constant humid storage; however, it promoted map-cracking. Regardless of the air content, freezing and thawing increased greatly the concrete expansion in the presence of ASR, even after ASR was almost complete; freezing and thawing also greatly promoted surface cracking. On the other hand, all cylinders early sealed with silane, oligosilixane, or polysiloxane did not either significantly expand or show map-cracking, whatever the exposure conditions and the air content; these cylinders progressively lost mass with time. On the other hand, the epoxy resin was not effective. The linseed oil prevented map-cracking while significantly reducing expansion, however not sufficiently. After one or 1.5 years, some expanding cylinders were sealed with silane, oligosiloxane, or polysiloxane; they started to loose mass and contracted immediately after being sealed, whatever the exposure conditions. The results obtained thus indicate that a good sealer may greatly improve the aesthetic appearance (e.g., map-cracking) and stop expansion of ASR-affected concrete elements of 255 mm or less in thickness, made with a water-to-cement ratio in the range of 0.50, and exposed to wetting and drying, freezing and thawing, and salt water.Key words: air entrained, alkali–silica reaction, concrete, cracking, expansion, freezing and thawing, sealer, silane, siloxane, wetting and drying.

scholarly journals HYDROGEOCHEMICAL CONDITION OF THE PIKROLIMNI LAKE (KILKIS GREECE)

2004 ◽  
Vol 36 (1) ◽  
pp. 192
Author(s):  
E. Dotsika ◽  
Y. Maniatis ◽  
E. Tzavidopoulos ◽  
D. Poutoukis ◽  
K. Albanakis
Keyword(s):  
Fresh Water ◽  
Major Ions ◽  
Salt Water ◽  
Field Measurements ◽  
The Other ◽  
Chemical Analyses ◽  
Temperature Conductivity ◽  
Analytical Scheme ◽  
Hydrochemical Data ◽  
High Degree

In order to understand the hydrogeochemical conditions of the basin of Pikrolimni we collected water samples from the borehole in the thermal spa of Pikrolimni and samples of brine and sediments from the lake. We also sampled fresh water of the region. The depth of the borehole in the thermal spa is approximately 250 meters. This water is naturally sparkling, with a metallic aftertaste and a slight organic smell. The samples were taken twice during the year: in summer (8/2002) and in winter (2003). The analytical scheme includes field measurements of temperature, conductivity and pH. Major ions (Na+, K+, Ca2+, Mg2\ CI", Br, S04 2", C03 2", HC03", N03"), F and Br were determined, in laboratory, according to standard analytical methods. Samples were also subjected to isotopie analysis of δ Ο and δ2Η. The results from the chemical analyses of the samples, show that the waters taken from the borehole, are of the type Mg- (Na-Ca)-HCC>3 and the salts of the lake are of the type Na-CI- (CO3-S04). The salts of the lake result from mixing and condensation of the waters which are accumulated in the basin of the lake, and come not only from sources that feed the lake, e.g. waters from borehole, but also from rain water. The waters of these sources are mainly of meteoritic origin and circulate deeply, mixing probably with salt water of deeper and probably of warmer horizons. The latter comes in agreement with the hydrothermal field, which exists in the area. From hydrochemical data, the brines of summer clearly correspond to waters, which have been submitted under high degree of evaporation: they are residual mother solutions before the step of the precipitation of halite. During winter, dilution of brines and dissolution of depositing minerals by fresh water are observed. On the other hand, evaporating conditions are created in the lake during summer.

Round Turbulent Thermals, Puffs, Starting Plumes and Starting Jets in Uniform Crossflow

2003 ◽  
Vol 125 (6) ◽  
pp. 1046-1057 ◽  
Author(s):  
F. J. Diez ◽  
L. P. Bernal ◽  
G. M. Faeth
Keyword(s):  
Fresh Water ◽  
Salt Water ◽  
Water Channel ◽  
Reynolds Numbers ◽  
Ccd Cameras ◽  
Experimental Conditions ◽  
Time Resolved ◽  
Buoyant Flows ◽  
Video Images ◽  
Density Ratios

The self-preserving properties of round turbulent thermals, puffs, starting plumes and starting jets, in unstratified and uniform crossflow, were investigated experimentally. The experiments involved dye-containing fresh water (for nonbuoyant flows) and salt water (for buoyant flows) sources injected vertically downward into crossflowing fresh water within a water channel. Time-resolved video images of the flows were obtained using CCD cameras. Experimental conditions were as follows: source exit diameters of 3.2 and 6.4 mm, source Reynolds numbers of 2,500–16,000, source/ambient velocity ratios of 4–35, source/ambient density ratios (for buoyant flows) of 1.073 and 1.150, volumes of injected source fluid (for thermals and puffs) comprising 16–318 source diameters, streamwise (vertical) penetration distances of 0–200 source diameters and 0–13 Morton length scales (for buoyant flows) and crosstream (horizontal) penetration distances of 0–620 source diameters. Near-source behavior varied significantly with source properties and distance from the source but the flows generally became turbulent for streamwise distances within 5 source diameters from the source and became self-preserving for streamwise distances from the source greater than 40–50 source diameters. Crosstream motion satisfied the no-slip convection approximation. Streamwise motion for self-preserving conditions satisfied the behavior of corresponding self-preserving flows in still fluids: round thermals and puffs in still fluids for round thermals and puffs in crossflow and two-dimensional line thermals and puffs in still fluids for round starting plumes and jets in crossflow. The no-slip convection approximation for crossflow motion combined with self-preserving approximations for streamwise motion were also effective for predicting flow trajectories at self-preserving conditions for steady round turbulent plumes and jets in crossflow.

Survival of certain naturally acquired freshwater parasites of juvenile sockeye salmon, Oncorhynchus nerka (Walbaum), in hosts held in fresh and sea water, and implications for their use as population tags

1989 ◽  
Vol 67 (7) ◽  
pp. 1757-1766 ◽  
Author(s):  
R. E. Bailey ◽  
L. Margolis ◽  
G. D. Workman
Keyword(s):  
British Columbia ◽  
Fresh Water ◽  
Water Samples ◽  
Sockeye Salmon ◽  
Sea Water ◽  
Salt Water ◽  
Oncorhynchus Nerka ◽  
The Other ◽  
Maximum Life Span ◽  
Natural Tags

Sockeye salmon (Oncorhynchus nerka) smolts were captured from the outlet streams of Cultus Lake, British Columbia, in 1985 and 1986, and from Fraser Lake, British Columbia, in 1986. Samples collected in 1985 were reared in salt water. Samples collected from each lake in 1986 were divided equally into two groups: one group was reared in fresh water, the other was maintained in salt water. Initially biweekly, and later monthly, subsamples from each group were examined for seven parasite taxa: Myxidium salvelini, Diplostomulum sp. metacercaria, Phyllodistomum umblae, Eubothrium sp. (immature), Proteocephalus sp. (immature), Neoechinorhynchus salmonis, and Salmincola californiensis. The maximum life-span was greater than the duration of the experiments (32–40 weeks) for all species in hosts reared in fresh water (except for S. californiensis, which was removed from all freshwater hosts). Survival of M. salvelini, P. umblae, and S. californiensis was reduced in hosts reared in sea water. No differences in survival of each of Diplostomulum sp. metacercaria, Eubothrium sp., Proteocephalus sp., and N. salmonis were observed between hosts held in fresh water or salt water. Implications for the use of these parasites as natural tags are discussed.

scholarly journals Cyclic strengthening of lake ice

2020 ◽  
pp. 1-4
Author(s):  
Andrii Murdza ◽  
Aleksey Marchenko ◽  
Erland M. Schulson ◽  
Carl E. Renshaw
Keyword(s):  
Flexural Strength ◽  
Fresh Water ◽  
Stress Amplitude ◽  
Fiber Stress ◽  
Lake Ice ◽  
Water Ice ◽  
Outer Fiber

Abstract Further to systematic experiments on the flexural strength of laboratory-grown, fresh water ice loaded cyclically, this paper describes results from new experiments of the same kind on lake ice harvested in Svalbard. The experiments were conducted at −12 °C, 0.1 Hz frequency and outer-fiber stress in the range from ~ 0.1 to ~ 0.7 MPa. The results suggest that the flexural strength increases linearly with stress amplitude, similar to the behavior of laboratory-grown ice.

scholarly journals XII. An easy method to distill fresh water from salt water at sea; by Capt. Newland

1772 ◽  
Vol 62 ◽  
pp. 90-92 ◽  
Keyword(s):  
Fresh Water ◽  
Salt Water ◽  
Easy Method

The materials necessary for this process are the following; a copper or iron pot of 15 or 20 gallons, an empty cask, some sheet lead, a small jar, a few wood-ashes or soap, and billet-wood for fewel.

Intercalation Processes in Cobalt Substituted Nickel Oxyhydroxides

1990 ◽  
Vol 210 ◽  
Author(s):  
Claude Delmas
Keyword(s):  
Ir Spectroscopy ◽  
Mechanical Treatment ◽  
Positive Charge ◽  
Van Der Waals ◽  
The Other ◽  
Hydrolysis Reaction ◽  
Water Molecules ◽  
Layered Oxides ◽  
Experimental Conditions ◽  
Cobalt Ions

AbstractChimie douce reactions (hydrolysis and reduction) from layered oxides : NaNiO2, NaxCoO2 and NaNil-xCoxO2 lead to numerous oxyhydroxides and hydroxides which differ by the composition of the intersheet space.According to the experimental conditions of the hydrolysis reaction, the oxyhydroxides can be unhydrated or intercalated with one or two layers of water molecules. From the most hydrated phases, the other ones can be obtained by chemical, thermal and even mechanical treatment.The reduction of Co-substituted nickel oxyhydroxides leads to hydroxides in which nickel and cobalt ions are respectively divalent and trivalent. In order to compensate the excess of positive charge in the (Ni, Co)O2 sheet, anions (OH-, CO32-, SO42-, NO3-) are inserted in the Van der Waals gap.For the highest anion amounts, well ordered α*-type materials are obtained. Water molecules are simultaneously inserted in the interslab space. Their structure is strongly related to the hydrotalcite one. When the amouit of anions in the intersheet space is not sufficient, interstratified materials are obtained. In this case the (Ni,Co)(OH)2 slabs are separated by a layer of CO32- anions and water molecules (α*-type) or by an empty Van der Waals gap (β(II)-type). The amount of α*-type planes in the structure increases with the cobalt amount. All these materials have been characterized by IR spectroscopy which allows to detect the existence of two types of O-H bonds (free in α*-type plane or hydrogen bonded in ²(II)-type plane).

In Vitro Binding of Zearalenone to Different Adsorbents

2005 ◽  
Vol 68 (3) ◽  
pp. 613-615 ◽  
Author(s):  
DANTE J. BUENO ◽  
LILIANA DI MARCO ◽  
GUILLERMO OLIVER ◽  
ALICIA BARDÓN
Keyword(s):  
Activated Carbon ◽  
Calcium Sulfate ◽  
Fusarium Species ◽  
The Other ◽  
Experimental Conditions ◽  
In Vitro Binding ◽  
Other Hand ◽  
Vitro Binding ◽  
Dose Levels

Zearalenone (ZEA) is a potent estrogenic metabolite produced by some Fusarium species. No treatment has been successfully employed to get rid of the ZEA contained in foods. This study was conducted to evaluate the ability (adsorptive power) of five adsorbents—activated carbon, bentonite, talc, sandstone, and calcium sulfate—to trap ZEA in vitro. Activated carbon was the best adsorbent, binding 100% ZEA (pH 3 and 7.3) at 0.1, 0.25, 0.5, and 1% dose levels. Bentonite, talc, and calcium sulfate were less efficient than activated carbon but still could bind ZEA to some extent. On the other hand, sandstone was inactive in the experimental conditions employed. Our results indicate that activated carbon could be a good candidate for detoxification of ZEA present in foods.

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