Fertilizers. Physical properties. Method for the determination of bulk density (tapped)

1981 ◽  
1996 ◽  
Vol 150 ◽  
pp. 301-308 ◽  
Author(s):  
A.C. Levasseur-Regourd

AbstractRecent progress has been reported in the determination of the zodiacal thermal emission, brightness and polarization. These results, of interest to estimate the foreground sources in astrophysical observations, do not provide immediately information on the dust distribution, and on its optical and thermal properties. To infer local information about the bulk density, and the physical properties of the dust particles, it is necessary to compare the observations with realistic models or to invert the line-of-sight data. The latter approach typically suggests that the bulk density is (in the symmetry plane) inversely proportional to the solar distance, that the particles are not spheroidal, but rather irregular in shape, that their physical properties change with their distance to the Sun and their orbital inclination, and finally that they do not emit like a blackbody. The heterogeneity noticed in the cloud is due to various sources of dust particles, the size, shape or albedo of which evolve as a function of time, under collision and/or evaporation processes.


2009 ◽  
Vol 55 (No. 4) ◽  
pp. 165-169 ◽  
Author(s):  
M.C. Ndukwu

The research looked at some selected physical properties of <I>Brachystegia eurycoma</I>, such as axial dimension, roundness, sphericity, surface area, bulk density, solid density, porosity, and volume which are essential in the design and construction of the processing and handling equipments of <I>Brachystegia eurycoma</I>. All the above physical properties measured showed some deviations from the average values which is typical of agricultural biomaterials. Solid density showed the highest deviation of 4.04 g/mm<sup>3</sup> while the volume showed the least deviation of 0.01 mm<sup>3</sup> when compared to those of other physical properties. The angle of repose increased with the increase in the moisture content with a coefficient of determination of 0.98.


2020 ◽  
Vol 8 (2) ◽  
pp. 122-128
Author(s):  
Mustofa Mustofa

Determination of the physical properties of rice is intended to facilitate the processing and handling to produce final product with best quality. These properties include geometry, surface area, volume, density, bulk density, porosity, and angle of repose. Determination of the physical properties of rice in terms of geometry is carried out by measuring length (L), width (W), and thickness (T). The measurement of these parameters uses a digital caliper with an accuracy of 0.01 mm. The volume of rice can be determined based on dimensional parameters. Density, bulk density and porosity of rice were determined by measuring its mass using a digital scale with an accuracy of 0.001 gr and based on the determination of the volume. Angle of repose is determined by spilling rice on the flat surface of a container so that the height (h) of the pile of rice and the diameter (D) is known. Based on the research results, it is known that the geometry of Membramo, Superwin, and Cimelati rices does not have a significant difference, in fact there are similarities in the eccentricity aspect, where all three have the same value, namely 0.96. The average surface area value of Cimelati rice is greater than that of Membramo and Superwin rice, as well as its volume. The average of surface area and volume of Cimelati rice were 23.89 mm2 and 13.41 mm3, respectively. Meanwhile, Superwin rice has the largest individual and bulk densities, 1.42 gr/cm3 and 0.80 gr/cm3, respectively. In addition, Superwin and Cimelati rices have the lowest porosity and angle of repose, namely 40.69% and 26.59o.


Author(s):  
Paulo C. Corrêa ◽  
Gabriel H. H. de Oliveira ◽  
Wander L. Vasconcelos ◽  
Guillermo A. Vargas-Elías ◽  
Fábio L. Santos ◽  
...  

ABSTRACT The determination of physical properties is an important factor in the design of machinery and the scaling of post-harvest operations. The present study evaluates the influence of the level of roasting and the size of grinding on the physical properties of coffee during storage. The following physical properties were evaluated: true and bulk density, and intergranular porosity. Raw coffee beans (Coffea canephora and Coffea arabica), hulled and dried, were roasted to two different levels: medium light (SCAA#65) and moderately dark (SCAA#45). The beans were then grinded into three different sizes: fine (0.59 mm), medium (0.84 mm) and coarse (1.19 mm). An additional coffee lot was kept whole. Following grinding, samples were stored at two different temperatures (10 and 30 ºC) and analyzed after five different storage durations (0, 30, 60, 120 and 180 days). The medium light roast had higher values for each of the measured physical properties. Finely ground samples had higher true and bulk densities, and porosities. It is concluded that the size of grinding, level of roasting and duration of storage significantly affect the physical properties of coffee.


Sign in / Sign up

Export Citation Format

Share Document