Equilibrium moisture content of dead fine fuels of selected central European tree species

2013 ◽  
Vol 22 (6) ◽  
pp. 797 ◽  
Author(s):  
Christian Schunk ◽  
Clemens Leutner ◽  
Michael Leuchner ◽  
Clemens Wastl ◽  
Annette Menzel
Keyword(s):  
Moisture Content ◽  
Equilibrium Moisture Content ◽  
Input Parameter ◽  
Fire Danger ◽  
Pedunculate Oak ◽  
Salt Solutions ◽  
Test Procedures ◽  
Climate Chamber ◽  
Central European ◽  
Fine Fuels

Fine fuel moisture content is a key parameter in fire danger and behaviour applications. For modelling purposes, equilibrium moisture content (EMC) curves are an important input parameter. This paper provides EMC data for central European fuels and adds methodological considerations that can be used to improve existing test procedures. Litter samples of Norway spruce (Picea abies (L.) Karst.), Scots pine (Pinus sylvestris L.), European beech (Fagus sylvatica L.) and pedunculate oak (Quercus robur L.) were subjected to three different experiments using conditioning in a climate chamber and above saturated salt solutions. Climate chamber conditioning yielded the best results and can generally be recommended, however saturated salt solutions are able to produce lower relative humidities, which are relevant to forest fire applications as they represent the highest fire danger. Results were within the range of published sorption isotherms for forest fine fuels. A fairly clear gradation was present with higher EMC values in leaf litters than in needle litters. These differences are in accord with values from the literature and suggest general differences in the sorption properties of leaves and needles, which may be caused by differing chemical and physical properties. The influence of temperature on EMC described in the literature could be confirmed.

Equilibrium moisture content and timelag of dead Pinus pinaster needles

2014 ◽  
Vol 23 (5) ◽  
pp. 721 ◽  
Author(s):  
Sérgio Lopes ◽  
Domingos Xavier Viegas ◽  
Luís Teixeira de Lemos ◽  
Maria Teresa Viegas
Keyword(s):  
Moisture Content ◽  
Equilibrium Moisture Content ◽  
Pinus Pinaster ◽  
Predictive Ability ◽  
Food Products ◽  
Forest Fuels ◽  
Best Fitting ◽  
Fine Fuels ◽  
Almost All ◽  
Moisture Content Determination

Modelling adsorption and desorption processes and equilibrium moisture content of dead fine fuels below fibre saturation is required to provide an accurate prediction of their drying and wetting processes within the range where flammability increases rapidly with decreasing moisture content. Data from laboratory tests on sorption processes and equilibrium moisture content isotherms of dead Pinus pinaster (Ait.) needles were used to evaluate several models applicable to fine forest fuels and agricultural and food products. Laboratory and field data were used to assess model accuracy in predicting drying and wetting curves and equilibrium moisture content isotherms showing a medium to high predictive ability for almost all cases. The best fitting combinations were obtained with the application of agricultural and food products models for drying and wetting phases and fine forest fuel models for equilibrium moisture content determination.

The Horizontal Flame-Propagation Rate of Undyed Cotton Fabrics

1976 ◽  
Vol 46 (4) ◽  
pp. 238-246 ◽  
Author(s):  
Leon Segal ◽  
G. L. Drake
Keyword(s):  
Relative Humidity ◽  
Moisture Content ◽  
Equilibrium Moisture Content ◽  
Flame Propagation ◽  
Propagation Rate ◽  
Cotton Fabrics ◽  
Horizontal Position ◽  
Test Procedures ◽  
Oven Drying ◽  
Usual Test

Differentiation of the flammabilities of nonflame-retardant, all-cotton fabrics cannot be accomplished by the usual test procedures, as these merely provide the means for determining when a fabric exceeds a certain set standard. The desired differentiation, however, can be obtained by measurement of the flame-propagation rate using the Ahiba Flammability Tester with the sample in the horizontal position. Eight nonflame-retardant, undyed cotton fabrics of different constructions were studied. The weights of the fabrics fell into four groups: 3.1, 3.6–3.8, 4.1–4.4, and 7.5 oz/yd2. Specimens were cut from the warp and filling directions of the fabrics; one set of specimens was oven-dried prior to testing, while another set was conditioned to equilibrium moisture content at 65% relative humidity and 70°F. Burning was different in the warp and filling directions. Differences in flame-propagation rates were found that were not weight dependent. In general, flame-propagation rate was not constant over the length of the specimen; in the warp direction the rates increased with distance from point of ignition, while in the filling direction constant and decreasing rates were also found. Flame-propagation rate was not effected to the extent expected by changing from oven drying to conditioning to equilibrium moisture content; only four of the eight fabrics showed significant changes. Burning in the filling directions of two fabrics was markedly changed; smaller differences were found in the warp direction only of a third fabric and in both the warp and filling directions of a fourth fabric.

Predicting the elevated dead fine fuel moisture content in gorse (Ulex europaeus L.) shrub fuels

2009 ◽  
Vol 39 (12) ◽  
pp. 2355-2368 ◽  
Author(s):  
Stuart A.J. Anderson ◽  
Wendy R. Anderson
Keyword(s):  
Moisture Content ◽  
Response Time ◽  
Equilibrium Moisture Content ◽  
Fire Danger ◽  
Weather Data ◽  
Fuel Moisture ◽  
Fire Weather Index ◽  
Ulex Europaeus ◽  
Fuel Layer ◽  
Fuel Moisture Content

Methods were developed to predict the moisture content of the elevated dead fine fuel layer in gorse ( Ulex europaeus L.) shrub fuels. This layer has been observed to be important for fire development and spread in these fuels. The accuracy of the Fine Fuel Moisture Code (FFMC) of the Canadian Fire Weather Index System to predict the moisture content of this layer was evaluated. An existing model was used to determine the response time and equilibrium moisture content from field data. This response time was incorporated into a bookkeeping model, combining the FFMC and this response time–equilibrium moisture content model. The FFMC poorly predicted the elevated dead fuel moisture content in gorse fuels, and attempts to improve its accuracy through regression modelling were unsuccessful. The response time of the elevated dead fine fuel layer was very fast (38–77 min) and has important implications for fire danger rating. The bookkeeping approach was the most promising method to predict elevated dead fuel moisture content. A limitation was the inability to model fuel-level meteorology. However, this model warrants further validation and extension to other shrub fuels and could be incorporated into existing fire danger rating systems that can utilize hourly weather data.

Analysis of the moisture content of maize kernels in over-ripe plants

2006 ◽  
Vol 54 (4) ◽  
pp. 425-430
Author(s):  
T. Árendás ◽  
L. C. Marton ◽  
P. Bónis ◽  
Z. Berzsenyi
Keyword(s):  
Linear Regression ◽  
Moisture Content ◽  
Grain Yield ◽  
Equilibrium Moisture Content ◽  
Weather Conditions ◽  
Positive Correlation ◽  
Maize Grain Yield ◽  
Maize Grain ◽  
Maize Kernels

The effect of varying weather conditions on the moisture content of the maize grain yield was investigated in Martonvásár, Hungary from late August to late September, and from the 3rd third of September to the 1st third of Novemberbetween 1999 and 2002. In every year a close positive correlation (P=0.1%) could be observed between the moisture content in late September and the rate of drying down in October. Linear regression was used each year to determine the equilibrium moisture content, to which the moisture content of kernels returned if they contained less than this quantity of water in late September and harvesting was delayed. In the experimental years this value ranged from 15.24-19.01%.

Sensitivity of acoustic tools to variation in equilibrium moisture content of small clear samples of loblolly pine (Pinus taeda)

2017 ◽  
Vol 15 (1) ◽  
pp. 10-20 ◽  
Author(s):  
Charles Essien ◽  
Brian K. Via ◽  
Thomas Gallagher ◽  
Timothy Mcdonald ◽  
Lori Eckhardt
Keyword(s):  
Moisture Content ◽  
Pinus Taeda ◽  
Equilibrium Moisture Content ◽  
Loblolly Pine

scholarly journals Water adsorption isotherms and isosteric sorption heat of spray-dried and freeze-dried dehydrated passion fruit pulp with additives and skimmed milk

2011 ◽  
Vol 35 (6) ◽  
pp. 1196-1203 ◽  
Author(s):  
Kelly Tafari Catelam ◽  
Carmen Sílvia Fávaro Trindade ◽  
Javier Telis Romero
Keyword(s):  
Moisture Content ◽  
Equilibrium Moisture Content ◽  
Gum Arabic ◽  
Passion Fruit ◽  
Drying Methods ◽  
Fruit Pulp ◽  
Heat Of Sorption ◽  
Freeze Dried ◽  
Equilibrium Data ◽  
Skimmed Milk

Moisture equilibrium data of passion fruit pulp powders with maltodextrin and gum arabic were obtained by two different drying methods (spray drying and freeze drying) and determined at 20, 30, 40 and 50º C. Skimmed milk was used to substitute part of these additives in the samples. One formulation using passion fruit pulp/maltodextrin/skimmed milk (PMS) was prepared, and another using passion fruit pulp/gum arabic/skimmed milk (PGS). The behavior of curves was type III, according to Brunauer's classification. GAB models were fitted to experimental equilibrium data. The parameters obtained from GAB models was affected by the presence of additives. The behavior of the sorption isotherms for different temperatures are similar, noting only a small effect of temperature. There were little differences between both drying methods and additives used in relation to equilibrium moisture content. The parameters obtained with the addition of the skimmed milk were considered satisfactory (Xm values ranged from 0,04084 to 0,06488 in dry basis), demonstrating that it is an effective and cheap alternative for regular additives. A progressive increase in the heat of sorption in relation to decreasing moisture content was observed and the heat of sorption values of different samples are all similar, comparing the relative equilibrium moisture content.

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