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Showing 1 to 20 of 83 for “"size fractions"”.
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Determination of Size Fractions and Concentrations of Airborne Particulate Matter Generated From Construction and Demolition Waste Processing Facilities
… devices were employed to quantify the particle sizes of interest. Results were compared to United States Environmental Protection Agency (EPA) National Ambient Air Quality Standards(NAAQS) and United States Occupational Safety and Health Administration (OSHA)standards.The results from this study …
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Studies of the mechanisms of stabilization of organic matter in semiarid soils
… (mineralization) experiments using soil particle size fractions as sources of native soil OM of different chemical quality. These experiments examined microbial utilization and transformations of the C and P associated with the particle size fractions. The characteristics of particle size …
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Quantifying soil particulate organic matter using image analysis
… quantification of soil organic carbon (SOC) fractions that are responsive to management will improve soil health assessment and associated decision support tools. The particulate organic matter (POM) fraction of SOC is of interest due to its sensitivity to management and significant …
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Environmental influences on particle size distribution of Dreissena polymorpha environmental DNA in a Texas reservoir
… results. For example, research of eDNA particle size distribution (PSD), which describes the abundance and range of sizes of eDNA-bearing particles in the environment, can guide filter size selection for optimal capture of target eDNA. Previous PSD research has mainly targeted fish and has tended …
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Clay mineralogy of the southwest equatorial Atlantic sediments
… fold, (1) the determination of the partial grain-size distribution and (2) the mineralogy of the clay/fine silt size fractions of the equatorial Atlantic bottom sediments. From these data, it was hoped to find the controlling factors for the size distribution and mineralogy of the bottom …
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Effect of the fractionation and immobilization on the sorption properties of humanic acid
… technique was used to obtain eight size fractions of the humic acid. The extracted humic acid and its fractions were characterized by potentiometric acid-base titration, elemental analysis and different spectroscopic methods (NMR, UV-VIS and FT-IR spectroscopy). Clear chemical …
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Heavy Metal Content in Stream Sediments Adjacent to the Wright County, Missouri, Sanitary Landfill
… as a control for the analysis. The two sediment size fractions used in the heavy metal analysis were the < 63 micron and the 150-250 micron size. The mean element content for each of the five metals was higher in the < 63 micron size fraction than in the 150-250 micron size fraction in the …
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Development of a theory of particle mixtures and its application to aggregates, mortars and concretes
… computer simulation from a knowledge of the mean size, voids ratio and relative density of each of the components. The Theory involves mathematical formulae and geometrical models to explain the roles of void filling and particle interference which determine the properties of mixtures. The …
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K-Metasomatism in Uppermost Precambrian Rocks in West-Central Wisconsin and Southeastern Missouri
K/Ar dating of different size fractions of I/S samples reveals three episodes of illitization in the alteration profiles: 432-424 Ma, 410-383 Ma, and ${\sim}{-}314$ Ma. Rb-Sr and oxygen isotopic data suggest I/S of the 432-424 episode may have formed from the same fluids that formed the …
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Investigation into the partitioning of Lindane between air and dust in indoor environments
… These dynamic tests were carried out for two size fractions (<20µm and >45µm<63µm) and whole dust samples to determine the effect of size fraction on adsorption. For the >45µm to <63µm, k1 = 0.568h-1 and k2 = 0.047h-1, (standard error 0.119 and 0.030 respectively), for the <20µm fraction, k1 = …
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Modeling the microstructure development in gray iron castings
… of manufacturing defects in castings. Grain size and other microstructural features such as second phase morphology and distribution are the primary factors in determining the mechanical properties in cast metals. In this work, a representation of nucleation and growth kinetics for gray cast …
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The batch and continuous bacterial leaching kinetics of a refractory gold-bearing pyrite concentrate
… with the experimental data. Three narrow size fractions of the pyrite concentrate were subjected to batch and continuous bacterial oxidation, using a Thiobacillus ferrooxidans culture. Time profile data of the pyrite oxidation were obtained for the batch reactor study. Similarly, retention …
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Evaluating alternative macroinvertebrate sampling methodologies in wetlands: Influence of sieve mesh size on relationships between environmental and assemblage variables
… invertebrates and particulate matter into four size fractions. The 6-mm fraction included material retained on the 6-mm sieve, the 4-mm fraction included material retained on both 4- and 6-mm sieves, the 2-mm size fraction included material retained on 2-, 4-, and 6-mm sieves, and the 500-à µm …
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Characterizing the physical and hydraulic properties of pine bark soilless substrates
… and reduced plant growth. Understanding pore size distributions, water dynamics, and gas diffusivity of these substrates is essential to promote plant growth. The effects of different particle sizes of soilless media on processes such as infiltration, hydraulic conductivity, and gas …
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CO2 sequestration using brine impacted fly fish
It was hypothesized that South African FA and brine could sequester CO2 through mineral carbonation. A statistical approach was undertaken to optimize the % CaCO3 formed from FA/brine/CO2 interaction with input parameters of temperature, pressure, particle size and solid/liquid ratio (S/L) being …
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Modeling Plankton Community Structure Under Environmental Forcing on the Southeastern United States Continental Shelf
… of nitrate, ammonium, two phytoplankton size fractions, five copepod developmental stages, doliolids, and a detrital pool. Model dynamics are based primarily upon data obtained from field and laboratory experiments made for southeastern U.S. continental shelf plankton populations. …
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The morphological, flow and failure characteristics of fractionated natural bulk material. Evaluation of flowability of fractionated powdered liquorice using a specially designed flowmeter. The particle morphology was assessed by computer image analysis and the failure properties by shear cell testing.
… rhizome products were classified into 23 narrow size fractions to investigate the particle and bulk characteristics of the material, and to study the influence of particle shape on powder flowability. The morphology of the fibrous particulate was investigated by using a Quantimet 720 Image …
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Feeding of Naupliar and Adult Carnivorous Cyclopoids (Crustacea : Copepoda)
… and NVI-CIII on bacteria-coated detritus (known size fractions), algae, and dissolved organics: The best methods to use for these foods are predator survivorship, and radiolabeled prey, with modifications in the method of the current study.
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Municipal Solid Waste Incineration (MSWI) Ash Characterization and Physical Concentration
… the sample was ground and subjected to particle size distribution, wet magnetic separation, and a float-sink test. As for the chemical and mineralogical characterization, the sample was subjected to XRD, XRF, SEM-EDX, and elemental composition analysis. Additionally, sequential chemical …
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Caractérisation de la matière organique dissoute de l'estuaire du Saint-Laurent par un système HPLC-FTIR
… Fourier transform infrared spectroscopy (FTIR). Size-exclusion chromatography (SEC) was used to apply a molecular size-based separation. This system enabled the characterization of ultrafiltered DOM (UDOM) and fulvic acid (FA) samples from the St. Lawrence Estuary and its tributaries and the …
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