scholarly journals Monitoring moisture content and evaporation kinetics from mine slurries through albedo measurements to help predict and prevent dust emissions

2021 ◽  
Vol 8 (7) ◽  
pp. 210414
Author(s):  
Josée Maurais ◽  
Frédéric Orban ◽  
Emrik Dauphinais ◽  
Patrick Ayotte
Keyword(s):  
Moisture Content ◽  
Bauxite Residue ◽  
Spectroscopic Characterization ◽  
Mitigation Strategies ◽  
Optical Methods ◽  
Integrating Sphere ◽  
Dust Emissions ◽  
Prediction And Prevention ◽  
Drying Rates ◽  
Surface Drying

The prediction and prevention of fugitive dust emissions from mine tailings surfaces depend largely on our ability to monitor and monitor and predict the evolution of tailings moisture content (TMC). Albedo measurements are demonstrated here to be valuable tools to quantify TMC in bauxite residue samples under controlled conditions in the laboratory. The difference in albedo between 1.30 and 1.55 µm obtained through the infrared integrating sphere method shows good correlations with those acquired with a field spectroradiometer while both are strongly correlated with TMC. Additionally, continuous spectroscopic characterization of evaporating residues is shown to reveal the evolution in their surface drying rates. These optical methods could help predict surface drying state, thereby improving the accuracy of dust emissions risk assessment protocols that support mining industries intervention and mitigation strategies.

scholarly journals Effects of microwave irradiation on the moisture content of various wood chip fractions obtained from different tree species

2021 ◽  
Vol 67 (1) ◽  
Author(s):  
Monika Aniszewska ◽  
Krzysztof Słowiński ◽  
Ewa Tulska ◽  
Witold Zychowicz
Keyword(s):  
Moisture Content ◽  
Microwave Irradiation ◽  
Microwave Power ◽  
Irradiation Time ◽  
Initial Moisture Content ◽  
Radiant Energy ◽  
Wood Chip ◽  
Wood Chips ◽  
Chip Size ◽  
Drying Rates

AbstractThe paper proposes the use of microwave irradiation to lower the initial moisture content of wood chips. The study involved willow and fir chips fractionated by means of a sieve separator and unfractionated ash chips. The wood chips were exposed to a constant microwave power of 800 W for 30 s, 60 s, 120 s and 180 s. The chips were weighed before and after irradiation to measure loss of moisture. It was found that the decline in moisture content increased with wood chip size for a given irradiation time and microwave power. The initial moisture content of wood chips was not found to significantly affect loss of moisture as the drying rates of wood chips with higher and lower moisture content exposed to microwaves were not statistically different. The results showed that irradiation intensity increased with the time of exposure to microwaves and unit radiant energy per unit of evaporated moisture decreased with increasing wood chip size in the 3.15–31.50 mm range.

scholarly journals Drying and storage of Eugenia involucrata DC. seeds

2003 ◽  
Vol 60 (3) ◽  
pp. 471-475 ◽  
Author(s):  
Angela Maria Maluf ◽  
Denise Augusta Camargo Bilia ◽  
Claudio José Barbedo
Keyword(s):  
Moisture Content ◽  
Water Content ◽  
Cold Storage ◽  
Native Species ◽  
Plastic Bags ◽  
Physiological Quality ◽  
Drying Rates ◽  
And Storage ◽  
Water Contents

The physiological quality of seeds of native species is important to produce healthy saplings and therefore guarantee the success of programs to recover disturbed vegetation. This reinforces the necessity for investigating the physiological quality of those seeds. To evaluate the effects of different drying rates on the germination, moisture content and storability of Eugenia involucrata diaspores, mature fruits collected at Mogi Guaçu, SP, Brazil had their epi- and mesocarps removed by washing and were dried at 30, 40 or 50ºC until their water content was reduced from 57% (fresh diaspores) to 13% (final drying), totaling six drying levels. In a second experiment, diaspores had their moisture content reduced from 57% to 49%, at 30ºC, totaling six drying levels (0h, 1h, 2h, 3h, 4h and 5h), and were kept for 180 days in plastic bags under cold storage. The drying rate had no effect on tolerance to desiccation by E. involucrata diaspores; water contents lower than 51% decreased both germinability and storability. Diaspores can be stored for up to 180 days as long as their water content is reduced to 53% and they are kept inside plastic bags under cold storage.

Air speed effects during drying of harvested pasture material

1965 ◽  
Vol 16 (3) ◽  
pp. 385 ◽  
Author(s):  
W Shepherd
Keyword(s):  
Moisture Content ◽  
Laboratory Tests ◽  
External Surface ◽  
Field Tests ◽  
High Moisture Content ◽  
High Moisture ◽  
High Speeds ◽  
Field Investigations ◽  
Air Speed ◽  
Drying Rates

Laboratory and field investigations indicated effects of air speed on the drying rates of harvested clover and ryegrass. In laboratory tests, the drying rates of material of high moisture content increased with increasing air speed to 0.4 m sec-1 past single units or through bulked material, and to 4 m sec-1 over bulked material. These critical air speeds decreased as drying progressed. Critical through-speeds, initially unattainable even with high speeds over bulked material, could then be attained at moderate over-speeds. The effects were confirmed during field tests involving material bulked into swaths and windrows such as are employed in the field drying of mown pasture for conservation as hay. Effective external (surface) resistances of material in swaths and windrows were estimated to be 8–12 times those of plant units exposed singly. Evidence is presented that "turning" of material during field drying, to release entrapped water vapour, is necessary even on windy days in the early stages of drying, and on still days in the later stages. Under still but otherwise favourable conditions, turning appears necessary also as a substitute for the continuous supply of warm air to spaces within the bulk.

scholarly journals Optimization of drum drying parameters for gac powder

2018 ◽  
Vol 192 ◽  
pp. 03046
Author(s):  
Pornthip Suriyajunhom ◽  
Maradee Phongpipatpong
Keyword(s):  
Moisture Content ◽  
Gum Arabic ◽  
Total Phenolic ◽  
Tropical Fruit ◽  
Drying Temperature ◽  
Drum Drying ◽  
Processing Variables ◽  
Lycopene Content ◽  
Fruit Powder ◽  
Surface Drying

Gac (Momordica cochinchinensis Spreng.) is a tropical fruit which contains a rich nutrient source, especially lycopene. However, fresh gac fruit can spoil rapidly due to its high moisture content. Drum drying is a process to remove moisture from food in order to preserve nutrients and extend shelf life. In this study, gac fruit powder was produced by using drum drying technique. The present research was aimed to determine the optimum drum drying condition for gac powder. Response Surface Methodology was employed with three processing variables, including drum surface drying temperature (115, 125, 135˚C) maltodextrin content (100, 150, 200%) and gum arabic content (10, 20, 30%). The response variables were moisture content, solubility, hygroscopicity, total phenolic content and lycopene content of gac fruit powder. Regression analysis was then performed to obtain the mathematical relation between the processing variables and the responses in the form of second-order polynomial equations.. The results showed that optimum conditions for drum drying of gac fruit was at 135˚C of drum surface drying temperature, 138% of added maltodextrin and 10% of added gum arabic, which provided the highest amount of total phenolic and lycopene content.

WEATHER EFFECTS ON HAY DRYING RATES

1974 ◽  
Vol 54 (3) ◽  
pp. 479-484 ◽  
Author(s):  
H. N. HAYHOE ◽  
L. P. JACKSON
Keyword(s):  
Moisture Content ◽  
Dry Matter ◽  
Weather Data ◽  
Potential Evaporation ◽  
High Quality ◽  
Drying Time ◽  
Weather Effects ◽  
Maximum Production ◽  
Drying Rates

Observations taken at Nappan, N.S. of drying rates of field-cured hay and the corresponding weather data are reported. Three consecutive good days were chosen as the standard for good hay drying weather. Based on 30 yr of weather records, the highest probability (36%) of having this good weather at Nappan occurs in the first 2 wk of July. Maximum production of digestible dry matter in hay occurs about mid-June. Rapid storage of high quality forage is desirable. To facilitate harvest, early cuttings of forage should be taken as ensilage. An equation is developed which relates the observed moisture content in the field to the accumulation of potential evaporation from the time of cutting. The effect of precipitation on drying time is considered. An index based on potential evaporation and precipitation is proposed as a measure of the suitability of weather data for predicting field drying rates. A good drying day is defined in terms of this index and used in the estimation of the probability of sequences of good drying days from 30 yr of weather data from Nappan, N.S.

scholarly journals An Experimental Study and Analysis on Solar Drying of Bitter Gourd Using an Evacuated Tube Air Collector in Thanjavur, Tamil Nadu, India

2013 ◽  
Vol 2013 ◽  
pp. 1-4 ◽  
Author(s):  
AR. Umayal Sundari ◽  
P. Neelamegam ◽  
C. V. Subramanian
Keyword(s):  
Moisture Content ◽  
Tamil Nadu ◽  
Research Work ◽  
Bitter Gourd ◽  
Sun Drying ◽  
Solar Dryer ◽  
Drying Rates ◽  
Evacuated Tube ◽  
Drying Chamber

The objective of this research work is to design and develop a forced convection solar dryer using evacuated tube air collector and study its performance on bitter gourd in Thanjavur District, Tamilnadu, India. The designed solar dryer consists of a drying chamber, evacuated tube air collector, a blower, and a chimney. Drying parameters, moisture ratio and drying rates, are calculated and their performance is compared with natural sun drying. The results of the present study show that the proposed solar dryer has greater efficiency, and the moisture content of bitter gourd is reduced from 91% to 6.25% in 6 hours as compared to 10 hours in natural sun drying. In this solar dryer, the products are uniformly dried, and the moisture content of the sample is controlled. It is found that the quality of the dried bitter gourd using solar dryer is higher than the natural sun-dried bitter gourd.

scholarly journals Potential of microwave drying technology for increase drying rate and physical quality of kaffir lime (Citrus hystrix DC) leaves

2021 ◽  
Vol 924 (1) ◽  
pp. 012045
Author(s):  
F Su’aidah ◽  
I Taruna
Keyword(s):  
Moisture Content ◽  
Power Level ◽  
Preference Test ◽  
Color Difference ◽  
Microwave Drying ◽  
Drying Rate ◽  
Physical Quality ◽  
Oven Drying ◽  
Drying Rates

Abstract The effects of microwave power on microwave drying rates and the physical quality of kaffir lime leaves were studied. Three power levels were used in this study, high (723 watts), medium (537 watts), and low (420 watts). The moisture content, drying rate, color (L, a, b), and organoleptic parameters of each power level will be compared with the oven drying method (60°C). The result shows that the final moisture content of the high, medium, and low power of microwave drying are 6.06, 4.26%, and 6.16%db respectively, which is lower than oven drying, 16.62%db. Besides, the drying rate of microwave drying is 26.39-48.71%db/minute, higher than oven drying 0.32%db/minute. Dried kaffir lime leaves with medium level power (537 watt) has the lowest color difference (ΔE = 1.0 ± 0.29) compared to fresh leaves. While, the color and aromatic preference test dried kaffir lime leaves by microwave drying was preferable than oven drying.

Modelling of apple slice moisture content by optical methods

2012 ◽  
Vol 41 (Supplement 1) ◽  
pp. 39-51 ◽  
Author(s):  
L. Dénes ◽  
V. Zsom-Muha ◽  
L. Baranyai ◽  
J. Felföldi
Keyword(s):  
Moisture Content ◽  
Optical Methods ◽  
Apple Slice

Investigation into thin layer drying rates and equilibrium moisture content of abattoir paunch waste

2018 ◽  
Vol 124 ◽  
pp. 95-102 ◽  
Author(s):  
Jennifer Spence ◽  
David Buttsworth ◽  
Bernadette K. McCabe ◽  
Craig Baillie ◽  
Diogenes L. Antille ◽  
...  
Keyword(s):  
Moisture Content ◽  
Thin Layer ◽  
Equilibrium Moisture Content ◽  
Thin Layer Drying ◽  
Drying Rates

A survey of moisture distribution in two sets of Scots pine logs by NIR-spectroscopy

Holzforschung ◽  
2008 ◽  
Vol 62 (4) ◽  
Author(s):  
Kyösti Karttunen ◽  
Asta Leinonen ◽  
Matti-Paavo Sarén
Keyword(s):  
Moisture Content ◽  
Scots Pine ◽  
Near Infrared ◽  
Nir Spectroscopy ◽  
Optical Probe ◽  
Moisture Distribution ◽  
Least Squares Regression ◽  
Step Procedure ◽  
Surface Drying ◽  
Automated Scanning

Abstract Moisture content distributions of Scots pine logs in the green state were measured by a novel multi-step procedure. After sample preparation, the transverse sections of the wood surfaces were scanned by an automated scanning device with a fiber optical probe connected to a Fourier transform near-infrared spectroscope. In the course of the measurement sequences, several issues were addressed, such as surface drying, measurement geometry, ease of automation and interconnected data handling. The near-infrared (NIR) data were first modeled separately for heartwood and sapwood by means of multivariate partial least squares regression. The models for moisture content were evaluated by root mean square error of prediction, the result being 0.8% for heartwood and 10% for sapwood. The two models were then applied to the NIR data collected from sets of disks cut from nine logs. The results of the calculated moisture contents were evaluated by methods of descriptive statistics, and they indicated clear differences and trends in the distribution of moisture content in transverse or longitudinal regions of a log. Additionally, inter-tree variation in moisture content was detected.

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