NATURAL ABUNDANCES AND MINERALOGICAL PARTITIONING OF TRACE ELEMENTS IN SELECTED ALBERTA SOILS

1980 ◽  
Vol 60 (4) ◽  
pp. 763-771 ◽  
Author(s):  
M. J. DUDAS ◽  
S. PAWLUK
Keyword(s):  
Particle Size ◽  
Trace Elements ◽  
Size Fraction ◽  
The Other ◽  
Particle Size Fraction ◽  
Background Levels ◽  
Copper And Zinc ◽  
Cu And Zn ◽  
Specific Particle

Background levels of As, Cd, Co, Cu, Pb, and Zn in Chernozemic and Luvisolic soils from Alberta were established and are similar to the average terrestrial abundances in shale and granite. Redistribution of As, Cd, Co, Cu, and Zn within the solum was more pronounced in Luvisolic soils than in Chernozems. Partitioning of the six trace elements, determined by analysis of particle size separates, was unique for each element. Copper and zinc were more uniformly enriched in clay separates than were the other four trace elements. Differences in the content of trace elements within and among soils arise not only from textural variation, but also from large variations in the quantity of trace elements within a specific particle size fraction.

scholarly journals Effects of processing whole oats on the analysis and fate of mycotoxins and ergosterol

2020 ◽  
Vol 13 (1) ◽  
pp. 45-56 ◽  
Author(s):  
S.A. Tittlemier ◽  
R. Blagden ◽  
J. Chan ◽  
T.L. McMillan ◽  
K. Pleskach ◽  
...  
Keyword(s):  
Particle Size ◽  
Plant Transformation ◽  
Size Fraction ◽  
Transformation Product ◽  
The Other ◽  
Particle Sizes ◽  
Particle Size Fraction ◽  
Fraction Distribution ◽  
Mycotoxin Analysis ◽  
Sample Heterogeneity

Grinding and dividing equipment were evaluated for their ability to comminute and divide ground oats in preparation for mycotoxin analysis. Four different grinders, using various settings, were evaluated for their ability to comminute oats and produce small particle sizes. Rotor beater type grinders produced the more desirable finer ground samples as compared to burr type mills. Four different division methods (manual scooping, rotary sample division, and two designs of gravity-fed dividers) were assessed for their ability to produce sub-samples with consistent particle size fraction distributions. No practical differences were observed on the particle size fraction distribution of test portions of finely ground oats produced using the four different division methods; therefore, no effects on mycotoxin analysis were anticipated. The effects of processing naturally contaminated whole oats on mycotoxin concentrations was also assessed. Laboratory scale dehulling, steaming, and kilning were examined. Dehulling showed the greatest impact and removed 60-100% of various Fusarium- and Alternaria-produced mycotoxins, as well as ergosterol, present on the naturally contaminated whole oats. Different from the other analytes studied, only 48% of the mycotoxin plant transformation product deoxynivalenol-3-glucoside was present in hulls and removed during dehulling. Steaming and kilning appeared to increase ergosterol in groats, as well as decrease deoxynivalenol and deoxynivalenol-3- glucoside. The observed inconsistent changes in concentrations of tentoxin after heat treatment of groats appeared to be due to sample heterogeneity.

Distribution of total bacteria and staphylococci in PM2.5, PM10 and total dust in the emission of two fattening pig houses/Verteilung von Gesamtbakterien und Staphylokokken in PM2,5, PM10 und Gesamtstaub in der Emission von zwei Mastschweineställen

Gefahrstoffe ◽  
2020 ◽  
Vol 80 (09) ◽  
pp. 344-348
Author(s):  
M. Clauß ◽  
S. Linke ◽  
A. C. Springorum
Keyword(s):  
Particle Size ◽  
Size Fraction ◽  
Airborne Bacteria ◽  
Dispersion Modelling ◽  
Particle Size Fraction ◽  
Collection System ◽  
Total Dust ◽  
Dust Distribution ◽  
Selective Collection ◽  
Total Bacteria

The particle size distribution of airborne bacterial conglomerates is an important factor in calculating possible spread distances of the bacteria over the air. Therefore, a size-selective collection system based on an emission impinger was developed to compare the distribution of total bacteria and staphylococci in particle fractions PM2.5, PM10 and total dust in the emission of two fattening pig stables. Mean emissions of 7.2 × 104 cfu/m³ total bacteria, 6.1 × 104 cfu/m³ staphylococci and 2.8 × 106 cells/m3 measured. About 30% of total bacteria and staphylococci were found in the PM2.5 particle size fraction and about 60% in PM10. The average dust distribution was 80% PM10 and 60% PM2.5. The results show that airborne bacteria from fattening pig units mainly occur on larger particles and do not correlate with dust fractions. The found conditions should be considered in future dispersion modelling.

scholarly journals Laser Diffraction as An Innovative Alternative to Standard Pipette Method for Determination of Soil Texture Classes in Central Europe

Water ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1232
Author(s):  
Dušan Igaz ◽  
Elena Aydin ◽  
Miroslava Šinkovičová ◽  
Vladimír Šimanský ◽  
Andrej Tall ◽  
...  
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Soil Texture ◽  
Polynomial Regression ◽  
Texture Classification ◽  
Size Fraction ◽  
Laser Diffraction ◽  
Classification Systems ◽  
Particle Size Fraction

The paper presents the comparison of soil particle size distribution determined by standard pipette method and laser diffraction. Based on the obtained results (542 soil samples from 271 sites located in the Nitra, Váh and Hron River basins), regression models were calculated to convert the results of the particle size distribution by laser diffraction to pipette method. Considering one of the most common soil texture classification systems used in Slovakia (according to Novák), the emphasis was placed on the determination accuracy of particle size fraction <0.01 mm. Analysette22 MicroTec plus and Mastersizer2000 devices were used for laser diffraction. Polynomial regression model resulted in the best approximation of measurements by laser diffraction to values obtained by pipette method. In the case of particle size fraction <0.01 mm, the differences between the measured values by pipette method and both laser analyzers ranged in average from 3% up to 9% and from 2% up to 11% in the case of Analysette22 and Mastersizer2000, respectively. After correction, the differences decreased to average 3.28% (Analysette22) and 2.24% (Mastersizer2000) in comparison with pipette method. After recalculation of the data, laser diffraction can be used alongside the sedimentation methods.

scholarly journals Determination of the content of Pb, Cd, Cu, Zn in dairy products from various regions of Poland

2019 ◽  
Vol 17 (1) ◽  
pp. 694-702
Author(s):  
Monika Sujka ◽  
Urszula Pankiewicz ◽  
Radosław Kowalski ◽  
Artur Mazurek ◽  
Katarzyna Ślepecka ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Dairy Products ◽  
The Other ◽  
Human Organism ◽  
Copper And Zinc ◽  
Zn Concentration ◽  
Cu And Zn ◽  
Milk And Dairy Products

AbstractThe toxicity of heavy metals and their capacity for accumulation in the human organism make it necessary to conduct monitoring of their concentration in food. The objective of the study was to determine the content of lead, cadmium, copper and zinc in milk and dairy products from various regions of Poland: the Lublin Region, Podlasie, Podkarpacie, and Silesia. The study showed the presence of the analysed heavy metals in most of the products. The content of lead was related to the level of industrialisation of a region. Higher levels of Pb were found in products from Silesia than in those from the other regions. The study revealed the presence of cadmium in 50% of the samples. Its content varied in range from 0.0067 to 0.0058 mg/kg. The levels of Cu and Zn concentration in the analysed products were within broad ranges, from 0.0015 to 4.94 mg/kg and from 0.01 to 56.44 mg/kg, respectively. In the case of all analysed elements an increase in their concentration was noted in cheese spreads and cottage cheeses. No relationship was found between the content of heavy metals in the analysed products, and the region of their origin.

scholarly journals Temporal Variation of Radiocarbon Concentration in Airborne Particulate Matter in Tokyo

Radiocarbon ◽  
2004 ◽  
Vol 46 (1) ◽  
pp. 485-490 ◽  
Author(s):  
Ken Shibata ◽  
Michio Endo ◽  
Naomichi Yamamoto ◽  
Jun Yoshinaga ◽  
Yukio Yanagisawa ◽  
...  
Keyword(s):  
Particle Size ◽  
Particulate Matter ◽  
Size Fraction ◽  
Airborne Particulate Matter ◽  
Coarse Particles ◽  
Particle Size Fraction ◽  
Airborne Particulate ◽  
Carbonaceous Particles ◽  
Secondary Particles ◽  
Insight Into

The temporal radiocarbon variation (in terms of percent Modern Carbon: pMC) of size-fractionated airborne particulate matter (APM) collected in Tokyo between April 2002 and February 2003 was analyzed in order to get an insight into the sources of carbonaceous particles. Results indicated significant biogenic origins (approximately 40 pMC on average). In general, the seasonal and particle size variations in pMC were relatively small, with 2 exceptions: elevated pMC in coarse particles in April and October 2002, and relatively low pMC in the finest particle size fraction collected in August 2002. The former finding could be tentatively attributed to the abundance of coarse particles of biological origins, such as pollen; the latter might be due to an increased fraction of anthropogenic secondary particles.

scholarly journals Microstructure and Mechanical Properties of an Advanced Nickel-Based Superalloy in the as-HIP Form

2011 ◽  
Vol 278 ◽  
pp. 265-270 ◽  
Author(s):  
J.R. May ◽  
M.C. Hardy ◽  
M.R. Bache ◽  
David D. Kaylor
Keyword(s):  
Heat Treatment ◽  
Particle Size ◽  
Crack Growth ◽  
Powder Particle ◽  
Size Fraction ◽  
Fine Powder ◽  
Powder Particle Size ◽  
Particle Size Fraction ◽  
Coarse Powder ◽  
Nickel Based Superalloy

This study evaluates the suitability of as-hot isostatically pressed (HIP) RR1000 for non-critical applications in aero-engine components. RR1000, an advanced powder nickel-based superalloy, was developed for disc rotor components in aero-engines. For these critical applications, the consolidated alloy powder particles are extruded to break down carbide and oxide networks, known as prior particle boundaries (PPBs), and to refine the structure into a fine grain size for isothermal forging. In this study, hot isostatically pressed compacts, made from two different powder particle size fractions have been assessed following heat treatments below and above the gamma prime solvus temperature. A microstructural evaluation shows a greater degree of PPB decoration occurs in the finer powder particle size fraction. Following a super-solvus heat treatment these PPBs pin grain boundaries of the fine powder particle size compacts, whilst the reduction of PPB decoration in coarse powder particle compacts allows significant grain growth. Tensile test results of as-HIP RR1000 show, good yield strengths, ultimate tensile strengths and ductility, which are comparable with extruded and isothermal forged RR1000 disc material. Dwell crack propagation tests show that finer powder particle size compacts, which have received a sub-solvus heat treatment, give the highest crack growth rates; whilst the remaining material conditions show markedly improved crack growth resistance. In conclusion, as-HIP RR1000 demonstrates clear potential for use in non-critical applications, employing either powder particle size fraction used in this study subject to the appropriate solution heat treatment.

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