Three-dimensional spatial distribution of adults of Cryptolestes ferrugineus (Coleoptera: Laemophloeidae) in stored wheat under different temperatures, moisture contents, and adult densities

Storability of properly harvested, mature hulless oats (Avena nuda L. ’Terra’) of 9.7–10.5% moisture content was determined from a 24-mo field trial of two 11.5-t lots of oats stored in two wooden farm bins in Manitoba during 1976–78. Oats were stored safely with very low levels of infestation by preharvest fungi, mites and insects and negligible quality loss for up to about 20 mo. Afterwards the grain moisture contents at the bottom layers of both bins rose from about 10 to 13–16%; this led to heavy floor level infestations by the fungi Penicillium and Aspergillus versicolor, and mites Caloglyphus berlesei and Tarsonemus granarius. Fat acidity values rose from the first year levels of about 30 to 50–78 mg KOH/100 g of dry grain. Populations of Cryptolestes ferrugineus and Tribolium castaneum, introduced to one bin, did poorly during the first summer and failed to survive during the second year. A third beetle, Oryzaephilus surinamensis, continued to multiply in small numbers after 22 mo. Low storage temperature levels during most of the years seemed to have affected adversely the multiplication of insects and to a lesser extent mites in farm-stored oats.

Download Full-text

Propagation velocity model of stress waves in larch wood (Larix gmelinii) three-dimensional space with different moisture contents

BioResources ◽

10.15376/biores.15.3.6680-6695 ◽

2020 ◽

Vol 15 (3) ◽

pp. 6680-6695

Author(s):

Xiwen Wei ◽

Liping Sun ◽

Hongjv Zhou ◽

Yang Yang ◽

Yifan Wang ◽

...

Keyword(s):

Moisture Content ◽

Wave Velocity ◽

Stress Wave ◽

Propagation Velocity ◽

Dimensional Space ◽

Three Dimensional ◽

Stress Waves ◽

Moisture Contents ◽

Direction Angle ◽

Stress Wave Velocity

Based on the effects of stress wave propagation in larch (Larix gmelinii) wood, the propagation mechanism of stress wave was explored, and a theoretical model of the propagation velocity of stress waves in the three-dimensional space of wood was developed. The cross and longitudinal propagation velocities of stress wave were measured in larch wood under different moisture contents (46% to 87%, 56% to 96%, 20% to 62%, and 11% to 30%) in a laboratory setting. The relationships between the propagation velocity of stress waves and the direction angle or chord angle with different moisture contents were analyzed, and the three-dimensional regression models among four parameters were established. The analysis results indicated that under the same moisture content, stress wave velocity increased as the direction angle increased and decreased as chord angle increased, and the radial velocity was the largest. Under different moisture contents, stress wave velocity gradually decreased as moisture content increased, and the stress wave velocity was more noticeably affected by moisture content when moisture content was below the fiber saturation point (FSP, 30%). The nonlinear regression models of the direction angle, chord angle, moisture content, and the propagation velocity of stress wave fit the experiment data well (R2 ≥ 0.97).

Download Full-text

Where Does the Galaxy End?

Symposium - International Astronomical Union ◽

10.1017/s0074180900230568 ◽

1996 ◽

Vol 169 ◽

pp. 669-680

Author(s):

F.D.A. Hartwick

Keyword(s):

Spatial Distribution ◽

Globular Clusters ◽

Semimajor Axis ◽

Three Dimensional ◽

Minor Axis ◽

Spatial Extension ◽

The Galaxy ◽

Nested Hierarchy ◽

Satellite Galaxies ◽

Dimensional Surface

The spatial distribution of the outlying satellites of the Galaxy has been determined by fitting a three dimensional surface to the positions of 10 companion galaxies and 13 distant globular clusters. Both groups show a highly flattened distribution whose minor axes are aligned to within ∼ 5°. The combined group of 23 objects shows a triaxial distribution with semimajor axis extending ∼ 400 kpc. The minor axis is inclined at ∼ 76° to the Galactic poles. There is a suggestion of a nested hierarchy consisting of satellite galaxies, globular clusters, and distant halo field stars, in order of decreasing spatial extension.

Download Full-text

Mechanical Properties of Grains Sorghum Subjected to Compression at Different Moisture Contents

Journal of Agricultural Science ◽

10.5539/jas.v11n4p279 ◽

2019 ◽

Vol 11 (4) ◽

pp. 279

Author(s):

Gabrielly B. Rodrigues ◽

Osvaldo Resende ◽

Daniel E. C. de Oliveira ◽

Lígia C. de M. Silva ◽

Weder N. Ferreira Junior

Keyword(s):

Mechanical Properties ◽

Moisture Content ◽

Uniaxial Compression ◽

Deformation Modulus ◽

Grain Sorghum ◽

Parallel Plates ◽

Compression Force ◽

Moisture Contents ◽

Rest Position ◽

Different Temperatures

This study aimed to evaluate the influence of drying at different temperatures on the mechanical properties of grains of grain sorghum subjected to compression at the natural rest position. Grains dried at temperatures of 60, 80 and 100 °C with different moisture contents (0.515; 0.408; 0.315; 0.234; 0.162 and 0.099 (d.b.)) were subjected to uniaxial compression between two parallel plates, applied at their natural rest position, at a rate of 0.001 m s-1. The force required to rupture in grains of grain sorghum increased as their moisture contents decreased, with values of 47.17 to 78.44 N, 61.81 to 69.66 N and 52.07 to 70.89 N for the temperatures of 60, 80 and 100 °C, respectively. The compression force required to deform grain sorghum decreased with the increment in moisture content, and the proportional deformation modulus increases with moisture content reduction. Within the studied range of moisture content, the values were 87 × 10-7 to 354.99 × 10-7 Pa, 132.63 × 10-7 to 465.98 × 10-7 Pa and 80.18 × 10-7 to 429.85 × 10-7 Pa for the temperatures of 60, 80 and 100 °C, respectively.

Download Full-text