scholarly journals Propagation probability and spread rates of self-sustained smouldering fires under controlled moisture content and bulk density conditions

2016 ◽  
Vol 25 (4) ◽  
pp. 456 ◽  
Author(s):  
Nuria Prat-Guitart ◽  
Guillermo Rein ◽  
Rory M. Hadden ◽  
Claire M. Belcher ◽  
Jon M. Yearsley
Keyword(s):  
Moisture Content ◽  
Bulk Density ◽  
Infrared Camera ◽  
Fire Spread ◽  
Spread Rate ◽  
Critical Moisture Content ◽  
Moisture Contents ◽  
Milled Peat ◽  
Critical Moisture ◽  
Smouldering Combustion

The consumption of large areas of peat during wildfires is due to self-sustained smouldering fronts that can remain active for weeks. We studied the effect of peat moisture content and bulk density on the horizontal propagation of smouldering fire in laboratory-scale experiments. We used milled peat with moisture contents between 25 and 250% (mass of water per mass of dry peat) and bulk densities between 50 and 150 kg m–3. An infrared camera monitored ignition, spread and extinction of each smouldering combustion front. Peats with a bulk density below 75 kg m–3 and a moisture content below 150% self-sustained smouldering propagation for more than 12 cm. Peat with a bulk density of 150 kg m–3 could self-sustain smouldering propagation up to a critical moisture content of 115%. A linear model estimated that increasing both moisture content and bulk density significantly reduced the median fire spread rate (which ranged between 1 and 5 cm h–1). Moisture content had a stronger effect size on the spread rate than bulk density. However, the effect of bulk density on spread rate depends upon the moisture content, with the largest effect of bulk density at low moisture contents.

Developing a Linearization Method to Determine Optimum Blending for Surimi with Varied Moisture Contents Using Linear Programming

2019 ◽  
Vol 0 (0) ◽  
Author(s):  
Hyeon W. Park ◽  
Jae W. Park ◽  
Won B. Yoon
Keyword(s):  
Linear Programming ◽  
Moisture Content ◽  
Standard Procedure ◽  
Unit Cost ◽  
Linearization Method ◽  
Model Parameters ◽  
Additional Information ◽  
Moisture Contents ◽  
Design Variables ◽  
Critical Moisture

AbstractNovel algorithm to determine the least cost formulation of a surimi blend was developed using linear programming (LP). Texture properties and the unit cost of surimi blend at the target moisture content were used as constraint functions and the objective function, respectively. The mathematical models to describe the moisture content dependence of the ring tensile properties were developed using critical moisture content, and the model parameters were used for the least cost LP (LCLP) model. The LCLP model successfully predicted the quality of surimi blend. Sensitivity analysis was used to obtain an additional information when the perturbations of design variables are provided. A standard procedure to determine the least cost formulation for blending surimi with varied moisture contents was systematically developed.

Characterisation of the fuel and fire environment in southern Ontario’s tallgrass prairie

2015 ◽  
Vol 24 (8) ◽  
pp. 1118 ◽  
Author(s):  
Susan Kidnie ◽  
B. Mike Wotton
Keyword(s):  
Moisture Content ◽  
Tallgrass Prairie ◽  
Prescribed Burning ◽  
Fire Spread ◽  
Fuel Load ◽  
Prairie Restoration ◽  
Prescribed Burn ◽  
Spread Rate ◽  
Prescribed Burns ◽  
Tallgrass Prairie Restoration

Prescribed burning can be an integral part of tallgrass prairie restoration and management. Understanding fire behaviour in this fuel is critical to conducting safe and effective prescribed burns. Our goal was to quantify important physical characteristics of southern Ontario’s tallgrass fuel complex prior to and during prescribed burns and synthesise our findings into useful applications for the prescribed fire community. We found that the average fuel load in tallgrass communities was 0.70 kg m–2. Fuel loads varied from 0.38 to 0.96 kg m–2. Average heat of combustion did not vary by species and was 17 334 kJ kg–1. A moisture content model was developed for fully cured, matted field grass, which was found to successfully predict moisture content of the surface layers of cured tallgrass in spring. We observed 25 head fires in spring-season prescribed burns with spread rates ranging from 4 to 55 m min–1. Flame front residence time averaged 27 s, varying significantly with fuel load but not fire spread rate. A grassland spread rate model from Australia showed the closest agreement with observed spread rates. These results provide prescribed-burn practitioners in Ontario better information to plan and deliver successful burns.

scholarly journals Draft Requirement of Two Animal - Drawn Institute for Agricultural Research (IAR) Weeders

2020 ◽  
pp. 14-20
Author(s):  
Y. A. Unguwanrimi ◽  
A. M. Sada ◽  
G. N. Ugama ◽  
H. S. Garuba ◽  
A. Ugoani
Keyword(s):  
Soil Moisture ◽  
Moisture Content ◽  
Bulk Density ◽  
Soil Moisture Content ◽  
Agricultural Research ◽  
Soil Samples ◽  
Soil Conditions ◽  
Experimental Plot ◽  
Moisture Contents ◽  
Loam Soil

Draft requirements of two animal – drawn (IAR) weeders operating on loam soil were determined in the study. The implements include a straddle row weeder and an emcot attached rotary weeder evaluated under the same soil conditions, using a pair of white Fulani breed of oxen. The animal draft requirement was first estimated from the animal ergonomics measurements. Using area of 0.054 hectare as experimental plot for each implement the draft requirement of each implement was investigated after taking soil samples for soil moisture content and bulk density determinations. The implements tested showed variation in their average draft requirement. The straddle row weeder had the highest value of 338.15 N respectively while the emcot attached rotary weeder had the lowest value of 188.12 N with 47.03%, respectively. The average soil moisture contents and bulk density were 13.0% and 1.46%/cm3, respectively.

Effects of distribution of bulk density and moisture content on shrub fires

2013 ◽  
Vol 22 (5) ◽  
pp. 625 ◽  
Author(s):  
Ambarish Dahale ◽  
Selina Ferguson ◽  
Babak Shotorban ◽  
Shankar Mahalingam
Keyword(s):  
Moisture Content ◽  
Spatial Variation ◽  
Bulk Density ◽  
Solid Fuel ◽  
Numerical Solutions ◽  
Propagation Speed ◽  
Fire Spread ◽  
Fuel Moisture ◽  
Combustion Heat ◽  
Fuel Moisture Content

Formulation of a physics-based model, capable of predicting fire spread through a single elevated crown-like shrub, is described in detail. Predictions from the model, obtained by numerical solutions to governing equations of fluid dynamics, combustion, heat transfer and thermal degradation of solid fuel, are found to be in fairly good agreement with experimental results. In this study we utilise the physics-based model to explore the importance of two parameters – the spatial variation of solid fuel bulk density and the solid fuel moisture content – on the burning of an isolated shrub in quiescent atmosphere. The results suggest that vertical fire spread rate within an isolated shrub and the time to initiate ignition within the crown are two global parameters significantly affected when the spatial variation of the bulk density or the variation of fuel moisture content is taken into account. The amount of fuel burnt is another parameter affected by varying fuel moisture content, especially in the cases of fire propagating through solid fuel with moisture content exceeding 40%. The specific mechanisms responsible for the reduction in propagation speed in the presence of higher bulk densities and moisture content are identified.

Effects of Moisture Content and Compaction Pressure on Bulk Density of Rye

2021 ◽  
Vol 37 (3) ◽  
pp. 491-494
Author(s):  
Jonathan Chiputula ◽  
Emmanuel Ajayi ◽  
Ray Bucklin ◽  
Ann R Blount
Keyword(s):  
Moisture Content ◽  
Bulk Density ◽  
Compaction Pressure ◽  
Applied Pressure ◽  
Grain Storage ◽  
List Type ◽  
Moisture Contents ◽  
Storage Structures ◽  
Square Box

HighlightsRye grain compaction was measured for three different moisture contents (8%, 12%, and 16% wet basis) at five different compaction pressures (7, 14, 34, and 55 kPa)Bulk densities were found to be statistically significantly dependent (p < 0.0001) on both the moisture content and applied pressure.Compacted bulk densities increased with increasing applied pressure for all moisture contents.Abstract. Bulk density of agricultural grains is needed to determine the quantity of grain in storage structures and to calculate grain pressures. The objective of this study was to investigate the effects of moisture content and applied pressure on bulk density of rye grain at moisture contents and pressures typical of those seen in storage structures. Rye compaction was measured for three moisture contents (8%, 12%, and 16% wet basis) at four compaction pressures (7, 14, 34, and 55 kPa) using a square box (based on the design used by Thompson and Ross, 1983). Data from the compaction tests were used to calculate the bulk densities for the three moisture contents and four compaction pressures. The bulk densities were found to be significantly dependent (p <0.0001) both on moisture contents and the pressure applied. Bulk densities varied with increasing moisture content as has been observed in similar studies for rye and other agricultural grains such as wheat and soybeans. These results provide guidance for estimating bulk density of rye in bins and other storage structures. Keywords: Grain compaction, Grain storage, Kernel rearrangement, Kernel elasticity.

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