Moisture transport in coated wood. Part 1: Analysis of sorption rates and moisture content profiles in spruce during liquid water uptake

Abstract. Organic compounds and liquid water are major aerosol constituents in the southeast United States (SE US). Water associated with inorganic constituents (inorganic water) can contribute to the partitioning medium for organic aerosol when relative humidities or organic matter to organic carbon (OM ∕ OC) ratios are high such that separation relative humidities (SRH) are below the ambient relative humidity (RH). As OM ∕ OC ratios in the SE US are often between 1.8 and 2.2, organic aerosol experiences both mixing with inorganic water and separation from it. Regional chemical transport model simulations including inorganic water (but excluding water uptake by organic compounds) in the partitioning medium for secondary organic aerosol (SOA) when RH  >  SRH led to increased SOA concentrations, particularly at night. Water uptake to the organic phase resulted in even greater SOA concentrations as a result of a positive feedback in which water uptake increased SOA, which further increased aerosol water and organic aerosol. Aerosol properties, such as the OM ∕ OC and hygroscopicity parameter (κorg), were captured well by the model compared with measurements during the Southern Oxidant and Aerosol Study (SOAS) 2013. Organic nitrates from monoterpene oxidation were predicted to be the least water-soluble semivolatile species in the model, but most biogenically derived semivolatile species in the Community Multiscale Air Quality (CMAQ) model were highly water soluble and expected to contribute to water-soluble organic carbon (WSOC). Organic aerosol and SOA precursors were abundant at night, but additional improvements in daytime organic aerosol are needed to close the model–measurement gap. When taking into account deviations from ideality, including both inorganic (when RH  >  SRH) and organic water in the organic partitioning medium reduced the mean bias in SOA for routine monitoring networks and improved model performance compared to observations from SOAS. Property updates from this work will be released in CMAQ v5.2.

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Effect of a Combination of Moderate-Temperature Heat Treatment and Subsequent Wax Impregnation on Wood Hygroscopicity, Dimensional Stability, and Mechanical Properties

Forests ◽

10.3390/f11090920 ◽

2020 ◽

Vol 11 (9) ◽

pp. 920 ◽

Cited By ~ 3

Author(s):

Lin Yang ◽

Hong-Hai Liu

Keyword(s):

Mechanical Properties ◽

Heat Treatment ◽

Water Uptake ◽

Significant Influence ◽

Liquid Water ◽

Dimensional Stability ◽

Bending Strength ◽

Wood Properties ◽

Moderate Temperature ◽

Temperature Heat Treatment

Wood is an environmentally friendly material, but some natural properties limit its wide application. To study the effect of a combination of heat treatment (HT) and wax impregnation (WI) on wood hygroscopicity, dimensional stability, and mechanical properties, samples of Pterocarpus macrocarpus Kurz wood were subjected to HT at a moderate temperature of 120 °C and a high temperature of 180 °C, for a 4 h duration. Subsequently, half of the 120 °C HT samples were treated with WI at 90 °C. The results showed that 180 °C HT and WI decreased the capacity of adsorption and liquid water uptake and swelled the wood significantly, while WI had the biggest reduction. The effect of 120 °C HT was significant only on decreasing the capacity of adsorption and the swelling of liquid water uptake. The bending strength (MOR) of wood decreased only after 180 °C HT, and 120 °C/4h HT and WI had no significant influence on MOR. The bending stiffness (MOE) increased significantly after 180 °C HT and WI, while 120 °C/4h HT had no significant influence on MOE. Therefore, the combination of moderate-temperature HT can act synergistically in the improvement of certain aspects of wood properties such as capacity of water adsorption and liquid water uptake. WI effectively improved wood hygroscopicity, dimensional stability, and mechanical properties.

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Effects of Wetting Treatment Period and Moisture Content on Water Uptake by Wheat Grain During Germination and .ALPHA.-amylase activity.

Japanese Journal of Crop Science ◽

10.1626/jcs.67.165 ◽

1998 ◽

Vol 67 (2) ◽

pp. 165-169 ◽

Cited By ~ 4

Author(s):

Satoshi NAKATSU

Keyword(s):

Moisture Content ◽

Treatment Period ◽

Water Uptake ◽

Amylase Activity ◽

Alpha Amylase ◽

Wheat Grain

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Water Uptake and Germination of Caper (Capparis spinosa L.) Seeds

Agronomy ◽

10.3390/agronomy10060838 ◽

2020 ◽

Vol 10 (6) ◽

pp. 838

Author(s):

María Laura Foschi ◽

Mariano Juan ◽

Bernardo Pascual ◽

Núria Pascual-Seva

Keyword(s):

Moisture Content ◽

Water Uptake ◽

Sensu Stricto ◽

Physical Dormancy ◽

Seed Moisture Content ◽

Mediterranean Countries ◽

Capparis Spinosa ◽

Viable Seeds ◽

Two Phases ◽

Almost All

Caper is a perennial deciduous sub-shrub that grows in almost all circum-Mediterranean countries. The specialized literature presents three possible dormancy types that can cause low germination of caper seeds: Physiological dormancy (PD), physical dormancy (PY), and combinational dormancy (PY + PD). We conducted three experiments to analyze the imbibition, viability, and germination of seeds of different ages, provenances, and the level of deterioration of the seed cover. None of the commercialized lots of standard seeds tested exceeded 6% germination, nor 35% viability, while the owned seeds reached 90% in both parameters, indicating that all viable seeds germinated. The seed moisture content along the soaking period followed the first two phases of the typical triphasic model of water uptake in seed germination: The imbibition and lag phases (phase I and II of germination, respectively). Seed hydration began through the hilar region. The fact that all viable owned seeds germinated, together with their moisture content being lower than that of standard seeds, indicated that caper seeds do not have a water-impermeable coat sensu stricto, i.e., they do not show PY; nevertheless, the need to use gibberellic acid to obtain high germination percentages, demonstrated the presence of PD.

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Non-isothermal Moisture Transport calculations with DIM 3.1 / Nicht-isotherme Berechnungen des Feuchtigkeitstransportes mit Hilfe des Porgrammes DIM 3.1

Restoration of Buildings and Monuments ◽

10.1515/rbm-2000-5487 ◽

2000 ◽

Vol 6 (4) ◽

pp. 367-384

Author(s):

J. Grunewald ◽

R. Plagge

Keyword(s):

Water Vapour ◽

Liquid Water ◽

Balance Equation ◽

Constitutive Equations ◽

Moisture Transport ◽

Moisture Transfer ◽

Transport Model ◽

Transport Coefficients ◽

Equation System ◽

Transport Processes

Abstract The application of a general thermodynamical mass and energy transport model to the coupled heat and moisture transfer in porous materials results in a balance equation system and the related constitutive equations of the considered quantities. The constitutive equations describe moisture transport in a phase-separated manner leading into phase-divided hygric transport coefficients (liquid water permeability, water vapour diffusivity). A conceptual model is presented in the paper in order to circumvent the difficulties resulting from non-isothermal overlaying moisture transport processes. Since phase-divided hygric transport coefficients are not directly measurable, but moisture transport coefficients in distinct hygric ranges, moisture conductivities and a phase dividing function are introduced. The moisture conductivities include liquid water and water vapour transport. For a known phase dividing function, the phase-divided hygric transport coefficients of the balance equation system can be calculated from the measurable moisture conductivities. The influence of a variation of the introduced phase-dividing function on non-isothermal moisture transport processes is investigated by means of computer simulations.

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Effect of Moisture Absorption on the Bending Strength of Carbon/Epoxy Composites with Voids

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.311-313.165 ◽

2011 ◽

Vol 311-313 ◽

pp. 165-168

Author(s):

A Ying Zhang ◽

Jian She Zhang ◽

Jia Zhi Wang ◽

Di Hong Li ◽

Dong Xing Zhang ◽

...

Keyword(s):

Moisture Content ◽

Water Uptake ◽

Immersion Time ◽

Room Temperature ◽

Moisture Absorption ◽

Bending Strength ◽

Experimental Results ◽

Epoxy Composites ◽

Effect Of Moisture

The effects of voids on the bending strength of T300/914 laminates that exposed to room temperature, hygrothermal and drying environment was discussed in this paper. The experimental results revealed that the saturated moisture content and the rate of water uptake increased with porosity increasing from 0.71% to 1.50%, which proved that voids facilitate moisture absorption. The bending strength of the unaged, aged and dried specimens were characterized and analyzed. The results revealed that the bending strength of the aged specimens decreased with the increasing void contents and immersion time. Compared to the unaged specimens, the bending strength of the aged specimens decreased 13.33% and 18.78% with porosity of 0.71% and 1.50%, respectively. The bending strength of the dried specimens was higher than that of the aged specimens and lower than that of the unaged specimens in the case of similar porosity.

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Water Uptake of Corn Roots as Influenced by Soil Moisture Content and Soil Moisture Tension

Soil Science Society of America Journal ◽

10.2136/sssaj1957.03615995002100050006x ◽

1957 ◽

Vol 21 (5) ◽

pp. 481-484 ◽

Cited By ~ 23

Author(s):

D. B. Peters

Keyword(s):

Soil Moisture ◽

Moisture Content ◽

Water Uptake ◽

Soil Moisture Content ◽

Corn Roots

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Germination characteristics of seven Stylosanthes species

Australian Journal of Experimental Agriculture ◽

10.1071/ea9760723 ◽

1976 ◽

Vol 16 (82) ◽

pp. 723 ◽

Cited By ~ 6

Author(s):

JG McIvor

Keyword(s):

Moisture Content ◽

High Temperatures ◽

Water Uptake ◽

Water Loss ◽

Initial Rate ◽

Germination Rate ◽

Moisture Stress ◽

Germination Response ◽

Germination Characteristics

The germination response of dehulled, scarified seeds to a range of constant and alternating temperatures, and to moisture stress was measured in seven Stylosanthes species. Rates of water uptake and loss were also measured. With constant temperatures, both total germination and germination rate were greatest at 25�C for all species except for S. hamata which germinated faster at 30�C. Both higher and lower temperatures slowed and depressed germination. Constant and alternating temperatures produced similar results except at high temperatures where germination was less with the alternating regime. Moisture stress greatly reduced germination of S. guyanensis cv. Cook, S. scabra and S. viscosa but had little effect on S. fruticosa, S. guyanensis CPI 40294 and S. subsericea. Initial rate of water uptake was greatest for S. hamata and S. subsericea but moisture content was similar for all species by 18 hours. There were no differences between species in rate of water loss from imbibed seeds.

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