scholarly journals Effect of variable content of organic matter and carbonates on results of determination of granulometric composition by means of Casagrande’s areometric method in modification by Prószyński

2018 ◽  
Vol 69 (1) ◽  
pp. 39-48 ◽  
Author(s):  
Hubert Warzyński ◽  
Agnieszka Sosnowska ◽  
Andrzej Harasimiuk
Keyword(s):  
Organic Matter ◽  
Calcium Carbonate ◽  
Granulometric Composition ◽  
Considerable Effect ◽  
Study Results ◽  
Variable Content ◽  
Practical Conclusion

Abstract The paper discusses the issue of the admixtures’ effect on results of granulometric composition determinations by Casagrande’s areometric method in modification by Prószyński. An experiment was conducted involving preparation of samples with known granulometric composition and determination of their composition by means of the aerometric method. Three types of samples were prepared: base (control), containing organic matter, and containing carbonates. Results of the determinations showed a considerable effect of the admixture of organic matter and calcium carbonate on the accordance of determinations, depending on their percent content. The study results also confirmed known dependencies of disturbances in proportions between the sandy and silty-clayey fraction. A practical conclusion from the research is the determination of the threshold of the organic matter and carbonates percent content at which the determination should be absolutely preceded by processes of mineralisation and decalcification.

A source of error in the estimation of the organic matter content of samples containing calcium carbonate

1972 ◽  
Vol 79 (3) ◽  
pp. 541-542 ◽  
Author(s):  
F. D. DeB. Hovell ◽  
E. R. Ørskov
Keyword(s):  
Organic Matter ◽  
Calcium Carbonate ◽  
Volatile Fatty Acids ◽  
Organic Matter Content ◽  
Matter Content ◽  
Carbonate Content ◽  
Apparent Digestibility ◽  
High Calcium ◽  
The Difference

The conventional method for the determination of the organic matter content of diets and faeces is by ashing the sample at 550 °C (A.O.A.C, 1965)Organic matter (O.M.) = dry matter (D.M.)–ash.If the sample contains calcium carbonate, then some of this carbonate will be converted to oxide (Vogel, 1951) and the weight of carbon dioxide evolved will be calculated as organic matter. The amount of carbonate converted will be dependent upon the temperature at which the sample is ashed and the duration of the ashing process. We have found (Ørskov, Hovell & Allen, 1966; Hovell & Greenhalgh, 1972) that when calcium salts of volatile fatty acids are included in diets given to sheep, most of the calcium is excreted in the faeces as carbonate, and since apparent digestibility is the difference between the amounts of nutrient ingested and excreted, the estimation of the apparent digestibility of organic matter will be in error if no correction is made for the high calcium carbonate content of the faeces. For example, a diet which contained 9·2% of calcium acetate had a true organic matterapparent digestibility of 86·8%. Had no correction been made this would have been estimated as 84·9%.

scholarly journals Determination of the Atterberg Limits of Eemian Gyttja on Samples with Different Composition

2020 ◽  
Vol 42 (2) ◽  
pp. 168-178 ◽  
Author(s):  
Katarzyna Goławska ◽  
Zbigniew Lechowicz ◽  
Władysław Matusiewicz ◽  
Maria Jolanta Sulewska
Keyword(s):  
Organic Matter ◽  
Calcium Carbonate ◽  
Organic Matter Content ◽  
Liquid Limit ◽  
Matter Content ◽  
Carbonate Content ◽  
Test Results ◽  
Plastic Limit ◽  
Calcium Carbonate Content

AbstractThe paper presents the results of laboratory tests of plastic limit wP and liquid limit wL of Eemian gyttja characterized by different organic matter content Iom and calcium carbonate content CaCO3. Comparison of the liquid limit wL determined with the use of the Casagrande apparatus wLC and a cone penetrometer with cones having apex angles of 60° wL60 and 30° wL30 is shown. Based on statistical analysis of the test results, single- and two-factor empirical relationships for evaluating the plastic limit wP and liquid limit wL of Eemian gyttja depending on the organic matter content Iom and/or calcium carbonate content CaCO3 are presented in this study.

Optimum Design of Journal Bearings Dimensions for Rotating Machines

2020 ◽  
Vol 38 (10A) ◽  
pp. 1481-1488
Author(s):  
Tariq M. Hammza ◽  
Ehab N. Abas ◽  
Nassear R. Hmoad
Keyword(s):  
Aspect Ratio ◽  
Dynamic Response ◽  
Numerical Solution ◽  
Critical Speed ◽  
Design Method ◽  
Considerable Effect ◽  
Journal Bearings ◽  
Rotating Machines ◽  
Bearing Clearance ◽  
Study Results

The values of Many parameters which involve in the design of fluid film journal bearings mainly depend on the bearing applied load when using the conventional design method to design the journal bearings, in this study, as well as applied bearing load, the dynamic response and critical speed have been used to calculate the dimensions of journal bearings. In the field of rotating machine, especially a heavy-duty rotating machines, the critical speed and response are the main parameters that specify bearing dimensions. The bearing aspect ratio (bearing length to bore diameter) and bearing clearance have been determined based on rotor maximum critical speed and minimum response displacement. The analytical solution of rotor Eq. of motion was verified by numerical solution via using ANSYS Mechanical APDL 18.0 and by comparing the numerical solution with the preceding study. The final study results clearly showed that the bearing aspect ratio has little effect on the critical speed, but it has a high effect on the dynamic response also the bearing clearance has little effect on the critical speed and considerable effect on the dynamic response. The study showed that the more accurate values of bearing aspect ratio to make the response of rotor as low as possible are about 0.65 - 1 and bearing percent clearance is about 0.15 - 0.2 for different rotor dimensions.

scholarly journals A Quantitative Analysis of Factors Influencing Organic Matter Concentration in the Topsoil of Black Soil in Northeast China Based on Spatial Heterogeneous Patterns

2021 ◽  
Vol 10 (5) ◽  
pp. 348
Author(s):  
Zhenbo Du ◽  
Bingbo Gao ◽  
Cong Ou ◽  
Zhenrong Du ◽  
Jianyu Yang ◽  
...  
Keyword(s):  
Land Use ◽  
Organic Matter ◽  
Soil Erosion ◽  
Soil Type ◽  
Northeast China ◽  
Black Soil ◽  
Factors Affecting ◽  
Soil Zone ◽  
Rainfed Farming ◽  
Study Results

Black soil is fertile, abundant with organic matter (OM) and is exceptional for farming. The black soil zone in northeast China is the third-largest black soil zone globally and produces a quarter of China’s commodity grain. However, the soil organic matter (SOM) in this zone is declining, and the quality of cultivated land is falling off rapidly due to overexploitation and unsustainable management practices. To help develop an integrated protection strategy for black soil, this study aimed to identify the primary factors contributing to SOM degradation. The geographic detector, which can detect both linear and nonlinear relationships and the interactions based on spatial heterogeneous patterns, was used to quantitatively analyze the natural and anthropogenic factors affecting SOM concentration in northeast China. In descending order, the nine factors affecting SOM are temperature, gross domestic product (GDP), elevation, population, soil type, precipitation, soil erosion, land use, and geomorphology. The influence of all factors is significant, and the interaction of any two factors enhances their impact. The SOM concentration decreases with increased temperature, population, soil erosion, elevation and terrain undulation. SOM rises with increased precipitation, initially decreases with increasing GDP but then increases, and varies by soil type and land use. Conclusions about detailed impacts are presented in this paper. For example, wind erosion has a more significant effect than water erosion, and irrigated land has a lower SOM content than dry land. Based on the study results, protection measures, including conservation tillage, farmland shelterbelts, cross-slope ridges, terraces, and rainfed farming are recommended. The conversion of high-quality farmland to non-farm uses should be prohibited.

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