Characterization of thin water layers in pulp by tritium exchange. Part 1: Methods development

Holzforschung ◽  
2007 ◽  
Vol 61 (2) ◽  
pp. 115-119 ◽  
Author(s):  
Frances L. Walsh ◽  
Sujit Banerjee
Keyword(s):  
Water Content ◽  
Surface Area ◽  
Tritiated Water ◽  
Bound Water ◽  
Free Water ◽  
Fiber Surface ◽  
Bulk Water ◽  
Methods Development ◽  
A Value ◽  
A New Technique

Abstract A new technique for measuring the monolayer water content of fiber is presented. Tritiated water is added to a pulp/water suspension, whereupon the tritium partitions between the bulk water and the pulp. In the pulp phase the tritium can exchange with free water, bound water, and with hydroxyl and other protons present in the pulp matrix. The free water in the pulp is then removed by displacement with acetone. The tritium remaining in the pulp is mostly associated with tightly bound water, with a small fraction being tied up with the exchangeable hydrogen in pulp. The procedure provides a value of 10% for the tightly bound water content of hardwood or softwood fiber, either bleached or unbleached. If this water is assumed to cover the fiber surface as a monolayer, then an estimate of the wet surface area of the fiber can be obtained. This estimate compares well with independent measurements of surface area.

scholarly journals Effects of Solar Radiation on the Formation of Weak Wet Snow

1989 ◽  
Vol 13 ◽  
pp. 120-123 ◽  
Author(s):  
Kaoru Izumi
Keyword(s):  
Solar Radiation ◽  
Water Content ◽  
Thin Section ◽  
Field Experiments ◽  
Free Water ◽  
Quantitative Relationship ◽  
A Value ◽  
Wet Snow

Laboratory and field experiments on hardness of snow have shown that the free water contained in snow decreases its hardness, and that solar radiation further decreases hardness down to a value below the limit of that which would result only from the influence of the water content of snow. A quantitative relationship between the amount of solar radiation absorbed by snow and decrease in snow hardness was derived. Thin-section analyses of snow were used to reveal the mechanism of decrease in snow hardness which had been caused by solar radiation.

Moisture in softwoods: fiber saturation point, hydroxyl site content, and the amount of micropores as determined from NMR relaxation time distributions

Holzforschung ◽  
2013 ◽  
Vol 67 (3) ◽  
pp. 291-300 ◽  
Author(s):  
Ville-Veikko Telkki ◽  
Miikka Yliniemi ◽  
Jukka Jokisaari
Keyword(s):  
Melting Point ◽  
Relaxation Times ◽  
Bound Water ◽  
Nmr Relaxation ◽  
Free Water ◽  
Bulk Water ◽  
Fiber Saturation Point ◽  
Saturation Point ◽  
Fiber Saturation ◽  
Nmr Relaxation Times

Abstract Distributions of nuclear magnetic resonance (NMR) relaxation times provide detailed information about the moisture absorbed in wood. In this work, T2*, T2, and T1 distributions were recorded from fresh sapwood and heartwood samples of pine (Pinus sylvestris) and spruce (Picea abies) at various temperatures. Below the melting point of bulk water, free water is frozen and its signal disappears from the distributions. Then, the low-temperature distributions of the unfrozen bound water contain more information about its components, because the large free water peaks hiding some smaller bound water peaks are absent and the exchange between free and bound water is prevented. Comparison of the total moisture signal integrals above and below the bulk melting point enables the determination of fiber saturation point (FSP), which, in this context, denotes the total water capacity of cell wall. T2*, T2, and T1 distributions offer different kinds of information about moisture components. All the peaks in the distributions were assigned, and it was demonstrated that the accessible hydroxyl site content and the amount of micropores can be estimated based on the peak integrals.

Characterization of thin water layers in pulp by tritium exchange. Part 2: Effect of refining on water absorption

Holzforschung ◽  
2007 ◽  
Vol 61 (2) ◽  
pp. 120-123 ◽  
Author(s):  
Frances L. Walsh ◽  
Sujit Banerjee
Keyword(s):  
Tritiated Water ◽  
Bound Water ◽  
Bulk Water ◽  
Primary Cell Wall ◽  
Fiber Structure ◽  
Bleached Kraft Pulp ◽  
Water Layers ◽  
S2 Layer ◽  
Bound Water Content

Abstract The surface area of pulp increases upon refining, which also increases the quantity of bound water. The subfraction of water attached to the surface as a monolayer can be determined by adding tritiated water to a pulp/water suspension and measuring the distribution of tritium between the pulp and bulk water. For bleached kraft pulp the tightly bound water slowly increases with progressive refining, increases sharply at 360 ml Canadian Standard Freeness (CSF), and then falls below CSF 220 ml. The fiber saturation point displays a similar profile, although the changes are much less pronounced. It is proposed that refining occurs in three discrete stages. First, refining down to CSF 360 ml removes the primary cell wall and S1 layer, while the S2 layer begins to swell. Next, internal delamination occurs within the S2 layer between CSF 360 and 220 ml, as confirmed by scanning electron microscopy. The onset of delamination is sudden: dramatic changes in fiber structure occur at CSF 360 ml, at which point the tightly bound water content rapidly increases. Finally, fiber destruction occurs below CSF 220 ml.

Thermodynamic Properties of Water in Compacted Bentonite Under External Pressure-free Conditions

1994 ◽  
Vol 353 ◽  
Author(s):  
Yuji Torikai ◽  
Seichi Sato ◽  
Hiroshi Ohashi
Keyword(s):  
Thermodynamic Properties ◽  
Water Content ◽  
Pure Water ◽  
Bound Water ◽  
Free Water ◽  
External Pressure ◽  
Dry Density ◽  
X Ray Diffraction ◽  
Molar Gibbs Free Energy ◽  
Compacted Bentonite

AbstractIn an attempt to determine the thermodynamic properties of water in bentonite, the vapor pressure of water in compacted bentonite was measured as functions of water content and temperature, under external pressure-free conditions. The relative partial molar Gibbs free energy ΔGH2O, enthalpy ΔHH2Oand entropy ΔSH2O of tne waler in bentonite were determined at temperature of 298.15K. The interlayer distance of montmorillonite in bentonite was also measured by X-ray diffraction.It is probable that one fourth of the total water included in the bentonite at water content of 20.3wt% and dry density of 1.76 × 103kg/m3 is nearly free water; the water is not regarded as dilute electrolytic solution but the solution with higher ionic strength. Another one fourth of the water in the bentonite at the water content is bound water; the partial molar entropy of the bound water referred to pure water is from a half to whole of solidification entropy of pure water. The remainder is regarded as intermediately bound water.

scholarly journals Total and Fractional Composition of Water in Pear Leaves Depending on the Optimised Fertiliser

2021 ◽  
Vol 24 (3) ◽  
pp. 45-51
Author(s):  
Roman Yakovenko
Keyword(s):  
Water Content ◽  
Fractional Composition ◽  
Physiological State ◽  
Bound Water ◽  
Free Water ◽  
Practical Significance ◽  
Total Water Content ◽  
Total Water ◽  
Important Indicator ◽  
Positive Effect

The water content in tissues is an important indicator of the physiological state of the plant and is of great importance in the comparative assessment of their cultivation measures that increase productivity. One of such measures is rational fertilisation of plantings, which determines the relevance of the study. The purpose of the study was to establish the effect of optimised fertiliser on the water content in pear tree leaves and the fractional composition of water during stressful growing periods. One of the critical problems is drought, which negatively affects the growth and productivity of plantings. Under such conditions, the turgor of plant cells decreases and the passage of biochemical and physiological processes in the plant slows down. The paper considers the results of studying the water regime of leaves (the content of total, available, and inaccessible moisture) of pear varieties Konferentsia and Osnovianska on vegetative rootstock Quince A grown using optimised fertiliser in nonirrigated plantations. The study was conducted in 2011 and 2018 in a certified educational and research laboratory of the Uman National University of Horticulture. It was found that during the age periods of growth and fruiting, there was a change in the total water content in the pear leaves of the studied varieties. Leaves from pear trees of the Konferentsia variety had a higher water content compared to the Osnovianska variety. Fertiliser options increased the total water content in the leaves, which had a positive effect on the condition of the trees. It was found that at the beginning of the growing season, the free water content in the leaves of pear varieties Konferentsia and Osnovianska was higher, while it significantly decreased in the middle of the season. The bound water content was higher in all studied options. Under stressful situations (drought, temperature increase), fertiliser application had a positive effect on the water content in the leaves of both studied pear varieties. The practical significance of the study is to recommend the production of a rational fertiliser system for nonirrigated pear plantations in different age periods of growth and fruiting, which positively affected the water content in leaves and the fractional composition of water during stressful periods of cultivation

Analysis on Unfrozen Water Content of Mohe Permafrost Based on NMR Method

2014 ◽  
Vol 881-883 ◽  
pp. 1185-1188
Author(s):  
Hao Lin Yu ◽  
Wei Wang ◽  
Yuan Shun Ma ◽  
Xue Yan Xu
Keyword(s):  
Water Content ◽  
Bound Water ◽  
Free Water ◽  
Physical And Mechanical Properties ◽  
Frozen Soil ◽  
Unfrozen Water ◽  
Nmr Method ◽  
Unfrozen Water Content ◽  
Ice Content ◽  
Function Relationship

Unfrozen water content has an important influence on the physical and mechanical properties of frozen soil. Little research has been done on unfrozen water content of permafrost in the Northeast Region, China, so the experimental investigation was performed on Mohe permafrost (4 kinds of samples were taken from 4 kinds of undisturbed frozen soil) based on NMR method, and the relationship and between frozen temperatures (-1°C, -4°C, -7°C, -11°C, -14°C, -16°C) and unfrozen water content was obtained. The test results indicate that, Unfrozen water content decreased with the reduction of frozen temperature of permafrost and there was a power function relationship between unfrozen water content and frozen temperature. The unfrozen water content reduction of No.3 sample was the slowest, because it had the lowest water content and the least frost-heave and thawed amount. It also can be attained that ice content of Mohe permafrost became more and more, but bound water and free water content got less and less while frozen temperature fell continuously.

scholarly journals Solubilization of Methylene Blue in Reversed Micelles, Effect of Water

1980 ◽  
Vol 35 (6) ◽  
pp. 741-745 ◽  
Author(s):  
Norio Miyoshi ◽  
Giiti Tomita
Keyword(s):  
Methylene Blue ◽  
Water Content ◽  
Bound Water ◽  
Free Water ◽  
Reversed Micelles ◽  
Absorption Bands ◽  
Effect Of Water ◽  
Head Groups

Abstract The solubilization of methylene blue in dodecylammonium propionate reversed micelles in cyclohexane depended strongly on the solubilized water content. Methylene blue solubilized in the micelle of which head groups are not completely hydrated by bound water exhibited the new absorption bands at 495 and 270 nm, but these bands did not appear in the micelle containing free water. This dye had the absorption bands at 655 and 290 nm in the latter micelle. The solubilizing process and solubilized state of methylene blue in the reversed micelles were discussed with results obtained.

Influence of the free water content on the dewaterability of sewage sludges

2001 ◽  
Vol 44 (10) ◽  
pp. 177-183 ◽  
Author(s):  
J. Kopp ◽  
N. Dichtl
Keyword(s):  
Binding Energy ◽  
Sewage Sludge ◽  
Water Content ◽  
Water Distribution ◽  
Bound Water ◽  
Free Water ◽  
Binding Energies ◽  
Intracellular Water ◽  
Water Binding ◽  
Free Water Content

Dewaterabilty of sewage depends on the physical water distribution. The various types of water in sewage sludge are mainly distinguished by type and intensity of their physical bonding to the solids. In a sewage sludge suspension different types of water can be distinguished. These are free water, which is not bound to the particles, interstitial water, which is bound by capillary forces between the sludge flocs, surface water, which is bound by adhesive forces and intracellular water. Only free water can be separated during mechanical dewatering. It can be shown, that thermo-gravimteric measurement of the free water content leads to an exact prediction of full-scale dewatering results. Maximum dewatering results are reached by separating all free water during centrifugation. Furthermore on the basis of the drying curve an estimation of water binding energies can be achieved. The binding energy for free water is less than 0,28 kJ/kg water. The binding energy for bound water (sum of surface and intracellular water) is higher than 5 kJ/kg water.

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