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Sample records for clay mineral content

  1. Application of short-wave infrared (SWIR) spectroscopy in quantitative estimation of clay mineral contents

    International Nuclear Information System (INIS)

    You, Jinfeng; Xing, Lixin; Pan, Jun; Meng, Tao; Liang, Liheng

    2014-01-01

    Clay minerals are significant constituents of soil which are necessary for life. This paper studied three types of clay minerals, kaolinite, illite, and montmorillonite, for they are not only the most common soil forming materials, but also important indicators of soil expansion and shrinkage potential. These clay minerals showed diagnostic absorption bands resulting from vibrations of hydroxyl groups and structural water molecules in the SWIR wavelength region. The short-wave infrared reflectance spectra of the soil was obtained from a Portable Near Infrared Spectrometer (PNIS, spectrum range: 1300∼2500 nm, interval: 2 nm). Due to the simplicity, quickness, and the non-destructiveness analysis, SWIR spectroscopy has been widely used in geological prospecting, chemical engineering and many other fields. The aim of this study was to use multiple linear regression (MLR) and partial least squares (PLS) regression to establish the optimizing quantitative estimation models of the kaolinite, illite and montmorillonite contents from soil reflectance spectra. Here, the soil reflectance spectra mainly refers to the spectral reflectivity of soil (SRS) corresponding to the absorption-band position (AP) of kaolinite, illite, and montmorillonite representative spectra from USGS spectral library, the SRS corresponding to the AP of soil spectral and soil overall spectrum reflectance values. The optimal estimation models of three kinds of clay mineral contents showed that the retrieval accuracy was satisfactory (Kaolinite content: a Root Mean Square Error of Calibration (RMSEC) of 1.671 with a coefficient of determination (R 2 ) of 0.791; Illite content: a RMSEC of 1.126 with a R 2 of 0.616; Montmorillonite content: a RMSEC of 1.814 with a R 2 of 0.707). Thus, the reflectance spectra of soil obtained form PNIS could be used for quantitative estimation of kaolinite, illite and montmorillonite contents in soil

  2. Characterization of clay minerals

    International Nuclear Information System (INIS)

    Diaz N, C.; Olguin, M.T.; Solache R, M.; Alarcon H, T.; Aguilar E, A.

    2002-01-01

    The natural clays are the more abundant minerals on the crust. They are used for making diverse industrial products. Due to the adsorption and ion exchange properties of these, a great interest for developing research directed toward the use of natural clays for the waste water treatment has been aroused. As part of such researches it is very important to carry out previously the characterization of the interest materials. In this work the results of the mineral and elemental chemical composition are presented as well as the morphological characteristics of clay minerals from different regions of the Mexican Republic. (Author)

  3. Evaluation of the lithology contents and types of clay minerals using downhole spectral analyzer of natural gamma radiation

    International Nuclear Information System (INIS)

    Zivanov, M.; Savicic, M.; Grbovic, G.

    1992-01-01

    The microprocessor downhole spectrum analyzer of natural gamma radiation is an important part of the new generation of geophysical well logging systems. This instrument produces complete energy spectra of the penetrated formations. here physical principles of logging are shown. based on the logging results from one of the wells complex lithology was identified, together with shale contents in the formation and types of clay and minerals. (author)

  4. X-ray-phase and IR-spectral study of clay rocks mineral content of the Caspian Sea Gulf depression

    International Nuclear Information System (INIS)

    Zakonov, A.N.; Mukhanova, M.U.

    2000-01-01

    Samples of clays selected from different oil fields (Sazankurak, Kemerkol, Kozha and others) and deposition depths are examined on both the X-ray diffractometers (Dron-2 and Dron-4) and the infrared-spectrometers (IR-20). In this diagnostic the American file with different minerals X-ray systematized data is used. The X-ray reflections, which are in compliance with suitable inter-plane distances and clay impurities reflex intensities are determined. With confirmation purpose for mineral content correctness obtained according X-ray-phase analysis the infrared-spectrometric method is used, in which principal attention was paid to absorption field (3,400-3,700 cm -1 ) of H 2 O and OH valency frequency vibrations

  5. Clay mineral type effect on bacterial enteropathogen survival in soil.

    Science.gov (United States)

    Brennan, Fiona P; Moynihan, Emma; Griffiths, Bryan S; Hillier, Stephen; Owen, Jason; Pendlowski, Helen; Avery, Lisa M

    2014-01-15

    Enteropathogens released into the environment can represent a serious risk to public health. Soil clay content has long been known to have an important effect on enteropathogen survival in soil, generally enhancing survival. However, clay mineral composition in soils varies, and different clay minerals have specific physiochemical properties that would be expected to impact differentially on survival. This work investigated the effect of clay materials, with a predominance of a particular mineral type (montmorillonite, kaolinite, or illite), on the survival in soil microcosms over 96 days of Listeria monocytogenes, Salmonella Dublin, and Escherichia coli O157. Clay mineral addition was found to alter a number of physicochemical parameters in soil, including cation exchange capacity and surface area, and this was specific to the mineral type. Clay mineral addition enhanced enteropathogen survival in soil. The type of clay mineral was found to differentially affect enteropathogen survival and the effect was enteropathogen-specific. © 2013.

  6. Hyperspectral analysis of clay minerals

    Science.gov (United States)

    Janaki Rama Suresh, G.; Sreenivas, K.; Sivasamy, R.

    2014-11-01

    A study was carried out by collecting soil samples from parts of Gwalior and Shivpuri district, Madhya Pradesh in order to assess the dominant clay mineral of these soils using hyperspectral data, as 0.4 to 2.5 μm spectral range provides abundant and unique information about many important earth-surface minerals. Understanding the spectral response along with the soil chemical properties can provide important clues for retrieval of mineralogical soil properties. The soil samples were collected based on stratified random sampling approach and dominant clay minerals were identified through XRD analysis. The absorption feature parameters like depth, width, area and asymmetry of the absorption peaks were derived from spectral profile of soil samples through DISPEC tool. The derived absorption feature parameters were used as inputs for modelling the dominant soil clay mineral present in the unknown samples using Random forest approach which resulted in kappa accuracy of 0.795. Besides, an attempt was made to classify the Hyperion data using Spectral Angle Mapper (SAM) algorithm with an overall accuracy of 68.43 %. Results showed that kaolinite was the dominant mineral present in the soils followed by montmorillonite in the study area.

  7. Hydrogen isotope ratios of clay minerals constituting clay veins found in granitic rocks in Hiroshima Prefecture

    International Nuclear Information System (INIS)

    Kitagawa, Ryuji; Kakitani, Satoru; Kuroda, Yoshimatsu; Matsuo, Sadao; Suzuoki, Tetsuro.

    1980-01-01

    The deuterium content of the constitutional and interlayer water extracted from the clay minerals (illite, montmorillonite, interstratified illite-montmorillonite mineral, kaolinite, halloysite) constituting the clay veins found in the granitic rocks in Hiroshima Prefecture was measured. The clay minerals were heated at 270 deg C to extract the interlayer water, then heated to 1,400 or 1,500 deg C to extract the constitutional water. The deuterium content of the local surface water collected from sampling points was measured. In the clay veins formed along perpendicular joints, the constituent clay minerals change from lower to upper part: illite → montmorillonite → kaolinite → halloysite. The deuterium content values of the constitutional water for illite and montmorillonite were estimated to be -67 to -69% and -86 to -89%, respectively. The deuterium content values of the constitutional water for halloysite range from -68 to -80% and for kaolinite from -63 to -67%. (J.P.N.)

  8. Multifaceted role of clay minerals in pharmaceuticals

    OpenAIRE

    Khurana, Inderpreet Singh; Kaur, Satvinder; Kaur, Harpreet; Khurana, Rajneet Kaur

    2015-01-01

    The desirable physical and physiochemical properties of clay minerals have led them to play a substantial role in pharmaceutical formulations. Clay minerals like kaolin, smectite and palygorskite-sepiolite are among the world's most valuable industrial minerals and of considerable importance. The elemental features of clay minerals which caused them to be used in pharmaceutical formulations are high specific area, sorption capacity, favorable rheological properties, chemical inertness, swelli...

  9. Soil clay content underlies prion infection odds

    Science.gov (United States)

    David, Walter W.; Walsh, D.P.; Farnsworth, Matthew L.; Winkelman, D.L.; Miller, M.W.

    2011-01-01

    Environmental factors-especially soil properties-have been suggested as potentially important in the transmission of infectious prion diseases. Because binding to montmorillonite (an aluminosilicate clay mineral) or clay-enriched soils had been shown to enhance experimental prion transmissibility, we hypothesized that prion transmission among mule deer might also be enhanced in ranges with relatively high soil clay content. In this study, we report apparent influences of soil clay content on the odds of prion infection in free-ranging deer. Analysis of data from prion-infected deer herds in northern Colorado, USA, revealed that a 1% increase in the clay-sized particle content in soils within the approximate home range of an individual deer increased its odds of infection by up to 8.9%. Our findings suggest that soil clay content and related environmental properties deserve greater attention in assessing risks of prion disease outbreaks and prospects for their control in both natural and production settings. ?? 2011 Macmillan Publishers Limited. All rights reserved.

  10. Control of clay minerals effect in flotation. A review

    Directory of Open Access Journals (Sweden)

    Taner Hasan Ali

    2016-01-01

    Full Text Available The increased exposure to low grade ores highlights the importance of understanding phyllosilicate gangue mineralogy which consists of common gangue minerals. To improve the flotation performance and ore quality the negative effect of the clay minerals on flotation should be identified. The presence of clay minerals leads to problems, such as changing the froth stability, which are related to swelling behaviour, increase in pulp viscosity, overconsumption of reagents, slime coating and mechanical entrainment. The clay content in the ore is changing from time to time and it is necessary to provide quick solutions to the issues caused by the new ore composition. The objective of this paper is to give an overview how to control the colloidal properties of clay minerals on flotation.

  11. Climatic control on clay mineral formation

    Indian Academy of Sciences (India)

    Many physico-chemical variables like rock-type,climate,topography and exposure age affect weathering environments.In the present study,an attempt is made to understand how the nature of clay minerals formed due to weathering differs in tropical regions receiving high and low rainfall. Clay mineralogy of weathering pro ...

  12. Wave liquefaction in soils with clay content

    DEFF Research Database (Denmark)

    Kirca, Özgür; Sumer, B. Mutlu; Fredsøe, Jørgen

    2012-01-01

    The paper presents the results of an experimental study of the influence of clay content (in silt-clay and sand-clay mixtures) on liquefaction beneath progressive waves. The experiments showed that the influence of clay content is very significant. Susceptibility of silt to liquefaction is increa...

  13. Mineral acquisition from clay by budongo forest chimpanzees

    NARCIS (Netherlands)

    Reynolds, Vernon; Lloyd, Andrew W.; English, Christopher J.; Lyons, Peter; Dodd, Howard; Hobaiter, Catherine; Newton-Fisher, Nicholas; Mullins, Caroline; Lamon, Noemie; Schel, Anne Marijke; Fallon, Brittany

    2015-01-01

    Chimpanzees of the Sonso community, Budongo Forest, Uganda were observed eating clay and drinking clay-water from waterholes. We show that clay, clay-rich water, and clay obtained with leaf sponges, provide a range of minerals in different concentrations. The presence of aluminium in the clay

  14. The influence of clay minerals on acoustic properties of sandstones

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, Olav

    1997-12-31

    This thesis aims to provide better understanding of the relationship between the acoustic properties and the petrophysical/mineralogical properties in sand-prone rock. It emphasizes the influence of clay minerals. The author develops a method to deposit clay minerals/mineral aggregates in pore space of a rigid rock framework. Kaolinite aggregates were flushed into porous permeable Bentheimer sandstone to evaluate the effect of pore filling minerals on porosity, permeability and acoustic properties. The compressional velocity was hardly affected by the clay content and it was found that the effect of minor quantities of pore filling minerals may be acoustically modelled as an ideal suspension, where the pore fluid bulk modulus is modified by the bulk modulus of the clay minerals. The influence of clays on acoustic velocities in petroleum reservoir rocks was investigated through ultrasonic measurements of compressional- and shear-waves on core material from reservoir and non-reservoir units on the Norwegian Continental Shelf. The measured velocities decrease as the porosity increases, but are not strongly dependent on the clay content. The measured velocities are less dependent on the petrophysical and lithological properties than indicated by previous authors and published mathematical models, and stiffness reduction factors are introduced in two of the models to better match the data. Velocities are estimated along the wellbores based on non-sonic well logs and reflect well the actual sonic log well measurements. In some wells the compressional velocity cannot be modelled correctly by the models suggested. Very high compressional wave anisotropy was measured in the dry samples at atmospheric conditions. As the samples were saturated, the anisotropy was reduced to a maximum of about 30% and decreases further upon pressurization. Reservoir rocks retrieved from 2500 m are more stress dependent than those retrieved from less than 200 m depth. 168 refs., 117 figs., 24

  15. Uranyl adsorption at clay mineral surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Roesch, N. [Technische Univ. Muenchen (Germany). Fachgebiet Theoretische Chemie

    2016-11-01

    This first systematic survey of actinide adsorption at complex clay mineral surfaces, which provided new insights at the atomic level, is currently being extended to neptunyl NpO{sub 2}{sup +} and more complex minerals, like iron-substituted phyllosilicates. In this way we examine if the concepts developed so far can be applied more generally to support the interpretation of pertinent experiments. A further facet of these studies is to account also for the dynamic nature of the mineral/water interface by means of exemplary dynamic simulations.

  16. Evaluation of the bleaching flux in clays containing hematite and different clay minerals

    International Nuclear Information System (INIS)

    Silva Junior, E.M.; Lusa, T.; Silva, T.M.; Medeiros, B.B.; Santos, G.R. dos; Morelli, M.R.

    2016-01-01

    Previous studies have shown that the addition of a synthetic flux in a clay mineral constituted by illite phase in the presence of iron oxide with the hematite, promotes color change of the firing products, making the reddish color firing into whiteness. This flow is constituted of a vitreous phase of the silicates family obtained by fusion/solidification of oxides and carbonates. Thus, the objective of this work was that of studying the interaction of the iron element in the final color mechanism of the different types of mineral crystal phase of the clays. In order to study the phenomenon, we obtained different compositions between the select clays and the synthetic flow, and characterization using X-ray diffraction (XRD) and visual analysis. The results showed that the action of the synthetic flow as a modifying agent for color depends on the mineral crystal phase of the clays. The color firing modification does not occur in the clays content high levels of kaolinite mineral phase. (author)

  17. Effects of clay mineral type and organic matter on the uptake of radiocesium by pasture plants

    International Nuclear Information System (INIS)

    D'Souza, T.J.

    1980-10-01

    Studies were undertaken to examine the influence of interaction of clay minerals and organic matter on the uptake of radiocesium by two pasture plants, namely, ryegrass (Lolium italicum L) and red clover (Trifolium pratense L). The clay minerals used were bentonite (2.1 layer type) and kaolinite (1/1 layer type). Mixtures of clay and sand were prepared with 0.5, 10, 20 and 40 per cent clay and treated with organic matter (forest turf) at 0,5 and 10 per cent of the clay-sand mixtures. Results indicated that 134 Cs uptake by plants grown on the kaolinite-clay medium was greater than that on the bentonite-clay medium at a given organic matter level. Increasing the clay content of mixtures resulted in reduction in 134 Cs uptake by both plant species. The plant uptake of 134 Cs increased with additions of organic matter at a given clay content. (author)

  18. Isotopic exchange of 65Zn with stable Zn adsorbed on reference clay minerals

    International Nuclear Information System (INIS)

    Bourg, A.C.M.; Filby, R.H.

    1976-01-01

    For reference clays of low organic content, Zn adsorbed on the clay minerals is in kinetic equilibrium with 65 Zn in solution. Thus the specific activity approach applied to the transport of 65 Zn(II) at the water-reference clay interface is intrinsically valid. (author)

  19. Mineral Acquisition from Clay by Budongo Forest Chimpanzees.

    Directory of Open Access Journals (Sweden)

    Vernon Reynolds

    Full Text Available Chimpanzees of the Sonso community, Budongo Forest, Uganda were observed eating clay and drinking clay-water from waterholes. We show that clay, clay-rich water, and clay obtained with leaf sponges, provide a range of minerals in different concentrations. The presence of aluminium in the clay consumed indicates that it takes the form of kaolinite. We discuss the contribution of clay geophagy to the mineral intake of the Sonso chimpanzees and show that clay eaten using leaf sponges is particularly rich in minerals. We show that termite mound soil, also regularly consumed, is rich in minerals. We discuss the frequency of clay and termite soil geophagy in the context of the disappearance from Budongo Forest of a formerly rich source of minerals, the decaying pith of Raphia farinifera palms.

  20. Mineral Acquisition from Clay by Budongo Forest Chimpanzees.

    Science.gov (United States)

    Reynolds, Vernon; Lloyd, Andrew W; English, Christopher J; Lyons, Peter; Dodd, Howard; Hobaiter, Catherine; Newton-Fisher, Nicholas; Mullins, Caroline; Lamon, Noemie; Schel, Anne Marijke; Fallon, Brittany

    2015-01-01

    Chimpanzees of the Sonso community, Budongo Forest, Uganda were observed eating clay and drinking clay-water from waterholes. We show that clay, clay-rich water, and clay obtained with leaf sponges, provide a range of minerals in different concentrations. The presence of aluminium in the clay consumed indicates that it takes the form of kaolinite. We discuss the contribution of clay geophagy to the mineral intake of the Sonso chimpanzees and show that clay eaten using leaf sponges is particularly rich in minerals. We show that termite mound soil, also regularly consumed, is rich in minerals. We discuss the frequency of clay and termite soil geophagy in the context of the disappearance from Budongo Forest of a formerly rich source of minerals, the decaying pith of Raphia farinifera palms.

  1. Moessbauer spectroscopy of iron in clay minerals

    International Nuclear Information System (INIS)

    Raclavsky, K.; Sitek, J.; Lipka, J.

    1975-01-01

    Selected pure clay minerals predominantly of Czechoslovak origin were studied, such as montmorillonite, nontronite, beidellite, glauconite, seladonite, illite, vermiculite, saponite, palygorskite, goethite. Moessbauer measurements were performed at room temperature with a 57 Co in Pd source. The spectra were fitted by the least square method. The parameters of the measured Moessbauer spectra are given. The values of isomer shifts, quadrupole splittings and line widths were obtained with an error of +- 0.03 mm/sec. (Z.S.)

  2. Sorption Energy Maps of Clay Mineral Surfaces

    International Nuclear Information System (INIS)

    Cygan, Randall T.; Kirkpatrick, R. James

    1999-01-01

    A molecular-level understanding of mineral-water interactions is critical for the evaluation and prediction of the sorption properties of clay minerals that may be used in various chemical and radioactive waste disposal methods. Molecular models of metal sorption incorporate empirical energy force fields, based on molecular orbital calculations and spectroscopic data, that account for Coulombic, van der Waals attractive, and short-range repulsive energies. The summation of the non-bonded energy terms at equally-spaced grid points surrounding a mineral substrate provides a three dimensional potential energy grid. The energy map can be used to determine the optimal sorption sites of metal ions on the exposed surfaces of the mineral. By using this approach, we have evaluated the crystallographic and compositional control of metal sorption on the surfaces of kaolinite and illite. Estimates of the relative sorption energy and most stable sorption sites are derived based on a rigid ion approximation

  3. Feasibility of classification of clay minerals by using PAS

    International Nuclear Information System (INIS)

    Honda, Y; Yoshida, Y; Akiyama, Y; Nishijima, S

    2015-01-01

    After the nuclear power plant disaster, the evaluation of radioactive Cs kept in soil, especially in clay minerals and the elucidation of its movement are urgent subjects to promote decontamination. It is known that the extractable level of Cs depends on the sort of clay minerals. We tried to find the characteristics of clay minerals belonging to phillosilicate group using positron annihilation spectroscopy (PAS) and the relationship between the results of PAS and the amounts of substantially extracted Cs from the clay minerals. The results showed that each clay mineral was found to be distinguishable from other clay minerals by PAS and the extraction rate of Cs was different among those clay minerals, however the direct correlation between the results of PAS and the extraction rates of Cs was not found. (paper)

  4. Study of Adsorption of Phenanthrene on Different Types of Clay Minerals

    International Nuclear Information System (INIS)

    Contreras, M. L.; Escolano, O.; Rodriguez, V.; Diaz, F. J.; Perez, R.; Garcia, S.; Garcia Frutos, F. J.

    2003-01-01

    The fate and behaviour of non-ionic hydrophobic organic compounds in deep soil is mainly controlled by the mineral fraction present in the soil due to the very low organic carbon content of the deep soil. The mineral fraction that may greatly influence the fate and transport of these compounds due to its presence and properties are the clay minerals. Clay minerals also become increasingly important in low organic matter content soils. There tree, studies of non-ionic hydrophobic organic compounds adsorption on clay minerals without organic matter are necessary lo better understand the fate and transport of these compounds. In this work we used phenanthrene as model compound of non-ionic hydrophobic organic compound and four pure clay minerals: kaolinite, illite, montmorillonite, and vermiculite including muscovite mica. These clays minerals are selected due to its abundance in represents ve Spanish soils and different properties as its structural layers and expanding capacity. Batch experiments were performed using phenanthrene aqueous solutions and the clays selected. Phenanthrene sorption isotherms for all clays, except muscovite mica, were best described by the Freundlich model. Physical sorption on the external surfaces is the most probable adsorption mechanisms. In this sense, the presence of non-polar nano-sites on clay surfaces could determine the adsorption of phenanthrene by hydrophobic interaction on these sites. (Author) 22 refs

  5. Geochemical Investigation of Clay Minerals in Marte, Borno State, Nigeria

    Directory of Open Access Journals (Sweden)

    F. D. Adams

    2017-10-01

    Full Text Available Clay deposit collected from various locations in Marte (Northern Borno, were studied to determine their physical and chemical characteristics in order to evaluate their suitability for industrial uses. Major and trace element analyses were carried out on clay samples using Inductively Couple Plasma-Optical Emission Spectrometry (ICP-OES and X- Ray Fluorescence (XRF. The result of the chemical analysis of the ten (10 samples collected showed significant amounts of SiO2 and Al2O3. Silica content ranges from 51.48 to 62.44 % while alumina varies from 12.49 to 19.00 %. The calcium oxide ranges from 1.17 to 3.39 %, Na2O ranges from 1.1 to 8.61 %, K2O from 1.54 to 3.66 %, MgO varies from 0.04 to0.14 %, Fe2O3 varies from 0.3 to 2.7 % and MnO ranges from 0.01 to 1.03 %. The result showed that the clays are mainly smectite with quartz and felspar as the main non-clay minerals. Generally, the geochemical results of the samples do not meet the standard for industrial utilization when compared to the Industrial specifications. However, for industrial utilization, some of the clay samples may be used after necessary beneficiations.

  6. Recent advances in clay mineral-containing nanocomposite hydrogels.

    Science.gov (United States)

    Zhao, Li Zhi; Zhou, Chun Hui; Wang, Jing; Tong, Dong Shen; Yu, Wei Hua; Wang, Hao

    2015-12-28

    Clay mineral-containing nanocomposite hydrogels have been proven to have exceptional composition, properties, and applications, and consequently have attracted a significant amount of research effort over the past few years. The objective of this paper is to summarize and evaluate scientific advances in clay mineral-containing nanocomposite hydrogels in terms of their specific preparation, formation mechanisms, properties, and applications, and to identify the prevailing challenges and future directions in the field. The state-of-the-art of existing technologies and insights into the exfoliation of layered clay minerals, in particular montmorillonite and LAPONITE®, are discussed first. The formation and structural characteristics of polymer/clay nanocomposite hydrogels made from in situ free radical polymerization, supramolecular assembly, and freezing-thawing cycles are then examined. Studies indicate that additional hydrogen bonding, electrostatic interactions, coordination bonds, hydrophobic interaction, and even covalent bonds could occur between the clay mineral nanoplatelets and polymer chains, thereby leading to the formation of unique three-dimensional networks. Accordingly, the hydrogels exhibit exceptional optical and mechanical properties, swelling-deswelling behavior, and stimuli-responsiveness, reflecting the remarkable effects of clay minerals. With the pivotal roles of clay minerals in clay mineral-containing nanocomposite hydrogels, the nanocomposite hydrogels possess great potential as superabsorbents, drug vehicles, tissue scaffolds, wound dressing, and biosensors. Future studies should lay emphasis on the formation mechanisms with in-depth insights into interfacial interactions, the tactical functionalization of clay minerals and polymers for desired properties, and expanding of their applications.

  7. Reconstruction of a digital core containing clay minerals based on a clustering algorithm

    Science.gov (United States)

    He, Yanlong; Pu, Chunsheng; Jing, Cheng; Gu, Xiaoyu; Chen, Qingdong; Liu, Hongzhi; Khan, Nasir; Dong, Qiaoling

    2017-10-01

    It is difficult to obtain a core sample and information for digital core reconstruction of mature sandstone reservoirs around the world, especially for an unconsolidated sandstone reservoir. Meanwhile, reconstruction and division of clay minerals play a vital role in the reconstruction of the digital cores, although the two-dimensional data-based reconstruction methods are specifically applicable as the microstructure reservoir simulation methods for the sandstone reservoir. However, reconstruction of clay minerals is still challenging from a research viewpoint for the better reconstruction of various clay minerals in the digital cores. In the present work, the content of clay minerals was considered on the basis of two-dimensional information about the reservoir. After application of the hybrid method, and compared with the model reconstructed by the process-based method, the digital core containing clay clusters without the labels of the clusters' number, size, and texture were the output. The statistics and geometry of the reconstruction model were similar to the reference model. In addition, the Hoshen-Kopelman algorithm was used to label various connected unclassified clay clusters in the initial model and then the number and size of clay clusters were recorded. At the same time, the K -means clustering algorithm was applied to divide the labeled, large connecting clusters into smaller clusters on the basis of difference in the clusters' characteristics. According to the clay minerals' characteristics, such as types, textures, and distributions, the digital core containing clay minerals was reconstructed by means of the clustering algorithm and the clay clusters' structure judgment. The distributions and textures of the clay minerals of the digital core were reasonable. The clustering algorithm improved the digital core reconstruction and provided an alternative method for the simulation of different clay minerals in the digital cores.

  8. Reconstruction of a digital core containing clay minerals based on a clustering algorithm.

    Science.gov (United States)

    He, Yanlong; Pu, Chunsheng; Jing, Cheng; Gu, Xiaoyu; Chen, Qingdong; Liu, Hongzhi; Khan, Nasir; Dong, Qiaoling

    2017-10-01

    It is difficult to obtain a core sample and information for digital core reconstruction of mature sandstone reservoirs around the world, especially for an unconsolidated sandstone reservoir. Meanwhile, reconstruction and division of clay minerals play a vital role in the reconstruction of the digital cores, although the two-dimensional data-based reconstruction methods are specifically applicable as the microstructure reservoir simulation methods for the sandstone reservoir. However, reconstruction of clay minerals is still challenging from a research viewpoint for the better reconstruction of various clay minerals in the digital cores. In the present work, the content of clay minerals was considered on the basis of two-dimensional information about the reservoir. After application of the hybrid method, and compared with the model reconstructed by the process-based method, the digital core containing clay clusters without the labels of the clusters' number, size, and texture were the output. The statistics and geometry of the reconstruction model were similar to the reference model. In addition, the Hoshen-Kopelman algorithm was used to label various connected unclassified clay clusters in the initial model and then the number and size of clay clusters were recorded. At the same time, the K-means clustering algorithm was applied to divide the labeled, large connecting clusters into smaller clusters on the basis of difference in the clusters' characteristics. According to the clay minerals' characteristics, such as types, textures, and distributions, the digital core containing clay minerals was reconstructed by means of the clustering algorithm and the clay clusters' structure judgment. The distributions and textures of the clay minerals of the digital core were reasonable. The clustering algorithm improved the digital core reconstruction and provided an alternative method for the simulation of different clay minerals in the digital cores.

  9. Clay mineral distribution on tropical shelf: an example from the western shelf of India

    Digital Repository Service at National Institute of Oceanography (India)

    Hashimi, N.H.; Nair, R.R.

    Seventy-five sediment samples collected from the Kerala continental shelf and slope during the 17th and 71st Cruises of RV Gaveshani were analysed by X-ray diffraction for clay mineral content. The distribution of total clay ( 4 mu fraction...

  10. [Mechanism of tritium persistence in porous media like clay minerals].

    Science.gov (United States)

    Wu, Dong-Jie; Wang, Jin-Sheng; Teng, Yan-Guo; Zhang, Ke-Ni

    2011-03-01

    To investigate the mechanisms of tritium persistence in clay minerals, three types of clay soils (montmorillonite, kaolinite and illite) and tritiated water were used in this study to conduct the tritium sorption tests and the other related tests. Firstly, the ingredients, metal elements and heat properties of clay minerals were studied with some instrumental analysis methods, such as ICP and TG. Secondly, with a specially designed fractionation and condensation experiment, the adsorbed water, the interlayer water and the structural water in the clay minerals separated from the tritium sorption tests were fractionated for investigating the tritium distributions in the different types of adsorptive waters. Thirdly, the location and configuration of tritium adsorbed into the structure of clay minerals were studied with infrared spectrometry (IR) tests. And finally, the forces and mechanisms for driving tritium into the clay minerals were analyzed on the basis of the isotope effect of tritium and the above tests. Following conclusions have been reached: (1) The main reason for tritium persistence in clay minerals is the entrance of tritium into the adsorbed water, the interlayer water and the structural water in clay minerals. The percentage of tritium distributed in these three types of adsorptive water are in the range of 13.65% - 38.71%, 0.32% - 5.96%, 1.28% - 4.37% of the total tritium used in the corresponding test, respectively. The percentages are different for different types of clay minerals. (2) Tritium adsorbed onto clay minerals are existed in the forms of the tritiated hydroxyl radical (OT) and the tritiated water molecule (HTO). Tritium mainly exists in tritiated water molecule for adsorbed water and interlayer water, and in tritiated hydroxyl radical for structural water. (3) The forces and effects driving tritium into the clay minerals may include molecular dispersion, electric charge sorption, isotope exchange and tritium isotope effect.

  11. The systems containing clays and clay minerals from modified drug release: a review.

    Science.gov (United States)

    Rodrigues, Luís Alberto de Sousa; Figueiras, Ana; Veiga, Francisco; de Freitas, Rivelilson Mendes; Nunes, Lívio César Cunha; da Silva Filho, Edson Cavalcanti; da Silva Leite, Cleide Maria

    2013-03-01

    Clays are materials commonly used in the pharmaceutical industry, either as ingredients or as active ingredients. It was observed that when they are administered concurrently, they may interact with drugs reducing their absorption. Therefore, such interactions can be used to achieve technological and biopharmaceutical advantages, regarding the control of release. This review summarizes bibliographic (articles) and technological (patents) information on the use of systems containing clays and clay minerals in modified drug delivery. In this area, formulations such natural clay, commercial clay, synthetic clay, composites clay-polymers, nanocomposites clay-polymers, films and hidrogels composites clay-polymers are used to slow/extend or vectorize the release of drugs and consequently they increase their bioavailability. Finally, this review summarizes the fields of technology and biopharmaceutical applications, where clays are applied. Copyright © 2012 Elsevier B.V. All rights reserved.

  12. Clay minerals behaviour in thin sandy clay-rich lacustrine turbidites (Lake Hazar, Turkey)

    Science.gov (United States)

    El Ouahabi, Meriam; Hubert-Ferrari, Aurelia; Lamair, Laura; Hage, Sophie

    2017-04-01

    Turbidites have been extensively studied in many different areas using cores or outcrop, which represent only an integrated snapshot of a dynamic evolving flow. Laboratory experiments provide the missing relationships between the flow characteristics and their deposits. In particular, flume experiments emphasize that the presence of clay plays a key role in turbidity current dynamics. Clay fraction, in small amount, provides cohesive strength to sediment mixtures and can damp turbulence. However, the degree of flocculation is dependent on factors such as the amount and size of clay particles, the surface of clay particles, chemistry and pH conditions in which the clay particles are dispersed. The present study focuses on thin clayey sand turbidites found in Lake Hazar (Turkey) occurring in stacked thin beds. Depositional processes and sources have been previously studied and three types were deciphered, including laminar flows dominated by cohesion, transitional, and turbulence flow regimes (Hage et al., in revision). For the purpose of determine the clay behavior in the three flow regimes, clay mineralogical, geochemical measurements on the cores allow characterising the turbidites. SEM observations provide further information regarding the morphology of clay minerals and other clasts. The study is particularly relevant given the highly alkaline and saline water of the Hazar Lake. Clay minerals in Hazar Lake sediments include kaolinite (1:1-type), illite and chlorite (2:1-type). Hazar lake water is alkaline having pH around 9.3, in such alkaline environment, a cation-exchange reaction takes place. Furthermore, in saline water (16‰), salts can act as a shield and decrease the repulsive forces between clay particle surfaces. So, pH and salt content jointly impact the behaviour of clays differently. Since the Al-faces of clay structures have a negative charge in basic solutions. At high pH, all kaolinite surfaces become negative-charged, and then kaolinite

  13. Impact-Induced Clay Mineral Formation and Distribution on Mars

    Science.gov (United States)

    Rivera-Valentin, E. G.; Craig, P. I.

    2015-01-01

    Clay minerals have been identified in the central peaks and ejecta blankets of impact craters on Mars. Several studies have suggested these clay minerals formed as a result of impact induced hydrothermalism either during Mars' Noachian era or more recently by the melting of subsurface ice. Examples of post-impact clay formation is found in several locations on Earth such as the Mjolnir and Woodleigh Impact Structures. Additionally, a recent study has suggested the clay minerals observed on Ceres are the result of impact-induced hydrothermal processes. Such processes may have occurred on Mars, possibly during the Noachian. Distinguishing between clay minerals formed preor post-impact can be accomplished by studying their IR spectra. In fact, showed that the IR spectra of clay minerals is greatly affected at longer wavelengths (i.e. mid-IR, 5-25 micron) by impact-induced shock deformation while the near-IR spectra (1.0-2.5 micron) remains relatively unchanged. This explains the discrepancy between NIR and MIR observations of clay minerals in martian impact craters noted. Thus, it allows us to determine whether a clay mineral formed from impact-induced hydrothermalism or were pre-existing and were altered by the impact. Here we study the role of impacts on the formation and distribution of clay minerals on Mars via a fully 3-D Monte Carlo cratering model, including impact- melt production using results from modern hydrocode simulations. We identify regions that are conducive to clay formation and the location of clay minerals post-bombardment.

  14. Clay minerals in sandstone uranium deposits: radwaste applications

    International Nuclear Information System (INIS)

    Brookins, D.G.

    1990-01-01

    Clay minerals play an important role in the genesis of uranium deposits in sandstones. They incorporate the rate earths (REE), U, Sb, Th, Cs, Rb, Sr, Y, Ba, and even small amounts of chalcophiles. These minerals possess analog elements for many of the radwaste fission products as well as actinides and some actinide daughters. In sandstone uranium deposits, clay minerals are also associated with sulfide minerals, usually pyrite, and organic carbonaceous matter. The primary clay minerals are usually smectites, illites, chlorites and mixed layer varieties. The integrity of these clay minerals is demonstrated by their retention of formational-mineralization ages determined by Rb-Sr geochronologic investigation of the Grants Mineral Belt of the United States. The importance of the clay minerals as analog for parts of the multi-barrier concept in radwaste disposal is their ability to impede water penetration into - and movement of key elements out of uranium rich zones. The clay minerals further sorb and in other ways incorporate into their structures many fission products and actinide analogs from man-made nuclear wastes. 22 refs., 1 fig., 3 tabs

  15. Dynamic mechanical properties and anisotropy of synthetic shales with different clay minerals under confining pressure

    Science.gov (United States)

    Gong, Fei; Di, Bangrang; Wei, Jianxin; Ding, Pinbo; Shuai, Da

    2018-03-01

    The presence of clay minerals can alter the elastic behaviour of reservoir rocks significantly as the type of clay minerals, their volume and distribution, and their orientation control the shale's intrinsic anisotropic behaviours. Clay minerals are the most abundant materials in shale, and it has been proven extremely difficult to measure the elastic properties of natural shale by means of a single variable (in this case, the type of clay minerals), due to the influences of multiple factors, including water, TOC content and complex mineral compositions. We used quartz, clay (kaolinite, illite and smectite), carbonate and kerogen extract as the primary materials to construct synthetic shale with different clay minerals. Ultrasonic experiments were conducted to investigate the anisotropy of velocity and mechanical properties in dry synthetic and natural shale as a function of confining pressure. Velocities in synthetic shale are sensitive to the type of clay minerals, possibly due to the different structures of the clay minerals. The velocities increase with confining pressure and show higher rate of velocity increase at low pressures, and P-wave velocity is usually more sensitive than S-wave velocity to confining pressure according to our results. Similarly, the dynamic Young's modulus and Poisson's ratio increase with applied pressure, and the results also reveal that E11 is always larger than E33 and ν31 is smaller than ν12. Velocity and mechanical anisotropy decrease with increasing stress, and are sensitive to stress and the type of clay minerals. However, the changes of mechanical anisotropy with applied stress are larger compared with the velocity anisotropy, indicating that mechanical properties are more sensitive to the change of rock properties.

  16. Performance Study of the Natural Rubber Composite with Clay Minerals

    International Nuclear Information System (INIS)

    Nyo Nyo Myint; Tin Tin Aye; Kyaw Myo Naing; Nyunt Wynn

    2008-03-01

    The preparation, characterization and some applications of natural rubber clay composite have been studied. This study investigated the possibility of natural rubber latex to replace some part of natural clays. In formulation of rubber clay composite from natural rubber latex and various clay minerals, three main steps were involved (i) preparation of latex cream (ii) prevulcanization of latex cream (iii) mixing vulcanized latex compound, with other ingredients. In each step, several parameters have been carefully investigated to optimize the performance of natural rubber clay composite production. The composite products were of better quality and can be considered to be more cost effective.

  17. Lability of soil organic carbon in tropical soils with different clay minerals

    DEFF Research Database (Denmark)

    Bruun, Thilde Bech; Elberling, Bo; Christensen, Bent Tolstrup

    2010-01-01

    Soil organic carbon (SOC) storage and turnover is influenced by interactions between organic matter and the mineral soil fraction. However, the influence of clay content and type on SOC turnover rates remains unclear, particularly in tropical soils under natural vegetation. We examined the lability...... of SOC in tropical soils with contrasting clay mineralogy (kaolinite, smectite, allophane and Al-rich chlorite). Soil was sampled from A horizons at six sites in humid tropical areas of Ghana, Malaysian Borneo and the Solomon Islands and separated into fractions above and below 250 µm by wet sieving....... Basal soil respiration rates were determined from bulk soils and soil fractions. Substrate induced respiration rates were determined from soil fractions. SOC lability was significantly influenced by clay mineralogy, but not by clay content when compared across contrasting clay minerals. The lability...

  18. Dynamics of water confined in clay minerals

    International Nuclear Information System (INIS)

    Le Caer, S.; Pommeret, S.; Renault, J.Ph.; Lima, M.; Righini, R.; Gosset, D.; Simeone, D.; Bergaya, F.

    2012-01-01

    Ultrafast infrared spectroscopy of the O-D stretching mode of dilute HOD in H 2 O probes the local environment and the hydrogen bond network of confined water. The dynamics of water molecules confined in the interlayer space of montmorillonites (Mt) and in interaction with two types of cations (Li + and Ca 2+ ) but also with the negatively charged siloxane surface are studied. The results evidence that the OD vibrational dynamics is significantly slowed down in confined media: it goes from 1.7 ps in neat water to 2.6 Ps in the case of Li + cations with two water pseudo-layers (2.2-2.3 ps in the case of Ca 2+ cations) and to 4.7 ps in the case of Li + cations with one water pseudo-layer. No significant difference between the two cations is noticed. In this 2D confined geometry (the interlayer space being about 0.6 nm for two water pseudo-layers), the relaxation time constants obtained are comparable to the ones measured in analogous concentrated salt solutions. Nevertheless, and in strong opposition to the observations performed in the liquid phase, anisotropy experiments evidence the absence of rotational motions on a 5 ps time scale, proving that the hydrogen bond network in the interlayer space of the clay mineral is locked at this time scale. (authors)

  19. Characterization of clay minerals; Caracterizacion de minerales arcillosos

    Energy Technology Data Exchange (ETDEWEB)

    Diaz N, C.; Olguin, M.T.; Solache R, M.; Alarcon H, T.; Aguilar E, A. [Gerencia de Ciencias Basicas, Direccion de Investigacion Cientifica, Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    2002-07-01

    The natural clays are the more abundant minerals on the crust. They are used for making diverse industrial products. Due to the adsorption and ion exchange properties of these, a great interest for developing research directed toward the use of natural clays for the waste water treatment has been aroused. As part of such researches it is very important to carry out previously the characterization of the interest materials. In this work the results of the mineral and elemental chemical composition are presented as well as the morphological characteristics of clay minerals from different regions of the Mexican Republic. (Author)

  20. Toxicological evaluation of clay minerals and derived nanocomposites: a review.

    Science.gov (United States)

    Maisanaba, Sara; Pichardo, Silvia; Puerto, María; Gutiérrez-Praena, Daniel; Cameán, Ana M; Jos, Angeles

    2015-04-01

    Clays and clay minerals are widely used in many facets of our society. This review addresses the main clays of each phyllosilicate groups, namely, kaolinite, montmorillonite (Mt) and sepiolite, placing special emphasis on Mt and kaolinite, which are the clays that are more frequently used in food packaging, one of the applications that are currently exhibiting higher development. The improvements in the composite materials obtained from clays and polymeric matrices are remarkable and well known, but the potential toxicological effects of unmodified or modified clay minerals and derived nanocomposites are currently being investigated with increased interest. In this sense, this work focused on a review of the published reports related to the analysis of the toxicological profile of commercial and novel modified clays and derived nanocomposites. An exhaustive review of the main in vitro and in vivo toxicological studies, antimicrobial activity assessments, and the human and environmental impacts of clays and derived nanocomposites was performed. From the analysis of the scientific literature different conclusions can be derived. Thus, in vitro studies suggest that clays in general induce cytotoxicity (with dependence on the clay, concentration, experimental system, etc.) with different underlying mechanisms such as necrosis/apoptosis, oxidative stress or genotoxicity. However, most of in vivo experiments performed in rodents showed no clear evidences of systemic toxicity even at doses of 5000mg/kg. Regarding to humans, pulmonary exposure is the most frequent, and although clays are usually mixed with other minerals, they have been reported to induce pneumoconiosis per se. Oral exposure is also common both intentionally and unintentionally. Although they do not show a high toxicity through this pathway, toxic effects could be induced due to the increased or reduced exposure to mineral elements. Finally, there are few studies about the effects of clay minerals on

  1. Clay mineral distribution on the Kerala continental shelf and slope

    Digital Repository Service at National Institute of Oceanography (India)

    Rao, V.P.; Nair, R.R.; Hashimi, N.H.

    Seventy-five sediment samples collected from the Kerala continental shelf and slope during the 17th and 71st Cruises of @iRV gaveshani@@ were analysed by X-ray diffraction for clay mineral cntent. The distribution of total clay (< 4~k fraction...

  2. Distribution of Clay Minerals in Light Coal Fractions and the Thermal Reaction Products of These Clay Minerals during Combustion in a Drop Tube Furnace

    Directory of Open Access Journals (Sweden)

    Sida Tian

    2016-06-01

    Full Text Available To estimate the contribution of clay minerals in light coal fractions to ash deposition in furnaces, we investigated their distribution and thermal reaction products. The light fractions of two Chinese coals were prepared using a 1.5 g·cm−3 ZnCl2 solution as a density separation medium and were burned in a drop-tube furnace (DTF. The mineral matter in each of the light coal fractions was compared to that of the relevant raw coal. The DTF ash from light coal fractions was analysed using hydrochloric acid separation. The acid-soluble aluminium fractions of DTF ash samples were used to determine changes in the amorphous aluminosilicate products with increasing combustion temperature. The results show that the clay mineral contents in the mineral matter of both light coal fractions were higher than those in the respective raw coals. For the coal with a high ash melting point, clay minerals in the light coal fraction thermally transformed more dehydroxylation products compared with those in the raw coal, possibly contributing to solid-state reactions of ash particles. For the coal with a low ash melting point, clay minerals in the light coal fraction produced more easily-slagging material compared with those in the raw coal, playing an important role in the occurrence of slagging. Additionally, ferrous oxide often produces low-melting substances in coal ash. Due to the similarities of zinc oxide and ferrous oxide in silicate reactions, we also investigated the interactions of clay minerals in light coal fractions with zinc oxide introduced by a zinc chloride solution. The extraneous zinc oxide could react, to a small extent, with clay minerals in the coal during DTF combustion.

  3. [Analysis of XRD spectral characteristics of soil clay mineral in two typical cultivated soils].

    Science.gov (United States)

    Zhang, Zhi-Dan; Luo, Xiang-Li; Jiang, Hai-Chao; Li, Qiao; Shen, Cong-Ying; Liu, Hang; Zhou, Ya-Juan; Zhao, Lan-Po; Wang, Ji-Hong

    2014-07-01

    The present paper took black soil and chernozem, the typical cultivated soil in major grain producing area of Northeast, as the study object, and determinated the soil particle composition characteristics of two cultivated soils under the same climate and location. Then XRD was used to study the composition and difference of clay mineral in two kinds of soil and the evolutionary mechanism was explored. The results showed that the two kinds of soil particles were composed mainly of the sand, followed by clay and silt. When the particle accumulation rate reached 50%, the central particle size was in the 15-130 microm interval. Except for black soil profile of Shengli Xiang, the content of clay showed converse sequence to the central particle in two soils. Clay accumulated under upper layer (18.82%) in black soil profile while under caliche layer (17.41%) in chernozem profile. Clay content was the least in parent material horizon except in black profile of Quanyanling. Analysis of clay XRD atlas showed that the difference lied in not only the strength of diffraction peak, but also in the mineral composition. The main contents of black soil and chernozem were both 2 : 1 clay, the composition of black soil was smectite/illite mixed layer-illite-vermiculite and that of chernozem was S/I mixture-illite-montmorillonite, and both of them contained little kaolinite, chlorite, quartz and other primary mineral. This paper used XRD to determine the characteristics of clay minerals comprehensively, and analyzed two kinds of typical cultivated soil comparatively, and it was a new perspective of soil minerals study.

  4. Clay minerals in the sediments around the Andaman Islands

    Digital Repository Service at National Institute of Oceanography (India)

    Rao, V.P

    on the Island proper and the slope samples show contribution from the Ganges. Distribution of detrital minerals such as quartz and feldspar support the above conclusions. The 2 distinct clay mineral provenances result because the Andaman Islands appear to be a...

  5. Significance of saturation index of certain clay minerals in shallow ...

    Indian Academy of Sciences (India)

    Significance of saturation index of certain clay minerals in shallow ... The value of ionic activity product (IAP) for a mineral ... where γi is the activity coefficient of ionic species ...... Domenico P A and Schwartz W 1990 Physical and Chemical.

  6. Kinetics and Products of Chromium(VI) Reduction by Iron(II/III)-Bearing Clay Minerals.

    Science.gov (United States)

    Joe-Wong, Claresta; Brown, Gordon E; Maher, Kate

    2017-09-05

    Hexavalent chromium is a water-soluble pollutant, the mobility of which can be controlled by reduction of Cr(VI) to less soluble, environmentally benign Cr(III). Iron(II/III)-bearing clay minerals are widespread potential reductants of Cr(VI), but the kinetics and pathways of Cr(VI) reduction by such clay minerals are poorly understood. We reacted aqueous Cr(VI) with two abiotically reduced clay minerals: an Fe-poor montmorillonite and an Fe-rich nontronite. The effects of ionic strength, pH, total Fe content, and the fraction of reduced structural Fe(II) [Fe(II)/Fe(total)] were examined. The last variable had the largest effect on Cr(VI) reduction kinetics: for both clay minerals, the rate constant of Cr(VI) reduction varies by more than 3 orders of magnitude with Fe(II)/Fe(total) and is described by a linear free energy relationship. Under all conditions examined, Cr and Fe K-edge X-ray absorption near-edge structure spectra show that the main Cr-bearing product is a Cr(III)-hydroxide and that Fe remains in the clay structure after reacting with Cr(VI). This study helps to quantify our understanding of the kinetics of Cr(VI) reduction by Fe(II/III)-bearing clay minerals and may improve predictions of Cr(VI) behavior in subsurface environments.

  7. Influence of Clay Content, Mineralogy and Fabric On Radar Frequency Response of Aquifer Materials

    Science.gov (United States)

    West, L. J.; Handley, K.

    High frequency electromagnetic methods such as ground penetrating radar (GPR) and time domain reflectometry (TDR) are widely employed to measure water saturation in the vadose zone and water filled porosity in the saturated zone. However, previous work has shown that radar frequency dielectric properties are strongly influenced by clay as well as by water content. They have also shown that that the dielectric response of clay minerals is strongly frequency dependent, and that even a small proportion of clay such as that present in many sandstone aquifers can have a large effect at typi- cal GPR frequencies (around 100MHz). Hence accurate water content/porosity deter- mination requires clay type and content to be taken into account. Reported here are dielectric measurements on clay-sand mixtures, aimed at investigating the influence of clay mineralogy, particle shape, and the geometrical arrangement of the mixture constituents on GPR and TDR response. Dielectric permittivity (at 50-1000MHz) was measured for mixtures of Ottawa Sand and various clay minerals or clay size quartz rock flour, using a specially constructed dielectric cell. Both homogeneous and layered mixtures were tested. The influence of pore water salinity, clay type, and particle arrangement on the dielectric response is interpreted in terms of dielectric dispersion mechanisms. The appropriateness of var- ious dielectric mixing rules such as the Complex Refractive Index Method (CRIM) for determination of water content or porosity from field GPR and TDR data are dis- cussed.

  8. Development of the methodology of sample preparation to X-ray diffractometry of clay minerals at Petrobras Research Center

    International Nuclear Information System (INIS)

    Alves, D.B.

    1987-01-01

    Various procedures can be used in the analysis of the clay mineral content of rocks by X-ray diffraction. This article describes the principal ones and discusses those adopted in the X-ray clay mineral laboratory of the PETROBRAS Research Center (CENPES) in Rio de Janeiro. This article presents the methodology used and provides users with information about its application and limitations. The methodology has been developed to study polymineral samples. The aim to identify clay mineral groups and to estimate their relative proportions. Of the four main steps of this analysis - separation and concentration of clay minerals, preparation of oriented specimens, X-ray irradiation under standard conditions and interpretation of X-ray diffraction patterns - only the first three are discussed here. Clay minerals occur mainly in the [pt

  9. Modeling of Cation Binding in Hydrated 2:1 Clay Minerals - Final Report

    International Nuclear Information System (INIS)

    Smith, David E.

    2000-01-01

    Hydrated 2:1 clay minerals are high surface area, layered silicates that play a unique role in determining the fate of radionuclides in the environment. This project consisted of developing and implementing computer simulation methods for molecular characterization of the swelling and ion exchange properties of Hydrated 2:1 clay minerals, and the subsequent analysis and theoretical modeling with a view toward improving contaminant transport modeling as well as soil remediation and radionuclide containment strategies. Project results included the (a) development of simulation methods to treat clays under environmentally relevant conditions of variable water vapor pressure; (b) calculation of clay swelling thermodynamics as a function of interlayer ion size and charge (calculated quantities include immersion energies, free energies, and entropies of swelling); and (c) calculation of ion exchange free energies, including contributions from changing interlayer water contents and layer spacing

  10. Enchanted Clays: 44th Annual Meeting of the Clay Minerals Society (June 2007)

    Energy Technology Data Exchange (ETDEWEB)

    Randall T. Cygan

    2007-06-01

    “Enchanted Clays: 44th Annual Meeting of the Clay Minerals Society” was held in early June 2007 in beautiful and historic Santa Fe, New Mexico, USA. Santa Fe provided an idyllic location in the southwestern United States for the attendees to enjoy technical and social sessions while soaking up the diverse culture and wonderful climate of New Mexico—The Land of Enchantment. The meeting included a large and varied group of scientists, sharing knowledge and ideas, benefitting from technical interactions, and enjoying the wonderful historic and enchanted environs of Santa Fe. Including significant number of international scientists, the meeting was attended by approximately two hundred participants. The meeting included three days of technical sessions (oral and poster presentations), three days of field trips to clay and geological sites of northern New Mexico, and a full day workshop on the stabilization of carbon by clays. Details can be found at the meeting web site: www.sandia.gov/clay.

  11. Crystallite size distribution of clay minerals from selected Serbian clay deposits

    Directory of Open Access Journals (Sweden)

    Simić Vladimir

    2006-01-01

    Full Text Available The BWA (Bertaut-Warren-Averbach technique for the measurement of the mean crystallite thickness and thickness distributions of phyllosilicates was applied to a set of kaolin and bentonite minerals. Six samples of kaolinitic clays, one sample of halloysite, and five bentonite samples from selected Serbian deposits were analyzed. These clays are of sedimentary volcano-sedimentary (diagenetic, and hydrothermal origin. Two different types of shape of thickness distribution were found - lognormal, typical for bentonite and halloysite, and polymodal, typical for kaolinite. The mean crystallite thickness (T BWA seams to be influenced by the genetic type of the clay sample.

  12. Spatial distribution and longitudinal variation of clay minerals in the Central Indian Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Valsangkar, A.

    in the Central Indian Basin (CIB). The average sand content in the basin is 3.8%, which decreases systematically and longitudinally to 0.3% towards south. The average illite and chlorite major clay mineral abundance also decrease southwards along the four...

  13. Soil Microbes and soil microbial proteins: interactions with clay minerals

    International Nuclear Information System (INIS)

    Spence, A.; Kelleher, B. P.

    2009-01-01

    Bacterial enumeration in soil environments estimates that the population may reach approximately 10 1 0 g - 1 of soil and comprise up to 90% of the total soil microbial biomass. Bacteria are present in soils as single cells or multicell colonies and often strongly adsorb onto mineral surfaces such as sand and clay. The interactions of microbes and microbial biomolecules with these minerals have profound impacts on the physical, chemical and biological properties of soils. (Author)

  14. Heteroaggregation of Silver Nanoparticles with Clay Minerals in Aqueous System

    Science.gov (United States)

    Liu, J.; Burrow, E.; Hwang, Y.; Lenhart, J.

    2013-12-01

    Nanoparticles are increasingly being used in industrial processes and consumer products that exploit their beneficial properties and improve our daily lives. Nevertheless, they also attract attention when released into natural environment due to their potential for causing adverse effects. The fate and transport of nanoparticles in aqueous systems have been the focus of intense study. However, their interactions with other natural particles have received only limited attention. Clay minerals are ubiquitous in most aquatic systems and their variably charged surfaces can act as deposition sites that can alter the fate and transport of nanoparticles in natural aqueous environments. In this study, we investigated the homoaggregation of silver nanoparticles with different coating layers and their heteroaggregation behavior with clay minerals (illite, kaolinite, montmorillonite) in neutral pH solutions. Silver nanoparticles with a nominal diameter of 80 nm were synthesized with three different surface coating layers: uncoated, citrate-coated and Tween-coated. Illite (IMt-2), kaolinite (KGa-2), and montmorillonite (SWy-2) were purchased from the Clay Mineral Society (Indiana) and pretreated to obtain monocationic (Na-clay) and dicationic (Ca-clay) suspensions before the experiments. The change in hydrodynamic diameter as a function of time was monitored using dynamic light scattering (DLS) measurements in order to evaluate early stage aggregation as a function of electrolyte concentration in both the homo- and heteroaggregation scenarios. A shift in the critical coagulation concentration (CCC) values to lower electrolyte concentrations was observed in binary systems, compared to single silver nanoparticle and clay systems. The results also suggest more rapid aggregation in binary system during the early aggregation stage when compared to the single-particle systems. The behavior of citrate-coated silver nanoparticles was similar to that of the bare particles, while the

  15. Depth distribution of 137Cs adsorption property of clay minerals influenced by mineral weathering

    International Nuclear Information System (INIS)

    Nakao, Atsushi; Funakawa, Shinya; Kosaki, Takashi

    2007-01-01

    Radiocesium adsorption potential of mica clay mineral can increase as it is weathered, because K depletion in mica interlayer sites generates new Cs selective sites. However, in soils weathered under field conditions, the increase in 137 Cs adsorption potential associated with mineral weathering has not been observed extensively. We investigated four soil profiles from Japan and Thailand with different soil pH ranges (3.3-4.0, 4.2-4.3, 5.0-5.7, and 5.5-7.3). The solid/liquid distribution coefficients of Cs ( Cs Kd) in clay ( 137 Cs adsorption potential of mica clay minerals. In three soil profiles, Cs Kd value in clay was the largest at a surface horizon and was decreased with depth, whereas in the most acidic of Podzolic soil profile, it was the largest at B horizon. The large Cs Kd value in surface clays relative to deeper horizons were well associated with that of 2.0-1.0 μm clay fraction. We assumed that the 137 Cs adsorption potential increased at surface horizons mainly because coarser clay micas were weathered and generated Cs selective sites. The exceptional result obtained in Podzolic soil profile suggests that too intensive weathering destruct mica structure and may decrease in Cs adsorption potential of mica clay minerals. (author)

  16. Fixation of Selenium by Clay Minerals and Iron Oxides

    DEFF Research Database (Denmark)

    Hamdy, A. A.; Nielsen, Gunnar Gissel

    1977-01-01

    In studying Se fixation, soil components capable of retaining Se were investigated. The importance of Fe hydrous oxides in the fixation of Se was established. The clay minerals common to soils, such as kaolinite, montmorillonite and vermiculite, all exhibited Se fixation, but greater fixation occ...

  17. Picloram and Aminopyralid Sorption to Soil and Clay Minerals

    Science.gov (United States)

    Aminopyralid sorption data are lacking, and these data are needed to predict off-target transport and plant available herbicide in soil solution. The objective of this research was to determine the sorption of picloram and aminopyralid to five soils and three clay minerals and determine if the pote...

  18. Optimization method for quantitative calculation of clay minerals in soil

    Indian Academy of Sciences (India)

    However, no reliable method for quantitative analysis of clay minerals has been established so far. In this study, an attempt was made to propose an optimization method for the quantitative ... 2. Basic principles. The mineralogical constitution of soil is rather complex. ... K2O, MgO, and TFe as variables for the calculation.

  19. Sorption of Metal Ions on Clay Minerals.

    Science.gov (United States)

    Schlegel; Manceau; Chateigner; Charlet

    1999-07-01

    The local structural environment of Co sorbed on hectorite (a magnesian smectite) has been investigated by polarized EXAFS (P-EXAFS) spectroscopy on a self-supporting film of Co-sorbed hectorite. This sorption sample was prepared by contacting Co and hectorite at pH 6.5 and at high ionic strength (0.3 M NaNO3) to favor pH-dependent sorption reaction over cation exchange. A self-supporting film was elaborated after 120 h of reacting time, when apparent quasi-equilibrium conditions were attained. The half-width at half maximum of the orientation distribution of c* axis of individual clay platelets off the film normal was determined by quantitative texture analysis, and found to be equal to 18.9 degrees. Co K-edge P-EXAFS spectra were recorded at angles between the incident beam and the film normal equal to 0 degrees, 35 degrees, 50 degrees, and 60 degrees; the 90 degrees spectrum was obtained by extrapolation. Spectral analysis led to the identification of the two nearest cationic subshells containing 1.6 +/- 0.4 Mg at 3.03 Å and 2.2 +/- 0.5 Si at 3.27 Å. These distances are respectively characteristic of edge-sharing linkages between Mg and Co octahedra and of corner-sharing linkages between Co octahedra and Si tetrahedra, as in clay structures. The angular dependence of the Co-Mg and Co-Si contributions indicates that Co-Mg pairs are oriented parallel to the film plane, whereas Co-Si pairs are not. These results are interpreted by the formation of Co inner-sphere mononuclear surface complexes located at the edges of hectorite platelets, in the continuity of the (Mg, Li) octahedral sheet. Copyright 1999 Academic Press.

  20. Clay-mineral assemblages from some levels of K-118 drill core of Maha Sarakham evaporites, northeastern Thailand

    Science.gov (United States)

    Suwanich, Parkorn

    Clay-mineral assemblages in Middle Clastic, Middle Salt, Lower Clastic, Potash Zone, and Lower Salt, totalling 13 samples from K-118 drill core, in the Maha Sarakham Formation, Khorat Basin, northeastern Thailand were studied. The clay-size particles were separated from the water-soluble salt by water leaching. Then the samples were leached again in the EDTA solution and separated into clay-size particles by using the timing sedimentation. The EDTA-clay residues were divided and analyzed by using the XRD and XRF method. The XRD peaks show that the major-clay minerals are chlorite, illite, and mixed-layer corrensite including traces of rectorite? and paragonite? The other clay-size particles are quartz and potassium feldspar. The XRF results indicate Mg-rich values and moderate MgAl atom ratio values in those clay minerals. The variable Fe, Na, and K contents in the clay-mineral assemblages can explain the environment of deposition compared to the positions of the samples from the core. Hypothetically, mineralogy and the chemistry of the residual assemblages strongly indicate that severe alteration and Mg-enrichment of normal clay detritus occurred in the evaporite environment through brine-sediment interaction. The various Mg-enrichment varies along the various members reflecting whether sedimentation is near or far from the hypersaline brine.

  1. X-ray diffraction identification of clay minerals by microcomputer

    International Nuclear Information System (INIS)

    Rodrigues, S.; Imasava, F.J.

    1988-01-01

    The identification of clay minerals by X-ray powder diffraction are done by searching an unknown pattern with a file of standard X-ray diffraction patterns. For this searching done by hand is necessary a long time. This paper shows a program in ''Basic'' language to be utilized in microcomputers for the math of the unknown pattern, using the high velocity of comparison of the microcomputer. A few minutes are used for the match. (author) [pt

  2. Decontamination of radioactive liquid systems by modified clay minerals

    OpenAIRE

    Petrushka, Ihor; Moroz, Olexandr

    2016-01-01

    The process mechanism for sorption of strontium and cesium from liquid radioactive waste using modified bentonites from Yaziv sulfur deposit was investigated. The technique for predicting the intensity of the sorption process based on the comparison of experimental and calculated values of mass transfer coefficients was proposed. It was detected that the process of sorption extraction of strontium and cesium from liquid medium using modified clay minerals may be bes...

  3. Heterogeneous uptake of the C1 to C4 organic acids on a swelling clay mineral

    Directory of Open Access Journals (Sweden)

    M. A. Tolbert

    2007-08-01

    Full Text Available Mineral aerosol is of interest due to its physiochemical impacts on the Earth's atmosphere. However, adsorbed organics could influence the chemical and physical properties of atmospheric mineral particles and alter their impact on the biosphere and climate. In this work, the heterogeneous uptake of a series of small organic acids on the swelling clay, Na-montmorillonite, was studied at 212 K as a function of relative humidity (RH, organic acid pressure and clay mass. A high vacuum chamber equipped with a quadrupole mass spectrometer and a transmission Fourier transform infrared spectrometer was used to detect the gas and condensed phases, respectively. Our results show that while the initial uptake efficiency was found to be independent of organic acid pressure, it increased linearly with increasing clay mass. Thus, the small masses studied allow access to the entire surface area of the clay sample with minimal effects due to surface saturation. Additionally, results from this study show that the initial uptake efficiency for butanoic (butyric acid on the clay increases by an order of magnitude as the RH is raised from 0% to 45% RH at 212 K while the initial uptake efficiency of formic, acetic and propanoic (propionic acids increases only slightly at higher humidities. However, the initial uptake efficiency decreases significantly in a short amount of time due to surface saturation effects. Thus, although the initial uptake efficiencies are appropriate for initial times, the fact that the uptake efficiency will decrease over time as the surface saturates should be considered in atmospheric models. Surface saturation results in sub-monolayer coverage of organic acid on montmorillonite under dry conditions and relevant organic acid pressures that increases with increasing humidity for all organic acids studied. Additionally, the presence of large organic acids may slightly enhance the water content of the clay above 45% RH. Our results indicate

  4. Surveying Clay Mineral Diversity in the Murray Formation, Gale Crater, Mars

    Science.gov (United States)

    Bristow, T.F.; Blake, D. F..; Vaniman, D. T.; Chipera, S. J.; Rampe, E. B.; Grotzinger, J. P.; McAdam, A. C.; Ming, D. W..; Morrison, S. M.; Yen, A. S.; hide

    2017-01-01

    The CheMin XRD instrument aboard Mars Science Laboratory (MSL) has documented clay minerals in various drill samples during its traverse of Gale Crater's floor and ascent of Mt. Sharp. The most recent samples, named Marimba, Quela and Sebina were acquired from the Murray Formation in the Murray Buttes region of lower Mt. Sharp. Marimba and Quela come from a approx. 30 m package of finely laminated lacustrine mudstones. Sebina comes from an overlying package of heterolithic mudstone-sandstones. Clay minerals make up approx.15-25 wt.% of the bulk rock with similar contributions to XRD patterns in all three samples. Broad basal reflections at approx. 10deg 2(theta) CoK(alpha) indicate the presence of 2:1 group clay minerals. The 02(lambda) clay mineral band lies at approx. 22.9deg 2(theta), a region typically occupied by Fe-bearing dioctahedral 2:1 clay minerals like nontronite or Fe-illite. The low humidity within the CheMin instrument, which is open to the martian atmosphere, promotes loss of interlayer H2O and collapse of smectite interlayers making them difficult to distinguish from illites. However, based on the low K content of the bulk samples, it appears that smectitic clay minerals are dominant. Peak dehydroxylation of the Marimba sample measured by the SAM instrument on MSL occurred at 610C and 780C. Fe-bearing smectites are not consistent with these dehydroxylation temperatures. Thus, we suggest that a mixture of dioctahedral and trioctahedral smectite phases are present giving the appearance of intermediate octahedral occupancy in XRD. Dioctahedral smectites have not previously been reported in Gale Crater by MSL. Earlier in the mission, relatively clay mineral rich samples (approx. 20 wt.%) from lacustrine mudstones in Yellowknife Bay (YKB) were found to contain ferrian saponites. It is proposed that YKB saponites formed via isochemical aqueous alteration of detrital olivine close to the time of sediment deposition, under anoxic to poorly oxidizing

  5. Methylene blue adsorption in clay mineral dealt with organic cation

    International Nuclear Information System (INIS)

    Silva, T.L.; Lemos, V.P.

    2011-01-01

    The interaction among organic cations, as the methylene blue (AM) and benzyltrimethylammonium (BTMA), and clay minerals of the group of the smectite they result in the formation of applied materials in the adsorption of organic pollutant presents in waters, soils and you cultivate. In this work they were prepared the adsorbents (organic-clays) smectite - AM and smectite-BTMA. The precursory sample of smectite was collected in Rio Branco-Acre. We were also used an smectite sample collected in Sena Madureira (SM)-Acre already characterized in previous work and a sample of standard smectite Swy-2-Na-Montmorillonite (SWy-2) of Wymong - USA. The organic agents selected for this study they were: Blue of Methylene, denominated AM and Benzyltrimethylammonium, denominated BTMA. They were appraised the capacities adsorptive of the treated samples with BTMA being used AM as adsorbate. The results of these evaluations detected that ran total adsorption of AM (concentrations varying from 1 to 10 ppm) for the treated samples with BTMA. The organic cation, BTMA, interacting with the surfaces of the natural clay was more efficient in the adsorption of AM than the clay without the previous treatment with this salt. (author)

  6. Geochemical study of evaporite and clay mineral-oxyhydroxide samples from the Waste Isolation Pilot Plant site

    International Nuclear Information System (INIS)

    Brookins, D.G.

    1993-06-01

    Samples of clay minerals, insoluble oxyhydroxides, and their host evaporites from the WIPP site have been studied for their major and minor elements abundances, x-ray diffraction characteristics, K-Ar ages, and Rb-Sr ages. This study was undertaken to determine their overall geochemical characteristics and to investigate possible interactions between evaporates and insoluble constituents. The evaporite host material is water-soluble, having Cl/Br ratios typical of marine evaporites, although the Br content is low. Insoluble material (usually a mixture of clay minerals and oxyhydroxide phases) yields very high Cl/Br ratios, possibly because of Cl from admixed halide minerals. This same material yields K/Rb and Th/U ratios in the normal range for shales; suggesting little, if any, effect of evaporite-induced remobilization of U, K, or Rb in the insoluble material. The rare-earth element (REE) data also show normal REE/chondrite (REE/CHON) distribution patterns, supporting the K/Rb and Th/U data. Clay minerals yield K-Ar dates in the range 365 to 390 Ma and a Rb-Sr isochron age of 428 ± 7 Ma. These ages are well in excess of the 220- to 230-Ma formational age of the evaporites, and confirm the detrital origin of the clays. The ages also show that any evaporite or clay mineral reactions that might have occurred at or near the time of sedimentation and diagenesis were not sufficient to reset the K-Ar and Rb-Sr systematics of the clay minerals. Further, x-ray data indicate a normal evaporitic assemblage of clay minerals and Fe-rich oxyhydroxide phases. The clay minerals and other insoluble material appear to be resistant to the destructive effects of their entrapment in the evaporites, which suggests that these insoluble materials would be good getters for any radionuclides (hypothetically) released from the storage of radioactive wastes in the area

  7. Adsorption of Nucleic Acid Bases, Ribose, and Phosphate by Some Clay Minerals

    Directory of Open Access Journals (Sweden)

    Hideo Hashizume

    2015-02-01

    Full Text Available Besides having a large capacity for taking up organic molecules, clay minerals can catalyze a variety of organic reactions. Derived from rock weathering, clay minerals would have been abundant in the early Earth. As such, they might be expected to play a role in chemical evolution. The interactions of clay minerals with biopolymers, including RNA, have been the subject of many investigations. The behavior of RNA components at clay mineral surfaces needs to be assessed if we are to appreciate how clays might catalyze the formation of nucleosides, nucleotides and polynucleotides in the “RNA world”. The adsorption of purines, pyrimidines and nucleosides from aqueous solution to clay minerals is affected by suspension pH. With montmorillonite, adsorption is also influenced by the nature of the exchangeable cations. Here, we review the interactions of some clay minerals with RNA components.

  8. Clays and Clay Minerals and their environmental application in Food Technology

    Science.gov (United States)

    del Hoyo Martínez, Carmen; Cuéllar Antequera, Jorge; Sánchez Escribano, Vicente; Solange Lozano García, Marina; Cutillas Díez, Raul

    2013-04-01

    The clay materials have led to numerous applications in the field of public health (del Hoyo, 2007; Volzone, 2007) having been demonstrated its effectiveness as adsorbents of all contaminants. Some biodegradable materials are used for for adsorption of chemical contaminants: lignins (Valderrabano et al., 2008) and also clays and clay minerals, whose colloidal properties, ease of generating structural changes, abundance in nature, and low cost make them very suitable for this kind of applications. Among the strategies used at present to preserve the quality of the water and this way to diminish the environmental risk that supposes the chemical pollution, stands out the use of adsorbents of under cost, already they are natural or modified, to immobilize these compounds and to avoid the pollution of the water with the consequent reduction of environmental and economic costs Thanks to the development of the science and the technology of the nourishment in the last 50 years, there have revealed itself several new substances that can fulfill beneficial functions in the food, and these substances, named food additives, are today within reach of all. The food additives recover a very important role in the complex nourishing supply. The additives fulfill several useful functions in the food, which often we give for sat. Nevertheless the widespread use of food additives in the food production also influences the public health. The food industries, which are very important for the economy, spill residues proved from its activity that they have to be controlled to evaluate the environmental impact and to offer the necessary information about the quantitative evaluation of the chemical risk of the use of food additives for the public health. We have studied the adsorption of several contaminants by natural or modified clays, searching their interaction mechanisms and the possible recycling of these materials for environmental purposes and prevention of the health. References

  9. Aqueous suspensions of natural swelling clay minerals. 2. Rheological characterization.

    Science.gov (United States)

    Paineau, Erwan; Michot, Laurent J; Bihannic, Isabelle; Baravian, Christophe

    2011-06-21

    We report in this article a comprehensive investigation of the viscoelastic behavior of different natural colloidal clay minerals in aqueous solution. Rheological experiments were carried out under both dynamic and steady-state conditions, allowing us to derive the elasticity and yield stress. Both parameters can be renormalized for all sizes, ionic strength, and type of clay using in a first approach only the volume of the particles. However, applying such a treatment to various clays of similar shapes and sizes yields differences that can be linked to the repulsion strength and charge location in the swelling clays. The stronger the repulsive interactions, the better the orientation of clay particles in flows. In addition, a master linear relationship between the elasticity and yield stress whose value corresponds to a critical deformation of 0.1 was evidenced. Such a relationship may be general for any colloidal suspension of anisometric particles as revealed by the analysis of various experimental data obtained on either disk-shaped or lath- and rod-shaped particles. The particle size dependence of the sol-gel transition was also investigated in detail. To understand why suspensions of larger particles gel at a higher volume fraction, we propose a very simplified view based on the statistical hydrodynamic trapping of a particle by an another one in its neighborhood upon translation and during a short period of time. We show that the key parameter describing this hydrodynamic trapping varies as the cube of the average diameter and captures most features of the sol-gel transition. Finally, we pointed out that in the high shear limit the suspension viscosity is still closely related to electrostatic interactions and follows the same trends as the viscoelastic properties. © 2011 American Chemical Society

  10. Ice nucleation efficiency of clay minerals in the immersion mode

    Directory of Open Access Journals (Sweden)

    V. Pinti

    2012-07-01

    Full Text Available Emulsion and bulk freezing experiments were performed to investigate immersion ice nucleation on clay minerals in pure water, using various kaolinites, montmorillonites, illites as well as natural dust from the Hoggar Mountains in the Saharan region. Differential scanning calorimeter measurements were performed on three different kaolinites (KGa-1b, KGa-2 and K-SA, two illites (Illite NX and Illite SE and four natural and acid-treated montmorillonites (SWy-2, STx-1b, KSF and K-10. The emulsion experiments provide information on the average freezing behaviour characterized by the average nucleation sites. These experiments revealed one to sometimes two distinct heterogeneous freezing peaks, which suggest the presence of a low number of qualitatively distinct average nucleation site classes. We refer to the peak at the lowest temperature as "standard peak" and to the one occurring in only some clay mineral types at higher temperatures as "special peak". Conversely, freezing in bulk samples is not initiated by the average nucleation sites, but by a very low number of "best sites". The kaolinites and montmorillonites showed quite narrow standard peaks with onset temperatures 238 K<Tonstd<242 K and best sites with averaged median freezing temperature Tmedbest=257 K, but only some featuring a special peak (i.e. KSF, K-10, K-SA and SWy-2 with freezing onsets in the range 240–248 K. The illites showed broad standard peaks with freezing onsets at 244 K Tonstd<246 K and best sites with averaged median freezing temperature Tmedbest=262 K. The large difference between freezing temperatures of standard and best sites shows that characterizing ice nucleation efficiencies of dust particles on the basis of freezing onset temperatures from bulk experiments, as has been done in some atmospheric studies, is not appropriate. Our investigations

  11. Adsorption and Desorption of Cesium in Clay Minerals: Effects of Natural Organic Matter and pH

    Science.gov (United States)

    Yoon, Hongkyu; Ilgen, Anastasia; Mills, Melissa; Lee, Moo; Seol, Jeung Gun; Cho, Nam Chan; Kang, Hyungyu

    2017-04-01

    Cesium (Cs) released into the environment (e.g., Fukushima accident) poses significant environmental concerns and remediation challenges. A majority of Cs in the environment have remained within the surface soils due to the strong adsorption affinity of Cs towards clay minerals. Different clay minerals have different bonding sites, resulting in various adsorption mechanisms at nanometer scale. For example, the illite commonly has a basal spacing of 1.0 nm, but becomes wider to 1.4 nm once other cations exchange with K in the interlayer site. Cs adsorbs into these expanded wedged zone strongly, which can control its mobility in the environment. In addition, natural organic matter (NOM) in the surface soils can interact with clay minerals, which can modify the mechanisms of Cs adsorption on the clay minerals by blocking specific adsorption sites and/or providing Cs adsorption sites on NOM surface. In this work, three representative clay minerals (illite, vermiculite, montmorillonite) and humic acid (HA) are used to systematically investigate the adsorption and desorption behavior of Cs. We performed batch adsorption experiments over a range of Cs concentrations on three clay minerals with and without HA, followed by sequential desorption batch testing. We tested desorption efficiency as a function of initial adsorbed Cs concentration, HA content, sodium concentration, and pH. The sequential extraction results are compared to the structural changes in clay minerals, measured using extended X-ray absorption fine structure spectroscopy (EXAFS) and aberration-corrected (scanning) transmission electron microscopy (TEM) - energy dispersive X-ray spectroscopy (EDX). Hence, this work aims to identify the mechanisms of Cs fixation at the nanometer (or atomic-) scale as a function of the clay mineral properties (e.g. expandability, permanent surface charge) and varying organic matter content at different pH values and to enhance our atomic-scale mechanistic understanding of

  12. Evaluation of the bleaching flux in clays containing hematite and different clay minerals; Avaliacao do fundente descolorante em argilas contendo hematita e diferentes argilominerais

    Energy Technology Data Exchange (ETDEWEB)

    Silva Junior, E.M.; Lusa, T.; Silva, T.M.; Medeiros, B.B.; Santos, G.R. dos [Universidade Tecnologica Federal do Parana (DAMEC/UFTPR), Pato Branco, PR (Brazil); Morelli, M.R., E-mail: geocrisr@utfpr.edu.com, E-mail: morelli@power.ufscar.br [Universidade Federal de Sao Carlos (DEMa/PPGCEM/UFSCar), SP (Brazil)

    2016-07-01

    Previous studies have shown that the addition of a synthetic flux in a clay mineral constituted by illite phase in the presence of iron oxide with the hematite, promotes color change of the firing products, making the reddish color firing into whiteness. This flow is constituted of a vitreous phase of the silicates family obtained by fusion/solidification of oxides and carbonates. Thus, the objective of this work was that of studying the interaction of the iron element in the final color mechanism of the different types of mineral crystal phase of the clays. In order to study the phenomenon, we obtained different compositions between the select clays and the synthetic flow, and characterization using X-ray diffraction (XRD) and visual analysis. The results showed that the action of the synthetic flow as a modifying agent for color depends on the mineral crystal phase of the clays. The color firing modification does not occur in the clays content high levels of kaolinite mineral phase. (author)

  13. Geothermal alteration of clay minerals and shales: diagenesis

    Energy Technology Data Exchange (ETDEWEB)

    Weaver, C.E.

    1979-07-01

    The objective of this report is to perform a critical review of the data on the mineral and chemical alterations that occur during diagenesis and low-grade metamorphism of shale and other clay-rich rocks - conditions similar to those expected from emplacement of heat-producing radioactive waste in a geologic repository. The conclusions drawn in this document are that the following type of alterations could occur: smectite alteration, ion mobilization, illitic shales, kaolinite reactions, chlorite reactions, organic reactions, paleotemperatures, low temperature shales, high temperature shales, and phase equilibrium changes.

  14. Geothermal alteration of clay minerals and shales: diagenesis

    International Nuclear Information System (INIS)

    Weaver, C.E.

    1979-07-01

    The objective of this report is to perform a critical review of the data on the mineral and chemical alterations that occur during diagenesis and low-grade metamorphism of shale and other clay-rich rocks - conditions similar to those expected from emplacement of heat-producing radioactive waste in a geologic repository. The conclusions drawn in this document are that the following type of alterations could occur: smectite alteration, ion mobilization, illitic shales, kaolinite reactions, chlorite reactions, organic reactions, paleotemperatures, low temperature shales, high temperature shales, and phase equilibrium changes

  15. Radiolysis of alanine adsorbed in a clay mineral

    Energy Technology Data Exchange (ETDEWEB)

    Aguilar-Ovando, Ellen Y.; Negron-Mendoza, Alicia [Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico (UNAM), Circuito Exterior s/n, Ciudad Universitaria, Apartado Postal 70-543, Deleg. Coyoacan, C.P. 04510 (Mexico)

    2013-07-03

    Optical activity in molecules is a chemical characteristic of living beings. In this work, we examine the hypothesis of the influence of different mineral surfaces on the development of a specific chirality in organic molecules when subjected to conditions simulating the primitive Earth during the period of chemical evolution. By using X-ray diffraction techniques and HPLC/ELSD to analyze aqueous suspensions of amino acids adsorbed on minerals irradiated in different doses with a cobalt-60 gamma source, the experiments attempt to prove the hypothesis that some solid surfaces (like clays and meteorite rocks) may have a concentration capacity and protective role against external sources of ionizing radiation (specifically {gamma}-ray) for some organic compounds (like some amino acids) adsorbed on them. Preliminary results show a slight difference in the adsorption and radiolysis of the D-and L-alanine.

  16. Radiolysis of alanine adsorbed in a clay mineral

    International Nuclear Information System (INIS)

    Aguilar-Ovando, Ellen Y.; Negrón-Mendoza, Alicia

    2013-01-01

    Optical activity in molecules is a chemical characteristic of living beings. In this work, we examine the hypothesis of the influence of different mineral surfaces on the development of a specific chirality in organic molecules when subjected to conditions simulating the primitive Earth during the period of chemical evolution. By using X-ray diffraction techniques and HPLC/ELSD to analyze aqueous suspensions of amino acids adsorbed on minerals irradiated in different doses with a cobalt-60 gamma source, the experiments attempt to prove the hypothesis that some solid surfaces (like clays and meteorite rocks) may have a concentration capacity and protective role against external sources of ionizing radiation (specifically γ-ray) for some organic compounds (like some amino acids) adsorbed on them. Preliminary results show a slight difference in the adsorption and radiolysis of the D-and L-alanine

  17. Towards an understanding of the role of clay minerals in crude oil formation, migration and accumulation

    Science.gov (United States)

    Wu, Lin Mei; Zhou, Chun Hui; Keeling, John; Tong, Dong Shen; Yu, Wei Hua

    2012-12-01

    This article reviews progress in the understanding of the role of clay minerals in crude oil formation, migration and accumulation. Clay minerals are involved in the formation of kerogen, catalytic cracking of kerogen into petroleum hydrocarbon, the migration of crude oil, and the continued change to hydrocarbon composition in underground petroleum reservoirs. In kerogen formation, clay minerals act as catalysts and sorbents to immobilize organic matter through ligand exchange, hydrophobic interactions and cation bridges by the mechanisms of Maillard reactions, polyphenol theory, selective preservation and sorptive protection. Clay minerals also serve as catalysts in acid-catalyzed cracking of kerogen into petroleum hydrocarbon through Lewis and Brønsted acid sites on the clay surface. The amount and type of clay mineral affect the composition of the petroleum. Brønsted acidity of clay minerals is affected by the presence and state of interlayer water, and displacement of this water is a probable driver in crude oil migration from source rocks. During crude oil migration and accumulation in reservoirs, the composition of petroleum is continually modified by interaction with clay minerals. The clays continue to function as sorbents and catalysts even while they are being transformed by diagenetic processes. The detail of chemical interactions and reaction mechanisms between clay minerals and crude oil formation remains to be fully explained but promises to provide insights with broader application, including catalytic conversion of biomass as a source of sustainable energy into the future.

  18. Study of adsorption of Phenanthrene on Different Types of Clay Minerals; Estudio de Adsorcion de Fenentreno en Diferentes Tipos de Arcillas

    Energy Technology Data Exchange (ETDEWEB)

    Contreras, M L; Escolano, O; Rodriguez, V; Diaz, F J; Perez, R; Garcia, S; Garcia Frutos, F J

    2003-07-01

    The fate and behaviour of non-ionic hydrophobic organic compounds in deep soil is mainly controlled by the mineral fraction present in the soil due to the very low organic carbon content of the deep soil. The mineral fraction that may greatly influence the fate and transport of these compounds due to its presence and properties are the clay minerals. Clay mineral also become increasingly important in low organic matter content soils. There tree, studies of non-ionic hydrophobic organic compounds adsorption on clay minerals without organic matter are necessary lo better understand the fate and transport of these compounds. In this work we used phenanthrene as model compound of non-ionic hydrophobic organic compound and four pure clay minerals: kaolinite, illite, montmorillonite, and vermiculite including muscovite mica. These clays minerals are selected due to its abundance in represent ve Spanish soils and different properties as its structural layers and expanding capacity. Batch experiments were performed using phenanthrene aqueous solutions and the clays selected. Phenanthrene sorption isotherms for all clays, except muscovite mica, were best described by the Freundlich model. Physical sorption on the external surfaces is the most probable adsorption mechanisms. In this sense, the presence of non-polar nano-sites on clay surfaces could determine the adsorption of phenanthrene by hydrophobic interaction on these sites. (Author) 22 refs.

  19. [Research on characteristics of soil clay mineral evolution in paddy field and dry land by XRD spectrum].

    Science.gov (United States)

    Zhang, Zhi-dan; Li, Qiao; Luo, Xiang-li; Jiang, Hai-chao; Zheng, Qing-fu; Zhao, Lan-po; Wang, Ji-hong

    2014-08-01

    The present paper took the typical saline-alkali soil in Jilin province as study object, and determinated the soil clay mineral composition characteristics of soil in paddy field and dry land. Then XRD spectrum was used to analyze the evolutionary mechanism of clay mineral in the two kinds of soil. The results showed that the physical and chemical properties of soil in paddy field were better than those in dry land, and paddy field would promote the weathering of mineral particles in saline-alkali soil and enhance the silt content. Paddy field soil showed a strong potassium-removal process, with a higher degree of clay mineral hydration and lower degree of illite crystallinity. Analysis of XRD spectrum showed that the clay mineral composition was similar in two kinds of soil, while the intensity and position of diffraction peak showed difference. The evolution process of clay mineral in dry land was S/I mixture-->vermiculite, while in paddy field it was S/I mixture-->vermiculite-->kaolinite. One kind of hydroxylated 'chlorite' mineral would appear in saline-alkali soil in long-term cultivated paddy field. Taking into account that the physical and chemical properties of soil in paddy field were better then those in dry land, we could know that paddy field could help much improve soil structure, cultivate high-fertility soil and improve saline-alkali soil. This paper used XRD spectrum to determine the characteristics of clay minerals comprehensively, and analyzed two'kinds of land use comparatively, and was a new perspective of soil minerals study.

  20. Kinetic Study of Denatonium Sorption to Smectite Clay Minerals.

    Science.gov (United States)

    Crosson, Garry S; Sandmann, Emily

    2013-06-01

    The denatonium cation, as a benzoate salt, is the most bitter cation known to modern society and is frequently added to consumer products to reduce accidental and intentional consumption by humans and animals. Denatonium can enter the environment by accidental discharges, potentially rendering water supplies undrinkable. Interactions of denatonium with soil components ( i.e. , smectite minerals) ultimately control the environmental fate of denatonium, but the current literature is devoid of studies that evaluate denatonium sorption to smectite minerals. This study investigated the mechanism and kinetics of denatonium sorption to smectite clay minerals as a function of smectite type, temperature, pH and ionic strength. Uptake by synthetic mica montmorillonite (Syn-1), Wyoming montmorillonite (SWy-2), and Texas montmorillonite (STx-1b) at 305K was rapid, with equilibrium being reached within 2 min for all clays. Complete removal of denatonium was observed for STx-1b at pH 6.9, while partial removal was observed for Syn-1 and SWy-2. Kinetic behavior of SWy-2 and Syn-1 is consistent with a pseudo-second-order model at 305K. An activation energy of +25.9 kJ/mol was obtained for sorption to Syn-1 and was independent of temperature between 286K and 338K. Activation-free energy (Δ G *), activation enthalpy (Δ H *), and activation entropy (Δ S *) for Syn-1 were found to be +62.91 kJ/mol, +23.36 kJ/mol, and -0.130 kJ/(K·mol), respectively. Sorption capacities at pH 3.6, 6.9, and 8.2 were constant at 1.3×10 -2 g denatonium/g clay; however, the kinetic rate constant increased by 56%, going from acidic to basic solution conditions. Distribution coefficients were negatively correlated with ionic strength, suggesting cation exchange. Collectively, results suggested that smectite minerals can serve as efficient sinks for denatonium cations. This is much-needed information for agencies developing regulations regarding denatonium usage and for water treatment professionals

  1. Beyond clay - using selective extractions to improve predictions of soil carbon content

    Science.gov (United States)

    Rasmussen, C.; Berhe, A. A.; Blankinship, J. C.; Crow, S. E.; Druhan, J. L.; Heckman, K. A.; Keiluweit, M.; Lawrence, C. R.; Marin-Spiotta, E.; Plante, A. F.; Schaedel, C.; Schimel, J.; Sierra, C. A.; Thompson, A.; Wagai, R.; Wieder, W. R.

    2016-12-01

    A central component of modern soil carbon (C) models is the use of clay content to scale the relative partitioning of decomposing plant material to respiration and mineral stabilized soil C. However, numerous pedon to plot scale studies indicate that other soil mineral parameters, such as Fe- or Al-oxyhydroxide content and specific surface area, may be more effective than clay alone for predicting soil C content and stabilization. Here we directly address the following question: Are there soil physicochemical parameters that represent mineral C association and soil C content that can replace or be used in conjunction with clay content as scalars in soil C models. We explored the relationship of soil C content to a number of soil physicochemical and physiographic parameters using the National Cooperative Soil Survey database that contains horizon level data for > 62,000 pedons spanning global ecoregions and geographic areas. The data indicated significant variation in the degree of correlation among soil C, clay and Fe-/Al-oxyhydroxides with increasing moisture variability. Specifically, dry, water-limited systems (PET/MAP > 1) presented strong positive correlations between clay and soil C, that decreased significantly to little or no correlation in wet, energy-limited systems (PET/MAP soil C to oxalate extractable Al+Fe increased significantly with increasing moisture availability. This pattern was particularly well expressed for subsurface B horizons. Multivariate analyses indicated similar patterns, with clear climate and ecosystem level variation in the degree of correlation among soil C and soil physicochemical properties. The results indicate a need to modify current soil C models to incorporate additional C partitioning parameters that better account for climate and ecoregion variability in C stabilization mechanisms.

  2. Impact of clay mineral on air oxidation of PAH-contaminated soils.

    Science.gov (United States)

    Biache, Coralie; Kouadio, Olivier; Lorgeoux, Catherine; Faure, Pierre

    2014-09-01

    This work investigated the impact of a clay mineral (bentonite) on the air oxidation of the solvent extractable organic matters (EOMs) and the PAHs from contaminated soils. EOMs were isolated from two coking plant soils and mixed with silica sand or bentonite. These samples, as well as raw soils and bentonite/soil mixtures, were oxidized in air at 60 and 100 °C for 160 days. Mineralization was followed by measuring the CO2 produced over the experiments. EOM, polycyclic aromatic compound (PAC), including PAH, contents were also determined. Oxidation led to a decrease in EOM contents and PAH concentrations, these diminutions were enhanced by the presence of bentonite. Transfer of carbon from EOM to insoluble organic matter pointed out a condensation phenomenon leading to a stabilization of the contamination. Higher mineralization rates, observed during the oxidation of the soil/bentonite mixtures, seem to indicate that this clay mineral had a positive influence on the transformation of PAC into CO2.

  3. Crude oil polycyclic aromatic hydrocarbons removal via clay-microbe-oil interactions: Effect of acid activated clay minerals.

    Science.gov (United States)

    Ugochukwu, Uzochukwu C; Fialips, Claire I

    2017-07-01

    Acid treatment of clay minerals is known to modify their properties such as increase their surface area and surface acidity, making them suitable as catalysts in many chemical processes. However, the role of these surface properties during biodegradation processes of polycyclic aromatic hydrocarbons (PAHs) is only known for mild acid (0.5 M Hydrochloric acid) treated clays. Four different clay minerals were used for this study: a montmorillonite, a saponite, a palygorskite and a kaolinite. They were treated with 3 M hydrochloric acid to produce acid activated clay minerals. The role of the acid activated montmorillonite, saponite, palygorskite and kaolinite in comparison with the unmodified clay minerals in the removal of PAHs during biodegradation was investigated in microcosm experiments. The microcosm experiments contained micro-organisms, oil, and clays in aqueous medium with a hydrocarbon degrading microorganism community predominantly composed of Alcanivorax spp. Obtained results indicated that acid activated clays and unmodified kaolinite did not enhance the biodegradation of the PAHs whereas unmodified montmorillonite, palygorskite and saponite enhanced their biodegradation. In addition, unmodified palygorskite adsorbed the PAHs significantly due to its unique channel structure. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Clay mineral distribution from Bhimunipatnam to Pudimadaka along cental eastern continental shelf of India

    Digital Repository Service at National Institute of Oceanography (India)

    Reddy, N.P.C.; Rao, K.M.

    Forty eight sediment samples, collected from 50-100m depth, have been analysed for their clay mineral composition and distribution. Kaolinite with chlorite (K + C) is the predominant mineral followed by illite and montmorillonite. K + C and illite...

  5. Clay minerals trap hydrogen in the Earth's crust: Evidence from the Cigar Lake uranium deposit, Athabasca

    Science.gov (United States)

    Truche, Laurent; Joubert, Gilles; Dargent, Maxime; Martz, Pierre; Cathelineau, Michel; Rigaudier, Thomas; Quirt, David

    2018-07-01

    Hydrogen (H2)-rich fluids are observed in a wide variety of geologic settings including gas seeps in serpentinized ultramafic rocks, sub-seafloor hydrothermal vents, fracture networks in crystalline rocks from continental and oceanic crust, and volcanic gases. Natural hydrogen sources can sustain deep microbial ecosystems, induce abiotic hydrocarbons synthesis and trigger the formation of prebiotic organic compounds. However, due to its extreme mobility and small size, hydrogen is not easily trapped in the crust. If not rapidly consumed by redox reactions mediated by bacteria or suitable mineral catalysts it diffuses through the rocks and migrates toward the surface. Therefore, H2 is not supposed to accumulate in the crust. We challenge this view by demonstrating that significant amount of H2 may be adsorbed by clay minerals and remain trapped beneath the surface. Here, we report for the first time H2 content in clay-rich rocks, mainly composed of illite, chlorite, and kaolinite from the Cigar Lake uranium ore deposit (northern Saskatchewan, Canada). Thermal desorption measurements reveal that H2 is enriched up to 500 ppm (i.e. 0.25 mol kg-1 of rock) in these water-saturated rocks having a very low total organic content (reported elsewhere for pure clay minerals or shales. Sudoite (Al-Mg di-trioctahedral chlorite) is probably the main mineral responsible for H2 adsorption in the present case. The presence of multiple binding sites in interlinked nanopores between crystal layers of illite-chlorite particles offers the ideal conditions for hydrogen sorption. We demonstrate that 4 to 17% of H2 produced by water radiolysis over the 1.4-Ga-lifetime of the Cigar Lake uranium ore deposit has been trapped in the surrounding clay alteration haloes. As a result, sorption processes on layered silicates must not be overlooked as they may exert an important control on the fate and mobility of H2 in the crust. Furthermore, the high capacity of clay minerals to sorb molecular

  6. Preparation of Synthetic Zeolites from Myanmar Clay Mineral

    International Nuclear Information System (INIS)

    Phyu Phyu Win

    2004-04-01

    Faujasite type zeolite X was successfully synthesized from Myanmar clay mineral kaolinite, by treating with sodium hydroxide at 820 C followed by dissolution in water and hydrothermal treatment. It was found that the solution of fused clay powder can be crystallized at 90C under ambient pressure to synthesize faujasite type zeolite X. The effects of aging time and the amount of water on the formation of the product phase and Si/ Al ratios of the resulting products were investigated. Most of the Si and Al components in kaolinite might be dissolved into an alkaline solution and reacted to form ring-like structures. Then it was effectively transformed into zeolite materials. The maximum relative crystallinity of faujasite zeolite obtained was found to be 100%. Zeolite P was found to be a competitive phase present in some resulting products during hydrothermal treatment. The cation exchange capacity of kaolinite is very low, but increased after a proper treatment. It was found that the prepared faujasite type zeolite X, zeolite P and hydrogen zeolite (HZ) can reduce the hardness, the alkalinity, the total dissolved solid and the dissolved iron of raw water in the batch wise operation of water treatment. Therefore, it can be used as the cation exchanged resin for water treatment

  7. Quality-assured evaluation of effective porosity using fit-for-purpose estimates of clay-mineral volume fraction

    Science.gov (United States)

    Worthington, Paul F.

    2010-05-01

    Reservoirs that contain dispersed clay minerals traditionally have been evaluated petrophysically using either the effective or the total porosity system. The major weakness of the former is its reliance on "shale" volume fraction ( Vsh) as a clay-mineral indicator in the determination of effective porosity from well logs. Downhole clay-mineral indicators have usually delivered overestimates of fractional clay-mineral volume ( Vcm) because they use as a reference nearby shale beds that are often assumed to comprise clay minerals exclusively, whereas those beds also include quartzitic silts and other detritus. For this reason, effective porosity is often underestimated significantly, and this shortfall transmits to computed hydrocarbons in place and thence to estimates of ultimate recovery. The problem is overcome here by using, as proxy groundtruths, core porosities that have been upscaled to match the spatial resolutions of porosity logs. Matrix and fluid properties are established over clean intervals in the usual way. Log-derived values of Vsh are tuned so that, on average, the resulting log-derived porosities match the corresponding core porosities over an evaluation interval. In this way, Vsh is rendered fit for purpose as an indicator of clay-mineral content Vcm for purposes of evaluating effective porosity. The method is conditioned to deliver a value of effective porosity that shows overall agreement with core porosity to within the limits of uncertainty of the laboratory measurements. This is achieved through function-, reservoir- and tool-specific Vsh reduction factors that can be applied to downhole estimates of clay-mineral content over uncored intervals of similar reservoir character. As expected, the reduction factors can also vary for different measurement conditions. The reduction factors lie in the range of 0.29-0.80, which means that in its raw form, log-derived Vsh can overestimate the clay-mineral content by more than a factor of three. This

  8. Clay content evaluation in soils through GPR signal processing

    Science.gov (United States)

    Tosti, Fabio; Patriarca, Claudio; Slob, Evert; Benedetto, Andrea; Lambot, Sébastien

    2013-10-01

    The mechanical behavior of soils is partly affected by their clay content, which arises some important issues in many fields of employment, such as civil and environmental engineering, geology, and agriculture. This work focuses on pavement engineering, although the method applies to other fields of interest. Clay content in bearing courses of road pavement frequently causes damages and defects (e.g., cracks, deformations, and ruts). Therefore, the road safety and operability decreases, directly affecting the increase of expected accidents. In this study, different ground-penetrating radar (GPR) methods and techniques were used to non-destructively investigate the clay content in sub-asphalt compacted soils. Experimental layout provided the use of typical road materials, employed for road bearing courses construction. Three types of soils classified by the American Association of State Highway and Transportation Officials (AASHTO) as A1, A2, and A3 were used and adequately compacted in electrically and hydraulically isolated test boxes. Percentages of bentonite clay were gradually added, ranging from 2% to 25% by weight. Analyses were carried out for each clay content using two different GPR instruments. A pulse radar with ground-coupled antennae at 500 MHz centre frequency and a vector network analyzer spanning the 1-3 GHz frequency range were used. Signals were processed in both time and frequency domains, and the consistency of results was validated by the Rayleigh scattering method, the full-waveform inversion, and the signal picking techniques. Promising results were obtained for the detection of clay content affecting the bearing capacity of sub-asphalt layers.

  9. Importância das espécies minerais no potássio total da fração argila de solos do Triângulo Mineiro Importance of mineral species in total potassium content of clay fraction in soils of the Triângulo Mineiro, Minas Gerais State, Brazil

    Directory of Open Access Journals (Sweden)

    V. F. Melo

    2003-10-01

    arenito da Formação Uberaba, migmatito/micaxisto do Grupo Araxá e basalto da Formação Serra Geral.Few studies relate the K reserve in soils developed in a humid tropic climate with the minerals found in the clay fraction. Nineteen soils were collected for this purpose in the Triângulo Mineiro region, Minas Gerais State, Brazil, developed from different parent materials and different weathering degrees. Due to the greater occurrence, a larger number of samples of the Bauru Group was collected, comprising all the geological formations found in the region. The total K content in soil and the sand, silt, and clay fractions were determined after the digestion of the soil samples by HF, HNO3 and H2SO4. To quantify the contribution of each mineral species to the total K content, Na-saturated clay samples were submitted by a sequential and selective mineral extraction procedure, following the order: amorphous Al and Fe oxides; crystalline Fe oxides; kaolinite and gibbsite; mica and other 2:1 minerals and; feldspar and resistant minerals. The clay mineralogy composition reflects the high weathering and leaching degree in soils of the Triângulo Mineiro, with low contents of amorphous minerals, a predominant proportion of kaolinite and the presence of other secondary resistant minerals. In spite of this mineral composition, the clay fraction presented the highest total K content, mainly in the most weathered soils. Due to the high proportion of kaolinite in the clay fraction, this mineral was an important source of non-exchangeable K forms. On the other hand, the contribution of amorphous Fe and Al oxides and crystalline Fe oxides to the total K content of the clay fraction was negligible. In general, easily weathered primary minerals (mica and feldspar contributed largely to the total K of the clay fraction, principally to the youngest soils developed from the Uberaba (sandstone and Serra Geral (basalt Formations, and the Araxá Group (migmatite/micaschist.

  10. Prediction of clay content from water vapour sorption isotherms considering hysteresis and soil organic matter content

    DEFF Research Database (Denmark)

    Arthur, E.; Tuller, M.; Møldrup, Per

    2015-01-01

    Soil texture, in particular the clay fraction, governs numerous environmental, agricultural and engineering soil processes. Traditional measurement methods for clay content are laborious and impractical for large-scale soil surveys. Consequently, clay prediction models that are based on water...... within a RH range from 3 to 93%. The clay contents, which ranged between 1 and 56%, were measured with a combination of sieving and sedimentation methods. Two regression models were developed for both adsorption and desorption at 10 RH levels (5, 10, 20, 30, 40, 50, 60, 70, 80 and 90%). While the first...

  11. Preferred Orientation and Anisotropy of Clay minerals and Pores in Posidonia Shales

    Science.gov (United States)

    Kanitpanyacharoen, W.; Chen, K.; Wenk, H.

    2010-12-01

    Shales compose a large part of sedimentary basins and form the seal and source rocks for hydrocarbon reservoirs. They are also of great interest in context of repositories for nuclear waste and carbon sequestration. A comprehensive study of shale properties is thus crucial for seismic prospecting, particularly due to high elastic anisotropy that is contributed by the alignment of constituent clay minerals during compaction and diagenesis. In this study, we quantitatively analyze composition, crystal preferred orientation (or texture), and the 3D porosity structure in four Posidonia shales from Germany using high energy synchrotron x-rays. We can infer texture information from x-ray diffraction images relying on the Rietveld method, as well as determine the 3D porosity structure from tomography images. We observed that quartz and calcite are dominating phases while illite-smectite, illite-mica and kaolinite are the major clay minerals. The texture strength of clays range from 4.22 to 6.12 m.r.d. A comparison of shallow Posidonia shales with deep shales from the North Sea, Saudi Arabia, and the Gulf of Mexico documents that P-wave anisotropy increases with increasing phyllosilicate content (mainly illite-smectite and kaolinite) and increasing burial. Low absorption features in microtomography images indicate porosity (including kerogen and fractures), which is estimated at 1 vol% and observed to be anisotropic, mainly organized parallel to bedding with little connectivity of flat pores in direction perpendicular to the bedding plane.

  12. Influence of the mineral composition of clay rocks on the stability of oil wells

    International Nuclear Information System (INIS)

    Amorocho, P. R; Badillo, Juan

    2012-01-01

    In the oil companies, the operation of drilling well bore could be more expensive if the composition of the rocks is clay, the cost could increase between 10 and 15% from the starting budget. In order to decrease this problem, the oil industry has spent too much money for developing mechanisms that can provide better control and stability in clay formations during the drilling. The Society Petroleum Engineers (SPE) in some researches have published that the main chemical effects that are involved in the interaction of perforation fluids and the clay formation are: 1) chemical osmosis; and 2) hydration stresses, although, there are others like: Capillary effects, dehydration, differences in pressure and cationic exchange. These factors are not present generally in independent form. At Piedemonte Llanero the problem of the well bore stability represents a high spending of money for oil companies, caused in this region by chemical factors between fluid/rock and mechanical factors as resulted of the stresses in the area. Metil Blue Testing (MBT) and X-ray Diffraction (DR-X) were made in samples of clay; these were taken from cuts extracted of boreholes drilled in some places of the Colombian Llanos. It was found that these samples had a moderate content of reactive and low content of swell minerals.The samples main component was kaolinite, this mineral does not let the rock get swell, but it produces caving in the hole. However, it is necessary to do other tests to quantify the damages and evaluate the influence of there gime of the stress during the perforation of well bore.

  13. Removal of Phenol in Aqueous Solution Using Kaolin Mineral Clay

    International Nuclear Information System (INIS)

    Sayed, M.S.

    2008-01-01

    Kaolin clay were tested for phenol removal as toxic liquid waste from aqueous waste water. Several experimental conditions such as weight and particle size of clay were investigated to study batch kinetic techniques, also the ph and concentration of the phenol solution were carried out. The stability of the Langmuir adsorption model of the equilibrium data were studied for phenol sorbent clay system. Infrared spectra, thermogravimetric and differential thermal analysis techniques were used to characterize the behavior of kaolin clay and kaolin clay saturated with phenol. The results obtained showed that kaolin clay could be used successfully as an efficient sorbent material to remove phenol from aqueous solution

  14. Thermal Analysis: A Complementary Method to Study the Shurijeh Clay Minerals

    Directory of Open Access Journals (Sweden)

    Golnaz Jozanikohan

    2015-06-01

    Full Text Available Clay minerals are considered the most important components of clastic reservoir rock evaluation studies. The Shurijeh gas reservoir Formation, represented by shaly sandstones of the Late Jurassic-Early Cretaceous age, is the main reservoir rock in the Eastern Kopet-Dagh sedimentary Basin, NE Iran. In this study, X-ray diffraction (XRD, X-ray fluorescence (XRF, scanning electron microscopic (SEM studies, and thermal analysis including differential thermal analysis (DTA, and thermogravimetric analysis (TGA techniques were utilized in the characterization of the Shurijeh clay minerals in ten representative samples. The XRF studies showed that silica and aluminum oxides are present quantities. The XRD test was then used to determine the mineralogical composition of bulk components, as well as the clay fraction. The XRD patterns indicated the presence of dominant amount of quartz and plagioclase, with moderate to minor amounts of alkali feldspar, anhydrite, carbonates (calcite and dolomite, hematite and clay minerals. The most common clays in the Shurijeh Formation were illite, chlorite, and kaolinite. However, in very few samples, glauconite, smectite, and mixed layer clay minerals of both illite-smectite and chlorite-smectite types were also recognized. The XRD results were quantified, using the elemental information from the XRF test, showing that each Shurijeh exhibited low to moderate amounts of clay minerals, typically up to 21%. The amount of illite, the most dominant clay mineral, reached maximum of 13.5%, while the other clay types were significantly smaller. Based on the use of SEM and thermal data, the results of the identification of clay minerals, corresponded with the powder X-ray diffraction analysis, which can be taken into account as an evidence of the effectiveness of the thermal analysis technique in clay typing, as a complementary method besides the XRD.

  15. Change effects in the land use about the mineral clay

    International Nuclear Information System (INIS)

    Cespedes Payret, C.; Gutierrez, O; Panario, D.; Pineiro, G

    2012-01-01

    The Pampas land changes during the Quaternary, left their mark on the mineralogy of soil clays. This work is oriented to compare the mineralogical composition of the clays and the value of potassium in an eucalyptus forestation. These results show that the mineralogical illite alteration is the cause of its destruction. This clay is the main reservoir of potassium for the agricultural soils

  16. Studies in Finishing Effects of Clay Mineral in Polymers and Synthetic Fibers

    Directory of Open Access Journals (Sweden)

    Faheem Uddin

    2013-01-01

    Full Text Available The use of clay mineral in modifying the properties of polymeric material is improved in application. The current interest in modifying the polymeric materials, particularly polyethylene, polypropylene, polystyrene, and nylon using clay mineral for improved flame retardancy, thermal stability, peak heat release rate, fracture, and strength properties generated significant research literature. This paper aims to review some of the important recent modification achieved in the performance of polymeric materials using organoclay mineral. Degradation of clay mineral-polymer (nm composite is discussed with appropriate known examples. Clay mineral (nm loading of 5 wt.% to 7 wt.% that was significantly smaller than the percent loading of conventional fillers in polymeric materials introduced significant improvement in terms of thermal and physical stability. An attempt is made to emphasize flammability and thermal stability and to indicate the areas that are relatively little explored in modification of fiber-forming polymers to enhance further research interest.

  17. Phase transformations of pyrophyllite clay mineral after heat treatment

    International Nuclear Information System (INIS)

    Salvadori, M.C.

    1988-01-01

    The termal transformation of the Pyrophyllite clay mineral, given by the equations: AL sub(2) O sub(3).4SiO sub(2).H sub(2) O → Al sub(2) O sub(3).4SiO sub(2) + H sub(2) O Pyrophyllite Anhydride Water vapour. 3 (Al sub(2) O sub(3).4SiO sub(2)) → 3 Al sub(2) O sub(3). 2SiO sub(2) + 10 (SiO sub(2)) Pyrophyllite Anhydride Mullite Cristobalite, were studied by Transmission Electron Microscopy (TEM) associated to Selected Area Electron Diffraction (SAD), applied to a very pure sample, colected at Diamantina, M.G. Some other tgechniques were also used, as X-ray Diffraction (XRD), Differential Thermal Analysis (DTA) and Thermogravimetric Analysis (TGA), applied to other different Pyrophyllite samples. A thermodynamical theoretical study was undertaken to estimate the values for the entropyu of formation, enthalpy and molar thermal capacity for the Pyrophyllite Anhydride. (author)

  18. Redox properties of structural Fe in clay minerals: 3. Relationships between smectite redox and structural properties.

    Science.gov (United States)

    Gorski, Christopher A; Klüpfel, Laura E; Voegelin, Andreas; Sander, Michael; Hofstetter, Thomas B

    2013-01-01

    Structural Fe in clay minerals is an important redox-active species in many pristine and contaminated environments as well as in engineered systems. Understanding the extent and kinetics of redox reactions involving Fe-bearing clay minerals has been challenging due to the inability to relate structural Fe(2+)/Fe(total) fractions to fundamental redox properties, such as reduction potentials (EH). Here, we overcame this challenge by using mediated electrochemical reduction (MER) and oxidation (MEO) to characterize the fraction of redox-active structural Fe (Fe(2+)/Fe(total)) in smectites over a wide range of applied EH-values (-0.6 V to +0.6 V). We examined Fe(2+)/Fe(total )- EH relationships of four natural Fe-bearing smectites (SWy-2, SWa-1, NAu-1, NAu-2) in their native, reduced, and reoxidized states and compared our measurements with spectroscopic observations and a suite of mineralogical properties. All smectites exhibited unique Fe(2+)/Fe(total) - EH relationships, were redox active over wide EH ranges, and underwent irreversible electron transfer induced structural changes that were observable with X-ray absorption spectroscopy. Variations among the smectite Fe(2+)/Fe(total) - EH relationships correlated well with both bulk and molecular-scale properties, including Fe(total) content, layer charge, and quadrupole splitting values, suggesting that multiple structural parameters determined the redox properties of smectites. The Fe(2+)/Fe(total) - EH relationships developed for these four commonly studied clay minerals may be applied to future studies interested in relating the extent of structural Fe reduction or oxidation to EH-values.

  19. Clays as mineral dust aerosol: An integrated approach to studying climate, atmospheric chemistry, and biogeochemical effects of atmospheric clay minerals in an undergraduate research laboratory

    Science.gov (United States)

    Hatch, C. D.; Crane, C. C.; Harris, K. J.; Thompson, C. E.; Miles, M. K.; Weingold, R. M.; Bucuti, T.

    2011-12-01

    Entrained mineral dust aerosol accounts for 45% of the global annual atmospheric aerosol load and can have a significant influence on important environmental issues, including climate, atmospheric chemistry, cloud formation, biogeochemical processes, visibility, and human health. 70% of all mineral aerosol mass originating from Africa consists of layered aluminosilicates, including illite, kaolinite, and montmorillonite clays. Clay minerals are a largely neglected component of mineral aerosol, yet they have unique physiochemical properties, including a high reactive surface area, large cation exchange capacities, small particle sizes, and a relatively large capacity to take up adsorbed water, resulting in expansion of clay layers (and a larger reactive surface area for heterogeneous interactions) in some cases. An integrated laboratory research approach has been implemented at Hendrix College, a Primarily Undergraduate Institution, in which undergraduate students are involved in independent and interdisciplinary research projects that relate the chemical aging processes (heterogeneous chemistry) of clay minerals as a major component of mineral aerosol to their effects on climate (water adsorption), atmospheric chemistry (trace gas uptake), and biogeochemistry (iron dissolution and phytoplankton biomarker studies). Preliminary results and future directions will be reported.

  20. The role of clay minerals in the preservation of organic matter in sediments of Qinghai Lake, NW China

    Science.gov (United States)

    Yu, Bingsong; Dong, Hailiang; Jiang, Hongchen; Lv, Guo; Eberl, Dennis D.; Li, Shanying; Kim, Jinwook

    2009-01-01

    The role of saline lake sediments in preserving organic matter has long been recognized. In order to further understand the preservation mechanisms, the role of clay minerals was studied. Three sediment cores, 25, 57, and 500 cm long, were collected from Qinghai Lake, NW China, and dissected into multiple subsamples. Multiple techniques were employed, including density fractionation, X-ray diffraction, scanning and transmission electron microscopy (SEM and TEM), total organic carbon (TOC) and carbon compound analyses, and surface area determination. The sediments were oxic near the water-sediment interface, but became anoxic at depth. The clay mineral content was as much as 36.8%, consisting mostly of illite, chlorite, and halloysite. The TEM observations revealed that organic matter occurred primarily as organic matter-clay mineral aggregates. The TOC and clay mineral abundances are greatest in the mid-density fraction, with a positive correlation between the TOC and mineral surface area. The TOC of the bulk sediments ranges from 1 to 3% with the non-hydrocarbon fraction being predominant, followed by bitumen, saturated hydrocarbon, aromatic hydrocarbons, and chloroform-soluble bitumen. The bimodal distribution of carbon compounds of the saturated hydrocarbon fraction suggests that organic matter in the sediments was derived from two sources: terrestrial plants and microorganisms/algae. Depthrelated systematic changes in the distribution patterns of the carbon compounds suggest that the oxidizing conditions and microbial abundance near the water-sediment interface promote degradation of labile organic matter, probably in adsorbed form. The reducing conditions and small microbial biomass deeper in the sediments favor preservation of organic matter, because of the less labile nature of organic matter, probably occurring within clay mineral-organic matter aggregates that are inaccessible to microorganisms. These results have important implications for our

  1. Radiation-induced catalysis of fatty acids adsorbed onto clay minerals

    International Nuclear Information System (INIS)

    Negron-Mendoza, A.; Ramos-Bernal, S.; Colin-Garcia, M.; Mosqueira, F.G.

    2015-01-01

    We studied the behavior of small fatty (acetic acid) and dicarboxylic acids (succinic and malonic acids) adsorbed onto Na + -montmorillonite (a clay mineral) and exposed to gamma radiation. A decarboxylation reaction was found to predominate when the clay was present. This preferential synthesis promoted the formation of a compound with one less carbon atom than its target compound. In the system without clay, dimerization was the predominate outcome following radiolysis. (author)

  2. Characterization of sands and mineral clays in channel and floodplain deposits of Portuguesa river, Venezuela

    Directory of Open Access Journals (Sweden)

    Orlando José González Clemente

    2013-11-01

    Full Text Available In the main channel and floodplain of Portuguesa River were studied the mineralogical characteristics of sand and clay minerals respectively. The methodology consisted of X-ray diffraction (XRD analysis, for both mineral fractions. The results indicated the presence of mainly of quartz sands with minor amounts of chlorite, muscovite, calcite and feldspar which are considered quartz sand mature. Its origin is related to the source area and rework of soils and sediments of the floodplain. The clay fraction is characterized by the presence of 13 mineral crystalline phases consisting mainly of quartz, muscovite and chlorite, and clay minerals such as kaolinite, vermiculite, montmorillonite and nontronita. Its detrital origin may be due to mineral neoformation and inheritance. Therefore both mineral fractions consist mainly of quartz and kaolinite, which are essential components of the source area as well as the Quaternary alluvial deposits and the soils that make up the region.

  3. Synthesis and characterization of carbon nanotubes on clay minerals and its application to a hydrogen peroxide biosensor

    International Nuclear Information System (INIS)

    Hsu, H.-L.; Jehng, J.-M.

    2009-01-01

    In this study, we demonstrate the synthesis of carbon nanotubes (CNTs) on clay minerals, and the development of biosensors based on Nafion-CNT/Clay-Au and Nafion-CNT/Clay-Au-Glucose oxidase (GOD) composite films for the detection of hydrogen peroxide (H 2 O 2 ) and glucose, respectively. The CNTs are synthesized on nickel cation exchanged clay mineral platelets. From field-emission scanning electron microscope images, X-ray diffraction, Fourier transfer infrared and thermogravimetric analysis results, the clay layers are exfoliated and delaminated after the growth of CNTs on them. The mixed hybrid film of Nafion, CNT/Clay, Au particles and GOD is coated on the glassy carbon (GC) electrode to detect H 2 O 2 or glucose. This film exhibits a detection limit of 5.0 x 10 -5 M for H 2 O 2 with a sensitivity of 280 nA mM -1 . In addition, the amperometric response for glucose containing 2.0 mg mL -1 GOD in the Nafion-CNT/Clay-Au-GOD modified GC electrode exhibits a sensitivity of 620 nA mM -1 with a linear range up to 1850 μM. A higher sensitivity and shorter response time are observed with increasing GOD content in the composite matrix film. Besides, the highest sensitivity of 2032 nA mM -1 is obtained with the addition of the 10.0 mg mL -1 GOD in the composite film. Consequently, the CNT/Clay/Nafion medium can probably be a useful electrode for the development of sensors due to its high sensitivity and applicability

  4. Clay minerals as palaeoenvironment indicators exemplified on a Karoo sequence from the Bothaville area, South Africa

    International Nuclear Information System (INIS)

    Buehmann, C.; Buehmann, D.

    1990-01-01

    The whole-rock and clay mineral composition of 74 samples from a 184 m borehole core from the Ecca Group and Dwyka Formation from the vicinity of Bothaville, 100 km southwest of Johannesburg, South Africa, has been determined by means of X-ray diffractometry. The objective was to establish the salinity and pH of the water of the original environments of deposition. The sediment investigated was subjected to a low degree of diagenesis. Clay mineral associations display characteristic variations while distinctive vertical trends in kaolinite occurrence have been established. Mineralogical trends are ascribed to fundamental changes, which must have existed in the pore fluid composition during deposition (palaeoenvironment setting) which have been maintained through the early stages of diagenesis. Conditions were alkaline-marine during the Dwyka and in the lower section of the Vryheid Formation, as indicated by the dominance of 2:1 layer silicates. From the middle section of the Vryheid Formation the entire brackish water mixing range is recorded mineralogically by kaolinite contents which increase progressively at the cost of 2:1 layer silicates. Acid-freshwater conditions, characterised by the dominance of kaolinite are interpreted for the upper section of the Vryheid Formation. 26 refs., 6 figs., 2 tabs

  5. The acid solubility test of clay mineral under microwave

    International Nuclear Information System (INIS)

    Zheng Ying; Niu Yuqing; Wu Peisheng; Niu Xuejun

    2001-01-01

    The acid solubility test of Al 3+ in clay from some uranium ores under microwave is introduced. The result shows that the concentration of Al 3+ in solution and the acid consumption increase rapidly under microwave comparing with normal leaching condition. It is infeasible to adopt microwave slacking method for intensively leaching uranium from uranium ore containing more clay

  6. Simulation of the long term alteration of clay minerals in engineered bentonite barriers: nucleation and growth of secondary clay particles

    International Nuclear Information System (INIS)

    Fritz, B.; Clement, A.; Zwingmann, H.; Noguera, C.

    2010-01-01

    Document available in extended abstract form only. The long term stability of clay rich rocks used as barriers to the migration of radionuclides in the environment of nuclear wastes has been intensively studied, looking at the geochemical interactions between clay minerals and aqueous solutions. These studies combine experimental approaches for the short term and numerical modellings for the long term extrapolations, in the frame of the research supported by ANDRA in the French design for High Level Waste (HLW) repository. The main objective of the geochemical numerical tools devoted to clay-solutions interaction processes was to predict the feed-back effects of mineralogical and chemical transformations of clay mineral, in repository conditions as defined by Andra, on their physical and transport properties (porosity, molecular diffusion, permeability). The 1D transport-reaction coupled simulation was done using the code KIRMAT, at 100 deg. C for 100000 years. The fluid considered is that of the Callovo-Oxfordian geological formation (COX) and assumed to diffuse into the clay barrier from one side. On the other side, ferrous iron, is provided by the steel overpack corrosion. Under these conditions, montmorillonite of the clay barrier is only partially transformed into illite, chlorite, and saponite. The simulation shows that only outer parts of the clay barrier is significantly modified, mainly at the interface with the geological environment. These modifications correspond to a closure of the porosity, followed by a decrease of mass transport by molecular diffusion. Near the COX, the swelling pressure of the clays from the barrier is predicted to decrease, but in its major part, the engineered barrier seems to keep its initial physical properties (porosity, molecular diffusion, permeability, swelling pressure). In this modelling approach, the very important role of secondary clay minerals has to be taken into account with relevant kinetic rate laws; particularly

  7. Effect of organic matter properties, clay mineral type and thermal maturity on gas adsorption in organic-rich shale systems

    Science.gov (United States)

    Zhang, Tongwei; Ellis, Geoffrey S.; Ruppel, Stephen C.; Milliken, Kitty; Lewan, Mike; Sun, Xun; Baez, Luis; Beeney, Ken; Sonnenberg, Steve

    2013-01-01

    A series of CH4 adsorption experiments on natural organic-rich shales, isolated kerogen, clay-rich rocks, and artificially matured Woodford Shale samples were conducted under dry conditions. Our results indicate that physisorption is a dominant process for CH4 sorption, both on organic-rich shales and clay minerals. The Brunauer–Emmett–Teller (BET) surface area of the investigated samples is linearly correlated with the CH4 sorption capacity in both organic-rich shales and clay-rich rocks. The presence of organic matter is a primary control on gas adsorption in shale-gas systems, and the gas-sorption capacity is determined by total organic carbon (TOC) content, organic-matter type, and thermal maturity. A large number of nanopores, in the 2–50 nm size range, were created during organic-matter thermal decomposition, and they significantly contributed to the surface area. Consequently, methane-sorption capacity increases with increasing thermal maturity due to the presence of nanopores produced during organic-matter decomposition. Furthermore, CH4 sorption on clay minerals is mainly controlled by the type of clay mineral present. In terms of relative CH4 sorption capacity: montmorillonite ≫ illite – smectite mixed layer > kaolinite > chlorite > illite. The effect of rock properties (organic matter content, type, maturity, and clay minerals) on CH4 adsorption can be quantified with the heat of adsorption and the standard entropy, which are determined from adsorption isotherms at different temperatures. For clay-mineral rich rocks, the heat of adsorption (q) ranges from 9.4 to 16.6 kJ/mol. These values are considerably smaller than those for CH4 adsorption on kerogen (21.9–28 kJ/mol) and organic-rich shales (15.1–18.4 kJ/mol). The standard entropy (Δs°) ranges from -64.8 to -79.5 J/mol/K for clay minerals, -68.1 to -111.3 J/mol/K for kerogen, and -76.0 to -84.6 J/mol/K for organic-rich shales. The affinity of CH4 molecules for sorption on organic matter

  8. Plutonium content in uranium minerals

    International Nuclear Information System (INIS)

    Garzon Ruiperez, L.

    1975-01-01

    Starting from a ore model constituted by a uniformily dispersed UO 2 into a granite matrix, the Pu/U ratio as a function of UO 2 concentration in the ore have been deduced. The calculated values are roughly one or two orders of magnitude less than the experimental ones carried out in several types of ores. However, taking into account the H content in the matrix (as a water component) the obtained values agree satisfactorili with the experimental ones. (author) [es

  9. Correlation of index tests with smectite content determined with XRD in bentonite and smectite rich clays

    International Nuclear Information System (INIS)

    Kumpulainen, Sirpa; Kiviranta, Leena; Korkeakoski, Petri

    2012-01-01

    Document available in extended abstract form only. Various index tests are used by bentonite producers and users to assess the amount of swelling minerals in bentonites and smectite rich clays. Index tests are meant to provide relative fast and inexpensive way of testing the amount of swelling minerals, and their performance should not require sophisticated equipment. Such index tests are e.g. methylene blue absorption test, liquid limit and swelling index test (free swelling). In order to select appropriate index test to control the quality of buffer and backfill materials to be used in nuclear waste end disposal in Finland, results from various index tests were correlated with the smectite content determined with XRD and Rietveld refinement. Tests evaluated were: water absorption capacity (WAC) based on DIN 18132, swelling index (SI) based on ASTM D 5890-06, cation exchange capacity (CEC) based on Cu(II)-trien adsorption by Meier and Kahr (1999) and Ammann et al. (2005), liquid limit (LL) based on CEN ISO/TS 17892- 12:2004, methylene blue absorption (MB) based on SFS-EN 933-9, and specific surface area based on absorption of ethylene glycol monoethyl ether (EGME) described by Cerato and Lutenegger (2002). The number of samples tested was 6-25 (exact number of samples was dependent on the test method), and included natural Na-bentonites, natural Ca-bentonites, sodium activated Ca-bentonites and smectite rich clays from Wyoming/USA, Milos/Greece, Gujarat/India and Friedland/Germany. Smectite content in samples was determined after Kiviranta and Kumpulainen (2011) by x-ray diffraction (XRD), optical microscopy, chemical analyses, and full-pattern fitting with the Rietveld method using Siroquant software. Exchangeable cation composition was determined after Belyayeva (1967) and Jackson (1975). In order to achieve correlation of index test results with smectite content, water absorption capacity, liquid limit, and swelling index methods required additional information

  10. Adsorption of zinc and lead on clay minerals

    Directory of Open Access Journals (Sweden)

    Katarína Jablonovská

    2006-12-01

    Full Text Available Clays (especially bentonite, zeolite and quartz sand are widely used as landfill barriers to prevent contamination of subsoil and groundwater by leachates containing heavy metals. The sorption of zinc and lead on these clays was studied as a function of time and it was found that the initial 1 h our was sufficient to exchange most of the metal ions. The retention efficiency of clay samples of Zn2+ and Pb2+ follows the order of bentonite > zeolite> quartz sand. Whatever the clay sample, lead is retained more than zinc. The concentration of elements in the solution was followed by atomic adsorption spectrofotometry. Bacillus cereus and Bacillus pumilus, previously isolated from the kaoline deposit Horna Prievrana was added into the clay samples to comparise the accumulation of Zn2+ and Pb2+ from the model solution. The study of heavy metal adsorption capacity of bacteria- enriched clay adsorbent showed a high retention efficiency for lead ions as comparised with zinc ions. Biosorption is considered a potential instrument for the removal of metals from waste solutions and for the precious metals recovery as an alternative to the conventional processes.

  11. Influence of non-clay minerals on the interaction between metallic iron and Callovo-Oxfordian clay fraction

    International Nuclear Information System (INIS)

    Rivard, C.; Pelletier, M.; Villieras, F.; Michau, N.

    2012-01-01

    Document available in extended abstract form only. In the context of the geological disposal of high-level radioactive waste, it is of prime importance to understand the interaction mechanisms between the geological matrix, Callovo-Oxfordian clay rock (COx) and metallic iron, from the package overpack. In order to evidence the individual role of each clay component entering in the mineralogy of the COx, interactions between metallic iron and pure clays (smectites, illite and kaolinite) were first conducted. To investigate the role of the other minerals, the reactivity of COx, COx clay fraction (COxCF) and mixtures between COxCF and quartz, calcite or pyrite, was studied. Clays and additional minerals were put in contact with powder metallic iron with a weight ratio iron:clay fixed at 1:3 and a clay:solution ratio of 1:20. Proportions of non-clay minerals were deduced from the average COx composition: 50% clays, 24.5% quartz, 24.5% calcite and 1% pyrite. Batch experiments were carried out in anoxic conditions at 90 deg. C in the presence of background electrolyte (NaCl 0.02 M.L -1 , CaCl 2 0.04 M.L -1 ) in Parr reactors for durations of one, three or nine months. After reaction, solid and liquid phases were separated by centrifugation and characterized by classical techniques combining chemical analyses (liquid analyses, transmission electron microscopy combined with Energy Dispersive of X-rays spectroscopy TEM-EDS), mineralogical (X-ray diffraction), spectroscopic ( 57 Fe Moessbauer) and morphometric techniques (TEM, scanning electron microscopy and N 2 adsorption). For COx, COxCF and all the pure clay phases, major evolutions were observed during the first month, which shows that the oxidation of metallic iron is rapid in our experimental conditions. Release of iron cations in solution, pH increase (8-10) and Eh decrease (reductive conditions) are responsible for the partial dissolution of initial clay phases. Released iron is involved in the crystallization of Fe

  12. Estimation of bitumen and clay content in fine tailings

    International Nuclear Information System (INIS)

    Motta Cabrera, S.C.; Bryan, J.; Kantzas, A.

    2007-01-01

    Fine tailings are the components of tailings ponds and the by-product of the oil sand extraction process, consisting mostly of water with small amounts of bitumen, sand, silts and clays. Because of the large volumes of tailings, an important environmental and production process issue involves the reduction of the remaining bitumen in the tailings stream. This paper presented the results of a study that used low field nuclear magnetic resonance (NMR) in order to estimate the bitumen, clay and water content of synthetic tailings samples. NMR is a non-destructive technique that is utilized to determine compositions of oil and brine emulsions and the viscosity of heavy oil and bitumen as well as in reservoir characterization, measuring properties such as permeability, porosity, mobile and immobile fluids, and fluid saturations. The study prepared and tested numerous samples with variable water, bitumen, sand and clay concentrations in the NMR tool under ambient conditions. Two qualities of water and bitumen were used to prepare the synthetic samples. Each type of water and bitumen was analyzed as a single substance and in a mixture with the typical solids found in tailings composition. These included kaolinite, illite, sodium montmorillonite and sand. These synthetic samples were analyzed using different mixing configurations, as a function of time and in two different NMR tools. It was concluded that NMR is a potential application for on-line determination of tailings streams composition. 18 refs., 3 tabs., 17 figs

  13. Reconstruction of late Quaternary monsoon oscillations based on clay mineral proxies using sediment cores from the western margin of India

    Digital Repository Service at National Institute of Oceanography (India)

    Thamban, M.; Rao, V.P.; Schneider, R.R.

    sites were from the hinterland rocks and soils. Careful evaluations of several factors that could complicate the clay distribution in marine environment indicate that the clay mineral parameters can be used as proxies for the intensity of summer monsoon...

  14. Distribution of clay minerals in marine sediments off Chennai, Bay of Bengal, India: Indicators of sediment sources and transport processes .

    Digital Repository Service at National Institute of Oceanography (India)

    Veerasingam, S.; Venkatachalapathy, R.; Ramkumar, T.

    Clay mineralogy, texture size and statistical analyses were carried out on surface sediments from the continental shelf of Chennai, Bay of Bengal, India. The purpose of this study is to characterize the clay mineral distribution and its relation...

  15. Ground Truthing Orbital Clay Mineral Observations with the APXS Onboard Mars Exploration Rover Opportunity

    Science.gov (United States)

    Schroeder, C.; Gellert, R.; VanBommel, S.; Clark, B. C.; Ming, D. W.; Mittlefehldt, D. S.; Yen, A. S.

    2016-01-01

    NASA's Mars Exploration Rover Opportunity has been exploring approximately 22 km diameter Endeavour crater since 2011. Its rim segments predate the Hesperian-age Burns formation and expose Noachian-age material, which is associated with orbital Fe3+-Mg-rich clay mineral observations [1,2]. Moving to an orders of magnitude smaller instrumental field of view on the ground, the clay minerals were challenging to pinpoint on the basis of geochemical data because they appear to be the result of near-isochemical weathering of the local bedrock [3,4]. However, the APXS revealed a more complex mineral story as fracture fills and so-called red zones appear to contain more Al-rich clay minerals [5,6], which had not been observed from orbit. These observations are important to constrain clay mineral formation processes. More detail will be added as Opportunity is heading into her 10th extended mission, during which she will investigate Noachian bedrock that predates Endeavour crater, study sedimentary rocks inside Endeavour crater, and explore a fluid-carved gully. ESA's ExoMars rover will land on Noachian-age Oxia Planum where abundant Fe3+-Mg-rich clay minerals have been observed from orbit, but the story will undoubtedly become more complex once seen from the ground.

  16. Use of thermogravimetry on rational analysis of clay minerals from state of Mato Grosso do Sul

    International Nuclear Information System (INIS)

    Salvetti, Alfredo Roque; Rodrigues, Henrique Mauro

    1997-01-01

    The rational analysis on clay minerals, normally uses as structural water, the mass loss by firing. The presence of organic materials, sulphur or others minerals, can cause an error on quantification of structural water. With the use of thermal gravimetric analysis, we can calculate, in a more precise way, the quantity of mass loss by dehydroxylation, without take into account the loss of mass from others process. We compared the rational chemical analysis on some clay minerals from state of Mato Grosso do Sul using burning loss and thermal gravimetric analysis. (author)

  17. Molecular Basis of Clay Mineral Structure and Dynamics in Subsurface Engineering Applications

    Science.gov (United States)

    Cygan, R. T.

    2015-12-01

    Clay minerals and their interfaces play an essential role in many geochemical, environmental, and subsurface engineering applications. Adsorption, dissolution, precipitation, nucleation, and growth mechanisms, in particular, are controlled by the interplay of structure, thermodynamics, kinetics, and transport at clay mineral-water interfaces. Molecular details of these processes are typically beyond the sensitivity of experimental and analytical methods, and therefore require accurate models and simulations. Also, basal surfaces and interlayers of clay minerals provide constrained interfacial environments to facilitate the evaluation of these complex processes. We have developed and used classical molecular and quantum methods to examine the complex behavior of clay mineral-water interfaces and dynamics of interlayer species. Bulk structures, swelling behavior, diffusion, and adsorption processes are evaluated and compared to experimental and spectroscopic findings. Analysis of adsorption mechanisms of radionuclides on clay minerals provides a scientific basis for predicting the suitability of engineered barriers associated with nuclear waste repositories and the fate of contaminants in the environment. Similarly, the injection of supercritical carbon dioxide into geological reservoirs—to mitigate the impact of climate change—is evaluated by molecular models of multi-fluid interactions with clay minerals. Molecular dynamics simulations provide insights into the wettability of different fluids—water, electrolyte solutions, and supercritical carbon dioxide—on clay surfaces, and which ultimately affects capillary fluid flow and the integrity of shale caprocks. This work is supported as part of Center for Frontiers of Subsurface Energy Security, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science and by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, Geosciences Research Program

  18. Clay mineral formation under oxidized conditions and implications for paleoenvironments and organic preservation on Mars.

    Science.gov (United States)

    Gainey, Seth R; Hausrath, Elisabeth M; Adcock, Christopher T; Tschauner, Oliver; Hurowitz, Joel A; Ehlmann, Bethany L; Xiao, Yuming; Bartlett, Courtney L

    2017-11-01

    Clay mineral-bearing locations have been targeted for martian exploration as potentially habitable environments and as possible repositories for the preservation of organic matter. Although organic matter has been detected at Gale Crater, Mars, its concentrations are lower than expected from meteoritic and indigenous igneous and hydrothermal reduced carbon. We conducted synthesis experiments motivated by the hypothesis that some clay mineral formation may have occurred under oxidized conditions conducive to the destruction of organics. Previous work has suggested that anoxic and/or reducing conditions are needed to synthesize the Fe-rich clay mineral nontronite at low temperatures. In contrast, our experiments demonstrated the rapid formation of Fe-rich clay minerals of variable crystallinity from aqueous Fe 3+ with small amounts of aqueous Mg 2+ . Our results suggest that Fe-rich clay minerals such as nontronite can form rapidly under oxidized conditions, which could help explain low concentrations of organics within some smectite-containing rocks or sediments on Mars.

  19. Clay mineral formation under oxidized conditions and implications for paleoenvironments and organic preservation on Mars

    Energy Technology Data Exchange (ETDEWEB)

    Gainey, Seth R.; Hausrath, Elisabeth M.; Adcock, Christopher T.; Tschauner, Oliver; Hurowitz, Joel A.; Ehlmann, Bethany L.; Xiao, Yuming; Bartlett, Courtney L. (CIW); (UNLV); (CIT); (SBU)

    2017-11-01

    Clay mineral-bearing locations have been targeted for martian exploration as potentially habitable environments and as possible repositories for the preservation of organic matter. Although organic matter has been detected at Gale Crater, Mars, its concentrations are lower than expected from meteoritic and indigenous igneous and hydrothermal reduced carbon. We conducted synthesis experiments motivated by the hypothesis that some clay mineral formation may have occurred under oxidized conditions conducive to the destruction of organics. Previous work has suggested that anoxic and/or reducing conditions are needed to synthesize the Fe-rich clay mineral nontronite at low temperatures. In contrast, our experiments demonstrated the rapid formation of Fe-rich clay minerals of variable crystallinity from aqueous Fe3+ with small amounts of aqueous Mg2+. Our results suggest that Fe-rich clay minerals such as nontronite can form rapidly under oxidized conditions, which could help explain low concentrations of organics within some smectite-containing rocks or sediments on Mars.

  20. Contact angles at the water-air interface of hydrocarbon-contaminated soils and clay minerals

    Science.gov (United States)

    Sofinskaya, O. A.; Kosterin, A. V.; Kosterina, E. A.

    2016-12-01

    Contact angles at the water-air interface have been measured for triturated preparations of clays and soils in order to assess changes in their hydrophobic properties under the effect of oil hydrocarbons. Tasks have been to determine the dynamics of contact angle under soil wetting conditions and to reveal the effect of chemical removal of organic matter from soils on the hydrophilicity of preparations. The potentialities of static and dynamic drop tests for assessing the hydrophilic-hydrophobic properties of soils have been estimated. Clays (kaolinite, gumbrine, and argillite) have been investigated, as well as plow horizons of soils from the Republic of Tatarstan: heavy loamy leached chernozem, medium loamy dark gray forest soil, and light loamy soddy-calcareous soil. The soils have been contaminated with raw oil and kerosene at rates of 0.1-3 wt %. In the uncontaminated and contaminated chernozem, capillary water capacity has been maintained for 250 days. The contact angles have been found to depend on the degree of dispersion of powdered preparation, the main type of clay minerals in the soil, the presence and amount of oxidation-resistant soil organic matter, and the soil-water contact time. Characteristic parameters of mathematical models for drop behavior on triturated preparations have been calculated. Contamination with hydrocarbons has resulted in a reliable increase in the contact angles of soil preparations. The hydrophobization of soil surface in chernozem is more active than in soils poorer in organic matter. The complete restoration of the hydrophilic properties of soils after hydrocarbon contamination is due to the oxidation of easily oxidizable organic matter at the low content of humus, or to wetting during several months in the absence of the mazut fraction.

  1. Characterization of Heat-treated Clay Minerals in the Context of Nuclear Waste Disposal

    Science.gov (United States)

    Matteo, E. N.; Wang, Y.; Kruichak, J. N.; Mills, M. M.

    2015-12-01

    Clay minerals are likely candidates to aid in nuclear waste isolation due to their low permeability, favorable swelling properties, and high cation sorption capacities. Establishing the thermal limit for clay minerals in a nuclear waste repository is a potentially important component of repository design, as flexibility of the heat load within the repository can have a major impact on the selection of repository design. For example, the thermal limit plays a critical role in the time that waste packages would need to cool before being transferred to the repository. Understanding the chemical and physical changes, if any, that occur in clay minerals at various temperatures above the current thermal limit (of 100 °C) can enable decision-makers with information critical to evaluating the potential trade-offs of increasing the thermal limit within the repository. Most critical is gaining understanding of how varying thermal conditions in the repository will impact radionuclide sorption and transport in clay materials either as engineered barriers or as disposal media. A variety of repository-relevant clay minerals (illite, mixed layer illite/smectite, and montmorillonite), were heated for a range of temperatures between 100-1000 °C. These samples were characterized to determine surface area, mineralogical alteration, and cation exchange capacity (CEC). Our results show that for conditions up to 500 °C, no significant change occurs, so long as the clay mineral remains mineralogically intact. At temperatures above 500 °C, transformation of the layered silicates into silica phases leads to alteration that impacts important clay characteristics. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's Nation Nuclear Security Administration under contract DE-AC04-94AL85000. SAND Number: SAND2015-6524 A

  2. Bioremediation of PAHs and VOCs: Advances in clay mineral-microbial interaction.

    Science.gov (United States)

    Biswas, Bhabananda; Sarkar, Binoy; Rusmin, Ruhaida; Naidu, Ravi

    2015-12-01

    Bioremediation is an effective strategy for cleaning up organic contaminants, such as polycyclic aromatic hydrocarbons (PAHs) and volatile organic compounds (VOCs). Advanced bioremediation implies that biotic agents are more efficient in degrading the contaminants completely. Bioremediation by microbial degradation is often employed and to make this process efficient, natural and cost-effective materials can serve as supportive matrices. Clay/modified clay minerals are effective adsorbents of PAHs/VOCs, and readily available substrate and habitat for microorganisms in the natural soil and sediment. However, the mechanism underpinning clay-mediated biodegradation of organic compounds is often unclear, and this requires critical investigation. This review describes the role of clay/modified clay minerals in hydrocarbon bioremediation through interaction with microbial agents in specific scenarios. The vision is on a faster, more efficient and cost-effective bioremediation technique using clay-based products. This review also proposes future research directions in the field of clay modulated microbial degradation of hydrocarbons. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Clay mineralogical studies on Bijawars of the Sonrai Basin: palaeoenvironmental implications and inferences on the uranium mineralization

    International Nuclear Information System (INIS)

    Jha, Surendra Kumar; Shrivastava, J.P.; Bhairam, C.L.

    2012-01-01

    Clays associated with the Precambrian unconformity-related (sensu lato) uranium mineralization that occur along fractures of Rohini carbonate, Bandai sandstone and clay-organic rich black carbonaceous Gorakalan shale of the Sonrai Formation from Bijawar Group is significant. Nature and structural complexity of these clays have been studied to understand depositional mechanism and palaeoenvironmental conditions responsible for the restricted enrichment of uranium in the Sonrai basin. Clays ( chlorite> illite > smectite mineral assemblages, whereas, Solda Formation contains kaolinite > illite > chlorite clays. It has been found that the former mineral assemblage resulted from the alteration process is associated with the uranium mineralization and follow progressive reaction series, indicating palaeoenvironmental (cycles of tropical humid to semi-arid/arid) changes prevailed during maturation of the Sonrai basin. The hydrothermal activity possibly associated with Kurrat volcanics is accountable for the clay mineral alterations

  4. Exploring biotic vs. abiotic controls on syngenetic carbonate and clay mineral precipitation

    Science.gov (United States)

    Nascimento, Gabriela S.; McKenzie, Judith A.; Martinez Ruiz, Francisca; Bontognali, Tomaso R. R.; Vasconcelos, Crisogono

    2016-04-01

    A possible syngenetic relationship between carbonate and clay mineral precipitation has been reported for sedimentary rocks deposited in both lacustrine and marine sedimentary environments throughout the geological record. In particular, the mineral dolomite is often found associated with Mg-rich clays, such as stevensite. It is notable that this carbonate/clay association has been recorded in numerous samples taken from modern dolomite precipitating environments; for example, the Coorong lakes, South Australia, coastal sabkhas, Abu Dhabi, UAE and coastal hypersaline lagoons (Lagoa Vermelha and Brejo do Espinho) east of Rio de Janeiro, Brazil. An HRTEM study of samples from these three locations indicates a possible physical/chemical association between the Ca-dolomite and Mg-rich clays, demonstrating a probable co-precipitation. To test this hypothesis, we have conducted a series of biotic and abiotic laboratory experiments. If this syngenesis actually occurs in nature, what, if any, are the biogeochemical processes controlling these precipitation reactions? Our experiments were designed to determine the extent of the biotic versus abiotic component influencing the mineral precipitation and, in the case of a biotic influence, to understand the mechanism through which microorganisms might mediate the formation of clay minerals. The experiments were carried out in the Geomicrobiology Laboratory of ETH Zürich using cultures of living microbes and artificial organic compounds that simulate functional groups present in natural biofilms formed under both aerobic and anaerobic conditions. In addition, pure inorganic experiments were designed to understand possible physico-chemical conditions for diagenetic processes that could induce dissolution of Mg-carbonates and precipitation of Mg-rich clays. Our results show a remarkable biotic influence during the formation of clay minerals. Specifically, extracellular polymeric substances (EPS), released by microbes in their

  5. Investigation of mineral composition of differently treated devonian, quaternary and triassic clays of Latvia

    International Nuclear Information System (INIS)

    Kosorukovs, A.; Viss, R.

    1999-01-01

    Clayey fractions (particle size less than 5 μm )of the Latvian Devonian (Kuprava and Liepa deposits), Quaternary (Laza and Ugale deposits) and Triassic (Akmene deposit, Republic of Lithuania) clays have been obtained. The clayey fractions were converted in the form in which all the cations were exchanged for magnesium ions. After the ion exchange the fractions were treated with dimethyl sulfoxide or glycerol in the course for two days, one sample being subjected to thermal treatment at 550±110 C for two hours. Diffractograms for the treated samples have been obtained using a DRON-2,0 diffractometer (Co-radiation). Analysis of the obtained diffractograms show that: 1) the main clayey minerals of the Devonian clays occur to be hydromicas (mainly hydromuscovite) containing admixtures of kaolinite and quartz; 2) the main clayey minerals of the Quarternary clays also occur to be hydromicas - mixtures of hydrobiotite and hydromuscovite containing admixtures of kaolinite and iron-containing chlorite; 3) smectite occurs to be the main mineral of the Triassic clay; it contains admixtures of hydromica and chlorite; 4) the Triassic and Quaternary clays contain fine- and coarse-grained carbonates, mainly calcite, in quantities of 10-16%; 5) iron and titanium are included in fine grained minerals. (author)

  6. Mineral potential of clays that cover the gypsum deposits in Araripina-PE region

    International Nuclear Information System (INIS)

    Lira, B.B.; Anjos, I.F. dos; Rego, S.A.B.C.

    2011-01-01

    In the present work the applicability of the clays that cover the deposits of Gypsum Plaster in the region of Araripina - PE for use as the ceramic pigments and for bricks production in the red ceramic industry was analyzed. The clay minerals contained the illite, kaolinite and smectite, with high proportion of the last one. The possibility of industrial application of this mineral clay is considerable; however, the mining industries that mine and process the gypsum in the region do not take the clays into account as the potential mineral. In general, industries use the clay minerals in manufacturing processes or as key raw materials, or as the alternatives for some kinds of the chemical processing industries. This paper aims to highlight the potential of materials that cover the deposits of gypsum in reference. The material sampled from different deposit layers was characterized and the physical treatment of ore was applied. The results showed that the material analyzed can be used in various kinds of industry, such as the production of natural ceramic pigments. (author)

  7. Atom exchange between aqueous Fe(II) and structural Fe in clay minerals.

    Science.gov (United States)

    Neumann, Anke; Wu, Lingling; Li, Weiqiang; Beard, Brian L; Johnson, Clark M; Rosso, Kevin M; Frierdich, Andrew J; Scherer, Michelle M

    2015-03-03

    Due to their stability toward reductive dissolution, Fe-bearing clay minerals are viewed as a renewable source of Fe redox activity in diverse environments. Recent findings of interfacial electron transfer between aqueous Fe(II) and structural Fe in clay minerals and electron conduction in octahedral sheets of nontronite, however, raise the question whether Fe interaction with clay minerals is more dynamic than previously thought. Here, we use an enriched isotope tracer approach to simultaneously trace Fe atom movement from the aqueous phase to the solid ((57)Fe) and from the solid into the aqueous phase ((56)Fe). Over 6 months, we observed a significant decrease in aqueous (57)Fe isotope fraction, with a fast initial decrease which slowed after 3 days and stabilized after about 50 days. For the aqueous (56)Fe isotope fraction, we observed a similar but opposite trend, indicating that Fe atom movement had occurred in both directions: from the aqueous phase into the solid and from the solid into aqueous phase. We calculated that 5-20% of structural Fe in clay minerals NAu-1, NAu-2, and SWa-1 exchanged with aqueous Fe(II), which significantly exceeds the Fe atom layer exposed directly to solution. Calculations based on electron-hopping rates in nontronite suggest that the bulk conduction mechanism previously demonstrated for hematite1 and suggested as an explanation for the significant Fe atom exchange observed in goethite2 may be a plausible mechanism for Fe atom exchange in Fe-bearing clay minerals. Our finding of 5-20% Fe atom exchange in clay minerals indicates that we need to rethink how Fe mobility affects the macroscopic properties of Fe-bearing phyllosilicates and its role in Fe biogeochemical cycling, as well as its use in a variety of engineered applications, such as landfill liners and nuclear repositories.

  8. In-situ nanoscale imaging of clay minerals with atomic force microscopy

    International Nuclear Information System (INIS)

    Bosbach, D.

    2010-01-01

    Document available in extended abstract form only. Clay minerals play a key role in many concepts for high-level nuclear waste repository systems in deep geological formations. Various aspects related to the long-term safety of nuclear disposal are linked to their fundamental physical-chemical properties, in particular with respect to their reactivity in aqueous environments. Atomic Force Microscopy (AFM) allows high resolution imaging of clay minerals in-situ while they are exposed to an aqueous solution. The presentation is intended to provide an overview of examples of AFM studies on clay minerals: 1. AFM is an ideal tool to visualize the shape of individual clay particles down to molecular scales including a quantitative description of for example their aspect ratio. Furthermore, the particle size can be easily extracted from AFM data for individual particles as well as particle size distribution. 2. Surface area of clay minerals is a key issue when discussing heterogeneous reactions such as dissolution, adsorption or (surface) precipitation - total surface area, BET surface area, reactive surface area need to be distinguished. In particular reactive surface area is linked to specific reactive surface sites. AFM is of course able to identify such sites and consequently AFM data allow to characterize and to quantify reactive surface area. 3. The reactivity of clay mineral surfaces in aqueous environments controls the behaviour of clay minerals under repository conditions and also affects the migration/retention of radionuclides. It could be shown that the dissolution of smectite particles under acidic conditions at room temperature primarily occurs at (hk0) particle edges, whereas the reactivity of the (001) basal surfaces is very limited. The heterogeneous (surface) precipitation of secondary iron (hydr)oxides phase could be unraveled by AFM observations. Surface precipitation occurs preferentially at (hk0) edges surfaces. Ignoring the surface site specific

  9. Mineral content prediction for unconventional oil and gas reservoirs based on logging data

    Science.gov (United States)

    Maojin, Tan; Youlong, Zou; Guoyue

    2012-09-01

    Coal bed methane and shale oil &gas are both important unconventional oil and gas resources, whose reservoirs are typical non-linear with complex and various mineral components, and the logging data interpretation model are difficult to establish for calculate the mineral contents, and the empirical formula cannot be constructed due to various mineral. The radial basis function (RBF) network analysis is a new method developed in recent years; the technique can generate smooth continuous function of several variables to approximate the unknown forward model. Firstly, the basic principles of the RBF is discussed including net construct and base function, and the network training is given in detail the adjacent clustering algorithm specific process. Multi-mineral content for coal bed methane and shale oil &gas, using the RBF interpolation method to achieve a number of well logging data to predict the mineral component contents; then, for coal-bed methane reservoir parameters prediction, the RBF method is used to realized some mineral contents calculation such as ash, volatile matter, carbon content, which achieves a mapping from various logging data to multimineral. To shale gas reservoirs, the RBF method can be used to predict the clay content, quartz content, feldspar content, carbonate content and pyrite content. Various tests in coalbed and gas shale show the method is effective and applicable for mineral component contents prediction

  10. Role of clay minerals in the formation of atmospheric aggregates of Saharan dust

    Science.gov (United States)

    Cuadros, Javier; Diaz-Hernandez, José L.; Sanchez-Navas, Antonio; Garcia-Casco, Antonio

    2015-11-01

    Saharan dust can travel long distances in different directions across the Atlantic and Europe, sometimes in episodes of high dust concentration. In recent years it has been discovered that Saharan dust aerosols can aggregate into large, approximately spherical particles of up to 100 μm generated within raindrops that then evaporate, so that the aggregate deposition takes place most times in dry conditions. These aerosol aggregates are an interesting phenomenon resulting from the interaction of mineral aerosols and atmospheric conditions. They have been termed "iberulites" due to their discovery and description from aerosol deposits in the Iberian Peninsula. Here, these aggregates are further investigated, in particular the role of the clay minerals in the aggregation process of aerosol particles. Iberulites, and common aerosol particles for reference, were studied from the following periods or single dust events and locations: June 1998 in Tenerife, Canary Islands; June 2001 to August 2002, Granada, Spain; 13-20 August 2012, Granada; and 1-6 June 2014, Granada. Their mineralogy, chemistry and texture were analysed using X-ray diffraction, electron microprobe analysis, SEM and TEM. The mineral composition and structure of the iberulites consists of quartz, carbonate and feldspar grains surrounded by a matrix of clay minerals (illite, smectite and kaolinite) that also surrounds the entire aggregate. Minor phases, also distributed homogenously within the iberulites, are sulfates and Fe oxides. Clays are apparently more abundant in the iberulites than in the total aerosol deposit, suggesting that iberulite formation concentrates clays. Details of the structure and composition of iberulites differ from descriptions of previous samples, which indicates dependence on dust sources and atmospheric conditions, possibly including anthropic activity. Iberulites are formed by coalescence of aerosol mineral particles captured by precursor water droplets. The concentration of

  11. Influence of clay minerals on curcumin properties: Stability and singlet oxygen generation

    Science.gov (United States)

    Gonçalves, Joyce L. S.; Valandro, Silvano R.; Poli, Alessandra L.; Schmitt, Carla C.

    2017-09-01

    Curcumin (CUR) has showed promising photophysical properties regarding to biological and chemical sciences. However, the main barrier for those applications are their low solubility and stability in aqueous solution. The effects of two different clay minerals, the montmorillonite (SWy-2) and the Laponite RD (Lap) nanoclay, on the stabilization of Curcumin were investigated. Their effects were compared with two well-established environments (acidic and neutral aqueous media). CUR/clay hybrids were prepared using a simple and fast method, where CUR solution was added into clay suspensions, to obtain well dispersed hybrids in water. The degradation process of CUR and CUR/clays hybrids was investigated using UV-Vis spectroscopic. For both studied hybrids, the CUR degradation process was suppressed by the presence of the clay particles. Furthermore, the Lap showed a great stabilization effect than SWy-2. This behavior was due to the smaller particle size and higher exfoliation ability of Lap, providing a large surface for CUR adsorption compared to SWy-2. The degradation process of CUR solutions and CUR/clay hybrids was also studied in the presence of light. CUR photodegradation process was faster not only in the aqueous solution but also in the clay suspension compared to those studied in the dark. The presence of clay particles accelerated the photodegradation of CUR due to the products formation in the reactions between CUR and oxygen radicals. Our results showed that the singlet oxygen quantum yield (ΦΔ) of CUR were about 59% higher in the clay suspensions than CUR in aqueous solution. Therefore, the formation of CUR/clay hybrids, in particularly with Lap, suppressed the degradation in absence light of CUR and increased the singlet oxygen generation, which makes this hybrids of CUR/clay a promising material to enlarge the application of CUR in the biological sciences.

  12. Climatic control on clay mineral formation: Evidence from ...

    Indian Academy of Sciences (India)

    are the most important factors that determine kinetics of chemical weathering. Mineral alteration ... perature, pressure and microbial activity. Among various factors ... physical factor) and rainfall (a chemical factor). (Velde 1992, p. 118).

  13. Rheological properties of different minerals and clay soils

    Directory of Open Access Journals (Sweden)

    Dolgor Khaydapova

    2015-07-01

    Full Text Available Rheological properties of kaolinite, montmorillonite, ferralitic soil of the humid subtropics (Norfolk island, southwest of Oceania, alluvial clay soil of arid subtropics (Konyaprovince, Turkey and carbonate loess loam of Russian forest-steppe zone were determined. A parallel plate rheometer MCR-302 (Anton Paar, Austria was used in order to conduct amplitude sweep test. Rheological properties allow to assess quantitatively structural bonds and estimate structural resistance to a mechanical impact. Measurements were carried out on samples previously pounded and capillary humidified during 24 hours. In the amplitude sweep method an analyzed sample was placed between two plates. The upper plate makes oscillating motions with gradually extending amplitude. Software of the device allows to receive several rheological parameters such as elastic modulus (G’, Pa, viscosity modulus (G", Pa, linear viscoelasticity range (G’>>G”, and point of destruction of structure at which the elastic modulus becomes equal to the viscosity modulus (G’=G”- crossover. It was found out that in the elastic behavior at G '>> G " strength of structural links of kaolinite, alluvial clay soil and loess loam constituted one order of 105 Pa. Montmorillonit had a minimum strength - 104 Pa and ferrallitic soil of Norfolk island [has] - a maximum one -106 Pa. At the same time montmorillonite and ferralitic soil were characterized by the greatest plasticity. Destruction of their structure (G '= G" took place only in the cases when strain was reaching 11-12%. Destraction of the kaolinite structure happened at 5% of deformation and of the alluvial clay soil and loess loam - at 4.5%.

  14. Molecular dynamics of interfacial water and cations associated with clay minerals

    International Nuclear Information System (INIS)

    Cygan, Randall T.; Greathouse, Jeffery A.; Teich-McGoldrick, Stephanie L.; Nenoff, Tina M.; Daemen, Luke L.

    2012-01-01

    Document available in extended abstract form only. Clay mineral interfaces, including interlayer and external surfaces, play an essential role in many geochemical processes. Adsorption, dissolution, precipitation, nucleation, and growth mechanisms, in particular, are controlled by the interplay of structure, thermodynamics, kinetics, and transport at clay mineral-water interfaces. Molecular details of these geochemical processes are especially important in evaluating the fate of radionuclide waste in the environment. Such details are typically beyond the sensitivity of experimental and analytical methods and therefore require accurate models and simulations. Also, the basal surfaces and interlayers of clay minerals offer structurally constrained interfacial environments to better evaluate the local molecular chemistry. We have developed and used classical and quantum methods to examine the complex behavior of clay mineral-water interfaces and dynamics of interlayer species. Bulk structures, swelling behavior, diffusion, and adsorption processes are evaluated and compared to experimental and spectroscopic findings. In particular, inelastic neutron scattering methods provide a successful probe of vibrational behavior of interlayer species to help guide the simulations. Librations involving rock, wag, and twist motions of water molecules are particularly sensitive to the interlayer environment of smectite minerals such as montmorillonite and beidellite. Trends in librational modes for interlayer water as a function of clay structure and cation hydration energy are readily explained using structural and vibrational analysis derived from molecular simulation. Molecular dynamics simulations of virtual phases, including hydrated pyrophyllite, help to explain the behavior of interlayer water that is not associated with cation species. Additionally, we use large-scale molecular dynamics simulations of other layered minerals, such as muscovite, to evaluate adsorption

  15. Treatment and conditioning of radioactive waste solution by natural clay minerals

    International Nuclear Information System (INIS)

    El-Dessouky, M.I.; El-Massry, E.H.; Khalifa, S.M.; Aly, H.F.

    1999-01-01

    Natural inorganic exchangers. Was used to remove caesium, cobalt and europium using zinc sulfate as coagulant also different clay minerals. These calys include, feldrspare, aswanly, bentionite, hematite, mud, calcite, basalt, magnetite, kaoline sand stone, limonite and sand. The factros affecting the removal process namely PH, particle size, temperature and weight of the clay have been studied. Highest removal for Cs-137, Co-60 and Eu-152 and 154 was achived by asswanly and bentonite. Sand stone is more effective than the other clays. Removal of Cs-137 from low level waste solution is in the order the sequence, aswanly (85.5%)> bentonite (82.2%)> sandstone (65.4%). Solidified cement products have been evaluated to determine optimum conditions of mixing most sludges contained clays by testing mechanical strength and leaching rates of the waste products. The solidified waste forms were found more acceptable for handing, storage and ultimate disposal

  16. Degradative crystal–chemical transformations of clay minerals under the influence of cyanobacterium-actinomycetal symbiotic associations

    Directory of Open Access Journals (Sweden)

    Ekaterina Ivanova

    2014-04-01

    Full Text Available Cyanobacteria and actinomycetes are essential components of soil microbial community and play an active role in ash elements leaching from minerals of the parent rock. Content and composition of clay minerals in soil determine the sorption properties of the soil horizons, water-holding capacity of the soil, stickiness, plasticity, etc. The transformative effect of cyanobacterial–actinomycetes associations on the structure of clay minerals – kaolinite, vermiculite, montmorillonite, biotite and muscovite – was observed, with the greatest structural lattice transformation revealed under the influence of association in comparison with monocultures of cyanobacterium and actinomycete. The range of the transformative effect depended both on the type of biota (component composition of association and on the crystal–chemical parameters of the mineral itself (trioctahedral mica – biotite, was more prone to microbial degradation than the dioctahedral – muscovite. The formation of the swelling phase – the product of biotite transformation into the mica–vermicullite mixed-layered formation was revealed as a result of association cultivation. Crystal chemical transformation of vermiculite was accompanied by the removal of potassium (К, magnesium (Mg and aluminum (Al from the crystal lattice. The study of such prokaryotic communities existed even in the early stages of the Earth's history helps to understand the causes and nature of the transformations undergone by the atmosphere, hydrosphere and lithosphere of the planet.contribution of treatments on structure induces and model parameters are discussed in the paper.

  17. Selenium containing clays minerals as additive for the discoloration of glass

    NARCIS (Netherlands)

    Timmer, K.; Limpt, J.A.C. van; Fischer, H.R.

    2010-01-01

    While selenium is applied as decolorizing agent for flint container glass or tableware glass, the retention of selenium in glass however is very low. Generally more than 75% of the total selenium input sublimes from the glass melt and leaves the clay minerals due to the high volatility of

  18. THE STUDYING OF COLLOIDAL-CHEMICAL PROPERTIES OF CLAY MINERALS DISPERSIONS

    Directory of Open Access Journals (Sweden)

    A. F. Tymchuk

    2015-02-01

    Full Text Available The element structure is studied, the microscopic analysis of fine-dispersed min­eral systems (ground sediments of a mouth of the river Danube is carried out. The sedimentation process of clay minerals dispersions in solutions of surfactants and macromolecular substances is studied. Concentration intervals of stabilization of investigating dispersions were defined.

  19. Sedimentological and clay mineral studies in Kakinada Bay, east coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Reddy, N.P.C.; Rao, K.M.

    are of sandy sediments (2.9 to 3.05 phi). Interrelationships of size statistical parameters and the CM diagram of the bay sediments suggest a mechanism of slow deposition from quiet water. Montmorillonite is the predominant clay mineral followed by kaolinite...

  20. Modeling selenate adsorption behavior on oxides, clay minerals, and soils using the triple layer model

    Science.gov (United States)

    Selenate adsorption behavior was investigated on amorphous aluminum oxide, amorphous iron oxide, goethite, clay minerals: kaolinites, montmorillonites, illite, and 18 soil samples from Hawaii, and the Southwestern and the Midwestern regions of the US as a function of solution pH. Selenate adsorpti...

  1. Clay mineral distribution in the continental shelf and slope off Saurashtra, West coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Rao, V.P.

    Clay mineral distribution in the sediments of the west coast of India indicates that the illite and chlorite-rich sediments, derived from the Indus, occupy the continental shelf of the northern part of the Gulf of Kutch. Montmorillonite derived from...

  2. Influence of clay and surfactant content in non-aqueous fluid rheology

    International Nuclear Information System (INIS)

    Guedes, I.C.; Gomes, N.L.; Menezes, R.R.; Campos, L.F.A.; Ferreira, H.S.

    2012-01-01

    The bentonite clay used as viscosity agent in the production of non-aqueous fluids cannot be used without organic treatment for their surfaces to become hydrophobic. These clays are called organophilic clays, and are generally obtained by adding, in an aqueous way, ionic or a nonionic surfactant. Recent studies of the variables involved in the dispersion of bentonite clays and in the process of organophilization, showed their lack of influence. This work aims to study the influence of clay content and surfactants on the rheology of nonaqueous fluids. To this end, the clays were treats and characterized, evidencing the incorporation of the surfactant, and then formulated non-aqueous fluids, following PETROBRAS standards, being possible to verify the influence of clay content and surfactant both from the point of view as the characterizing and rheological behavior. (author)

  3. Enhancement of the glass corrosion in the presence of clay minerals: testing experimental results with an integrated glass dissolution model

    International Nuclear Information System (INIS)

    Godon, N.; Vernaz, E.Y.

    1992-01-01

    Recent glass dissolution experiments, conducted at 90 deg C in the presence of potential backfill materials, indicate remarkably faster glass corrosion in the presence of clay, compared to tests where the glass is leached either alone or with alternative backfill materials. This effect correlates with the clay content in the backfill, and may be attributed to the removal of silica from solution. Scorpion, or dissolution with reprecipitation of a silica-rich clay, have been proposed as possible mechanisms for the silica consumption. The results of some experiments have been tested against a glass dissolution model, in which a widely used kinetic equation for glass corrosion is coupled with diffusive silica transport through a single porosity, linearly sorbing medium, which represents the backfilling. Because the glass corrosion rates imposed by the kinetic equation are inversely proportional to the silicic acid concentration of the leachant contacting the glass, the model predicts enhanced glass dissolution if silica is sorbed by the porous medium. The experimental data proved to be consistent with the predicted enhancement of the glass dissolution. Moreover, the model-estimated distribution coefficients for silica sorption (K d ) fall within the range of values extracted from available literature data, thus supporting the hypothesis that the observed high corrosion rates are due to sorption of silica on the clay mineral surfaces. (author)

  4. Geotechnical properties of Karwar marine clay

    Digital Repository Service at National Institute of Oceanography (India)

    Bhat, S.T.; Nayak, B.U.; Naik, R.L.

    Karwar marine clay possesses high plasticity characteristics with natural water content higher than the liquid limit. Liquidity index was as high as 1.7. Predominant clay mineral was kaolinite. Undrained shear strength showed an increasing trend...

  5. Experiments on the reduction of radiocesium in pigs by adding clay minerals to the contaminated feed

    International Nuclear Information System (INIS)

    Holdt, C.S.

    1987-05-01

    For some time now clay minerals are used as feed additives in animal production but are even discussed lately as a possibility of decontamination of radiocesium in the living animal because of their ion exchange property. The nuclear accident of Chernobyl in April 1986 induced the Austrian government to set radioactivity limits for contamination with Cs-137 and 134. For pork the total of 5nCi Cs-137 and 134/kg was set which proved to be a problem for pig fattening when fed on whey and concentrate. The aim of this study was to see if the addition of clays to the animal feed can reduce the cesium content in the meat. After 3 short-term-trials with the total amount of 21 animals one long-term pig-fattening experiment with 40 animals was conducted. For 70 days their feed contained fallout Cs in form of dried whey. The control group was fed the normal ration, for test group 1 bentonite and for test group 2 bolus alba were mixed into the concentrate in amounts corresponding to 5%. After administering fallout-Cs for 70 days 5 animals of each group were slaughtered and the Cs-activity specified in leg, butt, neck, liver, kidney and blood. With exception of the liver the mean values of the control group reached higher levels than 5nCi Cs-137 and 134, test group 2 showed the same tendency in the leg. Test group 1 proved satisfactorily with all mean values well beyond the limit with highly significant response. Feeding the remaining animals with uncontaminated rations of feed it could be demonstrated that bentonite decreases the biological half-life of cesium. 52 refs., 10 figs., 26 tabs

  6. Comparison studies adsorption of thorium and uranium on pure clay minerals and local Malaysian soil sediments

    International Nuclear Information System (INIS)

    Syed, H.S.

    1999-01-01

    Adsorption studies of thorium and uranium radionuclides on 9 different pure clay minerals and 4 local Malaysian soil sediments were conducted. Solution containing dissolved thorium and uranium at pH 4.90 was prepared from concentrate sludges from a long term storage facility at a local mineral processing plant. The sludges are considered as low level radioactive wastes. The results indicated that the 9 clay minerals adsorbed more uranium than thorium at pH ranges from 3.74 to 5.74. Two local Malaysian soils were observed to adsorb relatively high concentration of both radionuclides at pH 3.79 to 3.91. The adsorption value 23.27 to 27.04 ppm for uranium and 33.1 to 50.18 ppm for thorium indicated that both soil sediments can be considered as potential enhanced barrier material for sites disposing conditioned wastes containing uranium and thorium. (author)

  7. Influence of composition of the raw materials on phase formation in solid compounds based on slag and clay minerals

    International Nuclear Information System (INIS)

    Galkin, A.V.; Tolebaev, T.; Omarova, V.I.; Burkitbaev, M.; Blynskiy, A.P.; Bachilova, N.V.; Matsynina, V.I.

    2003-01-01

    Full text: Activation of solidification processes in a compound formed on the basis of slag and clay minerals using sodium hydroxide - the output product from processing the BN-350 sodium coolant it is expedient to form the final product with a phase composition representing (in terms of long term storage) hydro-alumino-silicates incorporating Na-22 and Cs-137 radionuclides, which isomorphly replace other atoms in the crystal lattice sites. Combination of mineral phases, such as alkaline and alkaline-earth hydro-alumino-silicates with zeolite-like structure, providing sorptive properties, and the tobermorite like low-base hydro silicates of calcium defining the physico-mechanical properties of compound is the necessary condition for the compound stability. Investigations of phase formation in the mixtures of Kazakhstan clay, slag materials and alkali have been conducted targeted to control the physico-chemical properties of solid compound. The mixtures of alkali, thermal power plant ashes and clays of various mineralogical genesis (kaolinite, bentonite, Ca-Na-smectite montmorillonite) have been studied. The ashes and phosphorous slag while interacting with alkali are determined to form the non-alkaline hydro-silicates of stavrolite and indianite (anortite) type with free alkali being found in an unbound state. Both alkaline and alkaline-alkaline-earth hydro-silicates of Na 2 Ca 2 Si 2 O 7 H 2 O type are only formed in a compounds containing metallurgical slag. Formation of alkaline hydro-alumino-silicates of NaAlSiO 4 H 2 0 type as well as tomsonite (Na 4 Ca 8 [Al 20S i 20 O 80 ] 24H 2 O) - the zeolite like mineral have been detected in a two-component alkali-clay mixtures. Besides the quantity of tomsonite was determined to be not only dependent on Al 2 O 3 content in clay component but is also defined by stoichiometric composition of the mixture, because zeolite synthesis takes place under conditions of gels co-deposition and high pH value. Maximum quantity of

  8. Bone mineral content measurement by bone mineral analyzer

    International Nuclear Information System (INIS)

    Yamamoto, Itsuo; Dokoh, Shigeharu; Fukunaga, Masao; Torizuka, Kanji; Kosaka, Tadako.

    1976-01-01

    With a bone mineral analyzer (Studsvik Bone Scanner 7102), bone mineral content (BMC) was validated using various concentrations of standard CaCO 3 . Seventy-five normal subjects, nineteen patients with rheumathoid arthritis (RA) and twenty-two patients with abnormal thyroid function were investigated by this method. Some inherent problems concerning the present measurements were also discussed. Reproducibility of BMC in sixteen normal subjects during a four months interval was +-4% on the mid-shaft of the radius and +-5% on the distal head of the radius, respectively. Although correlation of the single energy method and the dual energy method with the bone scanner was high (r=0.970), the single energy method was probably underestimated due to the fat layer. BMC in normal subjects was highest in 30th and 40th decades for both males and females, and gradually decreased with aging. Males had higher BMC and BMC/bone width than did females. All of the stage 1 group of RA patients, according to roentgenographic staging, revealed normal BMC, but most of stage 2 and 3 groups had abnormally low BMC, suggesting that progression of the disease may be an important factor in BMC values. The BMC of hyperthyroid patients was low, whereas that of euthyroid patients was normal. Serial measurements of BMC in a hyperparathyroid patient and a hyperthyroid patient revealed distinct recurrence of BMC after treatment. (Evans, J.)

  9. Influence of the clay content and drying of successive no solvents change in the morphology of polyamide 6 / clay membranes

    International Nuclear Information System (INIS)

    Pereira, C.H.; Ferreira, R.S.B.; Bezerra, E.B.; Leite, A.M.D.; Araujo, E.D.; Lira, H.L.

    2014-01-01

    Membranes of polyamide 6/clay nanocomposites with different contents (1 and 3%) of Brazilian bentonite clay using the technique of phase inversion was obtained. The nanocomposites were obtained in a co-rotating twin screw extruder, by the melt intercalation method and were characterized by x-ray diffraction (XRD), which showed possibly an exfoliated and / or partially exfoliated structure was obtained. The membranes were dried at room temperature and also by successive exchange of non-solvents, to prevent collapse the pores using ethanol and n-hexane as a non-solvent. From the photomicrographs of top surface by scanning electron microscopy (SEM) showed to morphology change in the membranes from the presence of different clay contents as well as drying the same by successive exchange of non-solvents, obtaining membranes with larger amount of pores uniformly distributed. (author)

  10. Adsorption of Dissolved Gases (CH4, CO2, H2, Noble Gases) by Water-Saturated Smectite Clay Minerals

    Science.gov (United States)

    Bourg, I. C.; Gadikota, G.; Dazas, B.

    2016-12-01

    Adsorption of dissolved gases by water-saturated clay minerals plays important roles in a range of fields. For example, gas adsorption in on clay minerals may significantly impact the formation of CH4 hydrates in fine-grained sediments, the behavior of CH4 in shale, CO2 leakage across caprocks of geologic CO2 sequestration sites, H2 leakage across engineered clay barriers of high-level radioactive waste repositories, and noble gas geochemistry reconstructions of hydrocarbon migration in the subsurface. Despite its importance, the adsorption of gases on clay minerals remains poorly understood. For example, some studies have suggested that clay surfaces promote the formation of CH4 hydrates, whereas others indicate that clay surfaces inhibit the formation of CH4 hydrates. Here, we present molecular dynamics (MD) simulations of the adsorption of a range of gases (CH4, CO2, H2, noble gases) on clay mineral surfaces. Our results indicate that the affinity of dissolved gases for clay mineral surfaces has a non-monotone dependence on the hydrated radius of the gas molecules. This non-monotone dependence arises from a combination of two effects: the polar nature of certain gas molecules (in particular, CO2) and the templating of interfacial water structure by the clay basal surface, which results in the presence of interfacial water "cages" of optimal size for intermediate-size gas molecules (such as Ne or Ar).

  11. Clay mineral association in the salt formation of the Transylvanian Basin and its paleoenvironmental significance

    Directory of Open Access Journals (Sweden)

    Nicoleta Bican-Bris̡an

    2006-04-01

    Full Text Available The investigated clay fraction was separated from salt samples recovered from three boreholes located in the Praid salt deposit area. For comparison, samples collected from Turda deposit (Franz Josef adit, the Rudolf and Ghizele chambers and from the salt massif from Sărăţel were also analyzed. The qualitative investigations evidenced a clay minerals association dominated by illite and chlorite accompanied by subordinate amounts of kaolinite, smectite, fibrous clays (sepiolite, palygorskite, and in minor amounts, by 14/14 chlorite/vermiculite and chlorite/smectite interstratifications. A quantitative evaluation (% including a standard graphical representation was performed only for the borehole samples (Praid, according to the vertical distribution. The genetical interpretation of the identified clay minerals association took into account the influence of the sedimentation mechanisms and the climate control on the mineral phases. The environment of formation for the salt in the Transylvanian Basin was defined by the presence of specific climatic factors, also suggested by the palynological investigations.

  12. Clay mineral distribution and provenance in the Heuksan mud belt, Yellow Sea

    Science.gov (United States)

    Cho, Hyen Goo; Kim, Soon-Oh; Kwak, Kyeong Yoon; Choi, Hunsoo; Khim, Boo-Keun

    2015-12-01

    The Heuksan mud belt (HMB), located in the southeastern Yellow Sea, runs parallel to the southwest coast of Korea. In this study, the distribution and relative contribution of four major clay minerals are investigated using 101 surface sediment samples collected in the course of KIOST (2001, 2010, 2011) and KIGAM (2012) cruises, as well as 33 river sediment samples (four from the Huanghe River, three from the Changjiang River, and 26 from Korean rivers) in order to clarify the provenance of fine-grained sediments in the HMB. Based on this currently largest and most robust dataset available for interpretation, the clay mineral assemblages of the fine-grained sediments in the HMB are found to be on average composed of 64.7% illite, 17.9% chlorite, 11.4% kaolinite, and 5.9% smectite. Overall, the clay mineral assemblages are similar in both the northern and the southern parts of the HMB, although smectite seems to be relatively enriched in the southern part, whereas kaolinite is slightly more dominant in the northern part. This clearly indicates that the clays are mostly derived from Korean rivers and, in the southern part of the HMB, partly also from the Huanghe River in China. The new data thus confirm and strengthen the tentative interpretation of some earlier work based on a more limited dataset.

  13. Modified clay minerals efficiency against chemical and biological warfare agents for civil human protection.

    Science.gov (United States)

    Plachá, Daniela; Rosenbergová, Kateřina; Slabotínský, Jiří; Kutláková, Kateřina Mamulová; Studentová, Soňa; Martynková, Gražyna Simha

    2014-04-30

    Sorption efficiencies of modified montmorillonite and vermiculite of their mono ionic Na and organic HDTMA and HDP forms were studied against chemical and biological warfare agents such as yperite and selected bacterial strains. Yperite interactions with modified clay minerals were observed through its capture in low-density polyethylene foil-modified clay composites by measuring yperite gas permeation with using chemical indication and gas chromatography methods. The antibacterial activities of synthetized organoclays were tested against selected Gram-positive and Gram-negative bacterial species in minimum inhibitory concentration tests. The obtained results showed a positive influence of modified clay minerals on the significant yperite breakthrough-time increase. The most effective material was the polyethylene-Na form montmorillonite, while the polyethylene-Na form vermiculite showed the lowest efficiency. With increasing organic cations loading in the interlayer space the montmorillonite efficiency decreased, and in the case of vermiculite an opposite effect was observed. Generally the modified montmorillonites were more effective than modified vermiculites. The HDP cations seem to be more effective compare to the HDTMA. The antibacterial activity tests confirmed efficiency of all organically modified clay minerals against Gram-positive bacteria. The confirmation of antibacterial activity against Y. pestis, plague bacteria, is the most interesting result of this part of the study. Copyright © 2014 Elsevier B.V. All rights reserved.

  14. Water-mineral interaction in hygromechanics of clays exposed to environmental loads

    International Nuclear Information System (INIS)

    Hueckel, T.A.

    1992-01-01

    Water-mineral interaction in narrow interstices (<3 nm) in dense, saturated clays is discussed in view of recent experimental findings and molecular dynamics simulations. Consequences to the macroscopic behavior are considered. A mixture theory for two interacting constituents is developed. Effects of temperature and chemicals are discussed. A postulate of mass transfer of absorbed water from solid to fluid fraction caused by thermal or chemical load is then discussed. Theory of plasticity of clays affected by heat or chemicals is developed to deal with the effects of thermal and chemical consolidation

  15. Clay minerals, metallic oxides and oxy-hydroxides and soil organic carbon distribution within soil aggregates in temperate forest soils

    Science.gov (United States)

    Gartzia-Bengoetxea, Nahia; Fernández-Ugalde, Oihane; Virto, Iñigo; Arias-González, Ander

    2017-04-01

    Soil mineralogy is of primary importance for key environmental services provided by soils like carbon sequestration. However, current knowledge on the effects of clay mineralogy on soil organic carbon (SOC) stabilization is based on limited and conflicting data. In this study, we investigated the relationship between clay minerals, metallic oxides and oxy-hydroxides and SOC distribution within soil aggregates in mature Pinus radiata D.Don forest plantations. Nine forest stands located in the same geographical area of the Basque Country (North of Spain) were selected. These stands were planted on different parent material (3 on each of the following: sandstone, basalt and trachyte). There were no significant differences in climate and forest management among them. Moreover, soils under these plantations presented similar content of clay particles. We determined bulk SOC storage, clay mineralogy, the content of Fe-Si-Al-oxides and oxyhydroxides and the distribution of organic C in different soil aggregate sizes at different soil depths (0-5 cm and 5-20 cm). The relationship between SOC and abiotic factors was investigated using a factor analysis (PCA) followed by stepwise regression analysis. Soils developed on sandstone showed significantly lower concentration of SOC (29 g C kg-1) than soils developed on basalts (97 g C kg-1) and trachytes (119 g C kg-1). The soils on sandstone presented a mixed clay mineralogy dominated by illite, with lesser amounts of hydroxivermiculite, hydrobiotite and kaolinite, and a total absence of interstratified chlorite/vermiculite. In contrast, the major crystalline clay mineral identified in the soils developed on volcanic rocks was interstratified chlorite/vermiculite. Nevertheless, no major differences were observed between basaltic and trachytic soils in the clay mineralogy. The selective extraction of Fe showed that the oxalate extractable iron was significantly lower in soils on sandstone (3.7%) than on basalts (11.2%) and

  16. Oxygen isotope fractionation effects in soil water via interaction with cations (Mg, Ca, K, Na) adsorbed to phyllosilicate clay minerals

    Science.gov (United States)

    Oerter, Erik; Finstad, Kari; Schaefer, Justin; Goldsmith, Gregory R.; Dawson, Todd; Amundson, Ronald

    2014-07-01

    In isotope-enabled hydrology, soil and vadose zone sediments have been generally considered to be isotopically inert with respect to the water they host. This is inconsistent with knowledge that clay particles possessing an electronegative surface charge and resulting cation exchange capacity (CEC) interact with a wide range of solutes which, in the absence of clays, have been shown to exhibit δ18O isotope effects that vary in relation to the ionic strength of the solutions. To investigate the isotope effects caused by high CEC clays in mineral-water systems, we created a series of monominerallic-water mixtures at gravimetric water contents ranging from 5% to 32%, consisting of pure deionized water of known isotopic composition with homoionic (Mg, Ca, Na, K) montmorillonite. Similar mixtures were also created with quartz to determine the isotope effect of non-, or very minimally-, charged mineral surfaces. The δ18O value of the water in these monominerallic soil analogs was then measured by isotope ratio mass spectrometry (IRMS) after direct headspace CO2 equilibration. Mg- and Ca-exchanged homoionic montmorillonite depleted measured δ18O values up to 1.55‰ relative to pure water at 5% water content, declining to 0.49‰ depletion at 30% water content. K-montmorillonite enriched measured δ18O values up to 0.86‰ at 5% water content, declining to 0.11‰ enrichment at 30% water. Na-montmorillonite produces no measureable isotope effect. The isotope effects observed in these experiments may be present in natural, high-clay soils and sediments. These findings have relevance to the interpretation of results of direct CO2-water equilibration approaches to the measurement of the δ18O value of soil water. The adsorbed cation isotope effect may bear consideration in studies of pedogenic carbonate, plant-soil water use and soil-atmosphere interaction. Finally, the observed isotope effects may prove useful as molecular scale probes of the nature of mineral

  17. Evaluation of mineral kaolinite present in portuguese clays for use in porcelain stoneware; Avaliacao do mineral caulinita presente em argilas portuguesas para uso em gres porcelanato

    Energy Technology Data Exchange (ETDEWEB)

    Luna da Silveira, G.C. [Instituto Federal do Rio Grande do Norte (IFRN), RN (Brazil); Acchar, W.; Gomes, U.U.; Luna da Silveira, R.V. [Universidade Federal do Rio Grnde do Norte (UFRN), RN (Brazil); Labrincha, A.; Miranda, C.M.P., E-mail: glebacoelli@hotmail.com [Universidade de Aveiro (Portugal)

    2016-07-01

    Kaolinite is a mineral from the kaolin, product resulting from transformation in depth of alumino silicate mineral type, such as feldspars, plagioclase and feldspars contained in the rocks. Clays are raw materials that have as main characteristic the plasticity property, which gives the product, after applying a certain pressure, a defined shape and an increase in the mechanical resistance when they become from green to dry and then to sintered. Given these characteristics, this paper analyzes the presence of the existing mineral kaolinite in two portuguese clays who are used in the preparation of formulations of porcelain stoneware tiles. The analyzes of the two clays were made by fluorescence x-ray diffraction of x-rays, thermal analysis, particle size and scanning electron microscopy, to better use of this mineral in the formulations. In both clays were found aluminum oxide, as well as mineral quartz, kaolinite and illite. (author)

  18. Subsurface water and clay mineral formation during the early history of Mars.

    Science.gov (United States)

    Ehlmann, Bethany L; Mustard, John F; Murchie, Scott L; Bibring, Jean-Pierre; Meunier, Alain; Fraeman, Abigail A; Langevin, Yves

    2011-11-02

    Clay minerals, recently discovered to be widespread in Mars's Noachian terrains, indicate long-duration interaction between water and rock over 3.7 billion years ago. Analysis of how they formed should indicate what environmental conditions prevailed on early Mars. If clays formed near the surface by weathering, as is common on Earth, their presence would indicate past surface conditions warmer and wetter than at present. However, available data instead indicate substantial Martian clay formation by hydrothermal groundwater circulation and a Noachian rock record dominated by evidence of subsurface waters. Cold, arid conditions with only transient surface water may have characterized Mars's surface for over 4 billion years, since the early-Noachian period, and the longest-duration aqueous, potentially habitable environments may have been in the subsurface.

  19. Clay mineral facies and lateritization in basalts of the southeastern Parana Basin, Brazil

    International Nuclear Information System (INIS)

    Oliveira, M.T.G. de; Formoso, M.L.L.; Trescases, J.J.; Meunier, A.

    1998-01-01

    Seventeen samples from two lateritic profiles, each with five facies, were studied. These profiles occur on the old planation surface of the plateau basalts of the southern part of ParanáBasin, Brazil. Optical microscopy, X-ray diffraction, electron microprobe, Mössbauer spectroscopy and Fourier Transform Infrared Spectra were used to obtain information about the nature and chemical composition of each weathering facies. In addition, scanning electron microscopy and analyses of clay minerals were performed to detect microcrystalline environmental changes. Both profiles have two major parts: a loose red-clay latosol separated from an underlying mottled clay and an alterite facies; a stone line may or may not be present between the latosol and the underlying units. In both profiles the latosol consists principally of kaolinite, hematite and goethite. Two alterite facies, shaped by differential weathering, are also present in the lower profile: a halloysite–nontronite clayey matrix with a well developed fissure system occurs in the argillaceous alterite and a network of Al–goethite aggregates is typical of the highly porous cortex of the boulder alterite that is found in the stone line and below it. Gibbsite has crystallized in the large pores of porphyritic boulder alterite but is absent in the small pores of the subaphyric boulder alterite. Clay minerals observed in fissures include halloysite associated with goethite and manganese oxides. The basalt has hydrothermal green-clays (mixed layers and trioctahedral smectites) that formed between primary plagioclase, pyroxene and Ti–magnetite crystals while fresh corestones of the boulder alterite have cryptocrystalline iron-rich material. The study of these profiles shows one principal evolutionary trend for clay minerals. This trend is from smectite and mixed layers that form green clays in altered bedrock at the base of the profile to an intermediate association of nontronite and halloysite in the argillaceous

  20. Estimation of hydraulic conductivity on clay content in soil determined from resistivity data

    Energy Technology Data Exchange (ETDEWEB)

    Shevnin, Vladimir; Delgado-Rodriguez, Omar; Mousatov, Aleksandr [Mexican Petroleum Institute, Mexico, D.F. (Mexico); Ryjov, Albert [Moscow State Geological Prospecting Academy, Geophysical Faculty, Moscow (Russian Federation)

    2006-07-15

    The influence of clay content in sandy and clayey soils on hydraulic conductivity (filtration coefficient) is considered. A review of published experimental data on the relationship of hydraulic conductivity with soil lithology and grain size, as dependent on clay content is presented. Theoretical calculations include clay content. Experimental and calculated data agree, and several approximation formulas for filtration coefficient vs clay content are presented. Clay content in soil is estimated from electric resistivity data obtained from 2D VES interpretation. A two-step method is proposed, the first step including clay content calculating from soil resistivity and groundwater salinity, and the second step including filtration coefficient estimating from clay content. Two applications are presented. [Spanish] El contenido de arcilla en suelos areno-arcillosos influye sobre la permeabilidad hidraulica (coeficiente de filtracion). Se presenta una revision de datos experimentales publicados que relacionan el coeficiente de filtracion con el tipo litologico del suelo y el tamano de las particulas. A partir de calculos teoricos, se modifican las conocidas formulas que relacionan el coeficiente de filtracion con el contenido de arcilla. Se estima el contenido de arcilla a partir de los datos interpretados por el metodo SEV, y se propone un procedimiento para la estimacion del coeficiente de filtracion: (a) calculo del contenido de arcilla a partir de la resistividad del suelo y de la salinidad del agua subterranea, (b) estimacion del coeficiente de filtracion a partir del contenido de arcilla. Se presentan algunos ejemplos de la aplicacion de esta metodologia.

  1. Competitive sorption between glyphosphate and inorganic phosphate on clay minerals and low organic matter soils

    International Nuclear Information System (INIS)

    Dion, H.M.; Hill, H.H.Jr.; Washington State Univ., Pullmann, WA; Harsh, J.B.; Washington State Univ., Pullmann, WA

    2001-01-01

    Inorganic phosphate may influence the adsorption of glyphosate to soil surface sites. It has been postulated that glyphosphate sorption is dominated by the phosphoric acid moiety, therefore, inorganic phosphate could compete with glyphosate for surface sorption sites. Sorption of glyphosate is examined in low organic carbon systems where clay minerals dominate the available adsorption sites using 32 P-labeled phosphate and 14 C-labeled glyphosate to track sorption. Glyphosate sorption was found to be strongly dependent on phosphate additions. Isotherms were generally of the L type, which is consistent with a limited number of surface sites. Most sorption on whole soils could be accounted for by sorption observed on model clays of the same mineral type as found in the soils. (author)

  2. An update on synthetic dyes adsorption onto clay based minerals: A state-of-art review

    CSIR Research Space (South Africa)

    Ngulube, T

    2017-04-01

    Full Text Available of Environmental Management An update on synthetic dyes adsorption onto clay based minerals: A state- of-art review Tholiso Ngulube a,*, Jabulani Ray Gumbo b, Vhahangwele Masindi c,d, Arjun Maity e a Department of Ecology and Resources Management..., University of Venda, Private Bag X5050, Thohoyandou, 0950, Limpopo, South Africa b Department of Hydrology and Water Resources, School of Environmental Sciences, University of Venda, Private Bag X5050, Thohoyandou, 0950, Limpopo, South Africa c Council...

  3. Effect of clay minerals on the stabilization of black cotton and lateritic soils

    International Nuclear Information System (INIS)

    Nyambok, I.O.

    1986-01-01

    The problem associated with black cotton and lateritic soils because of the swelling-shrinkage property of their constituent clay minerals were investigated. Samples of black cotton lateritic soils were collected from different parts of Kenya. The samples were analysed for their mineral compositions and later treated with hydrated lime in order to eliminate the swelling shrinkage behaviour. The samples were subsequently tested for their engineering properties in a soil mechanics laboratory using shear box and Casagrande apparatus. It was found that the chemical treatment of the soils with hydrated lime removes their plastic property and improves their shear strength. (author)

  4. Cathodoluminescence (CL) and electron paramagnetic resonance (EPR) studies of clay minerals

    International Nuclear Information System (INIS)

    Goetze, J.; Ploetze, M.; Goette, T.; Neuser, R.D.; Richter, D.K.

    2002-01-01

    Sheet silicates of the serpentine-kaolin-group (serpentine, kaolinite, dickite, nacrite, halloysite), the talc-pyrophyllite-group (talc, pyrophyllite), the smectite-group (montmorillonite), and illite (as a mineral of the mica-group) were investigated to obtain information concerning their cathodoluminescence behavior. The study included analyses by cathodoluminescence (CL microscopy and spectroscopy), electron paramagnetic resonance (EPR), x-ray diffraction (XRD), scanning electron microscopy (SEM) and trace element analysis. In general, all dioctahedral clay minerals exhibit a visible CL. Kaolinite, dickite, nacrite and pyrophyllite have a characteristic deep blue CL, whereas halloysite emission is in the greenish-blue region. On the contrary, the trioctahedral minerals (serpentine, talc) and illite do not show visible CL. The characteristic blue CL is caused by an intense emission band around 400 nm (double peak with two maxima at 375 and 410 nm). EPR measurements indicate that his blue emission can be related to radiation induced defect centers (RID), which occur as electron holes trapped on apical oxygen (Si-O center) or located at the Al-O-Al group (Al substituting Si in the tetrahedron). Additional CL emission bands were detected at 580 nm in halloysite and kaolinite, and between 700 and 800 nm in kaolinite, dickite, nacrite and pyrophyllite. Time-resolved spectral CL measurements show typical luminescence kinetics for the different clay minerals, which enable differentiation between the various dioctahedral minerals (e.g. kaolinite and dickite), even in thin section. (author)

  5. Sodium-calcium ion exchange on clay minerals at moderate to high ionic strengths

    International Nuclear Information System (INIS)

    Rogers, W.J.

    1979-12-01

    Sodium-calcium ion exchange on several clay minerals was studied at ionic strengths ranging from 0.01 to above 1.0. The minerals studied included attapulgite, illite, kaolin, and several montmorillonites. Distribution coefficients of calcium and sodium were obtained for the minerals over a wide range of solution conditions at pH five and equilibrium constants were calculated. The distribution coefficient of calcium, D/sub Ca/, was studied as a function of time, solution pH, loading, sodium concentration, and ionic strength fraction of sodium in constant ionic strength solutions. The distribution coefficient of sodium, D/sub Na/, was also studied as a function of time, loading, and sodium ionic strength fraction in constant total ionic strength solutions. Values of equilibrium constants calculated from distribution coefficients for solutions of constant ionic strength scattered bwteen 2 and 10 kg/kg for the montmorillonites and attapulgite while equilibrium constants for illite ranged from 5 to 10 kg/kg. No equilibrium constants for kaolin were calculated since distribution coefficients of sodium on this clay were too small to be measured. It was found that equilibrium constants at trace sodium loading were generally lower than those for higher sodium loadings by an order of magnitude or more due to the sensitivity of sodium distribution coefficients to the concentration of sodium in the clay at low loadings. Theoretical and experimental treatments of ion exclusion were included

  6. Application of clay minerals from Cayo Guan, Cuba, as sorbents of heavy metals and ceramic raw materials

    International Nuclear Information System (INIS)

    Fonseca, D.; Barba, F.; Callejas, P.; Recio, P.

    2012-01-01

    It has been studied by Analysis Heating Microscope Optical the behaviour of some kaolinitic clays from a reservoir of Cayo Guan rich in iron oxides and low silica content proving to be a refractory materials whose softening appears after 1500 degree centigrade. It has obtained the workability diagram of the different clay minerals calculating the plasticity by the method of Casagrande spoon; only one of the samples is in the area suitable for extrusion. Vitrification diagrams report that the capacity of water absorption is 2 +, Cr 3 +. The results of the immobilization of these elements have been compared with those obtained with thermally activated vermiculite at 800 degree centigrade, showing that the treated samples show sorption of both cadmium and chromium below the vermiculite, but the non-treated ones are suitable to remove chromium; this is because these clays do not contain in its composition exchangeable ions (Ca 2 +, Mg 2 +, Na + , K + ), and even if they are chemically activated only the presence of Fe ions is which produces form bindings (Cr x .Fe 1 -x) (OH) 3 which favor Cr sorption. (Author) 26 refs.

  7. Mineral carbonation of gaseous carbon dioxide using a clay-hosted cation exchange reaction.

    Science.gov (United States)

    Kang, Il-Mo; Roh, Ki-Min

    2013-01-01

    The mineral carbonation method is still a challenge in practical application owing to: (1) slow reaction kinetics, (2) high reaction temperature, and (3) continuous mineral consumption. These constraints stem from the mode of supplying alkaline earth metals through mineral acidification and dissolution. Here, we attempt to mineralize gaseous carbon dioxide into calcium carbonate, using a cation exchange reaction of vermiculite (a species of expandable clay minerals). The mineralization is operated by draining NaCI solution through vermiculite powders and continuously dropping into the pool of NaOH solution with CO2 gas injected. The mineralization temperature is regulated here at 293 and 333 K for 15 min. As a result of characterization, using an X-ray powder diffractometer and a scanning electron microscopy, two types of pure CaCO3 polymorphs (vaterite and calcite) are identified as main reaction products. Their abundance and morphology are heavily dependent on the mineralization temperature. Noticeably, spindle-shaped vaterite, which is quite different from a typical vaterite morphology (polycrystalline spherulite), forms predominantly at 333 K (approximately 98 wt%).

  8. Influence of clay content on wave-induced liquefaction

    DEFF Research Database (Denmark)

    Kirca, V.S. Ozgur; Sumer, B. Mutlu; Fredsøe, Jørgen

    2014-01-01

    of measurements were carried out: (1) pore-water pressure measurements across the soil depth and (2) water-surface elevation measurements. These measurements were synchronized with video recordings of the liquefaction process from the side. The ranges of the various quantities in the experiments were wave height...... of silt and clay was not liquefied. Sand may become prone to liquefaction with the introduction of clay, contrary to the general perception that this type of sediment is normally liquefaction-resistant under waves. For instance, sand with d50 50:4 mmwas liquefied with CC510:8%, whereas sand with d50 50...

  9. Clay mineral distribution in the shelf sediments off the northern part of the east coast of india

    Digital Repository Service at National Institute of Oceanography (India)

    Rao, V.P.; Reddy, N.P.C.; Rao, Ch.M.

    Forty-eight sediment samples from the continental shelf between Visakhapatnam and the Ganges were analysed by X-ray diffraction for the composition and distribution of clay minerals. Estuarine samples of the Hooghly are dominated by illite...

  10. Provenance and distribution of clay minerals in the sediments of the western continental shelf and slope of India

    Digital Repository Service at National Institute of Oceanography (India)

    Rao, V.P.; Rao, B.R.

    -Goa (93 samples) For the convenience of description, the Saurashtra-Goa region has been divided into the Saurashtra, Gulf of Cambay-Ratnagiri and Ratnagiri-Goa sectors based on variations in clay mineral abundances. The boundaries between these sectors... are approximate and variations in the mineral abundances tend to grade one to the other. Smectite is the most abundant mineral in the inner shelf sediments of all the sectors [Fig. 3(Ba), 3(Ca) and Provenance and distribution of clay minerals 1763 0 Sm*ctlt* m...

  11. Clay minerals: Properties and applications to dermocosmetic products and perspectives of natural raw materials for therapeutic purposes-A review.

    Science.gov (United States)

    Moraes, Jemima Daniela Dias; Bertolino, Silvana Raquel Alina; Cuffini, Silvia Lucia; Ducart, Diego Fernando; Bretzke, Pedro Eriberto; Leonardi, Gislaine Ricci

    2017-12-20

    Clay minerals are layered materials with a number of peculiar properties, which find many relevant applications in various industries. Since they are easily found everywhere, they are particularly attractive due to their economic viability. In the cosmetic industry, clay minerals are often used as excipients to stabilize emulsions or suspensions and to modify the rheological behavior of these systems. They also play an important role as adsorbents or absorbents, not only in cosmetics but also in other industries, such as pharmaceuticals. This reviewer believes that since this manuscript is presented as covering topical applications that include pharmaceuticals, some types of clay minerals should be considered as a potential material to be used as drug delivery systems. We review several applications of clay minerals to dermocosmetic products, relating them to the underlying properties of these materials and exemplifying with a number of clay minerals available in the market. We also discuss the use of clay minerals in topically-applied products for therapeutic purposes, specially for skin treatment and protection. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Quantitative image of bone mineral content

    International Nuclear Information System (INIS)

    Katoh, Tsuguhisa

    1990-01-01

    A dual energy subtraction system was constructed on an experimental basis for the quantitative image of bone mineral content. The system consists of a radiographing system and an image processor. Two radiograms were taken with dual x-ray energy in a single exposure using an x-ray beam dichromized by a tin filter. In this system, a film cassette was used where a low speed film-screen system, a copper filter and a high speed film-screen system were layered on top of each other. The images were read by a microdensitometer and processed by a personal computer. The image processing included the corrections of the film characteristics and heterogeneity in the x-ray field, and the dual energy subtraction in which the effect of the high energy component of the dichromized beam on the tube side image was corrected. In order to determine the accuracy of the system, experiments using wedge phantoms made of mixtures of epoxy resin and bone mineral-equivalent materials in various fractions were performed for various tube potentials and film processing conditions. The results indicated that the relative precision of the system was within ±4% and that the propagation of the film noise was within ±11 mg/cm 2 for the 0.2 mm pixels. The results also indicated that the system response was independent of the tube potential and the film processing condition. The bone mineral weight in each phalanx of the freshly dissected hand of a rhesus monkey was measured by this system and compared with the ash weight. The results showed an error of ±10%, slightly larger than that of phantom experiments, which is probably due to the effect of fat and the variation of focus-object distance. The air kerma in free air at the object was approximately 0.5 mGy for one exposure. The results indicate that this system is applicable to clinical use and provides useful information for evaluating a time-course of localized bone disease. (author)

  13. The redox properties of the natural iron-bearing clay mineral ferruginous smectite SWA-1: a combined electrochemical and spectroscopic study

    International Nuclear Information System (INIS)

    Gorski, Christopher A.; Voegelin, Andreas; Sander, Michael; Hofstetter, Thomas B.

    2012-01-01

    Document available in extended abstract form only. Iron-bearing clay minerals are ubiquitous in the environment and clay-mineral-based materials have been proposed to be part of backfill material in nuclear waste repositories. Laboratory and field studies have confirmed that structural iron (Fe) in clay minerals participates in redox reactions with organic pollutants, metals, and radionuclides, thus influencing their transport and reactivity. Knowledge of the redox properties of Fe-bearing clay minerals is therefore essential for understanding and predicting the fate, mobility, and bioavailability subsurface contaminants. A quantitative understanding of clay mineral redox behavior remains lacking, however, due to constraints in previous experimental approaches and the complex structural changes that accompany changes in the Fe oxidation state. This work provides a quantitative means for measuring the redox properties of Fe-bearing clay minerals, which can be applied to both field and laboratory studies tracking radionuclide-clay mineral redox reactions. Here we use mediated electrochemical reduction and oxidation to determine the electron accepting and donating capacities of several natural Fe-bearing clay minerals with different structural Fe content (2.3 to 21 wt-%) and varied redox histories. Results indicate that the fraction of redox-active Fe in clay minerals is mineral-dependent, and is linked to the thermodynamics of reduction and oxidation as well as to the ability of clay minerals to conduct electrons and facilitate structural re-arrangements required to maintain charge balance. The reduction potential (E H ) characteristics of a natural ferruginous smectite (SWa-1) were further characterized as a function of solution conditions and repeated Fe reduction and oxidation cycles. SWa-1 samples were analyzed with Moessbauer spectroscopy (MS) and X-ray absorption spectroscopy (XAS) to link observed redox potential behavior to structural properties and changes

  14. Distribution of clay minerals in the process streams produced by the extraction of bitumen from Athabasca oil sands

    Energy Technology Data Exchange (ETDEWEB)

    Kaminsky, H.A.W.; Etsell, T.H.; Ivey, D.G. [Alberta Univ., Edmonton, AB (Canada). Dept. of Chemical and Materials Engineering; Omotoso, O. [Natural Resources Canada, Devon, AB (Canada). CETC

    2009-02-15

    The clay minerals present in the oil sands were studied with particular reference to how they are partitioned in bitumen ore during the extraction process. Bitumen production from surface-mined oil sands accounts for nearly two-thirds of the total bitumen production in Alberta. Every cubic meter of mined ore results in 1.3 cubic meters of mature fine tailings (MFT). The characteristic differences between the clay minerals that report to the froth versus the tailings streams were also examined to determine which minerals could impact different unit operations in the bitumen extraction process. X-ray diffraction and random powder samples were used to quantify the clay minerals. Particle size distribution and clay activity balances were also conducted. The degree of partitioning during the conditioning and flotation stages in a batch extractor was determined by the surface properties of the clay minerals. The water-continuous tailings stream was separated into fine and coarse tailings fractions through sedimentation. The study showed that bitumen-clay interactions may be dominated by kaolinite or iron oxides. Clays are responsible for the poor settling behaviour of MFTs. The clay minerals present in the oil sands include illite, illite-smectite, kaolinite, kaolinite-smectite, and chlorite. The close proximity of the tailings ponds to the Athabasca River and volatile organic compounds (VOCs) emission require that the ponds be reclaimed to a natural landscape before mine closure. In addition to its impact on fine tailings reclamation, clay mineralogy plays a role in extraction froth flotation and emulsion stability during froth treatment. The mineralogy of the froth solids was found to be different from the mineralogy of the middlings and tailings solids. 39 refs., 6 tabs., 6 figs.

  15. Transmission X-ray Microscopy—A New Tool in Clay Mineral Floccules Characterization

    Directory of Open Access Journals (Sweden)

    Ray L. Frost

    2012-10-01

    Full Text Available Effective flocculation and dewatering of mineral processing streams containing clays are microstructure dependent in clay-water systems. Initial clay flocculation is crucial in the design and for the development of a new methodology of gas exploitation. Microstructural engineering of clay aggregates using covalent cations and Keggin macromolecules have been monitored using the new state of the art Transmission X-ray Microscope (TXM with 60 nm tomography resolution installed in a Taiwanese synchrotron. The 3-D reconstructions from TXM images show complex aggregation structures in montmorillonite aqueous suspensions after treatment with Na+, Ca2+ and Al13 Keggin macromolecules. Na-montmorillonite displays elongated, parallel, well-orientated and closed-void cellular networks, 0.5–3 µm in diameter. After treatment by covalent cations, the coagulated structure displays much smaller, randomly orientated and openly connected cells, 300–600 nm in diameter. The average distances measured between montmorillonite sheets was around 450 nm, which is less than half of the cell dimension measured in Na-montmorillonite. The most dramatic structural changes were observed after treatment by Al13 Keggin; aggregates then became arranged in compacted domains of a 300 nm average diameter composed of thick face-to-face oriented sheets, which forms porous aggregates with larger intra-aggregate open and connected voids.

  16. Treatment and Conditioning of Radioactive Waste Solution by Natural Clay Minerals

    International Nuclear Information System (INIS)

    El-Dessouky, M.I.; Abdel-Raouf, M.W.; El-Massry, E.H.; Khalifa, S.M.; Aly, H.F.

    1999-01-01

    Chemical precipitation processes have been used for the treatment of radioactive elements from aqueous solution. The volume reduction is not very great and storage facilities are expensive. There are some radionuclides which are so difficult to be precipitated by this common method, so they may be precipitated by adding solid materials such as natural inorganic exchangers. In this woek, improvement the removal of caesium, cobalt and europium with zinc sulfate as coagulant and different clay minerals have been investigated. These include, Feldespare, Aswanly, Bentionite, Hematite, Mud, Calcite, Basalt, Magnetite, Kaoline, Sand stone, Limonite and Sand. The parameters affecting the precipitation process such as pH, particle size, temperature and weight of the clay have been studied. The results indicate that, the highest removal for Cs-137, Co-60 and Eu-152 and154 by Asswanly, Bentonite and Sand stone is more than the other clays. Removal of Cs-137 from low level waste solution with these three natural clays took the sequence, Aswanly (85.5%) > Bentonite (82.2%) > Sandstone (65.4%). Solidified cement products have been evaluated to determine mechanical strength and leaching rates of the waste products. The solidified waste forms were found more acceptable for handling ,storage and ultimate disposal

  17. Pre-treatment of Used-Cooking Oil as Feed Stocks of Biodiesel Production by Using Activated Carbon and Clay Minerals

    Directory of Open Access Journals (Sweden)

    Rudy Syah Putra

    2014-02-01

    Full Text Available Many low-cost feedstock i.e. used-cooking oil (UCO for the production of biodiesel fuel (BDF has contained a large amount of water and high proportion of free fatty acids (FFAs. Therefore, a pre-treatment process to reduce the water content (<0.1 wt.% and FFAs (<2.0 wt.% were necessary in order to avoid an undesirable side reactions, such as saponification, which could lead to serious problem of product separation and low fatty acid methyl ester (FAME yield. . In this study, a pre-treatment process of used cooking oil as a feedstock for the production of BDF by using various adsorbents such as Activated Carbon (AC and various clay minerals, for example Smectite (S, Bentonite (B, Kaolinite (K, and Powdered Earthenware (PE were evaluated. The oil obtained from pre-treatment was compared with oil without pre-treatment process. In this study, we reported a basic difference in material ability to the oil, depending on the adsorption condition with respect to the physico-chemical parameters, e.g. refractive index (R, density (ρ, FFAs, and water content (W. The results showed that the water content and FFAs in the oil has decreased when using AC as an adsorbent compared with clay minerals. However, the refractive index of oil has similar with the oil without pre-treatment process as well; meanwhile, the density of oil has increased after the pre-treatment process by using clay minerals.

  18. Cortical bone mineral content in primary hyperparathyroidism

    International Nuclear Information System (INIS)

    Mautalen, C.; Reyes, H.R.; Ghiringhelli, G.; Fromm, G.

    1986-01-01

    The bone mineral content (BMC) of 35 patients with primary hyperparathyroidism (PHPT) was measured at the mid radius (95% cortical bone) by photon absorptiometry of a 241 Am source. The majority of the patients had an overt disease of moderate to severe degree. Average serum calcium of the group was 12.3 mg/100 ml (range 10.6 to 18.0 mg/100 ml). The percentage of normality of the BMC was (Av +- 1 SD) 75.1 +- 13.0% for the whole group. The average increment of BMC in 14 patients 9 to 26 months after parathyroidectomy was 9.9%, with a wide dispersion. However, a highly significant negative correlation (r: 0.83; P < 0.01) was found between the initial bone mass and the percentage increment per month after surgery. No furhter gain was observed 2 years after parathyroidectomy except in one patient with an extremely severe bone loss. In spite of the gain obtained after surgery the bone mass remained markedly diminished in most patients showing that the cortical bone loss caused by PHPT is mainly irreversible. (author)

  19. Redox properties of clay-rich sediments as assessed by mediated electrochemical analysis : Separating pyrite, siderite and structural Fe in clay minerals

    NARCIS (Netherlands)

    Hoving, Alwina L.; Sander, Michael; Bruggeman, Christophe; Behrends, Thilo

    2017-01-01

    Redox reactions with Fe-containing minerals in clay-rich sediments largely affect the speciation, mobility, and (bio-) availability of redox-sensitive contaminants. Here, we use mediated electrochemical oxidation (MEO) and reduction (MER), to quantify the electron accepting and donating capacities

  20. Clay minerals related to the circulation of geothermal fluids in boreholes at Rittershoffen (Alsace, France)

    Science.gov (United States)

    Vidal, Jeanne; Patrier, Patricia; Genter, Albert; Beaufort, Daniel; Dezayes, Chrystel; Glaas, Carole; Lerouge, Catherine; Sanjuan, Bernard

    2018-01-01

    Two geothermal wells, GRT-1 and GRT-2, were drilled into the granite at Rittershoffen (Alsace, France) in the Upper Rhine Graben to exploit geothermal resources at the sediment-basement interface. Brine circulation occurs in a permeable fracture network and leads to hydrothermal alteration of the host rocks. The goal of the study was to characterize the petrography and mineralogy of the altered rocks with respect to the permeable fracture zones in the granitic basement. As clay minerals are highly reactive to hydrothermal alteration, they can be used as indicators of present-day and paleo-circulation systems. Special attention has been paid to the textural, structural and chemical properties of these minerals. The fine-grained clay fraction (smectite ( 10% smectite) provide a promising guide for identifying the fracture zones that control the present-day circulation of geothermal fluids in the Rittershoffen wells. However, multistage paleo-circulation systems could lead to an abundance of heterogeneous and fine-grained illitic minerals that could plug the fracture system. The permeability of fracture zones in the GRT-1 well was likely reduced because of an intense illitization, and the well was stimulated. The occurrence of chlorite in the permeable fracture zones of GRT-2 is indicative of less intense illitization, and the natural permeability is much higher in GRT-2 than in GRT-1.

  1. Fluorescence X-ray microscopy on hydrated tributyltin-clay mineral suspensions

    Science.gov (United States)

    Neuhäusler, U.; Schmidt, C.; Hoch, M.; Susini, J.

    2003-03-01

    Using the scanning transmission X-ray microscope at ID21 beamline of the ESRF in fluorescence mode, we mapped tin at a bulk concentration of 1000 μg(Sn)/ml within hydrated tributyltin (TBT)-clay mineral (Kaolinite) dispersion with sub-300 nm spatial resolution. Using the L absorption edges of tin at 3929, 4156 and 4465 eV fluorescence radiation was excited in tin atoms with incident photon energies of 4 and 4.5 keV. When using 4 keV radiation, only tin fluorescence is excited. For 4.5 keV X rays, both the fluorescence of tin and calcium (which is present in the solid phase) can be measured. Methodologically, we were interested in assessing and proving the possibilities and limitations of fluorescence mapping using the L absorption edges of tin, where the fluorescence yield is significantly lower compared to other elements with their K edges in the same energy range. Scientifically, organotin-clay mineral interactions are of environmental concern because this factor influences significantly the distribution of toxic TBT in the aquatic System. On one hand, the half-life of TBT deposited to the sediment phase increases, and consequently the time of its bioavailability. On the other hand, the adsorption process is reversible, which means that contaminated sediments can act as a source of pollution. The adsorption and desorption effects can be studied directly with high spatial resolution and brought into connection to the surface properties of the clay mineral under study as well as to other experimental parameters, like pH or salinity.

  2. Effect of clay content on morphology and processability of electrospun keratin/poly(lactic acid) nanofiber.

    Science.gov (United States)

    Isarankura Na Ayutthaya, Siriorn; Tanpichai, Supachok; Sangkhun, Weradesh; Wootthikanokkhan, Jatuphorn

    2016-04-01

    This research work has concerned the development of volatile organic compounds (VOCs) removal filters from biomaterials, based on keratin extracted from chicken feather waste and poly(lactic acid) (PLA) (50/50%w/w) blend. Clay (Na-montmorillonite) was also added to the blend solution prior to carrying out an electro-spinning process. The aim of this study was to investigate the effect of clay content on viscosity, conductivity, and morphology of the electrospun fibers. Scanning electron micrographs showed that smooth and bead-free fibers were obtained when clay content used was below 2 pph. XRD patterns of the electrospun fibers indicated that the clay was intercalated and exfoliated within the polymers matrix. Percentage crystallinity of keratin in the blend increased after adding the clay, as evidenced from FTIR spectra and DSC thermograms. Transmission electron micrographs revealed a kind of core-shell structure with clay being predominately resided within the keratin rich shell and at the interfacial region. Filtration performance of the electrospun keratin/PLA fibers, described in terms of pressure drop and its capability of removing methylene blue, were also explored. Overall, our results demonstrated that it was possible to improve process-ability, morphology and filtration efficiency of the electrospun keratin fibers by adding a suitable amount of clay. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Clay minerals assemblage in the Neogene fluvial succession of the Pishin Belt, Pakistan

    DEFF Research Database (Denmark)

    Kasi, Aimal Khan; Kassi, Akhtar Muhammad; Friis, Henrik

    2014-01-01

    indicate derivation of material from the Pre-Miocene sedimentary and meta-sedimentary terrains of the Pishin Belt. X-ray diffraction (XRD) analyses indicate that clay minerals in various mudstones and sandstone samples are identical and detrital in nature and include smectite, chlorite, illite, serpentine...... and kaolinite. Smectite and chlorite are most probably derived from the metavolcanic and mafic volcanic rocks, respectively. Presence of serpentine in samples of the Bostan Formation indicates altered ultramafic rocks as one of the source terrains. Illite is probably recycled from the older sedimentary...

  4. Study of influence of content organoclay on mechanical properties of propylene and bentonite clay nanocomposites

    International Nuclear Information System (INIS)

    Farias, Giselly M.G.; Costa, Jonei M.; Pachekoski, Wagner; Barbosa, Joseane D. Viana; Farias, Romulo

    2011-01-01

    In this work we studied activated organoclay nanocomposites in pilot scale, obtained by physical mixing in twin screw extruder co-rotating. The organophilic clay content included in the formulation of these compounds ranged from 2 to 6% by weight. The clays were characterized using the techniques of x-ray. Systems PP / clay were characterized by tensile test, flexural and impact strength. The results indicated that there was no loss of mechanical properties and thermo-mechanical properties of the nanocomposite obtained. (author)

  5. Ball clay

    Science.gov (United States)

    Virta, R.L.

    2001-01-01

    Part of the 2000 annual review of the industrial minerals sector. A general overview of the ball clay industry is provided. In 2000, sales of ball clay reached record levels, with sanitary ware and tile applications accounting for the largest sales. Ball clay production, consumption, prices, foreign trade, and industry news are summarized. The outlook for the ball clay industry is also outlined.

  6. The growth of multi-walled carbon nanotubes on natural clay minerals (kaolinite, nontronite and sepiolite)

    International Nuclear Information System (INIS)

    Pastorková, K.; Jesenák, K.; Kadlečíková, M.; Breza, J.; Kolmačka, M.; Čaplovičová, M.; Lazišťan, F.; Michalka, M.

    2012-01-01

    The suitability of clay minerals - kaolinite, nontronite and sepiolite - is studied for synthesis of nanocomposites based on carbon nanotubes. Particles of iron were used as catalysts. Prior to synthesis, kaolinite and sepiolite were doped by the catalytically active metal, whereas in the case of nontronite the presence was used of this metal in the matrix of this mineral. Synthesis of CNTs was performed by hot filament chemical vapor deposition method. The produced nanocomposites were examined by transmission and scanning electron microscopies and energy dispersive X-ray spectroscopy. The experiment verified the potential of the three microcrystalline phyllosilicates for the growth of carbon nanotubes. Under the same technology conditions, the type of catalyst carrier affects the morphology and structure of the nanotube product markedly.

  7. Paleoenvironmental Implications of Clay Minerals at Yellowknife Bay, Gale Crater, Mars

    Science.gov (United States)

    Bristow, Thomas F.; Blake, David F.

    2014-01-01

    The Mars Science Laboratory (MSL) Rover, Curiosity spent approx 150 sols at Yellowknife Bay (YKB) studying a section of fluvio-lacustrine sedimentary rocks (with potential indications of volcanic influence), informally known as the Yellowknife Bay formation. YKB lies in a distal region of the Peace Vallis alluvial fan, which extends from the northern rim of Gale Crater toward the dune field at the base of Mt Sharp. Sedimentological and stratigraphic observations are consistent with the Yellowknife Bay formation being part of a distal fan deposit, which could be as young as middle Hesperian to even early Amazonian in age (approx. 3.5 to 2.5 Ga). The Yellowknife Bay formation hosts a unit of mudstone called the Sheepbed member. Curiosity obtained powdered rock samples from two drill holes in the Sheepbed Member, named John Klein and Cumberland, and delivered them to instruments in Curiosity. Data from CheMin, a combined X-ray diffraction (XRD)/X-ray fluorescence instrument (XRF), has allowed detailed mineralogical analysis of mudstone powders revealing a clay mineral component of approx. 20 wt.% in each sample. The clay minerals are important indicators of paleoenvironmental conditions and sensitive recorders of post-depositional alteration processes. The XRD pattern of John Klein reveals a 02l band consistent with a trioctahedral phyllosilicate. A broad peak at approx. 10A with a slight inflexion at approx. 12A indicates the presence of 2:1 type clay minerals in the John Klein sample. The trioctahedral nature of the clay minerals, breadth of the basal reflection, and presence of a minor component with larger basal spacing suggests that John Klein contains a trioctahedral smectite (probably saponite), whose interlayer is largely collapsed because of the low-humidity conditions. The XRD patterns show no evidence of corrensite (mixed-layer chlorite/smectite) or chlorite, which are typical diagenetic products of trioctahedral smectites when subjected to burial and

  8. The First X-ray Diffraction Patterns of Clay Minerals from Gale Crater

    Science.gov (United States)

    Bristow, Thomas; Blake, David; Bish, David L.; Vaniman, David; Ming, Douglas W.; Morris, Richard V.; Chipera, Steve; Rampe, Elizabeth B.; Farmer, Jack, D.; Treiman, Allan H; hide

    2013-01-01

    The Mars Science Laboratory (MSL) Rover, Curiosity spent approx 150 sols at Yellowknife Bay (YKB) studying a section of fluvio-lacustrine sedimentary rocks (with potential indications of volcanic influence), informally known as the Yellowknife Bay formation. YKB lies in a distal region of the Peace Vallis alluvial fan, which extends from the northern rim of Gale Crater toward the dune field at the base of Mt Sharp. Sedimentological and stratigraphic observations are consistent with the Yellowknife Bay formation being part of a distal fan deposit, which could be as young as middle Hesperian to even early Amazonian in age (approx 3.5 to 2.5 Ga). The Yellowknife Bay formation hosts a unit of mudstone called the Sheepbed member. Curiosity obtained powdered rock samples from two drill holes in the Sheepbed Member, named John Klein and Cumberland, and delivered them to instruments in Curiosity. Data from CheMin, a combined X-ray diffraction (XRD)/X-ray fluorescence instrument (XRF), has allowed detailed mineralogical analysis of mudstone powders revealing a clay mineral component of approx 20 wt.% in each sample. The clay minerals are important indicators of paleoenvironmental conditions and sensitive recorders of post-depositional alteration processes. The XRD pattern of John Klein reveals a 021 band consistent with a trioctahedral phyllosilicate. A broad peak at approx 10A with a slight inflexion at approx 12A indicates the presence of 2:1 type clay minerals in the John Klein sample. The trioctahedral nature of the clay minerals, breadth of the basal reflection, and presence of a minor component with larger basal spacing suggests that John Klein contains a trioctahedral smectite (probably saponite), whose interlayer is largely collapsed because of the low-humidity conditions. The XRD patterns show no evidence of corrensite (mixed-layer chlorite/smectite) or chlorite, which are typical diagenetic products of trioctahedral smectites when subjected to burial and heating

  9. The Composition and Physical Properties of Some Clays of Cross ...

    African Journals Online (AJOL)

    ... and quartz as the main subsidiary non-clay mineral. The high plasticity index of the clays corresponds to the more transported clays of the tertiary- to –recent environment. The percentage of linear shrinkage varied from 11-16% with the lowest shrinkage (11%), having the coarsest features. Silica (SiO2) content of the clays ...

  10. Molecular Structural Transformation of 2:1 Clay Minerals by a Constant-Pressure Molecular Dynamics Simulation Method

    International Nuclear Information System (INIS)

    Wang, J.; Gutierre, M.S.

    2010-01-01

    This paper presents results of a molecular dynamics simulation study of dehydrated 2:1 clay minerals using the Parrinello-Rahman constant-pressure molecular dynamics method. The method is capable of simulating a system under the most general applied stress conditions by considering the changes of MD cell size and shape. Given the advantage of the method, it is the major goal of the paper to investigate the influence of imposed cell boundary conditions on the molecular structural transformation of 2:1 clay minerals under different normal pressures. Simulation results show that the degrees of freedom of the simulation cell (i.e., whether the cell size or shape change is allowed) determines the final equilibrated crystal structure of clay minerals. Both the MD method and the static method have successfully revealed unforeseen structural transformations of clay minerals upon relaxation under different normal pressures. It is found that large shear distortions of clay minerals occur when full allowance is given to the cell size and shape change. A complete elimination of the interlayer spacing is observed in a static simulation. However, when only the cell size change is allowed, interlayer spacing is retained, but large internal shear stresses also exist.

  11. Evidence of cyclic climatic changes recorded in clay mineral assemblages from a continental Paleocene-Eocene sequence, northwestern Argentina

    Science.gov (United States)

    Do Campo, Margarita; Bauluz, Blanca; del Papa, Cecilia; White, Timothy; Yuste, Alfonso; Mayayo, Maria Jose

    2018-06-01

    The continental Paleocene-Eocene sequence investigated in this study belongs to the Salta Group, deposited in an intracontinental rift, the Salta Basin (NW Argentina), that evolved from the lower Cretaceous to the middle Paleogene, and is subdivided into the Pirgua, the Balbuena and the Santa Barbara Subgroups. The Maíz Gordo Formation (200 m thick) is the middle unit of the Santa Bárbara Subgroup, deposited during late post-rift sedimentation. We studied the mineralogy of fine-grained horizons of this formation by X-ray diffraction and Scanning Electron Microscopy (SEM) in order to examine the connection between vertical changes in clay mineralogy in alluvial sediments and paleosols, and global paleoclimatic changes registered during the Paleogene. Paleosols vary from calcic vertisols in the lowermost levels, to inseptisols and gleysols in intermediate positions, to gleyed oxisols in the upper section, indicating increased chemical weathering through time. Clay mineral relative abundances vary with a general increase in kaolinite content from bottom to top. However, at one site there are significant variations in kaolinite/muscovite (Kln/Ms) that define five cycles of kaolinite abundance and Kln/Ms. that indicate cyclic patterns of paleoprecipitation and paleotemperature. These are interpreted as several short-lived hyperthermals during the Paleocene-early Eocene in the Southern Hemisphere, which correlate with well-established episodes of warmth documented from the Northern Hemisphere.

  12. Clay content drives carbon stocks in soils under a plantation of Eucalyptus saligna Labill. in southern Brazil

    Directory of Open Access Journals (Sweden)

    Tanise Luisa Sausen

    2014-06-01

    Full Text Available Soil carbon accumulation is largely dependent on net primary productivity. To our knowledge, there have been no studies investigating the dynamics of carbon accumulation in weathered subtropical soils, especially in managed eucalyptus plantations. We quantified the seasonal input of leaf litter, the leaf decomposition rate and soil carbon stocks in an commercial plantation of Eucalyptus saligna Labill. in southern Brazil. Our goal was to evaluate, through multiple linear regression, the influence that certain chemical characteristics of litter, as well as chemical and physical characteristics of soil, have on carbon accumulation in soil organic matter fractions. Variables related to the chemical composition of litter were not associated with the soil carbon stock in the particulate and mineral fractions. However, certain soil characteristics were significantly associated with the carbon stock in both fractions. The concentrations of nutrients associated with plant growth and productivity, such as phosphorus, sulfur, copper and zinc, were associated with variations in the labile carbon pool (particulate fraction. Clay content was strongly associated with the carbon stock in the mineral fraction. The carbon accumulation and stabilization in weathered subtropical Ultisol seems to be mainly associated with the intrinsic characteristics of the soil, particularly clay content, rather than with the quantity, chemical composition or decomposition rate of the litter.

  13. The role of organic matter and clay content in sediments for bioavailability of pyrene.

    Science.gov (United States)

    Spasojević, Jelena; Maletić, Snežana; Rončević, Srđan; Grgić, Marko; Krčmar, Dejan; Varga, Nataša; Dalmacija, Božo

    2018-01-01

    Evaluation of the bioavailable fractions of organic contaminants such as polycyclic aromatic hydrocarbons (PAHs) is extremely important for assessing their risk to the environment. This available fraction, which can be solubilised and/or easily extracted, is believed to be the most accessible for bioaccumulation, biosorption and/or transformation. Sediment organic matter (OM) and clay play an important role in the biodegradation and bioavailability of PAHs. The strong association of PAHs with OM and clay in sediments has a great influence not only on their distribution but also on their long-term environmental impact. This paper investigates correlations between bioavailability and the clay and OM contents in sediments. The results show that OM is a better sorbent for pyrene (chosen as a model PAH) and that increasing the OM content reduces the bioavailable fraction. A mathematical model was used to predict the kinetic desorption, and these results showed that the sediment with the lowest content of OM had an F fast value of 24%, whereas sediment with 20% OM gave a value of 9%. In the experiments with sediments with different clay contents, no clear dependence between clay and rate constants of the fast desorbing fractions was observed, which can be explained by the numerous possible interactions at the molecular level.

  14. Electron paramagnetic resonance studies on silver atoms and clusters in regularly interstratified clay minerals

    International Nuclear Information System (INIS)

    Yamada, H.; Tamura, K.; Shimomura, S.; Sadlo, J.; Turek, J.; Michalik, J.

    2004-01-01

    The formation and stabilization of reduced silver species in the regularly interstratified clay minerals, trioctahedral smectite/chlorite (tri-Sm/Ch) and dioctahedral smectite/mica (di-Sm/M), have been studied by electron paramagnetic resonance (EPR) spectroscopy. Both minerals loaded with Ag + cations after degassing and dehydration were γ-irradiated at 77 K and monitored by EPR as the temperature increased. Some samples were exposed to water or methanol vapor after dehydration. In both hydrated and dehydrated samples only the doublets to Ag 0 atoms were observed with no evidence of the formation of Ag clusters. However, the EPR parameter of silver atoms in both matrices are different. In tri-Sm/Ch the narrow anisotropic EPR lines overlap with the broader isotropic lines, whereas in di-Sm/M only broad lines are recorded. The hyperfine splitting - A iso (Ag 0 ) is larger in tri-Sm/Ch than in di-Sm/M. Also the stability of Ag 0 in both clay minerals is distinctly different. Ag 0 doublet in di-Sm/M disappears completely above 230 K, Whereas in tri-Sm/Ch it is still recorded at 310 K. It is proposed, basing on the EPR results that Ag 0 atoms appear at different sites in both matrices: - in tri-Sm/Ch in the middle of smectite interlayer and in hexagonal cavities in the silicate sheets of tetrahedron layer and in di-Sm.M in hexagonal cavities only. When samples had been exposed to methanol before irradiation, the silver clusters become stabilized in the interlayer sites. In tri-Sm/M matrix the silver dimer Ag 2 + formed by gamma-irradiation at 77 K is transformed to tetrameric cluster, Ag 4 + at 150 K. In di-Sm/M the radiation-induced silver agglomeration proceeds in a similar way, but with a slower rate and Ag tetramer is formed only above 190 K. In both clay minerals, Ag 4 + clusters decay above 250 K. (author)

  15. Clay mineral formation and fabric development in the DFDP-1B borehole, central Alpine Fault, New Zealand

    International Nuclear Information System (INIS)

    Schleicher, A.M.; Sutherland, R.; Townend, J.; Toy, V.G.; Van der Pluijm, B.A.

    2015-01-01

    Clay minerals are increasingly recognised as important controls on the state and mechanical behaviour of fault systems in the upper crust. Samples retrieved by shallow drilling from two principal slip zones within the central Alpine Fault, South Island, New Zealand, offer an excellent opportunity to investigate clay formation and fluid-rock interaction in an active fault zone. Two shallow boreholes, DFDP-1A (100.6 m deep) and DFDP-1B (151.4 m) were drilled in Phase 1 of the Deep Fault Drilling Project (DFDP-1) in 2011. We provide a mineralogical and textural analysis of clays in fault gouge extracted from the Alpine Fault. Newly formed smectitic clays are observed solely in the narrow zones of fault gouge in drill core, indicating that localised mineral reactions are restricted to the fault zone. The weak preferred orientation of the clay minerals in the fault gouge indicates minimal strain-driven modification of rock fabrics. While limited in extent, our results support observations from surface outcrops and faults systems elsewhere regarding the key role of clays in fault zones and emphasise the need for future, deeper drilling into the Alpine Fault in order to understand correlative mineralogies and fabrics as a function of higher temperature and pressure conditions. (author).

  16. Effect of clay content in rock on oil extraction under alkaline seam conditions

    Energy Technology Data Exchange (ETDEWEB)

    Vezirov, D Sh; Gorbunov, A T; Kasimov, Sh A; Kashchavtsev, V E; Tairov, N D

    1978-01-01

    When oil beds are flooded with alkaline solutions, the alkaline concentration in the solution can be significantly reduced as a result of the interaction between clay and alkali. Large losses of alkali in the bed can render the flooding method ineffective. Experimental studies were conducted on porous media containing up to 25% clay at a constant permeability of 1 D in order to determine the oil extraction indices for clay-containing rock. Constant permeability is maintained by using clays, marshalite, and quartz sand in various proportions. Oil having a viscosity of 99.17 sP, and containing a large amount of surfactants, including 1.1% naphthenic acid, was extracted by fresh water and a 0.25% solution of NaOH. The extraction of oil by fresh water and NaOH solution from quartz sand indicated the advantage of using alkaline solutions. The extraction coefficient increased by 11% with the use of this method. As clay is added to the sand, the extraction coefficient decreases, and is reduced to 12.7% when the clay content reaches 25%. Nevertheless, a comparison of data obtained for quartz sand with fresh water on a porous medium containing 25% clay with an alkaline solution, indicates that the extraction coefficient is just 1.5% lower even in the presence of such a large amount of clay. Consequently, alkaline flooding should still be given preference over the usual methods under specific conditions and where the rock has a comparatively large amount of clay, in view of all the basic factors that influence the extraction process. The results obtained can be used for selecting alkaline concentration in evaluating the efficiency of flooding oil beds with alkaline solutions. 2 figures, 2 tables.

  17. Multi-scale experimental and numerical study of the structure and the dynamics of water confined in clay minerals

    International Nuclear Information System (INIS)

    Guillaud, Emmanuel Bertrand

    2017-01-01

    Clay are complex minerals with a multi-scale porosity and a remarkable ability to swell under humid atmosphere. These materials have many applications in catalysis, waste management, construction industry... However, the properties of confined water are still not fully understood, due in particular to the complexity of water itself. The aim of this work is, using mainly molecular simulations and vibrational spectroscopy, to understand the structure and the dynamics of water confined in clay minerals. To evaluate the accuracy of numerical models to describe water confined in clay minerals, and to understand the origin of its structural and dynamical properties, a large part of the work was devoted to the building blocks of clays: pure bulk water, water at the surface of a solid, and salt water. To this extent, the viscoelastic properties of water from the deeply supercooled regime to the boiling temperature were investigated using classical molecular dynamics. The evolution of the friction properties of water on a prototypical solid surface was also analyzed, and the accuracy of ab initio approaches and empirical salt models was studied. In a second part, those results were confronted to the properties of water confined in clay minerals at low and room temperature, studied both experimentally and numerically. Experimental work consisted mostly in extensive far- and -mid infrared absorption spectrometry measurements, whereas numerical work mainly consisted in empirical molecular dynamics simulations. Especially, the existence of confinement- or temperature-induced phase transitions of confined water was investigated. (author)

  18. Soft X-ray spectromicroscopy study of mineral-organic matter associations in pasture soil clay fractions.

    Science.gov (United States)

    Chen, Chunmei; Dynes, James J; Wang, Jian; Karunakaran, Chithra; Sparks, Donald L

    2014-06-17

    There is a growing acceptance that associations with soil minerals may be the most important overarching stabilization mechanism for soil organic matter. However, direct investigation of organo-mineral associations has been hampered by a lack of methods that can simultaneously characterize organic matter (OM) and soil minerals. In this study, STXM-NEXAFS spectroscopy at the C 1s, Ca 2p, Fe 2p, Al 1s, and Si 1s edges was used to investigate C associations with Ca, Fe, Al, and Si species in soil clay fractions from an upland pasture hillslope. Bulk techniques including C and N NEXAFS, Fe K-edge EXAFS spectroscopy, and XRD were applied to provide additional information. Results demonstrated that C was associated with Ca, Fe, Al, and Si with no separate phase in soil clay particles. In soil clay particles, the pervasive C forms were aromatic C, carboxyl C, and polysaccharides with the relative abundance of carboxyl C and polysaccharides varying spatially at the submicrometer scale. Only limited regions in the soil clay particles had aliphatic C. Good C-Ca spatial correlations were found for soil clay particles with no CaCO3, suggesting a strong role of Ca in organo-mineral assemblage formation. Fe EXAFS showed that about 50% of the total Fe in soils was contained in Fe oxides, whereas Fe-bearing aluminosilicates (vermiculite and Illite) accounted for another 50%. Fe oxides in the soil were mainly crystalline goethite and hematite, with lesser amounts of poorly crystalline ferrihydrite. XRD revealed that soil clay aluminosilicates were hydroxy-interlayered vermiculite, Illite, and kaolinite. C showed similar correlation with Fe to Al and Si, implying a similar association of Fe oxides and aluminosilicates with organic matter in organo-mineral associations. These direct microscopic determinations can help improve understanding of organo-mineral interactions in soils.

  19. Heteroagglomeration of zinc oxide nanoparticles with clay mineral modulates the bioavailability and toxicity of nanoparticle in Tetrahymena pyriformis.

    Science.gov (United States)

    Gupta, Govind Sharan; Senapati, Violet Aileen; Dhawan, Alok; Shanker, Rishi

    2017-06-01

    The extensive use of zinc oxide nanoparticles (ZnO NPs) in cosmetics, sunscreens and healthcare products increases their release in the aquatic environment. The present study explored the possible interaction of ZnO NPs with montmorillonite clay minerals in aqueous conditions. An addition of ZnO NPs on clay suspension significantly (pclay particles from 1652±90nm to 2158±13nm due to heteroagglomeration. The electrokinetic measurements showed a significant (pclay association (-1.37±0.03μmcm/Vs) that results to the electrostatic interaction between ZnO NPs and clay particles. The attenuated total reflectance Fourier transform infrared spectroscopy analysis of ZnO NPs-clay association demonstrated the binding of ZnO NPs with the Si-O-Al region on the edges of clay particles. The increase in size of ZnO NPs-clay heteroagglomerates further leads to their sedimentation at 24h. Although, the stability of ZnO NPs in the clay suspension was decreased due to heteroagglomeration, but the bioavailability and toxicity of ZnO NPs-clay heteroagglomerates in Tetrahymena pyriformis was enhanced. These observations provide an evidence on possible mechanisms available in natural environment that can facilitate nanoparticles entry into the organisms present in lower trophic levels of the food web. Copyright © 2017 Elsevier Inc. All rights reserved.

  20. Terrestrial Analogs for Clay Minerals at Yellowknife Bay, Gale Crater, Mars

    Science.gov (United States)

    Treiman, Allan H; Morris, Richard V.; Bristow, Thomas; Ming, Douglas W.; Achillies, Cherie; Bish, David L.; Blake, David; Vaniman, David; Chipera, Steve

    2013-01-01

    the last three varieties may be contemporaneous. One sample shows agate (alpha- quartz) that was precipitated between the episodes of deposition of the fine-grained and coarse-grained 'griffithite.' 'Griffithite' is not unique as a possible terrestrial analog - some clay minerals from the Doushantou formation, China, have similar 02L diffraction bands, and many basalts contain smectites in vesicles and as replacements after olivine. Similar trioctahedral smectites occur also in the nakhlite martian meteorites - as veinlets and replacements of olivine. By understanding the formation of these terrestrial clays, we hope to constrain the nature and mechanism of formation of the Sheepbed clay mineral.

  1. Preparation of Al/Fe-Pillared Clays: Effect of the Starting Mineral.

    Science.gov (United States)

    Muñoz, Helir-Joseph; Blanco, Carolina; Gil, Antonio; Vicente, Miguel-Ángel; Galeano, Luis-Alejandro

    2017-11-28

    Four natural clays were modified with mixed polyoxocations of Al/Fe for evaluating the effect of the physicochemical properties of the starting materials (chemical composition, abundance of expandable clay phases, cationic exchange capacity and textural properties) on final physicochemical and catalytic properties of Al/Fe-PILCs. The aluminosilicate denoted C2 exhibited the highest potential as starting material in the preparation of Al/Fe-PILC catalysts, mainly due to its starting cationic exchange capacity (192 meq/100 g) and the dioctahedral nature of the smectite phase. These characteristics favored the intercalation of the mixed (Al 13- x /Fe x ) 7+ Keggin-type polyoxocations, stabilizing a basal spacing of 17.4 Å and high increase of the BET surface (194 m²/g), mainly represented in microporous content. According to H₂-TPR analyses, catalytic performance of the incorporated Fe in the Catalytic Wet Peroxide Oxidation (CWPO) reaction strongly depends on the level of location in mixed Al/Fe pillars. Altogether, such physicochemical characteristics promoted high performance in CWPO catalytic degradation of methyl orange in aqueous medium at very mild reaction temperatures (25.0 ± 1.0 °C) and pressure (76 kPa), achieving TOC removal of 52% and 70% of azo-dye decolourization in only 75 min of reaction under very low concentration of clay catalyst (0.05 g/L).

  2. Understanding the role of clay minerals in the chromium(VI) bioremoval by Pseudomonas aeruginosa CCTCC AB93066 under growth condition: microscopic, spectroscopic and kinetic analysis.

    Science.gov (United States)

    Kang, Chunxi; Wu, Pingxiao; Li, Yuewu; Ruan, Bo; Li, Liping; Tran, Lytuong; Zhu, Nengwu; Dang, Zhi

    2015-11-01

    Laboratory batch experiments were conducted to investigate the role of clay minerals, e.g., kaolinite and vermiculite, in microbial Cr(VI) reduction by Pseudomonas aeruginosa under growth condition in glucose-amended mediums as a method for treating Cr(VI)-contaminated subsurface environment such as soil. Our results indicated that glucose could acted as an essential electron donor, and clay minerals significantly enhanced microbial Cr(VI) reduction rates by improving the consumption rate of glucose and stimulating the growth and propagation of P. aeruginosa. Cr(VI) bioreduction by both free cells and clay minerals-amended cells followed the pseudo-first-order kinetic model, with the latter one fitting better. The mass balance analyses and X-ray photoelectron spectroscopy analysis found that Cr(VI) was reduced to Cr(III) and the adsorption of total chromium on clay minerals-bacteria complex was small, implying that Cr(VI) bioremoval was not mainly due to the adsorption of Cr(VI) onto cells or clay minerals or clay minerals-cells complex but mainly due to the Cr(VI) reduction capacity of P. aeruginosa under the experimental conditions studied (e.g., pH 7). Atomic force microscopy revealed that the addition of clay minerals (e.g. vermiculite) decreased the surface roughness of Cr(VI)-laden cells and changed the cell morphology and dimension. Fourier transform infrared spectroscopy revealed that organic matters such as aliphatic species and/or proteins played an important role in the combination of cells and clay minerals. Scanning electron microscopy confirmed the attachment of cells on the surface of clay minerals, indicating that clay minerals could provide a microenvironment to protect cells from Cr(VI) toxicity and serve as growth-supporting materials. These findings manifested the underlying influence of clay minerals on microbial reduction of Cr(VI) and gave an understanding of the interaction between pollutants, the environment and the biota.

  3. Characterization of element and mineral content in Artemisia annua ...

    African Journals Online (AJOL)

    Characterization of element and mineral content in Artemisia annua and Camellia sinensis leaves by handheld X-ray fluorescence. Traore Alassane, Diallo Mouhamadou, Gueye Papa El Hadji Omar, Wague Ahmadou, Lutgen Pierre, Sarr Ousmane, Mboup Souleymane ...

  4. Minerals and Total Polyphenolic Content of Some Vegetal Powders

    Directory of Open Access Journals (Sweden)

    Roxana E. TUFEANU

    2017-11-01

    Full Text Available The total polyphenolic content and minerals were determined for chia seeds, Psyllium husks and watermelon rind powder. The minerals content was performed by using the Inductively Coupled Plasma Optical Emissions Spectrometer and Atomic Absorption Spectrometer, technique FIAS-Furnace (for Se. The sample with the highest content of polyphenols was chia (2.69 mg GAE/g s. followed by the watermelon rind powder. Reduced amounts of polyphenols were found in the Psyllium husks. Also, the total polyphenol concentration increased with the increase of the extraction time on the ultrasonic water bath. Minerals analysis indicated that powders obtained from chia seeds and watermelon rind contained large amounts of potassium, calcium, phosphorus and magnesium. The most abundant mineral in the Psyllium husks powder was found potassium, followed by calcium. In conclusion, these powders can be used as ingredients for functional food and food supplements production due to the high nutritional content and bioactive properties.

  5. Mineral, vitamin C and crude protein contents in kale (Brassica ...

    African Journals Online (AJOL)

    ajl yemi

    2011-10-27

    Oct 27, 2011 ... Key words: Kale (Brassica oleracea var. acephala), harvesting stage, vitamin C, crude protein, mineral content. .... L-ascorbic acid (or vitamin C) in plant tissues. .... Cooking methods of Brassica rapa affect the preservation of.

  6. The influence of mineralization on the phase composition and properties of low-burned clay-dolomited composition materials

    International Nuclear Information System (INIS)

    Shirin-zade, I.N.; Ganbarov, D.M.

    2008-01-01

    With aim of acceleration of dissociation of carbonates in clay-dolomited compositions Na 2 SiF 6 was added. Addition mineralization raise stability of composition reaches 20-30 MPa. Na 2 SiF 6 mineralization makes more active decomposition of dolomite and accelerate appearance of new creations. It was experimentally proved that adding of mineralization of Na 2 SiF 6 promote to appearance in mixture of intermediate double salts which are bring down temperature of dissociation of carbonates. Accelerated action of mineralization Na 2 SiF 6 accepted by x-ray, DTA and x-ray spectroscopy

  7. Effect of clay mineral on utilization of some mineral elements in ruminant feeding

    International Nuclear Information System (INIS)

    IBRAHIM, A.K.M.

    2012-01-01

    This study was carried out to evaluate the effects of tafla and bentofarm addition on feed intake, water intake, digestibility, nutritive values, some rumen parameters, nitrogen retention, some minerals retention and some blood parameters of rams, growth performance and some blood constituents of growing lambs. Twenty seven Rahmani mature rams, averaged 45 kg of live body weight were divided randomly to three main groups each main group subdivided into three treatments (three animals each). Main first group fed 100% bereseam and served as control (T 1 ), the other two subgroups fed the T 1 diet plus 3% tafla (T 2 ) or 3% bentofarm (T 3 ).The second main group fed 50% bereseam and 50% concentrate feed mixture (T 4 ), the other two subgroups fed the T 4 diet plus 3% tafla (T 5 ) or 3% bentofarm (T 6 ).The third main group fed 100% concentrate feed mixture and rice straw (T 7 ), the other subgroups fed (T 7 )diet plus 3% tafla (T 8 ) or 3% bentofarm (T 9 ).To carry out the growth trial, forty eight growing baladi male lambs about 2 months of age and average live body weight 17 kg were divided into six similar groups (eight lambs for each) according to their body weight. The experimental rations were: T 4 -T 9 in previous tasted rations. The results of digestibility of DM and CP significantly (P<0.05) decreased as a result of tafla and bentofarm addition than that of the control, while OM, CF, EE and NFE digestibilities were slightly improved with tafla or bentofarm compared with those of control, but the differences were not significant among treatments. However, the results of nutritive values as TDN, SV and DCP showed no significant differences among treatments. The results of ruminal parameters as TVFA's, ph and microbial protein significantly increased as a result of tafla and bentofarm addition than that of the control, but the values of ammonia-N concentrations significantly decreased by addition of tafla and bentofarm compared with the control treatments.

  8. The Imprint of Atmospheric Evolution in the D/H of Hesperian Clay Minerals on Mars

    Science.gov (United States)

    Mahaffy, P. R.; Webster, C. R.; Stern, J. C.; Brunner, A. E.; Atreya, S. K.; Conrad, P. G.; Domagal-Goldman, S.; Eigenbrode, J. L.; Flesch, G. J.; Christensen, L. E.; hide

    2014-01-01

    The deuterium-to-hydrogen (D/H) ratio in strongly bound water or hydroxyl groups in ancient Martian clays retains the imprint of the water of formation of these minerals. Curiosity's Sample Analysis at Mars (SAM) experiment measured thermally evolved water and hydrogen gas released between 550 degrees Centigrade and 950 degrees Centigrade from samples of Hesperian-era Gale crater smectite to determine this isotope ratio. The D/H value is 3.0 (plus or minus 0.2) times the ratio in standard mean ocean water. The D/H ratio in this approximately 3-billion-year-old mudstone, which is half that of the present Martian atmosphere but substantially higher than that expected in very early Mars, indicates an extended history of hydrogen escape and desiccation of the planet.

  9. Wind-blown sandstones cemented by sulfate and clay minerals in Gale Crater, Mars

    Science.gov (United States)

    Milliken, R. E.; Ewing, R. C.; Fischer, W. W.; Hurowitz, J.

    2014-02-01

    Gale Crater contains Mount Sharp, a ~5 km thick stratigraphic record of Mars' early environmental history. The strata comprising Mount Sharp are believed to be sedimentary in origin, but the specific depositional environments recorded by the rocks remain speculative. We present orbital evidence for the occurrence of eolian sandstones within Gale Crater and the lower reaches of Mount Sharp, including preservation of wind-blown sand dune topography in sedimentary strata—a phenomenon that is rare on Earth and typically associated with stabilization, rapid sedimentation, transgression, and submergence of the land surface. The preserved bedforms in Gale are associated with clay minerals and elsewhere accompanied by typical dune cross stratification marked by bounding surfaces whose lateral equivalents contain sulfate salts. These observations extend the range of possible habitable environments that may be recorded within Gale Crater and provide hypotheses that can be tested in situ by the Curiosity rover payload.

  10. Bacillus subtilis biofilm development in the presence of soil clay minerals and iron oxides.

    Science.gov (United States)

    Ma, Wenting; Peng, Donghai; Walker, Sharon L; Cao, Bin; Gao, Chun-Hui; Huang, Qiaoyun; Cai, Peng

    2017-01-01

    Clay minerals and metal oxides, as important parts of the soil matrix, play crucial roles in the development of microbial communities. However, the mechanism underlying such a process, particularly on the formation of soil biofilm, remains poorly understood. Here, we investigated the effects of montmorillonite, kaolinite, and goethite on the biofilm formation of the representative soil bacteria Bacillus subtilis . The bacterial biofilm formation in goethite was found to be impaired in the initial 24 h but burst at 48 h in the liquid-air interface. Confocal laser scanning microscopy showed that the biofilm biomass in goethite was 3-16 times that of the control, montmorillonite, and kaolinite at 48 h. Live/Dead staining showed that cells had the highest death rate of 60% after 4 h of contact with goethite, followed by kaolinite and montmorillonite. Atomic force microscopy showed that the interaction between goethite and bacteria may injure bacterial cells by puncturing cell wall, leading to the swarming of bacteria toward the liquid-air interface. Additionally, the expressions of abrB and sinR , key players in regulating the biofilm formation, were upregulated at 24 h and downregulated at 48 h in goethite, indicating the initial adaptation of the cells to minerals. A model was proposed to describe the effects of goethite on the biofilm formation. Our findings may facilitate a better understanding of the roles of soil clays in biofilm development and the manipulation of bacterial compositions through controlling the biofilm in soils.

  11. Considering Organic Carbon for Improved Predictions of Clay Content from Water Vapor Sorption

    DEFF Research Database (Denmark)

    Arthur, Emmanuel; Tuller, Markus; Moldrup, Per

    2014-01-01

    Accurate determination of the soil clay fraction (CF) is of crucial importance for characterization of numerous environmental, agricultural, and engineering processes. Because traditional methods for measurement of the CF are laborious and susceptible to errors, regression models relating the CF...... to water vapor sorption isotherms that can be rapidly measured with a fully automated vapor sorption analyzer are a viable alternative. In this presentation we evaluate the performance of recently developed regression models based on comparison with standard CF measurements for soils with high organic...... carbon (OC) content and propose a modification to improve prediction accuracy. Evaluation of the CF prediction accuracy for 29 soils with clay contents ranging from 6 to 25% and with OC contents from 2.0 to 8.4% showed that the models worked reasonably well for all soils when the OC content was below 2...

  12. First principles molecular dynamics insight into acid-base chemistry of clay minerals

    International Nuclear Information System (INIS)

    Liu, Xiandong; Lu, Xiancai; Wang, Rucheng; Meijer, Evert Jan

    2012-01-01

    Document available in extended abstract form only. Microscopic knowledge on the interfaces between clay minerals (2:1- and 1:1-type) and water is critical for both understanding natural processes and guiding development of advanced hybrid materials. Due to the unique layered structures of clay minerals, their surfaces are usually grouped into basal surfaces and edge surfaces (i.e. broken surfaces). Thanks to previous studies, structures and properties of basal surfaces have been well recognized: these surfaces are terminated with siloxanes and surface Si-O six-member rings normally act as the adsorbing sites of cations. In contrast, edge surfaces are more complicated structures and have more subtle chemical properties. On these surfaces, there are a lot of dangling bonds and under ambient conditions they are usually saturated by chemically adsorbed waters. These edge groups are usually amphoteric, which is responsible to the pH dependent behaviors of many interfacial processes, such as cations complexing. For example, adsorption of heavy metal cations (e.g. Ni 2+ , Co 2+ , Zn 2+ , Cd 2+ ) on clay basal surfaces is through cation exchange mechanism and that is hardly influenced by environmental pH. In contrast, it has been well accepted that the adsorption on edge surfaces is pH-dependent. The ubiquitous isomorphic substitutions further increase the complexity of their interfacial chemistry. Due to the high heterogeneity and rather small sizes, it is quite difficult to reveal the complex interfacial chemistry with experiments alone. FPMD method (first principles molecular dynamics), a combination of density functional theory and molecular dynamics, can provide valuable information. With FPMD [1, 2] and free-energy calculation techniques [3, 4], we investigated the microscopic structures and acid chemistry of these clay-water interfaces [5, 6]. According to systematic simulations, the following has been achieved. (1) Acidity of interlayer waters. The simulations show

  13. Effects of magnesium minerals representative of the Callovian-Oxfordian clay-stone on borosilicate glass alteration

    International Nuclear Information System (INIS)

    Debure, M.

    2012-01-01

    Borosilicate glasses dissolution has been studied in presence of magnesium minerals. Those minerals (dolomite, illite, smectite...) belong to the Callovo-Oxfordian (COx) clay-stone layer, studied in France as a potential site for nuclear waste disposal. Such minerals contain magnesium, an element able to sustain glass alteration when it is available in solution. In the confined media of the wastes disposal, the solids reactivity controls the solution composition and can be the driving force of nuclear glass alteration. Experiments show that magnesium carbonates (hydro-magnesite and dolomite) increase in the glass alteration: the precipitation of magnesium silicates consumes silicon which slows down the formation of the glass passivating layer. The lower the magnesium mineral solubility, the lower the glass alteration. The purified clay phases (illite, smectite...) from the COx layer increase the glass alteration. Half the magnesium was replaced by sodium during the purification process. In such conditions, the effect of clay phases on glass alteration is in part due to the acidic pH-buffering effect of the clay fraction. The GRAAL model implemented in the geochemical transport code HYTEC has confirmed and quantified the mechanisms put in evidence in the experiments. Cells diffusion experiments where the two solids were separated by an inert diffusion barrier allow to valid reactive transport modelling. Such experiments are more representative of the glass package which will be separated from the COx by corrosion products. They show that glass alteration rate is reduced when solids are not close. (author) [fr

  14. Complexity of clay mineral formation during 120,000 years of soil development along the Franz Josef chronosequence, New Zealand

    International Nuclear Information System (INIS)

    Dietel, J.; Dohrmann, R.; Guggenberger, G.; Meyer-Stueve, S.; Turner, S.; Schippers, A.; Kaufhold, S.; Butz-Braun, R.; Condron, L.M.; Mikutta, R.

    2017-01-01

    Weathering of primary silicates to secondary clay minerals over time affects multiple soil functions such as the accumulation of organic matter and nutrient cations. However, the extent of clay mineral (trans)formation as a function of soil development is poorly understood. In this study, the degree of weathering of sediments along a 120 kyr soil formation gradient was investigated using X-ray diffraction, Fourier transform infrared spectroscopy and X-ray fluorescence spectroscopy. Irrespective of site age, mica and chlorite were the dominant clay minerals. During weathering, a remarkable suite of transitional phases such as vermiculite and several interstratifications with vermiculitic, smectitic, chloritic and micaceous layers developed. The degree of weathering was correlated with soil pH and depletion of K, Ca, Na, Fe and Al, regarding both soil depth and site age. Kaolinite occurred especially at the 120 kyr site, indicating slow formation via transitional phases. The findings of this study revealed that long-term soil development caused complex clay mineral assemblages, both temporally and spatially, and linking this variability to soil functioning warrants further research. (author).

  15. Radiation-related retrograde hydrogen isotope and K-Ar exchange in clay minerals

    International Nuclear Information System (INIS)

    Halter, C.; Pagel, M.; Sheppard, S.M.F.; Weber, F.; Clauer, N.

    1987-01-01

    Hydrogen and oxygen isotope studies have been widely applied to characterize the origin of fluids during ore-foaming processes. The primary isotope record, however, may be disturbed by retrograde exchange reactions, thus complicating the interpretation of the data. The susceptibility of minerals to retrograde isotope and chemical exchange is variable, reflecting differences in the mechanism and rate of isotope exchange. Results are presented on deuterium depletion, K/Ar ages and H 2 O + content of illites associated with uranium mineralization from the Athabasca basin (Canada). (author)

  16. Laboratory experiments on ammoniated clay minerals with relevance for asteroid (1) Ceres

    Science.gov (United States)

    De Angelis, Simone; Stefani, Stefania; De Sanctis, Maria Cristina; Piccioni, Giuseppe; Ammannito, Eleonora

    2017-04-01

    Recent observations with VIR spectrometer onboard Dawn spacecraft [1] have suggested the presence of ammoniated phyllosilicates widespread on the surface of asteroid (1) Ceres [2,3]. The global surface composition of Ceres as suggested by VIR average infrared spectrum in the 1-4 micron range appears to be due to a mixture of NH4-bearing phyllosilicates, serpentine, carbonates and a dark absorbing phase (magnetite or amorphous carbon) [2]. An absorption feature occurring near 3.1 micron in the average spectrum is considered the main evidence for the presence of NH4-bearing phase; nevertheless in the past several authors tried to explain this feature, as observed with telescopic spectra, invoking the presence of brucite, cronstedtite, water ice or clays [4]. In this project we are carrying out laboratory experiments with the aim of studying ammoniated phyllosilicates in the visible-infrared range. A suite of 9 clay minerals has been used for this study, including illite, nontronite and montmorillonite. In order to produce the ammoniated species we followed a modified procedure based on the one described in Bishop et al. (2002) [5]. All minerals were reduced in fine grain size (features, appearing at different wavelengths near 2, 3, 6 and 7 micron. In some cases the spectral shape of already existent absorption bands resulted deeply modified. A few species did not show the appearance of new features. These results suggest that NH4+ ions fix in various ways in different minerals. Nontronite and montmorillonite appear to be the best candidates, among the studied suite, to be used in future laboratory reproduced analog mixtures. [1] Russell C.T. et al., 2004, Planetary and Space Science, 52, 465-489 [2] De Sanctis M.C. et al., 2015, Nature, 528, 241-244 [3] Ammannito E. et al., 2016, Science, vol.353, issue 6303 [4] Rivkin A.S. et al., 2011, Space Science Reviews, 163, 95-116 [5] Bishop J.L. et al., 2002, Planetary and Space Science, 50, 11-19

  17. Bone mineral content and bone metabolism in young adults with severe periodontitis

    DEFF Research Database (Denmark)

    Wowern von, N.; Westergaard, J.; Kollerup, G.

    2001-01-01

    Bone loss, bone markers, bone metabolism, bone mineral content, osteoporosis, severe periodontitis......Bone loss, bone markers, bone metabolism, bone mineral content, osteoporosis, severe periodontitis...

  18. Beyond clay: Towards an improved set of variables for predicting soil organic matter content

    Science.gov (United States)

    Rasmussen, Craig; Heckman, Katherine; Wieder, William R.; Keiluweit, Marco; Lawrence, Corey R.; Berhe, Asmeret Asefaw; Blankinship, Joseph C.; Crow, Susan E.; Druhan, Jennifer; Hicks Pries, Caitlin E.; Marin-Spiotta, Erika; Plante, Alain F.; Schadel, Christina; Schmiel, Joshua P.; Sierra, Carlos A.; Thompson, Aaron; Wagai, Rota

    2018-01-01

    Improved quantification of the factors controlling soil organic matter (SOM) stabilization at continental to global scales is needed to inform projections of the largest actively cycling terrestrial carbon pool on Earth, and its response to environmental change. Biogeochemical models rely almost exclusively on clay content to modify rates of SOM turnover and fluxes of climate-active CO2 to the atmosphere. Emerging conceptual understanding, however, suggests other soil physicochemical properties may predict SOM stabilization better than clay content. We addressed this discrepancy by synthesizing data from over 5,500 soil profiles spanning continental scale environmental gradients. Here, we demonstrate that other physicochemical parameters are much stronger predictors of SOM content, with clay content having relatively little explanatory power. We show that exchangeable calcium strongly predicted SOM content in water-limited, alkaline soils, whereas with increasing moisture availability and acidity, iron- and aluminum-oxyhydroxides emerged as better predictors, demonstrating that the relative importance of SOM stabilization mechanisms scales with climate and acidity. These results highlight the urgent need to modify biogeochemical models to better reflect the role of soil physicochemical properties in SOM cycling.

  19. Characterization of clay used for red ceramic fabrication

    International Nuclear Information System (INIS)

    Pereira, P.S.; Morais, A.S.C.; Caldas, T.C.C.; Monteiro, S.N.; Vieira, C.M.F.

    2011-01-01

    The objective of this work is to characterize a clay used in the red ceramics fabrication, from Campos dos Goytacazes north of the State of Rio de Janeiro. The clay was submitted for physical, chemical and mineralogical tests. The results showed that the clay has a high content of clay minerals with kaolinitic predominance, high loss on ignition and low flux oxides. It is recommended that this clay is mixed with non-plastic materials. (author)

  20. On the origin of mixed-layered clay minerals from the San Andreas Fault at 2.5-3 km vertical depth (SAFOD drillhole at Parkfield, California)

    Science.gov (United States)

    Schleicher, A. M.; Warr, L. N.; van der Pluijm, B. A.

    2009-02-01

    A detailed mineralogical study is presented of the matrix of mudrocks sampled from spot coring at three key locations along the San Andreas Fault Observatory at depth (SAFOD) drill hole. The characteristics of authigenic illite-smectite (I-S) and chlorite-smectite (C-S) mixed-layer mineral clays indicate a deep diagenetic origin. A randomly ordered I-S mineral with ca. 20-25% smectite layers is one of the dominant authigenic clay species across the San Andreas Fault zone (sampled at 3,066 and 3,436 m measured depths/MD), whereas an authigenic illite with ca. 2-5% smectite layers is the dominant phase beneath the fault (sampled at 3,992 m MD). The most smectite-rich mixed-layered assemblage with the highest water content occurs in the actively deforming creep zone at ca. 3,300-3,353 m (true vertical depth of ca. 2.7 km), with I-S (70:30) and C-S (50:50). The matrix of all mudrock samples show extensive quartz and feldspar (both plagioclase and K-feldspar) dissolution associated with the crystallization of pore-filling clay minerals. However, the effect of rock deformation in the matrix appears only minor, with weak flattening fabrics defined largely by kinked and fractured mica grains. Adopting available kinetic models for the crystallization of I-S in burial sedimentary environments and the current borehole depths and thermal structure, the conditions and timing of I-S growth can be evaluated. Assuming a typical K+ concentration of 100-200 ppm for sedimentary brines, a present-day geothermal gradient of 35°C/km and a borehole temperature of ca. 112°C for the sampled depths, most of the I-S minerals can be predicted to have formed over the last 4-11 Ma and are probably still in equilibrium with circulating fluids. The exception to this simple burial pattern is the occurrence of the mixed layered phases with higher smectite content than predicted by the burial model. These minerals, which characterize the actively creeping section of the fault and local thin film

  1. The effect of motor vehicle emission towards lead (Pb content of rice field soil with different clay content

    Directory of Open Access Journals (Sweden)

    C.C.Wati

    2015-10-01

    Full Text Available Motor vehicle gas emission contains lead (Pb which is a hazardous and toxic substance. Agricultural land, especially rice field, which is located nearby roads passed by many motor vehicle, are susceptible to the accumulation of Pb. If Pb is permeated by plants cultivated in the rice field, it will be very hazardous for humans as they are the final consumers. Hence, it is essential to identify Pb content of rice-field soil initiated by motor vehicle gas emission. This study was aimed to identify the effects of motor vehicle density, the distance between rice-field and road, and the clay content of soil towards Pb content of soils in Blitar and Ngawi Regencies of East Java. The method used for the study was survey method managed by using three-factor nested design with three replicates. The results of this study showed that motor vehicle density and the distance of rice field to road provide significant affected the total of Pb content of soil. However, the dissemination pattern of Pb in the soil was irregular due to the factors of climate and environment. Before Pb reached soil surface, Pb was spread out in the air due to the effect of temperature, wind velocity, vehicle velocity, size of vehicle, and road density. Consequently, the location with low motor vehicle density and positioned faraway to the road had higher total rate of Pb than the location with high motor vehicle density and positioned nearby the road. Clay content affected the total rate of Pb content as much as 37%, every 1% increase of clay content increased the total rate of Pb as much as 0.08 mg/kg.

  2. Computed-tomographic determination of mineral content of bones

    International Nuclear Information System (INIS)

    Delov, I.; Tabakov, S.

    1988-01-01

    The problem of precise computed-tomographic densitometry of the mineral content of bones is pointed out. A method is proposed including the use of standard density and observance of definite radiation, scanning and image estimation parameters. A good correlation of the results obtained for the mineral content of the lumbar vertebrae with literature data are reported. A method is also described for determining the mineral content of tubular bones based on densiprofile check-up of the computed-tomographic density. The procedure takes 10-15 minutes and includes 1 or 2 scans. It might therefore gain wide acceptance for the diagnosis and tracing of osteoporosis and other osteopathies associated with distrorted calcium metabolism

  3. Luminescent Oxygen Gas Sensors Based on Nanometer-Thick Hybrid Films of Iridium Complexes and Clay Minerals

    Directory of Open Access Journals (Sweden)

    Hisako Sato

    2014-01-01

    Full Text Available The use of Ir(III complexes in photo-responsive molecular devices for oxygen gas sensing is reviewed. Attention is focused on the immobilization of Ir(III complexes in organic or inorganic host materials such as polymers, silica and clays in order to enhance robustness and reliability. Our recent works on constructing nanometer-thick films comprised of cyclometalated cationic Ir(III complexes and clay minerals are described. The achievement of multi-emitting properties in response to oxygen pressure is demonstrated.

  4. Study on rich alumina alkali-activated slag clay minerals cementitious materials for immobilization of radioactive waste

    International Nuclear Information System (INIS)

    Li Yuxiang; Qian Guangren; Yi Facheng; Shi Rongming; Fu Yibei; Li Lihua; Zhang Jun

    1999-01-01

    The composition and some properties of its pastes of rich alumina alkali-activated slag clay minerals (RAAASCM) cementitious materials for immobilization of radioactive waste are studied. Experimental results show that heat activated kaolinite, Xingjiang zeolite, modified attapulgite clay are better constituents of RAAASCM. RAAASCM cementitious materials pastes exhibit high strength, low porosity, fewer harmful pore, and high resistance to sulphate corrosion as well as gamma irradiation. The Sr 2+ , Cs + leaching portion of the simulated radioactive waste forms based on RAAASCM, is low

  5. Characterization of clay deposits from Egypt and assessment of their potential application for waste water treatment: How dissolved organic matter determines the interaction of heavy metals and clay minerals

    NARCIS (Netherlands)

    Refaey Mohammed, Y.B.

    2016-01-01

    The main aim of this study was to investigate the potential of using clay minerals abundant in local soils in Egypt as low cost materials to reduce Cu, Ni and Zn pollution of soil and groundwater originating from polluted wastewater; specifically focusing on the influence of the interaction of clay

  6. Effect of carbonate content on the mechanical behaviour of clay fault-gouges

    Science.gov (United States)

    Bakker, Elisenda; Niemeijer, André; Hangx, Suzanne; Spiers, Chris

    2015-04-01

    Carbon dioxide capture and storage (CCS) in depleted oil and gas reservoirs is considered to be the most promising technology to achieve large-scale reduction in anthropogenic emissions. In order to retain the stored CO2 from the atmosphere for the very long-term, i.e. on timescales of the order of 103-104 years, it is essential to maintain the integrity of the caprock, and more specifically of any faults penetrating the seal. When selecting suitable CO2-storage reservoirs, pre-exisiting faults within the caprock require close attention, as changes in the stress state resulting from CO2-injection may induce fault slip motion which might cause leakage. Little is known about the effect of fluid-rock interactions on the mineral composition, mechanical properties and the integrity and sealing capacity of the caprock. Previous studies on the effect of mineral composition on the frictional properties of fault gouges have shown that friction is controlled by the dominant phase unless there is a frictionally weak, through-going fabric. However, the effect on stability is less clear. Since long-term CO2-exposure might cause chemical reactions, potentially resulting in the dissolution or precipitation of carbonate minerals, a change in mineralogy could affect the mechanical stability of a caprock significantly. Calcite, for example, is known to be prone to micro-seismicity and shows a transition from velocity-strengthening to velocity-weakening behaviour around 100-150°C. Therefore, we investigated the effect of varying clay:carbonate ratios on fault friction behaviour, fault reactivation potential and slip stability, i.e. seismic vs. aseismic behaviour. Three types of simulated fault gouges were used: i) carbonate-free, natural clay-rich caprock samples, consisting of predominantly phyllosilicates (~80%) and quartz ~20%), ii) pure calcite, and iii) mixtures of carbonate-free clay-rich caprock and pure calcite, with predetermined clay:carbonate ratios. For the natural clay

  7. Mineral content of traditional leafy vegetables from western Kenya

    DEFF Research Database (Denmark)

    Orech, F.O.; Christensen, Dirk Lund; Larsen, T.

    2007-01-01

    and diseases. This paper describes the mineral (calcium, iron and zinc) contents in some 54 traditional vegetable species collected from Nyang'oma area of Bondo district, western Kenya. Atomic absorption spectroscopy was used to determine the mineral content. We found that most traditional leafy vegetables......, domesticated and wild, generally contain higher levels of calcium, iron and zinc compared with the introduced varieties such as spinach (Spanacia oleracea), kale (Brassica oleracea var. acephala) and cabbage (Brassica oleracea var. capitata). The results of this study could contribute towards identification...

  8. Comparing Kriging and Regression Approaches for Mapping Soil Clay Content in a diverse Danish Landscape

    DEFF Research Database (Denmark)

    Adhikari, Kabindra; Bou Kheir, Rania; Greve, Mette Balslev

    2013-01-01

    Information on the spatial variability of soil texture including soil clay content in a landscape is very important for agricultural and environmental use. Different prediction techniques are available to assess and map spatial variability of soil properties, but selecting the most suitable techn...... the prediction in OKst compared with that in OK, whereas RT showed the lowest performance of all (R2 = 0.52; RMSE = 0.52; and RPD = 1.17). We found RKrr to be an effective prediction method and recommend this method for any future soil mapping activities in Denmark....... technique at a given site has always been a major issue in all soil mapping applications. We studied the prediction performance of ordinary kriging (OK), stratified OK (OKst), regression trees (RT), and rule-based regression kriging (RKrr) for digital mapping of soil clay content at 30.4-m grid size using 6...

  9. Effects of Organic Matter and Clay Content in Soil on Pesticide Adsorption Processes

    Directory of Open Access Journals (Sweden)

    Rada Đurović

    2009-01-01

    Full Text Available The effect of organic matter and clay content on the adsorption of atrazine, acetochlor, clomazone, pendimethalin and oxyfluorfen in soil samples was studied. In order to determine whether and to what degree different soil properties affect the process of determinationof selected pesticides, three soils with different clay and organic matter contents were used. An optimized liquid-solid extraction procedure followed by SPME measurement was applied to analyse the selected pesticides in soil samples. Detection and quantificationwere done by gas chromatography-mass spectrometry (GC/MS. Relative standard deviation (RSD values for multiple analyses of soil samples fortified at 30 μg/kg of each pesticide were below 19%. Limits of detection (LODs for all compounds studied were less than 2 μg/kg. The results indicate that soils with different physico-chemical properties have different effects on the adsorption of most pesticides, especially at higher concentration levels.

  10. Sorption kinetics and chemical forms of Cd(II) sorbed by thiol-functionalized 2:1 clay minerals

    International Nuclear Information System (INIS)

    Malferrari, D.; Brigatti, M.F.; Laurora, A.; Pini, S.; Medici, L.

    2007-01-01

    The interaction between Cd(II) in aqueous solution and two 2:1 expandable clay minerals (i.e., montmorillonite and vermiculite), showing different layer charge, was addressed via batch sorption experiments on powdered clay minerals both untreated and amino acid (cysteine) treated. Reaction products were characterized via X-ray powder diffraction (XRDP), chemical analysis (elemental analysis and atomic absorption spectrophotometry), thermal analysis combined with evolved gasses mass spectrometry (TGA-MSEGA) and synchrotron-based X-ray absorption spectroscopy via extended X-ray absorption fine structure (EXAFS) characterization. Sorption isotherms for Cd(II) in presence of different substrates, shows that Cd(II) uptake depends both on Cd(II) starting concentration and the nature of the substrate. Thermal decomposition of Cd-cysteine treated clay minerals evidences the evolution of H 2 O, H 2 S, NO 2 , SO 2 , and N 2 O 3 . These results are well consistent with XRDP data collected both at room and at increasing temperature and further stress the influence of the substrate, in particular cysteine, on the interlayer. EXAFS studies suggest that Cd(II) coordinates with oxygen atoms, to give monomer complexes or CdO molecules, either on the mineral surface and/or in the interlayer. For Cd-cysteine complexes EXAFS data agree with the existence of Cd-S clusters, thus suggesting a predominant role of the thiol group in the bonding of Cd with the amino acid

  11. Clay content prediction using on-the-go proximal soil sensor fusion

    DEFF Research Database (Denmark)

    Tabatabai, Salman; Knadel, Maria; Greve, Mogens Humlekrog

    on soil usability, very few studies so far have provided robust and accurate predictions for fields with high clay content variability. An on-the-go multi-sensor platform was used to measure topsoil (25cm) VNIR spectra and temperature as well as electrical conductivity of top 30cm and top 90cm in 5 fields...... least squares regression (PLSR) and support vector machines regression (SVMR) were performed using VNIR spectra, EC and soil temperature as predictors and clay content as the response variable. PLSR and SVMR models were validated using full and 20-segment cross-validation respectively. The results were...... highly accurate with R2 of 0.91 and 0.93, root mean square error (RMSE) of 1.19 and 1.08, and ratio of performance to interquartile range (RPIQ) of 4.6 and 5.1 for PLSR and SVMR respectively. This shows the high potential of on-the-go soil sensor fusion to predict soil clay content and automate...

  12. Visible-near-infrared spectroscopy can predict the clay/organic carbon and mineral fines/organic carbon ratios

    DEFF Research Database (Denmark)

    Hermansen, Cecilie; Knadel, Maria; Møldrup, Per

    2016-01-01

    The ratios of mineral fines (carbon (OC), consisting of the n-ratio (i.e., the clay/OC ratio) and m-ratio (i.e., the fines/OC ratio) have recently been used to analyze and predict soil functional properties such as tilth conditions, clay dispersibility, degree...... from seven Danish and one Greenlandic fields, with a large textural range (clay: 0.027–0.355 kg kg−1; OC: 0.011–0.084 kg kg−1; n-ratio: 0.49–16.80; m-ratio: 1.46–32.14), were analyzed for texture and OC and subsequently scanned with a vis-NIR spectrometer from 400 to 2500 nm. The spectral data were...

  13. Characterization and technological properties of mineral clays used in the Southwest of Parana and West of Santa Catarina states

    International Nuclear Information System (INIS)

    Valdameri, C.Z.; Ciesca, D.F.; Zatta, L.; Anaissi, F.J.

    2014-01-01

    This paper aims to characterize clay minerals used in the ceramic industry in southwestern region of Parana and west of Santa Catarina states. The precursors used were the same used by industries in these regions for the production of bricks. The precursors were characterized,preliminary results are shown with respect to structural, chemical and physical precursors (XRD, EDS and plasticity). The specimens were characterized for technological burning properties: linear shrinkage, water absorption, flexural tension and density. The results show that the clays present Typical chemical composition of raw clay, however, the evaluation of technological properties after burning indicate negative results to be applied to the manufacture of red ceramic because did not meet the regulatory requirements. (author)

  14. Effects of Calcined clay minerals and Silica fume on the compressive strength of concrete

    Directory of Open Access Journals (Sweden)

    Abolfazl Soltani

    2017-05-01

    Full Text Available Pozzolanic materials are well known as potential replacements for cement manufacturing in order to increase compressive strength and improve durability of concrete in different environments and leading to save energy particularly reducing global warming effect. The present study reveals the effect of calcined clay minerals as natural pozzolanic material, separately and in combination with and without silica fume. To achieve this aim, 15 mixed designs with a constant water to cementitious ratio of  0.38 is made. In six mixed designs only metakaolin, zeolite or silica fume  and in eight other designs metakaolin and silica fume or zeolite and silica fume have been combined. Mixes containing metakaolin or zeolite with ratio of 10 or 20 percent and silica fume with 7 or 10 percent show significant increasing in compressive strength and improving durability, being valuable replacement for cement (in percentages. In particular, the best practice is attributed to the age of 28 days for compressive strength the replacement of the composition is 10% zeolite with 7% of silica fume and for electrical resistance the replacement of the composition is 10% zeolite with 7% of silica fume.

  15. Stochastic Approach to Determine CO2 Hydrate Induction Time in Clay Mineral Suspensions

    Science.gov (United States)

    Lee, K.; Lee, S.; Lee, W.

    2008-12-01

    A large number of induction time data for carbon dioxide hydrate formation were obtained from a batch reactor consisting of four independent reaction cells. Using resistance temperature detector(RTD)s and a digital microscope, we successfully monitored the whole process of hydrate formation (i.e., nucleation and crystal growth) and detected the induction time. The experiments were carried out in kaolinite and montmorillonite suspensions at temperatures between 274 and 277 K and pressures ranging from 3.0 to 4.0 MPa. Each set of data was analyzed beforehand whether to be treated by stochastic manner or not. Geochemical factors potentially influencing the hydrate induction time under different experimental conditions were investigated by stochastic analyses. We observed that clay mineral type, pressure, and temperature significantly affect the stochastic behavior of the induction times for CO2 hydrate formation in this study. The hydrate formation kinetics along with stochastic analyses can provide basic understanding for CO2 hydrate storage in deep-sea sediment and geologic formation, securing its stability under the environments.

  16. Antioxidant capacity and mineral contents of edible wild Australian mushrooms.

    Science.gov (United States)

    Zeng, X; Suwandi, J; Fuller, J; Doronila, A; Ng, K

    2012-08-01

    Five selected edible wild Australian mushrooms, Morchella elata, Suillus luteus, Pleurotus eryngii, Cyttaria gunnii, and Flammulina velutipes, were evaluated for their antioxidant capacity and mineral contents. The antioxidant capacities of the methanolic extracts of the dried caps of the mushrooms were determined using a number of different chemical reactions in evaluating multi-mechanistic antioxidant activities. These included the Trolox equivalent antioxidant capacity, ferric ion reducing antioxidant power, and ferrous ion chelating activity. Mineral contents of the dried caps of the mushrooms were also determined by inductively coupled plasma-optical emission spectroscopy. The results indicated that these edible wild mushrooms have a high antioxidant capacity and all, except C. gunnii, have a high level of several essential micro-nutrients such as copper, magnesium, and zinc. It can be concluded that these edible wild mushrooms are good sources of nutritional antioxidants and a number of mineral elements.

  17. Bone mineral content of the forearm in healthy Dutch women

    NARCIS (Netherlands)

    Barentsen, R.; Raymakers, J.A.; Landman, J.O.; Duursma, S.A.

    1988-01-01

    Single energy photon absorptiometry is a reliable technique for assessing the bone mineral content (BMC) of cortical bone in the forearm. It can also be used for BMC measurement in the ultradistal part of the forearm, where there is a considerable proportion of trabecular bone. The results of a BMC

  18. Semen quality, biochemistry and mineral content of five strains of ...

    African Journals Online (AJOL)

    The study was conducted to evaluate the genetic effect on semen quality, biochemistry and mineral content of three strains of Nigerian indigenous and two exotic cocks. One hundred (100) adult local breeding cocks comprising 20 normal, 20 frizzle and 20 naked necks, 20 dominant black and 20 dominant blue feather were ...

  19. Mineral, vitamin C and crude protein contents in kale ( Brassica ...

    African Journals Online (AJOL)

    This study compares mineral, vitamin C and crude protein contents at different harvesting stages in kale (Brassica oleraceae var. acephala). Three different harvest periods as first harvest stage (at the rosette stage), second harvest stage (at the budding stage) and third harvest stage (at the flowering/blooming stage) were ...

  20. Mineral content in French type bread with sodium replacement using ...

    African Journals Online (AJOL)

    Mineral content in French type bread with sodium replacement using fluorescence spectrometry X-rays by energy dispersive. Thaisa A. Souza Gusmão, Rennan P. De Gusmão, Severina De Sousa, Mário Eduardo R. Moreira Cavalcanti Mata, Maria Elita M Duarte, Rossana Maria F. De Figuereido, Ricardo T Moreira ...

  1. Biomass, Mineral Elements and Protein Contents of Six Freshwater ...

    African Journals Online (AJOL)

    The biomass, mineral elements and protein contents of six freshwater macrophytes found in Ghana are reported in this paper. The plants are Ceratophyllum demersum (a submerged plant), Eichhornia crassipes and Pistia stratiotes (free-floating plants), Echinochloa pyramidalis and Typha domingensis (emergent plants) ...

  2. Use of clay-mineral alteration patterns to define syntectonic permeability of joints (cleat) in Pennsylvania anthracite coal

    Energy Technology Data Exchange (ETDEWEB)

    Daniels, E.J.; Marshak, S.; Altaner, S.P. [Chevron Oil Field Research Company, La Habra, CA (United States)

    1996-10-15

    Joints (cleat) in Pennsylvania anthracite contain two distinct clay-mineral assemblages, both of which formed by alteration of preexisting kaolinite at peak metamorphic conditions during the Alleghanian orogeny. The first assemblage, NH{sub 4} - illite or pyrophyllite {+-} quartz, formed by reaction of kaolinite with methane-rich fluids derived from within the coal. The second assemblage, sudoite {+-} tosudite {+-} rectorite {+-} berthierine, formed by the reaction of kaolinite with ferromagnesian-bearing hydrothermal fluids which must have come from outside the coal. In an earlier paper, the authors suggested that the first assemblage indicated clay diagenesis in low-permeability environments, and that the second assemblage indicated clay diagenesis in high-permeability environments. If this premise is correct, then the distribution of clay-mineral alteration assemblages serves to define syntectonic permeability variations in coal cleat. The first assemblage dominates in the coal matrix itself, in isolated cleat, in cleat that parallel the regional trend of Alleghanian folds, and in the mirror portions of cleat oriented perpendicular to the fold trends, suggesting that these regions are low-permeability environments. The second assemblage dominates in the hackle fringe of interconnected cleat that trend perpendicular to the strike of the Appalachian orogen, suggesting that these regions are high-permeability environments. These results emphasize that syntectonic cleat permeability is a function of cleat orientation, macroscopic cleat interconnetivity and orientation, as well as microscopic cleat-surface morphology.

  3. Mineral-produced high-pressure striae and clay polish: Key evidence for nonballistic transport of ejecta from Ries crater

    Science.gov (United States)

    Chao, E.C.T.

    1976-01-01

    Recently discovered mineral-produced, deeply incised striae and mirror-like polish on broken surfaces of limestone fragments from the sedimentary ejecta of the Ries impact crater of southern Germany are described. The striae and polish were produced under high confining pressures during high-velocity nonballistic transport of the ejecta mass within the time span of the cratering event (measured in terms of seconds). The striae on these fragments were produced by scouring by small mineral grains embedded in the surrounding clay matrix, and the polish was formed under the same condition, by movements of relatively fragment-free clay against the fragment surfaces. The occurrence of these striae and polish is key evidence for estimating the distribution and determining the relative importance of nonballistic and ballistic transport of ejecta from the shallow Ries stony meteorite impact crater.

  4. Radiostratigraphy and heavy mineral content of the Weches Formation (Eocene), Nacogdoches County, Texas

    International Nuclear Information System (INIS)

    Jobe, K.; Ledger, E.B.; Sharp, P.; Crocker, M.C.

    1993-01-01

    The Weches Formation of eastern Texas is a mudstone containing green sand-size clay aggregates. A vertical sequence of 43 samples was analyzed along an excavated cliff to determine radionuclide content. Samples average 5 ppm uranium and range from 2 to about 7 ppm. Thorium averages 20 ppm and ranges from 13 to almost 36 ppm. the gamma-ray spectrometer employed exhibits a certainty of about ±10% (one standard deviation) at the levels measured. Heavy mineral studies of mudstones are few, so one sample of the Weches mudstone was selected for heavy mineral separation and point counting of grain mounts. A total of 2606 grains were counted giving mineral percentages of zircon (28.8%), garnet (17.9%), tourmaline (10.5%), titanite (8.7%), apatite (7.6%), staurolite (6.4%), green hornblende (5.2%), epidote (5.1%), sillimanite (2.8%), monatite (2.2%), kyanite (1.9%), basaltic hornblende (1.5%), and biotite (1.3%). In addition, actinolite, spinel, rutile, and collophane were observed but not counted. Previous studies found a similar heavy mineral suite in the underlying Queen City Formation, but in different proportions. Differences in heavy mineral percentages probably reflect different water-flow regimes at the time of deposition. Heavy minerals in the Weches and Queen City formations are from the same general source area Measured radionuclide ratios are similar to granitic ratios and suggest that detrital heavy minerals, particularly zircon and monazite, are the main site of uranium and thorium and their decay products in the Weches Formation

  5. Content and distribution of fluorine in rock, clay and water in fluorosis area Zhaotong, Yunnan Province

    Energy Technology Data Exchange (ETDEWEB)

    Luo, K.; Li, H.; Feng, F. (and others) [Chinese Academy of Sciences, Beijing (China)

    2007-04-15

    About 160 samples of coal, pyritic coal balls, coal seam gangue, clay, corn, capsicum and drinking water were collected from the endemic fluorosis area of Zhenxiong and Weixin county, China to determine the fluorine content, distribution pattern and source in this fluorosis area. The study shows that the average fluorine content in the coal samples collected from 3 coal mines of the Late Permian coals in Zhenxiong and Weixin county, Zhaotong City, which are the main mining coals there, is 77.13 mg/kg. The average fluorine content coals collected form thee typical fluorosis villages in 72.56 mg/kg. Both of them are close to the world average and little low than the Chinese average. The fluorine content of drinking water is lower than 0.35 mg/L, the clay used as an additive for coal-burning and as a binfer in briquette-making by local residents has a high content of fluorine, ranging from 367-2,435 mg/kg, with the majority higher than 600 mg/kg and an average of 1,084.2 mg/kg. 29 refs., 5 tabs.

  6. Quantifying the clay content with borehole depth and impact on reservoir flow

    Science.gov (United States)

    Sarath Kumar, Aaraellu D.; Chattopadhyay, Pallavi B.

    2017-04-01

    This study focuses on the application of reservoir well log data and 3D transient numerical model for proper optimization of flow dynamics and hydrocarbon potential. Fluid flow through porous media depends on clay content that controls porosity, permeability and pore pressure. The pressure dependence of permeability is more pronounced in tight formations. Therefore, preliminary clay concentration analysis and geo-mechanical characterizations have been done by using wells logs. The assumption of a constant permeability for a reservoir is inappropriate and therefore the study deals with impact of permeability variation for pressure-sensitive formation. The study started with obtaining field data from available well logs. Then, the mathematical models are developed to understand the efficient extraction of oil in terms of reservoir architecture, porosity and permeability. The fluid flow simulations have been done using COMSOL Multiphysics Software by choosing time dependent subsurface flow module that is governed by Darcy's law. This study suggests that the reservoir should not be treated as a single homogeneous structure with unique porosity and permeability. The reservoir parameters change with varying clay content and it should be considered for effective planning and extraction of oil. There is an optimum drawdown for maximum production with varying permeability in a reservoir.

  7. Mineral content of the honey produced in Zulia state, Venezuela.

    Science.gov (United States)

    Sulbarán de Ferrer, Betzabé; Ojeda de Rodríguez, Graciela; Peña, Jorge; Martínez, Janeth; Morán, María

    2004-09-01

    The mineral content of the honey produced in five zones of the Zulia state, Venezuela, during dry and rainy seasons was determined. The analyzed elements were: sodium, potassium (by emission spectroscopy), calcium, magnesium, copper, iron, manganese (by atomic absorption spectroscopy), phosphorus (phosphate ions, by colorimetric method), and ash content of raw honey samples directly collected from different beekeepers. The mean values for Na, K, Ca, Mg, Cu, Fe, Mn, and P were 353+84; 1774+138; 237+66; 52+24; 0.76+0.43; 13.5+10.23; 0.92+0.42 and 1642+323 mg/kg respectively. The mean ash content was 0.431+0.15%. Potassium was the most abundant of the elements determined. This results confirm that Zulian honey can be considered a good source of minerals.

  8. Monitoring water content in Opalinus Clay within the FE-Experiment: Test application of dielectric water content sensors

    Science.gov (United States)

    Sakaki, T.; Vogt, T.; Komatsu, M.; Müller, H. R.

    2013-12-01

    The spatiotemporal variation of water content in the near field rock around repository tunnels for radioactive waste in clay formations is one of the essential quantities to be monitored for safety assessment in many waste disposal programs. Reliable measurements of water content are important not only for the understanding and prediction of coupled hydraulic-mechanic processes that occur during tunnel construction and ventilation phase, but also for the understanding of coupled thermal-hydraulic-mechanical (THM) processes that take place in the host rock during the post closure phase of a repository tunnel for spent fuel and high level radioactive waste (SF/HLW). The host rock of the Swiss disposal concept for SF/HLW is the Opalinus Clay formation (age of approx. 175 Million years). To better understand the THM effects in a full-scale heater-engineered barrier-rock system in Opalinus Clay, a full-scale heater test, namely the Full-Scale Emplacement (FE) experiment, was initiated in 2010 at the Mont Terri underground rock laboratory in north-western Switzerland. The experiment is designed to simulate the THM evolution of a SF/HLW repository tunnel based on the Swiss disposal concept in a realistic manner during the construction, emplacement, backfilling, and post-closure phases. The entire experiment implementation (in a 50 m long gallery with approx. 3 m diameter) as well as the post-closure THM evolution will be monitored using a network of several hundred sensors. The sensors will be distributed in the host rock, the tunnel lining, the engineered barrier, which consists of bentonite pellets and blocks, and on the heaters. The excavation is completed and the tunnel is currently being ventilated. Measuring water content in partially saturated clay-rich high-salinity rock with a deformable grain skeleton is challenging. Therefore, we use the ventilation phase (before backfilling and heating) to examine the applicability of commercial water content sensors and to

  9. Dielectric properties of clay-rock and their influence on water content measurement with TDR probes

    International Nuclear Information System (INIS)

    Bore, T.; Coelho, D.; Robinet, J.C.; Delepine-Lesoille, S.; Placko, D.; Gatabin, C.; Sabouroux, P.; Six, G.; Taillade, F.

    2012-01-01

    Document available in extended abstract form only. Clays constitute major components for radioactive waste repositories managed by Andra. Water content monitoring is one of the indicators chosen to evaluate the health of the structure. In this perspective, several TDR probes have been installed in various structures, made of three types of clay materials: the bentonite, the clay-rock (Callovo-Oxfordian mud-stone) and the compacted crushed clay-rock. . The technique consists of a time-of-flight measurement of an electric pulse along the TDR probes. To convert flight time propagation delay into water content, calibrations are required. This conversion is however neither accurate, nor generalizable for other mixtures. For precise understanding and modeling of the sensing chain, a better knowledge the complex permittivity of clay materials is necessary. Chosen TDR sensing lines make use of a step electric pulse (such as Campbell TDR100). Considering the rise time of this system, the frequency content of the measured TDR wave form extends from about 20 kHz to roughly 1.5 GHz. Material dielectric must thus be characterized over a broad band frequency. The determination of the electromagnetic properties using non resonant method is fundamentally deduced from their impedance and the wave velocities in the materials. This kind of technique relies on a device able to direct the electromagnetic energy towards a material and to collect the reflected and transmitted parts. In a first step, we designed a transmission line to provide electromagnetic characterizations of clay material. The clay material under test is inserted into a brass coaxial cell specifically designed for our purposes. Two conical transition units surround the specimen holder. The electromagnetic properties of the sample are based on the reflection from the material and the transmission through the material measured by a vector network analyser (VNA). The determination of the electromagnetic properties from

  10. Physicochemical Study of Photocatalytic Activity of TiO2 Supported Palygorskite Clay Mineral

    Directory of Open Access Journals (Sweden)

    Lahcen Bouna

    2013-01-01

    Full Text Available This study deals with the influence of physicochemical parameters, namely, the photocatalyst loading, dye concentration, and pH of polluted solutions, on the degradation efficiency of Orange G (OG solutions containing TiO2 nanoparticles supported on palygorskite clay mineral (TiO2-Pal. The TiO2 photocatalyst attached to natural palygorskite fibers was elaborated by colloidal sol-gel route. It exhibits the anatase structure that is the most photoactive crystallographic form. The highest performances of supported photocatalyst on OG degradation were found using an optimum amount of TiO2-Pal around 0.8 g·L−1, which corresponds properly to ca. 0.4 g·L−1 of TiO2. This amount is interestingly lower than the 2.5 g·L−1 generally reported when using pure unsupported TiO2 powder. The photodegradation rate increases by decreasing OG initial concentration, and it was found significantly higher when the OG solution is either acidic (pH<4 or basic (pH≈11. For OG concentrations in the range 5×10-6– 5×10-4 M, the kinetic law of the OG degradation in presence of TiO2-Pal is similar to that reported for unsupported TiO2 nanopowder. It follows a Langmuir-Hinshelwood model with a first-order reaction and an apparent rate constant of about 2.9×10-2 min−1.

  11. Influence of Laurolactam Content on the Clay Intercalation of Polyamide 6,12/Clay Nanocomposites Synthesized by Open Ring Anionic Polymerization

    Directory of Open Access Journals (Sweden)

    E. N. Cabrera Álvarez

    2012-01-01

    Full Text Available In situ anionic homo- and copolymerization of caprolactam (CL and laurolactam (LL with sodium montmorillonite clay (NaMMT was carried out using two different initiators, sodium caprolactamate (CLNa and caprolactam magnesium bromide (CLMgBr. Degree of conversion and final molecular weight were used to assess the advancement and efficiency of the polymerization reaction and X-ray diffraction and electron microscopy were used to evaluate the sodium montmorillonite clay intercalation/exfoliation. The use of CLNa as initiator produced a higher conversion degree and molecular weight than the use of CLMgBr. Through DSC, it was observed that CLNa and CLMgBr tended to produce random and block copolymer structures, respectively, and either random or block, this eventually has an effect on the clay dispersion within the polymer matrix. In all cases, increasing the LL content produced a decrease in the conversion degree and in the molecular weight of the resulting polymer.

  12. The content of minerals and trace elements in meals

    International Nuclear Information System (INIS)

    Bognar, A.; Schelenz, R.; Gruenewald, T.; Frahm, H.; Heine, K.; Wiechen, A.; Bundesanstalt fuer Milchforschung, Kiel

    1981-07-01

    Within the frame work of the research programme 'School Feeding', 68 menu items of different producers were investigated for the content of the minerals calcium, chlorine, iron, potassium, magnesium, sodium and phosphorus, and for the trace elements antimony, barium, bromine, cesium, chromium, hafnium, iridium,cobalt, copper, manganese, mercury, rubidium, scandium, selenium, silver, strontium, tin and zinc. For the analytical determination of the elements, instrumental neutron activation analysis and X-ray fluorometry were applied. The studies showed that a calculation of the content of minerals and trace elements in meals on the basis of recipes and nutritive tables for raw foods is not justified, expect for sodium and phosphorus, because incorrect results can be obtained for the majority of meals. (orig./MG) [de

  13. Mineral contents of some plants used in Iran.

    Science.gov (United States)

    Rahmatollah, Rahimi; Mahbobeh, Rabani

    2010-07-01

    In this work, mineral contents of 4 plants used in Iran were determined by Inductively Coupled Plasma-Atomic Emission Spectrometry. The concentrations were calculated on a dry weight basis. All materials contained high amounts of Na, Al, Ca, Fe, K, Mg, P, Zn, and I. On a moisture-free basis, the highest levels of Ca, P, and Mg were found in spinach to be 3200 mg/100 g, 2150 mg/100 g, and 460 mg/100 g, respectively. Bi, Cd, Li, Pb, and Se contents of condiments were found to be very low. The results were compared with those from the Spanish, Turkish, and Indian. This work attempts to contribute to knowledge of the nutritional properties of these plants. These results may be useful for the evaluation of dietary information and concluded that the green vegetables are the good sources of minerals.

  14. Predicting soil particle density from clay and soil organic matter contents

    DEFF Research Database (Denmark)

    Schjønning, Per; McBride, R.A.; Keller, T.

    2017-01-01

    Soil particle density (Dp) is an important soil property for calculating soil porosity expressions. However, many studies assume a constant value, typically 2.65Mgm−3 for arable, mineral soils. Fewmodels exist for the prediction of Dp from soil organic matter (SOM) content. We hypothesized...

  15. The influence of shale depositional fabric on the kinetics of hydrocarbon generation through control of mineral surface contact area on clay catalysis

    Science.gov (United States)

    Rahman, Habibur M.; Kennedy, Martin; Löhr, Stefan; Dewhurst, David N.; Sherwood, Neil; Yang, Shengyu; Horsfield, Brian

    2018-01-01

    Accurately assessing the temperature and hence the depth and timing of hydrocarbon generation is a critical step in the characterization of a petroleum system. Clay catalysis is a potentially significant modifier of hydrocarbon generation temperature, but experimental studies of clay catalysis show inconsistent or contradictory results. This study tests the hypothesis that source rock fabric itself is an influence on clay mineral catalysis as it controls the extent to which organic matter and clay minerals are physically associated. Two endmember clay-organic fabrics distinguish the source rocks studied: (1) a particulate fabric where organic matter is present as discrete, >5 μm particles and (2) a nanocomposite fabric in which amorphous organic matter is associated with clay mineral surfaces at sub-micron scale. High-resolution electron imaging and bulk geochemical characterisation confirm that samples of the Miocene Monterey Formation (California) are representative of the nanocomposite source rock endmember, whereas samples from the Permian Stuart Range Formation (South Australia) represent the particulate source rock endmember. Kinetic experiments are performed on paired whole rock and kerogen isolate samples from these two formations using open system, non-isothermal pyrolysis at three different heating rates (0.7, 2 and 5 K/min) to determine the effects of the different shale fabrics on hydrocarbon generation kinetics. Extrapolation to a modelled geological heating rate shows a 20 °C reduction in the onset temperature of hydrocarbon generation in Monterey Formation whole rock samples relative to paired kerogen isolates. This result is consistent with the Monterey Formations's nanocomposite fabric where clay catalysis can proceed because reactive clay minerals are intimately associated with organic matter. By contrast, there is no significant difference in the modelled hydrocarbon generation temperature of paired whole rock and kerogen isolates from the

  16. Investigating Interactions between the Silica and Carbon Cycles during Precipitation and Early Diagenesis of Authigenic Clay/Carbonate-Mineral Associations in the Carbonate Rock Record

    Science.gov (United States)

    McKenzie, J. A.; Francisca Martinez Ruiz, F.; Sanchez-Roman, M.; Anjos, S.; Bontognali, T. R. R.; Nascimento, G. S.; Vasconcelos, C.

    2017-12-01

    The study of authigenic clay/carbonate-mineral associations within carbonate sequences has important implications for the interpretation of scientific problems related with rock reservoir properties, such as alteration of potential porosity and permeability. More specifically, when clay minerals are randomly distributed within the carbonate matrix, it becomes difficult to predict reservoir characteristics. In order to understand this mineral association in the geological record, we have undertaken a comparative study of specially designed laboratory experiments with modern environments, where clay minerals have been shown to precipitate together with a range of carbonate minerals, including calcite, Mg-calcite and dolomite. Two modern dolomite-forming environments, the Coorong lakes, South Australia and Brejo do Espinho Rio de Janeiro, Brazil, were selected for this investigation. For comparative evaluation, enrichment microbial culture experiments, using natural pore water from Brejo do Espinho as the growth medium to promote mineral precipitation, were performed under both aerobic and anaerobic conditions. To establish the environmental parameters and biological processes facilitating the dual mineral association, the experimental samples have been compared with the natural minerals using HRTEM measurements. The results demonstrate that the clay and carbonate minerals apparently do not co-precipitate, but the precipitation of the different minerals in the same sample has probably occurred under different environmental conditions with variable chemistries, e.g., hypersalinity versus normal salinity resulting from the changing ratio of evaporation versus precipitation. Thus, the investigated mineral association is not a product of diagenetic processes but of sequential in situ precipitation processes related to changes in the silica and carbon availability. Implications for ancient carbonate formations will be presented and discussed in the context of a specific

  17. Sorption of VX to Clay Minerals and Soils: Thermodynamic and Kinetic Studies

    Science.gov (United States)

    2012-12-01

    Kaolinite, a member of the kaolin family, is a 1:1 clay, consisting of a single silicon-containing tetrahedral sheet linked to a single aluminum...14,15,18,19 The kaolinite is a white-firing, plastic kaolinite mined from claystone deposits in Georgia. This clay, identified as no. 6 tile kaolin , was...Validation of Model Predictions for the Dispersion and Fate of Reactive Chemical Releases in a Sub- Estuary of the Chesapeake Bay. Presented at the 2011

  18. Clay minerals and metal oxides strongly influence the structure of alkane-degrading microbial communities during soil maturation.

    Science.gov (United States)

    Steinbach, Annelie; Schulz, Stefanie; Giebler, Julia; Schulz, Stephan; Pronk, Geertje J; Kögel-Knabner, Ingrid; Harms, Hauke; Wick, Lukas Y; Schloter, Michael

    2015-07-01

    Clay minerals, charcoal and metal oxides are essential parts of the soil matrix and strongly influence the formation of biogeochemical interfaces in soil. We investigated the role of these parental materials for the development of functional microbial guilds using the example of alkane-degrading bacteria harbouring the alkane monooxygenase gene (alkB) in artificial mixtures composed of different minerals and charcoal, sterile manure and a microbial inoculum extracted from an agricultural soil. We followed changes in abundance and community structure of alkane-degrading microbial communities after 3 and 12 months of soil maturation and in response to a subsequent 2-week plant litter addition. During maturation we observed an overall increasing divergence in community composition. The impact of metal oxides on alkane-degrading community structure increased during soil maturation, whereas the charcoal impact decreased from 3 to 12 months. Among the clay minerals illite influenced the community structure of alkB-harbouring bacteria significantly, but not montmorillonite. The litter application induced strong community shifts in soils, maturated for 12 months, towards functional guilds typical for younger maturation stages pointing to a resilience of the alkane-degradation function potentially fostered by an extant 'seed bank'.

  19. Water and solute transport in agricultural soils predicted by volumetric clay and silt contents

    DEFF Research Database (Denmark)

    Karup, Dan; Møldrup, Per; Paradelo Pérez, Marcos

    2016-01-01

    tracer mass could be well fitted to an analytical solution to the classical convection-dispersion equation. Both cumulative tracer mass and concentration as a function of time were hereby reasonable well predicted from the simple inputs of bulk density, clay and silt contents, and applied tracer mass......Solute transport through the soil matrix is heterogeneous and greatly affected by soil texture, soil structure, and macropore networks. This study examined the relationship between tracer breakthrough characteristics, soil hydraulic properties, and basic soil properties. Hundred...... of the soil structure rather than the actual formation of macropores causing preferential flow. The arrival times of 5 % and up to 50 % of the tracer mass were found to be strongly correlated with volumetric fines content. The hereby predicted tracer concentration breakthrough points up to 50% of applied...

  20. Effects of clay minerals, hydroxides, and timing of dissolved organic matter addition on the competitive sorption of copper, nickel, and zinc : a column experiment

    NARCIS (Netherlands)

    Refaey, Y.; Jansen, B.; Parsons, J.R.; de Voogt, P.; Bagnis, S.; Markus, A.; El-Shater, A.-H.; El-Haddad, A.-A.; Kalbitz, K.

    2017-01-01

    Infiltration of heavy metal (HM) polluted wastewater can seriously compromise soil and groundwater quality. Interactions between mineral soil components (e.g. clay minerals) and dissolved organic matter (DOM) play a crucial role in determining HM mobility in soils. In this study, the influence of

  1. [Rapid determination of major and trace elements in the salt lake clay minerals by X-ray fluorescence spectrometry].

    Science.gov (United States)

    Wang, Xiao-Huan; Meng, Qing-Fen; Dong, Ya-Ping; Chen, Mei-Da; Li, Wu

    2010-03-01

    A rapid multi-element analysis method for clay mineral samples was described. This method utilized a polarized wave-length dispersive X-ray fluorescence spectrometer--Axios PW4400, which had a maximum tube power of 4 000 watts. The method was developed for the determination of As, Mn, Co, Cu, Cr, Dy, Ga, Mo, P, Pb, Rb, S, Sr, Ni, ,Cs, Ta, Th, Ti, U, V, Y, Zn, Zr, MgO, K2O, Na2O, CaO, Fe2O3, Al2O3, SiO2 and so on. Thirty elements in clay mineral species were measured by X-ray fluorescence spectrometry with pressed powder pellets. Spectral interferences, in particular the indirect interferences of each element, were studied. A method to distinguish the interference between each other periodic elements in element periodic table was put forward. The measuring conditions and existence were mainly investigated, and the selected background position as well as corrected spectral overlap for the trace elements were also discussed. It was found that the indirect spectral overlap line was the same important as direct spectral overlap line. Due to inducing the effect of indirect spectral overlap, some elements jlike Bi, Sn, W which do not need analysis were also added to the elements channel. The relative standard deviation (RSD) was in the range of 0.01% to 5.45% except three elements Mo, Cs and Ta. The detection limits, precisions and accuracies for most elements using this method can meet the requirements of sample analysis in clay mineral species.

  2. Effect of hyperthyroidism and its treatment on bone mineral content

    International Nuclear Information System (INIS)

    Toh, S.H.; Claunch, B.C.; Brown, P.H.

    1985-01-01

    Patients with hyperthyroidism may develop osteopenia associated with fractures; however, there has been no general agreement on the incidence of osteopenia in hyperthyroidism or the recovery of the mineral loss after treatment of hyperthyroidism. The authors conducted a longitudinal prospective study on the effect of hyperthyroidism and its treatment on bone mineral content (BMC) using photon absorptiometry. They observed that both young and older hyperthyroid patients showed a significantly decreased baseline BMC compared with age- and sex-matched controls. They also observed a slight recovery of BMC in hyperthyroid patients at the two-year interval after a euthyroid state had been achieved. However, the BMC was still much lower than that of controls, and they did not find any significant restoration of BMC following ''cure'' of hyperthyroidism

  3. Heavy sediment influx during early Holocene: Inference from clay mineral studies in a core from the western Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Reddy, N.P.C.; Rao, K.M.

    is attributed to heavy sediment influx du r- ing Mid Termination (MT) (12,500 ? 10,000 years BP), due to i n creased precipitation and run - off resulting from high inte n sity monsoonal regime. C LAY minerals are a powerful source for the interpret a... to address to the prov e nance of the sediments in a sediment core from the western Bengal Fan. In this paper, we report clay mi n eralogy and provide an explanation for the heavy sed i ment deposition du r ing the Holocene. A sediment core of 650...

  4. Adsorption Properties of Hydrocarbons (n-Decane, Methyl Cyclohexane and Toluene on Clay Minerals: An Experimental Study

    Directory of Open Access Journals (Sweden)

    Jie Zhang

    2017-10-01

    Full Text Available Adsorption of hydrocarbons may significantly affect hydrocarbon migration in unconventional reservoirs. Clay minerals form the primary adsorbent surfaces for hydrocarbons adsorbed in mudstone/shale. To study the adsorption properties of hydrocarbons (n-decane (C10H22, methyl cyclohexane (C7H14 and toluene (C7H8 on clay minerals (i.e., cookeite, ripidolite, kaolinite, illite, illite/smectite mixed-layer, Na-montmorillonite and Ca-montmorillonite, hydrocarbon vapor adsorption (HVA tests were conducted at 298.15 K. The results showed that (i the adsorption amounts of C10H22, C7H14 and C7H8 ranged from 0.45–1.03 mg/m2, 0.28–0.90 mg/m2 and 0.16–0.53 mg/m2, respectively; (ii for cookeite, ripidolite and kaolinite, the adsorption capacity of C10H22 was less than C7H14, which was less than C7H8; (iii for illite, Na-montmorillonite and Ca-montmorillonite, the adsorption capacity of C10H22 was greater than that of C7H8, and the adsorption capacity of C7H14 was the lowest; (iv for an illite/smectite mixed-layer, C7H14 had the highest adsorption capacity, followed by C10H22, and C7H8 had the lowest capacity. Adsorption properties were correlated with the microscopic parameters of pores in clay minerals and with experimental pressure. Finally, the weighted average method was applied to evaluate the adsorption properties of C10H22, C7H14 and C7H8 on clay minerals in oil-bearing shale from the Shahejie Formation of Dongying Sag in the Bohai Bay Basin, China. For these samples, the adsorbed amounts of C7H14 ranged from 18.03–28.02 mg/g (mean 23.33 mg/g, which is larger than that of C10H22, which ranges from 15.40–21.72 mg/g (mean 18.82 mg/g. The adsorption capacity of C7H8 was slightly low, ranging from 10.51–14.60 mg/g (mean 12.78 mg/g.

  5. Comparison of clay mineral stratigraphy to other proxy palaeoclimate indicators in the Mesozoic of NW Europe.

    Science.gov (United States)

    Ruffell, Alastair; McKinley, Jennifer M; Worden, Richard H

    2002-04-15

    This paper reviews the opportunities and pitfalls associated with using clay mineralogical analysis in palaeoclimatic reconstructions. Following this, conjunctive methods of improving the reliability of clay mineralogical analysis are reviewed. The Mesozoic succession of NW Europe is employed as a case study. This demonstrates the relationship between clay mineralogy and palaeoclimate. Proxy analyses may be integrated with clay mineralogical analysis to provide an assessment of aridity-humidity contrasts in the hinterland climate. As an example, the abundance of kaolinite through the Mesozoic shows that, while interpretations may be difficult, the Mesozoic climate of NW Europe was subject to great changes in rates of continental precipitation. We may compare sedimentological (facies, mineralogy, geochemistry) indicators of palaeoprecipitation with palaeotemperature estimates. The integration of clay mineralogical analyses with other sedimentological proxy indicators of palaeoclimate allows differentiation of palaeoclimatic effects from those of sea-level and tectonic change. We may also observe how widespread palaeoclimate changes were; whether they were diachronous or synchronous; how climate, sea level and tectonics interact to control sedimentary facies and what palaeoclimate indicators are reliable.

  6. Adhesion of the clay minerals montmorillonite, kaolinite, and attapulgite reduces respiration of Histoplasma capsulatum.

    Science.gov (United States)

    Lavie, S; Stotzky, G

    1986-01-01

    The respiration of three phenotypes of Histoplasma capsulatum, the causal agent of histoplasmosis in humans, was markedly reduced by low concentrations of montmorillonite but was reduced less by even higher concentrations of kaolinite or attapulgite (palygorskite). The reduction in respiration followed a pattern that suggested saturation-type kinetics: an initial sharp reduction that occurred with low concentrations of clay (0.01 to 0.5% [wt/vol]), followed by a more gradual reduction with higher concentrations (1 to 8%). Increases in viscosity (which could impair the movement of O2) caused by the clays were not responsible for the reduction in respiration, and the clays did not interfere with the availability of nutrients. Scanning electron microscopy after extensive washing showed that the clay particles were tightly bound to the hyphae, suggesting that the clays reduced the rate of respiration of H. capsulatum by adhering to the mycelial surface and, thereby, interfered with the movement of nutrients, metabolites, and gases across the mycelial wall.

  7. Preparation and characterization of polymer nanocomposites based on chitosan and clay minerals

    International Nuclear Information System (INIS)

    Fiori, Ana Paula Santos de Melo; Gabiraba, Victor Parizio; Praxedes, Ana Paula Perdigao; Nunes, Marcelo Ramon da Silva; Balliano, Tatiane L.; Silva, Rosanny Christhinny da; Tonholo, Josealdo; Ribeiro, Adriana Santos

    2014-01-01

    In this work nanocomposites based on chitosan and different clays were prepared using polyethyleneglycol (PEG) as plasticizer. The samples obtained were characterized by Fourier Transform Infrared Spectroscopy (FTIR), X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), thermogravimetric analysis (TGA/DTG) and by mechanical characterization (tensile test) with the aim of investigating the interactions between chitosan and clay. The nanocomposite films prepared using sodium bentonite (Ben) showed an increase of 81.2% in the maximum tensile stress values and a decrease of 16.0% in the Young’s modulus when compared to the chitosan with PEG (QuiPEG) films, evidencing that the introduction of the clay into the polymer matrix provided a more flexible and resistant film, whose elongation at break was 93.6% higher than for the QuiPEG film. (author)

  8. Quantitative computed tomography for measuring bone mineral content

    International Nuclear Information System (INIS)

    Felsenberg, D.; Kalender, W.A.; Banzer, D.; Schmilinsky, G.; Heyse, M.; Fischer, E.; Schneider, U.; Siemens A.G., Erlangen; Krankenhaus Zehlendorf, Berlin

    1988-01-01

    Quantitative computed tomography (QCT) for measuring bone mineral content of lumbar vertebrae is increasingly used internationally. The effect of using conventional CT (single energy CT, SE-CT) and dual energy CT (DE-CT) on reproducibility has been examined. We defined a standard measurement protocol, which automatically evaluates a calibration phantom. This should ensure an in vivo reproducibility of 1 to 2%. Reference data, which has been obtained with this protocol from 113 normal subjects, using SE-CT ad DE-CT, are presented. (orig.) [de

  9. Electrical properties of multiphase composites based on carbon nanotubes and an optimized clay content

    Science.gov (United States)

    Egiziano, Luigi; Lamberti, Patrizia; Spinelli, Giovanni; Tucci, Vincenzo; Guadagno, Liberata; Vertuccio, Luigi

    2016-05-01

    The experimental results concerning the characterization of a multiphase nanocomposite systems based on epoxy matrix, loaded with different amount of multi-walled carbon nanotubes (MWCNTs) and an optimized Hydrotalcite (HT) clay content (i.e. 0.6 wt%), duly identified by an our previous theoretical study based on Design of Experiment (DoE), are presented. Dynamic-mechanical analysis (DMA) reveal that even the introduction of higher HT loading (up to 1%wt) don't affect significantly the mechanical properties of the nanocomposites while morphological investigations show an effective synergy between clay and carbon nanotubes that leads to peculiar micro/nanostructures that favor the creation of the electrical conductive network inside the insulating resin. An electrical characterization is carried out in terms of DC electrical conductivity, percolation threshold (EPT) and frequency response in the range 10Hz-1MHz. In particular, the measurements of the DC conductivity allow to obtain the typical "percolation" curve also found for classical CNT-polymer mixtures and a value of about 2 S/m for the electrical conductivity is achieved at the highest considered CNTs concentration (i.e. 1 wt%). The results suggest that multiphase nanocomposites obtained incorporating dispersive nanofillers, in addition to the conductive one, may be a valid alternative to the polymer blends, to improve the properties of the polymeric materials thus able to meet high demands, particularly concerning their mechanical and thermal stability and electrical features required in the aircraft engineering.

  10. The effect of high pH alkaline solutions on the mineral stability of the Boom Clay - Batch experiments at 60 deg. C

    International Nuclear Information System (INIS)

    Honty, M.; De Craen, M.; Wang, L.; Madejova, J.; Czimerova, A.; Pentrak, M.; Stricek, I.; Van Geet, M.

    2010-01-01

    Boom Clay is currently viewed as a reference host formation for studies on deep geological disposal of radioactive waste in Belgium. The interactions between bulk rock Boom Clay and 0.1 M KOH, 0.1 M NaOH, 0.1 M Ca(OH) 2 , young cement water and evolved cement water solutions, ranging in pH from 12.5 to 13.2, were examined as static batch experiments at 60 deg. C to simulate alkaline plume perturbations, which are expected to occur in the repository due to the presence of concrete. Both liquids and solids were investigated at specific times between 90 and 510 days in order to control the elemental budget and to search for potential mineralogical alterations. Also, the clay fraction was separated from the whole-rock Boom Clay at the end of each run and characterized for its mineralogical composition. Thereby, the importance of the mineral matrix to buffer the alkaline attack and the role of organic matter to protect clay minerals were also addressed. The results indicate that the degree of geochemical perturbation in Boom Clay is dependent on the initial pH of the applied solution together with the nature of the major cation in the reactant fluids. The higher the initial pH of the media, the stronger its interaction with Boom Clay. No major non-clay mineralogical alteration of the Boom Clay was detected, but dissolution of kaolinite, smectite and illite occurred within the studied experimental conditions. The dissolution of clays is accompanied by the decrease in the layer charge, followed by a decrease in the cation-exchange capacity. The highest TOC values coincide with the highest total elemental concentrations in the leachates, and correspondingly, the highest dissolution degree. However, no quantitative link could be established between the degree of organic matter decomposition and clay dissolution.

  11. New aluminium-rich alkali slag matrix with clay minerals for immobilizing simulated radioactive Sr and Cs waste

    International Nuclear Information System (INIS)

    Qian Guangren; Sun, Darren Delai; Tay, Joo Hwa

    2001-01-01

    A new aluminium-rich alkali-activated slag matrix (M-AAS) with clay absorbents has been developed for immobilization of simulated radioactive Sr or Cs waste by introducing metakaolin, natural zeolite and NaOH-treated attapulgite clay minerals into alkali-activated slag matrix (AAS). The results revealed that the additions of metakaolin and clay absorbents into the cementitious matrixes would greatly enhance the distribution ratio, R d , of selective adsorption whether the matrix was OPC matrix or AAS matrix. The new immobilizing matrix M-AAS not only exhibited the strongest selective adsorption for both Sr and Cs ions, but also was characterized by lower porosity and small pore diameter so that it exhibited the lowest leaching rate. Hydration product analyses also demonstrated that (Na+Al)-substituted C-S-H(I) and self-generated zeolite were major hydration products in the M-AAS matrix, which provided this new immobilizing matrix with better selective adsorption on Sr and Cs and lower leaching rate

  12. Influence of the chemical modification and content of the clay on the mechanical properties of polypropylene and national bentonite composites

    International Nuclear Information System (INIS)

    Libano, Elaine V.D.G.; Pacheco, Elen B.A.V.; Visconte, Leila L.Y.

    2011-01-01

    The polypropylene/national clay composite was prepared by melt intercalation in a counter-rotating twin screw extruder, using bentonite as filler either in the natural (BENT) form or modified with the ammonium salt, cetyltrimethylammonium chloride (BENT-org). The clay was used in 1, 3 and 5%w. The influence of the modification and content of clay on the mechanical properties of this system was analysed. The analyses of infrared spectroscopy (FTIR) and X-ray diffraction (XRD) showed that clay organophilization did occur. The tensile modulus and the tensile strength at the yield point were not affected by chemical modification (BENT and BENT-org) or clay content. On the other hand, it was evidenced that the elongation at the yield point decreased with the addition of BENT and BENT-org to polypropylene. According to the thermogravimetric results, it was evidenced that the incorporation of clay into polypropylene improved thermal stability of the polymer in the composites with 5%w of BENT and 3 and 5%w of BENT-org. (author)

  13. Adsorption of Sr(II) on clay minerals: effects of salt concentration, loading and pH

    International Nuclear Information System (INIS)

    Rafferty, P.; Shiao, S.Y.; Binz, C.M.; Meyer, R.E.

    1981-01-01

    The adsorption of Sr(II) on a number of clay minerals has been investigated by means of a batch technique in solutions of sodium salts. Generally the results can be approximated by ideal ion exchange equations. Distribution coefficients at trace loading follow the linear relation log D = s log [Na(I)sub(aq)] + b where b is a constant and s had values of from about - 1.5 to - 2.0, which are fairly close to the ideal valve of - 2. Adsorption isotherms at constant pH and salt concentration are linear in the low loading region. Distribution coefficients for montmorillonite are almost independent of pH in the intermediate pH region 5 to 7 but for illite and kaolinite, increases in the distribution coefficient with pH are observed. Comparison of these results with literature values, insofar as it is possible, shows that distribution coefficients are usually within a factor of two or three for the same mineral with similar capacities under the same conditions even if techniques of preparation and measurement are different, but values may vary considerably more if the capacities of the different mineral samples are greatly different. Values of the distribution coefficient at very high salt concentration are very low, considerably less than unity at 4 M NaCl. Thus migration rates of Sr(II), relative to water flow, through geologic formations whose adsorption behavior is dominated by these clay minerals are likely to be high at high salt concentrations. (author)

  14. Limestone doses affecting mineral contents in tropical grass forage

    International Nuclear Information System (INIS)

    Armelin, M.J.A.; Saiki, M.

    2005-01-01

    Field trial was performed at the experimental farm of Southeast Embrapa Cattle, Sao Carlos - SP, Brazil, on a 16 year old Brachiaria decumbens pasture, grown on a distrophic Hapludox (Oxisol), recovered by the use of limestone and fertilizer. The experiments were carried out in random blocks, with 6 replications and 5 treatments. The 100 m 2 blocks were established in the pasture. Each block received a sequence of limestone doses of 0, 1, 2, 4 and 8 t/ha. The forage samples were taken one year after limestone application on soil surface. Instrumental neutron activation analysis (INAA) followed by gamma-ray spectrometry was the analytical method used to determine mineral contents. The statistical analysis showed a negative linear correlation of Br, Co, Cr, Mn and Zn contents in forage with the limestone doses, while the uptake of Mg was affected in a positive way. (author)

  15. Mineral composition and ash content of six major energy crops

    Energy Technology Data Exchange (ETDEWEB)

    Monti, Andrea; Venturi, Gianpietro [Department of Agroenvironmental Science and Technologies (DiSTA), University of Bologna, Viale G. Fanin, 44, 40127 Bologna (Italy); Di Virgilio, Nicola [Institute of Biometeorology, National Research Council, Via P. Gobetti, 101 I, 40129 Bologna (Italy)

    2008-03-15

    The chemical composition of biofuels has not received adequate attention given that it is an important aspect in the introduction of energy crops. In this study, the ash content and mineral composition (C, N, Al, Ca, Cl, Fe, K, Mg, Na, P, S, Si) of stems, leaves and reproductive organs of some promising energy crops were determined and compared with the respective recommended thresholds reported in literature. Overall, cynara exhibited the highest ash and mineral contents, which indicate high slagging, fouling and corrosion tendencies. However, cynara also showed the lowest Si content, both in leaves (4.3 g kg{sup -1}) and in stems (0.9 g kg{sup -1}). Sweet sorghum and giant reed exhibited the highest N content (up to 16 g kg{sup -1}), which greatly exceeded the recommended limits in leaves. Importantly, Cl always exceeded the recommended limits (up to 18 mg kg{sup -1} in cynara), both in stems and in leaves, thus resulting in a major stumbling block for all crops. Several significant correlations among elements were found at a single plant part; conversely these correlations were generally very weak considering different plant components, with the exception of K (r=0.91**), P (r=0.94**) and ashes (r=0.64**). Generally, leaves resulted in a significant deterioration of biofuel quality when compared with stems and flower heads. Therefore, agricultural strategies aimed at reducing the leaf component (e.g. by delaying the harvest) may considerably improve the suitability of biofuels for current combustion plants. (author)

  16. Structural Investigation of Alkali Activated Clay Minerals for Application in Water Treatment Systems

    Science.gov (United States)

    Bumanis, G.; Bajare, D.; Dembovska, L.

    2015-11-01

    Alkali activation technology can be applied for a wide range of alumo-silicates to produce innovative materials with various areas of application. Most researches focuse on the application of alumo-silicate materials in building industry as cement binder replacement to produce mortar and concrete [1]. However, alkali activation technology offers high potential also in biotechnologies [2]. In the processes where certain pH level, especially alkaline environment, must be ensured, alkali activated materials can be applied. One of such fields is water treatment systems where high level pH (up to pH 10.5) ensures efficient removal of water pollutants such as manganese [3]. Previous investigations had shown that alkali activation technology can be applied to calcined clay powder and aluminium scrap recycling waste as a foam forming agent to create porous alkali activated materials. This investigation focuses on the structural investigation of calcined kaolin and illite clay alkali activation processes. Chemical and mineralogical composition of both clays were determined and structural investigation of alkali activated materials was made by using XRD, DTA, FTIR analysis; the microstructure of hardened specimens was observed by SEM. Physical properties of the obtained material were determined. Investigation indicates the essential role of chemical composition of the clay used in the alkali activation process, and potential use of the obtained material in water treatment systems.

  17. International Longitudinal Paediatric Reference Standards for Bone Mineral Content

    Science.gov (United States)

    Baxter-Jones, Adam DG; McKay, Heather; Burrows, Melonie; Bachrach, Laura K; Lloyd, Tom; Petit, Moira; Macdonald, Heather; Mirwald, Robert L; Bailey, Don

    2014-01-01

    To render a diagnosis pediatricians rely upon reference standards for bone mineral density or bone mineral content, which are based on cross-sectional data from a relatively small sample of children. These standards are unable to adequately represent growth in a diverse pediatric population. Thus, the goal of this study was to develop sex and site specific standards for BMC using longitudinal data collected from four international sites in Canada and the United States. Data from four studies were combined; Saskatchewan Paediatric Bone Mineral Accrual Study (n=251), UBC Healthy Bones Study (n=382); Penn State Young Women’s Health Study (n=112) and Stanford’s Bone Mineral Accretion study (n=423). Males and females (8 to 25 years) were measured for whole body (WB), total proximal femur (PF), femoral neck (FN) and lumbar spine (LS) BMC (g). Data were analyzed using random effects models. Bland-Altman was used to investigate agreement in predicted and actual data. Age, height, weight and ethnicity independently predicted BMC accrual across sites (P accrual; Hispanic 75.4 (28.2) g less BMC accrual; Blacks 82.8 (26.3) g more BMC accrual with confounders of age, height and weight controlled. Similar findings were found for PF and FN. Female models for all sites were similar with age, height and weight all independent significant predictors of BMC accrual (P accounting for age, size, sex and ethnicity. In conclusion, when interpreting BMC in paediatrics we recommend standards that are sex, age, size and ethnic specific. PMID:19854308

  18. International longitudinal pediatric reference standards for bone mineral content.

    Science.gov (United States)

    Baxter-Jones, Adam D G; Burrows, Melonie; Bachrach, Laura K; Lloyd, Tom; Petit, Moira; Macdonald, Heather; Mirwald, Robert L; Bailey, Don; McKay, Heather

    2010-01-01

    To render a diagnosis pediatricians rely upon reference standards for bone mineral density or bone mineral content, which are based on cross-sectional data from a relatively small sample of children. These standards are unable to adequately represent growth in a diverse pediatric population. Thus, the goal of this study was to develop sex and site-specific standards for BMC using longitudinal data collected from four international sites in Canada and the United States. Data from four studies were combined; Saskatchewan Paediatric Bone Mineral Accrual Study (n=251), UBC Healthy Bones Study (n=382); Penn State Young Women's Health Study (n=112) and Stanford's Bone Mineral Accretion study (n=423). Males and females (8 to 25 years) were measured for whole body (WB), total proximal femur (PF), femoral neck (FN) and lumbar spine (LS) BMC (g). Data were analyzed using random effects models. Bland-Altman was used to investigate agreement between predicted and actual data. Age, height, weight and ethnicity independently predicted BMC accrual across sites (Paccrual; Hispanic 75.4 (28.2) g less BMC accrual; Blacks 82.8 (26.3) g more BMC accrual with confounders of age, height and weight controlled. We report similar findings for the PF and FN. Models for females for all sites were similar with age, height and weight as independent significant predictors of BMC accrual (Paccounting for age, size, sex and ethnicity. In conclusion, when interpreting BMC in pediatrics we recommend standards that are sex, age, size and ethnic specific. Copyright (c) 2009 Elsevier Inc. All rights reserved.

  19. Transport of vanadium (V in saturated porous media: effects of pH, ionic-strength and clay mineral

    Directory of Open Access Journals (Sweden)

    Yulu Wang

    2016-10-01

    Full Text Available Vanadium, a hazardous pollutant, has been frequently detected in soil and groundwater, however, its transport behavior in porous media were not clearly understood. In this study, the effects of solution pH, ionic strength (IS and the effect of clay mineral on the transport of vanadium in saturated porous media were investigated. Laboratory experiments using a series of columns packed with quartz sand were carried out to explore the retention and transport of vanadium with a range of ionic-strength (0.001–0.1 M and pH (4–8 and two different types of clay minerals montmorillonite and kaolinite. Results of the breakthrough experiments showed that vanadium was highly mobile in the saturated porous media. The increase in pH rendered a higher transport of vanadium in saturated porous media. The study also indicated an easier transfer of vanadium with an increase in IS. Montmorillonite enhanced the mobility of vanadium in the column when compared to kaolinite. A mathematical model based on advection-dispersion equation coupled with equilibrium and kinetic reactions was used to describe the retention and transport of vanadium in the columns very well.

  20. Pure and impure clays and their firing products

    International Nuclear Information System (INIS)

    Murad, E.; Wagner, U.

    1989-01-01

    Moessbauer spectroscopy is highly suited for the study of clays whose industrial uses depend on the iron content. Reactions that take place during clay firing can be readily monitored by Moessbauer spectroscopy. Following dehydroxylation of clay minerals, the quadrupole splitting of octahedrally coordinated iron (III) increases abruptly, but reverts to lower values upon the formation of new, better ordered phases at higher temperatures. It is also shown that iron oxides may account for a considerably higher proportion of the total iron content of many clays than is commonly recognized, and their existence must be taken into consideration for a correct interpretation of the Moessbauer spectra of clays. (orig.)

  1. The clay mineral and Sr-Nd isotopic composition for fine-grained fraction of sediments from northwestern South China Sea: implications for sediment provenance

    Science.gov (United States)

    Cai, G.

    2013-12-01

    *Guanqiang Cai caiguanqiang@sina.com Guangzhou Marine Geological Survey, Guangzhou, 510760, P.R. China As the largest marginal sea in the western pacific, the South China Sea (SCS) receives large amount of terrigenous material annually through numerous rivers from surrounding continents and islands, which make it as the good place for the study of source to sink process. Yet few studies put emphasis on the northwestern continental shelf and slope in the SCS, even though most of the detrital materials derived from the Red River and Hainan Island are deposited in this area, and northwestern shelf plays a significant role in directly linking the South China, the Indochina and the South China Sea and thus controlling the source to sink process of terrestrial sediment. We presented the clay mineral and Sr-Nd isotopic composition of fine-grained fraction for sediments from northwestern SCS, in order to identify sediment source and transportation. The results show that the clay mineral of northwestern SCS sediments are mainly illite (30%~59%), smectite (20%~40%) and kaolinite (8%~35%), with minor chlorite. The illite chemical index varies between 0.19 and 0.75 with an average of 0.49, indicating an intensive hydrolysis in the source region. The 87Sr/86Sr ratios of sediments range from 0.716288 to 0.734416 (average of 0.724659), and ɛ Nd(0) values range from -10.31 to -11.62 (average of -10.93), which suggest that the source rocks of these sediments are derived from continental crust. The Hainan Island is an important source for sediments deposited in the nearshore and western shelf, especially for illite, kaolinite and smectite clay minerals. Furthermore, the relatively high contents of kaolinite and smectite in sediments from eastern shelf and southern slope of Hainan Island are also controlled by the supply of terrigenous materials from Hainan, which cannot be resulted from sedimentary differentiation of the Pearl and Red river sediments. And the correlation analysis

  2. Effects of hydrogen peroxide pretreatment of clay minerals on the adsorption of Sr-85 and Tc-95m under anoxic conditions

    International Nuclear Information System (INIS)

    Relyea, J.F.; Washburne, C.D.

    1979-01-01

    Treatment of three clay minerals with hydrogen peroxide affects the observed adsorption behavior of technetium relative to untreated clay under anoxic conditions. A possible adsorption mechanism of Tc is the reduction of TcO - 4 to a more positively charged or better adsorbed species. Oxidation of the clay by H 2 O 2 would hinder the reduction of TcO - 4 by buffering the clay-water system at a higher Eh value, although a difference in measured Eh value may go undetected. Sorption of strontium by the clays under the same conditions is not affected by a pretreatment with H 2 O 2 . The behavior of strontium follows that expected from ion exchange theory. 13 tables

  3. Relationship between the isotopic composition of strontium in newly formed continental clay minerals and their source material

    International Nuclear Information System (INIS)

    Clauer, N.

    1979-01-01

    The 87 Sr/ 86 Sr ratios of recent montmorillonites and kaolinites newly formed in weathering profiles of western and central Africa and of Nosy Be and La Reunion islands near Madagascar are directly related to the composition and age of the parent rocks or minerals. They may, therefore, be used as a genetic tracer. The 87 Sr/ 86 Sr ratios are about 0.704 when these clays crystallise from recent basalts and they are higher than 0.715 when the parent rocks are of sialic composition and old in age. Kaolinites newly formed in situ from feldspars contain small amounts of Sr with abnormally high 87 Sr/ 86 Sr ratios: in this study they are higher than 1.094. When these minerals crystallize from biotites, their 87 Sr/ 86 Sr ratios are much lower and can be close to the value of the primary Sr trapped in the biotites during their crystallization. On the other hand, the 87 Sr/ 86 Sr of continental montmorillonites are less scattered: they range, in this study, between 0.704 and 0.722. These low values, as well as the high adsorption capacities of these minerals in the sedimentary environment, allow the assumption that they frequently have 87 Sr/ 86 Sr ratios close to that of marine Sr during sedimentation. Therefore, montmorillonites are able to form homogeneous authigenic minerals by synsedimentary alterations. (Auth.)

  4. Equilibrium, kinetic and thermodynamic studies on the adsorption of the toxins of Bacillus thuringiensis subsp. kurstaki by clay minerals

    Energy Technology Data Exchange (ETDEWEB)

    Fu Qingling; Deng Yali; Li Huishu; Liu Jie [Key Laboratory of Subtropical Agricultural Resource and Environment, Ministry of Agriculture, Huazhong Agricultural University, Wuhan, 430070 (China); Hu Hongqing, E-mail: hqhu@mail.hzau.edu.cn [Key Laboratory of Subtropical Agricultural Resource and Environment, Ministry of Agriculture, Huazhong Agricultural University, Wuhan, 430070 (China); Chen Shouwen [Key Laboratory of Subtropical Agricultural Resource and Environment, Ministry of Agriculture, Huazhong Agricultural University, Wuhan, 430070 (China); Sa Tongmin [Department of Agricultural Chemistry, College of Agriculture, Chungbuk National University, Cheongju, 361-763 (Korea, Republic of)

    2009-02-01

    The persistence of Bacillus thuringiensis (Bt) toxins in soil is further enhanced through association with soil particles. Such persistence may improve the effectiveness of controlling target pests, but impose a hazard to non-target organisms in soil ecosystems. In this study, the equilibrium adsorption of the Bt toxin by four clay minerals (montmorillonite, kaolinite, goethite, and silicon dioxide) was investigated, and the kinetic and thermodynamic parameters were calculated. The results showed that Bt toxin could be adsorbed easily by minerals, and the adsorption was much easier at low temperature than at high temperature at the initial concentration varying from 0 to 1000 mg L{sup -1}. The adsorption fitted well to both Langmuir and Freundlich isotherm models, but the Freundlich equation was more suitable. The pseudo-second-order (PSO) was the best application model to describe the adsorption kinetic. The adsorption process appeared to be controlled by chemical process, and the intra-particle diffusion was not the only rate-controlling step. The negative standard free energy ({Delta}{sub r}G{sub m}{sup {theta}}) values of the adsorption indicated that the adsorption of the Bt toxin by the minerals was spontaneous, and the changes of the standard enthalpy ({Delta}{sub r}H{sub m}{sup {theta}}) showed that the adsorption of the Bt toxin by montmorillonite was endothermic while the adsorption by the other three minerals was exothermic.

  5. Equilibrium, kinetic and thermodynamic studies on the adsorption of the toxins of Bacillus thuringiensis subsp. kurstaki by clay minerals

    International Nuclear Information System (INIS)

    Fu Qingling; Deng Yali; Li Huishu; Liu Jie; Hu Hongqing; Chen Shouwen; Sa Tongmin

    2009-01-01

    The persistence of Bacillus thuringiensis (Bt) toxins in soil is further enhanced through association with soil particles. Such persistence may improve the effectiveness of controlling target pests, but impose a hazard to non-target organisms in soil ecosystems. In this study, the equilibrium adsorption of the Bt toxin by four clay minerals (montmorillonite, kaolinite, goethite, and silicon dioxide) was investigated, and the kinetic and thermodynamic parameters were calculated. The results showed that Bt toxin could be adsorbed easily by minerals, and the adsorption was much easier at low temperature than at high temperature at the initial concentration varying from 0 to 1000 mg L -1 . The adsorption fitted well to both Langmuir and Freundlich isotherm models, but the Freundlich equation was more suitable. The pseudo-second-order (PSO) was the best application model to describe the adsorption kinetic. The adsorption process appeared to be controlled by chemical process, and the intra-particle diffusion was not the only rate-controlling step. The negative standard free energy (Δ r G m θ ) values of the adsorption indicated that the adsorption of the Bt toxin by the minerals was spontaneous, and the changes of the standard enthalpy (Δ r H m θ ) showed that the adsorption of the Bt toxin by montmorillonite was endothermic while the adsorption by the other three minerals was exothermic.

  6. The Influence of SAND’s Gradation and Clay Content of Direct Sheart Test on Clayey Sand

    Science.gov (United States)

    Wibisono, Gunawan; Agus Nugroho, Soewignjo; Umam, Khairul

    2018-03-01

    The shear strength of clayey-sand can be affected by several factors, e.g. gradation, density, moisture content, and the percentage of clay and sand fraction. The same percentage of clay and sand fraction in clayey-sand mixtures may have different shear strengths due to those factors. This research aims to study the effect of clay content on sand that cause the change of its shear strength. Samples consisted of different clay and sand fractions were reconstituted at a certain moisture content. Sand fractions varied from well-graded to poorly-graded sand. Shear strength was measured in terms of the direct shear test. Prior to the test, surcharge loads were applied to represent overburden pressures. Shear strength results and their components (i.e. Cohesion and internal angle of friction) were correlated with physical properties of samples (i.e. grading coefficient of curvature, coefficient of uniformity, and density). Results showed that samples classified as well-graded and dense sand had higher shear strength. In the other hand, the shear strengths decreased when the mixtures became poorly-graded and less dense. The inclusion of the clay fraction increased cohesion component and decreased internal angle of friction.

  7. Obtaining and Organophilisation of Smectite Clays with Reduced Iron Oxide Content

    Directory of Open Access Journals (Sweden)

    Karasa Jūlija

    2016-05-01

    Full Text Available Raw clays from the Baltic region are characterized as smectite containing clays with significant amount of naturally occurring impurities that limiting the potential applications of crude Baltic clay resources. Purification of clay samples from Šaltiškių deposit (Venta basin was carried out by varied concentration hydrochloric acid solutions and resulted in fine removal of carbonates and iron oxide. The main idea of this work is to widen the possible applications of local clay resources providing a new type of raw material for further organoclay production.

  8. Nanoscale spatial analysis of clay minerals containing cesium by synchrotron radiation photoemission electron microscopy

    Science.gov (United States)

    Yoshigoe, Akitaka; Shiwaku, Hideaki; Kobayashi, Toru; Shimoyama, Iwao; Matsumura, Daiju; Tsuji, Takuya; Nishihata, Yasuo; Kogure, Toshihiro; Ohkochi, Takuo; Yasui, Akira; Yaita, Tsuyoshi

    2018-01-01

    A synchrotron radiation photoemission electron microscope (SR-PEEM) was applied to demonstrate the pinpoint analysis of micrometer-sized weathered biotite clay particles with artificially adsorbed cesium (Cs) atoms. Despite the insulating properties of the clay, we observed the spatial distributions of constituent elements (Si, Al, Cs, Mg, and Fe) without charging issues and clarified reciprocal site-correlations among these elements with nanometer resolution. We found that Cs atoms were likely to be adsorbed evenly over the entire particle; however, we identified an occupational conflict between Cs and Mg atoms, implying that Cs sorption involves ion exchange processes. Spatially resolved X-ray absorption spectra (XAS) of the Cs4,5 M-edge region showed Cs to be present in a monocation state (Cs+) as typically observed for Cs compounds. Further pinpoint XAS measurements were also performed at the Fe L2,3-edge to determine the chemical valence of the Fe atoms. The shapes of the spectra were similar to those for Fe2O3, indicating that Fe in the clay was in a 3+ oxidation state. From these observations, we infer that charge compensation facilitates Cs adsorption in the vicinity of a substitution site where Si4+ ions are replaced by Fe3+ ions in SiO4 tetrahedral sheets. Our results demonstrate the utility of SR-PEEM as a tool for spatially resolved chemical analyses of various environmental substances, which is not limited by the poor conductivity of samples.

  9. Influence of organic matter and clay minerals in migration of derivative compounds of hydrocarbons; Influencia da materia organica e argilominerais na migracao de compostos derivados de hidrocarbonetos

    Energy Technology Data Exchange (ETDEWEB)

    Ramos, Denize Gloria Barcellos; Mendonca Filho, Joao Graciano de; Polivanov, Helena [Universidade Federal, Rio de Janeiro, RJ (Brazil). Inst. de Geociencias. Dept. de Geologia]. E-mail: denize@geologia.ufrj.br; graciano@geologia.ufrj.br; helena@acd.ufrj.br

    2003-07-01

    Soil samples from the Guanabara Bay in Duque de Caxias city (RJ) were submitted to mineralogical and organic geochemistry analyses. This proceeding was used mainly to determine a possible interaction of hydrocarbons contaminants with the organic matter and the clay minerals presents in this mangrove. The sampling was carried out using Direct Push techniques. Thus, the mainly clay minerals characterizes were: gibbsite, illite, caulinite and smectite. The compositional analysis of organic constituents showed a predominance of amorphous material (degraded cuticles), followed of wood material and sporomorphs constituents, suggesting that the biological degradation occurred in situ. (author)

  10. Total body and regional bone mineral content in hemodialysis patients

    International Nuclear Information System (INIS)

    Hagiwara, Satoshi; Aratani, Hideyui; Miki, Takami; Nishizawa, Yoshiki; Okamura, Terue; Koizumi, Yoshiko; Ochi, Hironobu; Morii, Hirotoshi

    1994-01-01

    Bone mineral content (BMC) in the total body and lumbar spine was evaluated in 126 hemodialysis patients (60 males, 66 females) by dual photon absorptiometry with the Norland DBD 2600. Measurements of: 1) total body BMC divided by lean body mass (BMC TB /LBM), 2) bone mineral density (BMD) of total body, 3) BMD of four regional sections (head, trunk, pelvis, and legs), and 4) BMD of lumbar spine, generally showed a significant decrease in the hemodialysis patients compared to the reference population. However, arm BMD did not show a significant difference between patients and control populations. The z-score of BMC TB /LBM declined significantly throughout the duration of hemodialysis, although that of the lumbar spine BMD did not. It should be noted that the degree of decrease in BMC was more prominent in the total body measurement than in the lumbar spine measurement. There was preferential osteopenia of the total body in the hemodialysis patients. Although the lumbar spine BMD showed a lower value than the control population, the lumbar spine is not the recommended region to monitor the BMD change in hemodialysis patients. (author)

  11. Nuclear medical methods for determination of bone mineral content

    International Nuclear Information System (INIS)

    Fischer, M.; Kempers, B.; Tschepke, H.D.; Spitz, J.

    1988-01-01

    Osteoporosis is becoming recognized as a major social and economical health problem. Bone mineral content (BMC) depends on many hormonal and metabolic factors. The pathophysiological mechanism of the loss of bone mass is still unclear. For preventive diagnosis and treatment of osteoporosis, quantitative technology is required that will measure BMC with high precision and reproducibility. Nuclear medical methods permit the BMC of the appendicular skeleton to be measured by single photon absorptiometry. Whole-body BMC, as well as spine and femur BMC, can be measured by dual photon absorptiometry. The results from both procedures are reasonably precise and correlate well with the ash weight of isolated bone. The radiation exposure level in both SPA and DPA is low. SPA and DPA may be used for cost-effective screening of high-risk patients to predict the likelihood of future fractures and control osteoporosis therapy. (orig.) [de

  12. Red-clay ceramic powders as geopolymer precursors: Consideration of amorphous portion and CaO content

    Czech Academy of Sciences Publication Activity Database

    Keppert, M.; Vejmelková, E.; Bezdička, Petr; Doleželová, M.; Čáchová, M.; Scheinherrová, L.; Pokorný, J.; Vyšvařil, M.; Rovnaníková, P.; Černý, R.

    2018-01-01

    Roč. 161, SEP (2018), s. 82-89 ISSN 0169-1317 Institutional support: RVO:61388980 Keywords : Amorphous content * Calcium oxide * Composition * Geopolymers * Red-clay ceramics Subject RIV: CA - Inorganic Chemistry OBOR OECD: Inorganic and nuclear chemistry Impact factor: 3.101, year: 2016

  13. Pb-Zn mineralization of the Ali ou Daoud area (Central High Atlas, Morocco): characterisation of the deposit and relationships with the clay assemblages; Mineralisation Pb-Zn du type MVT de la region d'Ali ou Daoud (Haut Atlas Central, Maroc): caracterisations du gite et relations avec les corteges de mineraux argileux

    Energy Technology Data Exchange (ETDEWEB)

    Mouguina, E. M.; Daoudi, L.

    2008-07-01

    Zn-Pb-Fe ores in the Ali ou Daoud deposit (Central High Atlas) are found as stratiform levels and as karst fillings in carbonate platforms facies of Bajocian age. Tectonic structures (e.g., syn sedimentary faults) played a relevant role in the ore emplacement. The dolomitic ore-related host-rock levels are characterized by the presence of kaolinite enrichment in clay levels in amounts directly related to the proportion of the clay minerals. The latter is evidenced by correlation between kaolinite and sulphide contents, suggesting that the installation of kaolinite and mineralizations would result from the same hydrothermal fluid. (Author) 55 refs.

  14. Characterization of clay minerals and organic matter in shales: Application to high-level nuclear waste isolation

    International Nuclear Information System (INIS)

    Gueven, N.; Landis, C.R.; Jacobs, G.K.

    1988-10-01

    The objective of the Sedimentary Rock Program at the Oak Ridge National Laboratory is to conduct investigations to assess the potential for shale to serve as a host medium for the isolation of high-level nuclear wastes. The emphasis on shale is a result of screening major sedimentary rock types (shale, sandstone, carbonate , anhydrite, and chalk) for a variety of attributes that affect the performance of repositories. The retardation of radionuclides was recognized as one of the potentially favorable features of shale. Because shale contains both clay minerals and organic matter, phases that may provide significant sorption of radioelement, the characterization of these phases is essential. In addition, the organic matter in shale has been identified as a critical area for study because of its potential to play either a favorable (reductant) or deleterious (organic ligands) role in the performance of a repository sited in shale. 36 refs., 36 figs., 10 tabs

  15. Characterization of clay used for red ceramic fabrication; Caracterizacao de argila utilizada para fabricacao de ceramica vermelha

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, P.S.; Morais, A.S.C.; Caldas, T.C.C.; Monteiro, S.N.; Vieira, C.M.F. [Universidade Estadual do Norte Fluminense Darcy Ribeiro (LAMAV/UENF), Campos dos Goytacazes, RJ (Brazil). Laboratorio de Materiais Avancados; Ribeiro, M.M., E-mail: patriciasp_@hotmail.com [Instituto Federal Fluminense (IFF), Campos dos Goytacazes, RJ (Brazil)

    2011-07-01

    The objective of this work is to characterize a clay used in the red ceramics fabrication, from Campos dos Goytacazes north of the State of Rio de Janeiro. The clay was submitted for physical, chemical and mineralogical tests. The results showed that the clay has a high content of clay minerals with kaolinitic predominance, high loss on ignition and low flux oxides. It is recommended that this clay is mixed with non-plastic materials. (author)

  16. Error Analysis of Clay-Rock Water Content Estimation with Broadband High-Frequency Electromagnetic Sensors—Air Gap Effect

    Directory of Open Access Journals (Sweden)

    Thierry Bore

    2016-04-01

    Full Text Available Broadband electromagnetic frequency or time domain sensor techniques present high potential for quantitative water content monitoring in porous media. Prior to in situ application, the impact of the relationship between the broadband electromagnetic properties of the porous material (clay-rock and the water content on the frequency or time domain sensor response is required. For this purpose, dielectric properties of intact clay rock samples experimental determined in the frequency range from 1 MHz to 10 GHz were used as input data in 3-D numerical frequency domain finite element field calculations to model the one port broadband frequency or time domain transfer function for a three rods based sensor embedded in the clay-rock. The sensor response in terms of the reflection factor was analyzed in time domain with classical travel time analysis in combination with an empirical model according to Topp equation, as well as the theoretical Lichtenecker and Rother model (LRM to estimate the volumetric water content. The mixture equation considering the appropriate porosity of the investigated material provide a practical and efficient approach for water content estimation based on classical travel time analysis with the onset-method. The inflection method is not recommended for water content estimation in electrical dispersive and absorptive material. Moreover, the results clearly indicate that effects due to coupling of the sensor to the material cannot be neglected. Coupling problems caused by an air gap lead to dramatic effects on water content estimation, even for submillimeter gaps. Thus, the quantitative determination of the in situ water content requires careful sensor installation in order to reach a perfect probe clay rock coupling.

  17. Error Analysis of Clay-Rock Water Content Estimation with Broadband High-Frequency Electromagnetic Sensors—Air Gap Effect

    Science.gov (United States)

    Bore, Thierry; Wagner, Norman; Delepine Lesoille, Sylvie; Taillade, Frederic; Six, Gonzague; Daout, Franck; Placko, Dominique

    2016-01-01

    Broadband electromagnetic frequency or time domain sensor techniques present high potential for quantitative water content monitoring in porous media. Prior to in situ application, the impact of the relationship between the broadband electromagnetic properties of the porous material (clay-rock) and the water content on the frequency or time domain sensor response is required. For this purpose, dielectric properties of intact clay rock samples experimental determined in the frequency range from 1 MHz to 10 GHz were used as input data in 3-D numerical frequency domain finite element field calculations to model the one port broadband frequency or time domain transfer function for a three rods based sensor embedded in the clay-rock. The sensor response in terms of the reflection factor was analyzed in time domain with classical travel time analysis in combination with an empirical model according to Topp equation, as well as the theoretical Lichtenecker and Rother model (LRM) to estimate the volumetric water content. The mixture equation considering the appropriate porosity of the investigated material provide a practical and efficient approach for water content estimation based on classical travel time analysis with the onset-method. The inflection method is not recommended for water content estimation in electrical dispersive and absorptive material. Moreover, the results clearly indicate that effects due to coupling of the sensor to the material cannot be neglected. Coupling problems caused by an air gap lead to dramatic effects on water content estimation, even for submillimeter gaps. Thus, the quantitative determination of the in situ water content requires careful sensor installation in order to reach a perfect probe clay rock coupling. PMID:27096865

  18. Error Analysis of Clay-Rock Water Content Estimation with Broadband High-Frequency Electromagnetic Sensors--Air Gap Effect.

    Science.gov (United States)

    Bore, Thierry; Wagner, Norman; Lesoille, Sylvie Delepine; Taillade, Frederic; Six, Gonzague; Daout, Franck; Placko, Dominique

    2016-04-18

    Broadband electromagnetic frequency or time domain sensor techniques present high potential for quantitative water content monitoring in porous media. Prior to in situ application, the impact of the relationship between the broadband electromagnetic properties of the porous material (clay-rock) and the water content on the frequency or time domain sensor response is required. For this purpose, dielectric properties of intact clay rock samples experimental determined in the frequency range from 1 MHz to 10 GHz were used as input data in 3-D numerical frequency domain finite element field calculations to model the one port broadband frequency or time domain transfer function for a three rods based sensor embedded in the clay-rock. The sensor response in terms of the reflection factor was analyzed in time domain with classical travel time analysis in combination with an empirical model according to Topp equation, as well as the theoretical Lichtenecker and Rother model (LRM) to estimate the volumetric water content. The mixture equation considering the appropriate porosity of the investigated material provide a practical and efficient approach for water content estimation based on classical travel time analysis with the onset-method. The inflection method is not recommended for water content estimation in electrical dispersive and absorptive material. Moreover, the results clearly indicate that effects due to coupling of the sensor to the material cannot be neglected. Coupling problems caused by an air gap lead to dramatic effects on water content estimation, even for submillimeter gaps. Thus, the quantitative determination of the in situ water content requires careful sensor installation in order to reach a perfect probe clay rock coupling.

  19. Action of a clay suspension on an Fe(0) surface under anoxic conditions: Characterization of neoformed minerals at the Fe(0)/solution and Fe(0)/atmosphere interfaces

    International Nuclear Information System (INIS)

    Le Pape, Pierre; Rivard, Camille; Pelletier, Manuel; Bihannic, Isabelle; Gley, Renaud; Mathieu, Sandrine; Salsi, Lise; Migot, Sylvie; Barres, Odile; Villiéras, Frédéric; Michau, Nicolas

    2015-01-01

    Highlights: • Immersion of an Fe(0) foil in a clay suspension at 90 °C and in anoxic conditions. • Magnetite was observed on the atmospheric part. • Iron-rich 7 Å serpentines were observed on the clay suspension part. • A gradient in serpentine cristallochemistry was observed. • A pure Fe–Si phyllosilicate was identified at the Fe(0)/clay suspension contact. - Abstract: To better understand the reaction mechanisms involved at the Fe(0)/clay minerals interface, we investigate in the present study the reaction between an Fe(0) surface and a clay suspension extracted from the Callovo-Oxfordian claystone (COx). Batch experiments were carried out under anoxic conditions in sealed autoclave, at 90 °C to mimic predicted radioactive waste disposal conditions. An Fe(0) foil was introduced into the autoclave so that the lower part of the foil was immersed in the clay suspension while the upper part was contacted with the atmosphere of the experimental setup. After two months, the mineralogical deposits that precipitated at the surface of the Fe(0) foil were analyzed using multiple techniques, namely X-ray diffraction (XRD), scanning/transmission electron microscopy associated to microanalysis (SEM/TEM–EDXS), and micro-spectroscopic measurements (μ-FTIR and μ-Raman). Both parts of the Fe(0) foil were then shown to react: magnetite was the main resulting mineral formed at the Fe(0) surface in the atmospheric conditions whereas serpentine 1:1 phyllosilicates were the main end-products in the clay suspension. The analyses performed on the immersed part of the foil revealed a spatial heterogeneity in both serpentine cristallochemistry and morphology, with a gradient from the Fe(0) contact point toward the clay suspension. A pure Fe–Si phyllosilicate ring was observed at the direct contact point with the Fe(0) foil and a progressive incorporation of Al instead of Fe into the clay phases was identified as deposit thickness increased from the Fe(0) surface to

  20. Natural variation and QTL analysis for cationic mineral content in seeds of Arabidopsis thaliana.

    NARCIS (Netherlands)

    Vreugdenhil, D.; Aarts, M.G.M.; Koornneef, M.; Nelissen, H.J.M.; Ernst, W.H.O.

    2004-01-01

    Naturally occurring genetic variation for contents of cationic minerals in seeds of Arabidopsis thaliana was studied by screening a series of accessions (ecotypes) for Ca, Fe, K, Mg, Mn, Na, Zn, and for total contents of P. Variation was observed for all minerals and correlations between contents of

  1. The effect of clay content in sands used for cementitious materials in developing countries

    International Nuclear Information System (INIS)

    Fernandes, V.A.; Purnell, P.; Still, G.T.; Thomas, T.H.

    2007-01-01

    The cost of building materials in Less Economically Developed Countries (LEDCs) is one of the single largest contributing factors to housing costs. They are often transported over relatively large distances at considerable expense. Local sands may contain significant amounts of clay, considered by local artisans to be detrimental to concrete strength; however, in an LEDC context, there is little evidence to support this. In this study, the compressive strength and workability of representative LEDC clay-contaminated concrete was determined. Clay-cement interactions were studied using X-Ray Diffraction (XRD). Different clays appeared to have fundamentally different effects on both workability and strength. No chemical interactions were detected. It was concluded that satisfactory concrete could be made from clay-contaminated sand

  2. Stratigraphic and climatic implications of clay mineral changes around the Paleocene/Eocene boundary of the northeastern US margin

    Science.gov (United States)

    Gibson, T.G.; Bybell, L.M.; Mason, D.B.

    2000-01-01

    Kaolinite usually is present in relatively small amounts in most upper Paleocene and lower Eocene neritic deposits of the northern US Atlantic Coastal Plain. However, there is a short period (less than 200,000 k.y.) in the latest Paleocene (upper part of calcareous nannoplankton Zone NP 9) when kaolinite-dominated clay mineral suites replaced the usual illite/smectite-dominated suites. During this time of global biotic and lithologic changes, kaolinite increased from less than 5% of the clay mineral suite to peak proportions of 50-60% of the suite and then returned to less than 5% in uppermost Paleocene/lowermost Eocene strata. This kaolinite pulse is present at numerous localities from southern Virginia to New Jersey. These sites represent both inner and middle neritic depositional environments and reflect input from several river drainage systems. Thus, it is inferred that kaolinite-rich source areas were widespread in the northeastern US during the latest Paleocene. Erosion of these source areas contributed the kaolinite that was transported and widely dispersed into shelf environments of the Salisbury embayment. The kaolinite increase, which occurred during a time of relatively high sea level, probably is the result of intensified weathering due to increased temperature and precipitation. The southern extent of the kaolinite pulse is uncertain in that uppermost Paleocene beds have not been identified in the southern Atlantic Coastal Plain. The late Paleocene kaolinite pulse that consists of an increase to peak kaolinite levels followed by a decrease can be used for detailed correlation between more upbasin and more downbasin sections in the Salisbury embayment. Correlations show that more upbasin Paleocene/Eocene boundary sections are erosionally truncated. They have varying portions of the kaolinite increase and, if present at all, discontinuous portions of the subsequent kaolinite decrease. As these truncated sections are disconformably overlain by lower

  3. Mineralogy and heavy metal content of secondary mineral salts: A ...

    African Journals Online (AJOL)

    Secondary minerals associated with acid mine drainage play an important role in metal cycling and may pose a geochemical hazard. The occurrence of secondary minerals indicates prevailing and past geochemical conditions. Detecting and characterising secondary minerals is necessary to the planning of remediation ...

  4. Geochemical simulation of the evolution of granitic rocks and clay minerals submitted to a temperature increase in the vicinity of a repository for spent nuclear fuel

    International Nuclear Information System (INIS)

    Fritz, B.; Kam, M.; Tardy, Y.

    1984-07-01

    The alteration of a granitic rock around a repository for spent nuclear fuel has been simulated considering the effect of an increase of temperature due to this kind of induced geothermal system. The results of the simulation have been interpreted in terms of mass transfer and volumic consequences. The alteration proceeds by dissolution of minerals (with an increase of the volumes of fissures and cracks) and precipitation of secondary miminerals as calcite and clay minerals particularly (with a decrease of the porosity). The increase of the temperature from 10 degrees C to about 100 degrees C will favour the alteration of the granitic rock around the repository by the solution filling the porosity. The rock is characterized by a very low fissure porosity and a consequent very low water velocity. This too, favours intense water rock interactions and production of secondary clays and the total possible mass transfer will decrease the porosity. A combination of these thermodynamic mass balance calculations with a kinetic approach of mineral dissolutions gives a first attempt to calibrate the modelling in the time scale: the decrease of porosity can be roughly estimated between 2 and 20% for 100,000 years. The particular problem of Na-bentonites behaviour in the proximate vicinity of the repository has been studied too. One must distinguish between two types of clay-water interactions: -within the rock around the repository, Na-bentonites should evolute with illitization in slighltly open system with low clay/water ratios, -within the repository itself, the clay reacts in a closed system for a long time with high clay/water ratios and a self-buffering effect should maintain the bentonite type. This chemical buffering effect is a positive point for the use of this clay as chemical barrier. (Author)

  5. Evidence of contrasting low-grade metamorphic conditons from clay mineral assablages in Triassic Alpujárride-Maláguide transtional units in the Betic Cordilleras, Spain

    Czech Academy of Sciences Publication Activity Database

    Ruiz Cruz, M. D.; Franco, F.; Sanz de Galdeano, C.; Novák, Jiří Karel

    2006-01-01

    Roč. 41, 2 (2006), s. 621-638 ISSN 0009-8558 Institutional research plan: CEZ:AV0Z30130516 Keywords : low-grade metamorphism * clay minerals * Betic Cordilleras Subject RIV: DB - Geology ; Mineralogy Impact factor: 0.974, year: 2006

  6. Rates and time scales of clay-mineral formation by weathering in saprolitic regoliths of the southern Appalachians from geochemical mass balance

    Science.gov (United States)

    Jason R. Price; Michael A. Velbel; Lina C. Patino

    2005-01-01

    Rates of clay formation in three watersheds located at the Coweeta Hydrologic Laboratory, western North Carolina, have been determined from solute flux-based mass balance methods. A system of mass balance equations with enough equations and unknowns to allow calculation of secondary mineral formation rates as well as the more commonly determined primary-...

  7. Recovery of Porosity and Permeability for High Plasticity Clays

    DEFF Research Database (Denmark)

    Krogsbøll, Anette; Foged, Niels Nielsen

    to be the case for high plasticity clays that are uncemented, and with a high content of clay minerals, especially smectite. Oedometer tests on samples from the Paleogene period show that 80% or more of the compaction will recover when unloaded, and if unloaded to a stress lower than in situ stress level...

  8. Impact of clay mineral, wood sawdust or root organic matter on the bacterial and fungal community structures in two aged PAH-contaminated soils.

    Science.gov (United States)

    Cébron, Aurélie; Beguiristain, Thierry; Bongoua-Devisme, Jeanne; Denonfoux, Jérémie; Faure, Pierre; Lorgeoux, Catherine; Ouvrard, Stéphanie; Parisot, Nicolas; Peyret, Pierre; Leyval, Corinne

    2015-09-01

    The high organic pollutant concentration of aged polycyclic aromatic hydrocarbon (PAH)-contaminated wasteland soils is highly recalcitrant to biodegradation due to its very low bioavailability. In such soils, the microbial community is well adapted to the pollution, but the microbial activity is limited by nutrient availability. Management strategies could be applied to modify the soil microbial functioning as well as the PAH contamination through various amendment types. The impact of amendment with clay minerals (montmorillonite), wood sawdust and organic matter plant roots on microbial community structure was investigated on two aged PAH-contaminated soils both in laboratory and 1-year on-site pot experiments. Total PAH content (sum of 16 PAHs of the US-EPA list) and polar polycyclic aromatic compounds (pPAC) were monitored as well as the available PAH fraction using the Tenax method. The bacterial and fungal community structures were monitored using fingerprinting thermal gradient gel electrophoresis (TTGE) method. The abundance of bacteria (16S rRNA genes), fungi (18S rRNA genes) and PAH degraders (PAH-ring hydroxylating dioxygenase and catechol dioxygenase genes) was followed through qPCR assays. Although the treatments did not modify the total and available PAH content, the microbial community density, structure and the PAH degradation potential changed when fresh organic matter was provided as sawdust and under rhizosphere influence, while the clay mineral only increased the percentage of catechol-1,2-dioxygenase genes. The abundance of bacteria and fungi and the percentage of fungi relative to bacteria were enhanced in soil samples supplemented with wood sawdust and in the plant rhizospheric soils. Two distinct fungal populations developed in the two soils supplemented with sawdust, i.e. fungi related to Chaetomium and Neurospora genera and Brachyconidiellopsis and Pseudallescheria genera, in H and NM soils respectively. Wood sawdust amendment favoured the

  9. Sorption of radionuclides by tertiary clays

    International Nuclear Information System (INIS)

    Wagner, J.F.; Czurda, K.A.

    1990-01-01

    The sorption capacity of different clay types for some metals (Co, Cs, Sr and Zn), occurring as common radionuclides in radioactive waste deposits, had been analysed by a static (batch technique) and a dynamic method (percolation tests, in which the driving force is a hydraulic gradient). Sorption capacity generally increased with an increasing pH of solution. A decrease of sorption capacity had been observed in the order Zn > Cs ≥ Co > Sr for the batch and Cs > Zn > Sr > Co for the percolation tests. Clay marls showed a distinctly higher sorption respectively retention capacity as pure clays. Sorption capacity depends on solution parameters like type and concentration of radionuclide, pH, salt concentration, etc., and on rock parameters like mineral content (e.g. swelling clay minerals and carbonates), organic material, rock pH, micro fabric, etc. A third parameter of great influence is the contact time between clay and solution. The adsorption isotherms reflect two different adsorption mechanisms: a very rapid adsorption (a few minutes) on the external surfaces of clay minerals and a slow adsorption process (weeks and longer), due to the diffusion of metal ions into the interlayer space of clay minerals. 12 refs., 9 figs., 1 tab

  10. Radiation-induced defects in clay minerals, markers of the mobility of the uranium in solution in the unconformity-type uranium deposits

    International Nuclear Information System (INIS)

    Morichon, E.

    2008-10-01

    This study presents the works driven on three groups of clay minerals (kaolins, illite, sudoite (di-tri-octahedral chlorites)) characteristics of the alteration halos surrounding unconformity-type uranium deposits, in order to reveal uranium paleo-circulations in the intra-cratonic meso-Proterozoic basins (1,2 - 1,6 Ga). Thanks to Electron Paramagnetic Resonance Spectroscopy (EPR), we were able to highlight the persistence of structural defects in kaolin-group minerals contemporaneous of the basin diagenesis, and demonstrate the existence of relatively stable defects in illites and sudoites contemporaneous of the uranium deposits setting. Thus, the main defect in illite (Ai centre) and the main defect in sudoite (As centre) are characterized by their g components such as, respectively, gt = 2,003 et g// = 2,051 for illite and gt = 2,008 et g// = 2,051 for sudoite. As the main defect in kaolins (kaolinite/dickite), the main defects in illite and sudoite are perpendicularly oriented according to the (ab) plane, on the tetrahedral Si-O bound. However, their thermal stabilities seem different. The observation of samples from different zones (background, anomal or mineralized) of the Athabasca basin (Canada) allowed to identify a parallel evolution between actual defects concentration measured in the different clay minerals and the proximity of the mineralisation zones. Consequently, clays minerals can be considered as potential plotters of zones where uranium-rich solutions have circulated. (author)

  11. Effect of the platinum content on the microstructure and micropore size distribution of Pt/alumina-pillared clays.

    Science.gov (United States)

    Barrera-Vargas, M; Valencia-Rios, J; Vicente, M A; Korili, S A; Gil, A

    2005-12-15

    The aim of this work is to study the effect of the platinum content (0-1.8 wt % Pt) on the microstructure of an alumina-pillared clay. For this purpose, the nitrogen physisorption data at -196 degrees C, the micropore size distributions of the supported platinum catalysts, and the hydrogen chemisorption results at 30 degrees C have been analyzed and compared. The preparation of the catalysts has modified the textural properties of the Al-pillared clay support, giving rise to a loss of surface area and micropore volume. After reduction at 420 degrees C, the presence of dispersed metallic platinum with mean crystallite size in the 22-55 A range has been found by hydrogen adsorption. Comparison of all results reveals that the platinum species block the micropore entrances by steric hindrance to nitrogen access as the platinum content increases.

  12. Modelling of niobium sorption on clay minerals in sodium and calcium perchlorate solutions

    Energy Technology Data Exchange (ETDEWEB)

    Ervanne, Heini; Hakanen, Martti; Lehto, Jukka [Helsinki Univ. (Finland). Laboratory of Radiochemistry

    2014-11-01

    The sorption behaviour of niobium on kaolinite and illite minerals in sodium and calcium perchlorate solutions was evaluated with use of the mass distribution coefficient, Rd, obtained in batch sorption experiments. Very high distribution coefficient values, about 100 m{sup 3}/kg, were obtained for both minerals in the neutral pH range between 6 and 8. Values were somewhat lower at pH 5. In NaClO{sub 4} solution, the sorption of niobium starts to decrease at pH higher than 8. This is in agreement with the increase, with pH, in the proportion of anionic niobate species, which are presumed to be low or non-sorbing. A similar decrease was not observed in Ca(ClO{sub 4}){sub 2} solution, probably owing to the influence of Ca on niobium solution speciation and surface species. The surface complexation model was applied to model the Rd values. The model fitted well for the NaClO{sub 4} solution but only at pH below 9 for the Ca(ClO{sub 4}){sub 2} solution. The discrepancy between the strong sorption of niobium in calcium-bearing solution at high pH and the calculated speciation is due in part to the non-inclusion of calcium niobate solution species and Ca-Nb compounds in the present NEA and other similar thermodynamic databases.

  13. Evaluation of Minerals Content of Drinking Water in Malaysia

    Science.gov (United States)

    Azlan, Azrina; Khoo, Hock Eng; Idris, Mohd Aizat; Ismail, Amin; Razman, Muhammad Rizal

    2012-01-01

    The drinking and mineral water samples obtained from different geographical locations had concentrations of the selected minerals lower than the standard limits, except for manganese, arsenic, and fluoride. The concentrations of manganese and arsenic in two mineral water samples were slightly higher than the standard international recommended limits. One mineral water sample had a fluoride concentration higher than the standard limits, whereas manganese was not detected in nine drinking and mineral water samples. Most of the selected minerals found in the tap water samples were below the international standard limits, except for iron and manganese. The concentrations of iron and manganese in the tap water samples were higher than the standard limits, which were obtained from one and three of the studied locations, respectively. The potable water obtained from various manufacturers and locations in Peninsular Malaysia is safe for consumption, as the minerals concentrations were below the standard limits prescribed by the Malaysian Food Regulations of 1985. The data obtained may also provide important information related to daily intake of these minerals from drinking water. PMID:22649292

  14. Evaluation of Minerals Content of Drinking Water in Malaysia

    Directory of Open Access Journals (Sweden)

    Azrina Azlan

    2012-01-01

    Full Text Available The drinking and mineral water samples obtained from different geographical locations had concentrations of the selected minerals lower than the standard limits, except for manganese, arsenic, and fluoride. The concentrations of manganese and arsenic in two mineral water samples were slightly higher than the standard international recommended limits. One mineral water sample had a fluoride concentration higher than the standard limits, whereas manganese was not detected in nine drinking and mineral water samples. Most of the selected minerals found in the tap water samples were below the international standard limits, except for iron and manganese. The concentrations of iron and manganese in the tap water samples were higher than the standard limits, which were obtained from one and three of the studied locations, respectively. The potable water obtained from various manufacturers and locations in Peninsular Malaysia is safe for consumption, as the minerals concentrations were below the standard limits prescribed by the Malaysian Food Regulations of 1985. The data obtained may also provide important information related to daily intake of these minerals from drinking water.

  15. Evaluation of minerals content of drinking water in Malaysia.

    Science.gov (United States)

    Azlan, Azrina; Khoo, Hock Eng; Idris, Mohd Aizat; Ismail, Amin; Razman, Muhammad Rizal

    2012-01-01

    The drinking and mineral water samples obtained from different geographical locations had concentrations of the selected minerals lower than the standard limits, except for manganese, arsenic, and fluoride. The concentrations of manganese and arsenic in two mineral water samples were slightly higher than the standard international recommended limits. One mineral water sample had a fluoride concentration higher than the standard limits, whereas manganese was not detected in nine drinking and mineral water samples. Most of the selected minerals found in the tap water samples were below the international standard limits, except for iron and manganese. The concentrations of iron and manganese in the tap water samples were higher than the standard limits, which were obtained from one and three of the studied locations, respectively. The potable water obtained from various manufacturers and locations in Peninsular Malaysia is safe for consumption, as the minerals concentrations were below the standard limits prescribed by the Malaysian Food Regulations of 1985. The data obtained may also provide important information related to daily intake of these minerals from drinking water.

  16. Antibiotic eluting clay mineral (Laponite®) for wound healing application: an in vitro study.

    Science.gov (United States)

    Ghadiri, M; Chrzanowski, W; Rohanizadeh, R

    2014-11-01

    Different materials in form of sponge, hydrogel and film have been developed and formulated for treating and dressing burn wounds. In this study, the potential of Laponite, a gel forming clay, in combination with an antimicrobial agent (mafenide), as a wound dressing material was tested in vitro. Laponite/mafenide (Lap/Maf) hydrogel was formulated in three different ratios of Lap/Maf 1:1, 1:2, 1:3. Laponite/mafenide/alginate (Lap/Maf/Alg) film was also formulated by combining Lap/Maf gel (1:1) with alginate. Intercalation rate of mafenide into the layers of Laponite nanoparticles and physico-chemical properties, including wound dressing characteristics of materials were studied using various analytical methods. Furthermore, the degradation of materials and the release profile of mafenide were investigated in simulated wound exudates fluid and antibacterial effectiveness of the eluted mafenide was tested on a range of bacterial species. The cytotoxicity of materials was also evaluated in skin fibroblast culture. The results showed that mafenide molecules were intercalated between the nano-sized layers of Laponite. The eluted mafenide showed active antibacterial effects against all three tested bacteria. All intercalated mafenide released from Lap/Maf 1:1 and 1:2 gel formulations and nearly 80% release from 1:3 formulation during test period. No significant difference was observed in release profile of mafenide between Lap/Maf/Alg film and Lap/Maf formulations. Wound dressing tests on Lap/Maf/Alg film showed it is a breathable dressing and has capacity to absorb wound exudates. The study showed that prepared Lap/Maf composite has the potential to be used as an antibiotic eluting gel or film for wound healing application. Additionally, Laponite has shown benefits in wound healing processes by releasing Mg(2+) ions and thereby reducing the cytotoxic effect of mafenide on fibroblast cells.

  17. A REVIEW OF QUANTITATIVE METHODS FOR STUDIES OF MINERAL-CONTENT OF INTRAORAL INCIPIENT CARIES LESIONS

    NARCIS (Netherlands)

    TENBOSCH, JJ; ANGMARMANSSON, B

    Modern prospective caries studies require the measurement of small changes in tooth mineral content. Quantitative measurements of changes in mineral content in a single caries lesion is desirable. Quantitative methods can be either destructive or non-destructive. The latter type permits longitudinal

  18. Relationships between birefringence and mineral content in artificial caries lesions of enamel.

    NARCIS (Netherlands)

    Theuns, H.M.; Shellis, R.P.; Groeneveld, A.; Dijk, J.W. van; Poole, D.F.

    1993-01-01

    The microradiographic mineral content and birefringence in water and Thoulet's solution were measured at selected points in sections of caries-like lesions. Birefringence was not related to mineral content in sound superficial enamel immersed in Thoulet's solution or in the lesion body immersed in

  19. Measurement of bone mineral content by dual photon absorptiometry in patients with metabolic bone diseases

    International Nuclear Information System (INIS)

    Ohtani, Masami; Hino, Megumu; Ikekubo, Katsuji

    1991-01-01

    Dual photon absorptiometry was used to measure bone mineral content in 225 patients with metabolic bone diseases (84 males and 102 females) and 186 healthy subjects (25 males and 200 females). Mineral content of the lumbar vertebrae tended to rapidly decrease after the age of 40 in healthy female subjects. For males, gradual decrease in mineral content was associated with aging. Bone mineral content showed a correlation with the severity of osteoporosis as shown on X-ray films. Mineral content tended to be decreased in the lumbar vertebrae in patients with vertebral compression fracture, and in the femur in patients with vertebral or femoral fracture. For hyperthyroidism, mineral content of the lumbar vertebrae was decreased in some females, but was within normal limit in males. Hyperparathyroidism and hypoparathyroidism tended to be associated with decrease and increase in mineral content, respectively. Two each patients with osteomalacia or Cushing syndrome had a decreased mineral content. In these patients, it was increased after the treatment. (N.K.)

  20. Measurement of bone mineral content by dual photon absorptiometry in patients with metabolic bone diseases

    Energy Technology Data Exchange (ETDEWEB)

    Ohtani, Masami; Hino, Megumu; Ikekubo, Katsuji (Kobe City General Hospital (Japan)) (and others)

    1991-12-01

    Dual photon absorptiometry was used to measure bone mineral content in 225 patients with metabolic bone diseases (84 males and 102 females) and 186 healthy subjects (25 males and 200 females). Mineral content of the lumbar vertebrae tended to rapidly decrease after the age of 40 in healthy female subjects. For males, gradual decrease in mineral content was associated with aging. Bone mineral content showed a correlation with the severity of osteoporosis as shown on X-ray films. Mineral content tended to be decreased in the lumbar vertebrae in patients with vertebral compression fracture, and in the femur in patients with vertebral or femoral fracture. For hyperthyroidism, mineral content of the lumbar vertebrae was decreased in some females, but was within normal limit in males. Hyperparathyroidism and hypoparathyroidism tended to be associated with decrease and increase in mineral content, respectively. Two each patients with osteomalacia or Cushing syndrome had a decreased mineral content. In these patients, it was increased after the treatment. (N.K.).

  1. Reduction and long-term immobilization of technetium by Fe(II) associated with clay mineral nontronite

    International Nuclear Information System (INIS)

    Jaisi, Deb P.; Dong, Hailiang; Plymale, Andrew E.; Fredrickson, Jim K.; Zachara, John M.; Heald, S.; Liu, Chongxuan

    2009-01-01

    99Tc is formed mostly during nuclear reactions and is released into the environment during weapons testing and inadvertent waste disposal. The long half-life, high environmental mobility (as Tc(VII)O4-) and its possible uptake into the food chain cause 99Tc to be a significant environmental contaminant. In this study, we evaluated the role of Fe(II) in biologically reduced clay mineral, nontronite (NAu-2), in reducing Tc(VII)O4- to poorly soluble Tc(IV) species as a function of pH and Fe(II) concentration. The rate of Tc(VII) reduction by Fe(II) in NAu-2 was higher at neutral pH (pH 7.0) than at acidic and basic pHs when Fe(II) concentration was low (< 1 mmol/g). The effect of pH, however, was insignificant at higher Fe(II) concentrations. The reduction of Tc(VII) by Fe(II) associated with NAu-2 was also studied in the presence of common subsurface oxidants including iron and manganese oxides, nitrate, and oxygen, to evaluate the effect of the oxidants on the enhancement and inhibition of Tc(VII) reduction, and reoxidation of Tc(IV). Addition of iron oxides (goethite and hematite) to the Tc(VII)-NAu-2 system, where Tc(VII) reduction was ongoing, enhanced reduction of Tc(VII), apparently as a result of re-distribution of reactive Fe(II) from NAu-2 to more reactive goethite/hematite surfaces. Addition of manganese oxides stopped further Tc(VII) reduction, and in case of K+-birnessite, it reoxidized previously reduced Tc(IV). Nitrate neither enhanced reduction of Tc(VII) nor promoted reoxidation of Tc(IV). Approximately 11% of Tc(IV) was oxidized by oxygen. The rate and extent of Tc(IV) reoxidation was found to strongly depend on the nature of the oxidants and concentration of Fe(II). When the same oxidants were added to aged Tc reduction products (mainly NAu-2 and TcO2nH2O), the extent of Tc(IV) reoxidation decreased significantly relative to fresh Tc(IV) products. Increasing NAu-2 concentration also resulted in the decreased extent of Tc(IV) reoxidation. The results

  2. Influence of mineralogy and moisture content on plasticity and induced anisotropic damage of a clay-stone: application to nuclear waste disposals

    International Nuclear Information System (INIS)

    Chiarelli, A.S.; Sibai, M.; Karami, M.; Ledesert, B.; Hoteit, N.

    2000-01-01

    The influence of mineralogy and moisture content on mechanical behaviour of a clay-stone rock is studied by the way of uniaxial and triaxial compression tests and microscopic observations. Some parameters characteristic of phenomena like plasticity and induced anisotropic damage are discussed as a function of these two factors. Rock behaviour becomes more brittle when calcite content grows or when clay or moisture content decreases. At the micro-level, plasticity is induced by slip of clay sheets and induced anisotropic damage appears by growth of oriented microcracks at the interface between grains and matrix. (authors)

  3. Column studies on the sorption of radioactive isotopes by some natural clay minerals

    International Nuclear Information System (INIS)

    Abdel-Gawad, A.S.; Misak, N.Z.; Maghrawy, H.B.; Shafik, A.

    1982-01-01

    Different types of naturally occuring minerals have been investigated in respect of the sorption of various radioisotopes. The present work deals with column studies of the sorption of 89 Sr and 60 Co on four natural bentonites. Columns having a cross section of 1.47 cm 2 were used for determining the breakthrough capacities for both Sr and Co. The applicability of the Glueckauf plate theory to the systems was tested. It was found that HETP is constant for a given system of column and cationic species, which proves the applicability of the theory. From this, it follows that the data obtained for the short laboratory columns can be used to predict the breakthrough behaviour for longer columns. (author)

  4. [Analysis of changes in minerals contents during cider fermentation process by inductively coupled plasma mass spectrometry].

    Science.gov (United States)

    Ye, Meng-qi; Yue, Tian-li; Gao, Zhen-peng; Yuan, Ya-hong; Nie, Gang

    2015-01-01

    The changes in mineral elements during cider fermentation process were determined using ICP-MS. The results showed that the main minerals in the fermentation liquor included K, Na, Ca, Mg, Fe, Mn, Zn, Cu, Sr and B. The content of K was the highest in both the apple juice and the cider, being 1 853. 83 and 1 654. 38 mg . L-1 respectively. The content of minerals was in dynamic changes along with the fermentation process. As a whole, during 72-120 h and 144-216 h, most of the minerals contents underwent great fluctuation. Especially when fermented for 192 h, the content of most of the minerals reached peak value or valley value. The content of Fe and Zn achieved their peak value, while the content of K, Na, Ca, Mg, Mn and B achieved valley value. But during the following 24 h, the content of minerals underwent a sharp reversal. After fermentation, the content of K, Mg, Cu, Zn and B decreased significantly, while the content of Na, Ca, Mn, Fe and Sr did not change significantly. The correlational analysis was conducted to evaluate the correlation between the mineral elements, and the result showed that the correlation between Ca and Mn was the most significant, with the correlation index reaching 0. 924. The information of this study will supply sufficient data for the fermentation process control and quality improvement of cider.

  5. Nanoporous polymer--clay hybrid membranes for gas separation.

    Science.gov (United States)

    Defontaine, Guillaume; Barichard, Anne; Letaief, Sadok; Feng, Chaoyang; Matsuura, Takeshi; Detellier, Christian

    2010-03-15

    Nanohybrid organo-inorgano clay mineral-polydimethylsiloxane (PDMS) membranes were prepared by the reaction of pure and/or modified natural clay minerals (Sepiolite and montmorillonite) with PDMS in hexane, followed by evaporation of the solvent at 70 degrees C. The membranes were characterized by means of XRD, SEM, ATD-TG and solid state (29)Si magic angle spinning (MAS) and cross-polarization (CP) CP/MAS NMR. The morphology of the membranes depends on the content loading of clay mineral. For low content, the membrane composition is homogeneous, with well dispersed nanoparticles of clay into the polymer matrix, whereas for higher clay content, the membranes are constituted also of a mixture of well dispersed nanoparticles into the polymer, but in the presence of agglomerations of small clay particles. Quantitative (29)Si MAS NMR demonstrated a strong correlation between the clay content of the membrane and the average length of the PDMS chain, indicating that the nanohybrid material is made of clay particles covalently linked to the PDMS structure. This is particularly the case for Sepiolite with has a high density of Q(2) silanol sites. The separation performances of the prepared membranes were tested for CO(2)/CH(4) and O(2)/N(2) mixtures. The observed separation factors showed an increase of the selectivity in the case of CO(2)/CH(4) in comparison with membranes made from PDMS alone under the same conditions. 2009 Elsevier Inc. All rights reserved.

  6. Effect of water content nitrogen gross mineralization and immobilization

    International Nuclear Information System (INIS)

    Videla C, Ximena; Parada, Ana Maria; Nario M, Adriana; Pino N, Ines; Hood, Rebeca

    2005-01-01

    The decomposition of organic matter in soil, and the accompanying mineralization and immobilization of inorganic N, are key processes in the soil plant cycle. It is hypothesized that moisture regime may also play an important role on these processes. Two laboratory studies were carried out to investigate the effect of moisture regime on gross mineralization and immobilization of N, in and Ultisol soil, which was incubated at 25 o C, under two moisture regimes, field capacity (CC) (40% w/w) and 85% of field capacity (34% w/w): Using mirror image 15 N isotope dilution techniques, it was possible to determine gross nitrification and mineralization rates. The rates of gross mineralization and nitrification rate in this soil was extremely rapid and efficient, specially with 85% CC. The N transformations varied with moisture regime (author)

  7. Characterization of element and mineral content in Artemisia annua ...

    African Journals Online (AJOL)

    Dr DIALLO

    2013-06-26

    Jun 26, 2013 ... The mineral elements are present in different kinds of herbal leaves in various proportions .... rare earth elements (Dy, Eu, Gd, Sm, Tb and Yb) were not detected in ..... behaviour of leached aluminum in tea infusions. The Sci.

  8. Cs adsorption mechanism on clay minerals based on material sciences using synchrotron radiation and first principle calculation

    International Nuclear Information System (INIS)

    Yaita, Tsuyoshi; Kobayashi, Toru; Ikeda, Takashi; Matsumura, Daiju; Machida, Masahiko; Okumura, Masahiko; Nakamura, Hiroki

    2014-01-01

    The radioactive Cs released from Fukushima Dai-ichi Nuclear Power Plant accident is one of the important sources to increase air dose rate in environment, and thus the local and Japanese governments are still promoting the decontamination project in the contaminated area in Fukushima. On this backgrounds, in this study, 'the comprehensive researches', i.e., the elucidation of Cs speciation through the structural and electronic structural studies in clay minerals for supporting to develop the promising volume reduction methods of soil wastes (we will not touch the chemical treatment, wet classification, incineration, and alkaline fusion methods in this article) and the evaluation of Cs stability in soil wastes over mid- to long-term period, and the field investigation for elucidation of seasonal variation of bottom soil of agricultural reservoir in litate village on considering the features of local soil in Fukushima, have been performed. In this article, we introduce a part of the results obtaining by the synchrotron based X-ray analysis and the first principle molecular dynamics simulation methods. (author)

  9. Kinetic and Thermodynamic Studies for the Removal of Europium Ions from Waste Solution Using Some Local Clay Minerals

    International Nuclear Information System (INIS)

    El-Kamash, A.M.; El-Masry, E.H.; El-Dessouky, M.I.

    2008-01-01

    Thermodynamic and kinetic investigations on the removal of Eu 3+ ions from aqueous waste solution using bentonite and sandstone, as local clay minerals, has been done using batch technique. The influences of ph, contact time between liquid and solid phases, initial metal ion concentration, and temperature have been evaluated. Pseudo first-order and pseudo second-order kinetic models were used to analyze the sorption rate data and the results showed that the pseudo second-order model is best correlate the kinetic data. Equilibrium isotherms were determined to assess the maximum sorption capacity of bentonite and sandstone and the equilibrium sorption data were analyzed using Freundlich, Langmuir and Dubinin-Radushkevich (D-R) isotherm models. All tested models fit the data reasonably well in terms of regression coefficients. The maximum sorption capacity of bentonite was found to be greater than that of sandstone and the mean free energy is in all cases in the range corresponding to the ion exchange type of sorption. Sorption studies were also performed at different temperatures to obtain the thermodynamic parameters of the process. The numerical value of δG degree decreases with an increase in temperature, indicating that the sorption reaction is more favorable at higher temperature. The positive values of δH degree correspond to the endothermic nature of the sorption process

  10. Mild acid and alkali treated clay minerals enhance bioremediation of polycyclic aromatic hydrocarbons in long-term contaminated soil: A 14C-tracer study.

    Science.gov (United States)

    Biswas, Bhabananda; Sarkar, Binoy; Rusmin, Ruhaida; Naidu, Ravi

    2017-04-01

    Bioremediation of polycyclic aromatic hydrocarbon (PAH)-contaminated soils requires a higher microbial viability and an increased PAH bioavailability. The clay/modified clay-modulated bacterial degradation could deliver a more efficient removal of PAHs in soils depending on the bioavailability of the compounds. In this study, we modified clay minerals (smectite and palygorskite) with mild acid (HCl) and alkali (NaOH) treatments (0.5-3 M), which increased the surface area and pore volume of the products, and removed the impurities without collapsing the crystalline structure of clay minerals. In soil incubation studies, supplements with the clay products increased bacterial growth in the order: 0.5 M HCl ≥ unmodified ≥ 0.5 M NaOH ≥ 3 M NaOH ≥ 3 M HCl for smectite, and 0.5 M HCl ≥ 3 M NaOH ≥ 0.5 M NaOH ≥ 3 M HCl ≥ unmodified for palygorskite. A 14 C-tracing study showed that the mild acid/alkali-treated clay products increased the PAH biodegradation (5-8%) in the order of 0.5 M HCl ≥ unmodified > 3 M NaOH ≥ 0.5 M NaOH for smectite, and 0.5 M HCl > 0.5 M NaOH ≥ unmodified ≥ 3 M NaOH for palygorskite. The biodegradation was correlated (r = 0.81) with the bioavailable fraction of PAHs and microbial growth as affected particularly by the 0.5 M HCl and 0.5 M NaOH-treated clay minerals. These results could be pivotal in developing a clay-modulated bioremediation technology for cleaning up PAH-contaminated soils and sediments in the field. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Structural changes in a clay-containing nanocomposite with a different moisture content caused by its deformation

    International Nuclear Information System (INIS)

    Fajtel'son, E.A.; Glaskova, T.I.; Korkhovm, V.P.; Aniskevich, A.N.

    2010-01-01

    This paper presents the results of an investigation of the properties of a clay-containing nanocomposite with an epoxy binder under moisture-temperature and mechanical action. It has been established that whatever the moisture content, the nanocomposite crystallizes under the thermomechanical action (upon reaching the glasstransition temperature). When the nanocomposite is heated to 70 C, the restructuring process is reversible, and its heating to above 150 C leads to its amorphization. The presence of clay nanoparticles (up to 6 mass percent) does not influence the temperature of structural transitions of the nanocomposite and does not cause a substantial strengthening effect. The sorbed moisture plasticizes the nanocomposite and decreases its glasstransition temperature by 10 C. The specific features of the thermomechanical behavior of nanocomposites upon their tensile prestrain or creep are due to the formation of an oriented structure. Their crystallization begins at lower temperatures and with a higher degree of crystallinity than that of unloaded nanostructures. (authors)

  12. Viscosity and Plasticity of Latvian Illite Clays

    OpenAIRE

    Jurgelāne, I; Vecstaudža, J; Stepanova, V; Mālers, J; Bērziņa-Cimdiņa, L

    2012-01-01

    Due to viscosity and plasticity, clays and clay minerals are used in civil engineering, pottery and also in cosmetics and medicine as thickening agents and emulsion and suspension stabilizers. The rheological properties of clay suspensions are complex. Mostly it is an interaction between mineral composition, clay particle size and pH value and also depends on clay minerals. Clay-water suspension is non-Newtonian fluid showing thixotropic and pseudoplastic properties. Results showed that plast...

  13. Physical Properties of Latvian Clays

    OpenAIRE

    Jurgelāne, I; Stepanova, V; Ločs, J; Mālers, J; Bērziņa-Cimdiņa, L

    2012-01-01

    Physical and chemical properties of clays mostly depends on its mineral and chemical composition, particle size and pH value. The mutual influence of these parameters is complex. Illite is the most abundant clay mineral in Latvia and usually used in building materials and pottery. The viscosity and plasticity of Latvian clays from several deposits were investigated and correlated with mineral composition, particle size and pH value. Fractionated and crude clay samples were used. The p...

  14. Pulp antioxidant activities, mineral contents and juice nutritional ...

    African Journals Online (AJOL)

    Statistical differences among the citrus pulps were established for the contents of phenols, flavonoids and carotenoids, the quantification of bioactive compounds revealed distinct contents amongst the analysed materials. Phenolic and flavonoid contents presented a value between 3108.78 and 4046.20 mg gallic acid/100 g ...

  15. Variations in the mineral composition and heavy metals content of ...

    African Journals Online (AJOL)

    Babayemi

    The parts of Moringa oleifera were assessed for mineral composition and some heavy metal ... cadmium from aqueous system (Sharma et al., 2006). ... Crude extracts and essential oil from M. oleifera possess ... into some probable chemical interactions between the .... processing methods that may lead to detoxification and.

  16. Mineral Elements Content of some Coarse Grains used as staple ...

    African Journals Online (AJOL)

    Analysis of mineral elements were carried out on some coarse grains used as staple food in Kano metropolis. The levels of Magnesium, Calcium, Manganese, Iron, Copper and Zinc were determined using atomic absorption spectrophotometer (AAS), and that of Sodium and Potassium were obtained using flame photometer ...

  17. Quantitative XRD analysis: tools to investigate link between hydrous strain and clay mineral CEC

    International Nuclear Information System (INIS)

    Oueslati, W.; Ammar, M.; Ben Rhaiem, H.; Ben Haj Amara, A.

    2012-01-01

    Document available in extended abstract form only. This work aims at examining, by quantitative XRD analysis, the effect of an applied hydrous strain in the cationic exchange process of a di-octahedral smectite (Na-rich montmorillonite SWy-2). The hydrous constraint was created by a continuous, in situ, hydration-dehydration cycles using a variation of the %RH rate. Respectively, The starting, the intermediate and the final stressed samples was deposed in contact with saturated Me 2+ (i.e. Cd 2+ , Co 2+ , Zn 2+ and Ni 2+ ) chloride solutions respectively in order to examine the effect of the retained materials stress on the CEC of the host materials. An XRD profile modelling approach is adopted to describe all structural changes created by the environmental evolution of the %RH rate. This investigation allowed us to determine several structural parameters related to the nature, abundance, size, position and organization of exchangeable cation and water molecule in the inter-lamellar space along the c* axis. The obtained qualitative results show a considerable change in the hydration behaviour, versus the number of hydration - dehydration cycle, from homogeneous '2W' to heterogeneous '1W-2W' hydration state indicating an interstratified hydration phases and due probably to a new organization of the inter-lamellar space content. Quantitatively, the theoretical Mixed Layer Structure MLS suggest the coexistence of more one 'crystallite' species. Which are saturated by more than one exchangeable cations, indicating a partial saturation of all exchangeable sites. Using optimum structural parameter values, deduced from XRD modelling profile approach, some equations which described the evolution of exchangeable cation amount versus the applied hydrous strain were derived. (authors)

  18. Stable silicon isotope signatures of marine pore waters - Biogenic opal dissolution versus authigenic clay mineral formation

    Science.gov (United States)

    Ehlert, Claudia; Doering, Kristin; Wallmann, Klaus; Scholz, Florian; Sommer, Stefan; Grasse, Patricia; Geilert, Sonja; Frank, Martin

    2016-10-01

    Dissolved silicon isotope compositions have been analysed for the first time in pore waters (δ30SiPW) of three short sediment cores from the Peruvian margin upwelling region with distinctly different biogenic opal content in order to investigate silicon isotope fractionation behaviour during early diagenetic turnover of biogenic opal in marine sediments. The δ30SiPW varies between +1.1‰ and +1.9‰ with the highest values occurring in the uppermost part close to the sediment-water interface. These values are of the same order or higher than the δ30Si of the biogenic opal extracted from the same sediments (+0.3‰ to +1.2‰) and of the overlying bottom waters (+1.1‰ to +1.5‰). Together with dissolved silicic acid concentrations well below biogenic opal saturation, our collective observations are consistent with the formation of authigenic alumino-silicates from the dissolving biogenic opal. Using a numerical transport-reaction model we find that approximately 24% of the dissolving biogenic opal is re-precipitated in the sediments in the form of these authigenic phases at a relatively low precipitation rate of 56 μmol Si cm-2 yr-1. The fractionation factor between the precipitates and the pore waters is estimated at -2.0‰. Dissolved and solid cation concentrations further indicate that off Peru, where biogenic opal concentrations in the sediments are high, the availability of reactive terrigenous material is the limiting factor for the formation of authigenic alumino-silicate phases.

  19. Determination of Mineral Contents in Unpolished Rice and Bean Samples by Neutron Activation Analysis

    International Nuclear Information System (INIS)

    Moon, J. H.; Kim, S. H.; Baek, S. Y.; Chung, Y. S.

    2012-01-01

    As scientists have focused their researches on the health impacts caused by mineral nutrient deficiencies and hazardous elements, public concern regarding mineral intake from dietary food is rising. In this reason, the dietary habits of Koreans have been shifted from white rice to more nutrient rice like unpolished rice and rice mixed with beans. It is known that unpolished rice and beans contain more protein, vitamin and mineral contents than white rice and are more beneficial to human health, even though they sometimes cause indigestion or allergy. The objectives of this study were to determine the mineral contents in unpolished rice and bean samples by a neutron activation analysis (NAA) and to compare the level of mineral contents between the samples

  20. Inverse Opal Scaffolds with Gradations in Mineral Content for Spatial Control of Osteogenesis.

    Science.gov (United States)

    Zhu, Chunlei; Qiu, Jichuan; Pongkitwitoon, Suphannee; Thomopoulos, Stavros; Xia, Younan

    2018-05-30

    The design and fabrication of inverse opal scaffolds with gradations in mineral content to achieve spatial control of osteogenesis are described. The gradient in mineral content is established via the diffusion-limited transport of hydroxyapatite nanoparticles in a closely packed lattice of gelatin microbeads. The mineral-graded scaffold has an array of uniform pores and interconnected windows to facilitate efficient transport of nutrients and metabolic wastes, ensuring high cell viability. The graded distribution of mineral content can provide biochemical and mechanical cues for spatially regulating the osteogenic differentiation of adipose-derived stromal cells. This new class of scaffolds holds promise for engineering the interfaces between mineralized and unmineralized tissues. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Determination of Mineral Contents in Unpolished Rice and Bean Samples by Neutron Activation Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Moon, J. H.; Kim, S. H.; Baek, S. Y.; Chung, Y. S. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2012-05-15

    As scientists have focused their researches on the health impacts caused by mineral nutrient deficiencies and hazardous elements, public concern regarding mineral intake from dietary food is rising. In this reason, the dietary habits of Koreans have been shifted from white rice to more nutrient rice like unpolished rice and rice mixed with beans. It is known that unpolished rice and beans contain more protein, vitamin and mineral contents than white rice and are more beneficial to human health, even though they sometimes cause indigestion or allergy. The objectives of this study were to determine the mineral contents in unpolished rice and bean samples by a neutron activation analysis (NAA) and to compare the level of mineral contents between the samples

  2. Application of clay minerals from Cayo Guan, Cuba, as sorbents of heavy metals and ceramic raw materials; Aplicaciones de los minerales arcillosos de Cayo Guan, Cuba, como adsorbentes de metales pesados y materia prima ceramica

    Energy Technology Data Exchange (ETDEWEB)

    Fonseca, D.; Barba, F.; Callejas, P.; Recio, P.

    2012-11-01

    It has been studied by Analysis Heating Microscope Optical the behaviour of some kaolinitic clays from a reservoir of Cayo Guan rich in iron oxides and low silica content proving to be a refractory materials whose softening appears after 1500 degree centigrade. It has obtained the workability diagram of the different clay minerals calculating the plasticity by the method of Casagrande spoon; only one of the samples is in the area suitable for extrusion. Vitrification diagrams report that the capacity of water absorption is <0.6 % when the temperature of 1400 degree centigrade is achieved. We have designed a program to calculate compositions of porcelain stoneware prepared from these modified clays adding low-cost raw materials that facilitate the formation of glassy phase ((potassium feldspar and glass cullet) and/or increase the silica (sand and diatomaceous earth used as filters in the brewing industry). With one of these compositions, prepared in the laboratory (60 % of clay, 30 % feldspar and 10 % of diatomaceous earth), calcined at 1250 degree centigrade with a heating rate of 15 degree centigrade/min, the results were: water absorption 0.8 %, and linear shrinkage 21 % without any deformation observed. These clays have been treated with acid to eliminate its high iron content and study its application as an sorbent of heavy metals as Cd{sup 2}+, Cr{sup 3}+. The results of the immobilization of these elements have been compared with those obtained with thermally activated vermiculite at 800 degree centigrade, showing that the treated samples show sorption of both cadmium and chromium below the vermiculite, but the non-treated ones are suitable to remove chromium; this is because these clays do not contain in its composition exchangeable ions (Ca{sup {sub 2}} +, Mg{sup 2} +, Na{sup +}, K{sup +}), and even if they are chemically activated only the presence of Fe ions is which produces form bindings (Cr{sub x}.Fe{sub 1}-x) (OH){sub 3} which favor Cr sorption

  3. Pb-Zn mineralization of Ali ou Daoud area (Central High Atlas, Morocco: characterisation of deposit and relationship with the clay assemblages

    Directory of Open Access Journals (Sweden)

    Daoudi, L.

    2008-12-01

    Full Text Available Zn-Pb-Fe ores in the Ali ou Daoud deposit (Central High Atlas are found as stratiform levels and as karst fillings in carbonate platforms facies of Bajocian age. Tectonic structures (e.g., synsedimentary faults played a relevant role in the ore emplacement. The dolomitic ore-related host-rock levels are characterized by the presence of kaolinite enrichment in clay levels in amounts directly related to the proportion of the clay minerals. The latter is evidenced by correlation between kaolinite and sulphide contents, suggesting that the installation of kaolinite and mineralisations would result from the same hydrothermal fluid.[Français] Dans les séries sédimentaires carbonatées d’Ali ou Daoud (Haut Atlas Central, les minéralisations à Zn, Pb et Fe en amas stratiformes forment les faciès de remplissage des karsts d’une plateforme carbonatée bajocienne. Le contrôle structural joue un rôle capital dans la localisation du gîte en bordure de plateforme sur des failles synsédimentaires. Dans les niveaux dolomitiques encaissants des minéralisations, les assemblages argileux sont caractérisés par la présence de kaolinite dont la teneur varie parallèlement avec celle du minerai. Ceci suggère que la mise en place de la kaolinite et des minéralisations résulterait du même fluide hydrothermal. [Español] En las series sedimentarias carbonatadas de Ali ou Daoud (Alto Atlas Central, las mineralizaciones de Zn, Pb y Fe aparecen en niveles estratiformes como facies de reemplazamiento de los karsts de una plataforma carbonatada Bajociense. El control estructural desempeña un papel crucial en la localización del yacimiento a lo largo de la plataforma sobre fallas sinsedimentarias. En los niveles dolomíticos que incluyen las mineralizaciones, las asociaciones arcillosas se caracterizan por la presencia de caolinita, cuyo contenido varía paralelamente al de la mineralización. Esto sugiere que la creación de caolinita y de la

  4. Normal values for bone mineral content measured by dual photon absorptiometry in children

    International Nuclear Information System (INIS)

    Tison, F.; Lecouffe, P.; Rousseau, J.; Marchandise, X.; Ythier, H.

    1990-01-01

    The results of dual photon absorptiometry measurements in 43 normal children are analyzed. Results were correlated with age, body weight, and stature. Reference stature-specific values for bone mineral content in children are proposed. Furthermore, the results show that mineralization continues beyond the end of statural growth [fr

  5. Comparison Of Mineral Content Of Some Ripe And Unripe Fruits In ...

    African Journals Online (AJOL)

    The mineral contents of ripe and unripe banana (Musa sapientum), avocado pear (Pearsea americana), pineapple (Ananas cosmosus) and soursop (Anona muricata), were determined to ascertain the influence of ripening on the localization of minerals in these fruits. High levels of sodium and potassium were obtained in ...

  6. A Comparative Analysis of Nutrients and Mineral Elements Content ...

    African Journals Online (AJOL)

    (Mg), Iron (Fe), Copper (Cu) and Zinc (Zn) content, while P. pedicellatum has high ... INTRODUCTION ... central to animal production and productivity. .... for growth and serve as structural element in all plant ... the animal's body, it ensured correct maintenance of ... Ash content because Ash is the approximation of total.

  7. Normal bone mineral content but unfavourable muscle/fat ratio in Klinefelter syndrome

    DEFF Research Database (Denmark)

    Aksglaede, L.; Mølgaard, Christian; Skakkebaek, N.E.

    2008-01-01

    OBJECTIVE: To evaluate body composition and bone mineral content (BMC) in children and adolescents with Klinefelter syndrome (KS). DESIGN: Retrospective cross-sectional study. SETTING: Tertiary endocrine clinic at the University Hospital, Copenhagen. PATIENTS: Eighteen untreated boys with KS...

  8. The content of mineral elements on whole blood and hair in ...

    African Journals Online (AJOL)

    user

    2012-02-14

    Feb 14, 2012 ... The mineral content of forage, whole blood and hair samples of Moschus sifanicus were analyzed and ... of the Chinese State Key Protected Wildlife List in 2002. ... of the comparison group match, the result shows that.

  9. Proximate composition and mineral contents of Pebbly fish, Alestes ...

    African Journals Online (AJOL)

    ACSS

    /100 g) were significantly .... Proximate analysis of A. baremoze fillets according to sample sizes in a study in. Uganda .... present in the fish tissues in trace amounts. ... The zinc contents in fish samples of ..... (mercury, cadmium, lead, tin and.

  10. On the role of clay minerals in the disposal of radioactive waste in a clay geological formation; Les mineraux argileux. Leur role et importance dans un site de stockage de dechets radioactifs en couche argileuse profonde

    Energy Technology Data Exchange (ETDEWEB)

    Clauer, N. [Centre National de la Recherche Scientifique (CNRS), Centre de Geochimie de la Surface, 67 - Strasbourg (France)

    2005-05-01

    Clay minerals represent appropriate candidates in the search of geological sites and man-made barriers for potential underground storage of nuclear waste, because of their cation-exchange capabilities and swelling properties. However, this statement needs also to take into consideration other aspects such as physical parameters specific (imbrication of the mineral aggregates, occurrence of oxy-hydroxides and/or organic matter), or not of the rocks (temperature, compaction, etc), and the evolutionary history of the target units as they might indirectly modify the above potentials. Alternatively, original micro-discontinuities (micro-fractures) or those induced by the construction of the site do not appear to represent potential drains for fluid escapes, at least over long distances. The few examples presented here emphasize also that one should be careful about generalizing any conclusion, and that analytical data acquisition should be privileged in order to control better the reliability of the results and the potentials of the applied method. (author)

  11. Quantitative determination of bone mineral content (QCT) - intercomparison of computer tomographs of the same construction

    International Nuclear Information System (INIS)

    Andresen, R.; Banzer, D.; Felsenberg, D.; Wolf, K.J.

    1994-01-01

    An intercomparison of 4 CT scanners of the same manufacturer was performed. The bone mineral content of 11 lumbar vertebral columns removed directly post mortem was determined in a specially constructed lucite-water phantom. Even devices of the same construction were shown to yield a variation in the quantitative evaluation markedly exceeding the annual physiological mineral loss. As long as scanner adjustment by physical calibration phantoms has not yet been established, a course assessment and therapy control of bone mineral content should always be carried out on the same QCT scanner. (orig.) [de

  12. Methylene blue adsorption in clay mineral dealt with organic cation; Sorcao de azul de metileno em argila esmectitica tratada com cation organico

    Energy Technology Data Exchange (ETDEWEB)

    Silva, T.L. [Universidade Federal do Para (UFPA), Maraba, PA (Brazil). Faculdade de Engenharia de Materiais; Lemos, V.P., E-mail: tls1981@hotmail.com [Universidade Federal do Para (UFPA), Belem, PA (Brazil). Centro de Geociencias

    2011-07-01

    The interaction among organic cations, as the methylene blue (AM) and benzyltrimethylammonium (BTMA), and clay minerals of the group of the smectite they result in the formation of applied materials in the adsorption of organic pollutant presents in waters, soils and you cultivate. In this work they were prepared the adsorbents (organic-clays) smectite - AM and smectite-BTMA. The precursory sample of smectite was collected in Rio Branco-Acre. We were also used an smectite sample collected in Sena Madureira (SM)-Acre already characterized in previous work and a sample of standard smectite Swy-2-Na-Montmorillonite (SWy-2) of Wymong - USA. The organic agents selected for this study they were: Blue of Methylene, denominated AM and Benzyltrimethylammonium, denominated BTMA. They were appraised the capacities adsorptive of the treated samples with BTMA being used AM as adsorbate. The results of these evaluations detected that ran total adsorption of AM (concentrations varying from 1 to 10 ppm) for the treated samples with BTMA. The organic cation, BTMA, interacting with the surfaces of the natural clay was more efficient in the adsorption of AM than the clay without the previous treatment with this salt. (author)

  13. Clastic compaction unit classification based on clay content and integrated compaction recovery using well and seismic data

    Directory of Open Access Journals (Sweden)

    Zhong Hong

    2016-11-01

    Full Text Available Abstract Compaction correction is a key part of paleo-geomorphic recovery methods. Yet, the influence of lithology on the porosity evolution is not usually taken into account. Present methods merely classify the lithologies as sandstone and mudstone to undertake separate porosity-depth compaction modeling. However, using just two lithologies is an oversimplification that cannot represent the compaction history. In such schemes, the precision of the compaction recovery is inadequate. To improve the precision of compaction recovery, a depth compaction model has been proposed that involves both porosity and clay content. A clastic lithological compaction unit classification method, based on clay content, has been designed to identify lithological boundaries and establish sets of compaction units. Also, on the basis of the clastic compaction unit classification, two methods of compaction recovery that integrate well and seismic data are employed to extrapolate well-based compaction information outward along seismic lines and recover the paleo-topography of the clastic strata in the region. The examples presented here show that a better understanding of paleo-geomorphology can be gained by applying the proposed compaction recovery technology.

  14. Clay mineral assemblages of terrestrial records (Xining Basin, China) during the Eocene-Oligocene climate Transition (EOT) and its environmental implications

    Science.gov (United States)

    Zhang, C.; Guo, Z.

    2013-12-01

    The Eocene-Oligocene Transition (EOT) between ~34.0 and 33.5 million years ago, where global climate cooled from 'greenhouse' to 'icehouse' at ~33.5 Ma ago, is one of the great events during Cenozoic climate deterioration. In contrast to the marine records of the EOT, significantly less research has focused on the continental climate change during this time, particularly in inner Asia. We present a comprehensive study of the upper Eocene to lower Oligocene succession with regular alternations of laterally continuous gypsum/gypsiferous layers and red mudstone beds in Tashan section of Xining Basin, which is located at the northeastern margin of the Tibetan Plateau. Clay minerals, which were extracted from this succession, were analyzed qualitatively and semi-quantitatively by using X-ray differaction (XRD). Base on detailed magnetostratigraphic time control, clay mineral compositions of this succession (33.1-35.5 Ma) are compared with open ocean marine records and Northern Hemisphere continental records to understand the process and characteristics of Asian climate change before, during and after EOT. Our results indicate that illite is the dominant clay mineral with less chlorite and variable smectite. Multi-parameter evidence suggests that the source areas of detrital inputs in Tashan have not changed and climate is the main control for the composition of the clay fraction. The characteristics of clay mineral concentrations suggest warm and humid fluctuations with cold and dry conditions and intense of seasonality during ~35.5-34.0 Ma in inner Asian. This changed to cold and dry condition at ~34 Ma and remained so from ~34-33.1 Ma. The comparisons between continental and marine records indicate that the climate changes experienced in the Xining basin region are more consistent with Northern Hemisphere rather than open oceans records. This indicates that paleoclimate changes for inner Asian before, during and after EOT was not controlled by Antarctic ice growth

  15. Mineral content in four browse species from northeastern mexico

    International Nuclear Information System (INIS)

    Tilo, G.; Gomez, D.; Roque, G.; Lonano, R.; Lozano, R.

    2014-01-01

    The aim of the present study was to determine and compare macro (Ca, K, Mg, Na and P) and micro (Cu, Fe, Mn and Zn) nutrient foliar content in Acacia amentacea (DC.), Celtis pallida (Torr.), Forestiera angustifolia (Torr.) and Parkinsonia texana (A. Gray). Leaf samples were collected monthly from January throughout December 2009 in China, Linares and Los Ramones counties in the state of Nuevo Leon, Mexico. All nutrients were significantly different among sites, months and species; double and triple interactions were also significant. Among sites, samples from Los Ramones County showed the higher macronutrient content, followed by China and Linares. As for species, Celtis pallida showed the highest values while A. amentacea had the lowest macronutrient content. Micronutrient content showed the following decreasing order: China>Los Ramones>Linares. Parkinsonia texana was characteristically the most abundant in micronutrient content, while, A. amentacea was the poorest in this respect. Regardless of species, site or timing, Ca (total mean = 30 g kg-1), K (15; except A. amentacea), Mg (5.2; except A. amentacea), Na (1.9; only F. angustifolia), Fe (100 mg kg-1), Mn (51; only F. angustifolia) and Zn (35; except A. amentacea) were determined to be present in suitable amounts to meet nutritional requirements of range ruminants, while Na (1.9; except F. angustifolia), P (1.3 g kg-1) and Cu (6 mg kg-1) were marginally deficient throughout the year. (author)

  16. Contribution in the study of the stability of Callovo-Oxfordian clay rock minerals in the presence of iron at 90 deg C

    International Nuclear Information System (INIS)

    Rivard, Camille

    2011-01-01

    In the context of underground disposal of high-level radioactive waste, it is of prime importance to understand the interaction mechanisms between Callovo-Oxfordian clay rock (COx), selected as a potential host-rock by Andra (French national radioactive waste management agency) and metallic iron, that enters the composition of containers and disposal cells. Interactions between metallic iron and COx clay-rock, COx Callovo-Oxfordian clay fraction (SCOx) and pure clay phases (kaolinite, illite, smectites) were investigated at 90 deg. C under anoxic atmosphere in chlorine solution. In order to study the role of COx non clay minerals, the reactivity of mixtures between SCOx and quartz, calcite, dolomite or pyrite, was also studied. Liquid and solid by-products were characterised by chemical analyses, mineralogical and morphometric techniques, at different scales. In our experimental conditions, major evolutions were observed during the first month, which shows that the oxidation of metallic iron is rapid. The release of iron cations in solution, pH increase (8-10) and Eh decrease (reductive conditions) are responsible for the partial dissolution of initial clay phases. Released iron is involved in the crystallization of Fe-serpentines (odinite or berthierite mainly) or precipitates under the form of magnetite in low amount. Fe-serpentine stability is controlled by the redox conditions as the introduction of dioxygen into the system leads to iron exsolution under the form of iron oxides and hydroxides and precipitation of clay particles with composition close to the initial ones. Whereas carbonates and pyrite do not significantly influence SCOx-metallic iron interactions, reaction pathways are modified in the presence of quartz. Indeed, in such conditions one observes a slight decrease of pH, an increase in Eh, the absence of magnetite and differences in the crystal chemistry of Fe-serpentines that are silica enriched, in comparison with those formed without any quartz

  17. Evaluation of mineral contents in Cleome gynandra leaves and ...

    African Journals Online (AJOL)

    Cleome gynandra is an herbal plant highly consumed and appreciated by populations from Burkina Faso and other parts of Africa. Two samples of Cleome gynandra were collected and submitted to a comparative analysis by ICP-AES to determine the content of nutritive and toxic elements in leaves and stalks as fresh or ...

  18. Effect of conservation methods on the mineral contents of some ...

    African Journals Online (AJOL)

    SARAH

    2015-10-31

    Oct 31, 2015 ... Results: The ash contents of local varieties were better preserved in the granary than in the attic or the jute bag because ... barley, and maize, are important basic foodstuffs in ..... improved high-lysine, high-oil maize for young.

  19. Some physico-chemical properties and mineral contents of sweet ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-06-17

    Jun 17, 2009 ... contents of sweet cherry (Prunus avium L.) type grown in Konya .... Working conditions of ICP-AES. Instrument: ICP-AES ... The volume of fruit (V) and fruit density (Pt), were determined using the liquid ... These differences can.

  20. Mineral content in some Cameroonian household foods eaten in ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-09-03

    Sep 3, 2008 ... Their zinc, copper, manganese and iron contents were between 0.49 ± 0.06 and. 12.08 ± 0.83 mg/100 g, ... garlic, beef meat, pepper, spices. 11) Corn meal with .... 0.49 ± 0.06 to 12.08 ± 0.83 mg/100g in green cooked banana ...

  1. A Comparative Analysis of Nutrients and Mineral Elements Content ...

    African Journals Online (AJOL)

    crude protein (Cp) ad crude fibre (Cf) content than A. gayanus. The high Cp .... protein. This gives an indication of relatively high quality of this grass species as livestock feed than its counterpart. Proteins play an important role in Carbon- dioxide fixation during .... Ruminant Nutrition, 1st edition, Macmillan Press. Ltd, London ...

  2. Table 5 Mineral content of ashed bean samples

    African Journals Online (AJOL)

    Dr Mamiro

    2012-08-05

    Aug 5, 2012 ... vegetables; dry bean grains are used in various food preparations, and both are used as relish or side dishes together ... Eastern Africa and Latin America. Zinc content of beans is one of the ... Kidney bean leaves and fresh bean grains, which are prepared as relish and consumed by a number of families in ...

  3. Studying the Effect of Crystal Size on Adsorption Properties of Clay

    International Nuclear Information System (INIS)

    Abdellatif, M.M.

    2012-01-01

    Sorption of radionuclides on mineral surfaces strongly affects their fate and mobility in the geosphere. Therefore using of clay minerals as a barrier In LLW repositories can delay the dispersion of radionuclides into environment. That is of fundamental importance for maintaining environmental quality and for the safety and long-term performance of waste repositories. In this study XRD analysis was applied to investigate three different types of clay minerals for quantitative analysis of each type and the Mud Master program for the measurement of the crystallite thickness distribution (CTD) according to of the BWA (Bertaut-Warren Averbach) technique. Six sample s of the three types of clay (Kaolin, Aswan clay and Ball clay) were studied. XRD and Mud Master were used to investigate the relation between CTD and Cs -137 uptake mechanism onto the clay. It was found that the best adsorption capacity related to the kaolinite content and the lowest CTD

  4. Reducing the cadmium content of crude phosphates and mineral fertilizers

    Energy Technology Data Exchange (ETDEWEB)

    Plessen, H von; Schimmel, G

    1987-10-01

    Crude sedimentary phosphates generally contain cadmium together with traces of other heavy metals. These Cd traces generally end up in fertilizers produced from the crude phosphates. Processes have therefore been developed to separate the Cd from the crude phosphate or from the crude phosphoric acids arising therefrom as intermediates. In this way, the Cd content of the crude phosphate can be reduced to less the 10% of its original value, and to 50% thereof by extractive treatment with acidic calcium nitrate solution. Older calcination processes for crude phosphate have been improved to give residual Cd contents of 10 to 50% at temperatures of 800 to 1000/sup 0/C. Cadmium can be removed almost quantitatively from crude phosphate by means of dialkyl dithiophosphoric acid esters by extraction, binding to adsorbents, or ion flotation. Cadmium can be extracted from crude acids in high yield by long-chained amines. After partial neutralization of the crude acids, precipitation as cadmium sulphide is also possible.

  5. Proximate Composition and Mineral Content in Different ,Types of

    African Journals Online (AJOL)

    The: concentration of protein in traditional and ... resuiis:in d;je~t types o[togwa wjth yariatiOl? in proximate comfX?sition, energy density and~mirieral content. " . ..... hi the preparation of simulated togwa l .,. "'.' .. IngredientS ,Dtj<: "\\C!~de P~o-.' Ct;ude fi-. Fat: --Ash. Caroo-. Energy matte; r tein (0/0) . ,; bee hydrate value .: (%).

  6. Determination of some mineral contents of prickly pear (Opuntia ficus-indica L.) seed flours.

    Science.gov (United States)

    Al-Juhaimi, Fahad; Özcan, Mehmet Musa

    2013-05-01

    The aim of this study was to determine some mineral contents of prickly pear (Opuntia fıcus-indica L.) seeds collected from different locations. The mineral contents of seeds were established by inductively coupled plasma atomic emission spectrometry. All the seeds contained Ca, K, Mg and P at high levels. Calcium content ranged between 268.5 (sample no. 11) and 674.8 ppm (sample no. 4). The level of K changed between 346.7 (sample no. 1) and 676.1 ppm (sample no. 13). Phosphorus content of seeds varied between 1,173.6 (sample no. 14) and 1,871.3 ppm (sample no. 1). It is apparent that seeds are good sources of the macro and micro minerals and can be consumed as a food ingredient to provide nutrition.

  7. Stepwise effects of the BCR sequential chemical extraction procedure on dissolution and metal release from common ferromagnesian clay minerals: A combined solution chemistry and X-ray powder diffraction study

    Energy Technology Data Exchange (ETDEWEB)

    Ryan, P.C. [Geology Department, Middlebury College, Middlebury, Vermont 05753 (United States)], E-mail: pryan@middlebury.edu; Hillier, S. [Macaulay Institute, Aberdeen, AB15 8QH UK (United Kingdom); Wall, A.J. [Department of Geosciences, Penn State University, University Park, Pennsylvania, 16802 (United States)

    2008-12-15

    Sequential extraction procedures (SEPs) are commonly used to determine speciation of trace metals in soils and sediments. However, the non-selectivity of reagents for targeted phases has remained a lingering concern. Furthermore, potentially reactive phases such as phyllosilicate clay minerals often contain trace metals in structural sites, and their reactivity has not been quantified. Accordingly, the objective of this study is to analyze the behavior of trace metal-bearing clay minerals exposed to the revised BCR 3-step plus aqua regia SEP. Mineral quantification based on stoichiometric analysis and quantitative powder X-ray diffraction (XRD) documents progressive dissolution of chlorite (CCa-2 ripidolite) and two varieties of smectite (SapCa-2 saponite and SWa-1 nontronite) during steps 1-3 of the BCR procedure. In total, 8 ({+-} 1) % of ripidolite, 19 ({+-} 1) % of saponite, and 19 ({+-} 3) % of nontronite (% mineral mass) dissolved during extractions assumed by many researchers to release trace metals from exchange sites, carbonates, hydroxides, sulfides and organic matter. For all three reference clays, release of Ni into solution is correlated with clay dissolution. Hydrolysis of relatively weak Mg-O bonds (362 kJ/mol) during all stages, reduction of Fe(III) during hydroxylamine hydrochloride extraction and oxidation of Fe(II) during hydrogen peroxide extraction are the main reasons for clay mineral dissolution. These findings underscore the need for precise mineral quantification when using SEPs to understand the origin/partitioning of trace metals with solid phases.

  8. Can mud (silt and clay) concentration be used to predict soil organic carbon content within seagrass ecosystems?

    KAUST Repository

    Serrano, Oscar

    2016-09-07

    The emerging field of blue carbon science is seeking cost-effective ways to estimate the organic carbon content of soils that are bound by coastal vegetated ecosystems. Organic carbon (C-org) content in terrestrial soils and marine sediments has been correlated with mud content (i.e., silt and clay, particle sizes <63 mu m), however, empirical tests of this theory are lacking for coastal vegetated ecosystems. Here, we compiled data (n = 1345) on the relationship between C-org and mud contents in seagrass ecosystems (79 cores) and adjacent bare sediments (21 cores) to address whether mud can be used to predict soil C-org content. We also combined these data with the delta C-13 signatures of the soil C-org to understand the sources of Corg stores. The results showed that mud is positively correlated with soil C-org content only when the contribution of seagrass-derived C-org to the sedimentary C-org pool is relatively low, such as in small and fast-growing meadows of the genera Zostera, Halodule and Halophila, and in bare sediments adjacent to seagrass ecosystems. In large and long-living seagrass meadows of the genera Posidonia and Amphibolis there was a lack of, or poor relationship between mud and soil C-org content, related to a higher contribution of seagrass-derived C-org to the sedimentary C-org pool in these meadows. The relatively high soil C-org contents with relatively low mud contents (e.g., mud-C-org saturation) in bare sediments and Zostera, Halodule and Halophila meadows was related to significant allochthonous inputs of terrestrial organic matter, while higher contribution of seagrass detritus in Amphibolis and Posidonia meadows disrupted the correlation expected between soil C-org and mud contents. This study shows that mud is not a universal proxy for blue carbon content in seagrass ecosystems, and therefore should not be applied generally across all seagrass habitats. Mud content can only be used as a proxy to estimate soil C-org content for

  9. The correlation between metacarpal bone mineral content and bone mineral density of the jawbone in implant patients

    International Nuclear Information System (INIS)

    Kuroda, Toshinobu; Takamori, Hitoshi; Yosue, Takashi

    2006-01-01

    This study estimated the relationship between metacarpal bone mineral content and jawbone density. The subjects were 141 patients who desired implant treatment and had undergone a thorough pre-operative CT examination. In the maxilla, bone mineral density (BMD) was measured at the cancellous bone between the nasal cavity and the maxillary sinus. In the mandible, BMD was measured at the cancellous bone beneath the mental foramen. The CT numbers were corrected by the quantitative computer tomography (QCT) method. Furthermore, the cortical indices of the mandible, i.e. C-PMI (Central-Panoramic Mandibular Index), and MCW (Mandibular Cortical Width) were measured and calculated from panoramic radiographs. The bone mineral content of the total body was obtained by ΣGS/D and MCI through Microdensitometry. The following results were obtained. Between the maxillary BMD and ΣGS/D and between the mandibular BMD and ΣGS/D, there was a correlation in females but no correlation in males. Between the maxillary BMD and MCI, there was a correlation in females but no correlation in males. However, in the mandibular BMD and MCI there was no correlation in females and males. Between C-PMI and ΣGS/D there was a correlation in both females and males. Between C-PMI and MCI there was a correlation in both females and males. Between MCW and ΣGS/D there was a correlation in both females and males. Between MCW and MCI there was a correlation in females, but no correlation in males. From the above results, it was concluded that the maxillary BMD and the cortical index of the mandible reflected changes in the metacarpal bone mineral content, while mandibular BMD did not. (author)

  10. Enhancement of Au-Ag-Te contents in tellurium-bearing ore minerals via bioleaching

    Science.gov (United States)

    Choi, Nag-Choul; Cho, Kang Hee; Kim, Bong Ju; Lee, Soonjae; Park, Cheon Young

    2018-03-01

    The purpose of this study was to enhance the content of valuable metals, such as Au, Ag, and Te, in tellurium-bearing minerals via bioleaching. The ore samples composed of invisible Au and Au paragenesis minerals (such as pyrite, chalcopyrite, sphalerite and galena) in combination with tellurium-bearing minerals (hessite, sylvanite and Tellurobismuthite) were studied. Indigenous microbes from mine drainage were isolated and identified as Acidithiobacillus ferrooxidans, which were used in bioleaching after adaption to copper. The effect of the microbial adaption on the bioleaching performance was then compared with the results produced by the non-adaptive process. The microbial adaption enhanced the Au-Ag-Te contents in biological leaching of tellurium-bearing ore minerals. This suggests that bioleaching with adapted microbes can be used both as a pretreatment and in the main recovery processes of valuable metals.

  11. Clay minerals in uraniferous deposit of Imouraren (Tim Mersoi basin, Niger): implications on genesis of deposit and on ore treatment process

    International Nuclear Information System (INIS)

    Billon, Sophie

    2014-01-01

    Nigerian uraniferous deposits are located in carboniferous and Jurassic formations of Tim Mersoi basin. AREVA is shareholder of 3 mine sites in this area: SOMAIR and COMINAK, both in exploitation since 1960's and IMOURAREN, 80 km further South, whose exploitation is planned for 2015. Mineralization of Imouraren deposit is included in the fluvial formation of Tchirezrine 2 (Jurassic), composed of channels and flood plains. Facies of channel in-fillings range from coarse sandstones to siltstones, while overflow facies are composed of analcimolites. Secondary mineralogy was acquired during 2 stages: 1- diagenesis, with formation of clay minerals, analcime, secondary quartz and albites, and 2- stage of fluids circulations, which induced alteration of detrital and diagenetic minerals, formation of new phases and uranium deposition. A mineralogical zoning, at the scale of deposit resulted from this alteration. The heterogeneity of Tchirezrine 2, at the level of both facies and mineralogy, is also evidenced during ore treatment, as ore reacts differently depending on its source, with sometimes problems of U recovery. Ore treatment tests showed that analcimes and chlorites were both penalizing minerals, because of 1- the sequestration of U-bearing minerals into analcimes, 2- their dissolution which trends to move away from U solubilization conditions (pH and Eh) and to form numerous sulfates, and 3- problems of percolation. A detection method of analcime-rich ores, based on infrared spectroscopy, was developed in order to optimize ore blending and so to reduce negative effects during ore treatment process. (author)

  12. Determination of minerals content in leaves of Moringa Oleifera by neutron activation analysis

    International Nuclear Information System (INIS)

    Th Rina Mulyaningsih; Saeful Yusuf

    2018-01-01

    Moringa oleifera ( Mo) or kelor is a high-value plant, distributed in many tropical and subtropical countries. This plant can be used as a vegetable, cosmetic oil, and medicinal plant. The leaves of Mo is rich in essential minerals needed by the body’s health. Moringa oleifera widely cultivated in various places in Indonesia, easily obtained and inexpensive so precious can be used to overcome malnutrition. Research on the macro-micro mineral content in Moringa leaves here is still limited. Mineral composition in leaves include Mo leaves varies depending on location grow. The purpose of this research is to determine the mineral content in the leaves of the Mo taken from Indonesia. For the preliminary study samples was taken from Central Java to be compared with the results of studies conducted in several other countries. Leaf samples were collected randomly from sampling area. Mineral content in the samples is determined using Neutron Activation Analysis (NAA). Irradiation was carried out at rabbit system of Multipurpose Reactor G.A Siwabessy on neutron flux ~10 13 n.cm -2 .dt -1 . The results obtained indicate that Mo is rich in essential minerals, mainly Ca, Mg, K, Zn, Fe and Cl. Content in dried leaves include: calcium (3.45 % ), magnesium (0.66 %), potassium (3.35 %), chloride (0.25 %), iron (147.20 mg/kg), sodium ( 152.52 mg/kg ), zinc (35.71 mg/kg), and manganese (102.10 mg/kg). Mo also contains other minerals such as chromium (4.76 mg/kg), bromine (4.82 mg/kg), cobalt (0.16 mg/kg), and aluminium (150.40 mg/kg) in addition to other element. Compared with the results of existing studies, it shows that mineral composition in Mo leaves varies depending on the location where the plant is grown. (author)

  13. Mineral content of the peripheral skeleton in patients with diabetes mellitus

    International Nuclear Information System (INIS)

    Vogl, T.; Frey, K.W.; Rohloff, R.; Doerfler, H.; Muenchen Univ.

    1981-01-01

    In order to determine the effect of diabetes mellitus on bone mineral content, measurements with the iodine 125 isotope method of Cameron were carried out in the distal ulna and calcaneus of 40 patients. 38% of female and 20% of male diabetic patients showed abnormally low values. The most severe changes were found in patients with complications of diabetes. There was a correlation between the duration of the diabetes and the severity of the mineral loss. (orig.) [de

  14. Mineral content of the peripheral skeleton in patients with diabetes mellitus

    Energy Technology Data Exchange (ETDEWEB)

    Vogl, T; Frey, K W; Rohloff, R; Doerfler, H

    1981-07-01

    In order to determine the effect of diabetes mellitus on bone mineral content, measurements with the iodine 125 isotope method of Cameron were carried out in the distal ulna and calcaneus of 40 patients. 38% of female and 20% of male diabetic patients showed abnormally low values. The most severe changes were found in patients with complications of diabetes. There was a correlation between the duration of the diabetes and the severity of the mineral loss.

  15. Bone mineral content in hyperthyroid patients after combined medical and surgical treatment

    International Nuclear Information System (INIS)

    Nielsen, H.E.; Mosekilde, L.; Charles, P.

    1979-01-01

    Bone mineral content (BMC) and bone mineral concentration (BMC') of the forearm were determined by photon absorptiometry in 20 untreated hyperthyroid patients and in 33 patients previously treated for hyperthyroidism. In untreated hyperthyroidism a significant decrease was found in both BMC and BMC'. In treated hyperthyroidism BMC and BMC' were normalized. The findings suggest that a previous hyperthyroid state is not a risk factor for development of spontaneous fractures providing the hyperthyroid state is effectively treated. (Auth.)

  16. Gas detection in sands of high silt-clay content in the Cook Inlet area

    International Nuclear Information System (INIS)

    Bettis, F.

    1976-01-01

    When a sand contains a large amount of silt and clay it is often difficult to detect zones that contain gas using only the Archie Saturation Relationship. However, gas may be detected in these shaly formations using certain quick-look techniques. Log examples of these are presented in this paper. The first quick-look technique is an overlay of the neutron log on a density log. The neutron log is shifted relative to the density log to make the two porosity curves track in shaly water sands. Gas-bearing intervals become readily apparent from separations of the two curves where the density porosity is reading higher than the shifted neutron porosity. The second is an overlay of a neutron log on the sonic interval-transit-time log. The sonic log is shifted so as to match the neutron log in average tight sands in the section. This method has proved to be more optimistic than the density-neutron overlay above. It will find the gas-bearing zones, but may result in testing a zone or two which is nonproductive. The third method, used when no neutron log has been run, is a crossplot of the difference, sonic porosity minus density porosity, versus gamma ray API units. This is the most unreliable of the three methods because of the difficulty of determining the end points and the slope of the line on the plot which separates the gas zones from the non-gas zones

  17. Mineral content of insect infested stored legumes treated with edible oils.

    Science.gov (United States)

    Modgil, R

    2000-12-01

    Mineral content of three insect (pulse beetle, Callosobruchus chinensis L.) infested legumes viz. chick pea, mung pea and pigeon pea stored for six months and treated with three edible oils viz. groundnut, mustard and coconut oil has been studied. With increase in storage period significant increase in calcium, phosphorus and iron content of untreated legumes was observed. After three months of storage slight increase in three minerals was observed in the legumes treated with coconut oil which continued till the end of sixth months as compared to other two oil treated counterparts. The storage period was associated with insect infestation which in turn influenced the mineral content of legumes. Ground nut and mustard oils were able to protect legumes for six months against insect infestation when applied in small amounts (0.5%). Whereas coconut oil had protective effect against insect infestation for four months only.

  18. Minerals

    Directory of Open Access Journals (Sweden)

    Vaquero, M. P.

    1998-08-01

    Full Text Available The possible changes in the mineral composition of food during frying could be the consequence of losses by leaching, or changes in concentrations caused by exchanges between the food and culinary fat of other compounds. The net result depends on the type of food, the frying fat used and the frying process. Moreover, the modifications that frying produces in other nutrients could indirectly affect the availability of dietary minerals. The most outstanding ones are those that can take place in the fat or in the protein. With respect to the interactions between frying oils and minerals, we have recent knowledge concerning the effects of consuming vegetable oils used in repeated fryings of potatoes without turnover, on the nutritive utilization of dietary minerals. The experiments have been carried out in pregnant and growing rats, which consumed diets containing, as a sole source of fat, the testing frying oils or unused oils. It seems that the consumption of various frying oils, with a polar compound content lower or close to the maximum limit of 25% accepted for human consumption, does not alter the absorption and metabolism of calcium, phosphorous, iron or copper. Magnesium absorption from diets containing frying oils tends to increase but the urinary excretion of this element increases, resulting imperceptible the variations in the magnesium balance. The urinary excretion of Zn also increased although its balance remained unchanged. Different studies referring to the effects of consuming fried fatty fish on mineral bioavailability will also be presented. On one hand, frying can cause structural changes in fish protein, which are associated with an increase in iron absorption and a decrease in body zinc retention. The nutritive utilization of other elements such as magnesium, calcium and copper seems to be unaffected. On the other hand; it has been described that an excess of fish fatty acids in the diet produces iron depletion, but when fatty

  19. Clays causing adhesion with tool surfaces during mechanical tunnel driving

    Science.gov (United States)

    Spagnoli, G.; Fernández-Steeger, T.; Stanjek, H.; Feinendegen, M.; Post, C.; Azzam, R.

    2009-04-01

    During mechanical excavation with a tunnel boring machine (TBM) it is possible that clays stick to the cutting wheel and to other metal parts. The resulting delays in the progress of construction work, cause great economic damage and often disputes between the public awarding authorities and executing companies. One of the most important factors to reduce successfully the clay adhesion is the use of special polymers and foams. But why does the clay stick to the metal parts? A first step is to recognize which kind of clay mineralogy shows serious adhesion problems. The mechanical properties of clay and clay suspensions are primarily determined by surface chemistry and charge distribution at the interfaces, which in turn affect the arrangement of the clay structure. As we know, clay is a multi-phase material and its behaviour depends on numerous parameters such as: clay mineralogy, clay fraction, silt fraction, sand fraction, water content, water saturation, Atterberg limits, sticky limit, activity, cation exchange capacity, degree of consolidation and stress state. It is therefore likely that adhesion of clay on steel is also affected by these clay parameters. Samples of clay formations, which caused problems during tunnel driving, will be analyzed in laboratory. Mineralogical analyses (diffractometry, etc.) will be carried out to observe which minerals are responsible for adherence problems. To manipulate the physical properties, batch tests will be carried out in order to eliminate or reduce the adhesion on tool surfaces through variation of the zeta potential. Second step is the performance of vane shear tests on clay samples. Different pore fluid (distilled water, pure NaCl solution, ethanol and methanol) will be used to study the variation of the mechanical behaviour of clay depending on the dielectric constant of the fluids. This project is funded by the German Federal Ministry of Education and Research (BMBF) and the DFG (German Research Foundation) in the

  20. Clay Mineralogy of Coal-Hosted Nb-Zr-REE-Ga Mineralized Beds from Late Permian Strata, Eastern Yunnan, SW China: Implications for Paleotemperature and Origin of the Micro-Quartz

    Directory of Open Access Journals (Sweden)

    Lixin Zhao

    2016-05-01

    Full Text Available The clay mineralogy of pyroclastic Nb(Ta-Zr(Hf-REE-Ga mineralization in Late Permian coal-bearing strata from eastern Yunnan Province; southwest China was investigated in this study. Samples from XW and LK drill holes in this area were analyzed using XRD (X-ray diffraction and SEM (scanning electronic microscope. Results show that clay minerals in the Nb-Zr-REE-Ga mineralized samples are composed of mixed layer illite/smectite (I/S; kaolinite and berthierine. I/S is the major component among the clay assemblages. The source volcanic ashes controlled the modes of occurrence of the clay minerals. Volcanic ash-originated kaolinite and berthierine occur as vermicular and angular particles, respectively. I/S is confined to the matrix and is derived from illitization of smectite which was derived from the original volcanic ashes. Other types of clay minerals including I/S and berthierine precipitated from hydrothermal solutions were found within plant cells; and coexisting with angular berthierine and vermicular kaolinite. Inferred from the fact that most of the I/S is R1 ordered with one case of the R3 I/S; the paleo-diagenetic temperature could be up to 180 °C but mostly 100–160 °C. The micro-crystalline quartz grains (<10 µm closely associated with I/S were observed under SEM and were most likely the product of desiliconization during illitization of smectite.

  1. Evaluation of photon-absorptiometry for determination of bone mineral content in experimental animals

    International Nuclear Information System (INIS)

    Krasznai, I.; Szathmary, M.; Horvath, Cs.; Hollo, G.; Fabu, G.

    1994-01-01

    Instruments commonly used for determination of bone mineral content in human were evaluated for their use in small laboratory animals. By measuring bone phantoms and rat femurs in vitro, authors found 0.015 and 0.034 g/cm sensitivity for (SPA) and (DEXA) methods, respectively. High reproducibility was obtained, with values of relative standard deviations being <2 and approximately 4% for SPA and DEXA, respectively. Both techniques were found suitable for determination of bone mineral content of laboratory animals, but DEXA is suggested as the preferred method for evaluations under in vivo circumstances. (N.T.)

  2. Late-Quaternary variations in clay minerals along the SW continental margin of India: Evidence of climatic variations

    Digital Repository Service at National Institute of Oceanography (India)

    Chauhan, O.S.; Sukhija, B.S.; Gujar, A.R.; Nagabhushanam, P.; Paropkari, A.L.

    Down-core variations in illite, chlorite, smectite and kaolinite (the major clays) in two sup(14)C-dated cores collected along the SW continental margin of India show that illite and chlorite have enhanced abundance during 20-17, 12.5, 11-9.5, and 5...

  3. Clay mineral distribution in the continental shelf sediments from Krishna to Ganges river mouth, east coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Rao, V.P.

    Ninety six sediment samples (less than 2 mu m fractions) of the eastern continental shelf of India between Ganges in the north and Krishna in the south have been studiEd. by X-ray diffraction. On the basis of nature and abundance of different clay...

  4. Redox properties of structural Fe in clay minerals. 2. Electrochemical and spectroscopic characterization of electron transfer irreversibility in ferruginous smectite, SWa-1.

    Science.gov (United States)

    Gorski, Christopher A; Klüpfel, Laura; Voegelin, Andreas; Sander, Michael; Hofstetter, Thomas B

    2012-09-04

    Structural Fe in clay minerals is an important, albeit poorly characterized, redox-active phase found in many natural and engineered environments. This work develops an experimental approach to directly assess the redox properties of a natural Fe-bearing smectite (ferruginous smectite, SWa-1, 12.6 wt % Fe) with mediated electrochemical reduction (MER) and oxidation (MEO). By utilizing a suite of one-electron-transfer mediating compounds to facilitate electron transfer between structural Fe in SWa-1 and a working electrode, we show that the Fe2+/Fe3+ couple in SWa-1 is redox-active over a large range of potentials (from E(H) = -0.63 V to +0.61 V vs SHE). Electrochemical and spectroscopic analyses of SWa-1 samples that were subject to reduction and re-oxidation cycling revealed both reversible and irreversible structural Fe rearrangements that altered the observed apparent standard reduction potential (E(H)(ø)) of structural Fe. E(H)(ø)-values vary by as much as 0.56 V between SWa-1 samples with different redox histories. The wide range of E(H)-values over which SWa-1 is redox-active and redox history-dependent E(H)(ø)-values underscore the importance of Fe-bearing clay minerals as redox-active phases in a wide range of redox regimes.

  5. Determination of mineral contents of wild Boletus edulis mushroom and its edible safety assessment.

    Science.gov (United States)

    Su, Jiuyan; Zhang, Ji; Li, Jieqing; Li, Tao; Liu, Honggao; Wang, Yuanzhong

    2018-04-06

    This study aimed to determine the contents of main mineral elements of wild Boletus edulis and to assess its edible safety, which may provide scientific evidence for the utilization of this species. Fourteen mineral contents (Ba, Ca, Cd, Co, Cr, Cu, Fe, Mg, Mn, Na, Ni, Sr, V and Zn) in the caps and stipes of B. edulis as well as the corresponding surface soils collected from nine different geographic regions in Yunnan Province, southwest China were determined. The analyses were performed using inductively coupled plasma atomic emission spectrometer (ICP-AES) after microwave digestion. Measurement data were analyzed using variance and Pearson correlation analysis. Edible safety was evaluated according to the provisionally tolerable weekly intake (PTWI) of heavy metals recommended by United Nations Food and Agriculture Organization and World Health Organization (FAO/WHO). Mineral contents were significantly different with the variance of collection areas. B. edulis showed relative abundant contents of Ca, Fe, Mg and Na, followed by Ba, Cr, Cu, Mn and Zn, and the elements with the lower content less were Cd, Co, Ni, Sr and V. The elements accumulation differed significantly in caps and stipes. Among them, Cd and Zn were bioconcentrated (BCF > 1) while others were bioexcluded (BCF < 1). The mineral contents in B. edulis and its surface soil were positively related, indicating that the elements accumulation level was related to soil background. In addition, from the perspective of food safety, if an adult (60 kg) eats 300 g fresh B. edulis per week, the intake of Cd in most of tested mushrooms were lower than PTWI value whereas the Cd intakes in some other samples were higher than this standard. The results indicated that the main mineral contents in B. edulis were significantly different with respect to geographical distribution, and the Cd intake in a few of regions was higher than the acceptable intakes with a potential risk.

  6. Rheological properties and mineral content of buckwheat enriched wholegrain wheat pasta

    Directory of Open Access Journals (Sweden)

    Nedeljković Nataša

    2014-01-01

    Full Text Available Light buckwheat flour (LBF was used to substitute 20% of whole wheat flour (WWF in the formulation of wholegrain wheat pasta. Wholegrain wheat pasta (WWP and buckwheat enriched wholegrain wheat pasta (BWWP were produced on an industrial scale. Substitution level of buckwheat flour (20% was based on previously conducted rheological tests on LBF/WWF blends which were performed using 10, 20 and 30% of LBF. The obtained Mixolab profiles have indicated that wheat blend containing 20% LBF expressed the most similar rheological parameters to WWF. Proximate composition, cooking quality and mineral content of BWWP were analyzed and compared with those of WWP. The substitution of WWF with LBF in the pasta formulation resulted in significantly increased (P < 0.05 contents of P, Mg, K and Zn compared to WWP in dry pasta. The reduction in mineral content of BWWP during cooking was significantly higher (P < 0.05 compared to WWP. The content of P, Mg and K were at same level in both type of pasta after cooking. The obtained results suggest that enrichment of WWP with LBF at the level of 20% did not improve the mineral content of cooked pasta, although increase in minerals was observed in dry pasta. [Projekat Ministarstva nauke Republike Srbije, br. TR31029

  7. Desaturation of a clay-stone around a ventilated gallery: numerical modelling of pressures and water contents under various conditions

    International Nuclear Information System (INIS)

    Ababou, Rachid; Mansouri, Nahla; Bailly, David; Poutrel, Adrien

    2012-01-01

    (cylindrical drift) is discretized and internalized as a 3D 'macro-porous' body within the computational porous domain. Secondly, the properties of this internal macro-porous body are adjusted in such a way that it will transmit properly the imposed suction (or pressure, or flux, as the case may be) from external to internal boundaries. Here, the suction is imposed on the entry face of the gallery (external boundary), and it is transmitted to the clay/gallery interface (internal boundary). The macro-porous body has a porosity of 100%, a large Darcy permeability compared to the clay-stone, and other special nonlinear and non-isotropic unsaturated properties. Briefly, numerical modelling was conducted with BIGFLOW 3D, an implicit finite volume solver of the saturated/unsaturated Richards equation in mixed form (moisture content 'θ', pressure head 'h'). We used the nonlinear Van Genuchten / Mualem conductivity and water retention curves (K(h); θ(h)) in the unsaturated zone. A specific elastic storativity (S S ) was added in the saturated zone to take into account slight deformation mechanisms in a simplified way (the storativity model does not deal with total stress; it assumes δσ EFF ∼ δp, where p is pore pressure, and σ EFF is Terzaghi's effective stress taken positive when extensional). Finally, the BIGFLOW code can also handle 3D heterogeneity and nonlinear diagonal anisotropy, that is: [Kii(h,x,y,z); θ(h,x,y,z)]. We used these additional capabilities of the code in some of the tests. Figs.1 and 2 show the evolution of desaturation for a 'Type I' test, i.e., with suction imposed on a flat horizontal piece of wall located at the roof of the drift. The drift 'radius' (half-side) is R=2 m. The case shown here is only 'moderately dry': the prescribed suction is ψ=3000 m (∼30 MPa), corresponding to H R =80.74% at T AIR =25 C and P ATM =1 bar (according to Kelvin's law). The imposed desaturation of the porous medium at the drift wall is significant (more than 50% drop

  8. Minerals

    Science.gov (United States)

    Minerals are important for your body to stay healthy. Your body uses minerals for many different jobs, including keeping your bones, muscles, heart, and brain working properly. Minerals are also important for making enzymes and hormones. ...

  9. Content of arsenic, selenium, mercury in the coal, food, clay and drinking water on the Zhaotong fluorosis area, eastern Yunnan Province

    Energy Technology Data Exchange (ETDEWEB)

    Luo Kun-li; Li Hui-jie; Chen Tong-bin (and others) [Chinese Academy of Sciences, Beijing (China). Institute of Geographic Sciences and Natural Resources Research

    2008-03-15

    About 160 samples of coal, corn, capsicum and drinking water were collected from the endemic fluorosis area of Zhenxiong and Weixin County, Zhaotong City of Yunnan Province, to determine the arsenic (As), selenium (Se) and mercury (Hg) content by AAF-800. The study found that the As content in the main coal seam from the Late Permian coal mines in Zhaotong City is 8.84 mg/kg and some civil coal can reach 89.09 mg/kg. The Se and Hg in the coal samples of Late Permian is lower, but Se and Hg are more concentrated in the pyritic coal balls and the pyritic gangue of the coal seam. The As content in corn and capsicum dried by coal-burning is more than 0.7 mg/kg, the natural standard amount of arsenic content permitted in food by China. The Se and Hg content in corn dried by coal-burning is lower than the natural standard of Se and Hg content in food in China but the Se and Hg content of capsicum dried by coal-burning exceeds the amount permitted by the natural standard for food in China. Clay, used as an additive for the coal-burning process and as a binder in making briquettes, contains a high content of As, generally more than 16 mg/kg. However, the Se and Hg content of clay itself are low. The As, Se and Hg content of drinking water are lower than the natural standard of As, Se and Hg content in the drinking water. So, there is high-As content coal and high-As content dried corn and capsicum in the endemic fluorosis area of Zhaotong City of Yunnan Province. The high As content of the dried corn and capsicum might have originated from the high arsenic content of burnt coal and clay. 30 refs., 4 tabs.

  10. Metal oxides, clay minerals and charcoal determine the composition of microbial communities in matured artificial soils and their response to phenanthrene.

    Science.gov (United States)

    Babin, Doreen; Ding, Guo-Chun; Pronk, Geertje Johanna; Heister, Katja; Kögel-Knabner, Ingrid; Smalla, Kornelia

    2013-10-01

    Microbial communities in soil reside in a highly heterogeneous habitat where diverse mineral surfaces, complex organic matter and microorganisms interact with each other. This study aimed to elucidate the long-term effect of the soil mineral composition and charcoal on the microbial community composition established in matured artificial soils and their response to phenanthrene. One year after adding sterile manure to different artificial soils and inoculating microorganisms from a Cambisol, the matured soils were spiked with phenanthrene or not and incubated for another 70 days. 16S rRNA gene and internal transcribed spacer fragments amplified from total community DNA were analyzed by denaturing gradient gel electrophoresis. Metal oxides and clay minerals and to a lesser extent charcoal influenced the microbial community composition. Changes in the bacterial community composition in response to phenanthrene differed depending on the mineral composition and presence of charcoal, while no shifts in the fungal community composition were observed. The abundance of ring-hydroxylating dioxygenase genes was increased in phenanthrene-spiked soils except for charcoal-containing soils. Here we show that the formation of biogeochemical interfaces in soil is an ongoing process and that different properties present in artificial soils influenced the bacterial response to the phenanthrene spike. © 2012 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

  11. Mineral, protein and nitrate contents in leaves of Pereskia aculeata subjected to nitrogen fertilization

    Directory of Open Access Journals (Sweden)

    Maria Regina de Miranda Souza

    2016-03-01

    Full Text Available Considering that nitrogen is directly related to leaf protein content, the nitrogen fertilization in Pereskia aculeata plants may affect the protein content and increase its nutritional potential. This study aimed at assessing the effect of nitrogen fertilization on mineral, protein and nitrate contents, as well as the yield of P. aculeata leaves. A randomized blocks design was used, with three replications and five treatments, consisting of increasing topdressing nitrogen doses (0-400 kg ha-1, in soil with organic matter content of 4.0 dag kg-1. Three harvests were performed for leaf analysis. No significant effect was observed for mineral and protein content or leaf fresh mass yield. The mean values for mineral composition were: 3.52 dag kg-1 of N, 0.47 dag kg-1 of P, 4.65 dag kg-1 of Ca, 0.71 dag kg-1 of Mg, 0.25 dag kg-1 of S, 36.64 mg kg-1 of Zn and 174.13 mg kg-1 of Fe. The mean content for protein was 21.86 % and the leaf fresh mass yield was 0.971 kg plant-1. K levels decreased from 50 kg ha-1 of N. Nitrate increased linearly with the nitrogen fertilization, reaching a maximum value of 78.2 mg kg-1 of fresh mass, well below the health risk threshold. It was concluded that a soil with high organic matter content does not require nitrogen fertilization. However, doses up to 400 kg ha-1 of nitrogen ensure adequate leaf yield and protein and mineral contents within the desired range for the species, being a food rich in proteins, iron and calcium.

  12. Influence of Bifidobacterium bifidum on release of minerals from bread with differing bran content.

    Science.gov (United States)

    Nalepa, Beata; Siemianowska, Ewa; Skibniewska, Krystyna Anna

    2012-01-01

    Bread is considered an important source of minerals; however, the presence of fiber and phytic acid reduces bioavailability of minerals from cereal products. It is well established that activity of microorganisms in human gut increases the amount of nutrients released during digestion. The aim of this study was to determine the influence of Bifidobacterium bifidum on release of some minerals from bread using an in vitro process of enzymatic digestion. White bread and with addition of 15, 30, or 45% of bran was baked in a bakery by traditional methods, with addition of yeasts and rye leaven, from flour made of wheat, Tonacja variety. Concentrations of calcium, magnesium, manganese, zinc, copper, and iron were determined by atomic absorption spectrometry. Bread was enzymatically digested in vitro without and with the addition of Bifidobacterium bifidum KD6 (inoculum 10(6) CFU/cm(3)) and percentages of minerals released were determined. The concentration of minerals released during enzymatic digestion varied depending upon the element, quantity of bran, and presence of bacteria. Increase in bran content decreased release of elements. Bifidobacterium bifidum KD6 enhanced amounts of magnesium and zinc released from all types of bread, while manganese and copper rose only from white bread with 15% bran addition. Bacteria decreased amounts of calcium and iron released from bread. Data indicate that diets rich in beneficial bacteria (probiotics) but not balanced with minerals might increase mineral deficiency.

  13. Clay minerals in sediments of Portuguese reservoirs and their significance as weathering products from over-eroded soils: a comparative study of the Maranhão, Monte Novo and Divor Reservoirs (South Portugal)

    Science.gov (United States)

    Fonseca, Rita M. F.; Barriga, Fernando J. A. S.; Conceição, Patrícia I. S. T.

    2010-12-01

    The Southern region of Portugal is subjected to several forms of over-erosion. Most leached products, mainly composed of fine particles containing nutrients, metals or pesticides, are easily transported by river flows. When these are hindered by a physical barrier such as a dam, the particulate load accumulates on the bottom of the reservoirs, often leading to a pronounced decrease of water quality. Bottom sediments from three reservoirs were subjected to grain-size analysis and a study of clay minerals by X-ray diffraction. Most sediments contain a diverse set of clay minerals, mostly illites, smectites, chlorites and kaolinites. The nature of the clay minerals reflects the nature of the parent rocks. During the cycles of transport and temporary deposition, they may undergo significant chemical and physical transformations, which lead to an increase of expandable properties and therefore, to a higher cationic exchange capacity, determining its important role as vehicles of environmental pollutants.

  14. Quantification of SOC and Clay Content Using Visible Near-Infrared Reflectance–Mid-Infrared Reflectance Spectroscopy With Jack-Knifing Partial Least Squares Regression

    DEFF Research Database (Denmark)

    Peng, Yi; Knadel, Maria; Gislum, René

    2014-01-01

    A total of 125 soil samples were collected from a Danish field varying in soil texture from sandy to loamy. Visible near-infrared reflectance (Vis-NIR) and mid-infrared reflectance (MIR) spectroscopy combined with chemometric methods were used to predict soil organic carbon (SOC) and clay content...

  15. [Content of mineral elements of Gastrodia elata by principal components analysis].

    Science.gov (United States)

    Li, Jin-ling; Zhao, Zhi; Liu, Hong-chang; Luo, Chun-li; Huang, Ming-jin; Luo, Fu-lai; Wang, Hua-lei

    2015-03-01

    To study the content of mineral elements and the principal components in Gastrodia elata. Mineral elements were determined by ICP and the data was analyzed by SPSS. K element has the highest content-and the average content was 15.31 g x kg(-1). The average content of N element was 8.99 g x kg(-1), followed by K element. The coefficient of variation of K and N was small, but the Mn was the biggest with 51.39%. The highly significant positive correlation was found among N, P and K . Three principal components were selected by principal components analysis to evaluate the quality of G. elata. P, B, N, K, Cu, Mn, Fe and Mg were the characteristic elements of G. elata. The content of K and N elements was higher and relatively stable. The variation of Mn content was biggest. The quality of G. elata in Guizhou and Yunnan was better from the perspective of mineral elements.

  16. MINERALS, MICROELEMENTS AND POLYPHENOLS CONTENT IN THE SOYBEAN VARIETIES GROWN IN DIFFERENT LOCALITIES OF SLOVAKIA

    Directory of Open Access Journals (Sweden)

    Mária Timoracká

    2015-02-01

    Full Text Available The aim of this study was to evaluate the influence of the grown locality on minerals and risky metal intake from the soil and on polyphenols formation in the soybean seeds. The research was realised in five localities of Slovakia using the seven soybean varieties. From the point of the soil hygiene, all determined values of heavy metals content in soils were lower than given hygienic limits, with the exception of Cd. Minerals and heavy metals contents in the soybean samples show significant differences between cultivars and localities. The values show imbalance between the potassium contents and other minerals. The order of the elements levels was determined as following: Fe > Zn > Mn > Cu > Ni > Pb > Cr ≈ Co > Cd. The risky elements contents, with exception of Cd, Cu, Pb and Ni content (only in some localities, did not exceed a limit for legumes by Food Codex SR. The total polyphenols content ranged from 817.6 to 1281.0 μg eq. tannic acid/g and suggest the variety dependence, but the locality influence was not significantly confirmed.

  17. INTERACTION BETWEEN DIETARY MINERAL AND PHYTASE ON BIOLOGICAL PERFORMANCES OF JAPANESE FLOUNDER, Paralichthys olivaceus. PART II. MINERAL DIGESTIBILITY AND VERTEBRAL MINERAL CONTENT

    Directory of Open Access Journals (Sweden)

    Asda Laining

    2015-06-01

    Full Text Available Interactive effects between dietary inorganic phosphorus (IP and phytase (P on mineral digestibility and vertebral mineral content were investigated in a 30 days feeding trial followed by three weeks digestibility trial with Japanese flounder, Paralichthys olivaceus. Eight experimental diets were formulated based on two levels of dietary Ca at 0% and 0.2% combined with either 0% or 0.25% of dietary IP and either with 0 and 2,000 fytase unit (FTU/kg of phytase in diet, respectively. Result indicated that digestibility of total phosphorus significantly increased by three dietary compounds where the highest was observed in fish fed diet contained 0.25% IP and 2,000 FTU phytase/kg and dietary Ca also included in diet. Significant interaction was only detected between dietary IP and P on this parameter. Supplementation of IP and Ca not phytase significantly improved Ca digestibility. Ca digestibility was very poor when dietary IP and Ca were not supplemented in diet even with when phytase supplemented in diet. There was significant interaction between dietary IP and Ca on Ca digestibility. Vertebral total phosphorus, Ca, and Mg content as well as Ca:P ratio were significantly enhanced by dietary IP and phytase. Dietary Ca has significant effect only on vertebral total phosphorus. Interaction between dietary IP and Ca was significantly found on vertebral Ca content and Ca:P ratio. No significant second-order interaction was observed among the three dietary mineral on overall parameters. Based on total phosphorus and Ca digestibility as well vertebral phosphorus content found in this study, dietary IP, Ca, and phytase at rate of 0.25%, 0.2%, and 2,000 FTU phytase/kg diet, respectively are needed to supplement in diet for a better mineral absorption and bone mineralization.

  18. A measurement instrument for bone mineral content of adult and children

    International Nuclear Information System (INIS)

    Liu Shaofang

    1996-01-01

    The γ radiation source was used in bone mineral content measurement analysis of adult and children and a new instrument is developed successfully. It's precision is +2%. The advantage of this instrument is light, cheap and reliable. It can be used widely in medical science and clinic for diagnosis on certain diseases and research work

  19. A multicenter study of the influence of fat and lean mass on bone mineral content

    DEFF Research Database (Denmark)

    Hla, M M; Davis, J W; Ross, P D

    1996-01-01

    We examined the relative influence of fat and lean mass on bone mineral content (BMC) among 1600 early postmenopausal women aged 45-59 y from four geographical locations (Nottingham, United Kingdom; Portland, OR; Honolulu; and Copenhagen). Bone sites investigated included the major fracture sites...

  20. Dual-photon absorptiometry: A new method of determining bone mineral content. Pt. 1

    International Nuclear Information System (INIS)

    Buttermann, G.; Eiber, J.; Hennig, J.; Pabst, H.W.

    1988-01-01

    Cortical (neck of femur) and trabecular (L 2-4) bone mass has been determined repeatedly with DPA using 153 Gd (NOVO Lab 22 a) in 545 females and 112 males with no evidence of bone diseases. Measured 'normal' (age- and sex-related average) values for bone mineral content (BMC) differed significantly (p [de

  1. Mineral content in grains of seven food-grade sorghum hybrids grown in Mediterranean environment

    Science.gov (United States)

    Sorghum is a major crop used for food, feed and industrial purposes worldwide. The objective of this study was to determine the mineral content in grains of seven white food-grade sorghum hybrids bred and adapted for growth in the central USA and grown in a Mediterranean area of Southern Italy. The ...

  2. Common clay and shale

    Science.gov (United States)

    Virta, R.L.

    2000-01-01

    Part of the 1999 Industrial Minerals Review. The clay and shale market in 1999 is reviewed. In the U.S., sales or use of clay and shale increased from 26.4 million st in 1998 to 27.3 million st in 1999, with an estimated 1999 value of production of $143 million. These materials were used to produce structural clay products, lightweight aggregates, cement, and ceramics and refractories. Production statistics for clays and shales and for their uses in 1999 are presented.

  3. Detection of Soluble and Fixed NH4+ in Clay Minerals by DTA and IR Reflectance Spectroscopy : A Potential Tool for Planetary Surface Exploration

    Science.gov (United States)

    Janice, Bishop; Banin, A.; Mancinelli, R. L.; Klovstad, M. R.; DeVincenzi, Donald L. (Technical Monitor)

    2001-01-01

    Nitrogen is an essential element for life. It is the only element among the six major biogenic elements, C, O, S, O, P, H, whose presence in the Martian soil has not been positively and directly established. We describe here a study assessing the ability to detect NH4 in soils by two methods: differential thermal analysis (DTA) and infrared (IR) reflectance spectroscopy. Four standard clay minerals (kaolinite, montmorillonite, illite and attapulgite) and an altered tephra sample from Mauna Kea were treated with NH4 in this study. Samples of the NH4-treated and leached clays were analyzed by DTA and infrared (IR) reflectance spectroscopy to quantify the delectability of soluble and sorbed/fixed NH4. An exotherm at 270-280 C was clearly detected in the DTA curves of NH4-treated (non-leached) samples. This feature is assigned to the thermal decomposition reaction of NH4. Spectral bands observed at 1.56, 2.05, 2.12, 3.06, 3.3, 3.5, 5.7 and 7.0 microns in the reflectance spectra of NH4-treated and leached samples are assigned to the sorbed/fixed ammonium in the clays. The montmorillonite has shown the most intense absorbance due to fixed ammonium among the leached samples in this study, as a result of its high cation sorption capacity. It is concluded that the presence of sorbed or fixed NH4 in clays may be detected by infrared (IR) reflectance or emission spectroscopy. Distinction between soluble and sorbed NH4 may be achieved through the presence or absence of several spectral features assigned to the sorbed NH4 moietyi and, specifically, by use of the 4.2 micrometer feature assigned to solution NH4. Thermal analyses furnish supporting evidence of ammonia in our study through detection of N released at temperatures of 270-330 C. Based on these results it is estimated that IR spectra measured from a rover should be able to detect ammonia if present above 20 mg NH4/g sample in the surface layers. Orbital IR spectra and thermal analyses measured on a rover may be able to

  4. Mineral Content in Leaves of Tomato Plants Grafted on Solanum Rootstocks

    OpenAIRE

    松添, 直隆; 間, 浩美; 花田, 勝美; モハメド, アリ; 大久保, 敬; 藤枝, 國光

    1995-01-01

    Nutrient uptake of tomato plants cv. Momotaro grafted on Solanum sisymbriifoliulm, S. torvum and S. toxicarium which are resistant to soil-born disease were compared with tomato grafted on its own root, a tomato/tomato, scion/rootstock combination. Mineral content in leaves of tomato/S. sisymbriifoliulm was nearly equal to that of tomato/tomato. In leaves of tomato/S. torvum, nitrogen content was higher, and magnesium content was lower than those of tomato/tomato. Furthermore, phosphorus and ...

  5. Effects of lactation on bone mineral content in healthy postpartum women

    International Nuclear Information System (INIS)

    Hayslip, C.C.; Klein, T.A.; Wray, H.L.; Duncan, W.E.

    1989-01-01

    Bone mineral contents were estimated by dual photon absorptiometry of the lumbar spine (L2-L4) and single photon absorptiometry of the mid- and distal radius in 19 healthy women on their second postpartum day and at 6 months postpartum. All bone mineral measurements were performed by one technician, and the single and dual photon absorptiometry results were read by one observer. Daily oral calcium intakes were estimated from dietary histories obtained by a dietitian. Twelve women who breast-fed exclusively throughout the first 6 months postpartum were compared with seven formula-feeding women who did not breast-feed or who breast-fed for less than 3 months postpartum. No differences were found in age, parity, height, weight, or daily calcium intake between the breast- and formula-feeding women. Breast-feeding women had a significant decrease (averaging 6.5%) in bone mineral of the lumbar spine at 6 months postpartum as compared with 2 days postpartum (1.14 +/- 0.03 versus 1.22 +/- 0.03 g/cm2, mean +/- SEM; P less than .001), whereas no significant change occurred in the formula-feeding women at 6 months (1.24 +/- 0.03 versus 1.26 +/- 0.04 g/cm2). At 6 months postpartum, the breast-feeding women had a significantly lower mean bone mineral content of the lumbar spine than did formula-feeding women (P less than .05). No significant changes were noted in bone mineral content of the mid- or distal radius in either group of women during the period of evaluation. We conclude that during the first 6 months postpartum, breast-feeding is associated with bone mineral loss from the lumbar spine, but not from the mid- or distal radius

  6. Studies of coherent/Compton scattering method for bone mineral content measurement

    International Nuclear Information System (INIS)

    Sakurai, Kiyoko; Iwanami, Shigeru; Nakazawa, Keiji; Matsubayashi, Takashi; Imamura, Keiko.

    1980-01-01

    A measurement of bone mineral content by a coherent/Compton scattering method was described. A bone sample was irradiated by a collimated narrow beam of 59.6 keV gamma-rays emitted from a 300 mCi 241 Am source, and the scattered radiations were detected using a collimated pure germanium detector placed at 90 0 to the incident beam. The ratio of coherent to Compton peaks in a spectrum of the scattered radiations depends on the bone mineral content of the bone sample. The advantage of this method is that bone mineral content of a small region in a bone can be accurately measured. Assuming that bone consists of two components, protein and bone mineral, and that the mass absorption coefficient for Compton scattering is independent of material, the coherent to Compton scattering ratio is linearly related to the percentage in weight of bone mineral. A calibration curve was obtained by measuring standard samples which were mixed with Ca 3 (PO 4 ) 2 and H 2 O. The error due to the assumption about the mass absorption coefficient for Compton scattering and to the difference between true bone and standard samples was estimated to be less than 3% within the range from 10 to 60% in weight of bone mineral. The fat in bone affects an estimated value by only 1.5% when it is 20% in weight. For the clinical application of this method, the location to be analyzed should be selected before the measurement with two X-ray images viewed from the source and the detector. These views would be also used to correct the difference in absorption between coherent and Compton scattered radiations whose energies are slightly different from each other. The absorbed dose to the analyzed region was approximately 150 mrad. The time required for one measurement in this study was about 10 minutes. (author)

  7. Laboratory studies on the retention and release of some radioisotopes by clay minerals and fresh water stream biota

    International Nuclear Information System (INIS)

    Farah, M.Y.; Abdel-Gawad, A.S.; Misak, N.Z.; Abdelmalik, W.E.; Mitry, E.; Maghrawy, H.B.

    1982-01-01

    The subject of long-lived radioactive waste disposal and its implications on human environment is of prime importance. The disposal of liquid waste into ground or surface water constitutes one of the main approaches to this subject. The present survey comprises two main parts. The first one deals with the sorption of long-lived radioactive waste by some clays collected from localities in the vicinity of Cairo, the Reactor Centre at Inshas and Borg El-Arab site. The second part describes the behaviour of some long-lived radioelements in aquaria containing bottom sediments of Ismailia Canal, Canal water and aquatic biota. (author)

  8. Review of Studies of Clay Minerals as Significant Component of Potential Host Rocks or Engineering Barriers for Radioactive Waste Disposals Performed at Comenius University in Bratislava

    International Nuclear Information System (INIS)

    Peter, Uhlik; Vladimir, Sucha; Maria, Caplovicova; Igor, Stricek

    2013-01-01

    About 50 % of electric power is produced by nuclear power plants in Slovakia. In spite of the significant production of nuclear waste, Slovakia has not defined basic strategy of radioactive-waste isolation. However, some pilot projects and studies have been carried out. Five areas were determined as prospective sites for construction of deep geological repository (DGR). Two of them are situated in the south of Slovakia. Szecseny schlier (mixture of siltstones and Clay-stones) of Lucenec Formation (Egerian) is one of the most prospective host rocks from lithological, structural and spatial perspective. Besides the investigation of potential host rock for DGR the studies of bentonite properties as important part of engineering barriers for radioactive waste disposals were performed. Detailed mineral and structural analyses of smectites from the bentonitic material exposed to laboratory Mock-Up test were realised. Particular interest has been focused on interaction between Fe and smectites. Other field of interest is investigation of sorption of Cs and Sr on natural and modified bentonites, including irradiation. Purpose of this work is to present a short review of other studies done by our group with partial focusing to interaction of organic dye (Rhoda-mine 6G) with smectite that is connected with changes of layer charge after treatment; possibilities to measure preferential orientation of clays after compaction by TEM and to effort to use X-ray micro-tomography for inner structure of sediments. (authors)

  9. The study of mineral content in Thalictrum foetidum L. herb and roots

    Directory of Open Access Journals (Sweden)

    E. V. Savelieva

    2016-04-01

    Full Text Available Aim. The physiological role of mineral substances is extremely important for human’s organism. It is necessary to maintain constantly the required level of irreplaceable macro- and microelements in organism, which are part of food products, mineral or mineral-vitamin complexes, medical plants and drugs on their basis. Methods and results. With the purpose to expand information about chemical composition of raw material, the qualitative composition and quantitative content of macro- and microelements in Thalictrum foetidum L. herb and roots has been determined. The atomic emission spectroscopy method has been used for research. The content of 15 macro- and microelements has been determined in Thalictrum foetidum L. herb and roots. Conclusions. Analyzing the general content of elements in raw material of Thalictrum foetidum L., sufficiently high content of neurogenic macro- and microelements (in particular, manganese, magnesium, potassium, and molybdenum has been noted. This fact makes herbal material promising for subsequent phytochemical and pharmacological research, and it can be used for new neurogenic drugs creation.

  10. Mineral Composition, Total Phenol Content and Antioxidant Activity of a Macrolichen Everniastrum cirrhatum (Fr. Hale (Parmeliaceae

    Directory of Open Access Journals (Sweden)

    T. R. Prashith Kekuda

    2011-01-01

    Full Text Available In the present study, we investigated for the first time mineral composition, total phenol content and antioxidant activity of a foliose macrolichen Everniastrum cirrhatum (Fr. Hale (Parmeliaceae from Bhadra wildlife sanctuary, Karnataka, India. Mineral content of the lichen was estimated by Atomic absorption spectrophotometer after acid digestion. The secondary metabolites were detected by thin layer chromatography (TLC and phytochemical assays. The lichen material was extracted with methanol in soxhlet apparatus. Total phenol content was estimated by folin ciocalteu method. Antioxidant activity was determined by DPPH, Ferric reducing and metal chelating assays. Among the principal elements, calcium was found in high concentration followed by magnesium, potassium and phosphorus. Among trace elements, iron was detected in high amount followed by zinc, manganese and copper. The DPPH radical scavenging activity was found to be dose dependent with an IC50 of 6.73 μg/mL. In ferric reducing assay, the absorbance increased with the concentration of extract suggesting reducing power. The extract exhibited good metal chelating activity with an IC50 value of 29.28 μg/mL. Total phenol content was 101.2 mg tannic acid equivalents per gram of extract. Phytochemical analysis revealed the presence of alkaloids, saponins, tannins and terpenoids. TLC revealed atranorin, salazinic acid and protolichesterinic acid. The lichen can be consumed as a source of minerals required for the body as appreciable amount of minerals has been detected. The marked antioxidant activity may be attributed to the presence of phenol content in the extract. Further studies on isolation of metabolites and their bioactivities are under investigation.

  11. Improvement of Soil Moisture Retrieval from Hyperspectral VNIR-SWIR Data Using Clay Content Information: From Laboratory to Field Experiments

    Directory of Open Access Journals (Sweden)

    Rosa Oltra-Carrió

    2015-03-01

    Full Text Available The aim of this work is to study the constraints and performance of SMC retrieval methodologies in the VNIR (Visible-Near InfraRed and SWIR (ShortWave InfraRed regions (from 0.4 to 2.5 µm when passing from controlled laboratory conditions to field conditions. Five different approaches of signal processing found in literature were considered. Four local criteria are spectral indices (WISOIL, NSMI, NINSOL and NINSON. These indices are the ratios between the spectral reflectances acquired at two specific wavelengths to characterize moisture content in soil. The last criterion is based in the convex hull concept and it is a global method, which is based on the analysis of the full spectral signature of the soil. The database was composed of 464 and 9 spectra, respectively, measured over bare soils in laboratory and in-situ. For each measurement, SMC and texture were well-known and the database was divided in two parts dedicated to calibration and validation steps. The calibration part was used to define the empirical relation between SMC and SMC retrieval approaches, with coefficients of determination (R2 between 0.72 and 0.92. A clay content (CC dependence was detected for the NINSOL and NINSON indices. Consequently, two new criteria were proposed taking into account the CC contribution (NINSOLCC and NINSONCC. The well-marked regression between SMC and global/local indices, and the interest of using the CC, were confirmed during the validation step using laboratory data (R² superior to 0.76 and Root mean square errors inferior to 8.3% m3∙m−3 in all cases and using in-situ data, where WISOIL, NINSOLCC and NINSONCC criteria stand out among the NSMI and CH.

  12. Mineral Content and Biochemical Variables of Aloe vera L. under Salt Stress

    Science.gov (United States)

    Murillo-Amador, Bernardo; Córdoba-Matson, Miguel Víctor; Villegas-Espinoza, Jorge Arnoldo; Hernández-Montiel, Luis Guillermo; Troyo-Diéguez, Enrique; García-Hernández, José Luis

    2014-01-01

    Despite the proven economic importance of Aloe vera, studies of saline stress and its effects on the biochemistry and mineral content in tissues of this plant are scarce. The objective of this study was to grow Aloe under NaCl stress of 0, 30, 60, 90 and 120 mM and compare: (1) proline, total protein, and enzyme phosphoenolpyruvate carboxylase (PEP-case) in chlorenchyma and parenchyma tissues, and (2) ion content (Na, K, Ca, Mg, Cl, Fe, P. N, Zn, B, Mn, and Cu) in roots, stems, leaves and sprouts. Proline and PEP-case increased as salinity increased in both parenchyma and chlorenchyma, while total protein increased in parenchyma and decreased in chlorenchyma, although at similar salt concentrations total protein was always higher in chlorenchyma. As salinity increased Na and Cl ions increased in roots, stems, leaves, while K decreased only significantly in sprouts. Salinity increases typically caused mineral content in tissue to decrease, or not change significantly. In roots, as salinity increased Mg decreased, while all other minerals failed to show a specific trend. In stems, the mineral concentrations that changed were Fe and P which increased with salinity while Cu decreased. In leaves, Mg, Mn, N, and B decreased with salinity, while Cu increased. In sprouts, the minerals that decreased with increasing salinity were Mg, Mn, and Cu. Zinc did not exhibit a trend in any of the tissues. The increase in protein, proline and PEP-case activity, as well as the absorption and accumulation of cations under moderate NaCl stress caused osmotic adjustment which kept the plant healthy. These results suggest that Aloe may be a viable crop for soil irrigated with hard water or affected by salinity at least at concentrations used in the present study. PMID:24736276

  13. Evaluation of mineral content and heavy metals of dromedary camel milk in Iran

    Directory of Open Access Journals (Sweden)

    Mahdieh MOSTAFIDI

    Full Text Available Abstract The aim of this study was to determine the amount of major mineral compounds and heavy metals of camel milk in Iran. For this purpose camel milk samples were collected from seven regions of Iran include Qazvin, Golestan, Semnan, Sistan-Baluchestan, Khuzestan, Bushehr and Tehran. The samples were analyzed using Inductively Coupled Plasma-Optical Emission Spectrometer (ICP-OES method. The results showed that among the mineral contents, iron and zinc of camel milk were greater than bovine milk. Based on the codex standard 193-2007 standards, the maximum acceptable limit for lead and cadmium is 20 µg/kg and 10 µg/kg, respectively. The results of this study showed that the measured amounts of lead, cadmium and nickel in all samples were less than the acceptable limit for bovine milk. Bovine milk and dairy products are a poor source of iron, while the obtained data revealed that camel milk is a major source of minerals, especially iron. The camel milk’s iron was 10 times more than bovine milk. However, variations in mineral content in camel milk could be due to feed, stage of lactation, milk collection time, drought conditions, environmental conditions and associated analytical methods. Camel milk recommended as a valuable source of food for the human.

  14. California Bearing Ratio (CBR) test on stabilization of clay with lime addition

    Science.gov (United States)

    Hastuty, I. P.; Roesyanto; Limbong, M. N.; Oberlyn, S. J.

    2018-02-01

    Clay is a type of soil with particles of certain minerals giving plastic properties when mixed with water. Soil has an important role in a construction, besides as a building material in a wide variety of civil engineering works, soil is also used as supporting foundation of the building. Basic properties of clay are rock-solid in dry and plastic with medium water content. In high water content, clay becomes sticky like (cohesive) and soften. Therefore, clay stabilization is necessary to repair soil’s mechanical properties. In this research, lime is use as a stabilizer that contains the Ca+ element to bond bigger particles. Lime used is slaked lime Ca(OH)2. Clay used has liquid limitation (LL) value of 47.33%, plasticity index of 29.88% and CBR value 6.29. The results explain about 10% lime mixture variation gives the optimum stabilized clay with CBR value of 8.75%.

  15. Characterisation of the wall-slip during extrusion of heavy-clay products

    Science.gov (United States)

    Kocserha, I.; Gömze, A. L.; Kulkov, S.; Kalatur, E.; Buyakova, S. P.; Géber, R.; Buzimov, A. Y.

    2017-01-01

    During extrusion through the extrusion die, heavy-clay compounds are usually show plug flow with extensive slip at the wall of the die. In this study, the viscosity and the thickness of the slip layer were investigated. For the examination a brick-clay from Malyi (Hungary) deposit was applied as a raw material. The clay was characterised by XRPD, BET, SEM and granulometry. As the slip layer consists of suspension of the fine clay fraction so the clay minerals content of the clay (dviscosity of suspension with different water content was measured by means of rotational viscosimeter. The thickness of the slip layer was calculated from the measured viscosity and other data obtained from an earlier study with capillary rheometer. The calculated thickness value showed a tendency to reach a limit value by increasing the extrusion speed.

  16. Heavy Metal Contents in Some Commonly Consumed Vegetables

    African Journals Online (AJOL)

    dell

    This work reports on the levels of cadmium, lead, copper, manganese and ... source of both heavy metals and essential trace elements due to their ... content, clay mineral and other soil chemical ... addition, the interactions of soil-plant root-.

  17. Bone mineral content measurement in small infants by single-photon absorptiometry: current methodologic issues

    International Nuclear Information System (INIS)

    Steichen, J.J.; Asch, P.A.; Tsang, R.C.

    1988-01-01

    Single-photon absorptiometry (SPA), developed in 1963 and adapted for infants by Steichen et al. in 1976, is an important tool to quantitate bone mineralization in infants. Studies of infants in which SPA was used include studies of fetal bone mineralization and postnatal bone mineralization in very low birth weight infants. The SPA technique has also been used as a research tool to investigate longitudinal bone mineralization and to study the effect of nutrition and disease processes such as rickets or osteopenia of prematurity. At present, it has little direct clinical application for diagnosing bone disease in single patients. The bones most often used to measure bone mineral content (BMC) are the radius, the ulna, and, less often, the humerus. The radius appears to be preferred as a suitable bone to measure BMC in infants. It is easily accessible; anatomic reference points are easily palpated and have a constant relationship to the radial mid-shaft site; soft tissue does not affect either palpation of anatomic reference points or BMC quantitation in vivo. The peripheral location of the radius minimizes body radiation exposure. Trabecular and cortical bone can be measured separately. Extensive background studies exist on radial BMC in small infants. Most important, the radius has a relatively long zone of constant BMC. Finally, SPA for BMC in the radius has a high degree of precision and accuracy. 61 references

  18. Health Effects Due to Radionuclides Content of Solid Minerals within Port of Richards Bay, South Africa

    Directory of Open Access Journals (Sweden)

    Felix B. Masok

    2016-11-01

    Full Text Available This study assessed the radiological health hazards to various body organs of workers working within Transnet Precinct in Richards Bay in Kwazulu-Natal, South Africa due to radionuclide content of mineral ores often stored within the facility. Thirty samples were collected from five mineral ores (rock phosphate, rutile, zircon, coal and hematite and analyzed for 238U, 234U, 226Ra, 210Pb, 235U, 232Th, 228Ra, 228Th and 40K using delayed neutron activation analysis and low energy gamma spectroscopy. Rutile was found to be the most radioactive mineral ore within the facility with 210Pb concentration of 759.00 ± 106.00 Bq·kg−1. Effective annual dose rate in (mSv·y−1 delivered to different organs of the body: testes, bone marrow, whole body, lungs and ovaries from mineral ores were such that dose from mineral ores decreased in the order coal > rutile > rock phosphate > hematite > zircon. The organs with the highest received dose rate were the testes and this received dose was from coal. However, all of the calculated absorbed dose rates to organs of the body were below the maximum permissible safety limits.

  19. Comparing heavy metal contents in crops receiving mineral fertilisers and animal manure

    DEFF Research Database (Denmark)

    Christensen, Bent Tolstrup; Elsgaard, Lars

    2014-01-01

    Spring barley (grain, straw), grass-clover (two cuts), winter wheat (grain, straw) and silage maize grown in the Askov long-term experiment with different levels (0, ½, 1, 1½, 2) of mineral fertiliser (NPK) and animal manure (AM) had concentrations of As, Pb, Cd and Hg below the EC maximum permis...... of NPK and AM does not pose a threat in terms of feed quality. However, the long-term accumulation of heavy metals added with mineral fertilisers and animal manure is essentially irreversible and may threaten soil quality....... in the analysed metal contents between crops grown with NPK and AM. Crop contents of uranium and thallium were below the analytical detection limits regardless of nutrient source and addition rate. Thus in a farming context similar to that of the Askov experiment, the long-term application of standard rates...

  20. Phenolic Profiles, Phytchemicals and Mineral Content of Decoction and Infusion of Opuntia ficus-indica Flowers.

    Science.gov (United States)

    Ammar, Imene; Ennouri, Monia; Bouaziz, Mohamed; Ben Amira, Amal; Attia, Hamadi

    2015-12-01

    Opuntia flowers are a natural source of biologically active compounds and they have been used as medicinal plant for a long time. Despite the various uses reported for the decoction and infusion of these flowers, their characterization has been discarded. In this study, the decoction and infusion prepared from Opuntia ficus-indica were analyzed with respect to their content in minerals and phytochemicals in order to evaluate its nutritional characteristics. The obtained data proved that these preparations are a rich source of minerals mainly K and Ca. Moreover, the phytochemical analysis revealed that they have important polyphenols, flavonoids and tannins contents with the infusion that presented the highest polyphenol levels. LC-MS analyses of decoction and infusion allowed the characterization of 20 phenolic compounds. It is mainly identified by the presence of flavonols glycosides.

  1. Investigation of the mineral contents of some varieties of powder milk by pixe

    International Nuclear Information System (INIS)

    Ahmad, N.; Aejaz, S.M.H.; Naeem, A.; Shahnawaz, M; Saadat, S.

    2010-01-01

    Milk and milk products constitute an important ingredient of human nutrition all over the world. Macro mineral contents like sodium, potassium, calcium, phosphorus and micro mineral contents like iron, copper, zinc, manganese of some varieties of powder milk available in the local market have been investigated by Proton Induced X-Ray Emission (PIXE). These elements are essential for the optimal functioning of various chemical processes taking place in the human body. Any toxic element present in milk can also be detected simultaneously. PIXE is a powerful and universal elemental analysis technique with high detection sensitivity for elements with Z> 11 in the periodic table. The technique is non-destructive and may be applied to samples as small as a cell to a large painting. (author)

  2. [Effects of nandrolone decanoate on bone mineral content and intestinal absorption of calcium].

    Science.gov (United States)

    Nuti, R; Righi, G A; Turchetti, V; Vattimo, A

    1984-01-28

    To evaluate the effects of a long-term treatment with nandrolone decanoate on metabolism of the skeleton, a double-blind randomized study was carried out in women with joint diseases without metabolic bone derangement. Ten patients were treated with 50 mg of nandrolone decanoate every three weeks for two years; in six subjects a treatment with placebo was performed. As it concerns plasma calcium and phosphate, serum alkaline phosphatase, urinary excretion of calcium, phosphate, hydroxyproline and cAMP, as parathyroid index, it was not observed significant differences in the two examined groups. While in placebo group at the end of the study the intestinal radiocalcium remained unchanged and bone mineral content showed a slight decrease, on the contrary nandrolone decanoate treatment promoted a significant improvement in intestinal calcium absorption and an increase in bone mineral content.

  3. Error analysis of the microradiographical determination of mineral content in mineralised tissue slices

    International Nuclear Information System (INIS)

    Jong, E. de J. de; Bosch, J.J. ten

    1985-01-01

    The microradiographic method, used to measure the mineral content in slices of mineralised tissues as a function of position, is analysed. The total error in the measured mineral content is split into systematic errors per microradiogram and random noise errors. These errors are measured quantitatively. Predominant contributions to systematic errors appear to be x-ray beam inhomogeneity, the determination of the step wedge thickness and stray light in the densitometer microscope, while noise errors are under the influence of the choice of film, the value of the optical film transmission of the microradiographic image and the area of the densitometer window. Optimisation criteria are given. The authors used these criteria, together with the requirement that the method be fast and easy to build an optimised microradiographic system. (author)

  4. Sugar Profile, Mineral Content, and Rheological and Thermal Properties of an Isomerized Sweet Potato Starch Syrup

    OpenAIRE

    Dominque, Brunson; Gichuhi, Peter N.; Rangari, Vijay; Bovell-Benjamin, Adelia C.

    2013-01-01

    Currently, corn is used to produce more than 85% of the world's high fructose syrup (HFS). There is a search for alternative HFS substrates because of increased food demand and shrinking economies, especially in the developing world. The sweet potato is a feasible, alternative raw material. This study isomerized a high glucose sweet potato starch syrup (SPSS) and determined its sugar profile, mineral content, and rheological and thermal properties. Rheological and thermal properties were meas...

  5. Influence of packaging and conditions of storaging on content of mineral water Guber-Srebrenica

    OpenAIRE

    Blagojević Dragana D.; Lazić Dragica; Škundrić Branko; Škundrić Jelena; Vukić Ljiljana

    2008-01-01

    Mineral waters are found in nature in greater depths most often in reduction conditions, so after surfacing their content alters in contact with oxygen, which is caused by oxidation of certain components. Due to this, efforts were made to make these waters more stabile so they could be used after certain time. This work monitors the stability of Guber (Argentaria)-Srebrenica water exposed to light and with addition of ascorbic acid. The methods of analysis and the parameters analyzed are: gra...

  6. Development of the in vivo measurement system of bone mineral content using monoenergetic gamma rays

    International Nuclear Information System (INIS)

    Nardocci, A.C.

    1990-08-01

    A system, developed for in vivo measurement of bone mineral content (BMC) using monoenergetic gamma-rays of 241 Am, is described. It presents a discussion of the theoretical and practical aspects of the technique, with details of acquisition and data processing and also discusses the calibration procedure used. The results obtained with in vivo measurements are presented and BMC values of clinically normal subjects and chronic renal patients are compared. (author)

  7. Determination of sorption mechanisms of radionuclides onto clay minerals using extended x-ray absorption fine structure (EXAFS) spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Daehn, R.; Scheidegger, A.; Baeyens, B.; Bradbury, M.H

    2001-03-01

    Much of the experimental work in the Waste Management Laboratory at PSI concentrates on trying to understand the processes and mechanisms which govern the release of safety-relevant radionuclides from waste matrices, and their transport through engineered barrier systems and the surrounding geosphere. For this reason, detailed sorption studies of radionuclides (Cs, Sr, Ni, Zn, Eu, Am, Th and Se) in clay and cement systems are being conducted. The sorption and modelling studies are combined with kinetic investigations and advanced spectroscopic and microscopic methods in order to understand the sorption mechanism on an atomic level. This approach is part of a new multidisciplinary research field called Molecular Environmental Science (MES). In this paper, a case study of Ni sorption on montmorillonite is presented to illustrate how EXAFS can be used successfully to better understand sorption processes. (author)

  8. Determination of sorption mechanisms of radionuclides onto clay minerals using extended x-ray absorption fine structure (EXAFS) spectroscopy

    International Nuclear Information System (INIS)

    Daehn, R.; Scheidegger, A.; Baeyens, B.; Bradbury, M.H.

    2001-01-01

    Much of the experimental work in the Waste Management Laboratory at PSI concentrates on trying to understand the processes and mechanisms which govern the release of safety-relevant radionuclides from waste matrices, and their transport through engineered barrier systems and the surrounding geosphere. For this reason, detailed sorption studies of radionuclides (Cs, Sr, Ni, Zn, Eu, Am, Th and Se) in clay and cement systems are being conducted. The sorption and modelling studies are combined with kinetic investigations and advanced spectroscopic and microscopic methods in order to understand the sorption mechanism on an atomic level. This approach is part of a new multidisciplinary research field called Molecular Environmental Science (MES). In this paper, a case study of Ni sorption on montmorillonite is presented to illustrate how EXAFS can be used successfully to better understand sorption processes. (author)

  9. Mineral content analysis of root canal dentin using laser-induced breakdown spectroscopy

    Science.gov (United States)

    2018-01-01

    Objectives This study aimed to introduce the use of laser-induced breakdown spectroscopy (LIBS) for evaluation of the mineral content of root canal dentin, and to assess whether a correlation exists between LIBS and scanning electron microscopy/energy dispersive spectroscopy (SEM/EDS) methods by comparing the effects of irrigation solutions on the mineral content change of root canal dentin. Materials and Methods Forty teeth with a single root canal were decoronated and longitudinally sectioned to expose the canals. The root halves were divided into 4 groups (n = 10) according to the solution applied: group NaOCl, 5.25% sodium hypochlorite (NaOCl) for 1 hour; group EDTA, 17% ethylenediaminetetraacetic acid (EDTA) for 2 minutes; group NaOCl+EDTA, 5.25% NaOCl for 1 hour and 17% EDTA for 2 minutes; a control group. Each root half belonging to the same root was evaluated for mineral content with either LIBS or SEM/EDS methods. The data were analyzed statistically. Results In groups NaOCl and NaOCl+EDTA, the calcium (Ca)/phosphorus (P) ratio decreased while the sodium (Na) level increased compared with the other groups (p LIBS and SEM/EDS analyses (r = 0.84, p LIBS method proved to be reliable while providing data for the elemental composition of root canal dentin. PMID:29487841

  10. Mineral content as a basis for food selection by western lowland gorillas in a forest clearing.

    Science.gov (United States)

    Magliocca, Florence; Gautier-Hion, Annie

    2002-06-01

    The forests in northwest Republic of Congo contain a number of herbaceous swamp clearings that provide foraging sites for lowland gorillas (G.g. gorilla). A 10-month study at the Maya Nord clearing (Parc National d'Odzala) showed that feeding activities occupied 72% of the time visiting gorillas spent on the clearing. They fed on four plant species: Enydra fluctuans (Asteraceae), Cyperus sp., Pycreus mundtii, and Rhynchospora corymbosa (Cyperaceae) among the 45 species recorded on the clearing. These clearing food species have higher mineral contents (especially Na and Ca) than the dominant Marantaceae species (Haumania liebrechtsiana) that constituted a staple food plant for gorillas in this forest. They also have higher potassium contents and contain less lignin than non-eaten clearing items/species. Finally, the most actively searched for clearing food (Enydra fluctuans) was characterized by the highest amount of Na and Ca. These results suggest that the mineral content (especially in Na, Ca, and/or K) could determine the feeding selectivity of gorillas at the clearing. They also tend to confirm that the amount of fiber plays a deterrent role in food selectivity, as has been found by many authors. The high density of gorillas in that region could result from the combination of the large areas of Marantaceae forests that provide abundant though monotonous food, and the number of clearings that provide sufficient mineral supplies. Clearings should thus be considered as key habitats for the conservation of gorillas. Copyright 2002 Wiley-Liss, Inc.

  11. A retrospective analysis of longitudinal changes in bone mineral content in cystic fibrosis.

    Science.gov (United States)

    Chirita-Emandi, Adela; Shepherd, Sheila; Kyriakou, Andreas; McNeilly, Jane D; Dryden, Carol; Corrigan, Donna; Devenny, Anne; Ahmed, Syed Faisal

    2017-08-28

    We aimed to describe the longitudinal changes in bone mineral content and influencing factors, in children with cystic fibrosis (CF). One hundred children (50 females) had dual X-ray absorptiometry (DXA) performed. Of these, 48 and 24 children had two to three scans, respectively over 10 years of follow-up. DXA data were expressed as lumbar spine bone mineral content standard deviation score (LSBMCSDS) adjusted for age, gender, ethnicity and bone area. Markers of disease, anthropometry and bone biochemistry were collected retrospectively. Baseline LSBMCSDS was >0.5 SDS in 13% children, between -0.5; 0.5 SDS, in 50% and ≤-0.5 in the remainder. Seventy-eight percent of the children who had baseline LSBMCSDS >-0.5, and 35% of the children with poor baseline (LSBMCSDS0.5), showed decreasing values in subsequent assessments. However, mean LS BMC SDS did not show a significant decline in subsequent assessments (-0.51; -0.64; -0.56; p=0.178). Lower forced expiratory volume in 1 s percent (FEV1%) low body mass index standard deviation scores (BMI SDS) and vitamin D were associated with reduction in BMC. Bone mineral content as assessed by DXA is sub-optimal and decreases with time in most children with CF and this study has highlighted parameters that can be addressed to improve bone health.

  12. Mineral and water content of A. gigas scales determine local micromechanical properties and energy dissipation mechanisms

    Science.gov (United States)

    Troncoso, Omar P.; Gigos, Florian; Torres, Fernando G.

    2017-11-01

    Arapaima gigas scales are natural laminated composite materials made of individual layers with different degrees of mineralization, accompanied of varying mechanical properties. This natural design provides scales with hardness and flexibility, and can serve as a source of inspiration for the development of new layered composites with a hard surface and flexible base. In this paper, we have carried out cyclic micro-indentation tests on both; the internal and the highly mineralized external surface of air dried and wet scales, in order to assess the variation of their local micromechanical properties with regard to the mineral and water content. The load-penetration (P-h) curves showed that creep takes place throughout the application of a constant force during the micro-indentation tests, confirming the time dependent response of A. gigas scales. A model that accounted for the elastic, plastic and viscous responses of the samples was used to fit the experimental results. The penetration depth during loading and creep, as well as the energy dissipated are dependent on the water content. The used model suggests that the viscous response of the internal layer increases with the water content.

  13. Physico-chemical properties, antioxidant activity and mineral contents of pineapple genotypes grown in china.

    Science.gov (United States)

    Lu, Xin-Hua; Sun, De-Quan; Wu, Qing-Song; Liu, Sheng-Hui; Sun, Guang-Ming

    2014-06-23

    The fruit physico-chemical properties, antioxidant activity and mineral contents of 26 pineapple [Ananas comosus (L.) Merr.] genotypes grown in China were measured. The results showed great quantitative differences in the composition of these pineapple genotypes. Sucrose was the dominant sugar in all 26 genotypes, while citric acid was the principal organic acid. Potassium, calcium and magnesium were the major mineral constituents. The ascorbic acid (AsA) content ranged from 5.08 to 33.57 mg/100 g fresh weight (FW), while the total phenolic (TP) content varied from 31.48 to 77.55 mg gallic acid equivalents (GAE)/100 g FW. The two parameters in the predominant cultivars Comte de Paris and Smooth Cayenne were relative low. However, MD-2 indicated the highest AsA and TP contents (33.57 mg/100 g and 77.55 mg GAE/100 g FM, respectively), and it also showed the strongest antioxidant capacity 22.85 and 17.30 μmol TE/g FW using DPPH and TEAC methods, respectively. The antioxidant capacity of pineapple was correlated with the contents of phenolics, flavonoids and AsA. The present study provided important information for the further application of those pineapple genotypes.

  14. Modelling of the physico-chemical behaviour of clay minerals with a thermo-kinetic model taking into account particles morphology in compacted material.

    Science.gov (United States)

    Sali, D.; Fritz, B.; Clément, C.; Michau, N.

    2003-04-01

    Modelling of fluid-mineral interactions is largely used in Earth Sciences studies to better understand the involved physicochemical processes and their long-term effect on the materials behaviour. Numerical models simplify the processes but try to preserve their main characteristics. Therefore the modelling results strongly depend on the data quality describing initial physicochemical conditions for rock materials, fluids and gases, and on the realistic way of processes representations. The current geo-chemical models do not well take into account rock porosity and permeability and the particle morphology of clay minerals. In compacted materials like those considered as barriers in waste repositories, low permeability rocks like mudstones or compacted powders will be used : they contain mainly fine particles and the geochemical models used for predicting their interactions with fluids tend to misjudge their surface areas, which are fundamental parameters in kinetic modelling. The purpose of this study was to improve how to take into account the particles morphology in the thermo-kinetic code KINDIS and the reactive transport code KIRMAT. A new function was integrated in these codes, considering the reaction surface area as a volume depending parameter and the calculated evolution of the mass balance in the system was coupled with the evolution of reactive surface areas. We made application exercises for numerical validation of these new versions of the codes and the results were compared with those of the pre-existing thermo-kinetic code KINDIS. Several points are highlighted. Taking into account reactive surface area evolution during simulation modifies the predicted mass transfers related to fluid-minerals interactions. Different secondary mineral phases are also observed during modelling. The evolution of the reactive surface parameter helps to solve the competition effects between different phases present in the system which are all able to fix the chemical

  15. Influence of bone marrow fat on the determination of bone mineral content by QCT

    International Nuclear Information System (INIS)

    Ikeda, Toshiaki; Sakurai, Kiyoko

    1994-01-01

    Single-energy quantitative CT (SEQCT) is thought to be suitable for long-term observation of changes in bone mineral content in individual patients. However, in patients with osteoporosis, an increase in bone marrow fat cannot be ignored. The relationship between bone marrow fat and bone mineral density (BMD) at different tube voltages of 80 kV and 120 kV was investigated using a set of solution phantoms that we devised, and was also studied in healthy volunteers. On the basis of the results obtained using the solution phantoms, the influence of bone marrow fat accounted for a decrease of 8.9 mg/cm 3 in BMD value at 80 kV and of 10.8 mg/cm 3 at 120 kV in the presence of 10 vol% fat. These findings suggested that the influence of fat was less at a lower tube voltage. The formulas used to estimate the true bone mineral and fat contents from the BMD values at low and high tube voltages were derived by eliminating the influence of beam hardening. Using these formulas, we studied healthy volunteers, and found that the difference between the true BMD value and the BMD value calibrated for beam hardening averaged 17.8 mg/cm 3 at 80 kV and 22.6 mg/cm 3 at 120 kV. Moreover, the estimated concentration of bone marrow fat in the volunteers averaged 25.0 vol%. In conclusion, because SEQCT performed at a low tube voltage is less influenced by bone marrow fat, it should be selected for assessment of the clinical response to therapy and for studying sequential changes. However, in patients with a low bone mineral content indicated by SEQCT, it would be worthwhile trying to estimate both true mineral and fat contents in bone using the formulas obtained in this study in order to differentiate decrease in bone mineral from interference by bone marrow fat. (author)

  16. Substantiation of the hydrodynamic disintegration of hydraulic fluid’s mineral component of high-clay sand in precious metals placers

    Directory of Open Access Journals (Sweden)

    N.P. Khrunina

    2018-03-01

    Full Text Available General regularities and theoretical approaches determining hydroimpulsive effects on the mineral component of the hydraulic fluid are analyzed, with reference to the disintegration of high-clay sands of gold-bearing placers. Theoretical conclusions on the hydrodynamic effect on the solid component of the hydraulic fluid give insight into emerging processes in multicomponent media under hydrodynamic influences initiated by various sources of physical and mechanical influence. It is noted that the theoretical justification of the structurally complex hydrodynamic effect on the hydraulic fluid with the formation of phenomena arising from the collision of solid components with each other and obstacles includes the consideration of changes in such force characteristics as speed, pressure, flow power, and also changes in design parameters and characteristics of the environment. A conceptual approach is given to the theoretical substantiation of the disintegration of the hydraulic fluid’s mineral component using the example of the proposed installation. Calculation of economic indicators for the use of a hydrodynamic generator in comparison with processes based on known technologies has shown significant advantages of using the proposed installation, which can increase productivity and quality production indicators.

  17. Characterization of karak clay from pakistan for pharmaceutical and cosmetic applications

    International Nuclear Information System (INIS)

    Shah, L.A.; Silva-Valenzuela, M.G.; Valenzuela-Diaz, F.R.; Sayeg, I.J.; Carvalho, F.M.S.

    2012-01-01

    Full text: Clay, the most important, plentiful, and low cost naturally occurring mineral, is widely used in variety of industrial application including Pharmaceutical and cosmetic. Clay is the fine grained aluminosilicate mineral which shows the property of plasticity at appropriate water content, and becomes hard upon drying. In Pakistan there are different types of clay but till now neither of them properly identified nor characterize for specific industrial application. The objective of this work is to characterize Karak clay for pharmaceutical and cosmetic applications collected from deposit located at Shagai region, District Karak, Pakistan. The clay was characterized through Xray diffractometry (XRD), X-ray Fluorescence (XRF), trace elemental Analysis, Microbiological analysis, Cation exchange capacity (CEC), pH and swelling assays according to European, United States of America and Brazilian Pharmacopeias. Bulk Chemical analysis shows that the Aluminum oxide and silica oxide are present in large quantity which was confirmed by XRD that this sample has montmorillonite as a major while illite and kaolinite as minor clay minerals. Quartz of small quantity was also found as a non-clay mineral. After analyzing the results for sample it was concluded that the clay is a strong candidate for cosmetic purposes. (author)

  18. Evaluation of Acid Digestion Procedures to Estimate Mineral Contents in Materials from Animal Trials

    Directory of Open Access Journals (Sweden)

    M. N. N. Palma

    2015-11-01

    Full Text Available Rigorously standardized laboratory protocols are essential for meaningful comparison of data from multiple sites. Considering that interactions of minerals with organic matrices may vary depending on the material nature, there could be peculiar demands for each material with respect to digestion procedure. Acid digestion procedures were evaluated using different nitric to perchloric acid ratios and one- or two-step digestion to estimate the concentration of calcium, phosphorus, magnesium, and zinc in samples of carcass, bone, excreta, concentrate, forage, and feces. Six procedures were evaluated: ratio of nitric to perchloric acid at 2:1, 3:1, and 4:1 v/v in a one- or two-step digestion. There were no direct or interaction effects (p>0.01 of nitric to perchloric acid ratio or number of digestion steps on magnesium and zinc contents. Calcium and phosphorus contents presented a significant (p0.01 calcium or phosphorus contents in carcass, excreta, concentrate, forage, and feces. Number of digestion steps did not affect mineral content (p>0.01. Estimated concentration of calcium, phosphorus, magnesium, and zinc in carcass, excreta, concentrated, forage, and feces samples can be performed using digestion solution of nitric to perchloric acid 4:1 v/v in a one-step digestion. However, samples of bones demand a stronger digestion solution to analyze the mineral contents, which is represented by an increased proportion of perchloric acid, being recommended a digestion solution of nitric to perchloric acid 2:1 v/v in a one-step digestion.

  19. Effects of clay minerals and organic matter in formulated sediments on the bioavailability of sediment-associated uranium to the freshwater midge, Chironomus dilutus

    Energy Technology Data Exchange (ETDEWEB)

    Crawford, Sarah E., E-mail: sarah.crawford@usask.ca [Toxicology Centre, University of Saskatchewan, 44 Campus Drive, Saskatoon, SK S7N 5B3 (Canada); Liber, Karsten, E-mail: karsten.liber@usask.ca [Toxicology Centre, University of Saskatchewan, 44 Campus Drive, Saskatoon, SK S7N 5B3 (Canada); School of Environment and Sustainability, 117 Science Place, University of Saskatchewan, Saskatoon, SK S7N 5C8 (Canada); Institute of Loess Plateau, 92 Wucheng Road, Shanxi University, Taiyuan, Shanxi 030006 (China)

    2015-11-01

    It is well established that bioavailability influences metal toxicity in aquatic ecosystems. However, the factors and mechanisms that influence uranium (U) bioavailability and toxicity in sediment have not been thoroughly evaluated, despite evidence that suggests different sediment components can influence the sorption and interaction of some metals. Given that dissolved U is generally accepted as being the primary bioavailable fraction of U, it is hypothesized that adsorption and interaction of U with different sediment components will influence the bioavailability of U in sediment. We investigated the effects of key sediment physicochemical properties on the bioavailability of U to a model freshwater benthic invertebrate, Chironomus dilutus. Several 10-day spiked sediment bioaccumulation experiments were performed, exposing C. dilutus larvae to a variety of formulated sediments spiked with different concentrations of U (5, 50 and/or 200 mg U/kg d.w.). Mean accumulation of U in C. dilutus larvae decreased significantly from 1195 to 10 mg U/kg d.w. as kaolin clay content increased from 0% to 60% in sediment spiked with 50 mg U/kg d.w. Similarly, higher organic matter content also resulted in a significant reduction of U bioaccumulation in C. dilutus larvae, indicating a reduction in U bioavailability. Concentrations of U in both the overlying water and sediment pore water displayed a strong positive relationship to U bioaccumulation in C. dilutus larvae (r{sup 2} = 0.77, p < 0.001 and r{sup 2} = 0.57, p < 0.001, respectively) for all experiments, while total U concentrations in the sediment had a poor relationship to U bioaccumulation (r{sup 2} = 0.10, p = 0.028). Results from this research confirm that sediment clay and organic matter content play a significant role in altering U bioavailability, which is important in informing risk assessments of U contaminated sites and in the development of site-specific sediment quality guidelines for U. - Highlights: • We

  20. Association of Protein Intake with Bone Mineral Density and Bone Mineral Content among Elderly Women: The OSTPRE Fracture Prevention Study.

    Science.gov (United States)

    Isanejad, M; Sirola, J; Mursu, J; Kröger, H; Tuppurainen, M; Erkkilä, A T

    2017-01-01

    It has been hypothesized that high protein intakes are associated with lower bone mineral content (BMC). Previous studies yield conflicting results and thus far no studies have undertaken the interaction of body mass index (BMI) and physical activity with protein intakes in relation to BMC and bone mineral density (BMD). To evaluate the associations of dietary total protein (TP), animal protein (AP) and plant protein (PP) intakes with BMC and BMD and their changes. We tested also the interactions of protein intake with, obesity (BMI ≤30 vs. >30 kg/m2) and physical activity level (passive vs. active). Design/ Setting: Prospective cohort study (Osteoporosis Risk-Factor and Fracture-Prevention Study). Participants/measures: At the baseline, 554 women aged 65-72 years filled out a 3-day food record and a questionnaire covering data on lifestyle, physical activity, diseases, and medications. Intervention group received calcium 1000 mg/d and cholecalciferol 800 IU for 3 years. Control group received neither supplementation nor placebo. Bone density was measured at baseline and year 3, using dual energy x-ray absorptiometry. Multivariable regression analyses were conducted to examine the associations between protein intake and BMD and BMC. In cross-sectional analyses energy-adjusted TP (P≤0·029) and AP (P≤0·045) but not PP (g/d) were negatively associated with femoral neck (FN) BMD and BMC. Women with TP≥1·2 g/kg/body weight (BW) (Ptrend≤0·009) had lower FN, lumbar spine (LS) and total BMD and BMC. In follow-up analysis, TP (g/kg/BW) was inversely associated with LS BMD and LS BMC. The detrimental associations were stronger in women with BMI30 kg/m2 and physical activity.

  1. The effect of type, concentration and volume of dispersing agent on the magnitude of the clay content determined by the hydrometer analysis

    OpenAIRE

    Kaur, A; Fanourakis, G C

    2016-01-01

    Knowledge of the physical properties of soils, including the clay content, is of utmost importance in the field of geotechnical engineering. The hydrometer analysis is the most widely used technique for the analysis of the particle size distribution of the fine-grained fraction of a soil, calculated using sedimentation principles. The hydrometer analysis utilises a dispersing agent - Calgon 33:7 (comprising 33 grams of sodium hexametaphosphate and 7 grams of sodium carbonate when mixed in 1 l...

  2. Sugar Profile, Mineral Content, and Rheological and Thermal Properties of an Isomerized Sweet Potato Starch Syrup

    Directory of Open Access Journals (Sweden)

    Brunson Dominque

    2013-01-01

    Full Text Available Currently, corn is used to produce more than 85% of the world’s high fructose syrup (HFS. There is a search for alternative HFS substrates because of increased food demand and shrinking economies, especially in the developing world. The sweet potato is a feasible, alternative raw material. This study isomerized a high glucose sweet potato starch syrup (SPSS and determined its sugar profile, mineral content, and rheological and thermal properties. Rheological and thermal properties were measured using a rheometer and DSC, respectively. Sweet potato starch was hydrolyzed to syrup with a mean fructose content of 7.6±0.4%. The SPSS had significantly higher (P<0.05 mineral content when compared to commercial ginger and pancake syrups. During 70 days of storage, the SPSS acted as a non-Newtonian, shear-thinning liquid in which the viscosity decreased as shear stress increased. Water loss temperature of the SPSS continually decreased during storage, while pancake and ginger syrups’ peak water loss temperature decreased initially and then increased. Further and more detailed studies should be designed to further enhance the fructose content of the syrup and observe its stability beyond 70 days. The SPSS has the potential to be used in human food systems in space and on Earth.

  3. Heavy metal content and potential health risk of geophagic white clay from the Kumasi Metropolis in Ghana

    Directory of Open Access Journals (Sweden)

    Marian Asantewah Nkansah

    Full Text Available Geophagia is the craving for non-food substances and commonly practiced among pregnant women and children. Consumption of geophagic clay samples can have serious implications on the health of the consumers as a result of the presence of toxic metals such as Pb, As, Hg and Cd. This study sought to determine the levels of heavy metals in the studied geophagic clay samples and to determine the potential risks of heavy metals as cumulative carcinogenic and non-carcinogenic risks to the health of the consumers via oral (ingestion and dermal exposure routes. A total of thirty (30 white clay samples were analysed using Niton Thermo scientific XRF Analyser (Mobile Test S, NDTr-XL3t-86956, com 24. The clay samples were found to contain essential elements such as Ca, Fe, K and Zn as well as toxic metals such as As and Pb. There were isolated cases of the presence of Hg and all samples had Cd levels below detection. Health risk indices such as hazard quotient and cancer risk were calculated and the results indicated that consumers are likely to suffer from cancer through ingestion of geophagic clay. Bioaccessibility studies were done on zinc and it did not indicate any potential toxicity due to zincs essential nature. The levels of heavy metals in some of the geophagic clay consumed by some residents in the Kumasi were high compared to the Permitted Maximum Tolerable Daily Intake (PMTDI by (WHO/FAO and may pose potential health threat over time. Keywords: Geophagia, White clay, Heavy metals, Health risk assessment, Permitted maximum tolerable daily intake

  4. Possible influence of clay contamination on B isotope geochemistry of carbonaceous samples

    International Nuclear Information System (INIS)

    Deyhle, Annette; Kopf, Achim

    2004-01-01

    The authors report results from an experimental study on mixtures of pure endmembers of natural clay and carbonate. The scientific rationale is an evaluation as to what extent B contents and B isotopes of carbonate samples may be obscured as a result of contamination with clay, particularly since both authigenic carbonates and biogenic carbonates (e.g. microfossil tests) often contain some clay. Three aliquots of a series of samples (each containing 0, 20, 40, 60, 80, 100% clay) were analyzed. Set 1 was washed with distilled, de-ionized water; for set 2 the HCl soluble parts were dissolved in 2 M HCl after washing; set 3 was completely digested with 30M HF prior to a series of ion exchanges. Isotope data of the endmembers are 6.6 per mille (100% marble) and -4.6%o (100% clay), with the clay being the dominant B source (ca. 50 ppm compared with 11 B adsorbed =12.9-14.1%o±0.5%o), while no B was mobilized from the carbonate. The HCl-dissolvable B in washed samples of set 2 show slightly increasing B contents with higher clay contents, suggesting that dissolution of the marble as well as B mobilization from the clay account for this trend. δ 11 B isotopes tend towards more negative values when clay content increases, indicating that some structurally-bound B is lost from the sheets of linked (Si, Al)O 4 tetrahedra of the clay mineral. This result shows that not only B adsorption, but possibly diffusion or weathering of broken edges of clay minerals releases some structurally bound B of clay minerals. Set 3, where bulk samples were completely HF-digested, shows as expected a linear increase in B concentrations and decreasing δ 11 B ratios with increasing clay content. The overall results suggest that relatively small amounts of clay (e.g. as contamination in a microfossil test) have no significant impact on the B content and δ 11 B measured for the carbonate, but that care has to be taken if clay exceeds 10wt.% (e.g. carbonate concretions, chimneys, etc.)

  5. Effect of Probiotics Supplementation on Bone Mineral Content and Bone Mass Density

    Directory of Open Access Journals (Sweden)

    Kolsoom Parvaneh

    2014-01-01

    Full Text Available A few studies in animals and a study in humans showed a positive effect of probiotic on bone metabolism and bone mass density. Most of the investigated bacteria were Lactobacillus and Bifidobacterium . The positive results of the probiotics were supported by the high content of dietary calcium and the high amounts of supplemented probiotics. Some of the principal mechanisms include (1 increasing mineral solubility due to production of short chain fatty acids; (2 producing phytase enzyme by bacteria to overcome the effect of mineral depressed by phytate; (3 reducing intestinal inflammation followed by increasing bone mass density; (4 hydrolysing glycoside bond food in the intestines by Lactobacillus and Bifidobacteria. These mechanisms lead to increase bioavailability of the minerals. In conclusion, probiotics showed potential effects on bone metabolism through different mechanisms with outstanding results in the animal model. The results also showed that postmenopausal women who suffered from low bone mass density are potential targets to consume probiotics for increasing mineral bioavailability including calcium and consequently increasing bone mass density.

  6. Ab-Initio Modelling Of Surface Site Reactivity And Fluid Transport In Clay Minerals Case Study: Pyrophyllite

    International Nuclear Information System (INIS)

    Churakov, S.V.

    2005-01-01

    Pyrophyllite, Al 2 [Si 4 O 10 ](OH) 2 , is the simplest structural prototype for 2:1 dioctahedral phyllosilicate. Because the net electric charge in pyrophyllite is zero, it is the best candidate for investigating the non electrostatic contribution to sorption and transport phenomena in clays. Using ab-initio simulations, we have investigated the reactivity and structure of the water-solid interface on the basal plane and edge sites of pyrophyllite. The calculations predict slightly hydrophobic behaviour of the basal plane. For the high water coverage (100), (110) and (-110), lateral facets have a lower energy than for the (010), (130) and (-130) surfaces. Analysis of the surface reactivity reveals that the =Al-OH groups are most easily protonated on the (010), (130) and (-130) facets. The =Al-O-Si= sites will be protonated on the (100), (130), (110), (-110) and (-130) surfaces. The =Al-OH 2 complexes are more easily de-protonated than the =Si-OH and =Al-OH sites. A spontaneous, reversible exchange of the protons between the solution and the edge sites has been observed in ab-initio molecular dynamics simulations at 300 K. Such near-surface proton diffusion may result in a significant contribution to the diffusion coefficients measured in neutron scattering experiments. (author)

  7. Measurement of hand bone mineral content using single-photon absorptiometry

    International Nuclear Information System (INIS)

    Nicoll, J.J.; Smith, M.A.; Law, E.; Tothill, P.; Reid, D.; Brown, N.; Nuki, G.

    1987-01-01

    A single photon absorption imaging technique has been developed to assess the bone mass of the hand, especially in patients with rheumatoid arthritis or bronchial asthma. A modified rectilinear scanner images the hand by transmission scanning in a water bath with a 7.4 GBq 125 I source. A microcomputer is used to calculate the bone mineral distribution, and the total bone mineral content (BMC) of the hand is determined from that distribution. The precision (coefficient of variation) of the measurement is 1.9%. A control population of 20 men and 58 women has been studied to determine normal variations in hand bone mineral content with age, sex, body size, hand volume and years since menopause. The normal men are found to have an average hand BMC of 25.1 g with a coefficient of variation (CV) of 22%, which is reduced to 12% by normalising for body size using span. The normal women had an average hand BMC of 18.0 g +- 15%. The CV is reduced to 13% by normalising for span and years post-menopause. (author)

  8. An objective algorithm for the determination of bone mineral content using dichromatic absorptiometry

    International Nuclear Information System (INIS)

    Appledorn, C.R.; Witt, R.M.; Wellman, H.N.; Johnston, C.C.

    1985-01-01

    The determination of vertebral column bone mineral content by dual photon absorptiometric methods is a problem of continued clinical interest. The more successful methods suffer from the frequent need of operator interaction in order to maintain good precision results. The authors have introduced a new objective algorithm that eliminates the subjectiveness of operator interaction without sacrificing reproducibility. The authors' system consists of a modified rectilinear scanner interfaced to a CAMAC acquisition device coupled to a PDP-11V03 minicomputer. The subject is scanned in the supine position with legs elevated to minimize lordosis. The source (Gd-153) and detector are collimated defining an area of 10mm x 10mm at the level of the spine. The transverse scan width is usually 120 mm. Scanning from the iliac crests toward the head, 50 transverses at 3mm y-increments are acquired at approximately 1mm increments. The data analysis begins with the calculation of R-value for each pixel in the scan. The calculations for bone mineral content are performed and various quantities are accumulated. In a reproducibility study of 116 patient studies, the authors achieved a bone mineral/bone area ratio precision (std dev/mean) of 1.37% without operator interaction nor vertebral body selection

  9. OPAQUE MINERAL CONTENT OF DUTLUCA VOLCANICS (BURHANİYE - BALIKESİR: THE EFFECT OF HYDROTHERMAL ALTERATION ON THESE MINERALS

    Directory of Open Access Journals (Sweden)

    Şükrü KOÇ

    2016-12-01

    Full Text Available Dutluca volcanics, which are known as Hallaçlar Formation in regional scale in the study area (Kurshens- ky, 1976, are composed of hydrothermally altered andesite and basaltic andesite. In these rocks, sulfidic minerals such as pyrite, enargite and chalcosine, and oxide and hydroxide minerals such as magnetite, hematite and goethite were detected as opaque minerals. The presence of enargite in opaque mineral para- genesis, and the changes observed in structures and textures of opaque and silicate minerals indicate that examined volcanics have been altered by highly sulfidic hydrothermal solutions. During the hydrothermal alteration process, which indicates at least in two phases, a diffuse pyritization rich in H S in reducing conditions and enargite mineral, which is known as pathfinder minerals in such processes, formed in the first phase. Later on; the extensive martitization developed in oxidizing conditions.

  10. Local differences in mineral content in vertebral trabecular bone measured by dual-energy computed tomography

    International Nuclear Information System (INIS)

    Nepper-Rasmussen, J.; Mosekilde, L.; Aarhus Univ.

    1989-01-01

    Twelve lumbar vertebral bodies from cadavers were examined with dual-energy CT, to measure the calcium content in a big central region of interest (ROI). In each of five vertebrae the calcium content was also measured in six small ROI. After completed scanning, six small cylinders were drilled out from each vertebra, and the ash-density of each cylinder was measured. The dual-energy CT measurements correlated well with the ash-density. Both ash-density and dual-energy CT showed a significantly higher mineral content in the posterior part of the vertebrae than in the anterior part, and this difference might be responsible for problems encountered with the reproducibility of dual-energy CT. (orig.)

  11. Influence of somatic cell count on mineral content and salt equilibria of milk

    Directory of Open Access Journals (Sweden)

    Primo Mariani

    2010-01-01

    Full Text Available Aim of this research was to study the effect of somatic cell count on mineral content and salt equilibria at the level of quarter milk samples. Ten Italian Friesian cows, in which two homologous quarters (front quarters in 1 cow, rear quarters in 6 cows and both rear and front quarters in 3 cows were characterised by a milk SCC400,000 cells/mL (HC-milk, respectively, were selected. Cows were milked at quarter level during the morning milking and a single sample was collected from each selected quarter, thus, 26 quarter milk samples were collected. Compared to LC-milk, HC-milk was characterised by a lower content of phosphorus and potassium and by a higher content of both sodium and chloride. The equilibrium of calcium, phosphorus and magnesium between the colloidal and soluble phase of milk and the mineralisation degree of the casein micelles, were not different between HC and LC milk.

  12. Improved process control through real-time measurement of mineral content

    Energy Technology Data Exchange (ETDEWEB)

    Turler, Daniel; Karaca, Murat; Davis, William B.; Giauque, Robert D.; Hopkins, Deborah

    2001-11-02

    In a highly collaborative research and development project with mining and university partners, sensors and data-analysis tools are being developed for rock-mass characterization and real-time measurement of mineral content. Determining mineralogy prior to mucking in an open-pit mine is important for routing the material to the appropriate processing stream. A possible alternative to lab assay of dust and cuttings obtained from drill holes is continuous on-line sampling and real-time x-ray fluorescence (XRF) spectroscopy. Results presented demonstrate that statistical analyses combined with XRF data can be employed to identify minerals and, possibly, different rock types. The objective is to create a detailed three-dimensional mineralogical map in real time that would improve downstream process efficiency.

  13. Clay Play

    Science.gov (United States)

    Rogers, Liz; Steffan, Dana

    2009-01-01

    This article describes how to use clay as a potential material for young children to explore. As teachers, the authors find that their dialogue about the potential of clay as a learning medium raises many questions: (1) What makes clay so enticing? (2) Why are teachers noticing different play and conversation around the clay table as compared to…

  14. Osteoporotic-like effects of cadmium on bone mineral density and content in aged ovariectomized beagles

    International Nuclear Information System (INIS)

    Sacco-Gibson, N.; Abrams, J.; Chaudhry, S.; Hurst, D.; Peterson, D.; Bhattacharyya, M.

    1992-01-01

    Our purpose was to evaluate the effects of ovariectomy in conjunction with cadmium (Cd) exposure on bone. Aged female beagles with 45 Ca-labeled skeletons ovariectomized and exposed to Cd. Successive vertebral scans by dual photon absorptiometry monitored changes in bone mineral density (BMD) in each dog with time. Results showed that ovariectomy or Cd exposure alone caused significant decreases in BMD; ovariectomy with Cd exposure caused the greatest decrease. Ovariectomy alone did not decrease BMD in the distal end or mid-shaft of the tibia while BMD of the distal tibia decreased significantly due to Cd exposure alone. Combination treatment resulted in significant decreases in BMD of both tibial regions. At necropsy, tibiae, humeri, lumbar vertebrae and ribs were obtained for biochemical analysis. No group-to-group differences in bone weights (wet, dry, ash), in ash/dry ratios, or in long bone and vertebral Ca/dry or Ca/ash ratios were observed. Significantly higher total 45 Ca content and 45 Ca/dry and 45 Ca/ash ratios were observed in long bones and vertebrae of OV- and OV+ groups. In contrast, intact ribs showed significantly decreased Ca/dry and Ca/ash ratios compared to the SO-group. Quartered ribs demonstrated regional responses to specific treatment; decreases in total Ca content were greatest in the mid-rib region (-36 to -46%). Results suggest that in the aged female beagle, bone mineral loss associated with estrogen depletion is not only related to bone type (trabecular versus cortical) but also to bone Ca pools. Our results also suggest that a regional heterogeneity of bone plays a role in responsiveness to ovariectomy and Cd exposure. These aspects suggest that Cd is an exogenous factor affecting bone mineral loss independently of estrogen depletion. However, estrogen depletion primes bone for responsiveness to Cd-induced bone mineral loss

  15. Osteoporotic-like effects of cadmium on bone mineral density and content in aged ovariectomized beagles

    Energy Technology Data Exchange (ETDEWEB)

    Sacco-Gibson, N.; Abrams, J.; Chaudhry, S.; Hurst, D.; Peterson, D.; Bhattacharyya, M.

    1992-12-31

    Our purpose was to evaluate the effects of ovariectomy in conjunction with cadmium (Cd) exposure on bone. Aged female beagles with {sup 45}Ca-labeled skeletons ovariectomized and exposed to Cd. Successive vertebral scans by dual photon absorptiometry monitored changes in bone mineral density (BMD) in each dog with time. Results showed that ovariectomy or Cd exposure alone caused significant decreases in BMD; ovariectomy with Cd exposure caused the greatest decrease. Ovariectomy alone did not decrease BMD in the distal end or mid-shaft of the tibia while BMD of the distal tibia decreased significantly due to Cd exposure alone. Combination treatment resulted in significant decreases in BMD of both tibial regions. At necropsy, tibiae, humeri, lumbar vertebrae and ribs were obtained for biochemical analysis. No group-to-group differences in bone weights (wet, dry, ash), in ash/dry ratios, or in long bone and vertebral Ca/dry or Ca/ash ratios were observed. Significantly higher total {sup 45}Ca content and {sup 45}Ca/dry and {sup 45}Ca/ash ratios were observed in long bones and vertebrae of OV- and OV+ groups. In contrast, intact ribs showed significantly decreased Ca/dry and Ca/ash ratios compared to the SO-group. Quartered ribs demonstrated regional responses to specific treatment; decreases in total Ca content were greatest in the mid-rib region ({minus}36 to {minus}46%). Results suggest that in the aged female beagle, bone mineral loss associated with estrogen depletion is not only related to bone type (trabecular versus cortical) but also to bone Ca pools. Our results also suggest that a regional heterogeneity of bone plays a role in responsiveness to ovariectomy and Cd exposure. These aspects suggest that Cd is an exogenous factor affecting bone mineral loss independently of estrogen depletion. However, estrogen depletion primes bone for responsiveness to Cd-induced bone mineral loss.

  16. Ovariectomy-induced changes in aged beagles: Histomorphometry and mineral content of the rib

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, A.K.; Bhattacharyya, M.H.; Hurst, D. [Argonne National Lab., IL (United States). Center for Mechanistic Biology and Biotechnology; Miller, S. [Univ. of Utah, Salt Lake City, UT (United States). Radiobiology Div.; Sacco-Gibson, N. [Proctor and Gamble Pharmaceuticals, Cincinnati, OH (United States)

    1997-08-01

    The effects of ovariectomy on the aged beagle skeleton were studied by histomorphometric analysis of the cortical bone in sequential rib biopsies. Biopsies were taken from each ovariectomized (OV) or sham-operated (SO) dog at the time of surgery and at 1, 4, and 8.5 months after surgery. Tetracycline, calcein, and xylenol orange, respectively, were administered by a fluorochrome labeling procedure (2d-10d-2d) just prior to each postoperative biopsy to provide markers of bone formation. Analysis of sequential biopsies provided a means to follow the response to ovariectomy over time and compare each animal against its own baseline. Examination of sequential biopsies indicated that cortical porosity increased by the fourth month after ovariectomy and remained high at 8.5 months. Ovariectomy did not influence histomorphometric indices at one month after surgery, but substantial differences were observed at later times. Ovariectomy stimulated a transient increase in bone formation and was increased six-fold over that of SO dogs at four months. Ribs were also analyzed for mineral content at necropsy. The rib was heterogeneous along its length for calcium content and concentration. In the midrib where biopsies for histomorphometric analysis were taken, ovariectomy induced a decrease in mass and mineral content; total calcium was decreased by approximately 31%. These data demonstrate that the rib cortical bone is a responsive site for the effects of ovariectomy in female dogs.

  17. Bone mineral content (bmc and bone mineral density (bmd in postmenopausal women formerly practising kayaking and fencing

    Directory of Open Access Journals (Sweden)

    B Raczyńska

    2003-06-01

    Full Text Available The investigation was aimed at answering the following questions: 1 Can a prolonged career in sports associated with considerable training loads, in conjunction with other osteoporosis risk factors (both past and present, affect the bone mineral content (BMC and bone mineral density (BMD of the former female athletes in their postmenopausal period of life?, and 2 How does the present lifestyle of the tested women, including physical activity and diet (calcium intake, influence the preservation of the optimal bone mass in these subjects? The postmenopausal subjects recruited to the present study included 15 former athletes (ten kayakers and five fencers and 11 women who never actively engaged in sports (control group. BMC (g and BMD (g/cm2 were densitometrically determined in the lumbar segment (L2-L4 of the spine, and the bone stiffness coefficient was ultrasonically determined in calcaneus. The effects of the osteoporosis risk factors (both past and present were estimated from individual replies to the questionnaire inquiries about the past career in sports, present physical activity, gonadal dysfunctions (dysmenorrhoea during the career and the present need for hormonal supplementary treatment, and the current dietary patterns. The results indicate that mean BMC and BMD values detected in the former athletes did not differ significant from those obtained in the non-athlete, control women: the BMC values equalled to 54.5±10.5, 52.6±14.6, and 46.5±3.2 g in the kayakers, the fencers, and the control women, respectively, while the respective BMD values were 1.05±0.45, 0.96±0.66, and 1.08±0.58 g/cm2. The questionnaire-based studies showed that neither the former female athletes nor the non-athlete controls exhibited in the past longer (i.e., lasting more than three months periods of hormonal disorders (amenorrhoea. As assessed from the dietary intake, only in the former fencers the diet covered the demand for calcium in 100%. In conclusion

  18. Proximate composition, minerals and vitamins content of selected vegetables grown in Peshawar

    International Nuclear Information System (INIS)

    Bangash, J.A.; Arif, M.; Khan, M.A.; Khan, F.; Amin-ur-Rrahma; Hussain, I.

    2011-01-01

    Ten vegetables namely Pot purslane, Spinach, Turnip, Garlic, Mustard (Sarson), Radish, Bitter gourd, Lady finger, Bath sponge and Brinjal were analyzed for their proximate composition, vitamin and mineral contents to evaluate their importance in human nutrition. The results showed that almost all vegetables contain appreciable amount of essential nutrients. The maximum content of moisture, carbohydrate, crude protein, crude fat, crude fiber, and ash recorded in these vegetables was (92.50 %, 26.88 %, 5.0%, 0.40%, 1.4% and 1.9%), respectively, with a minimum content (66.80 %, 3.91 %, 0.7%, 0.08%, 0.4% and 0.38%), respectively. Maximum concentration of macro minerals K, Ca, Mg, and Na, observed was (400, 210, 109, and 55) mg/100 g, respectively, with a minimum concentration (26, 15, 17, and 10) mg/100 g, respectively. Maximum concentration of micro minerals Fe, Cu, Zn, Mn and Cr observed was (29, 0.33, 3.05, 1.70, and 0.36) mg/100 g with a minimum concentration (2, 0.05, 0.43, 0.21, and 0.06) mg/100 g, respectively. Maximum concentration of water soluble vitamins i.e. thiamine, riboflavin, niacin and ascorbic acid recorded was (0.280, 0.190, 0.69, and 65) mg/100 g with a minimum concentration (0.011, 0.015, 0.23, and 4.00) mg/100 g, respectively. From this study it can be concluded that consumption of vegetables in different combinations could provide a reasonable daily recommended amount of essential nutrients for the maintenance of healthy life and normal body functioning. (author)

  19. Effects of glyphosate on the mineral content of glyphosate-resistant soybeans (Glycine max).

    Science.gov (United States)

    Duke, Stephen O; Reddy, Krishna N; Bu, Kaixuan; Cizdziel, James V

    2012-07-11

    There are conflicting claims as to whether treatment with glyphosate adversely affects mineral nutrition of glyphosate-resistant (GR) crops. Those who have made claims of adverse effects have argued links between reduced Mn and diseases in these crops. This article describes experiments designed to determine the effects of a recommended rate (0.86 kg ha(-1)) of glyphosate applied once or twice on the mineral content of young and mature leaves, as well as in seeds produced by GR soybeans (Glycine max) in both the greenhouse and field using inductively coupled plasma mass spectrometry (ICP-MS). In the greenhouse, there were no effects of either one application (at 3 weeks after planting, WAP) or two applications (at 3 and 6 WAP) of glyphosate on Ca, Mg, Mn, Zn, Fe, Cu, Sr, Ba, Al, Cd, Cr, Co, or Ni content of young or old leaves sampled at 6, 9, and 12 WAP and in harvested seed. Se concentrations were too low for accurate detection in leaves, but there was also no effect of glyphosate applications on Se in the seeds. In the field study, there were no effects of two applications (at 3 and 6 WAP) of glyphosate on Ca, Mg, Mn, Zn, Fe, Cu, Sr, Ba, Al, Cd, Cr, Co, or Ni content of young or old leaves at either 9 or 12 WAP. There was also no effect on Se in the seeds. There was no difference in yield between control and glyphosate-treated GR soybeans in the field. The results indicate that glyphosate does not influence mineral nutrition of GR soybean at recommended rates for weed management in the field. Furthermore, the field studies confirm the results of greenhouse studies.

  20. Follow-up of bone mineral contents by single and dual photon absorptiometry

    International Nuclear Information System (INIS)

    Krasznai, Istvan; Lakatos, Peter; Horvath, Csaba; Hollo, Istvan

    1988-01-01

    Quality control, performance and long-range reproducibility of SPA and DPA techniques were tested in model experiments. The relative minimum detectable change in bone mineral content, determined with appropriately checked and calibrated instrument amounts to 2.5-3.0 percent by SPA and 4.0-6.0 percent by DPA. To achieve this potential at least two parallel measurements are needed but in case of long-range measurements following-up measurements have to be repeated at least quarterly. DPA requires the same person to evaluate. (author) 6 refs.; 5 tabs

  1. Minerals

    Science.gov (United States)

    ... Aren't minerals something you find in the earth, like iron and quartz? Well, yes, but small ... canned salmon and sardines with bones leafy green vegetables, such as broccoli calcium-fortified foods — from orange ...

  2. Spectral Assessment of Soil Properties: Standoff Quantification of Soil Organic Matter Content in Surface Mineral Soils and Alaskan Peat

    Science.gov (United States)

    2017-08-01

    Soil Properties Standoff Quantification of Soil Organic Matter Content in Surface Mineral Soils and Alaskan Peat En gi ne er R es ea rc h an d D...ERDC 6.2 GRE ARTEMIS STO-R DRTSPORE ERDC TR-17-9 August 2017 Spectral Assessment of Soil Properties Standoff Quantification of Soil Organic...Matter Content in Surface Mineral Soils and Alaskan Peat Stacey L. Jarvis, Karen L. Foley, Robert M. Jones, Stephen D. Newman, and Robyn A. Barbato

  3. Mineral and heavy metal contents of the outer and inner tissues of commonly used fruits.

    Science.gov (United States)

    Özcan, Mehmet Musa; Harmankaya, Mustafa; Gezgin, Sait

    2012-01-01

    The rate of heavy metal pollution in some minor fruit samples growing at roadsides in Turkey were determined by inductively coupled plasma-atomic emission spectrometry (ICP-AES). The mineral contents of samples were found to be different depending on the several parts Citrus fruits. The highest minor and heavy metal levels for Citrus fruits were determined between 17.24 and 45.30 mg/kg boron, 2.08 and 15.05 mg/kg copper, 1.01 and 16.00 mg/kg iron and 2.35 and 9.87 mg/kg zinc. Boron content ranged from 16.54 mg/kg (Deveci pear inner pulp) to 89.89 mg/kg (Arjantin apple outer skin). The level of Fe ranged from 1.49 mg/kg (quince pulp) to 25.05 mg/kg (Ankara pear pulp). Cu content of fruits ranged between 2.52 mg/kg (Fuji apple skin) and 25.93 mg/kg quince skin). Zn content was found between 0.46 mg/kg (Golden apple pulp) and 14.34 mg/kg (quince skin). P contents ranged from 651 mg/kg (Golden apple pulp) to 1269 mg/kg (quince skin). Na was found between 500 mg/kg (Fuji apple skin) and 907 mg/kg (Arjantin apple skin).

  4. Elastic properties of woven bone: effect of mineral content and collagen fibrils orientation.

    Science.gov (United States)

    García-Rodríguez, J; Martínez-Reina, J

    2017-02-01

    Woven bone is a type of tissue that forms mainly during fracture healing or fetal bone development. Its microstructure can be modeled as a composite with a matrix of mineral (hydroxyapatite) and inclusions of collagen fibrils with a more or less random orientation. In the present study, its elastic properties were estimated as a function of composition (degree of mineralization) and fibril orientation. A self-consistent homogenization scheme considering randomness of inclusions' orientation was used for this purpose. Lacuno-canalicular porosity in the form of periodically distributed void inclusions was also considered. Assuming collagen fibrils to be uniformly oriented in all directions led to an isotropic tissue with a Young's modulus [Formula: see text] GPa, which is of the same order of magnitude as that of woven bone in fracture calluses. By contrast, assuming fibrils to have a preferential orientation resulted in a Young's modulus in the preferential direction of 9-16 GPa depending on the mineral content of the tissue. These results are consistent with experimental evidence for woven bone in foetuses, where collagen fibrils are aligned to a certain extent.

  5. Bone mineral content in the senescent rat femur: an assessment using single photon absorptiometry

    International Nuclear Information System (INIS)

    Kiebzak, G.M.; Smith, R.; Howe, J.C.; Sacktor, B.

    1988-01-01

    The single photon absorptiometry technique was evaluated for measuring bone mineral content (BMC) of the excised femurs of the rat, and the system was used to examine the changes in cortical and trabecular bone from young adult (6 mo), mature adult (12 mo), and senescent (24 mo) male and female animals. BMC of the femur midshaft, representing cortical bone, apparently increased progressively with advancing age. The width of the femur at the scan site also increased with age. Normalizing the midshaft BMC by width partially compensated for the age-associated increase. However, when bone mineral values were normalized by the cortical area at the scan site, to take into account the geometric differences in the femurs of different aged animals, maximum bone densities were found in the mature adult and these values decreased slightly in the femurs from senescent rats. In contrast, the BMC of the femur distal metaphysis, representing trabecular bone, decreased markedly in the aged rat. The loss of trabecular bone was also evident from morphological examination of the distal metaphysis. These findings indicated that bone mineral loss with age was site specific in the rat femur. These studies provided additional evidence that the rat might serve as a useful animal model for specific experiments related to the pathogenesis of age-associated osteopenia

  6. Antioxidant Capacity, Mineral Content and Sensory Properties of Gluten-Free Rice and Buckwheat Cookies

    Directory of Open Access Journals (Sweden)

    Mladenka Pestorić

    2015-01-01

    Full Text Available Light buckwheat flour was used to substitute rice fl our at the level of 10, 20 and 30 % to produce gluten-free cookies. The substitution of gluten-free cookie formulation with light buckwheat fl our contributed to the signifi cantly higher mineral content, especially magnesium, potassium, iron and copper, in comparison with the control rice cookies (p<0.05. Gluten-free cookies made with rice fl our and buckwheat fl our exhibited signifi cantly higher total phenolic and rutin content, scavenging activity against 1,1-diphenyl 2-picrylhydrazyl radicals (DPPH•, antioxidant activity and reducing power than the control cookies (p<0.05. Comparing all evaluated sensory properties, cookies containing 20 % of light buckwheat flour had the most acceptable sensory properties. The obtained results of principal component analysis showed that the cookies with 20 and 30 % buckwheat flour had better antioxidant and sensory properties in comparison with other two cookie samples.

  7. Detailed mineralogical characterization of the Bullfrog and Tram members USW-G1, with emphasis on clay mineralogy

    International Nuclear Information System (INIS)

    Bish, D.L.

    1981-10-01

    The detailed mineralogy of the Bullfrog and Tram Members of the Crater Flat Tuff from drill hole USW-G1 has been examined, primarily to characterize fully the amounts and types of clay minerals in the tuffs and the possible effects clay minerals have on rock properties. Results of bulk sample x-ray diffraction analyses agree closely with previous determinations, although slightly higher clay mineral contents were found in this study. X-ray diffraction analysis of fine fractions revealed that the clay minerals in the tuffs are sodium-saturated montmorillonite-beidellites with typical layer charges and no high-charge layers. These smectites are found in virtually all samples of the Bullfrog and Tram, and there is no correlation between the amounts of smectites and the amounts of zeolite, quartz, and feldspar. Smectites are present in both welded and nonwelded horizons and are scarce in some zones with slight-to-absent welding

  8. Plant litter chemistry alters the content and composition of organic carbon associated with soil mineral and aggregate fractions in invaded ecosystems.

    Science.gov (United States)

    Tamura, Mioko; Suseela, Vidya; Simpson, Myrna; Powell, Brian; Tharayil, Nishanth

    2017-10-01

    Through the input of disproportionate quantities of chemically distinct litter, invasive plants may potentially influence the fate of organic matter associated with soil mineral and aggregate fractions in some of the ecosystems they invade. Although context dependent, these native ecosystems subjected to prolonged invasion by exotic plants may be instrumental in distinguishing the role of plant-microbe-mineral interactions from the broader edaphic and climatic influences on the formation of soil organic matter (SOM). We hypothesized that the soils subjected to prolonged invasion by an exotic plant that input recalcitrant litter (Japanese knotweed, Polygonum cuspidatum) would have a greater proportion of plant-derived carbon (C) in the aggregate fractions, as compared with that in adjacent soil inhabited by native vegetation that input labile litter, whereas the soils under an invader that input labile litter (kudzu, Pueraria lobata) would have a greater proportion of microbial-derived C in the silt-clay fraction, as compared with that in adjacent soils that receive recalcitrant litter. At the knotweed site, the higher C content in soils under P. cuspidatum, compared with noninvaded soils inhabited by grasses and forbs, was limited to the macroaggregate fraction, which was abundant in plant biomarkers. The noninvaded soils at this site had a higher abundance of lignins in mineral and microaggregate fractions and suberin in the macroaggregate fraction, partly because of the greater root density of the native species, which might have had an overriding influence on the chemistry of the above-ground litter input. At the kudzu site, soils under P. lobata had lower C content across all size fractions at a 0-5 cm soil depth despite receiving similar amounts of Pinus litter. Contrary to our prediction, the noninvaded soils receiving recalcitrant Pinus litter had a similar abundance of plant biomarkers across both mineral and aggregate fractions, potentially because of

  9. Impact of Oriented Clay Particles on X-Ray Spectroscopy Analysis

    Science.gov (United States)

    Lim, A. J. M. S.; Syazwani, R. N.; Wijeyesekera, D. C.

    2016-07-01

    Understanding the engineering properties of the mineralogy and microfabic of clayey soils is very complex and thus very difficult for soil characterization. Micromechanics of soils recognize that the micro structure and mineralogy of clay have a significant influence on its engineering behaviour. To achieve a more reliable quantitative evaluation of clay mineralogy, a proper sample preparation technique for quantitative clay mineral analysis is necessary. This paper presents the quantitative evaluation of elemental analysis and chemical characterization of oriented and random oriented clay particles using X-ray spectroscopy. Three different types of clays namely marine clay, bentonite and kaolin clay were studied. The oriented samples were prepared by placing the dispersed clay in water and left to settle on porous ceramic tiles by applying a relatively weak suction through a vacuum pump. Images form a Scanning Electron Microscope (SEM) was also used to show the comparison between the orientation patterns of both the sample preparation techniques. From the quantitative analysis of the X-ray spectroscopy, oriented sampling method showed more accuracy in identifying mineral deposits, because it produced better peak intensity on the spectrum and more mineral content can be identified compared to randomly oriented samples.

  10. Study of alteration in the mechanical properties in hybrid nanocomposite of polypropylene/sisal fibers/mineral clay irradiated with gamma rays

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, Nilson C.; Terence, Mauro C.; Miranda, Leila F., E-mail: nilpereira@mackenzie.com.b [Universidade Presbiteriana Mackenzie, Sao Paulo, SP (Brazil). Escola de Engenharia. Curso de Engenharia de Materiais

    2009-07-01

    A new material class formed with reinforced filler, hybrid of organic and inorganic materials provides the technological development of materials with modified properties. And among great numbers of properties that can be modified by presence of hybrid filler to stand out the tension resistance. Polymer shows behavior of tensions and deformation that are not related of simple form. The answer of this material at mechanicals solicitations depends of structural factors and externals variables. As structural factors can be, for example, molecular weight, ramifications and crosslink. As external variables can be, for example, temperature, time or velocity of deformation, kind of solicitation and others. This work was possible to verify as nanostructures materials behavior, mechanically, after were submitted gamma radiation. This work utilized as polymeric matrix, recycled polypropylene, and as hybrid filler, a mixture of montimorillonite mineral clay with natural sisal fibers. It is known that form to magnify the tensile resistance is increase the number of crosslink of principal chain for gamma radiation. After irradiation the polypropylene was crosslinked structures that are result recombination of radicals formed during process of irradiation. It.s known that radicals formed occur preferentially in the amorphous region of polymer. Considering that polymeric matrix polypropylene, without addition fillers suffer strong structural influence when irradiated, was possible verify change in the extension, tensile strength and also maxim tensile in rupture, when this matrix was incorporated with fillers hybrids. (author)

  11. Study of alteration in the mechanical properties in hybrid nanocomposite of polypropylene/sisal fibers/mineral clay irradiated with gamma rays

    International Nuclear Information System (INIS)

    Pereira, Nilson C.; Terence, Mauro C.; Miranda, Leila F.

    2009-01-01

    A new material class formed with reinforced filler, hybrid of organic and inorganic materials provides the technological development of materials with modified properties. And among great numbers of properties that can be modified by presence of hybrid filler to stand out the tension resistance. Polymer shows behavior of tensions and deformation that are not related of simple form. The answer of this material at mechanicals solicitations depends of structural factors and externals variables. As structural factors can be, for example, molecular weight, ramifications and crosslink. As external variables can be, for example, temperature, time or velocity of deformation, kind of solicitation and others. This work was possible to verify as nanostructures materials behavior, mechanically, after were submitted gamma radiation. This work utilized as polymeric matrix, recycled polypropylene, and as hybrid filler, a mixture of montimorillonite mineral clay with natural sisal fibers. It is known that form to magnify the tensile resistance is increase the number of crosslink of principal chain for gamma radiation. After irradiation the polypropylene was crosslinked structures that are result recombination of radicals formed during process of irradiation. It.s known that radicals formed occur preferentially in the amorphous region of polymer. Considering that polymeric matrix polypropylene, without addition fillers suffer strong structural influence when irradiated, was possible verify change in the extension, tensile strength and also maxim tensile in rupture, when this matrix was incorporated with fillers hybrids. (author)

  12. Impact of medicated feed along with clay mineral supplementation on Escherichia coli resistance to antimicrobial agents in pigs after weaning in field conditions.

    Science.gov (United States)

    Jahanbakhsh, Seyedehameneh; Kabore, Kiswendsida Paul; Fravalo, Philippe; Letellier, Ann; Fairbrother, John Morris

    2015-10-01

    The aim of this study was to examine changes in antimicrobial resistance (AMR) phenotype and virulence and AMR gene profiles in Escherichia coli from pigs receiving in-feed antimicrobial medication following weaning and the effect of feed supplementation with a clay mineral, clinoptilolite, on this dynamic. Eighty E. coli strains isolated from fecal samples of pigs receiving a diet containing chlortetracycline and penicillin, with or without 2% clinoptilolite, were examined for antimicrobial resistance to 15 antimicrobial agents. Overall, an increased resistance to 10 antimicrobials was observed with time. Supplementation with clinoptilolite was associated with an early increase but later decrease in blaCMY-2, in isolates, as shown by DNA probe. Concurrently, a later increase in the frequency of blaCMY-2 and the virulence genes iucD and tsh was observed in the control pig isolates, being significantly greater than in the supplemented pigs at day 28. Our results suggest that, in the long term, supplementation with clinoptilolite could decrease the prevalence of E. coli carrying certain antimicrobial resistance and virulence genes. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Accuracy of lumbar spine bone mineral content by dual photon absorptiometry

    International Nuclear Information System (INIS)

    Gotfredsen, A.; Podenphant, J.; Norgaard, H.; Nilas, L.; Nielsen, V.A.; Christiansen, C.

    1988-01-01

    The accuracy of measurement of the bone mineral content (BMC, g) and bone mineral density (BMD, g/cm 2 ) of the lumbar spine by dual photon absorptiometry (DPA) was estimated by means of two different spine scanners (a Nuclear Data 2100 and a Lunar Radiation DP3). The lumbar spines of 13 cadavers were used. BMC and BMD were measured in situ and on the excised vertebrae in a solution of water/ethanol; and covered with ox muscle/porcine muscle/lard. The actual mineral weight and areal density were determined after chemical maceration, fat extraction, drying to a constant weight, ashing for 24 hr at 600 degrees C, and correction for the transverse processes. The true are was measured by parallax free X rays and planimetry. All measurements of BMC or BMD were highly interrelated (r = 0.94-0.99). The standard error of estimate (s.e.e.) of BMC in situ versus BMC in water/ethanol was 5.2%. The agreement between the BMD values of the two scanners was very good (s.e.e. = 2.9%). BMC in situ predicted the actual vertebral mineral mass with an s.e.e. of 8.1%. BMD in situ and BMD in water/ethanol predicted the actual area density with s.e.e.s of 10.3% and 5.0%, respectively. This study discloses the correlation and accuracy error of spinal DPA measurements in situ in whole cadavers versus the actual BMC and BMD. The error, which is underestimated in in vitro studies, amounts to 10%

  14. Comparative analysis of bone mineral contents with dual-energy quantitative computed tomography

    International Nuclear Information System (INIS)

    Choi, T. J.; Yoon, S. M.; Kim, O. B.; Lee, S. M.; Suh, S. J.

    1997-01-01

    The Dual-Energy Quantitative Computed Tomography(DEQCT) was compared with bone equivalent K 2 HPO 4 standard solution and ash weight of animal cadaveric trabecular bone in the measurement of bone mineral contents(BMC). The attenuation coefficient of tissues highly depends on the radiation energy, density and effective atomic number of composition. The bone mineral content of DEQCT in this experiments was determined from empirical constants and mass attenuation coefficients of bone, fat and soft tissue equivalent solution in two photon spectra. In this experiments, the BMC of DEQCT with 80 and 120kV p X rays was compared to ash weight of animal trabecular bone. We obtained the mass attenuation coefficient of 0.2409, 0.5608 and 0.2206 in 80kV p , and 0.2046, 0.3273 and 0.1971 cm 2 /g in 120kV p X-ray spectra for water, bone and fat equivalent materials, respectively. The BMC with DEQCT was accomplished with empirical constants K 1 =0.3232, K 2 =0.2450 and mass attenuation coefficients has very closed to ash weight of animal trabecular bone. The BMC of empirical DEQCT and that of manufacturing DEQCT were correlated with ash weight as a correlation r=0.998 and r=0.996, respectively. The BMC of empirical DEQCT using the experimental mass attenuation coefficients and that of manufacture have showed very close to ash weight of animal trabecular bone. (author)

  15. Effect of organic and conventional rearing system on the mineral content of pork.

    Science.gov (United States)

    Zhao, Yan; Wang, Donghua; Yang, Shuming

    2016-08-01

    Dietary composition and rearing regime largely determine the trace elemental composition of pigs, and consequently their concentration in animal products. The present study evaluates thirteen macro- and trace element concentrations in pork from organic and conventional farms. Conventional pigs were given a commercial feed with added minerals; organic pigs were given a feed based on organic feedstuffs. The content of macro-elements (Na, K, Mg and Ca) and some trace elements (Ni, Fe, Zn and Sr) in organic and conventional meat samples showed no significant differences (P>0.05). Several trace element concentrations in organic pork were significantly higher (Ppork: Cr (808 and 500μg/kg in organic and conventional pork, respectively), Mn (695 and 473μg/kg) and Cu (1.80 and 1.49mg/kg). The results showed considerable differences in mineral content between samples from pigs reared in organic and conventional systems. Our results also indicate that authentication of organic pork can be realized by applying multivariate chemometric methods such as discriminant analysis to this multi-element data. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Increased Leg Bone Mineral Density and Content During the Initial Years of College Sport.

    Science.gov (United States)

    Scerpella, John J; Buehring, Bjoern; Hetzel, Scott J; Heiderscheit, Bryan C

    2018-04-01

    Scerpella, JJ, Buehring, B, Hetzel, SJ, and Heiderscheit, BC. Increased leg bone mineral density and content during the initial years of college sport. J Strength Cond Res 32(4): 1123-1130, 2018-Bone mineral density (BMD) and bone mineral content (BMC) data are useful parameters for evaluating how training practices promote bone health. We used dual-energy X-ray absorptiometry (DXA) to longitudinally assess sport-specific growth in leg and total body BMD/BMC over the initial 2 years of collegiate training. Eighty-five Division 1 collegiate basketball, hockey, and soccer athletes (50 males and 35 females; age 19.0 [0.8] years) underwent annual DXA scans. Leg and total body BMD/BMC were compared within and across two 1-year intervals (periods 1 and 2) using repeated-measures analysis of variance, adjusting for age, sex, race, and sport. Leg BMD, leg BMC, and total body BMC all increased over period 1 (0.05 g·cm [p = 0.001], 0.07 kg [p = 0.002], and 0.19 kg [p BMC (p BMC (p = 0.005). Leg lean mass increased more during period 2 than period 1 (p = 0.018). Sports participation was the only significant predictor of change in leg BMD. Significant increases in both leg BMD and BMC were demonstrated over both 2-year periods, with greater gains during period 1. These gains highlight the importance of attentive training procedures, capitalizing on attendant physical benefits of increased BMD/BMC. Additional research in young adults, evaluating bone mass acquisition, will optimize performance and decrease risk of bone stress injury among collegiate athletes.

  17. The assessment of cortical and spongy bone mineral content with quantitative computed tomography

    International Nuclear Information System (INIS)

    Sakurai, Kiyoko; Matsubayashi, Takashi; Aritomi, Hiroshi; Iwanami, Shigeru; Kusano, Shouichi; Marumo, Fumiaki.

    1991-01-01

    The CT numbers of cortex at the level of 20 cm (CT20) and spongiosa in the lateral condyle at the level of 2 cm (CT02) proximal from the distal end of the femur, and the bone mineral density of spongiosa in the L3 body (BMD), were obtained by QCT. The study included 43 female patients with rheumatoid arthritis (RA), 71 female patients with primary osteoporosis (OP), 20 female nondialyzed patients with chronic renal failure (CRF: nonHD), 37 hemodialyzed patients (CRF: HD),including 13 parathyroidectomized patients (CRF: HD, PTX), and 10 healthy volunteers. CT20 correlated closely with age in RA. CT02 and BMD correlated closely with age in RA and OP. CT20 and CT02 correlated closely with the duration of hemodialysis in CRF:HD, but not with the duration of disease in RA. The values of CT20 and CT02 in the CRF: HD. PTX group was significantly lower than those in the other CRF groups. BMD in the RA group was not different from that of healthy volunteers. The CT20 values of the one-third of RA patients older than 60 years were extremely low compared with those of the other two-thirds. The results indicated that BMD was useful in assessing bone mineral content in OP, but not in RA. CT02 and CT20 were useful in assessing bone mineral content in these three diseases, CT20 was especially useful for patients in the CRF: HD group and those with RA older than 60 years, but it was not useful in the CRF: nonHD group. (author)

  18. Proximate composition, mineral content and functional properties of Tarap (Artocarpus odoratissimus seed flour

    Directory of Open Access Journals (Sweden)

    Noorfarahzilah, M.

    2017-06-01

    Full Text Available Tarap seed (Artocarpus odoratissimus is one of the popular snacks among Borneo Island people especially in Sabah, Malaysia. Their flesh and seed are such a potential food source but they are not fully exploited. Therefore, this study was conducted to determine its nutritional composition, mineral content and functional properties of Tarap seed flour (TSF. The proximate analysis (protein, carbohydrate, fat, crude fiber, ash, moisture, minerals content and functional properties (powder particle size, bulk density, oil and water absorption capacity, emulsion capacity, foaming ability, least gelling concentration, swelling ability and pasting properties were determined. The proximate analysis results obtained showed that TSF had 49.65% carbohydrate, 15.60% crude fat, 12.3% crude fibers, 8.8% crude protein, 1.17 % ash and 12.5% moisture. Most abundant mineral found in Tarap flour was potassium, followed by magnesium, calcium, and natrium. The results showed that TSF has an average particle size of 166.02μm with low bulk density (0.57g/cm3 as compared to wheat flour. Water and oil absorption capacities of TSF were 2.61 and 1.69g/g, respectively, while the efficiency of emulsification was 14.8%. Least gelation concentration was found to be 12% while foaming ability was 7%. Swelling ability results showed a steady increment from 60°C to 70°C but sharp increased observed from 70°C to 80°C. From the results presented, it can be concluded that TSF has a great potential for use in the formulation of composite flours to be used as ingredients in the food industry.

  19. Homogeneity vs. Heterogeneity of Porosity in Boom Clay

    International Nuclear Information System (INIS)

    Hemes, Susanne; Desbois, Guillaume; Urai, Janos L.; De Craen, Mieke; Honty, Miroslav

    2013-01-01

    Microstructural investigations on Boom Clay at nano- to micrometer scale, using BIB-SEM methods, result in porosity characterization for different mineral phases from direct observations on high resolution SE2-images of representative elementary areas (REAs). High quality, polished surfaces of cross-sections of ∼ 1 mm 2 size were produced on three different samples from the Mol-Dessel research site (Belgium). More than 33,000 pores were detected, manually segmented and analyzed with regard to their size, shape and orientation. Two main pore classes were defined: Small pores (< 500 nm (ED)) within the clay matrices of samples and =big' pores (> 500 nm (ED)) at the interfaces between clay and non-clay mineral (NCM) grains. Samples investigated show similar porosities regarding the first pore-class, but differences occur at the interfaces between clay matrix and NCM grains. These differences were interpreted to be due to differences in quantitative mineralogy (amount of non-clay mineral grains) and grain-size distributions between samples investigated. Visible porosities were measured as 15 to 17 % for samples investigated. Pore-size distributions of pores in clay are similar for all samples, showing log-normal distributions with peaks around 60 nm (ED) and more than 95 % of the pores being smaller than 500 nm (ED). Fitting pore-size distributions using power-laws with exponents between 1.56 and 1.7, assuming self-similarity of the pore space, thus pores smaller than the pore detection resolution following the same power-laws and using these power-laws for extrapolation of pore-size distributions below the limit of pore detection resolution, results in total estimated porosities between 20 and 30 %. These results are in good agreement with data known from Mercury Porosimetry investigations (35-40 % porosity) and water content porosity measurements (∼ 36 %) performed on Boom Clay. (authors)

  20. Clay vein and its implication for uranium exploration activity in the northern part of the Alligator Rivers Uranium Field, northern Australia

    International Nuclear Information System (INIS)

    Sasao, Eiji

    2003-01-01

    Clay veins have been found by uranium exploration drilling around the Black Rock uranium prospect in the northern part of the alligator Rivers Uranium Field (ARUF), northern Australia. The mineralogical and chemical features are described to clarify relations with uranium mineralization, because it is not accompanied by uranium mineralization. X-ray diffraction and chemical analysis for major elements indicate that the clay vein consists mainly of chlorite (clinochlore to ferroan clinochlore) and lesser mica clay mineral (t-1M dominant). The clay vein is compared with the clay alteration zone around the uranium deposits in ARUF in terms of mode of occurrence, mineral and chemical compositions. Mineral composition of the clay vein is only in accordance with that of the inner alteration halo of the clay alteration zone. It is, however, different from mineral composition of the outer alteration halo in terms of lack of Fe chlorite in the clay vein. Chemical composition of the clay vein is similar to that of the clay alteration zone, except for lack in the vein of high iron content which is observed in some samples of the alteration zone. As a whole, the feature of the clay vein corresponds to the inner alteration zone around the uranium deposit in ARUF. The mode of occurrence of the clay vein is very different from that of the clay alteration zone. Mode of occurrence, and mineral and chemical compositions of the clay vein resemble a chlorite vein in the Lower to Middle Proterozoic sandstone above the Jabiluka deposit, one of major uranium deposit in the ARUF. Because of the similarity between the clay and the chlorite veins, the clay vein is regarded as marginal facies of an alteration zone. The fluid that formed the clay vein is estimated to have been oxidized, because of the existence of hematite and ubiquitous Mg chlorite. This nature is in accordance with the mineralizing fluid that formed the inner alteration zone in the Nabarlek deposit. In conclusion, the vein

  1. Moessbauer study of the transformations occurring in egyptian alluvial and calcareous clays during firing

    International Nuclear Information System (INIS)

    Sallam, H.A.; Gomma, N.S.; El Meligy, W.M.; Eissa, N.A.

    1994-01-01

    Egyptian alluvial and calcareous clay samples, which are used in pottery production, were heated at different temperatures in air up to 1100 degree C. The physicochemical transformations were followed up and could be separated in two main stages; i) the dehydroxilation, of the clay mineral, stage for firing up to 700 degree C, ii) the second stage for firing at 900 degree C and higher. In the later stage the effect of calcium content was very pronounced. 2 figs

  2. Conteúdo de minerais dos ingredientes e da multimistura Mineral content of ingredients and multimixture

    Directory of Open Access Journals (Sweden)

    Celma de Oliveira Barbosa

    2006-12-01

    Full Text Available Os objetivos deste estudo foram determinar o conteúdo de minerais dos ingredientes e da multimistura, produzida e comercializada em Teresina-PI e avaliar a composição mineral da multimistura, relacionando-a com a ingestão diária recomendada (IDR. As amostras estudadas foram multimistura, pó da folha de macaxeira, farelo de arroz, farelo de trigo, farinha de trigo e fubá de milho. Os minerais Ca, Cu, K, Mn, Zn, Fe, Mg, Na e P foram determinados usando a técnica de espectrometria de emissão atômica com fonte de plasma indutivamente acoplado (ICP OES. A análise estatística dos dados foi realizada por meio de médias e desvios padrão. As amostras apresentaram baixos teores para a maioria dos minerais analisados, com exceção dos ingredientes farelo de trigo e farinha de trigo. Em especial, observou-se que a multimistura não atingiu o mínimo necessário de 25% do valor diário (VD, para ser considerada complemento nutricional pelo Ministério da Saúde, para os minerais analisados, com exceção do Mn e Mg. Concluiu-se que não existe uma padronização nas quantidades dos ingredientes no preparo da multimistura e que os teores dos minerais não atendem às recomendações diárias necessárias para crianças.The objectives of this study were to determine the mineral content of ingredients and multimixture produced and commercialized in Teresina-PI/Brazil and evaluate the mineral composition in relation to the dietary reference intakes (DRI. The studied samples were multimixture, cassava leaf powder, rice bran, wheat bran, wheat flour and corn flour. The minerals Ca, Cu, K, Mn, Zn, Fe, Mg, Na and P were determined using the atomic emission spectrometry (ICP OES. The statistics analysis of the data was carried out by mean and standard deviations. The samples had low levels in most of the analyzed minerals, except for wheat bran and wheat flour. In particular, it was observed that the multimixture did not reach the minimum of 25% of the

  3. Proximate Composition, Mineral Content and Fatty Acids Analyses of Aromatic and Non-Aromatic Indian Rice

    Directory of Open Access Journals (Sweden)

    Deepak Kumar Verma

    2017-01-01

    Full Text Available Awareness on nutritive value and health benefits of rice is of vital importance in order to increase the consumption of rice in daily diet of the human beings. In this study, a total of six aromatic and two non-aromatic rice accessions grown in India were analysed for their nutritional quality attributes including proximate composition, mineral contents and fatty acids. Data with three replications were used to measure Pearson's simple correlation co-efficient in order to establish the relationship among various nutritional quality attributes. The result on proximate composition showed that Govind Bhog had the highest moisture (13.57% and fat (0.92% content, which signifies its tasty attribute. Badshah Bhog exhibited the highest fibre content (0.85%, carbohydrate content (82.70% and food energy (365.23 kCal per 100 g. Among the minerals, the higher Ca (98.75 mg/kg, Zn (17.00 mg/kg and Fe (31.50 mg/kg were in Gopal Bhog, whereas the highest Na (68.85 mg/kg was in Badshah Bhog, the highest K (500.00 mg/kg was in Swetganga, Khushboo and Sarbati. The highest contents of unsaturated fatty acids viz. oleic acid (49.14%, linoleic acid (46.99% and linolenic acid (1.27% were found in Sarbati, whereas the highest content of saturated fatty acids viz. myristic acid (4.60% and palmitic acid (31.91% were found in Govind Bhog and stearic acid (6.47% in Todal. The identified aromatic rice accessions Gopal Bhog, Govind Bhog and Badshah Bhog and non-aromatic rice accession Sarbati were found nutritionally superior among all eight tested accessions. The nutritional quality oriented attributes in this study were competent with recognized prominent aromatic and non-aromatic rice accessions as an index of their nutritional worth and recommend to farmers and consumers which may be graded as export quality rice with good unique nutritional values in international market.

  4. The carbon isotope ratios and contents of mineral elements in leaves of Chinese medicinal plants

    International Nuclear Information System (INIS)

    Lin Zhifang; Sun Guchou; Wang Wei

    1989-01-01

    Leaf carbon isotope ratios and 13 kinds of mineral elements were measured on 36 species of common Chinese medicinal plants in a subtropical monsoon forest of Ding Hu Shan in Guangdong Province. The .delta.13C value were from -26.4 to -32.6%, indicating that all of the species belonged the photosynthetic C3 types. The relative lower value of δ13C was observed in the life form of shrubs. The contents of 7 elements (N, P, K, Ca, Na Mg, Si) were dependent upon the species, life form, medicinal function and medicinal part. Herb type medicine and the used medicinal part of leaves or whole plant showed higher levels of above elements than the others. Among the nine groups with different medicinal functions, it was found that more nitrogen was in the leaves of medicinal plants for hemophthisis, hypertension and stomachic troubles, more phosphorus and potassium were in the leaves for cancer and snake bite medicines, but more calcium and magnesium were in the leaves for curing rheumatics. Ferric, aluminium and manganese were the main composition of microelements in leaves. There were higher content of ferric in leaves for hemophthisis medicine, higher zinc in leaves for cold and hypertension medicine, and higher Cup in leaves of stomachic medicine. It was suggested that the pattern of mineral elements in leaves of Chinese medicinal plants reflected the different properties of absorption and accumulation. Some additional effect due to the high content of certain element might be associated with the main function of that medicine

  5. Effect of liming and fertilizer on mineral content and productivity of Brachiaria Decumbens grass forage

    International Nuclear Information System (INIS)

    Armelin, M.J.A.; Saiki, M.

    2007-01-01

    To restore a degraded pasture of Brachiaria decumbens, located in Sao Carlos - SP, southeastern Brazil, under altitude tropical climate, an experiment was carried out to study the effects of limestone, buried or not buried in the soil, and fertilizer use on mineral content and forage yield, after 3 years of treatment. Limestone and phosphorus were applied once, one month before starting. NK were applied after each cutting, for fertilized plots, four to five times a year. Experimental design was a random block (100 m 2 ), with 6 replications and 4 treatments. Each block received 4 t/ha of limestone, except the control. Forage samples were collected 14 cm above soil surface. Instrumental neutron activation analysis (INAA) followed by gamma-ray spectrometry was the analytical method used to determine the mineral contents. Dry matter yield was affected positively with liming when compared with the limestone control, but the effect of limestone use was more pronounced with the concomitant use of NK fertilizer. The contents of Ca, Cs, Fe, La, Mg, Rb, Sc, Sm and Th in forage were negatively affected with the NK use, perhaps due to a dilution effect, while a reverse were observed for K, Cl, perhaps due to input of KCl, besides Br, Mn and Se. It seems that limestone is not a key input to restore degraded tropical pastureland, grown on acid soils, when nitrogen is lacking. INAA allowed the monitoring of some not routine elements that may be under observation to avoid potential plant nutritional disorders in production systems with high limestone and fertilizer use. (author)

  6. Clay Houses

    Science.gov (United States)

    Pedro, Cathy

    2011-01-01

    In this article, the author describes a project designed for fourth-graders that involves making clay relief sculptures of houses. Knowing the clay houses will become a family heirloom makes this lesson even more worth the time. It takes three classes to plan and form the clay, and another two to underglaze and glaze the final products.

  7. Metal ions released from fixed orthodontic appliance affect hair mineral content.

    Science.gov (United States)

    Mikulewicz, Marcin; Wołowiec, Paulina; Loster, Bartłomiej; Chojnacka, Katarzyna

    2015-02-01

    The objective was to evaluate metal ion accumulation in hair of patients undergoing orthodontic treatment with fixed appliances in time. The patients (N = 47) participated in a questionnaire survey. Hair sampling was performed at the beginning and in the 4th, 8th, and 12th month of the treatment. The content of metals (Cr, Ni, Fe) in hair was analyzed by ICP-OES equipped with USN nebulizer. The peak release of Cr and Fe occurred after 4 months of the treatment, and the peak release of Ni gradually increased throughout the whole year of the therapy. During 1 year treatment, an average accumulation of metals in hair tissue was 7.42 ± 14.19 μg of Ni, 8.94 ± 13.1 μg of Cr, and 131 ± 279 μg of Fe. The mean content of Cr was higher than the 90th percentile value for this element. The upper limit of literature reference ranges for Cr, Ni, and Fe in hair was not exceeded. The value of exposure (kinetics and dose) of orthodontic patients to metal ions released from orthodontic appliances can be assessed by hair mineral analysis. The content of Cr was statistically significantly higher during the treatment than before the beginning of therapy.

  8. Chemical composition, mineral content and amino acid and lipid profiles in bones from various fish species.

    Science.gov (United States)

    Toppe, Jogeir; Albrektsen, Sissel; Hope, Britt; Aksnes, Anders

    2007-03-01

    The chemical composition, content of minerals and the profiles of amino acids and fatty acids were analyzed in fish bones from eight different species of fish. Fish bones varied significantly in chemical composition. The main difference was lipid content ranging from 23 g/kg in cod (Gadus morhua) to 509 g/kg in mackerel (Scomber scombrus). In general fatty fish species showed higher lipid levels in the bones compared to lean fish species. Similarly, lower levels of protein and ash were observed in bones from fatty fish species. Protein levels differed from 363 g/kg lipid free dry matter (dm) to 568 g/kg lipid free dm with a concomitant inverse difference in ash content. Ash to protein ratio differed from 0.78 to 1.71 with the lowest level in fish that naturally have highest swimming and physical activity. Saithe (Pollachius virens) and salmon (Salmo salar) were found to be significantly different in the levels of lipid, protein and ash, and ash/protein ratio in the bones. Only small differences were observed in the level of amino acids although species specific differences were observed. The levels of Ca and P in lipid free fish bones were about the same in all species analyzed. Fatty acid profile differed in relation to total lipid levels in the fish bones, but some minor differences between fish species were observed.

  9. Sugar Profile, Mineral Content, and Rheological and Thermal Properties of an Isomerized Sweet Potato Starch Syrup.

    Science.gov (United States)

    Dominque, Brunson; Gichuhi, Peter N; Rangari, Vijay; Bovell-Benjamin, Adelia C

    2013-01-01

    Currently, corn is used to produce more than 85% of the world's high fructose syrup (HFS). There is a search for alternative HFS substrates because of increased food demand and shrinking economies, especially in the developing world. The sweet potato is a feasible, alternative raw material. This study isomerized a high glucose sweet potato starch syrup (SPSS) and determined its sugar profile, mineral content, and rheological and thermal properties. Rheological and thermal properties were measured using a rheometer and DSC, respectively. Sweet potato starch was hydrolyzed to syrup with a mean fructose content of 7.6 ± 0.4%. The SPSS had significantly higher (P syrups. During 70 days of storage, the SPSS acted as a non-Newtonian, shear-thinning liquid in which the viscosity decreased as shear stress increased. Water loss temperature of the SPSS continually decreased during storage, while pancake and ginger syrups' peak water loss temperature decreased initially and then increased. Further and more detailed studies should be designed to further enhance the fructose content of the syrup and observe its stability beyond 70 days. The SPSS has the potential to be used in human food systems in space and on Earth.

  10. ANTIOXIDANT CAPACITY, MINERAL CONTENT AND ESSENTIAL OIL COMPOSITION FROM SELECT ALGERIAN MEDICINAL PLANTS

    Directory of Open Access Journals (Sweden)

    Hadjira Guenane1

    2017-10-01

    Full Text Available The objective of the present study was to analyze the total antioxidant capacity, minerals contents of four plants (Juniperus oxycedrus, Thymus capitatus, Laurus nobilis and Eruca vesicaria and chemical composition of the essential oils of the aerial parts of T. capitatus. Their antioxidant activity was assessed by DPPH, ABTS and FRAPS assays. Total phenol and flavonoid contents of the extracts were also determined. The results showed that the L. nobilis extract had the highest total phenolic and flavonoids contents (19.11 ± 0.22 mg GAE•g-1 dw, 4.47 ± 0.12 mg QE•g-1 dw, respectively. The extract of E. vesicaria had the highest value of TEAC for scavenging DPPH, whereas L. nobilis extract was active for ABTS and FRAP. GC/MS analysis revealed that the essential oil from the aerial parts of T. capitatus contained thirty-seven compounds; thymol was the major constituent (82.79 %. Atomic absorption spectroscopy showed high levels of Ca, K, Mg and Fe, and trace amounts of Zn, Cu and Mn in all four extracts.

  11. Total antioxidant capacity, total phenolic content and mineral elements in the fruit peel of Myrciaria cauliflora

    Directory of Open Access Journals (Sweden)

    Clináscia Rodrigues Rocha Araújo

    2013-12-01

    Full Text Available The in vitro antioxidant capacity, total phenolic content and mineral elements of the fruit peel of Myrciaria cauliflora were investigated. The antio