Mineral magnetic measurements as a particle size proxy for urban roadside soil pollution (part 1)

2014 ◽  
Vol 16 (3) ◽  
pp. 542-547 ◽  
Author(s):  
C. J. Crosby ◽  
C. A. Booth ◽  
M. A. Fullen
Keyword(s):  
Particle Size ◽  
Soil Pollution ◽  
Magnetic Measurements ◽  
Roadside Soil ◽  
Urban Roadside Soil ◽  
Mineral Magnetic

PROBLEMS AND POTENTIAL OF MINERAL MAGNETIC MEASUREMENTS AS A SOIL PARTICLE SIZE PROXY/MAGNETINIŲ MINERALŲ MATAVIMŲ, SIEKIANT JAIS PAKEISTI GRANULIOMETRINĖS SUDĖTIES ANALIZĘ, PROBLEMOS IR POTENCIALAS/ ПРОБЛЕМЫ И ПОТЕНЦИАЛЬНЫЕ ВОЗМОЖНОСТИ ПРИМЕНЕНИЯ МАГНИТНЫХ ИЗМЕРЕНИЙ МИНЕРАЛОВ ДЛЯ ЗАМЕНЫ АНАЛИЗА ГРАНУЛОМЕТРИЧЕСКОГО СОСТАВА ПОЧВЫ

2008 ◽  
Vol 16 (3) ◽  
pp. 151-158 ◽  
Author(s):  
Colin A. Booth ◽  
Michael A. Fullen ◽  
John Walden ◽  
Annie T. Worsley ◽  
Saulius Marcinkonis ◽  
...  
Keyword(s):  
Particle Size ◽  
Size Effects ◽  
Magnetic Measurements ◽  
Analytical Data ◽  
Clay Content ◽  
Fine Sand ◽  
Size Fractions ◽  
Particle Size Effects ◽  
Isle Of Man ◽  
Mineral Magnetic

The use of mineral magnetic concentration parameters (χLF, χARM and SIRM) as a potential particle size proxy for soil samples collected from the Isle of Man (British Isles) is explored as an alternative means of normalizing particle size effects. Comparison of soil‐related analytical data by correlation analyses between each magnetic parameter and individual particle size classes (i.e. sand, silt and clay), more discrete intervals within classes (e.g. fine sand or medium silt) and cumulative size fractions (e.g. clay + fine silt) are reported. Both χLF and χARMparameters reveal significant (p < 0.05; n = 46), but relatively weak (rs = 0.297 and 0.369), associations with clay content, while χLF, χARM and SIRM parameters have no significant relationship with sand and silt content or any discrete or cumulative size fractions. Contrary to earlier research findings, this indicates that magnetic measurements are not always a suitable particle size proxy and it is only certain environments and/or specific settings that are appropriate for granulometric normalization by this technique. However, if future researchers working in other soil settings can identify a formal predictable relationship, the technique is known to offer a simple, reliable, rapid, sensitive, inexpensive and non‐destructive approach that could be a valuable particle size proxy for normalizing particle size effects in soil contamination studies. Santrauka Tyrimuose atskleistas mineralų magnetinių koncentracijos parametrų panaudojimas (χLF, χARM ir SIRM) kaip potencialiai alternatyvus metodas granuliometrinės sudėties nustatymo analizei Isle of Man (Britų salos) surinktiems dirvožemio pavyzdžiams tirti ir dalelių dydžio reiškiniui normalizuoti. Aprašytas su dirvožemiu susijusių analizinių duomenų palyginimas koreliacinių analizių būdu, t. y. tarp kiekvieno magnetizmo parametro ir atskirų dydžių dalelių frakcijų (t. y. smėlio, dulkių ir dumblo) ir tarpinių šių intervalų frakcijų (pavyzdžiui, smulkaus smėlio ar vidutinio rupumo dulkių) ir jungtinių frakcijų (pavyzdžiui, dumblo + smulkių dulkių). Tiek χLF, tiek χARM parametrai atskleidžia reikšmingas (p <0,05; n = 46), bet palyginti nereikšmingas (rs = 0,297 ir 0,369) ryšių asociacijas su dumblo kiekiu, o χLF, χARM ir SIRM parametrai neturi reikšmingų priklausomybių nuo smėlio ir dulkių kiekių, nei su atskiromis ar jungtinėmis dalelių dydžių frakcijomis. Priešingai ankstyvesniems tyrinėjimų rezultatams, tai rodo, kad magnetiniai matavimai ne visada yra tinkama alternatyva granuliometrinės sudėties analizei pakeisti ir tiktai tam tikroje, specifinėje aplinkoje yra tinkami granuliometrinei sudėčiai normalizuoti. Tačiau jei ateityje tyrėjai, tiriantys kitas dirvožemio savybes, nustatytų proporcingas prognozuojamas priklausomybes, šis matavimų metodas siūlo paprastą, patikimą, greitą, tikslų, nebrangų ir neardomąjį metodą, kuris galėtų būti vertinga granuliometrinės analizės alternatyva normalizuojant dalelių dydžio reiškinius studijuojant užterštus dirvožemius. Резюме Исследована возможность использования магнитных параметров (χLF, χARM и SIRM) как альтернативного потенциального метода для определения гранулометрического состава почв, отобранных в Isle of Man (Британские острова), и нормализирования эффекта по величине частиц. Описано сравнение связанных с почвой аналитических данных на основе метода корреляционного анализа, т. е. между каждым параметром магнетизма и частиц отдельных фракций (песок, пыль, глина) и промежуточных фракций этих интервалов (например, глина + мелкая пыль). Параметры как χLF, так и χARM показывают существенную (p <0.05; n = 46), однако сравнительно слабую (rs = 0.297 ir 0.369) связь с количеством пыли, в то время как параметры χLF, χARM и SIRM не имели существенной зависимости от количества глины и песчаных частиц как для отдельных, так и для смешанных фракций. В отличие от результатов предыдущих исследований данные результаты свидетельствуют о том, что магнитные измерения не всегда являются приемлемой альтернативой для замены метода определения гранулометрического состава и лишь в определенных специфических условиях могут применяться для этого. Если в будущем исследователи, изучающие другие свойства почвы, смогут установить пропорциональные прогнозируемые зависимости, этот магнитный метод измерения сможет применяться, так как он предлагает простой, достоверный, быстрый, точный, недорогой и неизменяющийся способ, который может быть альтернативой анализа гранулометрического состава с целью нормализации эффекта величины частиц при изучении загрязненных почв.

scholarly journals Factor Analysis of Particle Size Specific Mineral Magnetic Measurements on Agricultural Topsoils from the Isle of Man

2006 ◽  
Vol 37 (1-2) ◽  
pp. 249-273 ◽  
Author(s):  
Colin A. Booth ◽  
Michael A. Fullen ◽  
John P. Smith ◽  
Michael D. Hallett ◽  
John Walden ◽  
...  
Keyword(s):  
Particle Size ◽  
Factor Analysis ◽  
Magnetic Measurements ◽  
Isle Of Man ◽  
Mineral Magnetic

DC and AC Measurements of Magnetite Nanoparticulates and Implications for Nonlinear Response

2008 ◽  
Vol 1138 ◽  
Author(s):  
Silvia Liong ◽  
Ricky Lamar Moore
Keyword(s):  
Particle Size ◽  
Magnetic Properties ◽  
Polymer Composites ◽  
Magnetic Measurements ◽  
Bulk Material ◽  
Low Frequency ◽  
Anisotropy Field ◽  
Coaxial Line ◽  
Magnetic Data ◽  
Order Of Magnitude

AbstractThis paper discusses preparation, characterization and measurement of linear DC and AC magnetic properties of magnetite (Fe3O4) nanoparticles (size ranges of 7-50 nm and 5 microns) and polymer composites of those particulates. Selected data and analysis are taken from the PhD thesis of Liong [1]. The goal of this research is to obtain magnetic data, specifically magnetization, anisotropy and coercivity as functions of particle size. These will be used as inputs to non linear magnetic simulations and in planning for future nonlinear magnetic measurements. Magnetite nanoparticles were synthesized by chemical coprecipitation, a method that allowed for the production of samples in gram quantities. Vibrating sample magnetometry was used to measure the room-temperature DC magnetization and coercivity of the particulates. Coaxial line impedance measurements were used to measure low frequency and dispersive AC permeability of Fe3O4–polymer composites from 1 Megahertz to 10 Gigahertz. AC data are applied to infer particulate magnetic susceptibility and anisotropy field change with particle size. Particle size was calculated from XTD data and supported by TEM images.Measured DC saturation magnetization and coercivity decreased with particle dimension while anisotropy was calculated to increase. Magnetization data are consistent with models that calculate nanoparticle magnetization as a volumetric average of a spherical bulk material core and a passive outer shell. The shell thickness was calculated at 0.84 nm, very near one lattice constant of bulk Fe3O4, 0.8394 nm. Composites containing particulate volume fractions less than 20% were fabricated. Effective media theory was applied to measured AC composite permeability to extract particle magnetic properties and thereby anisotropy field, which increased by an order of magnitude from the bulk. Permeability decreased with particulate size.

scholarly journals Size Effects on Magnetic Properties ofNi0.5Zn0.5Fe2O4Prepared by Sol-Gel Method

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Min Zhang ◽  
Zhenfa Zi ◽  
Qiangchun Liu ◽  
Peng Zhang ◽  
Xianwu Tang ◽  
...  
Keyword(s):  
Particle Size ◽  
Magnetic Measurements ◽  
Sol Gel ◽  
Domain Wall Motion ◽  
Blocking Temperature ◽  
Particle Sizes ◽  
X Ray Diffraction ◽  
Gel Method ◽  
Sol Gel Method ◽  
Cation Redistribution

Ni0.5Zn0.5Fe2O4particles with different particle sizes have been synthesized by sol-gel method. X-ray diffraction results show that all the samples are pure cubic spinel structure with their sizes ranging from 9 to 96 nm. The lattice constant significantly decreases with further increasing annealing temperature. The magnetic measurements show superparamagnetic nature below the particle size of 30 nm, while others show ferrimagnetic nature above the corresponding blocking temperature. The blocking temperature increases with the increase in particle size, which can be explained by Stoner-Wohlfarth theory. The saturation magnetization increases as the particle size increases, which can be explained by the cation redistribution on tetrahedral A and octahedral B sites and the domain wall motion. The variation of coercivity as a function of particle size is based on the domain structure.

Synthesis of Undoped and Manganese-Doped HgTe Nanoparticles Using [Hg(TeCH2CH2NMe2)2] as a Single Source Precursor

2008 ◽  
Vol 8 (9) ◽  
pp. 4500-4505 ◽  
Author(s):  
Gotluru Kedarnath ◽  
Sandip Dey ◽  
Vimal K. Jain ◽  
Gautam K. Dey ◽  
Ramakant M. Kadam
Keyword(s):  
Particle Size ◽  
Room Temperature ◽  
Magnetic Measurements ◽  
Lattice Parameter ◽  
Crystalline Solid ◽  
Single Source ◽  
Epr Spectrum ◽  
Single Source Precursor ◽  
Ferromagnetic Ordering ◽  
Mn Doped

The Reaction of [HgCl2(tmeda)] with NaTeCH2CH2NMe2 gave a mercury tellurolate, [Hg(TeCH2CH2·NMe2)2] (1) as a yellow crystalline solid, which was characterized by elemental analysis, UV-vis, mass and NMR (1H, 13C, 125Te, 199Hg) spectroscopy. Thermolysis of 1 in hexadecylamine (HDA) at 90 °C in the absence and presence of Mn(OAc)2·4H2O gave undoped and Mn-doped HgTe nanoparticles which were characterized by XRD, EDAX, TEM, EPR and magnetic measurements. These particles could be synthesized with mean particle size of 6–7 nm (from TEM). Manganese substitution at Hg site in HgTe lead to a linear decrease in lattice parameter with increasing concentration of Mn. Magnetization measurements showed ferromagnetic ordering at room temperature with very small coercive field (Hc, 50 Oe) for Hg0.973Mn0.027 Te sample. This sample also exhibited distinct ferromagnetic resonance (FMR) in the EPR spectrum.

Structural, morphological, magnetic and hydrogen absorption properties of LaNi5 alloy: A comprehensive study

2014 ◽  
Vol 28 (14) ◽  
pp. 1450079 ◽  
Author(s):  
Reza Sarhaddi ◽  
Hadi Arabi ◽  
Faiz Pourarian
Keyword(s):  
Particle Size ◽  
Hydrogen Absorption ◽  
Magnetic Measurements ◽  
Kinetic Mechanism ◽  
Absorption Properties ◽  
Jma Model ◽  
Experimental Apparatus ◽  
Diffraction Patterns ◽  
Hydriding Reaction ◽  
Comprehensive Study

A comprehensive study of structural, morphological, magnetic and hydrogen absorption properties of LaNi 5–H system was investigated. The X-ray diffraction patterns show that as-synthesized LaNi 5 alloy is single phase with CaCu5-type structure while some weak peaks of elemental nickel also appeared after several hydrogenation/dehydrogenation (H/D) cycling. The presence of pure Ni was also followed using the room temperature magnetic measurements. After H/D cycling, the particle size decreases and particle size distribution was found nearly uniform compared to noncycled alloy. The pressure-composition isotherms (PCIs) of the hydrogen absorption reaction were determined in the temperature range 20–80°C using a homemade Sievert's type experimental apparatus, and then the enthalpy and entropy of hydride formation were calculated. The hydriding kinetic mechanism of LaNi 5 was evaluated using the different fitting models: Jander diffusion model (JDM), Johnson–Mehl–Avrami (JMA) and Chou models. All employed models confirm an increase in the hydriding reaction rate with temperature. However, the calculated results using JMA model show a better agreement with the experimental data and hence we believe that diffusion along with nucleation and growth is the rate-controlling step for the hydriding reaction. The values of activation energy for hydriding reaction were also obtained by JD and JMA models.

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