Use of spherical and spheroidal models to calculate zooplankton biovolume from particle equivalent spherical diameter as measured by an optical plankton counter

2005 ◽  
Vol 3 (3) ◽  
pp. 183-189 ◽  
Author(s):  
Alexander T. Mustard ◽  
Thomas R. Anderson
Keyword(s):  
Equivalent Spherical Diameter ◽  
Spherical Diameter

scholarly journals Light Scattering and Gloss of an Experimental Quartz-filled Composite

1986 ◽  
Vol 65 (6) ◽  
pp. 892-894 ◽  
Author(s):  
P.M. Campbell ◽  
W.M. Johnston ◽  
W.J. O'Brien
Keyword(s):  
Surface Roughness ◽  
Light Scattering ◽  
Weight Percent ◽  
Optical Scattering ◽  
Scattering Coefficient ◽  
Filler Material ◽  
Short Fibers ◽  
Equivalent Spherical Diameter ◽  
Spherical Diameter ◽  
Filled Composite

For samples of polymethylmethacrylate with and without quartz filler, the inverse of the contrast-gloss ratio is shown to be related to surface roughness and to the optical scattering coefficient. This finding adds to the importance of optical scattering, which has been widely studied because of its relation to color and translucency of materials. Furthermore, optical scattering by composite fillers is shown to be linearly related to the concentration of the filler material within the range of concentrations studied. Quartz fillers were incorporated at concentrations from 5 to 20 weight percent and were short fibers or granular powder, with the granular particles ranging in median equivalent spherical diameter from 15 to 3.3 μm. The efficiency of optical scattering for the granular quartz filler increased as the size of the filler decreased.

Size and Thickness Measurement of Polydisperse Clay Samples

Clay Minerals ◽  
1993 ◽  
Vol 28 (4) ◽  
pp. 485-494 ◽  
Author(s):  
B. R. Jennings
Keyword(s):  
Axial Ratio ◽  
Thickness Measurement ◽  
Measurement Methods ◽  
Theoretical Concepts ◽  
Equivalent Spherical Diameter ◽  
Cylindrically Symmetric ◽  
Heterogeneous Samples ◽  
Spherical Diameter ◽  
Method Of Measurement ◽  
Parameter Distributions

AbstractMeasurement of clay particle size invariably presents data in the form of equivalent spherical diameters. For asymmetric particles the equivalent spherical diameter varies with the method of measurement. Based upon an understanding of the theoretical concepts involved, a method has been proposed whereby comparison of data on a given sample from two different techniques can reveal information about the minor dimension of the particle. Theoretical expressions are given for the equivalent spherical diameter of cylindrically symmetric rods and discs from which it is shown that some of the existing measurement methods are more dependent upon size than the degree of non-sphericity whilst for others the reverse is true. It is shown how for rods and discs one can obtain information on both an average axial ratio and the distribution of this parameter for heterogeneous samples. Illustrated data are given for three kaolin samples. Far from showing inconsistency between the variable spherical diameters yielded by different instruments, the data produce compatible size and thickness parameters which match those observed in supplementary, unreported electron microscope experiments. A method of measuring particle major and minor parameter distributions is indicated.

Influence of aggregate architecture and minerals on living habitats and soil organic matter

1997 ◽  
Vol 77 (3) ◽  
pp. 367-377 ◽  
Author(s):  
C. M. Monreal ◽  
H. Kodama
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Ammonium Oxalate ◽  
Clay Content ◽  
Integrated Approach ◽  
Soil Particle ◽  
Organic C ◽  
Equivalent Spherical Diameter ◽  
Primary Particles ◽  
Spherical Diameter

We used an integrated approach to determine the effects of soil particle architecture and minerals on living habitats and soil organic matter (SOM). Macroaggregate (> 250 µm), microaggregate 1 (50–250 µm), and microaggregate 2 (< 50 µm) fractions of adjacent forested and cultivated Gleysolic soil were obtained by wet sieving. The forested site was used as a reference to evaluate the effects of cultivation on soil particle architecture. Aggregates and respective clay fractions were characterized using optical, chemical, physical and microbial methods. Microaggregates 1 had primary particles with the largest mean equivalent spherical diameter (ESD) and void volume of all aggregate fractions. These physical characteristics were paralleled by the highest SOM and microbial biomass content, and number of microorganisms. Cultivation increased the weathering of primary particles and SOM loss, and decreased the content of microbial pools, suggesting deteriorated living habitats. Soil organic C content in aggregates correlated significantly with the amount of ammonium oxalate extractable Al, chloritized vermiculite, and vermiculite, and was inversely associated with the total clay content. The mean ESD of primary particles and expandable phyllosilicates of aggregates influenced living habitats by supplying substrates, and providing different void and protective space for soil microorganisms. Key words: Aggregate, mean equivalent spherical diameter, bacteria, fungi, actinomycetes, microbial biomasss, organic carbon, vermiculite, non-crystalline inorganic soil components

scholarly journals Upscaling nanoparticle synthesis by sputter deposition in ionic liquids

2021 ◽  
Vol 23 (6) ◽  
Author(s):  
M. Meischein ◽  
A. Ludwig
Keyword(s):  
Ionic Liquid ◽  
Ionic Liquids ◽  
Nanoparticle Synthesis ◽  
Sputter Deposition ◽  
Capping Agent ◽  
Cu Nanoparticles ◽  
Long Time ◽  
Spherical Diameter ◽  
Nanoparticle Fabrication

AbstractUpscaling of nanoparticle fabrication by sputtering into an ionic liquid is shown for the example of Cu. Long-time sputtering (24 h) into a large amount (50 mL) of the ionic liquid 1-butyl-3-methylimidazolium bis-(trifluoromethylsulfonyl)imide [Bmim][(Tf)2 N] yields an amount of approximately 1 g Cu nanoparticles (mean spherical diameter (2.6 ± 1.1) nm), stabilized in ionic liquid without agglomerations. Extraction of Cu nanoparticles from the stabilizing ionic liquid was performed with the capping agent hexadecylamine. Extracted particles could be redispersed in other solvents, thus enabling applications of sputtered nanoparticles beyond ionic liquids.

Particle size measurement: the equivalent spherical diameter

1988 ◽  
Vol 419 (1856) ◽  
pp. 137-149 ◽  
Keyword(s):  
Particle Size ◽  
Quantitative Measure ◽  
Axial Ratio ◽  
Particle Size Analysis ◽  
Size Analysis ◽  
Particle Size Measurement ◽  
Particle Dimension ◽  
Prolate Spheroids ◽  
Spherical Diameter ◽  
Analyse Data

In particle size analysis, it is commonplace to analyse data for anisodiametric particles as if the particles were spheres. Expressions are given herein for the equivalent spherical diameters (ESD) for discs, rods and the more general oblate and prolate spheroids. The dependence of the ESD on the true major dimension and axial ratio differs with the physical basis of measurement, and identity of the ESD values from different methods cannot be expected. A comparison between any two sets of experimental data leads to estimation of the minor particle dimension and a quantitative measure of the particle non-sphericity.

scholarly journals Inferring phytoplankton carbon and eco-physiological rates from diel cycles of spectral particulate beam-attenuation coefficient

2011 ◽  
Vol 8 (2) ◽  
pp. 3009-3050 ◽  
Author(s):  
G. Dall'Olmo ◽  
T. K. Westberry ◽  
M. J. Behrenfeld ◽  
E. Boss ◽  
C. Courties ◽  
...  
Keyword(s):  
Carbon Cycle ◽  
Attenuation Coefficient ◽  
Ocean Carbon Cycle ◽  
Diel Cycles ◽  
Carbon Biomass ◽  
Beam Attenuation ◽  
Spherical Diameter ◽  
Ocean Carbon ◽  
Diel Variability ◽  
Beam Attenuation Coefficient

Abstract. The diurnal fluctuations in solar irradiance impose a fundamental frequency on ocean biogeochemistry. Observations of the ocean carbon cycle at these frequencies are rare, but could be considerably expanded by measuring and interpreting the inherent optical properties. A method is presented to analyze diel cycles in particulate beam-attenuation coefficient (cp) measured at multiple wavelengths. The method is based on fitting observations with a size-structured population and optical model to infer the particle size distribution and physiologically relevant parameters of the cells responsible for the measured diel cycle in cp. Results show that the information related to size and contained in the spectral data can be exploited to independently estimate growth and loss rates during the day and night. In addition, the model can characterize the population of particles affecting the cp diel variability. Application of this method to spectral cp measured at a station in the oligotrophic Mediterranean Sea suggests that most of the observed variations in cp can be ascribed to a synchronized population of cells with an equivalent spherical diameter between 1 and 4 μm. The inferred carbon biomass of these cells was about 8–13 mg m−3 and accounted for approximately 20% of the total particulate organic carbon. If successfully validated and implemented on autonomous platforms, this method could improve our understanding of the ocean carbon cycle.

scholarly journals Isolation and identification of a halophilic and alkaliphilic microalgal strain

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7189
Author(s):  
Chenxi Liu ◽  
Jiali Liu ◽  
Songmiao Hu ◽  
Xin Wang ◽  
Xuhui Wang ◽  
...  
Keyword(s):  
Optimal Growth ◽  
Living Condition ◽  
Morphological Observation ◽  
Homologous Region ◽  
Alkaline Soil ◽  
Songnen Plain ◽  
Isolation And Identification ◽  
Starch Grains ◽  
Metabolic Characteristics ◽  
Spherical Diameter

Halophilic and alkaliphilic microalgal strain SAE1 was isolated from the saline–alkaline soil of Songnen Plain of Northeast China. Morphological observation revealed that SAE1 has a simple cellular structure, single cell, spherical, diameter of four to six μm, cell wall of about 0.22 μm thick, two chloroplasts and one nucleus. Analysis of the phylogenetic tree constructed by 18S sequence homology suggests that SAE1 is highly homologous to Nannochloris sp. BLD-15, with only four base substitutions in the homologous region. SAE1 was initially considered as Nannochloris sp. Analysis of the halophilic and alkaliphilic characteristics of SAE1 indicates that it can grow under one M NaHCO3 and NaCl concentrations, with optimal growth under 400 mM NaHCO3 and 200 mM NaCl. The intracellular ultrastructure of SAE1 significantly changed after NaCl and NaHCO3 treatments. A large number of starch grains accumulated after treatment with 400 mM NaHCO3 in cells, but few were found after treatment with 200 mM NaCl and none in the living condition without treatment. We conjectured that one of the metabolic characteristics of alkaliphilic (NaHCO3) microalga SAE1 is the formation of massive starch grains, which induce glycerol anabolism and increase osmotic pressure, thereby enhancing its ability to resist saline–sodic conditions. This feature of alkaliphilic (NaHCO3) microalga SAE1 contributes to its growth in the carbonate soil of Songnen Plain.

scholarly journals SeaFlow data v1, high-resolution abundance, size and biomass of small phytoplankton in the North Pacific

2019 ◽  
Vol 6 (1) ◽  
Author(s):  
François Ribalet ◽  
Chris Berthiaume ◽  
Annette Hynes ◽  
Jarred Swalwell ◽  
Michael Carlson ◽  
...  
Keyword(s):  
Pacific Ocean ◽  
Sampling Site ◽  
Data Sets ◽  
Northeast Pacific ◽  
The North ◽  
Spatial And Temporal Distributions ◽  
Spherical Diameter ◽  
Small Phytoplankton ◽  
Station Aloha ◽  
Northeast Pacific Ocean

AbstractSeaFlow is an underway flow cytometer that provides continuous shipboard observations of the abundance and optical properties of small phytoplankton (<5 μm in equivalent spherical diameter, ESD). Here we present data sets consisting of SeaFlow-based cell abundance, forward light scatter, and pigment fluorescence of individual cells, as well as derived estimates of ESD and cellular carbon content of picophytoplankton, which includes the cyanobacteria Prochlorococcus, Synechococcus and small-sized Crocosphaera (<5 μm ESD), and picophytoplankton and nanophytoplankton (2–5 μm ESD). Data were collected in surface waters (≈5 m depth) from 27 oceanographic cruises carried out in the Northeast Pacific Ocean between 2010 and 2018. Thirteen cruises provide high spatial resolution (≈1 km) measurements across 32,500 km of the Northeast Pacific Ocean and 14 near-monthly cruises beginning in 2015 provide seasonal distributions at the long-term sampling site (Station ALOHA) of the Hawaii Ocean Time-Series. These data sets expand our knowledge of the current spatial and temporal distributions of picophytoplankton in the surface ocean.

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