Journal articles: 'Capillary freezing'

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MAEDA, NOBUO, and VASSILI V. YAMINSKY. "EXPERIMENTAL OBSERVATIONS OF SURFACE FREEZING." International Journal of Modern Physics B 15, no. 23 (September 20, 2001): 3055–77. http://dx.doi.org/10.1142/s0217979201007051.

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Capillary phase transitions and those induced by interfaces, like pre-melting, have been studied for decades. The related phenomenon of surface freezing has not been explored so extensively. We review experiments on surface freezing, those of long-chain n-alkanes in particular, and place the results within the wider thermodynamic framework of surface phase transitions. Surface freezing plays an important role in nucleation and crystallization of bulk long-chain n-alkanes. Implications for capillary melting and freezing of substances at nanoscales are discussed. Theoretical aspects of condensed capillary phase transitions will be reviewed separately.

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Erlandsen, S., A. Holzer, M. Gavin, C. Frethem, and C. Wells. "High Pressure Freezing/Freeze Substituion: Comparison of Chemical Fixation Versus Cryoimmobilization of Candida Albicans Cultured in Cellulose Tubing." Microscopy and Microanalysis 5, S2 (August 1999): 434–35. http://dx.doi.org/10.1017/s143192760001549x.

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In the interactions of Candida albicans with host cells, the cell wall of the yeast may play important roles in the adhesion of yeast cells to tissues. The outer cell wall of yeast (e.g. Saccharomyces cerevisiae, C. albicans) has been shown to consist of a dense network of radially projecting fibrils composed of mannoproteins that are known as fimbriae and which previously have required cryopreservation either by jet propane freezing or by plunge freezeing for their visualization. High pressure freezing provides an advantage over jet or plunge freezing in terms of the higher consistancey in the quality of freezing, and the minimization of formation of ice I with this method. Hohenberg et al reported a method utilizing cellulose capillary tubes to cryoimmobilize suspensions of microoganisms by high pressure freezing (HPF) and freeze substitution (FS), and herein, we describe an adaptation of this method by culturing microorganisms within the tubing to increase cell density prior to high pressure freezing and freeze substution.

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Christenson, H. K. "Liquid Capillary Condensates below the Freezing Point." Physical Review Letters 74, no. 23 (June 5, 1995): 4675–78. http://dx.doi.org/10.1103/physrevlett.74.4675.

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Tad Pfeffer, W., Tissa H. Illangasekare, and Mark F. Meier. "Analysis and Modeling of Melt-Water Refreezing in Dry Snow." Journal of Glaciology 36, no. 123 (1990): 238–46. http://dx.doi.org/10.1017/s0022143000009497.

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AbstractA dynamic zone of thermal disequilibrium is described which separates wet snow at 0 ° C from dry, sub-freezing snow. The dynamic zone tends to be eliminated by thermal equilibrium through freezing, but is sustained and propagated into the sub-freezing snow by water flow from the wet snow. The width of the dynamic zone is controlled by the rate of water inflow, and by the rate of freezing of water on to sub-freezing ice grains, which is in turn controlled by the ice/water geometry. Two ice/water geometries are investigated: isolated ice spheres and capillary tubes of ice into which water is pulled by capillary suction. The rate of freezing of water is calculated for the two models for various initial dimensions and temperatures. Equilibrium times are short (typically about 0.5 s), but depend on the assumed geometry, which is poorly constrained by existing data. Equilibration times and freeze-on mass fluxes are calculated for a variety of general conditions. These results can be used in numerical models of wetting-front propagation into cold snow.

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Tad Pfeffer, W., Tissa H. Illangasekare, and Mark F. Meier. "Analysis and Modeling of Melt-Water Refreezing in Dry Snow." Journal of Glaciology 36, no. 123 (1990): 238–46. http://dx.doi.org/10.3189/s0022143000009497.

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AbstractA dynamic zone of thermal disequilibrium is described which separates wet snow at 0 ° C from dry, sub-freezing snow. The dynamic zone tends to be eliminated by thermal equilibrium through freezing, but is sustained and propagated into the sub-freezing snow by water flow from the wet snow. The width of the dynamic zone is controlled by the rate of water inflow, and by the rate of freezing of water on to sub-freezing ice grains, which is in turn controlled by the ice/water geometry. Two ice/water geometries are investigated: isolated ice spheres and capillary tubes of ice into which water is pulled by capillary suction. The rate of freezing of water is calculated for the two models for various initial dimensions and temperatures. Equilibrium times are short (typically about 0.5 s), but depend on the assumed geometry, which is poorly constrained by existing data. Equilibration times and freeze-on mass fluxes are calculated for a variety of general conditions. These results can be used in numerical models of wetting-front propagation into cold snow.

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Basavappa, Ravi, Edward T. Petri, and Blanton S. Tolbert. "A quick and gentle method for mounting crystals in capillaries." Journal of Applied Crystallography 36, no. 5 (September 8, 2003): 1297–98. http://dx.doi.org/10.1107/s0021889803014006.

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The capillary mounting of protein crystals is still necessary under some circumstances, despite its being supplanted by loop mounting/flash freezing as the favored method for crystal mounting prior to data collection. Traditional capillary mounting methods require a degree of dexterity and finesse that causes apprehension among many crystallographers. Here a simple method for capillary mounting that uses a loop for depositing the crystal in the capillary is described.

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Henry, Karen S., and Robert D. Holtz. "Geocomposite capillary barriers to reduce frost heave in soils." Canadian Geotechnical Journal 38, no. 4 (August 1, 2001): 678–94. http://dx.doi.org/10.1139/t01-010.

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We investigated the potential for geosynthetic capillary barriers to reduce frost heave in soils by freezing upright, cylindrical soil specimens with horizontal disks of geosynthetics placed in them. During freezing, water was freely available at 25 mm above the base of 150 mm high specimens. The geosynthetics were located 5 mm above the water supply. We measured frost heave and final water content profiles of specimens containing geosynthetic capillary barriers and control specimens. The thermal conditions of the tests were typical of pavements in cold regions. Geotextiles prepared to simulate field conditions (i.e., moistened and containing soil fines) failed to significantly reduce frost heave. However, geocomposites comprising needle-punched polypropylene geotextiles sandwiching a drainage net, prepared in the same way as the moistened geotextiles containing soil fines, reduced frost heave when the soil water suction head in the overlying soil was 1800 mm or more. The geocomposites did not significantly reduce heave when the soil water suction head in the overlying soil was 800 mm or less. This is probably due to water migration between the two layers of soil, through the geotextiles and along the net of the geocomposite.Key words: capillary barrier, frost heave, geosynthetic, geotextile, geocomposite, soil freezing.

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Yakovlev, S., and K. Downing. "Freezing in Sealed Capillary as an Alternative to HPF." Microscopy and Microanalysis 17, S2 (July 2011): 240–41. http://dx.doi.org/10.1017/s1431927611002078.

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9

Fretwell, H. M., J. A. Duffy, M. A. Alam, and R. Evans. "Anomalous freezing and melting behaviour of capillary confined CO2." Journal of Radioanalytical and Nuclear Chemistry Articles 210, no. 2 (November 1996): 575–82. http://dx.doi.org/10.1007/bf02056398.

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10

Zhang, Jiwen, Qingyi Mu, Hongjian Liao, and Jie Cao. "An unfrozen water retention curve for capturing soil density and specific surface effects." E3S Web of Conferences 195 (2020): 02018. http://dx.doi.org/10.1051/e3sconf/202019502018.

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Unfrozen water retention curve (UWRC) defines the relationship between temperature and unfrozen water content in frozen soils. Although many models have been proposed for the UWRC, these existing models cannot predict UWRC well over a wide temperatures range. In this study, a new UWRC model is proposed with explicit considerations of both capillarity and adsorption. In this model, capillarity is considered dominating when the freezing of soil pore water at higher temperatures (above -2oC), whereas the effects of adsorption pronounce at temperatures below -2oC. Moreover, effects of void ratio on the freezing of capillary water are incorporated. The proposed model was applied to predict UWRCs of silt and clay at different initial void ratios over a wide temperature range (from -50 to 0oC). Predicted results by this new model are compared with predictions by three well-known existing models. The new model can capture the density effects on UWRC. Moreover, the new model can predict better UWRC over a wide temperature range since it explicitly considers both effects of capillarity and adsorption.

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11

FULLERTON (nee Landsburg), S., and S. PAWLUK. "THE ROLE OF SEASONAL SALT AND WATER FLUXES IN THE GENESIS OF SOLONETZIC B HORIZONS." Canadian Journal of Soil Science 67, no. 4 (November 1, 1987): 721–30. http://dx.doi.org/10.4141/cjss87-071.

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Seasonal salt and water fluxes into Black Solonetz soils were evaluated at two sites in east-central Alberta. The dominant mode of moisture movement into the soil pedon was by capillary movement of water upwards from the water table. Solonization occurred in the Bntj horizons as a consequence of salt transport; the salts responsible were NaHCO3 and Na2SO4. Seasonal salt and water fluxes were identified at both research sites. From May to November when soil temperatures were above 0 °C, capillary movement and evaporation were the major mechanisms responsible for salt transport, concentration and deposition. From December to March when soil temperatures were below 0 °C water moved upwards from the water table towards the freezing zone depositing salts upon freezing. Key words: Genesis, solonetzic; season, groundwater, salt flux, water flux

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12

HOHENBERG, H., K. MANNWEILER, and M. MÜLLER. "High-pressure freezing of cell suspensions in cellulose capillary tubes." Journal of Microscopy 175, no. 1 (July 1994): 34–43. http://dx.doi.org/10.1111/j.1365-2818.1994.tb04785.x.

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13

De La Fuente, Maria, Jean Vaunat, and Héctor Marín-Moreno. "Modelling Methane Hydrate Saturation in Pores: Capillary Inhibition Effects." Energies 14, no. 18 (September 7, 2021): 5627. http://dx.doi.org/10.3390/en14185627.

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Experimental and field observations evidence the effects of capillarity in narrow pores on inhibiting the thermodynamic stability of gas hydrates and controlling their saturation. Thus, precise estimates of the gas hydrate global inventory require models that accurately describe gas hydrate stability in sediments. Here, an equilibrium model for hydrate formation in sediments that accounts for capillary inhibition effects is developed and validated against experimental data. Analogous to water freezing in pores, the model assumes that hydrate formation is controlled by the sediment pore size distribution and the balance of capillary forces at the hydrate–liquid interface. To build the formulation, we first derive the Clausius–Clapeyron equation for the thermodynamic equilibrium of methane and water chemical potentials. Then, this equation is combined with the van Genuchten’s capillary pressure to relate the thermodynamic properties of the system to the sediment pore size distribution and hydrate saturation. The model examines the influence of the sediment pore size distribution on hydrate saturation through the simulation of hydrate formation in sand, silt, and clays, under equilibrium conditions and without mass transfer limitations. The results show that at pressure–temperature conditions typically found in the seabed, capillary effects in very fine-grained clays can limit the maximum hydrate saturation below 20% of the host sediment porosity.

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14

Thomachot, C., N. Matsuoka, N. Kuchitsu, and M. Morii. "Frost damage of bricks composing a railway tunnel monument in Central Japan: field monitoring and laboratory simulation." Natural Hazards and Earth System Sciences 5, no. 4 (July 14, 2005): 465–76. http://dx.doi.org/10.5194/nhess-5-465-2005.

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Abstract. Bricks of tunnels and bridges of Usui Pass railway (Japan) exposed to north are subject to frost damage. Average depth of erosion due to detachment of angular blocks is around 1-1.5 cm. In order to assess this weathering and to understand its mechanism, an experimental study was carried out in the field and laboratory. Field monitoring showed the combination of seasonal and diurnal freezing with a maximum of heave when the freezing front reached 5 cm depth. Bricks taken from the site were submitted to unidirectional freezing at capillary and vacuum saturation in the laboratory. Results showed that frost damage of bricks was favoured by high saturation level and repetition of freeze-thaw cycles.

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15

Gray, D. M., and R. J. Granger. "In situ measurements of moisture and salt movement in freezing soils." Canadian Journal of Earth Sciences 23, no. 5 (May 1, 1986): 696–704. http://dx.doi.org/10.1139/e86-069.

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The paper presents the results of field studies on the movement of moisture and salts during freezing of Prairie soils. It is shown that large fluxes of water can migrate to the freezing front and move upward into the frozen soil above. The fluxes are largest in light-textured soils (e.g., silt loam) having a water table at shallow depth. However, substantial amounts of soil moisture may also move in silty clay, silty clay loam, and clay soils under dryland farming provided there is sufficient water present to support capillary flow.The dynamics of soil moisture transfer under natural conditions as a result of freezing involves movement of water in both vapor and liquid phases. In the shallow surface layer of soil, to a depth of 300–400 mm, vapor flow predominates; in the depth below, water usually moves primarily as a liquid. It is demonstrated that the accumulation of ice with time increases because of the downward movement of the freezing front and the upward movement of water into the frozen soil above. In a silt loam with large fluxes, the ice content of the frozen zone rapidly reaches a level (80–85% pore saturation) where measurable migration ceases. Conversely, in a silty clay the movement of moisture into the frozen soil is observed to continue throughout most of the freezing period, and the ice content reaches 93% pore saturation. The greater movement in the finer grained soil is attributed to a higher freezing-point depression, a larger number of capillary pores, and a higher concentration of soluble salts in the liquid films.A close association is observed between changes in the ice content and electrical conductivity of a silt loam after freezing. In a silty clay the agreement is less clear, probably the result of the exchange of ions between the migrating liquid water and the clay particles. Maximum amounts of exchangeable ions moving into a 1 m depth of soil by the freezing action are estimated to be 11.9 t/ha in a silt loam and 15.7 t/ha in a silty clay loam.Data showing the redistribution of water and salts during thawing are also presented and discussed.

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16

Henry, Karen S. "Geotextiles to Mitigate Frost Effects in Soils: A Critical Review." Transportation Research Record: Journal of the Transportation Research Board 1534, no. 1 (January 1996): 5–11. http://dx.doi.org/10.1177/0361198196153400102.

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The use of geotextiles to mitigate frost effects in soils has been studied, but few techniques have been developed. Guidelines developed for the placement of granular capillary barriers are presented to serve as preliminary guidelines for geotextile capillary barriers. Laboratory research shows that pore size distribution, wettability, and, for some geotextiles, thickness influence capillary barrier performance in a given soil. Geotextiles that easily wet do not reduce frost heave and may even exacerbate it. On the basis of the literature reviewed, guidance for selection of geotextile capillary barriers in field trials is given. If geotextiles function as capillary barriers during freezing and reinforce or separate and filter the subgrade at the base course interface during thaw, then the potential exists for their use in a combination of functions to reduce frost-related damage in geotechnical structures. It was found that properly designed geotextiles have the potential to reduce frost heave by functioning as capillary barriers, they can be filters for capillary barriers, and they can provide reinforcement or separation or filtration (or all of these) of the subgrade soil to reduce thaw-related damage.

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17

Schranz and Soprunyuk. "Water in Mesoporous Confinement: Glass-To-Liquid Transition or Freezing of Molecular Reorientation Dynamics?" Molecules 24, no. 19 (October 1, 2019): 3563. http://dx.doi.org/10.3390/molecules24193563.

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The first mechanical relaxation measurements (f = 400 Hz) of water confined in micro-porous silica were performed more than 40 years ago. The authors reported a so called “capillary transition” (here denoted as P3) of water in the core of the pores and a second one at a lower temperature, which they called the “adsorbate transition” (P1 in present work) related to water near the surface of the pores. The capillary transition was identified with the freezing of water in the centre of the pores. However, even 40 years later, the origin of the adsorbate transition is not yet clear. One study relates it to the liquid-to-glass transition of the supercooled water in the pores, and another study to the freezing of the proton reorientations at the lattice defects. The present work shows the data from extensive dynamic mechanical analysis (DMA) measurements (f = 0.1 Hz–70 Hz) of water confined in mesoporous silica (d = 2.5, 5 and 10 nm), which are in favour of a liquid-to-glass scenario.

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Tumidajski, Peter J. "Effect of slag, silica fume, and finishing on the sorptivities of field concrete." Canadian Journal of Civil Engineering 33, no. 8 (August 1, 2006): 1022–26. http://dx.doi.org/10.1139/l06-048.

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For Canadian Standards Association C-2 exposure conditions (i.e., nonstructurally reinforced concrete exposed to chlorides and freezing and thawing) after 1 year, the effect of cement binder and finishing techniques on the capillary suction sorptivities of commercially batched and field-placed, cured, and finished concrete is reported. It was found that the addition of 40% ground granulated blast furnace slag or 8% silica fume is very effective in reducing sorptivities of field concrete. Furthermore, finishing techniques that do not overwork the surface assist in reducing sorptivities of field concrete.Key words: capillary suction, saturation, sorptivity, silica fume, slag, finish.

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Salnikov, M. V., A. V. Fedoseev, and G. I. Sukhinin. "Thermo conductivity in melting and freezing processes of the capillary-porous bodies." Journal of Physics: Conference Series 1105 (November 2018): 012063. http://dx.doi.org/10.1088/1742-6596/1105/1/012063.

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GUNNINK, B. W. "CRITICAL ANALYSIS OF CONDUCTOMETRIC PHASE TRANSITION POROSIMETRY: 1. CAPILLARY FREEZING AND MELTING." Particulate Science and Technology 7, no. 3 (January 1989): 229–39. http://dx.doi.org/10.1080/02726358908906541.

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Yan, Dongming, Lingjun Xie, Xiaoqian Qian, Shaoqin Ruan, and Qiang Zeng. "Compositional Dependence of Pore Structure, Strengthand Freezing-Thawing Resistance of Metakaolin-Based Geopolymers." Materials 13, no. 13 (July 3, 2020): 2973. http://dx.doi.org/10.3390/ma13132973.

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The understanding of the composition dependent properties and freezing-thawing (F-T) resistance of geopolymer materials is vital to their applications in cold regions. In this study, metakaolin-based geopolymer (MKG) mortars were fabricated by controlling the Si/Al ratio and the Na/Al ratio. The pore structure and strength were measured by mercury intrusion porosimetry and compression tests, respectively, which both showed obvious correlations with the material composition. Mass loss, strength loss, visual rate, and microscopic observation were adopted to assess the changes of the material properties and microstructure caused by F-T loads. The results showed that the strength-porosity relationship roughly followed a linear plot. Increases of the Si/Al ratio increased the capillary pore volume, but decreased the gel pore volume and the F-T resistance. Increases of the Na/Al ratio decreased the gel pore, but roughly enhanced the F-T resistance. The MKG mortar at the Na/Al ratio of 1.26 showed the lowest total pore volume and the best F-T resistance. The mechanisms of our experimental observations were that the abundantly distributed air voids connected by the capillary pores facilitated the relaxation of hydraulic pressures induced by the freezing of the pore liquid. The findings of this work help better clarify the compositional dependence of the pore structure, strength, and freezing-thawing resistance of MKG materials and provide fundamental bases for their engineering applications in cold regions.

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Peng, Ningbo, Jie Hong, Ye Zhu, Yun Dong, Bo Sun, and Jizhong Huang. "Experimental Investigation of the Influence of Freeze–Thaw Mode on Damage Characteristics of Sandstone." Applied Sciences 12, no. 23 (December 3, 2022): 12395. http://dx.doi.org/10.3390/app122312395.

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The influence of rock weathering caused by freezing–thawing on stone cultural relics cannot be ignored. For immovable stone cultural relics, different parts under different environmental conditions will be under different freeze–thaw actions and suffer different degrees of damage. In this paper, three typical freeze–thaw cycle tests of sandstone are designed, namely immersion test, capillary action test, and periodic saturation test. The macroscopic and microscopic morphologies of rock samples under different freeze–thaw cycles were analyzed. Weathering indicators such as porosity, water content, wave velocity, and surface hardness were tested, as well as uniaxial compressive strength. The variation law of weathering index and uniaxial compressive strength under different freezing–thawing cycles was obtained, and the quantitative relationship between each index parameter was further analyzed. The results show that under different freezing–thawing conditions, the apparent morphology of rock samples is different, and the trend of weathering indexes is similar, but the rate of change is different. The water content of rock has a great influence on the test results of wave velocity but has little influence on the surface hardness. The function relationship between weathering index and compressive strength under different freezing–thawing modes is similar, but the fitting parameters are different. Finally, the strength and wave velocity damage factors were used to quantitatively evaluate the degree of rock weathering. The results show that the immersion freeze–thaw damage is the highest, the periodic saturated freeze–thaw damage is the second highest, and the capillary freeze–thaw damage is the least highest. This is consistent with the field observation results. The conclusion of this paper can provide reference for the detection of stone cultural relics and provides a scientific basis for the anti-weathering protection of stone cultural relics.

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Kurz, Mareike, Beat Blattmann, Andres Kaech, Christophe Briand, Paul Reardon, Urs Ziegler, and Markus G. Gruetter. "High-throughput counter-diffusion capillary crystallization andin situdiffraction using high-pressure freezing in protein crystallography." Journal of Applied Crystallography 45, no. 5 (September 13, 2012): 999–1008. http://dx.doi.org/10.1107/s0021889812034061.

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Post-crystallization treatments such as manual fishing of crystals and soaking in cryoprotectant solutions, especially of large macromolecular complexes and membrane proteins, are cumbersome and often lead to crystal damage and reduced diffraction data quality. Here, a capillary crystallization plate is presented that simultaneously allows counter-diffusion crystallization at the nanolitre scale in a high-throughput screening mode, low-temperaturein situdiffraction data collection from crystals after cryoprotection and low-temperaturein situdata collection of crystals without the addition of any cryoprotectant after high-pressure (HP) freezing. The development of this plate and plunge cooling of crystals in the capillaries is a major step towards implementing automatedin situhigh-throughput crystal diffraction data collection at a synchrotron beamline. In combination with HP freezing this offers a new opportunity to obtain structural information from fragile crystals of supramolecular complexes that might otherwise not be feasible.

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White, T. L., and P. J. Williams. "The influence of soil microstructure on hydraulic properties of hydrocarbon-contaminated freezing ground." Polar Record 35, no. 192 (January 1999): 25–32. http://dx.doi.org/10.1017/s0032247400026309.

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AbstractThe significance of the thermodynamic relations of ice and water within the paniculate and porous soil medium has been widely demonstrated in recent decades. The existence of unfrozen water along with ice at temperatures below 0°C, because of capillary and mineral surface forces, is responsible for the specific thermal, mechanical, and hydraulic properties of soils exposed to seasonal or perennial freezing. The introduction of a hydrocarbon contaminant into this dynamic porous medium has significant consequences for the thermodynamics of the unfrozen water–ice interactions. Techniques recently developed have allowed examination of microstructures of soils exposed to freezing. It has been shown that freeze–thaw cycles produce complex changes in particle aggregation and pore space distribution, which in turn affect soil water energy. An examination of the microstructure of a hydrocarbon-contaminated, frostaffected soil revealed differences in morphology from that of similar but uncontaminated samples. These differences are in turn responsible for differences in hydraulic conductivity between uncontaminated and contaminated freezing soils.

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Marcolli, Claudia, Fabian Mahrt, and Bernd Kärcher. "Soot PCF: pore condensation and freezing framework for soot aggregates." Atmospheric Chemistry and Physics 21, no. 10 (May 21, 2021): 7791–843. http://dx.doi.org/10.5194/acp-21-7791-2021.

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Abstract. Atmospheric ice formation in cirrus clouds is often initiated by aerosol particles that act as ice-nucleating particles. The aerosol–cloud interactions of soot and associated feedbacks remain uncertain, in part because a coherent understanding of the ice nucleation mechanism and activity of soot has not yet emerged. Here, we provide a new framework that predicts ice formation on soot particles via pore condensation and freezing (PCF) that, unlike previous approaches, considers soot particle properties, capturing their vastly different pore properties compared to other aerosol species such as mineral dust. During PCF, water is taken up into pores of the soot aggregates by capillary condensation. At cirrus temperatures, the pore water can freeze homogeneously and subsequently grow into a macroscopic ice crystal. In the soot-PCF framework presented here, the relative humidity conditions required for these steps are derived for different pore types as a function of temperature. The pore types considered here encompass n-membered ring pores that form between n individual spheres within the same layer of primary particles as well as pores in the form of inner cavities that form between two layers of primary particles. We treat soot primary particles as perfect spheres and use the contact angle between soot and water (θsw), the primary particle diameter (Dpp), and the degree of primary particle overlap (overlap coefficient, Cov) to characterize pore properties. We find that three-membered and four-membered ring pores are of the right size for PCF, assuming primary particle sizes typical of atmospheric soot particles. For these pore types, we derive equations that describe the conditions for all three steps of soot PCF, namely capillary condensation, ice nucleation, and ice growth. Since at typical cirrus conditions homogeneous ice nucleation can be considered immediate as soon as the water volume within the pore is large enough to host a critical ice embryo, soot PCF becomes limited by either capillary condensation or ice crystal growth. We use the soot-PCF framework to derive a new equation to parameterize ice formation on soot particles via PCF, based on soot properties that are routinely measured, including the primary particle size, overlap, and the fractal dimension. These properties, along with the number of primary particles making up an aggregate and the contact angle between water and soot, constrain the parameterization. Applying the new parameterization to previously reported laboratory data of ice formation on soot particles provides direct evidence that ice nucleation on soot aggregates takes place via PCF. We conclude that this new framework clarifies the ice formation mechanism on soot particles in cirrus conditions and provides a new perspective to represent ice formation on soot in climate models.

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Olevsky, Eugene, and Xuan Wang. "Graded Powder Composites by Freeze Drying, Electrophoretic Deposition and Sintering." Materials Science Forum 534-536 (January 2007): 1533–36. http://dx.doi.org/10.4028/www.scientific.net/msf.534-536.1533.

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Two approaches for the fabrication of tailored powder composites with specially distributed pore-grain structure and chemical composition are investigated. Electrophoretic Deposition (EPD) followed by microwave sintering is employed to obtain functionally graded materials (FGM) by in-situ controlling the deposition bath suspension composition. Al2O3/ZrO2 and zeolite FGM are successfully synthesized using this technique. In order to fabricate an aligned porous structure, unidirectional freezing followed by freeze drying and sintering is employed. By controlling the temperature gradient during freezing of powder slurry, a unidirectional ice-ceramic structure is obtained. The frozen specimen is then subjected to freeze drying to sublimate the ice. The obtained capillary-porous ceramic specimen is consolidated by sintering. The sintering of the graded structure is modeled by the continuum theory of sintering.

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Jiang, Shaoyi, Charles L. Rhykerd, and Keith E. Gubbins. "Layering, freezing transitions, capillary condensation and diffusion of methane in slit carbon pores." Molecular Physics 79, no. 2 (June 10, 1993): 373–91. http://dx.doi.org/10.1080/00268979300101281.

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Lavin, C. A., W. A. Mohler, H. H. Keating, and J. G. White. "Capturing Developmental Events of the C. Elegans Embryo by High Pressure Freezing After Monitoring by a Multi-Photon Imaging System." Microscopy and Microanalysis 3, S2 (August 1997): 291–92. http://dx.doi.org/10.1017/s1431927600008345.

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High pressure freezing enables the rapid arrest of developmental events without prefixation. Standard chemical fixation is a time dependent event and may cause artifacts in sensitive cytoskeletal components. We are studying two developmental events in embryonic Caenorhabditis elegans: that involve changes in the cytoskeleton: spindle alignment and membrane fusion. The mitotic spindle undergoes rapid rotational alignment prior to certain differentiative divisions. We are trying to capture these events by anticipation their timing and rapid freezing. Precursor hypodermal cells of embryonic C. elegans undergo a transition from individual cells to a syncytium at the onset of morphogenesis. In an effort to visualize the fusion events, embryos were stained with the vital probe FM4-64 to highlight cell membranes. Development was monitored by fluorescent microscopy using multiple-photon excitation imaging to minimize photobleaching while providing clear images of deep sections. Small cellulose capillary tubes, as described by Hohenberg for isolation and high pressure freezing of individual cells, were not of sufficient optical quality for monitoring by a laser-scanning microscope.

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Kitago, Yu, Nobuhisa Watanabe, and Isao Tanaka. "Semi-automated protein crystal mounting device for the sulfur single-wavelength anomalous diffraction method." Journal of Applied Crystallography 43, no. 2 (February 12, 2010): 341–46. http://dx.doi.org/10.1107/s0021889809054272.

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Use of longer-wavelength X-rays has advantages for the detection of small anomalous signals from light atoms, such as sulfur, in protein molecules. However, the accuracy of the measured diffraction data decreases at longer wavelengths because of the greater X-ray absorption. The capillary-top mounting method (formerly the loopless mounting method) makes it possible to eliminate frozen solution around the protein crystal and reduces systematic errors in the evaluation of small anomalous differences. However, use of this method requires custom-made tools and a large amount of skill. Here, the development of a device that can freeze the protein crystal semi-automatically using the capillary-top mounting method is described. This device can pick up the protein crystal from the crystallization drop using a micro-manipulator, and further procedures, such as withdrawal of the solution around the crystal by suction and subsequent flash freezing of the protein crystal, are carried out automatically. This device makes it easy for structural biologists to use the capillary-top mounting method for sulfur single-wavelength anomalous diffraction phasing using longer-wavelength X-rays.

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Vetterlein, F., F. Hoffmann, J. Pedina, M. Neckel, and G. Schmidt. "Disturbances in renal microcirculation induced by myoglobin and hemorrhagic hypotension in anesthetized rat." American Journal of Physiology-Renal Physiology 268, no. 5 (May 1, 1995): F839—F846. http://dx.doi.org/10.1152/ajprenal.1995.268.5.f839.

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The question was studied of whether myoglobin (Mb), when released into the general circulation during hemorrhagic hypotension (HH), causes disturbances of renal blood flow. In anesthetized rats 250 mg/kg Mb was intravenously infused within 1 h; HH at 50 mmHg with subsequent retransfusion was induced for 30 min. By allowing two dyes to circulate for 1 and 3 min, respectively, and detecting their localization histologically after rapid freezing of the organ, intrarenal distribution of capillary blood flow was studied. In contrast to the results obtained with Mb or HH alone, when Mb was infused during HH, the development of large areas within cortex and medulla lacking any capillary perfusion was observed. In > 70% of the tissue, a distance > 60 microns to the next dye-labeled capillary was found (in controls 0%). At this time total renal flow had decreased from 5.3 to 0.20 ml/min (HH without Mb: 5.1 to 1.1 ml/min). It is concluded that the observed changes in renal blood flow contribute to the known direct nephrotoxic potential of Mb.

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Konrad, J. M. "Influence of overconsolidation on the freezing characteristics of a clayey silt." Canadian Geotechnical Journal 26, no. 1 (February 1, 1989): 9–21. http://dx.doi.org/10.1139/t89-002.

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Laboratory freezing tests were performed on a saturated clayey silt at various overconsolidation ratios (OCR) to establish the relationship between initial void ratio and stress history, and the amount of moisture transfer during freezing. The frost heave tests were analysed in terms of the segregation potential as well as a function of the temperature of ice lens formation and the overall hydraulic conductivity of the frozen fringe. All other factors being the same, the segregation potential was found to increase with increasing values of OCR (decreasing initial void ratios). However, the combined effects of decreasing void ratio and increasing suction at the frost line, all other factors being identical in all freezing tests, resulted in decreasing segregation potentials. This trend was the result of a decrease in the temperature of ice lens formation and the concomitant decrease in overall hydraulic conductivity of the frozen fringe. A simple model showed that the capillary unfrozen water between clay particles increases when the particles pack closer together, as overconsolidation increases, allowing the migratory water to freeze within the frozen soil at a colder temperature. Key words: frost heave, clayey silt, overconsolidation, void ratio.

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Bloßfeld, Wolfgang Moritz, Joachim Bluhm, and Tim Ricken. "Simulation of Freezing and Thawing Processes with Capillary Effects in fluid filled porous media." PAMM 12, no. 1 (December 2012): 365–66. http://dx.doi.org/10.1002/pamm.201210171.

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Blahut, Aleš, Jiří Hykl, Pavel Peukert, and Jan Hrubý. "Dual-capillary dilatometer for density measurements of supercooled water." EPJ Web of Conferences 264 (2022): 01004. http://dx.doi.org/10.1051/epjconf/202226401004.

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An apparatus tailored to accurate density measurements of supercooled water, i.e. liquid water in a metastable state below the freezing point temperature, was recently developed at the Institute of Thermomechanics of the Czech Academy of Sciences. The apparatus, dual-capillary dilatometer, is described, together with the measurement procedure and the evaluation methodology. The primary result of the dual-capillary method are relative densities with respect to the density at a reference temperature and given pressure. In order to calculate absolute densities, densities at the reference temperature as a function of pressure are needed. For calculation of such pressure dependence of density, so called thermodynamic integration involving literature thermodynamic data and our experimental results is used. The dual-capillary dilatometer was successfully employed in density measurements of ordinary water, heavy water and seawater. The data in the temperature range from 238.15 to 303.15 K at pressures from atmospheric up to 200 MPa are presented and compared with respective IAPWS formulations of thermodynamic properties. The data for ordinary water are also compared with an accurate equation of state for supercooled water of Holten et al. (2014) revealing good mutual agreement. The expanded uncertainty of relative densities acquired by means of the dual-capillary method is estimated to be lower than 50 ppm.

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Sikula, Ondrej, and Martin Mohapl. "2D Model of Capillary Transport of Water in Aerated Concrete." Advanced Materials Research 649 (January 2013): 287–90. http://dx.doi.org/10.4028/www.scientific.net/amr.649.287.

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Aerated concrete from the viewpoint of the transport of liquid moisture appears to be a material with highly variable properties strongly dependent on the porosity and liquid water exposure conditions. Saturation degree of aerated concrete strongly affects not only all its thermal-technical properties, but regarding to the risk freezing, also the strength properties. To predict the degree of saturation and moisture distribution, we used certain mathematical and physical methods supplemented with experimentally identified parameters. The aim of this paper is to discuss existing approaches to model capillary moisture transport in aerated concrete and description of the new, simplified 2D computer mathematical-physical model for the solution of this phenomenon. The results of the model are compared with experiments carried out. The conclusion discusses the limits of this new model, and mentions further possibilities for its improvement.

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Ann, Ki Yong, Min Jae Kim, Jun Pil Hwang, Chang-geun Cho, and Ki Hwan Kim. "Chloride Transport in OPC Concrete Subjected to the Freeze and Thaw Damage." Advances in Materials Science and Engineering 2017 (2017): 1–7. http://dx.doi.org/10.1155/2017/8212856.

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To predict the durability of a concrete structure under the coupling degradation consisting of the frosting and chloride attack, microstructural analysis of the concrete pore structure should be accompanied. In this study, the correlation between the pore structure and chloride migration for OPC concrete was evaluated at the different cement content in the concrete mix accounting for 300, 350, and 400 kg/m3 at 0.45 of a free water cement ratio. The influence of frosting damage on the rate of chloride transport was assessed by testing with concrete specimens subjected to a rapid freezing and thawing cyclic environment. As a result, it was found that chloride transport was accelerated by frost damage, which was more influential at the lower cement content. The microscopic examination of the pore structure showed that the freezing environment increased the volume of the large capillary pore in the concrete matrix.

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Hong, Se-Hee, Tian-Feng Yuan, Jin-Seok Choi, and Young-Soo Yoon. "Assessing the Effects of Steelmaking Slag Powder on the Pore Structure and Durability of Concrete." Journal of the Korean Society of Hazard Mitigation 21, no. 1 (February 28, 2021): 1–11. http://dx.doi.org/10.9798/kosham.2021.21.1.1.

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This study analyzes the pore structure and durability of concrete according to four different ratios of steelmaking slag powder (SSP). Concrete containing SSP increased the formation of gel and capillary pores due to delayed hydration, and the largest cumulative pore volume was observed when the incorporation ratio was 20%. In terms of durability, the incorporation of SSP had decreased performance compared to concrete without SSP (NN), which was due to changes in the pore structure caused by incorporating SSP. In the case of the freezing and thawing resistance, concrete containing 10% SSP showed a remarkable relative dynamic elastic modulus of more than 80%, and a similar carbonation depth was predicted within 15% of SSP. In addition, the resistance performance of chloride ion migration in concrete with SSP was excellent. Accordingly, it can be utilized as a supplementary cementitious material if the freezing and thawing resistance of concrete containing 15% SSP is secured.

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Claeys, Myriam, Vladimir V. Yushin, Jan L. M. Leunissen, Jef Claeys, and Wim Bert. "Self-Pressurised Rapid Freezing (SPRF): an easy-to-use and low-cost alternative cryo-fixation method for nematodes." Nematology 19, no. 8 (2017): 871–81. http://dx.doi.org/10.1163/15685411-00003093.

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Self-Pressurised Rapid Freezing (SPRF), an easy-to-use and low-cost alternative cryo-fixation method, was evaluated based on a comparative analysis of the ultrastructure of spermatozoa of the nematodes Acrobeles complexus and Caenorhabditis elegans. Sealed copper tubes, packed with active nematodes in water, were plunged into nitrogen slush, a semi-solid form of nitrogen. The water inside the capillary copper tube expands upon cooling due to the formation of hexagonal ice, thereby generating high pressure intrinsically for cryo-fixation of the sample. For sperm cells cryo-fixed by SPRF, the preservation of the ultrastructure was comparable to that achieved with high pressure freezing. This was evidenced by the clear details in mitochondria, membranous organelles and cytoskeleton in the pseudopod. It was demonstrated that SPRF fixation did not destroy antigenicity, based on the results of the immunolocalisation of the major sperm protein in both species. In conclusion, SPRF is a low-cost alternative cryo-fixation method for nematodes.

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Oraltay, R. G., and J. Hallett. "The Melting Layer: A Laboratory Investigation of Ice Particle Melt and Evaporation near 0°C." Journal of Applied Meteorology and Climatology 44, no. 2 (February 1, 2005): 206–20. http://dx.doi.org/10.1175/jam2194.1.

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Abstract Melting, freezing, and evaporation of individual and aggregates of snow crystals are simulated in the laboratory under controlled temperature, relative humidity, and air velocity. Crystals of selected habit are grown on a vertical filament and subsequently melted or evaporated in reverse flow, with the velocity adjusted for appropriate fall speed to reproduce conditions of the melting layer. Nonequilibrium conditions are simulated for larger melting ice particles surrounded by smaller drops at a temperature up to +5°C or growth of an ice crystal surrounded by freezing ice particles down to −5°C. Initial melting of well-defined faceted crystals, as individuals or in combination, occurs as a water layer >10 μm thick. For larger (>100 μm) crystals the water becomes sequestered by capillary forces as individual drops separated by water-free ice regions, often having quasiperiodic locations along needles, columns, or arms from evaporating dendrites. Drops are also located at intersections of aggregate crystals and dendrite branches, being responsible for the maximum of the radar scatter. The drops have a finite water–ice contact angle of 37°–80°, depending on ambient conditions. Capillary forces move water from high-curvature to low-curvature regions as melting continues. Toward the end of the melting process, the ice separating the drops becomes sufficiently thin to fracture under aerodynamic forces, and mixed-phase particles are shed. Otherwise ice-free drops are shed. The melting region and the mechanism for lowering the melting layer with an increasing precipitation rate are associated with smaller ice particle production capable of being lofted in weaker updrafts.

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Antolinc, David, Katarina Černe, and Zvonko Jagličić. "Risk of Using Capillary Active Interior Insulation in a Cold Climate." Energies 14, no. 21 (October 20, 2021): 6890. http://dx.doi.org/10.3390/en14216890.

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The retrofitting of cultural heritage buildings for energy efficiency often requires the internal thermal insulation of external walls. Most of the in situ studies of capillary active interior insulation were performed in mild oceanic climate regions, and they showed an excellent performance. However, as a large part of Central–Eastern Europe belongs to a continental climate with cold winters and long periods of temperatures below the freezing temperature, the applicability of the capillary active interior insulation in cold climate was studied. The hydrothermal behaviour of the three walls was determined—each consists of one of three different interior insulations—and the original wall is made of historic regular solid bricks. Two interior thermal insulations were capillary active (aerated cellular concrete, calcium silicate) and one vapour-tight (glass foam). A hot box–cold box experiment and a steady-state model were used to demonstrate an increase in the original wall mass due to the water condensation only when the capillary active interior insulation is used. The combination of the water condensation and the low sub-zero temperature may lead to a risk of freeze–thaw damage to the original wall. The numerical simulation of the water vapour condensation for the considered walls for the Slovenian town Bled with sub-zero average winter temperatures was performed to obtain the whole temperature and moisture profile. It showed good agreement between an experimentally and numerically obtained amount of water condensation. The capillary active interior insulation proved to be unsuitable for improving the thermal insulation of buildings in cold continental climate, and only a vapour-tight system can be recommended.

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40

Miller, J. J., and J. A. Brierley. "Solonetzic soils of Canada: Genesis, distribution, and classification." Canadian Journal of Soil Science 91, no. 5 (October 2011): 889–902. http://dx.doi.org/10.4141/cjss10040.

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Miller, J. J. and Brierley, J. A. 2011. Solonetzic soils of Canada: Genesis, distribution, and classification. Can. J. Soil Sci. 91: 889–902. Soils of the Solonetzic order are defined as having a Solonetzic B horizon designated as a Bn or Bnt horizon. The Solonetzic Order includes four great groups: Solonetz, Solodized Solonetz, Solod, and Vertic Solonetz. Solonetzic soils are thought to develop via the stepwise pedogenic processes of salinization, solonization (desalinzation and alkalization), and solodization. Soluble salts are brought into the soil pedon of Solonetzic soils by capillary movement and evaporation from spring to fall, and upward water flow from the water table to the freezing zone in the winter deposits salts upon freezing. Solonization proceeds when desalinization lowers the total salt content and alkalization is initiated by high exchangeable Na. Solodization occurs when anisotropic flow conditions or a change in vertical hydraulic gradients prevent capillary rise and replenishment of soluble Na in the Bn horizon. Two common Solonetzic catenas are found in the prairies. In the first sequence, Gleyed Solonetz or Solonetz occur in the depressional areas of the landscape, and soils then grade through Solodized Solonetz, Solods, and in some cases, Chernozems or normal zonal soils at higher elevations. In the second sequence, Solods are found in the lowest topographic position, while Solodized Solonetz, Solonetz and Chernozems are found at progressively higher slope positions. Solonetzic soils have unique properties that adversely affect their use for agriculture and other land uses (e.g., construction, septic systems). Further interdisciplinary research is required to better understand the genesis of these soils at the “meter scale” or local landscape level because of the extreme spatial variability of these soils.

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Comtet, Jean, Antoine Niguès, Vojtech Kaiser, Benoit Coasne, Lydéric Bocquet, and Alessandro Siria. "Nanoscale capillary freezing of ionic liquids confined between metallic interfaces and the role of electronic screening." Nature Materials 16, no. 6 (March 27, 2017): 634–39. http://dx.doi.org/10.1038/nmat4880.

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DOMBROSKI, CAROL S., LEE-ANN JAYKUS, DAVID P. GREEN, and BRIAN E. FARKAS. "Use of a Mutant Strain for Evaluating Processing Strategies to Inactivate Vibrio vulnificus in Oysters." Journal of Food Protection 62, no. 6 (June 1, 1999): 592–600. http://dx.doi.org/10.4315/0362-028x-62.6.592.

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Vibrio vulnificus is a ubiquitous marine bacterium frequently isolated from shellfish and associated with severe and often fatal disease in humans. Various control strategies to reduce the disease risk associated with V. vulnificus contamination in shellfish have been proposed. However, evaluating the efficacy of these control strategies is complicated because of the difficulty in distinguishing V. vulnificus from the high levels of background environmental Vibrio spp. The purpose of this research was to develop a model indicator V. vulnificus strain that could be readily differentiated from background microflora and used to facilitate the evaluation of processing efficacy. A spontaneous nalidixic acid–resistant strain of V. vulnificus (Vv-NA) was prepared from a wild-type parent (Vv-WT) using selective plating techniques. Vv-NA was very similar to Vv-WT with respect to biochemical characteristics, appearance on selective plating media, detection limits using most probable number and polymerase chain reaction, and growth rate. In comparative freeze inactivation studies on pure cultures, Vv-WT and Vv-NA had similar freeze inactivation profiles at −20°C (conventional freezing), at −85°C (cold blast freezing), and in liquid nitrogen (cryogenic freezing). In oyster homogenates artificially inoculated with Vv-NA, the organism was inactivated 95 to 99% after freezing, irrespective of freezing temperature. Thermal inactivation comparisons of pure cultures of Vv-WT and Vv-NA using the capillary tube method revealed statistically significant differences in D values at 47°C (2.2 versus 3.0 min, respectively) and 50°C (0.83 versus 0.56 min, respectively), but nearly identical values at 52°C (0.21 versus 0.22 min, respectively). However, these D values were notably higher than those reported by other investigators and hence provided a conservative means by which to evaluate thermal inactivation. In oyster homogenates seeded with Vv-NA, D values of 1.3 ± 0.09 min and 0.41 ± 0.01 min were obtained at 46°C and 48°C, respectively. This study demonstrated that Vv-NA is readily enumerated and could be used as a surrogate for evaluating the degree of V. vulnificus inactivation provided by freezing and thermal treatments of oyster homogenates.

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Wang, Chao, Zhao-Lei Liu, and Lei Yu. "Relationship between Anti-frozen Durability and Pore Structure on Concrete in Freeze and Thaw Cycle Environment." MATEC Web of Conferences 238 (2018): 02010. http://dx.doi.org/10.1051/matecconf/201823802010.

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To detect which micro structure index can make an effected on the anti-frozen durability on concrete, 3 kinds of concrete with different mix proportion have been made. The dynamic modulus of elasticity and pore structure index were detected and the relativity of them was analysed. The result shows that the dynamic modulus of elasticity decreases after freezing and wary with porosity. Critical pore size becomes larger. The gel pore amount decreases. The capillary and macro pore amount increase. There is a good relativity between frost-resistance performance and pore parameters. By decreasing porosity and the amount of macro pore, increasing gel pore amount, the anti-frozen durability can be enhanced.

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Zhou, Jing, Minghao Pan, Chuping Chang, Ao Wang, Yongqi Wang, and Hang Lyu. "Migration Law of LNAPLs in the Groundwater Level Fluctuation Zone Affected by Freezing and Thawing." Water 14, no. 8 (April 15, 2022): 1289. http://dx.doi.org/10.3390/w14081289.

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Freezing and thawing can cause dynamic fluctuations of the groundwater level, resulting in the migration and retention of LNAPLs. However, this process is difficult to observe visually, and a suitable simulation method for its quantitative calculation is lacking. In this study, a numerical simulation is established by coupling the HYDRUS-1D software and the TOUGH program to realize dynamic simulation of the entire process of soil temperature changes, water migration, water level fluctuation, and redistribution of LNAPLs during the freeze–thaw process. The results of the study show that the process of soil freezing and thawing causes water migration, which in turn causes groundwater level fluctuation, leading to the migration and redistribution of LNAPLs within the water level fluctuation zone. In this process, the soil particle size and porosity control the response degree and speed of the water level under freezing and thawing and the spatiotemporal distribution of LNAPLs by affecting the soil temperature, capillary force, and water migration. The migration ability of free LNAPLs is determined by their own density and viscosity; the retention of residual LNAPLs is affected by soil porosity and permeability as well as LNAPL viscosity. The results of this study can not only be used to develop a simulation method for the migration and retention mechanism of LNAPLs in cold regions but also serve as a scientific and theoretical basis for LNAPL pollution control in seasonal frozen soil regions.

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Mac Sweeney, Aengus, and Allan D'Arcy. "A simple and rapid method for mounting protein crystals at room temperature." Journal of Applied Crystallography 36, no. 1 (January 21, 2003): 165–66. http://dx.doi.org/10.1107/s0021889802019623.

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Cryocooling of protein crystals for X-ray data collection has now become a routine method in the majority of biostructural laboratories. The improvement of facilities at synchrotron sources and their increased use has made it essential to have properly frozen crystals for optimal data collection. Although in general crystals can be cooled without significant damage, there are often cases in which crystals with slight disorder or twinning problems suffer considerably during the freezing process. In other cases, poor or mosaic diffraction may be blamed on the cryoprotectant or cooling protocol. Many crystals may be wasted in searching for the best freezing conditions when the intrinsic quality of the crystals is poor. In principle, the collection of room-temperature diffraction data would provide a reference that would allow the detection of crystal damage caused by addition of cryoprotectant or by cryocooling. In practice, however, many investigators are reluctant to do this, one reason being that capillary mounting of crystals is a tedious method, especially for those who are new to crystallography. Here a simplified method for mounting crystals at room temperature is reported, which requires little expertise and no expensive equipment.

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Liu, Zhi Chao, and Will Hansen. "Sorptivity as a Measure of Salt Frost Scaling Resistance of Air-Entrained Concrete." Key Engineering Materials 629-630 (October 2014): 195–200. http://dx.doi.org/10.4028/www.scientific.net/kem.629-630.195.

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Salt frost scaling is the progressive deterioration of the concrete surface associated with freezing and thawing in the presence of a salt solution. Its major mechanism has been confirmed to be cryogenic suction that promotes continuous ice growth in the surface region. In this paper, salt frost scaling of different air-entrained concretes is investigated, alone with the room-temperature sorptivity measurement. A clear correlation is found between the two properties, which is supported by a theoretical analysis on the sorptivity. These findings explain why HPC of low w/b ratio and associated low capillary porosity has much improved scaling resistance. Similar benefits are obtained for regular w/b ratio concrete containing high cementitious replacement level of slag cement.

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Kiefersauer, Reiner, Manuel E. Than, Holger Dobbek, Lothar Gremer, Marcos Melero, Stefan Strobl, João M. Dias, Tewfik Soulimane, and Robert Huber. "A novel free-mounting system for protein crystals: transformation and improvement of diffraction power by accurately controlled humidity changes." Journal of Applied Crystallography 33, no. 5 (October 1, 2000): 1223–30. http://dx.doi.org/10.1107/s0021889800008049.

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A novel device for capillary-free mounting of protein crystals is described. A controlled stream of air allows an accurate adjustment of the humidity at the crystal. The crystal is held on the tip of a micropipette. With a video system (CCD camera), the two-dimensional shadow projections of crystals can be recorded for optical analysis. Instead of the micropipette, a standard loop can also be used. Experiments and results for different crystal systems demonstrate the use of this method, also in combination with shock-freezing, to improve crystal order. Working with oxygen-free gases offers the possibility of crystal measurements under anaerobic conditions. Furthermore, the controlled application of arbitrary volatile substances with the gas stream is practicable.

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Vetterlein, F., B. Demmerle, A. Bardosi, U. Gobel, and G. Schmidt. "Determination of capillary perfusion pattern in rat brain by timed plasma labeling." American Journal of Physiology-Heart and Circulatory Physiology 258, no. 1 (January 1, 1990): H80—H84. http://dx.doi.org/10.1152/ajpheart.1990.258.1.h80.

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The pattern of capillary perfusion was studied in the brain of anesthetized rats. Two plasma labels were used to demonstrate the density of capillaries perfused during a 10-min period [fluorescein isothiocyanate (FITC) globulin], as well as during a 10-, 3-, or 1-s period [lissamine-rhodamine B 200 (RB200) globulin, infused into the left heart chamber], respectively. A special biopsy cutting-freezing system was used to withdraw brain tissue via a cranial window for histological analysis of dye distribution at the end of the infusion period. Complete labeling of all capillaries was already found after 10 s of dye circulation. However, intra-arterial dye infusion for 3 and 1 s led to reduced filling of capillaries: cortex 86.6 +/- 5.2 and 6.8 +/- 1.8%, hippocampus 95.0 +/- 1.6 and 9.9 +/- 2.1%, and thalamus 97.9 +/- 1.0 and 11.7 +/- 1.8%, respectively. The period of 1 s was found to be the circulation time from left heart chamber to brain capillaries. It can thus be concluded that in the studied brain areas greater than 85% of capillaries are reached by a plasma flow within 2 s and that the remaining small fraction completely fills within 10 s.

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Hou, Bowen, Jisheng Qiu, Peng Guo, Xujun Gao, and Ruyi Zhang. "Freezing-Thawing Damage Mechanism of Coal Gangue Concrete Based on Low-Field Nuclear Magnetic Resonance, Scanning Electron Microscopy, and N2 Adsorption." Advances in Civil Engineering 2021 (February 4, 2021): 1–11. http://dx.doi.org/10.1155/2021/8842195.

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To study waterborne frost heaving failure mechanism of coal gangue ceramsite concrete (CGCC) under freeze-thaw cycles, capillary water absorption test, nonmetallic ultrasonic testing test, low-field nuclear magnetic resonance (LNMR) test, N2 adsorption test, and other tests were used to determine the effect of freeze-thaw cycles on the porosity, relative dynamic elastic modulus (RDM), and capillary adsorption rate of different coal gangue ceramsite (MT) replacement rates (0, 20%, 40%, and 60%). Combining the changes of performance indexes and the changes of micropore structure under freeze-thaw cycles, the freeze-thaw failure mechanism of normal concrete (OC) and CGCC was analyzed. In view of the particularity of MT material, the method based on pore size is put forward to distinguish M pores from T pores, and the reasons for different properties are analyzed from the microperspective. The results show that the freeze-thaw cycle changes the microstructure of coal gangue concrete and has an obvious influence on its properties. And when the replacement rate is 40%, degradation mitigation performance is optimal. Due to the particularity of MT shape, T pores are dominant in coal gangue concrete matrix, which is different from the microstructure of ordinary concrete and can reduce the structural deterioration caused by freeze-thaw. The research results of this paper can provide a reference for the research and application of CGCC in freeze-thaw environment.

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Wesołowska, Maria, and Anna Kaczmarek. "The Effect of Modifications on Humidity Parameters of Cement Mortar." Materials Science Forum 865 (August 2016): 178–82. http://dx.doi.org/10.4028/www.scientific.net/msf.865.178.

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Current wall constructions utilize cement mortars, the properties of which have been modified with introducing lime or plasticizers. The complex structure of these mortars as well as their very large inner area results in large differences in capillary moisture transport. Macroscopic studies do not allow to accurately predict the mortar behaviour in contact with water. Capillary rise as well as drying and freezing of water are dependent on the size and the layout of pores. The biggest adsorption capacity is featured by micropores. Moisture transport takes place in mesoporous material, and moisture adsorption takes place on the surface of such materials. Macropores mainly act as a transport medium and carry moisture to mesoporous material and micropores. In terms of mesoporous material and macropores mercury porosimetry is more suitable. Mortar structure plays an important role in the moisture transport. Mortar additives, that have been introduced in the form of lime and plasticizers, modify the distribution and size of pores. Porosimetric study results concerning selected mortars have been presented in this article. The structure changes resulting from the introduction additives to mortars have been analyzed and the impact on humidity of such mortars has been defined.

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Journal articles on the topic 'Capillary freezing'

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