scholarly journals Movement of Grain Boundary in Sea Ice

1985 ◽  
Vol 6 ◽  
pp. 274-275
Author(s):  
Toshiyuki Kawamura
Keyword(s):  
Experimental Study ◽  
Grain Boundary ◽  
Sea Ice ◽  
Horizontal Plane ◽  
Sea Water ◽  
Horizontal Component ◽  
The Other ◽  
Boundary Groove ◽  
Thin Sections ◽  
The Difference

An experimental study on the preferred growth of grains in sea ice was performed. As a seed an artificial bi-crystal was prepared by welding two single crystals; the c-axis of one grain was in a horizontal plane, that of the other made an angle of α with the horizontal plane, and they intersected at right angles. An angle between a resulting grain boundary and the vertical line, Θ, was measured on thin sections of sea ice after it grew about 10 cm downward in sea water. The relation between a and ? was given by ? = 0.4α + 6, when a was varied from -25º to 25º. When α = 0º , that is c-axes of both the grains are at right angles on a horizontal plane, encroachment still occurs, which is contrary to the earlier studies. These results can be explained by the difference in the horizontal component of growth rate between neighbouring grains at the grain boundary groove.

scholarly journals Movement of Grain Boundary in Sea Ice

1985 ◽  
Vol 6 ◽  
pp. 274-275
Author(s):  
Toshiyuki Kawamura
Keyword(s):  
Experimental Study ◽  
Grain Boundary ◽  
Sea Ice ◽  
Horizontal Plane ◽  
Sea Water ◽  
Horizontal Component ◽  
The Other ◽  
Boundary Groove ◽  
Thin Sections ◽  
The Difference

An experimental study on the preferred growth of grains in sea ice was performed. As a seed an artificial bi-crystal was prepared by welding two single crystals; the c-axis of one grain was in a horizontal plane, that of the other made an angle of α with the horizontal plane, and they intersected at right angles. An angle between a resulting grain boundary and the vertical line, Θ, was measured on thin sections of sea ice after it grew about 10 cm downward in sea water. The relation between a and ? was given by ? = 0.4α + 6, when a was varied from -25º to 25º. When α = 0º , that is c-axes of both the grains are at right angles on a horizontal plane, encroachment still occurs, which is contrary to the earlier studies. These results can be explained by the difference in the horizontal component of growth rate between neighbouring grains at the grain boundary groove.

scholarly journals The Formation of Brine Drainage Features in Young Sea Ice

1975 ◽  
Vol 14 (70) ◽  
pp. 137-154 ◽  
Author(s):  
Lars Ingolf Eide ◽  
Seelye Martin
Keyword(s):  
Sea Ice ◽  
Laboratory Experiments ◽  
Sea Water ◽  
Salt Water ◽  
Pressure Head ◽  
Drainage Channels ◽  
The Difference ◽  
Thin Plastic ◽  
Ice Water ◽  
Brine Channel

Laboratory experiments on the growth of sea ice in a very thin plastic tank filled with salt water, cooled from above and insulated with thermopane, clearly show the formation and development of brine drainage channels. The sea-water freezing cell is 0.3 cm thick by 35 cm wide by 50 cm deep; the thermopane insulation permits the ice interior to be photographed. Experimentally, we observe that vertical channels with diameters of 1 to 3 mm and associated smaller feeder channels extend throughout the ice sheet. Close examination of the brine channels show that their diameter at the ice-water interface is much narrower than higher up in the ice, so that the channel has a “neck” at the interface. Further, oscillations occur in the brine channels, in that brine flows out of the channel followed by a flow of sea-water up into the channel. Theoretically, a qualitative theory based on the difference in pressure head between the brine inside the ice and the sea-water provides a consistent explanation for the formation of the channels, and the onset of a convective instability explains the existence of the neck. Finally, an analysis based on the presence of the brine-channel neck provides an explanation for the observed oscillations.

scholarly journals The Formation of Brine Drainage Features in Young Sea Ice

1975 ◽  
Vol 14 (70) ◽  
pp. 137-154 ◽  
Author(s):  
Lars Ingolf Eide ◽  
Seelye Martin
Keyword(s):  
Sea Ice ◽  
Laboratory Experiments ◽  
Sea Water ◽  
Salt Water ◽  
Pressure Head ◽  
Drainage Channels ◽  
The Difference ◽  
Thin Plastic ◽  
Ice Water ◽  
Brine Channel

Laboratory experiments on the growth of sea ice in a very thin plastic tank filled with salt water, cooled from above and insulated with thermopane, clearly show the formation and development of brine drainage channels. The sea-water freezing cell is 0.3 cm thick by 35 cm wide by 50 cm deep; the thermopane insulation permits the ice interior to be photographed. Experimentally, we observe that vertical channels with diameters of 1 to 3 mm and associated smaller feeder channels extend throughout the ice sheet. Close examination of the brine channels show that their diameter at the ice-water interface is much narrower than higher up in the ice, so that the channel has a “neck” at the interface. Further, oscillations occur in the brine channels, in that brine flows out of the channel followed by a flow of sea-water up into the channel. Theoretically, a qualitative theory based on the difference in pressure head between the brine inside the ice and the sea-water provides a consistent explanation for the formation of the channels, and the onset of a convective instability explains the existence of the neck. Finally, an analysis based on the presence of the brine-channel neck provides an explanation for the observed oscillations.

scholarly journals Catheter contact angle influences local impedance drop during radiofrequency catheter ablation: Insight from a porcine experimental study with 2 different LI-sensing catheters

2021 ◽  
Author(s):  
Gen Matsuura ◽  
Hidehira Fukaya ◽  
Emiyu Ogawa ◽  
Sota Kawakami ◽  
Hitoshi Mori ◽  
...  
Keyword(s):  
Experimental Study ◽  
Contact Angle ◽  
Catheter Ablation ◽  
Angular Dependence ◽  
Radiofrequency Catheter Ablation ◽  
Lesion Size ◽  
Contact Angles ◽  
The Other ◽  
Tissue Temperature ◽  
The Difference

Background: Local impedance (LI) can indirectly measure catheter contact and tissue temperature during radiofrequency catheter ablation (RFCA). However, data on the effects of catheter contact angle on LI parameters are scarce. This study aimed to evaluate the influence of catheter contact angle on LI changes and lesion size with 2 different LI-sensing catheters in a porcine experimental study. Methods: Lesions were created by the INTELLANAV MiFi™ OI (MiFi) and the INTELLANAV STABLEPOINT™ (STABLEPOINT). RFCA was performed with 30 watts and a duration of 30 seconds. The CF (0, 5, 10, 20, and 30 g) and catheter contact angle (30°, 45°, and 90°) were changed in each set (n=8 each). The LI rise, LI drop, and lesion size were evaluated. Results: The LI rise increased as CF increased. There was no angular dependence with the LI rise under all CFs in the MiFi. On the other hand, the LI rise at 90° was lower than at 30° under 5 and 10 g of CF in STABLEPOINT. The LI drop increased as CF increased. Regarding the difference in catheter contact angles, the LI drop at 90° was lower than that at 30° for both catheters. The maximum lesion widths and surface widths were smaller at 90° than at 30°, whereas there were no differences in lesion depths. Conclusion: The LI drop and lesion widths at 90° were significantly smaller than those at 30°, although the lesion depths were not different among the 3 angles for the MiFi and STABLEPOINT.

scholarly journals EXPERIMENTAL STUDY OF CONCRETE PERFORMANCE

2020 ◽  
Vol 2 (1) ◽  
pp. 48-61
Author(s):  
Sang Kee ◽  
Yuhee Park ◽  
Eun Choi
Keyword(s):  
Experimental Study ◽  
Compressive Strength ◽  
Rice Husk ◽  
Rice Husk Ash ◽  
Strength Test ◽  
The Other ◽  
Average Score ◽  
Two Samples ◽  
The Difference ◽  
B Test

This study was experimental in nature and conducted with the view to make comparison between two samples. The first sample consisted of concrete with rice husk ash mixed in it and the other sample was without such addition. The first test conducted to test the performance was simple measurements. The results show that for the sample without addition of rice husk ash, the density was 2355.97 and for included sample, the density was 2354.44 with insignificant differences (t-stat= 0.766, P>.05). For V-B test, the sample without addition of rice husk as was 8.34 and for include sample, it was 8.01. The differences for V-B for both samples were statistically insignificant (t-stat=1.431, P>.05). The slump test without for the sample without addition of rice husk was 12.75 and for included sample, it was 18.56. The difference was statistically significant (t-stat=2.455, P<.05). The compressive strength for excluded sample was 24.32 and for included sample was 20.01. The results were statistically insignificant (t-value= 1.13, P>.05). For flexural strength test, for excluded sample, the average score was 9.02 and for included sample, the average score was 9.19. The difference was statistically insignificant (t-stat=1.45, P>.05). Overall, the results lead to the conclusion that there are insignificant differences of addition of rice husk ash in concrete.

scholarly journals How to show empathy as a coach: The effects of coaches’ imagine-self versus imagine-other empathy on the client’s self-change and coaching outcome

2021 ◽  
Author(s):  
Sandra J. Diller ◽  
Christina Mühlberger ◽  
Nele Löhlau ◽  
Eva Jonas
Keyword(s):  
Experimental Study ◽  
Practical Implication ◽  
Cognitive Empathy ◽  
The Other ◽  
Survey Study ◽  
Future Research ◽  
Personnel Development ◽  
The Difference ◽  
Positive Effect

AbstractCognitive empathy, expressed as either imagine-self (imagining oneself in the other’s situation) or imagine-other (imagining the other person in his/her situation) empathy, is essential for self-change and satisfaction in coaching. In two studies, we investigated the difference between coaches’ imagine-self versus imagine-other empathy. In a survey study (N1 = 242), we found that the more important coaches perceived the client’s self-change, the more valuable they not only rated empathy in general but also imagine-other (but not imagine-self) empathy in particular. In an experimental study (N2 = 57), we manipulated the coaches’ imagine-self versus imagine-other empathy and examined the effect on the clients’ self-change and coaching satisfaction. The results revealed a positive effect of imagine-other (but not imagine-self) empathy on these coaching outcome factors. Thus, one main practical implication is the relevance of showing imagine-other instead of imagine-self empathy as a coach. However, future research should investigate other personnel development approaches like mentoring or training with regard to imagine-self versus imagine-other empathy. 

scholarly journals Observations on sea-ice and surface-water geochemistry–implications for importance of sea ice in geochemical cycles in the northern Baltic Sea

2001 ◽  
Vol 33 ◽  
pp. 311-316 ◽  
Author(s):  
M. A. Granskog ◽  
J. Virkanen
Keyword(s):  
Surface Water ◽  
Sea Ice ◽  
Baltic Sea ◽  
Trace Element ◽  
Sea Water ◽  
Ice Cores ◽  
The Other ◽  
Ice Formation ◽  
Nutrient Concentrations ◽  
Element Concentrations

AbstractSea-ice and surface-water samples collected in January-April 1999 in coastal areas in the northern Baltic Sea were analyzed for particle, nutrient and trace-element concentrations and salinity. Stratigraphic analyses of ice cores were also carried out. Bulk nutrient and trace-element concentrations in sea ice fluctuated widely. Nutrient concentrations in sea ice normalized to sea-water salinities showed that sea ice had, almost without exception, an excess of nutrients compared to underlying waters. For phosphorus and phosphate this can be explained by particle incorporation and snow-ice formation, whereas for nitrogen and the sum of nitrite and nitrate snow-ice formation and other mechanisms are important. The levels of Al, Cu, Fe and Ni in the ice were similar to those observed in underlying waters. Pb was observed in detectable concentrations in the ice only. This indicates that sea ice contributes lead to underlying waters during melting, and in some degree also affects the other elements. Furthermore, the observations indicate that incorporation of lead into the ice cover is governed by different processes than for the other elements studied.

scholarly journals Ecological and non-environmental constitutional resistance of the protoplasm of marine algae

1952 ◽  
Vol 31 (2) ◽  
pp. 307-315 ◽  
Author(s):  
Richard Biebl
Keyword(s):  
Intertidal Zone ◽  
Marine Algae ◽  
Sea Water ◽  
Light Exposure ◽  
Ecological Factors ◽  
The Other ◽  
Ecological Group ◽  
Ecological Groups ◽  
Chemical Substances ◽  
The Difference

Marine algae supply good examples of the difference between ‘ecological’ and ‘non-environmental constitutional’ resistance of the protoplasm of their cells to variations in the environment. The resistance to ecological factors such as diluted or concentrated sea water, to desiccation, or to light exposure is very similar among algae occupying the same habitat. On the basis of the degree of resistance shown, three ecological groups can be distinguished: (1) algae from the intertidal zone; (2) algae from the low-water level and tide-pools; and (3) sublittoral algae.On the other hand, there is no similarity in the resistance to chemical substances (H3BO3, ZnSO4, MnSO4, VOSO4) of algae within a given ecological group. It is characteristic for a given species.

scholarly journals XXIII.—On the Chemical Changes which take place in the Composition of the Sea-Water associated with Blue Muds on the Floor of the Ocean

1895 ◽  
Vol 37 (2) ◽  
pp. 481-507 ◽  
Author(s):  
John Murray ◽  
Robert Irvine
Keyword(s):  
Specific Gravity ◽  
Sea Water ◽  
The Other ◽  
Sea Salts ◽  
General Law ◽  
Observational Errors ◽  
The Difference ◽  
Analysis Point ◽  
Bathymetrical Distribution ◽  
Dissolved Salts

The numerous analyses of sea-water by Forchhammer previous to 1865, and the later analyses by Dittmar, from samples collected during the “Challenger” Expedition, show that while the salinity—i.e., the amount of dissolved salts contained in 100 parts of seawater—varies greatly in different regions of the ocean, still the composition of these dissolved salts—i.e., the ratio of the constituents of sea-salts—remains practically the same in all the superficial waters of the ocean. Consequently, it is only necessary to determine the chlorine in a definite weight of water to ascertain at once the respective quantities of the other salts present in the sample. Dittmar's examination of the “Challenger” waters has, however, shown that lime is slightly, although distinctly, more abundant in samples of sea-water collected in greater depths than in those samples collected nearer the surface of the ocean, and Dittmar's tables showing the difference between the chlorine calculated from the specific gravity and the chlorine found by analysis point to differences in the composition of the sea-salts, but the observations are relatively so few, these differences so slight, so mixed up with observational errors, and so irregular in their geographical and bathymetrical distribution, that they cannot be said to indicate any general law other than a greater quantity of lime in deep water.

Identification of Voids and Cracks by Ultrasonic Technique

2006 ◽  
Vol 326-328 ◽  
pp. 665-668 ◽  
Author(s):  
Shiuh Chuan Her ◽  
Ming Chih Chang
Keyword(s):  
Experimental Study ◽  
Nondestructive Evaluation ◽  
Incident Wave ◽  
The Other ◽  
Ultrasonic Technique ◽  
Evaluation Technique ◽  
Meaningful Difference ◽  
Significant Difference ◽  
Scattering Wave ◽  
The Difference

Ultrasonic is one of the most wide use of nondestructive evaluation technique. Voids and cracks are the most common defects in a solid. In this investigation, the ultrasonic technique is used to distinguish the defects between the void and crack. As an incident wave impinges on the crack tip, the diffractive wave can be detected from various angles. The amplitude of the diffraction is dependent on the receiving angle. For a void, the incident wave is scattered, the amplitude of the scattering wave is also dependent on the receiving angle. By comparing the amplitudes between the diffractive wave and the scattering wave, one is able to identify the defect of a void or a crack from the other. In this work, 5MHz of longitudinal and shear transducers are used and placed in a variety of incident and receiving angles to examine the difference between the void and crack. The experimental results are validated by the theoretical calculation. In order to identify the void and crack, it is required to have significant difference between the diffractive and scattering waves. The range of the detecting angle, which possesses a meaningful difference between the diffractive and scattering waves, is proposed through the numerical and experimental study to help the identification of the void and crack.

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