scholarly journals Particle size composition of spawning gravel of Ayu （Plecoglossus altivelis） in Lake Biwa basin.

2020 ◽  
Vol 22 (2) ◽  
pp. 149-154
Author(s):  
Toshiaki MIZUNO ◽  
Yoshihiro AZUMA ◽  
Takeshi KITAI
Keyword(s):  
Particle Size ◽  
Lake Biwa ◽  
Size Composition ◽  
Plecoglossus Altivelis ◽  
Particle Size Composition

scholarly journals The effect of liquid pig manure on the wheat yield, content and balance of nutrients in light-gray forest soil with light particle-size composition

2019 ◽  
Vol 20 (5) ◽  
pp. 456-466
Author(s):  
V. I. Titova ◽  
L. D. Varlamova ◽  
R. N. Rybin ◽  
T. V. Andronova
Keyword(s):  
Particle Size ◽  
Spring Wheat ◽  
Wheat Yield ◽  
Size Composition ◽  
Light Particle ◽  
Pig Manure ◽  
Wheat Crop ◽  
Dry Matter Content ◽  
Particle Size Composition ◽  
Positive Balance

The research has been carried out under production conditions on light gray forest soils with light particle-size composition at an area of 550 hectares where liquid pig manure (LPM) of a large pig breeding complex is annually used as an organic fertilizer at doses of 60 and 90 t/ha. The average characteristics of LPM are as follows: dry matter content is 9.5%, pH 7.7 units, nitrogen 0.22%, phosphorus 0.11%, and potassium 0.12%. The cultivated grain crops were presented by winter and spring wheat varieties, Moskovskaya 39 and Esther, respectively. It has been established that at the dose of 60 t/ha LPM for two years of research at an average a mean wheat yield was 3.0-3.75 t/ha, and at the dose of 90 t/ha - up to 4.75 t/ha. The return on investments for fertilizers in the “winter wheat → spring wheat” crop rotation link at the dose of 60 t/ha of LPM was 5.41 kg of grain per 1 kg of active substance of manure, at the dose of 90 t/ha - 4.57 kg / kg. A positive balance of nutritional elements developed on all fields, but it was better balanced when the dose of LPM was 60 t/ha and the yield was 3.0 t/ha of grain annually, or when the LPM dose was 90 t/ha and the yield of wheat was 4.75 t/ha. In this case, the estimated potassi-um supply of soil occurs at a lower rate than that of nitrogen and phosphorus. The application of 120 t of LPM during two years in total on loamy sand and of 180 t/ha on light loamy soil provided an increase in the content of mobile phosphorus compounds by 5-22 mg/kg, and potassium - by 11-30 mg/kg with a variation coefficient of 28-57% and 21-49%, respectively.

Statistical Modelling of the Particle Size Composition of an Alumina Matrix for No-Cement Self-Flowing Refractory Castables

2006 ◽  
Vol 514-516 ◽  
pp. 604-608 ◽  
Author(s):  
Abílio P. Silva ◽  
Ana M. Segadães ◽  
Tessaleno C. Devezas
Keyword(s):  
Particle Size ◽  
Water Content ◽  
Raw Materials ◽  
Size Composition ◽  
Statistical Modelling ◽  
Matrix Composition ◽  
Mechanical Resistance ◽  
Particle Size Composition ◽  
Refractory Castables ◽  
System Properties

In the processing of any particulate system (including refractory castables), the finer sized particle fraction (matrix or filler) is mostly responsible for the final system properties. Alumina fine powders were used in this work as raw materials, namely two tabular alumina fractions (–500 mesh and –230 mesh) and a commercial reactive alumina. Statistical modelling and the Response Surface Methodology (Statistica, Mixtures Designs and Triangular Surfaces module) were used to optimise the particle size composition of the three-component mixtures leading to matrix maximum flowability. The mixing methodology, aimed at minimising the water content, was kept constant. No-cement alumina castables produced with the various fine size powder mixtures, were used to prepare test-pieces. After drying and sintering, their mechanical resistance (MoR), density, porosity, water absorption, thermal shock behaviour and microstructure were evaluated. The results obtained evidenced the relevance of variables such as the water content per unit specific surface area, needed to reach the self-flow “turning point”, and validated the statistical optimisation method used. Moreover those results showed the existence of a matrix composition range, which favours the formation of a flow-bed that enables the aggregate self-flow.

Effect of particle — size composition of pegmatite on glass quality

1957 ◽  
Vol 14 (9) ◽  
pp. 331-332
Author(s):  
M. V. Vadova ◽  
M. I. Levchenko
Keyword(s):  
Particle Size ◽  
Size Composition ◽  
Glass Quality ◽  
Particle Size Composition ◽  
Effect Of Particle Size

scholarly journals Determination of soil grain size composition by measuring apparent weight of float submerged in suspension

2017 ◽  
Vol 31 (1) ◽  
pp. 61-72 ◽  
Author(s):  
Jarosław Kaszubkiewicz ◽  
Witold Wilczewski ◽  
Tibor József Novák ◽  
Przemysław Woźniczka ◽  
Krzysztof Faliński ◽  
...  
Keyword(s):  
Particle Size ◽  
Size Composition ◽  
Digital Transmission ◽  
Weight Changes ◽  
Laser Method ◽  
Particle Size Composition ◽  
Apparent Weight ◽  
High Level ◽  
The Stokes Equation

AbstractTexture is one of the most significant physical properties of soils. Over the years, several methods of its measuring were developed. The paper presents a method for determining the particle size composition of soils, based on the separation of particles in the sedimentation process. Density of suspension is determined on the basis of apparent weight changes of a float submerged in it. The weight of the float suspended on a thin line, at a given depth in the suspension, is measured with a sensitive piezoelectric dynamometer. The Stokes equation is used to calculate the content of soil fractions with equivalent diameters in the range of 0.001 to 0.1 mm. Digital transmission of results from the dynamometer, the temperature sensor and measurements of the distance defining the depth of immersion of the float to the computer enable calculations of particle size composition to be performed automatically. This paper presents the results of measurements of the particle size composition of artificially generated mixtures of ‘silt’ and ‘clay’. The results are compared with results obtained with other methods (including the laser method). A high level of repeatability of the results and satisfactory compatibility in relation to the reference pipette method are noted.

scholarly journals Redistribution of particle-size fractions in ordinary chernozem affected by long-term irrigation and chemical melioration with phosphogypsum

2020 ◽  
pp. 95-101
Author(s):  
T. K. Makarova ◽  
N. N. Maksуmova ◽  
G. V. Нapich ◽  
I. V. Chushkina
Keyword(s):  
Particle Size ◽  
Size Composition ◽  
Ordinary Chernozem ◽  
Physical Clay ◽  
Size Fractions ◽  
Particle Size Fractions ◽  
Particle Size Composition ◽  
Leached Chernozem ◽  
Application Rates

The article reveals the issue of redistribution of particle-size fractions in ordinary low-humus leached chernozem on loamy loess in the condition of Northern Steppe of Ukraine affected by the irrigation with II class water and chemical melioration with phosphogypsum. Rather long use of water for irrigation from the reservoir on the Samara River in the Dniprovskyi district of the Dnipropetrovsk region deteriorated the soil properties due to salinization development in it, which led to the use of phosphogypsum. The calculated application rates of phosphogypsum 1,4 t/ha, 3 t/ha and 6 t/ha were applied along with irrigation and without it. The effect of chemical melioration and irrigation on the ecological and ameliorative condition of soil that resulted in the change of its particle-size composition, bulk density and structure was studied. It is established that irrigation of the soil with an average irrigation rate of 1500 m3/ha reduces the content of physical clay by 0,12-0,06% compared to the options without irrigation. When applying phosphogypsum along with irrigation there are minor changes in the redistribution of particle-size fractions: an increase in the fractions of physical sand and a decrease in the fractions of physical clay. It was determined that the particle-size composition of soil is more resistant to the effect of phosphogypsum rather than to the effect of irrigation. In non-irrigated variants when applying chemical melioration with phosphogypsum, the content of physical sand increases by 0,54-0,91% compared to the reference variant and the content of physical clay decreases by 0,87-1,13%. With increasing the rate of phosphogypsum, the content of physical sand also increases. The effect of improving the structure and loosening of the soil is observed in the variants where phosphogypsum at the rate of 6 t/ha was applied under the main tillage and at the rate of 3 t/ha under spring cultivation.

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