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Evaluating the character and preservation of DNA within allophane clusters (microaggregates) in buried soils on Holocene tephras, northern New Zealand
Evaluating character preservation DNA allophane clusters (microaggregates) buried soils Holocene tephras
2012/3/30
Clay minerals possess sorptive capacities for organic and inorganic matter, including DNA (Lorenz and Wackernagel, 1994), and hence reduce the utilization and degradation of organic matter or DNA by m...
Dielectric-Relaxation Spectroscopy of Kaolinite, Montmorillonite, Allophane, and Imogolite under Moist Conditions
Allophane Bound Water Complex Permittivity Dielectric-Relaxation Spectroscopy Imogolite Interfacial Polarization Kaolinite Montmorillonite Time-Domain Reflectometry
2011/12/2
Abstract: The dielectric behavior of kaolinite, montmorillonite, allophane, and imogolite samples adjusted to a water potential of 33 kPa was examined using a time-domain reflectometry method over a w...
Five-Coordinate Aluminum in Allophane
Allophane Five-coordinate Aluminum NMR Spectroscopy Silica Springs
2011/12/2
Abstract: Samples of Silica Springs allophane from Tongariro National Park, New Zealand, having Al/Si atomic ratios in the range 1.1–1.9, were studied by 27Al nuclear magnetic resonance (NMR) spectros...
Water Retention by Colloidal Allophane and Imogolite with Different Charges
Allophane Imogolite Net Charge pH Pressure Potential Water Retention
2011/12/8
Abstract: Water retention curves of colloidal allophane and imogolite with different charges and different pretreatments were measured using a tension plate and a pressure plate apparatus. An irrevers...
Size and Shape of Allophane Particles in Dispersed Aqueous Systems
Allophane Cluster Colloid Domain Light Scattering Shape Size Ultrafiltration Viscosity
2011/12/27
Abstract: Aqueous suspensions of allophane show relatively high viscosity, presumably because of strong particle interaction between the unit particles. To test this hypothesis, we measured the partic...
The Electrophoretic Mobility of Imogolite and Allophane in the Presence of Inorganic Anions and Citrate
Anion adsorption Cryolite Inner-sphere complex Outer-sphere complex Point of zero charge Point of zero mobility Specific adsorption
2011/12/30
The purpose of this study was to investigate bonding mechanisms of representative inorganic anions and citrate with imogolite and allophane using electrophoresis. The electrophoretic mobility (EM) of ...
Formation of Allophane and Beidellite During Hydrothermal Alteration of Volcanic Glass Below 200°C
Allophane Amorphous aluminum-silicate coating Experimental alteration Smectite Transitional material Volcanic glass
2011/12/31
Experimental alteration of volcanic glass has been carried out in distilled water at 200°C and 150°C. The formation and transformation processes of alteration products have been examined by scanning e...
Synthetic Allophane and Layer-Silicate Formation in SiO2-Al2O3-FeO-Fe2O3-MgO-H2O Systems at 23°C and 89°C in a Calcareous Environment
Allophane Hisingerite Hydrous feldspathoid Nontronite Poorly-ordered layer silicates “Protoimogolite” Saponite Synthesis
2012/1/4
Solutions containing AlCl3 and Si(OH)4 (concentrations ≤ 1.5 mM with molar Si:Al ratios of 1:2, 1:1 and 3:1) and FeCl2 (0, 0.5 and 1.0 mM) were adjusted to pH 8 with Ca(OH)2, and incubated at 23°C and...
Size Distribution of Allophane Unit Particles in Aqueous Suspensions
Allophane High-resolution transmission electron microscopy Morphology Particle size Small-angle neutron scattering Surface area
2012/2/2
The size distribution of unit particles of two New Zealand allophanes (An and Rh), in dilute (0.8% w/v) aqueous suspensions, has been determined by small-angle neutron scattering (SANS). In addition, ...
Small-Angle X-Ray Powder Diffraction, Morphology, and Structure of Allophane and Imogolite
Allophane Dehydroxylation Imogolite Infrared spectroscopy Morphology Small angle scattering
2012/2/1
Small-angle X-ray powder diffraction analyses and high-resolution electron microscopy of allophane samples (SiO2/Al2O3 ratio, 1.12 to 1.68) showed that allophanes consist of nearly identical spherical...
Chemisorption of Cu(II) and Co(II) on Allophane and Imogolite
Allophane Chemisorption Cobalt Copper Electron spin resonance Imogolite SiO2/Al2O3
2012/2/6
Adsorption of Cu2+ and Co2+ by synthetic imogolite, synthetic allophanes with a range of SiO2/Al2O3 ratios, and allophanic clay fractions from volcanic ash soils was measured in an ionic medium of 0.0...
Cation and Anion Retention by Natural and Synthetic Allophane and Imogolite
Adsorption Allophane Anion retention Cation retention Imogolite SiO2/Al2O3 ratio Surface charge
2012/2/6
The negative surface charge of synthetic allophanes with a range of Si/Al ratios decreased and positive charge increased with increasing alumina content at a given pH. The phosphate adsorption capacit...
Surface Properties of Allophane, Halloysite, and Imogolite
Adsorption Allophane Halloysite Imogolite Infrared spectroscopy Phosphate Surface charge
2012/2/7
The adsorption of sodium, chloride, and phosphate ions by allophane, imogolite, and halloysite has been studied in relation to the surface structure of the mineral samples. The high adsorption of phos...
Effect of SiO2/Al2O3 Ratio on the Thermal Reactions of Allophane. II. Infrared and X-Ray Powder Diffraction Data
Allophane Imogolite Infrared spectroscopy Silica/alumina ratio Thermal stability X-ray powder diffraction
2012/2/8
Allophanes with SiO2/Al2O3 molar ratios from 1.38 to 1.92 were heated at temperatures up to 500°C, and the changes induced were investigated by means of infrared spectroscopy (IR) and X-ray powder dif...
Identification and Structure of Two Types of Allophane from Volcanic Ash Soils and Tephra
Allophane Deuterium exchange Halloysite Imogolite Infrared spectroscopy
2012/2/9
Samples containing allophane with molar Al/Si ratios from 1.0 to 2.0 have been examined by infrared spectroscopy, X-ray fluorescence, and phosphate adsorption methods. The infrared spectra of allophan...